JP4285116B2 - Cooling water passage branching structure for heater of internal combustion engine for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water-cooled cooling device for an internal combustion engine for a vehicle provided with a heater for heating a passenger compartment, and more particularly to an improvement in a branch structure at a branch portion where a heater coolant passage branches from a coolant circulation system including a radiator.
[0002]
[Prior art]
As disclosed in Patent Document 1, in a vehicle internal combustion engine equipped with a water-cooling type cooling device, a part of the cooling water that has become hot in the internal combustion engine is taken out from the cooling water circulation system and used for vehicle compartment heating. A configuration in which the air is passed through the heater core and returned to an appropriate position upstream of the water pump is widely used. The heater coolant passage leading to the heater core is generally configured to branch from a position relatively close to the water jacket outlet of the internal combustion engine in the coolant circulation system.
[0003]
[Patent Document 1]
JP 2000-186548 A
[Problems to be solved by the invention]
In the cooling water circulation system, air may be mixed in with the cooling water to some extent, but bubbles are likely to stay relatively concentrated near the outlet of the water jacket. For this reason, when the flow rate of the cooling water is changed, bubbles may flow out of the water jacket and flow into the heater cooling water passage together with the cooling water. When cooling water containing bubbles flows through the heater core in this way, a large water flow noise is generated, which gives the passenger a sense of discomfort.
[0005]
Therefore, an object of the present invention is to provide a heater cooling water passage branching structure that prevents bubbles from flowing into the heater cooling water passage even when cooling water containing bubbles flows out of the water jacket. Yes.
[0006]
[Means for Solving the Problems]
The present invention is directed to a water-cooled cooling device for an internal combustion engine for a vehicle as described in claim 1, and includes a water jacket, a water pump, and a radiator of the internal combustion engine, and the water jacket and the radiator. A cooling water circulation system configured to circulate cooling water between the cooling water circulation system and a branching portion on the downstream side of the water jacket in the cooling water circulation system, and the upstream side of the water pump. And a heater cooling water passage provided with a heater core in the middle.
[0007]
The branch portion is located at a curved portion where a cooling water pipe that is a part of the cooling water circulation system is bent in the horizontal direction, and a heater cooling water passage is branched upward from the cooling water pipe. The heater cooling water passage is connected to a position offset from the passage center of the curved portion toward the outer peripheral side.
[0008]
Further , a cylindrical portion surrounding the opening at the tip of the heater coolant passage is provided in the passage of the coolant pipe. Then, the bottom of the cooling water pipe upper Symbol cylindrical portion is opposed, it is recessed to partially downward.
[0009]
When cooling water containing bubbles flows through a curved portion that curves in the horizontal direction, only cooling water having a high specific gravity passes through the outer peripheral side, and conversely, bubbles having a low specific gravity gather on the inner peripheral side due to centrifugal force. Then, a part of the cooling water passing through the outer peripheral side of the cooling water pipe in this way is diverted upward to the heater cooling water passage. Accordingly, the number of bubbles flowing into the heater coolant passage is very small.
[0010]
In particular, in the configuration in which the cylindrical portion protrudes into the passage of the cooling water pipe, even when the flow rate of the cooling water is low, the bubbles flowing above the passage of the cooling water pipe are difficult to flow into the heater cooling water passage.
[0011]
In the description of the claims, “curve in the horizontal direction” refers to a state of being curved along a horizontal plane, but may be substantially horizontal and is not limited to strict horizontal.
[0012]
【The invention's effect】
According to the present invention, even if air bubbles are mixed in the cooling water flowing through the cooling water pipe, the air bubbles hardly flow into the heater cooling water passage branched from the air, so that the cooling water containing air bubbles passes through the heater core. It is possible to suppress the generation of a large water flow sound.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0014]
First, based on FIGS. 1-3, the structure of the whole water cooling type cooling device of the internal combustion engine which concerns on this invention is demonstrated. This embodiment is an example applied to a cooling device for a V-type 6-cylinder internal combustion engine. FIG. 1 schematically shows the configuration of the entire water-cooled cooling device, and FIG. 3 shows a specific configuration of its main part. Is shown.
