JP2010203293A - Exhaust manifold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate uneven cooling of cooling water flowing in cooling water passages in an exhaust manifold provided with the plurality of cooling water passages along a cylinder arrangement direction of an engine. <P>SOLUTION: In the exhaust manifold provided with the cooling water passages 4 along the cylinder arrangement direction of an engine E mounted on a vehicle, the plurality of cooling water passages 4 are provided in parallel, and individual water supply port 41a, 41b, 41c are provided on the plurality of the cooling water passages 4 (4a-4c), respectively. Cooling water flowing in at least one cooling water passage 4 out of the plurality of cooling water passages 4 (4a-4c) flows in a direction reverse to a direction of cooling water flowing in other cooling water passages 4. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an exhaust manifold provided with a cooling water passage along a cylinder arrangement direction of an engine mounted on a vehicle.

  In the exhaust manifold connected to the engine, high-temperature exhaust gas is always discharged, so that the exhaust manifold also becomes high temperature. Especially in a diesel engine or the like, the above tendency is strong due to the afterburning phenomenon.

  In general, the exhaust gas temperature in the exhaust manifold exhausted from the engine rises to about 800 to 850 ° C. Therefore, the outer wall temperature of the exhaust manifold through which the exhaust gas flows is about 650 ° C. The temperature is raised to a high temperature of 700 ° C.

  Due to such a rise in exhaust gas temperature, each member of the exhaust manifold is repeatedly expanded and contracted due to the temperature change, and the respective members are likely to be cracked due to thermal stress, catalyst deterioration, damage, etc. .

  Therefore, a cooling water passage is formed inside or outside the exhaust manifold along the cylinder arrangement direction of the engine, and the cooling gas such as water is circulated in the cooling water passage to exhaust gas in the exhaust manifold. An exhaust manifold that can suppress an increase in temperature has been proposed (see, for example, Patent Document 1).

  Specifically, these exhaust manifolds have, for example, a water supply port and a water discharge port for introducing the cooling water connected to both ends of the cooling water passage, and the cooling water is supplied from the water supply port. Is supplied (pressure fed) into the cooling water passage by a water pump or the like.

  The supplied cooling water takes heat from the exhaust manifold or exhaust gas that has been heated while flowing through the cooling water passage (hereinafter referred to as “heat receiving”), and is discharged from the water discharge port. This suppresses an increase in the exhaust gas temperature in the exhaust manifold.

  Then, the cooling water after receiving heat discharged from the water discharge port is sent to a cooling device such as a radiator to be cooled, and the cooled cooling water is supplied again from the water supply port by a water pump or the like. .

  However, as described above, the exhaust gas temperature in the exhaust manifold is very high, and therefore, the cooling effect is often insufficient with one cooling water passage for receiving heat.

  Therefore, recently, in order to reliably obtain the cooling effect, a structure in which a plurality of cooling water passages are provided along the cylinder arrangement direction of the engine has been developed (see Patent Document 2).

  In this exhaust manifold, a plurality of cooling water passages are provided along the cylinder arrangement direction of the engine, and cooling water such as water is circulated in these cooling water passages to receive heat from the exhaust manifold or exhaust gas. This is superior in that the cooling effect during the operation can be improved and the rise in the exhaust gas temperature in the exhaust manifold can be suppressed.

Japanese Patent Laid-Open No. 5-1539 JP 2002-256868 A

  However, in this exhaust manifold, cooling water is supplied (pressure-fed) from a common water supply port to a plurality of cooling water passages, receiving heat in each cooling water passage, and receiving the cooling water after receiving the heat. The water is discharged from a common water outlet.

  That is, the exhaust manifold is configured such that all the cooling water flowing in the plurality of cooling water passages flows in the same direction to receive heat and is discharged from the water discharge port.

  Therefore, a temperature difference occurs between the cooling water temperature immediately after being supplied from the water supply port (before heat reception) and the cooling water temperature just before being discharged from the water discharge port (after heat reception), and before the heat reception. There is a considerable difference between the cooling efficiency due to the cooling water temperature and the cooling efficiency due to the cooling water temperature after receiving heat.

  Therefore, since the exhaust gas temperature of the exhaust manifold passing near the water supply port is cooled by the cooling water temperature before receiving heat, the exhaust manifold can be reliably cooled and exhausted, while the exhaust manifold temperature passing near the water discharge port is Since the exhaust gas temperature is cooled by the cooling water temperature after receiving heat, the exhaust gas temperature may be exhausted without being cooled much.

