JP3435554B2 - Engine cooling control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling control apparatus for a water-cooled engine, and more particularly to an engine cooling control apparatus having a flow control valve for varying a cooling water flow rate in a cooling water circulating water passage connecting the engine and a radiator. .

[0002]

2. Description of the Related Art Conventionally, various types of engine cooling control devices for water-cooled engines have been proposed and disclosed, but a conventional example illustrated by FIG. 1 will be described below.

In FIG. 1, an engine 1, a water jacket 2 which is formed inside the engine 1 and circulates cooling water, a lead-out portion 3 which is an inlet / outlet of cooling water of the water jacket 2, and an introduction portion 4 are cooled. The water channels 5 and 6 are attached, and the cooling water channels 5 and 6 are connected to the inflow port 7 and the outflow port 8 which are the cooling water inflow and outflow ports of the radiator 9. A bypass water channel 10 is formed between the cooling water channels 5 and 6 of the circulating water channel, and a thermostat 12 is disposed near the connection portion between the cooling water channel 5 and the bypass water channel 10.

In such an engine cooling water circulation channel, the engine thermostat 1 that has started warm-up operation
The state of the valve valve body built in 2 is a closed state so that the cooling water does not circulate in the radiator 9 and become supercooled. In order to warm up the engine early, the cooling water is passed through the bypass water passage 10. Circulate. When the warm-up operation is completed and the temperature of the cooling water rises, the valve of the thermostat 12 operates to open the state, and the cooling water moves to the circulating water passage to the radiator 9 and is radiatively cooled by the radiator 9 to radiatively cool the water jacket. It becomes a cycle to 2. The above-described device senses the temperature of the cooling water circulated by the thermostat 12 to operate the valve valve element through the volume expansion and contraction of the wax contained in the thermostat 12 and enclosed therein, thereby cooling the flow rate of the cooling water in the circulating water channel. Is a cooling device of a mechanism for controlling the temperature and controlling the temperature of the cooling water circulated to the water jacket 2.

Further, instead of the thermostat 12 described above, a temperature sensor is arranged in the circulating water passage to detect the cooling water temperature,
The butterfly valve that controls the flow rate of the cooling water and the stepping motor that drives this valve element by operating the detection signal and various operating parameters from the engine by arithmetic processing and operating the butterfly valve in the same manner as described above. An apparatus for controlling the temperature of cooling water is also disclosed in JP-A-5-179948 and the like.

[0006]

In the engine cooling device having the thermostat described above, the volume change of the wax enclosed in the thermostat operates the valve valve element to control the flow rate of the cooling water to control the temperature of the cooling water. For this reason, the control information is limited only to the temperature factor of the circulating cooling water, and it is impossible to control the temperature of the cooling water in consideration of the control information of other factors.

In the cooling device during the warm-up operation of the engine, the valve body of the thermostat is kept closed until the cooling water reaches the set temperature. At this stage, foreign matter is mixed into the thermostat. In the event of malfunction due to mechanical failure or mechanical failure, the valve valve remains closed even if the cooling water reaches the set temperature, the cooling water does not circulate to the radiator, and the temperature of the engine rises, causing overheating. Includes the causal risk.

In order to improve the thermal efficiency of the engine at the time of low rotation and low load such as warm-up operation to reduce fuel consumption, when the set temperature of the thermostat is set so as to raise the engine temperature to the overheat limit, When a sudden load is applied to the engine, the thermostat cannot follow the rapid load, resulting in overheating, which may damage the engine. That is,
It is difficult for a thermostat, which has been generally used in the past, to control the cooling of the engine in accordance with the quick response of the valve valve element that follows the temperature change of the circulating cooling water and the variable operating condition of the engine.

On the other hand, a butterfly valve for arranging a temperature sensor in the circulating water channel to detect the cooling water temperature as a signal and processing the detected signal and various operating parameters from the engine to control it to a predetermined cooling water flow rate and this valve If a device for controlling the temperature of the cooling water is operated by operating a stepping motor that drives the body, the device itself becomes a complicated mechanism and becomes expensive in terms of price.

