DESC:FORM 2

THE PATENTS ACT, 1970

(39 of 1970)

&

THE PATENT RULES, 2003

COMPLETE SPECIFICATION

[See Section 10 and Rule 13]

TITLE:

“AN IDLE AIR CONTROL VALVE”

APPLICANT:

PADMINI VNA MECHATRONICS LIMITED
A company incorporated under the Indian Companies Act, 1956
having address at
Plot No. 100-101, Sector 35, Phase VII, Udyog Vihar,
Gurgaon-122001, Haryana, India

PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF THE INVENTION
The present invention relates to an idle air control valve. More particularly, the present invention relates to provide an idle air control valve with enhanced actuator efficiency, consistent air flow while vehicle idling, enhanced axial clearance and reduced complexity of assembly thereof.

BACKGROUND OF THE INVENTION
An idle air control valve, often referred to as an IACV, serves as an electronically controlled linear actuator that plays a vital role in managing airflow within an engine system. Its primary function is to regulate the amount of air and to control the engine's idling rotational speed (RPM). Typically, this component is situated on the throttle body of fuel-injected engines. It operates under the command of the vehicle's engine control unit (ECU), and its placement allows it to either divert air around the throttle or directly manipulate the throttle valve.
This operation involves the regulation of airflow through a bypass circuit surrounding the throttle valve to either increase or decrease the engine's idle speed. When the engine's idle speed strays beyond a predetermined range specified in the ECU's programming, the engine control unit instructs the valve to adjust the bypass airflow accordingly. This precise control of air and fuel ratios within the engine leads to reduced emissions, contributing to environmental pollution reduction.
Typically, the idle air control valve is composed of various elements, including but not limited to a set of wire winding coils, a stator, a rotor, a mechanism for facilitating the linear movement of the pintle, electrical supply terminals, a bush, a stator cup, and a bobbin. These components are intricately arranged within a sophisticated design.
During the assembly process, the bush is typically pressed into the stator cup, and subsequently, the stator cup assembly is pressed into the bobbin sub-assembly. However, assembling these components through pressing can introduce challenges, particularly in maintaining the precise concentricity of the bush concerning the inner diameter of the bobbin sub-assembly. Therefore, ensuring the concentricity of each part is critical, as it significantly impacts performance. When this concentricity deviates from the specified requirements, it can lead to irregularities in the rotation of the rotor assembly, causing it to exhibit an oval motion instead of the intended circular one. This deviation from the desired operation can result in a loss of efficiency in the actuator and increase noise and vibration due to the non-uniform movement of the rotor assembly. Additionally, in the conventional air control valve, any molding defect over the shaft region causes obstruction in smooth rotation of motor or immobilization of the motor.
CN105889573 discloses, an air control valve mounted in a pneumatic actuator. The air control valve comprises a valve body, wherein a switching cavity as well as a first channel, a second channel and a third channel which are respectively communicated with the switching cavity, a first switching hole communicated with the switching cavity is formed in one end of the first channel, the other end of the first channel is an air source mounting hole, a communicating hole communicated with the switching cavity is formed in one end of the second channel, the other end of the second channel is a non-spring cavity mounting hole, a second switching hole communicated with the switching cavity is formed in one end of the third channel, the other end of the third channel is a spring cavity mounting hole, a main valve element moving according to air pressure is arranged in the switching cavity, an exhaust channel communicating the second channel with the outside is arranged in the valve body, and a unidirectional circulation assembly only allowing gas to flow to the outside from the second channel is arranged in the exhaust channel. The main drawback of this invention is that it does not provide any solution for uneven rotation of the motor or immobilization of the motor caused due to molding defect in the shaft region.
WO2013181959 discloses two-way air control valve, comprising a valve body and an air cylinder, wherein the valve body is provided with an inlet, an outlet and a movable valve core; the air cylinder is internally provided with a slidable piston; the centre of the piston is connected with a piston rod capable of pressing the valve core to move to open/close a channel arranged between the inlet and the outlet; and the outer wall of the air cylinder is provided with an air control interface. The two-way air control valve is characterized in that a spacer bush is sheathed between the air cylinder and the piston rod, and one side of the spacer bush is fixedly connected to the valve body and the other side of the spacer bush is rotatably connected to the air cylinder. The air cylinder portion of the two-way air control valve is rotatable and provides convenience in installation for a client during usage, and the service life of a sealing gasket is prolonged. The main drawback of this invention is that it does not provide any solution for uneven rotation of the motor or immobilization of the motor caused due to molding defect in the shaft region.
Therefore, there is a need of an idle air control valve which reduces the uneven rotation of the motor or immobilization of the motor caused due to molding defect over the shaft region.

