Pressure switching valve and pressure switching cleaning method for drain pipes

Abstract

To provide a pressure switching valve capable of appropriately switching a water pressure applied to an in-pipe cleaning nozzle during a series of cleaning operations for individual dedicated drain pipes and shared drain pipes.SOLUTION: A pressure switching valve comprises: a water receiving part 7a that receives high-pressure water, and a water sending part 7b that sends the high-pressure water to an in-pipe cleaning nozzle 5; a pressure reduction path formed between the water receiving part and the water sending part, including an orifice 7e that constricts a flow path of the high-pressure water, and a bypass path 7f formed between the water receiving part and the water sending part to bypass the orifice; and a sealing body 7c that moves in one direction under gravity to seal a first opening 7g leading from the water receiving part to the bypass path, thereby sending the high-pressure water to the water sending part via the pressure reduction path, and moves in the other direction under gravity to seal a second opening 7h leading from the water receiving part to the pressure reduction path, thereby sending the high-pressure water to the water sending part via the bypass path.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a pressure switching valve capable of switching the injection pressure of high-pressure water applied to an internal cleaning nozzle of a drain pipe, and a pressure switching cleaning method for a drain pipe. [Background technology]

[0002] From the viewpoint of effective land use, many high-rise apartment buildings are being constructed in urban areas and their suburbs. Domestic wastewater (sewage) discharged from these apartment buildings is discharged from dedicated drainage pipes laid horizontally inside each house, through shared drainage pipes (also called standpipes) laid vertically inside the building, and into horizontal pipes outside, thereby maintaining a good living environment.

[0003] However, because this domestic wastewater contains a large amount of food residues, oils, etc., these residues, oils, etc. become solid matter and adhere to the walls of not only the individual dedicated drainage pipes but also the shared drainage pipes, and over a considerable period of time, this can cause problems such as blockage of the drainage pipes. In addition, the solid matter adhering to the pipe walls can give off a foul odor, worsening the living environment. In order to prevent such deterioration of the living environment and to maintain a good living environment, it is necessary to clean the drain pipes at regular intervals.

[0004] As mentioned above, one method for cleaning and removing solid matter adhering to the inside of a drain pipe is the high-pressure water jet cleaning method, which is used to spray high-pressure water from a cleaning nozzle attached to the end of a water supply hose toward the solid matter adhering to the inside of the drain pipe to remove the solid matter.

[0005] Many proposals have already been made regarding high-pressure water injection nozzles for use in cleaning the inside of drainage pipes as described above, and the applicant has previously proposed an in-pipe cleaning nozzle that can be used by switching the high-pressure water injection port so as to be suitable for cleaning all of the above-mentioned individual dedicated drainage pipes, shared drainage pipes, and horizontal pipes, as well as a method of cleaning drainage pipes using this nozzle, which is disclosed in Patent Document 1.

[0006] Figures 7 and 8 show an example of the pipe cleaning nozzle disclosed in Patent Document 1, and show the pipe cleaning nozzle in cross section cut in the axial direction. Figure 7 shows the nozzle body 11 with the tip portion facing downward, and Figure 8 shows the nozzle body 11 with the axis 13 facing horizontally. The nozzle body 11 defines a water supply space 14 along its axis 13 for supplying high-pressure water from the hose connection port 12. A ball-shaped sealing body 15 that moves under the influence of gravity is housed within the large diameter portion of the water supply space 14.

[0007] When the nozzle body 11 is oriented with the tip end facing down as shown in Fig. 7, the sealing body 15 moves to the front side of the nozzle body 11 due to gravity. When the nozzle body 11 is oriented horizontally as shown in Fig. 8, the sealing body 15 enters the pocket 14a formed at a position away from the central axis 13.

[0008] On the other hand, on the front side of the nozzle body 11, a plurality of jet nozzles 17 are formed radially obliquely toward the rear, and on the rear side of the nozzle body 11, a plurality of jet nozzles 16 are formed radially obliquely toward the front. Therefore, in the state shown in Figure 7 where the front of nozzle body 11 is set facing downward when viewed from the side of a hose (not shown) connected to hose connection port 12, sealing body 15 moves forward and blocks circular opening 19, thereby sealing off the high-pressure water reaching diagonally rearward nozzle 17 formed in the nozzle body, and high-pressure water is sprayed from diagonally forward nozzle 16.

[0009] Furthermore, in the state shown in Figure 8 where nozzle body 11 is arranged so as to face horizontally, sealing body 15 enters pocket 14a and closes circular opening 18, thereby sealing off the high-pressure water reaching obliquely forward nozzle 16 formed in nozzle body 11, and high-pressure water is sprayed from obliquely backward nozzle 17.

[0010] Therefore, when the nozzle body 11 is inserted into a horizontal dedicated drain pipe installed in an individual house, for example, high-pressure water is sprayed from the jet nozzle 17 facing diagonally backward, and the nozzle body 11 receives a forward propulsive force and moves inside the dedicated drain pipe toward the standpipe. Even after the nozzle body 11 has advanced to the joining part of the standpipe, the nozzle body 11 continues to spray high-pressure water and the hose is sent out, so that the nozzle body 11 moves downward inside the standpipe. As a result, the inside of the dedicated drain pipe and the standpipe are cleaned by the water sprayed from the nozzle.

[0011] When the supply of high-pressure water is stopped while the nozzle body 11 is positioned inside the standpipe, the sealing body 15 inside the nozzle body 11 closes the opening 19 communicating with the nozzle outlet 17. By supplying water again in this state, high-pressure water is sprayed from the nozzle outlet 16 diagonally forward of the nozzle body 11, and the nozzle body 11 receives a propulsive force in the backward direction. This reduces the burden on the worker required to pull back the nozzle body 11. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Patent No. 4279870 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0013] Incidentally, in the pipe cleaning nozzle disclosed in Patent Document 1, when the nozzle body 11 is inserted into a dedicated horizontal drainage pipe installed in an individual house, for example, the ball-shaped seal 15 provided in the nozzle body 11 does not necessarily enter the pocket 14a, as shown in FIG. 8. That is, the ball-shaped sealing body 15 enters the pocket 14a only when the pocket 14a is in the state shown in FIG. 8 in which the pocket 14a is positioned downward, thereby performing the normal spraying operation of spraying high-pressure water from the nozzle 17 obliquely rearward.

