JP2006281901A - Cooling water temperature estimation device for vehicle, and air-conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate the temperature of cooling water of a water-cooled engine for travel of a vehicle. <P>SOLUTION: An electronic control device 30 of an air-conditioner for the vehicle calculates an average value Neave of rotational speed of the water-cooled engine for the vehicle (step S140) to obtain temperature rise TWne of the cooling water based on the average value Neave and a control map recorded in a flash memory 31a (step S150), and sets outside air temperature TAM as an initial value TWin of the cooling water temperature to set a value obtained by adding the temperature rise TWne to the set TWin as a cooling water temperature estimated value TWfail (=TWin+TWne) in trouble of a water temperature sensor 43 (step S160). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicular coolant temperature estimation device that estimates the water temperature of a water-cooled engine, and a vehicular air conditioner.

  Conventionally, in a vehicle air conditioner, a blower that is housed in the air conditioning casing and blows air toward the passenger compartment, an evaporator that cools the air blown from the blower, a cool air blown from the evaporator, a heater core, and a heater core A bypass passage that bypasses and passes cool air, and an air mix door that adjusts the temperature of the air-conditioning air blown into the vehicle interior by adjusting the ratio of the amount of cold air flowing into the heater core and the amount of cold air flowing into the bypass passage There is something with.

  In this structure, the heater core heats the cold air blown from the evaporator by the cooling water that cools the traveling water-cooled engine. For this reason, the electronic control unit controls the blower based on the output signal from the water temperature sensor that detects the cooling water temperature, and operates the blower when the cooling water temperature is equal to or higher than a certain temperature, so that the cooling water temperature is constant. When the temperature is lower than the temperature, the blower is stopped.

  Therefore, it is possible to prevent the cooling water temperature from being low and the cold air from being heated by the heater core and being blown out through the heater core while the air temperature is low.

  By the way, in the above vehicle air conditioner, if the water temperature sensor fails, the electronic control unit cannot control the blower based on the cooling water temperature as described above. For this reason, when the running engine is started, cold air may pass through the heater core without being heated by the heater core and be blown into the passenger compartment, which may cause discomfort to the passenger.

  In view of the above, the present invention has as its first object to provide a vehicle coolant temperature estimation device that estimates the coolant temperature of a water-cooled engine, and a temperature sensor that detects the coolant temperature of a water-cooled engine is provided. It is a second object of the present invention to provide a vehicle air conditioner that prevents a passenger from feeling uncomfortable due to cold air even if a failure occurs.

  The present invention has been made paying attention to the fact that it is possible to estimate the coolant temperature from the operation time of the water-cooled engine and the average rotational speed during the operation period.

Specifically, in the invention described in claim 1,
Calculation means (S140) for calculating an average rotational speed of the water-cooled engine for the vehicle;
Storage means (31a) for storing data indicating the relationship between the operation time of the water-cooled engine, the average rotational speed during the operation period of the water-cooled engine, and the coolant temperature of the water-cooled engine;
Estimation means (S130, S150 to S200) for estimating the temperature of the cooling water according to the storage data stored by the storage means and the rotation speed detected by the rotation speed detection means.

  Since the temperature of the cooling water can be estimated as described above, it is possible to provide a vehicular cooling water temperature estimation device that estimates the cooling water temperature of a water-cooled engine.

Specifically, as in the invention described in claim 2,
An outside air temperature detecting means (S110) for detecting the outside air temperature as an initial value of the cooling water temperature;
The estimation means includes
According to the stored data of the storage means and the rotational speed detected by the rotational speed detection means, the temperature rise of the cooling water accompanying the operation of the water-cooled engine is calculated, and the calculated temperature rise The cooling water may be estimated based on the outside air temperature detected by the outside air temperature detecting means.

  Moreover, if the vehicle coolant temperature estimation device according to claim 1 or 2 is applied to a vehicle air conditioner as in the invention described in claim 3, even if a sensor for detecting the coolant temperature fails. Since the cooling water temperature is estimated and the blower can be controlled based on the estimated temperature, it is possible to avoid discomforting the occupant by blowing cold air into the passenger compartment.

