JP5577788B2 - Engine cooling system - Google Patents

Description

  The present invention relates to an engine cooling apparatus.

Conventionally, an engine is generally cooled by cooling water. Conventionally, an engine provided with a fuel injection valve so that fuel can be directly injected into a cylinder is known.
In this regard, for example, Patent Document 1 discloses a piston for a direct injection engine in which a ceramic film is formed at a position where fuel injected from an injector hits, as a technique considered to be related to the present invention in terms of configuration. . As a technique considered to be related to the present invention in configuration, for example, Patent Document 2 discloses a cylinder liner in which a high thermal conductive film is formed on an upper outer peripheral surface in the axial direction.

JP 2000-8857 A JP 2007-16735 A

By the way, when the fuel injection valve is provided so that the fuel can be directly injected into the cylinder, the portion where the injected fuel collides is preferably at a high temperature because vaporization of the fuel can be promoted. However, there is a demand for cooling in the engine. For example, if only the cooling performance of the part is lowered in order to promote the vaporization of the fuel, there is a possibility that knocking may be induced in the part. In this respect, since the upper part of the cylinder and the exhaust side part are hotter than the intake side part, it is a suitable part for injecting fuel to promote fuel vaporization. It is considered that there is a high risk of triggering.
On the other hand, in cooling the engine, it is desired that high thermal efficiency can be realized. For this purpose, it is desirable to improve the thermal efficiency by reducing the cooling loss that accounts for a large proportion of the total energy loss while suppressing the occurrence of knocking.

  Therefore, the present invention has been made in view of the above problems, and by promoting the vaporization of fuel while taking into consideration the cooling performance of the engine, the present invention is directed toward the upper part of the cylinder and the exhaust side while suppressing the occurrence of knocking. Another object of the present invention is to provide an engine cooling device that can promote vaporization of fuel directly injected into a cylinder and that can suitably reduce cooling loss in a compatible manner.

In order to solve the above problems, the present invention includes a cylinder block in which a cylinder is formed, a cylinder head, and a fuel injection valve provided so as to be able to directly inject fuel toward an upper portion of the cylinder and a predetermined portion on the exhaust side. With respect to the engine, through the predetermined portion while improving the conductivity of heat that is performed at the upper portion of the cylinder and other than the predetermined portion and including a main upper portion including the upper portion and the lower portion of the predetermined portion. It is an engine cooling device provided with a cooling structure that lowers the conductivity of heat to be performed at least lower than the main upper portion.

Further, the present invention controls the cooling capacity of the cylinder head by controlling the cooling capacity adjusting means capable of suppressing the cooling capacity of the cylinder head and the cooling capacity adjusting means without suppressing the cooling capacity of the cylinder block. It is preferable that the configuration further includes control means for performing control for suppression. In the present invention, the cooling structure includes a cooling medium passage provided in a peripheral portion of the cylinder, and the cooling medium passage passes through a portion corresponding to the predetermined portion of the cooling medium flowing through the cooling medium passage. You may provide the distribution | circulation prevention part which prevents doing. Further, in the present invention, the cooling structure includes a cylinder liner at a portion corresponding to the cylinder, and the cylinder and the cylinder liner corresponding to the predetermined portion have an adhesiveness to the main upper portion and the cylinder. You may provide the adhesive fall part which reduces rather than the adhesiveness with a cylinder liner.

  According to the present invention, fuel that is injected directly into the cylinder toward the upper part of the cylinder and toward the exhaust side while suppressing the occurrence of knocking by promoting the vaporization of the fuel in consideration of the cooling performance of the engine. Can promote vaporization. Further, according to the present invention, the cooling loss can be suitably reduced in a compatible manner.

1 is a schematic configuration diagram of an engine cooling device (hereinafter simply referred to as a cooling device) according to a first embodiment; 1 is a schematic configuration diagram of an engine according to Embodiment 1. FIG. 1 is a schematic configuration diagram of an ECU (Electronic Control Unit). It is a figure which shows the classification | category of an engine operation state typically. It is a figure which shows operation | movement of ECU with a flowchart. It is a figure which shows the mode of heat conduction with the cooling structure concerning Example 1. FIG. It is a figure which shows the heat transfer rate and surface area ratio of a combustion chamber according to a crank angle. It is a schematic block diagram of the engine concerning Example 2. FIG. It is a figure which shows the mode of heat conduction with the cooling structure concerning Example 2. FIG. It is a schematic block diagram of the engine concerning Example 3. FIG. It is a figure which shows the mode of heat conduction with the cooling structure concerning Example 3. FIG.

