WO2011135714A1

WO2011135714A1 - Engine

Info

Publication number: WO2011135714A1
Application number: PCT/JP2010/057682
Authority: WO
Inventors: 能川真一郎
Original assignee: トヨタ自動車株式会社
Priority date: 2010-04-30
Filing date: 2010-04-30
Publication date: 2011-11-03
Also published as: JPWO2011135714A1; JP5278603B2

Abstract

Disclosed is an engine (50) which includes a cylinder block (51) with a plurality of cylinders (51a) formed therein. Each of the plurality of cylinders (51a) includes an intake port (52a) which is capable of cooling a wall portion (51c) from a surface thereof, the wall portion being formed between the adjacent cylinders of the plurality of cylinders (51a); a fuel injection valve (58); and an oil jet (59). The engine (50) is provided with the intake port (52a), the fuel injection valve (58), and the oil jet (59) so that the wall portion (51c) between the two cylinders of the plurality of cylinders (51a) is cooled in a symmetrical manner.

Description

engine

The present invention relates to an engine, and more particularly to an engine that performs cooling.

Conventionally, the engine is generally cooled. In this regard, for example, Patent Document 1 discloses a technique that is considered to be related to the present invention in that the engine is cooled with oil injected from an oil jet.

JP 2008-163936 A

By the way, in the engine, the temperature of the wall portion formed between the cylinders is particularly likely to rise due to the structure. Specifically, as shown in FIG. 4, the temperature of the wall portion formed between the cylinders shown in (a) is compared with the temperature of the cylinder wall portion formed on the engine intake side shown in (b). High in all engine operating conditions. Further, when the operating state of the engine changes from the low rotation / low load operation region to the high rotation / high load operation region, the temperature of the wall portion formed between the cylinders shown in FIG. Compared with the temperature of the cylinder wall portion formed on the engine intake side shown in FIG. In this respect, the temperature rise of the wall portion formed between the cylinders is problematic in that it causes abnormal consumption of engine oil.

On the other hand, in the internal combustion engine disclosed in Patent Document 1, an oil jet is similarly provided for each wall portion formed between the cylinders. For this reason, in this internal combustion engine, it is thought that each of these wall parts can be cooled equally.
However, in an engine, cooling with a cooling medium is generally performed, and the cooling capacity of the cooling medium gradually decreases as heat is received. For this reason, depending on the engine, the walls formed between the cylinders may not be equally cooled by the cooling medium due to the structure of the cooling medium passage through which the cooling medium flows. Therefore, in this case, even when the walls formed between the cylinders are cooled equally by the oil jet, there is a possibility that insufficient cooling occurs in some of the walls. In this respect, there is a concern that such insufficient cooling may occur at the time of high-rotation and high-load operation in an engine in which the temperature of the combustion chamber wall surface becomes higher, such as an engine that performs high-speed combustion. Such a lack of cooling is problematic in that it hinders improvement in fuel consumption, particularly in an engine that performs high-speed combustion to improve fuel consumption.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide an engine that can suitably prevent or suppress the occurrence of insufficient cooling at a wall portion formed between cylinders.

In order to solve the above problems, the present invention can cool from the surface a cylinder block formed with a plurality of cylinders and a wall formed between adjacent cylinders of the plurality of cylinders for each of the plurality of cylinders. A cooling means, and the cooling means is provided between the first cylinder and the second cylinder so that the mode of cooling the wall portion is symmetrical between the first cylinder and the second cylinder, and the cooling means At least one of an injection means for injecting toward the wall and an intake air introduction means for introducing intake air so as to flow toward the wall, and the injection means is a fuel injection valve or an oil jet. At least one of these engines.

According to the present invention, the cooling medium flows through the cylinder block along the plurality of cylinders and from among the plurality of cylinders toward the cylinder side positioned at one end from the cylinder side positioned at one end in the crank axis direction. A cooling medium passage is formed, and the first cylinder is a cylinder located on the most downstream side in the flow direction of the cooling medium flowing through the cooling medium passage among the plurality of cylinders; It is preferable that the cylinder is configured such that, among the plurality of cylinders, one of the cylinders located upstream of the first cylinder in the flow direction of the cooling medium flowing through the cooling medium passage.