Specifically, in the invention according to claim 3,
A blower (13) for blowing air conditioned air toward the passenger compartment;
When the temperature of the cooling water estimated by the estimating means is less than a threshold, the blower is stopped, and when the temperature of the cooling water estimated by the estimating means is equal to or higher than the threshold, the blower is operated. And control means (S210).

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

  FIG. 1 shows an overall system configuration of a vehicle air conditioner to which a vehicle coolant temperature estimating device of the present invention is applied. The most upstream side of an air flow of an air conditioning unit 10 constituting an indoor unit of a vehicle air conditioning control device. An inside / outside air switching box 11 having an outside air introduction port 11a and an inside air introduction port 11b is arranged, and an inside / outside air switching door 12 is rotatably installed in the inside / outside air switching box 11.

  The inside / outside air switching door 12 is disposed at a branch point between the outside air introduction port 11a and the inside air introduction port 11b and is driven by the actuator 12a to switch the air introduced into the air conditioning unit 10 between the inside air and the outside air, or Adjust the mixing ratio of outside air.

  The blower 13 as a blower means sucks air into the inside / outside air switching box 11 and blows it to the downstream side of the air conditioning unit 10, and has a blower motor 14 and a centrifugal blower fan 15 connected to a rotating shaft thereof. is doing.

  An evaporator 16 and a heater core 17 are provided downstream of the blower fan 15. The evaporator 16 is a heat exchanger for cooling, and is combined with a compressor or the like driven by a vehicle engine (not shown) to constitute a refrigeration cycle. The low-pressure refrigerant in the interior absorbs heat from the air and evaporates to cool the air. To do.

  The heater core 17 is a heat exchanger for heating, and coolant (hot water) of a water-cooled engine for travel (not shown) circulates inside, and heats the air using the engine coolant as a heat source.

  On the upstream side of the heater core 17, an air mix door 18 as a blown air temperature adjusting means is rotatably provided, and the opening degree of the air mix door 18 is adjusted by being driven by an actuator 18a. Thereby, the ratio of the air passing through the heater core 17 and the air bypassing the heater core 17 is adjusted, and the temperature of the air blown out into the passenger compartment is adjusted.

  At the most downstream side of the air conditioning unit 10, a defroster door 20 that opens and closes a defroster (DEF) outlet 19, a face door 22 that opens and closes a face (FACE) outlet 21, and a foot door 24 that opens and closes a foot (FOOT) outlet 23. Is provided.

  Each of these doors 20, 22 and 24 constitutes an air outlet mode switching means, and is driven by an actuator 25 to open and close the air outlets 19, 21 and 23, thereby opening various air outlet modes (face mode, bi-level mode, Foot mode, foot differential mode, defroster mode, etc.) are set. Then, the temperature-adjusted air is blown out into the passenger compartment from the blow-out opening that opens in accordance with each blowing mode.

  The electronic control unit 30 has a microcomputer 31, and the microcomputer 31 controls the blower motor 14 of the blower 13 via the drive circuit 32, thereby controlling the blown amount of the centrifugal blower fan 15. The microcomputer 31 also controls the actuators 12 a, 18 a, 25 other than the blower motor 14 via the drive circuit 32.

  In addition, an operation signal is input to the microcomputer 31 from an air conditioning operation unit 33 installed in the vehicle interior instrument panel. The air conditioning operation unit 33 includes an AUTO switch 34 for setting an automatic control state of the air conditioner, an inside / outside air switching switch 35 for manually setting the inside / outside air mode, and a blowing mode for manually setting the blowing mode. A changeover switch 36, an airflow amount changeover switch 37 for manually setting the airflow amount of the fan 23, a temperature setting switch (setting means) 38 for setting a passenger's preferred vehicle interior temperature (desired temperature), and the like are provided. It has been.

