JP2011179475A - Throttle body heating device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throttle body heating device for an internal combustion engine capable of appropriately maintaining a state of heating a throttle body, while securing warming-up performance of the engine at a low air temperature well, by using only one valve mechanism. <P>SOLUTION: An upstream end of a throttle heating pipe H6, which leads cooling water for heating to the throttle body 5, is connected to an outlet of a thermostat 2 or a discharge opening of a water pump 3. When the temperature of air is high and a valve 21 of the thermostat 2 is opened. the cooling water collected from an engine body E and the cooling water cooled by a radiator 1 are mixed, and thereafter, the mixed cooling water is led into the throttle body 5 through the throttle heating pipe H6. With this structure, knocking is prevented without heating beyond necessity the intake air flowing in an intake passage formed inside of the throttle body 5, and high intake charging efficiency can be obtained. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a throttle body heating device that heats a throttle body using cooling water of an internal combustion engine. In particular, the present invention relates to a measure for optimizing the heating state of the throttle body.

  Conventionally, in a general automobile engine (for example, a gasoline engine), a throttle body is disposed in the middle of an intake pipe, and an opening degree control of a throttle valve (intake air amount adjusting valve) disposed inside the throttle body. The intake air amount is adjusted by.

  By the way, when the outside air temperature is low, such as in winter, moisture contained in the intake air freezes (icing) around the throttle valve, and this throttle valve freezes on the inner surface of the intake pipe (inner surface of the intake passage of the throttle body). There is a possibility of sticking. In such a situation, the throttle valve does not operate normally, which hinders driving of the engine.

  In order to prevent or eliminate freezing and sticking of the throttle valve, as disclosed in, for example, Patent Document 1 below, a water flow is formed in the throttle body, and the engine cooling water is allowed to flow through this water flow. Heating the body is done.

  Further, as disclosed in Patent Document 2, it has been proposed to use a thermo valve or the like to stop the supply of cooling water to the throttle body when the hot water flowing through the throttle body exceeds a predetermined temperature. ing. As a result, in normal use areas where icing does not occur or in high outdoor temperatures, the intake air is heated and knocking is likely to occur, or the engine output decreases as intake charging efficiency decreases. To prevent that.

  However, the configuration of Patent Document 2 requires a special valve mechanism such as a thermo valve, which complicates the system and increases the cost.

  Therefore, as disclosed in Patent Document 3, a pipe for separately dividing the cooling water flowing out from the engine main body is provided to each of the throttle body, the radiator, and the heater core, and this pipe is connected to one thermostat. A new valve mechanism has been proposed. That is, by the switching operation of the thermostat, the cooling water flowing out from the engine body is caused to flow through the pipes at a low outside temperature, and only to the pipes connected to the radiator at a high outside temperature.

JP 2003-120296 A JP 2005-120882 A Japanese Patent Laid-Open No. 7-119499

  However, in the configuration of Patent Document 3 described above, the cooling water flows through the piping connected to the radiator at a low outside air temperature (for example, during warm-up operation), which adversely affects the warm-up performance of the engine and It may take longer to complete the machine.

  As described above, in the conventional configuration, a configuration in which the heating state of the throttle body is properly maintained while ensuring good engine warm-up performance at a low outside air temperature or the like with a single valve mechanism has not been realized. It was.

  The present invention has been made in view of such a point, and the object of the present invention is to use only one valve mechanism, while ensuring a good warm-up performance of the engine at a low outside temperature, etc. An object of the present invention is to provide a throttle body heating device for an internal combustion engine capable of appropriately maintaining the heating state of the throttle body.

-Principle of solving the problem-
The solution principle of the present invention devised in order to achieve the above object is that a relatively high temperature cooling water is allowed to flow from the thermostat to the throttle body without flowing the cooling water to the radiator at a low outside air temperature in accordance with the switching operation of the thermostat. In the high outside air temperature, the cooling water cooled by the radiator is mixed and the cooling water that has become relatively low temperature is introduced from the thermostat to the cooling water passage of the throttle body. ing.

