ES3031572A1 - PNEUMATIC VALVE FOR CONTROLLING AIR FLOW - Google Patents

Abstract

Pneumatic valve for controlling an air flow. The invention relates to a pneumatic valve for controlling an air flow, configured by means of a body (8) comprising inside an inlet chamber (7) with an inlet orifice (2) that communicates with the outside, an outlet chamber (6) with an outlet orifice (3) that communicates with the outside, a bellows (5) housed inside the outlet chamber (6), where the inlet chamber (7) and the outlet chamber (6) are communicated by means of an internal orifice (4), the bellows (5) has extension and compression capacity and is configured to close and open, in these movements respectively, the internal orifice (4), the essential characteristic of the valve being the fact that it is formed in a single monobloc piece, and manufactured in an elastic material. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

PNEUMATIC VALVE FOR CONTROLLING AIR FLOW

OBJECT OF THE INVENTION

The object of the present invention is a pneumatic valve intended to control the flow of air circulating through a pneumatic system circuit. It is characterized by being made of an elastic material and in a single, monobloc piece.

The object of the present invention is also a pneumatic system incorporating the pneumatic valve and the manufacturing method of the pneumatic valve.

The invention belongs to the field of mechanical engineering, and can be used particularly in a circuit of any pneumatic system that requires flow control, a pneumatic safety valve or a quick exhaust valve.

BACKGROUND OF THE INVENTION

Air flow control valves are well known in the state of the art. However, these valves are made of materials that, while mobile, are also rigid. Typically, aluminum and steel are used for their manufacture, which makes them dependent on the proper functioning of the moving elements. Furthermore, since they incorporate moving parts, the manufacturing cost is high, while their useful life is short, as it depends on the life cycle of the moving elements that comprise them.

US5133380A discloses a pneumatic control valve including a valve body with a fixed aperture plate, a movable redirector, and a force motor. The force motor supports the redirector adjacent to the aperture surface of the fixed aperture plate and is operable to move the redirector back and forth along a line without contacting the aperture surface. The aperture surface has a plurality of apertures with metering edges. The redirector has redirector cavities with metering edges. The force motor biases the redirector to positions where one or more of the cavities in the redirector connect two or more of the apertures and direct fluid out of some apertures and into other apertures. The location, length, and shape of the metering edges can be varied as needed to obtain desired fluid flow characteristics.

US4744391A discloses a flow control valve for variably controlling the flow of a fluid therethrough. The invention further comprises a check valve incorporated within the flow control valve. The flow control valve, with a check valve incorporated therein, allows the valve to be used to inflate a tank or other container, such as a blood pressure monitor, to a pressurized state, with the check valve thereof functioning to maintain pressure within the tank during and after pressurization. The pressurized container may then be depressurized by purging fluid therefrom by variably opening the flow control valve from a closed position.

In the article "Desktop fabrication of monolithic soft robotic devices with embedded fluidic control circuits”, by authors Zhai, Y., De Boer, A., Yan, J., Shih, B., Faber, M., Speros, J., Gupta, R. & Tolley, M. T., published by Science Robotics on June 21, 2023, a series of all-or-nothing valves are used for flow control. These valves use flexible materials and do not require control elements.

However, this valve has certain limitations, as it operates on an all-or-nothing basis and would not be suitable for controlling air flow.

DESCRIPTION OF THE INVENTION

The present invention relates to a pneumatic valve intended to control the flow of air circulating through a pneumatic circuit of a given system.

The pneumatic valve is configured by a longitudinally arranged body comprising an inlet chamber with an inlet opening, an outlet chamber with an outlet opening, and a bellows housed inside the outlet chamber. The two openings connect the respective chamber to the outside. Furthermore, the inlet and outlet chambers are connected by an internal opening.

The bellows, for its part, has the capacity to extend and compress and is configured so that, in these movements, it closes and opens, respectively, the internal orifice, blocking and unlocking it with one of the ends.

However, the main purpose of the invention is that the valve is made of an elastic material and is comprised of a single, monobloc part, eliminating the need for internal mechanical elements, as is the case with conventional air flow valves. This eliminates the need for different parts in contact with each other and causing relative movement. This reduces potential malfunctions, extends the valve's useful life, greatly simplifies the manufacturing process, and significantly reduces costs.

This elastic material can be a thermoplastic elastomer or a silicone, preferably with low resistance.

