Damper and manufacturing method of damper

Abstract

To provide a damper which can easily secure quality as a damper without impairing the strength of a casing, and can improve assembling workability.SOLUTION: A damper 100 is constituted of a cylindrical casing 10 whose both ends 11 (111, 112) are opened, a blade 20 to which a rod-shaped support shaft 21 is fixed in advance before being assembled into the casing 10, and two shaft support means attached into the casing 10, and supporting both ends of the support shaft 21. The damper 100 also has a rectangular hole 12 formed at a side face of the casing 10, a block plate 40 for blocking the rectangular hole 12, and having a first circular hole 41 into which one end 211 of the support shaft 21 is inserted via one shaft support means, and a second circular hole which is formed in a position opposing the rectangular hole 12 of the casing 10, and into which the other end of the support shaft 21 is inserted via the other shaft support means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a damper and a method for manufacturing a damper. [Background technology]

[0002] 2. Description of the Related Art Conventionally, disaster prevention dampers for preventing the spread of fire and dampers installed in ducts for adjusting the air volume during air conditioning and ventilation are known. Conventionally, when attaching the blades and the shaft to the casing during the assembly of the damper, the shaft is passed through the casing, and then the blades are fixed to the shaft inside the casing. The blades can be fixed to the shaft by means of screws or the like, but welding is sometimes used to improve the strength of the damper.

[0003] Patent Document 1 describes a variable air volume unit, in which a casing 51 of this variable air volume unit has a damper maintenance opening 514 in at least one side wall portion, and a damper maintenance opening cover 516 that covers the damper maintenance opening 514 and is detachably attached to the casing 51. The damper 54 is arranged such that one end of a rotating shaft 541 is pivotally attached to the other side wall portion of the casing 51, and the other end of the rotating shaft 541 is pivotally attached to the damper maintenance opening cover 516, and the damper 54 can be moved in and out of the casing through the damper maintenance opening 514 with the damper maintenance opening cover 516 removed (see FIGS. 1 and 9).

[0004] Meanwhile, Patent Document 2 describes a fire damper device that can be attached to a desired location of an existing duct. This fire damper device has a frame 2 that surrounds almost half of the outside of a duct 1, both ends of a damper shaft 5 are supported by this frame 2, the automatic opening spring, latch rod and release mechanism A of a damper 16 are positioned outside the frame 2, and the frame 2 is sized to completely cover the cut in the duct 1, so that the damper 16 can be easily attached by simply forming a cut in a part of the existing duct 1 that is about half the size of the cut (see Fig. 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-052931 A [Patent Document 2] Japanese Utility Model Application Publication No. 55-032971 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the variable air volume unit described in Patent Document 1, as shown in Fig. 9, the blades (damper 54) are inserted into the casing 51 through an opening (damper maintenance opening 514), and if an opening large enough to allow the blades to be inserted and removed is provided in the casing like this, the strength of the casing cannot be ensured. Also, if the opening is large, there is a risk that air leakage from inside the casing will increase, reducing airtightness.

[0007] Furthermore, the fire damper device described in Patent Document 2 is a unit made up of the damper shaft 5, damper 16, and frame 2 covering the notch, and as shown in Figure 2, the notch is large enough to allow this unit to be attached from the outside, so this also does not ensure the strength and airtightness of the duct equivalent to the casing of the present application. Furthermore, because the unit must be installed on-site as a separate unit into the existing duct, operation must be checked before and after installation, which means it takes more effort to ensure quality than dampers in which the casing, blades, and support shaft are integrated.

[0008] Furthermore, if a method of welding the blades to the shaft inside the casing is adopted, the welding work is very difficult inside the casing, and the quality of the welding varies depending on the worker. In particular, if the casing is small in diameter, the space for welding is very narrow, so the welding quality decreases and the welding takes a long time. In addition, post-processing such as removing spatter generated during welding and repair painting of welded parts is also very difficult.

