KR950005832B1 - Engine cooling system - Google Patents

Abstract

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Description

Engine Cooling System

1 is a block diagram showing a schematic configuration of an engine cooling apparatus according to the present invention.

2A and 2B are flow charts showing the procedure of the cooling fan control of the first embodiment executed by the controller 2 of the first speed diagram.

3A and 3B are flow charts showing the procedure of the cooling fan control of the second embodiment executed by the controller 2 of the first speed diagram.

4 is a graph showing the relationship between methanol mixing rate (B), fuel oil (T _F ), and cooling fan operating time f ₁ (B, T _F ).

5 is a graph showing the relationship between the intake air temperature (T _A ) and the cooling fan operating time f ₂ (T _A ).

6 is a graph showing the relationship between the cooling water temperature (T _W ) and the cooling fan operating time f ₃ (T _W ).

7 is a graph showing the relationship between methanol mixing ratio and saturated steam pressure.

* Explanation of symbols for main parts of the drawings

1: engine body 2: controller

4: Mixing rate sensor (sensor means) 6: Fuel temperature sensor (sensor means)

8: water temperature sensor (sensor means) 12: absorption temperature sensor (sensor means)

13: fan motor 14: cooling fan (cooling fan means)

16: ignition switch

The present invention relates to an engine cooling apparatus, and more particularly, to a cooling apparatus of an internal combustion engine operable by either of alcohol and gasoline, or a mixed fuel thereof.

When a vehicle, for example a car, turns off the engine immediately after driving down a hill of a steep grade or after a high-speed driving, the temperature in the engine lume rises because there is no coolant, and the fuel injection valve and the fuel supply passage Since the vapor lock occurs, the behavior may become unstable at the engine restart. For this reason, when the engine is stopped, the cooling fan is operated to lower the temperature of the engine itself or the temperature inside the engine run.

However, if the cooling fan is operated indefinitely after the engine stops, the battery, which is a power source, is consumed uselessly and noise can be generated unnecessarily.

Therefore, conventionally, after stopping the engine, the engine atmosphere temperature such as fuel temperature, intake temperature or cooling water temperature is monitored, and when they are above a predetermined value, the cooling fan is driven by driving a cooling fan until a predetermined time or until they reach a predetermined value. Is doing.

The engine cooling device described above can provide a certain effect on the prevention of vapor lock in a conventional gasoline engine car.

By the way, although an alcohol engine car is attracting attention as a low pollution vehicle in recent years, when methanol is used as an alcohol fuel, it is hypothesized that not only methanol but also gasoline alone or mixed oils thereof will be used.

FIG. 7 shows the relationship between the methanol mixing rate, that is, the mixing ratio of methanol to gasoline and the saturated steam pressure of the mixed fuel, and within a range where the methanol mixing rate is constant, the saturated steam pressure of the fuel is not only when the methanol mixing rate is l00%, When it is 0%, that is, when it is a pure gasoline, the phenomenon that rises significantly, so-called azeotropy can be seen. The azeotropy is not limited to the case where it is mixed with gasoline and methanol, and is widely observed when two or more kinds of different fuels are mixed and used. This azeotropy causes a problem that vapor lock is very likely to occur when a mixed fuel such as gasoline and methanol is used in an alcohol engine car.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an engine cooling apparatus designed to effectively and efficiently prevent vapor lock when a mixed fuel is used in an alcohol engine car, for example.

In order to achieve the above object, the engine cooling apparatus of the present invention comprises: an internal combustion engine capable of operating at least two kinds of fuels or mixed fuels thereof, cooling fan means for cooling the internal combustion engine or its atmosphere, And a mixing ratio sensor for detecting a mixing ratio of the at least two kinds of fuels, and a control for controlling operation by the cooling fan means based on a detection value detected by the mixing ratio sensor after the internal combustion engine is stopped.

According to the engine cooling apparatus described above, since the internal combustion engine controls the operation of the cooling fan means for cooling the atmosphere based on the value of the mixing rate detected by the mixing rate sensor after the internal combustion engine is stopped, when the cooling according to the mixing rate is necessary. It is possible to appropriately perform the required amount. As a result, it is possible to effectively and efficiently prevent vapor lock caused by azeotropy, which is widely seen when two or more different fuels are mixed.

Hereinafter, a first embodiment of the present invention will be described in detail with reference to Figs. 1, 2a and 2b.

1 shows a configuration of an engine cooling apparatus according to the present invention.

The engine cooling apparatus is used especially for an alcohol engine car which uses a mixture of methanol and gasoline as fuel, but the apparatus for operating the engine main body 1 and the engine main body 1 is basically a normal gasoline. Since there is no change with the engine car, the description is omitted here.

