JP7597374B2 - Pipe cleaning nozzle - Google Patents

Description

The present invention relates to a nozzle for cleaning the inside of drainage pipes installed in apartment buildings and the like, which uses a high-pressure water jet to remove solid matter such as food residue, oil and grease adhering to the inside of the 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 discharged from dedicated drainage pipes laid horizontally inside each house, through shared drainage pipes (also called standpipes) laid vertically inside the building, and into a horizontal pipe outside, thereby maintaining a good living environment.

However, because this domestic wastewater contains a large amount of food residue, 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.

As mentioned above, one method for cleaning and removing solid objects stuck inside drain pipes has traditionally been the high-pressure water jet cleaning method. This method involves spraying high-pressure water from a cleaning nozzle attached to the end of a water supply hose at the solid objects stuck inside the drain pipe to remove them.

Many proposals have already been made regarding the high-pressure water jet nozzles used to clean the inside of the drain pipes mentioned above, and the applicant has previously proposed an in-pipe cleaning nozzle that can be used by switching the high-pressure water jet nozzle so that it is suitable for cleaning the individual dedicated drain pipes, shared drain pipes, and horizontal pipes mentioned above, as well as a method of cleaning drain pipes 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 cut in the axial direction of the pipe cleaning nozzle. Fig. 7 shows the nozzle body 11 with the tip facing downward, and Fig. 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 into which high-pressure water is supplied 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 in a state where the tip of the nozzle body 11 is facing down as shown in Figure 7, the sealing body 15 moves forward 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 enters the 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 facing 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 nozzle 17 formed in the nozzle body, and high-pressure water is sprayed from the diagonally forward jet nozzle 16.

In addition, in the state shown in Figure 8 where the nozzle body 11 is arranged so that it faces horizontally, the sealing body 15 enters the pocket 14a described above, and the sealing body 15 closes the circular opening 18, 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 backward jet nozzle 17.

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 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 join point of the standpipe, the nozzle body 11 continues to spray high-pressure water and the hose is sent out, causing the nozzle body 11 to move 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.

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 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 pull back 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, for example, in an individual house, the ball-shaped seal 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 Figure 8 in which the pocket 14a is located downward, thereby performing the normal injection operation of injecting high-pressure water from the injection port 17 obliquely rearward.

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 to 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.

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 collective housing, 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 upper part or lower part 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.

In this case, for individual dedicated drainage 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 drainage pipes, and for shared drainage pipes with a large inner diameter, it is desirable to set the water pressure high to increase the cleaning power, from the perspective of improving the efficiency of the cleaning work.

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.

The pipe cleaning nozzle according to the present invention, which has been made to solve the above problems, is a pipe cleaning nozzle that 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 having different spray angles relative to the axis of the nozzle body, and the nozzle body is provided with a cavity with a longitudinal direction along the axis, and a sealing body that is housed in the cavity and moves longitudinally within the cavity under gravity, and a first opening that communicates with the first nozzle is formed at one longitudinal end of the cavity, and a second opening that communicates with the second nozzle is formed at the other longitudinal end of the cavity, and the first opening is sealed by the movement of the sealing body toward the first opening side due to gravity, and high-pressure water is sprayed from the second nozzle, and the second opening is sealed by the movement of the sealing body toward the second opening side due to gravity, 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 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 when 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 to the spray of high-pressure water.

In addition, the first and second jet nozzles each include a plurality of jet nozzles, the first jet nozzles are arranged at equal intervals around the circumference of the nozzle body, and the second jet nozzles are 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 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 path 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 path formed between the receiving section and the water supply section and 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 path, thereby supplying the high-pressure water via the pressure reduction path to the water supply section, and moves in the other direction under the influence of gravity and seals a second opening leading from the receiving section to the pressure reduction path, thereby supplying the high-pressure water via the bypass path to the water supply section, 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.

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 individual house in an apartment building and a shared drainage pipe laid vertically to collect and drain the wastewater from each dedicated drainage pipe, the 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 and water is supplied to the pipe cleaning nozzle, high-pressure water is sprayed from a first nozzle formed in the pipe cleaning nozzle, and the pipe cleaning nozzle is advanced from inside the dedicated drainage pipe to the junction of the shared 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 steps of: 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 junction 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 sprayed water; and 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 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 sprayed water again.

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 individual house in an apartment building and a common drainage pipe laid vertically through which wastewater from each dedicated drainage pipe is collected and discharged, 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 guided from inside the dedicated drainage pipe to the common drainage pipe. The nozzle is characterized by the steps of: advancing the nozzle to the junction of the dedicated drain pipe and cleaning the inside of the dedicated drain pipe with the jet of water; and, with the nozzle for cleaning the inside of the pipe proceeding into the shared drain pipe, stopping the supply of high-pressure water to the pressure change valve, switching the pressure change valve from the reduced pressure mode to the non-reduced pressure mode, and then restarting the water supply to spray high-pressure water from the second jet of the nozzle for cleaning the inside of the pipe, while lowering the nozzle for cleaning the inside of the pipe to the junction of the dedicated drain pipe and the shared drain pipe of at least one lower layer, thereby cleaning the inside of the shared drain pipe with the jet of water.

