JP5235704B2 - Cooling device for internal combustion engine - Google Patents

Description

  The present invention relates to a cooling device that cools an internal combustion engine (hereinafter also referred to as an engine) by circulating cooling water between a fluid passage formed in the internal combustion engine and a radiator.

In this type of engine cooling device, a structure has been proposed in which the cooling performance of the engine is improved by controlling the circulation flow path of the cooling water (refrigerant).
For example, Patent Document 1 discloses a radiator circulation path in which refrigerant that has flowed out of an engine returns to the engine via a radiator, a heater circulation path that returns to the engine via a heater core of an air conditioner, and a refrigerant that passes through the radiator. An engine cooling device is disclosed that includes a bypass flow path that returns to the engine instead.

  The engine cooling device further includes a thermostat that adjusts the flow rate of the refrigerant between the radiator circulation passage and the bypass passage according to the temperature of the refrigerant, and an open / close valve that controls the flow rate of the refrigerant in the bypass passage. The open / close valve is configured to be open when the temperature of the refrigerant is high and closed when the temperature of the refrigerant is low.

  The thermostat is configured to communicate with the radiator circulation channel when the temperature of the refrigerant becomes equal to or higher than a preset temperature, and to block the radiator circulation channel and communicate with the bypass channel when the temperature is equal to or lower than the predetermined temperature. .

  According to the configuration of the cooling device described above, when the temperature of the refrigerant is low, the radiator circulation path is blocked by the thermostat to prevent the refrigerant from being cooled by the radiator, and the opening / closing valve is opened and closed. The flow rate of the refrigerant is adjusted between the heater circulation flow path and the bypass flow path to increase the temperature raising efficiency of the heater.

JP 2000-289444 A

By the way, in the engine cooling device having the above-described structure, for example, when the engine speed is increased while the engine is not warmed up, the rotation speed of the cooling water circulation pump (water pump) increases. Cause the following problems.
That is, as the engine speed increases, the water pump speed increases, so the pressure of the cooling water increases. As a result, the thermostat (T / ST) is forcibly opened, and cold cooling water with insufficient warm-up through the radiator flows into the engine, preventing rapid engine temperature rise. become.

  In order to solve this, if the valve opening pressure of the thermostat (T / ST) is set high, the internal pressure of the thermostat increases and the durability of the thermostat decreases.

  The present invention has been made in view of such circumstances, and can control the flow of cooling water at the time of warm-up in a required state, is excellent in temperature rise efficiency at the time of engine start, and simplifies and configures the entire apparatus. An object of the present invention is to obtain a cooling device for an internal combustion engine that can reduce the number of parts and can be reduced in size and size.

The cooling device for an internal combustion engine according to the present invention (the invention according to claim 1) made to solve the above-described problem is a circulating flow of cooling water between a fluid passage formed in the internal combustion engine and a radiator. A cooling device for an internal combustion engine having a passage formed between a cooling water outlet portion of the internal combustion engine and a cooling water inlet portion of the radiator, wherein a cooling water pressure at the cooling water outlet portion of the internal combustion engine is set There is provided a valve unit in which a differential pressure valve that opens when the pressure is exceeded is provided inside the valve unit, and the valve unit allows the cooling water branched from the circulation flow path to pass through the branch passage with a heater core portion interposed therebetween. The cooling water pressure at the cooling water outlet portion of the internal combustion engine is set to a set pressure, and is configured to flow through a thermostat disposed between the cooling water outlet portion of the radiator and the cooling water inlet portion of the internal combustion engine. The valve opening operation of the differential pressure valve when it becomes more, the cooling water through the bypass passage bypassing the heater core portion configured to flow into the thermostat, the valve unit is in the V-type internal combustion engine A pair of cooling water intake passages for respectively taking in cooling water from the left and right engine heads, and a collecting path for collecting the cooling water by communicating the pair of cooling water intake passages are formed in the valve unit. A communicating portion to the radiator communicating with the collecting passage, and a communicating portion to the branch passage communicating with the collecting passage, respectively, and a differential pressure valve chamber in which the differential pressure valve is accommodated from the collecting passage. A communication portion to the bypass passage is formed, and the pair of cooling water is taken into one side of the collecting path in the valve unit. Communicating portion to the road and the radiator is formed, characterized in that the communication portion to the branch passage to the other, the communicating portion to the differential pressure valve chamber and the bypass passage are formed.

