JP7784173B2 - Pressure switching valve and drainage pipe pressure switching cleaning method - Google Patents

Description

This invention relates to a pressure switching valve that can switch the spray pressure of high-pressure water applied to a nozzle used to clean the inside of a drain pipe, and to a pressure switching cleaning method for drain pipes.

In order to make effective use of land, many high-rise apartment buildings are being constructed in urban areas and their suburbs. Domestic wastewater (sewage) discharged from these apartment buildings is routed from dedicated drainage pipes laid horizontally within each home to shared drainage pipes (also known as standpipes) laid vertically within the building, before being discharged into an outdoor horizontal pipe, thereby maintaining a good living environment.

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

As mentioned above, one method of cleaning and removing solids adhering to the inside of drainage pipes has traditionally been high-pressure water jet cleaning. This method involves spraying high-pressure water from a cleaning nozzle attached to the end of a water supply hose toward the solids adhering to the inside of the drainage pipe, removing the solids.

Many proposals have already been made for high-pressure water spray nozzles used to clean the inside of drainage pipes, as described above. The applicant has previously proposed an in-pipe cleaning nozzle that can be used by switching the high-pressure water spray nozzle, making it particularly suitable for cleaning the individual dedicated drainage pipes, shared drainage pipes, and horizontal pipes, as well as a drainage pipe cleaning method using this nozzle, which is disclosed in Patent Document 1.

7 and 8 show an example of the pipe cleaning nozzle disclosed in Patent Document 1, and are cross-sectional views of the pipe cleaning nozzle cut in the axial direction. Fig. 7 shows the nozzle body 11 with the tip thereof facing downward, and Fig. 8 shows the nozzle body 11 with its axis 13 facing horizontally.
The nozzle body 11 has a water supply space 14 formed 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.

When the nozzle body 11 is oriented with its tip facing downwards, as shown in Figure 7, the sealing body 15 moves toward the front of the nozzle body 11 due to gravity. When the nozzle body 11 is oriented horizontally, as shown in Figure 8, the sealing body 15 fits into a pocket 14a formed at a position away from the central axis 13.

On the other hand, a plurality of jet nozzles 17 are formed radially on the front side of the nozzle body 11 so as to face diagonally backward, and a plurality of jet nozzles 16 are formed radially on the rear side of the nozzle body 11 so as to face diagonally forward.
Therefore, in the state shown in Figure 7 where the front of the nozzle body 11 is set downward when viewed from the side of a hose (not shown) connected to the hose connection port 12, the sealing body 15 moves forward and closes the circular opening 19, thereby sealing off the high-pressure water reaching the diagonally rearward jet port 17 formed in the nozzle body and allowing the high-pressure water to be jetted from the diagonally forward jet port 16.

Furthermore, in the state shown in Figure 8 where the nozzle body 11 is positioned horizontally, the sealing body 15 enters the pocket 14a and closes the circular opening 18, thereby sealing off the high-pressure water reaching the diagonally forward jet nozzle 16 formed in the nozzle body 11, and high-pressure water is sprayed from the diagonally rearward jet nozzle 17.

Therefore, when the nozzle body 11 described above is inserted into a horizontal dedicated drain pipe installed within an individual home, for example, high-pressure water is sprayed from the jet nozzle 17 facing diagonally backward, and the nozzle body 11 receives forward propulsion and moves through the dedicated drain pipe toward the standpipe. Even after the nozzle body 11 reaches the join point of the standpipe, the nozzle body 11 continues to spray high-pressure water and the hose is fed out, causing the nozzle body 11 to move downward within the standpipe. As a result, the inside of the dedicated drain pipe and the standpipe are cleaned with water sprayed from the nozzle.

When the supply of high-pressure water is stopped while the nozzle body 11 is positioned inside the standpipe, the seal 15 inside the nozzle body 11 closes the opening 19 that communicates with the nozzle port 17. When water is supplied again in this state, high-pressure water is sprayed from the nozzle port 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 retract the nozzle body 11.

Patent No. 4279870

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 sealing body 15 provided in the nozzle body 11 does not necessarily enter the pocket 14a, as shown in Figure 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 injection operation of injecting high-pressure water from the injection port 17 obliquely rearward.

Therefore, with the nozzle for cleaning inside a pipe disclosed in Patent Document 1, the worker 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 immediately and accurately, and improving the operability and reliability of the spray switching operation is an important issue in terms of improving work efficiency.

