Claims:We claim:

1. An intake manifold of the internal combustion engine, the intake manifold is integrated with a coolant passage provided with a degassing point, wherein the integrated coolant passage ensures an efficient cooling by reducing the pressure drop in the cooling circuit.

2. An intake manifold as claimed in claim 1, wherein the coolant passage is integrated with the intake manifold by casting both together.

3. Integrated intake manifold as claimed in claim 2, wherein the integrated intake manifold comprises:

• an intake manifold body with an air-plenum for storing charge air;

• a coolant passage cast integrated with the intake manifold body;

wherein an inlet is provided at the front end of the coolant passage for introducing the coolant supplied by the EGR cooler via a coolant hose, and first coolant outlet is provided at the other end of the coolant passage for directing a portion of the coolant from the coolant passage to the thermostat housing and a second coolant outlet is provided as a degassing point at the top of the coolant passage and disposed near the first outlet for diverting a portion of the coolant from the coolant passage to the degassing tank.

4. Integrated intake manifold as claimed in claim 3, wherein a respective press-fit tube is provided at the inlet of the coolant passage for coolant received from the EGR cooler and at the first outlet of the coolant passage for supplying a portion of the coolant from the EGR cooler to the thermostat housing, the press-fit tubes being connected to a respective coolant hose.

5. Integrated intake manifold as claimed in claim 3, wherein the coolant passage is cast at the top of the air-intake manifold plenum for enabling additional cooling of the charge air contained therein by means of the coolant coming from the EGR cooler and channeled through it and then passed on to the thermostat housing and the cooled charge air is subsequently supplied to the cylinder head.
6. Integrated intake manifold as claimed in claim 5, wherein the coolant passage is cylindrical and the coolant inlet and the first coolant outlet thereof are disposed in-line.

7. Integrated intake manifold as claimed in claim 5, wherein the second coolant outlet is disposed adjacent the first coolant outlet and the axes of the first and second coolant outlets are disposed perpendicular to each other.

8. Integrated intake manifold as claimed in claim 7, wherein the second coolant outlet acts as degassing point for the coolant passing through the coolant passage.

9. An intake manifold made by casting an integrated coolant passage therewith for a diesel engine, wherein the integrated intake manifold comprises:

• an intake manifold body with an air-plenum for storing charge air to be cooled and supplied to the cylinder head;

• a coolant passage with a respective press-fit tube provided at the first outlet and the second outlet of the coolant passage for connecting a respective coolant hose to the EGR cooler and thermostat housing and a degassing point for diverting a portion of coolant for cooling the charge air in a degassing tank;

wherein an inlet is provided at the front end of the coolant passage for introducing the coolant supplied by the EGR cooler via a coolant hose, and the first coolant outlet is provided at the other end of the coolant passage for directing a portion of the coolant from the coolant passage to the thermostat housing and the second coolant outlet is provided as a degassing point at the top of the coolant passage and disposed near the first outlet for diverting a portion of the coolant from the coolant passage to the degassing tank.

10. Integrated intake manifold as claimed in claim 9, wherein the wall thickness around the cast coolant passage is in a range of 3 to 5 mm, preferably at least 4.5 mm.
11. Integrated intake manifold as claimed in claim 9, wherein the diameters and the position of the coolant passage is configured depending on the charge air flow and the type of casting method used.

12. Integrated intake manifold as claimed in claim 9, wherein the inner diameter of the coolant passage is configured to facilitate minimum restrictions therein and to cause the least pressure drop for increasing the cooling efficiency.

Dated: this day of 1st March, 2017. (SANJAY KESHARWANI)
APPLICANT’S PATENT AGENT , Description:FIELD OF INVENTION

The present invention relates to integration of the cooling passage into the intake manifold of an internal combustion engine (ICE). In particular, the present invention relates to cooling of the intake air charge for the diesel engine in an integrated cooling passage of the air-intake manifold thereof. More particularly, the present invention relates to an integrated cooling passage cast in the air-intake manifold of the diesel engine for cooling the charge air entering the cylinder head from the intake manifold thereof.

