JP2013068175A - Cooling device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device of an internal combustion engine which can promote warming up properly, while preventing the generation of hitting sounds of a piston.SOLUTION: The cooling device 100 includes: an engine passage that is embedded in a first circulation path C1 for making coolant water of the internal combustion engine 2 flow, and in which a flow rate of the flowing coolant water is restricted at engine warming-up more than after the engine warming-up; a bore-to-bore passage T that is provided between cylinder bores B of the internal combustion engine 2, and is embedded in a second circulation path C2 for making the coolant water of the internal combustion engine 2 flow in a flow path different from the first circulation path C1; and a second control valve 22 for controlling flow of the coolant water flowing in the second circulation path C2 of the circulation paths C1 and C2. The second control valve 22 controls the flow of the coolant water flowing in the second circulation path C2 in accordance with a temperature of a wall of the cylinder bore B in the internal combustion engine 2 at the engine warming-up.

Description

  The present invention relates to a cooling device for an internal combustion engine, and more particularly to a cooling device for an internal combustion engine that controls the flow of cooling water when the engine is warmed up.

  For example, Patent Document 1 discloses a technique that is considered to be related to the present invention regarding a cooling device for an internal combustion engine. Patent Document 1 discloses a control device for an electric water pump that stops an electric water pump when the temperature of cooling water in an internal combustion engine is equal to or lower than a predetermined temperature.

JP 2008-169750 A

  In an internal combustion engine, warm-up can be promoted by restricting the flow of cooling water. However, if the circulation of the cooling water is completely stopped when the engine is warmed up, the cylinder bore is heated greatly due to the temperature easily rising especially at the wall between the bores sandwiched between the adjacent cylinder bores. As a result of the deformation, piston hitting may occur.

  In view of the above problems, an object of the present invention is to provide a cooling device for an internal combustion engine that can favorably promote warm-up while preventing occurrence of piston hitting sound.

  The present invention is incorporated in a first circulation path through which cooling water of an internal combustion engine is circulated, and an engine passage portion in which the flow rate of the circulating cooling water is more limited than after engine warm-up when the engine is warmed up, and a cylinder bore of the internal combustion engine An inter-bore passage portion that is provided in a second circulation path that is provided in between and that circulates cooling water of the internal combustion engine through a circulation path different from the first circulation path, and the first and second circulation paths A control valve capable of controlling the flow of the cooling water flowing through the second circulation path, and the control valve according to the temperature of the cylinder bore wall of the internal combustion engine when the engine is warmed up. A cooling device for an internal combustion engine that controls the flow of cooling water flowing through a circulation path.

  The present invention restricts the flow of cooling water flowing through the second circulation path when the temperature of the cylinder bore wall of the internal combustion engine is lower than a predetermined value, and the control valve restricts the temperature of the cylinder bore wall of the internal combustion engine. When the value is higher than the predetermined value, the restriction on the circulation of the cooling water flowing through the second circulation path can be released.

  The present invention may be configured such that the engine passage portion and the inter-bore passage portion are provided so that cooling water can be supplied individually.

  According to the present invention, warm-up can be favorably promoted while preventing occurrence of piston hitting sound.

It is a whole block diagram of the cooling device of an internal combustion engine. It is a top view of a cylinder block. It is a figure which shows the 1st distribution state of a cooling water. It is a figure which shows the 2nd distribution state of a cooling water. It is a figure which shows the 3rd distribution state of cooling water. It is a figure which shows the control action of ECU with a flowchart. It is a figure which shows the 4th distribution state of a cooling water. It is a figure which shows the modification of the channel | path part between bores.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall configuration diagram of a cooling device (hereinafter simply referred to as a cooling device) 100 for an internal combustion engine. FIG. 2 is a top view of the cylinder block 2a. Each component shown in FIG. 1 is mounted on a vehicle (not shown). The cooling device 100 includes a water pump (hereinafter referred to as W / P) 1, an internal combustion engine 2, an oil cooler 3, an EGR cooler 4, a heater 5, an ATF (Automatic Transmission Fluid) warmer 6, and a radiator 7. The first thermostat 11, the second thermostat 12, the first control valve 21, the second control valve 22, and the ECU 30 are provided. The internal combustion engine 2 includes a cylinder block 2a and a cylinder head 2b.

