Straight pipe pressure balance expansion joint for wind tunnel

Abstract

The invention relates to a straight pipe pressure balance expansion joint for a wind tunnel, comprising a left pipe joint, a left working bellows, a left spinal tube, a balance bellows, a right spinal tube, a right working bellows and a right pipe joint which are rigidly connected in sequence; and also comprising a left pull plate and a right pull plate; the small diameter end of the left spinal tube is connected with a left middle pipe joint which is located inside the left spinal tube and extends to the right, and the right end of the left middle pipe joint and the left end of the right pipe joint are connected by a plurality of left pull plates evenly distributed along the circumference; the small diameter end of the right spinal tube is connected with a right middle pipe joint which is located inside the right spinal tube and extends to the left, and the left end of the right middle pipe joint and the right end of the left pipe joint are connected by a plurality of right pull plates evenly distributed along the circumference; the right pipe joint and the left pipe joint are mutually clamped, and the left pull plates and the right pull plates are alternately arranged. The pull plate effectively supports the pipe joint end to avoid the "cantilever beam" effect of the pipe joint; the guide tube section is shorter than the conventional design, which reduces the vibration of the guide tube when the high-speed airflow scours.

Description

Technical Field

[0001] The invention relates to the technical field of bellows expansion joints, in particular to a straight pipe pressure-balanced expansion joint for a wind tunnel. Background Art

[0002] In small wind tunnels, expansion joints are generally not installed on the wind tunnel body or are simply designed. In large wind tunnels, since the pipelines are extremely large, if expansion joints are not installed, the pipeline stress will be large and the compressor pipe mouth will be subjected to excessive force. Due to limited conditions, only straight pipe pressure balance expansion joints can be used.

[0003] The pull plate used in the existing straight tube pressure balanced expansion joint is used to connect the working wave end and the balance wave end to withstand the transmission of pressure thrust. The conventional left and right pull plate structure adopts a strip tooth structure that is staggered and engaged. It is not only large in size and complex in structure, but also due to the thermal deformation of the hole, the structure needs to transmit additional lateral thrust, resulting in great force on the pull plate.

[0004] In addition, the length of the pull plate strip tooth structure needs to be connected from the outermost end of the working wave to the outermost end of the balancing wave. This structural design will make the pull plate very long (about 5 to 6 meters), and the pull plate must also consider the stability of the pressure rod under negative pressure conditions, so the structural design is very large. Summary of the invention

[0005] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a straight tube pressure-balanced expansion joint for a wind tunnel, thereby solving the technical problems of excessive load caused by the complex structure of conventional pull plates and poor stability caused by their long length.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A straight tube pressure-balancing expansion joint for a wind tunnel comprises a left connecting pipe, a left working bellows, a left spinal tube, a balancing bellows, a right spinal tube, a right working bellows and a right connecting pipe, which are rigidly connected in sequence; and also comprises a left pull plate and a right pull plate; the small-diameter end of the left spinal tube is connected with a left intermediate connecting pipe located inside the left spinal tube and extending to the right, and the right end of the left intermediate connecting pipe is connected to the left end of the right connecting pipe by a plurality of circumferentially evenly distributed left pull plates; the small-diameter end of the right spinal tube is connected with a right intermediate connecting pipe located inside the right spinal tube and extending to the left, and the left end of the right intermediate connecting pipe is connected to the right end of the left connecting pipe by a plurality of circumferentially evenly distributed right pull plates; the right connecting pipe and the left connecting pipe are mutually clamped, and at the same time, the left pull plate and the right pull plate are alternately arranged at intervals.

[0008] As a further improvement of the above technical solution:

[0009] The inner diameter of the left middle connecting pipe is larger than the inner diameter of the right connecting pipe, so that the left pull plate is tilted from left to right along the axial direction; the inner diameter of the right middle connecting pipe is larger than the inner diameter of the left connecting pipe, so that the right pull plate is tilted from right to left along the axial direction.

[0010] A right guide cylinder section is integrally extended to the left from the left end of the right connecting pipe, and a left guide cylinder section is integrally extended to the right from the right end of the left connecting pipe; the right connecting pipe and the left connecting pipe are mutually clamped through the right guide cylinder section and the left guide cylinder section, and the left pull plate and the right pull plate are alternately arranged in sequence.