In the present invention, it is preferable that the intake air introduction means introduces intake air so as to further generate a swirling airflow.

According to the present invention, it is possible to suitably prevent or suppress the occurrence of insufficient cooling at the wall portion formed between the cylinders.

It is a schematic block diagram of the engine concerning an Example. It is a schematic diagram which shows the principal part of the engine concerning an Example in a horizontal cross section. It is a schematic diagram which shows the principal part of the engine concerning an Example by a vertical cross section. It is a figure which shows an example of the temperature of the cylinder peripheral part according to the driving | running state of an engine. In FIG. 4, the amount of heat generated according to the operating state of the engine is also shown by a broken line for reference.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

An engine 50 shown in FIG. 1 is an in-line four-cylinder direct fuel injection gasoline engine, and includes a cylinder block 51, a cylinder head 52, a piston 53, an intake valve 55, an exhaust valve 56, and a spark plug 57. And a fuel injection valve 58 and an oil jet 59. The cylinder block 51 is formed with a cylinder 51a and a water jacket 51b. A piston 53 is accommodated in the cylinder 51a. A cylinder head 52 is fixed to the upper surface of the cylinder block 51. The combustion chamber 54 is formed as a space surrounded by the cylinder block 51, the cylinder head 52 and the piston 53.

The cylinder head 52 has an intake port 52a and an exhaust port 52b. The intake port 52 a guides the intake air S to the combustion chamber 54, and the exhaust port 52 b exhausts the gas in the combustion chamber 54. The cylinder head 52 is provided with intake and

exhaust valves

55 and 56 for opening and closing these intake and

exhaust ports

52a and 52b. The cylinder head 52 is provided with a spark plug 57 with an electrode protruding substantially at the center of the upper portion of the combustion chamber 54. Further, the cylinder head 52 is provided with a fuel injection valve 58 so that the fuel F can be directly injected into the cylinder. In the engine 50, an oil jet 59 is provided in a lower part of the cylinder block 51. The oil jet 59 includes first and

second nozzles

59 a and 59 b, and the first nozzle 59 a is provided on the back side of the piston 53 so as to inject engine oil P that is lubricating oil of the engine 50. .

As shown in FIGS. 2 and 3, the cylinder block 51 has a plurality of cylinders 51a (four in this case). The plurality of cylinders 51a are provided in series with each other and constitute from # 1 cylinder to # 4 cylinder. A wall 51c is formed between adjacent cylinders among the plurality of cylinders 51a.
In the cylinder block 51, a water jacket 51b is formed along the plurality of cylinders 51a. Specifically, the water jacket 51b is provided in the cylinder block 51 around the plurality of cylinders 51a so as to surround the entire plurality of cylinders 51a. The water jacket 51b of the plurality of cylinders 51a constitutes a cylinder (here, # 4 cylinder) located at the other end from a cylinder (here, a cylinder constituting # 1 cylinder) located at one end in the crank axis direction L. The cooling water W is circulated toward the cylinder) side. The cooling water W flowing through the water jacket 51b provided in this way sequentially cools each of the plurality of cylinders 51a from one end side to the other end side.

In the engine 50, the intake air S is introduced in each cylinder 51a so as to circulate toward the wall 51c. The intake air S is further introduced so as to generate a swirling airflow in the cylinder. The intake air S thus introduced is specifically introduced so as to generate an oblique tumble flow as a swirling airflow. In the engine 50, an intake port 52a is provided for each cylinder 51a so that the intake air S can be introduced in this manner. The intake port 52a that introduces the intake air S in this manner can cool the wall 51c from the surface.

In the engine 50, the fuel F is injected toward the wall 51c in each cylinder 51a. The injection direction of the fuel F is set so that the fuel F can flow in synchronization with the flow of the intake air S introduced so as to flow toward the wall portion 51c. Transported by tumble flow. In the engine 50, each cylinder 51a is provided with a fuel injection valve 58 so that the fuel F can be injected in such a manner. The fuel injection valve 58 that injects the fuel F in this manner can cool the wall 51c from the surface.