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

  A cooling device 1A shown in FIG. 1 is mounted on a vehicle (not shown), and includes a water pump (hereinafter referred to as W / P) 11, a radiator 12, a thermostat 13, a flow control valve 14, an engine 50A, 1 to 4 partial flow control valves 61 to 64 are provided. W / P11 is a cooling medium pumping means, which is a variable W / P that pumps the cooling water that is the cooling medium and makes the flow rate of the cooling water pumped variable. The cooling water pumped by the W / P 11 is supplied to the engine 50A.

  The engine 50A includes a cylinder block 51 and a cylinder head 52 made of metal (here, aluminum alloy). The cylinder block 51 is formed with a block-side water jacket (hereinafter referred to as block-side W / J) 511 that is a first cooling medium passage. The block side W / J 511 forms one cooling system in the cylinder block 51. On the other hand, the cylinder head 52 is formed with a head side water jacket (hereinafter referred to as head side W / J) 521 which is a second cooling medium passage. The head side W / J 521 forms a plurality (four in this case) of cooling systems in the cylinder head 52. Specifically, the cooling water pumped by the W / P 11 is supplied to the block side W / J 511 and the head side W / J 521.

In this regard, the cooling device 1A has a plurality of cooling water circulation paths.
As the cooling water circulation path, for example, there is a block side circulation path C1 which is a circulation path in which the block side W / J 511 is incorporated. The cooling water flowing through the block-side circulation path C1 is discharged from the W / P 11 and then flows through the block-side W / J 511 and further through the thermostat 13 or through the radiator 12 and the thermostat 13. To come back. The radiator 12 is a heat exchanger, and cools the cooling water by exchanging heat between the circulating cooling water and the air. The thermostat 13 switches the distribution route communicating with the W / P 11 from the entrance side. Specifically, the thermostat 13 sets the flow path that bypasses the radiator 12 when the coolant temperature is lower than a predetermined value, and sets the flow path that flows through the radiator 12 when the temperature of the cooling water is equal to or higher than the predetermined value.

  Further, as the cooling water circulation path, for example, there is a head side circulation path C2 which is a circulation path in which the head side W / J 521 is incorporated. The cooling water flowing through the head-side circulation path C2 is discharged from the W / P 11, and then the flow control valve 14, at least one of the first to fourth partial flow control valves 61 to 64, and the head side At least one of the four cooling systems formed by the W / J 521 is circulated, and is further returned to the W / P 11 via the thermostat 13 or via the radiator 12 and the thermostat 13.

  The flow rate adjusting valve 14 is provided in a part of the head side circulation path C2 after the circulation paths C1 and C2 are branched, and in a part upstream of the cylinder head 52. 4 is provided at a portion upstream of the partial flow rate control valves 61 to 64. The flow rate adjusting valve 14 is a cooling capacity adjusting means capable of adjusting the cooling capacity of the cylinder head 52. In this regard, the flow rate adjusting valve 14 specifically adjusts the cooling capacity of the cylinder head 52 by adjusting the overall flow rate of the cooling water flowing through the head side W / J 521. It is a means.

Further, the flow rate adjusting valve 14 provided in this way serves as a cooling capacity adjusting means capable of suppressing the cooling capacity of the cylinder head 52 without suppressing the cooling capacity of the cylinder block 51. Specifically, for example, the flow rate control valve 14 has a cooling capacity of the cylinder block 51 and a cooling capacity of the cylinder head 52 at the time of high rotation and high load in which both the cylinder block 51 and the cylinder head 52 circulate cooling water. This is a cooling capacity adjusting means capable of suppressing the cooling capacity of the cylinder head 52 without suppressing the cooling capacity of the cylinder block 51 with respect to the cooling capacity.
Further, the flow rate adjusting valve 14 thus provided increases the cooling capacity of the cylinder block 51 when the flow rate of the cooling water flowing through the head side W / J 521 is adjusted so as to suppress the cooling capacity of the cylinder head 52. Thus, the cooling capacity adjusting means is capable of adjusting the flow rate of the cooling water flowing through the block side W / J511.

