EP3885051A1

EP3885051A1 - Automatic switching nozzle

Info

Publication number: EP3885051A1
Application number: EP21162264.2A
Authority: EP
Inventors: Yolanda TOMÁS PUCHADES
Original assignee: Istobal SA
Current assignee: Istobal SA
Priority date: 2020-03-25
Filing date: 2021-03-12
Publication date: 2021-09-29
Also published as: ES1247064U; ES1247064Y

Abstract

The invention relates to an automatic switching nozzle to be connected in a vehicle washing system wherein the casing (1) comprises an inlet opening (4) and an outlet opening (5) wherein it is located coaxially, leaving a separation that configures a channel (6), an inner capsule (3) open at the ends and configured by means of chambers (12, 13) separated by a transverse opening (15) through which a piston (7) slides, which piston comprising a head (10), a longitudinal recess (8), a transverse hole and a widening in the open base, wherein the head (10) of the piston (7) is located in one of the chambers (13) while the open base of the piston (7) is located in the other chamber (12) wherein there is also a spring (18) clasping the piston (7) to force it to be in contact with the end of the outer casing (2).

Description

OBJECT OF THE INVENTION

The object of the present invention consists of a nozzle to be incorporated into vehicle washing lances intended to project fluids both at low pressure or foam and at high pressure so that a single washing lance is used which, with the automatic switching of the nozzle, enables one outlet to be isolated from the other reducing the necessary equipment in the installation.
It has a special application in the scope of the industry of apparatuses for cleaning and/or disinfecting vehicles.

TECHNICAL PROBLEM TO BE RESOLVED AND BACKGROUND OF THE INVENTION

In washing facilities in the current state of the art, a washing phase is first carried out with high-density foam that adheres to the surface of the vehicle to weaken the most encrusted dirt and subsequently a targeted washing is carried out by spraying the high pressure fluid. These two actions are carried out with independent lances. The first lance incorporates a nozzle that contains a large diameter opening that creates a fan with a greater angle to project foam on a larger surface of the vehicle, while the second lance incorporates a nozzle with a small-sized opening that enables the spraying of the fluid to be targeted.
Each one of the lances entails the use of a hydraulic circuit and all the necessary equipment to supply each fluid to the corresponding lance thereof, making it difficult to use each one of them, as well as an increase in the cost of the installation due to the duplication of components.
Furthermore, the fact of having multiple lances on the same washing track is a disadvantage when it comes to choosing the lance associated with each washing program.
From the state of the art, washing lances are known that have independent inlets and outlets in the same lance, i.e., they have a specific channel to spray the fluid at high pressure, this one ending in a nozzle with a small-sized opening, and a second channel to project the foam, which ends in a second nozzle with a larger-sized opening. An example of this double channel system is anticipated in document DE3214180A1 , which describes a washing lance that has an additional device that enables the fluid to be channelled through a second channel by using a valve. This system has the drawback that by doubling the channel, the weight of the device increases, making it more uncomfortable for the user.
Another arrangement known in the state of the art consists of using a single channel for the fluid, either at low pressure or at high pressure, being able to switch the ending of the channel between a small opening nozzle and a large opening nozzle, depending on the washing program.
This known arrangement is described in multiple ways in different documents. For example, documents DE10257783B3 and EP0146795A describe a nozzle connected to a washing lance with two different positions that are switched manually, modifying the path that the fluid follows until it reaches the outlet opening. However, these arrangements have the drawback that the switching must be done manually, so it is not guaranteed that, during the selection of the washing program, the fluid will exit through the appropriate opening, which may cause incorrect foaming.
A different arrangement is also known that incorporates a shared channel, as described in documents DE3544340 and EP1663504B1 , which use a nozzle that automatically switches between two positions. When the fluid has enough pressure to advance the plunger to the high pressure position, the system works properly. However, when the device is in a low pressure position, the described systems have the drawback that the fluid circulates through both openings, both through the opening arranged for low pressure or foam and through the high pressure opening. When the foamy fluid passes through the high pressure opening, as a result of having a smaller diameter, it breaks the foam generating a jet of fluid without foam that in turn breaks the foam, which is projected through the larger diameter nozzle, thus projecting a low density or quality foam.

