EP2901058A2

EP2901058A2 - Inductive energy optimized vacuum solenoid valve

Info

Publication number: EP2901058A2
Application number: EP13841757.1A
Authority: EP
Inventors: Kabir BHANDARI; Amardip KUMAR; Abhishek Kumar; Ravi GOSWAMI
Original assignee: Padmini VNA Mechatronics Pvt Ltd
Current assignee: Padmini VNA Mechatronics Pvt Ltd
Priority date: 2012-09-25
Filing date: 2013-09-24
Publication date: 2015-08-05
Also published as: WO2014049608A3; WO2014049608A2; EP2901058A4

Abstract

The present invention provides a vacuum solenoid valve which minimizes the switch off or inductive energy to such an extent so that it prevents sudden damage of an electric control unit in a motor vehicle from increased inductive load. Inductive energy optimized vacuum solenoid valve is able to respond to the ON/OFF signal from the ECU at very low inductive load of 17.4mJ at 26V, RT and 24.7mJ at 26V, -40⁰C. This optimized inductive load is almost insufficient to damage the ECU or other electrical components on sudden increase or decrease in temperature in a motor vehicle parts.

Description

"INDUCTIVE ENERGY OPTIMIZED VACUUM SOLENOID VALVE"

FIELD OF THE INVENTION

The invention relates to an inductive energy optimized vacuum solenoid valve. More particularly, this invention relates to an improved design of a vacuum solenoid valve for optimization of switch off energy or inductive energy wherein the said valve is used in an electrical control unit (ECU) of a motor vehicle.

BACKGROUND OF THE INVENTION

An Electrical Control Unit (ECU) is meant for managing the engine system of a motor vehicle. Generally, a vacuum solenoid valve is meant for responding to the ON/OFF signal from the ECU. When it is ON, a vacuum signal from the suction pipe or compressor outlet is fed into the valve actuator. The actuator is hard to open at this time. When the control unit sends an OFF signal, the solenoid coil pulls the plunger upward and cuts the route to the suction pipe. Therefore, a vacuum solenoid valve plays an important role in controlling air flow to achieve a particular pressure and to isolate vacuum volumes from pumps in a motor vehicle.

Most vacuum solenoid valves operate on a digital principle. They, therefore, possess two distinct states; first, when the coil is activated by an electrical current, and second, when the valve is resting in the absence of electricity. Vacuum solenoid valves are generally designed for those applications where reduced energy consumption is a determinant for operation or transmission of a device. A short electrical impulse enables opening and closing of the solenoid valve, and due to the residual effects of a permanent magnet, this impulse is sufficient to maintain the valve in a particular working position with almost no electrical energy consumption. However, when power is provided through ECU to the solenoid coil of the vacuum valve, the coil starts building a magnetic field induced current that is many times higher than the amount of provided current. The initial current flow is called inrush current and the current that holds the armature in the energized position is called holding current. If the coil is powered with DC voltage, an inductive voltage is created within the device. This inductive voltage is called an inductive kick, is up to ten times the applied voltage and is in reverse polarity to the applied voltage. A diode or other type of suppression device must be connected across the coil of the solenoid to protect any other electronic components in the circuit from being damaged by this voltage. When the solenoid coil is de-energized, the inductive voltage has opposite polarity to the power supply, so it flows through the diode and back into the coil. Since the coil is made of a large length of wire, the inductive voltage energy dissipates as it moves through the wire. This renders this excessive inductive voltage harmless. However, sometimes this inductive load may damage controlling devices due to high temperature variation during vehicle transmission or operation.

This inductive load cannot be lowered by any means beyond a certain minimum extent. And, it always remains within the vacuum solenoid valve in the form of inductive load. Many vacuum solenoid valves are available in the prior art which claim to achieve an inductive voltage only till 20.42mJ at 26V, room temperature and 30.2mJ at 26V,-40°C. However, even this much amount of inductive load is sufficient to damage ECU and other electrical components of a motor vehicle. Therefore, there is a need to further minimize this inductive voltage to a very significant lowest point where the possibility of damage to the controlling units would be almost negligible at any sudden temperature variation during vehicle transmission or operation.