  In the first to fourth partial flow rate adjusting valves 61 to 64, the four cooling systems formed by the head side W / J 521 in the portion between the flow rate adjusting valve 14 and the cylinder head 52 in the head side circulation path C2. It is provided corresponding to the system. These partial flow rate adjusting valves 61 to 64 are cooling capacity adjusting means capable of adjusting the cooling capacity of the cylinder head 52, and more specifically, the flow rate of the cooling water flowing through the head side W / J 521 is partially set. By adjusting to the cooling capacity adjustment means, the cooling capacity of the cylinder head 52 can be partially adjusted.

  In the cooling device 1A, the cooling water flowing through the block-side circulation path C1 is not circulated through the head-side W / J 521 until one cycle after the cooling water is pumped by the W / P 11. Further, in the cooling device 1A, the cooling water flowing through the head-side circulation path C2 is not circulated through the block side W / J 511 until one cycle after the cooling water is pumped by the W / P 11. That is, in the cooling device 1A, the block side W / J511 and the head side W / J521 are incorporated in different coolant circulation paths.

  Next, the engine 50A will be described more specifically. As shown in FIG. 2, a cylinder 51 a is formed in the cylinder block 51. The cylinder 51a is provided with a piston 53 via a cylinder liner 54A. A cylinder head 52 is fixed to the cylinder block 51 via a gasket 55 having high heat insulating properties. The gasket 55 suppresses heat transfer from the cylinder block 51 to the cylinder head 52 by its high heat insulating property. The cylinder 51a, the cylinder head 52, and the piston 53 form a combustion chamber 56. The cylinder head 52 is formed with an intake port 52 a that guides intake air to the combustion chamber 56 and an exhaust port 52 b that discharges combustion gas from the combustion chamber 56. A spark plug 57 is provided in the cylinder head 52 so as to face the substantially upper center of the combustion chamber 56.

Further, the cylinder head 52 is provided with a fuel injection valve 58. The fuel injection valve 58 is provided so that fuel can be directly injected into the cylinder. Specifically, the fuel injection valve 58 is provided on the intake side of the cylinder head 52 and on a portion closer to the cylinder block 51 than the intake port 52a. The fuel injection valve 58 provided in this way is provided so that fuel can be directly injected toward the upper portion of the cylinder 51a and a predetermined portion on the exhaust side.
On the other hand, the cylinder liner 54A is an upper portion of the cylinder 51a, and a portion corresponding to a main upper portion other than the predetermined portion is a high heat conducting portion 54aA, and a portion corresponding to the predetermined portion is a low heat conducting portion. It has a heat conduction structure of 54bA.

Specifically, the heat conducting portions 54aA and 54bA, for example, form a high thermal conductive film on a portion corresponding to the main portion of the outer peripheral surface of the cylinder liner 54A, and form a low thermal conductive coating on a portion corresponding to a predetermined portion. Can be configured.
In this regard, the high thermal conductive film is a film that can enhance the thermal conductivity performed through the main part compared to the case where the high thermal conductive film is not specifically formed, and the low thermal conductive film is a low thermal conductive film. Compared with the case where no special formation is performed, the film can reduce the thermal conductivity performed through the predetermined portion.
The heat conduction structure of the cylinder liner 54A constituting the heat conducting portions 54aA and 54bA is higher than the case where the high heat conducting portion 54aA is not specifically constructed, while improving the heat conductivity performed through the main upper portion, It has a cooling structure that lowers the conductivity of heat performed via at least the main portion.

Specifically, the block side W / J 511 includes a portion W / J 511a which is a first partial cooling medium passage. The portion W / J511a is provided in the peripheral portion of the cylinder 51a.
Specifically, the head side W / J 521 includes a plurality of portions W / J 521a, a portion W / J 521b, a portion W / J 521c, and a portion W / J 521d which are second partial cooling medium passages. The portion W / J 521a is provided at the peripheral portion of the intake port 52a, the portion W / J 521b is provided at the peripheral portion of the exhaust port 52b, and the portion W / J 521c is provided at the peripheral portion of the spark plug 57. Further, the portion W / J 521d is provided for cooling between the intake / exhaust valves 52a and 52b and other portions. The portion W / J521a to the portion W / J524d are separately incorporated in the four cooling systems formed by the head side W / J521. The first partial flow rate adjustment valve 61 is in the portion W / J 521a, the second partial flow rate adjustment valve 62 is in the portion W / J 521b, the third partial flow rate adjustment valve 63 is in the portion W / J 521c, and the fourth Partial flow rate adjustment valves 64 are provided corresponding to the respective portions W / J521d.