  W / P1 circulates the cooling water of the internal combustion engine 2. W / P 1 is a mechanical pump that is driven by the output of the internal combustion engine 2. W / P1 may be an electrically driven pump. The cooling water discharged from the W / P 1 is supplied to the first thermostat 11 and the oil cooler 3. The 1st thermostat 11 switches the distribution destination of cooling water according to the temperature of cooling water. The oil cooler 3 exchanges heat between the lubricating oil of the internal combustion engine 2 and the cooling water to cool the lubricating oil.

  The internal combustion engine 2 includes a passage portion W. The passage portion W forms a first flow path P1 through which cooling water flows through the cylinder block 2a and the cylinder head 2b, and a second flow path P2 through which cooling water flows through the cylinder head 2b. Specifically, when the temperature of the cooling water is lower than the predetermined value α, the first thermostat 11 sets the distribution destination of the cooling water as the second distribution path P2, and the temperature of the cooling water exceeds the predetermined value α. Is higher (specifically, when it is equal to or greater than the predetermined value α in this case), the distribution destination of the cooling water is switched according to the temperature of the cooling water by setting the distribution destination of the cooling water to the distribution paths P1 and P2.

  Specifically, the first flow path P1 allows the cooling water to flow in from the cylinder block 2a, causes the cooling water that has flowed in to flow in the order of the cylinder block 2a, the cylinder head 2b, and then flows out from the cylinder head 2b. The cylinder head 2b merges with the second flow path P2. In this regard, the first distribution path P1 merges with the second distribution path P2 at the upstream portion.

  Specifically, cooling water is supplied from the first thermostat 11 to the cylinder head 2 b via the first control valve 21. The first control valve 21 is a flow rate adjustment valve capable of changing the flow rate of the cooling water flowing through the second flow path P2. The first control valve 21 can stop the flow of the cooling water in the internal combustion engine 2 together with the first thermostat 11 by setting the flow rate of the cooling water to zero when the temperature of the cooling water is lower than the predetermined value α. .

  Cooling water flowing through the internal combustion engine 2 is diverted toward the EGR cooler 4, the heater 5, and the ATF warmer 6. Then, the remaining cooling water flows through the radiator 7. The cooling water divided toward the EGR cooler 4, the heater 5, and the ATF warmer 6 merges with the cooling water that has circulated through the oil cooler 3, and then flows through the EGR cooler 4, the heater 5, and the ATF warmer 6.

  The EGR cooler 4 exchanges heat with the exhaust gas (EGR gas) recirculated to the internal combustion engine 2 to cool the EGR gas. The heater 5 heats the air by exchanging heat between the air and the cooling water. The heated air is used for heating the passenger compartment. The ATF warmer 6 exchanges heat between the ATF and the cooling water to heat the ATF. The radiator 7 exchanges heat between the air and the cooling water to cool the cooling water.

  The cooling water flowing through the EGR cooler 4, the heater 5, and the ATF warmer 6 returns to W / P1 as it is. The cooling water that has flowed through the radiator 7 returns to W / P1 via the second thermostat 12. The second thermostat 12 cancels the cooling water flow restriction and the flow restriction according to the temperature of the cooling water. Specifically, when the temperature of the cooling water is lower than a predetermined value β, the second thermostat 12 restricts (specifically, prohibits here) the flow of the cooling water, and the temperature of the cooling water is a predetermined value. When it is higher than β (specifically, when it is equal to or larger than the predetermined value β here), the circulation restriction of the cooling water is released (specifically, distribution is permitted here). Thus, the circulation of the cooling water is limited when the engine is warmed up, and the circulation restriction of the cooling water is released after the engine is warmed up. The predetermined value β is set lower than the predetermined value α.