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 through which wastewater from each dedicated drainage pipe is collected and discharged, the process 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 in 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 by the following steps: while the water has advanced into the pipe, the supply of high-pressure water to the pressure switching valve is stopped, and after the pressure switching valve is switched from the reduced pressure mode to the non-reduced pressure mode, 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 junction 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 sprayed water; while the pressure switching valve is kept in the non-reduced pressure mode, the spraying of high-pressure water from the second nozzle of the in-pipe cleaning nozzle is continued, and the in-pipe cleaning nozzle is raised along the inside of the common drain pipe, thereby cleaning the inside of the common drain pipe with the sprayed water again.

In the above-described 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 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.

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.

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.

FIG. 2 is a schematic diagram illustrating a drainage pipe cleaning method according to the present invention. 1 is a perspective view showing an embodiment of a nozzle for cleaning inside a pipe according to the present invention. 3 is a cross-sectional view of a rotor attached to the nozzle for cleaning inside the pipe 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. 11 is a schematic diagram showing a second example of a drainage pipe cleaning method. FIG. 11 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. 13 is a perspective view of the nozzle oriented horizontally.

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 is a schematic diagram showing an example of the layout of drainage pipes in a multi-family housing complex and an example of implementing a 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 each 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).
In addition, a cleaning port 4 of the horizontal pipe is generally installed at an appropriate position of the horizontal pipe 3 outdoors (on the ground).

As already explained, the example shown in FIG. 1 shows an example in which, when cleaning a shared drain pipe (standpipe), it is difficult to insert an in-pipe cleaning nozzle from the upper opening (cleaning port) of the standpipe installed on the roof of a building, for example, in which an in-pipe cleaning nozzle 5 is inserted into a shared drain pipe 2 by 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 this pressure switching valve 7 and nozzle 5.

2 is a perspective view of an example of a pipe cleaning nozzle that can be suitably used in the present invention. The pipe cleaning nozzle 5 is composed of a nozzle body 5A and a rotor 5B, and the nozzle body 5A and the rotor 5B are both made of metal materials.
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 able to rotate about its axis.
A hose connection pipe 9, which will be described later, is attached to the hose connection port 5b, and the internal pipe cleaning nozzle 5 is connected to the tip of the water supply hose 6 via this hose connection pipe 9.

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 communicates with the longitudinal center of a cavity 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 within 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 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., 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 is formed in the head portion 5a of the nozzle body 5A, and communicates with the first opening 5g to inject high-pressure water fed through the hose 6.
The first jet ports 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 backward 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.
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.

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. However, three or more second injection ports 5k may be provided as necessary.

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 therebetween, 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 5k constitutes a rotary nozzle that sprays high-pressure water fed via the water supply hose 6 while rotating in the circumferential direction of the nozzle body 5A.

Therefore, with the above-mentioned 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. Also, 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, even if the position of the nozzle 5 changes, the high-pressure water continues to be sprayed from the same nozzle. 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 is sprayed from the corresponding nozzle depending on the position of the nozzle 5 when the supply of high-pressure water was stopped.

Fig. 4 is a perspective view showing a state in which a water supply hose 6 is connected to the above-mentioned internal pipe cleaning nozzle 5 via a hose connection tube 9. In the internal pipe cleaning nozzle 5 shown in Fig. 4, representative parts corresponding to the respective parts of the internal 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 body, and the other end constitutes a cylindrical hose connection portion 9b.

When the attachment 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 to have this be in the range of 150 degrees to 170 degrees.

Therefore, when an in-pipe cleaning nozzle 5 using a hose connection tube 9 as shown in Figure 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 in-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 internal pipe cleaning nozzle 5 receives a forward propulsive force and can move forward from within the dedicated drain pipe 1a toward the shared drain pipe (standpipe) 2.

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 even when a conventional hose connection tube 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, 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 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.

FIG. 5 is a perspective view showing an embodiment of the pressure changeover valve 7. This pressure changeover valve 7 has the function of changing over the injection pressure of the high-pressure water applied to the above-mentioned 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.
The water receiving section 7a and the water supplying section 7b are fitted with hose connecting pipes (not shown) respectively, similar to the hose connecting port 5b provided on the above-mentioned nozzle 5 for cleaning inside a 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 shown by the arrows on the left and right.

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 sealing body 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 sealing body 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.

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.

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 pressure of 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.

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 valve 8 shown in FIG. 1 that 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 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, with the solid line indicating that the pressure switching valve 7 is in the reduced pressure mode and the dashed line indicating that the pressure switching valve 7 is in the non-reduced pressure mode .

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 changeover valve 7 is set to the above-mentioned "reduced pressure mode". That is, the pressure changeover 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.

