Duct cleaning tools

Abstract

This prevents the oscillating material from getting caught at bends and preventing it from moving forward, allowing duct cleaning to be performed while avoiding the need for drilling. [Solution] The oscillating member 21, fixed to a head 22 attached to the tip of the pressure hose 1 that supplies cleaning air, oscillates when air is sprayed from the air nozzle, striking and cleaning the inner surface of the duct 7. At least half of the head 22 at the tip is spherical, and the half at the rear end does not protrude laterally relative to the tip. Because the contact area of ​​the head 22 with the inner surface of the duct 7 is small, it can move forward without getting caught at bends in the duct 7. The head 22 is detachably attached to the pressure hose 1.

Description

Technical Field

[0001] The invention of the present application relates to a tool used in duct cleaning.

Background Art

[0002] In buildings such as office buildings, commercial facilities, warehouses, and apartment houses, ducts for ventilation, air conditioning, etc. are installed. If this type of duct is used for a considerable period of time, dust accumulates on the inner surface, which becomes a factor in deteriorating the indoor environment. For this reason, duct cleaning to remove the accumulated dust is regularly performed. Also, duct cleaning is increasingly being carried out in ordinary houses such as detached houses and individual stores. Furthermore, in means of transportation such as railway vehicles and airplanes, the ducts provided to maintain the environment may be regularly cleaned.

[0003] In duct cleaning, tools (devices) suitable for knocking out dust by air injection are often used. Hereinafter, in this specification, this type of tool is called a duct cleaning tool. A duct cleaning tool is a tool that performs cleaning by injecting air from a pressure supply hose, and utilizes the fact that the tip portion of the pressure supply hose swings violently during air injection. More specifically, the pressure supply hose is inserted from an end opening on one side of the duct to be cleaned, pressure is applied by a compressor to inject air, and the tip portion is swung to strike the inner surface. Then, while continuing the air injection, the tip portion of the pressure supply hose is advanced little by little, and the dust is knocked out on the inner surface of the portion ahead little by little. At this time, a suction fan is arranged at the end opening on the other side of the duct, and the knocked-out dust is sucked by the suction fan and collected in a dust collection bag. Incidentally, as disclosed in Patent Document 1, a structure in which a flexible belt-like member is fixed to the tip portion of the hose may be adopted. The member provided at the tip of such a hose is a member for swinging by air injection to knock out dust, and may be called a "lance", but in this specification, it is called a "swinging member". In the following explanation, the side where the air for cleaning is sent (downstream side) will be referred to as the "front" or "tip," and the opposite side where the air is sent (upstream side) will be referred to as the "back" or "rear end." [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Utility Model Publication No. 06-052981 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In recent years, duct structures have become more complex, and many ducts now have numerous bends. This has led to certain problems. These problems will be explained with reference to Figure 12. Figure 12 is a schematic diagram illustrating the challenges in cleaning ducts with bends. When the oscillating member 21 is inserted into the duct 7 and advanced, and the oscillating member 21 is advanced while cleaning is performed by air injection, the oscillating member 21 reaches a bend, as shown in Figure 12. At this time, the member that fixes the base of the oscillating member 21 (hereinafter referred to as the head in this specification) 22 often comes into contact with the bend. In the example in Figure 12, the bend is at a 90-degree angle, and the head 22 becomes stuck in the bend. When this happens, the oscillating member 21 cannot be advanced even if the pressure supply hose 1 is pushed in, and cleaning of the duct 7 beyond the bend becomes impossible.

[0006] In such cases, a hole is made in the duct 7 near the point where the oscillating member 21 cannot advance, and the oscillating member 21 is inserted through the hole to clean the duct 7 beyond the bend. After cleaning is complete, the hole is sealed and the duct 7 is restored to its original condition. However, depending on the circumstances of the facility where the ducts are installed, it may not be possible to drill holes in the ceiling. In private homes, for example, the owner may be reluctant to have holes drilled in the ceiling. Furthermore, the extra work of drilling and then filling the holes and restoring the ducts to their original condition adds to the time required to complete the cleaning and increases the cost. Therefore, it is desirable to perform duct cleaning without drilling holes.