  Further, the microcomputer 31 has an internal air temperature sensor 39 for detecting an air temperature (inside air temperature) TR in the vehicle interior, an air temperature outside the vehicle interior (outside) as a signal for detecting an environmental condition affecting the air conditioning state in the vehicle interior. Each signal is input from an outside air temperature sensor 40 that detects the temperature (TAM) and a solar radiation sensor 41 that detects the amount of solar radiation (intensity of solar radiation) TS that enters the vehicle interior.

  Further, each signal from the evaporator temperature sensor 42 for detecting the evaporator temperature (specifically, the evaporator blown air temperature) TE, the water temperature sensor 43 for detecting the engine water temperature TW circulating through the heater core 17, and the like are also sent to the microcomputer 31. Is input.

  In addition to the I / O circuit and RAM (volatile memory), the electronic control unit 30 includes a flash memory (nonvolatile memory) 31a that holds stored data even when power is not supplied. As will be described later, a control map (which corresponds to the data described in claim 1) used for estimating the engine water temperature when the water temperature sensor 43 fails is stored.

  The electronic control unit 30 is connected with an engine electronic control unit (engine ECU) 50 for controlling a traveling water-cooled engine via an in-vehicle LAN. The microcomputer 31 of the electronic control unit 30 includes: The rotation speed Ne of the water-cooled engine detected by the engine electronic control unit 50 is input.

  Here, the engine electronic control unit 50 measures the rotational speed of the water-cooled engine at regular intervals after the operation of the water-cooled engine starts, and at each measurement, the engine rotational speed (Ne1, Ne2, Ne3,... Nen ) To the electronic control unit 30.

  Ne1, Ne2, Ne3... Nen are engine speeds measured at regular intervals.

  Next, the operation of this embodiment will be described with reference to FIGS. FIG. 2 is a flowchart showing the air conditioning initial control process. When the ignition switch IG is turned on, the electronic control unit 30 executes the computer program according to the flowchart of FIG.

  That is, a volatile memory such as a RAM is initialized (step S100), and a sensor signal output from the outside air temperature sensor 40 and a sensor signal output from the water temperature sensor 43 are sampled (step S110).

  Thereafter, whether or not the water temperature sensor 43 has failed is determined based on a sensor signal output from the water temperature sensor 43. Specifically, based on the sensor signal output from the water temperature sensor 43, it is determined whether or not the cooling water temperature detected by the water temperature sensor 43 is within a certain range.

  Here, when the coolant temperature detected by the coolant temperature sensor 43 deviates from a certain range, it is determined that the coolant temperature sensor 43 has failed (step S120: YES). In this case, estimation processing for estimating the cooling water temperature is executed as described below (steps S130 to S200).

  First, in step S130, the outside air temperature TAM detected by the outside air temperature sensor 40 is set as the initial value (initial value) TWin of the cooling water temperature (TWin = TAM).

  Next, as described above, the average value Neave {= (Ne1 + Ne2 + Ne3 +... + Nen) / T} of the engine speeds (Ne1, Ne2, Ne3... Nen) obtained from the engine electronic control unit 50 for a certain period is calculated. (Step S140). Note that T is the number of engine revolutions measured by the engine electronic control unit 50 after the operation of the water-cooled engine is started.

  Next, an increase TWne of the coolant temperature is calculated using a control map stored in advance in the flash memory 31a (step S150).

  Here, the increase TWne means an increase in the coolant temperature that has risen from the start of the water-cooled engine to the current time. As shown in FIG. 3, the control map includes a rising axis TWne on the vertical axis, an operating time Tn of the water-cooled engine on the horizontal axis, an increasing value TWne, an operating time Tn, and an average value Neave of the engine speed. Is a data showing graphs A, B, C, and D. The operation time Tn means the time from the start of the water-cooled engine to the current time.

  Graph A shows the relationship between TWne and Tn when Neve ≧ 3000 rpm, Graph B shows the relationship between TWne and Tn when 3000 rpm> Neve ≧ 2000 rpm, and Graph C shows TWne when 2000 rpm> Neve ≧ 1000 rpm. And Tn, and D represents the relationship between TWne and Tn when Neave ≦ 1000 rpm.