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 multi-family housing buildings, there are cases where an opening for standpipe cleaning is not installed on the roof, etc., and there are also cases where it is difficult to insert the inside-pipe cleaning nozzle 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 drainpipe installed in each individual home and clean the dedicated drainpipe and the standpipe.

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.

This invention was made based on the above-mentioned technical viewpoint, 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.
In addition, the main objective of this project is to provide a pressure switching valve that can appropriately switch the water pressure applied to the in-pipe cleaning nozzle during a series of cleaning operations on individual dedicated drainage pipes and shared drainage pipes, and to provide a pressure switching cleaning method for drainage pipes that improves cleaning work efficiency by combining the in-pipe cleaning nozzle with a pressure switching valve.

The pipe cleaning nozzle of this invention, which was devised to solve the above-mentioned problems, is attached to the tip of a water supply hose and can selectively spray high-pressure water sent through the water supply hose from a first nozzle or a second nozzle, each of which has a different spray angle relative to the axis of the nozzle body. The nozzle body has a cavity with its longitudinal direction along the axis, and a seal housed in the cavity and moving longitudinally within the cavity under the influence of gravity. A first opening communicating with the first nozzle is formed at one longitudinal end of the cavity, and a second opening communicating with the second nozzle is formed at the other longitudinal end of the cavity. When the seal moves due to gravity toward the first opening, the first opening is sealed and high-pressure water is sprayed from the second nozzle. When the seal moves due to gravity toward the second opening, the second opening is sealed and high-pressure water is sprayed from the first nozzle.

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 relative 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 viewed 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 force caused by the spray of high-pressure water.

In addition, the first and second jet nozzles each consist of a plurality of jet nozzles, with the first jet nozzles arranged at equal intervals around the circumference of the nozzle body, and the second jet nozzles arranged on the rotor at equal intervals around the circumference of the rotor.

On the other hand, it is desirable to use a pressure switching valve for the above-mentioned nozzle for cleaning inside the pipe, which switches the spray pressure of 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 water receiving section that receives high-pressure water from a high-pressure water supply source, a water supply section that supplies high-pressure water to the pipe cleaning nozzle, a pressure reduction path formed between the water receiving section and the water supply section with an orifice that narrows the flow path of the high-pressure water, and a bypass path formed between the water receiving section and the water supply section that bypasses the orifice, and a sealing body that moves in one direction under the influence of gravity and seals a first opening from the water receiving section to the bypass path, thereby supplying the high-pressure water to the water supply section via the pressure reduction path, and moves in the other direction under the influence of gravity and seals a second opening from the water receiving section to the pressure reduction path, thereby supplying the high-pressure water to the water supply section via the bypass path, and the movement of the sealing body due to gravity switches the high-pressure water supplied from the water receiving section to the water supply section between a pressure reduction mode and a non-pressure reduction mode.

Furthermore, according to one preferred embodiment of the pressure switching drainage pipe cleaning method of the present invention, which was made to solve the above-mentioned problems, when cleaning dedicated drainage pipes laid horizontally within individual homes in an apartment building and a shared drainage pipe laid vertically that collects and flows wastewater from each dedicated drainage pipe, the in-pipe cleaning nozzle attached to the tip of the water supply hose is inserted into the dedicated drainage pipe, the pressure switching valve is set to the decompression mode, water is supplied to the in-pipe cleaning nozzle, high-pressure water is sprayed from a first spray nozzle formed on the in-pipe cleaning nozzle, and the in-pipe cleaning nozzle is advanced from inside the dedicated drainage pipe to the confluence of the shared drainage pipe, and the inside of the dedicated drainage pipe is cleaned with the sprayed water. The system is characterized by the execution of the following steps: a process of cleaning the inside of the shared drain pipe with the water jet; a process of continuing to spray high-pressure water from the first nozzle of the in-pipe cleaning nozzle while the pressure switching valve is in the decompression mode, and lowering the in-pipe cleaning nozzle to the confluence of the dedicated drain pipe and the shared drain pipe on at least one lower layer, thereby cleaning the inside of the shared drain pipe with the water jet; and a process of 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 restarting the water supply by spraying high-pressure water from the second nozzle of the in-pipe cleaning nozzle while raising the in-pipe cleaning nozzle along the inside of the shared drain pipe, thereby again cleaning the inside of the shared drain pipe with the water jet.