The present invention has been made in view of the above problems of the prior art, and detects the temperature of the cooling water circulating through the cooling water passage, and processes the signal with various parameters from the engine to determine the operating condition of the engine. It is an object of the present invention to provide an engine cooling device capable of appropriately controlling the cooling water temperature according to the above.

[0011]

In order to achieve the above object, the first feature of the engine cooling control device of the present invention is that the cooling water passages 44a, 44b formed between the water-cooled engine E and the radiator R are provided. 45, a bypass water channel 49 formed from the cooling water channel 44a to the cooling water channel 45, and a flow rate control means for adjusting the flow rate of the cooling water to the radiator R,
Detecting means for detecting the cooling water temperature of the circulating cooling water passage and operation for controlling the operation of the flow rate controlling means in accordance with the cooling water temperature parameter of the circulating cooling water passage by accumulating various operating parameters detected by the engine as the engine operates. And a casing configured to allow the cooling water circulating between the cooling water channels to flow in from an inlet and to flow out from a discharge port, and a flow rate control unit. A valve body that opens and closes a water passage of cooling water; a wax case in which wax is sealed; and a heating element for heating the wax in the wax case,
Lid opening / closing means for transmitting the expansion of the wax in the wax case accompanying the heating by the heating element to the valve element to open / close the valve element, wherein the wax case and the heating element are The casing is arranged at a position separated from the cooling water channel. Also,
A second feature is that the heating element is a cartridge. Further, as a third feature, an electronic element is used as the heating element, a heat absorbing fin is fitted in the wax case, and a heat radiating fin is arranged on the bottom side of the electronic element.

[0012]

Since the present invention is constructed as described above,
It works as follows. The temperature setting of the circulating cooling water is
It is calculated from a table created based on the water temperature at the engine outlet and various parameters detected from the operating engine. Based on the calculated numerical value, the operation control unit gives a control instruction to the flow rate control unit to adjust the flow rate of the cooling water circulating through the engine and the radiator, and adjust the temperature of the cooling water to the set temperature. The flow rate adjusting valve as the flow rate adjusting means,
By heating and cooling the wax contained therein in accordance with the instruction of the operation control means, the valve portion is operated and the flow rate of the cooling water is adjusted.

[0013]

Embodiments of the present invention will be sequentially described below with reference to the drawings from a first embodiment to a third embodiment.

First, FIGS. 2 to 4 show a first embodiment of the present invention, and FIG. 2 is a basic configuration diagram of an engine cooling control device. In FIG. 2, the water-cooled engine E is provided with a water jacket 41 (not shown), which has a cooling water outlet 42 and an inlet 43, and cooling water passages 44a, 44b and 45 between the radiator R and the radiator R. Has been. A bypass channel 49 that bypasses the radiator R is provided between the cooling channel 45 and the cooling channel 44a formed by the outlet 47 of the radiator R and the water jacket 41.
Is provided. In the cooling water passages 44a and 44b formed between the lead-out portion 42 of the water jacket 41 and the inflow port 46 of the radiator R, the flow control valve 13 which is an example of flow control means and the water jacket 41 upstream of the water passage 41 are provided.
A water temperature sensor 14 which is an example of an outlet water temperature detecting means for detecting the outlet water temperature of the engine E is disposed near the outlet 42 of the engine.

FIG. 3 is a cross-sectional view of the flow control valve 13 disposed in the middle of the cooling water passages 44a and 44b. Inside the casing 13a, 13b, a thermoelement portion, a drive portion and a valve portion are provided. Then, the circulating cooling water flows from the cooling water passage 44a into the water supply port 29 formed in the upper portion of the casing 13a, and the discharge port 30 formed on the side portion thereof.
Flow control valve 1 in an open state that flows out to the cooling water passage 44b
3 shows a state in which the pulse control voltage is not applied from the control device (hereinafter abbreviated as ECU) 15 which is an example of operation control means shown in FIG. 2 and described later when the engine is stopped.