  The cooling device 100 is further provided with a third distribution path P3. The third distribution path P3 is a distribution path that divides the coolant that is circulated from the first thermostat 11 to the cylinder head 2b into the first distribution path P1. Specifically, the third flow path P3 branches from a flow path through which cooling water flows from the first thermostat 11 to the first control valve 21, and the cooling water flows from the first thermostat 11 to the cylinder block 2a. It is a distribution channel that merges with the distribution channel to be performed.

  A second control valve 22 is provided in the third flow path P3. The second control valve 22 is a control valve capable of controlling the flow of the cooling water flowing through the third flow path P3. Specifically, the flow rate of the cooling water flowing through the third flow path P3 can be changed. It is a flow control valve. The second control valve 22 permits the flow of the cooling water when the temperature of the cooling water is lower than the predetermined value α, so that even when the first thermostat 11 uses the second distribution path P2 as the distribution destination, Cooling water can be circulated through one distribution path P1.

  In the cooling device 100 configured as described above, for example, the following circulation paths C1 and C2 are formed. The first circulation path C1 is a circulation path through which cooling water flows in the order of W / P1, the first thermostat 11, the cylinder block 2a, and the cylinder head 2b when circulating the cooling water to the internal combustion engine 2. The second circulation path C2 circulates the cooling water in the order of W / P1, the first thermostat 11, the second control valve 22, the cylinder block 2a, and the cylinder head 2b when circulating the cooling water to the internal combustion engine 2. It is a route. For this reason, the second control valve 22 corresponds to a control valve capable of controlling the circulation of the cooling water flowing through the second circulation path C2 out of the circulation paths C1 and C2.

  The first circulation path C1 incorporates a portion of the passage portion W along the first circulation path P1. This portion is a portion through which cooling water flows in the order of the cylinder block 2a and the cylinder head 2b. Further, when the temperature of the cooling water is lower than the predetermined value α, the circulation destination of the cooling water is the second distribution path P2, and when the temperature of the cooling water is higher than the predetermined value α, the circulation of the cooling water. According to the operation of the first thermostat 11 with the flow paths P1 and P2 as the destination, the flow rate of the circulating cooling water is a part that is more restricted when the engine is warmed than after the engine is warmed. A portion of the passage portion W along the first distribution path P1 corresponds to the engine passage portion.

  Similarly to the first circulation path C1, the second circulation path C2 includes a portion of the passage portion W along the first circulation path P1. In this regard, as shown in FIG. 2, in the internal combustion engine 2, the inter-bore passage portion T is provided between the cylinder bores B as a part of the passage portion W along the first flow path P <b> 1.

  For this reason, the inter-bore passage portion T is a distribution route different from the first circulation route C1 by incorporating the entire portion of the passage portion W along the first circulation route P1 in the second circulation route C2. It is incorporated in a second circulation path C2 through which the cooling water of the internal combustion engine 2 flows. In this regard, the present invention includes a case where the inter-bore passage portion is provided as a part of the engine passage portion, and the engine passage portion is incorporated in the first and second circulation paths.

  Next, the circulation state of the cooling water will be described with reference to FIGS. 3 is a diagram showing a first circulation state of cooling water, FIG. 4 is a diagram showing a second circulation state of cooling water, and FIG. 5 is a diagram showing a third circulation state of cooling water. . The first circulation state is a state in which the circulation of the cooling water in the internal combustion engine 2 is stopped, and the second circulation state is the circulation of the cooling water to the cylinder head 2b of the cylinder block 2a and the cylinder head 2b. The third flow mode is a state in which cooling water is circulated through the cylinder block 2a and the cylinder head 2b. In FIG. 3 to FIG. 5, the distribution route through which the cooling water is distributed is indicated by a solid line, and the distribution route in which the circulation of the cooling water is stopped is indicated by a broken line. 3 to 5 show the case where the second control valve 22 is closed.

