JPH0422030Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention connects an engine body and a radiator with a lead-out waterway and an inlet waterway so that cooling water can circulate, and a are connected by a bypass waterway, and an on-off valve is installed at the branch of the outlet waterway.
The present invention relates to an engine cooling water temperature control device that includes a water pump at the confluence of introduction waterways.

[Prior Art] As shown in FIG. 3, for example, in this known engine cooling water temperature control device, cooling water from a water pump 30 is passed through an introduction waterway 25 to a cylinder block 21 constituting the engine body. It flows into the cylinder head 22, which also constitutes the engine body, and cools the engine block and the cylinder head 22. The cooling water heated by the engine body is then transferred to the thermostat 28.
It flows into the radiator 23 from the outlet waterway 24 through the outlet waterway 24 . The cooling water cooled by the radiator 23 is then pressure-fed to the introduction waterway 25 from the water pump 30. Normal engine coolant temperature is for example 80℃~86
℃, and below the set temperature, the thermostat 28 is closed, so that the cooling water from the cylinder head 22 flows through the thermostat 28.
The water is sucked into the water pump 30 through a bypass waterway 26 branched from a branch portion 27 of the water pump 30 . When the temperature of the cooling water exceeds the set temperature, the thermostat closes the bypass water passage 26, so that the cooling water flows to the radiator 23 and is cooled.

However, especially in winter or in cold regions, if the cooling water is circulated through the bypass waterway in this way, the cooling water in the bypass waterway 26, water pump 30, and introduction waterway 25 must also be heated. 24 and cylinder head 22 takes time. For example, Utility Model Application No. 59-140079 filed by the present applicant proposed a technique for controlling the opening/closing valve of a branch section of a bypass waterway using outside air sound, thereby promoting warm-up and preventing overheating.

However, in warm-up operation, the purpose can basically be achieved by first warming up the engine body and then heating the cooling water temperature of the engine body to a predetermined temperature, but with conventional technology, warming up the bypass passage etc. Since the cooling water was being heated unnecessarily, the warm-up time was inevitably longer.

In addition, in the known technology described in Japanese Utility Model Publication No. 48-44491, the thermostat is simply opened and closed depending on the water temperature, so when the temperature exceeds a predetermined temperature,
The thermostat opens and as a result the cooling water in the lines passes through the radiator, increasing the warm-up time. For this reason, if the predetermined temperature is increased, the cold water in the pipe will temporarily cool the engine rapidly when the thermostat is opened, which is undesirable.

[Problem to be Solved] Therefore, the purpose of the present invention is to provide an engine cooling method that can shorten the warm-up time as much as possible and also prevent cold cooling water from suddenly flowing into the engine after the engine has been warmed up. We are in the process of providing equipment.

[Means for Solving the Problems] According to the present invention, the engine body and the radiator are connected by a lead-out waterway and an introduction waterway so that cooling water can circulate, and the lead-out waterway and the introduction waterway are connected by a bypass waterway. In the engine cooling water temperature control device, the engine cooling water temperature control device is provided with an on-off valve at a branch part of the outlet waterway and a water pump at a confluence part of the introduction waterway,
A valve and a valve driving means for opening and closing the valve are provided in the bypass waterway, a temperature sensor is provided on the upstream side of a branch part of the outlet waterway, and the valve driving means is controlled in response to the temperature detected by the temperature sensor. A control device is provided to control the opening degree of the valve.

[Explanation of effects] Therefore, when starting warm-up operation, since the cooling water temperature is low, the water temperature in the water conduit from the cylinder head is low, and the temperature sensor detects this low water temperature, and the bypass water valve is activated. is closed. Since the thermostat is also closed as in the conventional case, the outlet waterway is in a closed state, so that the cooling water in the cylinder block and cylinder head does not flow. Therefore, the amount of water discharged by the water pump is zero, and the driving horsepower of the water pump is also relatively small. Then, when the engine body is warmed up and reaches a predetermined temperature lower than the temperature at which the thermostat opens, the control device receives a signal from the water temperature sensor and operates the valve drive means to open the valve in accordance with the water temperature, so the water temperature is low. Only a small amount of time flows. Therefore, only the amount of water flows into the cylinder block and cylinder head at first, and the problem of rapid cooling of the engine body does not occur. In this way, as the water temperature rises, the hull gradually opens, so the water temperature in the circulation system, that is, the bypass waterway and the water pump introduction waterway, rises one after another.

When the temperature of the water in the circulation system rises sufficiently due to sufficient warming up, the thermostat opens as in conventional operation.

