JP2012188950A - Engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine 1 in which inner passages 13, 14 and an outer passage 2 are made to be a closed loop and a cooling liquid can be circulated, which can rapidly complete warm-up while uniformly controlling a temperature of the warm-up.SOLUTION: A control device 20 includes: a temperature rise promoting means for stopping a water pump 4 accompanying cold start of the engine 1 to stop the circulation of the cooling liquid; a first determination section for determining whether a cooling liquid temperature TcH of the inner passages 13, 14 is above an upper limit temperature Th1 set higher than a warm-up completion temperature Th0 in a stop state of the water pump 4; and a first temperature controller for intermittently operating the water pump 4 if determined affirmatively by the first determination section.

Description

  The present invention relates to an engine in which coolant can be circulated with an internal passage and an external passage of the engine as a closed loop.

  For example, in paragraph 0024 of Patent Document 1, in an internal combustion engine equipped with an electric water pump, the temperature of cooling water discharged from the discharge port of the head side water jacket is detected by a temperature sensor, and the detected temperature is equal to or lower than a predetermined temperature. In this case, it is described that the warm-up of the engine is promoted by stopping the water pump.

  Further, paragraphs 0025 and 0026 of Patent Document 1 address the problem that the cooling water locally boils at the cylinder head or the like when the water pump is stopped when the engine is warmed up. ing. That is, before starting the stop control of the water pump, the coolant in the cooling water passage is supplied to the temperature sensor by driving the water pump, and based on the cooling water temperature detected by the temperature sensor. Determine the possibility of boiling of the cooling water. And when it determines with the possibility of boiling being low, permitting the start of stop control of the said water pump is described.

  In addition, for example, in paragraphs 0014-0017 of Patent Document 2, when the temperature of the cooling water in the cylinder head is lower than a predetermined temperature, the electric water pump is periodically rotated forward, stopped, and reversely rotated. By performing a series of controls, it is described that the cooling water is agitated within a limited range of cooling water channels provided in the cylinder block and the cylinder head, thereby trying to avoid heat spots in the cooling water channels. .

JP 2008-169750 A JP 2005-016435 A

  In the case of the above-mentioned Patent Document 2, a series of controls such as forward rotation, stop, and reverse rotation of the water pump are performed as necessary, but after flowing the cooling water in the circulation direction by rotating the water pump forward, Even if the water pump is stopped and then rotated backward, the cooling liquid does not immediately flow backward with respect to the flow in the circulation direction due to the inertia of the cooling water. Even if a reverse rotation is made after a delay of a predetermined time, the flow of the cooling water is considered to be weakened or stopped. Therefore, it is considered that the effect of stirring the cooling water in the cooling water channel is thin, and it takes too much time to stir. There is room for improvement here.

  In view of such circumstances, an object of the present invention is to enable quick completion of warm-up while uniformly controlling the temperature of an engine in which an internal passage and an external passage of the engine are closed loops so that the coolant can be circulated. It is said.

  The present invention relates to a water pump that allows coolant to circulate using an internal passage and an external passage of the engine as a closed loop, a control device that controls the operation and stop of the water pump, A flow rate control valve provided in the passage and closed when the coolant is lower than the warm-up completion temperature, and fully opened when the temperature is higher than the warm-up completion temperature, and the coolant flow in the external passage more than the flow control valve A variable volume tank provided upstream in the direction and acting to push out the coolant discharged from the internal passage, and the control device stops the water pump at the cold start. And a temperature rise promoting means for stopping the circulation of the coolant, and the coolant temperature in the internal passage when the water pump is stopped is higher than the warm-up completion temperature. First determination means for determining whether or not the upper limit temperature is set higher or higher, and first temperature adjustment means for intermittently operating the water pump when the first determination means makes an affirmative determination. It is a feature.