[0015]
As shown in FIG. 1, water jackets 1a, 2a, and 3a are formed in the cylinder block 1 and the left and right cylinder heads 2 and 3 of the internal combustion engine, respectively, and a water pump 4 provided at the front end of the cylinder block 1 is used. Cooling water is fed into the water jacket 1a in the cylinder block 1, and a part of the water jackets 2a and 3a in the left and right cylinder heads 2 and 3 is diverted as shown in FIG. The cooling water outlets 2b and 3b provided at the rear ends of the water jackets 2a and 3a of both banks are combined into one flow path by the cooling water outlet collecting pipe 14 corresponding to the cooling water pipe which is the main part of the present invention. They are gathered and their end portions are curved along the side of the cylinder head 3 so as to be directed forward of the engine. One end of the radiator inlet pipe 5 is connected to the cooling water outlet collecting pipe 14, and the other end is connected to one tank 6 a of the radiator 6.
[0016]
On the upstream side of the water pump 4, a thermostat valve 7 that switches the flow path according to the coolant temperature is disposed. In addition to the radiator outlet pipe 8 that has one end connected to the other tank 6 b of the radiator 6. The end is connected to the thermostat valve 7. Further, a bypass passage 9 for bypassing the radiator 6 is provided between the radiator inlet pipe 5 and the thermostat valve 7, and the radiator outlet pipe 8 is connected to the thermostat valve during the warm-up when the cooling water temperature is low. 7, the cooling water is circulated through the bypass passage 9. Further, an oil cooler passage 10 is provided in parallel with the bypass passage 9 between the radiator inlet pipe 5 and the thermostat valve 7, and an oil cooler 11 is interposed in the middle thereof. Although not shown in FIG. 1, as shown in FIG. 3, a throttle valve heater passage 13 is further provided from the radiator inlet pipe 5 in order to keep the temperature of the intake throttle chamber 12 provided with the throttle valve. Is branched.
[0017]
The above-described water jacket 1a, 2a, 3a, water pump 4, radiator 6, radiator inlet pipe 5, radiator outlet pipe 8, thermostat valve 7, etc. constitute a cooling water circulation system.
[0018]
On the other hand, as shown in FIG. 1, a heater core 15 is provided in an air conditioner in the passenger compartment, and is connected to the cooling water circulation system via a heater inlet pipe 16 and a heater outlet pipe 17 serving as a heater cooling water passage. Has been. Specifically, the heater inlet pipe 16 branches off from a cooling water circulation system at a branching portion 18 to be described later of the cooling water outlet collecting pipe 14, and the heater outlet pipe 17 has a tip at the thermostat valve. 7 is connected to the cooling water circulation system.
[0019]
In FIG. 3, the cylinder block 1 and the cylinder heads 2 and 3 are not shown, and the thermostat valve 7 attached to the cylinder block 1 is also omitted, but the tip of the bypass passage 9 and the tip of the heater outlet pipe 17 Is attached to the housing of the thermostat valve 7. Further, the tip of the above-described throttle valve heater passage 13 joins the heater outlet pipe 17. The heater outlet pipe 17 always communicates with the suction side of the water pump 4 regardless of whether the thermostat valve 7 is opened or closed depending on the temperature condition, and accordingly, a part of the cooling water heated by the water jackets 1a, 2a, 3a. However, it always diverts to the heater core 15 side and circulates to the water pump 4 suction side. The reservoir passages 19 and 20 branched from the heater inlet pipe 16 and the heater outlet pipe 17 communicate with a reservoir tank (not shown).
[0020]
Next, based on FIGS. 4-7, the concrete structure of the cooling water exit collection pipe 14 and its branch part 18 which are the principal parts of this invention is demonstrated.
[0021]
The cooling water outlet collecting pipe 14 is integrally cast from, for example, a metal material such as an aluminum alloy. The cooling water outlet collecting pipe 14 has a linear shape so as to be disposed along the rear ends of the pair of cylinder heads 2 and 3. A first flange portion 21 having a communication hole 21a connected to the cooling water outlet 2b of one cylinder head 2 is provided at an end portion, and a cooling water outlet 3b of the other cylinder head 3 is provided at an intermediate portion. The 2nd flange part 22 provided with the communicating hole 22a connected to is provided. That is, the linear portion having the first and second flange portions 21 and 22 is disposed in a substantially horizontal state along the direction orthogonal to the rotation axis of the internal combustion engine. And the front-end | tip part 23 connected to the radiator inlet pipe 5 mentioned above differs in a 90 degree direction with respect to said linear part so that it may face the front of an internal combustion engine. A portion extending from the linear portion to the tip portion 23 is a curved portion 24 having an appropriate curvature radius and curved 90 ° in the horizontal direction, that is, along the horizontal plane. Here, as is clear from FIG. 6, the wall portion on the inner peripheral side of the curved portion 24 is curved in an arc shape with a substantially constant curvature, whereas the wall portion on the outer peripheral side is expanded. The protruding portion 24a has a substantially triangular shape that partially protrudes toward the outer peripheral side. More specifically, the bulging portion 24a is located slightly downstream from the intermediate point of the bending portion 24 (the 45 ° position in the 90 ° bending), and is located on the upper surface of the bulging portion 24a. The branch portion 18 is provided.
