A robust idle air control valve

Abstract

The present invention provides a robust idle air control valve (200) comprises a housing (207), a mounting flange (209), a terminal cover, a terminal, a bobbin sub assembly, a guiding bush, a ball, a coil, a magnet, a lead screw, an armature (206), a bush, a pintle lock (205), a spring (204), a pintle (203) and an O-ring (201). Further, the pintle (203) has an outer profile and has a reduced length, which prevents vacuum generation at a spring resting area. Further the reduced profile length allows better fluid dynamics and minimizes obstruction to flow. So higher flow range can be achieved in same travel, here it's not required to make a new design as same approach can be used to enhance the total flow capability range of part, also it helps in overall reliability as it will travel less up and down for same flow rate regulation as compared to prior art, so so less travel mean less wear and tear over the life time. Furthermore, a metal sleeve (202) is provided for the pintle (203) to ensure a precise manufacturing tolerances, which results in better alignment of the O-ring (201) with a motor shaft axis with symmetric hole feature left (210) and hole feature right (211) to support sleeve from top side for better resting in the molding.

Description

[0001] “A ROBUST IDLE AIR CONTROL VALVE”

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of idle air control valve. More particularly, the present invention relates to a robust idle air control valve with improved air flow management in the bore to assist precise movement of pintle, enhanced radial sealing performance and improved center alignment and precision. Further, the present invention achieves higher flow rates with least travel and which less time for getting to desired locations to achieve target flow.

[0004] BACKGROUND OF THE INVENTION

[0005] An idle air control valve is a component in internal combustion engine that regulates the amount of air bypassing the throttle plate to maintain a stable engine idle speed. The idle air control valve plays a role in managing engine performance, especially at idle condition, by ensuring that the engine receives the correct air-fuel mixture when the throttle is closed.

[0006] Some of the key functions of the idle air control valve are regulation of airflow, idle speed maintenance, combustion optimization. The idle air control valve is typically controlled by the control unit of vehicle, which sends signals based on real time data from various sensors, such as the throttle position sensor and engine load sensor. The idle air control valve open or closes incrementally to adjust the airflow bypassing the throttle, thereby ensuring the engine operates smoothly at idle.

[0007] Several type of idle air control valve are available in the market and several modifications have been done in the idle air control valve. Despite of these modification, the currently available idle air control valve faces challenge in air flow management in bore, radial sealing performance, center alignment and precision.

[0008] W02021006139 discloses an air flow control device featuring a motor with a metal case for improved heat dissipation, a resin base member, and a seal ring fitted to a support portion. However, the seal ring in this invention is fitted on the resin surface,which is not ideal for better manufacturing tolerance control and surface finish required for radial sealing and precise center alignment in the bore. Also, pintle shown is of full length which restrict the flow management in the bore due to blind bore of pintle which covers the spring.

[0009] EP2561600 discloses an idle air control valve, featuring a plastic housing that enhances durability and aesthetic appeal. The actuator converts rotational motion from a rotor assembly into linear motion via a shaft, with an innovative heat-formed connection to a connector structure ensuring airtight integrity. However, this invention has cylindrical grime shield which restrict better air flow management several issues like, low sealing performance due to O-ring on inner wall of protective motor housing of plastic, reduced alignment and precision are observed.

[0010] Therefore, there is a need to provide a robust idle air control valve with improved flow management, enhanced sealing performance and improved alignment and precision.

[0011] OBJECT OF THE INVENTION

[0012] The main object of the present invention is to provide a robust idle air control valve with improved flow management, enhanced sealing performance and improved alignment and precision.

[0013] Another object of the present invention is to provide a robust idle air control valve that improved flow management by shortening the outer profile length of the pintle or adjuster which will help to increase the flow range in same travel length.

[0014] Another object of the present invention is to provide a robust idle air control valve that achieves higher flow rates with least travel and which requires less time for getting to desired locations to achieve target flow.

[0015] Yet another object of the present invention is to provide a robust idle air control valve that enhances the sealing capabilities, minimizing fluid leakage and improving the overall reliability of the system.Yet another object of the present invention is to provide a robust idle air control valve that have higher precision and alignment, thereby providing efficient operation.

