JP2019044610A - Internal combustion engine - Google Patents

Abstract

To simply materialize a mechanism capable of independently controlling the temperature of a cylinder block and a cylinder head of an internal combustion engine.SOLUTION: Cooling water circulating in the inside of an internal combustion engine 0 is divided into a plurality of flows L1 and L2. One flow L1 is supplied to a cylinder block 1 containing an air cylinder, the other flow L2 is supplied to a cylinder head 2 configuring a ceiling portion and an intake port of a combustion chamber, and cooling water L3 is made to flow into a radiator 4, thereby lowering the temperature of the cooling water. A first control valve 6 opening/closing a flow path is provided on the flow path in which the cooling water L1 supplied to the cylinder block 1 flows, and a second control valve 7 is provided on a flow path in which the cooling water L3 flowing into the radiator 4 flows. According to the level of output of the internal combustion engine 0, a state opening both of the fist control valve 6 and the second control valve 7, a state closing the first control valve 6 and opening the second control valve 7, and a state closing both of the first control valve 6 and the second control valve 7 are switched.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water-cooled (or liquid-cooled) internal combustion engine mounted on a vehicle or the like.

  In the existing water-cooled internal combustion engine, the cooling water (or cooling liquid) discharged by the water pump is made to sequentially flow into the cylinder block containing the cylinders and the cylinder head constituting the ceiling of the combustion chamber and the intake port, Cool these. Then, after the raised coolant water is dissipated in the radiator, the coolant water is circulated such that the water pump sucks and discharges it again and feeds it to the cylinder block.

  A thermostat, which is a control valve for opening and closing the flow path, is attached to the flow path through which the cooling water flowing into the radiator flows. The thermostat opens when the temperature of the cooling water reaches a predetermined high temperature and allows the cooling water to flow toward the radiator. Conversely, when the temperature of the cooling water is below a predetermined level, the thermostat closes the valve to prevent the cooling water from flowing into the radiator and prevent the cooling water and hence the internal combustion engine from being overcooled (the above See, for example, the following patent documents).

JP, 2014-196671, A

  If the temperature of the cylinder block is unduly lowered, the friction loss between the cylinder bore and the piston ring of the cylinder and the cooling loss due to the combustion gas being cooled during the expansion stroke are increased, resulting in the efficiency of the internal combustion engine Getting worse. On the other hand, if the temperature of the cylinder head rises excessively, the density of intake air drawn into the cylinder through the intake port decreases, the amount of intake air charged into the cylinder decreases, and the output of the internal combustion engine decreases.

  However, in the coolant system of the conventional internal combustion engine, it has been difficult to heat the cylinder block independently from the cylinder head or to cool the cylinder head independently from the cylinder block.

  An object of the present invention is to realize a mechanism capable of controlling temperatures of a cylinder block and a cylinder head of an internal combustion engine independently of each other simply and at low cost.

  In order to solve the problems described above, according to the present invention, the cooling water flowing inside the internal combustion engine is divided into a plurality of flows, and one of the flows is supplied to the cylinder block including the cylinders, and the other flow is A cylinder head comprising a combustion chamber ceiling portion and an intake port, and a cooling water system for lowering the temperature of the cooling water by causing the cooling water to flow into the radiator, and supplying the cylinder block A first control valve for opening and closing the flow path is provided on the flow path where the cooling water flows, and a second control valve for opening and closing the flow path is provided on the flow path for the cooling water flowing into the radiator The first control valve and the second control valve are both closed according to the level of the output of the internal combustion engine, and the second control valve is opened while the first control valve is closed. , The first control valve and the first The control valves together comprise an internal combustion engine and a state of opening.

  According to the present invention, a mechanism capable of independently controlling the temperatures of the cylinder block and the cylinder head of the internal combustion engine can be realized easily and at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows typically the circuit structure of the cooling water system of the internal combustion engine of one Embodiment of this invention. The figure which shows the driving | operation area | region of the internal combustion engine in the embodiment. The figure which shows the relationship between the driving | operation area | range of an internal combustion engine and the cooling water temperature in the same embodiment, and valve opening / closing of each control valve.

  One embodiment of the present invention will be described with reference to the drawings. The structure of the cooling water system of the internal combustion engine 0 of this embodiment is shown in FIG. In the drawing, the flow of cooling water flowing through the inside of the internal combustion engine 0 is indicated by arrows.

  The water pump 3 for sucking and discharging the cooling water may be a mechanical pump that receives the transmission of rotational driving force from a crankshaft that is an output shaft of the internal combustion engine 0, or an electric pump driven by an electric motor. In some cases, basically, the higher the engine speed, the higher the discharge amount and discharge pressure of the cooling water. Needless to say, the mechanical water pump 3 follows the crankshaft of the internal combustion engine 0, and its rotational speed is proportional to the engine rotational speed.