The cooling device for an internal combustion engine according to the present invention (the invention according to claim 2 ) is the invention according to claim 1 , wherein the pair of cooling water intake passages formed in the valve unit are used as openings. A hook-like fastening portion for attaching the valve unit to the engine head so as to surround the opening is formed.

The cooling device for an internal combustion engine according to the present invention (the invention according to claim 3 ) is the invention according to claim 1 or claim 2 , wherein the valve unit includes a communicating portion to the bypass passage, and left and right engine heads. The collecting passage for collecting and collecting the cooling water, the differential pressure valve chamber in which the differential pressure valve is accommodated, and one cooling water intake passage are formed so as to be located in the same cross section. .

The cooling device for an internal combustion engine according to the present invention (the invention according to claim 4 ) is the invention according to claim 1 or 2 , wherein the valve unit includes a communicating portion to the branch passage, and left and right engine heads. The collecting passage for collecting and collecting the cooling water and the communicating portion to the radiator are formed so as to be located in the same cross section.

An internal combustion engine cooling device according to the present invention (invention according to claim 5 ) is characterized in that, in the invention according to any one of claims 1 to 4 , in the cooling water intake passage in the valve unit, A sensor is arranged.

  According to the cooling apparatus for an internal combustion engine having the above-described configuration according to the present invention, it is possible to eliminate the bypass pipe that bypasses the radiator when it is cold, which is always necessary in the conventional structure, and to the branch passage that interposes the heater core portion. Since cooling water flows preferentially, the heater performance during warm-up is improved, and the system can be simplified.

  In other words, the water pump (W / P) is generally a mechanical type that is directly connected to the crankshaft of the engine, and therefore, when the engine rotates at a high speed, the rotation (output) of the water pump increases, and the flow rate in the cooling water circuit (Flow rate) increases. At that time, the flow velocity decreases in the passage through the heater core portion having a high water flow resistance. As a result, the pressure difference between the water pump inlet portion and the outlet portion becomes large, and cavitation is likely to occur.

  In addition, when the water pump is at a high speed, the thermostat (T / ST) is forced to open due to an increase in fluid pressure, resulting in overcooling, delay in warm-up, and heater capacity. There are problems such as lowering of fuel consumption, fuel consumption, and exhaust gas.

  On the other hand, according to the present invention, when the increase in the flow rate of the cooling water accompanying the high rotation of the water pump exceeds a certain value, the differential pressure valve of the valve unit is opened and the flow path to the heater core part is bypassed (relieved). Since it communicates with the bypass path, it is possible to avoid the above problems while ensuring the flow rate of cooling water to the heater core, and it is not necessary to provide an expensive electric water pump or large water pump, which is advantageous from the viewpoint of power consumption. There are advantages such as being.

  Further, in the conventional cooling device, it is necessary to send the cooling water to the bypass circuit and the heater circuit, the cooling water easily flows to the bypass circuit with a small pressure loss, and the cooling water sent to the heater circuit is not sufficient. Therefore, there was a tendency to increase the size of the water pump and increase the flow rate in order to ensure the heater capacity. However, according to the present invention, since the bypass circuit can be eliminated, the size of the water pump does not have to be increased. In addition, sufficient heater performance can be ensured.

  Further, according to the present invention, a valve unit incorporating a differential pressure valve is used, and the valve unit includes a cooling water intake passage, a communication portion to the radiator, a communication portion to the branch passage, a communication portion to the bypass passage, and the like. Since the configuration is formed, the configuration of the entire apparatus can be simplified and the number of components can be reduced.

  Furthermore, according to the present invention, the valve unit is formed so that the above-described specific communication portion and the like are located in the same cross section. Therefore, when the valve unit is die-cast or resin-molded, for example, Therefore, there is an advantage that it is possible to ensure the ease of processing, is excellent in terms of formability, and is advantageous in terms of cost.