[0014] Therefore, in the case of the nozzle for cleaning inside a pipe disclosed in Patent Document 1, an operator may be forced to repeatedly supply water to the nozzle body 11 while appropriately rotating the nozzle body 11 via a hose, and check whether the nozzle body is spraying normally. Therefore, in the above-mentioned pipe cleaning nozzle in which the spray direction can be switched, it is necessary that the spray direction switching operation can be performed instantly and accurately, and improving the operability and reliability of the spray switching operation is an important issue in terms of improving work efficiency.

[0015] On the other hand, when cleaning the above-mentioned shared drainage pipe (standpipe), the nozzle is usually inserted from the upper opening (cleaning port) of the standpipe installed on the roof of the building, etc. However, in recent building-type apartment buildings, there are cases where an opening for cleaning the standpipe is not installed on the roof, etc., and there are also cases where it is difficult to insert the nozzle for cleaning inside the pipe directly into the standpipe from near the top or bottom of the standpipe. In such cases, it is necessary to insert a nozzle into the standpipe through a dedicated drain pipe installed in each individual home and clean the dedicated drain pipe and the standpipe.

[0016] In this case, for individual dedicated drain pipes with a relatively small inner diameter, it is desirable to set the water pressure sprayed from the nozzle low to reduce damage caused by the water pressure to the dedicated drain pipes, and for shared drain pipes with a large inner diameter, it is desirable to set the water pressure high to increase the cleaning power, in order to improve the efficiency of the cleaning work.

[0017] The present invention has been made based on the above-mentioned technical viewpoints, and aims to improve the reliability of the jet direction switching operation in a nozzle for cleaning inside a pipe in which the jet direction is switchable. Another major objective of this invention is to provide a pressure switching valve that can appropriately switch the water pressure applied to an in-pipe cleaning nozzle during a series of cleaning operations for individual dedicated drainage pipes and shared drainage pipes, and to provide a pressure switching cleaning method for drainage pipes that improves the efficiency of cleaning work by combining an in-pipe cleaning nozzle with a pressure switching valve. [Means for solving the problem]

[0018] The nozzle for cleaning inside a pipe according to the present invention, which has been made to solve the above-mentioned problems, is a nozzle for cleaning inside a pipe, which is attached to the tip of a water supply hose and enables high-pressure water supplied through the water supply hose to be selectively sprayed from a first nozzle or a second nozzle having different spray angles relative to the axis of a nozzle body, wherein a cavity is formed within the nozzle body, the longitudinal direction of which is along the axis, and a sealing body is provided which is housed within the cavity and moves within the cavity in the longitudinal direction under the influence of gravity, a first opening is formed at one longitudinal end of the cavity which communicates with the first nozzle, and a second opening is formed at the other longitudinal end of the cavity which communicates with the second nozzle, and the first opening is sealed when the sealing body moves due to gravity towards the first opening side, and the high-pressure water is sprayed from the second nozzle, and the second opening is sealed when the sealing body moves due to gravity towards the second opening side, and the high-pressure water is sprayed from the first nozzle.

[0019] In this case, it is desirable that the nozzle body be attached to the tip of the water supply hose via a hose connection tube, and that the hose connection tube be bent within an obtuse angle range with respect to the axis of the nozzle body and connected to the water supply hose. In one preferred embodiment, the first nozzle is formed in the nozzle body so as to spray high-pressure water diagonally rearward as seen from the water supply hose side, and the second nozzle is formed on a rotor that is rotated relative to the nozzle body by a reaction to the spray of high-pressure water.

[0020] In addition, the first and second jet ports are each composed of a plurality of jet ports, the first jet ports are arranged at equal intervals around the circumference of the nozzle body, and the second jet ports are arranged on the rotor at equal intervals around the circumference of the rotor.

[0021] On the other hand, it is desirable to use a pressure switching valve for the above-mentioned inside-pipe cleaning nozzle, which switches the injection pressure of the high-pressure water from the nozzle depending on the part to be cleaned. In a preferred embodiment of this pressure switching valve, the valve comprises a receiving section which receives high-pressure water from a high-pressure water supply source, and a water supply section which supplies high-pressure water to the pipe cleaning nozzle, a pressure reduction passage formed between the receiving section and the water supply section and having an orifice which narrows the flow path of the high-pressure water, and a bypass passage formed between the receiving section and the water supply section which bypasses the orifice, and a sealing body which moves in one direction under the influence of gravity and seals a first opening leading from the receiving section to the bypass passage, thereby supplying the high-pressure water to the water supply section via the pressure reduction passage, and which moves in the other direction under the influence of gravity and seals a second opening leading from the receiving section to the pressure reduction passage, thereby supplying the high-pressure water to the water supply section via the bypass passage, and the movement of the sealing body due to gravity switches the high-pressure water supplied from the receiving section to the water supply section between a pressure reduction mode and a non-pressure reduction mode.

[0022] According to a preferred embodiment of the pressure switching cleaning method for drainage pipes according to the present invention, which has been made to solve the above-mentioned problems, when cleaning a dedicated drainage pipe laid horizontally in each house in an apartment building and a common drainage pipe laid vertically to collect and flow wastewater from each dedicated drainage pipe, the in-pipe cleaning nozzle attached to the tip of a water supply hose is inserted into the dedicated drainage pipe, and the pressure switching valve is set to the decompression mode to supply water to the in-pipe cleaning nozzle, whereby high-pressure water is sprayed from a first nozzle formed in the in-pipe cleaning nozzle, and the in-pipe cleaning nozzle is advanced from inside the dedicated drainage pipe to the junction of the common drainage pipe, and the inside of the dedicated drainage pipe is cleaned with the sprayed water. The method is characterized in that it executes the following steps: cleaning the inside of the shared drain pipe with the jet of water; continuing to spray high-pressure water from the first nozzle of the in-pipe cleaning nozzle while keeping the pressure switching valve in the decompression mode, and lowering the in-pipe cleaning nozzle to the confluence of the dedicated drain pipe and the common drain pipe of at least one lower layer, thereby cleaning the inside of the common drain pipe with the jet of water; stopping the supply of high-pressure water to the pressure switching valve, switching the pressure switching valve from the decompression mode to the non-decompression mode, and then starting the water supply again to spray high-pressure water from the second nozzle of the in-pipe cleaning nozzle while pulling up the in-pipe cleaning nozzle along the common drain pipe, thereby cleaning the inside of the common drain pipe with the jet of water again.

