Gas flow adjusting device for gas combustion appliance and gas combustion appliance

Abstract

A gas flow regulating device (24) for a gas combustion appliance has a housing (27), a throttle valve (25) and an actuator (26). The housing (27) provides an inlet (28) for airflow and an outlet (29) for airflow. The throttle valve (25) is configured to adjust an amount of airflow from the inlet (28) to the outlet (29), where the throttle valve (25) has a static element (34) and a moving element (25), where the moving element (35) is configured to move in a linear direction relative to the static element (34), where a relative position of the moving element (35) relative to the static element (34) defines the amount of airflow from the inlet (28) to the outlet (29). The actuator (26) has a motor (36) and a threaded spindle (37), where the motor (36) is configured to rotate the threaded spindle (37), where the threaded spindle (37) is configured to move the moving element (35) in a linear direction relative to the static element (34) when the motor (36) rotates the threaded spindle (37). A moving element (35) of the throttle valve (25) is made of plastic. The moving element (35) of the throttle valve (25) and / or the actuator (26) includes at least one alignment feature (40, 41, 44, 46, 47, 51, 52, 56) configured to provide an accurate relative position of the moving element (35) with respect to the static element (34).

Description

Technical Field

[0001] The present disclosure relates to an airflow regulating device for a gas combustion appliance. Further, the present disclosure relates to a gas combustion appliance having an airflow regulating device. Background Art

[0002] EP 2667097A1 discloses a gas burner with an airflow adjustment device and a method for operating such a gas burner. During the burner opening phase of the gas burner, a defined gas / air mixture with a defined mixing ratio of gas and air is provided to the combustion chamber of the gas burner for burning the defined gas / air mixture. The defined gas / air mixture is provided by a mixing device, which mixes the airflow provided by the air duct with the airflow provided by the gas duct. The mixing device can be provided by a venturi nozzle. The airflow flowing through the air duct is provided by a fan, so that the fan speed of the fan depends on the desired burner load of the gas burner, wherein the fan speed range of the fan defines the so-called modulation range of the gas burner. Preferably, the defined mixing ratio of the gas and air of the defined gas / air mixture is kept constant over the entire modulation range of the gas burner by a pneumatic controller of a gas control valve located upstream of the airflow adjustment device in the gas duct. The gas safety valve is located upstream of the gas control valve. The pneumatic controller of the gas control valve uses the pressure difference between the gas pressure of the gas flow in the gas pipeline and a reference pressure, wherein the pressure difference between the gas pressure of the gas flow in the gas pipeline and the reference pressure is pneumatically determined and controlled. The combustion quality can be monitored based on a signal provided by a combustion quality sensor (such as a flame ionization sensor). According to EP2667097A1, during the burner start-up phase, a defined mixing ratio of gas and air of a defined gas / air mixture can be calibrated to provide a desired combustion quality. The calibration can be performed based on the signal provided by the combustion quality sensor, i.e., by adjusting the opening position of a gas flow adjustment device positioned in the gas pipeline based on the signal provided by the combustion quality sensor.

[0003] GB 2242257A discloses a gas safety valve for a gas burner. EP 1613881B1 and EP 1697667B1 both disclose a valve unit having a gas control valve and a gas safety valve. EP 3792531A1 discloses a gas flow modulator. Summary of the invention

[0004] Based on this background, a new air flow adjustment device for a gas burning appliance is provided, which allows the air flow through the air flow adjustment device to be adjusted more accurately. Furthermore, a gas burning appliance having such an air flow adjustment device is provided.

[0005] An air flow adjustment device according to a first aspect of the present disclosure is defined in claim 1 .

[0006] According to a first aspect of the present disclosure, the moving element of the throttle valve is made of plastic, wherein the moving element of the throttle valve and / or the actuator comprises at least one alignment feature configured to provide a precise relative position of the moving element with respect to the static element. Such an airflow adjustment device allows a more precise adjustment of the airflow through the airflow adjustment device while providing a simple and cost-effective design of the airflow adjustment device.

