JP6581922B2 - Vehicle control device - Google Patents

Description

  In the present invention, the first water jacket is formed at a position relatively close to the combustion chamber, and the cooling water is circulated through the cylinder head having the second water jacket formed at a position relatively close to the exhaust port. The present invention relates to a vehicle control device.

  Conventionally, in a cylinder head of an engine, a first water jacket is formed at a position relatively close to the combustion chamber as a cooling water flow path, and a second water jacket is relatively positioned near the exhaust port. (For example, Patent Document 1).

  In the engine described in Patent Document 1, when the temperature of the cooling water is lower than a predetermined temperature threshold, the cooling water flow to the second water jacket is blocked and the cooling water is allowed to flow only to the first water jacket. Thus, the cooling of the exhaust gas is suppressed and the temperature is increased to a temperature at which the catalyst is activated at an early stage.

  Further, when the temperature of the cooling water is equal to or higher than the above temperature threshold, the cooling water is circulated also to the second water jacket, and the amount of the cooling water flowing through the cylinder head is increased, so that the cylinder head can be efficiently Cooling.

JP 2010-121561 A

  However, in the above engine, the amount of the cooling water flowing through the first water jacket is reduced by flowing the cooling water through the first water jacket and the second water jacket, so that the wall temperature of the combustion chamber increases. As a result, knocking may occur.

  Then, an object of this invention is to provide the vehicle control apparatus which can suppress knocking.

  In order to solve the above-described problem, the vehicle control apparatus of the present invention has a first water jacket formed at a position relatively close to the combustion chamber as a cooling water flow path and relatively close to the exhaust port. A cylinder head in which a second water jacket is formed at a position to be turned on, a valve for switching the flow and blocking of the cooling water to and from the second water jacket, a temperature sensor for measuring the temperature of the cooling water, and an open / closed state of the valve A control unit that switches between the two, and the control unit shuts off the cooling water to the second water jacket by closing the valve when the temperature measured by the temperature sensor is equal to or higher than a predetermined high temperature threshold. Then, cooling water is circulated through the first water jacket in the cylinder head.

  Further, when the temperature measured by the temperature sensor is less than a low temperature threshold lower than the high temperature threshold, the control unit closes the valve and shuts off the cooling water to the second water jacket, Cooling water may be circulated through the first water jacket in the cylinder head.

  Further, the control unit opens the valve when the temperature measured by the temperature sensor is lower than the high temperature threshold and is equal to or higher than the low temperature threshold, and the first water jacket is formed in the cylinder head. And it is good to distribute | circulate a cooling water to the said 2nd water jacket.

  According to the present invention, knocking can be suppressed.

It is a figure which shows the structure of a vehicle control apparatus. It is a figure explaining the composition of an engine. It is a figure explaining the distribution | circulation state of the cooling water of a water jacket. It is a flowchart which shows the flow of control processing.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating a configuration of the vehicle control device 1. In FIG. 1, the cooling water channel 16 is indicated by a solid arrow, and the signal flow is indicated by a broken arrow. As shown in FIG. 1, the vehicle control device 1 includes an engine 10, a radiator 12, a water pump 14, a cooling water channel 16, and a control unit 18, and the engine 10, the radiator 12, and the water pump 14 are provided with cooling. Cooling water flows through the water channel 16.

  The engine 10 includes a cylinder block 30 and a cylinder head 32. A plurality of cylinder bores 34 are formed in the cylinder block 30, and a piston (not shown) is slidably accommodated in each cylinder bore 34.

  The radiator 12 is provided in the middle of the cooling water channel 16 and cools the cooling water by radiating the heat of the cooling water flowing through the cooling water channel 16 to the outside. The water pump 14 is rotationally driven by the rotational power of the engine 10 and circulates the cooling water in the cooling water passage 16.