[0007] The present invention was made to solve the problems in conventional duct cleaning, and aims to prevent the oscillating material from getting caught at bends and being unable to move forward, thereby enabling duct cleaning while avoiding the need for drilling holes. [Means for solving the problem]

[0008] To solve the above problems, this specification discloses an invention for a duct cleaning tool. The duct cleaning tool according to the disclosed invention is a tool used for cleaning the inner surface of a duct. This duct cleaning tool comprises a pressure supply hose for supplying cleaning air, a head attached to the end of the pressure supply hose and having an air nozzle, and a oscillating member fixed to the head that oscillates when air is sprayed from the air nozzle to strike the inner surface of the duct. Furthermore, the head has a shape in which at least the front half is spherical, and the rear half does not protrude laterally from the front. Furthermore, in order to solve the above problems, the head of this duct cleaning tool may have a spherical portion in the front half and from the middle to the rear end. Furthermore, in order to solve the above problems, the surface of the head of this duct cleaning tool may be a ground surface or a polished surface. Furthermore, in order to solve the above problems, the head of this duct cleaning tool may be detachably attached to the pressure supply hose. [Effects of the Invention]

[0009] As explained below, according to the duct cleaning tool of the disclosed invention, since the head on which the oscillating material is fixed is spherical, the head does not get caught at bends in the duct, and the oscillating material can be sent beyond the bends and deep into the duct. Furthermore, the above effect is enhanced if the head has a spherical portion in the front half and from the middle to the rear end. Furthermore, if the surface of the head is ground or polished, the head will slide more easily on the inner surface of the duct, thus enhancing the above effect. Furthermore, the detachable head configuration makes it easy to clean the duct's inner surface using appropriate heads and oscillating elements depending on the size and shape of the cross-sectional area. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic perspective view of a duct cleaning tool according to the first embodiment. [Figure 2] This is a schematic cross-sectional view showing the structure of the tip unit. [Figure 3] This is a schematic front view illustrating duct cleaning using the duct cleaning tool of the first embodiment. [Figure 4] This is a schematic plan view illustrating duct cleaning using the duct cleaning tool of the first embodiment. [Figure 5] This is a schematic plan view illustrating duct cleaning using the duct cleaning tool of the first embodiment. [Figure 6] This is a schematic diagram showing variations in head shape. [Figure 7] This is a schematic diagram illustrating the effect of the intermediate member. [Figure 8] This is a schematic perspective view of a duct cleaning tool according to the second embodiment. [Figure 9] This is a schematic cross-sectional view showing an example of the connecting structure of each flexible elongated body. [Figure 10] It is a schematic cross-sectional view showing the structure of the tip unit in the second embodiment. [Figure 11] It is a schematic plan view showing duct cleaning using the duct cleaning tool of the second embodiment. [Figure 12] It is a schematic view showing problems in cleaning a duct with a bent portion.

Mode for Carrying Out the Invention

[0011] Next, a mode for carrying out the present invention (hereinafter, embodiment) will be described. FIG. 1 is a schematic perspective view of a duct cleaning tool according to the embodiment. As shown in FIG. 1, the duct cleaning tool includes a pressure supply hose 1 for sending cleaning air, and a swing member 21 that is connected to the tip side of the pressure supply hose 1 and can swing when air is injected to strike the inner surface of the duct. The swing member 21 constitutes the tip unit 2. In this embodiment, an intermediate member 6 is provided as a member connecting the pressure supply hose 1 and the tip unit 2.

[0012] As the pressure supply hose 1, a hose made of a material having appropriate rigidity and elasticity is used. For example, a hard nylon tube is used as the pressure supply hose 1. The thickness is such that the outer diameter is about 10 to 20 mm and the inner diameter is about 5 to 15 mm. The thickness of the pressure supply hose 1 is selected according to the size of the cross-sectional area of the duct to be cleaned. For a duct with a large cross-sectional area, a thicker pressure supply hose 1 is used, and cleaning is performed by increasing the air injection amount. However, when the pressure supply hose 1 becomes thick, the contact area with the inner surface of the duct becomes large and the frictional resistance becomes large, so there is a drawback that it becomes difficult to feed the pressure supply hose 1 over a longer length. Therefore, in the case of a duct with a small cross-sectional area or the like, a thinner pressure supply hose 1 is often used. In addition, a connector 5 connected to a compressor is fixed to the rearmost end (pressure supply source) of the pressure supply hose 1.

