JPH01237315A - Cooling water control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To make it possible to control water temperature with high responsiveness by providing, in a cooling water circulating system a variable water pump, whose discharged amount can be changed by means of adjusting the effective width of fins on a variable impeller, and adjusting the effective width according to a deviation between a detected water temperature and the set water temperature. CONSTITUTION:A variable water pump 4, which is interposed in the middle of the cooling water circulating system of an engine, has a rotary base body 7 which is fixed to one end of a rotary shaft 6 and an adjusting board 9 which rotates integrally with the rotary base body 7 and which is freely movable in the axial direction by an actuator 10. The rotary base body 7 is formed approximately in a disk shape, and has an impeller 11 to which plural fins 111 are annularly arranged. Effective width of fins 111, that is, discharged amount of the pump can be changed by inserting/ detaching a covering part 14 on outer peripheral side of the adjusting board 9 in/from the respective fins 111. The actuator 10 is activated by negative pressure which is adjusted according to a deviation between a detected value of cooling water temperature and its set value.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a device for controlling water temperature in a cooling water circulation system of an internal combustion engine, and particularly to a device for controlling water temperature by the discharge amount of a water pump.

(Prior Art) Cooling water in a cooling water circulation system of an internal combustion engine is circulated by a water pump, which operates to absorb heat from the engine body during circulation and release it to the atmosphere through a radiator. By the way, in a conventional cooling water circulation system, the flow rate of the cooling water increases or decreases depending on the engine speed, and the heat radiation characteristics also change. For this reason, during warm-up when the cooling water temperature is low, the thermo valve is closed to prevent heat radiation.
When warm-up is complete, the thermo valve is opened to ensure heat dissipation and maintain the engine at a steady temperature.

(The problem that Rimei is trying to solve) In this way, in conventional equipment, the water pump is driven directly by the engine's crankshaft, so its discharge amount is proportional to the engine rotation speed, and when the water pump is warmed up, the cooling water is This interferes with the heating process and wastes the engine's output. Moreover, when the vehicle is driven at low speed after warming up, heat dissipation performance tends to decrease.

For this reason, it is necessary to increase the pump capacity or keep the pump rotation relatively high, which also causes output loss.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling water control device for an internal combustion engine that can maintain the engine body at an appropriate temperature at all times without increasing output loss.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a variable impeller that is installed in the cooling water circulation system of an internal combustion engine and that changes the discharge amount by increasing or decreasing the effective width of the fins on the variable impeller. a water pump, an actuator that increases or decreases the effective width of the fins, a water temperature sensor that outputs water temperature information of the cooling water circulation system, a water temperature setting means that sets a target water temperature of the cooling water circulation system, and a current cooling water circulation system. and pump control means for operating the actuator to correct the water temperature to the target water temperature.

(Function) The pump control means receives the target water temperature from the water temperature setting means, determines the deviation between this value and the current water temperature, and adjusts the effective width of the fins of the variable impeller to the actuator so as to reduce this deviation. You can increase or decrease the value via .

(Example) Figure 1 shows the overall configuration of a cooling water control device for an internal combustion engine. This cooling water control device includes a cooling water circulation system R that follows a water jacket (not shown) in the engine body 1 of the engine E, and this cooling water circulation system is formed by a water pipe 2, a radiator 3, and a variable water pump 4. has been done.

Here, the cooling water circulation system R does not include a thermo valve, and the flow of cooling water is controlled by a variable water pump 4 externally attached to the engine.

As shown in FIG. 3, the variable water pump 4 includes a casing 5, which includes a rotating shaft 6, a rotating base 7 fixed to one end of the rotating shaft, and an adjustment board 9 that rotates integrally with the rotating base 7. , is provided with an actuator 10 that moves this adjustment board 9 in the axial direction Y, and an input rotating body 8 is fixed to the other end of the rotating shaft 6. This input rotating body 8 fixes a pulley (not shown), which is directly connected to the crankshaft of the engine via a belt.

The rotating base 7 has a substantially disk shape, and the impeller 11 has a plurality of fins 111 arranged in an annular shape (see FIG. 4), with each fin 111 protruding in the axial direction Y.

A cylindrical portion 13 of the adjustment board 9 is fitted into the boss 12 at the center of the rotating base 7 so as to be slidable in the axial direction Y. A plurality of long grooves 15 are formed in the cover portion 14 on the outer peripheral side of the cylindrical portion 13, through which the respective fins 111 are inserted (see FIG. 6).