  Further, the cooling device 1A includes an ECU 70 shown in FIG. The ECU 70 includes a microcomputer including a CPU 71, a ROM 72, a RAM 73, and the like and input / output circuits 75 and 76. These components are connected to each other via a bus 74. The ECU 70 includes a crank angle sensor 81 for detecting the rotational speed of the engine 50A, an air flow meter 82 for measuring the intake air amount, an accelerator opening sensor 83 for detecting the accelerator opening, and cooling water. Various sensors and switches such as a water temperature sensor 84 for detecting the temperature of the water are electrically connected. In this regard, the load on the engine 50 </ b> A is detected by the ECU 70 based on the outputs of the air flow meter 82 and the accelerator opening sensor 83. The ECU 70 is electrically connected to various control objects such as the W / P 11, the flow rate adjustment valve 14, and the first to fourth partial flow rate adjustment valves 61 to 64.

  The ROM 72 is configured to store a program in which various processes executed by the CPU 71 are described, map data, and the like. When the CPU 71 executes processing while using the temporary storage area of the RAM 73 based on a program stored in the ROM 72 as necessary, various control means, determination means, detection means, calculation means, and the like are functional in the ECU 70. To be realized.

In this regard, in the ECU 70, for example, a control unit that performs control for suppressing the cooling capacity of the cylinder head 52 is functionally realized.
Specifically, the control means is realized to perform control for suppressing the cooling capacity of the cylinder head 52 when the engine operating state is a high load.
More specifically, the control means controls the flow control valve 14 when the engine operating state is a low rotation and high load, thereby controlling the cooling capacity exhibited based on the head side W / J 521. Is realized to do.
In addition to the case where the engine operating state is a high load, the control means is realized to perform control for establishing the operation of the engine 50A in other operating states.

  In this respect, the engine operation state is specifically classified into six categories shown in FIG. 4 according to whether the engine 50A is in the cold operation or the engine start in addition to the rotation speed and load of the engine 50A. It is classified from D1 to D6. In the cooling device 1A, in consideration of the consistency and simplification of the overall control, when the control means is W / P11, the discharge amount increases as the rotational speed increases basically according to the rotational speed of the engine 50A. The control for driving the W / P 11 is performed so as to increase, and the partial flow rate control valves 61 to 64 are basically controlled to be fully opened. On the other hand, the flow control valve 14 is more specifically realized to perform the following control.

In other words, the control means includes a case where the engine operating state is an idle state corresponding to the section D1, a case where the engine operating state is a light load corresponding to the section D2, a time when the engine is cold corresponding to the section D5, and a section D6. When the engine is started corresponding to the above, the control for closing the flow rate adjusting valve 14 is performed.
Further, the control means closes the flow rate adjustment valve 14 or suppresses the flow of cooling water to the cylinder head 52 while the engine operating state is a low rotation and high load corresponding to the section D3. It implement | achieves so that control for valve opening may be performed in the aspect (henceforth a boiling suppression aspect) which can suppress the boiling of the cooling water in.
The control means is realized to perform control for fully opening the flow rate control valve 14 when the engine operating state is a high rotation and high load corresponding to the section D4.

  In this regard, when the engine operating state is a low rotation and high load corresponding to the section D3, in performing the control for opening the flow rate adjustment valve 14 in the boiling suppression mode, the control means specifically includes, for example, any The flow control valve 14 is opened at the minimum necessary opening that can suppress the boiling of the cooling water under the conditions, the temperature of the cooling water flowing through the cylinder head 52 is detected or estimated, and the temperature of the cooling water is adjusted. Based on this, it is possible to open the flow rate control valve 14 intermittently, or to open the flow rate control valve 14 at a predetermined rotational speed or higher. Thereby, in suppressing the cooling capacity of the cylinder head 52, it is possible to suppress the flow rate adjusting valve 14 from being opened more than necessary while suppressing the boiling of the cooling water.