[0007] Preferably, the moving element of the throttle valve comprises flexible tongues as alignment features, wherein a first flexible tongue is elastically deformable in a first direction extending perpendicularly to the linear movement direction of the moving element, wherein a second flexible tongue is elastically deformable in the first direction and in a second direction extending perpendicularly to the first direction and perpendicularly to the linear movement direction of the moving element, and wherein when the moving element is moved relative to the static element, both the first flexible tongue and the second flexible tongue contact respective surfaces of the housing and provide alignment of the moving element relative to the static element. The flexible tongues provide clearance compensation and thereby allow a more precise adjustment of the airflow through the airflow adjustment device.

[0008] Preferably, the moving element of the throttle valve comprises a flexible protrusion with a partial thread as an alignment feature, wherein the flexible protrusion of the moving element is elastically deformable in a direction extending perpendicular to the linear movement direction of the moving element, and wherein the partial thread of the flexible protrusion of the moving element engages the threaded spindle of the actuator and provides alignment of the moving element relative to the static element when the moving element is moved relative to the static element. The moving element may comprise a first rigid protrusion with a partial thread and a second rigid protrusion with a partial thread as additional alignment features, wherein the first rigid protrusion and the second rigid protrusion of the moving element engage the threaded spindle to be axially and radially offset relative to the flexible protrusion. The flexible protrusion and the rigid protrusion provide clearance and hysteresis compensation and also allow for a more precise adjustment of the airflow through the airflow adjustment device.

[0009] Preferably, the moving element of the throttle valve comprises a rigid stop as an alignment feature, which provides alignment of the moving element relative to the static element when the throttle valve is in a minimum open position. The rigid stop also allows a more precise adjustment of the minimum air flow.

[0010] The moving element, the first and second flexible tongues, the flexible protrusions, the first and second rigid protrusions, and the rigid stop member may all be integrally formed, thereby providing a unitary element made of plastic. Precise adjustment of the airflow may be provided, while also providing a simple and cost-effective design of the airflow adjustment device.

[0011] Preferably, the actuator includes a flexible joint as an alignment feature, wherein the flexible joint is configured to flexibly couple the threaded spindle to the motor at a first end thereof, wherein the flexible joint is further configured to provide alignment of the threaded spindle relative to the moving element, and thereby provide precise linear movement of the moving element relative to the static element when the motor rotates the threaded spindle. The flexible joint provides eccentricity compensation and allows for more precise regulation of the airflow.

[0012] The actuator may include a rigid bearing element for the threaded spindle as an additional alignment feature, wherein the rigid bearing element is configured to align the threaded spindle at a second end of the threaded spindle opposite to the first end of the threaded spindle where the flexible joint is located. The rigid bearing element also allows for more precise regulation of the airflow.

[0013] An airflow adjustment device according to the second aspect of the present disclosure is defined in claim 13. According to the second aspect of the present disclosure, the moving element and the static element of the throttle valve define a flow opening limited by its side walls, the side walls being arcuate and configured to limit the airflow between a minimum airflow amount and a maximum airflow amount. Preferably, the moving element of the throttle valve comprises a circular opening configured to limit the minimum airflow amount. Such an airflow adjustment device allows for a more precise adjustment of the airflow through the airflow adjustment device while providing a simple and cost-effective design of the airflow adjustment device.

[0014] Preferably, the first aspect and the second aspect may be used in combination to allow accurate regulation of the air flow through the air flow regulating device while providing a simple and cost effective design of the air flow regulating device.

[0015] The present application further provides a gas burning appliance having an air flow adjustment device according to the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Preferred developments of the invention are provided by the dependent claims and the subsequent description. An exemplary embodiment is explained in more detail based on the drawings, in which:

[0017] Figure 1 A schematic diagram showing an exemplary gas burning appliance having an air flow adjustment device is shown,

[0018] Figure 2a is a first perspective view of the airflow adjustment device,

[0019] Figure 2b is a second perspective view of the airflow adjustment device,

[0020] Figure 3 is an exploded view of the airflow adjustment device.