[0009] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a damper that does not impair the strength of the casing, that can easily ensure the quality of the damper, and that can improve the ease of assembly. [Means for solving the problem]

[0010] The damper according to the present invention comprises a cylindrical casing having both ends open; a substantially disk-shaped blade that opens and closes a flow path in the casing, the blade having a rod-shaped support shaft that is longer than an outer diameter of the blade and has one end that is fixed in advance before being assembled into the casing so as to extend beyond a peripheral portion of the blade; A damper comprising: two shaft support means that are attached within the casing and support both ends of the support shaft; A rectangular hole extending in a longitudinal direction of the casing is provided on a side surface of the casing; a closing plate for closing the rectangular hole, the closing plate having a first circular hole through which one end of the support shaft is inserted via one of the shaft support means; a second circular hole provided in the casing at a position opposite to the rectangular hole, through which the other end of the support shaft is inserted via the shaft support means; has.

[0011] As a result, since the rectangular hole extends and opens in the longitudinal direction of the casing, even after one end of the extending spindle passes through the hole, the spindle can be moved along the opening surface (particularly along the longitudinal direction of the casing). Therefore, after one end of the shaft has passed through the hole, the shaft can be tilted further, so that the blade and the other end of the shaft protruding from one of the openings at either end of the casing can be accommodated within the opening, or the position of the shaft can be changed within the casing. Therefore, even after one end of the support shaft has passed through the rectangular hole, the blade and the other end of the support shaft can be pulled into the casing and the other end of the support shaft can pass through the second circular hole. Note that both ends of the support shaft are firmly supported by the shaft support means, closing plates, etc.

[0012] In particular, the closing plate is curved to match the outer surface shape of the portion of the casing where the rectangular hole is provided, It is also desirable that a protrusion of the same size as the rectangular hole is provided so as to fill the thickness of the casing and make the inner surface of the casing flush.

[0013] As a result, the closing plate is curved to match the outer shape of the casing, so that when the closing plate closes the rectangular hole, the closing plate fits snugly against the casing. Also, the protrusions fill in the steps caused by the thickness of the casing, making the inner surface of the casing flush.

[0014] On the other hand, a manufacturing method of a damper according to the present invention is a manufacturing method of a damper including a cylindrical casing having both open ends, a substantially disk-shaped blade for opening and closing a flow passage in the casing, a rod-shaped support shaft longer than the diameter of the blade, two shaft support means, and a closing plate, fastening a shaft to the blade such that one end of the shaft extends beyond the circumference of the blade; a step of inserting one end of the support shaft into a rectangular hole provided in a side surface of the casing and extending in a longitudinal direction of the casing from one of both ends of the casing; a step of inserting the other end of the support shaft through a second circular hole provided in the casing at a position opposite to the rectangular hole from either one of the two ends of the casing, via another shaft support means; a step of inserting one end of the support shaft through a first circular hole provided in the closing plate via one of the shaft support means and closing the rectangular hole with the closing plate; Includes. Effect of the Invention

[0015] (1) With the above-mentioned configuration, the damper according to the present invention can be assembled (attached) to the casing later by drilling a rectangular hole in the casing, even if the blades and the support shaft are fixed in advance, as described above. Therefore, the blades can be assembled into the casing after the blades are fixed to the support shaft, eliminating the need to fix the blades to the support shaft inside the casing, improving workability. In particular, when the blades and the support shaft are fixed by welding, the welding quality improves because there is no need to perform the welding inside the casing. Also, there is no need to perform post-processing such as removing spatter that is scattered inside the casing during welding, improving assembly efficiency.

[0016] (2) Furthermore, since components such as the blades, shafts, and shaft support means can be easily removed from within the casing, the components can be easily replaced without placing an excessive burden on the worker. This allows dampers to be regularly maintained, and as a result, product quality can be ensured over the long term. Since disaster prevention dampers are required to function reliably in emergencies (such as fires), ensuring quality is particularly important.

[0017] (3) In addition, because the closing plate is curved and has a convex portion, the closing plate fits snugly to the casing and the inner surface of the casing is flush, so that the leakage of air flowing from the upstream to the downstream of the damper can be reduced, and the inner surface shape of the casing is maintained, so that the flow path pressure loss does not increase. In addition, the openings provided in the casing can be made the minimum necessary opening size, so that the strength and airtightness of the casing are not impaired.