  Of the graphs A, B, C, and D as described above, a graph corresponding to the average value Neave calculated in step S140 is selected, and an increase TWne is obtained based on the selected graph and the operation time Tn. . Thereafter, an increase TWne is added to the initial value TWin of the cooling water temperature to calculate an estimated value TWfail (= TWin + TWne) of the cooling water temperature when the water temperature sensor 43 fails.

  Here, when TWfail is 35 ° C. or higher (step S170: Yes), it is determined that the cooling water temperature is sufficiently warm for heating the air with the heater core 17, and the cooling water temperature TW = 50 ° C. (default) The cooling water temperature TW is used for a warm-up control process to be described later.

  On the other hand, when the cooling water temperature TWfail is less than 35 ° C. (step S170: NO), it is determined that the cooling water temperature is cold (that is, the heater core 17 is not warm enough to heat the air). Without using the cooling water temperature, the cooling water temperature TW is set to TWfail, and this cooling water temperature TW is used for a warm-up control process to be described later.

  Further, when it is determined that the coolant temperature detected by the coolant temperature sensor 43 is within a certain range and the coolant temperature sensor 43 is normal (step S120: NO), the temperature actually detected by the coolant temperature sensor 43 is detected. Is used as a cooling water temperature TW for a warm-up control process to be described later.

  When the cooling water temperature TW is calculated as described above, the process proceeds to step S210 and the warm-up control is processed.

  First, the fan output voltage output to the blower motor 14 is determined based on the control map shown in FIG. 4 and the coolant temperature TW. The control map shown in FIG. 4 is data indicating the relationship between the coolant temperature TW and the fan output voltage in the graph E. When TW ≦ TW1 (= 20 ° C.), the fan output voltage = VLo (= 0V). When TW2 (35 ° C.)> TW> TW1 (20 ° C.), the fan output voltage is set to rise to Vh (> VLo) as the coolant temperature TW rises.

  The fan output voltage is determined based on the control map and the coolant temperature TW as described above, and when the fan output voltage is less than Vh, the determined fan output voltage is output to the blower motor 14.

  For this reason, when TW ≦ TW1 (= 20 ° C.), the fan output voltage = VLo (= 0 V), so that no voltage is applied to the blower motor 14 and the blower 13 is stopped. On the other hand, when TW2 (35 ° C.)> TW> TW1 (20 ° C.), the fan output voltage rises as the cooling water temperature TW rises. Therefore, as the cooling water temperature TW rises, the amount of air blown by the blower 13 becomes To increase.

  When step S100 to step S210 as described above are repeatedly performed and the cooling water temperature TW exceeds TW2, the air conditioning initial control process is terminated and this normal air conditioning control process is executed.

  This normal air conditioning control process calculates a target blowing temperature TAO from a desired temperature Tset (set temperature), an inside air temperature TR, an outside air temperature TAM, a solar radiation amount TS, etc., and this target blowing temperature TAO, evaporator temperature TE, This is a well-known control process for controlling the blower motor and the actuators 12a, 18a, 25 using the cooling water temperature TW or the like.

Here, in the normal air-conditioning control process, when the water temperature sensor 43 is out of order, as described above, the estimation process (steps S130 to S200) for estimating the cooling water temperature is executed, and the estimated cooling water temperature. TW is used.
Next, the effect of this embodiment is demonstrated.

  The electronic control unit 30 according to the present embodiment calculates an average value Neave {= (Ne1 + Ne2 + Ne3 +... + Nen) / T} of the rotational speed of the water-cooled engine for the vehicle, and stores the calculated average value Neve and the flash memory 31a. Based on the control map (that is, data indicating the relationship between the operation time Tn of the water-cooled engine, the average rotational speed during the operation period, and the cooling water temperature), the temperature rise TWne of the cooling water is obtained.

  On the other hand, the electronic control unit 30 sets the outside air temperature TAM detected by the outside air temperature sensor 40 as the initial value (initial value) TWin of the cooling water temperature, and adds a value obtained by adding the temperature increase TWne to the set TWin. The estimated value TWfail (= TWin + TWne) of the cooling water temperature at the time of failure of the water temperature sensor 43 is used.