BACKGROUND OF THE INVENTION

In automobiles, internal combustion engines (ICEs) are used as prime movers to burn fuel for generating power. For burning fossil fuels used in these ICEs, air is required for combustion thereof. For allowing the entry of air into the combustion chamber required for combustion of fuel, e.g. diesel or petrol, an intake or inlet manifold is connected to one or more cylinder inlets of the ICE for supplying air required for generating power. Similarly, for releasing the exhaust gases, while an exhaust manifold is connected to said one or more cylinder outlets of the ICE. Here, the main function of the intake manifold is to distribute the combustion mixture (or just air in a direct injection engine) uniformly to each intake port in the cylinder head(s).

A uniform distribution of the incoming air or air-fuel mixture is important for optimizing the combustion efficiency and thereby the overall performance of the IC engine. Therefore, supplying optimum quantity of air required for combustion in the combustion chamber is a critical value for the existing diesel engines, which significantly affects emissions, performance and fuel economy thereof. Combustion air control involves a process that ensures the supply of sufficient amount of air to the combustion chamber at all possible operating conditions.

This process includes steps to meet the following requirements:

• Sufficient quantity of oxygen is for ensuring a complete combustion,

• Sufficient diluent, i.e. EGR to control the combustion temperature,

• Controlled temperature and pressure (density) of the charge air,

• Imparting suitable bulk motion and kinetic energy to the charge air within the cylinder/s for proper mixing of air, fuel and intermediate combustion products, and

• Acceptable size and concentration of impurities, such as dust and dirt.

The design and orientation of the intake manifold is a major factor in the volumetric efficiency of an engine. Any abrupt change in its contour causes a pressure drop, which results in lesser air (and/or fuel) entering the combustion chamber.

High-performance manifolds have smooth contours and gradual transitions between adjacent segments thereof.

Therefore, the intake manifold is one of the primary components in ICEs, e.g. diesel engines. The main functions of the intake manifold are:

1. To act as reservoir for the air required for the diesel engine combustion.

2. To provide the air with the required velocity and the uniformity to the individual cylinder intake port.

3. To provide the cooled air from the charge cooler to the diesel engine.

4. To house the bolts connecting the intake manifold and cylinder head and transfer the bolt load to the intake manifold gasket.

5. To provide sealing land for the intake manifold gasket.

Apart from the abovementioned functions, the intake manifold also supports components like common rail, EGR cooler, cooling pipes and hoses for the engine accessories.

It may also be used as a structural support for several other engine components or parts of the vehicle.
DISADVANTAGES WITH THE PRIOR ART

Conventional engines have cooling pipes and hoses routed around the periphery of the intake and exhaust system. Separate tubes and hoses carry coolants to be distributed to different engine accessories and radiator through the thermostat housing. In the existing design of the Intake manifold has the following disadvantages:

1. It provides support to the cooling pipes and hoses only. There is no secondary function for the intake manifold.

2. Different positions of the accessories result in longer pipes and tubes, which lead to higher pressure drop and lower cooling circuit efficiency.

3. Longer cooling pipes and tubes also increase the overall cost of components.

4. Longer pipes and hoses also degrade the aesthetics of the engine.

Therefore, there is an existing need to eliminate the abovementioned disadvantages of conventional intake manifold of ICEs, while simultaneously meeting the multiple objectives of efficient cooling, good performance improvement and the overall cost-reduction.

OBJECTS OF THE INVENTION

Some of the objects of the present invention satisfied by at least one embodiment of the present invention are as follows:

An object of the present invention is to provide the as cast cooling passage inside the intake manifold for the additional cooling of charge air.

Another object of the present invention is to eliminate the long routing of the pipes and hoses.

Another object of the present invention is to improve the cooling jacket efficiency.
Another object of the present invention is to reduce the number of parts and the overall manufacturing cost of the intake manifold.

Another object of the present invention is to improve the aesthetics of the IC engine.

A further object of the present invention is to reduce the complexity of assembly of the ICE.

A still further object of the present invention is to enhance the performance of the intake manifold.

These and other objects and advantages of the present invention will become more apparent from the following description when read with the accompanying figures of drawing, which are, however, not intended to limit the scope of the present invention in any way.