[0018] In addition, according to the method for manufacturing a damper according to the present invention, it is possible to achieve the same effects as those of the damper according to the present invention. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic perspective view of a damper according to an embodiment of the present invention. [Diagram 2] 1. (i) is a front view of the damper shown in FIG. 1, (ii) is a plan view of the damper shown in FIG. 1, (iii) is a right side view of the damper shown in FIG. 1, and (iv) is a left side view of the damper shown in FIG. [Diagram 3] 2(ii) is a cross-sectional view taken along line BB of FIG. 2(ii), and FIG. 2(iii) is a diagram showing the blade of this embodiment. [Figure 4] 1A to 1C are diagrams showing a closing plate of the present embodiment, in which (i) is a schematic front view, (ii) is a schematic left side view, and (iii) is a schematic rear view. [Diagram 5] 8A to 8C are diagrams for explaining a manufacturing process of a damper based on the damper shown in FIGS. [Figure 6] 8A to 8C are diagrams for explaining a manufacturing process of a damper based on the damper shown in FIGS. [Figure 7] FIG. 1 is a schematic perspective view of a damper according to an embodiment of the present invention having an opening and closing device. [Figure 8] FIG. 2 is a schematic perspective view of a damper according to another embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The following describes an embodiment of the present invention in detail. The description of the components described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to the following content unless the gist of the present invention is changed.

[0021] The configurations of dampers 100 and 200 according to the present invention will be described with reference to Figs. 1-4, 7 and 8. In this embodiment, the damper 100 (Figs. 1-4 and 7) is a damper for adjusting air volume, and the damper 200 (Fig. 8) is a disaster prevention damper. The same reference numerals are used in the drawings to designate components common to these dampers, and repeated explanations will be omitted. For the convenience of explaining the manufacturing process of the damper, the dampers 100 and 200 shown in Figs. 7 and 8 show a state before the one shaft support means 31, the closing plate 40, the opening / closing device 50, etc. are assembled.

[0022] [Damper 100] The damper 100 has a cylindrical casing 10 with both ends 11 in the longitudinal direction D open, blades 20 incorporated in the casing 10, one shaft support means 31 and another shaft support means 32, and a closing plate 40 (see FIGS. 1 and 2). Hereinafter, in this description, the one shaft support means 31 and the other shaft support means 32 may be simply referred to as "shaft support means 31, 32." Furthermore, since the damper 100 is usually installed (connected) horizontally to a horizontal duct, as shown in Figures 1 and 7, the direction extending in the longitudinal direction D is defined as the front-to-rear direction, and the top, bottom, left, and right directions when viewed from the front are defined as the up-down direction and the left-right direction, respectively.

[0023] [Casing 10] The casing 10 is open at both ends 11 , but for the sake of convenience in this description, the front end of the casing 10 will be referred to as one end 111 and the rear end of the casing 10 as the other end 112 . One end 111 and the other end 112 of the casing 10 are connected to the duct. The casing 10 is provided with an outer rib 19 protruding outward from the casing 10 and an inner rib 18 protruding inward from the casing 10 as reinforcement to prevent the casing 10 from deforming, and the outer rib 19 defines the insertion margin into the duct. In other words, the outer rib 19 serves as a stopper when the casing 10 is inserted into the duct.

[0024] Further, a rectangular hole 12 and a second circular hole 13 are provided on the side surface of the casing 10 (see FIGS. 1, 2 and 7). The rectangular hole 12 has a shape extending in the longitudinal direction D of the casing 10 (see FIG. 7). The rectangular hole 12 is provided in approximately the center of the casing 10 in the front-rear direction.

[0025] The second circular hole 13 is provided at a position facing the rectangular hole 12 (on the opposite side of the casing 10) (see FIG. 2(i)). The other end 212 of the support shaft 21 is inserted through the second circular hole 13 via a shaft support means 32.

[0026] In this embodiment, when the length of the longitudinal direction D of the casing 10 (see FIG. 1) is 400 mm and the inner diameter R2 of the casing 10 (see FIG. 2(i)) is 350 mm, the size of the rectangular hole 12 is, when the shorter side of the rectangular shape is vertical V and the longer side of the rectangular shape is horizontal B (see FIG. 7), the length of vertical V is 17 mm and the length of horizontal B is 80 mm. The size of the rectangular hole 12 is an example, and the vertical V is a length through which the shaft support means 31 (diameter 15 mm in this embodiment) can pass, and the horizontal B is a length that allows one end 211 of the support shaft 21 to pass through the rectangular hole 12 and then the blade 20 to be attached inside the casing 10, as described below. By keeping the size of the rectangular hole 12 to a minimum, the strength of the casing 10 can be ensured and air passing through the casing 10 can be prevented from leaking from the rectangular hole 12.