According to another preferred embodiment of the pressure switching cleaning method for drainage pipes of this invention, when cleaning dedicated drainage pipes laid horizontally within individual houses in an apartment building and a shared drainage pipe laid vertically to collect and discharge 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, the pressure switching valve is set to the decompression mode, water is supplied to the in-pipe cleaning nozzle, and high-pressure water is sprayed from a first nozzle formed in the in-pipe cleaning nozzle, and the in-pipe cleaning nozzle is then used to spray high-pressure water from within the dedicated drainage pipe. This system is characterized by the steps of: advancing the nozzle to the confluence of the shared drain pipe and cleaning the inside of the dedicated drain pipe with a jet of water; and, while the in-pipe cleaning nozzle is in the shared drain pipe, stopping the supply of high-pressure water to the pressure switching valve, switching the pressure switching valve from the pressure reduction mode to the non-pressure reduction mode, and then restarting the water supply to spray high-pressure water from the second jet port of the in-pipe cleaning nozzle, while lowering the in-pipe cleaning nozzle to the confluence of the shared drain pipe and the dedicated drain pipe on at least one lower layer, thereby cleaning the inside of the shared drain pipe with a jet of water.

Furthermore, according to another preferred embodiment of the pressure switching drainage pipe cleaning method of the present invention, when cleaning dedicated drainage pipes laid horizontally within individual houses in an apartment building and a shared drainage pipe laid vertically to collect and carry 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, 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 drainage pipe to the confluence of the shared drainage pipe, thereby cleaning the inside of the dedicated drainage pipe with the sprayed water; The system is characterized by the following steps: while the water has entered the pipe, the supply of high-pressure water to the pressure switching valve is stopped, the pressure switching valve is switched from the decompression mode to the non-decompression mode, and the water supply is restarted to spray high-pressure water from the second nozzle of the in-pipe cleaning nozzle while the in-pipe cleaning nozzle is lowered to the confluence of the dedicated drain pipe and the common drain pipe on at least one lower layer, thereby cleaning the inside of the common drain pipe with the sprayed water; while the pressure switching valve is in the non-decompression mode, the spray of high-pressure water continues from the second nozzle of the in-pipe cleaning nozzle and the in-pipe cleaning nozzle is raised along the inside of the common drain pipe, thereby again cleaning the inside of the common drain pipe with the sprayed water.

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

The pressure switching valve according to the present invention is disposed upstream of the above-described pipe cleaning nozzle and serves to switch the water pressure of the high-pressure water applied to the nozzle.
This pressure switching valve is equipped with a pressure reduction path using an orifice that throttles the high-pressure water flow path, 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 or the pressure reduction path, thereby switching the high-pressure water sent to the pipe interior cleaning nozzle between a pressure reduction mode and a non-pressure reduction mode.
Therefore, for individual dedicated drain pipes with small inner diameters, 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 large inner diameters, the water pressure can be set high to increase the cleaning power, thereby contributing to improving the efficiency of cleaning work.

Furthermore, according to the pressure switching cleaning method for drainage pipes of this invention, individual dedicated drainage pipes and shared drainage pipes are cleaned simultaneously, and the above-mentioned pipe cleaning nozzle, which can switch the spray direction, and a pressure switching valve, which can switch the water pressure of the high-pressure water applied to this nozzle, are used in combination.
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 pressure changeover valve and the nozzle spray direction changeover can be synchronized as described above. Therefore, by combining the appropriate water pressure and nozzle spray pattern for each drain pipe, a highly efficient drain pipe cleaning method can be achieved.

1 is a schematic diagram illustrating a drainage pipe cleaning method according to the present invention. FIG. 1 is a perspective view showing an embodiment of a nozzle for cleaning inside a pipe according to the present invention. FIG. 3 is a cross-sectional view of a rotor attached to the pipe cleaning nozzle shown in FIG. 2 . 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. FIG. 1 is a perspective view showing an embodiment of a pressure switching valve according to the present invention. FIG. 1 is a schematic diagram showing a first example of a drainage pipe cleaning method. FIG. 10 is a schematic diagram showing a second example of a drainage pipe cleaning method. FIG. 10 is a schematic diagram showing a third example of a drainage pipe cleaning method. FIG. 1 is a perspective view of a conventional nozzle for cleaning inside a pipe, with the nozzle tip facing downward. FIG. 10 is a perspective view of the nozzle oriented horizontally.

