JP2016138453A - Cooling device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent insufficient cooling of a cylinder head around a combustion chamber while promoting the warming-up of a heater core.SOLUTION: A cooling device for an engine includes a first circulation passage 40 including an exhaust side flow path 22 passing through an exhaust port side 5a of a cylinder head 5A and a heater side flow path 15 passing through a heater core 6, a second circulation passage 41 including a main flow path 23 passing through another portion 5b than the exhaust port side of the cylinder head and an external flow path 35 outside the cylinder head, temperature detecting means 24 for detecting the temperature of the engine, and a flow path switching valve 2 for connecting the main flow path and the external flow path and for connecting the main flow path and the exhaust side flow path. When the temperature is within a first temperature range, the main flow path and the external flow path, and the main flow path and the exhaust side flow path are not connected, when the temperature is within a second temperature range higher than the first temperature range, the main flow path and the external flow path are not connected but the main flow path and the exhaust side flow path are connected, and when the temperature is within a third temperature range higher than the second temperature range, the main flow path and the external flow path are connected.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an engine cooling apparatus.

  2. Description of the Related Art Conventionally, an engine cooling device is known in which circulation of cooling water is limited during warm-up in order to promote engine warm-up (see, for example, Patent Document 1).

  The engine cooling device described in Patent Document 1 includes a combustion chamber-side water jacket that passes through the vicinity of the combustion chamber of the cylinder head, and a heater-side cooling water passage that is connected to the combustion chamber-side water jacket and passes through the heater core. A second cooling water circulation path including a first cooling water circulation path, an exhaust side water jacket passing through the vicinity of the exhaust passage of the cylinder head, and an exhaust side cooling water flow path connected to the exhaust side water jacket and passing through the heater core And a flow path switching valve that switches a circulation path through which the cooling water flows to one of the first cooling water circulation path or the second cooling water circulation path in accordance with the operating state of the engine.

  In the cooling device described in Patent Literature 1, when the engine is warming up due to the flow path switching operation of the flow path switching valve, the cooling water flows into the second cooling water circulation path, and the engine When in the warm-up completion state, the cooling water flows through the first cooling water circulation path.

  By performing such flow path switching, the heater core can be quickly warmed up during the warm-up operation of the engine, and the vehicle interior can be warmed up quickly.

JP 2009-47001 A

  However, in the cooling device described in Patent Document 1, in order to promote warm-up of the heater core, cooling water does not flow through the combustion chamber-side water jacket during the warm-up operation of the engine. There is a risk of insufficient cooling. Moreover, in order to promote warming-up of the heater core, there is a possibility that the amount of heat is insufficient only by giving heat to the cooling water from the exhaust water jacket.

  The present invention has been made in view of the above circumstances, and provides an engine cooling device capable of preventing insufficient cooling around a combustion chamber in a cylinder head while promoting warm-up of a heater core. Objective.

  In order to solve the above problems, the present invention provides an exhaust side flow path that passes through the exhaust port side of the cylinder head, and a heater side flow path that is connected to the exhaust side flow path and passes through the heater core of the air conditioner. Including a first circulation path through which cooling water circulates, a main flow path that passes through a portion other than the exhaust port side of the cylinder head, and an external flow path outside the cylinder head connected to the main flow path, A second circulation path through which the cooling water circulates, temperature detection means for detecting the temperature of the engine, and a first pump provided in the first circulation path for circulating the cooling water in the first circulation path; A second pump that is provided in the second circulation path and circulates the cooling water of the second circulation path; connection and disconnection of the main flow path and the external flow path; and the main flow path; Connection of the exhaust side flow path And a control unit that controls the operation of the flow path switching valve based on the detection result of the temperature detection means, and the main flow path is the exhaust side flow path Is connected to the first circulation path, and constitutes a path through which cooling water circulates together with the exhaust-side flow path and the heater-side flow path. (I) When the temperature detected by the temperature detection means is in the first temperature range, the main flow path and the external flow path, and the main flow path and the exhaust side flow path are not connected, and (ii) ) When the temperature detected by the temperature detection means is in a second temperature range higher than the first temperature range, the main flow path and the exhaust are not connected to the main flow path and the external flow path. (Iii) detected by the temperature detecting means And when the temperature is higher third temperature range below the second temperature range, and performs control to connect the external flow path and the main flow passage, to provide a cooling system of the engine.

  According to the present invention, the stage (i) in which the cooling water flows only in the first circulation path in a state where the main flow path is not incorporated, the first circulation path in the state where the main flow path is incorporated, and Since the stage (ii) in which the cooling water flows only in the first circulation path in the state where the main flow path is incorporated is provided between the stage (iii) in which the cooling water flows in the second circulation path, While promoting warming up of the heater core, insufficient cooling around the combustion chamber in the cylinder head can be prevented.

  That is, since high-temperature exhaust gas flows through the exhaust port, the cooling water flowing through the exhaust-side flow path is warmed more quickly than the cooling water flowing through the main flow path, and is warmed to a higher temperature. Therefore, during engine warm-up (during the controls (i) to (iii) above), the cooling water that has flowed through the exhaust-side flow path flows through the heater-side flow path. The heat of the side portion is applied, and the temperature rise of the heater core is promoted.

  In the initial stage of warm-up, since the part other than the exhaust side part (including the part around the combustion chamber) in the cylinder head is still in a low temperature state, control (i) that does not connect the main flow path and the exhaust side flow path is performed. Done. In this state, since the low-temperature cooling water in the main channel is not supplied to the heater core, the temperature drop of the heater core is suppressed.

  As the warm-up progresses, the temperature of the portion other than the exhaust side portion of the cylinder head rises, so control (ii) for connecting the main flow path and the exhaust side flow path is performed. As a result, the main flow path is incorporated into the first circulation path, and the cooling water circulates through the exhaust side flow path and the main flow path, so that the heater core includes the entire cylinder head (exhaust side portion and other portions). Gives heat. Therefore, warming up of the heater core can be promoted. In addition, since the cooling water flows through the main flow path and removes heat from the portion other than the exhaust side portion of the cylinder head, the cooling of the portion is promoted. Is suppressed.

  As the warm-up further proceeds, the temperature of the device (for example, auxiliary equipment) provided in the external flow path has sufficiently increased, so that the cooling water is circulated in both the first circulation path and the second circulation path. (Iii) is performed. Thereby, the apparatus provided in an external flow path can be cooled, promoting warming up of a heater core.

  In other words, if there is no control (ii), there is a risk of insufficient cooling around the combustion chamber of the cylinder head, and there is a risk that the warm-up of the heater core will not be sufficiently promoted, but the control (ii) distributes cooling water throughout the cylinder head. By doing so, while raising the temperature of the heater core, it is possible to suppress the surroundings of the combustion chamber from being insufficiently cooled.

  In the stage of (iii), the first circulation path and the second circulation path are not connected (the cooling water in the first circulation path and the cooling water in the second circulation path are not mixed with each other). State), or the state in which the first circulation path and the second circulation path are connected (the cooling water in the first circulation path and the cooling water in the second circulation path are mixed with each other). ).

  The present invention further includes a flow rate adjusting valve for adjusting a flow rate of the cooling water flowing through the external flow path, and the flow rate adjusting valve is connected to the main flow path and the external flow path by the flow path switching valve. It is preferable to limit the flow rate to a small amount during the initial predetermined period and then gradually increase the flow rate to a predetermined amount.

  According to this configuration, when the main flow path and the external flow path are connected, the low-temperature cooling water in the external flow path gradually flows into the main flow path, thereby suppressing a rapid temperature drop around the combustion chamber. be able to.