[0027] In this embodiment, the casing 10 is made from a steel plate having a thickness of 1.6 mm, and is processed by cutting, bending, welding, and the like.

[0028] [Feather 20] The blades 20 are incorporated in the casing 10 to open and close the flow passages in the casing 10. In addition, a rod-shaped support shaft 21 is fixed to the blades 20 before they are incorporated in the casing. Therefore, in this description, the blades 20 and the support shaft 21 fixed thereto are sometimes simply referred to as "blade 20."

[0029] The blade 20 has a substantially circular disk shape (see FIG. 3(iii)). The length L1 of the support shaft 21 is longer than the outer diameter R1 of the blade 20 in order to attach the opening and closing device 50 to one end 211 of the support shaft 21 protruding outside the casing 10 (see FIG. 7). Therefore, one end 211 of the support shaft 21 is fixed so as to extend beyond the peripheral edge of the blade 20. The other end 212 of the support shaft 21 is fixed slightly beyond the peripheral edge of the blade 20 to such an extent that the shaft support means 32 can be attached to the other end 212.

[0030] Also, the blade 20 has a step of about the diameter of the support shaft 21 at approximately the center, with the blade surface on the side where the support shaft 21 is fixed being designated as 201 and the blade surface on the opposite side being designated as 202 (see Figs. 3(i) to (iii)). Providing such a step can improve the strength of the blade 20. Also, since the support shaft 21 can be easily fixed along this step portion, the work efficiency when fixing the blade 20 to the support shaft 21 can be improved. Furthermore, when the blade 20 is fully closed inside the casing 10, the blade 20 abuts against the inner ribs 18 from the front and rear directions (see Figs. 1 and 3), thereby improving airtightness. After being installed in the casing 10, the blades 20 rotate about the support shaft 21 (see the arrows in Figs. 3(i) and (ii)), thereby opening and closing the flow passage in the casing 10. In the state shown in Figs. 3(i) and (ii), the blade surfaces 201 and 202 of the blades 20 are horizontal, so that the flow passage in the casing 10 is open.

[0031] Incidentally, the blades 20 are incorporated within the casing 10 and rotate around the support shaft 21 to open and close the cylindrical flow passage. Therefore, the outer diameter R1 of the blades 20 is designed to be slightly smaller than the inner diameter R2 (see FIG. 2(i)) of the casing 10 so that the blades 20 can rotate within the casing 10 and come into contact with the inner rib 18 protruding into the casing 10 when fully closed, thereby closing the flow passage.

[0032] In addition, the peripheral portions 203, 204 of the blades 20 to which the support shaft 21 is fixed are slightly notched along a direction perpendicular to the support shaft 21 (see the dashed line in Figure 3 (iii)) to prevent interference with the shaft support means 31, 32 inside the casing 10 and to ensure smooth rotation.

[0033] The shape of the support shaft 21 may be a round bar having a circular cross section, a polygonal column having a hexagonal cross section, etc. There are no particular limitations on the thickness and material of the support shaft 21 as long as it can smoothly rotate the blades 20 within the casing 10.

[0034] [Blocking plate 40] The closing plate 40 closes the rectangular hole 12 provided in the casing 10. The closing plate 40 shown in Fig. 4(i) is a view of the closing plate 40 shown in Fig. 7 seen from the right direction (i.e., a schematic front view of the closing plate 40), and as shown in Figs. 4(i) and 7, the closing plate 40 has a first circular hole 41 through which one end 211 of the support shaft 21 is inserted via the shaft support means 31.

[0035] As shown by the arrow in Fig. 4(ii), the closing plate 40 is curved to match the outer surface shape of the portion of the casing 10 where the rectangular hole 12 is provided. Therefore, when the closing plate 40 closes the rectangular hole 12, the closing plate 40 fits snugly against the casing 10. Of course, the curvature of the closing plate 40 can be changed in design to match the outer surface shape of the portion where the rectangular hole 12 is provided.