[0013] FIG. 2 is a schematic cross-sectional view showing the structure of the tip unit 2. In this embodiment, the tip unit 2 is composed of a swing member 21 which is a flexible tube-shaped member, and a head 22 fixed to one end of the swing member 21. The swing member 21 is formed of a highly flexible material such as vinyl chloride or silicone rubber. The length of the swing member 21 is selected according to the size (cross-sectional area) of the inner surface of the duct to be cleaned, and is about 5 cm to 35 cm. Note that, as the swing member 21, a plurality of tube-shaped members or one or more belt-shaped members may be adopted.

[0014] The head 22 forms a major feature point of the duct cleaning tool of the embodiment and is a spherical member. The head 22 is made of steel and is formed of iron, stainless steel, aluminum, etc. that have been plated. The head 22 is manufactured by cutting or the like, and its surface is a smooth surface that has been polished. When it is manufactured by cutting, there may be cases where it is not particularly polished after processing. Also, even when it is said to be polished, it does not have to be a mirror surface, and a smooth and slippery surface is sufficient. Note that, as the head 22, resin or ceramic ones may be used. In the case of resin, it may be manufactured by a 3D printer.

[0015] As shown in Figure 2, the head 22 is a hollow spherical member. The head 22 has a through hole 221 in the thicker part at the tip, and the oscillating member 21 is locked into the through hole 221 by a ring sleeve 222. More specifically, the ring sleeve 222 has an outer diameter slightly larger than the inner diameter of the oscillating member 21, and the rear end portion of the oscillating member 21 is placed over the ring sleeve 222, and the elasticity of the oscillating member 21 prevents the ring sleeve 222 from coming off. The through hole 221 is a circular cross-section hole with a diameter slightly larger than the outer diameter of the ring sleeve 222. The oscillating member 21, with its rear end portion placed over the ring sleeve 222, has its tip portion passing through the through hole 221 and protruding forward of the head 22, and its rear end portion is locked into the through hole 22. Specifically, the ring sleeve 222, over which the rear end portion of the oscillating member 21 is placed, is fitted into the through hole 221, and the trumpet-shaped rear end portion is caught on the edge of the through hole 222. This structure locks the oscillating member 21 into the through hole 221. This structure facilitates the replacement of the oscillating member 21. The oscillating member 21 is replaced when it wears out, and the above structure makes this easy. In addition, the oscillating member 21 may also be fixed by gluing it to the ring sleeve 222 or by gluing it to the head 22.

[0016] The head 22 has an opening in the thickened portion at its rear end, which is where the intermediate member 6 is attached. The intermediate member 6 is a component that provides appropriate elasticity at the tip of the duct cleaning tool. In this embodiment, the intermediate member 6 is a coil spring. The head 22 is attached to the tip of the intermediate member 6 by a tip connector 61. The tip connector 61 is a cylindrical component fixed to the tip of the intermediate member 6 by welding or other means, and the circumferential surface of the tip portion is threaded. The circumferential surface of the opening at the rear end of the head 22 is threaded, and the head 22 and the oscillating member 21 are fixed to the intermediate member 6 by screwing the tip connector 61 into the opening.

[0017] The rear end of the intermediate member 6 is fixed to the pressure hose 1 by a rear-end connector 62. The rear-end connector 62 is also a cylindrical member, and its tip is fixed to the rear end of the intermediate member 6 by welding or the like. A cylindrical fitting 11 with a threaded outer surface is fixed to the tip of the pressure hose 1 by adhesive. The inner surface of the rear end portion of the rear-end connector 62 is threaded to fit this. The intermediate member 6 is attached to the pressure hose 1 by inserting the fitting 11 into the rear end portion of the rear-end connector 62 and screwing it in.