The pipe cleaning nozzle and pressure switching valve, and the pressure switching cleaning method for drainage pipes according to the present invention will be described based on the embodiments shown in the drawings.
FIG. 1 shows a schematic diagram of an example of the installation of drainage pipes in a multi-family housing complex, as well as an example of implementing a pressure switching cleaning method for drainage pipes.
In Figure 1, A...C 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 then flows via an outdoor horizontal pipe 3 to a public sewer pipe (not shown).
In addition, a cleaning port 4 of the horizontal pipe is generally installed at an appropriate position on the horizontal pipe 3 outdoors (on the ground).

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, and an internal pipe cleaning nozzle 5 is inserted into the shared drain pipe 2 using a dedicated drain pipe 1a inside the 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.

2 is a perspective view of an example of a pipe cleaning nozzle suitable for use in the present invention. This pipe cleaning nozzle 5 is composed of a nozzle body 5A and a rotor 5B, both of which are made of metal.
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, connecting the two, and the rotor 5B, which is formed in an annular shape, is attached to this central shaft 5c so that it can rotate about its axis.
A hose connection pipe 9, which will be described later, is attached to the hose connection port 5b, and the pipe cleaning nozzle 5 is connected to the tip of the water supply hose 6 via this hose connection pipe 9.

A water supply space 5d for high-pressure water is formed within the central axis 5c of the nozzle body 5A, parallel to the axis Ax1 of the nozzle body connecting the center of the head 5a on the front end side to the center of the hose connection port 5b. The water supply space 5d is connected to the longitudinal center of a hollow portion 5f that houses a ball-shaped sealing body 5e.
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 axis Ax1 direction, under the influence of gravity.
Therefore, when the tip end of the nozzle body 5A is set to point slightly downward, the ball-shaped sealing body 5e moves forward within the hollow portion 5f due to gravity, and when the rear end of the nozzle body 5A is set to point slightly downward, the ball-shaped sealing body 5e moves backward within the hollow portion 5f due to gravity.

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., at 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., at the rear end side of the nozzle main body 5A.
A first injection port 5i is formed in the head portion 5a of the nozzle body 5A, and communicates with the first opening 5g to inject high-pressure water sent through the hose 6.
The first jet nozzles 5i are formed radially at approximately equal intervals in the circumferential direction of the nozzle body 5A, and act to jet high-pressure water diagonally rearward as viewed from the water supply hose 6. In this embodiment, the jet angle is set to about 45 degrees with respect to the axis Ax1 of the nozzle body 5A.
The 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.

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 Figure 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.

The two second jet nozzles 5k, which are opposed at 180 degrees, are formed symmetrically about the rotational 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 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 injection nozzle 5k constitutes a rotary nozzle that injects high-pressure water fed through the water supply hose 6 while rotating it in the circumferential direction of the nozzle body 5A.

Therefore, with the above-described pipe cleaning nozzle 5, the ball-shaped sealing body 5e moves due to gravity toward the first opening 5g, sealing the first opening 5g and spraying high-pressure water from the second nozzle 5k. Furthermore, the sealing body 5e moves due to gravity toward the second opening 5h, sealing the second opening 5h and spraying high-pressure water from the first nozzle 5i.

Therefore, when high-pressure water is continuously supplied to the above-mentioned pipe cleaning nozzle 5, the high-pressure water continues to be sprayed from the same nozzle even if the nozzle 5's position changes. When the supply of high-pressure water to the nozzle 5 is temporarily stopped and then restarted, the high-pressure water will be sprayed from the corresponding nozzle depending on the position of the nozzle 5 when the supply of high-pressure water was stopped.

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

When the attachment portion 9a on the nozzle body side is fitted into the hose connection port 5b of the internal pipe cleaning nozzle 5 and attached, 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 Figure 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 that this be in the range of 150 degrees to 170 degrees.

Therefore, when the pipe cleaning nozzle 5 using the hose connection pipe 9 shown in Figure 4 is placed inside a dedicated drain pipe 1a, for example, laid horizontally, the water supply hose 6 will be aligned with the inner bottom of the dedicated drain pipe 1a, so the head 5a of the 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 spray 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.