  In general, when the engine is cold-started, the temperature of the cylinder head is more easily raised than the cylinder block by the heat generated from the combustion chamber of the engine. At the cold start, the thermostat is closed and the coolant cannot be circulated. In this state, when the coolant in the internal passage of the engine is not circulated, the internal passage becomes high in the vicinity of the combustion chamber, so that the local coolant in the internal passage is excessively heated and tends to boil.

  On the other hand, in the configuration of the present invention, the water pump is operated intermittently or periodically when the cooling water is excessively heated in the internal passage of the engine during warm-up as described above. Yes.

  Therefore, during the period when the water pump is operated, the coolant in the internal passage is pushed out from the discharge port to the external passage by the discharge pressure, and the coolant is pushed into the variable volume tank. Then, when the water pump is stopped, the cooling liquid pushed into the variable volume tank is pushed out this time and flows backward from the discharge port to the internal passage.

  In this way, by intermittently operating the water pump, the coolant is taken in and out in the internal passage of the engine, so that the coolant is stirred so as to be shaken, and the temperature of the coolant in the internal passage The distribution becomes uniform. For this reason, it is possible to avoid boiling the coolant excessively at the local portion of the internal passage.

  Preferably, the control device determines whether or not the coolant temperature near the inlet of the coolant to the internal passage is equal to or higher than the warm-up completion temperature in the external passage during the intermittent operation of the water pump. 2 determination means and a second temperature adjustment means for continuously operating the water pump when an affirmative determination is made by the second determination means.

  Here, the operation mode of the water pump when the warm-up is completed is specified. In this case, when the coolant on the upstream side of the flow control valve reaches the warm-up completion temperature or more, the flow control valve is fully opened and the second temperature control means continuously operates the water pump. The coolant is discharged to the external passage, and is further returned from the external passage to the internal passage. In other words, the coolant is circulated with the internal passage and the external passage of the engine as a closed loop, and in this circulation of the coolant, the coolant recovers the heat of the cylinder head and the cylinder block, and is returned from the external passage to the atmosphere. Will be exhaled. Thereby, the temperature of the circulating coolant is kept at the warm-up completion temperature.

  Preferably, the water pump is an electric water pump operated by an electric motor. Here, the type of water pump is specified. This identification makes it easy to control the operation of the water pump.

  According to the present invention, in an engine in which an internal passage and an external passage of the engine are closed loops so that coolant can be circulated, warm-up can be quickly completed while the temperature is uniformly controlled.

It is a figure which shows typically the structure of the cooling system by one Embodiment of the engine which concerns on this invention. It is sectional drawing which shows schematic structure of the variable volume tank of FIG. 1, and has shown the state at the time of the stop of a water pump. It is sectional drawing which shows schematic structure of the variable volume tank of FIG. 1, and has shown the state at the time of the action | operation of a water pump. It is a flowchart regarding the temperature adjustment control of the engine by the control apparatus of FIG. It is a figure which shows typically the structure of the cooling system in other embodiment of the engine which concerns on this invention.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

  1 to 4 show an embodiment of the present invention. In this embodiment, an in-line multi-cylinder engine will be described as an example. The engine 1 shown in FIG. 1 includes at least a cylinder block 11 and a cylinder head 12.

  A water jacket 13 is provided in the cylinder block 11. A water jacket 14 is provided in the cylinder head 12. The block-side water jacket 13 and the head-side water jacket 14 are internal passages for the coolant. The coolant is an antifreeze such as an aqueous solution of ethylene glycol.

  The block-side water jacket 13 is opened toward the deck surface of the cylinder block 1, that is, the surface on which the cylinder head (not shown) is assembled. The cylinder block 1 provided with such a water jacket 13 is called a so-called open deck type. The head-side water jacket 14 is opened downward, that is, toward the cylinder block 1 side. That is, the coolant can flow between the cylinder block side water jacket 13 and the cylinder head side water jacket 14.

  In the cylinder block 13, an inlet 15 for introducing a coolant into the block-side water jacket 13 is provided on one end surface in the cylinder arrangement direction. Further, a discharge port 16 for discharging the coolant from the head side water jacket 14 is provided on the other end surface of the cylinder head 12 in the cylinder arrangement direction.