  In the present invention, the second circulation path further includes a radiator side flow path that is connected to the external flow path and passes through the radiator, and the flow path switching valve includes the radiator side flow path and the external flow path. The controller further connects and disconnects the radiator-side flow path when the temperature detected by the temperature detecting means is in a fourth temperature range higher than the third temperature range. It is preferable to connect to the flow path.

  According to this configuration, the cooling water can be cooled by the radiator.

  The present invention further comprises a flow rate adjusting valve for adjusting a flow rate of the cooling water flowing through the external flow channel and a flow rate of the cooling water flowing through the radiator-side flow channel, and an engine load detection means for detecting an engine load, The control unit further controls the operation of the flow rate control valve based on the detection results of the temperature detection unit and the engine load detection unit, and the temperature detected by the temperature detection unit is in the fourth temperature range. In addition, the larger the engine load detected by the engine load detecting means, the smaller the flow rate of the cooling water flowing through the external flow path, and the greater the flow rate of the cooling water flowing through the radiator side flow path. Is preferred.

  According to this configuration, the larger the engine load, the larger the flow rate of the cooling water flowing through the radiator. Therefore, when the engine load increases, for example, when climbing up, the engine body and the external flow path are provided. These devices can be operated properly by increasing the cooling function of the device.

  In the present invention, the control unit further controls the operation of the first pump based on detection results of the temperature detection means and the engine load detection means, and the temperature is in the fourth temperature range. In addition, it is preferable to perform control to increase the discharge amount of the first pump as the engine load detected by the engine load detecting means is larger.

  According to this configuration, as the engine load is larger, the flow rate of the cooling water flowing through the radiator increases. Therefore, when the engine load increases, for example, when climbing up, the engine body and the external flow path are provided. It is possible to increase the cooling function for the device and to adjust the temperature appropriately.

  In the present invention, it is preferable that the flow path switching valve individually includes only valves corresponding to the exhaust side flow path, the external flow path, and the radiator side flow path.

  According to this configuration, by opening and closing the valve corresponding to the exhaust-side flow path, the valve corresponding to the external flow path, and the valve corresponding to the radiator-side flow path, the engine cooling device is configured as described in (i) to (iii) above. ) And the stage of cooling the cooling water with the radiator. Moreover, since the flow path switching valve does not have a valve corresponding to the main flow path, the flow path switching valve can be configured easily.

  In the present invention, it is preferable that the heater side flow path further passes through a throttle body that adjusts an amount of intake air supplied to the cylinder head.

  According to this configuration, since the throttle body can be quickly warmed up, the throttle body can be quickly thawed even when the throttle body is frozen at the cold start of the engine. .

  In the present invention, the flow path switching valve further connects and disconnects the first circulation path and the second circulation path, and the controller detects the temperature detected by the temperature detection means. When the temperature is in the lower temperature range of the third temperature range, control is performed so as not to connect the first circulation path and the second circulation path, and the temperature detected by the temperature detection means is the third temperature range. It is preferable to perform control for connecting the first circulation path and the second circulation path when the temperature is in the high temperature range.

  According to this configuration, it is possible to more reliably perform the warm-up of the heater core and cool the device provided in the external flow path. That is, when the temperature detected by the temperature detecting means is in the lower temperature range of the third temperature range, the temperature of the device provided in the external flow path has risen, so that the second circulation path By controlling the circulation of the cooling water, the device provided in the external flow path is cooled. At this time, the low-temperature cooling water in the external flow path absorbs the heat of the cylinder head by flowing into the main flow path, and the temperature rises. Further, by performing control to circulate the cooling water in the first circulation path that is not connected to the second circulation path, that is, independent of the second circulation path, the low-temperature cooling water in the external flow path is The heater core can be warmed up while preventing it from flowing into the heater side flow path.

  When the temperature detected by the temperature detecting means is in the higher temperature range of the third temperature range, the second circulation path is connected to the first circulation path, and the cooling water is circulated through the entire circulation path. Control is performed. At the stage of connecting the second circulation path and the first circulation path, the temperature of the cooling water in the external flow path has already risen, so that when the cooling water flows into the heater side flow path from the external flow path The temperature drop of the heater core is suppressed. Therefore, the apparatus provided in the external flow path can be cooled while suppressing the temperature drop of the heater core.

  In the present invention, the first pump is preferably an electric pump.

  According to this configuration, by adopting the electric pump, it is possible to circulate only the necessary amount of cooling water when necessary without depending on the engine speed, and appropriately adjust the flow rate of the cooling water. Can do. Moreover, since the electric pump can be driven without using a timing chain that transmits the driving force of the engine, the number of parts can be reduced.

  In the present invention, the external flow path is preferably a flow path that passes through an auxiliary machine.

  According to this structure, an auxiliary machine can be cooled appropriately.

  As described above, according to the present invention, insufficient cooling around the combustion chamber in the cylinder head can be prevented while promoting warm-up of the heater core.

It is a block diagram which shows the whole structure of the cooling device of the engine which concerns on embodiment of this invention, and when the temperature of cooling water is less than T0, the state (water stop state) which stopped the flow of cooling water with the whole cooling device ). (A) is an expanded view of the surrounding wall of the rotary valve in the control state shown in FIG. 1, (b) is a figure which shows the position of the opening part provided in the housing surrounding a rotary valve. It is a block diagram which shows the whole structure of the cooling device of the engine which concerns on embodiment of this invention, and is a figure which shows the control state (control state A) when a combustion chamber wall temperature is more than T0 and less than T1. It is a block diagram which shows the whole structure of the cooling device of the engine which concerns on embodiment of this invention, and is a figure which shows the control state (control state B) when a combustion chamber wall temperature is more than T1 and less than T2. It is an expanded view of the surrounding wall of the rotary valve in the control state shown in FIG. It is a block diagram which shows the whole structure of the cooling device of the engine which concerns on embodiment of this invention, and is a figure which shows the control state (control state C) when a combustion chamber wall temperature is more than T2 and less than T3. It is an expanded view of the surrounding wall of the rotary valve in the control state shown in FIG. It is a block diagram which shows the whole structure of the cooling device of the engine which concerns on embodiment of this invention, and is a figure which shows the control state (control state D) when a combustion chamber wall temperature is more than T3 and less than T4. It is an expanded view of the surrounding wall of the rotary valve in the control state shown in FIG. It is a block diagram which shows the whole structure of the engine cooling device which concerns on embodiment of this invention, and is a figure which shows the control state (control state E) when a combustion chamber wall temperature is T4 or more and an engine load is less than predetermined value It is. It is an expanded view of the surrounding wall of the rotary valve in the operation state shown in FIG. It is a block diagram which shows the whole structure of the cooling device of the engine which concerns on embodiment of this invention, and is a figure which shows the control state (control state F) when a combustion chamber wall temperature is T4 or more and an engine load is more than predetermined value It is. It is an expanded view of the surrounding wall of the rotary valve in the operation state shown in FIG. It is a flowchart which shows the control action by ECU in embodiment of this invention. It is a flowchart which shows the control action by ECU in embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the engine 5 in the present embodiment includes a cylinder block 5B and a cylinder head 5A provided on the upper side of the cylinder block 5B.

  FIG. 1 shows the cylinder head 5A as viewed from above, and the cylinder block 5B as viewed from the intake side.

  1, 3, 4, 6, 8, 10, and 12, when an arrow is described in the flow path of the cooling water, it indicates that the cooling water is flowing through the flow path, When an arrow is not described in this, it means that cooling water is not flowing through the flow path.