[0023] According to another preferred embodiment of the pressure switching cleaning method for drainage pipes according to the present invention, when cleaning a dedicated drainage pipe laid horizontally in each house in an apartment building and a common drainage pipe laid vertically to collect and drain drainage from each dedicated drainage pipe, the in-pipe cleaning nozzle attached to the tip of a water supply hose is inserted into the dedicated drainage pipe, and the pressure switching valve is set to the decompression mode to supply water to the in-pipe cleaning nozzle, whereby high-pressure water is sprayed from a first nozzle formed in the in-pipe cleaning nozzle, and the in-pipe cleaning nozzle is moved from inside the dedicated drainage pipe to the The system is characterized in that it executes the steps of: advancing the in-pipe cleaning nozzle to the junction of the shared drain pipe and cleaning the inside of the dedicated drain pipe with jetted water; and, with the in-pipe cleaning nozzle advanced into the shared drain pipe, stopping the supply of high-pressure water to the pressure switching valve, switching the pressure switching valve from the reduced pressure mode to the non-reduced pressure mode, and then starting the water supply again to spray high-pressure water from the second nozzle of the in-pipe cleaning nozzle, while lowering the in-pipe cleaning nozzle to the junction of the dedicated drain pipe and the shared drain pipe of at least one layer below, thereby cleaning the inside of the shared drain pipe with jetted water.

[0024] Furthermore, according to another preferred embodiment of the pressure switching cleaning method for drainage pipes according to the present invention, when cleaning a dedicated drainage pipe laid horizontally in each house in an apartment building and a common drainage pipe laid vertically for collecting and flowing wastewater from each dedicated drainage pipe, the method includes inserting the in-pipe cleaning nozzle attached to the tip of a water supply hose into the dedicated drainage pipe, setting the pressure switching valve to the decompression mode and supplying water to the in-pipe cleaning nozzle to spray high-pressure water from a first nozzle formed on the in-pipe cleaning nozzle, and moving the in-pipe cleaning nozzle from inside the dedicated drainage pipe to the junction of the common drainage pipe to clean the inside of the dedicated drainage pipe with the sprayed water; The system is characterized in that it executes the following steps: while the water has progressed into the pipe, the supply of high-pressure water to the pressure switching valve is stopped, and after switching the pressure switching valve from the reduced pressure mode to the non-reduced pressure mode, the water supply is started again to spray high-pressure water from the second nozzle of the in-pipe cleaning nozzle, while lowering the in-pipe cleaning nozzle to the confluence of at least one lower layer of the dedicated drain pipe and the common drain pipe, thereby cleaning the inside of the common drain pipe with the sprayed water; and, while keeping the pressure switching valve in the non-reduced pressure mode, continuing to spray high-pressure water from the second nozzle of the in-pipe cleaning nozzle and pulling up the in-pipe cleaning nozzle along the common drain pipe, thereby cleaning the inside of the common drain pipe again with the sprayed water. Effect of the Invention

[0025] In the above-described pipe cleaning nozzle according to the present invention, a cavity is formed with its longitudinal direction along the axis of the nozzle body, and a seal that moves in the axial direction under gravity is disposed in the cavity. When the seal moves to one end or the other end of the longitudinal direction of the cavity, the first opening or the second opening communicating with each nozzle port is sealed by the seal, so that the nozzle port of the high-pressure water is selectively switched. This makes it possible, for example, by pointing the front end of the nozzle body slightly upward or downward, to instantly and accurately switch the spray direction, providing a nozzle for cleaning inside pipes with improved operability and reliability of the spray switching operation.

[0026] The pressure switching valve according to the present invention is disposed upstream of the above-mentioned nozzle for cleaning inside the pipe, and serves to switch the water pressure of the high-pressure water applied to the nozzle. This pressure switching valve is provided with a pressure reduction path by an orifice that narrows the flow path of high-pressure water, and a bypass path that bypasses the orifice, and a sealing body that moves under the influence of gravity acts to selectively seal the opening leading to the bypass path side or the pressure reduction path side, thereby switching the high-pressure water sent to the inside-of-pipe cleaning nozzle between a pressure reduction mode and a non-pressure reduction mode. Therefore, for individual dedicated drain pipes with a small inner diameter, the water pressure sprayed from the nozzle can be set low to reduce damage caused by the water pressure to the dedicated drain pipes, and for shared drain pipes with a large inner diameter, the water pressure can be set high to increase the cleaning power, thereby contributing to improving the efficiency of the cleaning work.

[0027] Furthermore, according to the pressure switching cleaning method for drainage pipes of the present invention, individual dedicated drainage pipes and shared drainage pipes are cleaned simultaneously, and the above-mentioned in-pipe cleaning nozzle, which can switch the spray direction, is used in combination with a pressure switching valve, which can switch the water pressure of the high-pressure water applied to the nozzle. By temporarily stopping the supply of high-pressure water to the pressure switching valve, the water pressure can be switched by the pressure switching valve, and the spray direction of the high-pressure water can also be switched based on the position of the internal pipe cleaning nozzle inside the drain pipe at that time. The switching of the water pressure by the pressure change valve and the switching of the jet direction of the nozzle for pipe cleaning can be performed in sync as described above. Therefore, by combining the appropriate water pressure and the jet form from the nozzle for each drain pipe, a highly efficient drain pipe cleaning method can be realized. [Brief description of the drawings]

