Air pipe flange connecting structure

Abstract

The invention discloses an air pipe flange connecting structure, and belongs to the technical field of air pipe connection. The device comprises a first flange and a second flange which are respectively fixed at the end parts of two sections of air pipes, and further comprises at least one locking insert strip and a plurality of fixing pins. The fixing pins are fixed to at least one flange edge of the first flange, and through holes corresponding to the fixing pins in position are formed in the corresponding flange edge of the second flange. And a penetrating deep and long through hole is formed in the fixing pin along the length direction of the flange edge. A plurality of locking insertion pieces are arranged on the locking insertion piece strip at intervals, and the locking insertion pieces can be inserted into and penetrate through the deep and long through holes of the fixing pins in a one-to-one correspondence mode. And a driving part is arranged on the locking insertion piece strip and used for driving the locking insertion piece strip to move in the length direction of the flange edge, the locking insertion piece is matched with the deep and long through hole in the moving process, tensioning force in the thickness direction of the flange is applied to the fixing pin, and therefore the two flanges are locked. The locking device has the advantages of being easy and convenient to operate, reliable in locking, even in stress and the like.

Description

Technical Field

[0001] This invention relates to the field of duct connection technology, and in particular to a duct flange connection structure. Background Technology

[0002] Air ducts are pipes used to transport air in industrial, civil, and high-rise buildings. Air ducts can be connected by welding, flanges, inserts, or other flangeless connections. Flanges are significantly more airtight and robust than inserts or other flangeless connections. They are also faster to install than welds, and less difficult and less expensive to install. Therefore, flanges are the most widely used air duct connection method.

[0003] Duct flanges are made of angle steel or other types of steel. Angle steel flanges are fixed with multiple bolts, while other flanges, such as plate flanges, are fixed with bolts and clamps to ensure the firmness and tightness of the duct connection.

[0004] In the classification of flanged duct connections, although angle steel flanges are fixed with multiple bolts, and the tightness and robustness of the duct connection meet the connection requirements of high, medium, and low pressure ducts, some obvious or potential problems still exist in actual use: In some buildings, ducts are designed and installed in locations where one or more flanges are tightly attached to a fixed surface, such as against a wall or ceiling. When tightening bolts manually, it is often difficult or impossible for operators to reach the bolt positions with their arms and tools. This results in several or more bolts not being tightened properly or several or more bolts being left untightened, which seriously affects the tightness, integrity, and safety of the duct installation. Such limited installation conditions on one or more sides are often common in the pipe shafts of newly built high-rise buildings.

[0005] Another situation is that, for hoisted air ducts, there may be several or more bolts on the flange edge that are not properly tightened or several or more bolts are missing, either at the top edge or on the flange edge that is not visible to personnel.

[0006] In the above situations, due to various reasons such as limited installation conditions, negligence of installers, or intentional acts, some bolts on the flanges of conventional flange-connected ducts are missing or not tightened, resulting in duct installation quality defects such as loose or unstable flange connections. There is an urgent need to find a reliable duct flange connection structure to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to address the problems existing in the background art by proposing a duct flange connection structure to solve the problem of duct installation quality defects caused by the absence or loosening of some bolts on conventional flange connections due to various reasons during duct installation.

[0008] The solution of the present invention is as follows: a duct flange connection structure, comprising a first flange and a second flange respectively fixed to the ends of two duct sections to be connected, and further comprising: At least one locking insert strip, wherein a plurality of locking inserts are spaced apart along its length; Multiple retaining pins are fixed to at least one flange edge of the first flange; The second flange has multiple through holes on its corresponding flange edge that correspond to the positions of the multiple fixing pins and allow them to pass through. The fixing pin has a deep through hole extending along the length of the flange edge; The locking tabs on the locking tab strip can be inserted into and pass through the deep through holes of the multiple fixing pins in a one-to-one correspondence; Each locking tab and its corresponding fixing pin form a connection point.

[0009] The locking insert strip is also provided with a driving part, which is used to drive the locking insert strip to move along the length direction of the flange edge under the action of external force, so that the locking insert, through the cooperation with the deep through hole during the movement, applies a tension force along the flange thickness direction to the fixing pin, thereby locking the first flange and the second flange.

[0010] As a preferred technical solution, the internal shape of the deep and long through hole is an arc or inclined structure with one end high and the other end low. When the locking insert moves in the deep and long through hole, the inclined side cooperates with the lower end of the deep and long through hole to lift the fixing pin, and the straight side is used to press the second flange.