-Solution-
Specifically, the present invention provides a first cooling water circulation operation for flowing cooling water flowing out from the internal combustion engine body to the thermostat by bypassing the radiator, and at least cooling water flowing out from the internal combustion engine body. The cooling water circulation can be switched between the second cooling water circulation operation in which a part is cooled by the radiator and then flowed to the thermostat, and the circulating cooling water is caused to flow in the cooling water passage formed in the throttle body. It is assumed that the throttle body heating device for an internal combustion engine is configured to heat the throttle body. For the throttle body heating device, the thermostat is arranged in the middle of a cooling water flow path for introducing the cooling water flowing out from the radiator toward the internal combustion engine body, and the cooling water for heating the throttle body flows. The throttle heating passage is branched from the downstream side of the thermostat.

  Due to this specific matter, for example, in a situation where the outside air temperature is low and the occurrence of the icing is concerned, the first cooling water circulation operation is performed, and the relatively high temperature cooling water flowing out from the internal combustion engine main body bypasses the radiator, and the thermostat. Washed away. Then, the thermostat is introduced into the cooling water passage of the throttle body through the throttle heating passage. As a result, the entire throttle body is heated by the relatively high-temperature cooling water, and the icing is reliably prevented or eliminated.

  On the other hand, in a situation where the outside air temperature is high and the icing does not occur, the second cooling water circulation operation is performed, and at least a part of the relatively high temperature cooling water flowing out from the internal combustion engine body is cooled by the radiator and then flows to the thermostat. It is. For this reason, in this thermostat, the cooling water cooled by the radiator and the cooling water flowing out of the internal combustion engine body and returning to the thermostat without being introduced into the radiator are mixed, and the temperature is relatively low. It becomes the cooling water. Then, this cooling water is introduced from the thermostat into the cooling water passage of the throttle body through the throttle heating passage. Thereby, the entire throttle body is heated, but as described above, the temperature of the cooling water is set to be relatively low by mixing the cooling water cooled by the radiator. The throttle body temperature does not increase excessively. For this reason, it is possible to prevent a situation in which knocking is likely to occur due to heating of the intake air or a decrease in engine output due to a decrease in intake charging efficiency.

  More specifically, the upstream end of the throttle heating passage may be connected to the discharge side of a thermostat or a water pump disposed between the thermostat and the internal combustion engine body.

  In the present invention, since the throttle heating passage through which the cooling water for heating the throttle body flows is branched from the downstream side of the thermostat, only one valve mechanism is used, and the warming-up performance of the engine at a low outside temperature or the like It is possible to maintain the heating state of the throttle body properly while ensuring the above.

It is a figure which shows typically the cooling water circulation circuit of the engine which concerns on embodiment. FIG. 2 is a view corresponding to FIG. 1 for explaining a cooling water circulation operation at a low outside air temperature. FIG. 2 is a view corresponding to FIG. 1 for explaining a cooling water circulation operation at a high outside air temperature. It is a figure which shows typically the cooling water circulation circuit which concerns on a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment demonstrates the case where this invention is applied to the cooling water circulation circuit of the engine for motor vehicles.

-Cooling water circulation circuit-
FIG. 1 is a diagram schematically showing a cooling water circulation circuit of an engine according to the present embodiment. As shown in FIG. 1, the cooling water circulation circuit includes a radiator 1, a thermostat 2, a water pump 3, a heater core 4, a throttle body 5, piping for connecting these devices 1, 2, 3, 4 and 5 and a hose H 1. -H7 are provided.

  Specifically, the outlet tank (not shown) of the radiator 1 and the thermostat 2 are connected by an outlet hose H1. A connection portion of the outlet hose H <b> 1 in the thermostat 2 can be opened and closed by a valve 21 accommodated in the thermostat 2. That is, when the valve 21 is opened, the radiator 1 and the thermostat 2 are communicated with each other through the outlet hose H1. On the other hand, when the valve 21 is closed, the radiator 1 and the thermostat 2 are not in communication. That is, the cooling water does not flow through the radiator 1.

  One cooling water outlet of the thermostat 2 is connected to the suction port of the water pump 3. The discharge port of the water pump 3 communicates with a water jacket formed in the engine body E. In this water jacket, the cooling water (heat recovery medium) discharged from the water pump 3 passes through the water jacket on the cylinder block CB side, and is then introduced into the water jacket on the cylinder head CH side. It can be taken out from the engine body E by three take-out tubes H2, H3, H4.