[0036] Furthermore, since the casing 10 has a thickness of 1.6 mm as described above, the closing plate 40 is provided with a protrusion 42 of the same size as the rectangular hole 12 so as to fill the thickness of the casing 10 and make the inner surface of the casing 10 flush. The thickness of the protrusion 42 is 1.6 mm, the same as the thickness of the casing 10. The protrusion 42 fills in the step caused by the thickness of the casing 10, making the inner surface of the casing 10 flush. In this embodiment, the protrusion 42 is provided on the back surface of the closing plate 40. The first circular hole 41 is provided in the center of the closing plate 40 (the protrusion 42) (see FIGS. 4(ii) and (iii)).

[0037] Additionally, the closing plate 40 has an elastic member (not shown) provided on the back surface thereof, which is in surface contact with the casing 10, except for the portion where the protrusion 42 is provided. The elastic member is, for example, a sponge packing or a rubber packing. By fixing the closing plate 40 to the casing 10 with screws or the like, the packing is interposed between the casing 10 and the closing plate 40, and it is possible to prevent air from leaking from the rectangular hole 12.

[0038] [Shaft support means 31, 32] Of the two shaft support means 31, 32, one shaft support means 31 is located inside the blocking plate 40 and attached to one end 211 of the support shaft 21 when one end 211 of the support shaft 21 is inserted into the first circular hole 41 (see Figure 7). On the other hand, the other shaft support means 32 is attached to the other end 212 of the shaft 21 inside the casing 10 when the other end 212 of the shaft 21 is inserted into the second circular hole 13 .

[0039] These shaft support means 31 and 32 support both ends of the support shaft 21 within the casing 10 to allow the blades 20 to rotate smoothly within the casing 10. In this embodiment, bushes are used as the shaft support means 31, 32, but these can be appropriately changed depending on the usage environment, usage purpose, etc. For example, when the operation frequency is high or when operational reliability is required, bearings can be used as the shaft support means 31, 32.

[0040] When a bush is used as the shaft support means 31, 32, the bush consists of a portion having a smaller diameter than the circular hole 13, 41 and a portion having a larger diameter than the circular hole 13, 41, and by attaching the bush to the circular hole 13, 41 from the inside of the casing 10 or the blocking plate 40, the bush is structured so that it will not fall off to the outside of the casing 10.

[0041] [Opening and closing device 501] The damper 100 shown in FIG. 7 further includes an opening and closing device 50 (501) in addition to the configuration of the damper 100 shown in FIG. The opening and closing device 50 opens and closes the blades 20 by rotating the support shaft 21, and is attached to one end 211 of the support shaft 21 protruding outside the casing 10 (see FIG. 7). The opening and closing device 501 of the damper 100 can adjust the opening degree of the blades 20 by manually rotating the handle 51 of the opening and closing device 501.

[0042] [Damper 200] The damper 200 (see FIG. 8) is a disaster prevention damper, and therefore further includes an opening / closing device 50 (502), an inspection port 60, and a hanging bracket 70.

[0043] [Switchgear 502] When the temperature inside the casing 10 rises during a fire, the temperature fuse 52 inserted inside the casing 10 melts, and a spring (not shown) provided inside the opening and closing device 502 of the damper 200 instantly closes the blades 20 in conjunction with the melting of the temperature fuse 52.

[0044] [Inspection port 60, hanging bracket 70] The inspection port 60 is for checking the opening and closing of the blades 20, the operating state of the thermal fuse 52, and the internal state of the damper 200, and is used when inspecting the damper 200 (see FIG. 8). In this embodiment, the hanging bracket 70 is attached to the upper part of the casing 10, and is used to suspend and secure the damper 200 by inserting a hanging bolt provided in the building structure through the hole 71 and securing it with a nut (see Figure 8).

[0045] [Damper manufacturing method] Next, a method for manufacturing a damper will be described based on the damper 100 with further reference to Figures 5 and 6. As described above, the damper 200 has the same configuration as the damper 100 except for the inspection port 60 and the hanging bracket 70, so this manufacturing method can also be used as a method for manufacturing the damper 200. Note that the configurations already described are given the same reference numerals in the drawings, and detailed descriptions thereof will be omitted.

[0046] 5 and 6 are diagrams showing the damper 100 shown in Fig. 1 as viewed from above, and are diagrams showing in chronological order how the blades 20 are assembled into the casing 10. In order to easily explain the manufacturing method of the damper 100, the blades 20 assembled into the casing 10 are shown by dashed lines in Figs.

[0047] First, the blade 20 is attached (welded) to the support shaft 21. If painting or coating is to be performed, painting or coating is performed after attachment (welding).

