JPH08144790A - Cooling device of internal combustion engine - Google Patents

Abstract

PURPOSE: To prevent lowering of output of an internal combustion engine caused by rising of intake air temperature at the time of warming-up in a cooling device of an internal combustion engine, which is adapted to prevent icing of a throttle valve at the time of cold by circulating cooling water in the periphery of a throttle body. CONSTITUTION: A branch path 20 is disposed in such a manner as to communicate with the main cooling passage 14 for introducing cooling water which flows out of a water jacket of an internal combustion engine into a radiator 22 or a thermostat 24. A water valve 26 which opens a valve only when the operating condition of a compartment heater is established is connected to the branch path 20. A heater passage 28 having a heater core functioning as a heat source of the compartment heater is connected to the downstream of the water valve 26. A throttle body passage 32 for introducing some of cooling water which flows through a heater passage 28 to the periphery of a throttle body 34 is provided on the downstream of the water valve 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an internal combustion engine, and more particularly to preventing icing of a throttle valve,
A cooling device for an internal combustion engine having a throttle body passage for circulating cooling water around a throttle body.

[0002]

2. Description of the Related Art In an on-vehicle internal combustion engine, it is known that when air containing water vapor is sucked in during cold weather such as winter, a phenomenon in which a throttle valve icing inside the intake pipe, that is, so-called icing occurs. ing. Since this icing becomes a factor that hinders the smooth operation of the throttle valve, for example, in Japanese Unexamined Patent Publication No. Hei 5-222932, a part of the cooling water of the internal combustion engine is guided to the periphery of the throttle body to prevent icing. A cooling device for an internal combustion engine is disclosed.

That is, with such a structure of the cooling device for the internal combustion engine, during the operation of the internal combustion engine, the appropriately heated cooling water circulates around the throttle body, and the throttle valve is appropriately warmed. Therefore, even if the intake air contains water vapor, the water vapor does not icy on the throttle valve, and icing is reliably prevented.

[0004]

However, in the above-described conventional cooling device, the structure body passage for guiding a part of the cooling water to the periphery of the throttle body is directly branched from the main cooling passage for circulating the cooling water to the radiator or the like. Is. Therefore, according to the above conventional device, the cooling water always circulates in the throttle body passage during the operation of the internal combustion engine.

On the other hand, the icing of the throttle valve as described above occurs only in cold weather such as winter, and there is no possibility of icing occurring in warm weather such as summer. Further, when the vicinity of the throttle body is heated by the cooling water, the air sucked into the internal combustion engine is heated. However, in order to improve the charging efficiency of the intake air, it is advantageous that the intake air has a low temperature. .

In this sense, the conventional cooling device described above is effective in preventing icing in cold weather such as winter.
On the other hand, there is a problem that it can be a factor that hinders the improvement of the output of the internal combustion engine during warm weather such as summer. The present invention has been made in view of the above points,
An object of the present invention is to provide a cooling device for an internal combustion engine that solves the above problems by circulating cooling water around the throttle body only during cold weather such as winter.

[0007]

SUMMARY OF THE INVENTION The above object is to provide a heater passage branched from a main cooling passage of an internal combustion engine to circulate cooling water to a heater core when an operating condition of a vehicle interior heater is satisfied, and a throttle body peripheral portion. In a cooling device for an internal combustion engine having a throttle body passage provided to circulate cooling water in the internal combustion engine, the throttle body passage is provided branching from the heater passage or provided in series with the heater passage. This is achieved by the cooling device.

[0008]

In the present invention, the throttle body passage is provided so as to branch from the heater passage or in series with the heater passage. Therefore, the cooling water circulates in the throttle body passage only when the cooling water circulates in the heater passage. On the other hand, in the heater passage, the cooling water circulates only when the in-vehicle heater condition is satisfied and the heater core needs to be heated. Therefore, cooling water circulates in the heater passage during cold weather when the operating condition of the vehicle interior heater is satisfied, while cooling water does not circulate in the heater passage flow during warm weather when the operating condition of the vehicle interior heater is not satisfied.

Therefore, the cooling water circulates in the throttle body passage only when it is cold, and the temperature rise of the intake air around the throttle body is prevented when the temperature is warm.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual diagram of the structure of a cooling device for an internal combustion engine according to the present invention. In the figure, the internal combustion engine 10 has a water jacket (not shown) for circulating cooling water therein.
It has. A cooling water discharge port of the water pump 12 is connected to the inlet side of the water jacket. The water pump 12 is a pump that operates using a part of the output torque of the internal combustion engine 10 as a drive source, and discharges cooling water into the water jacket at a predetermined pressure while the internal combustion engine 10 is operating.