By employing the hose connection pipe 9 shown in FIG. 4, it is possible to improve the reliability of the spray direction selection operation of this type of pipe internal cleaning nozzle 5, which has a switchable spray direction. However, even when a conventional hose connection pipe is used in which the axis Ax1 of the nozzle body 5A and the axis Ax2 of the hose connection portion 9b are collinear, the reliability of the selection operation can be ensured.
That is, when inserting the pipe cleaning nozzle 5 into the dedicated drain pipe 1a, by intentionally applying a force to the water supply hose 6 so as to press it toward the inner bottom of the dedicated drain pipe 1a, the head 5a of the nozzle 5 can be angled slightly upward. By supplying high-pressure water in this state, it is possible to reliably spray high-pressure water diagonally backward from the first jet port 5i.

FIG. 5 is a perspective view showing an embodiment of the pressure changeover valve 7, and this pressure changeover valve 7 functions to change the injection pressure of the high-pressure water applied to the above-mentioned pipe inside cleaning nozzle 5.
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 sends high-pressure water to the pipe cleaning nozzle 5, formed at opposite left and right ends.
The water receiving section 7a and the water supply section 7b are fitted with hose connection pipes (not shown) in the same manner as the hose connection port 5b provided on the nozzle 5 for cleaning inside the pipe.
Then, high-pressure water flows from the water receiving section 7a to the water supply section 7b via the front and rear hoses as shown by the arrows on the left and right.

This pressure switching valve 7 has 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 section 7a is connected to approximately the center of the seal accommodating space 7d in the longitudinal direction.
At one longitudinal end of the seal accommodating space 7d, a pressure reduction path 7e is formed by an orifice that narrows the flow path of high-pressure water, and the pressure reduction path 7e is connected to the water supply section 7b. At the other longitudinal end of the seal accommodating space 7d, a bypass path 7f is formed that bypasses the orifice and is connected to the water supply section 7b.

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 is turned upside down relative to the state shown in Figure 5 and receives high-pressure water, 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.

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 acts, as a preferred example, to send the high-pressure water of 25 MPa received in the water receiving part 7a directly to the water supply part 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 pressure of the high-pressure water of 25 MPa received in the water receiving part 7a to 20 MPa and send it to the water supply part 7b.
The aforementioned switching between the reduced pressure mode and the non-reduced pressure mode is selected depending on the position of the pressure changeover valve 7 when the supply of high-pressure water to the pressure changeover valve 7 is stopped.

Figures 6A to 6C illustrate a typical example of the 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 valve 8 shown in Figure 1, which can supply or stop high-pressure water, to clean the inside of a drainage pipe.
These Figures 6A to 6C show the movement trajectory of the pipe cleaning nozzle 5 moving from the dedicated drain pipe 1a in house A shown in Figure 1 to the shared drain pipe (standpipe) 2, with the solid line indicating that the pressure switching valve 7 is in decompression mode and the dashed line indicating that the pressure switching valve 7 is in non-decompression mode.
6A to 6C correspond to the inventions relating to the pressure switching cleaning method for drainage pipes described in claims 2 to 4.

Figure 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 the dedicated drainage pipe 1a.
At this time, the pressure switching valve 7 is set to the aforementioned "decompression mode." That is, the pressure switching valve 7 is set to the position shown in Figure 5 in which the internal sealing body 7c seals the first opening 7g by gravity.

In addition, if the axis Ax1 of the above-mentioned pipe cleaning nozzle 5 is bent at an obtuse angle by the hose connection pipe 9 shown in Figure 4 and attached to the water supply hose 6, then no special consideration is required; simply by opening the water supply valve 8 and starting the water supply, reduced-pressure water can be sprayed diagonally backward from the first spray port 5i of the nozzle 5.

On the other hand, if the axis Ax1 of the internal pipe cleaning nozzle 5 is attached in a straight line relative to the longitudinal direction of the water supply hose 6, as explained above, with the internal pipe cleaning nozzle 5 inserted into the dedicated drain pipe 1a, the head 5a of the nozzle 5 can be angled slightly upward by intentionally applying a force to the water supply hose 6 toward the inner bottom of the dedicated drain pipe 1a. In this state, by opening the water supply tap 8 and starting the water supply, reduced-pressure water can be sprayed diagonally backward from the first spray port 5i of the nozzle 5.