  The first distribution state shown in FIG. 3 corresponds to when the engine is warmed up. At this time, the cooling water temperature sensed by the first thermostat 11 is lower than the predetermined value α, and the first thermostat 11 sets the circulation destination of the cooling water as the second circulation path P2. Further, the first control valve 21 is closed under the control of the ECU 30. For this reason, in the first flow state, the flow of the cooling water in the internal combustion engine 2 is stopped. Further, when the engine is warmed up, the coolant temperature sensed by the second thermostat 12 is lower than the predetermined value β, and the second thermostat 12 prohibits the circulation of the coolant. For this reason, in the first distribution state, the circulation of the cooling water via the radiator 7 is also stopped.

  The second flow state shown in FIG. 4 corresponds to a low temperature after engine warm-up (for example, when the load of the internal combustion engine 2 is low). At this time, the cooling water temperature sensed by the first thermostat 11 is lower than the predetermined value α, and the first thermostat 11 sets the circulation destination of the cooling water as the second circulation path P2. Further, the first control valve 21 is opened under the control of the ECU 30. For this reason, in the second circulation state, the coolant flows through the cylinder head 2b out of the cylinder block 2a and the cylinder head 2b. Further, at a low temperature after the engine is warmed up, the coolant temperature sensed by the second thermostat 12 becomes higher than the predetermined value β, and the second thermostat 12 permits the coolant to flow. For this reason, the circulation of the cooling water via the radiator 7 is permitted in the second circulation state.

  The third flow state shown in FIG. 5 corresponds to a high temperature after engine warm-up (for example, when the load of the internal combustion engine 2 is high). At this time, the cooling water temperature sensed by the first thermostat 11 becomes higher than the predetermined value α, and the first thermostat 11 sets the circulation destination of the cooling water as the distribution paths P1 and P2. Further, the first control valve 21 is opened under the control of the ECU 30. For this reason, in the third circulation state, the cooling water is circulated through the cylinder block 2a and the cylinder head 2b. Moreover, the circulation of the cooling water via the radiator 7 is permitted as in the second circulation state.

  In the cooling device 100, the engine warm-up is promoted while appropriately cooling the internal combustion engine 2 by switching the flow state of the cooling water in this way. In this regard, a portion of the passage portion W along the first distribution path P1 more specifically includes a first distribution path P1 (that is, an engine passage section in other words) as a distribution destination. According to the operation of the thermostat 11, the flow rate of the circulating cooling water is limited when the engine is warmed up than when the engine is warmed up.

  Returning to FIG. 1, the ECU 30 is an electronic control unit, and control valves 21 and 22 are electrically connected to the ECU 30 as control targets. The ECU 30 is electrically connected to a water temperature sensor 41 for detecting the cooling water temperature. In this respect, the water temperature sensor 41 is provided in a downstream portion of the second flow path P2, and the cooling water temperature detected by the water temperature sensor 41 reflects the heat received from the cylinder bore B wall.

  The ROM is configured to store a program describing various processes executed by the CPU, map data, and the like. Various functions are realized in the ECU 30 when the CPU executes processing while using a temporary storage area of the RAM as required based on a program stored in the ROM. In this regard, in the ECU 30, for example, the following control unit is functionally realized.

  The control unit controls the flow of the cooling water flowing through the second circulation path C2 by controlling the second control valve 22 in accordance with the temperature of the cylinder bore B wall of the internal combustion engine 2 when the engine is warmed up. Specifically, the control unit restricts the flow of the cooling water flowing through the second circulation path C2 when the temperature of the cylinder bore B wall portion of the internal combustion engine 2 is lower than a predetermined value γ (specifically, prohibited here). ) To control the second control valve 22. In addition, when the temperature of the cylinder bore B wall portion of the internal combustion engine 2 is higher than a predetermined value γ (specifically, when the temperature is equal to or higher than the predetermined value γ here), the flow limitation of the cooling water flowing through the second circulation path C2 is restricted. The second control valve 22 is controlled to release (specifically, permission of distribution here).