[0028] [Figure 1] FIG. 2 is a schematic diagram illustrating a drainage pipe cleaning method according to the present invention. [Diagram 2]1 is a perspective view showing an embodiment of a nozzle for cleaning inside a pipe according to the present invention. [Diagram 3] 3 is a cross-sectional view of a rotor attached to the nozzle for cleaning inside the pipe shown in FIG. 2. [Figure 4] 3 is a perspective view of a state in which a hose is connected to the nozzle for cleaning inside a pipe shown in FIG. 2 via a hose connecting pipe. [Diagram 5] 1 is a perspective view showing an embodiment of a pressure switching valve according to the present invention. [Figure 6A] FIG. 1 is a schematic diagram showing a first example of a drainage pipe cleaning method. [Figure 6B] FIG. 11 is a schematic diagram showing a second example of a drainage pipe cleaning method. [Figure 6C] FIG. 11 is a schematic diagram showing a third example of a drainage pipe cleaning method. [Figure 7] FIG. 1 is a perspective view of a conventional nozzle for cleaning inside a pipe with its nozzle tip facing downward. [Figure 8] FIG. 13 is a perspective view of the nozzle oriented horizontally. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The in-pipe cleaning nozzle and pressure switching valve, as well as the pressure switching cleaning method for drainage pipes according to the present invention, will be described with reference to the embodiments shown in the drawings. FIG. 1 shows a schematic diagram of an example of the layout of drainage pipes in a multi-family housing complex, as well as an example of implementing the pressure switching cleaning method for drainage pipes. A...C in Fig. 1 indicate individual rooms on each floor of an apartment building, and domestic wastewater from the kitchen, washroom, laundry tub, bathroom, etc. of each room A...C is discharged into dedicated drainage pipes 1a...1c laid horizontally under the floor of each room A...C. This domestic wastewater is collected in a shared drainage pipe (standpipe) 2 laid vertically in the apartment building, and flows through an outdoor horizontal pipe 3 toward a public sewer pipe (not shown). Generally, a cleaning port 4 of the horizontal pipe is installed at an appropriate position of the horizontal pipe 3 outdoors (on the ground).

[0030] As already explained, the example shown in Figure 1 shows an example in which, when cleaning a shared drain pipe (standpipe), it is difficult to insert an internal pipe cleaning nozzle from the upper opening (cleaning port) of the standpipe installed on the roof of a building, for example, in which an internal pipe cleaning nozzle 5 is inserted into a shared drain pipe 2 using a dedicated drain pipe 1a inside a house, indicated by the symbol A. The nozzle 5 is attached to the tip of a water supply hose 6, and within reach of the cleaning worker P located inside the house A are a pressure switching valve 7 that can switch the water pressure of the high-pressure water applied to the nozzle 5, and a water supply tap 8 that can supply or stop high-pressure water from the high-pressure water supply source to the pressure switching valve 7 and the nozzle 5.

[0031] 2 shows a perspective view of an example of a pipe cleaning nozzle that can be suitably used in the present invention. This pipe cleaning nozzle 5 is composed of a nozzle body 5A and a rotor 5B, and these nozzle body 5A and rotor 5B are each made of a metal material. The nozzle body 5A has a cylindrical central shaft 5c formed between the hemispherical head 5a at its front end and the hose connection port 5b at its rear end, and the rotor 5B, which is formed in an annular shape, is attached to this central shaft 5c so as to be rotatable about its axis. A hose connection pipe 9, which will be described later, is attached to the hose connection port 5b, and the nozzle 5 for cleaning inside a pipe is connected to the tip of the water supply hose 6 via this hose connection pipe 9.

[0032] A high-pressure water supply space 5d is formed in the central axis 5c of the nozzle body 5A in parallel with the axis Ax1 of the nozzle body connecting the center of the head 5a on the front end side and the center of the hose connection port 5b. The water supply space 5d is connected to the longitudinal center of a hollow portion 5f in which a ball-shaped sealing body 5e is housed. The hollow portion 5f in which the sealing body 5e is housed forms a cylindrical inner surface with the longitudinal direction along the axis Ax1 of the nozzle main body 5A, and the sealing body 5e moves within the hollow portion 5f along the longitudinal direction, i.e., along the direction of the axis Ax1, under the influence of gravity. Therefore, when the tip end of the nozzle body 5A is set to face slightly downward, the ball-shaped sealing body 5e moves forward in the hollow portion 5f due to gravity, and when the rear end of the nozzle body 5A is set to face slightly downward, the ball-shaped sealing body 5e moves backward in the hollow portion 5f due to gravity.

[0033] On the other hand, a first opening 5g is formed at one longitudinal end of the hollow portion 5f in which the sealing body 5e is housed, i.e., the front end side of the nozzle main body 5A, and a second opening 5h is formed at the other longitudinal end of the hollow portion 5f, i.e., the rear end side of the nozzle main body 5A. A first injection port 5i that communicates with the first opening 5g and injects high-pressure water fed through the hose 6 is formed in the head 5a of the nozzle body 5A. The first jetting ports 5i are formed radially at approximately equal intervals in the circumferential direction of the nozzle body 5A, and the first jetting ports 5i act to jet high-pressure water diagonally backward as viewed from the water supply hose 6. In this embodiment, the jetting angle is set to about 45 degrees with respect to the axis Ax1 of the nozzle body 5A. Incidentally, the above-mentioned first injection ports 5i are provided, for example, in the number of about 2 to 6, along the circumferential direction of the head portion 5a of the nozzle body 5A.

[0034] In addition, the second opening 5h provided in the hollow portion 5f is connected to a ring-shaped water supply passage 5j formed along the inner surface of the rotor 5B, and a plurality of second injection ports 5k are formed on the outer surface of the rotor 5B along this ring-shaped water supply passage 5j at approximately equal intervals in the circumferential direction. As shown in FIG. 3, the second injection ports 5k are formed at positions 180 degrees apart on the rotor 5B, each in a direction perpendicular to the axis Ax1, but three or more second injection ports 5k may be provided as necessary.