[0016] Yet another object of the present invention is to provide a robust idle air control valve in which a radial sealing is guided by metal casing, so metal casing have more accuracy in manufacturing tolerances as compared to resin guide.

[0017] Still another object of the present invention is to provide a robust idle air control valve that uses a metal sleeve which is concentric with the motor axis and motor housing with feature to support during over molding the sleeve.

[0018] SUMMARY OF THE INVENTION

[0019] The present invention relates to a robust idle air control valve with improved flow management within same travel range, enhanced sealing performance and improved alignment and precision.

[0020] In an embodiment, the present invention provides a robust idle air control valve comprising a housing, a bobbin sub-assembly disposed within the housing, a lead screw operatively coupled to the bobbin sub-assembly, a pintle coupled to the lead screw via a pintle lock and configured for linear movement along a longitudinal axis and a spring biasing the pintle towards a closed position. The pintle has a reduced overall outer profile length along at least a portion thereof in such a manner that during reverse movement of the pintle from a fully closed position, a flow area around the pintle is increased, thereby reducing airflow restriction and vacuum generation within the robust idle air control valve. The robust idle air control valve includes a sleeve for supporting the O-ring.

[0021] The above objects and advantages of the present invention will become apparent from the hereinafter set forth brief description of the drawings, detailed description of the invention, and claims appended herewith.

[0022] BRIEF DESCRIPTION OF THE DRAWINGSAn understanding of the robust idle air control valve of the present invention may be obtained by reference to the following drawings:

[0023] Figure 1 is a perspective view of a conventional idle air control valve.

[0024] Figure 2 is a perspective view of the robust idle air control valve according to an embodiment of the present invention.

[0025] Figure 3 is a cross-sectional view of the robust idle air control valve according to an embodiment of the present invention.

[0026] Figure 4 is a bottom view of the robust idle air control valve according to an embodiment of the present invention.

[0027] Figure 5 is another cross-sectional view of the robust idle air control valve according to an embodiment of the present invention.

[0028] Figure 6 is another cross-sectional view of the robust idle air control valve according to an embodiment of the present invention.

[0029] Figure 7 is another cross-sectional view of the robust idle air control valve according to an embodiment of the present invention.

[0030] DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention will now be described hereinafter with reference to the accompanying drawings in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough, and will fully convey the scope of the invention to those skilled in the art.

[0032] Many aspects of the invention can be better understood with references made to the drawings below. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts throughthe several views in the drawings. Before explaining at least one embodiment of the invention, it is to be understood that the embodiments of the invention are not limited in their application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The embodiments of the invention are capable of being practiced and carried out in various ways. In addition, the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

[0033] The present invention now will be described hereinafter with reference to the detailed description, in which some, but not all embodiments of the invention are indicated. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Tike numbers refer to like elements throughout. The present invention is described fully herein with non-limiting embodiments and exemplary experimentation.

[0034] The present invention relates to a robust idle air control valve with improved air flow management, enhanced sealing performance and improved alignment and precision.

[0035] In an embodiment, the present invention provides a robust idle air control valve comprising a housing, a bobbin sub-assembly disposed within the housing, a lead screw operatively coupled to the bobbin sub-assembly, a pintle coupled to the lead screw via a pintle lock and configured for linear movement along a longitudinal axis and a spring biasing the pintle towards a closed position. The pintle has a reduced overall outer profile length along at least a portion thereof in such a manner that during reverse movement of the pintle from a fully closed position, a flow area around the pintle is increased, thereby reducing airflow restriction and vacuum generation within the robust idle air control valve. The robust idle air control valve includes a sleeve for supporting the O-ring.

[0036] Referring to Figure 1, a perspective view of a conventional idle air control valve is depicted therein and designated as (100). A seal ring (i.e. O-ring) (101) is fitted on a resin surface (102) of the conventional idle air control valve (100). Further a pintle(103) (with outer profile extended up to spring resting surface & top surface of motor casing (104)) of the conventional idle air control valve is also depicted in Figure 1.

