MOTOR VEHICLE"

FIELD OF THE INVENTION

The present invention relates to a noise dampening module for a vacuum modulator in a motor vehicle. More particularly, this invention relates to an improved design of vacuum modulator or electronic vacuum regulating valve (EVRV) wherein the said noise dampening module has been implemented by using sponge or alike material.

BACKGROUND OF THE INVENTION During operation period of engine when combustion temperature is very high atmospheric nitrogen react with oxygen to form oxides of nitrogen (NOx), which is one of the major components which cause air pollution. To prevent the formation of NOx the engine combustion temperature must be kept below the threshold temperature of NO _x . Exhaust gas recirculation (EGR) system is designed to achieve this reduction in temperature which reduces the amount of oxides of nitrogen produced. This is done by re-circulating a small amount of exhaust through the "exhaust gas recirculation" or EGR valve.

The vacuum modulator which drives the EGR valve in the transmission system is employed between the Electrical Control Unit (ECU) and the EGR valve. It changes an electric command from the ECU into a vacuum pneumatic command. The main function of the vacuum modulator is to monitor engine vacuum by a vacuum hose which is connected to the vehicle vacuum circuit. There is an inverse relation between engine vacuum and engine load. High vacuum is produced when the engine is under light load and the vacuum diminishes near to zero when the engine is under heavy load and vice versa. The vacuum modulator has a shaft which is attached to the throttle valve in the EGR valve. When the engine is under a very light load or no load, high vacuum act on the modulator which moves the throttle valve in one direction to allow early and soft transmission. However, when there is an increase in engine load, vacuum is diminished which moves the valve in other direction causing the transmission to shift later and more firmly.

The vacuum modulator in transmission control system acts on a modulator valve for pressure modulation in accordance with the engine vacuum. This modulated pressure is being used for controlling shift valve operation, line pressure regulation and other function in the transmission control system. The vacuum modulator comprises a subassembly including a diaphragm separating housing into two chambers, one chamber being open to the atmosphere and other chamber for connection to the engine's intake manifold. The lift valve of the EGR is controlled by the vacuum output of vacuum modulator. This output vacuum solely depends on the movement of plunger of vacuum modulator. Movement of the plunger is controlled by Pulse-width Modulation (PWM) input to vacuum modulator. When the Vacuum Modulator receives an electric command, the pressure on the output pipe is a modulated vacuum and it depends on the equivalent voltage (% PWM) applied on it. When the Vacuum Modulator doesn't receive electric command, the pressure on the output pipe must be the atmospheric pressure.

Conventional vacuum modulator operates at a very high noise level because there is always an air gap between plunger and the inner core. This air gap creates noise due to metal to metal contact. Moreover, the noise level increases very much during engine off-on condition. The noise can be eliminated by removing the inner gap by adding silicon oil, but the solution is not permanent as after some time oil evaporates and noise reappears.

Unfortunately, the prior art fails to provide an adequate and definite solution to the noise problem. Therefore, there is a need of reliable and efficient vacuum modulator with no operational noise, no noise during engine off-on time and provide rider a noise and vibration free driving.

OBJECT OF THE INVENTION

The main object of this invention is to provide an electronic vacuum regulating valve with reduce operational noise. Yet another object of this invention is to provide an improved design for electronic vacuum regulating valve.

Yet another object of this invention is to provide an electronic vacuum regulating valve with no noise on plunger movement.

Yet another object of this invention is to fill the air gap between plunger and inner core.

Yet another object of this invention is to provide a noise dampening between plunger and inner core of the vacuum modulator.

Yet another object of the invention is to reduce noise due to metal to metal contact. Still another object of this invention is to reduce the noise level during vehicle off -on condition.

SUMMARY OF THE INVENTION

The present invention relates to a noise dampening module for a vacuum modulator in a motor vehicle. More particularly, this invention relates to an improved design of vacuum modulator or electronic vacuum regulating valve (EVRV) wherein the said noise dampening module has been implemented by using sponge or alike material.