[0018] As shown in Figure 2, a communication tube 63 is provided inserted through the intermediate member 6. The tip of the pressure supply hose 1 is located inside the rear end connector 62. The rear end connector 62 has a cylindrical projection 621 on its tip side, and the rear end of the communication tube 63 is attached to the projection 621. The tip connector 61 also has a cylindrical projection 611 at its rear end, and the tip of the communication tube 63 is attached to it. Each projection 611, 621 has an outer diameter larger than the inner diameter of the communication tube 63, and its elasticity prevents the communication tube 63 from coming off the projections 611, 621. However, the communication tube 63 may also be bonded to each projection 611, 621. The communication tube 63 connects the inside of the rear end connector 62 and the inside of the tip connector 61. Therefore, the air supplied by the pressure supply hose 1 is ejected from the tip of the oscillating member 21 via the communication tube 63 and the head 22.

[0019] As can be seen from the above description, in this embodiment, the intermediate member 6 and the tip unit 2 are detachable from the pressure supply hose 1 and can be replaced with other parts. That is, the intermediate member 6 can be replaced with one of a different length or elasticity. The tip unit 2 is also detachable from the intermediate member 6 and can be replaced as appropriate with one of a different size head 22 or length oscillating member 21. These configurations are in order to accommodate the size and shape of the cross-section of the duct to be cleaned.

[0020] A duct cleaning method using the duct cleaning tool of this embodiment will be described with reference to Figures 3 to 5. Figures 3 to 5 are schematic diagrams showing duct cleaning using the duct cleaning tool of this embodiment, with Figure 3 being a front schematic view and Figures 4 and 5 being top schematic views. Figures 3 to 5 show an example of cleaning a ventilation duct 7.

[0021] When cleaning the ventilation duct 7, the pressure supply hose 1 is connected to the compressor 8 using the connector 5. The ventilation fan 91 is temporarily stopped, and the suction fan 93 is connected to the ventilation opening 92, located at the opposite end of the ventilation system from the ventilation fan 91, via the air guide duct 931. In this example, as shown in Figure 3, the ventilation fan 91 is temporarily removed, and the ventilation hood 95 located at the ventilation opening 92 is also temporarily removed. Then, the dust collection bag 94 is attached to the suction fan 93, and the suction fan 93 is started. The dust collection bag 94 is a filter-like bag that allows air drawn in by the intake fan 93 to pass through, but prevents dust from passing through. Then, as shown in Figures 3 and 4(1), the pressure supply hose 1 is held in the hand, and the tip unit 2 is inserted into the duct 7. With this in place, the compressor 8 is turned on, and cleaning is started.

[0022] In the inserted tip unit 2, the oscillating element 21 oscillates violently when pressurized air is injected through the through-hole 221, striking the inner surface of the duct 7. Dust adhering to the inner surface is knocked out by the impact of the oscillating element 21 and floats inside the duct 7. The floating dust is pushed forward by the suction fan 93, discharged from the ventilation opening 92, and collected in the dust collection bag 94. With the compressor 8 and suction fan 93 continuing to operate, the pressure supply hose 1 is gradually advanced, and the tip unit 2 is slowly moved forward. This gradually cleans the inner surface of the duct 7 in the area further forward.

[0023] Subsequently, as shown in Figure 4(2), the tip unit 2 reaches the bend in the duct 7. When the pressure hose 1 is pushed in a little more forcefully, the head 22 slides along the inner surface of the bend, as shown by the dashed line in Figure 4(2), and the intermediate member 6 becomes bent. When the pressure hose 1 is pushed in further, as shown in Figure 5(1), the tip unit 2 passes out of the bend, and the intermediate member 6 returns to its original position. Then, as the pressurized air injection continues and the pressurized hose 1 is pushed further, the tip unit 2 reaches the next bend, and as shown in Figure 5(2), the intermediate member 6 also bends there, the head 22 slides along the inner surface and moves, and the tip unit 2 passes through the bend.

[0024] In this manner, the pressure hose 1 is pushed in while cleaning with air jets, and the cleaning is complete when the tip unit 2 passes through each bend and reaches the end of the duct 7. After that, the compressor 8 is turned off, the pushed-in pressure hose 1 is pulled out, and the tip unit 2 is removed from the duct 7. Then, the operation of the suction fan 93 is stopped, and the dust collected in the dust collection bag 94 is removed and disposed of, completing the work.