DESCRIPTION OF THE PRESENT INVENTION

The present invention relates to a diesel engine air intake manifold configured with an integrated water cooling passage, which is made as a cooling passage cast inside the intake manifold. The invention is configured for channeling the coolant entering from the EGR cooler through the air intake manifold connected to the thermostat housing.

As cast cooling passage provides a path to the coolant coming out from the EGR cooler and leads it to the thermostat housing. This coolant passage in the intake manifold allows it to perform additional cooling of the charge air passing through the intake manifold and supplied to the cylinder head/s.

In view of the required engine downsizing for complying the emission norms and at the same time to deliver engine power and torque of the order of those developed by multi-cylinder engines, the diesel engines must run on substantially higher temperatures, which has negative effects on the engine cooling system.
Therefore, it is necessary to make the engine cooling system more efficient. The degassing tank, also referred to as de-aeration tank or expansion tank removes the entrapped gases/air from the engine cooling system. The intake manifold cast with an integrated cooling passage having a degassing point and made in accordance with the present invention also ensures an efficient cooling of the ICE.

Moreover, the requirement of separate coolant pipes and hoses is also eliminated by making the surrounding layout with less number of parts, which eventually leads to an overall cost-reduction as well.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided an intake manifold of the internal combustion engine, the intake manifold is integrated with a coolant passage provided with a degassing point, wherein the integrated coolant passage ensures an efficient cooling by reducing the pressure drop in the cooling circuit.

Typically, the coolant passage is integrated with the intake manifold by casting both together.

Typically, the integrated intake manifold comprises:

• an intake manifold body with an air-plenum for storing charge air;

• a coolant passage cast integrated with the intake manifold body;

wherein an inlet is provided at the front end of the coolant passage for introducing the coolant supplied by the EGR cooler via a coolant hose, and first coolant outlet is provided at the other end of the coolant passage for directing a portion of the coolant from the coolant passage to the thermostat housing and a second coolant outlet is provided as a degassing point at the top of the coolant passage and disposed near the first outlet for diverting a portion of the coolant from the coolant passage to the degassing tank.

Typically, a respective press-fit tube is provided at the inlet of the coolant passage for coolant received from the EGR cooler and at the first outlet of the coolant passage for supplying a portion of the coolant from the EGR cooler to the thermostat housing, the press-fit tubes being connected to a respective coolant hose.

Typically, the coolant passage is cast at the top of the air-intake manifold plenum for enabling additional cooling of the charge air contained therein by means of the coolant coming from the EGR cooler and channeled through it and then passed on to the thermostat housing and the cooled charge air is subsequently supplied to the cylinder head.

Typically, the coolant passage is cylindrical and the coolant inlet and the first coolant outlet thereof are disposed in-line.

Typically, Integrated intake manifold as claimed in claim 5, wherein the second coolant outlet is disposed adjacent the first coolant outlet and the axes of the first and second coolant outlets are disposed perpendicular to each other.

Typically, the second coolant outlet acts as degassing point for the coolant passing through the coolant passage.

In accordance with the present invention, there is also provided an intake manifold made by casting an integrated coolant passage therewith for a diesel engine, wherein the integrated intake manifold comprises:

• an intake manifold body with an air-plenum for storing charge air to be cooled and supplied to the cylinder head;

• a coolant passage with a respective press-fit tube provided at the first outlet and the second outlet of the coolant passage for connecting a respective coolant hose to the EGR cooler and thermostat housing and a degassing point for diverting a portion of coolant for cooling the charge air in a degassing tank;
wherein an inlet is provided at the front end of the coolant passage for introducing the coolant supplied by the EGR cooler via a coolant hose, and the first coolant outlet is provided at the other end of the coolant passage for directing a portion of the coolant from the coolant passage to the thermostat housing and the second coolant outlet is provided as a degassing point at the top of the coolant passage and disposed near the first outlet for diverting a portion of the coolant from the coolant passage to the degassing tank.

Typically, the wall thickness around the cast coolant passage is in a range of 3 to 5 mm, preferably at least 4.5 mm.