A wax case 23 in which a wax 20 which expands and contracts due to a temperature change is enclosed in the thermo element portion.
Is incorporated, and the desired valve closing temperature of the flow control valve 13 and the like can be adjusted by adjusting the wax 20. The PTC heater 21 of the first embodiment of the drive unit is
It is a positive temperature coefficient thermistor and is a heating element that generates heat when energized. A major feature of this heating element is that its resistance value rapidly increases when it reaches a specific temperature. ECU
The wax case 23 is heated by applying the pulse control voltage from 15 to the PTC heater 21. The wax case 23 efficiently transmits the volume change due to the expansion of the wax 20 due to the heating action to the rubber piston 25, the backup plate 38 and the piston 26, so that the piston 26 can be smoothly extended.
Are enclosed via the diaphragm 34. A series of operations from the application of the pulse control voltage to the piston 26 are instantaneously performed, and easily follow the constantly changing load state of the engine.

The end central axis of the valve shaft 27 is inserted into the valve portion at the central end axis of the piston 26, and the other end of the valve shaft 27 is locked to the valve valve body 28. A valve spring 31 is attached to the back surface of the valve valve body 28 between the valve spring 31 and the retainer 35.
In order to prevent the damage of the valve element 28 due to the extension of the valve shaft 27 beyond the limit and the damage of the wax element due to the excessive internal pressure of the wax 20 in the wax case 23, a biasing force is applied to the valve element 28. There is.
Further, a return spring 36 for restoring the expanded piston 26 to the contracted state is provided between the valve seat 37 and the retainer 35.

In FIG. 3, the flow control valve in a state where the pulse voltage from the ECU 15 is not applied to the PTC heater 21 due to operating parameters when the engine load is large, the cooling water temperature is high, and when the engine is stopped. 13, the wax case 23 is not heated by the PTC heater 21, and the valve valve body 28 is restored to the state when the piston 26 is contracted by the urging force of the return spring 36. Cooling water is allowed to flow between the body 28 and the valve seat 37, and a circulating cooling water passage to the radiator R is opened to suppress an increase in cooling water temperature. That is, the flow control valve 13 itself is provided with a so-called fail-safe function to operate the flow control valve in the valve opening direction to prevent overheating when the engine is stopped or the engine cooling control system fails.

FIG. 4 shows a state in which the pulse control voltage is applied to the PTC heater 21 of the flow rate control valve 13 according to the operating parameters when the temperature of the cooling water such as the warm-up operation of the engine is low. Wax 20 applied with control voltage and sealed in wax case 23
2, the valve 28 is extended through the piston 26 and the like, and the cooling water flows in from the cooling water passage 44a and the outflow to the cooling water passage 44b is cut off and regulated by the bypass water passage 49 as shown in FIG. Switch to the detour waterway to. By this action, the temperature of the cooling water is raised early and the thermal efficiency of the engine E is improved.

Incidentally, FIGS. 3 and 4 respectively show a fully open valve,
Although the state where the valve is completely closed is illustrated, the normal operation of the valve 28 is such that the opening and closing operation of the valve 28 is always performed according to the engine load condition and the cooling water temperature regardless of the warm-up operation of the engine E and the normal operation operation. Therefore, the flow rate of the radiator circulation and the bypass circulation is adjusted.

5 and 6, heating means for heating the other wax cases 23 of the second and third embodiments are shown and described below. In the second embodiment shown in FIG. 5, a nichrome wire heater 32 is used as a heating means for the wax case 23, and the wax case 23 is subjected to the same heating action as the PTC heater 21. Since the shape of the nichrome wire heater 32 can be set relatively freely as compared with the PTC heater 21, the heating area of the wax case can be installed in a wider range than heating by using the PTC heater 21 and heat generation can be performed. Since it does not take time, the reaction to the expansion of the wax is accelerated. That is, the responsiveness of the flow control valve 13 itself using the nichrome wire heater 32 can be a flow control valve having a quicker response function as compared with the one using the PTC heater 21.