  The coolant pumped by the water pump 3 branches into a plurality of flows L1 and L2, and one of the flows L1 flows into the cylinder block 1 including the cylinders of the internal combustion engine 0. The cooling water L1 exchanges heat with the cylinder block 1 to cool it, and ascends the inside of the cylinder block 1 to form a ceiling portion of the combustion chamber of each cylinder and an intake and exhaust port connected to the cylinder. Flow into 2

  The other flow L2 of cooling water bypasses the cylinder block 1, that is, flows directly into the cylinder head 2 without flowing into the cylinder block 1. Thus, both flows L 1 and L 2 merge in the cylinder head 2.

  The cooling water L1 and L2 flowing into the cylinder head 2 exchanges heat with the cylinder head 2 to cool it, and then travels to another heat exchanger 5 outside the internal combustion engine 0. The heat exchanger 5 is a heater core of an air conditioner that warms the air in the vehicle compartment, or an EGR cooler that cools EGR (Exhaust Gas Recirculation) gas that is mixed with the intake air by recirculating from the exhaust passage of the internal combustion engine 0 to the intake passage. It is a CVT (Continuously Variable Transmission) fluid warmer or an AT (Automatic Transmission) fluid warmer that warms the working fluid (transmission fluid) of an automatic transmission mounted on a vehicle. The cooling water L0 heat-exchanged with the vehicle interior air, the EGR gas, the working fluid of the transmission, etc. by the heat exchanger 5 is sucked into the water pump 3 again.

  The cooling water that has become high temperature inside the internal combustion engine 0 is air cooled by the radiator 4. Usually, the radiator 4 is accompanied by a fan for forced air cooling. When the cooling water L3 in the radiator 4 can not be sufficiently cooled only by the traveling air blown into the engine room as the vehicle travels, the radiator fan is rotated and the air is blown toward the radiator 4, thereby the heat between the cooling water L3 and the outside air Promote exchange. The cooling water L3 cooled by the radiator 4 is also sucked into the water pump 3 again.

  A first control valve 6 for opening and closing the flow path is installed on the flow path through which the cooling water L1 supplied to the cylinder block 1 flows. On the other hand, a control valve for opening and closing the flow passage is not provided on the flow passage through which the cooling water L2 supplied to the cylinder head 2 bypasses the cylinder block 1 flows.

  When the first control valve 6 is closed, the total amount L2 of cooling water discharged by the water pump 3 flows into the cylinder head 2. At this time, in the cylinder block 1, the flow of the cooling water L1 does not occur.

  When the first control valve 6 is opened, a portion L1 of the cooling water discharged by the water pump 3 flows into the cylinder block 1, and the remaining L2 flows into the cylinder head 2. Then, the flow of the cooling water L1 occurs in the cylinder block 1.

  Furthermore, a second control valve 7 for opening and closing the flow path is provided on the flow path through which the cooling water L3 cooled by the radiator 4 flows.

  When the second control valve 7 is closed, the entire amount L0 of the cooling water flowing out of the cylinder head 2 flows into the heat exchanger 5. At this time, the flow of the cooling water L3 does not occur in the radiator 4.

  When the second control valve 7 is opened, a portion L3 of the cooling water flowing out of the cylinder head 2 flows into the radiator 4, and the remaining L0 flows into the heat exchanger 5. Then, the flow of the cooling water L3 occurs in the radiator 4.

  In the present embodiment, each of the first control valve 6 and the second control valve 7 can be opened and closed by an ECU (Electronic Control Unit) that controls the operation of the internal combustion engine 0. Valve). The ECU is a microcomputer system having a processor, a memory, an input interface, an output interface and the like. The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates operating parameters, and controls the operation of the internal combustion engine.

  Furthermore, the ECU 0 operates the current operating range of the internal combustion engine 0 [engine speed, engine torque (or engine load factor, accelerator opening degree, intake pressure charged to the cylinder, intake amount to be charged to the cylinder, or fuel First control valve 6 and second control valve 7 are respectively opened and closed based on the temperature of the injection amount) and the cooling water (in particular, the cooling water L1 in the cylinder block 1), thereby the cylinder block of the internal combustion engine 0 The temperature of each of 1 and the cylinder head 2 is individually controlled.

  FIGS. 2 and 3 show the relationship between the operating region of the internal combustion engine 0 and the coolant temperature, and the opening / closing of the first control valve 6 and the second control valve 7.

  First, before the warm-up of the cold-started internal combustion engine 0 is completed, that is, at a time when the cooling water temperature has not risen to a threshold (for example, 80 ° C.) yet, regardless of the operating range of the internal combustion engine 0, Both the first control valve 6 and the second control valve 7 are closed.

  When the first control valve 6 is closed, the cooling water L2 circulates through only the cylinder head 2 of the internal combustion engine 0 and circulates, and the cooling water L1 filling the inside of the cylinder block 1 stagnates in the cylinder block 1 Do. Also, if the second control valve 7 is closed, the cooling water L3 will not flow into the radiator 4. Therefore, the temperature rise of the internal combustion engine 0 and the cooling water can be accelerated.

  Thereafter, if warm-up of internal combustion engine 0 is completed, that is, if the coolant temperature rises above the threshold value, the first control valve 6 and the second control valve 7 are made according to the operating region of the internal combustion engine 0 and the coolant temperature. Decide whether to open or close, respectively.