  A plurality of cylinders # 1 to # 4 into which pistons (not shown) are respectively inserted are formed in the cylinder head 5A and the cylinder block 5B. Specifically, a first cylinder # 1, a second cylinder # 2, a third cylinder # 3, and a fourth cylinder # 4 are formed in order from the left in FIG. The engine 5 is an in-line four-cylinder engine in which four cylinders # 1 to # 4 are arranged in series in the crankshaft direction. A rotary valve device 2 described later is provided at the end of the cylinder head 5A on the fourth cylinder # 4 side. The engine 5 is disposed in an engine room provided in the front part of the vehicle.

  A combustion chamber is formed above the piston. The cylinder head 5A is formed with an intake port and an exhaust port (both not shown) that open toward the combustion chamber. The intake port is located below the cylinders # 1 to # 4 in FIG. 1, and the exhaust port is located above the cylinders # 1 to # 4 in FIG. The intake port is for introducing intake air into each cylinder. The exhaust port is for exhausting exhaust from each cylinder.

  The cylinder head 5A is formed with an exhaust water jacket and a main water jacket. The exhaust-side water jacket passes through the portion on the exhaust port side of the cylinder head 5A from the first cylinder # 1 side to the fourth cylinder # 4 side in the cylinder row direction. The main water jacket has a portion other than a portion on the exhaust port side of the cylinder head 5A, that is, a portion around the combustion chamber and a portion on the intake port side in the cylinder row direction from the first cylinder # 1 side to the fourth cylinder # 4 side. pass.

  The exhaust side water jacket corresponds to an exhaust side flow path 22 (see FIG. 1) described later. The main water jacket corresponds to a main flow path 23 (see FIG. 1) described later. A partition wall 28 is provided between the exhaust side water jacket (exhaust side channel 22) and the main water jacket (main channel 23), and the exhaust side water jacket and the main water jacket are separated from each other via the partition wall 28. Is formed.

  The cylinder block 5B has a main water jacket provided around the cylinders # 1 to # 4. The main water jacket passes through the cylinder block 5B so as to go round from the first cylinder # 1 side to the fourth cylinder # 4 side to the first cylinder # 1 side. The water jacket of the cylinder block 5B corresponds to a block-side flow path 25 (see FIG. 1) described later.

  Next, the cooling device 1 for the engine 5 will be described in detail.

  As shown in FIG. 1, the cooling device 1 includes a heater circulation path 40, an auxiliary machine circulation path 41, water temperature sensors 7, 8, 24, an accelerator opening sensor 30, a crank angle sensor 32, An intake air temperature sensor 38, a heater side pump 4, an auxiliary machine side pump 3, a rotary valve device 2, and an ECU 31 (Electronic Control Unit) are provided.

  The heater side pump 4 is an electronically controlled electric pump. The heater-side pump 4 corresponds to the “first pump” in the present invention. The heater side pump 4 has one suction port and one discharge port. A downstream end of a heater-side flow path 15 described later is connected to the suction port. A branch pipe (not shown) that branches into two on the downstream side is connected to the discharge port. An upstream end of a communication channel 26 (see FIG. 1), which will be described later, is connected to one end of the branch pipe which is branched, and an upstream of an ETB-side channel 19 (see FIG. 1), which will be described later, is connected to the other end. The ends are connected.

  The auxiliary machine side pump 3 is a mechanical pump and operates by receiving the driving force of the engine. The auxiliary pump 3 corresponds to the “second pump” in the present invention.

  The auxiliary machine in this embodiment includes an EGR (Exhaust Gas Recirculation) cooler 9, an oil cooler 10, an EGR valve 11, an ATF (Automatic Transmission Fluid) warmer 12, an electronically controlled throttle body (hereinafter referred to as "ETB") 13, and This is a radiator 14.

<Configuration of Heater Circulation Path 40>
The heater circulation path 40 (see FIG. 1) is a path through which cooling water circulates, and includes an exhaust side flow path 22, a heater side flow path 15, an ETB side flow path 19, and a communication flow path 26. The heater circulation path 40 corresponds to the “first circulation path” in the present invention.

  The exhaust-side flow path 22 is a passage that passes through the portion on the exhaust port side 5a of the cylinder head 5A. One end of the exhaust side flow path 22 is connected to the block side flow path 25, and more specifically, is connected to a portion of the block side flow path 25 opposite to the rotary valve device 2. The other end of the exhaust side flow path 22 is connected to the rotary valve device 2.

  The heater side flow path 15 is a flow path that passes through the heater core 6 of the air conditioner. The upstream end portion of the heater-side flow channel 15 is connected to a midway portion of the exhaust-side flow channel 22, more specifically, a portion of the exhaust-side flow channel 22 opposite to the rotary valve device 2. A water temperature sensor 7 for detecting the temperature of the cooling water is provided downstream of the heater core 6 in the heater side flow path 15.

  The ETB side channel 19 is a channel that passes through the ETB 13. The downstream end of the ETB side channel 19 is connected to a section between the heater core 6 and the heater side pump 4 in the heater side channel 15.

  The communication channel 26 is a channel that connects the discharge port of the heater-side pump 4 and the exhaust-side channel 22. A downstream end portion of the communication flow path 26 is connected to a portion of the exhaust side flow path 22 near the rotary valve device 2.

<Configuration of rotary valve device 2>
As shown in FIG. 2 (b), the rotary valve device 2 includes a cylindrical rotary valve 2a, a rectangular parallelepiped housing 2b that houses the rotary valve 2a, and an electronically controlled electric motor that rotationally drives the rotary valve 2a. A motor (not shown). The rotary valve 2a is rotatable in the circumferential direction (axial direction) within the housing 2b.

  As shown in FIG. 2B, the housing 2b has openings H1, H2, and H3 and an opening outside the figure (hereinafter referred to as “an outside opening outside the figure”). The opening H1 is formed in the surface on the engine 5 side of the housing 2b (the left surface in FIG. 2B). The opening H2 is formed on the upper surface of the housing 2b (the upper surface in FIG. 2B). The opening H3 is formed on the lower surface of the housing 2b (the lower surface in FIG. 2B). These openings H1, H2, and H3 are holes through which cooling water passes.

  Between the opening H1 and the rotary valve 2a, a cylindrical lip 2c extending from the inner peripheral edge of the opening H1 toward the rotary valve 2a is provided. The end of the lip 2c on the opening H1 side is fixed to the inner periphery of the opening H1. The lip 2c is separate from the rotary valve 2a and is not fixed to the rotary valve 2a. The end surface of the lip portion 2c on the rotary valve 2a side has a shape along the outer peripheral surface of the rotary valve 2a. As a result, the end surface of the lip portion 2c on the rotary valve 2a side can be brought into sliding contact with the outer peripheral surface of the rotary valve 2a.

  A lip 2d similar to the lip 2c is also provided between the opening H2 and the rotary valve 2a. A lip 2e similar to the lip 2c is also provided between the opening H3 and the rotary valve 2a.

  As shown in FIG. 2A, the rotary valve 2a has cutout holes K1, K2, and K3 on its peripheral wall. An opening 36 (see FIG. 2B) is formed at the axial end of the rotary valve 2a.

  FIG. 2A is a development view of the rotary valve 2a in which the position on the circumferential surface of the rotary valve 2a is represented by an angle 0 ° to 360 ° around the axis of the rotary valve 2a. 2A is the axial direction of the rotary valve 2a, and the left-right direction in FIG. 2A is the circumferential direction of the rotary valve 2a. In order to show the positional relationship between the openings H1, H2, and H3 and the notches K1, K2, and K3, the openings H1, H2, and H3 are shown by two-dot chain lines in FIG. As shown in FIG. 2A, the center of the opening H1 is always at the reference position 0 °.