[0011] As a preferred technical solution, the fixing pin includes a protruding base and a body. The base is used for fixed connection with the first flange, and the body is used to pass through a through hole on the second flange. The deep through hole is formed inside the body.

[0012] As a preferred technical solution, the body of the fixing pin has a non-closed shape with one side cut open at the location where the deep through hole is opened.

[0013] As a preferred technical solution, the driving unit includes a screw, a fixing block, and a locking nut. The screw is fixedly connected to one end of the locking insert strip, the fixing block is fixedly mounted on the second flange, the screw passes through the fixing block, and the locking nut is threadedly connected to the end of the screw that extends out of the fixing block, for driving the locking insert strip to move.

[0014] As a preferred technical solution, the width of one straight edge on the locking insert used to set the driving part is increased and bent into an L-shaped or U-shaped cross section.

[0015] As a preferred technical solution, the deep through hole of the fixing pin is provided with a flared opening at the end for the locking insert to be inserted.

[0016] As a preferred technical solution, the duct is a square duct, and the first flange and the second flange each have four flange edges, one or two of which are connected by the locking insert strip and the fixing pin, and the remaining flange edges are connected by bolts.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention solves the flange connection problem when encountering single-sided or multi-sided installation constraints during the installation of flange-connected ducts. At the same time, the hole positions and hole spacing of the connection points meet the relevant requirements of the current national or industry standards for flange-connected duct installation. The duct flange connection structure of the present invention can lock one side with a single locking nut. When the locking nut is tightened to the appropriate position, it can drive the inclined side of the locking insert to lift the pin and press the flange, making the connection and locking effect visible. The duct flange connection structure of the present invention, after replacing the bolt connection, expands the contact range between each connection point and the duct flange, and reduces the deformation of the duct flange under stress. The duct flange connection structure of the present invention provides reliable connection, secure locking, and simple and convenient on-site operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall installation structure of a duct flange connection structure according to an embodiment of the present invention; Figure 2 This is a front view of the overall installation of the duct flange connection structure in an embodiment of the present invention; Figure 3 This is a left view of the overall installation of the duct flange connection structure in this embodiment of the invention; Figure 4 This is an overall bottom view of the installation of the duct flange connection structure in this embodiment of the invention; Figure 5 for Figure 2 Enlarged view of region A in the middle; Figure 6 These are views of the fixing pin in various directions in an embodiment of the present invention; Figure 7 These are views of the fixing pin cut across the cross-section in various directions, as described in this embodiment of the invention. Figure 8The views of various directions of the fixing pin with a flared shape machined on the inlet side of the locking insert in this embodiment of the invention; Figure 9 This is a left view of the overall installation of the duct flange connection structure in a further embodiment of the present invention; Figure 10 This is a diagram illustrating the effect of increasing the width of the straight edge of the locking insert strip and bending it into an L-shaped cross-section in an embodiment of the present invention.

[0019] Reference numerals in the attached diagram: 1. Left duct body; 2. Left duct flange; 3. Right duct flange; 4. Right duct body; 5. Locking nut; 6. Screw fixing block; 7. Screw; 8. Locking insert strip; 9. Fixing pin; 10. Bolt. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] A duct flange connection structure includes two duct sections 1 and 4 to be connected. The duct has a square cross-section. Two flanges 2 and 3 are fixed to the ends of the duct sections. Each flange has four flange edges. Two to three of the four flange edges of the duct connected by flanges can be easily connected using conventional bolts 10. One or two flange edges installed close to the edge are connected using the duct flange connection structure of this invention, including locking insert strips 8, fixing pins 9, etc.

[0022] As a preferred technical solution, three of the four sides of the duct have flanges that can be operated normally by personnel and bolted using conventional tools. These three flanges use a conventional drilling and bolting method.

[0023] As a preferred technical solution, the structure of the present invention is applied only to one flange edge where it is inconvenient for personnel and tools to operate. The structure of the present invention includes: The two duct flanges 2 and 3 connected by the structure of this invention have a row of uniform, through, and corresponding rectangular holes along one side of each flange. The position and center distance of the rectangular holes, i.e. the hole position and hole spacing of the connection point, meet the relevant requirements of the current national or industry standards for flange connection duct installation. The hole opening method can be mechanical punching, laser cutting, etc.