  Further, according to the present invention, since the differential pressure valve is provided in the valve unit at a position where it does not become a resistance with respect to the communication portion from the cooling water intake passage to the radiator, the flow rate of the cooling water can be secured. Furthermore, since the cooling water flows smoothly even when the differential pressure valve is operated, unnecessary water resistance is not generated.

  Further, according to the present invention, since the water temperature sensor is arranged in the cooling water intake passage in the valve unit, the influence of the cooling water temperature on the return side passing through the heater core portion is affected even if the differential pressure valve operates. Without receiving it, it becomes possible to grasp the exact water temperature state in the engine.

1 is a schematic diagram showing the overall configuration of a cooling device for an internal combustion engine according to the present invention. In the schematic diagram shown in FIG. 1, it is a schematic diagram explaining an effect | action when the driving | running state of an internal combustion engine changes. It is a perspective view of the valve unit used for the cooling device of an internal-combustion engine concerning the present invention. It is a top view of a valve unit. It is a perspective view of the valve unit of the state fractured from the AA line in FIG. It is sectional drawing of the valve unit seen from the AA line of FIG. 4 in the arrow direction. It is sectional drawing of the valve unit seen in the arrow direction from the BB line of FIG. It is the fragmentary sectional view which showed other embodiment of the valve unit.

  FIG. 1 shows an embodiment of a cooling apparatus for an internal combustion engine according to the present invention. In the figure, reference numeral 1 schematically shows an engine (Eng). A water jacket 2 as a fluid passage is formed. Cooling water circulation channels 4 and 5 are formed in which the cooling water flowing out from the outlet of the fluid passage 2 returns to the engine 1 via the radiator 3 (Rd).

  In the figure, the circulation flow path on the cooling water outflow side from the engine 1 is indicated by reference numeral 4, and the circulation flow path on the cooling water return side to the engine 1 is indicated by reference numeral 5. The circulation channels 4 and 5 are configured to circulate cooling water by a water pump 6 (W / P) provided at the cooling water inlet of the engine 1.

  In this embodiment, the valve unit 10 is connected in the middle of the circulation channel 4 between the cooling water outlet of the engine 1 and the cooling water inlet of the radiator 3 in the above-described cooling water circulation channel. ing. The valve unit 10 incorporates a differential pressure valve 11 that opens when the cooling water pressure at the cooling water outlet of the engine 2 exceeds a set pressure.

  The valve unit 10 is configured such that the cooling water branched from the circulation flow path 4 in the valve unit 10 is normally passed through the branch passage 13 with a heater core 12 used as a heat exchanger for indoor heating. It is configured to communicate with a thermostat 15 (T / ST) provided on the inlet side of the engine 1. Further, the valve unit 10 bypasses the relief pressure by opening the differential pressure valve 11 and relieving the cooling water by bypassing the heater core 12 when the cooling water on the outlet side of the engine 1 reaches a set pressure. The thermostat 15 is configured to flow through the passage 16.

  The thermostat 15 has a conventionally well-known structure, has a temperature sensing means such as wax that expands and contracts depending on the cooling water temperature, and opens and closes the passage when the temperature of the cooling water rises. It controls the flow of water and will not be described in detail.

  In such a configuration, when the warm-up operation is performed in the cold state, the cooling water from the engine 1 passes through the branch passage 13 branched from the circulation passage 4 as shown in FIG. After the replacement, the water pump 6 driven by the crankshaft (not shown) of the engine 1 is pumped from the inlet portion of the engine 1 to the inside through the thermostat 15. At this time, the thermostat 15 is in a closed state, and the cooling water is not exchanged by the radiator 3, so that the cooling water temperature can be controlled so that the temperature of the cooling water is raised during warm-up.

  When the cooling water temperature rises after the engine 1 is started, the thermostat 15 is opened as shown in FIG. 2 (a), and the cooling water flows to the radiator 3 via the circulation channel 4 to exchange heat. After cooling, the thermostat 15 and the water pump 6 are returned to the engine 1.

  Further, when the engine 1 is at a high speed and the water pump 6 is also at a high speed during the cold time, the passage of the heater core portion 12 becomes a water flow resistance as shown in FIG. As a result, the differential pressure valve 11 in the valve unit 10 is opened, and a part of the coolant flows to the thermostat 15 via the bypass passage 16 that bypasses the heater section 12. The flow returns to the engine 1.

