JPS6334287B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling control device for a water-cooled internal combustion engine.

In general, the appropriate cooling water temperature for each part of a water-cooled internal combustion engine must be set at a low level in the cylinder head to prevent abnormal combustion caused by knocking, for example, and in the cylinder block. It is necessary to maintain a high level at all times in order to reduce the sliding resistance between the piston and cylinder or the bearing loss of the crankshaft. however,
In conventional water-cooled internal combustion engines, a thermovalve that operates in response to the temperature of the cooling water establishes communication between the cooling water circulation circuit, which is provided to flow through the cylinder block to the cylinder head, and the cooling circuit that includes a radiator. The temperature of the engine is controlled as a single block. Therefore, it is extremely difficult to independently control each part of the engine at the appropriate temperature, which tends to cause knocking, and the viscosity of the lubricating oil becomes inappropriate, causing the crankshaft, piston, and camshaft to There are problems such as severe wear of each sliding member.

In order to deal with the above-mentioned problems of the conventional device, the present invention is designed to control the flow rate of cooling water cooled by a radiator and circulating through a cooling circuit in accordance with the operating state of the engine, in accordance with the temperature of the cooling water in the cooling circuit. The purpose is to

In order to achieve the above object, the present invention provides a cooling water circuit that connects the water pump, cylinder block, cylinder head, and radiator and circulates cooling water, and also connects the water pump's suction side and the engine. In addition to providing an engine bypass circuit connected to the outlet side of the engine, that is, the cylinder head, there is also a switching valve that selectively controls the opening and closing of either the main cooling water circuit or the engine bypass circuit. A throttle valve is installed to adjust the flow rate of cooling water when the water circuit is opened, and a temperature detection device detects the engine temperature, and a signal from the temperature detection device controls the operation of the switching valve and throttle valve. The switching valve and the throttle valve are integrated into one body.

With the above configuration, in the present invention, it is possible to appropriately control the cooling temperature of each part of the engine to enable optimal combustion according to the engine load, and to suppress the occurrence of the above-mentioned knocking and wear of the sliding parts. As a result, it is possible to improve fuel efficiency. In particular, in the present invention, the switching valve and the throttle valve are integrally configured to reduce manufacturing costs, and the number of water pumps is reduced to one, thereby reducing horsepower consumption. Furthermore, the piping length of the cooling water circuit is made as short as possible to reduce heat dissipation loss and cooling loss.

An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, a main cooling water circuit 10 is shown that connects the water pump WP, the cylinder block E ₁ of the engine E, the cylinder head E ₂ , and the radiator R.
is pumped by water pump WP to radiator R
Cooling water is circulated. The engine bypass circuit 11 connects the suction side of the water pump WP to the outlet side of the engine, that is, the cylinder head E2, and the second bypass circuit ₁₂ connects the discharge side of the water pump WP to the cylinder head _E2 . It is located in The on-off switching valve V ₁ selectively controls the opening and closing of either the main cooling water circuit 10 or the engine bypass circuit 11. In FIG. Shows closed state. The throttle valve V ₂ , which is integrally configured with the switching valve V ₁ , is connected to the main cooling water circuit 1 when the engine bypass circuit 11 is closed.
0 is opened, the flow rate of cooling water flowing through the main cooling water circuit 10 is adjusted stepwise or continuously. Here, the integrated structure of the switching valve V ₁ and the throttle valve V ₂ will be explained later based on FIG. 2. The throttle valve V ₃ arranged in the second bypass circuit 12 is
2nd from water pump WP to cylinder head E ₂
This controls the flow rate of cooling water that directly flows in through the bypass circuit. Note that a cooling fan F and a shutter ST are attached to the radiator R.

Now, when implementing the above embodiment, the switching valve V ₁ , throttle valve V ₂ ,
V ₃ , water pump WP, cooling fan F motor
The operation of actuator A of FM and shutter ST is controlled. In this case, the electronic control circuit 20
As input _signals , water temperature sensors _{S1 ,}
A signal representing the temperature of the cooling water detected by S ₂
D ₁ , D ₂ , signal D 3 representing vehicle speed detected by a known vehicle speed sensor S ₃ , _signal D ₄ representing manifold negative pressure detected by negative pressure sensor S ₄ provided in the intake manifold of engine E, cylinder Signals D ₅ and D ₆ representing the water pressure of the cooling water detected by pressure sensors S ₅ and S ₆ mounted on the block E ₁ and cylinder head E ₂ , respectively, and the voltage of the on-board battery detected by the sensor S ₇ . , and is configured to output the control signal according to these input signals D ₁ to _{D 7 .}

Note that A/D in the figure indicates an analog-to-digital converter, and a speed change circuit is disposed between the electronic control circuit 20 and the motor FM of the cooling fan F.

