Unmanned aerial vehicle based air flow bubble foam integrated cleaning and dusting device

Abstract

This invention discloses an integrated airflow and foam cleaning and vacuuming device based on drones. Utilizing drone technology, the device hovers above a car and uses a high-flow, low-pressure airflow generated by a centrifugal fan in forward rotation, combined with a first air duct and a spiral main air outlet, to achieve efficient, contactless cleaning of large areas of floating dust and light stains on the car's exterior. This avoids the risk of scratching the paint caused by traditional high-pressure water jets or roller brushes. For localized residue or stains in crevices, a foldable first nozzle assembly unfolds at multiple angles for targeted, powerful cleaning. When encountering stubborn stains, a foldable second nozzle assembly sprays cleaning foam to weaken the stain's adhesion before airflow removes it, significantly improving cleaning ability. Simultaneously, by setting a bidirectional airflow structure, the centrifugal fan reverses to generate negative pressure, drawing in dust-laden air through the first nozzle assembly for contactless adsorption and dust removal of the car's interior. This device integrates cleaning and vacuuming functions, featuring a compact structure and comprehensive functionality.

Description

Technical Field

[0001] This invention belongs to the field of drone application technology and relates to a household car washing device, specifically a drone-based airflow foam integrated cleaning and dust collection device. Background Technology

[0002] Currently, car exterior cleaning mainly relies on manual handheld high-pressure water guns or automated car washes. These traditional methods require high-pressure water pumps, air compressors, long hoses, and fixed washing areas. The equipment is bulky and takes up a large area, making it inconvenient to use outdoors in places without water or power. Furthermore, high-pressure water jets and mechanical brushes can easily cause minor scratches or abrasions to the paint, leading to a decrease in paint gloss over time. For everyday dust and light stains on the car body, high-pressure cleaning is an overkill and energy waste, while manual washing is time-consuming and labor-intensive. On the other hand, cleaning the car interior usually requires manual operation with a handheld vacuum cleaner. Vacuum cleaners struggle to thoroughly clean dust and debris in seat crevices and deep within floor mats without contact, and the power cord or battery life of vacuum cleaners also limits their convenience.

[0003] Existing drone applications are mostly concentrated in fields such as aerial photography and plant protection. The goal of this application is to design an integrated portable device that can automatically clean cars using drone technology. Summary of the Invention

[0004] To address the technical problems existing in the background art, this invention proposes an integrated airflow and foam cleaning and vacuuming device. It utilizes drone technology to hover on a car and uses airflow as the main cleaning medium, which significantly reduces the size and weight, achieving portable and automated operation. It is particularly suitable for rapid cleaning scenarios outdoors where there is no water or power source.

[0005] The objective of this invention can be achieved through the following technical solutions: The drone-based airflow foam integrated cleaning and vacuuming device includes: a drone body, a centrifugal fan, and a first nozzle assembly. The centrifugal fan is fixedly installed on the drone body. The top of the drone body has an air collection chamber that connects to the centrifugal fan, and the bottom of the drone body has a main air outlet. The main air outlet is connected to the air collection chamber through a first air duct. The first nozzle assembly is folded and installed on the side wall of the drone body so that it can extend at any preset angle during operation and fold against the side wall of the drone body when stored. The first nozzle assembly is connected to the air collection chamber through a second air duct.

[0006] Furthermore, the first nozzle assembly includes: a first folding arm, a second folding arm, and a nozzle. One end of the first folding arm is hinged to the side wall of the UAV body to rotate freely in the horizontal direction under the drive of a corresponding micro motor. The second folding arm is hinged to the other end of the first folding arm to rotate freely in the vertical direction under the drive of a corresponding micro motor. The nozzle is mounted on the second folding arm.

[0007] Furthermore, the drone cleaning device also includes: a nozzle control module, which is installed inside the drone body and electrically connected to the drone's flight control module to receive control commands from the drone control terminal through the drone's flight control module. The nozzle control module is electrically connected to the micro motor groups that drive the first folding arm and the second folding arm respectively, so as to control the rotation of the first folding arm and the second folding arm according to the control commands, so that the first nozzle assembly extends or folds at a preset angle.