OBJECT OF THE INVENTION
The main object of the present invention is to provide an idle air control valve with enhanced actuator efficiency.
Another object of the present invention is to provide an idle air control valve with enhanced axial clearance.
Yet another object of the present invention is to provide an idle air control valve with reduced complexity of assembly.
Yet another objective of the present invention is to provide an idle air control valve with consistent air flow at the time of vehicle idling.
Still another object of the present invention is to provide an idle air control valve with lower noise and vibration.

SUMMARY OF THE INVENTION
The present invention relates to an idle air control valve with improved rotor assembly which prevents motor immobilization, provides enhanced actuator efficiency and axial clearance between the rotor assembly and the bobbin sub-assembly.
In an embodiment, the present invention provides an idle air control valve, comprising a housing, a terminal cover, at least one terminal, a bobbin sub-assembly, a ball, plurality of coils, a rotor assembly, a bush, a pintle lock, a stator cup, a spring, a pintle, and an O-ring. The bush includes an elongation which rests over the bobbin sub-assembly and includes a guide which fits inside internal diameter of the bobbin sub-assembly by a clearance fit, a transition fit, a press fit or by any other means which includes but is not limited to welding, glued or like. The bush and a guiding bush are fitted in the bobbin sub-assembly such that the control of rotor concentricity is only dependent on the bobbin sub-assembly. The bush controls the axial clearance between the rotor assembly and the bobbin sub assembly. The improved idle air control valve also exhibits a significant reduction in ovality/roundness i.e. oval movement and consistent air flow.
Hence, the present invention provides an idle air control valve with improved rotor assembly which prevents motor immobilization, provides enhanced actuator efficiency, axial clearance between the rotor assembly and the bobbin sub assembly, consistent air flow while vehicle idling and reduced complexity of assembly thereof.