[0011] A left connecting rib plate is provided on the edge of the small diameter end of the left vertebral canal, and a right connecting rib plate is provided on the edge of the small diameter end of the right vertebral canal; a left connecting rib plate is provided on the edge of the left end of the left pipe, and a right connecting rib plate is provided on the edge of the right end of the right pipe.

[0012] The two ends of the left working bellows are respectively connected to the left end of the left connecting pipe and the small diameter end of the left vertebral canal. There are at least two groups of left working bellows, and the two groups of left working bellows are connected by an intermediate connecting pipe. It also includes a proportional pull rod, and the two ends of the proportional pull rod are respectively connected to the two ends of at least two groups of left working bellows to limit their axial position and move with the expansion and contraction of the bellows.

[0013] The two ends of the balancing bellows are respectively connected to the large diameter end of the left vertebral canal and the large diameter end of the right vertebral canal; there are at least two groups of balancing bellows, and the two groups of balancing bellows are connected by an intermediate connecting pipe; it also includes a proportional pull rod, and the two ends of the proportional pull rod are respectively connected to the two ends of at least two groups of balancing bellows to limit their axial position and move with the expansion and contraction of the bellows.

[0014] The two ends of the right working bellows are respectively connected to the small diameter end of the right vertebral canal and the right end of the right connecting pipe. There are at least two groups of the right working bellows, and the two groups of the right working bellows are connected by an intermediate connecting pipe. It also includes a proportional pull rod, and the two ends of the proportional pull rod are respectively connected to the two ends of at least two groups of the right working bellows to limit the axial position and move with the expansion and contraction of the bellows.

[0015] The structure of the proportional pull rod is as follows: it includes two axial connecting seats that are symmetrically arranged at intervals, a radial guide rod is connected between the two axial connecting seats, and guide holes are respectively opened at both ends of the radial guide rod; the upper parts of the two axial connecting seats are each connected to a radial connecting seat, and a scissor-type stroke amplification rod assembly is provided between the two radial connecting seats, and its two ends respectively move along the guide holes at the two ends of the radial guide rod through pins.

[0016] The middle part of the scissor-type stroke amplification rod assembly and the middle part of the radial guide rod are connected to the intermediate connecting pipe through the same pin shaft.

[0017] The balanced expansion joint has the same inclination as the pipeline, and the bottoms of the left vertebral canal and the right vertebral canal are connected with support seats.

[0018] The length of the left and right guide tube sections is much smaller than the length of the pipe body.

[0019] The beneficial effects of the present invention are as follows:

[0020] The pull plate provides effective support for the end of the connecting pipe, thereby effectively avoiding the "cantilever beam" effect of the connecting pipe; the guide tube section is shorter than the conventional design, which reduces the vibration of the guide tube when it is washed by high-speed airflow, thereby avoiding the need for further "patching" of the gaps left on the pull plate after the pull plate welding is completed due to the conventional structure, thereby effectively reducing the impact of the weld on the airflow.

[0021] The present invention also has the following advantages:

[0022] Each set of working waves and balancing waves of the expansion joint of the present invention adopts at least two sets of waves to meet the working requirements of the expansion joint with larger displacement. A proportional pull rod is arranged on the bellows to take into account the displacement distribution of the two sets of bellows, thereby improving the natural vibration frequency of the bellows.

[0023] The left and right side pipes at both ends of the expansion joint of the present invention are long, so that the lengths of the left and right pull plates can be greatly shortened, thereby greatly reducing the weight of the expansion joint, saving costs and facilitating transportation.

[0024] The pull plate of the present invention adopts a cross-arrangement structure of inclined pull plates, which can effectively avoid the stability problem of the compression rod of the conventional pull plate structure under negative pressure conditions. At the same time, the inclined pull plates also effectively support the pipes at both ends.

[0025] The left and right side pipes of the present invention are respectively provided with guide tube sections in an integrated manner. Compared with the guide tube sections of conventional designs, the guide tube sections are shorter in length, thereby reducing the vibration of the guide tube under high-speed scouring of the medium.

[0026] The inclinations of both ends of the expansion joint of the present invention are consistent with the tunnel pipe, and the guide tube adopts a cross-type manner, so that the resistance loss of the expansion joint is consistent with the pipeline, effectively reducing energy consumption and vibration.

[0027] The transition between the working wave and the balance wave of the present invention adopts a tapered tube structure. Compared with the traditional ring plate structure, the tapered tube structure does not need to set oblique reinforcing ribs, effectively reducing the weight of the expansion joint.