[0008] Furthermore, the second air duct includes: a first main channel, a second main channel, a first branch channel, a second branch channel, and a dust collection box. The first main channel is connected to the air collection chamber, the second main channel is connected to the first nozzle assembly, the first branch channel and the second branch channel are connected in parallel between the first main channel and the second main channel, and the dust collection box is connected to the second branch channel.

[0009] Furthermore, a first one-way valve is installed on the first branch channel to allow airflow to flow unidirectionally from the first main channel to the second main channel, and a second one-way valve is installed on the second branch channel to allow airflow to flow unidirectionally from the second main channel to the first main channel. The second one-way valve is located between the dust collection box and the first main channel.

[0010] Furthermore, the drone cleaning device also includes: a second nozzle assembly, which has the same structure as the first nozzle assembly and is arranged opposite to it. It is folded and installed on the peripheral side wall of the drone body. The drone body is provided with a cleaning fluid tank for storing cleaning fluid. The second nozzle assembly is connected to the air collection chamber and the cleaning fluid tank through a third air duct.

[0011] Furthermore, the third air duct includes: an air passage, a liquid passage, a mixing passage, and a foam generator. The air passage is connected between the air collection chamber and the foam generator, the liquid passage is connected between the cleaning liquid tank and the foam generator, and the mixing passage is connected between the foam generator and the second nozzle assembly.

[0012] Furthermore, the drone cleaning device also includes: a cleaning control module, which is installed inside the drone body and electrically connected to the drone's flight control module to receive control commands from the drone control terminal through the drone's flight control module; a first solenoid valve is provided in the first air duct; a second solenoid valve is provided in the second air duct; and a third solenoid valve is provided in the third air duct; the nozzle control module is electrically connected to the first, second, and third solenoid valves respectively to control the opening or closing of the first, second, and third solenoid valves according to the control commands.

[0013] Furthermore, the cleaning control module is electrically connected to the centrifugal fan to control the centrifugal fan to rotate forward for cleaning or reverse for dust extraction when the second solenoid valve is opened.

[0014] Furthermore, the cleaning control module is electrically connected to the foam generator to control the foam generator to start when the third solenoid valve is open and to control the foam generator to shut down when the third solenoid valve is closed.

[0015] The beneficial effects of this invention are as follows: The integrated airflow and foam cleaning and vacuuming device provided in this application utilizes drone technology to hover above a car. A high-flow, low-pressure airflow generated by a centrifugal fan, combined with a first air duct and a spiral main air outlet, achieves efficient, contactless cleaning of large areas of floating dust and light stains on the car's exterior. This avoids the risk of scratching the paint caused by traditional high-pressure water jets or roller brushes. For localized residues or stains in crevices, the foldable first nozzle assembly unfolds at multiple angles to achieve targeted, powerful cleaning. After operation, folding and storing the device does not increase flight resistance. When encountering stubborn stains, a cleaning foam is sprayed through the foldable second nozzle assembly to weaken the stain's adhesion before airflow removal, significantly improving cleaning ability. Simultaneously, by setting a bidirectional airflow structure, the centrifugal fan reverses to generate negative pressure, drawing in dust-laden air through the first nozzle assembly for contactless adsorption and dust removal of the car's interior. Integrating cleaning and vacuuming functions, this device is compact, fully functional, and does not rely on any ground-based auxiliary equipment, offering significant convenience and economy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall invention.

[0017] Figure 2 This is a schematic diagram of the internal structure of the present invention.

[0018] Figure 3 This is a bottom schematic diagram of the present invention.

[0019] Figure 4 This is a schematic diagram of the nozzle structure of the present invention.

[0020] Figure 5 This is a schematic diagram of the connection of the second air duct of the present invention.

[0021] Figure 6 This is a schematic diagram of the connection of the third air duct of the present invention.