BRIEF DESCRIPTION OF THE DRAWING
An understanding of the idle air control valve of the present invention may be obtained by reference to the following drawings:
Figure 1 is a cross sectional view of the conventional idle air control valve according to an embodiment of the present invention.
Figure 2 is a cross sectional view of the idle air control valve according to an embodiment of the present invention.
Figure 3(a) and Figure 3(b) are front and perspective views of the bush according to an embodiment of the present invention.
Figure 3(c) is a perspective views of the bush having different shapes according to an embodiment of the present invention.
Figure 4 is an exploded view of the idle air control valve according to an embodiment of the present invention.
Figure 5(a) is an enlarged view of the conventional idle air control valve according to an embodiment of the present invention.
Figure 5(b) is a perspective view of conventional bobbin sub-assembly and conventional stator cup assembly according to an embodiment of the present invention.
Figure 6(a) is an enlarged view of the idle air control valve according to an embodiment of the present invention.
Figure 6(b) is an exploded view of the stator and bobbin sub assembly according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
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.
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 through the 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.
The present invention relates to an idle air control valve with improved rotor assembly which prevents motor immobilization, provides enhanced actuator efficiency and axial clearance between the rotor assembly and the bobbin sub assembly.
In an embodiment, the present invention provides an idle air control valve (30), comprising a housing (13), a terminal cover (12), a plurality of terminals (11), a bobbin sub-assembly (3), a ball (9), plurality of coils (8), a rotor assembly (4), a bush (10), a pintle lock (5), a stator cup (1), a spring (7), a pintle (6), and an O-ring (14). The bush (10) includes an elongation (15) which rests over the bobbin sub-assembly (3) and includes a guide (16) which fits inside internal diameter of the bobbin sub-assembly (3) by a clearance fit, a transition fit, a press fit or any other means which includes but is not limited to welding, glued or like. The bush (10) and a guide (16) are fitted in the bobbin sub-assembly (3) such that the control of rotor concentricity is only dependent on the bobbin sub-assembly (3). The bush (10) controls the axial clearance between the rotor assembly and the bobbin sub-assembly (3). The improved idle air control valve (30) also exhibits a significant reduction in ovality/roundness i.e. oval movement and consistent air flow.
Referring to Figure 1, a cross sectional view of the conventional idle air control valve is shown. The conventional idle air control valve (20) comprises of a housing (13), a terminal cover (12), at least one terminal (11), a bobbin sub-assembly (3), a guiding bush (10), a ball (9), a coil (8), a rotor assembly (4), a bush (21), a pintle lock (5), a stator cup (31), a spring (7), a pintle (6), and an O-ring (14). The bush (21) is having a protrusion (21a) axially at one end, said protrusion end (21a) is axially inserted into the stator cup (31) in such a manner that outer circumferential periphery of the protrusion (21a) is press fitted to inner circumferential periphery of the stator cup (31) and pintle lock (5) is press fitted to stator cup (31). In the conventional idle air control valve each part has its own concentricity, due to this the overall concentricity of the assembly goes out of the specifications and creates ovality which further reduces the efficiency and performance of the actuator. Also any molding defect/flash over the shaft outer diameter shall cause interference in the inner diameter of the bush, which will obstruct the smooth rotation of the motor or immobilization due to shaft over-mold.
Referring to Figure 2, a cross sectional view of the idle air control valve is depicted. The idle air control valve (30) comprises of a housing (13), a terminal cover (12), at least one terminal (11), a bobbin sub-assembly (3), a guiding bush (10), a ball (9), plurality of coils (8), a rotor assembly (4), a bush (2), a pintle lock (5), a stator cup (1), a spring (7), a pintle (6), and an O-ring (14). The bush (2) includes an elongation (15) which rests over the bobbin sub assembly (3) and includes a guide (16) which fits inside internal diameter of the bobbin sub assembly (3) by a clearance fit, a transition fit, a press fit or any other means which includes but not limited to welding, glued or like. The bush (2) top surface (2a) is coincident with bottom surface (1a) of stator cup (1) and pintle lock (5) to avoid axial movement, further the bush (2) extends radially such that it is fitted against and is in direct contact with inner surface of the bobbin sub assembly (3) and then the stator cup (1) is fitted in bobbin sub-assembly (3). The control of concentricity of rotor assembly (4) is dependent only on bobbin sub-assembly (3) and a consistent air flow is achieved. The bush (2) controls the axial clearance between the rotor assembly (4) and the bobbin sub-assembly. The idle air control valve (30) also exhibits a significant reduction in ovality/roundness i.e. oval movement and consistent air flow.
Referring to Figure 3(a) and Figure 3(b), a front and a perspective view of the bush is depicted according to an embodiment of the present invention. The bush (2) includes an elongation (15) which rests over the bobbin sub assembly (3) and includes a guide (16) which fits inside internal diameter of the bobbin sub-assembly (3) by a clearance fit, a transition fit, a press fit or any other means which includes but is not limited to welding, glued or like. The shape of the bush (2) includes but is not limited to circular, square, rectangular or hexagonal or any other shape as depicted in Figure 3(c).
Referring to Figure 4, an exploded view of the idle air control valve is depicted according to an embodiment of the present invention. The idle air control valve (30) comprises of a housing (13), a terminal cover (12), a plurality of terminals (11), at least one bobbin sub-assembly (3), at least one guiding bush (10), at least one ball (9), a plurality of coils (8), a rotor assembly (4), at least one bush (2), a pintle lock (5), a stator cup (1), a spring (7), a pintle (6) and at least one O-ring (14). The bobbin sub-assembly (3) is provided with plurality of terminals (11), and coils (8) are wound around the bobbin sub-assembly (3), a terminal cover (12) is provided to cover the plurality of terminals (11), and placed into the housing (13) axially. The rotor assembly (4) is inserted axially into the bobbin sub-assembly (3), a guiding bush (10) is provided to support axial movement to the distal end of the rotor assembly (4) close to the bottom surface of the housing (13), a ball (9) is placed into the bottom of the housing (13) supporting the rotational movement of the rotor assembly (4). The bush (2) is provided such that it is supporting the rotor assembly (4) and said pintle lock (5) is attached on the top surface of the stator cup (1). Further, a spring (7) attached on the outer periphery surface of the pintle lock (5) and secured by a pintle (6) axially covering the spring (7) and an O-ring (14) is provided for leakage proof connection between mating component and said housing (13). The pintle (6) is restricted from rotation with the help of pintle lock (5) and is associated with the rotor assembly (4) such that rotation of the rotor assembly (4) causes linear movement of the pintle (6).
Referring to Figure 5(a), an enlarged view of the conventional idle air control valve is depicted. The bush (21) is having a protrusion (21a) at one end. The protrusion (21a) is pressed in the stator cup (31) and then stator cup assembly is pressed over bobbin sub assembly (3).
Referring to Figure 5(b), a perspective view of conventional bobbin sub-assembly and conventional stator cup assembly is depicted. The bush (21) is press fitted in stator cup (31), further said stator cup (31) is press fitted on bobbin sub-assembly (3). The protrusion (21a) of the bush (21) protrudes on the top surface (31a) of stator cup (31).
Referring to Figure 6(a), an enlarged view of the idle air control valve is depicted. The bush (2) includes an elongation (15) which rests over the bobbin sub-assembly (3) and includes a guide (16) which fits inside internal diameter of the bobbin sub-assembly (3) by a clearance fit, a transition fit, a press fit or any other means which includes but not limited to welding, glued or like. The bush (2) is provided such that it is supporting the improved rotor assembly (4) which include a groove (17). Any molding defect/flash over the shafts outer diameter shall cause interference in the inner diameter of the bush (2) is prevented by the groove (17). The stator cup (1) is connected to bobbin sub-assembly (3) in such a way that stator cup (1) is guided through the inner diameter of the bobbin sub-assembly (3). Further, this reduces the overall concentricity in individual parts and provides stability that further provides enhanced actuator efficiency.
Referring to Figure 6(b), an exploded view of the stator and bobbin sub-assembly is depicted. The bush (2) includes an elongation (15) which rests over the bobbin sub-assembly (3) and includes a guide (16) which fits inside internal diameter of the bobbin sub-assembly (3) by a clearance fit, a transition fit, a press fit or any other means which includes but not limited to welding, glued or like, that allows control of concentricity of rotor assembly (4) only on bobbin sub-assembly (3) and axial clearance between the rotor assembly (4) and the bobbin sub-assembly (3).
Therefore, the present invention provides the idle air control valve with reduced complexity in assembly as the bush (2) includes an elongation (15) and a guide (16) fitted to bobbin sub-assembly (3) which provides consistent air flow at the time of vehicle idling with reduced ovality of overall assembly thus increasing efficiency ranging from 25 to 35%. The assembly reduces the overall concentricity and ovality in rotation and provides more stability. The assembly prevents motor immobilization, provides enhanced actuator efficiency and axial clearance between the rotor assembly and the bobbin sub-assembly.
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 principals 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:CLAIMS