The cylindrical portion 13 is connected to the actuator 10 via a pin 16 that is long in the axial direction Y. This actuator 10 is
iI! due to the balance between the engine manifold negative pressure applied to the diaphragm 17 and the pressing force of the spring 18! I leveling 9
Move and hold in the alignment axis 9 direction Y. Here, when the negative pressure is small, the adjustment plate 9 reaches the maximum position P1, and when the negative pressure is large, the adjustment plate 9 reaches the minimum position P2. At this maximum position P1, fin 1
11 effective @ (amount of protrusion from the long groove 15) is maximum,
The pump discharge amount also becomes maximum, and conversely, at the minimum position P2, the fin effective width becomes zero, and the pump discharge amount also becomes zero,
At this time, the rotating base 7 and the adjustment board 9 rotate idly.

A negative pressure pipe 32 that transmits engine manifold negative pressure to the actuator 10 is connected or disconnected by a solenoid valve 19 . A controller 20 including a solenoid valve drive circuit 31 is connected to the solenoid valve 19 .

As shown in FIG. 2, the main parts of the controller 20 are formed by a microcomputer, and this input boat includes a crank angle sensor 21 that outputs engine speed information, a water temperature sensor 22 that outputs cooling water temperature information, and an intake air sensor. Air flow sensor 23 that outputs volume information, intake temperature sensor 24 that outputs intake temperature information, atmospheric pressure sensor 25, and humidity sensor 2
6. A knock sensor 27 etc. that outputs engine knock information is connected.

The CPU 28 of this controller includes a water temperature setting means 29 that sets a target water temperature T aim of the cooling water circulation system R, and a pump control means 30 that operates the actuator 10 to correct the current water temperature of the cooling water circulation system R to the target water temperature Ta1m. Equipped with the following functions.

Here, the water temperature setting means 29 receives intake air amount information A/N from each output of the crank angle sensor 21 and the air flow sensor 23.
is calculated, the rotational speed information N is taken in, the reference water temperature Tb is calculated from the data map shown in FIG. 6, the intake air correction value Tat is calculated from the intake air temperature data map shown in FIG.
Calculate the atmospheric pressure correction value Tap from the atmospheric pressure data map shown in the figure, calculate the knock correction value Tnk from the knock integral value data map shown in Fig. 9, calculate the humidity correction value Thu from the humidity data map shown in Fig. 10, and then , target water temperature Ta1m
is calculated from the following formula.

Taim=Tb+Tat+Tap+Tnk+Thu Next, the pump control means 30 calculates the difference ΔT between the current water temperature Tw and the target water temperature Ta1m, and the water temperature difference between this time and the previous time 5 seconds ago is ΔT/dt=Tv- Find T v ゛. Further, a corrected duty value ΔDUT is obtained from the data map shown in FIG. 11, the current DUTY value is rewritten by adding the corrected duty value ΔDUT value, and then the solenoid valve 19 is driven by the duty value DUTY.

Here, a valve drive routine and a valve stop routine for driving the electromagnetic valve will be explained with reference to FIGS. 12 and 13.

The valve drive routine is executed by a 50m5 timer interrupt, and the valve stop routine is executed by a 1ms timer interrupt.

That is, every 50m5, the solenoid valve is turned on and the counter CO
A DUTY value of 1/2 is set for U N T d.

This counter is decremented by 1 until the value reaches zero, and during this time the solenoid valve is opened.

At this time, the actuator is actuated by an amount corresponding to the negative pressure value to slide the adjustment panel, and the adjustment panel is moved between the maximum position P1 and the minimum position P1.
Hold between 2 and 3. As a result, the pump operates with a discharge amount corresponding to the effective width of the fins, circulating cooling water,
Bring the temperature of the cooling water closer to the target water temperature T aim. When the counter C0UNT reaches zero, the solenoid valve is turned off and the process returns.

The main routine shown in FIG. 14 will now be explained.