  Therefore, the second control valve 22 controls the flow of the cooling water flowing through the second circulation path C2 according to the temperature of the cylinder bore B wall portion of the internal combustion engine 2 when the engine is warmed up under the control of the control unit. Will do. Specifically, when the temperature of the cylinder bore B wall portion of the internal combustion engine 2 is lower than a predetermined value γ, the flow of the cooling water flowing through the second circulation path C2 is limited, and the temperature of the cylinder bore B wall portion of the internal combustion engine 2 Is higher than the predetermined value γ, the restriction on circulation of the cooling water flowing through the second circulation path C2 is released. The predetermined value γ is set to a temperature at which piston hitting sound can be generated as a result of the cylinder bore B being thermally deformed.

  In controlling the second control valve 22 according to the temperature of the cylinder bore B wall, specifically, the control unit controls the second control valve 22 based on the coolant temperature reflecting the heat received from the cylinder bore B wall. To do. However, the present invention is not limited to this, and the temperature of the cylinder bore B wall portion may be directly detected, for example. Specifically, the temperature of the cylinder bore B wall portion is preferably the temperature of the portion where the temperature is most likely to rise among the portions of the cylinder bore B wall portion (for example, the temperature of one of the bore wall portions).

  Next, the control operation of the ECU 30 will be described using the flowchart shown in FIG. The ECU 30 determines whether or not the engine is warming up (step S1). Whether the engine is warming up can be determined, for example, by determining whether the coolant temperature based on the output of the water temperature sensor 41 is lower than a predetermined value. If the determination is affirmative, the ECU 30 determines whether or not the coolant temperature is lower than a predetermined value γ ′ (step S2). The predetermined value γ ′ is a cooling water temperature corresponding to the predetermined value γ set with respect to the temperature of the cylinder bore B wall. In this regard, the case where the coolant temperature is lower than the predetermined value γ ′ corresponds to the case where the temperature of the cylinder bore B wall is lower than the predetermined value γ.

  If an affirmative determination is made in step S2, the ECU 30 controls the second control valve 22 so as to prohibit the circulation of the cooling water flowing through the second circulation path C2 (step S3). If a negative determination is made in step S2, the ECU 30 controls the second control valve 22 so as to permit the circulation of the cooling water flowing through the second circulation path C2 (step S4). After steps S3 and S4, the process returns to step S1. Then, when a negative determination is made in step S1, this flowchart is terminated.

  Next, main effects of the cooling device 100 will be described. FIG. 7 is a diagram showing a fourth flow state of the cooling water. The fourth distribution state is a distribution state corresponding to the time when the engine is warmed up, and is a distribution state when the second control valve 22 is open. In the cooling device 100, the second control valve 22 controls the flow of the cooling water flowing through the second circulation path C2 in accordance with the temperature of the cylinder bore B wall portion of the internal combustion engine 2 when the engine is warmed up.

  For this reason, even if the cooling device 100 restricts the flow rate of the cooling water flowing through the portion along the first flow path P1 in the passage portion W when the engine is warmed up, the thermal deformation of the cylinder bore B is suppressed. In a situation where piston hitting sound can occur due to the above, cooling water can be circulated through the inter-bore passage portion T. Thereby, it is possible to prevent the occurrence of piston hitting sound. Further, in a situation where no piston hitting sound is generated, warm-up can be promoted by preventing the cooling water from flowing through the inter-bore passage portion T. For this reason, the cooling device 100 can favorably promote warm-up while preventing the occurrence of piston hitting sound.