[0028] Compared with the traditional straight tube pressure balance expansion joint, the invention has higher stability, less material and lower manufacturing difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0030] Figure 2 for Figure 1 The structural schematic diagram of the left and right working bellows and the middle balancing bellows is hidden.

[0031] Figure 3 It is a schematic diagram of the connection structure of the left vertebral canal and the right connecting pipe of the present invention.

[0032] Figure 4 It is a schematic diagram of the connection structure of the right vertebral canal and the left side connecting pipe of the present invention.

[0033] Figure 5 It is an exploded view of the present invention.

[0034] Figure 6 for Figure 1 Enlarged view of part A in the middle.

[0035] Figure 7 It is a side view of the present invention.

[0036] Figure 8 for Figure 7 Cross-sectional view along section AA.

[0037] Fig. 9 for Figure 8 Enlarged view of the upper part.

[0038] Among them: 3. Balance bellows; 4. Middle connecting pipe; 5. Right working bellows; 6. Left working bellows; 7. Proportional pull rod; 8. Support seat; 9. Transport pull rod;

[0039] 101, right spinal canal; 102, right middle connecting pipe; 103, right pull plate; 104, right connecting pipe; 105, right connecting rib plate 2; 106, right connecting rib plate 1; 107, right guide tube section;

[0040] 201, left spinal canal; 202, left middle connecting pipe; 203, left pull plate; 204, left connecting pipe; 205, left connecting rib plate 2; 206, left connecting rib plate 1; 207, left guide tube section;

[0041] 71. Axial connecting seat; 72. Radial connecting seat; 73. Scissor-type stroke amplifying rod assembly; 74. Radial guide rod. DETAILED DESCRIPTION

[0042] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0043] like Figure 1-Figure 4 As shown, the straight pipe pressure balancing expansion joint for wind tunnel of this embodiment includes a left pipe 204, a left working bellows 6, a left spinal tube 201, a balancing bellows 3, a right spinal tube 101, a right working bellows 5 and a right pipe 104 which are rigidly connected in sequence;

[0044] Also includes a left pull plate 203 and a right pull plate 103;

[0045] The small diameter end of the left spinal canal 201 is connected with a left middle pipe 202 located inside the left spinal canal 201 and extending to the right, and the right end of the left middle pipe 202 is connected to the left end of the right pipe 104 through a plurality of left pull plates 203 evenly distributed along the circumferential direction;

[0046] The small diameter end of the right spinal canal 101 is connected with a right middle pipe 102 located inside the right spinal canal 101 and extending to the left. The left end of the right middle pipe 102 and the right end of the left pipe 204 are connected by a plurality of right pull plates 103 evenly distributed along the circumferential direction.

[0047] like Figure 2 , Figure 7-Figure 9 As shown, the right side connecting pipe 104 and the left side connecting pipe 204 are mutually engaged, and the left pull plate 203 and the right pull plate 103 are alternately arranged.

[0048] The inner diameter of the left middle connecting pipe 202 is larger than the inner diameter of the right connecting pipe 104, so that the left pull plate 203 is tilted from left to right along the axial direction; the inner diameter of the right middle connecting pipe 102 is larger than the inner diameter of the left connecting pipe 204, so that the right pull plate 103 is tilted from right to left along the axial direction.

[0049] A right guide cylinder section 107 is integrally extended to the left from the left end of the right side connecting pipe 104, and a left guide cylinder section 207 is integrally extended to the right from the right end of the left side connecting pipe 204; the right side connecting pipe 104 and the left side connecting pipe 204 are mutually clamped via the right guide cylinder section 107 and the left guide cylinder section 207, and at the same time, the left pull plate 203 and the right pull plate 103 are alternately arranged in sequence.

[0050] like Figure 3 and Figure 4 As shown, a left connecting rib plate 206 is provided on the edge of the small diameter end of the left spinal canal 201, and a right connecting rib plate 106 is provided on the edge of the small diameter end of the right spinal canal 101;

[0051] A left connecting rib plate 205 is provided on a circumferential edge of the left end of the left connecting pipe 204 , and a right connecting rib plate 105 is provided on a circumferential edge of the right end of the right connecting pipe 104 .