[0021] Figure 4 is the cross section through the airflow adjustment device,

[0022] Figure 5 for Figure 4 Details,

[0023] Figure 6 for Figure 4 A perspective view of further details,

[0024] Figure 7a A first perspective view of a moving element of a throttle valve of an air flow control device,

[0025] Figure 7b for Figure 7a A second perspective view of the moving element,

[0026] Figure 8 A perspective view showing further details of the airflow adjustment device,

[0027] Fig. 9 A cross section of the airflow adjustment device for further details,

[0028] Fig.10 A cross section of the airflow adjustment device for further details,

[0029] Fig.11 is a perspective view of a moving element of a throttle valve of an air flow control device together with a threaded spindle of an actuator of the air flow control device,

[0030] Fig.12 for Fig.11 A first cross section of the details,

[0031] Fig.13 for Fig.11 A second cross section of the details,

[0032] Fig.14 A perspective view showing further details of the airflow adjustment device,

[0033] Fig.15 A perspective view showing further details of the airflow adjustment device,

[0034] Fig.16 for Figure 4 A cross section of alternatives,

[0035] Fig.17 for Figure 4 A cross section of further alternatives. DETAILED DESCRIPTION

[0036] Figure 1A schematic diagram of an exemplary gas burning appliance 10 is shown. The gas burning appliance 10 comprises a gas combustion chamber 11 in which a defined gas / air mixture M with a defined mixing ratio of gas G and air A is burned during a burner-on phase of the gas burning appliance 10. The combustion of the gas / air mixture M produces a flame 12 and can be monitored by a combustion quality sensor, exemplified by a flame rod 13.

[0037] By mixing the flow of air A with the flow of gas G, a defined gas / air mixture M is provided to the combustion chamber 11 of the gas burning appliance 10. The fan 14 draws the air A flowing through the air duct 15 and the gas G flowing through the gas duct 16. The gas safety valve 17 and the gas control valve 18 are distributed to the gas duct 16. The defined gas / air mixture M having a defined mixing ratio of the gas G and the air A is provided to the combustion chamber 11 of the gas burning appliance 10.

[0038] A defined gas / air mixture M is provided by mixing a gas flow provided by the air duct 15 with a gas flow provided by the gas duct 16. The air flow and the gas flow are preferably mixed by a mixing device 19. The mixing device 19 may be provided by a venturi nozzle.

[0039] The amount of air flow and thus the amount of gas / air mixture flow is controlled by the fan 14, i.e. by the speed of the fan 14. The fan speed can be varied based on the desired burner load by an actuator 20 of the fan 14. The fan speed of the fan 14 is controlled by a controller 21 of the gas burning appliance, thereby generating a control variable for the actuator 20 of the fan 14.

[0040] The defined mixing ratio of the defined gas / air mixture M is controlled by the gas control valve 18. In the exemplary gas burning appliance 10 shown, the gas control valve 18 is controlled by a pneumatic controller 23. The pneumatic controller 23 of the gas control valve 18 controls the open / closed position of the gas control valve 18.

[0041] The position of the gas control valve 18 is adjusted by the pneumatic controller 23 based on the pressure difference between the gas pressure of the gas flow in the gas pipeline 16 and the reference pressure. The gas control valve 18 is controlled by the pneumatic controller 23 so that the outlet pressure of the gas control valve 18 is equal to the reference pressure. Figure 1 In the embodiment, the ambient pressure is used as the reference pressure. However, the air pressure of the air flow in the air duct 15 can also be used as the reference pressure.

[0042] The pressure difference between the gas pressure and the reference pressure is pneumatically determined by a pneumatic sensor 22 of a pneumatic controller 23. The defined mixing ratio of the gas / air mixture M is controlled by the pneumatic controller 22 so that the defined mixing ratio of gas G and air A of the gas / air mixture M remains constant over the entire modulation range of the gas burning appliance 10.

[0043] Alternatively, the constant mixing ratio of gas and air in the gas / air mixture can be controlled electrically or electronically based on a signal provided by an electric or electronic pressure sensor or flow meter (not shown). In this case, the electric or electronic sensor can provide the controller 21 with an actual value corresponding to the pressure ratio between the gas pressure in the gas pipeline and the air pressure in the air pipeline or corresponding to the pressure ratio between the gas pressure in the gas pipeline and the air pressure at a reference point, wherein the controller 21 can compare the actual value with the nominal value. In this case, the controller 21 can generate a control variable for the gas control valve 18 based on the control deviation between the actual value and the nominal value, wherein the gas control valve 18 can be operated based on the control variable to keep the defined mixing ratio of gas G and air A in the gas / air mixture M constant over the entire modulation range of the gas burning appliance 10.