  Since the temperature of the cooling water can be estimated as described above, it is possible to provide a vehicular cooling water temperature estimation device that estimates the cooling water temperature of a water-cooled engine.

  Further, since the cooling water temperature of the water-cooled engine can be estimated in this way and the blower 13 can be controlled based on this estimated value, the cold air is blown out into the passenger compartment in a state where the cooling water temperature is low, and the passengers feel uncomfortable. Can be avoided.

(Other embodiments)
Further, in the above-described embodiment, the example in which the cooling water temperature is estimated when the water temperature sensor 43 fails in the vehicle air conditioner has been described. The water temperature may be estimated.

  In the above-described embodiment, an example in which the vehicle coolant temperature estimation device is applied to a vehicle air conditioner has been described. However, the present invention is not limited to this, and the present invention may be applied to vehicle equipment other than the vehicle air conditioner.

Hereinafter, the correspondence relationship between the above-described embodiment and the configuration of the scope of the claims will be described. The calculation process of step S140 is “calculation means for calculating the average rotational speed of a water-cooled engine for a vehicle” according to claim 1. 2, the control map shown in FIG. 2 describes the relationship between the operation time of the water-cooled engine, the average rotational speed during the operation of the water-cooled engine, and the coolant temperature of the water-cooled engine. The flash memory 31a corresponds to the “storage means” according to claim 1,
In addition, the estimation processing of step S130 to step S200 is performed to estimate the temperature of the cooling water according to “the storage data stored by the storage unit and the rotation number detected by the rotation number detection unit”. Corresponds to the "estimating means"
The detection processing in step 110 corresponds to “outside air temperature detecting means for detecting the outside air temperature as an initial value of the cooling water temperature” according to claim 2.

  Further, the blower 13 corresponds to the “blower for blowing the conditioned air toward the passenger compartment” according to claim 3, and the warm-up control processing in step S 210 is performed as “the cooling water estimated by the estimation means”. When the temperature is lower than the threshold value, the blower is stopped, and when the temperature of the cooling water estimated by the estimation means is equal to or higher than the threshold value, it corresponds to “control means for operating the blower”.

It is a figure which shows one Embodiment of the vehicle air conditioner to which the vehicle coolant temperature estimation apparatus of this invention was applied. It is a flowchart which shows the air-conditioning initial control process by the electronic controller of FIG. It is a figure which shows the control map used by the air-conditioning initial control process of FIG. It is a figure which shows the control map used by the air-conditioning initial control process of FIG.

Explanation of symbols

30 ... Electronic control unit for vehicle air conditioner,
31a: flash memory,
S140 to S160: Calculation processing of the electronic control unit.

Claims (3)

Calculation means (S140) for calculating an average rotational speed of the water-cooled engine for the vehicle;
Storage means (31a) for storing data indicating the relationship between the operation time of the water-cooled engine, the average rotational speed during the operation period of the water-cooled engine, and the coolant temperature of the water-cooled engine;
Vehicle cooling comprising: estimation means (S130, S150 to S200) for estimating the temperature of the cooling water according to the storage data stored by the storage means and the rotation speed detected by the rotation speed detection means Water temperature estimation device. An outside air temperature detecting means (S110) for detecting the outside air temperature as an initial value of the cooling water temperature;
The estimation means includes
According to the stored data of the storage means and the rotational speed detected by the rotational speed detection means, the temperature rise of the cooling water accompanying the operation of the water-cooled engine is calculated, and the calculated temperature rise The vehicle coolant temperature estimation device according to claim 1, wherein the coolant is estimated based on the outside air temperature detected by the outside air temperature detecting means. A vehicle air conditioner comprising the vehicle coolant temperature estimation device according to claim 1 or 2,
A blower (13) for blowing air conditioned air toward the passenger compartment;
When the temperature of the cooling water estimated by the estimating means is less than a threshold, the blower is stopped, and when the temperature of the cooling water estimated by the estimating means is equal to or higher than the threshold, the blower is operated. And a control means (S210) for performing vehicle air conditioning.

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