In the cooling device 1A, under the control of the control means, the flow rate adjusting valve 14 reduces the flow rate of the cooling water flowing through the cylinder head 52 in this manner in the section D3, whereby the flow rate of the cooling water flowing through the engine 50A. Is reduced locally.
In the cooling device 1A, the cooling capacity of the cylinder head 52 is suppressed by suppressing the flow of the cooling water to the cylinder head 52 when the flow rate adjustment valve 14 is not fully opened. In this regard, in the cooling device 1A, more specifically, the cooling capacity of the cylinder head 52 is suppressed when the flow control valve 14 is closed or the flow control valve 14 is opened in a boiling suppression mode. Will be.

In the cooling device 1A, as a result of considering the consistency and simplification of the overall control, the control means performs control for closing the flow rate control valve 14 in the sections D1, D2, D5, and D6. Has been realized. However, the present invention is not limited to this, and the control means performs different control by appropriately controlling W / P11, the flow rate control valve 14 and the partial flow rate control valves 61 to 64 in the sections D1, D2, D5 and D6. It may be realized. Thereby, the operation of the engine 50A can be further preferably established in the sections D1, D2, D5, and D6.
When the engine operating state is a low rotation and high load corresponding to the section D3, for example, the flow control valve 14 is fully opened, and each of the partial flow control valves 61 to 64 is replaced with the flow control valve 14. It is also possible to realize control for opening the valve in a valve-closing manner or in a boiling suppression mode. When the engine operating state is a low rotation and high load, the control means fully opens the flow rate control valve 14 and at least one of the opening degrees (for example, thermal load) among the partial flow rate control valves 61 to 64. The partial flow rate control valve 62 and the partial flow rate control valve 63) corresponding to a large part of the valve can be intermittently opened from the fully closed state with a small opening. Thereby, the reliability of the cylinder head 52 can be suitably ensured in the section D3.

  Next, processing performed by the ECU 70 will be described with reference to a flowchart shown in FIG. The ECU 70 determines whether or not the engine is being started (step S1). If the determination is affirmative, the ECU 70 starts driving the W / P 11 (step S3) and closes the flow rate adjustment valve 14 (step S21). On the other hand, if a negative determination is made in step S1, the ECU 70 determines whether or not the engine is cold (step S5). Whether or not the engine is cold can be determined, for example, based on whether or not the cooling water temperature is a predetermined value (for example, 75 ° C.) or less. If it is affirmation determination by step S5, it will progress to step S21. On the other hand, if a negative determination is made in step S5, ECU 70 detects the rotational speed and load of engine 50A (step S11).

  Subsequently, the ECU 70 determines a classification corresponding to the detected rotation speed and load (from step S12 to S14). Specifically, if the corresponding category is the category D1, the process proceeds from step S12 to step S21. If the corresponding category is the category D2, the process proceeds from step S13 to step S21. On the other hand, if the corresponding category is category D3, the process proceeds from step S14 to step S31. At this time, the ECU 70 closes the flow rate control valve 14 or opens it in a boiling suppression mode (step S31). If the corresponding category is category D4, the process advances from step S14 to step S41, and the ECU 70 fully opens the flow rate control valve 14 (step S41).

Next, the effect of the cooling device 1A will be described. In the cooling device 1A, as shown in FIG. 6, the cooling structure of the cylinder liner 54A that constitutes the heat conducting portions 54aA and 54bA increases the heat conductivity performed through the main upper portion, while the predetermined portion on the exhaust side is Reducing the conductivity of the heat carried through.
Therefore, the cooling device 1A can promote the vaporization of the fuel injected toward the predetermined portion while improving the cooling performance of the engine 50A by increasing the heat conductivity through the main upper portion. Then, the cooling device 1A that improves the cooling performance of the engine 50A in this way can suppress the occurrence of knocking when promoting the vaporization of the fuel. For this reason, the cooling device 1A can promote the vaporization of the fuel directly injected into the cylinder toward the predetermined portion while suppressing the occurrence of knocking by promoting the vaporization of the fuel in consideration of the cooling performance of the engine 50A. .
In addition, the cooling device 1A that promotes fuel vaporization in this way has a structure in which the conductivity of heat performed through a predetermined portion can be set. Therefore, fuel vaporization is promoted under optimum or more preferable conditions. You can also

  On the other hand, it is desired to realize high thermal efficiency in the engine 50A. In this regard, the heat transfer coefficient and the surface area ratio of the combustion chamber 56 according to the crank angle of the engine 50A are as shown in FIG. As shown in FIG. 7, it can be seen that the heat transfer coefficient increases near the top dead center of the compression stroke. As for the surface area ratio, it can be seen that the surface area ratios of the cylinder head 52 and the piston 53 increase near the top dead center of the compression stroke. Therefore, it can be seen that the influence of the temperature of the cylinder head 52 is large on the cooling loss. On the other hand, knocking depends on the compression end temperature, and it can be seen that the surface area ratio of the cylinder wall is large in the intake compression stroke that affects the compression end temperature. Therefore, it can be seen that the influence of the temperature of the cylinder wall is large for knocking.