  An external passage 2 is connected to the introduction port 15 of the cylinder block 11 and the discharge port 16 of the cylinder head 12. The external passage 2 is provided with a water pump 4, a radiator 5, a heater core 6, and the like.

  The water pump 4 is provided at a position near the inlet 15 of the cylinder block 11 in the external passage 2.

  The radiator 5 is a heat exchanger for dissipating the heat of the cooling liquid to the atmosphere, and is provided upstream of the water pump 4 in the coolant flow direction in the external passage 2.

  The heater core 6 is a heat exchanger for heating the vehicle interior, and is provided upstream of the radiator 5 in the coolant flow direction in the external passage 2.

  A thermostat 8 is provided as a flow control valve at a position nearer to the discharge port 16 of the cylinder head 12 upstream of the heater core 6 in the coolant flow direction in the external passage 2.

  The thermostat 8 has a known configuration and is not shown in detail. However, when the temperature of the coolant at the thermostat installation location becomes lower than the warm-up completion temperature (for example, about 88 ° C.) Th0, the thermowax is coagulated and contracted. Since the pressure is lowered, the valve body is automatically closed to reduce the flow of the coolant from the external passage 2 to the water pump 4, but when the coolant temperature at the thermostat installation location becomes equal to or higher than the warm-up completion temperature Th0. Since the thermowax is melted and expanded to increase the wax pressure, the valve body is automatically fully opened to allow the coolant to flow from the external passage 2 to the water pump 4.

  Specifically, the thermostat 8 is fully closed when the temperature is lower than a predetermined temperature (for example, 82 ° C.) lower than the warm-up completion temperature Th0, starts to open from the predetermined temperature, and is fully opened when the warm-up completion temperature is reached. .

  Further, a variable volume tank 9 is connected to a region between the coolant discharge port 16 of the engine 1 and the thermostat 8 in the external passage 2. The variable volume tank 9 is cooled by being discharged from the internal passage (the block-side water jacket 13 and the head-side water jacket 14) when the water pump 4 is operated in a state where the thermostat 8 is closed or closed. The liquid is received and acts to push out the received cooling liquid when the water pump 4 is stopped in a state where the thermostat 8 is closed or closed.

  Specifically, the variable volume tank 9 includes a cylinder 91, a piston 92, a reverse spring 93, and the like. The cylinder 91 is an amount that generates a force for shaking the coolant in the internal passage when the local coolant temperature TcB in the internal passage (the block-side water jacket 13 and the head-side water jacket 14) is excessively increased. The volume is set so as to be able to accommodate the coolant. The piston 92 is accommodated in the cylinder 91 so as to be slidable back and forth. The reverse spring 93 biases the piston 92 in a direction to close the opening of the cylinder 91.

  The temperature of the engine 1 is controlled by the control device 20. The control device 20 is an electronic control unit (ECU), not shown in detail, but a CPU (central processing unit), ROM (program memory), RAM (data memory), and backup RAM (nonvolatile memory). It is set as the well-known structure provided with these.

  The ROM stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU executes arithmetic processing based on various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores calculation results in the CPU, data input from each sensor, and the like. The backup RAM is a nonvolatile memory that stores data to be saved when the engine 1 is stopped. It is memory.

  In this embodiment, a first temperature sensor 21 is provided near the inlet 15 of the cylinder block 2, and a second temperature sensor 22 is provided in the head-side water jacket 14.

  The first and second temperature sensors 21 and 22 output signals corresponding to the coolant temperature and input them to the control device 20. As a result, the control device 20 recognizes the coolant temperature TcB over a wide range of the engine based on the input of the detection output of the first temperature sensor 21, and based on the input of the detection output of the second temperature sensor 22, the head side water jacket 14. The local coolant temperature TcH is recognized.

  For example, the control device 20 performs various controls relating to the operation of the engine 1 and also performs temperature adjustment control of the engine 1 as described below.