[0022] Figure 7 This is a schematic diagram of the control system of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] This invention provides an integrated airflow and foam cleaning and vacuuming device based on drones. Utilizing drone technology, it hovers above a car to automatically clean it, combining the functions of blowing and washing the car's exterior with adsorption and dust removal from the interior. Figures 1-2 As shown, the drone cleaning device includes: a drone body 1, a centrifugal fan 2, a first nozzle assembly 3, and a second nozzle assembly 7. The centrifugal fan 2 is centrally mounted and fixed on the drone body 1 via a shock-absorbing support. The top of the drone body 1 has an air collection chamber 10 that connects to the centrifugal fan 2, thereby generating a large-flow, low-pressure airflow within the air collection chamber 10 through the centrifugal fan 2. This airflow is used to clean the car, targeting everyday dust and light stains. It eliminates the need for high-pressure water pumps, air compressors, and hoses, offering advantages such as automation, lightweight design, portability, low cost, and no damage to the paint.

[0025] The drone body 1 has a main air outlet 4 at its bottom. The main air outlet 4 is connected to the air collection chamber 10 through a trumpet-shaped first air duct 5. When the drone body 1 hovers above the car, the airflow in the air collection chamber 10 is directed out through the main air outlet 4 via the first air duct 5, completing a large-area blowing and cleaning of the car's exterior. For example... Figure 3 As shown, the main air outlet 4 is set as a spiral air outlet, which performs secondary rectification and pressurization on the airflow, and gathers the dispersed airflow into a high-speed concentrated rotating vortex flow to achieve powerful blowing and washing.

[0026] Four first nozzle assemblies 3 are provided, which are folded and installed on the four side walls of the drone body 1 respectively. They can be folded for storage and unfolded for operation. The first nozzle assembly 3 is connected to the air collection chamber 10 through the second air duct 6. After cleaning the entire vehicle, the first nozzle assembly 3 can be unfolded at any preset angle. The airflow in the air collection chamber 10 is directed out of the first nozzle assembly 3 through the second air duct 6 to perform targeted cleaning of local areas on the exterior of the car. After the operation is completed, the first nozzle assembly 3 is folded and attached to the side wall of the drone body 1 for storage without increasing the wind resistance of the drone body 1.

[0027] The second nozzle assembly 7 has the same structure as the first nozzle assembly 3 and is arranged opposite to it, folded and installed on the four side walls of the drone body 1. The drone body 1 has a cleaning fluid tank 8 for storing cleaning fluid. The second nozzle assembly 7 is connected to the air collection chamber 10 and the cleaning fluid tank 8 via a third air duct 9. When encountering stubborn stains that are difficult to remove, the cleaning fluid is mixed in the airflow through the third air duct 9 and sprayed onto the surface of the stubborn stains, wetting and weakening the adhesion of the stains and paint. This, combined with the first nozzle assembly 3, achieves targeted cleaning. The cleaning fluid is made by mixing household car wash concentrate with water at a ratio of 1:80-1:100, resulting in gentle cleaning with low corrosiveness.

[0028] The first nozzle assembly 3 includes a first folding arm 31, a second folding arm 32, and a nozzle 33. One end of the first folding arm 31 is hinged to the side wall of the UAV body 1, allowing it to rotate freely horizontally under the drive of a corresponding micro motor. The second folding arm 32 is hinged to the other end of the first folding arm 31, allowing it to rotate freely vertically under the drive of a corresponding micro motor. The nozzle 33 is mounted on the second folding arm 32. Specifically, both the first folding arm 31 and the second folding arm 32 have axially penetrating through holes in their middle portions. The nozzle 33 communicates with the through holes of the second folding arm 32. The two ends of the through holes of the first folding arm 32 are respectively sealed and connected to the through holes of the second folding arm 32 and the second air duct 6 via rubber hoses. Figure 4 As shown, nozzle 33 is a foldable lotus-shaped nozzle with an 8-petal lotus-like structure. When unfolded, the petals are fully open, allowing adjustment of the spray pitch angle to suit different cleaning surfaces of the vehicle body. When folded, the petals close together, not affecting the flight stability of the UAV body 1, and facilitating transportation and storage. As another implementation, those skilled in the art can directly use a multi-degree-of-freedom robotic arm to replace the simple folding arm structure in this application, and set an airflow channel connecting nozzle 33 and the second air duct 6 inside the robotic arm, which provides more precise and flexible control, but the manufacturing cost is high.