[0044] Modulation "1" means that the fan 14 is operated at the maximum fan speed (100% of the maximum fan speed) and thus at the full load of the gas-burning appliance 10. Modulation "2" means that the fan 14 is operated at 50% of the maximum fan speed and modulation "5" means that the fan 14 is operated at 20% of the maximum fan speed. By varying the fan speed of the fan 14, the burner load of the gas-burning appliance 10 can be adjusted. Over the entire modulation range of the gas-burning appliance 10, a defined mixing ratio of gas and air in a defined gas / air mixture remains constant.

[0045] As described above, the mixing ratio of the defined gas / air mixture M is controlled during the burner start phase so that the defined mixing ratio of the gas / air mixture M remains constant over the entire modulation range of the gas burning appliance 10. During the burner start phase, the defined mixing ratio of the gas G and the air A in the defined gas / air mixture M can be calibrated. The calibration is performed by the airflow adjustment device 24. The airflow adjustment device 24 includes a throttle valve 25 and an actuator 26 assigned to the throttle valve 25. The controller 21 can control the actuator 26 and thereby control the position of the throttle valve 25 during the calibration. The airflow adjustment device 24 can also be referred to as an airflow calibration device 24.

[0046] The present disclosure provides an airflow adjustment device 24 that allows for more precise adjustment of the airflow through the airflow adjustment device 24 while providing a simple and cost-effective design of the airflow adjustment device 24 .

[0047] The airflow adjustment device 24 includes a housing 27. The housing 27 provides an inlet 28 for airflow and an outlet 29 for airflow flowing through the airflow adjustment device 24. The housing 27 includes a top housing portion 30 providing the inlet 28 and a bottom housing portion 31 providing the outlet 29. The top housing portion 30 and the bottom housing portion 31 are mounted together by screws 32. A sealing element 33 is positioned between the top housing portion 30 and the bottom housing portion 31. The top housing portion 30 and the bottom housing portion 31 define an interior space that accommodates the components of the airflow adjustment device 24.

[0048] The airflow adjustment device 24 includes a throttle valve 25. The throttle valve 25 adjusts the amount of airflow from the inlet 28 to the outlet 29 of the airflow adjustment device 24. The throttle valve 25 includes a static element 34 and a moving element 35. The static element 34 of the throttle valve 25 can be formed integrally with the bottom housing portion 31. The moving element 35 of the throttle valve 25 is a separate component and is positioned inside the interior space of the housing 27. The moving element 35 of the throttle valve 25 is configured to move in a linear direction relative to the static element 34. The relative position of the moving element 35 relative to the static element 34 defines the amount of airflow from the inlet 28 to the outlet 29.

[0049] The air flow adjustment device 24 further comprises an actuator 26 having a motor 36 and a threaded spindle 37. The threaded spindle 37 is positioned inside the inner space of the housing 27. The motor 36 is mounted to the housing 27, ie to the bottom housing part 31, by means of screws 38. Figure 3 Further shown is a jack 50 for connecting the motor 36 of the actuator 26 to the controller 21. A sealing element 39 may be positioned between the motor 36 of the actuator 26 and the bottom housing portion 31 of the housing 27.

[0050] The motor 36 of the actuator 26 is configured to rotate the threaded spindle 37. The threaded spindle 37 of the actuator 26 is configured to move the moving element 35 of the throttle valve 25 relative to the static element 34 of the throttle valve 25 in the linear direction X when the motor 36 rotates the threaded spindle 37. The linear movement of the moving element 35 of the throttle valve 25 relative to the static element 34 of the throttle valve 25 defines the relative position between the moving element 35 of the throttle valve 25 and the static element 34 of the throttle valve 25, and thereby defines the amount of airflow from the inlet 28 to the outlet 29.

[0051] The moving element 35 of the throttle valve 25 is made of plastic. The moving element 35 of the throttle valve 25 and / or the actuator 26 include at least one alignment feature configured to provide a precise relative position of the moving element 35 of the throttle valve 25 with respect to the static element 34 of the throttle valve 25. This allows the airflow through the airflow adjustment device 24 to be precisely adjusted while providing a simple and cost-effective design of the airflow adjustment device 24.