  The first take-out pipe H2 is connected to an inlet tank (not shown) of the radiator 1. The second take-out pipe H3 is connected to the heater core 4. The third take-out pipe H4 is connected to one cooling water inlet of the thermostat 2. In the thermostat 2, the cooling water inlet to which the third take-out pipe H4 is connected is not opened and closed by the valve 21, and the water jacket on the cylinder head CH side and the thermostat 2 are always connected by the third take-out pipe H4. Communicate. Further, the third take-out pipe H4 may be provided with an open / close valve as necessary.

  On the other hand, the heater core 4 and the other cooling water inlet of the thermostat 2 are connected by a first recovery pipe H5. The cooling water inlet to which the first recovery pipe H5 is connected in the thermostat 2 is not opened and closed by the valve 21, and the heater core 4 and the thermostat 2 are always in communication with each other by the first recovery pipe H5. In addition, an opening / closing valve may be provided in the first recovery pipe H5 as necessary.

  As another feature of this embodiment, another cooling water outlet of the thermostat 2 and the throttle body 5 are connected by a throttle heating pipe H6 that constitutes a throttle heating passage. The throttle body 5 and the first recovery pipe H5 are connected by a second recovery pipe H7. The cooling water outlet to which the throttle heating pipe H6 is connected in the thermostat 2 is not opened and closed by the valve 21, and the throttle body 5 and the thermostat 2 are always in communication with each other through the throttle heating pipe H6. Further, the throttle heating pipe H6 may be provided with an on-off valve or a water pump as necessary.

  Hereinafter, the configuration and function of each device constituting the cooling water circulation circuit will be briefly described.

  The radiator 1 in this embodiment is of a cross flow type, and a radiator core 11 is provided between the inlet tank and the outlet tank. As a result, when the cooling water collected in the inlet tank from the engine body E through the first take-out pipe H2 flows inside the radiator core 11 toward the outlet tank, the outside air (air blown by driving air or driving the cooling fan) The cooling water is cooled by exchanging heat with each other and radiating heat to the outside air. In FIG. 1, 12 is a reservoir tank. The radiator 1 is not limited to the cross flow type but may be a down flow type.

  The thermostat 2 adjusts the temperature of the cooling water by switching the water path of the cooling water circulation circuit. For example, the internal valve 21 is opened and closed by utilizing the thermal expansion of wax sealed inside. It has a mechanism. By opening and closing the valve 21, as described above, the communication state and the non-communication state of the radiator 1 and the thermostat 2 are switched.

  When the outside air temperature is low (for example, below freezing) or during the warm-up operation of the engine body E, the valve 21 of the thermostat 2 is closed, and the communication between the thermostat 2 and the radiator 1 is cut off. By not flowing the cooling water, the temperature of the cooling water is raised at an early stage, and for example, the warm-up operation of the engine body E is completed early. On the other hand, when the outside air temperature is high (for example, at 20 ° C. or higher) or after the warm-up operation of the engine body E is completed, the valve 21 of the thermostat 2 is opened to connect the thermostat 2 and the radiator 1 to the radiator 1. By flowing a part of the cooling water, the heat recovered by the cooling water is released to the atmosphere by the radiator 1.

  The water pump 3 is for generating a water flow in the cooling water circulation circuit, and a transmission belt is stretched between a water pump pulley and a crankshaft pulley provided on the drive shaft. It is driven by the rotational force of the crankshaft.

  The heater core 4 is for heating the passenger compartment by using the heat of the cooling water, and faces the air duct of the air conditioner. In other words, the air-conditioned air flowing in the air duct is passed through the heater core 4 to be supplied to the vehicle interior as warm air during heating of the vehicle interior, while the air-conditioned air bypasses the heater core 4 in other cases (for example, during cooling). ing.