On the other hand, based on this knowledge, the cooling device 1A closes the flow rate control valve 14 or opens it in a boiling suppression mode when the engine operating state is a low rotation and high load. And by limiting the flow volume of the cooling water which distribute | circulates the head side W / J521 by this, the cooling capacity of the cylinder head 52 can be suppressed, Therefore The cooling loss which occupies a big ratio among energy losses can be reduced.
On the other hand, the occurrence of knocking is a concern in this case. On the other hand, in the cooling device 1 </ b> A, by controlling the flow rate adjusting valve 14 that can suppress the cooling capacity of the cylinder head 52 without suppressing the cooling capacity of the cylinder block 51, cooling that circulates through the head side W / J 521. Limit water flow. For this reason, in the cooling device 1A, the cooling of the cylinder wall can be maintained thereby, and the occurrence of knocking can also be suppressed.

  That is, in the cooling device 1 </ b> A, the heat transfer state is locally varied in a rational manner based on the above-described knowledge, so that the cylinder head 52 can be insulated (reduction in cooling loss), and at the same time, the cylinder block 51 The occurrence of knocking can be suppressed by cooling. And cooling device 1A can improve thermal efficiency by making reduction of cooling loss and knock performance compatible in this way. Moreover, 1 A of cooling devices can reduce a cooling loss suitably in the aspect compatible with the above-mentioned cooling structure by reducing a cooling loss in this way. In other words, the above-described cooling structure can preferably be compatible with the reduction of the cooling loss performed in this way.

Further, in the cooling device 1 </ b> A, when the flow rate adjustment valve 14 adjusts the flow rate of the cooling water flowing through the head side W / J 521 so as to suppress the cooling capability of the cylinder head 52, the cooling capability of the cylinder block 51 is increased. The flow rate of the cooling water flowing through the block side W / J 511 can be adjusted. Therefore, in the cooling device 1A, the intake air can be further cooled, and the occurrence of knocking can be more suitably suppressed.
In addition, the cooling device 1A can improve the thermal efficiency mainly at the time of low rotation and high load, but can establish the operation of the engine 50A even in other operation states. In this respect, at high rotation and high load, in addition to ensuring reliability and reducing knocking, it is also possible to reduce the thermal load on the catalyst due to, for example, a decrease in exhaust temperature. For this reason, the cooling device 1A can improve thermal efficiency not only in a specific operation state but also as a whole operation of the engine 50A that is normally performed.

  The cooling device 1B according to the present embodiment is substantially the same as the cooling device 1A except that the engine 50B is provided instead of the engine 50A. Further, the engine 50B is substantially the same as the engine 50A except that it includes a cylinder liner 54B instead of the cylinder liner 54A and further includes a flow blocking unit 59 as shown below. Yes. For this reason, the schematic configuration of the entire cooling device 1B is not shown.

As shown in FIG. 8, the cylinder liner 54B has a heat conduction structure in which a portion corresponding to the upper portion of the cylinder 51a is a high heat conduction portion 54aB. The high heat conduction portion 54aB can be configured, for example, by forming a high heat conduction film on a portion of the outer peripheral surface of the cylinder liner 54B corresponding to the upper portion of the cylinder 51a.
The flow blocking unit 59 is configured to partially block the flow of the cooling water flowing through the portion W / J 511a, and is provided in a portion corresponding to the predetermined portion of the portion W / J 511a. And the distribution | circulation prevention part 59 provided in this way can prevent the cooling water which distribute | circulates the part W / J511a from distribute | circulating the part corresponding to a predetermined part among the parts W / J511a.
In the present embodiment, a cooling structure is realized by the cylinder liner 54B and the flow blocking unit 59.