  Next, the temperature adjustment control of the engine 1 by the control device 20 will be described with reference to the flowchart shown in FIG.

  When the engine 1 is started, the control device 20 starts executing the processing of the flowchart shown in FIG. First, in step S1, it is determined whether or not the coolant temperature TcB in the wide range of the engine 1 (near the inlet 15 of the engine 1) in the external passage 2 is equal to or higher than the warm-up completion temperature Th0. Here, based on the output signal from the first temperature sensor 21, the coolant temperature TcB near the inlet 15 of the engine 1 is detected as a wide range of coolant temperature of the engine 1, and this detected value TcB and the warm-up completion temperature Th0 are detected. Can be determined by comparing.

  If TcB <Th0, a negative determination is made in step S1, and the water pump 4 is stopped in the subsequent step S2. Thereby, the coolant temperature of the head-side water jacket 14 and the block-side water jacket 13 gradually increases.

  However, if TcB ≧ Th0, an affirmative determination is made in step S1, and the process skips step S2 and proceeds to step S3.

  In step S3, it is determined whether or not the coolant temperature TcH in the local area (head side water jacket 14) of the engine 1 is equal to or higher than the upper limit temperature Th1. Here, based on the output signal from the second temperature sensor 22, the coolant temperature TcH in the head-side water jacket 14 is detected as a local coolant temperature of the engine 1, and the detected value TcH and the upper limit temperature Th1 are detected. This can be determined by comparison. The upper limit temperature Th1 is set to be higher than the warm-up completion temperature Th0. Specifically, for example, the upper limit temperature Th1 is set to the security temperature (about 95 ° C.) of the cylinder head 12.

  Here, if TcH <Th1, a negative determination is made in step S3, and the process returns to step S3. That is, the coolant temperature TcH in the local area (head side water jacket 14) of the engine 1 is raised by continuing the stop of the water pump 4. Thus, when TcH ≧ Th1, an affirmative determination is made in step S3, and the process proceeds to the subsequent step S4.

  In step S4, the water pump 4 is operated intermittently. Here, the interval between the operation timing and the stop timing of the water pump 4, that is, the cycle can be set as appropriate, and the operation time and the stop time of the water pump 4 can be set as appropriate. is there. The operation time and the stop time may be set to be the same or may be set to be different from each other. Incidentally, it can be said that if the interval between the operation timing and the stop timing of the water pump 4, that is, the cycle is set to be long, the swaying action of the coolant increases. In addition, it is also possible to set the discharge capacity at the time of operation of the water pump 4 as high as possible, and it can be said that the action of shaking the coolant is increased also in that case.

  As a result, during the period in which the water pump 4 is operating, the coolant in the internal passages (head-side water jacket 14 and block-side water jacket 13) is pushed out from the discharge port 16 to the external passage 2 by the discharge pressure. The cooling liquid is pushed into the variable volume tank 9. When the water pump 4 is stopped, the cooling liquid pushed into the variable volume tank 9 is now pushed out from the discharge port 16 to the internal passage (the head side water jacket 14 and the block side water jacket 13). It becomes to flow backward.

  As described above, when the water pump 4 is operated intermittently, the coolant is taken in and out in the internal passage (the head-side water jacket 14 and the block-side water jacket 13) of the engine 1, so that the coolant is shaken. As a result of stirring, the temperature distribution of the coolant in the internal passages (head-side water jacket 14 and block-side water jacket 13) is made uniform. For this reason, it is possible to avoid the temperature of the coolant from excessively rising and boiling in the local portion of the internal passage (the head-side water jacket 14 and the block-side water jacket 13).

  Thereafter, in step S5, it is determined whether or not the coolant temperature TcB in the wide range of the engine 1 (near the introduction port 15 of the engine 1) in the external passage 2 is equal to or higher than the warm-up completion temperature Th0. Here, as in step S1, the coolant temperature TcB near the inlet 15 of the engine 1 is detected as the coolant temperature in a wide range of the engine 1 based on the output signal from the first temperature sensor 21, and this detected value TcB And the warm-up completion temperature Th0 can be determined.