  When the water pump 6 is rotated at a high speed after the thermostat 15 is opened, the cooling water flows through the differential pressure valve 11 and the bypass passage 16 as shown in FIG. 2C, and the cooling water passes through the radiator 3. It will return to the engine 1 with the flow of.

  According to the engine cooling apparatus having such a configuration, a bypass circuit that bypasses the radiator when it is cold, which is always necessary in the conventional structure, can be eliminated. In addition, the warm air performance is improved by preferentially flowing the coolant through the heater core 12 during warm-up, and the heater core 12 is bypassed when the coolant pressure at the coolant outlet of the engine reaches a set value. By using the differential pressure valve 11 for relief, the temperature of the cooling water can be controlled, and the entire apparatus can be simplified and the number of components can be reduced.

  In general, the water pump 6 is a mechanical type that is directly connected to the crankshaft of the engine 1 and is driven. Therefore, when the engine 1 is rotated at a high speed, the rotation (output) of the water pump 6 is also increased, and the flow rate ( In this case, the flow rate of the heater core portion 12 having a high water flow resistance is reduced. As a result, the pressure difference between the inlet portion and the outlet portion of the water pump 6 increases, and cavitation occurs. It is easy to generate.

  Further, when the water pump 6 is rotated at a high speed, the fluid pressure increases and the thermostat 6 is forcibly opened, resulting in overcooling, completion of warm-up, delay in heater performance, deterioration in fuel consumption. There were problems such as leading to deterioration of exhaust gas. However, according to the above-described configuration, when the increase in the flow rate of the cooling water accompanying the high rotation of the water pump 6 exceeds a certain value, the differential pressure valve 11 of the valve unit 10 opens and bypasses the flow path to the heater core 12 ( Since the relief passage 16 is provided, the above-mentioned problems can be avoided while ensuring the flow rate to the heater core 12, and it is not necessary to provide an expensive electric water pump or large water pump, which is advantageous from the viewpoint of power consumption. There are advantages such as being.

  Furthermore, in the conventional structure, it is necessary to send the cooling water to the bypass circuit and the heater circuit, and the cooling water is likely to flow to the bypass circuit with a small pressure loss, so that the cooling water sent to the heater circuit is not sufficient. However, according to the configuration described above, the bypass circuit can be eliminated, so that it is sufficient even if the water pump 6 is not enlarged. While ensuring the heater performance, the temperature rise effect of the cooling water can also be ensured.

  3 to 7 show a preferred embodiment of the valve unit 10 used in the cooling device described above. In this embodiment, a description will be given according to an example in which a V-type engine is used as an engine and cooling water from the left and right engine heads is collected in the valve unit 10.

  3 to 7, reference numeral 20 denotes a unit body constituting the valve unit 10 described above, and the unit body 20 is formed of, for example, a synthetic resin. Thus, when the unit body 20 is made of resin, it is easy to improve the fuel consumption by reducing the weight, for example, to add a connecting portion to each device such as an EGR cooler, an ATF cooler, and an ATF warmer, thereby reducing the cost. Can be planned. This is because, when the unit body 20 is formed by die-casting such as aluminum, it is possible to take advantage of the characteristic that the pipe can be integrally formed if it is made of resin, where the connecting pipe must be separately press-fitted and joined. it can.

  3A and 3B are perspective views of the unit body 20 as viewed obliquely from above and from one side and the back side thereof. 4 is a top view of the unit body, and FIGS. 5 and 6 are a perspective view of the unit body taken along the line AA in FIG. 4 and a cross-sectional view seen in the arrow direction from the line AA. Further, FIG. 7 is a cross-sectional view seen in the arrow direction from the line BB in FIG.

  The unit body 20 constituting the valve unit 10 is formed such that a pair of cooling water intake passages 21 and 22 that respectively intake cooling water from the left and right engine heads in the V-type engine face the same direction. The pair of cooling water intake passages 21 and 22 are openings, and hook-like fastening portions (flanges) 23 and 24 are formed so as to surround the openings.