By the way, the fuel pressurized by the fuel pump not shown is supplied to the fuel injection valve 1a provided in the engine main body 1, and the methanol piping ratio of the mixed oil used, ie, to the fuel piping 3 which supplies this fuel, And a mixing rate sensor 4 and a temperature sensor means for detecting the mixing ratio of methanol to gasoline, and in particular a fuel temperature sensor 6 for detecting the fuel temperature, which is electrically connected to the controller 2, respectively. Is approached.

On the other hand, in the coolant passage 7 provided near the engine main body 1, a temperature sensor means is formed, and in particular, a water temperature sensor 8 for detecting the coolant temperature is provided, which is also provided on the input side of the controller 2. Is connected.

In addition, an intake passage 9 is connected to the cylinder head 1c to induce intake air into the combustion chamber 1b of the engine body 1. An air cleaner 10 is provided at the front end of the intake passage 9, and in this air cleaner 10, a temperature sensor means is formed, and in particular, an intake air temperature sensor 12 for detecting the intake air temperature is provided. It is installed. The intake air temperature sensor 129 is also electrically connected to the controller 2.

In addition, the ignition switch 16 is connected to the controller 2, and the on-off signal of the ignition switch 16 is supplied.

A fan motor 13 that drives the cooling fan 14 by using a battery (not shown) as a power source is connected to the output side of the controller 2. As the cooling fan 14, for example, a radiator fan is used.

Next, the procedure of the cooling fan control executed by the controller 2 will be described with reference to FIGS. 2A and 2B.

The controller 2 monitors the on-off position of the ignition switch 16 usually, and first, determines whether the ignition switch 16 is turned off (step S10).

If the determination result of step S10 is negative (No), step S10 is repeated.

If the result of the determination in step S10 is YES, that is, when the ignition switch 16 is turned off, the controller 2 next controls the methanol mixture B and fuel detected by the mixing rate sensor 4. The fuel temperature T _F detected by the temperature sensor 6, the coolant temperature T _W detected by the water temperature sensor 8, and the intake air temperature T _A detected by the intake air temperature sensor 12 are read (step). S12).

Then, it is first determined whether or not the methanol mixing ratio B is between the predetermined upper limit set value B _H and the predetermined lower limit set value B _L (step S14).

When the determination result of step S14 is negative, that is, when the methanol mixing ratio B is equal to or greater than the predetermined upper limit set value B _H or equal to or smaller than the predetermined lower limit set value B _L , the saturated steam pressure is low and there is a possibility of occurrence of vapor lock. Since it is low, it is determined that repeated cooling of the engine is unnecessary and the routine is terminated.

If the determination result of the step (S14) step, since the saturated vapor pressure of the fuel is high in accordance with any of the engine atmosphere temperature is high possibility of a vapor lock occurs, then in step (S12) the fuel temperature (T _F read in ) And the predetermined set value (T _FL ), the coolant temperature (T _W ) is determined in this order whether the predetermined rust value (T _WL ) and the intake temperature (T _A ) has exceeded the predetermined set value (T _AL ), respectively. (Steps S14 to 20).

If any of the determination results in steps S14 to S20 is negative, it is determined that the probability of occurrence of vapor lock is low, and the engine is not cooled as in the case of negative in step S14. Quit Routine.

When all of the determination results of steps S14 to S20 are processes, it is determined that the engine atmosphere temperature is also in a state where a vapor lock is likely to occur, and the engine is cooled as follows.

First, the tire is set at a predetermined time set in advance, and this is started (step S22). The predetermined time means that the engine atmosphere temperature such as the fuel temperature T _F can be lowered to a temperature at which the above-described conditions can be sufficiently satisfied by the cooling fan 14 within a range in which the battery is not consumed extremely. The time is set. The timer described above is for counting the predetermined time, and is an up counter for stopping the operation of the fan motor 13 at the time of counting up.

Next, the controller 2 energizes the fan motor 13 from a battery (not shown) to operate the cooling fan 14 (step S24) to start cooling the engine.

Then, it is determined whether or not the above-described timer has counted up (step S26).

If the determination result of step S26 is negative, this is repeated until the timer finishes counting up the predetermined time mentioned above.

When the determination result of step S26 is a process, the controller 2 stops energization from the battery to the fan motor 13 and ends cooling of the engine by the cooling fan 14 (step S28).

As described above, according to the first embodiment, the controller 2 includes the methanol mixture 8, fuel temperature T _F , cooling water temperature T _W , and intake temperature T _A , which have a great influence on the generation of vapor lock. Since the engine is cooled according to each detected value of V, it is possible to effectively prevent the occurrence of vapor lock based on the azeotropic phenomenon of fuel peculiar to a known engine vehicle.

Next, the second embodiment will be described in detail with reference to FIGS. 3A to 6. The second embodiment shows a procedure separate from that of the cooling fan control executed by the controller 2 of the first embodiment.