[0029] like Figure 5 As shown, the second air duct 6 includes: a first main air duct 61, a second main air duct 62, a first branch air duct 63, a second branch air duct 64, and a dust collection box 65. The first main air duct 61 is connected at one end to the air collection chamber 10, and at the other end to the first branch air duct 63 and the second branch air duct 64 respectively. The second main air duct 62 is connected at one end to the first branch air duct 63 and the second branch air duct 64 respectively, and at the other end to the first nozzle assembly 3. The first branch air duct 63 is connected at one end to the first main air duct 61, and at the other end to the second main air duct 62. The second branch air duct 64 is connected at one end to the second main air duct 62, and at the other end to the first main air duct 61.

[0030] A first one-way valve 66 is installed on the first branch channel 63, allowing airflow to flow unidirectionally from the first main channel 61 to the second main channel 62. When the centrifugal fan 2 rotates forward, airflow is ejected from the air collection chamber 10 through the first main channel 61, the first branch channel 63, and the second main channel 62, exiting from the first nozzle assembly 3 to clean the exterior of the car. A second one-way valve 67 is installed on the second branch channel 64, allowing airflow to flow unidirectionally from the second main channel 62 to the first main channel 61. When the centrifugal fan 2 reverses to suck in air, a negative pressure suction force is formed in the air collection chamber 10, drawing in dust-laden air from the first nozzle assembly 3, through the second main channel 62, the second branch channel 64, and the first main channel 61 into the air collection chamber 10, adsorbing and removing dust from the car's interior. A dust collection box 65 is connected to the second branch channel 64, and a high-density filter is installed inside the dust collection box 65 to filter and collect dust from the air. The second one-way valve 67 is located between the dust collection box 65 and the first main channel 61 to prevent it from being affected by dust.

[0031] like Figure 6 As shown, the third air duct 9 includes: an air passage 91, a liquid passage 92, a mixing passage 93, and a foam generator 94. One end of the air passage 91 is connected to the air collection chamber 10, and the other end is connected to the air inlet of the foam generator 94, so as to introduce the airflow from the air collection chamber 10 into the foam generator 94. The liquid inlet of the foam generator 94 is connected to the cleaning liquid tank 8 through the liquid passage 92, so as to draw cleaning liquid from the cleaning liquid tank 8. A foaming agent is added to the cleaning liquid to generate foam composed of numerous bubbles within the foam generator 94. One end of the mixing channel 93 is connected to the outlet of the foam generator 94, and the other end is connected to the second nozzle assembly 7. The cleaning fluid foam generated in the foam generator 94 enters the mixing channel 93 with the airflow and is sprayed out from the second nozzle assembly 7, precisely adhering to the stains on the car surface. The cleaning fluid foam does not flow, stays on the wall for a long time, and has strong penetration. It can stay on the stains to soak, emulsify, and decompose them. Bird droppings, tree sap, and oil spots can all be softened. In addition, the micro-impact generated during the bursting of bubbles, combined with the airflow, is equivalent to non-contact scrubbing, resulting in a strong cleaning effect. At the same time, since the cleaning fluid foam is a gas-liquid mixture, the coverage area is increased several times with the same amount of cleaning fluid, saving liquid, water, and reducing load.

[0032] like Figure 7As shown, to achieve automated cleaning, the drone cleaning device also includes a control system consisting of a nozzle control module and a cleaning control module. Both the nozzle control module and the cleaning control module are installed inside the drone body 1 and electrically connected to the drone's flight control module to receive control commands from the drone's control terminal. The nozzle control module is electrically connected to the micro motors driving the first folding arm 31 and the second folding arm 32, respectively, to control the rotation of the first folding arm 31 and the second folding arm 32 according to the control commands, so that the first nozzle assembly 3 unfolds for operation or folds for storage at a preset angle.

[0033] A first solenoid valve 51 is installed in the first air duct 5, a second solenoid valve 68 is installed in the second air duct 6, and a third solenoid valve 95 is installed in the third air duct 9. The nozzle control module is electrically connected to the first solenoid valve 51, the second solenoid valve 68, and the third solenoid valve 95 respectively, to control the opening or closing of the first solenoid valve 51, the second solenoid valve 68, and the third solenoid valve 95 according to control commands. The cleaning control module is electrically connected to the centrifugal fan 2, to control the centrifugal fan 2 to rotate forward for blowing or reverse for dust suction when the second solenoid valve 68 is open. The cleaning control module is electrically connected to the foam generator 94, to control the foam generator 94 to start when the third solenoid valve 95 is open, and to control the foam generator 94 to shut down when the third solenoid valve 95 is closed.