  The pair of cooling water intake passages 21 and 22 communicate with each other in the unit body 20 as shown in FIGS. 5 to 7 to form a collecting passage 25 for collecting cooling water from the pair of cooling water intake passages 21 and 22. Has been. This collective path 25 is formed around the line LL shown in FIG.

  In addition, a communication portion 30 to the radiator 3 is formed in a state of being in communication with the collecting passage 25 at a substantially central portion of the collecting passage 25 in the unit body 20. That is, the communication portion 30 to the radiator is formed such that the communication hole 30a faces in the same direction as the cooling water intake passages 21 and 22 described above. Therefore, when the unit body 20 is attached to the V-type engine using the fastening portions 23 and 24, the connection pipes (not shown) connecting the communication portion 30 and the radiator 3 are the left and right engine heads of the V-type engine. However, the present invention is not limited to this.

  On the other hand, a communication portion 31 to the branch passage 13 reaching the heater core portion 12 is formed at a substantially central portion of the collecting passage 25 in the unit body 20. As shown in the sectional view of FIG. 7, the communication portion 31 to the branch passage is a communication portion to the radiator described above with the LL line (that is, the collecting path 25) shown in FIG. The communication part 31 is formed in a state of being bent at a right angle upward from the center part of the unit body 20.

  Further, a differential pressure valve chamber 33 in which the differential pressure valve 11 is accommodated is formed in the unit body 20 adjacent to the communication portion 31 to the branch passage. This is illustrated in detail in FIGS. The differential pressure valve chamber 33 is also formed on the side opposite to the direction in which the cooling water intake passage 21 is formed with the LL line as the center, and is formed in the wall surface of the collecting passage 25 in the central portion. A differential pressure valve chamber 33 is formed through the flow hole 26.

  As described above, the communicating portion 31 to the branch passage 13 leading to the heater core portion 12 and the differential pressure valve chamber 33 in which the differential pressure valve 11 is accommodated, the cooling water intake passage 21 and the radiator 3 with the LL line as the center. By forming it on the opposite side to the direction in which the communication portion 30 is formed, it is possible to reduce the flow resistance of the cooling water, thereby smoothing the flow of the cooling water.

  The space of the differential pressure valve chamber 33 is formed to be slightly vertically long, and the valve body 11a in the differential pressure valve chamber 33 is normally configured to close (close) the differential pressure valve chamber 33 by a spring member 11b. Yes. Further, as described above, when the pressure of the cooling water from the engine becomes equal to or higher than the set value, the valve body 11a is pushed up so as to open.

  A communication portion 34 to the bypass passage 16 is formed in the upper portion of the differential pressure valve chamber 33, and cooling water generated by opening the differential pressure valve 11 is supplied from the communication portion 34 via the bypass passage 16 to the thermostat 15. Acts to be swept away.

  Further, a communication portion 36 to the ATF warmer is formed in the horizontal direction through the vicinity of the lower bottom portion of the differential pressure valve chamber 33. As is well known, this is used to shorten the warm-up operation time of the automatic transmission AT and to improve the fuel consumption immediately after starting.

  FIG. 8 is a partial sectional view showing another example of the unit body 20 constituting the valve unit 10. This example shows an example in which a water temperature sensor is arranged in the unit body 20, and a water temperature sensor 40 is arranged in one cooling water intake passage 22 in the unit body 20. Reference numeral 41 denotes a water temperature sensor connector attached to the outside of the unit body 20.

  By disposing the water temperature sensor 40 at the position shown in FIG. 8, even if the above-described differential pressure valve 11 is operated, the water temperature sensor 40 is not affected by the cooling water temperature on the return side passing through the heater core portion 12. Only the water temperature at the cooling water outlet is sensed. As a result, the accurate water temperature state in the engine 1 can be grasped, and preferable temperature control of the cooling water can be realized.

  In the embodiment described above, the communication portion 34 to the bypass passage in the unit body 20 constituting the valve unit, the collecting passage 25 for collecting and collecting cooling water from the left and right engine heads, and the differential pressure valve 11 respectively. Is formed so as to be located in the same cross section indicated by A-A in FIG. 4.