  As shown in FIG. 2A, the cutout holes K1, K2, and K3 are arranged in this order from one end side to the other end side in the axial direction of the rotary valve 2a.

  As the rotary valve 2a rotates, the positions of the cutout holes K1, K2, and K3 change in the circumferential direction (the left-right direction in FIG. 2A).

  The cutout hole K1 has a rectangular shape extending in the circumferential direction of the rotary valve 2a. At a certain point shown in FIG. 2A (when the flow of cooling water is stopped in the entire cooling device 1), the cutout hole K1 is 30 °. It extends from around 315 °.

  The cutout hole K2 includes a rectangular main portion K2c extending in the circumferential direction of the rotary valve 2a and having one end in the longitudinal direction (the left end in FIG. 2A) recessed in a concave shape, and the other longitudinal end of the main portion K2c. A constricted portion K2b which is provided continuously to the portion (the right end portion in FIG. 2A) and constricts in a triangular shape, and a protrusion K2a projecting from the tip of the constricted portion K2b. At a certain point shown in FIG. 2A, the cutout hole K2 extends from around 230 ° to around 45 °. The width of the main portion K2a of the notch hole K2 (the length along the axial direction of the rotary valve 2a) is larger than the width of the notch hole K1.

  The cutout hole K3 extends in the circumferential direction of the rotary valve 2a and is continuously provided in a rectangular main portion K3c whose one end in the longitudinal direction is recessed, and the other end in the longitudinal direction of the main portion K3c. It has a rounded portion K3b and a projection K3a that protrudes from the tip of the narrowed portion K3b. The circumferential length of the main portion K3c is shorter than the circumferential length of the main portion K2c in the cutout hole K2, and at a certain point shown in FIG. It extends over. The width of the main portion K3c of the notch hole K3 is equal to the width of the main portion K2c of the notch hole K2, and is larger than the width of the notch hole K1.

  The opening H1 is provided at a position where the opening H1 can overlap with the cutout hole K1 in accordance with the rotation of the rotary valve 2a, and is provided at a position centered on 0 ° shown in FIG. The diameter of the opening H1 is slightly larger than the width of the cutout hole K1. The opening H1 is connected to the end of the exhaust valve 22 on the rotary valve device 2 side.

  The opening H2 is provided at a position where the opening H2 can overlap with the cutout hole K2 in accordance with the rotation of the rotary valve 2a, and is provided at a position centered on 90 ° shown in FIG. The diameter of the opening H2 is slightly larger than the width of the cutout hole K2. The opening H2 is connected to an upstream flow path 34 in an auxiliary machine flow path 35 described later.

  The opening H3 is provided at a position where the opening H3 can overlap with the cutout hole K3 according to the rotation of the rotary valve 2a, and is provided at a position centered at 270 ° shown in FIG. The diameter of the opening H3 is slightly larger than the width of the cutout hole K3. The opening H3 is connected to an upstream end portion of a radiator-side flow path 33 described later.

  In this rotary valve device 2, when the notch hole K1 and the opening H1 overlap, the exhaust side flow path 22 and the rotary valve 2a communicate with each other, and when the notch hole K1 and the opening H1 do not overlap, the exhaust side The flow path 22 and the rotary valve 2a do not communicate (is blocked). Moreover, the area (communication area) where these overlap is changed according to rotation of the rotary valve 2a. That is, the flow rate regulating valve is configured by the cutout hole K1 and the opening H1. In the following description, the flow rate control valve constituted by the notch hole K1 and the opening H1 is referred to as a flow rate control valve V1.

  Similarly, a flow control valve is configured by the cutout hole K2 and the opening H2. Further, the flow rate adjusting valve is constituted by the cutout hole K3 and the opening H3. In the following description, the flow rate control valve configured by the notch hole K2 and the opening H2 is referred to as a flow rate control valve V2, and the flow rate control valve configured by the notch hole K3 and the opening H3 is referred to as a flow rate control valve V3.

  A gap is provided between the opening 36 (see FIG. 2B) at the axial end of the rotary valve 2a and the inner wall surface of the housing 2b facing the opening 36. The above-mentioned non-illustrated opening formed in the housing 2b is always in communication with the inside of the rotary valve 2a through the gaps and the cutout holes K1 to K3. The part that is always in communication is shown as a communication part 37 in FIG.

  In this rotary valve device 2, when all the flow rate adjusting valves V1, V2, and V3 are closed, the cooling water does not flow through the rotary valve device 2 (see FIGS. 1 and 3). That is, the cooling water does not flow in the rotary valve device 2.

  When only the flow rate control valve V1 is open, the cooling water flows between the exhaust side flow path 22 and the main flow path 23 through the rotary valve device 2 (see FIG. 4). That is, a flow path connecting the exhaust side flow path 22 and the main flow path 23 is formed in the rotary valve device 2.

  When only the flow rate control valve V2 is open, the cooling water flows between the auxiliary machine side flow path 35 and the main flow path 23 through the rotary valve device 2 (see FIG. 6). That is, a flow path that connects the auxiliary machine side flow path 35 and the main flow path 23 flow path is formed in the rotary valve device 2.

  When only the flow control valves V1, V2 are open, the cooling water flows between the exhaust side flow path 22, the main flow path 23, and the auxiliary machine side flow path 35 through the rotary valve device 2 (see FIG. 8). . That is, a flow path that connects the exhaust side flow path 22, the main flow path 23, and the auxiliary machine side flow path 35 is formed in the rotary valve device 2.

  When all of the flow rate control valves V1, V2, and V3 are open, the cooling water passes through the rotary valve device 2 and the exhaust side flow path 22, the main flow path 23, the auxiliary machine side flow path 35, and the radiator side flow path 33. (See FIGS. 10 and 12). That is, a flow path that connects the exhaust side flow path 22, the main flow path 23, the auxiliary machine side flow path 35, and the radiator side flow path 33 is formed in the rotary valve device 2.

  That is, the flow rate switching valves V1, V2, and V3 constitute a flow path switching valve.

  In order to allow the cooling water to flow through the heater circulation path 40, it is only necessary that the heater-side pump 4 is operating, and the flow rate control valves V1, V2, and V3 need not be opened (FIGS. 3, 4, 6, and 8). , 10, 12). That is, if the heater-side pump 4 is operating, the cooling water circulates in the heater circulation path 40 regardless of whether the flow rate control valves V1, V2, and V3 are open.

<Configuration of circulation path 41 for auxiliary machinery>
The auxiliary machine circulation path 41 (see FIG. 1) is a path through which the cooling water circulates. The block side flow path 25, the main flow path 23, the upstream flow path 34, the oil cooler side flow path 20, and the EGR valve side flow. A passage 21, an EGR cooler side passage 17, a return passage 16, a passage in the rotary valve device 2, and a radiator side passage 33 are provided. The auxiliary machine circulation path 41 corresponds to the “second circulation path” in the present invention.

  The oil cooler side flow path 20, the EGR valve side flow path 21, the EGR cooler side flow path 17, and the return flow path 16 constitute an auxiliary machine side flow path 35. The auxiliary machine side flow path 35 corresponds to the “external flow path” in the present invention.

  The block-side flow path 25 is a flow path that passes through the cylinder block 5B. The upstream end of the block side flow path 25 is connected to the discharge port of the auxiliary machine side pump 3.

  The main flow path 23 is a flow path that passes through a portion other than the exhaust port side portion of the cylinder head 5A, that is, a portion around the combustion chamber and a portion on the intake port side. The end of the main channel 23 opposite to the rotary valve device 2 is connected to the block-side channel 25.