[0024] The fixing pin 9 consists of a raised base and a body. The base of the fixing pin 9 is welded or fixed by other means to a flange edge of a duct flange 2 or 3 that does not have a locking insert strip 8. The body of the fixing pin 9 is just the right size to pass through the rectangular holes of the two flanges 2 and 3. The interior of the body of the fixing pin 9 has a suitable deep and long through hole along the length of the duct flange.

[0025] The locking insert strip 8 has multiple angled locking inserts that are spaced at the same distance as the fixing pin 9. Each locking insert is inserted into the deep through hole of the corresponding fixing pin 9 and can continue to move forward after passing through. As the locking insert moves, the angled side of the locking insert lifts the fixing pin 9 while the straight side presses against the flange it contacts.

[0026] It should be further explained that the width of the deep through hole inside the main body of the fixing pin 9 is sufficient to accommodate the locking insert. The shape of the deep through hole is not the cylindrical through hole of a conventional pin. The internal shape of the deep through hole is a custom shape that is high on one side and low on the other side with a slight arc, so as to facilitate the cooperation with the locking insert and facilitate the smooth movement of the locking insert in the deep through hole.

[0027] It should also be noted that, in order to facilitate the processing of the deep and long through hole with a custom shape inside the main body of the fixing pin 9, the main body of the fixing pin 9 can be cut on one side of the cross section at the position of the deep and long through hole, provided that the strength is satisfied.

[0028] A screw 7 is welded to one end of the locking insert strip 8 at an appropriate position facing the opening of the locking insert. The screw 7 passes through a drilled screw fixing block 6 welded to an appropriate position on the flange edge and protrudes to an appropriate length. The protruding length should be such that the locking nut 5 can be easily tightened by hand. The position of the screw fixing block 6 should be such that when the locking nut 5 tightens the screw 7, it drives the locking insert strip 8 to move towards the screw fixing block 6 without colliding with the screw fixing block 6. At the same time, it should meet the requirements of the locking insert strip 8 moving towards the screw fixing block 6, the inclined side of the locking insert lifting the fixing pin 9, and the straight side pressing the flange.

[0029] While the locking nut 5 tightens the screw 7, it drives the locking insert strip 8 to move toward the screw fixing block 6. During the process of the inclined side of the locking insert lifting the fixing pin 9 and the straight side pressing the flange, each connection point generates a sufficient preload force comparable to that of the bolt 10.

[0030] The connection of the screw fixing block 6 to the flange corner adjacent to it is made by drilling bolt holes and using bolts 10 in the conventional manner.

[0031] It should also be noted that the duct flange connection structure of the present invention can be applied to each side of the duct in open spaces or where there is sufficient operating space, or when necessary.

[0032] Example 1: like Figure 1 The two duct sections that need to be connected, as shown, adopt the preferred technical solution, in Figure 3 As can be seen, three of the sides are connected using conventional bolts, and the structure of the present invention is applied only to the side where it is inconvenient for personnel and tools to operate. The structure of the present invention includes: The two sections of duct connected by the structure of this invention have a row of uniform, through, and corresponding rectangular holes along one side of each of the two flanges on the opposite side. The position and center distance of the rectangular holes, i.e. the hole position and hole spacing of the connection point, meet the relevant requirements of the current national or industry standards for flange-connected duct installation. The hole opening method can be mechanical punching, laser cutting, etc. The fixing pin 9 consists of a raised base and a body. The base of the fixing pin is welded or fixed to the edge of a flange without a locking strip by other means. The body of the fixing pin is just the right size to pass through the rectangular holes of the two flanges. The interior of the fixing pin body has a suitable deep through hole along the length of the duct flange. like Figure 4 As shown, the width of the deep through hole inside the main body of the fixing pin 9 is sufficient to allow the locking insert 8 to pass through; like Figure 5 As shown, the height of the deep through hole inside the main body of the fixing pin 9 should be such that when the flanges of the two sections of the duct are initially joined, the locking insert can be inserted and slightly protruded, plus the distance required for locking the duct flange; the shape of the deep through hole is not the cylindrical through hole of the conventional pin, but a custom shape with one side higher than the other and slightly curved, so as to facilitate the cooperation with the locking insert and facilitate the smooth movement of the locking insert in the deep through hole; Figure 6 The fixing pin 9 shown is a closed structure with a through hole inside. The cross-section inside the through hole that mates with the locking insert is a custom shape that is high at one end and low at the other, and has a slight arc. like Figure 7 As shown, in order to facilitate the processing of the deep and long through hole with a custom shape inside the fixing pin body, the fixing pin 9 can be cut on one side of the cross section at the position of the deep and long through hole in the pin body, provided that the strength is satisfied. like Figure 8 The deep, elongated through hole with a custom shape inside the main body of the fixing pin can be machined into a flared shape on the side where the locking insert is inserted first, or the entrance side, so that the locking insert can be accurately inserted into the deep, elongated through hole even if the position is slightly off. like Figure 2As shown, the locking insert strip 8 has multiple inclined locking inserts with the same spacing as the fixing pin 9. The locking inserts are inserted into the deep through hole of the fixing pin 9 and can pass through it and continue to move outward. As the locking inserts move, the inclined side of the locking insert lifts the straight side of the fixing pin 9 and presses it against the flange 2. Each locking tab and its corresponding fixing pin form a connection point.