[0035] The two second jet nozzles 5k opposed at 180 degrees to each other are formed symmetrically with respect to the rotation axis of the rotor 5B, with a slight offset in the same direction, as shown in Fig. 3. Therefore, the rotor 5B is rotationally driven in the direction indicated by the arrow R in Fig. 3 by the reaction of the jet of high-pressure water discharged from the second jet nozzles 5k. As a result, the rotor 5B provided with the second nozzle orifices 5k constitutes a rotary nozzle that sprays high-pressure water fed through the water supply hose 6 while rotating in the circumferential direction of the nozzle main body 5A.

[0036] Therefore, according to the above-described pipe cleaning nozzle 5, the ball-shaped sealing body 5e moves toward the first opening 5g due to gravity, thereby sealing the first opening 5g and spraying high-pressure water from the second jetting port 5k. Also, the sealing body 5e moves toward the second opening 5h due to gravity, thereby sealing the second opening 5h and spraying high-pressure water from the first jetting port 5i.

[0037] Therefore, when high-pressure water is continuously supplied to the above-mentioned pipe cleaning nozzle 5, even if the attitude of the nozzle 5 changes, the high-pressure water continues to be sprayed from the same nozzle, and when the supply of high-pressure water to the nozzle 5 is temporarily stopped and the water supply is started again, the high-pressure water will be sprayed from the corresponding nozzle depending on the attitude of the nozzle 5 when the supply of high-pressure water was stopped.

[0038] Fig. 4 is a perspective view showing a state in which a water supply hose 6 is connected to the above-mentioned inside-pipe cleaning nozzle 5 via a hose connection pipe 9. In the inside-pipe cleaning nozzle 5 shown in Fig. 4, representative parts corresponding to the parts of the inside-pipe cleaning nozzle 5 shown in Fig. 2 are denoted by the same reference numerals, and therefore detailed description thereof will be omitted. One end of this hose connection pipe 9 constitutes an attachment portion 9a for attachment to the nozzle main body, and the other end constitutes a cylindrical hose connection portion 9b.

[0039] When the mounting portion 9a on the nozzle body side is fitted into and attached to the hose connection port 5b of the internal pipe cleaning nozzle 5, it is desirable that the axis Ax2 of the cylindrical hose connection portion 9b be bent within an obtuse angle range with respect to the axis Ax1 of the nozzle body 5A. In the example shown in FIG. 4, the water supply hose 6 is connected to the hose connection portion 9b in a state where it is bent at approximately 150 degrees with respect to the axis Ax1 of the nozzle body 5A, but in practice it is more desirable for this to be in the range of 150 degrees to 170 degrees.

[0040] Therefore, when an internal pipe cleaning nozzle 5 using a hose connection tube 9 as shown in FIG. 4 is placed inside, for example, a dedicated drain pipe 1a laid horizontally, the water supply hose 6 will be aligned along the inner bottom of the dedicated drain pipe 1a, so that the head 5a of the internal pipe cleaning nozzle 5 will be reliably positioned inside the pipe in an upward position. In this state, when high-pressure water is supplied through the water supply hose 6, the high-pressure water is sprayed diagonally backward from the first nozzle 5i formed on the head 5a side of the nozzle body 5A, so that the pipe cleaning nozzle 5 receives a forward propulsive force and can move forward from inside the dedicated drain pipe 1a toward the shared drain pipe (standpipe) 2.

[0041] By employing the hose connection tube 9 shown in FIG. 4, it is possible to improve the reliability of the spray direction selection operation of this type of inside-pipe cleaning nozzle 5, which has a switchable spray direction, but the reliability of the selection operation can be ensured even when using a conventional hose connection tube in which the axis Ax1 of the nozzle body 5A and the axis Ax2 of the hose connection part 9b are collinear. That is, when inserting the pipe cleaning nozzle 5 into the dedicated drain pipe 1a, the head 5a side of the nozzle 5 can be slightly directed upward by intentionally applying a force to the water supply hose 6 toward the inner bottom side of the dedicated drain pipe 1a. By supplying high-pressure water in this state, it is possible to reliably spray high-pressure water diagonally backward from the first nozzle 5i.

[0042] FIG. 5 is a perspective view showing an embodiment of the pressure changeover valve 7, and this pressure changeover valve 7 has the function of changing over the injection pressure of the high-pressure water given to the nozzle 5 for cleaning inside the pipe. This pressure switching valve 7 has a water receiving section 7a that receives high-pressure water from a high-pressure water supply source and a water supply section 7b that delivers high-pressure water to the pipe cleaning nozzle 5, formed at opposite left and right ends. In addition, the water receiving portion 7a and the water supplying portion 7b are fitted with hose connection pipes (not shown) respectively, similar to the hose connection port 5b provided on the nozzle 5 for cleaning inside the pipe. Then, high-pressure water is made to flow from the water receiving section 7a to the water supply section 7b via the front and rear hoses as indicated by the arrows on the left and right.

[0043] This pressure switching valve 7 is formed with a seal accommodating space 7d that accommodates a ball-shaped seal 7c so that it can move in a direction perpendicular to the left-right direction, and the water receiving portion 7a is connected to approximately the center of the seal accommodating space 7d in the longitudinal direction. At one end of the seal accommodating space 7d in the longitudinal direction, a pressure reduction path 7e is formed by an orifice that narrows the flow path of the high-pressure water, and the pressure reduction path 7e is connected to the water supply part 7b. At the other end of the seal accommodating space 7d in the longitudinal direction, a bypass path 7f is formed that bypasses the orifice and is connected to the water supply part 7b.

[0044] Therefore, when the pressure switching valve 7 receives high-pressure water in the position shown in Figure 5, the ball-shaped sealing body 7c seals the first opening 7g leading to the bypass path 7f, and the high-pressure water is sent to the water supply section 7b via the pressure reduction path 7e. Furthermore, when the pressure switching valve 7 receives high-pressure water in a state in which it is upside down relative to the state shown in Figure 5, the ball-shaped sealing body 7c seals the second opening 7h leading to the pressure reduction path 7e, and the high-pressure water is sent to the water supply section 7b via the bypass path 7f. As a result, the pressure switching valve 7 can switch the high-pressure water sent from the water receiving section 7a to the water supply section 7b between a reduced pressure mode and a non-reduced pressure mode by the movement of the ball-shaped sealing body 7c due to gravity.