[0052] The moving element 35 of the throttle valve 25 comprises a first flexible tongue as a first alignment feature 40 (see Figure 7a , 7b ), the first flexible tongue piece can be elastically deformed in a first direction Z extending perpendicular to the linear movement direction X of the moving element 35. The moving element 35 of the throttle valve 25 includes a second flexible tongue piece as a second alignment feature 41 (see Figure 7a , 7b ), the second flexible tongue can be elastically deformed in a first direction Z and in a second direction Y extending perpendicularly to the first direction Z and perpendicularly to the linear movement direction X of the moving element 35. The first flexible tongue 40 and the second flexible tongue 41 both contact the corresponding surfaces 42, 43 of the housing 27 (i.e., the bottom housing part 31 and / or the top housing part 30) (see Fig.10 ), and provides alignment of the moving element 35 relative to the static element 34 when the moving element 35 is moved relative to the static element 34. The first flexible tongue 40 contacts a surface 42 of the top housing part 30. The second flexible tongue 41 contacts a surface 43 of the bottom housing part 31. The surfaces 42, 43 provide sliding surfaces.

[0053] The flexible tongues 40, 41 provide in particular play compensation for the moving element 35 of the throttle valve 25 and allow precise adjustment of the air flow through the air flow adjustment device 24. The flexible tongues 40, 41 allow a stable and precise movement of the moving element 35 relative to the static element 34.

[0054] The moving element 35 of the throttle valve 25 comprises a flexible protrusion with a partial thread 45 as a third alignment feature 44 (see Fig.11 , 12 , 13). The flexible protrusion 44 of the moving element 35 can be elastically deformed in a direction Z extending perpendicular to the linear moving direction X of the moving element 35.

[0055] The partial threads 45 of the flexible protrusion 44 of the moving element 35 contact the threaded spindle 37 and provide alignment of the moving element 35 relative to the static element 34 when the moving element 35 is moved relative to the static element 35 .

[0056] The moving element 35 of the throttle valve 25 comprises a first rigid protrusion having a partial thread 48 and a second rigid protrusion having a partial thread 49 as a fourth alignment feature 46 and a fifth alignment feature 47 (see Fig.11 , 12 , 13). The first rigid protrusion 46 and the second rigid protrusion 37 of the moving element 35 engage the threaded spindle 37 and are axially and radially offset relative to the flexible protrusion 44.

[0057] The flexible protrusion 44 and the rigid protrusions 46 , 47 provide backlash and hysteresis compensation and also allow for more precise adjustment of the airflow through the airflow adjustment device 24 .

[0058] The tongues 40 , 41 of the moving element 35 of the throttle valve 25 are arranged at the side of the moving element 35 facing the top housing part 30 , while the projections 44 , 46 , 47 with partial threads 45 , 48 , 49 are arranged at the side of the moving element 35 facing the bottom housing part 31 .

[0059] The moving element 35 of the throttle valve 25 comprises a rigid stop member as a sixth alignment feature 51 (see Figure 4 , 9 ), the rigid stop member provides alignment of the moving element 35 relative to the static element 34 when the throttle valve 25 is in a minimum open position.

[0060] The rigid stop 51 allows a more precise regulation of the air flow when the throttle valve 25 and thus the moving element 35 is in its minimum open position. Thus, the rigid stop 51 allows a very precise minimum air flow through the air flow regulating device 24 to be provided.

[0061] The rigid stop member 51 is positioned at the side of the moving member 35 facing toward the bottom housing 31 .

[0062] The moving element 35, the first and second flexible tongues 40, 41, the flexible protrusion 44, the first and second rigid protrusions 46, 47 and the rigid stop member 51 of the throttle valve 25 are all integrally formed, thereby providing a unitary component made of plastic. Accurate adjustment of the airflow through the airflow adjustment device 24 can be provided, while also providing a simple and cost-effective design of the airflow adjustment device 24.