Next, the effect of the cooling device 1B will be described. Even in the cooling device 1B, the cooling structure realized by the cylinder liner 54B and the flow blocking unit 59 as shown in FIG. 9 improves the cooling performance of the engine 50B by increasing the heat conductivity through the main upper part, Vaporization of the fuel injected toward the predetermined portion on the exhaust side can be promoted, whereby knocking can be prevented from being induced when fuel vaporization is promoted.
Further, the cooling device 1B can be manufactured easily by providing a simple cylinder liner 54B as compared with the cooling device 1A when configuring the cooling structure.
The cooling device 1B can also suitably reduce the cooling loss in the same manner as the cooling device 1A in a manner compatible with such a cooling structure.

  The cooling device 1C according to the present embodiment is substantially the same as the cooling device 1A except that the engine 50C is provided instead of the engine 50B. Further, the engine 50C is substantially the same as the engine 50B except that it does not include the flow blocking unit 59 and further includes an adhesion lowering unit 60 as described below. For this reason, the schematic configuration of the entire cooling device 1C is not shown.

As shown in FIG. 10, the engine 50C is provided with an adhesion lowering portion 60 that lowers the adhesion between the cylinder 51a and the cylinder liner 54B for a predetermined portion on the exhaust side. Specifically, for example, at least one of the cylinder 51a and the cylinder liner 54B is formed in a shape capable of forming a gap between the cylinder 51a and the cylinder liner 54B for a predetermined portion on the exhaust side. Can be realized. In this respect, the shape may form a gap over the entire range for the predetermined portion on the exhaust side, and the predetermined portion on the exhaust side is distributed over the entire range by a plurality of irregularities and grooves. A gap may be formed.
In the present embodiment, a cooling structure is realized by the cylinder liner 54B and the adhesion lowering portion 60.

Next, the effect of the cooling device 1C will be described. Even in the cooling device 1C, the cooling structure realized by the cylinder liner 54B and the adhesion lowering portion 60 as shown in FIG. 11 improves the cooling performance of the engine 50C by increasing the heat conductivity through the main upper portion. Further, the vaporization of the fuel injected toward the predetermined portion on the exhaust side can be promoted, whereby the occurrence of knocking can be suppressed in promoting the vaporization of the fuel.
In addition, the cooling device 1C can reduce the number of components in that it does not require the flow blocking unit 59 as compared with the cooling device 1B when configuring the cooling structure.
The cooling device 1C can also suitably reduce the cooling loss in the same manner as the cooling device 1A in a manner compatible with the above-described cooling structure.

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 first embodiment, the case where the cylinder liner 54A configuring the heat conducting portions 54aA and 54bA has the cooling structure has been described. However, the present invention is not necessarily limited to this. For example, the cylinder may have a similar cooling structure.

1A, 1B, 1C Cooling device 11 W / P
14 Flow control valve 50A, 50B, 50C Engine 51 Cylinder block 51a Cylinder 511 Block side W / J
52 Cylinder head 521 Head side W / J
54A, 54B Cylinder liner 59 Flow prevention unit 60 Adhesion lowering unit 70 ECU

Claims (4)

An engine having a cylinder injection block in which a cylinder is formed, a cylinder head, and a fuel injection valve provided so as to be able to directly inject fuel toward a predetermined portion on the exhaust side of the cylinder head,
Heat generated through the predetermined portion while enhancing conductivity of the upper portion of the cylinder and a portion other than the predetermined portion and including a main upper portion including an upper portion and a lower portion of the predetermined portion. An engine cooling apparatus comprising a cooling structure that lowers the conductivity of at least the main upper portion. The engine cooling device according to claim 1,
Cooling capacity adjusting means capable of suppressing the cooling capacity of the cylinder head without suppressing the cooling capacity of the cylinder block;
The engine cooling apparatus further comprising: a control unit that performs control for suppressing the cooling capacity of the cylinder head by controlling the cooling capacity adjusting unit. The engine cooling device according to claim 1 or 2,
The cooling structure includes a cooling medium passage provided in a peripheral portion of the cylinder,
The cooling device for an engine, wherein the cooling medium passage includes a flow blocking unit that prevents a cooling medium flowing through the cooling medium passage from flowing through a portion corresponding to the predetermined portion. The engine cooling device according to claim 1 or 2,
The cooling structure includes a cylinder liner at a portion corresponding to the cylinder, and the close contact between the cylinder corresponding to the predetermined portion and the cylinder liner is close contact between the cylinder corresponding to the main upper portion and the cylinder liner. The cooling device of an engine provided with the adhesiveness fall part which lowers rather than the property.

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