  Specifically, the current operating range of the internal combustion engine 0 is in the low output (or low load) range, in other words, the current engine speed and engine torque (or engine load factor, etc.) are both low. Sometimes, the first control valve 6 and the second control valve 7 are both closed to suppress the temperature drop of the internal combustion engine 0 and the coolant, thereby suppressing the increase of the friction loss and the cooling loss.

  When the current operating range of the internal combustion engine 0 is in the medium output (medium load) range, in other words, at least one of the current engine speed and engine torque is higher than a certain level (above the low output range) While the first control valve 6 is closed, only the second control valve 7 is opened.

  In this case, the cooling water L3 flows into the radiator 4, and an excessive temperature rise of the internal combustion engine 0 and the cooling water can be prevented. Moreover, the cooling water L2 discharged by the water pump 3 can be made to flow directly into the cylinder head 2 bypassing the cylinder block 1, and the temperature drop of the intake port in the cylinder head 2 can be promoted. As a result, the temperature of the intake air drawn into the cylinder through the intake port does not become excessively high, the risk of occurrence of abnormal combustion represented by knocking decreases, and the volumetric efficiency of the internal combustion engine 0 improves and the cylinder is filled. The intake capacity is increased to improve the output performance of the internal combustion engine 0. Further, if abnormal combustion does not occur, it is permitted to further advance the ignition timing to the mixture, and the thermo-mechanical conversion efficiency of the internal combustion engine 0 is improved.

  Not only that, since the first control valve 6 is closed, the cooling water L1 that fills the inside of the cylinder block 1 stays without flowing in the cylinder block 1, and the cylinder block 1 is kept warm. Friction losses and increases in cooling losses can be avoided.

  Then, when the current operating range of the internal combustion engine 0 is in the high output (high load) range, in other words, at least one of the current engine speed and engine torque is further higher (than in the above-mentioned middle output range) The first control valve 6 and the second control valve 7 are both opened. As a result, the cooling water L3 flows into the radiator 4 and the cooling water L1 flows through the cylinder block 1, so that the temperature drop of the internal combustion engine 0, particularly the cylinder block 1, is promoted to prevent the occurrence of abnormal combustion. And protection of a component of internal-combustion engine 0 can be aimed at.

  However, if the cooling water temperature becomes higher than a predetermined value (this value is naturally higher than the warm-up determination threshold, for example, 95 ° C.), the current operating range of the internal combustion engine 0 is low power. The first control valve 6 and the second control valve 7 are both opened even if they are in the range or the middle output range (not in the high output range).

  In the present embodiment, the cooling water flowing inside the internal combustion engine 0 is divided into a plurality of flows L1 and L2, and then one of the flows L1 is supplied to the cylinder block 1 including the cylinder, and the other flow L2 is A cylinder block including a cooling water system for supplying a cooling water L3 to the radiator 4 and supplying the cooling water L3 to the radiator 4 while supplying the cooling water system to the cylinder head 2 constituting the ceiling portion of the combustion chamber and the intake port. A first control valve 6 for opening and closing the flow path is provided on the flow path through which the cooling water L1 supplied to 1 flows, and a second control valve for opening and closing the flow path on the flow path through which the cooling water L3 flowing into the radiator 4 flows The control valve 7 is provided, and the first control valve 6 and the second control valve 7 are both closed according to the current level of the output of the internal combustion engine 0, and the first control valve 6 is closed. Open the second control valve 7 while A state in which, and the first control valve 6 and the second control valve 7 together constituting an internal combustion engine 0 and a state to be opened.

  According to the present embodiment, a mechanism capable of controlling the temperatures of the cylinder block 1 and the cylinder head 2 of the internal combustion engine 0 independently of each other can be realized simply and at low cost.

  The present invention is not limited to the embodiments detailed above. The specific configuration of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to an internal combustion engine mounted on a vehicle or the like.

DESCRIPTION OF SYMBOLS 0 ... Internal combustion engine 1 ... Cylinder block 2 ... Cylinder head 4 ... Radiator 6 ... 1st control valve 7 ... 2nd control valve L1 ... Cooling water supplied to a cylinder block L2 ... Bypassing a cylinder block and supplying a cylinder head Cooling water L3 ... Cooling water flowing into the radiator

Claims (1)

Cooling water flowing inside the internal combustion engine is divided into a plurality of flows, and one of the flows is supplied to a cylinder block including a cylinder, and the other flow is a cylinder that constitutes a ceiling portion of the combustion chamber and an intake port. It is equipped with a cooling water system that lowers the temperature of the cooling water by supplying the cooling water to the radiator while supplying the head.
A first control valve for opening and closing the flow path is provided on the flow path through which the cooling water supplied to the cylinder block flows, and a second control valve for opening and closing the flow path on the flow path through which the cooling water flowing into the radiator flows Provided,
A state in which the first control valve and the second control valve are both closed according to the level of the current output of the internal combustion engine, and the second control valve is opened while the first control valve is closed. An internal combustion engine that switches between a state and a state in which both the first control valve and the second control valve are opened.

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