  If TcB <Th0, a negative determination is made in step S5, and the process returns to step S5. That is, by continuing the intermittent operation of the water pump 4, the coolant temperature TcB in the wide range of the engine 1 (near the inlet 15 of the engine 1) is increased. Thus, when TcB ≧ Th0, an affirmative determination is made in step S5, and the process proceeds to the subsequent step S6.

  In this step S6, the water pump 4 is continuously operated. The water pump 4 at this time is duty controlled. At this time, since the coolant on the upstream side of the thermostat 8 is also at the warm-up completion temperature Th0 or higher, the thermostat 8 is opened. Therefore, the internal passages (head-side water jacket 14 and block-side water jacket 13) of the engine 1 and the external passage 2 are in a closed loop so that the coolant is circulated.

  In this circulation process of the coolant, the coolant recovers the heat of the cylinder head 12 and the cylinder block 11 and is dissipated to the atmosphere by the radiator 5, so that the temperature of the circulated coolant is completely warmed up. The temperature Th0 is maintained.

  Thereafter, in the subsequent step S7, it is determined whether or not the coolant temperature TcB in the wide range of the engine 1 (near the inlet 15 of the engine 1) in the external passage 2 has become lower than the warm-up completion temperature Th0. Here, as in steps S1 and S5, based on the output signal from the first temperature sensor 21, the coolant temperature TcB near the inlet 15 of the engine 1 is detected as the coolant temperature in a wide range of the engine 1, and this detection is performed. This can be determined by comparing the value TcB with the warm-up completion temperature Th0.

  If TcB ≧ Th0, a negative determination is made in step S7, and the process returns to step S7. That is, by continuing the continuous operation of the water pump 4, the coolant temperature TcB in the wide range of the engine 1 (near the inlet 15 of the engine 1) is lowered. In this way, if TcB <Th0, an affirmative determination is made in step S7, and the process proceeds to the subsequent step S8.

  In this step S8, it is determined whether or not the coolant temperature TcB in the wide range of the engine 1 (near the inlet 15 of the engine 1) in the external passage 2 has become lower than the lower limit temperature Th2. Here, the coolant temperature TcB near the inlet 15 of the engine 1 is detected as the coolant temperature in a wide range of the engine 1 based on the output signal from the first temperature sensor 21 as in the steps S1, S5, S7, The detection value TcB can be determined by comparing the lower limit temperature Th2. The lower limit temperature Th2 is set lower than the warm-up completion temperature Th0, but specifically, for example, is set to a reference temperature (about 80 ° C.) necessary for the engine 1 to operate stably.

  If TcB ≧ Th2, a negative determination is made in step S8, and the process returns to step S7. That is, by continuing the continuous operation of the water pump 4, the coolant temperature TcB in the wide range of the engine 1 (near the inlet 15 of the engine 1) is lowered. Thus, when TcB <Th2, an affirmative determination is made in step S8, and the process returns to step S2. That is, by shifting to the stop control of the water pump 4, the coolant temperature TcB in the wide range of the engine 1 (near the inlet 15 of the engine 1) is increased.

  Thereafter, the temperature of the engine 1 is adjusted to be constant by repeating the steps S2 to S8.

As described above, in the embodiment to which the present invention is applied, the coolant can be circulated with the internal passage (block side water jacket 13 and head side water jacket 14) and the external passage (external passage 2) of the engine 1 being closed loops. In the engine 1 that has been warmed up, it is possible to avoid the cooling water from excessively rising and boiling in the local area of the internal passages (13, 14) of the engine 1, and to quickly complete warming up while uniformly controlling the temperature. In particular, it is only necessary to periodically operate and stop the water pump 4, as compared with the case of periodically rotating, stopping, and rotating reversely as in the conventional example (Patent Document 2). As a result, control can be simplified and the design of the control program can be facilitated, so that an increase in equipment cost can be suppressed.