The bellows can be presented in two configurations.

On the one hand, the bellows can be airtight and filled with an incompressible fluid.

On the other hand, the bellows may include a control orifice that connects it to the exterior of the pneumatic valve. This control orifice is intended for connecting an external device intended to provide constant pressure in the bellows. Furthermore, the pressure in the external device can be selected as needed.

The invention also relates to a circuit of a pneumatic system comprising the valve described above.

Furthermore, the invention also relates to the manufacturing process of the described pneumatic valve.

The pneumatic valve is manufactured in both versions using additive technology with flexible filament or by molding. This makes the valve simple and rapid to manufacture, reducing costs, since the pneumatic valve is manufactured in one piece, without the need to add additional mechanical elements or perform finishing operations.

DESCRIPTION OF THE DRAWINGS

To complement the description being made and in order to help better understand the characteristics of the invention, in accordance with a preferred example of practical implementation thereof, a set of drawings is attached as an integral part of said description, in which the following has been represented for illustrative and non-limiting purposes:

Figure 1.- Shows a perspective view of the compact monoblock pneumatic flow control valve in a first embodiment.

Figure 2.- Shows a sectional view of the pneumatic valve in Figure 1.

Figure 3.- Shows a perspective view of the compact monoblock flow control valve in a second embodiment, with an air flow control orifice.

Figure 4.- Shows a sectional view of the pneumatic valve in figure 3.

PREFERRED EMBODIMENT OF THE INVENTION

Figures 1 and 2 represent a first embodiment of the pneumatic valve of the invention.

The valve comprises a body (8), of elongated configuration, in which the following are located:

- an inlet chamber (7) incorporating an inlet orifice (2) intended to be coupled, by means of a pneumatic connection, to a pneumatic circuit through which a flow of air to be controlled flows,

- an outlet chamber (6) incorporating an outlet orifice (3) intended to be coupled, by means of a pneumatic connection, to the pneumatic circuit through which the already controlled air flow flows,

- an internal flow control orifice (4), which connects the inlet chamber (7) with the outlet chamber (6),

- a flow control bellows (5) housed in the outlet chamber (6), fixed to it at one end and the other end being configured to block or release the internal flow control orifice (4) by means of the expansion or contraction movement of the bellows (5). The bellows (5) is filled with an incompressible fluid which causes it to be subjected to a constant pressure.

As can be seen in these figures, the valve of the invention has an operating position, such that it is the weight of the bellows (5) itself that makes it fall to block the internal orifice (4).

In this way, the pneumatic air flow control valve comprises a single body (8), with a longitudinal configuration, of which two parts located inside can be differentiated.

Firstly, there is the air receiving part, located at one end of the body (8) and formed by an inlet chamber (7) comprising an inlet orifice (2) that communicates with the outside of the valve to receive the air from a pneumatic circuit through which a flow of air that is to be regulated circulates.

Secondly, there is the air evacuation part, located at the opposite end of the body (8) and formed by an outlet chamber (6) comprising a flow control bellows (5) housed inside and an outlet hole (3) located on a side face of the body (8) that communicates with the outside of the valve to return the air to the pneumatic circuit with the flow already regulated.

The inlet chamber (7) and the outlet chamber (6) are connected by an internal flow control orifice (4) such that the air flow to be controlled is located in the inlet chamber (7) and the already regulated air flow is located in the outlet chamber (6).

In this first embodiment, the air flow to be controlled circulates through the pneumatic circuit, as indicated above, and is connected to the inlet orifice (2) by means of a pneumatic connection. This air flow will fill the inlet chamber (7) and, as it passes through the internal orifice (4), will exert pressure on the bellows (5).

In this first embodiment, the bellows (5) forms a hermetic chamber and contains an incompressible fluid, so the pneumatic valve has a passive behavior.

In this way, if the pressure in the inlet chamber (7) is higher than the pressure exerted by the bellows (5), the bellows (5) will move upwards, releasing the passage of air towards the outlet chamber (6) through the internal orifice (4) and will exit through the outlet orifice (3). If the pressure in the inlet chamber (7) is lower than the pressure exerted by the flow control bellows (5), the latter will hermetically seal the internal orifice (4), and the air will accumulate in the inlet pressure chamber (7).