[0037] Referring to Figure 2, a perspective view of the robust idle air control valve is depicted therein and designated as (200). The robust idle air control valve (200) includes a pintle (203) includes a reduced outer profile for reducing vacuum generation at the spring resting area and its periphery. The outer profile length of the pintle (203) is formed by removal of a diametrical portion of the pintle (203). The pintle (203) is configured to reduce a pressure drop across the robust idle air control valve (200) during partial opening of the pintle (203). The pressure drop is reduced in range from 5 to 8 kPa during partial opening of the pintle (203). The reduced outer profile length of pintle (203) reduces total restriction in a throttle body (403) that helps in smooth air flow and high response in same travel. So it needs less travel to get same flow rate.

[0038] As described herein, the term “pintle” refers to a movable component that slides in and out to precisely regulate airflow, bypassing a main throttle plate to control engine idle speed, for allowing more air when retracted and restricting the same when extended, on the basis of commands received from electrical control unit for a stable performance.

[0039] As described herein, the term “diametrical portion” refers to a portion of the pintle in which an outer diameter of the pintle is locally reduced over a selected axial length, while maintain a generally cylindrical configuration of the pintle. The reduction of the diametrical portion does not involve complete removal of the pintle material across the diameter, but instead results in a reduced outer profile that increases an effective flow area around the pintle during the valve operations.

[0040] Further, the O-ring (201) of the present invention is mounted on a metal sleeve (202) concentric with a motor axis, wherein the sleeve (202) ensures precise alignment and enhanced sealing efficiency due to an improved accuracy and tolerance control in comparison to conventional materials. The sleeve (202) provides an improved durability, reduced leakage, thereby enabling efficient fluid flow regulation.The sleeve (202) provides a metallic seating surface for the O-ring (201) reduces air leakage in range from 14 to 20 cubic centimeters per minute under a vacuum condition of about 60 to 61 kPa. The sleeve (202) is press-fitted or interference-fitted into the bobbin sub-assembly. The sleeve (202) is made of stainless steel, aluminum or a hardened alloy to maintain tolerance stability and said sleeve (202) provides a metallic seating surface for the O-ring (201).

[0041] Referring to Figure 3, a cross-sectional view of the robust idle air control valve is depicted. The robust idle air control valve (200) comprises a housing (207), a mounting flange (209), a terminal cover, a terminal, a bobbin sub assembly, a guiding bush, a ball, a coil, a magnet, a lead screw, an armature (206), a bush, a pintle lock (205), a spring (204), a pintle (203) and an O-ring (201).

[0042] Further, the pintle (203) has the reduced outer profile surrounding the spring area which prevents vacuum generation at a spring resting area. Further, reduced outer profile length allows better fluid dynamics and minimizes obstruction to flow. Further, symmetric hole feature left (210) and hole feature right (211) are provided in housing to support sleeve from top side for better resting in the molding as shown in Figure 3 and Figure 4.

[0043] Also, the spring (204) biases the pintle (203) towards a closed or partially closed position during a valve operation.

[0044] Referring to Figure 5, another cross-sectional view of the robust idle air control valve (200) is depicted in a fully closed condition. The pintle (203) with the reduced outer profile seals the outlet passage, however the reduced outer profile alters the flow restriction characteristics such as improved air flow management, enhanced sealing performance and improved alignment and precision and reduction in the vacuum generation within the throttle body (403).

[0045] Referring to Figure 6, another cross-sectional view of the robust idle air control valve is depicted in a reversed or partially open condition. The reversal of the pintle (203) creates a larger effective flow area with lower restriction. As a result, higher airflow is achieved with reduced pressure drop and with comparatively lower pintle travel.This configuration in the robust idle air control valve (200) support higher flow rate applications.

[0046] Hence, in the conventional idle air control valve with conventional pintle, 60±2 kPa vacuum is maintained at full closing, when reversed 1.35 mm travel back to open the orifice area, which gives pressure drop and new value becomes up-to 15-20kPa (final value), however with reduced profile, the present invention gives 5-8 kPa which means overall restriction in body reduce which allow pressure to release effectively with low pintle travel so same parts are used for high flow rate application.