  The cooling water channel 16 includes a pipe 16a, a water jacket 36 formed in the cylinder head 32, a pipe 16b, a pipe 16c, and a pipe 16d. The pipe 16a is connected to the water pump 14 and the water jacket 36, respectively, and the water pump 14 and the water jacket 36 are communicated with each other through the pipe 16a.

  The water jacket 36 is branched into a first water jacket 36 a and a second water jacket 36 b on the upstream side of the cylinder head 32 to which the pipe 16 a is connected, and is integrated downstream of the plurality of cylinder bores 34.

  The first water jacket 36a communicates with the pipe 16a and is formed in the vicinity of the combustion chamber in the cylinder head 32 along the arrangement direction of the cylinder bores 34 as will be described in detail later.

  The second water jacket 36b is connected to the first water jacket 36a via the electronic control valve 20 that switches between opening and closing of the cooling water by opening and closing, and along the arrangement direction of the cylinder bores 34 in the cylinder head 32. As will be described in detail later, it is formed in the vicinity of the exhaust port.

  The pipe 16b is connected to the water jacket 36 and the radiator 12, respectively, and the water jacket 36 and the radiator 12 are communicated with each other through the pipe 16b. The pipe 16c is connected to the radiator 12 and the water pump 14, respectively, and the radiator 12 and the water pump 14 are communicated via the pipe 16c.

  An electronic control valve 22 is provided in the middle of the pipe 16b. A pipe 16 d is connected to the electronic control valve 22. The electronic control valve 22 causes the cooling water to flow through either the radiator 12 or the pipe 16d by switching the open / close state. In other words, the electronic control valve 22 switches between the circulation and blocking of the cooling water to the radiator 12.

  In the vehicle control apparatus 1 having such a configuration, when the water pump 14 is driven, the cooling water discharged from the water pump 14 is guided to the water jacket 36 of the cylinder head 32 through the pipe 16a. And if the electronic control valve | bulb 20 is an open state, the cooling water guide | induced to the water jacket 36 will be guide | induced to the piping 16b, after distribute | circulating the 1st water jacket 36a and the 2nd water jacket 36b. On the other hand, if the electronic control valve 20 is in the closed state, the cooling water guided to the water jacket 36 flows only through the first water jacket 36a and then is guided to the pipe 16b.

  The cooling water led to the pipe 16b is led to the water pump 14 via the radiator 12 and the pipe 16c, or to the water pump 14 via the pipe 16d and the pipe 16c, depending on the open / close state of the electronic control valve 22. It is burned. Thus, in the vehicle control device 1, the cooling water circulates in the cooling water channel 16.

  In addition, a temperature sensor 24 that measures the temperature (water temperature) of the cooling water flowing through the water jacket 36 is provided in the vicinity of the water jacket 36 in the pipe 16b. The temperature sensor 24 transmits a temperature signal indicating the measured temperature of the cooling water to the control unit 18.

  The control unit 18 is an ECU (Engine Control Unit), and is composed of a semiconductor integrated circuit including a central processing unit (CPU), a ROM storing a program, a RAM as a work area, and the like. The control unit 18 is connected to the electronic control valve 20, the electronic control valve 22, and the temperature sensor 24, and controls opening and closing of the electronic control valve 20 and the electronic control valve 22 based on a temperature signal transmitted from the temperature sensor 24. Then, the flow path through which the cooling water flows is switched. The control process in the control unit 18 will be described in detail later.

  Next, the configuration of the engine 10 will be described. FIG. 2 is a diagram illustrating the configuration of the engine 10. As shown in FIG. 2, the engine 10 is provided with a crankcase 38 integrally formed with the cylinder block 30 below the cylinder block 30, and the crankshaft 40 is rotatably supported in the crankcase 38. The A piston 44 is connected to the crankshaft 40 via a connecting rod 42, and the piston 44 is slidably accommodated in the cylinder bore 34. In the engine 10, a space surrounded by the cylinder block 30, the cylinder head 32, and the crown surface of the piston 44 is formed as a combustion chamber 46.