In the third embodiment shown in FIG. 6, an electronic element 33 is used as the heating and cooling means, and this electronic element 33 is a wax case as the heating element as in the first and second embodiments. At the same time as having a function of acting on 23, it also has a function of a cooling element by energizing the electronic element 33 by reversing the pulse control current from the ECU 15 from the time of heating. The flow control valve 13 having the function of forcibly cooling the wax 20 expanded by heating enhances the responsiveness of the flow control valve itself. In addition, in order to enhance the cooling capacity and the heat radiation effect of the electronic element 33, the heat absorbing fins 50 are fitted in the wax case 23, and the heat radiation fins 5 are provided on the bottom side of the electronic element 33.
1 is provided.

Next, a control device (E as an operating means for driving and controlling the flow rate control valve 13 which is the above-mentioned flow rate controlling means).
The CU) 15 will be described. The ECU 15 corresponds to the brain of each system detected from the vehicle and includes an input interface circuit, an A / D converter, an output interface circuit, a memory, a CPU, etc. (none of which is shown). The water temperature detected by the water temperature sensor 14 arranged in the cooling water passage 44a near the engine outlet, and the operating parameters 16 such as the engine speed indicating the load state of the engine and the intake pipe negative pressure are measured by respective sensors (none of which is shown). Detect and input to the input interface circuit, EC
The predetermined cooling water set water temperature is searched from the water temperature setting table provided in the memory of U15 in advance, and the pulse control voltage is output from the interface circuit PT so that this set water temperature is reached.
C heater 21, electronic element 33, nichrome wire heater 3
Output to 2 and control.

Here, when the application of the pulse control voltage is illustrated by using the operating parameter 16 of the engine speed N and the intake pipe negative pressure P, the engine speed N and the intake pipe negative pressure P are stored in the memory of the ECU 15. Table table of the desired cooling water set temperature Ts is stored, and the temperature deviation ΔT from the cooling water temperature Tm detected by the water temperature sensor 14 is stored.

## EQU00001 ## A control table map of proportional duty value P (%) value and integral duty value I (% / sec) value, which is a wax driving control pulse that can be optimally controlled for .DELTA.T = Ts-Tm, is stored. Let

The engine cooling apparatus according to this embodiment has the above-mentioned mechanism, and the subroutine for the water temperature setting process will be described below with reference to the flowchart of FIG.

First, in step 1, the operating parameters 16 detected by the respective sensors such as the engine speed N and the intake pipe negative pressure P, which indicate the operating condition when the engine E is started.
Start loading. After completion, move to step 2,
Based on these operating parameters, a predetermined cooling water set water temperature Ts is searched and set from a table map of the engine speed N, intake pipe negative pressure P, etc. stored in the memory unit of the ECU 15.

When the setting is completed, in step 3, the cooling water temperature parameter Tm from the water temperature sensor 14 is read. Then, in step 4, the temperature deviation ΔT is set to ΔT = Ts− from the cooling water set temperature Ts and the cooling water temperature parameter Tm.
Calculation processing is performed by Tm. Further, in step 5, the P (%) value and I (% /
sec) value is retrieved from the control table map to form a control pulse consisting of these two duty values P (%) value and I (% / sec) value.

In step 6, the cooling water set temperature Ts is compared with the cooling water temperature parameter Tm. If the cooling water set temperature Ts is higher than the cooling water temperature parameter Tm, the subroutine proceeds to step 7 and the flow control valve 13 PT
The C heater 21 or the nichrome wire heater 32, which is the heating means of the second embodiment, is applied and heated. Note that step 9 is a case where the electronic element 33 which is the heating means of the third embodiment described with reference to FIG. 6 is used, and is applied and heated similarly to step 7.

When the cooling water temperature parameter Tm is higher than the cooling water set temperature Ts in the comparison of step 6, the subroutine is shifted to steps 8 and 10, and in step 8, the PTC heater 21 or the nichrome wire heater 32 is used. Application to the wax case 23
Is naturally cooled, the piston 26 is retracted, the valve 28 is opened, and the flow rate of the circulating cooling water is adjusted. Step 10 is a case where a current in the opposite direction to that of step 9 is applied to the electronic element 33 of the third embodiment, but by reversing the current direction of the control pulse for heating and applying it to the electronic element 33. It is driven as a cooling element. The flow rate control valve 13 is provided with a function with excellent responsiveness that easily follows the constantly changing load state of the engine.