In the engine 50, the engine oil P is injected not only to the back side of the piston 53 but also to the wall 51c in each cylinder 51a. In this regard, in the engine 50, the second nozzle 59b provided in the oil jet 59 is provided so that the engine oil P can be injected toward the wall portion 51c. In the engine 50, an oil jet 59 is provided for each cylinder 51a so that the engine oil P can be injected in this manner. The oil jet 59 that injects the engine oil P in this manner can cool the wall 51c from the surface. Instead of providing the second nozzle 59b in the oil jet 59, for example, an oil jet capable of injecting the engine oil P toward the wall 51c can be separately provided.

Further, in the engine 50, the intake port 52a is provided so that the aspect of introducing the intake air S between the two cylinders 51a of the plurality of cylinders 51a is symmetrical, whereby the aspect of cooling the wall portion 51c is provided. It is provided to be symmetrical.
Specifically, the intake port 52a is a cylinder located on the most downstream side in the flow direction of the cooling water W flowing through the water jacket 51b among the plurality of cylinders 51a (here, a cylinder constituting the # 4 cylinder), A mode of introducing the intake air S (for example, a mode of cooling the wall portion 51c) between any of the cylinders located upstream of the cylinder (for example, a cylinder constituting the # 3 cylinder) is orthogonal to the crank axis L It is provided so that it may become symmetrical across the surface to perform.
Further, in the engine 50, the fuel injection valve 58 and the oil jet 59 respectively inject the fuel F between the two cylinders 51a between the two cylinders 51a as in the case of the intake port 52a. In the case of the oil jet 59, the mode for injecting the engine oil P is provided so as to be symmetrical, and thus the mode for cooling the wall 51c is provided so as to be symmetrical. Yes.

In this embodiment, the cooling water W corresponds to the cooling medium, and the water jacket 51b corresponds to the cooling medium passage. In the present embodiment, among the plurality of cylinders 51a, the cylinder constituting the # 4 cylinder is the first cylinder, and among the plurality of cylinders 51a, any of the cylinders constituting the # 1 cylinder to the # 3 cylinder is selected. Each corresponds to a second cylinder. In this embodiment, the intake port 52a corresponds to the intake air introduction means, and the fuel injection valve 58 and the oil jet 59 correspond to the injection means. In this embodiment, the intake port 52a, the fuel injection valve 58 and the oil jet 59 correspond to a cooling means.

Next, the function and effect of the engine 50 will be described. In the engine 50, each of the plurality of cylinders 51a can be cooled with the cooling water W flowing through the water jacket 51b. However, since the cooling capacity of the cooling water W decreases with heat reception, a wall formed between the adjacent cylinders 51a. There is a risk of insufficient cooling at some of the walls of each of the portions 51c.
On the other hand, in the engine 50, the wall 51c is cooled between two cylinders among the plurality of cylinders 51a (specifically, between the cylinders adjacent to each other with the wall 51c at which cooling may be insufficient). By providing the intake port 52a, the fuel injection valve 58, and the oil jet 59 so that the modes are symmetrical, it is possible to enhance the cooling of the wall portion 51c that may cause insufficient cooling. As a result, the engine 50 can preferably prevent or suppress the occurrence of insufficient cooling at the wall 51c in that it can prevent or suppress the occurrence of insufficient cooling at the wall 51c where temperature rise is a problem.

Further, in the engine 50, the water jacket 51b flows the cooling water W along the plurality of cylinders 51a and out of the plurality of cylinders 51a from the cylinder side located at one end to the cylinder side located at the other end in the cylinder arrangement direction. Since it is provided so as to circulate, there is a risk that insufficient cooling will occur in the wall portion 51c located on the most downstream side in the cooling direction of the cooling water W flowing through the water jacket 51b.
On the other hand, in the engine 50, in the cooling direction of the cooling water W flowing through the water jacket 51b, any one of a cylinder located on the most downstream side and a cylinder located on the upstream side of this cylinder among the plurality of cylinders 51a. The intake port 52a, the fuel injection valve 58, and the oil jet 59 are provided so that the mode of cooling the wall 51c is symmetrical between the heels. As a result, the engine 50 can prevent or suppress the occurrence of insufficient cooling at the wall 51c where the temperature rise is the most problematic, and therefore, the engine 50 as a whole is rational in light of the flow mode of the cooling water W. In particular, it is possible to prevent or suppress the occurrence of insufficient cooling at the wall 51c.

