JPS6319586Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is an internal combustion engine that has a main cooling system that connects the cylinder head cooling section and the radiator, and a bypass preheating system that connects the cylinder head cooling section and the intake manifold preheating section. Concerning water cooling equipment for engines.

(Prior Art) As this type of water cooling device, one shown in FIG. 1 has been known in the past. In this conventional example, a main cooling system A is configured by cylinder head cooling section a → thermostat b → radiator outgoing path c → radiator d → radiator returning path e → common return path f → water pump g → cylinder head cooling section a. On the other hand, the bypass preheating system B is connected by cylinder head cooling section a → thermostat b → preheating section outgoing path h → intake manifold preheating section i → preheating section return path j → common return path f → water pump g → cylinder head cooling section a. It consists of

The thermostat b is configured such that the radiator-side valve element that opens and closes the passage of the main cooling system A and the preheating-side valve element that opens and closes the passage of the bypass preheating system B are controlled to open and close by a single temperature-sensitive operating section. When the temperature of the cooling water is above a predetermined temperature, only the radiator outward path c is opened to circulate the cooling water to the main cooling system A, while when the temperature of the cooling water is below the predetermined temperature, the preheating Only the outward path h is opened to circulate cooling water to the bypass preheating system B.

In the conventional example, the water temperature of the intake manifold preheating section i (hereinafter referred to as preheating section water temperature) is controlled as indicated by X in FIG. 2. That is, after starting the internal combustion engine, the water temperature at the outlet of the cylinder head cooling section a (hereinafter referred to as measurement section water temperature) indicated by T in FIG.
°C) In the first zone until reaching t ₁ ,
While the bypass preheating system B is fully open, the main cooling system A is fully closed, and the preheating section water temperature rapidly rises to approximately the same temperature as the measurement section water temperature.

When the water temperature of the measuring section reaches the set temperature _t1 , the thermostat b starts the flow path switching operation. However, since the response of the thermostat b to the water temperature at the measuring section is not quick, the main cooling system A gradually opens, while the bypass preheating system B gradually closes. Therefore, the water temperature in the measuring section continues to rise and reaches the maximum temperature _t2 near when the thermostat b completely closes the bypass preheating system B. In the second zone during this period, a considerable amount of high-temperature cooling water circulates through the bypass preheating system B, so the preheating section water temperature does not decrease, but rather increases, albeit slightly.

When the measuring part water temperature reaches the maximum temperature _t2 and the bypass preheating system B is fully closed, while the main cooling system A is fully open, the temperature of the cooling water decreases due to the heat dissipation action of the radiator d, and the measuring part water temperature also decreases. In the third zone until the water temperature of the measurement part falls to around the set temperature _t1 , the water temperature of the preheating part also falls. At the same time, the bypass preheating system B gradually opens, while the main cooling system A gradually closes.

When the water temperature of the measuring section falls to around the set temperature _t1 , the bypass preheating system B becomes fully open, while the main cooling system A becomes fully closed, again exhibiting almost the same behavior as the second zone (see Figure 2). ), and then exhibits almost the same behavior as the third zone (indicated by ' in Figure 2). Thereafter, substantially the same behavior as in the second zone and substantially the same behavior as in the third zone are alternately repeated.

It should be noted that the water temperature changes shown in FIG. 2 are for normal conditions, excluding summer. A device substantially the same as the conventional example is disclosed in Japanese Utility Model Application Publication No. 57-129951.

(Problems to be solved by the invention) In the conventional example, since the water temperature in the intake manifold preheating section i is controlled as described above,
At the time of starting when the outside temperature is low, such as in winter, the engine warms up the intake air in the intake manifold, promotes atomization of gasoline, and has the effect of quickly warming up the engine (first zone). However, the second
The preheating section water temperature in the second zone and subsequent zones ', '... in the figure does not decrease much compared to the measurement section water temperature, and the set temperature t ₁
As the surrounding area moves up and down, the intake air in the intake manifold rises, leading to a decrease in the amount of intake air in the combustion chamber, which has the disadvantage of reducing the output of the internal combustion engine.

(Means for Solving the Problems) The present invention solves the drawbacks of the conventional example, namely, the second zone and subsequent zones in FIG.
In order to eliminate the drawback that the water temperature in the preheating section becomes high in ','..., a preheating section detour that bypasses the intake manifold preheating section is provided in the bypass preheating system, and the bypass preheating system is The present invention is characterized in that a throttle member is disposed at a location downstream of the point where the preheating section detour branches and upstream of the intake manifold preheating section.