[0025] According to the duct cleaning tool of the embodiment described above, since the head 22 to which the oscillating material 21 is fixed is spherical, the head 22 does not get caught at bends in the duct, and the oscillating material can be sent beyond the bends to the back of the duct. Therefore, duct cleaning can be performed while avoiding the need to drill holes. However, the present invention does not preclude the practice of drilling holes. In the case of ducts with complex structures that have many bends, it may be necessary to drill holes at the next bend after clearing the first or several bends. Even in this case, the number of drilling operations can be reduced, thus shortening the overall work time, including restoration to the original state. Clearing a bend means moving past the bend and continuing onward. Furthermore, in the duct cleaning tool of this embodiment, since the surface of the head 22 is a ground or polished surface, the head 22 slides more easily on the inner surface of the duct, and in this respect the above effect is further enhanced. Moreover, as mentioned above, the head 22 is detachable, making it easy to perform cleaning by using an appropriate head 22 or oscillating material 21 depending on the size and shape of the cross-sectional area of ​​the inner surface of the duct.

[0026] From the standpoint of facilitating passage through bends, it is preferable that the head 22 has a spherical shape at least half of its front end and a shape in which the rear end half does not protrude from the front end. This point will be explained below with reference to Figure 6. Figure 6 is a schematic diagram showing variations in the shape of the head 22. As shown in Figure 6(1), the head 22 may have a spherical tip and a cylindrical or cylindrical tip. In this case, the outer diameter of the tip half is the same as the diameter of the tip sphere (hemispheric). Alternatively, as shown in Figure 6(2), the tip half may be conical (tapered). It is preferable that the spherical portion is at least the tip half, but it is more preferable that the spherical shape extends beyond the tip towards the rear, as shown in Figure 2. On the other hand, a shape in which the rear half protrudes laterally from the tip half, as shown in Figure 6(3), is undesirable because the protruding rear portion is prone to snagging.

[0027] In the operation of the duct cleaning tool of the first embodiment described above, the intermediate member 6 has the effect of further preventing the tip unit 2 from getting caught at the bending point. This point will be explained below with reference to Figure 7. Figure 7 is a schematic cross-sectional view showing the effect of the intermediate member 6. As described above, when cleaning the duct 7, depending on the position when the duct 7 reaches a bend, the head 22 may come into contact with the corner of the bend and get stuck, as shown in Figure 7(1). In this state, the head 22 is in contact with the corner and the intermediate member 6 is bent by the pressure. When this happens, the pressure hose 1 is pulled out slightly to move the head 22 away from the corner. Then, as shown in Figure 7(2), the intermediate member 6 will swing in the opposite direction due to its elasticity. If the pressure hose 1 is pushed in again at that moment, the head 22 will move along the inner surface away from the corner, allowing the tip unit 2 to pass through the bend and move further forward.

[0028] The condition shown in Figure 7(1) is likely to occur when the pressure hose 1 retains a so-called coiled shape. The pressure hose 1 is coiled into a loop during storage and transportation, but if this condition persists for a long time, it may remain slightly bent (retaining a coiled shape) even when straightened. The intermediate member 6 serves to facilitate passage through the bend even in such cases.

[0029] Next, a duct cleaning tool according to a second embodiment will be described. Figure 8 is a schematic perspective view of the duct cleaning tool according to the second embodiment. The duct cleaning tool of the second embodiment differs from the first embodiment in that a component for sending the tip unit 2 deep into the duct is provided separately from the pressure hose 1. More specifically, the duct cleaning tool of the second embodiment includes a flexible elongated body 3 as a component separate from the pressure hose 1. The flexible elongated body 3 is a component that extends in the longitudinal direction of the pressure hose 1.

[0030] The flexible elongated body 3 is a component that is more rigid (less flexible) than the pressure hose 1. The flexible elongated body 3 is made of a hard plastic such as polypropylene. However, it may also be made of metal such as stainless steel or aluminum, or of ceramics if it has the necessary flexibility and durability. In addition, the flexible elongated body 3 may be made of a plastic material reinforced with glass fiber or carbon fiber.