  The upstream side flow path 34 supplies the cooling water flowing out from the opening H4 (flow rate control valve V2) of the rotary valve device 2 to the oil cooler side flow path 20, the EGR valve side flow path 21, and the EGR cooler side flow path 17. It is a flow path for guiding. The upstream end of the upstream channel 34 is connected to the opening H2. The downstream end of the upstream channel 34 is connected to the upstream ends of the oil cooler channel 20, the EGR valve channel 21, and the EGR cooler channel 17. The upstream flow path 34 is provided with a water temperature sensor 8 that detects the temperature of the cooling water.

  The downstream end of the oil cooler side flow path 20 is connected to the return flow path 16. An oil cooler 10 is provided in the oil cooler side flow path 20.

  The downstream end of the EGR valve side channel 21 is connected to the return channel 16. An EGR valve 11 and an ATF warmer 12 are provided in the EGR valve side flow path 21.

  The upstream end of the radiator-side flow path 33 is connected to the opening H3 (flow rate control valve V3) of the rotary valve device 2. The downstream end of the radiator side flow path 33 is connected to the return flow path 16. The radiator 14 is provided in the radiator-side flow path 33.

  The return flow path 16 is a flow path for returning the cooling water flowing out from the oil cooler side flow path 10, the EGR valve side flow path 21, the radiator side flow path 33, and the EGR cooler side flow path 20 to the auxiliary machine side pump 3. It is. The downstream end of the oil cooler side flow path 10, the EGR valve side flow path 21, the radiator side flow path 33, and the EGR cooler side flow path 20 is connected to an upstream portion or a middle flow portion of the return flow passage 16. The downstream end of the return flow path 16 is connected to the suction port of the auxiliary machine side pump 3.

  In order to circulate the cooling water in the auxiliary machine circulation path 41, at least one of the flow rate adjusting valve V2 or the flow rate adjusting valve V3 needs to be opened while the auxiliary pump 3 is operating. (See FIGS. 6, 8, 10, and 12).

  The water temperature sensor 24 is provided in the main channel 23 and detects the temperature of the cooling water flowing through the main channel 23. The water temperature sensor 7 is provided downstream of the heater core 6 in the heater side flow path 15 and detects the temperature of the cooling water flowing out of the heater core 6. The water temperature sensor 8 is provided in the upstream flow path 34 and detects the temperature of the cooling water flowing out from the rotary valve device 2. The accelerator opening sensor 30 detects the amount of depression of the accelerator pedal by the driver as the accelerator opening. The crank angle sensor 32 detects the rotation angle of the crankshaft. The intake air temperature sensor 38 detects the temperature of intake air flowing into the engine 5.

  The water temperature sensor 8, the accelerator opening sensor 30, the crank angle sensor 32, and the intake air temperature sensor 38 correspond to “temperature detection means” of the present invention. The accelerator opening sensor 30 corresponds to “engine load detecting means” of the present invention.

<Configuration of ECU 31>
The ECU 31 includes a CPU, RAM, ROM, and the like. The ECU 31 generates a control signal for controlling the operations of the rotary valve device 2 and the heater-side pump 4 based on signals indicating detection values received from the water temperature sensor 24, the accelerator opening sensor 30, and the crank angle sensor 32. Then, the control signal is transmitted to the rotary valve device 2 and the heater side pump 4. The ECU 31 corresponds to “temperature detection means”, “engine load detection means”, and “control unit” of the present invention.

  The detected values of the water temperature sensors 7 and 8 are used to determine whether the heater core 6 and the engine 5 are appropriately temperature-controlled while the ECU 31 controls the rotary valve device 2 and the heater-side pump 4. It is done. In the following description, the description of the control operation of the rotary valve device 2 and the heater side pump 4 using the detection values of the water temperature sensors 7 and 8 is omitted.

  Next, the control operation of the rotary valve device 2 and the heater side pump 4 by the ECU 31 will be described with reference to the flowcharts of FIGS.

  As shown in FIG. 14, first, the ECU 31 inputs signals indicating detection values from the water temperature sensor 24, the accelerator opening sensor 30, the crank angle sensor 32, and the intake air temperature sensor 38 (step S1).

  Next, the ECU 31 calculates an engine load generated by the engine (a driving torque generated by the engine) based on the accelerator opening detected by the accelerator opening sensor 30 (step S2).

  Next, the ECU 31 calculates the engine speed based on the crank angle detected by the crank angle sensor 32 (step S3).

  Next, the ECU 31 determines the wall surface temperature of the combustion chamber on the cylinder head 5A side of the engine 5 (hereinafter referred to as “combustion chamber wall temperature”) based on the coolant temperature, engine load, engine speed, and intake air temperature. Calculate (step S4). This combustion chamber wall temperature corresponds to the “engine temperature” in the present invention.

  Next, the ECU 31 determines whether or not the combustion chamber wall temperature is in a temperature range of level 0 (step S5). The temperature range of level 0 is a temperature lower than the temperature T0 corresponding to the cold state, and is included in the “first temperature range” in the present invention.

  If the ECU 31 makes a determination of YES in step S5, the ECU 31 controls the flow rate adjustment valves V1 to V3 to be fully closed and the heater pump 4 to be stopped (step S6).

  By performing the control in step S6, as shown in FIG. 2A, in the rotary valve device 2, the opening H1 and the cutout hole K1 do not overlap, and the opening H2 and the cutout hole K2 do not overlap. The opening H3 and the cutout hole K3 are not overlapped. Thereby, as shown in FIG. 1, the cooling water does not flow in any flow path of the cooling device 1, so that warm-up of the engine 5 is promoted. Hereinafter, the control state of step S6 is referred to as a “water stop state”. After executing the process of step S6, the ECU 31 returns to step S1.

  When it is determined NO in step S5, the ECU 31 determines whether the combustion chamber wall temperature is in the level 1 temperature range (step S7). The temperature range of level 1 is a temperature range (during warming-up) that is equal to or higher than temperature T0 and lower than T1, and is included in the “first temperature range” in the present invention.

  When the ECU 31 makes a determination of YES in step S7, the ECU 31 controls the heater side pump 4 to operate with the opening degree of the flow rate adjusting valves V1 to V3 being fully closed (step S8). The heater-side pump 4 operates in such a direction that the cooling water flows from the heater-side channel 15 side to the connecting channel 26 and the ETB-side channel 19 side.

  By performing the control in step S8, the cooling water flows through the exhaust side flow path 22, the heater side flow path 15, the communication flow path 26, and the ETB side flow path 19, as shown in FIG. That is, the cooling water circulates in the heater circulation path 40 including the exhaust side flow path 22, the heater side flow path 15, the communication flow path 26, and the ETB side flow path 19. Hereinafter, the control state in step S8 is referred to as “control state A”. The ECU 31 returns to step S1 after executing the process of step S8.

  When it is determined NO in step S7, the ECU 31 determines whether the combustion chamber wall temperature is in the temperature range of level 2 (step S9). The temperature range of level 2 is a temperature range (during warm-up) that is equal to or higher than temperature T1 and lower than T2, and corresponds to the “second temperature range” in the present invention.

  If the ECU 31 determines YES in step S9, the opening of the flow rate adjusting valve V1 is fully opened, the opening amounts of the flow rate adjusting valves V2, V3 are fully closed, and the heater side pump 4 is operated. Is performed (step S10).

  Specifically, when the rotary valve 2a rotates in the housing 2b, as shown in FIG. 5, in the rotary valve device 2, the opening H1 and the notch hole K1 overlap each other, and the opening H2 and the notch hole K2 The opening H3 and the cutout hole K3 are not overlapped with each other. Thereby, as shown in FIG. 4, the main flow path 23 and the exhaust side flow path 22 are connected. The main flow path 23 is connected to the exhaust side flow path 22 so as to be incorporated in the heater side circulation path 40 and constitutes a path through which the cooling water circulates together with the exhaust side flow path 22 and the heater side flow path 15.