[0048] Next, the blade 20 is inserted into the casing 10 from one end 111 of the casing 10 with the blade surface 201 facing upward (with the blade 20 in a horizontal position) with one end 211 of the support shaft 21 first (see FIGS. 5(i) and (ii)). At this time, the blade 20 is inserted into the casing 10 with the shaft support means 32 fitted into the other end 212 of the shaft 21.

[0049] Then, the blades 20 are rotated horizontally within the casing 10, and one end 211 of the support shaft 21 is projected from the rectangular hole 12 (see the arrow in FIG. 5(iii)).

[0050] At this time, the rectangular hole 12 extends and opens in the longitudinal direction D of the casing 10 (see Figures 5(iii) and 7), so that even after one end 211 of the support shaft 21 passes through the rectangular hole 12, the support shaft 21 can be moved within the range of the opening (particularly along the longitudinal direction D of the casing 10). Therefore, the blades 20 and the other end 212 of the shaft 21 protruding from the opening at one end 111 of the casing 10 can be contained within the opening, and the position of the shaft 21 can be changed within the casing 10, as shown in Figures 5(ii) and (iii).

[0051] In this way, since the posture of the support shaft 21 can be changed even after one end 211 of the support shaft 21 passes through the rectangular hole 12, that is, the blade 20 can be rotated within the casing 10, the other end 212 of the support shaft 21 can be moved to the position where the second circular hole 13 is located. Then, the other end 212 of the support shaft 21 can be inserted through the second circular hole 13 via the shaft support means 32.

[0052] 6(i) and 7 are diagrams showing a state where the other end 212 of the support shaft 21 has been moved to a position where it is inserted through the second circular hole 13 via the shaft support means 32. Next, from this state, the closing plate 40 is fitted through the shaft support means 31 onto the one end 211 of the support shaft 21 protruding from the rectangular hole 12.

[0053] Specifically, the shaft support means 31 is inserted from one end 211 of the support shaft 21, and then the one end 211 of the support shaft 21 is inserted into the first circular hole 41, thereby fitting the blocking plate 40 (see Figures 6 (ii) and (iii)).

[0054] Then, the blocking plate 40 is fixed to the casing 10 using screws or the like. Thereafter, the opening and closing device 50 (501) is attached to one end 211 of the support shaft 21 protruding outside the casing 10 (see FIG. 7).

[0055] As described above, according to the damper and damper manufacturing method of the present invention, even after one end 211 of the support shaft 21 has passed through the rectangular hole 12, the blade 20 integrated with the support shaft 21 can be pulled into the casing 10, and the other end 212 of the support shaft 21 can be passed through the second circular hole 13, thereby incorporating the blade 20 into the casing 10.

[0056] Therefore, as described above, it is no longer necessary to perform the task of fixing the blades 20 to the support shaft 21 inside the casing 10, thereby improving workability. In addition, welding may be used to fix the blades to the support shaft in order to improve strength, and the damper according to the present invention allows the blades 20 to be attached to the casing 10 with the support shaft 21 welded in advance, improving the workability of the welding process and the quality of the weld. Also, no post-processing is required inside the casing 10 during welding, improving assembly efficiency. Furthermore, painting or coating (for example, Teflon (registered trademark) coating to improve corrosion resistance) may be performed after welding. Even in such a case, painting or coating can be performed after the post-welding process is performed before attaching the blades 20 to the casing 10, improving the quality of the painting or coating.

[0057] Furthermore, since the work of fixing the support shaft 21 to the blade 20 inside the casing 10 does not occur before the blade 20 is assembled into the casing 10, it is possible to have an automatic machine separately perform the process of welding the support shaft 21 to the blade 20. Therefore, since the process of welding the support shaft 21 to the blade 20 in the manufacturing process of the damper according to the present invention can be realized by an automatic machine, it is possible to further improve the assembly efficiency and realize mass production and reduction in manufacturing costs.

[0058] Furthermore, since components such as the blades 20, the support shaft 21, and the shaft support means 31, 32 can be easily removed from within the casing 10, the components can be easily replaced without placing an excessive burden on the worker. Therefore, it is possible to realize periodic maintenance of the damper according to the present invention, and as a result, it is possible to ensure the quality of the product for a long period of time. In particular, in a disaster prevention damper such as the damper 200, reliable operation is required in an emergency (when a fire occurs), so ensuring the quality is important.