The reaction force of the high-pressure water jet from the first jet nozzle 5i directed diagonally backward exerts a forward movement on the pipe cleaning nozzle 5. Therefore, by letting out the water supply hose 6 into the dedicated drain pipe 1a, the cleaning worker P can move the nozzle 5 forward toward the shared drain pipe 2 and advance the nozzle 5 to the confluence of the shared drain pipe 2.
As a result, the inside of the dedicated drain pipe 1a is cleaned by the decompressed water jetted from the nozzle 5.

When the internal pipe cleaning nozzle 5 reaches the common drain pipe 2, the nozzle 5 moves downward within the common drain pipe 2. Therefore, by continuing to reel out the water supply hose 6, the pressure switching valve 7 remains in pressure reduction mode, and the nozzle 5 continues to spray high-pressure water from the nozzle 5i as it descends within the common drain pipe 2. As a result, the inside of the common drain pipe 2 is cleaned by the reduced-pressure water sprayed from the nozzle 5.

In this case, the pipe cleaning nozzle 5 must be lowered to the confluence of the dedicated drain pipe and the common drain pipe 2 on at least one lower layer.
The amount by which the nozzle 5 descends within the shared drain pipe 2 at this time 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 to the connection point 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 the supply of water 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."

When the water tap 8 is closed, the head 5a of the in-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. As a result, the injection direction of the in-pipe cleaning nozzle 5 is switched 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 "non-reducing pressure mode" described above.
Then, by opening the water supply valve 8 and starting water supply again, high-pressure water in the non-depressurized mode is sprayed from the pipe cleaning nozzle 5 in the circumferential direction while the rotor 5B is rotating.

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 set 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 indicated by "END" at the dedicated drain pipe 1a, the water supply valve 8 is closed, and this pressure switching cleaning method is completed.

After the cleaning method is completed, the water supply hose 6 is further pulled back and the 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 within the house, inserts an in-pipe cleaning nozzle 5, and cleans the shared drainage pipe 2 downward from this dedicated drainage pipe in the house, thereby making it possible to clean the shared drainage pipe 2 in units of levels.

FIG. 6B shows a second example of the pressure switching cleaning method for drainage pipes.
In this second example, the nozzle 5 for 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 begins to move downward inside the common drain pipe 2, the water supply valve 8 is closed, stopping the supply of water to the nozzle 5. The position of the nozzle 5 inside the common drain pipe 2 at this time is indicated by "STOP."

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. As a result, the injection direction of the internal pipe cleaning nozzle 5 is switched 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 "non-reducing mode" described above.
Then, by opening the water supply valve 8 and starting the water supply again, high-pressure water in non-reduced pressure mode can be sprayed from the pipe cleaning nozzle 5 in the circumferential direction while the rotor 5B is rotating.

In this state, by unwinding the water supply hose 6, the nozzle 5 descends into the shared drain pipe 2. The cleaning action at this time is performed with a high water pressure setting, which increases the cleaning power, and with the added cleaning effect of the rotating nozzle, the efficiency of the cleaning work inside the shared drain pipe 2 can be improved.
Then, the pipe cleaning nozzle 5 is lowered to the confluence of the dedicated drain pipe and the common drain pipe 2 on at least one lower layer, and the water supply valve 8 is closed at the nozzle position indicated by "END," thereby completing this pressure switching cleaning method.

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.
Then, by pulling back the water supply hose 6, the pipe cleaning nozzle 5 is returned from the shared drain pipe 2 to the dedicated drain pipe 1a and pulled out, thereby completing the cleaning work.
In the second example of this pressure switching cleaning method, a dedicated drain pipe in a different lower level of the house is used, and the pipe cleaning nozzle 5 is inserted to clean the shared drain pipe 2 downward from the dedicated drain pipe in the house, thereby allowing the shared drain pipe 2 to be cleaned in layer units.

FIG. 6C shows a third example of the 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 supply valve 8.
Then, the water supply hose 6 is pulled back and the nozzle 5 is pulled up at a constant speed, so that the common drain pipe 2 is again subjected to the cleaning action of the rotating nozzle.

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 this pressure switching cleaning method is completed.
Next, the water supply hose 6 is further pulled back and the pipe cleaning nozzle 5 is pulled out from the dedicated drain pipe 1a, thereby completing the cleaning operation.

In the third example shown in Figure 6C, compared to the second example shown in Figure 6B, a process has been added in which the pressure switching valve 7 remains in non-depressurization mode, the spraying of high-pressure water from the pipe cleaning nozzle 5 continues, 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.