  An intake port 48 and an exhaust port 50 are provided in the cylinder head 32 so as to communicate with the combustion chamber 46. Between the intake port 48 and the combustion chamber 46, the tip of an intake valve (not shown) is located, and between the exhaust port 50 and the combustion chamber 46, the tip of an exhaust valve (not shown) is located. The intake valve and the exhaust valve are rotated between the intake port 48 and the combustion chamber 46 and between the exhaust port 50 and the combustion chamber 46 by rotation of a cam fixed to a camshaft connected to the crankshaft 40 by a belt or the like. Open and close each.

  The cylinder head 32 is provided with an injector 52 and a spark plug 54 so that the tip is located in the combustion chamber 46. After the fuel is injected from the injector 52 at a predetermined timing, the fuel is ignited by the spark plug 54. Burned. By such combustion, the piston 44 reciprocates in the cylinder bore 34, and the reciprocating motion is converted into the rotational motion of the crankshaft 40 through the connecting rod 42.

An intake passage 56 including an intake manifold is communicated with the upstream side of the intake port 48. An air cleaner and a throttle valve are provided in the intake passage 56. Further, an exhaust passage 58 including an exhaust manifold communicates with the exhaust port 50 on the downstream side, and a three-way catalyst or a muffler is provided in the exhaust passage 58. The three-way catalyst includes, for example, platinum (Pt), palladium (Pd), and rhodium (Rh), and includes hydrocarbons (HC) and carbon monoxide in the exhaust gas discharged from the exhaust port 50 ( CO) and nitrogen oxides (NO _x ) are removed. The three-way catalyst is activated in a temperature range of 300 ° C. to 850 ° C., and efficiently removes hydrocarbons, carbon monoxide, and nitrogen oxides in the exhaust gas. The removal efficiency of hydrocarbons, carbon monoxide, and nitrogen oxides decreases.

  Further, the engine 10 is provided with a reflux path 60 that allows the intake path 56 and the exhaust path 58 to communicate with each other, and part of the exhaust gas flowing through the exhaust path 58 is refluxed to the intake path 56. The reflux path 60 is provided with an EGR cooler 62 that lowers the temperature of the exhaust gas, and an EGR valve 64 that controls the flow rate of the exhaust gas flowing through the reflux path 60. Hereinafter, the exhaust gas flowing through the reflux path 60 is also referred to as EGR gas.

  As described above, the water jacket 36 including the first water jacket 36 a and the second water jacket 36 b is formed in the cylinder head 32. The first water jacket 36 a is formed on the cylinder block 30 side (lower side in the figure) with respect to the second water jacket 36 b so as to surround the combustion chamber 46 at a position relatively close to the combustion chamber 46. Yes.

  The second water jacket 36b is formed on the side farther from the cylinder block 30 than the first water jacket 36a (upper side in the figure) and at a position relatively close to the exhaust port 50 so as to surround the exhaust port 50. ing.

  Therefore, in the engine 10, the cooling water flows through the first water jacket 36 a, so that the cooling water absorbs the heat generated by the combustion of the fuel in the combustion chamber 46 and cools the combustion chamber 46. Further, when the cooling water flows through the second water jacket 36b, the cooling water absorbs the heat of the exhaust gas flowing through the exhaust port 50, thereby cooling the exhaust gas.

  FIG. 3 is a diagram for explaining the circulation state of the cooling water in the water jacket 36. In FIG. 3, the first W / J indicates the first water jacket 36a, the second W / J indicates the second water jacket 36b, and the same applies to FIG. 4 described later. For example, when the engine 10 is not sufficiently warmed and the temperature of the cooling water is low, such as immediately after the engine 10 is started, if the cooling water is circulated through the second water jacket 36b, the temperature of the exhaust gas flowing through the exhaust port 50 Decreases, and it takes time for the temperature of the three-way catalyst provided in the exhaust passage 58 to reach the temperature range.