[0022]
Specifically, the branch portion 18 has a configuration in which a metal pipe 25 serving as a connector portion of the heater cooling water passage is attached to the cooling water outlet collecting pipe 14, and a rubber hose is attached to the metal pipe 25. A heater inlet pipe 16 is connected. That is, a cylindrical boss portion 26 is formed in the cooling water outlet collecting pipe 14, and the metal pipe 25 is inserted and fixed inside the boss portion 26. Further, as shown in FIG. 7, the boss portion 26 protrudes as a cylindrical portion 26 a in the passage of the cooling water outlet collecting pipe 14 and surrounds an opening 27 serving as a cooling water outlet. Here, the metal pipe 25 and the boss portion 26 are basically upward from the upper wall portion of the cooling water outlet collecting pipe 14 so as to be substantially orthogonal to the horizontal plane of the curved portion 24 curved in the horizontal direction. Although extending, it is slightly inclined from the vertical direction so as to follow the flow of the cooling water in the cooling water outlet collecting pipe 14 rather than the complete vertical direction. In other words, the metal pipe 25 is attached with a slight inclination in a direction in which the upper end of the metal pipe 25 is closer to the tip 23 (see FIG. 7). With respect to the inclination of the metal pipe 25 and the boss portion 26, the lower end 26b of the cylindrical portion 26a in the passage of the cooling water outlet collecting pipe 14 is horizontal as shown in FIG. It is formed along.
[0023]
As apparent from FIGS. 5 and 6, the metal pipe 25 is attached to the upper surface of the bulging portion 24 a, so that it extends from the passage center of the cooling water outlet collecting pipe 14 to the outer peripheral side in the curved portion 24. Connected to the offset position. As shown well in FIGS. 5 and 7, the cooling water outlet collecting pipe 14 at the portion of the branching portion 18 where the metal pipe 25 is disposed, in other words, at the portion facing the cylindrical portion 26 a. Is partially recessed downward as a recess 28. Therefore, a sufficiently large distance is secured below the position of the lower end 26b of the cylindrical portion 26a, and the passage cross-sectional area in the cooling water outlet collecting pipe 14 has the first and second flange portions 21, Compared to the linear portion having 22 and the vicinity of the distal end portion 23, it is partially enlarged.
[0024]
In the configuration of the above-described embodiment, when cooling water containing bubbles flows from the water jackets 2a and 3a to the cooling water outlet collecting pipe 14, when flowing through the curved portion 24, cooling with high specific gravity is performed by centrifugal force. Water flows toward the outer peripheral side, and conversely, bubbles with low specific gravity collect on the inner peripheral side. Therefore, the bubbles contained in the cooling water taken out from the metal pipe 25 located on the outer peripheral side are very small. In particular, since the bending portion 24 basically bends along a horizontal plane, the bubbles quickly flow to the downstream side through the inner peripheral side of the bending portion 24 without being influenced by the buoyancy.
[0025]
Further, when the flow rate of the cooling water flowing through the cooling water outlet collecting pipe 14 is relatively low, such as immediately after the start of the internal combustion engine, separation by centrifugal force is likely to be insufficient. Since there is a tendency to gather at the upper part of the water outlet collecting pipe 14, it flows around the cylindrical portion 26 a surrounding the opening 27, and the bubbles flowing into the metal pipe 25 are very little.
[0026]
Further, even when the flow is disturbed in the curved portion 24 due to a change in flow velocity or the like, the cylindrical portion 26a protrudes downward, and the bottom portion is recessed downward as a concave portion 28, so that the lower end 26b of the cylindrical portion 26a. Since a sufficiently large interval is ensured between them, bubbles do not stagnate and enter the opening 27.
[0027]
On the other hand, since the metal pipe 25 is inclined so as to follow the flow in the cooling water outlet collecting pipe 14, the cooling water is divided more smoothly. And while making the shape where the lower end 26b of the cylindrical part 26a was cut | disconnected along the horizontal surface, and having expanded the passage cross-sectional area partially by the recessed part 28, the increase in the passage resistance with respect to the flow of cooling water can be suppressed, Both the main flow rate toward the radiator 6 and the flow rate toward the heater core 15 can be improved.