(Function) According to the present invention, the flow rate of cooling water reaching the intake manifold preheating section can be controlled by simply adding a preheating section detour and a throttle member, and the water temperature of the preheating section can be adjusted to the desired level. As shown by Y in Figure 2, the second zone and subsequent zones,
′, ′... can be controlled to a low temperature.

(Example) The present invention will be specifically explained below based on the example shown in FIGS. 3 and 4.

The water cooling system shown in FIG. 3 is a bottom bypass type water cooling system, and as in the conventional example shown in FIG.
and a bypass preheating system 12 that connects the main cooling system 11 and the bypass preheating system 12, and a thermostat 2 as a temperature-sensitive control valve is arranged in an outlet housing 13 that is a branch of the main cooling system 11 and the bypass preheating system 12. .

The cylinder head cooling section 1 consists of a cylinder block water jacket and a cylinder head water jacket, and cools the cylinder block and the cylinder head.

The main cooling system 11 includes a cylinder head cooling section 1, a thermostat 2, a radiator outward path 3,
It is composed of a radiator 4, a radiator return path 5, a common return path 6, and a water pump 7. When the cooling water temperature is higher than a predetermined temperature, the thermostat 2 operates to open the main cooling system 11, and the cooling After the water is circulated in the above order, it returns to the original cylinder cooling section 1. At this time, the cooling water that has received heat in the cylinder head cooling section 1 and has risen in temperature is transferred to the radiator 4.
The heat is radiated and the temperature is lowered, and the cylinder head cooling section 1 becomes ready to be cooled again.

The bypass preheating system 12 includes a cylinder head cooling section 1, a thermostat 2, a preheating section outward path 8, an intake manifold preheating section 9, and a preheating section return path 1.
0, a common reflux path 6, a water pump 7, and a preheating section detour 14 that communicates the preheating section outgoing path 8 and the preheating section return path 10. A throttle member 15 is provided at a portion closer to the intake manifold preheating section 9 than the branch point of the preheating section detour 14 of the preheating section outgoing path 8, so that the flow rate θ ₁ of the cooling water flowing toward the preheating section detour 14 is adjusted. The flow rate of the cooling water flowing toward the intake manifold preheating section 9 is set to be larger than θ ₂ (for example, it is preferable that θ ₂ /θ ₁ ≦0.15).

When the cooling water temperature is below a predetermined temperature, the thermostat 2 operates to open the bypass preheating system 12, and the cooling water enters the preheating section outgoing path 8 via the cylinder head cooling section 1 and thermostat 2. Here, the majority of the cooling water flows out to the preheating part detour 14, bypasses the intake manifold preheating part 9, and reaches the preheating part return path 10, while the remaining cooling water flows through the preheating part outgoing path 8, the intake manifold preheating part 9, It flows to the preheating section return path 10 and preheats the intake air of the intake manifold. The cooling water that has merged in the preheating section return path 10 then returns to the cylinder head cooling section 1 via the common return path 6 and the water pump 7.

As shown in FIG. 4, the thermostat 2 is disposed within an outlet housing 13, and has a temperature-sensing operating portion 16 equipped with a radiator-side valve body 18 that opens and closes a valve hole 17 communicating with the radiator outgoing path 3, and the preheating portion. A valve hole 19 communicating with the outgoing path 8 is provided with a preheating side valve body 20 that opens and closes. Water temperature in the outlet housing 13 (measurement part water temperature)
is lower than the set temperature t ₁ , the radiator side valve body 1
8 is in a fully closed state, and the preheating side valve body 20 is in a fully open state. When the water temperature of the measurement part exceeds the set temperature _t1 ,
At the same time as the radiator side valve body 18 opens, the preheating side valve body 20 closes, and when the predetermined temperature _t2 is reached, the radiator side valve body 18 is fully open and the preheating side valve body 20 is fully closed. Become.

In the embodiment described above, the preheating section water temperature is controlled as indicated by Y in FIG. Changes in the water temperature at the measurement part are indicated by T in FIG. 2, as in the conventional example.

In the first zone after starting the internal combustion engine until the water temperature in the measuring section reaches the set temperature _t1 of the thermostat 2, the cooling water circulates only in the bypass preheating system 12, and this coolant flows through the preheating section outgoing path 8 and the preheating section bypass path 14. distributed to. The cooling water flowing into the intake manifold preheating section 9 through the preheating section outward path 8 preheats the intake air. In this first zone, as shown in FIG. 2, the preheating section water temperature rises with a slightly gentler curve than in the conventional example. Therefore, when starting the engine when the outside temperature is low, such as in winter, it is possible to warm up the intake air in the intake manifold, promote atomization of gasoline, and quickly warm up the engine.

