WO2016063216A1

WO2016063216A1 - Noise free vacuum modulator in a motor vehicle

Info

Publication number: WO2016063216A1
Application number: PCT/IB2015/058072
Authority: WO
Inventors: Kabir BHANDARI; Amardip KUMAR; Ravi GOSWAMI; Rachit SAXENA
Original assignee: Padmini Vna Mechatronics Pvt. Ltd.
Priority date: 2014-10-20
Filing date: 2015-10-20
Publication date: 2016-04-28
Also published as: DE112015004753T5

Abstract

The present invention relates to an improved design of vacuum modulator or electronic vacuum regulating valve (EVRV) which completely eliminates the noise at emission system. The invention further introduces an improved design of the vacuum modulator which keeps the vacuum force balanced and makes the Vacuum Modulator Noise Free, more reliable and more durable. The noise free vacuum modulator of the present invention is resulted by the introduction of new design of internal filter, change in design of diaphragm, change in design of Cap, and change in design of Housing Sub Assembly.

Description

"NOISE FREE VACUUM MODULATOR IN A MOTOR VEHICLE"

FIELD OF THE INVENTION

The present invention relates to a noise free vacuum modulator in a motor vehicle. More particularly, this invention relates to an improved design of vacuum modulator or electronic vacuum regulating valve (EVRV) which completely eliminates the noise from the emission system.

BACKGROUND OF THE INVENTION

During operation period of engine when combustion temperature is very high, the atmospheric nitrogen react with oxygen to form oxides of nitrogen (NOx), which is one of the major components which causes 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 modulate vacuum as per ECU command to EGR valve opening 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 with considerable level of noise because there is always an air gap between plunger and the inner core. 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 no operational noise.

Yet another object of this invention is to provide an improved design with structural alterations of said housing to provide adequate space to place an internal filter for filtering out the dust and particulate matter and further providing the structural modification for rotational locking of the vacuum modulator while in operation.

Yet another object of this invention is to optimize the compression ratio of the electronic vacuum for decreasing the operational noise.

Yet another object of this invention is to increase the compression ratio of the electronic vacuum.

Yet another object of this invention is to optimize the length and diameter of the electronic vacuum.

Yet another object of this invention is to provide a circular groove optimized inner and outer diameter range.

Still another object of the invention is to increase number of ribs of internal filter so as to provide more strength for structure.

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 prevent the dust entry into the device.

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

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

SUMMARY OF THE INVENTION

Accordingly, the present invention relates to a noise free vacuum modulator in a motor vehicle. More particularly, this invention relates to an improved design of vacuum modulator or electronic vacuum regulating valve (EVRV) which completely eliminates the noise at emission system. The invention further introduces an improved design of the vacuum modulator which keeps the vacuum force balanced and makes the Vacuum Modulator Noise Free, more reliable and more durable. The noise free vacuum modulator of the present invention is resulted by the introduction of new design of internal filter, change in design of diaphragm, change in design of Cap, and change in design of Housing Sub Assembly.

In one aspect, the present invention is directed to an introduction of new design of internal filter of the modulator. The new Internal Filter has been provided with 6 ribs and which is thicker than existing filter so that it can endure more fluctuating load. Since, the modified Diaphragm rests on the Internal Filter only, the 6 ribs and thickened parts provide a better reliability while operation.

In another aspect, the present invention is directed to a modified design of diaphragm of the modulator. The modified design of Diaphragm of the present invention has two circular ribs, one on the top and one on the bottom. The modified diaphragm has a lesser diameter so the compression of the diaphragm is balanced enough to help in vacuum force balancing.

In another aspect, the present invention is directed to a modified design of Cap of the modulator. The modified design of Cap is incorporated with a circular groove cut on the lower surface of the Cap that provides a better placement of the rib of the diaphragm.

In yet another aspect of the present invention, the invention provides a noise free vacuum modulator comprising: a. a housing with a bobbin, the housing forming a coil assembly having a

terminal electrically connected with a coil wire wrapped on the bobbin;

b. a stationary outer core fixed into said housing;

c. an inner core fitted into said outer core;

d. a spring seated on a sleeve housed in a plunger, said plunger being rested on said inner core;

e. a sealing disc assembly seated on said spring beneath a nipple fitted in a cap, the sealing disc assembly comprising of a sealing disc, a sealing ring having molded rubber; and

f. a flexible diaphragm extending through said housing sandwiched between said plunger and said closure cap which rests on an internal filter; wherein:

the structure of said housing is modified to provide adequate space to place an internal filter for filtering out the dust and particulate matter,

the housing is modified to provide rotational locking of the vacuum modulator while in operation;

the internal filter is provided with 6 ribs to endure more fluctuating load; a circular groove cut on the lower surface of the cap is provided for better placement of the rib of the diaphragm; and

the diameter of said diaphragm has lesser diameter and increased length due to the circular groove cut enabling optimized compression to help in vacuum force balancing.