First, in step a1, water temperature information is taken in and the current water temperature Tw is determined. Then, it is determined whether or not this value Tw is within the normal value range, and if it is abnormal, the duty value DUTY is rewritten to O in step a3 and the process returns. If the value is normal, the process proceeds to step a4, where abnormality is determined from the output of the air flow sensor. If abnormal, the process proceeds to step a5, the target water temperature Ta1m is set to 75° C., and the process proceeds to step a7, and if normal, the process proceeds to step a6. Here, intake air amount information A/N is calculated, rotation speed information N is taken in, and reference water temperature Tb is determined. Furthermore, intake correction value Tat, atmospheric pressure correction value Taρ, knock correction value Tnk, and humidity correction value Th
Take in u, find the target water temperature T aim from the following formula, and input it into the predetermined area.

Taim=Tb+Tat+Tap+Tnk+Thu When step a7 is reached, the water temperature deviation ΔT, which is the difference between the current water temperature TII+ and the target water temperature T aim, is determined, and further,
Water temperature difference between this time and the previous time 5 seconds ago ΔT/dt=Tω−Tw
”.Furthermore, from these two values, the corrected duty value Δ
DUTY is determined as F (8T, ΔT/dt) from the data map shown in FIG. 11, the corrected duty value ΔDUTY is added to the same value as the duty value DUTY, the process is rewritten, and the process returns.

In this way, this internal combustion engine cooling water control device determines the target water temperature T ain+ according to the operating state of the engine, calculates the deviation ΔT between this value and the current water temperature Tt+, and cancels this deviation. In order to dissipate heat from the cooling water, the discharge amount of the variable water pump 4 is controlled to control the water temperature.

Therefore, the pump discharge amount can be set to zero during warm-up, preventing output loss, shortening warm-up time, reducing fuel consumption, improving exhaust gas performance early, and improving heater performance. Moreover, since a thermovalve is not used, the flow path resistance of the discharge path of the pump is reduced, making it easy to increase the discharge amount, and as a result, it is easy to reduce the capacity of the pump. Furthermore, by abolishing the thermo valve, the fluidity of the cooling water in the water jacket of the engine body has been improved, and by accurately controlling the water volume, the capacity of the radiator and water jacket can be reduced, and the size of the engine has been reduced. It is also excellent in securing space. Furthermore, the cooling performance can be sufficiently improved during high load operation at low speeds and medium speeds, and the output of the engine can be improved.

(Effects of the Invention) According to the present invention, the variable water pump is operated to correct the current cooling water temperature to the target water temperature, and the discharge amount of this pump is increased or decreased from zero to the maximum flow rate. By optimizing the discharge channel, the temperature of the cooling water can be increased or decreased with good responsiveness, and in particular, unnecessary output loss can be reduced, and the pump capacity can be easily reduced.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of a cooling water control device for an internal combustion engine as an embodiment of the present invention, Fig. 2 is a functional block diagram of the controller of the same device, and Fig. 3 is a variable water pump used in the above device. 4 is a plan view of the rotating base of the pump, FIG. 5 is a bottom view of the adjustment panel of the pump, and FIG.
Figures 1 to 11 are different data maps built into the same controller as above, and are characteristic diagrams for determining the basic water temperature, intake temperature correction value, atmospheric pressure correction value, knock correction value, humidity correction value, and correction duty value, respectively; 12 and 13 are flowcharts of a valve drive routine and a valve stop routine executed by the controller, and FIG. 14 is a flowchart of the main routine executed by the controller. 10... Actuator, 11... Invera, 20
...Controller, 22...Water temperature sensor, 29...
・Water temperature setting means, 30... Pump control means, 31...
・Solenoid valve, E...Engine, R...Cooling water circulation system. Fig. 11 Fig. 12 Fig. 13 Fig. 14 Main routine Interrupt every 5 seconds Water temperature information A/F conversion → Tv a2 YES Tv Abnormal or N. ES a4 Afro sensor abnormality N. Target water temperature UTY4-075℃ a 6 Ta1m 4-T b (A/N, N) +Tat +Tap +Tnk 10Thu

Claims (1)

[Claims] A variable water pump that is attached to a cooling water circulation system of an internal combustion engine and that changes the discharge amount by increasing or decreasing the effective width of fins on a variable impeller; an actuator that increases or decreases the effective width of the fins; It has a water temperature sensor that outputs water temperature information, a water temperature setting device that sets a target water temperature of the cooling water circulation system, and a pump control device that operates the actuator to correct the current water temperature of the cooling water circulation system to the target water temperature. cooling water control system for internal combustion engines.