[0033] See Figure 5 One of the inclined locking tabs of the locking tab strip 8 engages with the fixing pin 9; See Figure 5 A screw 7 is welded to one end of the locking insert strip 8, which is open along its length. The screw 7 passes through a drilled screw fixing block 6 welded to a suitable position on the flange edge and protrudes to an appropriate length. The protruding length is such that the locking nut 5 can be easily tightened by hand. The position of the screw fixing block 6 is such that the locking nut 5 tightens the screw 7 while driving the locking insert strip 8 to move toward the screw fixing block 6 without colliding with the screw fixing block 6. At the same time, it meets the requirements of the locking insert strip 8 moving toward the screw fixing block 6 and the locking insert's inclined side lifting the fixing pin 9 to tighten the flange 2 and flange 3. As the locking nut tightens the screw, it moves the locking insert strip towards the screw fixing block. During the process of the inclined side of the locking insert lifting the fixing pin and the straight side pressing the flange, each connection point generates sufficient preload comparable to that of a bolt connection.

[0034] As required, to ensure the stability of the locking insert strip along its entire length, the width of the straight edge with the welded screw is increased and bends into an L-shaped cross-section to increase rigidity along the length. The bend effect is as follows: Figure 10 As shown; As needed, Figure 10 Based on this, the straight edge of the locking insert can be further folded into a U-shaped cross-section to further increase the rigidity in the length direction. The flange corner connection next to the screw fixing block 6 is connected by drilling bolt holes and using bolt 10 in the conventional manner.

[0035] The preferred embodiment of the duct flange connection structure of the present invention includes the following steps: Step S1: Prepare flange 2 and flange 3. Each of flange 2 and flange 3 has three corresponding sides with conventional bolt holes. The remaining side of flange 2 and flange 3, which is the side using the duct flange connection structure of this invention, has a row of uniform, through, and corresponding rectangular holes. See the hole positioning section. Figure 3 Note the positions of the bolts and fixing pins, and note that there are standard bolt holes at the corner of the flange closest to the bolt fixing block; Step S2: Weld the nut fixing block 6 to the appropriate position on the flange 2; Step S3: Weld the screw 7 to the open end of the locking insert strip 8; Step S4: Weld the prepared fixing pin 9 onto the flange 3. When welding, pay attention to the direction of the deep through hole inside the fixing pin 9. The side with the lower height of the deep through hole should face the nut fixing block 6 of the flange 2. Step S5: Fix flange 2 and left duct body 1, and fix flange 3 and right duct body 4; Step S6: Apply a sealing strip to one of the two mating surfaces of flange 2 and flange 3; Step S7: Combine flange 2 and flange 3 for trial assembly. Manually insert each locking piece of the prepared locking strip 8 into the deep through hole of the corresponding number of fixing pins 9 until there is slight resistance. At this time, the screw 7 should be able to pass smoothly through the reserved hole of the screw fixing block 6, and the length of the exposed thread should be approximately the same as the height of the locking nut 5. Step S8: Remove the locking insert strip 8 to separate flange 2 and flange 3; Step S9: Formally connect the two sections of ductwork. Combine flange 2 and flange 3 again. First, screw bolts 10 onto the three corners of the flange. Then, using a suitable clamping tool or by hand, insert each locking tab of the locking tab strip 8 into the deep through hole of the corresponding number of fixing pins 9 until there is slight resistance. At this time, the screw 7 will pass smoothly through the reserved hole of the screw fixing block 6, while exposing part of the thread. Then, screw on the locking nut 5 by hand. Step S10: Use a suitable long socket tool to tighten the locking nut 5. While tightening the locking nut 5, the locking insert 8 moves towards the screw fixing block 6. The inclined side of the locking insert lifts the fixing pin 9, and the straight side presses against the flange 2. The fixing pin 9 is fixed on the flange 3, which drives the flange 3 to move towards the flange 2 and press. After the locking nut 5 is tightened to the appropriate torque, each locking insert and the corresponding fixing pin will produce sufficient preload. Step S11: Use standard tools to thread and tighten the bolts on the other three sides one by one. This completes the duct connection.