  As described above, the conventional exhaust manifold has a problem that the cooling water temperature in the cooling water passage varies depending on the position of the cooling water passage (hereinafter referred to as “cooling unevenness”).

  An object of the present invention is to provide an exhaust manifold that can eliminate the uneven cooling of the temperature of the cooling water flowing through the plurality of cooling water passages.

To solve the above problem,
The present invention provides an exhaust manifold in which cooling water passages are provided along a cylinder arrangement direction of an engine mounted on a vehicle, and a plurality of the cooling water passages are provided side by side. An individual water supply port is provided, and the cooling water flowing in at least one of the plurality of cooling water passages is opposite to the cooling water flowing in the other cooling water passages. It is made to flow.

  Here, the cooling water is not limited to tap water, but also includes mixed water in which a coolant is mixed in the tap water.

  That is, in the present invention, since a plurality of cooling water passages are provided, the cooling effect when receiving heat from the exhaust manifold or the exhaust gas can be enhanced, and an increase in the exhaust gas temperature in the exhaust manifold can be reliably suppressed. .

  Moreover, since the present invention is provided with individual water supply ports, the cooling water flowing in at least one cooling water passage among the plurality of cooling water passages is changed to cooling water flowing in the other cooling water passages. On the other hand, it can be flowed in the opposite direction (pumped) easily by a water pump or the like.

  Therefore, the cooling water temperature flowing in the plurality of cooling water passages is offset by the cooling water temperature in the cooling water passages flowing in opposite directions, and the cooling water temperature in the cooling water passage becomes uniform. Unevenness can be prevented.

  Moreover, it is appropriately selected whether or not to allow any one of the plurality of cooling water passages to flow in the opposite direction to the cooling water flowing through the other cooling water passages.

  冷却 If the cooling water that flows in one cooling water passage among the plurality of cooling water passages flows in the opposite direction to the cooling water that flows in the other adjacent cooling water passage, It is preferable because it is easy to make the water temperature uniform and can prevent uneven cooling.

  Moreover, in this invention, it is also possible to construct a rib between the outer walls of the adjacent cooling water passage.

  In other words, by installing the ribs between the outer walls of the adjacent cooling water passages, not only the strength of the entire exhaust manifold is increased, but the heat possessed by the respective cooling water passages passes through the ribs. It is transmitted from the high temperature side to the low temperature side.

  Therefore, the heat possessed by the plurality of cooling water passages can be made uniform, cooling unevenness can be further prevented, and the radiating area can be increased by installing the ribs, so that the heat dissipation is improved. Also, the cooling efficiency can be increased.

  Furthermore, it is also possible to project a plurality of protrusions outwardly on the outer wall of the cooling water passage.

  As the plurality of protrusions, for example, one that protrudes from the outer wall of the cooling water passage and is formed in a rod shape, or one that radially protrudes fins on the outer wall of the cooling water passage, etc. can be considered. Any heat dissipation area can be employed as long as the heat radiation area of the outer wall can be increased to cool the cooling water passage efficiently.

  In addition, as a synergistic effect with the protrusions and the ribs, a reduction in radiated sound can be obtained as an additional effect.

  According to the exhaust manifold of the present invention, it is possible to eliminate uneven cooling of the temperature of the cooling water flowing in the plurality of cooling water passages.

1 is an overall front view schematically illustrating an exhaust manifold according to an embodiment. It is a top view of FIG. It is the expanded sectional view which cut the BB line of FIG. It is the whole top view which outlined the exhaust manifold of other embodiments. FIG. 5 is an enlarged cross-sectional view of a part of FIG. 4. It is an expanded sectional view of the principal part which outlined the exhaust manifold of other embodiment.

  Hereinafter, an embodiment of an exhaust manifold of the present invention will be described with reference to the drawings.

  FIG. 1 is a front view schematically illustrating an exhaust manifold according to the present embodiment. FIG. 2 is a plan view of FIG. FIG. 3 is an enlarged cross-sectional view taken along line BB in FIG.

  In the exhaust manifold A of this embodiment, an engine-side flange 1 attached to an engine E mounted on a vehicle and a plurality of branch pipes 21 connected to an exhaust hole (not shown) of the flange 1 merge downstream. The exhaust pipe 2 composed of the gathered portion 22 and a connecting flange 3 connected to the end of the exhaust pipe 2 are integrally formed. Further, the exhaust pipe 2 has a cylinder arrangement direction (see FIG. A plurality of cooling water passages 4 are provided side by side in the middle and left and right directions.

  Examples of the engine include various types such as a reciprocating engine, a diesel engine, a rotary engine, and a hybrid engine, but the type is not limited thereto.