When the measuring part water temperature reaches the set temperature _t1 , the bypass preheating system 12 is gradually closed. On the other hand, the main cooling system 11 gradually opens, and the cooling water that exits the cylinder head cooling section 1 is distributed to the main cooling system 11 and the bypass preheating system 12 at the thermostat 2, and the cooling water flowing through the bypass preheating system 12 is It is divided into a preheating section outward path 8 and a preheating section bypass path 14. In the second zone, let θ ₀ , θ ₁ , and θ ₂ be the flow rates of the cooling water flowing through the main cooling system 11 , the preheating section detour 14 , and the preheating section outgoing path 8 , respectively, so that θ ₀ >θ ₁ >θ ₂ A relationship is established. Therefore, while the flow rate θ ₂ of the cooling water flowing into the intake manifold preheating section 9 is small,
Since the flow rate θ ₀ of the cooling water flowing into the radiator 4 becomes large, the water temperature in the preheating section drops rapidly.

Zone 3 and subsequent zones ′, ′...
...also, the intake manifold preheating section 9
Since the flow rate θ ₂ of the cooling water flowing through the preheating section does not increase, the water temperature of the preheating section is maintained at a low temperature.

Therefore, according to the present invention, in the second zone and the subsequent zones ', '..., where preheating of the intake air of the intake manifold is unnecessary and harmful,
The water temperature of the preheating section can be maintained at a low temperature. Therefore, it suppresses the temperature rise of the intake air in the intake manifold,
It is possible to increase the amount of intake air into the combustion chamber and improve the output of the internal combustion engine.

The present invention can be configured in various ways other than those shown in the above embodiments. For example, as shown in Figure 5,
A throttle member 15 is provided in the preheating section outgoing path 8 near the entrance of the intake manifold preheating section 9,
Flow rate of cooling water flowing toward the preheating section detour 14 θ ₁
may be configured to be larger than the flow rate θ ₂ of the cooling water flowing toward the intake manifold preheating section 9. Further, in the above embodiment, a thermostat 2 is installed at the branch section 13 between the main cooling system 11 and the bypass preheating system 12 near the outlet of the cylinder head cooling section 1.
This thermostat 2 is placed in the 3rd thermostat.
As shown by the imaginary line in the figure, a confluence part (branching part as referred to in the present invention) 1 of the preheating section return path 10 and the radiator return path 5
It is also possible to arrange it at 3a.

(Effects of the invention) The present invention can reduce the water temperature of the preheating part when preheating the intake air of the intake manifold is unnecessary and harmful by simply adding a simple structure of arranging a preheating part detour and a throttle member. This eliminates the disadvantage of the conventional example that the temperature rises to a high temperature.In other words, in this case, the water temperature in the preheating section can be kept at a low temperature, thereby suppressing the temperature rise of the intake manifold and increasing the amount of intake air in the combustion chamber. This makes it possible to improve the output of the internal combustion engine.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a conventional example, Fig. 2 is a temperature state diagram showing changes in preheating section water temperature and measuring section water temperature, Fig. 3 is a system diagram of an embodiment of the present invention, and Fig. 4 is its temperature-sensitive control. FIG. 5 is a cross-sectional view showing one example of the valve, and FIG. 5 is a plan view showing a different aspect of the main part of the bypass preheating system from that of the above embodiment. DESCRIPTION OF SYMBOLS 1... Cylinder head cooling section, 2... Temperature-sensitive control valve, 4... Radiator, 9... Intake manifold preheating section, 11... Main cooling system, 12...
...Bypass preheating system, 13, 13a... Branch, 1
4...Preheating section detour, 15...Aperture member, 16...
...Temperature sensing operation part, 18...Radiator side valve body, 20
...Preheating side valve body.

Claims (1)

[Scope of utility model registration request] It has a main cooling system that connects the cylinder head cooling section and the radiator, and a bypass preheating system that connects the cylinder head cooling section and the intake manifold preheating section. The radiator side valve body that opens and closes the passage and the preheating side valve body that opens and closes the bypass preheating system passage are equipped with a temperature-sensitive control valve whose opening and closing are controlled by a single temperature-sensitive operation part, so that the cooling water temperature can be controlled. When the temperature is above a certain level, cooling water is circulated through the main cooling system,
In a water cooling system for an internal combustion engine configured to circulate cooling water through a bypass preheating system when the cooling water temperature is below a predetermined temperature, a preheating section bypass path that bypasses an intake manifold preheating section is provided in the bypass preheating system. Also, a water cooling device for an internal combustion engine, characterized in that a throttle member is disposed at a location downstream from a point where a preheating section detour of a bypass preheating system branches and upstream from an intake manifold preheating section.