  The throttle body 5 is provided with a throttle valve, and the amount of intake air into each cylinder of the engine body E is adjusted by controlling the opening of the throttle valve (for example, control of the throttle motor). Further, a cooling water flow (not shown) is formed inside the throttle body 5, and the upstream end of the cooling water passage is connected to the throttle heating pipe H6 and the downstream end is connected to the second recovery pipe H7. Has been. Therefore, when relatively high temperature cooling water is introduced from the thermostat 2 into the throttle heating pipe H6, the cooling water flows through the cooling water flow inside the throttle body 5, thereby heating the entire throttle body 5. In addition, icing caused by moisture contained in the intake air can be prevented or eliminated. Further, the cooling water that has heated the throttle body 5 is led to the second recovery pipe H7 and merged with the cooling water from the heater core 4 that is recovered toward the thermostat 2 by the first recovery pipe H5. Become.

−Cooling water circulation operation−
Next, the cooling water circulation operation in the cooling water circulation circuit configured as described above will be described.

  First, in a situation where the outside air temperature is low (for example, below freezing) and the occurrence of icing is concerned, the valve 21 of the thermostat 2 is closed as shown in FIG. The cooling water discharged from the pump 3 cools the engine body E while flowing through the water jacket of the cylinder block CB and the cylinder head CH, and the cooling water itself becomes a high temperature (for example, 90 ° C.). The cooling water that has passed through the water jacket flows out of the engine body E through the second extraction pipe H3 and the third extraction pipe H4, and the cooling water that has flowed out into the second extraction pipe H3 passes through the heater core 4 and the first recovery pipe H5. Then return to thermostat 2. On the other hand, the cooling water flowing out to the third take-out pipe H4 also returns to the thermostat 2. In this way, a part of the cooling water that has returned to the thermostat 2 passes again through the water pump 3 toward the water jacket of the cylinder block CB and the cylinder head CH. On the other hand, the other cooling water is introduced from the thermostat 2 through the throttle heating pipe H6 into the cooling water circulation inside the throttle body 5. As a result, the entire throttle body 5 is heated by the relatively high temperature cooling water, and the prevention or elimination of the icing is reliably performed. The cooling water after heating the throttle body 5 is led to the second recovery pipe H7, and merged with the cooling water from the heater core 4 recovered toward the thermostat 2 by the first recovery pipe H5, and the thermostat 2 Will be returned to. The above cooling water circulation operation is repeated in a situation where the outside air temperature is low.

  On the other hand, in a situation where the outside air temperature is high (for example, 20 ° C. or higher) and icing does not occur, as shown in FIG. 3, the valve 21 of the thermostat 2 is opened, and as shown by the arrow in FIG. The cooling water discharged from the water pump 3 cools the engine body E while flowing through the water jacket of the cylinder block CB and the cylinder head CH, and the cooling water itself becomes a high temperature. The cooling water that has passed through the water jacket flows out of the engine body E through the first extraction pipe H2, the second extraction pipe H3, and the third extraction pipe H4. The cooling water that has flowed out into the first take-out pipe H2 is introduced into the radiator 1 and is cooled by exchanging heat with the outside air when flowing through the radiator core 11 and radiating heat to the outside air. The cooled cooling water returns to the thermostat 2 through the outlet hose H1. Further, the cooling water flowing out to the second take-out pipe H3 returns to the thermostat 2 through the heater core 4 and the first recovery pipe H5. Further, the cooling water flowing out to the third take-out pipe H4 also returns to the thermostat 2. In this way, the cooling waters returned to the thermostat 2 are mixed with each other. Since a part of the mixed cooling water is cooled by the radiator 1, the temperature of the whole cooling water is lowered by this mixing. For example, when the temperature of the cooling water returning from the first recovery pipe H5 or the third take-out pipe H4 to the thermostat 2 is 90 ° C., the cooling water returning from the outlet hose H1 to the thermostat 2 is mixed, so that 80 ° C. Decrease to a degree.

  A part of the cooling water mixed in this way flows again through the water pump 3 toward the cylinder block CB and the water jacket of the cylinder head CH. On the other hand, the other cooling water is introduced from the thermostat 2 through the throttle heating pipe H6 into the cooling water circulation inside the throttle body 5. Thereby, the entire throttle body 5 is heated, but as described above, the temperature of the cooling water is relatively low (80 ° C.) due to the mixing of the cooling water cooled by the radiator 1. Is set). For this reason, the temperature of the throttle body 5 does not become excessively high. For this reason, it is possible to prevent a situation in which knocking is likely to occur due to heating of the intake air or a decrease in engine output due to a decrease in intake charging efficiency.