The controller 2 monitors the on-off position of the ignition switch 16 normally, and first determines whether the ignition switch 16 is turned off (step S10).

If the determination result of step S10 is negative (No), step s10 is repeated.

In the case where the determination result of step S10 is step (Yes), that is, when the ignition switch 16 is turned off, the controller 2 next controls the methanol mixing rate B detected by the mixing rate sensor 4, The fuel temperature T _F detected by the fuel temperature sensor 6, the coolant temperature T _W detected by the water temperature sensor 8, and the intake air temperature T _A detected by the intake air temperature sensor 12 are read ( Step S12).

4, 5, 6 and the following equation 1, the cooling fan operating time F is calculated as follows in step S14, which is an operating time calculating means.

f = ₁ (B, T _F ) + f ₂ (T _A ) + f ₃ (T _W ). … … … … … … … … … … … … … … … … … … ①

That is, in detail, first, the cooling fan operation time f ₁ (B, T _F ) is calculated | required from the methanol mixing ratio B and the fuel temperature T _{F which} were read in step S12 with reference to FIG.

4 shows the relationship between the methanol mixing ratio B and the cooling fan operating time f ₁ (B, T _F ) when the fuel temperature T _F is used as a parameter, and the fuel temperature T _F. Is constant, the approximate relationship between the methanol mixing ratio and the saturated vapor pressure shown in FIG. 7 above, that is, the maximum cooling fan operating time f in the region where the methanol mixture B is approximately 30% to 50%. _It is set so that ₁ (B, T _F ) can be obtained. On the other hand, when the mixing rate of methanol (B) constant are set to be longer the higher the fuel temperature (T _F), a cooling fan operating time ₁ f (B, T _F).

Next, referring to FIG. 5, the cooling fan operating time f ₂ (T _A ) is obtained from the intake air temperature T _A read in step S12.

Here, the five degrees, the intake air temperature (T _A) and and to see the relationship between the cooling fan operating time _{f 2 (T A), f} 2 (T A) is a (T _A) is up to a predetermined set point (T _A ^±) As 0, when (T _A ) exceeds (T _A ^± ), it is set to increase as a linear function thereafter (T _A ).

6, the cooling fan operating time f ₃ (T _W ) is obtained at the cooling water temperature T _W read in step S12.

Here, FIG. 6 shows the relationship between the coolant temperature TW and the cooling fan operating time f ₃ (T _W ), and f ₃ (T _W ) is 0 until (T _W ) is a predetermined set value (T _W ^± ). For example, when (T _W ) exceeds (T _W ^± ), it is set to increase as the first function of (T _W ) thereafter.

Cooling fan operation time f ₁ (B, T _F ), f ₂ (T _A ) and f ₃ (T _W ) set in this manner is substituted into the above equation, which is necessary to prevent vapor lock and also provide sufficient cooling. The fan operating time F is finally obtained.

In addition, when the above-mentioned methanol mixing ratio B and the like do not respectively reach a predetermined value, the cooling fan operating time F is determined as 0, and as a result, the engine may not be cooled.

Next, it is determined whether the cooling fan operating time F calculated in step S14 has exceeded the actual maximum cooling fan operating time F _max in order to prevent the power supply from excessively draining the battery (step S16).

When the determination result of step S16 is negative, a timer is set to the cooling fan operation time F computed in step S14, and this starts (step S22).

If the determination result of the step (S16) step, after it is determined in step (S18), substituted by a cooling fan operating time up to the cooling fan operating time (F _max) A (F) are described above, substituted means a step (S22 ) Is executed.

In addition, the above-mentioned timer is for counting the cooling fan operation time F calculated | required in step S14 or step S8, and is an up counter which stops operation of the fan motor 13 at the time of counting up. .

Next, the controller 2 energizes the fan motor 13 from a battery (not shown) to operate the cooling fan 14 (step S24) to start cooling the engine.

Then, it is determined whether or not the above timer has counted up the cooling fan operating time F (step S26).

If the determination result in step S26 is negative, this is repeated until the timer finishes counting up.

When the determination result of step S26 is a process, the controller 2 stops energization from the battery to the fan motor 13 and ends cooling of the engine by the cooling fan 14 (step S28).

As described above, according to the second embodiment, the controller 2 has a methanol mixing ratio B, a fuel temperature T _F , a coolant temperature T _W , and an intake temperature T _A , which have a great influence on the generation of vapor lock. Cooling of the engine is performed by setting the cooling fan operating time (F) appropriately according to each detected value. Therefore, azeotropy occurs when a mixed fuel is used in an alcohol engine vehicle while preventing the use of useless batteries and noise. This prevents the occurrence of vapor lock effectively and efficiently.