We claim:
1. An idle air control valve (30) comprising:
a housing (13); a terminal cover (12); a plurality of terminals (11); a bobbin sub-assembly (3); a rotor assembly (4); at least one bush (2); a pintle lock (5); a stator cup (1); a spring (7); a pintle (6); and an O-ring (14);
wherein:
said at least one bush (2) includes an elongation (15) which rests over the bobbin sub-assembly (3) and includes a guide (16) which fits inside internal diameter of the bobbin sub-assembly (3) such that the control of rotor concentricity is only dependent on the bobbin sub-assembly (3); and
said at least one bush (2) controls the axial clearance between the rotor assembly (4) and the bobbin sub-assembly (3).

2. The idle air control valve (30) as claimed in claim 1, wherein said guide (16) is fitted inside internal diameter of the bobbin sub-assembly (3) by at least one of a clearance fit, a transition fit, a press fit.

3. The idle air control valve (30) as claimed in claim 1, wherein said bush (2) has a top surface (2a) which is coincident with bottom surface (1a) of the stator cup (1) and pintle lock (5) to avoid axial movement.

4. The idle air control valve (30) as claimed in claim 1, wherein said control of concentricity of rotor assembly (4) is dependent on the bobbin sub-assembly (3), due to which consistent air flow is achieved in the idle air control valve (30) due to reduction in ovality or roundness, thereby increasing efficiency ranging from 25 to 35%.
5. The idle air control valve (30) as claimed in claim 1, wherein said bush (2) is at least one of a circular shape, a square shape, a rectangular shape and a hexagonal shape.

6. The idle air control valve (30) as claimed in claim 1, wherein said bobbin sub-assembly (3) is provided with plurality of terminals (11), and a plurality of coils (8) are wound around the bobbin sub-assembly (3) and said plurality of terminals (11) are covered via a terminal cover (12) and placed into the housing (13) in axial position.

7. The idle air control valve (30) as claimed in claim 1, wherein said rotor assembly (4) is inserted axially into the bobbin sub-assembly (3) and the bush (10) is provided to support axial movement to the distal end of the rotor assembly (4) close to the bottom surface of the housing (13), and a ball (9) is placed into the bottom of the housing (13) supporting the rotational movement of the rotor assembly (4).

8. The idle air control valve (30) as claimed in claim 1, wherein said spring (7) is attached on the outer periphery surface of the pintle lock (5) and is secured by the pintle (6) axially covering the spring (7).

9. The idle air control valve (30) as claimed in claim 1, wherein said O-ring (14) is provided for leakage proof connection between mating component and said housing (13).