The pipe cleaning nozzle 5 in the embodiment described above is equipped with a rotor 5B on a nozzle body 5A, with a first injection port 5i formed on the nozzle body 5A side and a second injection port 5k formed on the rotor 5B, but it is also possible to use a nozzle 5 equipped with a fixed second injection port without using a rotor 5B.
In addition, the embodiment shows an example in which the nozzle 5, which has a switchable spray direction, is bent within an obtuse angle range and attached to the water supply hose 6, 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 spray direction selection operation.

1a...1c Dedicated drain pipe 2 Common drain pipe (standpipe)
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 Sealing body 5f Hollow portion 5g First opening 5h Second opening 5i First jetting port 5j Water supply path 5k Second jetting port 6 Water supply hose 7 Pressure switching valve 7a Water receiving portion 7b Water supply portion 7c Sealing body 7d Sealing body accommodating space 7e Pressure reduction path (orifice)
7f Bypass path 7g First opening 7h Second opening 8 Water supply valve 9 Hose connection pipe 9a Mounting part on nozzle main body 9b Hose connection part A...C Individual house Ax1 Axis of nozzle main body Ax2 Axis of hose connection part P Cleaning worker

Claims (4)

A pressure switching valve that switches the injection pressure of high-pressure water applied to a pipe cleaning nozzle that can selectively inject high-pressure water from a first injection port or a second injection port that have different injection angles relative to the axis of the 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 water receiving section and the water supply section by an orifice that narrows the flow path of the high-pressure water, and a bypass path formed between the water receiving section and the water supply section that bypasses the orifice;
a sealing body 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 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 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 pressure reducing mode and a non-pressure reducing mode by the movement of the sealing body due to gravity. A pressure switching cleaning method for a drainage pipe that uses the pipe cleaning nozzle and pressure switching valve according to claim 1 to clean the inside of the drainage pipe,
When cleaning the dedicated drainage pipes laid horizontally in individual houses 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 the 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 spray nozzle formed on the in-pipe cleaning nozzle, and moving the in-pipe cleaning nozzle from inside the dedicated drain pipe to the confluence of 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 the confluence of the dedicated drain pipe and the shared drain pipe of at least one layer below;
a step of 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 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 pressure switching cleaning method for drainage pipes, characterized by carrying out the following. A pressure switching cleaning method for a drainage pipe that uses the pipe cleaning nozzle and pressure switching valve according to claim 1 to clean the inside of the drainage pipe,
When cleaning the dedicated drainage pipes laid horizontally in individual houses 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 the 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 spray nozzle formed on the in-pipe cleaning nozzle, and moving the in-pipe cleaning nozzle from inside the dedicated drain pipe to the confluence of 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 is advanced into the common drain pipe, switching the pressure switching valve from the pressure reduction mode to the non-pressure reduction mode, and then restarting the water supply to spray high-pressure water from the second nozzle of the in-pipe cleaning nozzle, and lowering the in-pipe cleaning nozzle to the confluence of at least one lower dedicated drain pipe and common drain pipe, thereby cleaning the inside of the common drain pipe with the sprayed water;
A pressure switching cleaning method for drainage pipes, characterized by carrying out the following. A pressure switching cleaning method for a drainage pipe that uses the pipe cleaning nozzle and pressure switching valve according to claim 1 to clean the inside of the drainage pipe,
When cleaning the dedicated drainage pipes laid horizontally in individual houses 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 the 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 spray nozzle formed on the in-pipe cleaning nozzle, and moving the in-pipe cleaning nozzle from inside the dedicated drain pipe to the confluence of 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 is advanced into the common drain pipe, switching the pressure switching valve from the pressure reduction mode to the non-pressure reduction mode, and then restarting the water supply to spray high-pressure water from the second nozzle of the in-pipe cleaning nozzle, and lowering the in-pipe cleaning nozzle to the confluence of at least one lower dedicated drain pipe and common drain pipe, thereby cleaning the inside of the common drain pipe with the sprayed water;
a step 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-depressurization mode, and again cleaning the inside of the shared drain pipe with the sprayed water by pulling up the pipe cleaning nozzle along the inside of the shared drain pipe;
A pressure switching cleaning method for drainage pipes, characterized by carrying out the following.