  Further, the communication part 31 to the branch passage in the unit body 20, the collecting path 25 for collecting and collecting the cooling water from the left and right engine heads, and the communication part 30 to the radiator are shown in FIG. It is formed so that it may be located in the same cross section shown by. Since each part is located in the same cross section as described above, there is an advantage that the molding can be easily removed during molding of the unit body 20 and the moldability is excellent.

  Further, a pair of cooling water intake passages 21 and 22 and a communication portion 30 to the radiator are formed on one side of the collecting passage 25 (L-L line) of the unit body 20 constituting the valve unit, and the other side A communication portion 31 to the branch passage, a differential pressure valve chamber 33, and a communication portion 34 to the bypass passage are formed.

  As described above, the unit body 20 can be arranged neatly and easily by die casting or the like by resin molding. In addition to the above, it is also possible to easily collect various cooling water circuits and pipes including connection pipes such as EGR cooler, ATF cooler, ATF warmer and the like.

1 Engine (Eng)
2 Fluid passage 3 Radiator (Rd)
4,5 Circulation channel 6 Water pump (W / P)
DESCRIPTION OF SYMBOLS 10 Valve unit 11 Differential pressure valve 11a Valve body 11b Spring member 12 Heater core part 13 Branch passage 15 Thermostat (T / ST)
16 Detour passage 20 Unit body 21, 22 Cooling water intake passage 23, 24 Fastening portion (flange)
25 communication path 26 communication hole 30 communication portion to radiator 30a communication hole 31 communication portion to branch passage 33 differential pressure valve chamber 34 communication portion to bypass passage 36 communication portion to ATF warmer 40 water temperature sensor

Claims (5)

A cooling device for an internal combustion engine in which a circulation path for cooling water is formed between a fluid passage formed in the internal combustion engine and a radiator,
A differential pressure valve is provided between the cooling water outlet of the internal combustion engine and the cooling water inlet of the radiator, and opens when the cooling water pressure at the cooling water outlet of the internal combustion engine exceeds a set pressure. Arranged valve unit,
The valve unit is disposed between the cooling water outlet portion of the radiator and the cooling water inlet portion of the internal combustion engine via a branch passage with a heater core portion interposed between the cooling water branched from the circulation flow path. Configured to flow through a separate thermostat,
By opening the differential pressure valve when the coolant pressure at the coolant outlet of the internal combustion engine becomes equal to or higher than a set pressure, the coolant is caused to flow to the thermostat via a bypass passage that bypasses the heater core. Composed of
The valve unit is formed with a pair of cooling water intake passages for taking in cooling water from left and right engine heads in a V-type internal combustion engine, and a collecting passage for collecting the cooling water by communicating the pair of cooling water intake passages. Has been
The valve unit is formed with a communicating portion to the radiator communicating with the collecting passage and a communicating portion to the branch passage communicating with the collecting passage, and the differential pressure valve from the collecting passage. A communication part to the bypass passage is formed through the accommodated differential pressure valve chamber,
A pair of cooling water intake passages and a communication portion to the radiator are formed on one side of the collecting path in the valve unit, and a communication portion to the branch passage, the differential pressure valve chamber, and the bypass passage are formed on the other side. The internal combustion engine cooling device is characterized in that each communication portion is formed . The pair of cooling water intake passages formed in the valve unit are used as openings, respectively, and a hook-like fastening portion for attaching the valve unit to the engine head is formed so as to surround the openings. The cooling device for an internal combustion engine according to claim 1 . A communicating portion to the bypass passage in the valve unit, the collecting passage for collecting and collecting cooling water from the left and right engine heads, a differential pressure valve chamber in which the differential pressure valve is accommodated, and one cooling water intake passage, The cooling device for an internal combustion engine according to claim 1 or 2 , wherein the cooling device is formed so as to be located in the same cross section. A communicating part to the branch passage in the valve unit, the collecting path for collecting cooling water from the left and right engine heads, and a communicating part to the radiator are formed so as to be located in the same cross section. The cooling apparatus for an internal combustion engine according to claim 1 or 2 , characterized in that The cooling device for an internal combustion engine according to any one of claims 1 to 4 , wherein a water temperature sensor is disposed in a cooling water intake passage in the valve unit.

Images