A GAS VALVE WITH CERAMIC DISC ELEMENT

Abstract

The invention relates to a gas valve unit, comprising a body having an inlet channel and an outlet channel in gas flow connection via an inner chamber surrounded by body a stationary disc element fixed in the inner chamber and having a through hole thereon that opens into the gas outlet channel ; a rotating disc element with an inner wall rotatably overlapping a front wall of the stationary disc element and a cavity that access to the outlet channelthrough the through holewhen rotated. The front wall and the inner wall of the stationary disc elementand the rotating disc element facing each other, respectively, are at least partially made of ceramic material.

Description

TECHNICAL FIELD

The invention relates to adjustable gas regulating valves for controlling the gas flow rate via control elements having the structure of the rotatable disc.

BACKGROUND OF THE INVENTION

The gas regulating valve units are ready-to-install units in household or outdoor appliances are provided between a burner and a gas supply. Gas valve units generally operate by rotating a control rod attached to the body by means of a rotary knob. Angular position of the knob determines the gas flow rate that the gas regulating valve limits.

WO2018216044A gas valve unit comprising a body provided with an inlet, fluidically connectable to a gas source and to at least one outlet, a main chamber, defined at least in part in said body, put into fluid communication with said gas inlet and provided with main outlet hole put into fluid communication with said outlet, a disc-shaped element which is housed in said main chamber, is provided with at least one through opening defining at least two zones, having a mutually different passage section in order to put said main chamber into communication with said main outlet hole.

SUMMARY OF THE INVENTION

The object of the invention is to increase the lifetime of disc type gas valves.

In order to achieve abovementioned objects, the invention comprises a gas valve unit, including a body having an inlet channel and an outlet channel in connection with an inner chamber that it surrounds so as to provide gas flow; a stationary disc element fixed in the inner chamber and having a through hole thereon that opens into the gas outlet channel; a rotating disc element with an inner wall rotatably overlapping a front wall of the stationary disc element and a transfer opening that rotates to reach the outlet channel through the through hole when rotated. Also, in the gas valve unit, the front wall and the inner wall of the stationary disc element and the rotating disc element facing each other, respectively, are at least partially made of ceramic material. Thereby, during the rotation of the rotating disc element on the stationary disc, the friction forces are reduced and the lifetime of the product is increased. The expression “partly made of ceramic material” should be interpreted as the use of a ceramic material coating, insert or completely ceramic material in the contacting parts of the front wall and inner wall.

In a preferred embodiment of the invention, the stationary disc element and the rotating disc element are made of solid ceramic material. In this case, it is possible to manufacture and use the stationary disc element or the rotating stationary disc in one piece by powder metallurgy or similar method. Further, the torque required to rotate the gas valve unit does not change even in case of wear caused by the movement of the fixed and rotating disc elements on each other in solid material. This allows the user to adjust the gas regulation without difficulty even after long periods of use.

A preferred embodiment of the invention comprises a rear wall parallel to the front wall and the stationary disc element is coupled from a peripheral wall between the front wall and the rear wall to an inner wall forming the inner periphery of the inner chamber. Thus, the impact forces in the direction of rotation applied to the stationary disc element via the rotating disc element form a reaction force by peripherally abutting on the inner periphery of the inner chamber.

A preferred embodiment of the invention includes a flexible gasket that is compressed towards the gas outlet channel in a gas-tight way surrounding the passage hole on the planar rear wall. The flexible gasket can be compressed such that it will provide sealing against a predetermined gas pressure by a pre-stress, together with the stationary disc element being mounted.

A preferred embodiment of the invention includes an oil film which is provided between the front wall and the inner wall, surrounding the through hole and the transfer opening in a gastight way and adjusted to a predetermined viscosity so as to allow rotation on one another. The oil film extends between the stationary disc element and the movable disc element, filling the gaps that may occur due to tolerance differences during production and ensuring gas tightness. It also reduces friction, allowing the rotating disc element to be rotated with less torque than directly contacting the stationary disc element.