Typically, the diameters and the position of the coolant passage is configured depending on the charge air flow and the type of casting method used.

Typically, the inner diameter of the coolant passage is configured to facilitate minimum restrictions therein and to cause the least pressure drop for increasing the cooling efficiency.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings, which include:

Figure 1 shows a perspective view of a 4-cylinder automobile engine fitted with a conventional intake manifold.

Figure 2 shows the typical cooling circuit layout for a diesel engine including the engine accessories thereof.

Figure 3a shows the conventional complex connections of long pipes and hoses for connecting the EGR cooler to the engine depicted in Figure 2.

Figure 3b shows the conventional intake manifold depicted in Figure 2.

Figure 4 shows front view of the intake manifold, in which the EGR cooler 310 is connected via a coolant passage integrated cast in the intake manifold 300 for supplying coolant to the thermostat housing as depicted further in Figure 5.

Figure 5 shows a perspective view of the diesel engine fitted with an intake manifold made with an integrated coolant passage cast therein and its interface with various accessories of the engine.

Figure 6 shows a perspective view of the coolant passage cast integrated with the intake manifold and its interfaces of the engine depicted in Figures 4 and 5.

Figure 7 shows the intake manifold having a body cast integrated with the coolant passage in accordance with the present invention.

Figure 8 shows a front view of the intake manifold of the diesel engine depicted in Figures 4 to 7 and made with a coolant passage cast integrated therewith

Figure 9 shows a cross-sectional view of the intake manifold of Figure 8 depicting the integrated coolant passage with different important features thereof.

Figure 10 shows a detailed cross-sectional view along section line A-A of Figure 9 to depict the and charge passage thereof to help in charge air cooling.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, different embodiments of the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1 shows a perspective view of a 4-cylinder automobile engine100 fitted with a conventional intake manifold 200. The intake manifold 200 is used only for providing a passage to the charge air and to support mounting of the peripheral accessories and mounting bosses for the coolant pipes and hoses. It shows the complex lay out of the pipes and hoses in conventional diesel engine 100 with an intake manifold 200, which results in higher pressure drop and complexity of the assembly thereof. It depicts the number of cooling pipes and hoses required in this conventional cooling circuit layout. However, due to the constraints in the packaging, additional bends and longer length pipes are necessary here, which result in a higher pressure drop and higher costs due to larger number of parts.

Figure 2 shows the typical cooling circuit layout for a diesel engine 100. Here, the engine accessories include an oil cooler 10 and an EGR cooler 20 connected to the crankcase 30 of the engine with cylinder head 40. The block diagram also depicts the other connections of the conventional cooling circuit layout, which include a degassing tank 50, a thermostat housing 60, a water pump 70, a radiator 80, an HVAC unit 90 and an air-compressor 100.

Figure 3a shows the conventional complex connections 250 of long pipes and hoses for connecting the intake manifold 200 to the engine 100 depicted in Figure 2.

Figure 3b shows the conventional intake manifold 200 depicted in Figure 2.

Figure 4 shows front view of the intake manifold 100, in which the EGR cooler 310 is connected via an coolant passage 320 integrated cast in the intake manifold 300 for supplying coolant to the thermostat housing 330 as depicted further in Figure 5.

Figure 5 shows a perspective view of the diesel engine 100 fitted with an intake manifold 300 made with an integrated coolant passage 310 cast therein and its interface with various accessories of the engine 100. This figure clearly shows the location of the EGR cooler 310 connected via an EGR cooler coolant outlet 316 to the integrated coolant passage 320. This coolant passage in turn has an outlet 322 for connecting the degassing tank 350 (not shown). A return hose 326 connected to the outlet 324 of the coolant passage 320 leads to the thermostat housing 330.