[0052] like Figure 1 , Figure 5 and Figure 6 As shown, the two ends of the left working bellows 6 are respectively connected to the left end of the left connecting pipe 204 and the small diameter end of the left vertebral canal 201, and there are at least two groups of left working bellows 6, which are connected by an intermediate connecting pipe 4; it also includes a proportional pull rod 7, and the two ends of the proportional pull rod 7 are respectively connected to the two ends of at least two groups of left working bellows 6 to limit the axial position thereof and move with the expansion and contraction of the bellows.

[0053] The two ends of the balancing bellows 3 are respectively connected to the large diameter end of the left vertebral canal 201 and the large diameter end of the right vertebral canal 101; there are at least two groups of balancing bellows 3, and the two groups of balancing bellows 3 are connected by an intermediate connecting tube 4; it also includes a proportional pull rod 7, the two ends of the proportional pull rod 7 are respectively connected to the two ends of at least two groups of balancing bellows 3, axially limit them and move with the expansion and contraction of the bellows.

[0054] The two ends of the right working bellows 5 are respectively connected to the small diameter end of the right vertebral canal 101 and the right end of the right connecting pipe 104. There are at least two groups of right working bellows 5, and the two groups of right working bellows 5 are connected by an intermediate connecting pipe 4; it also includes a proportional pull rod 7, and the two ends of the proportional pull rod 7 are respectively connected to the two ends of at least two groups of right working bellows 5 to limit their axial position and move with the expansion and contraction of the bellows.

[0055] The structure of the proportional pull rod 7 is as follows: it includes two axial connecting seats 71 symmetrically arranged at intervals, a radial guide rod 74 is connected between the two axial connecting seats 71, and guide holes are respectively opened at both ends of the radial guide rod 74; the upper parts of the two axial connecting seats 71 are each connected to a radial connecting seat 72, and a scissor-type stroke amplification rod assembly 73 is provided between the two radial connecting seats 72, and its two ends respectively move along the guide holes at both ends of the radial guide rod 74 through pin shafts.

[0056] The middle part of the scissor-type stroke amplification rod assembly 73 and the middle part of the radial guide rod 74 are connected to the middle connecting pipe 4 through the same pin shaft.

[0057] like Figure 1 As shown, the balanced expansion joint has the same inclination as the pipeline, and the bottom of the left vertebral canal 201 and the right vertebral canal 101 are connected to a support seat 8.

[0058] like Figure 6 As described above, each group of bellows is also connected with a transport pull rod 9, which is used to place the bellows to extend and retract back and forth during transportation, and can be removed during installation.

[0059] Design principle of the present invention:

[0060] In the present invention, each group of working waves and balancing waves adopts at least two groups of waves to meet the working requirements of large displacement of the expansion joint. A proportional pull rod 7 is arranged on the bellows to take into account the displacement distribution of the two adjacent groups of bellows, thereby increasing the natural vibration frequency of the bellows. The left and right side pipes are long, so that the length of the left and right pull plates is greatly shortened, reducing the weight of the expansion joint, saving costs and facilitating transportation. The pull plate adopts a cross-arrangement structure of inclined pull plates, which can effectively avoid the stability problem of the pressure rod of the conventional pull plate structure under negative pressure conditions. At the same time, the inclined pull plates also effectively support the pipes at both ends. The length of the left and right guide tube sections is shorter than that of the conventionally designed guide tube sections, which reduces the vibration of the guide tube under high-speed scouring of the medium. The transition between the working wave and the balancing wave adopts a conical tube structure. Compared with the traditional ring plate structure, the conical tube structure does not need to set oblique reinforcement ribs, effectively reducing the weight of the expansion joint.