  For this reason, it is possible to quickly complete stable warm-up while constructing the engine cooling system equipment at a relatively low cost, thereby contributing to the improvement of the fuel consumption of the engine 1.

  The correspondence relationship between the constituent elements described in the embodiment described above and the constituent elements described in the claims will be described. The temperature increase promotion means described in the claims corresponds to steps S1 and S2 shown in FIG. 4, and the first determination means described in the claims corresponds to step S3 shown in FIG. The adjustment means corresponds to step S4 shown in FIG. 4, the second determination means described in claims corresponds to step S5 shown in FIG. 4, and the second temperature adjustment means described in claims corresponds to step S6 shown in FIG. It corresponds to.

  In addition, this invention is not limited only to the said embodiment, It can change suitably in the range equivalent to the claim and the said range.

  (1) In the above embodiment, the heater core 6 is disposed downstream of the thermostat 8 in the coolant flow direction, but the present invention is not limited to this.

  For example, as shown in FIG. 5, the heater core 6 can be disposed upstream of the thermostat 8 and the variable volume tank 9 in the coolant flow direction. In the case of such a form, in addition to the effect | action and effect of the said embodiment, it becomes possible to perform vehicle heating using the heater core 6 also during warming-up.

  (2) In the above embodiment, an example is given in which the water pump 4 is an electric water pump, but the present invention is not limited to this.

  For example, the water pump 4 can be of a type called a known mechanical water pump. In that case, although not shown, for example, a belt is wound around the water pump pulley and the crankshaft pulley, and the water pump pulley is equipped with an electromagnetic clutch or the like, and this electromagnetic clutch is joined by the control device 20, The water pump 4 is controlled to be activated and stopped by being cut. In such a case, the same operation and effect as in the above embodiment can be obtained.

  (3) In the said embodiment, although the example which made the variable volume tank 9 the cylinder type is given, this invention is not limited to this. For example, although not shown, the variable volume tank 9 can be made to be shrinkable with a flexible material such as a rubber tube. In such a case, the same operation and effect as in the above embodiment can be obtained.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for an engine in which an internal passage and an external passage of the engine are closed loops so that coolant can be circulated.

1 Engine 11 Cylinder block 12 Cylinder head 13 Block side water jacket (internal passage)
14 Head side water jacket (internal passage)
15 Block side water jacket inlet 16 Head side water jacket outlet 2 External passage 4 Water pump 5 Radiator 8 Thermostat 9 Variable volume tank 20 Controller 21 First temperature sensor 22 Second temperature sensor

Claims (3)

In an engine that allows the coolant to circulate with the internal passage and the external passage of the engine as a closed loop,
A water pump for causing the coolant to flow, a control device for controlling operation and stop of the water pump, and the warm-up completion while the external passage is closed when the coolant is below the warm-up completion temperature. A flow rate control valve that is fully opened when the temperature is higher than the temperature control valve, and is provided upstream of the flow rate control valve in the external passage in the coolant flow direction and acts to push out after receiving the coolant discharged from the internal passage. And a variable volume tank
The control device includes a temperature increase promoting means for stopping the water pump and stopping the circulation of the coolant with the cold start,
First determination means for determining whether or not the coolant temperature in the internal passage is equal to or higher than an upper limit temperature set higher than the warm-up completion temperature in a stopped state of the water pump;
An engine comprising: first temperature control means for intermittently operating the water pump when an affirmative determination is made by the first determination means. The engine according to claim 1,
The control device determines whether or not the coolant temperature near the inlet of the coolant to the internal passage in the external passage becomes equal to or higher than the warm-up completion temperature during the intermittent operation of the water pump. When,
The engine further comprising: a second temperature control unit that continuously operates the water pump when the second determination unit makes a positive determination. The engine according to claim 1 or 2,
The engine, wherein the water pump is an electric water pump operated by an electric motor.

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