Conventional vacuum solenoid valves are unable to execute opening and closing operations with optimized inductive load with high precision. Moreover, while it is being used, the mechanical properties of a vacuum solenoid valve can change to such an extent that after a long operating period and altered environmental conditions, the vacuum solenoid valve will no longer be able to optimize the inductive load, even if it had originally been suited for this. Therefore, there is a need of a reliable and efficient vacuum solenoid valve which can withstand such wear and tear and environmental alterations so as to prevent damage of any control units by achieving lowest optimized inductive load.

OBJECT OF THE INVENTION

The main object of this invention is to provide an inductive energy optimized vacuum solenoid valve.

Yet another object of this invention is to optimize the inductive load in a vacuum solenoid valve.

Yet another object of this invention is to provide a system for controlling the inductive load in a motor vehicle.

Yet another object of this invention is to prevent the damage of controlling units from inductive kick in a vacuum solenoid valve.

Yet another object of this invention is to provide a reliable vacuum solenoid valve. Yet another object of this invention is to provide more efficient vacuum solenoid valve. Yet another object of this invention is to further minimize the inductive volt in a vacuum solenoid valve.

Yet another object of this invention is to increase the life of solenoid valve and electrical circuits of a motor vehicle.

Still another object of this invention is to provide a vacuum solenoid valve where the inductive voltage is optimized to less than or equal to about 24.7mJ at 26V, -40°C.

SUMMARY OF THE INVENTION

The present invention provides a vacuum solenoid valve which minimizes the switch off or inductive energy to such an extent so that it prevents sudden damage of an electric control unit in a motor vehicle from increased inductive load. Inductive energy optimized vacuum solenoid valve is able to respond to the ON/OFF signal from the ECU at very low inductive load of 17.4mJ at 26V, RT and 24.7mJ at 26V, -40°C. This optimized inductive load is almost insufficient to damage the ECU or other electrical components on sudden increase or decrease in temperature in a motor vehicle parts. The present invention thus combines the functions of vacuum flow control and damage control into a single unit which may be used in more efficient and effective ways over the existing devices.

The inductive energy optimized vacuum solenoid valve of the present invention utilizes a fix core and moving core geometry optimization which provides an improved reliability and lesser inductive load to prevent the damage of controlling units such as ECU in a motor vehicle. In one embodiment, it is provided that the optimized vacuum solenoid valve comprises of a housing with a stationary fix core fixed into the said housing. This valve is electrically connected with the coil wire and with other terminal of the valve. This coil wire is wound on the bobbin. This bobbin is made of a non-magnetic material and has a moving core fitting the stationary fix core therein. A fix core insert along with spring housed in the moving core thereby forming a unit to maintain a constant distance between the said moving core and fix core. Further characterized in that, at least one insert pin made up of non-magnetic material extends from the said fix core in a direction opposite to that of the said fix core insert. Further, the inner diameter of the said fix core of vacuum solenoid valve is optimized to a range of 2.5 mm to 4.75 mm so as to maintain the lowest inductive load in the said housing and ultimately minimize the switch off or inductive energy to such an extent so that it prevents sudden damage of an electric control unit in a motor vehicle from increased inductive load.

Various general and specific objects and advantages of the invention will become apparent when reference is made to the following description of the invention considered in conjunction with the related drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 2 is a sectional view showing vacuum solenoid valve according to this invention;

FIG. 3 is an exploded view of the vacuum solenoid valve according to this invention;

FIG. 4 is a sectional view of fix core assembly according to this invention;