  That is, the exhaust side flow path 22, the flow path in the rotary valve device 2 (flow path connecting the flow rate control valve V 1 and the communication portion 37), the main flow path 23, and the block side flow path 25 are opposite to the rotary valve device 2. A circulation path is constituted by the side portion, the heater-side flow path 15, the communication flow path 26, and the ETB-side flow path 19, and the cooling water circulates throughout the circulation path. Hereinafter, the control state of step S10 is referred to as “control state B”. The ECU 31 returns to step S1 after executing the process of step S10.

  If the determination in step S9 is NO, the ECU 31 determines whether or not the combustion chamber wall temperature is in the temperature range of level 3 (step S11). The temperature range of level 3 is a temperature range that is equal to or higher than temperature T2 and lower than T3 (during warm-up), and is included in the “third temperature range” in the present invention.

  If the ECU 31 makes a determination of YES in step S11, the flow control valves V1, V3 are fully closed, the opening of the flow control valve V2 is set to a small opening, and the heater side pump 4 is operated. (Step S12).

  Specifically, as shown in FIG. 7, the ECU 31 rotates the rotary valve 2a so that the cutout holes K1, K2, K3 advance from the left side to the right side in FIG. 7 (hereinafter referred to as “right rotation”). Called). By rotating the rotary valve 2a, as shown in FIG. 7, in the rotary valve device 2, the opening H1 and the cutout hole K1 do not overlap (the flow rate control valve V1 is in a fully closed state), and the opening H2 The protrusion K2a and the constricted portion K2b of the notch hole K2 overlap (the flow control valve V2 is in a small opening state), and the opening H3 and the notch hole K3 do not overlap (the flow control valve V3 is fully closed). It becomes.

  When the flow rate adjustment valve V2 is opened, as shown in FIG. 6, the main flow path 23 and the auxiliary machine side flow path 35 are connected. And by the pumping force of the auxiliary machine side pump 3, the main flow path 23, the flow path in the rotary valve device 2 (the flow path connecting the communication portion 37 and the flow rate adjusting valve V2), the auxiliary machine side flow path 35, and the block Cooling water circulates through the side flow path 25. That is, the cooling water circulates through the auxiliary circuit circulation path 41.

  Since the flow control valve V1 is closed, in the rotary valve device 2, the flow path between the exhaust side flow path 22 and the main flow path 23 is shut off, so the heater circulation path 40 and the auxiliary machine circulation path 41 are closed. Cooling water does not flow between. That is, the heater circulation path 40 and the heater circulation path 40 become independent circulation paths in which the cooling water does not mix, and the cooling water circulates separately in each circulation path.

  Further, since the flow rate adjusting valve V2 is in a small opening state, when the flow rate adjusting valve V2 is opened, the auxiliary side channel 35, that is, the oil cooler side channel 20, the EGR valve side channel 21, EGR. It is possible to prevent a large amount of low-temperature cooling water in the cooler-side channel 17 and the return channel 16 from flowing into the main channel 23 in a short time.

  In step S12, the opening H2 begins to overlap from the protrusion K2a of the cutout hole K2 (see FIG. 7). Therefore, the flow rate is limited to a small amount during the initial predetermined period in which the main flow path 23 and the auxiliary machine-side flow path 35 are connected. Thereafter, the flow rate gradually increases until the opening H2 overlaps the protrusion K2a and the narrowed portion K2b of the cutout hole K2. Therefore, when the main flow path 23 and the auxiliary machine side flow path 35 are connected, the low-temperature cooling water in the auxiliary machine side flow path 35 gradually flows into the main flow path 23, so that the rapid temperature around the combustion chamber is increased. The decrease can be suppressed. Hereinafter, the control state of step S12 is referred to as “control state C”.

  If NO is determined in step S11, the ECU 31 determines whether or not the combustion chamber wall temperature is in the temperature range of level 4 as shown in FIG. 15 (step S13). The temperature range of level 4 is a temperature range (during warm-up) that is equal to or higher than temperature T3 and lower than T4, and is included in the “third temperature range” in the present invention. The temperature T4 is a temperature that serves as a criterion for determining whether or not the engine is warming up. That is, if the combustion chamber wall temperature is lower than T4, the engine is warming up, and if it is equal to or higher than T4, the engine is in a warming-up completed state.

  If the ECU 31 makes a determination of YES in step S13, in the rotary valve device 2, the opening of the flow control valve V1 is fully opened, the opening of the flow control valve V3 is fully closed, and the flow control valve V2 is opened. Is set to a large opening (a state where the opening is slightly smaller than the fully opened state), and the heater side pump 4 is controlled to operate (step S14).

  Specifically, the ECU 31 rotates the rotary valve 2a to the right (see FIG. 9). When the rotary valve 2a rotates to the right, as shown in FIG. 9, in the rotary valve device 2, the opening H1 and the cutout hole K1 overlap (the flow control valve V1 is fully open), and the opening H2 and the cutout hole The constricted portion K2b and the main portion K2c of K2 overlap (the flow control valve V2 is in a large opening state), and the opening H3 and the cutout hole K3 do not overlap (the flow control valve V3 is in a fully closed state).

  As the opening degree of the flow rate control valve V2 increases, the amount of cooling water flowing out from the rotary valve device 2 to the accessory side flow path 35 increases.

  When the flow rate adjusting valves V1, V2 are opened, the exhaust side flow path 22, the main flow path 23, and the auxiliary machine side flow path 35 are connected as shown in FIG. Then, the cooling water flows through the auxiliary circuit circulation path 41 (not including the radiator-side flow path 33).

  Specifically, in the exhaust side flow path 22, the flow direction of the cooling water is opposite to that in the control state C, and the exhaust side flow path 22, the main flow path 23, and the flow paths (flow rate control valve) in the rotary valve device 2. An auxiliary machine circulation path 41 is configured by the flow path V 1, the flow path connecting the communication flow path 37 and the flow rate control valve V 2), the auxiliary machine side flow path 35, and the block side flow path 25.

  In addition, the flow path in the rotary valve device 2 (flow path connecting the flow rate control valve V1 and the flow rate control valve V2), the auxiliary side flow path 35, and the block side flow path 25 on the opposite side to the rotary valve device 2. The heater-side circulation path 40 is configured by the part of the exhaust-side flow path 22 opposite to the rotary valve device 2, the heater-side flow path 15, and the ETB-side flow path 19. That is, the heater circulation path 40 and the auxiliary machine circulation path 41 are connected, and the cooling water circulates throughout the heater circulation path 40 and the auxiliary machine circulation path 41. Hereinafter, the control state of step S14 is referred to as “control state D”.

  If the ECU 31 determines NO in step S13, the ECU 31 determines whether the engine load is less than a predetermined threshold (step S15). The threshold value is a value that serves as a criterion for determining whether or not the engine 5 is in a high load state. That is, if the engine load is less than the threshold value, the engine 5 is in a low load or medium load state, and if the engine load is equal to or greater than the threshold value, the engine 5 is in a high load state. If NO is determined in step S13, the combustion chamber wall temperature is T4 or higher. The temperature range of T4 or higher corresponds to the “fourth temperature range” in the present invention.

  If the ECU 31 makes a determination of YES in step S15, the flow control valves V1 and V2 are fully opened, the flow control valve V3 is set to an intermediate opening state, and the heater side pump 4 is operated (step S16). ).