[0034] When this invention is working: First, the drone body 1 is hovered above the car to perform a large-area, rapid cleaning of the car's roof and body for daily dust and light stains: The cleaning control module controls the first solenoid valve 51 in the first air duct 5 to open and the second solenoid valve 68 and the third solenoid valve 95 to close. At the same time, it controls the centrifugal fan 2 to rotate forward, forming a large-flow, low-pressure airflow in the air collection chamber 10. The airflow is led out from the main air outlet 4 at the bottom of the drone body 1 through the first air duct 5, and the powerful airflow over a wide area is used to efficiently clean the car's exterior. At this time, the first nozzle assembly 3 and the second nozzle assembly 7 are both kept in a folded and stored state and do not participate in the operation.

[0035] After completing the large-area blowing and washing, targeted blowing and washing is carried out on areas of the vehicle body that are difficult to be covered by a large area of ​​airflow, such as residual dust, gaps, and rearview mirrors: the nozzle control module controls the first nozzle assembly 3 to unfold at a preset angle and aim at the target area, the cleaning control module controls the first solenoid valve 51 to close and opens the second solenoid valve 68 in the second air duct 6, the centrifugal fan 2 continues to rotate forward, and the airflow is sprayed out from the nozzle 33 through the first main channel 61, the first branch channel 63, and the second main channel 62 to achieve precise targeted and powerful blowing and washing. After the operation is completed, the first nozzle assembly 3 is folded and stored.

[0036] When encountering stubborn stains such as bird droppings, resin, and dried mud spots that are difficult to remove by airflow alone, the nozzle control module controls the second nozzle assembly 7 to unfold at a preset angle and aim at the target area. The cleaning control module controls the third solenoid valve 95 in the third air duct 9 to open, and at the same time starts the foam generator 94. The airflow generated by the forward rotation of the centrifugal fan 2 enters the foam generator 94 through the air passage 91. The foam generator 94 draws cleaning liquid with added foaming agent from the cleaning liquid tank 8 and makes it into foam. The cleaning liquid foam follows the airflow into the mixing channel 93 and is finally sprayed out from the second nozzle assembly 7, precisely adhering to the surface of the stubborn stains. After the cleaning liquid foam has soaked and weakened the adhesion between the stains and the paint, it switches back to fixed-point blowing and uses the airflow of the first nozzle assembly 3 to blow away the loosened stains.

[0037] For dust and debris in areas such as car seats, floor mats, and dashboards, the drone body 1 can be hovered on the side or inside of the car. The nozzle control module controls the first nozzle assembly 3 to unfold and extend into the car through the window, aiming at the interior area to be cleaned. The cleaning control module controls the second solenoid valve 68 to open and close the first solenoid valve 51 and the third solenoid valve 95. At the same time, it controls the centrifugal fan 2 to reverse, creating a negative pressure suction force in the air collection chamber 10. Dust-laden air is drawn in from the first nozzle assembly 3 and passes through the second main channel 62 and the second branch channel 64 into the dust collection box 65. The high-density filter in the box intercepts and collects the dust, while clean air enters the air collection chamber 10 through the first main channel 61 and is discharged by the centrifugal fan 2. This achieves contactless adsorption and dust removal of the car interior, and the dust will not cause secondary pollution.

[0038] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A drone-based integrated airflow and foam cleaning and dust collection device, characterized in that, include: The drone body (1), centrifugal fan (2), and first nozzle assembly (3) are provided. The centrifugal fan (2) is fixedly installed on the drone body (1). The top of the drone body (1) is provided with an air collection chamber (10) that connects with the centrifugal fan (2). The bottom of the drone body (1) is provided with a main air outlet (4). The main air outlet (4) is connected to the air collection chamber (10) through the first air duct (5). The first nozzle assembly (3) is folded and installed on the side wall of the drone body (1) so that it can be unfolded at any preset angle when working and folded against the side wall of the drone body (1) when stored. The first nozzle assembly (3) is connected to the air collection chamber (10) through the second air duct (6).