FIG. 5 is an exploded view of fix core assembly according to this invention; FIG. 6a is a prospective view of moving core assembly according to this invention; FIG. 6b is a sectional view of moving core assembly according to this invention; FIG. 7 is a comparison chart of switch off energy at room temperature; and FIG. 8 is a comparison chart of switch off energy at -40°C. 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, and 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 housing 1 is made of a non-magnetic material and has a stationary fix core 10, a moving core 8, a coil wire 3, a bobbin 2 and a spring 9 built therein. On the other hand, the housing 1 forms a mounting bracket 5 into which there are inserted a terminal 4 electrically connected with the coil wire 3 and the other terminal. This coil wire 3 is wound on the bobbin 2. The bobbin 2 is made of a nonmagnetic material and has a moving core 8 fitting the stationary fix core 10 therein. The stationary fix core 10 has a fix core insert 11, into which there is inserted the spring 9 for urging a later-described moving core 8 away from the stationary fix core 10 at all times, and is fixed in the housing 1 by a moving core sub assembly 7. When the electric power is supplied from the other terminal through the terminal 4 to the coil wire 3, a magnetic power acts upon the stationary fix core 10 so that the moving core 8 is attracted by the stationary fix core 10 to act in a direction.

As shown in FIG. 2, the inner diameter of the said fix core 10 of the vacuum solenoid valve is optimized in a range of 2.5 mm to 4.75 mm as compared to convention fix core 10 as shown in FIG. 1 and to maintain the lowest inductive load in the said housing 1. At least one insert pin 12 made up of non-magnetic material extends from the said fix core 10 in a direction opposite to that of the said fix core insert 11.

As shown in FIG. 3, an exploded view of the vacuum solenoid valve having an insert pin 12 which is a separate part of the said fix core 10. The insert pin 12 is made up of non magnetic material/metal/alloy which is selected from the non-limiting group of nylon, resin, plastic, Aluminium, Brass Tin, Indium, Stainless steel and alike.

As shown in FIG. 4, a sectional view of the fix core assembly having an insert pin 12 which is a separate part of the said fix core 10. In an embodiment, plurality of the said insert pin 12 is arranged over the circumference of the said fix core 10 and it extends from the said fix core 10 in a direction opposite to that of the said fix core insert 11.

FIG. 5 is showing an exploded view of the fix¹ core assembly in accordance with the present invention.

FIG. 6a & 6b are showing perspective and sectional view of the moving core assembly in accordance with the present invention.

As shown in FIG. 7 & 8, the comparison chart of conventional solenoid valves with the present inductive energy optimized vacuum solenoid is tabulated wherein the inductive energy is optimized upto the level of 17.4 mJ at 26V, RT and 24.7 mj at 26V, - 40°C.

DESCRIPTION OF THE INVENTION

The present invention relates to an inductive energy optimized vacuum solenoid valve. The optimized inductive energy is achieved through the geometry optimization of Fix Core and Moving Core of the vacuum solenoid valve.

In accordance with the invention, the vacuum solenoid valve, arranged in the vacuum line connecting the ECU device is controlled as a function of vacuum flow control during vehicle transmission. In addition, the vacuum solenoid valve may be controlled as a function of damage control of the electrical components of the motor vehicle. Such control results in an interruption of the vacuum applied and generation of low switch off energy at the closing adjustment stage of the device in all operating states of the vehicle.

In accordance with a further characteristic of the invention, the inner diameter of fix core of the vacuum solenoid valve is increased to a certain extent (eg. 1.7 mm) and the length of suction pipe or insert pin is replaced by Aluminium pipe so that the vacuum flow control is maintained at its original position. This optimization in the geometry of fixed core and moving core of vacuum solenoid valve permits the generation of low switch off energy during the operation of the vehicle in one of the aforementioned operating states--for example, changeover from one gear to another through the neutral shift position-without immediate closing of the solenoid valve. In accordance with one exemplary embodiment of the invention, this geometry optimization is provided to control the excessive inductive load within the vacuum solenoid valve during the vehicle transmission or operation. This geometry optimization comprises a change in the inner diameter of the fix core and a replacement of insert pin with Aluminium metal. Instead of the continuous fix core extension of same metal, or in addition thereto, the Aluminium metal insert pin is included as moving core to dissipate the switch off energy very quickly when the motor vehicle is in transmission or in operational stage.