  Specifically, the ECU 31 rotates the rotary valve 2a to the right (see FIG. 11). When the rotary valve 2a rotates to the right, as shown in FIG. 11, in the rotary valve device 2, the opening H1 and the cutout hole K1 overlap (the flow control valve V1 is fully open), and the opening H2 and the cutout hole The main portion K2c of K2 overlaps (the flow control valve V2 is fully open), and the opening H3 overlaps the protrusion K3a, the constricted portion K3b and the main portion K3c of the notch K3 (the flow control valve V3 is in the middle). Opening state).

  As the opening degree of the flow rate control valve V2 increases, the amount of cooling water flowing out from the rotary valve device 2 to the accessory side flow path 35 increases.

  Since the exhaust side flow path 22, the main flow path 23, the auxiliary machine side flow path 35, and the radiator side flow path 33 are connected by opening the flow rate control valves V1, V2, and V3, it is shown in FIG. As described above, the cooling water flows between the heater circulation path 40 and the auxiliary machine circulation path 41 (including the radiator-side flow path 33). That is, the cooling water circulates in the heater circulation path 40 and the auxiliary machine circulation path 41 as a whole.

  When the flow rate control valve V3 is in the middle opening state, it is possible to prevent a large amount of low-temperature cooling water in the radiator-side flow path 33 from flowing into the main flow path 23 in a short time.

  In step S16, the opening H3 starts to overlap from the protrusion K3a of the cutout hole K3. Accordingly, the flow rate is limited to a small amount during the initial predetermined period when the main flow path 23 and the radiator side flow path 33 are connected. Thereafter, the flow rate gradually increases until the opening H3 overlaps the protrusion K3a and the narrowed portion K3b of the cutout hole K3. Accordingly, when the main flow path 23 and the radiator side flow path 33 are connected, the low-temperature cooling water in the radiator side flow path 33 gradually flows into the main flow path 23, so that a rapid temperature drop around the combustion chamber is prevented. Can be suppressed. Hereinafter, the control state of step S16 is referred to as “control state E”.

  If the ECU 31 makes a NO determination in step S15, the opening of the flow control valves V1, V3 is fully opened, the opening of the flow control valve V2 is set to a small opening, and the heater side pump 4 is operated. Is performed (step S17).

  Specifically, the ECU 31 rotates the rotary valve 2a to the right (see FIG. 13). When the rotary valve 2a rotates to the right, as shown in FIG. 13, in the rotary valve device 2, the opening H1 and the cutout hole K1 overlap (the flow rate control valve V1 is fully open), and the opening H2 and the cutout hole One end (recess side) of the main portion K2c of K2 overlaps (the flow control valve V2 is in a small open state), and the opening H3 overlaps with the main portion K3c of the notch hole K3 (the flow control valve V3 is in a fully open state) )

  By reducing the opening degree of the flow rate control valve V2, the amount of cooling water flowing out from the rotary valve device 2 to the auxiliary machine side flow path 35 is reduced.

  As the opening degree of the flow rate control valve V3 increases, the amount of cooling water flowing out from the rotary valve device 2 to the radiator-side flow path 33 increases. That is, the amount of cooling water that passes through the radiator 14 increases, and the cooling capacity of the radiator 14 increases. Hereinafter, the control state of step S17 is referred to as “control state F”.

  As described above, according to the present embodiment, the control state A in which the cooling water flows only in the heater circulation path 40 in the state where the main flow path 23 is not incorporated, and the state in which the main flow path 23 is incorporated. A control state in which the cooling water flows only in the heater circulation path 40 in which the main flow path 23 is incorporated between the heater-side circulation path 40 and the control state C in which the cooling water flows in the auxiliary machine-side circulation path 41. Since B is provided, it is possible to prevent insufficient cooling around the combustion chamber in the cylinder head 5A while promoting warm-up of the heater core 6.

  That is, since high-temperature exhaust gas flows through the exhaust port, the cooling water flowing through the exhaust-side flow path is warmed more quickly than the cooling water flowing through the main flow path, and is warmed to a higher temperature. Therefore, during engine warm-up (each stage of control states A to D), the cooling water that has flowed through the exhaust-side flow path 22 flows through the heater-side flow path 15, so that the temperature rise of the heater core 6 is promoted.

  In the initial stage of warm-up, the portion 5b (the portion around the combustion chamber and the intake side portion) other than the exhaust side portion in the cylinder head 5A is still in a low temperature state, so the main flow path 23 and the exhaust side flow path 22 are connected. No control (control state A) is performed. In this state, since the low-temperature cooling water in the main flow path 23 is not supplied to the heater core 6, the temperature drop of the heater core 6 is suppressed.

  As the warm-up progresses, the temperature of the portion 5b other than the exhaust-side portion of the cylinder head 5A rises, so that control (control state B) for connecting the main flow path 23 and the exhaust-side flow path 22 is performed. As a result, the main flow path 23 is incorporated into the heater circulation path 40. As the cooling water circulates through the exhaust side flow path 22 and the main flow path 23, heat is applied to the heater core 6 from the entire cylinder head 5A (exhaust side portion 5a and other portions 5b). Therefore, warming up of the heater core 6 can be promoted. In addition, since the cooling water flows through the main flow path 23 and removes heat from the portion 5b other than the exhaust side portion of the cylinder head 5A, the cooling of the portion 5b is promoted. Insufficient cooling around the room is suppressed.

  Further, when the warm-up progresses, the temperatures of the auxiliary machines 9 and 10 are sufficiently increased, so that the cooling water is circulated in both the heater circulation path 40 and the auxiliary circulation path 41 (control state C). ) Is performed. Thereby, the auxiliary machines 9 and 10 can be cooled, promoting warming up of the heater core 6.

  That is, if there is no control state B, there is a possibility that insufficient cooling will occur around the combustion chamber of the cylinder head 5A, and there is a possibility that the warm-up of the heater core will not be sufficiently promoted. As a result, the temperature rise of the heater core 6 is promoted, while the surroundings of the combustion chamber can be prevented from being insufficiently cooled.

  Further, according to the above embodiment, the flow rate adjusting valves V2, V3 limit the flow rate to a small amount during the initial predetermined period when the main flow path 23 and the auxiliary machine side flow path 35 are connected, and then the flow rate is reduced to a predetermined amount. Since it gradually increases, the low-temperature cooling water in the auxiliary machine-side flow path 35 gradually flows into the main flow path 23. Therefore, a rapid temperature drop around the combustion chamber can be suppressed.

  Further, when the combustion chamber wall temperature becomes equal to or higher than T4 (warming-up completion state), the radiator-side flow path 33 is connected to the accessory-side flow path 35, so that the cooling water is cooled by the radiator 14 after the warm-up is completed. be able to.

  Further, when the combustion chamber wall temperature becomes equal to or higher than T4, the larger the accelerator opening, the smaller the flow rate of the cooling water flowing through the accessory side flow path 35 and the flow rate of the cooling water flowing through the radiator side flow path 33. Therefore, when the engine load increases, for example, when climbing up, the cooling function of the engine 5 and the auxiliary machines 9 and 10 can be enhanced to operate them appropriately.

  Further, since the rotary valve device 2 has individually the flow control valves V1, V2, and V3 corresponding to the exhaust side flow path 22, the auxiliary machine side flow path 35, and the radiator side flow path 33, the exhaust side flow The cooling device 1 for the engine 5 is opened and closed by opening and closing the flow rate adjusting valve V1 corresponding to the passage 22, the flow rate adjusting valve V2 corresponding to the auxiliary side channel 35, and the flow rate adjusting valve V3 corresponding to the radiator side channel 33. It is possible to shift to each stage of the water stop state to the control state F. Further, since the rotary valve device 2 does not have a valve corresponding to the main flow path 23, the rotary valve device 2 can be configured easily.