  Thereafter, the cooling water after heating the throttle body 5 is led to the second recovery pipe H7 and merged with the cooling water from the heater core 4 recovered toward the thermostat 2 by the first recovery pipe H5. It will be returned to thermostat 2. The above cooling water circulation operation is repeated in a situation where the outside air temperature is high.

  Thus, in this embodiment, in a situation where the outside air temperature is high, the cooling water recovered from the engine body E and the cooling water cooled by the radiator 1 are mixed and the temperature of the cooling water is relatively lowered. It is introduced into the throttle body 5. For this reason, the intake air flowing through the intake passage formed inside the throttle body 5 is heated more than necessary, so that knocking is likely to occur, or the engine output decreases as the intake charging efficiency decreases. It is possible to prevent the occurrence of knocking, improve drivability by preventing the occurrence of knocking, and ensure engine performance by increasing the charging efficiency of intake air.

(Modification)
Next, a modified example will be described. This modification is different from that of the above-described embodiment in the connection location of the upstream end of the throttle heating pipe H6. Other configurations and the cooling water circulation operation are the same as those in the above embodiment. Therefore, only differences from the above embodiment will be described here.

  FIG. 4 is a diagram schematically showing an engine coolant circulation circuit according to this modification. As shown in FIG. 4, the connection location of the upstream end of the throttle heating pipe H <b> 6 in this modification is in the vicinity of the discharge port of the water pump 3. That is, a part of the cooling water pumped by the water pump 3 is introduced into the cooling water circulation inside the throttle body 5 through the throttle heating pipe H6. In this case, since the discharge pressure of the cooling water is higher than in the above-described embodiment, the flow rate of the cooling water inside the throttle body 5 is increased, and the throttle body 5 can be heated quickly.

  As a result, the entire throttle body 5 is heated even at a high outside air temperature. As in the case of the above-described embodiment, the temperature of the cooling water is the cooling water cooled by the radiator 1. By being mixed, it is set to be relatively low (about 80 ° C.). For this reason, the temperature of the throttle body 5 does not become excessively high. For this reason, it is possible to prevent the occurrence of knocking due to heating of the intake air or the engine output from decreasing due to a decrease in intake charging efficiency. The engine performance can be ensured by improving the air intake and increasing the charging efficiency of the intake air.

(Other embodiments)
The embodiment and the modification described above have described the case where the present invention is applied to a cooling water circulation circuit of an automobile engine. The present invention is not limited to this, and can also be applied to an engine coolant circulation circuit used for other purposes.

  Further, the thermostat 2 in the above-described embodiment and the modified example is for opening and closing the valve 21 by utilizing the thermal expansion of the wax sealed inside. Alternatively, the present invention may be configured such that the water path of the cooling water circulation circuit is switched by a valve mechanism including an electromagnetically driven on-off valve.

  The present invention is applicable to a cooling water circulation circuit for optimizing the heating state when the throttle body is heated by engine cooling water.

1 Radiator 2 Thermostat 3 Water pump 5 Throttle body E Engine body H1 Outlet hose (cooling water flow path)
H6 Throttle heating pipe (throttle heating passage)

Claims (2)

By the thermostat switching operation, at least a part of the cooling water flowing out from the internal combustion engine body bypasses the radiator and flows to the thermostat, and at least a part of the cooling water flowing out from the internal combustion engine body is cooled by the radiator. The cooling water circulation can be switched between the second cooling water circulation operation to be passed to the thermostat later, and the throttle body is heated by flowing the circulating cooling water through the cooling water passage formed in the throttle body. In the internal combustion engine throttle body heating device,
The thermostat is disposed in the middle of a cooling water flow path for introducing the cooling water flowing out from the radiator toward the internal combustion engine body, and a throttle heating passage through which the cooling water for heating the throttle body flows is provided. A throttle body heating device for an internal combustion engine, wherein the throttle body is branched from the downstream side of the thermostat. The throttle body heating apparatus for an internal combustion engine according to claim 1,
The throttle body heating device for an internal combustion engine, wherein the upstream end of the throttle heating passage is connected to a discharge side of a thermostat or a water pump disposed between the thermostat and the internal combustion engine body .

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