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 and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing electronic vacuum regulating valve or vacuum modulator.

FIG. 2 is an exploded view showing electronic vacuum regulating valve according to the present invention.

FIG. 3a is an outer view of present invention of housing sub assembly of vacuum modulator.

FIG. 3b is a sectional view of the housing sub assembly of vacuum modulator according to the present invention.

FIG. 4a is an outer view of cap of vacuum modulator according to present invention.

FIG. 4b is a sectional view of the cap of vacuum modulator according to the present invention. FIG. 5a is an outer view of dia phragm of vacuum modulator according to the present invention.

FIG. 5b is a sectional view of the diaphragm of vacuum modulator according to the present invention.

FIG. 6a is an outer view of an internal filter of vacuum modulator according to present invention.

FIG. 6b is a sectional view of the internal filter of vacuum modulator according to the present invention.

DETAILED 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 of electronic vacuum regulating valve is illustrated. Describing the vacuum modulator structure, the casing or housing 1 is formed in two pa rts. An outer core 22, has an integral inner core 23 & housing 1 which is secured in the left-hand end terminal 24. A diaphragm 5 is sandwiched between the plunger 2 and a closure cap 3. Dia phragm 5 separates the housing interior into two cha mbers. A sealing disc assembly comprises of sea ling disc 6 a nd a sea ling ring 4 having molded rubber seated on said spring 7 beneath a nipple 10 fitted in a cap 3. Spring 7 urges the diaphragm 5 rightwa rdly. On the other hand, the housing forms a Coil assembly having a terminal electrically connected with a coil wire 12 wrapped on the bobbin 13; As shown in Fig. 2, an exploded view showing electronic vacuum regulating valve according to the present invention is illustrated.

As shown in Fig. 3a, a sectional view of housing sub assembly of vacuum modulator is illustrated. As shown in Fig. 3b, a sectional view of the housing sub assembly 1 of vacuum modulator according to the present invention is illustrated. The modified design of Housing Sub Assembly 1 is changed so that the Internal Filter 25 can be properly placed and to provide the rotational locking while operation. The modified design of Housing Sub Assembly is changed so that the Internal Filter can be properly placed and to provide the rotational locking while operation. If an existing simple Housing Sub Assembly were used, that would not adequately eliminate the noise. This introduction has been shown to provide superior noise eliminating characteristics over the existing prior art. Consequently, objectionable noise is eliminated.

As shown in Fig. 4a, a sectional view of cap of vacuum modulator is illustrated. As shown in Fig. 4b, a sectional view of the cap 3 of vacuum modulator according to the present invention is illustrated. The modified design of Cap 3 is incorporated with a circular groove cut on the lower surface of the Cap 3 that provides a better placement of the rib of the diaphragm 5. The modified cap 3 also possesses the proper compression on it to help in vacuum force balancing. The modified design of Cap is incorporated with a circular groove cut on the lower surface of the Cap that provides a better placement of the rib of the diaphragm. The modified cap also possesses the proper compression on it to help in vacuum force balancing. If an existing simple cap were used, that would not adequately eliminate the noise. This introduction has been shown to provide superior noise eliminating characteristics over the existing prior art. Consequently, objectionable noise is eliminated. As shown in Fig. 5a, a sectional view of diaphragm of vacuum modulator is illustrated. As shown in Fig. 5b, a sectional view of the diaphragm 5 of vacuum modulator according to the present invention is illustrated. The modified design of Diaphragm 5 of the present invention has two circular ribs, one on the top and one on the bottom. The modified diaphragm 5 has a lesser diameter so the compression of the diaphragm 5 is balanced enough to help in vacuum force balancing. Thus, if an existing simple diaphragm were used, that would not adequately eliminate the noise. This introduction has been shown to provide superior noise eliminating characteristics over the existing prior art. Consequently, objectionable noise is eliminated.

As shown in Fig. 6a, a sectional view of internal filter of vacuum modulator is illustrated. As shown in Fig. 6b, a sectional view of the internal filter 25 of vacuum modulator according to the present invention is illustrated. The new Internal Filter 25 has been provided with 6 ribs and which is more thickened than existing filter so that it can endure more fluctuating load. Since, the modified Diaphragm 5 rest on the Internal Filter 25 only, the 6 ribs and thickened parts provide a better reliability while operation. The present introduction also prevents the Vacuum Modulator from the Dust Ingress and increases the life of the modulator. If an existing simple internal filter were used, that would not adequately eliminate the noise. This introduction has been shown to provide superior noise eliminating characteristics over the existing prior art. Consequently, objectionable noise is eliminated.