[0063] The actuator 26 of the air flow adjustment device 24 includes a flexible joint as a seventh alignment feature 52 (see Figure 4 , Figure 5 ), the flexible joint 52 is configured to flexibly couple the threaded spindle 37 at its first end 53 to the motor 36 of the actuator 26. The flexible joint 52 is further configured to provide alignment of the threaded spindle 37 of the actuator 26 relative to the moving element 35 of the throttle valve 25, and thereby provide precise linear movement of the moving element 35 of the throttle valve 25 relative to the static element 34 of the throttle valve 25 when the motor 36 rotates the threaded spindle 37. The flexible joint 52 radially surrounds the first end 53 of the threaded spindle 37 and the adjacent end 54 of the shaft 55 of the motor 36. The flexible joint 52 provides eccentricity compensation and also allows for more precise adjustment of the airflow through the airflow adjustment device 24.

[0064] The actuator 26 includes a rigid bearing element for the threaded spindle 37 as an eighth alignment feature 56 (see Figure 4 , 5 ), the rigid bearing element 56 is configured to align the threaded spindle 37 at a second end 57 of the threaded spindle 37, which is opposite to the first end 53 of the threaded spindle 37 where the flexible joint 52 is located. The rigid bearing element 56 also allows for more precise adjustment of the airflow through the airflow adjustment device 24.

[0065] Fig.16 and Fig.17 Both show alternatives, in which an additional ball bearing 58 is provided at the first end 53 of the main shaft 37. The ball bearing 58 can provide eccentricity compensation. Further, the ball bearing 58 improves the axial stability.

[0066] When such a ball bearing 58 is used at the first end 53 of the spindle 37, the eighth alignment feature 56 at the second end 57 of the spindle 37 can ultimately be omitted. Fig.16 In the embodiment shown in FIG. 5 , the eighth alignment feature 56 is present at the second end 57 of the main shaft 37 . Fig.16 and Fig.17 A seventh alignment feature 52 provided by the flexible joint is also utilized. Fig.16 and Fig.17 The flexible joint 52 has different shapes. The flexible joint 52 can be made of rubber. Fig.16 and Fig.17 In the embodiment shown in FIG. 1 , a first end 53 of the main shaft 37 may be connected to an adjacent end 54 of a shaft 55 of the motor 36 by a press-fit connection.

[0067] exist Fig.17 In the embodiment, the ball bearing is mounted from the top, and there is an additional sealing element 62 between the ball bearing 58 and the top housing part 30 of the housing 27. Fig.16 In FIG. 5 , the ball bearing 58 is mounted from one side of the motor 36 .

[0068] As discussed above, the relative position of the moving element 35 of the throttle valve 25 with respect to the static element 34 of the throttle valve 25 defines the amount of airflow from the inlet 28 to the outlet 29 of the airflow adjustment device 24 .

[0069] The static element 34 of the throttle valve 25 and the movable element 35 of the throttle valve 25 together define a flow opening 59 for the fuel gas (see Figure 8 In a first relative position of the moving element 35 with respect to the static element 34, the flow opening 59 is completely closed or blocked by a maximum overlap of the moving element 35 and the static element 34 (see Fig.14 , 15 ).

[0070] In the first relative position, the circular opening 60 in the moving element 35 (see Fig.14 , 15 ) defines the minimum amount of airflow through the airflow adjustment device 24. In this first relative position, the sixth alignment feature 51 of the moving element 35 provided by the rigid stop member abuts against the section 61 of the housing 27 (ie, the bottom housing portion 31) (see Fig. 9 ).

[0071] When the moving element 35 is moved relative to the static element 34 from the first relative position (see Fig.14 , 15 ), the overlap of the moving element 35 and the static element 34 is reduced (see Figure 8 ). Thus, the flow opening 59 is opened. As the moving element 35 moves relative to the static element 34, the overlap of the moving element 35 and the static element 34 is continuously adjusted, thereby continuously increasing or decreasing the opening of the flow opening 59 depending on the direction of movement.

[0072] The flow opening 59 is defined by a side wall 62 of the moving element 35 and by a side wall 63 of the static element 34. The two side walls 62 of the moving element 35 and the two side walls 63 of the static element 34 limit the flow opening 59 when the flow opening 59 is at least partially open. The side walls 62, 63 are arc-shaped.