  Specifically, in the cooling device 100, the second control valve 22 restricts the flow of the cooling water flowing through the second circulation path C2 when the temperature of the cylinder bore B wall portion of the internal combustion engine 2 is lower than the predetermined value γ. In the case where the temperature of the cylinder bore B wall portion of the internal combustion engine 2 is higher than the predetermined value γ, by canceling the flow restriction of the cooling water flowing through the second circulation path C2, while preventing the occurrence of piston hitting sound, Cooling water can be circulated through the inter-bore passage portion T so that warm-up can be preferably promoted.

  The cooling device 100 is a flow rate adjusting valve that can change the flow rate of the cooling water flowing through the second control valve 22, so that an appropriate amount of cooling water is supplied to the inter-bore passage portion T in order to prevent the occurrence of piston hitting sound. Can supply. And thereby, warming up can be further suitably accelerated | stimulated at the point which can prevent generation | occurrence | production of a piston hitting sound, preventing that warming up promotion is inhibited more than necessary.

  The inter-bore passage portion T may be provided as shown below. FIG. 8 is a view showing an inter-bore passage portion T ′ which is a modification of the inter-bore passage portion T. 8A shows the inter-bore passage portion T ′ in a top view of the cylinder block 2a ′, and FIG. 8B shows the inter-bore passage portion T ′ in the AA cross section shown in FIG. 8A. The cylinder block 2 a ′ is substantially the same as the cylinder block 2 a except that it includes a passage portion W ′ instead of the passage portion W and also includes an inter-bore passage portion T ′. The passage portion W ′ is substantially the same as the passage portion W except that the passage portion T between bores is not provided as a part.

  The inter-bore passage portion T ′ is provided so as to allow cooling water to flow into and out of a cylinder head (not shown). In this case, for example, the coolant is supplied from the second control valve 22 to the inlet of each inter-bore passage portion T ′ via the cylinder head, and the outlet of each inter-bore passage portion T ′ is connected to the passage portion W ′ and the cylinder head. , The second circulation path C2 incorporating the inter-bore passage portion T ′ can be formed. In this case, since the inter-bore passage portion T ′ and the passage portion W ′ (specifically, the portion corresponding to the engine passage portion) are provided so as to be able to supply cooling water individually, the generation of piston hitting noise is prevented. In preventing the cooling water, the cooling water can be circulated through the inter-bore passage portion T ′ while restricting the flow rate of the cooling water supplied to the passage portion W ′. For this reason, in this case, warming-up can be promoted more suitably because the flow rate of the cooling water supplied to the passage portion W ′ can be limited.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

W / P 1
Internal combustion engine 2
First thermostat 11
Second thermostat 12
First control valve 21
Second control valve 22
ECU 30
Cooling device 100

Claims (3)

An engine passage portion that is incorporated in a first circulation path for circulating cooling water of the internal combustion engine, and in which the flow rate of the circulating cooling water is more limited than after engine warm-up when the engine is warmed up;
An inter-bore passage portion installed in a second circulation path that is provided between cylinder bores of the internal combustion engine and that circulates cooling water of the internal combustion engine through a flow path different from the first circulation path;
A control valve capable of controlling the circulation of the cooling water flowing through the second circulation path among the first and second circulation paths;
With
A cooling apparatus for an internal combustion engine, wherein the control valve controls the flow of cooling water flowing through the second circulation path according to the temperature of a cylinder bore wall of the internal combustion engine when the engine is warmed up. A cooling device for an internal combustion engine according to claim 1,
When the temperature of the cylinder bore wall portion of the internal combustion engine is lower than a predetermined value, the control valve restricts the flow of cooling water flowing through the second circulation path, and the temperature of the cylinder bore wall portion of the internal combustion engine is the predetermined temperature. A cooling device for an internal combustion engine that releases the restriction on the flow of the cooling water flowing through the second circulation path when the value is higher than the value. A cooling device for an internal combustion engine according to claim 1 or 2,
A cooling apparatus for an internal combustion engine, wherein the engine passage portion and the inter-bore passage portion are provided so that cooling water can be supplied individually.

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