[0031] As shown in Figure 8, the duct cleaning tool in the second embodiment comprises a plurality of flexible elongated bodies 3. Each flexible elongated body 3 is the same length. In this embodiment, each flexible elongated body 3 is used by connecting them to each other in the longitudinal direction, and has connecting parts at both ends in the longitudinal direction. For example, a male connecting part 31 is provided at the front end and a female connecting part 32 is provided at the rear end.

[0032] Figure 9 is a schematic cross-sectional view showing an example of the connecting structure of each flexible elongated body 3. Each connecting part 31, 32 is a small cylindrical or cylindrical member made of metal (stainless steel, aluminum, etc.), and is fixed to its respective end by crimping or adhesive. As shown in Figure 9(1), the male connector 31 has a protruding portion 311 that protrudes with a smaller diameter than the portion fixed to the flexible elongated body 3. The protruding portion 311 is the portion that connects to the female connector 32. A movable projection 312 is formed in the middle of the protruding portion 311. The movable projection 312 has a tapered shape, with a small protrusion on the side opposite to the flexible elongated body 3 and a larger protrusion as it approaches the flexible elongated body 3. Furthermore, as shown in Figure 9(1), the male connector 31 has a spring material 313 built inside. In this example, the spring material 313 is a leaf spring and presses the movable projection 312 outward.

[0033] The female connector 32 is a cylindrical member having the same outer diameter as the male connector 31. The female connector 32 is connected to the male connector 31 at the connecting cylinder portion 321, which is the portion beyond the part fixed to the flexible elongated body 3. The connecting cylinder portion 321 has an inner diameter that matches the outer diameter of the protruding portion 311 of the male connector 31. The connecting cylinder portion 321 has a fitting hole 322 into which the movable projection 312 of the male connector 31 fits.

[0034] When the protruding portion 311 of the male connector 31 is inserted into the connecting cylinder portion 321 of the female connector 32 and pushed in, the movable projection 312 retracts against the elasticity of the spring material 313. When the movable projection 312 reaches the position of the fitting hole 322 of the female connector 32, as shown in Figure 9(2), the spring material 313 causes the movable projection 312 to fit into the fitting hole 322 and become hooked. As a result, the male connector 31 and the female connector 32 are connected and will not separate by simply pulling them. To release the connection, the movable projection 312 that is fitted into the fitting hole 322 is pressed down with a finger while the female connector 32 is pulled out from the male connector 31 (or the male connector 31 is pulled out from the female connector 32). With this connection structure, each flexible elongated body 3 can be interconnected.

[0035] Figure 10 is a schematic cross-sectional view showing the structure of the tip unit 2 in the second embodiment. The tip unit 2 in the second embodiment is almost the same as in the first embodiment, but the intermediate member 6 and the head 22 are fixed to the outermost flexible elongated body 3 (hereinafter referred to as the outermost elongated body). As shown in Figure 10, a fitting 33 is fixed to the tip of the outermost elongated body 3 by crimping or adhesive, and the rear end connector 62 of the intermediate member 6 is screwed to the fitting 33. A communication tube 63 is provided inserted through the intermediate member 6. The communication tube 63 is connected to the tip-side connector 61 and the rear end-side connector 62 by having its ends cover the respective protrusions 611 and 621, thereby connecting the two.

[0036] Duct cleaning performed using the duct cleaning tool of this second embodiment will be described with reference to Figure 11. Duct cleaning using the duct cleaning tool of the second embodiment is basically the same as that of the first embodiment. The connector 5 is connected to the compressor 8, and the tip unit 2 is inserted into the duct 7 from the end opening on one side of the duct 7. The suction fan 93 is connected to the opposite end opening via the air guide duct 931, and the dust collection bag 94 is attached. With this setup, the compressor 8 is turned on, and the oscillation of the oscillating material 21 is used to knock out and suck up the dust.