[0073] The curved side walls 62, 63 provide a very advantageous air flow regulation by moving the moving element 35 of the throttle valve 25 relative to the static element 34 of the throttle valve 25. When a stepper motor is used as the motor 36, each actuation step then results in the same percentage change in the air flow.

[0074] Reference Mark List

[0075] 10 Gas Burning Appliances

[0076] 11 Gas combustion chamber

[0077] 12 Flame

[0078] 13 Flame Rod

[0079] 14 Fan

[0080] 15 Air duct

[0081] 16 Gas pipeline

[0082] 17 Gas safety valve

[0083] 18 Gas control valve

[0084] 19Mixing device

[0085] 20Actuator

[0086] 21 Controller

[0087] 22 Pneumatic sensor

[0088] 23 Pneumatic controller

[0089] 24 Airflow adjustment device

[0090] 25 throttle valve

[0091] 26 Actuator

[0092] 27 Shell

[0093] 28Entrance

[0094] Exit 29

[0095] 30 Top housing part

[0096] 31 bottom shell part

[0097] 32 screws

[0098] 33 Sealing element

[0099] 34 Static components

[0100] 35 moving elements

[0101] 36 motors

[0102] 37 thread spindle

[0103] 38 screws

[0104] 39 Sealing element

[0105] 40 First alignment feature / flexible tongue

[0106] 41 Second alignment feature / flexible tongue

[0107] 42 Surface

[0108] 43 Surface

[0109] 44 Third alignment feature / flexible protrusion

[0110] 45 part thread

[0111] 46 Fourth alignment feature / rigid protrusion

[0112] 47 Fifth alignment feature / rigid protrusion

[0113] 48 part thread

[0114] 49 part thread

[0115] 50 sockets

[0116] 51 Sixth alignment feature / rigid stop component

[0117] 52 Seventh Alignment Feature / Flexible Joint

[0118] 53 end

[0119] 54 end

[0120] 55 axis

[0121] 56 Eighth Alignment Feature / Rigid Bearing Element

[0122] 57 Second end

[0123] 58 ball bearings

[0124] 59 Flow opening

[0125] 60 round opening

[0126] Sector 61

[0127] 62 side wall

[0128] 63 side wall

[0129] 64 Sealing element.

Claims

1. An airflow regulating device (24) for a gas burning appliance, comprising: a housing (27) providing an inlet (28) for a gas flow and an outlet (29) for said gas flow, a throttle valve (25) configured to adjust the amount of air flow from the inlet (28) to the outlet (29), The throttle valve (25) has a static element (34) and a moving element (25), wherein the moving element (35) is configured to move in a linear direction relative to the static element (34), wherein the relative position of the moving element (35) with respect to the static element (34) defines the amount of airflow from the inlet (28) to the outlet (29), an actuator (26) having a motor (36) and a threaded spindle (37), wherein the motor (36) is configured to rotate the threaded spindle (37), wherein the threaded spindle (37) is configured to move the moving element (35) relative to the static element (34) in a linear direction when the motor (36) rotates the threaded spindle (37), It is characterized in that The moving element (35) of the throttle valve (25) is made of plastic. The moving element (35) of the throttle valve (25) and / or the actuator (26) comprises at least one alignment feature (40, 41, 44, 46, 47, 51, 52, 56) configured to provide a precise relative position of the moving element (35) with respect to the static element (34).

2. The airflow adjustment device according to claim 1, characterized in that: The moving element (35) of the throttle valve (25) comprises a first flexible tongue as an alignment feature (40), which is elastically deformable in a first direction (Z) extending perpendicularly to the linear movement direction (X) of the moving element (35), The moving element (35) of the throttle valve (25) comprises a second flexible tongue as a further alignment feature (41), which second flexible tongue is elastically deformable in the first direction (Z) and in a second direction (Y) extending perpendicularly to the first direction (Z) and perpendicularly to the linear movement direction (X) of the moving element (35), Wherein both the first flexible tongue (40) and the second flexible tongue (41) contact respective surfaces (42, 43) of the housing (27) and provide alignment of the moving element (35) with the static element (34) when the moving element (35) is moved relative to the static element (34).