  Therefore, as shown in FIG. 3, when the temperature of the cooling water indicated by the temperature signal transmitted from the temperature sensor 24 is lower than a predetermined threshold T1 (low temperature threshold, for example, 30 ° C.), the control unit 18 performs electronic control. The valve 20 is closed and the flow of the cooling water to the second water jacket 36b is blocked. The threshold value T1 is set to a temperature at which the temperature of the cooling water is low and the temperature of the three-way catalyst does not reach the temperature range. When the temperature of the cooling water is less than a predetermined threshold T1 (for example, 30 ° C.), the control unit 18 controls the electronic control valve 22 to block the cooling water to the radiator 12.

  In this case, in the cylinder head 32, since the cooling water flows only to the first water jacket 36a, the temperature of the exhaust gas flowing through the exhaust port 50 is lowered by the cooling water flowing to the second water jacket 36b. It suppresses that. As a result, the three-way catalyst provided in the exhaust passage 58 is warmed up early by the exhaust gas, and can reach the temperature range to be activated early.

  Further, after the temperature rises to the temperature at which the three-way catalyst is activated, if the second water jacket 36b is kept shut off, the temperature of the exhaust gas, that is, the temperature of the EGR gas becomes high. The amount of exhaust gas flowing in must be reduced.

  Therefore, in the control unit 18, the temperature of the cooling water indicated in the temperature signal transmitted from the temperature sensor 24 is equal to or higher than the threshold T1 and lower than the threshold T2 (high temperature threshold, for example, 100 ° C.) higher than the threshold T1. In this case, the electronic control valve 20 is opened, and the cooling water is circulated to the second water jacket 36b. The threshold value T2 is set to a temperature at which knocking may occur in the engine 10.

  In this case, in the cylinder head 32, since the cooling water flows through both the first water jacket 36a and the second water jacket 36b, the heat generated in the combustion chamber 46 and the heat of the exhaust gas flowing through the exhaust port 50 are obtained. As a result, the cooling water is warmed up early. Thereby, in the vehicle control apparatus 1, the engine oil which distribute | circulates the inside of the cylinder block 30 or the cylinder head 32 is warmed at an early stage, and the flow resistance of engine oil can also be reduced.

  Further, in the vehicle control device 1, the temperature of the exhaust gas, that is, the temperature of the EGR gas can be lowered by circulating the cooling water through the second water jacket 36 b, and the EGR gas flowing into the intake passage 56 can be reduced. It becomes possible to increase the inflow amount. In the engine 10, by increasing the inflow amount of EGR gas, the fuel burns in the combustion chamber 46 in a state where the oxygen concentration is lower than the atmosphere, so the combustion temperature decreases. Thereby, in the vehicle control apparatus 1, the cooling loss for cooling the combustion chamber 46 (cylinder head 32) can be reduced.

  Further, in the vehicle control device 1, by increasing the inflow amount of EGR gas, the negative pressure in the intake passage 56 can be reduced and the pumping loss can be reduced. Furthermore, in the vehicle control device 1, the time loss (torque loss) due to the retard of the ignition timing can be reduced by reducing the retard amount for retarding the ignition timing of the spark plug 54 in order to prevent knocking. it can.

  Thereafter, if the cooling water is allowed to flow through the first water jacket 36a and the second water jacket 36b, the temperature of the cooling water rises, the temperature of the combustion chamber 46 also rises, and knocking may occur. To increase.

  Therefore, when the temperature of the cooling water indicated by the temperature signal transmitted from the temperature sensor 24 is equal to or higher than the predetermined threshold T2, the control unit 18 closes the electronic control valve 20 and cools the second water jacket 36b. Block water flow. In addition, the control unit 18 controls the electronic control valve 22 and causes the coolant to flow through the radiator 12.