The present invention thus provides an improved vacuum modulator with no operational noise. The compression ratio of the electronic vacuum is optimized to decrease the operational noise. The invention thus results in an increase in the compression ratio of the electronic vacuum range from 10% ~ 20% to 22 % ~ 31%. The modifications are aimed to optimize the length and diameter of the electronic vacuum. Thus, the outer diameter of Circular groove is in range 2~2.2mm. The suggested range of diameter of circular groove is to tolerate fluctuating load by 6 ribs of internal filter. Increasing number of ribs provides more strength for structure.

Accordingly, in most preferred embodiment of the present invention is proposed a noise free vacuum modulator comprising:

a. a housing with a bobbin, the housing forming a coil assembly having a

terminal electrically connected with a coil wire wrapped on the bobbin;

b. a stationary outer core fixed into said housing;

c. an inner core fitted into said outer core;

the structure of said housing is modified to provide adequate space to place an internal filter for filtering out the dust and particulate matter, the housing is modified to provide rotational locking of the vacuum modulator while in operation; the internal filter is provided with 6 ribs to endure more fluctuating load; a circular groove cut on the lower surface of the cap is provided for better placement of the rib of the diaphragm; and the diameter of said diaphragm has lesser diameter and increased length due to the circular groove cut enabling optimized compression to help in vacuum force balancing.

In another preferred embodiment, the noise free vacuum modulator is proposed with diaphragm having two circular ribs, one on the top and one on the bottom. The modified diaphragm optimizes noise dampening between plunger and inner core of the vacuum modulator.

In still another embodiment, the noise free vacuum modulator is provided with a cap that is incorporated with a circular groove cut of diameter in the range of 2.0 - 2.2mm on the lower surface.

In still another embodiment of the present invention, the noise free vacuum modulator comprises of a modified design of housing sub assembly completely eliminates the noise at emission system.

In still another embodiment of the present invention, the noise free vacuum modulator is provided with the novel internal filter that minimizes the noise while providing 6 ribs to endure more fluctuating load.

In still another embodiment of the present invention, the noise free vacuum modulator has the modulator compression ratio in vacuum force balancing increased in the range of 10-20% to 22-31%. In the embodiment described above, the system according to the present invention was described as applied for an automotive vehicle. The system according to the present invention is not limited to such an application. It can be applied similarly to various other automotive vehicles, and can bring about similar advantages.

The invention is not restricted to the embodiments described above. The embodiments are not intended as limitations on the scope of the invention. Processes, methods, apparatus, compositions, and the like described herein are exemplary and not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art. The scope of the invention is defined by the scope of the claims.

Claims

CLAIMS WE CLAIM:

1. A noise free vacuum modulator comprising: a. a housing with a bobbin, the housing forming a coil assembly having a terminal electrically connected with a coil wire wrapped on the bobbin;

b. a stationary outer core fixed into said housing;

c. an inner core fitted into said outer core;

e. a sealing disc assembly seated on said spring beneath a nipple fitted in a cap, the sealing disc assembly comprising of a sealing disc, a sea ling ring having molded rubber; and

f. a flexible diaphragm extending through said housing sa ndwiched between said plunger and said closure cap which rests on an internal filter;

wherein:

the structure of said housing is modified to provide adequate space to place an internal filter for filtering out the dust a nd pa rticulate matter, the housing is modified to provide rotational locking of the vacuum modulator while in operation; the internal filter is provided with 6 ribs to endure more fluctuating load; a circular groove cut on the lower surface of the cap is provided for better placement of the rib of the dia phragm; and the diameter of said diaphragm has lesser diameter and increased length due to the circular groove cut enabling optimized compression to help in vacuum force balancing.

2. The noise free vacuum modulator as claimed in claim 1, wherein said diaphragm having two circular ribs, one on the top and one on the bottom.

3. The noise free vacuum modulator as claimed in claim 2, wherein the modified diaphragm optimizes noise dampening between plunger and inner core of the vacuum modulator.

4. The noise free vacuum modulator as claimed in claim 1, wherein said cap is incorporated with a circular groove cut of diameter in the range of 2.0 - 2.2mm on the lower surface.

5. The noise free vacuum modulator as claimed in claim 1, wherein the modified design of housing sub assembly completely eliminates the noise at emission system.

6. The noise free vacuum modulator as claimed in claim 1, wherein the novel internal filter minimizes the noise while providing 6 ribs to endure more fluctuating load.

7. The noise free vacuum modulator as claimed in claim 1, wherein the modulator compression ratio in vacuum force balancing increases in the range of 10-20% to 22-31%.

8. The noise free vacuum modulator as claimed in claim, wherein the overall modification in said housing, said diaphragm, said cap and said internal filter completely eliminates the noise from the vacuum modulator.