2. The cleaning and vacuuming device according to claim 1, characterized in that, The first nozzle assembly (3) includes: a first folding arm (31), a second folding arm (32), and a nozzle (33). One end of the first folding arm (31) is hinged to the side wall of the UAV body (1) so that it can rotate freely in the horizontal direction under the drive of the corresponding micro motor. The second folding arm (32) is hinged to the other end of the first folding arm (31) so that it can rotate freely in the vertical direction under the drive of the corresponding micro motor. The nozzle (33) is mounted on the second folding arm (32).

3. The cleaning and vacuuming device according to claim 2, characterized in that, Also includes: The nozzle control module is installed inside the main body (1) of the UAV and is electrically connected to the flight control module of the UAV so as to receive control commands from the UAV control terminal through the flight control module of the UAV. The nozzle control module is electrically connected to the micro motors that drive the first folding arm (31) and the second folding arm (32) respectively, so as to control the first folding arm (31) and the second folding arm (32) to rotate according to the control commands, so that the first nozzle assembly (3) unfolds or folds at a preset angle.

4. The cleaning and vacuuming device according to claim 1, characterized in that, The second air duct (6) includes: a first main channel (61), a second main channel (62), a first branch channel (63), a second branch channel (64), and a dust collection box (65). The first main channel (61) is connected to the air collection chamber (10), the second main channel (62) is connected to the first nozzle assembly (3), the first branch channel (63) and the second branch channel (64) are connected in parallel between the first main channel (61) and the second main channel (62), and the dust collection box (65) is connected to the second branch channel (64).

5. The cleaning and vacuuming device according to claim 4, characterized in that, A first one-way valve (66) is provided on the first branch channel (63) to allow airflow to flow unidirectionally from the first main channel (61) to the second main channel (62). A second one-way valve (67) is provided on the second branch channel (64) to allow airflow to flow unidirectionally from the second main channel (62) to the first main channel (61). The second one-way valve (67) is located between the dust collection box (65) and the first main channel (61).

6. The cleaning and vacuuming device according to claim 1, characterized in that, Also includes: The second nozzle assembly (7) has the same structure as the first nozzle assembly (3) and is arranged opposite to it. It is folded and installed on the side wall of the drone body (1). The drone body (1) is provided with a cleaning fluid tank (8) for storing cleaning fluid. The second nozzle assembly (7) is connected to the air collection chamber (10) and the cleaning fluid tank (8) through the third air duct (9).

7. The cleaning and vacuuming device according to claim 6, characterized in that, The third air duct (9) includes: an air passage (91), a liquid passage (92), a mixing passage (93), and a foam generator (94). The air passage (91) is connected between the air collection chamber (10) and the foam generator (94). The liquid passage (92) is connected between the cleaning liquid tank (8) and the foam generator (94). The mixing passage (93) is connected between the foam generator (94) and the second nozzle assembly (7).

8. The cleaning and vacuuming device according to claim 7, characterized in that, Also includes: The cleaning control module is installed inside the main body (1) of the UAV and electrically connected to the flight control module of the UAV so as to receive control commands from the UAV control terminal through the flight control module of the UAV. The first air duct (5) is equipped with a first solenoid valve (51), the second air duct (6) is equipped with a second solenoid valve (68), and the third air duct (9) is equipped with a third solenoid valve (95). The nozzle control module is electrically connected to the first solenoid valve (51), the second solenoid valve (68), and the third solenoid valve (95) respectively so as to control the first solenoid valve (51), the second solenoid valve (68), and the third solenoid valve (95) to open or close according to the control commands.

9. The cleaning and vacuuming device according to claim 8, characterized in that, The cleaning control module is electrically connected to the centrifugal fan (2) to control the centrifugal fan (2) to rotate forward to blow or reverse to suck dust when the second solenoid valve (68) is opened.

10. The cleaning and vacuuming device according to claim 9, characterized in that, The cleaning control module is electrically connected to the foam generator (94) to control the foam generator (94) to start when the third solenoid valve (95) is open and to control the foam generator (94) to shut down when the third solenoid valve (95) is closed.

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