A preferred embodiment of the invention includes a plurality of pockets provided on the inner wall that store the oil droplet by feeding the oil film during the rotation of the rotating disc element. The pockets ensure that the film remains at a critical sealing thickness such that it prevents the oil film from losing its function over time with the rotational movement.

A preferred embodiment of the invention includes a control rod extending vertically outward by being attached to an outer wall of the rotating disc element. The control rod allows the rotating disc element to be rotated directly with the torque applied by the operator. Preferably, the control rod and the rotating disc element are concentric. Thus, it is possible, for example, to rotate the control rod with a control knob.

A preferred embodiment of the invention includes a cover that surrounds the control rod from one end and is fixed to the body from the other end. The cover prevents the materials such as dust and dirt that will affect the rotation from the outside environment from entering between the rotating disc element and the stationary disc element without impeding the rotational movement.

A preferred embodiment of the invention includes a compression spring adjusted inside the cover such that it abuts against the inside of the cover from one end and presses the rotating disc element from the other end. The compression spring ensures that the flexible gasket is compressed by the stationary disc element against the corresponding inner wall in the inner chamber, enabling a sealed flow in the body despite the gas pressure.

In a preferred embodiment of the invention, the stationary disc element and the rotating disc element are manufactured or coated from a material selected from the group consisting of alumina, silicon carbide, silicon nitride and zirconia. It has been determined that the selected group of materials provides a safe application against the passage of flammable gas therethrough. Also, surprisingly, it has been observed that said group wears less in the case of rotational movement compared to other ceramic materials.

In order to achieve the abovementioned objects, the invention is a gas cooker or heating device to which a gas valve unit is adapted according to any of the embodiments described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear perspective view of a representative embodiment of the gas regulating valve unit of the invention, with the inner chamber visible.

FIG. 2 is a perspective view from the rear wall of the stationary disc element in a representative embodiment of the ceramic gas regulating valve unit.

FIG. 3 is a perspective view from the inner wall of a rotating disc element suitable for use with the stationary disc element shown in FIG. 2.

FIG. 4 is a side view of a representative embodiment of the gas regulating valve unit of the invention.

FIG. 5 is the H-H cross-sectional illustration of the gas regulating valve given in FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the development of the invention has been described without any limitation and only with reference to the examples for a better explanation of the subject.

In FIG. 1, there is shown a representative embodiment of the gas valve unit of the invention with a safety outlet (17) in a partial cross-section so that an inner chamber (1) can be visible. The gas valve unit has a structure in which a flammable gas (e.g. natural gas) is transferred from an inner chamber (1) sealed by a metal body (10) to form a gas flow with an adjustable flow rate. The body (10) has segmented structure and the parts are sealed tightly to each other with gasket connections. An upper part (22) of the two-piece control rod (20) attached to the body (10) from the front, extends from its free end to the inner chamber (1) so that it rotates around its own axis by being connected to a control knob (not shown). A lower part (24) of the control rod (20) in the form of a pusher arm, which is movably connected with the upper part (22) of the control rod, extends to a safety assembly (60) located at the end of the inner chamber (1).

A stationary disc element (30) is fixed against axial and rotational movements in the inner chamber (1) by passing the inner chamber (1) perpendicular to the control rod (20) in transverse sections. The stationary disc element (30) is made of ceramic material and has a horizontal, flat form. From a segmented curved circumferential wall (33) of the inner chamber (30), it fits into a retainer boundary (18) having corresponding concave recesses surrounding the inner chamber (1) and defining the inner boundary of the inner chamber (1) from behind. A front wall (35) parallel to and opposite to a rear wall (31) of the stationary disc element (30) and a rotating disc element (40) from one inner wall (41) are overlapped in the inner chamber (1). An outer wall (43) of the rotating disc element (40) extends outward in a truncated conical structure such that it valveers. A rubber flexible sealing gasket (50) is placed on the rear Wall (31) of the stationary disc element (30). The gasket (50) completely surrounds the auxiliary hole (36), which is longitudinally drilled, by means of a through hole (34) of the stationary disc element (30), respectively, and a through hole (32) at an angular distance aligned around thereof. Thereby, the stationary disc element (30) abuts the gasket (50) against the flat rear wall (31) of the body (10) forming the forehead part of the inner chamber (1). Thus, the through hole (32) reaches a gas outlet (14) in a sealed way by means of the gasket (50).