There is always an air gap between the plunger and inner core of the vacuum modulator. This air gap creates noise due to metal to metal contact and noise intensity increases further during vehicle off-on condition. This air gap is eliminated by implementing a noise dampening module between the plunger and the inner core.

The said noise dampening module is made up of foam, sponge or sponge with PU or alike material.

In one aspect, the present invention is directed to an implementation of a noise dampener made of a sponge material secured between the plunger and inner core of the vacuum modulator. The module is provided to dampen noise resulting from the interaction between the metal to metal contacts during vehicle off-on condition. The sponge material may be at least slightly compressed and forced between the plunger and the inner core and frictionally retained there between. However, it is preferred to additionally positively secure the sponge material there between such as by adhering or other conventional securing means. If an ordinary simple rigid mass were used, such would not adequately dampen to reduce noise. Consequently, objectionable noise is reduced. This arrangement has been shown to provide superior noise dampening characteristics over the existing prior art. Implementation of sponge or alike material with the present invention provides improved noise dampening during vehicle off-on condition and provides rider a noise and vibration free driving.

The above advantages and other advantages, and features of the present description will be readily apparent from the following detailed description when taken alone or in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a conventional electronic vacuum regulating valve;

FIG. 2 is a sectional view showing electronic vacuum regulating valve according to the invention;

FIG. 3 is a sectional view showing noise dampening module according to the invention.

FIG. 4 is a cross sectional view of the noise dampening module according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. However, the invention is not limited to the following embodiments, but can be modified in various forms. The embodiments are provided to complete the disclosure of the invention and to completely notify the scope of the invention to those skilled in the art. As shown in FIG. 1, a sectional view showing a conventional electronic vacuum regulating valve is illustrated.

Describing the vacuum modulator structure, the casing or housing 1 is formed in two parts. An outer core 22, has an integral inner core 23 which is secured in the left- hand end terminal 24. A diaphragm 5 is sandwiched between the plunger 2 and a closure cap 3. Diaphragm 5 separates the housing interior into two chambers. A sealing ring 4 and a sealing disc 6 cover the sealing disc sub assembly 9 and there is provided a spring 7 seated on the sleeve 8 and a nipple 10 is fitted in cap 3. Spring 7 urges the diaphragm 5 rightwardly. On the other hand, the housing 1 forms a U- Armature 11 into which there are inserted a terminal 24 electrically connected with the coil wire 12 and the other terminal. This coil wire 12 is wound on the bobbin 13.

As shown in FIGS. 2 & 3, in vacuum regulating valve there is always gap between the plunger 2 and inner core 23 and this air gap creates the noise due to metal to metal contact and it creates more noise during vehicle off-on condition. This gap is optimized and implemented to a certain extent as compared to the conventional vacuum modulator as shown in FIG.l. The noise dampening module 16 is adhering or using other conventional securing means in between this air gap and is made up of sponge or alike material. As shown in FIG. 4, a cross-sectional view of the noise dampening module is illustrated. This module has been introduced to eliminate the air gap which is made up of foam or sponge with PU material. Silicon oil may also apply on the module while operating the device and it has life time oil. A reduction of noise level difference of 5-7 db has been observed while introducing this module between the plunger 2 and inner core 23.

As will be appreciated by one with ordinary skill in the art, the module described in FIGS. 1, 2, 3, and 4 may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, and the like. As such, various steps or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the objects, features, and advantages described herein, but are provided for ease of illustration and description. Although not explicitly illustrated, one with ordinary skill in the art will recognize that one or more of the illustrated steps, module, or functions may be repeatedly performed depending on the particular strategy being used.

As those with ordinary skill in the art will understand, various features of the examples illustrated and described with reference to any one of the Figures may be combined with features illustrated in one or more other Figures to produce alternative examples that are not explicitly illustrated and described. The combinations of features illustrated provide representative examples for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations. Those with ordinary skill in the art will recognize that the teachings of the present disclosure may be applied to other applications or implementations.

While the best mode has been described in detail, those familiar with the art will recognize various alternative designs and examples within the scope of the following claims.