Further, in the engine 50, the oblique tumble flow generated in the cylinder is maintained until the latter half of the compression stroke and collapsed, thereby causing disturbance in the atmosphere in the cylinder, thereby improving the combustion speed and performing high-speed combustion. . In this regard, in the engine 50 that performs high-speed combustion, the temperature of the combustion gas increases due to the improvement of the combustion speed, and the temperature boundary layer becomes thinner than the swirling airflow, and as a result, the heat transfer coefficient increases, so the combustion chamber 54 The wall temperature becomes higher. Further, in the engine 50 that performs high-speed combustion, as the rotational speed is larger and the load is higher, the amount of heat generated per unit time increases and the strength of the swirl airflow increases to further increase the heat transfer coefficient. That is, in the engine 50 that performs high-speed combustion, the temperature rise of the wall 51c is particularly problematic due to such circumstances.

On the other hand, the engine 50 includes an intake port 52a and a fuel injection valve 58 for cooling the wall 51c from the surface. According to the intake port 52a and the fuel injection valve 58, the engine 50 is inclined as a swirling airflow in the cylinder. A tumble flow can be generated and high-speed combustion can be realized. For this reason, the engine 50 is suitable in that it has a configuration suitable for high-speed combustion.
The engine 50 further includes an oil jet 59 that cools the wall 51c from the surface. According to the oil jet 59, the engine 50 is applied together with the intake port 52a and the fuel injection valve 58 to obtain a higher cooling effect. be able to. In this regard, in cooling the wall 51c from the surface, for example, at least one of the intake port 52a, the fuel injection valve 58, and the oil jet 59 can be applied. This is suitable for high-speed combustion in which the temperature rise of the wall 51c is particularly problematic.

The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.
For example, in the above-described embodiment, the case where the intake air introduction means is the intake port 52a has been described. However, the present invention is not necessarily limited to this, and the intake air introduction means is realized, for example, by an airflow control valve that is provided in the intake port and can control the flow of intake air, or a combination of the airflow control valve and the intake port. May be.

Further, for example, in the above-described embodiment, since the configuration is reasonable, each of the intake port 52a, the fuel injection valve 58, and the oil jet 59 has a wall portion 51c between two cylinders of the plurality of cylinders 51a. The case where the cooling mode is provided so as to be symmetrical with respect to the plane orthogonal to the crank axis L has been described. However, in the present invention, the cooling means is not necessarily limited to this. For example, the cooling means sandwiches a straight line extending between the first and second cylinders so that the wall cooling mode is orthogonal to the crank axis and extends along the cylinder extending direction. It may be provided so as to be symmetrical.

50 Engine 51 Cylinder block 51a Cylinder 51b Water jacket 51c Wall 52 Cylinder head 52a Intake port 58 Fuel injection valve 59 Oil jet

Claims

A cylinder block formed with a plurality of cylinders;
For each of the plurality of cylinders, a cooling unit capable of cooling a wall portion formed between adjacent cylinders from the surface of the plurality of cylinders,
Among the plurality of cylinders, the cooling means is provided between the first cylinder and the second cylinder so that the aspect of cooling the wall portion is symmetric,
The cooling means is at least one of an injection means for injecting toward the wall portion, or an intake air introduction means for introducing intake air so as to circulate toward the wall portion,
An engine in which the injection means is at least one of a fuel injection valve and an oil jet.
The engine according to claim 1,
A cooling medium passage that circulates the cooling medium through the cylinder block along the plurality of cylinders and from the cylinder side positioned at one end to the cylinder side positioned at the other end of the plurality of cylinders. Formed,
The first cylinder is a cylinder located on the most downstream side in the flow direction of the cooling medium flowing through the cooling medium passage among the plurality of cylinders,
The engine, wherein the second cylinder is any one of the plurality of cylinders that is located upstream of the first cylinder in the flow direction of the cooling medium flowing through the cooling medium passage.
The engine according to claim 1 or 2,
An engine in which the intake air introduction means introduces intake air so as to further generate a swirling airflow.