The body (10) has an inlet (12) for gas supply and a gas outlet (14) associated therewith to selectively transmit fluid. The inlet (12) and the gas outlet (14) are circular and form a passage path for gas flow from the inner chamber (1) with the connection of the cylindrical inlet channel (15) and the outlet channel (16), respectively. In addition, a safety outlet (17) parallel to the gas outlet (14) is connected to the inner chamber (1) on the body (10) so as to provide gas transmission.

In FIG. 2, the one-piece ceramic stationary disc element (30) is shown in perspective from its rear wall (31). The stationary disc element (30) in the form of a flat plate with a circumferential wall (33) formed by dividing the surroundings thereof with adjacent handle parts (331), has a channel (37) opened on its flat rear wall (31). The rubber gasket (50) corresponding to the channel (37) fits tightly. The depth of the channel (37) is adjusted below the height of the flexible gasket (50) in free state so that it will allow the flexible gasket (50) to partially protrude from the rear wall (31). A circular central hole (34) is cut in the center of the stationary disc element (30). Adjacent to this, there is a block (38) surrounded by the channel (37). The block (38) is in the form of a circular projection. The through hole (32) adjacent to the central hole (34) in the opposite direction to the block (38) is in an elongated form in the radial direction. An auxiliary through hole (36) is provided on the stationary disc element (30) as being adjacent to the through hole (32) adjacent to the central hole (34). The auxiliary through hole (36) is circular and has a small area than the through hole (32). The central hole (34), the through hole (32) and the auxiliary through hole (36) are extended from the channel (37) to the rear wall (31) with a flue part extending along the depth of the channel (37).

In FIG. 3, the one-piece ceramic rotating disc element (40) is shown in perspective from the inner wall 41 of the inner chamber (1), which fits on the corresponding forehead. The rotating disc element (40) is in the form of a truncated cone and its wide circular part forms the planar inner wall (41) thereof. In the center of the inner wall (41) there is a mounting hole (44) that is drilled from one end to the other. The mounting hole (44) has an expansion chamber (45) which is gradually and radially enlarged towards the inner wall (41). A side portion of the expansion chamber (45) includes a spirally extending cavity (42) in the inner wall (41) at radial distance to the mounting hole (44). The cavity (42) runs radially in the inner wall (41) with increasing width and depth, starting from a rounded rear end (421) forming a narrow portion (422) and extends continuously from a front end (424) through a wide part (423) that joins the expansion chamber (45) to the mounting hole (44) so as to provide gas transmission. At the junction of the expansion chamber (45) and the front end (424), the expansion chamber (45) leads through a passageway to a baffle wall (425), which is the outer part of the front end (424). The cavity (42) is provided adjacent and at a distance with a circular circumferential edge (46) of the inner wall (41). An L-like auxiliary channel extends from one end of the front end (424) to the expansion chamber (45) at a wide angle. Multiple pockets (47) are opened in the inner Wall (41) that form a lubricating channel in a multiple hemispherical structure distributed in planar sections. The pockets (47) are distributed on the inner wall 41 along the radial line delimited by the cavity (42). The pockets (47) are obtained by forming the planar inner wall (41) such that the ceramic material forms a cavity in its structure.