[0028]
In general, the cooling water outlet collecting pipe 14 is attached in advance to an internal combustion engine mounted on the vehicle, whereas the heater piping including the heater inlet pipe 16 is mounted on the vehicle after the internal combustion engine is mounted on the vehicle. Although it will be connected to the internal combustion engine side, in the above configuration, the metal pipe 25 serving as the connector portion is provided upward, and the heater inlet pipe 16 can be connected from above the engine room. Excellent workability. The same applies to maintenance inspections.
[0029]
As mentioned above, although one Example which applied this invention to the cooling device of V type internal combustion engine was described, this invention is not limited to this, For example, it can apply also to an in-line multicylinder engine etc. Further, the bending portion is not limited to the above-described 90 ° bending portion, but is preferably a bending portion whose direction changes to 45 ° or more when separating bubbles by centrifugal force. The cooling water outlet collecting pipe 14 is formed by casting, but the present invention can also be applied to a cooling water pipe formed into a predetermined shape by a synthetic resin.
[0030]
Furthermore, it is also possible to constitute a cylindrical part by projecting a metal pipe serving as a connector part into the passage of the curved part.
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing the configuration of the entire cooling device for a V-type internal combustion engine according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of the flow path from the same cylinder block to the cylinder head.
FIG. 3 is a perspective view showing a specific configuration of a main part of the cooling device.
FIG. 4 is a perspective view of a cooling water outlet collecting pipe that is a main part of the present invention.
FIG. 5 is a cross-sectional view of the cooling water outlet collecting pipe along the line AA in FIG. 4;
FIG. 6 is a longitudinal sectional view of a cooling water outlet collecting pipe.
7 is a cross-sectional view taken along line BB in FIG.
[Explanation of symbols]
14 ... Cooling water outlet collecting pipe 15 ... Heater core 16 ... Heater inlet pipe 18 ... Branching part 24 ... Curved part 24a ... Swelling part 25 ... Metal pipe 26a ... Cylindrical part

Claims (6)

A cooling water circulation system including a water jacket of an internal combustion engine, a water pump, and a radiator, and configured to circulate cooling water between the water jacket and the radiator; and a downstream side of the water jacket in the cooling water circulation system And a cooling water passage for a heater, which branches from the cooling water circulation system at a branching portion of the cooling water, joins a position upstream of the water pump, and includes a heater core in the middle. In the device
The branch portion is located in a curved portion where a cooling water pipe that is a part of the cooling water circulation system is bent in a horizontal direction, and a heater cooling water passage is branched upward from the cooling water pipe, and The heater coolant passage is connected to a position offset from the passage center of the curved portion toward the outer periphery ,
In the passage of the cooling water pipe, a cylindrical portion surrounding the opening at the front end of the heater cooling water passage is provided so as to protrude, and a bottom portion of the cooling water pipe facing the cylindrical portion is partially A cooling water passage branching structure for a heater of an internal combustion engine for a vehicle, which is recessed downward .   2. The cooling water passage branch structure for a heater of an internal combustion engine for a vehicle according to claim 1, wherein the direction of the curved portion changes to 45 [deg.] Or more.   The said cooling water piping is cast in the shape containing the said curved part, The metal pipe used as the connector part of the said cooling water channel for heaters is attached to this cooling water piping, or characterized by the above-mentioned. 3. A cooling water passage branch structure for a heater of an internal combustion engine for a vehicle according to 2. A bulging portion that partially protrudes to the outer peripheral side compared to the inner peripheral side curvature of the curved portion is formed on the outer peripheral side portion of the curved portion of the cooling water pipe, and the cooling water passage for the heater is The heater coolant cooling water branch structure according to any one of claims 1 to 3 , wherein the cooling water passage branch structure is connected to an upper surface of the bulging portion. The said cooling water passage for heaters is inclined and is connected to the cooling water piping so that the flow of the cooling water in the said cooling water piping may be followed, The cooling water piping in any one of Claims 1-4 characterized by the above-mentioned. A cooling water passage branch structure for a heater of a vehicle internal combustion engine. The cooling water pipe is formed in a straight line along the rear ends of the pair of cylinder heads so that the cooling water is collected from the cooling water outlets of the left and right banks in the V-type internal combustion engine, and one end is a cylinder. along the side of the head is curved to be directed to the engine forward to the bending portion, according to any one of claims 1 to 5, characterized in that cooling water passage for the heater is connected A cooling water passage branch structure for a heater of a vehicle internal combustion engine.

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