[0036] After installation, unlike conventional bolted ducts where each bolt needs to be checked individually, and it's unlikely that each bolt will be checked individually after the duct is installed on-site, the duct connected using the structure of this invention only needs to be checked to see if the locking nut 5 is tightened and whether the locking insert is fully inserted into the deep through hole of the fixing pin 9 to determine if this side of the duct is reliably connected.

[0037] It should be noted that steps S1 to S4 are usually completed in the factory rather than on-site at the duct connection site. Factory production has a series of advantages such as high efficiency and controllable quality.

[0038] Depend on Figure 5 As can be seen, compared with bolt 10, the contact length between each locking insert and the duct flange is much greater than that of bolt 10, thus reducing the concentrated pressure applied to the flange hole and effectively reducing the deformation of the flange under stress. Depend on Figure 5 As can be seen, compared with bolt 10, the contact length between the fixing pin and the duct flange is greater than that of bolt 10. Therefore, it reduces the concentrated pressure on the bolt holes of the flange as in conventional bolt connections and can effectively reduce the deformation of the flange under stress. Figure 9 This is a left view of the overall installation of the duct flange connection structure in a further embodiment of the present invention. Figure 9 As can be seen, when the installation conditions of the two adjacent sides of the duct are limited, the duct flange connection structure of the present invention is applied to the two sides of the flange.

[0039] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A duct flange connection structure, comprising a first flange and a second flange respectively fixed to the ends of two duct sections to be connected, characterized in that, Also includes: At least one locking insert strip, wherein a plurality of locking inserts are spaced apart along its length; Multiple retaining pins are fixed to at least one flange edge of the first flange; The second flange has multiple through holes on its corresponding flange edge that correspond to the positions of the multiple fixing pins and allow them to pass through. The fixing pin has a deep through hole extending along the length of the flange edge; The locking tabs on the locking tab strip can be inserted into and pass through the deep through holes of the multiple fixing pins in a one-to-one correspondence; The locking insert strip is also provided with a driving part, which is used to drive the locking insert strip to move along the length direction of the flange edge under the action of external force, so that the locking insert, through the cooperation with the deep through hole during the movement, applies a tension force along the flange thickness direction to the fixing pin, thereby locking the first flange and the second flange.

2. The duct flange connection structure according to claim 1, characterized in that, The locking insert has a beveled edge and a straight edge. The internal shape of the deep through hole is an arc or bevel structure with one end high and the other end low. When the locking insert moves in the deep through hole, the beveled edge cooperates with the lower end of the deep through hole to lift the fixing pin, and the straight edge is used to press the second flange.

3. The duct flange connection structure according to claim 2, characterized in that, The fixing pin includes a raised base and a body. The base is used to fix it to the first flange, and the body is used to pass through a through hole on the second flange. The deep through hole is formed inside the body.

4. The duct flange connection structure according to claim 3, characterized in that, The main body of the fixing pin has a non-closed shape with one side cut open at the location where the deep through hole is opened.

5. The duct flange connection structure according to claim 1, characterized in that, The driving unit includes a screw, a fixing block, and a locking nut. The screw is fixedly connected to one end of the locking insert strip. The fixing block is fixedly mounted on the second flange. The screw passes through the fixing block. The locking nut is threadedly connected to the end of the screw that passes through the fixing block, and is used to drive the locking insert strip to move.

6. The duct flange connection structure according to claim 1, characterized in that, The width of one straight edge on the locking insert used to set the drive part is increased and bent into an L-shaped or U-shaped cross section.

7. The duct flange connection structure according to claim 1, characterized in that, The deep through hole of the fixing pin has a flared end at the end into which the locking insert is inserted.

8. The duct flange connection structure according to claim 1, characterized in that, The duct is a square duct. The first flange and the second flange each have four flange edges. One or two flange edges are connected by the locking insert strip and the fixing pin, and the remaining flange edges are connected by bolts.

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