The rotating disc element (40) is placed concentrically on the stationary disc element (30). Both are made of alumina. The inner wall (41) of the rotating disc element (40) overlaps the front wall (35) of the stationary disc element (30). In the closed position, the cavity (42) is blocked by a flat portion of the front wall (35). On the other hand, the mounting hole (44) is coaxial with the central hole (34) and is opened to allow gas passage to each other. The spiral-shaped cavity (42) is spaced radially at an accessible 90° angle, with its front end (424) facing the through hole (32). The cavity (42) extends radially outward from the expansion chamber (45) to reach the baffle wall (425) and wherein it decreases in both cross section and depth from the wide portion (423) to the opposite rear end (421) where the narrow portion 422 is located. Since the control rod (20) extends axially through a cylindrical passage channel formed by the mounting hole (44) and the central hole (34), the gas flow supplied from the inlet (12) from the distance between the control rod (20) and the transition channel is first taken to the expansion chamber (45), then it hits the baffle wall (425) and proceeds from the front end (424) to the wide part (423), and from there through the cavity (42), which narrows both in width and depth, to the rear end (421). In the closed position, the cavity (42) completely covers the planar portion of the front wall (35) of the stationary disc element (30) in a sealed manner. In the maximum gas position in which the gas is directed to the gas outlet (14) at maximum flow rate, the wide part (423) is aligned with the passage hole (32) completely. In this case, a front edge (426) of the cavity (42) aligns with the through hole (32) and the entire area of the through hole (32) lies within the cavity (42). Thus, the stationary disc element (30) transmits the gas flow to the gas outlet (14) through the through hole (32).

In FIG. 4, the gas regulating valve unit is shown from the left. Here, the upper part (22) of the control rod (20) extending outward is visible on the body (10). The upper part (22) is mounted to the body (10) under a cover (26) rotating around its axis. The cover (26) is a hollow conical piece. At least two tabs (not shown) extend on the wide mouth of the cover (26) facing the body (10), wherein pressure is exerted on the stationary disc element (30) by the forms opened on the body (10) through the face corresponding to the body (10) from the mentioned tabs. Thus, sealing is provided by mechanical compression to the gasket (50) positioned on the stationary disc element (30).

In FIG. 5, H-H section is shown on a vertical axis passing through the inlet part (12). The retainer boundary (18) in which the stationary disc element (30) is placed from the circumferential wall (33) in the inner chamber (1) has recesses suitable for the handle parts (331). The stationary disc element (30) is placed on the retainer boundary (18) and fixed in the body (10) so as to divide the inner chamber (1). The gas flow (shown by arrows) supplied from the inlet part (12) proceeds through an inlet channel (15) in the body (10) and reaches the inner chamber (1).

By pushing the control rod (20) from the upper part (22) to which the button is attached, the gas flow is started by pushing the tab of the safety assembly (60) through the lower part (24). A compression spring (28) wound on the front end of the lower part (24) pushes the upper part (22) towards its original position. Meanwhile, the gas from the inlet channel (15) accumulated in the inner chamber (1) first reaches the rear wall (31), then stopped over the stationary disc element (30) and passes through the central hole (34) and reaches the mounting hole (44) of the rotating disc element (40). The gas flow proceeding to the cavity (42) therefrom through the expansion chamber (45), reaches the stationary disc element (30) again, this time from its front wall (35) adjacent to the cavity (42) and is directed through the wide part (423) of the cavity (42) to the through hole (32) located above thereof. The gas flow, which is delivered therefrom to an orifice reaching an outlet channel (16) from which the gas is discharged, reaches the gas outlet (14).

For regulating the gas flow, the control rod (20) is rotated in its reach axis. The control rod (20) is connected from its upper part (22) to an adapter socket (48) located at the front end (424) of the rotating disc element (40). Thereby, when the control rod (20) is rotated, the rotating disc element (40) rotates. The wide part (423) of the cavity (42) that reaches the through hole (32) by turning the rotating disc element (40) 90° from the closed position, is blocked by the planar part of the front wall (35) while rotating is continuing, and the through hole (32) is aligned with the narrowing section of the cavity (42). In the last step, the narrow part (422) is aligned with the auxiliary through hole (36). The auxiliary through hole (36) has a narrower area than the through hole (32) and is aligned with the narrow portion (422) of the spiral cavity (42) to ensure the minimum gas flow rate.