3. The airflow adjustment device according to claim 2, characterized in that: The moving element (35), the first flexible tongue (40) and the second flexible tongue (41) are integrally formed so as to provide a unitary element.

4. The airflow adjustment device according to any one of claims 1 to 3, characterized in that: The moving element (35) of the throttle valve (25) comprises a flexible protrusion with a partial thread (45) as an alignment feature (44), The flexible protrusion (44) of the moving element (35) can be elastically deformed in a direction (Z) extending perpendicularly to a linear moving direction (X) of the moving element (35), The partial threads (45) of the flexible protrusion (44) of the moving element (35) engage the threaded spindle (37) and provide alignment of the moving element (35) with the static element (34) when the moving element (35) is moved relative to the static element (34).

5. The airflow adjustment device according to claim 4, characterized in that: The moving element (35) and the flexible protrusion (44) are integrally formed so as to provide a unitary element.

6. The airflow adjustment device according to claim 4 or claim 5, characterized in that: The moving element (35) of the throttle valve (25) comprises a first rigid protrusion with a partial thread (48) and a second rigid protrusion with a partial thread (49) as additional alignment features (46, 47), The first rigid protrusion (46) and the second rigid protrusion (47) of the moving element (35) engage the threaded spindle (37) to be axially and radially offset relative to the flexible protrusion (44).

7. The airflow adjustment device according to claim 6, characterized in that: The moving element (35), the first rigid protrusion (46) and the second rigid protrusion (47) are integrally formed to provide a unitary element.

8. The airflow adjustment device according to any one of claims 1 to 7, characterized in that: The moving element (35) of the throttle valve (25) comprises a rigid stop as an alignment feature (51), which provides alignment of the moving element (35) with the static element (34) when the throttle valve (25) is in a minimum open position.

9. The airflow adjustment device according to claim 8, characterized in that: The moving element (35) and the rigid stop member (51) are integrally formed so as to provide a unitary element.

10. The airflow adjustment device according to any one of claims 1 to 9, characterized in that: The actuator (26) includes a flexible joint as an alignment feature (52), the flexible joint (52) being configured to flexibly couple the threaded spindle (37) to the motor (36) at its first end (53), the flexible joint (52) being further configured to provide alignment of the threaded spindle (37) with the moving element (35), and thereby provide precise linear movement of the moving element (35) relative to the static element (34) when the motor (36) rotates the threaded spindle (37).

11. The airflow adjustment device according to claim 10, characterized in that: The actuator (26) comprises a rigid bearing element (56) for the threaded spindle (37) as an additional alignment feature (56), the rigid bearing element (56) being configured to align the threaded spindle (37) at a second end (57) of the threaded spindle (37), the second end (57) being opposite to the first end (53) of the threaded spindle (37) where the flexible joint (52) is located.

12. The airflow adjustment device according to any one of claims 1 to 11, characterized in that: The housing (27) comprises a top housing portion (30) providing the inlet (28) and a bottom housing portion (31) providing the outlet (29), The static element (34) of the throttle valve (25) is formed integrally with the bottom housing part (31).

13. An airflow regulating device (24) for a gas burning appliance, comprising: a housing (27) providing an inlet (28) for the air flow and an outlet (29) for the air flow, a throttle valve (25) configured to adjust the amount of air flow from the inlet (28) to the outlet (29), The throttle valve (25) comprises a static element (35) and a movable element (34) movable in a linear direction relative to the static element (35). wherein the relative position of the moving element (35) with respect to the static element (34) defines the amount of airflow from the inlet (28) to the outlet (29), an actuator (26) configured to move the moving element (35) in a linear direction relative to the static element (34), It is characterized in that The moving element (35) and the static element (34) of the throttle valve (25) define a flow opening (59) limited by side walls (62, 63) thereof, wherein the side walls (62, 63) of the moving element (35) and the static element (34) are arc-shaped and configured to provide an air flow between a minimum air flow rate and a maximum air flow rate.

14. The airflow adjustment device according to claim 13, characterized in that: The moving element (35) of the throttle valve (35) comprises a circular opening (60) configured to define the minimum air flow rate.

15. A gas burning appliance having an air flow adjustment device according to any one of claims 1 to 14.

Images