[0037] Then, by holding the leading-edge elongated body 3 in the hand and pushing it into the duct 7, the tip unit 2 is gradually advanced further into the duct 7. Once the leading-edge elongated body 3 is inserted into the duct 7 to near its rear end, the next flexible elongated body 3 is connected to the leading-edge elongated body 3, and the connected flexible elongated body 3 is held in the hand and pushed to advance the tip unit 2 further into the duct 7. During this time, the air injection from the compressor is continued, and dust is continuously knocked out and sucked up. In this way, the tip unit 2 is advanced while sequentially connecting the flexible elongated bodies 3. At this point, when the tip unit 3 reaches a bend in the duct, the head 22 slides along the inner surface and exits the bend, similar to the first embodiment. Then, as the flexible elongated body 3 is pushed further in, the leading edge elongated body 3 reaches a bend, and the leading edge elongated body 3 bends elastically and exits the bend. After exiting, it returns to a straight position. The subsequent flexible elongated body 3 also bends once when it reaches a bend, then exits the bend and returns to its original position. An example of the bent state of each flexible elongated body 3 is shown in Figure 11. As this operation continues, cleaning is completed when the tip unit 2 reaches the opposite end opening in the duct.

[0038] In this second embodiment of the duct cleaning tool, a flexible elongated body 3 is provided separately from the pressure supply hose 1. The flexible elongated body 3 can be selected to have appropriate elasticity and rigidity regardless of the pressure supply, making it easier to clear bends and deliver the tip unit 2 to the end of the duct. The configuration of the first embodiment can be described as a configuration in which the pressure supply hose 1 is also used as the member that delivers the tip unit 2 to the back of the duct. This configuration has the advantage of being structurally simple, but in order to easily clear bends, it is necessary to have appropriate rigidity and elasticity, and it can be difficult to obtain a hose with such appropriate rigidity and elasticity. In the second embodiment, a flexible elongated body 3 is used as the member that delivers the tip unit 2, and any hose with any degree of flexibility can be used as the pressure supply hose 1.

[0039] Furthermore, the duct cleaning tool of the second embodiment is configured to use multiple flexible elongated bodies 3 connected together, which has the effect of easily cleaning even long ducts 7. For long ducts 7, if a correspondingly long flexible elongated body 3 is used, it is possible to clean even bends without using a connected system (even with just one flexible elongated body). However, if it is not a connected system, a longer flexible elongated body 3 will be used depending on the total length of the duct 7, which may lead to problems such as cumbersome handling, difficulty in transporting to the work site, and difficulty in finding storage space. With a connected system, such problems do not occur. Note that when each flexible elongated body 3 is bundled together, the pressure supply hose 1 will bend 180 degrees.

[0040] In the above description of duct cleaning using the duct cleaning tool, a ventilation duct 7 was used as an example, but the duct cleaning tool in each embodiment can be used to clean various types of ducts, such as air conditioning ducts and heating and cooling ducts. In terms of duct shape, it can be used similarly for ducts with a rectangular cross-section, as well as ducts with a circular cross-section and elliptical cross-section. In addition, in the structure of the above embodiment, a structure in which the pressure supply hose 1 is extended without using the connecting tube 63 can also be adopted. In this case, the pressure supply hose 1 is inserted into the intermediate member 6 and its tip is connected to the tip-side connector 61, and is in communication with the through hole 221 of the head 22. [Explanation of symbols]

[0041] 1. Pressure hose 2. Tip Unit 21 Oscillating element 22 heads 3 Flexible long body 31 Male connector 32 Female connectors 4 Binding tool 5 Connectors 6 Intermediate members 7 ducts 8 Compressors

Claims

1. A duct cleaning tool used to clean the inner surface of a duct, A pressure hose that supplies air for cleaning, A head attached to the end of the pressure hose, having an air nozzle, A oscillating element fixed to the head, which oscillates when air is sprayed from the air nozzle and strikes the inner surface of the duct, It is equipped with, A duct cleaning tool characterized in that the head has a spherical shape at least half of the front end, and the rear end half does not protrude laterally from the front end.

2. The duct cleaning tool according to claim 1, characterized in that the head has a spherical portion in the front half and from the middle to the rear end.

3. The duct cleaning tool according to claim 1, characterized in that the surface of the head is a ground surface or a polished surface.

4. The duct cleaning tool according to claim 1, 2, or 3, characterized in that the head is detachably attached to the pressure supply hose.

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