VSV ₁ to VSV ₃ indicate electromagnetic valves that apply negative pressure from a negative pressure source VS to each of the valves V ₁ , V ₂ , V ₃ and actuator A in accordance with the control signal.

That is, the electronic control circuit 20 is configured to execute the following control program.

First, when warming up the engine, selector valve _V1
operates to close the main cooling water circuit 10 and open the engine bypass circuit 11, and the throttle valve _V3 operates to close the main cooling water circuit 10 and open the engine bypass circuit 11, and the
A control signal that operates to completely throttle and close the opening of the bypass circuit 12 is output. Thereby, the cooling water circulates through the engine E not through the radiator R but through the engine bypass circuit 11.

Next, when the engine cooling water temperature rises and shifts to normal driving, the switching valve V ₁ closes the engine bypass circuit 11 and opens the main cooling water circuit 10, and the throttle valve V ₂ closes the engine bypass circuit 11 and opens the main cooling water circuit 10. outputs a control signal that operates to control the temperature and adjust the flow rate of cooling water. As a result, although the cooling water flows through the radiator R, it becomes possible to suppress the flow rate of the cooling water to the necessary minimum using the throttle valve _V2 .

Additionally, during overload operation, if a temperature rise occurs in the cylinder head _E2 due to abnormal combustion due to knocking, for example, the throttle valve _V2 adjusts the opening degree of the second bypass circuit 12 to circulate the cooling water. It outputs a control signal that operates as follows. As a result, the cooling water circulating through the cylinder head _E2 is delivered from both the main cooling water circuit 10 and the second bypass circuit 12. The cylinder head _E2 is therefore properly cooled. Here, an on-off valve for controlling opening and closing of the circuit may be installed in the second bypass circuit 12 instead of the throttle valve V ₂ to control the flow of cooling water flowing through the bypass circuit 12.

FIG. 2 shows a control valve device 50 that integrates the switching valve V ₁ and the throttle valve V ₂ described above. The device 50 includes a first body 52 with a first output port 51 and a second body 54 with an input port 53.
and a third body 56 having a second output port 55.
and a fourth body 58 having a negative pressure input port 57.
A housing is formed by integrally combining the two. The first output port 51 is connected to the engine bypass circuit 11, the second output port 55 is connected to the inlet side of the radiator R, the input port 53 is connected to the outlet side of the engine E, that is, to the cylinder head _E2 side, and the negative pressure input port 57 is not shown. The intake manifolds of the engine E are connected to each other through control valves that do not include the intake manifolds of the engine E. That is, the input port 53 and the first output port 51
A passage 59 communicating between the input port 5 and the input port 5 constitutes a part of the engine bypass circuit 11.
3 and the second output port 55.
constitutes a part of the main cooling water circuit 10. A diaphragm 61 is disposed inside the fourth body 58, and a negative pressure chamber 62 is formed by the diaphragm 61. The negative pressure chamber 62 is connected to the intake manifold from the negative pressure port 57 via a negative pressure signal control valve (not shown). It's communicating. This negative pressure signal control valve is
The electronic control circuit 20 controls the negative pressure from the intake manifold.
The negative pressure supplied to the negative pressure chamber 62 is controlled according to the signal from the negative pressure chamber 62. The diaphragm 61 is always urged downward in the drawing by springs 63 and 64.
One end of a transmission rod 65 is fixed to the diaphragm 61 so that it can move up and down integrally. A valve chamber 66 is formed within the second body 54, and the other end of the transmission rod 65 projects into the valve chamber 66. The first valve 67 disposed in the valve chamber 66 controls communication between the input port 53 and the first output port 51, and when the transmission rod 65 is displaced upward, it moves from the position where the illustrated passage 59 is closed. , is lifted by a screw member 68 fixed to the transmission rod 65 to open the passage 59. When the transmission rod 65 is further displaced downward from the illustrated state, the small diameter portion 6 of the transmission rod 65
5a and the first valve 67 perform a relative movement, that is, the small diameter portion 65a of the transmission rod 65 slides through the shaft hole of the first valve 67, and the first valve 67 holds the passage 59 in a closed state. On the other hand, the second valve 69 is fixed to the transmission rod 65 and is vertically displaced together with the rod 65. The second valve 69 controls the communication between the input port 53 and the second output port 55, that is, controls the opening and closing of the passage 60, and adjusts the degree of opening, that is, the cross-sectional area of the passage 60. A spring 70 is interposed between the two valves 69 and 67; one end of the spring 70 is held by the second valve 69, and the other end of the spring 70 constantly urges the first valve 67 downward.