[0061] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A straight pipe pressure-balanced expansion joint for a wind tunnel, characterized in that: It comprises a left side connecting pipe (204), a left working bellows (6), a left spinal canal (201), a balancing bellows (3), a right spinal canal (101), a right working bellows (5) and a right side connecting pipe (104) which are rigidly connected in sequence; It also includes a left pull plate (203) and a right pull plate (103); The small diameter end of the left vertebral canal (201) is connected to a left middle connecting pipe (202) located inside the left vertebral canal (201) and extending to the right, and the right end of the left middle connecting pipe (202) and the left end of the right connecting pipe (104) are connected via a plurality of left pull plates (203) evenly distributed along the circumferential direction; The small diameter end of the right spinal canal (101) is connected to a right middle pipe (102) located inside the right spinal canal (101) and extending to the left, and the left end of the right middle pipe (102) and the right end of the left pipe (204) are connected via a plurality of right pull plates (103) uniformly distributed along the circumferential direction; The right side pipe (104) and the left side pipe (204) are mutually clamped, and the left pull plate (203) and the right pull plate (103) are alternately arranged; The inner diameter of the left middle connecting pipe (202) is greater than the inner diameter of the right connecting pipe (104), thereby making the left pull plate (203) inclined from left to right along the axial direction; The inner diameter of the right middle connecting pipe (102) is greater than the inner diameter of the left connecting pipe (204), so that the right pull plate (103) is tilted from right to left along the axial direction; The two ends of the left working bellows (6) are respectively connected to the left end of the left connecting pipe (204) and the small diameter end of the left vertebral tube (201); the left working bellows (6) are provided with at least two groups, and the two groups of the left working bellows (6) are connected by an intermediate connecting pipe (4); and it also includes a proportional pull rod (7), the two ends of the proportional pull rod (7) are respectively connected to the two ends of at least two groups of the left working bellows (6), axially limit the left working bellows and move with the expansion and contraction of the bellows.

2. The straight tube pressure-balanced expansion joint for a wind tunnel according to claim 1, characterized in that: A right guide cylinder section (107) is integrally extended to the left from the left end of the right side connecting pipe (104), and a left guide cylinder section (207) is integrally extended to the right from the right end of the left side connecting pipe (204); the right side connecting pipe (104) and the left side connecting pipe (204) are mutually clamped via the right guide cylinder section (107) and the left guide cylinder section (207), and the left pull plate (203) and the right pull plate (103) are sequentially arranged in an alternating manner.

3. The straight pipe pressure-balanced expansion joint for a wind tunnel according to claim 1, characterized in that: A left connecting rib plate (206) is provided on the edge of the small diameter end of the left vertebral canal (201), and a right connecting rib plate (106) is provided on the edge of the small diameter end of the right vertebral canal (101); A left connecting rib plate 2 (205) is provided on a circumferential edge of the left end of the left connecting pipe (204), and a right connecting rib plate 2 (105) is provided on a circumferential edge of the right end of the right connecting pipe (104).

4. The straight pipe pressure-balanced expansion joint for a wind tunnel according to claim 1, characterized in that: The two ends of the balancing bellows (3) are respectively connected to the large diameter end of the left vertebral canal (201) and the large diameter end of the right vertebral canal (101); the balancing bellows (3) are provided with at least two groups, and the two groups of the balancing bellows (3) are connected via an intermediate connecting tube (4); and a proportional pull rod (7) is also included, the two ends of the proportional pull rod (7) are respectively connected to the two ends of at least two groups of the balancing bellows (3), axially limiting them and moving with the expansion and contraction of the bellows.

5. The straight pipe pressure-balanced expansion joint for a wind tunnel according to claim 1, characterized in that: The two ends of the right working bellows (5) are respectively connected to the small diameter end of the right vertebral canal (101) and the right end of the right connecting pipe (104); the right working bellows (5) are provided with at least two groups, and the two groups of the right working bellows (5) are connected by an intermediate connecting pipe (4); it also includes a proportional pull rod (7), the two ends of the proportional pull rod (7) are respectively connected to the two ends of at least two groups of the right working bellows (5), axially limit the bellows and move with the expansion and contraction of the bellows.

6. The straight pipe pressure-balanced expansion joint for a wind tunnel according to any one of claims 3 to 5, characterized in that: The structure of the proportional pull rod (7) is as follows: it includes two axial connecting seats (71) arranged symmetrically at intervals, a radial guide rod (74) is connected between the two axial connecting seats (71), and guide holes are respectively opened at both ends of the radial guide rod (74); the upper parts of the two axial connecting seats (71) are each connected to a radial connecting seat (72), and a scissor-type stroke amplification rod assembly (73) is provided between the two radial connecting seats (72), and its two ends respectively move along the guide holes at both ends of the radial guide rod (74) through pins.

7. The straight pipe pressure-balanced expansion joint for a wind tunnel according to claim 6, characterized in that: The middle part of the scissor-type stroke amplifying rod assembly (73) and the middle part of the radial guide rod (74) are connected to the intermediate connecting pipe (4) through the same pin shaft.

8. The straight pipe pressure-balanced expansion joint for a wind tunnel according to claim 1, characterized in that: The balanced expansion joint has the same inclination as the pipeline, and the bottoms of the left vertebral tube (201) and the right vertebral tube (101) are connected to a support seat (8).

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