[0047] The present invention attains higher flow range achieved in same travel, and enhances the total flow capability range of part, also the present invention helps in overall reliability as there is less travel less up and down for same flow rate regulation as compared to conventional solution. Due to reduction in travel there is reduction in wear and tear over the life time.

[0048] Referring to Figure 7, another cross-sectional view of the robust idle air control valve is depicted. The O-ring (201) positioned between the throttle body (403) and the stepper motor (401). The O-ring rests against the sleeve (202) and the sleeve (202) is a metallic sleeve or a metallic surface which enhances sealing reliability, reduces leakage and improve vacuum performance under operating conditions. Also, 61 kPa vacuum, leakage in normal case is 40-50 ccm (due to rubber seal guided by plastic surface and getting compressed against metal surface) in the conventional idle air control valve, however through the present invention leakage is in range from 14-20 ccm (due to rubber seal guided by metal surface).

[0049] Therefore, the present invention provides a robust idle air control valve with improved air flow management, enhanced sealing performance and improved alignment and precision. Further the present invention reduces the vacuum generation by shortening the outer profile of the pintle or adjuster, enhances the sealing capabilities, minimizing fluid leakage and improving the overall reliability, have higher precision and alignment, thereby providing efficient operation and uses a metal sleeve which is concentric with the motor axis.Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0050] The foregoing description of embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principle of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.

Claims

CLAIMSWe claim:

1. A robust idle air control valve (200) comprising:a housing (207);a bobbin sub-assembly disposed within the housing;a lead screw operatively coupled to the bobbin sub-assembly;a pintle (203) coupled to the lead screw via a pintle lock (205) and configured for linear movement along a longitudinal axis; anda spring (204) biasing the pintle (203) towards a closed position;wherein:said pintle (203) has a reduced overall outer profile length along at least a portion thereof in such a manner that during reverse movement of the pintle (203) from a fully closed position, a flow area around the pintle (203) is increased, thereby reducing airflow restriction and vacuum generation within the robust idle air control valve (200) and achieving higher flow rates with least travel; andsaid robust idle air control valve (200) includes a sleeve (202) for supporting the O-ring (201).

2. The robust idle air control valve (200) as claimed in claim 1, wherein the robust idle air control valve (200) comprises a terminal cover, a terminal, a guiding bush, a ball, a coil, a magnet, an armature (206) and a bush.

3. The robust idle air control valve (200) as claimed in claim 1 , wherein the outer profile length of the pintle (203) is formed by removal of a diametrical portion of the pintle (203).

4. The robust idle air control valve (200) as claimed in claim 1 , wherein the pintle (203) is configured to reduce a pressure drop across the robust idle air control valve (200) during partial opening of the pintle (203).

5. The robust idle air control valve (200) as claimed in claim 4, wherein the pressure drop is reduced in range from 5 to 8 kPa during partial opening of the pintle (203).

6. The robust idle air control valve (200) as claimed in claim 1, wherein the reduced outer profile length of pintle (203) reduces total restriction in a throttle body (403) that helps in smooth air flow and high response.

7. The robust idle air control valve (200) as claimed in claim 1, wherein the sleeve (202) is made of stainless steel, aluminum or a hardened alloy to maintain tolerance stability and said sleeve (202) provides a metallic seating surface for the O-ring (201).

8. The robust idle air control valve (200) as claimed in claim 7, wherein the sleeve (202) that provides the metallic seating surface for the O-ring (201) reduces air leakage in range from 14 to 20 cubic centimeters per minute under a vacuum condition of about 60 to 61 kPa.

9. The robust idle air control valve (200) as claimed in claim 1, wherein the sleeve (202) is press-fitted or interference-fitted into the bobbin sub-assembly.

10. The robust idle air control valve (200) as claimed in claim 1, wherein the spring (204) biases the pintle (203) towards a closed or partially closed position during a valve operation.

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