Through the above subroutine, the flow control valve 1
After the control of step 3 is completed, the process returns to step 1 again and the flow rate control valve 13 is controlled based on the same control sequence as described below to adjust the flow rate of the cooling water flowing into the radiator R to control the cooling water temperature to a predetermined set temperature. , Makes it possible to operate the engine efficiently.

[0031]

As described above, the engine cooling control device according to the present invention has the following effects.
The engine outlet water temperature and various parameters detected along with engine operation are calculated by the control device so that the circulating cooling water will have a water temperature according to the load condition of the engine, and the flow rate of the cooling water will be adjusted based on the set value. To control. As a result, the engine cooling effect is improved and
Fuel efficiency can be reduced as the engine thermal efficiency improves. Moreover, since the flow control valve is opened when the engine is stopped, it is possible to prevent overheating due to a failure of the flow control valve. Further, the heating and cooling means of the electronic element act on the control instruction from the control device on the wax as a drive unit built in the flow rate control valve, thereby adjusting the water temperature by adjusting the flow rate of the cooling water according to the load state of the engine. Is possible. Since it is a device that uses the change in the volume of the wax, the flow control mechanism can be simplified and the cost of the cooling control device can be reduced when compared to a device that uses a butterfly valve or step motor. Is possible.

[0032]

[Brief description of drawings]

FIG. 1 is a configuration diagram of an engine cooling control device according to a conventional technique.

FIG. 2 is a basic configuration diagram of an engine cooling control device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of the flow control valve according to the first embodiment of the present invention in an open state.

FIG. 4 is a sectional view of the flow control valve according to the first embodiment of the present invention in a closed state.

FIG. 5 is a sectional view of a flow control valve incorporating a nichrome wire heater according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a flow control valve incorporating an electronic device according to a third embodiment of the present invention.

FIG. 7 is a flowchart of cooling control according to the embodiment of the present invention.

[Explanation of symbols]

13 Flow control valve 14 Water temperature sensor 15 Control device 16 Operating parameters 20 wax 21 PTC heater 23 wax case 24 semi-liquid 26 pistons 32 Nichrome wire heater 33 Electronic device 44a Cooling channel 44b Cooling channel 45 Cooling channel 49 Bypass waterway 50 cooling fins 51 radiation fin E engine R radiator

Continuation of the front page (56) References JP-A-60-65215 (JP, A) JP-A-5-231148 (JP, A) JP-A-4-73473 (JP, A) Actual development Sho-61-132431 (JP , U) Actual development 64-56527 (JP, U) Actual development 4-64682 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F01P 7/16 F16K 31/68

Claims (3)

(57) [Claims] 1. A cooling water passage 44a, 44b and 45 formed between a water-cooled engine E and a radiator R, and a bypass water passage 4 formed from the cooling water passage 44a to the cooling water passage 45.
9, a flow rate control means for adjusting the flow rate of the cooling water to the radiator R, a detection means for detecting the cooling water temperature of the circulating cooling water passage, and various operating parameters detected by the engine as the engine is operated, and the circulating cooling water passage is integrated. And an operation control means for controlling the operation of the flow rate control means in accordance with the parameter of the cooling water temperature, wherein the flow rate control means is such that the cooling water circulating between the cooling water channels flows in from the inflow port and flows out from the ejection port. A casing configured to do so, a valve body that opens and closes a water passage of cooling water from the inflow port to the discharge port of the casing, a wax case in which wax is sealed, and the wax sealed in the wax case is heated. And an expansion of the wax in the wax case due to heating by the heating element for transmitting to the valve element to open and close the valve element. A cooling control device for an engine, comprising: a lid opening / closing means, wherein the wax case and the heating element are arranged at positions separated from a water channel of cooling water in the casing. 2. The engine cooling control device according to claim 1, wherein the heating element is configured as a cartridge. 3. An electronic element is used as the heating element, a heat absorbing fin is fitted in the wax case, and a heat radiating fin is arranged on the bottom side of the electronic element. The engine cooling control device according to 1 or 2.