The operation of the control valve device 50 will be explained based on the operation shown in FIG. First of all,
When the engine is warmed up, negative pressure is introduced into the negative pressure chamber 62, and the transmission rod 65 is displaced upward in the figure together with the diaphragm 61. At this time, transmission rod 6
The second valve 69 fixed to the transmission rod 65 closes the passage 60 and is held in the closed position, while the first valve 67 is displaced upward against the biasing force of the spring 70 by the threaded member 68 fixed to the transmission rod 65. It is held in its open position and passageway 59 is opened. As a result, the input port and the first output port 51 will communicate with each other,
The cooling water circulates through the engine bypass 11 without going through the radiator R.

Next, when the temperature of the cooling water rises and reaches the normal running time of the engine, the degree of negative pressure supplied from the intake manifold becomes low, and the degree of negative pressure in the negative pressure chamber 62 decreases. Therefore, the diaphragm 61 is displaced downward by the urging force of the springs 63 and 64, and at the same time, the transmission rod is also displaced downward. As a result, as shown in the figure, the second valve 69 is held in the open position, and at the same time, the first valve 67 is held in the closed position by the biasing force of the spring 70. Therefore, since the input port 53 and the second output port 55 communicate with each other, the cooling water is circulated through the main cooling water circuit 10. At this time,
The degree of negative pressure supplied to the negative pressure chamber 62 is controlled in response to the temperature of the cooling water. The amount of displacement of the transmission rod 65 is determined according to the degree of negative pressure, and the opening degree, that is, the cross-sectional area of the passage 60 is controlled. Therefore, the main cooling water circuit 10
The flow rate of cooling water flowing through is controlled. As described above, the small diameter portion 65a of the transmission rod 65 is connected to the first valve 6.
7, the transmission rod 65 can freely move vertically in response to the magnitude of the negative pressure input to the negative pressure chamber 62 while the first valve 67 is held in the closed position shown in the figure. be.

In this way, the control device 50 is a device that has the functions of both the switching valve V ₁ and the throttle valve V ₂ shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention;
FIG. 2 is a sectional view showing an embodiment of a control valve device in which the switching valve V ₁ and the throttle valve V ₂ in FIG. 1 are integrated. WP...Water pump, E...Engine, E ₁
...Cylinder block, _E2 ...Cylinder head,
R...Radiator, 10...Main cooling water circuit, 11
...Engine bypass circuit, V ₁ ...Switching valve, V ₂
... Throttle valve, 30 ... Electronic control device, 50 ... Control valve device, 67 ... First valve, 69 ... Second valve.

Claims (1)

[Claims] 1. A main cooling water circuit that connects the water pump, cylinder block, cylinder head, and radiator of the internal combustion engine and circulates cooling water, and an engine that connects the water pump's suction side and the cylinder head, that is, the engine outlet side. a bypass circuit, an on-off switching valve that selectively controls opening and closing of either the main cooling water circuit or the engine bypass circuit, and a flow rate of cooling water when the main cooling water circuit is opened due to the operation of the switching valve. a throttle valve that adjusts the temperature in stages or continuously; a temperature detection device that detects the temperature of the cooling water circulating between the cylinder block and the cylinder head; and a signal from the temperature detection device that controls the on-off switching valve and the throttle valve. 1. A control device for a water-cooled internal combustion engine, comprising a control device for controlling the operation of a water-cooled internal combustion engine, wherein the on-off switching valve and the throttle valve are integrally configured.