When the axis Ax1 of the above-mentioned 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 diagonally backward from the first nozzle 5i of the nozzle 5 by opening the water supply valve 8 and starting the water supply without any special consideration.

On the other hand, when 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 side of the dedicated drain pipe 1a. In this state, by opening the water supply tap 8 and starting the water supply, reduced pressure high-pressure water can be sprayed diagonally backward from the first nozzle 5i of the nozzle 5.

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 cleaned by the reduced pressure water jetted from the nozzle 5.

When the nozzle 5 for cleaning inside the pipe reaches the shared drain pipe 2, the nozzle 5 advances downward inside the shared drain pipe 2. Therefore, by extending the water supply hose 6, the nozzle 5 continues to descend inside the shared 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 shared drain pipe 2 is cleaned by the decompressed water sprayed from the nozzle 5.

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 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 supply valve 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 changeover valve 7 is turned upside down from the state shown in FIG. 5, the pressure changeover 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.

In this state, by pulling back the water supply hose and raising the nozzle 5 at a constant speed, the shared 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, together with the cleaning effect of the rotating nozzle, the efficiency of the cleaning work for the shared drain pipe 2 can be improved.
Then, when the pipe cleaning nozzle 5 is raised to the position of the dedicated drain pipe 1a, indicated by "END," the water supply valve 8 is closed, and the pressure switching cleaning method is completed.

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.

FIG. 6B shows a second example of the pressure switching cleaning method for drainage pipes.
In this second example, the nozzle 5 for cleaning inside the pipe 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 the supply of water to the nozzle 5 is stopped. The position of the nozzle 5 inside the shared 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 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 pipe cleaning nozzle 5 in the circumferential direction while the rotor 5B is rotating.

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 the 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 of 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.

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 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 operation.
In the second example of this pressure switching cleaning method, a dedicated drainage pipe in a different lower level of the house is used, and an in-pipe cleaning nozzle 5 is inserted to clean 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.

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 raised 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 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.

In the third example shown in FIG. 6C, compared to the second example shown in FIG. 6B, a process is added in which the pressure switching valve 7 is kept in the non-reducing mode, high-pressure water is continued to be sprayed from the inside-pipe cleaning nozzle 5, and the nozzle 5 is pulled up along the inside of the shared drain pipe, so that the inside of the shared drain pipe 2 is again cleaned by spraying water 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, 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 thereto, 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.

1a…1c Dedicated drain pipe 2 Common drain pipe (standpipe)
Reference Signs List 3 Horizontal pipe 4 Cleaning port 5 In-pipe cleaning nozzle 5A Nozzle body 5B Rotor 5a Head 5b Hose connection port 5c Central shaft 5d Water supply space 5e Sealing body 5f Cavity 5g First opening 5h Second opening 5i First jet port 5j Water supply passage 5k Second injection port 6 Water supply hose 7 Pressure switching valve 7a Water receiving section 7b Water supply section 7c Sealing body 7d Sealing body accommodation space 7e Pressure reduction passage (orifice)
7f Bypass passage 7g First opening 7h Second opening 8 Water supply valve 9 Hose connection pipe 9a Attachment part to nozzle body 9b Hose connection part A...C Individual house Ax1 Axis of nozzle body Ax2 Axis of hose connection part P Cleaning work Staff

Claims (4)

A nozzle for cleaning inside a pipe, which is attached to a tip of a water supply hose and is capable of selectively spraying high-pressure water sent through the water supply hose from a first nozzle or a second nozzle having different spray angles relative to an axis of a nozzle body,
A cavity having a longitudinal direction along the axis is formed in the nozzle body, and a sealing body is housed in the cavity and moves in the longitudinal direction within the cavity under gravity,
a first opening communicating with the first jet nozzle is formed at one longitudinal end of the cavity, and a second opening communicating with the second jet nozzle is formed at the other longitudinal end of the cavity, and when the sealing body moves due to gravity toward the first opening side, the first opening is sealed and high-pressure water is sprayed from the second jet nozzle, and when the sealing body moves due to gravity toward the second opening side, the second opening is sealed and high-pressure water is sprayed from the first jet nozzle. The nozzle for cleaning inside a pipe according to claim 1, characterized in that the nozzle body is attached to the tip of the water supply hose via a hose connection tube, and the hose connection tube is bent within an obtuse angle range with respect to the axis of the nozzle body and connected to the water supply hose. The nozzle for cleaning inside a pipe according to claim 1 or 2, characterized in that the first nozzle is formed in the nozzle body so as to spray high-pressure water diagonally backward as viewed from the water supply hose side, and the second nozzle is formed on a rotor that is driven to rotate relative to the nozzle body by a reaction to the spray of high-pressure water. 4. The nozzle for cleaning inside a pipe according to claim 3, wherein the first jet nozzle and the second jet nozzle each include a plurality of jet nozzles, the first jet nozzles are arranged at equal intervals around a circumference of the nozzle body, and the second jet nozzles are arranged on the rotor at equal intervals around the circumference of the rotor.

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