Thus, the passage of air through the internal orifice (4) is regulated by the flow control bellows (5). This bellows (5) is housed in the outlet chamber (6) with the capacity to extend longitudinally. To perform this function, the elastic material with which the bellows (5) is formed is essential, so that, due to the pressures to which it is subjected, it can both expand to close the internal orifice (4) and contract to open the passage of air through the internal orifice (4).

Figures 3 and 4 represent a second embodiment of the pneumatic air valve of the invention.

In this embodiment, the valve, in addition to the aforementioned elements, also comprises:

- an air flow control orifice (1), which connects the flow control bellows (5) to the outside, intended to be coupled, by means of a pneumatic connection, with an external device that allows varying the pressure limit of the flow control bellows (5).

In this second embodiment, the air flow to be controlled, which circulates through the pneumatic system, is connected to the inlet orifice (2) by means of a pneumatic connection. This air flow fills the inlet chamber (7) and, as it passes through the internal orifice (4), exerts pressure on the bellows (5), which contains air at a pressure that is supplied through the control orifice (1) from an external device that incorporates air at a predetermined pressure and which can be adjusted according to needs. In this way, it is ensured that the pressure inside the flow control bellows (5) is always a predetermined one and the air flow between the inlet orifice (2) and the outlet orifice (3) is controlled according to the pressure in the outlet chamber (6).

In the event that the pressure in the inlet chamber (7) is greater than the pressure exerted by the bellows (5), the bellows (5) will separate from the internal orifice (4), releasing the air from the inlet chamber (7) to the outlet chamber (6) through the internal orifice (4) and will exit through the outlet orifice (3).

In the event that the pressure in the inlet chamber (7) is lower than the pressure exerted by the bellows (5), the bellows (5) will hermetically block the internal orifice (4), and air will accumulate in the inlet pressure chamber (7).

In this embodiment, unlike the previous one, the valve of the invention can be located in any position, and not only vertically, since the pressure of the bellows (5) to block the internal orifice (4) is not caused by the weight, but by the external device.

Neither the pneumatic system containing the air flow to be regulated nor the external device have been represented in the figures.

As indicated, the characteristics of the material are of utmost importance in the invention, since it must provide the elasticity necessary to fulfill its function of blocking the internal orifice (4).

Thus, prototypes of the pneumatic valve of the invention have been made in which a thermoplastic polyurethane (TPU) has been used, and more specifically with Filaflex 82A filament, where some of its mechanical properties are the following:

- Young's modulus: 22 MPa (according to ISO 527)

- Tensile strength: 45 MPa (according to DIN 53504-S2)

- Elongation at break: 650% (according to DIN 53504-S2)

- Breaking strength: 70 N/mm (according to ISO 34-1)

However, there are a multitude of materials from the thermoplastic elastomer (TPE) family and even silicones, preferably with low hardness, that can be used, such as the commercial materials Filaflex 60, Fiflaflex 70 and AR-G1L. All of them have the quality of being materials adapted to be used in additive manufacturing, with an elongation range at break of between 100% and 1000%, according to DIN 53504-S2, with a hardness equal to or less than Shore 82A, according to DIN ISO 7619-1 (3s). Regarding breaking strength, it would be in a range between 40 N/mm and 70 N/mm, according to ISO 34-1.

Claims (6)

1. - Pneumatic valve for controlling an air flow, configured by means of a body (8) that comprises inside: - an inlet chamber (7) with an inlet orifice (2) communicating with the outside, - an outlet chamber (6) with an outlet orifice (3) communicating with the outside, - a bellows (5) housed inside the outlet chamber (6), where: - the inlet chamber (7) and the outlet chamber (6) are connected by an internal orifice (4), - the bellows (5) has the capacity to extend and compress and is configured to close and open, in these movements respectively, the internal hole (4), the pneumatic valve being characterized by: - is made from a single, monobloc piece, and - is made of an elastic material. 2. The pneumatic valve of claim 1, wherein the bellows (5) is airtight and filled with an incompressible fluid. 3. The pneumatic valve of claim 1, comprising a control hole (1) connecting the bellows (5) with the exterior. 4. The pneumatic valve of claim 1, which is made of a material selected from a thermoplastic elastomer and a silicone. 5. Pneumatic system characterized in that it comprises the valve of any of the preceding claims. 6. Manufacturing method of the pneumatic valve of claim 1, characterized in that it is carried out by means of a form to be selected between molding and by means of additive technology with flexible filament.