EXAMPLES

Now, the present invention will be described in further detail with reference to Examples and various Tables. However, it should be understood that the present invention is by no means restricted by such specific Examples and Tables.

EXAMPLE 1

The switch off energy has been calculated in various available vacuum solenoid valves such as Sample 1, Sample 2 and Sample 3 and is compared with the present invention device Gen.6. The optimized inductive switch off energy of various devices is compared in table 1.

Table: 1 Switch off Energy

EXAMPLE 2

Geometry optimization of fix core in Sample 3 and present invention device Gen.6 has been calculated in table-2

Table: 2 Geometry variations

Thus, the present invention has been described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same, and having set forth the best mode contemplated of carrying out this invention. We state that the subject matter, which we regard as being our invention, is particularly pointed out and distinctly asserted in what is claimed. It will be understood that variations, modifications, equivalents and substitutions for components of the above specifically-described embodiment of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

An inductive energy optimized vacuum solenoid valve comprising:

a. a housing (1) with bobbin (2);

b. a stationary fix core (10) fixed into the said housing (1);

c. a moving core (8) fitted between the said bobbin (2) and the said fix core (10); d. a spring (9) housed in the said moving core (8);

e. a fix core insert (11) housed in the said spring (9) thereby forming a unit to maintain a constant distance between the said moving core (8) and fix core (10); characterized in that:

at least one insert pin (12) made up of non-magnetic material extends from the said fix core (10) in a direction opposite to that of the said fix core insert (11); and the inner diameter of the said fix core (10) of the vacuum solenoid valve is optimized in a range of 2.5 mm to 4.75 mm to maintain the lowest inductive load in the said housing (1).

The inductive energy optimized vacuum solenoid valve as claimed in claim 1, wherein the said insert pin (12) is a separate part of the said fix core (10).

The inductive energy optimized vacuum solenoid valve as claimed in claim 1, wherein the said non magnetic material is selected from the non-limiting group of nylon, resin, plastic, Aluminium, Brass or Stainless steel.

The inductive energy optimized vacuum solenoid valve as claimed in claim 1, wherein plurality of the said insert pin (12) is arranged over the circumference of the said fix core (10) and it extends from the said fix core (10) in a direction opposite to that of the said fix core insert (11).

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5. The inductive energy optimized vacuum solenoid valve as claimed in claim 1, wherein the said vacuum solenoid valve has inner diameter preferably in range of 3.5 mm to 4.65 mm.

6. The inductive energy optimized vacuum solenoid valve as claimed in claim 1, wherein the inductive energy is optimized upto the level of 17.4 mJ at 26V, RT and 24.7 mJ at 26V, -40°C.

7. An inductive energy optimized vacuum solenoid valve comprising:

a. a housing (1) with bobbin (2);

b. a stationary fix core (10) fixed into the said housing (1);

at least one insert pin (12) made up of non-magnetic metal and alternately nonmagnetic alloy extends from the said fix core (10) in a direction opposite to that of the said fix core insert (11); and the inner diameter of the said fix core (10) of the vacuum solenoid valve is optimized in a range of 2.5 mm to 4.75 mm to maintain the lowest inductive load in the said housing (1)·

8. The inductive energy optimized vacuum solenoid valve as claimed in claim 6, wherein the said non magnetic metal or alloy is selected from the non-limiting group of Aluminium, Tin, Indium, Brass or Stainless steel.

9. A method of optimizing a vacuum solenoid valve as claimed in claim 1, wherein the said vacuum solenoid valve is particularly adapted for use in a motor vehicle and wherein the

2 said optimized inductive load is almost insufficient to damage the ECU or other electrical components on sudden increase or decrease in temperature in a motor vehicle.

10. The method of optimizing a vacuum solenoid valve as claimed in claim 9, wherein the said switch off energy is 17.4 mJ at 26V, RT and 24.7 mJ at 26V, -40°C.

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