[0045] In addition, when the non-reduced pressure mode in which high-pressure water is sent through the bypass path 7f is selected, the pressure switching valve 7 described above acts, as a preferred example, to send the high-pressure water of 25 MPa received in the water receiving portion 7a directly to the water supply portion 7b, and when the reduced pressure mode in which high-pressure water is sent through the reduced pressure path 7e using an orifice is selected, the pressure switching valve 7 acts to reduce the high-pressure water of 25 MPa received in the water receiving portion 7a to 20 MPa and send it to the water supply portion 7b. The aforementioned switching between the reduced pressure mode and the non-reduced pressure mode is selected depending on the attitude of the pressure changeover valve 7 when the supply of high-pressure water to the pressure changeover valve 7 is stopped.

[0046] 6A to 6C illustrate a representative example of a pressure switching cleaning method for drainage pipes according to the present invention, which uses the above-mentioned pipe cleaning nozzle 5 and pressure switching valve 7, as well as the water supply tap 8 shown in FIG. 1 that can start and stop the supply of high-pressure water to clean the inside of a drainage pipe. These Figures 6A to 6C show the movement trajectory of the in-pipe cleaning nozzle 5 moving from the dedicated drain pipe 1a in the house A shown in Figure 1 to the shared drain pipe (standpipe) 2, where the solid line indicates that the pressure switching valve 7 is in the pressure reduction mode, and the dashed line indicates that the pressure switching valve 7 is in the non-pressure reduction mode. 6A to 6C correspond to the inventions relating to the pressure switching cleaning method for drainage pipes described in claims 2 to 4. FIG.

[0047] FIG. 6A shows a first example of a pressure switching cleaning method for drainage pipes. In this example, an internal pipe cleaning nozzle 5 attached to the tip of a water supply hose 6 is inserted into the position indicated by “START” on a dedicated drainage pipe 1a. At this time, the pressure switching valve 7 is set to the above-mentioned "reduced pressure mode." That is, the pressure switching valve 7 is set to the posture shown in Fig. 5 in which the internal sealing body 7c seals the first opening 7g by gravity.

[0048] When the axis Ax1 of the above-mentioned internal pipe cleaning nozzle 5 is bent at an obtuse angle by the hose connection tube 9 shown in FIG. 4 and attached to the water supply hose 6, it is possible to spray reduced-pressure water obliquely backward from the first injection port 5i of the nozzle 5 by opening the water supply valve 8 and starting the water supply without any special consideration.

[0049] On the other hand, in the case where the axis Ax1 of the nozzle 5 for cleaning inside a pipe is attached in a straight line with respect to the longitudinal direction of the water supply hose 6, as described above, with the nozzle 5 for cleaning inside a pipe inserted into the dedicated drain pipe 1a, the head 5a side of the nozzle 5 can be angled slightly upward by intentionally applying a force to the water supply hose 6 toward the inner bottom side of the dedicated drain pipe 1a. In this state, by opening the water supply tap 8 and starting water supply, the first outlet 5i of the nozzle 5 can be made to spray decompressed high-pressure water diagonally backward.

[0050] The reaction force of the high-pressure water jet from the first jet nozzle 5i directed diagonally backward acts to advance the inside-pipe cleaning nozzle 5. Therefore, by the cleaning worker P feeding the water supply hose 6 toward the inside of the dedicated drain pipe 1a, the nozzle 5 advances toward the shared drain pipe 2, and the nozzle 5 can be advanced to the junction of the shared drain pipe 2. As a result, the inside of the dedicated drain pipe 1a is subjected to a cleaning action by the decompressed water jetted from the nozzle 5.

[0051] When the nozzle 5 for cleaning inside the pipe reaches the common drain pipe 2, the nozzle 5 advances downward inside the common drain pipe 2. Therefore, by continuing to pay out the water supply hose 6, the nozzle 5 descends inside the common drain pipe 2 while the pressure switching valve 7 remains in the decompression mode and continues to spray high-pressure water from the nozzle 5i. As a result, the inside of the common drain pipe 2 is cleaned by the decompressed water sprayed from the nozzle 5.

[0052] In this case, the nozzle 5 for cleaning inside the pipe must be lowered to the confluence of the dedicated drain pipe and the common drain pipe 2 on at least one lower layer. At this time, the amount by which the nozzle 5 descends within the shared drain pipe 2 is determined taking into consideration the ease of inserting the nozzle 5 into the dedicated drain pipe below the dedicated drain pipe 1a and the actual conditions of the work site, and for example, the nozzle 5 may be descended three layers or down to the connection with the horizontal pipe 3 at the lowest layer. When the nozzle 5 is lowered to a position determined according to the actual situation, the water supply valve 8 is closed and water supply to the nozzle 5 is stopped. The position of the nozzle 5 in the shared drain pipe 2 at this time is indicated by "STOP".

[0053] When the water faucet 8 is closed, the head 5a of the internal pipe cleaning nozzle 5 in the shared drain pipe 2 faces downward, and therefore the seal 5e in the nozzle 5 seals the first opening 5g. This causes the injection direction of the internal pipe cleaning nozzle 5 to be changed so that high-pressure water is injected from the second injection port 5k arranged in the rotor 5B. On the other hand, when the pressure switching valve 7 is turned upside down from the state shown in FIG. 5, the pressure switching valve 7 is set to the above-mentioned "non-reduced pressure mode". Then, by opening the water supply valve 8 and starting water supply again, high-pressure water in the non-reduced pressure mode is sprayed from the inside-pipe cleaning nozzle 5 in the circumferential direction while the rotor 5B is rotating.

[0054] In this state, by pulling back the water supply hose and raising the nozzle 5 at a constant speed, the common drain pipe 2 is again subjected to the cleaning action of the rotating nozzle. At this time, the cleaning action is performed at a high water pressure, increasing the cleaning power, and, combined with the cleaning effect of the rotating nozzle, the efficiency of the cleaning work for the common drain pipe 2 can be improved. Then, when the pipe cleaning nozzle 5 is raised to the position of the dedicated drain pipe 1a, as indicated by "END," the water supply valve 8 is closed, and the pressure switching cleaning method is completed.