  In this case, in the cylinder head 32, since the cooling water flows only to the first water jacket 36a, the flow rate (flow rate) of the cooling water flowing through the first water jacket 36a can be increased. For this reason, in the vehicle control apparatus 1, it becomes possible to absorb more heat generated in the combustion chamber 46, thereby lowering the temperature of the combustion chamber 46 as compared with the case where cooling water is circulated through the second water jacket 36b. Can be made.

  As a result, the vehicle control device 1 can prevent the occurrence of knocking, and also reduces the amount of retardation that retards the ignition timing of the spark plug 54 in order to prevent knocking, thereby retarding the ignition timing. The time loss due to can be reduced, and the fuel consumption can be improved.

  Next, the flow of the control process described above will be described in detail using the flowchart of FIG. This control process is performed at predetermined intervals.

  FIG. 4 is a flowchart showing the flow of control processing. As shown in FIG. 4, when the control process is executed, the control unit 18 acquires a temperature signal from the temperature sensor 24 (S100).

  And the control part 18 determines whether the temperature of the cooling water shown by the temperature signal is less than threshold value T1 (S102). As a result, when the temperature of the cooling water is lower than the threshold value T1 (YES in S102), the control unit 18 closes the electronic control valve 20 and distributes the cooling water only to the first water jacket 36a in the cylinder head 32. (S104).

  On the other hand, when the temperature of the cooling water is not lower than the threshold T1, that is, when the temperature of the cooling water is equal to or higher than the threshold T1 (NO in S102), the control unit 18 indicates that the temperature of the cooling water indicated by the temperature signal is lower than the threshold T2. It is determined whether it exists (S106). As a result, when the temperature of the cooling water is lower than the threshold value T2 (YES in S106), the control unit 18 opens the electronic control valve 20, and the cooling water is supplied to the first water jacket 36a and the second water in the cylinder head 32. It distribute | circulates to the water jacket 36b (S108).

  On the other hand, when the temperature of the cooling water is not lower than the threshold value T2, that is, when the temperature of the cooling water is equal to or higher than the threshold value T2 (NO in S106), the control unit 18 closes the electronic control valve 20 and Cooling water is circulated only through the first water jacket 36a (S104).

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  For example, in the embodiment described above, the temperature sensor 24 is provided in the pipe 16b. However, the temperature sensor 24 is not limited to this, and the pipe 16b is provided anywhere as long as the temperature of the cooling water can be measured at any position on the cooling water channel 16. It may be.

  In the present invention, the first water jacket is formed at a position relatively close to the combustion chamber, and the cooling water is circulated through the cylinder head having the second water jacket formed at a position relatively close to the exhaust port. It can be used for a vehicle control device.

DESCRIPTION OF SYMBOLS 1 Vehicle control apparatus 18 Control part 20 Electronic control valve (valve)
24 temperature sensor 32 cylinder head 36a first water jacket 36b second water jacket

Claims (3)

A cylinder head in which a first water jacket is formed at a position relatively close to the combustion chamber as a cooling water flow path, and a second water jacket is formed at a position relatively close to the exhaust port;
A valve for switching between circulation and blocking of the cooling water to the second water jacket;
A temperature sensor for measuring the temperature of the cooling water;
A control unit for switching the open / close state of the valve;
With
The controller is
When the temperature measured by the temperature sensor is equal to or higher than a predetermined high temperature threshold, the valve is closed to shut off the cooling water to the second water jacket and cool to the first water jacket in the cylinder head. A vehicle control apparatus characterized by circulating water. The controller is
When the temperature measured by the temperature sensor is lower than the low temperature threshold lower than the high temperature threshold, the valve is closed to shut off the cooling water to the second water jacket, and the first in the cylinder head The vehicle control device according to claim 1, wherein cooling water is circulated through one water jacket. The controller is
When the temperature measured by the temperature sensor is less than the high temperature threshold and not less than the low temperature threshold, the valve is opened, and the first water jacket and the second water jacket are placed in the cylinder head. The vehicle control device according to claim 2, wherein cooling water is circulated.

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