In the inner chamber (1), first the stationary disc element (30) and then the rotating disc element (40) are fully abutted from the inner wall (41) to the front wall (35) with an oil film (70) therebetween. Oil film (70) is a standard mineral oil used for sealing moving parts in gas valve units. The thickness and viscosity of the oil film (70) were chosen to allow an operator to easily rotate the rotating disc element (40). The stationary disc element (30) provides temporary blocking of the gas flow by partitioning the inner chamber (1) between the channel forming the rear part of the inner chamber (1) in the body (10) from its rear wall (31) and surrounding the control rod (20) from the lower part (24) and the rotating disc element (40) in the opposite direction. Each pocket (47) formed on the inner wall (41) of the rotating disc element (40) such that it faces the front wall (35) of the stationary disc element (30) has a hemispherical structure and has a diameter of 0.5 to 3 mm. By means of this size and form, when the rotating disc element (40) rotates, oil film (70) is fed from the pockets (47) so as to maintain a predetermined critical thickness of 2-10 microns in the radial direction.

REFERANCE NUMBERS
1	Inner chamber	40	Rotating disc element
10	Body	41	Inner wall
12	Inlet part	42	Cavity
14	Gas outlet	421	Rear end
15	Inlet channel	422	Narrow part
16	Outlet channel	423	Wide part
17	Safety outlet	424	Front end
18	Retainer boundary	425	Baffle wall
20	Control rod	426	Front edge
22	Upper part	43	Outer wall
24	Lower part	44	Mounting hole
26	Cover	45	Expansion chamber
28	Compression spring	46	Circumferential edge
30	Stationary discelement	47	Pocket
31	Rear Wall	48	Adaptor socket
32	Through hole	50	Gasket
33	Circumferential Wall	60	Safety assembly
331	Handle part	70	Oil film
34	Central hole
35	Front wall
36	Auxiliary through hole
37	Channel
38	Block

Claims

1. A gas valve comprising a body having an inlet channel and an outlet channel in gas flow connection via an inner chamber surrounded by body ; a stationary disc element fixed in the inner chamber and having a through hole thereon having access to the gas outlet channel ; a rotating disc element with an inner wall overlapping a front wall of the stationary disc element in a rotatable manner and a cavity that reach the outlet channel through the through hole when rotated characterized in that the front wall and the inner wall of the stationary disc element and the rotating disc element facing each other, respectively, are at least partially made of ceramic material.

2. The gas valve according to claim 1, wherein the stationary disc element and the rotating disc element are made of solid ceramic material.

3. The gas valve unit according to claim 1, wherein a rear wall is provided parallel to the front wall and the stationary disc elementis coupled by a peripheral wall between the front wall and the rear wall through a retainer wall forming the inner wall of the inner chamber .

4. The gas valve unit according to claim 3, wherein a flexible gasket is compressed towards the gas outlet channelon the planar rear wall such that it surrounds the through hole in a gas-tight way.

5. The gas valve unit according claim 1, wherein an oil film is provided between the front wall and the inner wall ,surrounding the through hole and the cavity in a gas-tight way and adjusted to a predetermined viscosity so as to allow rotation on one another.

6. The gas valve unit according to claim 5, wherein a plurality of pockets are provided on the inner wall and store the oil droplet inside so as to feed the oil film during the rotation of the rotating disc element .

7. The gas valve unit according to claim 1, wherein a control rod extends vertically outward by being attached to an outer wall of the rotating disc element .

8. The gas valve unit according to claim 7, wherein a cover surrounds the control rodfrom its upper part at one end and is fixed to the body at the other end.

9. The gas valve unit according to claim 8, wherein a compression spring is adjusted within the cover such that it abuts against the inside of the cover from one end and presses the rotating disc element from the other end.

10. The gas valve unit according to claim 1, wherein the stationary disc element and the rotating disc element are manufactured or coated from a material selected from the group consisting of alumina, silicon carbide, silicon nitride and zirconia.

11. A gas cooker or heating device to which the gas valve unit is adapted according claim 1.