DESCRIPTION OF THE INVENTION

In order to achieve the objectives and avoid the aforementioned drawbacks, the present invention describes an automatic switching nozzle intended to be connected in a vehicle washing system wherein there is a hydraulic circuit wherein a hose (29) is located for connecting a washing gun with a lance wherein the nozzle (1) is connected. The nozzle comprises an outer casing with a fluid inlet opening and a fluid outlet opening. Coaxially to the outer casing there is an inner capsule open at the ends and configured by means of a first chamber and a second chamber separated by a wall in which there is a narrowing wherein a transverse opening is located. A piston slides through this narrowing, which piston comprising a head, a longitudinal recess, a transverse hole and a widening in the open base. Furthermore, the inner capsule is separated from the outer casing by means of a separation that configures a channel.
The head of the piston is located in the second chamber while the open base of the piston is located in the first chamber wherein there is also a spring clasping the piston that is supported between the widening of the end and the separation wall of the chambers. In this way, the spring forces the piston to be in contact with the end of the outer casing. Furthermore, the transverse hole of the piston is aligned with the transverse opening of the inner capsule.
With the configuration of the nozzle that has been described, it can be seen that the nozzle behaves differently depending on whether the liquid enters inside at low pressure or at high pressure.
Thus, when the liquid enters at low pressure through the fluid inlet opening of the outer casing, the fluid enters the recess of the piston, continues through the transverse hole to be directed, through the channel, towards the fluid outlet opening, through which it leaves the nozzle.
However, as the high pressure liquid enters through the fluid inlet opening of the outer casing, the fluid enters the recess of the piston, pressing on the inner surface of the piston, exerting a force that exceeds that of the spring and moving the piston to cause the misalignment of the transverse hole with the transverse opening. In this way, the fluid circulates through the transverse hole of the piston and is directed towards the second chamber to exit through an internal opening located at the end towards the fluid outlet opening, through which it leaves the nozzle.
The force of the spring defines the working limit of the nozzle between low pressure and high pressure.
Finally, in order to create watertightness between the first chamber and the second chamber, one option is for the piston to slide through a first gasket located between the spring and the wall of the narrowing and through a second gasket located between the wall of the narrowing and a projection of the second chamber.

BRIEF DESCRIPTION OF THE FIGURES

To complement the following description and for the purpose of helping to better understand the features of the invention, a set of drawings is attached to the present specification on the basis of which the innovations and advantages of the device of the invention will be more readily understood.

Figure 1 represents a general cross sectional view of the nozzle of the invention in low pressure or foam position.
Figure 2 represents a general cross sectional view of the nozzle in high pressure position.
Figure 3 represents an example of a hydraulic circuit to attach the inlet channel to the lance.

A list of the references used in the figures is provided below:

1. Nozzle.
2. Outer casing.
3. Inner capsule.
4. Fluid inlet opening.
5. Fluid outlet opening.
6. Channel.
7. Piston.
8. Recess.
9. Interior surface.
10. Piston head.
11. Transverse hole.
12. First chamber.
13. Second chamber.
14. Internal opening.
15. Transverse opening.
16. First gasket.
17. Second gasket.
18. Spring.
19. Pressure group.
20. High pressure pump.
21. High pressure valve.
22. Bypass valve.
23. Dosing pump.
24. Check valve.
25. Low pressure valve.
26. Venturi.
27. Compressor.
28. Static mixer.
29. Hose.
30. Gun.
31. Lance.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Both Figure 1 and Figure 2 represent a front view and a longitudinal cross section of the nozzle of the invention in operating positions with fluid at low pressure and at high pressure, respectively.
The nozzle (1) of the invention is configured by means of an outer casing (2) that incorporates a fluid inlet opening (4) and a fluid outlet opening (5). Internally, it comprises a recessed inner capsule (3) open at the ends. It is attached to the outer casing (2) at the end wherein the fluid inlet opening (4) is located to extend coaxially towards the end wherein the fluid outlet opening (5) is located, wherein it incorporates an internal opening (14) for the outlet of fluid from the internal capsule (3). Furthermore, the inner capsule (3) configures a first chamber (12), located in the area closest to the fluid inlet opening (4) and a second chamber (13), located at the other end. The end of the first chamber (12) is open coaxially with the fluid inlet opening (4). The end of the second chamber (13) incorporates an internal opening (14) located coaxially with the fluid outlet opening (5).
The separation gap between the outer casing (2) and the inner capsule (3) configures a channel (6) for the circulation of the fluid in low pressure or foam conditions, as will be described later.
The attachment of the two chambers (12, 13) has a wall with a narrowing in which a transverse hole (11) is located that passes through the inner capsule (3), communicating the two chambers (12, 13) with the channel (6).
A piston (7) open at one end is supported on the end of the outer casing (2) that incorporates the fluid inlet opening (4) at the open end. The piston (7) passes tightly through the narrowing, leaving the closed end, or head (10) of the piston (7), located in the second chamber (13). The piston (7) also incorporates a transverse opening (15) so that, when it is supported on the outer casing (2), it is in correspondence with the transverse hole (11) of the inner capsule (3) leaving the recess (8) of the piston (7) connected to the channel (6).
The first chamber (12) further incorporates a spring (18) that clasps the piston (7). One end of the spring (18) is supported on the wall of the first chamber (12) wherein the narrowing is by means of a first gasket (16) while the other end of the spring (18) is supported on a widening that has the piston (7) at the open end by means of which it is supported on the outer casing (2). The spring (18) causes the piston (7), in a standby state, to be pressed against the outer casing (2).
The first gasket (16) clasps the piston (7) tightly to provide watertightness of the first chamber (12) with the narrowing. In the same way, a second gasket (17), of the rod seal type, clasps the end of the head (10) of the piston (7) tightly to provide watertightness between the narrowing and the second chamber (13).
Once the configuration of the nozzle (1) has been described, the functionality is described below.
The nozzle (1) is located at the free end of a lance (31) attached to a pressure gun (30) for washing vehicles.
As fluid enters the nozzle (1) through the inlet opening (4), it accesses the recess (8) of the piston (7). For the piston (7) to move, the force exerted by the fluid on the inner surface (9) of the head (10) of the piston (7) has to exceed the force of the spring (18).
The spring (18) has enough force to maintain the position thereof when the fluid enters at low pressure, between 1 and 6 bars. This is the situation represented in Figure 1. In this case, the fluid enters inside the nozzle (1) through the fluid inlet opening (4) to enter the recess (8) of the piston (7), exits through the transverse hole (11) and through the transverse opening (15) to enter the channel (6) and exit the nozzle (1) through the fluid outlet opening (5).
In situations in which the fluid enters the nozzle (1) at high pressure, between 100 and 120 bars, the spring (18) does not have enough force to counteract the pressure exerted by the fluid on the inner surface (9) of the piston (7), so that the piston (7) moves to a second position. This situation is represented in Figure 2.
The movement of the piston (7) causes the transverse hole (11) of the piston (7) to cease to be in correspondence with the transverse opening (15) of the inner capsule (3), blocking the access of the fluid to the channel (6). The transverse opening (15) of the piston (7) is positioned in the second chamber (13), enabling the fluid to access it to exit through the internal opening (14) and be directed towards the fluid outlet opening (5), with which it is aligned, to exit the nozzle (1).
Next, a preferred embodiment of the circuit upstream of the washing lance (31) that enables the nozzle (1) of the invention to be reached through the hose (18) of a washing gun (30) with a single channel is described, taking into account that in this embodiment only one type of water and one type of chemical product are described. The extension to different inlets of these fluids is a generalisation of the system that is described.
In the case of the high pressure program, to drive the liquid to the nozzle (1), there is a pressure group (19) at the inlet of the circuit, which drives the liquid towards a high pressure pump (20) through a high pressure valve (21) that opens and closes the circuit. This high pressure pump (20) makes it possible to reach the necessary pressure, between 100 and 120 bars, and can be adjusted through a bypass valve (22). A chemical product can be introduced between the pressure group (19) and the high pressure pump (20), through a dosing pump (23), blocking the circulation of the liquid in the opposite direction by means of a check valve (24).
In the case of the low pressure or foam program, the same pressure group (19) is used to drive the liquid to the nozzle (1) and, as the high pressure valve (21) does not open, a low pressure valve (26) acts, opening or closing the circuit through a second branch. The chemical product that enables the foam to be manufactured is introduced into said circuit through another dosing pump (23) connected to the corresponding check valve (24), which prevents the channelling of the liquid in the opposite direction. At this point, the initial fluid is mixed with the chemical product that passes through a Venturi (26) wherein a gas is introduced at a pressure lower than that of the fluid, through a compressor (27) that also incorporates a check valve (23) that enables the gas to flow only in the direction of the hydraulic circuit. This mixture of gas, water and chemical product is homogenised in a static mixer (28), producing a dense foam.
Before reaching the attachment point between the high pressure circuit and the foam circuit, there are respective check valves (23) that prevent the fluid from entering the opposite circuit, enabling the passage of fluid towards the hose (29) that connects with the nozzle (1) through the gun (30).
Lastly, it must be taken into account that the present invention must not be limited by the embodiment described herein. Other configurations may be carried out by those skilled in the art based on the present description. Accordingly, the scope of the invention is defined by the following claims.