[0055] After the cleaning method is completed, the water supply hose 6 is further pulled back and the internal pipe cleaning nozzle 5 is pulled out from the dedicated drain pipe 1a, thereby completing the cleaning work. Furthermore, the above-mentioned cleaning method utilizes a dedicated drainage pipe in a different lower level of the house, inserts an in-pipe cleaning nozzle 5, and cleans the shared drainage pipe 2 downward from the dedicated drainage pipe in the house, thereby making it possible to clean the shared drainage pipe 2 in units of levels.

[0056] FIG. 6B shows a second example of the pressure switching cleaning method for drainage pipes. In this second example, the nozzle 5 for internal pipe cleaning is inserted into the dedicated drain pipe 1a and then advanced to the confluence with the shared drain pipe 2, which is similar to the first example described based on Figure 6A. In this second example, when the nozzle 5 starts to move downward inside the shared drain pipe 2, the water supply valve 8 is closed and water supply to the nozzle 5 stops. The position of the nozzle 5 inside the shared drain pipe 2 at this time is indicated by "STOP."

[0057] At this time, the head 5a of the internal pipe cleaning nozzle 5 in the shared drain pipe 2 faces downward, and therefore the seal 5e in the nozzle 5 seals the first opening 5g. This causes the internal pipe cleaning nozzle 5 to switch the injection direction so that high-pressure water is injected from the second injection port 5k arranged in the rotor 5B. On the other hand, by turning the attitude of the pressure switching valve 7 upside down from the state shown in FIG. 5, the pressure switching valve 7 is set to the above-mentioned "non-reduced pressure mode". Then, by opening the water supply valve 8 and starting water supply again, high-pressure water in non-reduced pressure mode can be sprayed from the inside-pipe cleaning nozzle 5 in the circumferential direction while the rotor 5B is rotating.

[0058] In this state, by paying out the water supply hose 6, the nozzle 5 descends inside the shared drain pipe 2. The cleaning action at this time is performed with high water pressure set to increase cleaning power, and with the cleaning effect of the rotating nozzle, the efficiency of the cleaning work inside the shared drain pipe 2 can be improved. Then, the nozzle 5 for cleaning inside the pipe is lowered to the confluence of the dedicated drain pipe and the shared drain pipe 2 on at least one lower layer, and the water tap 8 is closed at the nozzle position indicated by "END", thereby completing this pressure switching cleaning method.

[0059] In the second example of the pressure switching cleaning method shown in Figure 6B, the amount of descent of the internal pipe cleaning nozzle 5 within the shared drainage pipe 2 is determined taking into consideration the ease of inserting the nozzle 5 into the dedicated drainage pipe below and the actual conditions of the work site, etc. Then, by pulling back the water supply hose 6, the nozzle 5 for cleaning inside the pipe is returned from the shared drain pipe 2 to the dedicated drain pipe 1a and pulled out, thereby completing the cleaning operation. In the second example of this pressure switching cleaning method, a dedicated drain pipe in a different house on a lower level is also used, and an in-pipe cleaning nozzle 5 is inserted to clean the shared drain pipe 2 downward from the dedicated drain pipe in the house, thereby making it possible to clean the shared drain pipe 2 in units of levels.

[0060] FIG. 6C shows a third example of a pressure switching cleaning method for drainage pipes. In this third example, when the position of the nozzle 5 in the second example shown in FIG. 6B reaches the position indicated by "END", the water supply continues without closing the water tap 8. Then, the water supply hose 6 is pulled back and the nozzle 5 is raised at a constant speed, so that the common drain pipe 2 is again subjected to the cleaning action of the rotating nozzle.

[0061] Then, when the pipe cleaning nozzle 5 is raised to the "END" position up to the dedicated drain pipe 1a, the water supply valve 8 is closed, and the pressure switching cleaning method is completed. Next, the water supply hose 6 is further pulled back and the internal pipe cleaning nozzle 5 is pulled out from the dedicated drain pipe 1a, thereby completing the cleaning operation.

[0062] In the third example shown in Figure 6C, compared to the second example shown in Figure 6B, an additional process is added in which the pressure switching valve 7 is kept in non-reducing mode, high-pressure water is continued to be sprayed from the internal pipe cleaning nozzle 5, and the nozzle 5 is pulled up along the inside of the shared drain pipe, thereby again cleaning the inside of the shared drain pipe 2 with water sprayed from the rotating nozzle.

[0063] The nozzle 5 for cleaning inside a pipe in the embodiment described above is equipped with a rotor 5B in a nozzle body 5A, with a first nozzle hole 5i formed on the nozzle body 5A side and a second nozzle hole 5k formed on the rotor 5B, but it is also possible to use a nozzle 5 equipped with a fixed second nozzle without using a rotor 5B. In addition, in the embodiment, an example is shown in which the nozzle 5, which has a switchable spray direction, is bent within an obtuse angle range relative to the water supply hose 6 and attached to it, thereby improving the reliability of the spray direction selection operation within a horizontal pipe. However, this configuration is not necessarily required in the practice of the present invention, and even if the axis of the nozzle body 5A and the water supply hose 6 are connected in the same straight line, it is possible to provide a nozzle for cleaning inside a pipe that can fully ensure the reliability of the selection operation of the spray direction. [Explanation of symbols]

[0064] 1a…1c Dedicated drainage pipe 2 Common drain pipe (stand pipe) 3 Horizontal pipe 4 Cleaning port 5. Pipe cleaning nozzle 5A Nozzle body 5B rotor 5a head 5b Hose connection port 5c central axis 5d water supply space 5e Encapsulation body 5f hollow part 5g 1st opening 5h 2nd opening 5i 1st injection port 5j water supply channel 5k 2nd injection port 6 Water Supply Hose 7 Pressure Switching Valve 7a Water receiving part 7b Water supply section 7c Encapsulation body 7d. Encapsulation housing space 7e Pressure reduction passage (orifice) 7f Bypass Road 7g 1st opening 7h 2nd opening 8 Water Tap 9 Hose connection pipe 9a Attachment part to nozzle body 9b Hose connection A…C Individual homes Ax1 Axis of nozzle body Ax2 Axis of hose connection P Cleaning worker