In this way, since the cooling water for only the engine body is heated at the beginning of warm-up operation, the warm-up time is short, and during that time, the driving horsepower of the water pump is also small, so fuel consumption can be reduced. Furthermore, since cooling water does not circulate, friction loss can also be reduced.

As described above, according to the present invention, the valve installed in the bypass waterway opens and closes depending on the water temperature, so the water in the bypass waterway, water pump, and introduction waterway gradually becomes hotter, so there is no adverse effect on the engine and it is possible to warm up the engine. Able to drive.

Furthermore, even when the coolant temperature is low in a cold region during low load or low rotation, for example, the coolant is not circulated, which improves engine efficiency and prevents so-called overcooling. Also, during normal operation, cooling water circulates through the radiator, so
Of course, no overheating occurs.

[Example] An example of the present invention will be described below with reference to FIG. In FIG. 1, 1 is an engine block, 2 is a cylinder head, and 3 is a cooling radiator. The cylinder head 2 and the radiator 3 are connected by an outlet waterway 4 and an introduction waterway 5, so that cooling water is circulated therebetween. Further, the outlet waterway 4 and the introduction waterway 5 are connected by a bypass waterway 6, so that cooling water can bypass the radiator 3. The branch part 7 of the outlet waterway 4 to which this bypass waterway 6 is connected is provided with an on-off valve 8 consisting of a thermostat.
On the other hand, a water pump 10 for circulating cooling water is provided at the junction 9 of the introduction waterway 5 to which the bypass waterway 6 is connected.

The bypass waterway 6 is provided with an electromagnetic valve 11 for opening and closing the waterway, and the drive means 13 is controlled by the control device 12 in accordance with the detection result of the water temperature sensor S disposed upstream of the branch part 7 of the outlet waterway 4. The solenoid valve 11 is controlled to open and close.

As shown in FIG. 2, the control device 12 sets the opening degree θ of the electromagnetic valve 11 to zero when the detected water temperature W of the water temperature sensor S is, for example, 20° C. or lower, and then gradually opens the opening θ of the on-off valve 8, that is, the thermostat. When the temperature is slightly lower than the temperature (eg, 80°C), for example, 70°C, the driving means 13 is operated so that the opening degree θ of the electromagnetic valve 11 is fully opened.

Therefore, cooling water does not circulate during warm-up operation,
Therefore, the temperature of the cooling water in the engine body can be increased, and the warm-up time can be shortened. When the water temperature exceeds 20℃, the cooling water is circulated little by little.
Cooling water in the bypass waterway, water pump, and introduction waterway is heated, and finally a half-open/close valve (thermostat) is opened and cooled by a radiator.

[Effects of the invention] As described above, the invention provides the following excellent effects.

(a) Since cooling water does not circulate between the engine block and cylinder head at the beginning of warm-up, the temperature rises quickly and warm-up time is shortened.

(b) When the temperature exceeds a predetermined temperature, the bypass water valve opens according to the water temperature, so the cooling water is circulated little by little, so there is no adverse effect on the engine.

(c) For this reason, the viscosity of the engine lubricating oil reaches the appropriate value relatively quickly, and then stabilizes, resulting in less wear on various parts of the engine, no loss of horsepower, and improved fuel efficiency.

(d) Overcooling can be prevented because the valve closes during low load or low rotation (so-called idling), especially in cold regions.

(e) A temperature sensor installed upstream of the branch allows accurate determination of engine warm-up.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an embodiment of an engine cooling water temperature control device embodying the present invention, Fig. 2 is an explanatory diagram of the operation of a solenoid valve, and Fig. 3 is a diagram of a conventional engine cooling water temperature control device. It is a schematic block diagram. 1... Engine block, 2... Cylinder head, 3... Radiator, 4... Outlet waterway, 5...
Introduction waterway, 6... Bypass waterway, 7, 9... Branch, 8... On-off valve (thermostat), 10...
Water pump, 11...Solenoid valve, 12...
...Control device, 13...Driving means, S...Water temperature sensor.

Claims (1)

[Scope of utility model registration request] The engine body and the radiator are connected by a lead-out waterway and an introduction waterway so that cooling water can circulate, and the lead-out waterway and the introduction waterway are connected by a bypass waterway,
In the engine cooling water temperature control device, an on-off valve is provided at a branch part of the outlet waterway, and a water pump is provided at a confluence part of the introduction waterway, and a valve and a valve driving means for opening and closing the valve are provided in the bypass waterway. A temperature sensor is provided on the upstream side of a branch part of the outlet waterway, and a control device is provided that controls the valve driving means in response to the temperature detected by the temperature sensor to control the opening degree of the valve. Engine cooling water temperature control device.