In addition, when the cooling fan operating time F exceeds the maximum cooling fan operating time F _max set in order to prevent excessive consumption of the battery, the cooling fan operating time F is replaced by the replacement means (step S18). ) Can be replaced with the maximum cooling fan operating time (F _max ), thereby avoiding the inconvenience that the battery is extremely consumed and causes a problem in driving.

In addition, although the above-mentioned 1st and 2nd embodiment demonstrated the alcohol engine car which uses the mixed oil of methanol and gasoline as a fuel, it is not limited to this, Of course, about the alcohol engine car which uses other mixed oil, of course to be. In the second embodiment, the present invention can also be applied to a gasoline engine car. In the case of a gasoline engine car, however, the methanol mixing rate B detected by the mixing rate sensor 4 is detected as 0, and the cooling fan control shown in FIGS. 3A and 3B is executed.

In addition, the installation position of each sensor mentioned above is not limited to the above-mentioned thing, It is possible to change suitably and to install in the position which can obtain a more suitable variable value, respectively by the occurrence of vapor lock prevention.

In addition, the variable detected and evaluated like the methanol mixing ratio B is limited to the fuel temperature T _F , the coolant temperature T _W or the intake temperature T _A when the ignition switch 16 is described above. Alternatively, for example, another engine atmosphere temperature such as the temperature of the engine main body 1, the engine room temperature, or the lubricant on may be used. In addition, any other variable between when the ignition switch 16 is on, that is, when the vehicle is driven or after the vehicle stops, is turned off, for example, the atmosphere temperature of the engine as well as the engine described above. The rotation speed black can also employ | adopt various variables, such as their duration, as a variable detected and evaluated like methanol mixing ratio B mentioned above.

In addition, the cooling fan 14 mentioned above is not necessarily limited to a radiator fan, You may make it provide the cooling fan 14 specially used or shared with another apparatus. In addition, the form of cooling can be changed in various ways, such as not only the engine main body 1 but also the fuel system, for example, the fuel piping 3, and the like.

As detailed above. According to the engine cooling apparatus of the present invention, since the operation of the cooling fan means for cooling the internal combustion engine or its atmosphere is controlled based on the value of the mixing rate detected by the mixing rate sensor after the internal combustion engine is stopped, when the cooling according to the mixing rate is necessary. It is possible to appropriately perform the required amount. As a result, there is an effect of effectively and efficiently preventing vapor lock due to azeotropy, which is widely seen when two or more different fuels are mixed.

Claims (8)

An internal combustion engine operable with any of at least two types of fuels or their mixed fuels, a cooling fan means for cooling the same internal combustion engine or its atmosphere, a mixing rate sensor for detecting a mixing ratio of the at least two types of fuels, and And a controller for controlling the operation of the cooling fan means based on the detection value detected by the mixing rate sensor after the internal combustion engine is stopped. The engine cooling apparatus according to claim 1, wherein the controller operates the cooling fan means when the mixing ratio detected by the mixing rate sensor is within a predetermined setting range. 3. The cooling engine means according to claim 2, further comprising a thermo sensor means for detecting the internal combustion engine or its ambient temperature, wherein the controller operates the cooling fan means when the temperature detected by the temperature sensor means exceeds a predetermined set value. Engine cooling system. 4. The engine cooling apparatus according to claim 3, wherein the temperature sensor means comprises a fuel temperature sensor for detecting a fuel temperature, an intake temperature sensor for detecting an intake temperature, and a coolant temperature sensor for detecting a coolant temperature. The engine cooling apparatus according to claim 1, wherein the controller has an operating time calculating means for setting an operating time of the cooling fan means. A fuel temperature sensor for detecting a fuel temperature, an intake air temperature sensor for detecting an intake temperature, and a cooling water temperature sensor for detecting a coolant temperature, wherein the operation time calculating means comprises: a mixing rate detected by the mixing rate sensor; And set the operation time according to each value of the fuel temperature slumped by the fuel temperature sensor, the intake temperature detected by the intake temperature sensor, and the coolant temperature detected by the coolant temperature sensor. Device. 7. The method of claim 6 wherein the operating time calculating means, the operation calculated from the mixing rate (B) and the operating time obtained from the fuel temperature _{(T F) f 1 (B} , T F) and, said intake air temperature (T _A) Based on the time f ₂ (T _A ) and the operating time f ₃ (T _W ) obtained from the cooling water temperature T _W , the operating time F is F = f ₁ (B, T _F ) + f ₂ (T _A ) + f ₃ (T _W ) Engine cooling apparatus characterized in that obtained by the formula. 6. The cooling fan means according to claim 5, wherein the cooling fan means is a vibrating cooling fan powered by a battery, and the controller controls an operating time set by the operating time calculating means to set a maximum cooling fan operating time set to prevent excessive consumption of the battery. When exceeding, the engine cooling apparatus having a replacement means for replacing the operation time obtained by said operation time calculation means with the maximum cooling fan operation time.