Claims

An automatic switching nozzle to be connected in a vehicle washing system which comprises a hydraulic circuit in which a hose (29) is located for the connection of a washing gun (30) with a lance in which the nozzle (1) is connected, the nozzle (1) being characterised in that it comprises an outer casing (1) with a fluid inlet opening (4) and a fluid outlet opening (5) in which it is located coaxially, leaving a separation that configures a channel (6), an inner capsule (3) open at the ends and configured by means of a first chamber (12) and a second chamber (13) separated by a wall with a narrowing that houses a transverse opening (15) and through which a piston (7) slides which comprises a head (10), a longitudinal recess (8), a transverse hole and a widening at the open base, wherein:
- the head (10) of the piston (7) is located in the second chamber (13) while the open base of the piston (7) is located in the first chamber (12) wherein there is also a spring (18) clasping the piston (7) to force it to be in contact with the end of the outer casing (2),

- the transverse hole (11) of the piston (7) is aligned with the transverse opening of the inner capsule (3),
so that, when the liquid enters through the fluid inlet opening (4), it enters the recess (8) of the piston (7), exerting a force on the inner surface (9) of the piston (7) such that,
- if the liquid enters at low pressure, the force exerted on the piston (7) does not exceed that of the spring (18), and the liquid circulates through the transverse hole (11) to be directed through the channel (6) towards the fluid outlet opening (5), through which it leaves the nozzle (1);

- if the liquid enters at high pressure, the force exerted on the piston (7) exceeds that of the spring (18), moving the piston (7) to cause the misalignment of the transverse hole (11) with the transverse opening (15) and unblocking the access of the fluid to the second chamber (13) to exit through an internal opening (14) towards the fluid outlet opening (5), through which it leaves the nozzle (1).
The automatic switching nozzle according to claim 1, characterised in that the spring (18) is located between a widening of the piston (7) at the open end and the wall of the narrowing of the inner capsule (3).
The automatic switching nozzle according to claim 1, characterised in that the piston (7) slides through a first gasket (16) located between the spring (18) and the wall of the narrowing and a second gasket (17) located between the wall of the narrowing and a projection of the second chamber (13), so that watertightness is created between the first chamber (12) and the second chamber (13).
The automatic switching nozzle according to claim 1, characterised in that the force of the spring (18) defines the working limit of the nozzle (1) between low pressure and high pressure.