On the outlet side of the water jacket, a radiator passage 16 and a bypass passage 18 constituting a main cooling passage 14 of the internal combustion engine 10, and further the main cooling passage 14 are provided.
A branch path 20 provided by branching from is communicated. The radiator passage 16 guides the cooling water heated in the water jacket to the radiator 22, and further cools the cooling water air-cooled in the radiator 22 to the first inlet 2 of the thermostat 24.
It is a passage leading to 4a. On the other hand, the bypass passage 18 keeps the cooling water flowing out of the water jacket from flowing into the radiator 22.
Bypass the 2nd inlet 2 of thermostat 24
It is a passage leading to 4b.

Here, the thermostat 24 is a functional component for electrically connecting the outlet 24c, which is provided in communication with the inlet of the water pump 12, with the first and second inlets at an appropriate ratio. Is higher, the first inlet 24a is mainly used, and as the cooling water temperature is lower, the second inlet 24b is mainly used as the outlet 24.
Conduct to c.

Therefore, when the temperature of the cooling water flowing out from the water jacket of the internal combustion engine 10 is low,
The outflowing cooling water mainly flows through the bypass passage 18,
On the other hand, when the cooling water temperature is high, the outflowing cooling water mainly flows through the radiator passage 18. In this case, since most of the cooling water does not flow through the radiator 22 immediately after the cold start of the internal combustion engine 10, early warming of the internal combustion engine 10 is realized, and after the warming of the internal combustion engine 10 is finished, most of the cooling water is Since the radiator flows through the radiator 22, a high cooling capacity is secured.

The branch passage 20 described above is provided with the water valve 2.
It communicates with the heater passage 28 via 6. Here, the heater passage 28 is a passage that guides the cooling water to the heater core 30 that functions as a heat source of the vehicle interior heater, and circulates the cooling water flowing out of the heater core 30 to the water pump 12. The water valve 26 is a valve that is opened only when the operating condition of the vehicle interior heater is satisfied in association with the operating state of the manual air conditioner or the automatic air conditioner.

That is, when the operating condition of the vehicle interior heater is not satisfied, the heater passage 28 is blocked from the branch passage 20 and the high temperature cooling water flowing out from the internal combustion engine 10 is not supplied to the heater core 30. On the other hand, when the operating condition of the vehicle interior heater is satisfied, high-temperature cooling water is introduced into the heater passage 28, and the heat amount is appropriately supplied to the heater core 30.

The internal combustion engine cooling system of this embodiment is provided with a throttle body passage 32 which branches from the heater passage 28 between the water valve 26 and the heater core 30 and communicates with the downstream side of the heater core 30. The throttle body passage 32 is a passage that guides a part of the cooling water flowing in the heater passage 28 to the periphery of the throttle body 34 arranged in the intake passage of the internal combustion engine 10.

That is, in the internal combustion engine 10, when air containing water vapor flows in the intake passage during cold weather such as winter, icing of a throttle valve (not shown) occurs in the throttle body 34, and the throttle valve is smoothly operated. Although the operation may be hindered as described above, according to the above configuration, as long as the cooling water flows through the heater passage 28, that is, the water valve 26.
As long as the valve is open, it is possible to reliably prevent icing of the throttle valve.

Further, in the case where the high-temperature cooling water constantly flows around the throttle body 34, the intake air may be heated more than necessary in warm weather such as summer, and as a result, the output of the internal combustion engine 10 may be reduced. However, according to the configuration of the present embodiment, as long as the water valve 26 is closed, the cooling water does not flow through the throttle body passage 32, and the open / closed state of the water valve 26 is controlled to prevent the above-mentioned harmful effects. Can be removed.

By the way, the water valve 26 is a valve that opens when the operating condition of the vehicle interior heater is satisfied as described above, and closes when the operating condition is not satisfied. Here, the operating condition of the vehicle interior heater is that when the vehicle is equipped with a manual air conditioner, the driver turns on the heater,
Further, when the vehicle is equipped with an automatic air conditioner, it is established by a predetermined temperature difference between the inside and outside of the vehicle.

The operating conditions of the vehicle interior heater are as follows:
Regardless of the type of air conditioner installed in the vehicle, it is almost certain that icing will occur in the throttle valve, that is, the outside temperature will be below freezing, while it will almost always be the case when the vehicle interior temperature is sufficiently high, such as during summer. It does not hold. Therefore, in the cooling system for an internal combustion engine of the present embodiment, during cold weather in which icing may occur in the throttle valve, the cooling water is surely introduced to the periphery of the throttle body 34, while warming in which icing does not occur in the throttle valve. At times, the circulation of the cooling water around the throttle body 34 is appropriately stopped.

As described above, the cooling device for an internal combustion engine according to the present embodiment can easily and reliably cool the internal combustion engine without adding any special element to the structure essentially required for the cooling device for an internal combustion engine. It has an effect that both prevention of icing of the throttle valve at time and prevention of decrease in output of the internal combustion engine 10 at the time of warming can be achieved at the same time. Figure 2
6 to FIG. 6 are schematic structural diagrams of the internal combustion engine cooling devices according to the second to sixth embodiments of the present invention, respectively.