Claims

1. A pressure switching valve for switching the injection pressure of high-pressure water applied to a nozzle for cleaning inside a pipe, the nozzle being capable of selectively injecting high-pressure water from a first injection port or a second injection port having different injection angles relative to an axis of a nozzle body, The pressure switching valve includes a water receiving section that receives high-pressure water from a high-pressure water supply source and a water supply section that sends high-pressure water to the pipe cleaning nozzle. A pressure reduction path formed between the receiving portion and the water supply portion and having an orifice that narrows the flow path of the high-pressure water, and a bypass path formed between the receiving portion and the water supply portion and bypassing the orifice; a seal that moves in one direction under the influence of gravity to seal a first opening leading from the water receiving section to the bypass passage, thereby sending the high-pressure water to the water sending section via the pressure reduction passage, and moves in the other direction under the influence of gravity to seal a second opening leading from the water receiving section to the pressure reduction passage, thereby sending the high-pressure water to the water sending section via the bypass passage; a pressure switching valve for switching the high-pressure water sent from the water receiving section to the water supply section between a reduced pressure mode and a non-reduced pressure mode by the movement of the sealing body due to gravity.

2. A pressure switching cleaning method for cleaning the inside of a drainage pipe using the pipe cleaning nozzle and pressure switching valve according to claim 1, When cleaning the dedicated drainage pipes laid horizontally in each individual house in an apartment building and the shared drainage pipes laid vertically that collect and discharge the wastewater from each dedicated drainage pipe, a step of inserting the in-pipe cleaning nozzle attached to the tip of a water supply hose into the dedicated drain pipe, setting the pressure switching valve to the decompression mode to supply water to the in-pipe cleaning nozzle, thereby spraying high-pressure water from a first nozzle formed on the in-pipe cleaning nozzle, and moving the in-pipe cleaning nozzle from inside the dedicated drain pipe to the junction with the shared drain pipe, and cleaning the inside of the dedicated drain pipe with the sprayed water; A process of continuing to spray high-pressure water from the first nozzle of the pipe cleaning nozzle while keeping the pressure switching valve in the decompression mode, and cleaning the inside of the shared drain pipe with the sprayed water by lowering the pipe cleaning nozzle to a junction of the dedicated drain pipe and the shared drain pipe of at least one lower layer; a step of stopping the supply of high-pressure water to the pressure switching valve, switching the pressure switching valve from the reduced pressure mode to a non-reduced pressure mode, and then restarting the water supply to spray high-pressure water from the second nozzle of the pipe cleaning nozzle while pulling up the pipe cleaning nozzle along the shared drain pipe, thereby cleaning the inside of the shared drain pipe again with the sprayed water; A drainage pipe pressure switching cleaning method characterized by carrying out the steps of:

3. A pressure switching cleaning method for cleaning the inside of a drainage pipe using the pipe cleaning nozzle and pressure switching valve according to claim 1, When cleaning the dedicated drainage pipes laid horizontally in each individual house in an apartment building and the shared drainage pipes laid vertically that collect and discharge the wastewater from each dedicated drainage pipe, a step of inserting the in-pipe cleaning nozzle attached to the tip of a water supply hose into the dedicated drain pipe, setting the pressure switching valve to the decompression mode to supply water to the in-pipe cleaning nozzle, thereby spraying high-pressure water from a first nozzle formed on the in-pipe cleaning nozzle, and moving the in-pipe cleaning nozzle from inside the dedicated drain pipe to the junction with the shared drain pipe, and cleaning the inside of the dedicated drain pipe with the sprayed water; a step of stopping the supply of high-pressure water to the pressure switching valve while the in-pipe cleaning nozzle has advanced into the common drain pipe, switching the pressure switching valve from the reduced pressure mode to a non-reduced pressure mode, and then restarting the water supply to spray high-pressure water from a second nozzle of the in-pipe cleaning nozzle, while lowering the in-pipe cleaning nozzle to a junction of at least one lower dedicated drain pipe and a common drain pipe, thereby cleaning the inside of the common drain pipe with the sprayed water; A drainage pipe pressure switching cleaning method characterized by carrying out the steps of:

4. A pressure switching cleaning method for cleaning the inside of a drainage pipe using the pipe cleaning nozzle and pressure switching valve according to claim 1, When cleaning the dedicated drainage pipes laid horizontally in each individual house in an apartment building and the shared drainage pipes laid vertically that collect and discharge the wastewater from each dedicated drainage pipe, a step of inserting the in-pipe cleaning nozzle attached to the tip of a water supply hose into the dedicated drain pipe, setting the pressure switching valve to the decompression mode to supply water to the in-pipe cleaning nozzle, thereby spraying high-pressure water from a first nozzle formed on the in-pipe cleaning nozzle, and moving the in-pipe cleaning nozzle from inside the dedicated drain pipe to the junction with the shared drain pipe, and cleaning the inside of the dedicated drain pipe with the sprayed water; a step of stopping the supply of high-pressure water to the pressure switching valve while the in-pipe cleaning nozzle has advanced into the common drain pipe, switching the pressure switching valve from the reduced pressure mode to a non-reduced pressure mode, and then restarting the water supply to spray high-pressure water from a second nozzle of the in-pipe cleaning nozzle, while lowering the in-pipe cleaning nozzle to a junction of at least one lower dedicated drain pipe and a common drain pipe, thereby cleaning the inside of the common drain pipe with the sprayed water; A process of continuing to spray high-pressure water from the second nozzle of the pipe cleaning nozzle while keeping the pressure switching valve in the non-reducing mode, and cleaning the inside of the shared drain pipe again with the sprayed water by pulling up the pipe cleaning nozzle along the inside of the shared drain pipe; A drainage pipe pressure switching cleaning method characterized by carrying out the steps of:

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