  Further, since the heater side flow path 15 passes through the ETB 13 that adjusts the amount of intake air supplied to the cylinder head 5A, the ETB 13 can be quickly warmed up. Thereby, even if the ETB 13 is frozen when the engine 5 is cold started, the ETB 13 can be quickly thawed.

  Further, by providing the control state C, the warm-up of the heater core 6 and the cooling of the auxiliary machines 9 and 10 can be performed more reliably.

  Further, since the heater-side pump 4 is an electric pump, it is possible to circulate only a necessary amount of cooling water when necessary without depending on the engine speed, and to appropriately adjust the flow rate of the cooling water. . Moreover, since the electric pump can be driven without passing through the timing chain that transmits the driving force of the engine 5, the number of parts can be reduced.

  In the above-described embodiment, the ECU 31 may further perform control to increase the discharge amount of the heater-side pump 4 as the accelerator opening increases when the combustion chamber wall temperature becomes T4 or higher. By performing this control, as the engine load increases, the flow rate of the cooling water flowing through the radiator 14 increases. Therefore, when the engine load increases, for example, when climbing up, the engine 5 and the auxiliary machines 9, 10 The cooling function can be further enhanced.

  Moreover, in the said embodiment, although the heater side pump 4 is flowing cooling water from the heater side flow path 15 side to the communication flow path 26 side and the ETB flow path 19 side, it is not restricted to this. The heater-side pump 4 may flow cooling water from the communication channel 26 side and the ETB channel 19 side to the heater-side channel 15 side. In this case, the direction of the cooling water flow in the heater circulation path 40 is reversed.

  Moreover, in the said embodiment, although the one rotary valve apparatus 2 has a function as a flow-path switching valve and a function as a flow control valve, it is not restricted to this. For example, you may provide separately the valve apparatus which has a function only of a flow-path switching valve, and the valve apparatus which has only a function as a flow control valve.

  Moreover, in the said embodiment, although the auxiliary machine side flow path 35 is connected to the main flow path 23 via the rotary valve apparatus 2, it is not restricted to this. The main flow path 23 may be connected to a flow path that passes through a device other than the auxiliary machine (one that requires cooling or warm-up using cooling water) via the rotary valve device 2.

1 Engine cooling device 2 Rotary valve device (flow path switching valve, flow control valve)
3 Auxiliary machine side pump (second pump)
4 Heater side pump (first pump)
5 Engine 5A Cylinder head 5B Cylinder block 5a Cylinder head exhaust port side part 5b Cylinder head part other than exhaust port side part 6 Heater core 9 EGR cooler 10 Oil cooler 11 EGR valve 12 ATF warmer 14 Radiator 15 Heater side flow path 16 Return Channel 17 EGR cooler side channel 19 ETB side channel 20 Oil cooler side channel 21 EGR valve side channel 22 Exhaust side channel 23 Main channel 24 Water temperature sensor (temperature detection means)
25 Block side flow path 26 Connection flow path 28 Bulkhead 30 Accelerator opening sensor (engine load detection means, temperature detection means)
31 ECU (control part, temperature detection means, engine load detection means)
32 Crank angle sensor (temperature detection means)
33 Radiator side flow path 34 Upstream side flow path 35 Auxiliary machine side flow path (external flow path)
37 Communication part 38 Intake air temperature sensor (temperature detection means)
40 Heater circulation path (first circulation path)
41 Auxiliary machinery circulation route (second circulation route)
H1, H2, H3 opening K1, K2, K3 Notch hole V1, V2, V3 Flow control valve

Claims (10)

A first circulation path through which cooling water circulates, including an exhaust side flow path that passes through the exhaust port side of the cylinder head, and a heater side flow path that is connected to the exhaust side flow path and passes through the heater core of the air conditioner; ,
A main flow path that passes through a portion other than the exhaust port side of the cylinder head, and an external flow path outside the cylinder head connected to the main flow path, and a second circulation path through which cooling water circulates;
Temperature detection means for detecting the temperature of the engine;
A first pump provided in the first circulation path and circulating the cooling water of the first circulation path;
A second pump provided in the second circulation path for circulating the cooling water of the second circulation path;
A flow path switching valve for connecting and disconnecting the main flow path and the external flow path, and connecting and disconnecting the main flow path and the exhaust side flow path;
A control unit for controlling the operation of the flow path switching valve based on the detection result of the temperature detection means,
The main flow path is connected to the exhaust side flow path to be incorporated in the first circulation path, and constitutes a path through which cooling water circulates together with the exhaust side flow path and the heater side flow path.
While the engine is warming up, the control unit (i) when the temperature detected by the temperature detecting means is in the first temperature range, the main flow path and the external flow path, the main flow path and the (Ii) when the temperature detected by the temperature detecting means is in a second temperature range higher than the first temperature range, the main flow path and the external flow path are not connected to each exhaust side flow path; Without connecting, connecting the main flow path and the exhaust side flow path, (iii) when the temperature detected by the temperature detection means is in a third temperature range higher than the second temperature range, A cooling device for an engine characterized by performing control for connecting a main flow path and the external flow path. A flow rate adjusting valve for adjusting the flow rate of the cooling water flowing through the external flow path;
The flow rate control valve is characterized in that the flow rate is limited to a small amount during an initial predetermined period when the main flow channel and the external flow channel are connected by the flow channel switching valve, and then the flow rate is gradually increased to a predetermined amount. The engine cooling device according to claim 1. The second circulation path further includes a radiator-side channel connected to the external channel and passing through the radiator,
The flow path switching valve further performs connection and disconnection of the radiator side flow path and the external flow path,
The controller is configured to connect the radiator-side flow path to the external flow path when the temperature detected by the temperature detecting means is in a fourth temperature range higher than the third temperature range. The engine cooling device according to claim 1 or 2. A flow rate adjusting valve that adjusts the flow rate of cooling water flowing through the external flow path and the flow rate of cooling water flowing through the radiator-side flow path;
Engine load detecting means for detecting engine load,
The control unit further controls the operation of the flow rate control valve based on detection results of the temperature detection means and the engine load detection means, and the temperature detected by the temperature detection means is in the fourth temperature range. Sometimes, as the engine load detected by the engine load detecting means is larger, the flow rate of the cooling water flowing through the external flow path is reduced and the flow rate of the cooling water flowing through the radiator side flow path is increased. The engine cooling device according to claim 3, wherein   The control unit further controls the operation of the first pump based on detection results of the temperature detection means and the engine load detection means, and when the temperature is in the fourth temperature range, the engine load The engine cooling apparatus according to claim 4, wherein control is performed such that the larger the engine load detected by the detection means, the larger the discharge amount of the first pump.   The said flow path switching valve has individually only the valve corresponding to the said exhaust side flow path, the said external flow path, and the said radiator side flow path, The Claim 3 thru | or 5 characterized by the above-mentioned. Engine cooling system.   The engine cooling device according to any one of claims 1 to 6, wherein the heater side passage further passes through a throttle body that adjusts an amount of intake air supplied to the cylinder head. The flow path switching valve further connects and disconnects the first circulation path and the second circulation path;
The control unit controls the first circulation path and the second circulation path not to be connected when the temperature detected by the temperature detection means is in a low temperature range of the third temperature range. And when the temperature detected by the temperature detecting means is in the higher temperature range of the third temperature range, control is performed to connect the first circulation path and the second circulation path. The engine cooling device according to any one of claims 1 to 7, wherein   The engine cooling apparatus according to any one of claims 1 to 8, wherein the first pump is an electric pump.   10. The engine cooling apparatus according to claim 1, wherein the external flow path is a flow path that passes through an auxiliary machine.

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