In the cooling system for an internal combustion engine shown in FIG. 2, the branch passage 20 is directly communicated with the heater passage 28 to dispose the water valve 26 on the downstream side of the heater passage 20 and on the upstream side of the water valve 26. This is a configuration in which a throttle body passage 32 branched from the heater passage 28 is provided.
That is, although the configuration shown in FIG. 1 is a configuration in which the circulation state of the cooling water in the heater passage 28 and the throttle body passage 32 is controlled by the water valve 26 arranged upstream thereof, the circulation state of the cooling water is The configuration for controlling the above is not limited to this, and the same function can be realized by the configuration in which the water valve 26 is arranged on the downstream side of the heater passage 28 and the throttle body passage 32 as shown in FIG. You can

The cooling device for an internal combustion engine shown in FIG. 3 has a structure in which the water valve 26 is disposed upstream of the heater passage 28 and the heater passage 28 and the throttle body passage 32 are connected in series. The internal combustion engine cooling device shown in FIG. 4 includes a water valve 26 disposed upstream of the heater passage 28 in the cooling device shown in FIG.
It is arranged downstream of the throttle body passage 32.

That is, in order to prevent both icing during cold weather and secure high output of the internal combustion engine during warm weather, cooling water is circulated through the throttle body passage 32 in accordance with the open / closed state of the water valve 26. It's enough if you can. Therefore, the communication state between the throttle body passage 32 and the heater passage 28 is not limited to the configuration in which the heater core 30 is bypassed by the throttle body passage 32 as shown in FIGS. 1 and 2, but is shown in FIGS. As described above, it is possible to connect both in series.

The position of the water valve 26 may be between the heater core 30 and the throttle body 30 in addition to the positions shown in FIGS. 3 and 4, and the heater passage 28 and the throttle body passage 32 may be the heater. The throttle body passage 32 may be connected to the upstream side of the passage 28. Furthermore, the cooling device for the internal combustion engine shown in FIGS.
Branch from the heater passage 28 to the downstream side of the heater core 30,
And the throttle body passage 3 that joins the heater passage 28
2 is provided, and the water valve 26 is provided on the upstream side or the downstream side of the heater passage 28, respectively.

That is, in the constructions shown in FIGS. 1 and 2, the throttle body passage 32 is arranged in parallel with the heater core 30 in order to secure the circulation amount of the cooling water to the throttle body passage 32 by utilizing the circulation resistance of the heater core 30. However, the configuration as shown in FIGS. 5 and 6 can also be obtained by appropriately adjusting the flow resistance at each place.

The positions of branching and merging of the throttle body passage 34 are as shown in FIG. 5 and FIG.
Is not limited to the downstream side, but as long as the open / closed state of the water valve 26 can be reflected in the flow state of the cooling water,
Branching and merging positions may be provided on the upstream side of the heater core 30.

[0028]

As described above, according to the present invention, the cooling water can be circulated around the throttle body in conjunction with the operation of the vehicle interior heater. For this reason, it is possible to appropriately heat the periphery of the throttle body during cold weather when the normal vehicle interior heater is turned on, without raising the temperature of the intake air more than necessary during warm weather when the normal vehicle interior heater is turned off. .

In other words, the cooling device for an internal combustion engine according to the present invention can achieve both good operability of the throttle valve in cold weather and good output characteristics of the internal combustion engine in warm weather. It has features.

[Brief description of drawings]

FIG. 1 is a structural conceptual diagram of a cooling device for an internal combustion engine that is a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of the configuration of a cooling device for an internal combustion engine that is a second embodiment of the present invention.

FIG. 3 is a conceptual diagram of the configuration of a cooling device for an internal combustion engine that is a third embodiment of the present invention.

FIG. 4 is a schematic diagram of the configuration of a cooling device for an internal combustion engine that is a fourth embodiment of the present invention.

FIG. 5 is a schematic diagram of the configuration of a cooling device for an internal combustion engine that is a fifth embodiment of the present invention.

FIG. 6 is a schematic diagram of the configuration of a cooling device for an internal combustion engine that is a sixth embodiment of the present invention.

[Explanation of symbols]

 10 Internal Combustion Engine 12 Water Pump 14 Main Cooling Passage 20 Branch Passage 22 Radiator 24 Thermostat 26 Water Valve 28 Heater Passage 30 Heater Core 32 Throttle Body Passage 34 Throttle Body

Claims (1)

[Claims] 1. A heater passage branching from a main cooling passage of an internal combustion engine to circulate cooling water to a heater core when the operating condition of a vehicle interior heater is satisfied, and a cooling passage to circulate cooling water around a throttle body. A cooling device for an internal combustion engine having a throttle body passage, wherein the throttle body passage is provided so as to branch from the heater passage or in series with the heater passage.