Figure 6 shows a perspective view of the coolant passage 320 cast integrated with the intake manifold 300 and its interfaces of the engine depicted in Figures 4 and 5. Due to this layout, the complex bends and the longer length of pipes of the conventional intake manifold are reduced to substantially lower the pressure drop in the cooling circuit. This reduction in pressure drop facilitates in a proper flow distribution across the engine accessories. Here, the coolant exiting from the outlet 314 of the EGR cooler 310 leads via the EGR cooler coolant hose 316 to the inlet 318 of the coolant passage 320. An outlet 322 leads to the degassing tank 350 and another outlet 324 is connected to another hose 326 leading to the thermostat housing 330. There is flexibility in the cooling passage layout. Since the coolant passage 320 is cast integrated with the intake manifold 300, this configuration helps in ensuring the effectiveness of the cooling circuit by proper degassing of the air generated in the cooling circuit. This layout also eliminates complex bends and reduces the length of pipes, which results in lower pressure drop for the cooling circuit and thereby facilitates in a proper flow distribution across the accessories.

Figure 7 shows the intake manifold 300 having a body cast integrated with the coolant passage 320 in accordance with the present invention. This integrated cast coolant passage 320 results in a simpler and compact layout for the cooling circuit. Moreover, the coolant received from the EGR cooler 310 is passed through the coolant passage 320 in the intake manifold 300. Subsequently, a portion of this cooler EGR coolant is guided to the degassing tank 350 and the remaining coolant is passed through another outlet 324 to the thermostat housing 330. This overall coolant flow through the intake manifold 300 results in an efficient cooling of the charge air being supplied to the IC engine which helps in improving the engine performance.

Figure 8 shows a front view of the intake manifold 300 of the diesel engine 100 depicted in Figures 4 to 7 and made with a coolant passage 320 cast integrated therewith. The layout of integrated coolant passage 320 is quite simple with omission of numerous long pipes and tubes of the conventional arrangement. The location of the outlet 322 leading to the degassing tank 350 is also shown here integrated with the intake manifold 300 to help in ensuring the effectiveness of the cooling circuit by proper degassing of the air generated in the cooling circuit. The coolant from the EGR cooler 310 enters the coolant flow passage 320 integrally configured with the intake manifold 300. Further, an outlet 324 leads the coolant passage 320 via another hose 326 to the thermostat housing 330.

Figure 9 shows a cross-sectional view of the intake manifold 300 of Figure 8 depicting the integrated coolant passage 320 with different important features thereof. The section line A-A is marked in this figure for further describing the intake manifold arrangement. The typical location of the coolant passage 320 above the air intake plenum 302 which helps in cooling the charge air entering the diesel engine 100, which substantially improves the performance of the diesel engine 100.

Figure 10 shows a detailed cross-sectional view along section line A-A of Fig.9 to depict the and charge passage thereof to help in charge air cooling. The cross-section of the intake manifold explaining the coolant passage and the charge passage. Location of the coolant passage will also help in cooling the change air which is entering the engine. This additional cooling will help in the improvement in engine performance.

WORKING OF THE INVENTION:

With the configuration of the cooling passage cast integrated with the intake manifold according to the present invention, it is possible to design the improved air intake manifold for an efficient cooling of the charge air being supplied to the diesel engine. This results in an optimal design of the cooling circuit layout to ensure an improved cooling efficiency. Although, the invention is disclosed and explained in terms of integrated coolant passage in the air intake manifold, the same can also be extended to any of the engine layouts, which include complexity of the cooling circuit and involve constraints of the packaging layout.
TECHNICAL ADVANTAGES OF THE PRESENT INVENTION

The integrated coolant passage casted in the intake manifold configured in accordance with the present invention has the following advantages:

• Ensures efficient cooling by reducing the pressure drop in the cooling circuit.

• Reduction in pressure drop due to simplified cooling is about 45% as compared to the conventional layout.

• Provides additional function of cooling the charge air passing through the intake manifold.

• Provides a location for the degassing for efficient air-cooling system.

• Less number of components lead to an eventual overall cost reduction.

• Reduction by about half in the number of components involved in routing the coolant to EGR cooler and back.

• Ease of assembly process.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to imply including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention. The description provided herein is purely by way of example and illustration.
Although, the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person in the art would readily recognize that these embodiments can be applied with modifications possible within the spirit and scope of the present invention as described in this specification by making innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies, in terms of their size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

While considerable emphasis has been placed on the specific features of the preferred embodiment described here, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiments without departing from the principles of the invention.

These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.