[0059] Furthermore, even if the damper of the present invention has an assembled structure, i.e., a structure in which a rectangular hole 12 is provided in the casing 10, the cover plate 40 fits snugly into this rectangular hole 12, and the protrusion 42 fills in the step, making the inner surface of the casing 10 flush, so that the fit of the cover plate 40 covering the rectangular hole 12 can be made more secure and the strength of the casing 10 can be ensured, and since the inner surface shape of the casing 10 is maintained, there is no increase in flow path pressure loss. In addition, since both ends of the support shaft 21 are firmly supported by the shaft support means 31, 32 and the blocking plate 40, the connection between the casing 10 and the blades 20 can be made stronger, thereby ensuring the strength of the damper 100.

[0060] The dampers 100 and 200 described above are merely examples of the dampers according to the present invention, and the configuration of the present invention is not limited to these examples without departing from the spirit of the present invention. For example, the position at which the rectangular hole 12 is provided on the side surface of the casing 10 can be appropriately changed in design.

[0061] In addition, in the manufacturing method of dampers 100, 200, the blades 20 are described as being inserted with the blade surfaces facing upward (the blades 20 are inserted horizontally), but the blades 20 can also be inserted into the casing 10 in a vertical position or in any other position. [Industrial Applicability]

[0062] The damper of the present invention is a damper in which the support shaft to which the blades are fixed in advance can be incorporated into the casing without compromising the strength of the casing, and since it can be used in a variety of buildings, etc., it is industrially useful. [Explanation of symbols]

[0063] 10 Casing 11 Both ends of the casing 111 One end of the casing 112 Other end of casing 12 Rectangular hole 13 Second circular hole 18 Inner rib 19 Outer rib 20 Feather 201 Blade surface (surface) 202 Blade surface (reverse side) 203, 204 Edge of the blade 21 Spindle 211 One end of the shaft 212 Other end of the shaft 31 One shaft support means 32 Other shaft support means 40 Closing plate 41 First circular hole 42 Convex 50 Switchgear 501 Opening and closing device for dampers to adjust airflow 502 Opening and closing device for disaster prevention dampers 51 Handle 52 Thermal fuse 60 Inspection Port 70 Hanging hardware 71 Hanging hardware hole 100,200 Damper D Casing longitudinal direction R1 Outer diameter of the blade R2 Casing inner diameter L1 Length of support shaft V Vertical of rectangular hole B: Side of rectangular hole

Claims

1. A cylindrical casing having both ends open; a substantially disk-shaped blade that opens and closes a flow path in the casing, the blade having a rod-shaped support shaft that is longer than an outer diameter of the blade and has one end that is fixed in advance before being assembled into the casing so as to extend beyond a peripheral portion of the blade; and two shaft support means that are attached within the casing and support both ends of the support shaft. A rectangular hole extending in a longitudinal direction of the casing is provided on a side surface of the casing; a closing plate for closing the rectangular hole, the closing plate having a first circular hole through which one end of the support shaft is inserted via one of the shaft support means; a second circular hole provided in the casing at a position opposite to the rectangular hole, through which the other end of the support shaft is inserted via the shaft support means; A damper having

2. the closing plate is curved to match an outer surface shape of a portion of the casing in which the rectangular hole is provided, In addition, a protrusion having the same size as the rectangular hole is provided so as to fill the thickness of the casing and make the inner surface of the casing flush. The damper according to claim 1 .

3. A method for manufacturing a damper including a cylindrical casing having both ends open, a substantially disk-shaped blade for opening and closing a flow passage in the casing, a rod-shaped support shaft longer than the diameter of the blade, two shaft support means, and a closing plate, comprising: fastening a shaft to the blade such that one end of the shaft extends beyond the circumference of the blade; a step of inserting one end of the support shaft into a rectangular hole provided in a side surface of the casing and extending in a longitudinal direction of the casing from one of both ends of the casing; a step of inserting the other end of the support shaft through a second circular hole provided in the casing at a position opposite to the rectangular hole from either one of the two ends of the casing, via another shaft support means; a step of inserting one end of the support shaft through a first circular hole provided in the closing plate via one of the shaft support means and closing the rectangular hole with the closing plate; A method for manufacturing a damper comprising the steps of:

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