  The flange 1 is attached to the cylinder head E1 of the engine E by bolting or the like, and each exhaust port of the cylinder head E1 is connected to the branch pipe 21 through the exhaust hole.

  Further, the connecting flange 3 which is a downstream portion of the exhaust pipe 2 is connected to a catalyst or the like and purified, and the purified exhaust gas is discharged from the muffler.

  Three cooling water passages 4a, 4b, and 4c are provided on the outer wall of the branch pipe 21 in the cylinder arrangement direction of the engine E, that is, the direction in which the plurality of branch pipes 21 are laid (left and right in the figure). It becomes.

  Specifically, the cooling water passages 4a, 4b, and 4c are provided in parallel at equal intervals, and the cooling water passages 4a, 4b, and 4c include a water pump (not shown) and the like. Thus, individual water supply ports 41a, 41b, and 41c through which the cooling water is supplied (pumped) into the respective cooling water passages 4 are provided.

  In the present embodiment, the cooling water passages 4a, 4b, and 4c are provided with individual water discharge ports 42a, 42b, and 42c, respectively.

  In the present embodiment, an example in which three cooling water passages 4a, 4b, and 4c are provided is illustrated, but the present invention is not limited to this, and two or more cooling water passages 4 are provided. It should be.

  Further, the shape of the cooling water passage 4 can be adopted as long as the exhaust gas in the branch pipe 21 can be efficiently cooled, but here, with respect to one branch pipe 21, on the branch pipe 21, Cooling water passages 4a, 4b, and 4c are respectively formed underneath to further increase the cooling efficiency.

  The cooling water passage 4 is not limited to the present embodiment. For example, a tubular passage may be formed inside the branch pipe 21 so as to penetrate the plurality of branch pipes 21. In short, the cooling water in the cooling water passage 4 can be adopted as long as it has a structure capable of receiving heat from the exhaust manifold or the exhaust gas to lower the exhaust gas temperature.

  Among the plurality of cooling water passages 4a, 4b, and 4c formed in this way, the cooling water that flows in at least one cooling water passage 4b is compared to the cooling water that flows in the other cooling water passages 4a and 4c. It flows in the opposite direction.

  For example, in the present embodiment, among the three systems of cooling water passages 4a, 4b, and 4c, the water supply port 41b and the water discharge port 42b of the cooling water passage 4b disposed in the center are replaced with the other two systems of cooling water passages. As shown by the arrow in the figure, only the cooling water in the central cooling water passage 4b flows in the opposite direction with respect to the other two cooling water passages 4a and 4c. It is configured as follows.

  The exhaust manifold A of the present embodiment configured as described above operates as follows.

  First, as the engine E is driven, the exhaust gas exhausted from the exhaust port is collected in the collecting portion 22 through each branch pipe 21, and the purified exhaust gas is sent from the muffler via a catalyst or the like. Discharged.

  When the exhaust gas temperature detected by an electronic control unit (ECU) or the like becomes equal to or higher than a certain temperature, the ECU or the like operates the water pump or the like so that the cooling water is supplied to the respective water supply ports 41a, 41b, Supplied from 41c.

  The supplied cooling water flows through the cooling water passages 4a, 4b, and 4c as shown by arrows in the figure, and at the same time, the exhaust manifold A that is in contact with the cooling water passages 4a, 4b, and 4c passes through the cooling water passages 4a, 4b, and 4c. Cooling and receiving heat from the exhaust manifold A or the exhaust gas heated to high temperature.

  Specifically, in this embodiment, among the three systems of cooling water passages 4a, 4b, and 4c, the cooling water flowing through the central cooling water passage 4b circulates from the left side to the right side in FIG. The cooling water flowing through the other two systems of cooling water passages 4a and 4c circulates from the right side to the left side in FIG.

  Therefore, the temperature of the cooling water flowing in the central cooling water passage 4b is gradually increased from the left side to the right side in FIG. 2, and is the lowest temperature immediately after the corresponding water supply port 41b, but the water discharge port 42b. Immediately before the maximum temperature is reached.

  On the contrary, the cooling water flowing through the other two cooling water passages 4a and 4c gradually rises from the right side to the left side in FIG. 2, and is at the lowest temperature immediately after the corresponding water supply ports 41a and 41c. However, it reaches the maximum temperature immediately before the discharge ports 42b and 42c.

  Therefore, for example, in the branch pipe 21 arranged at the left end in the figure, the cooling water temperature (minimum temperature) of the central cooling water passage 4b and the cooling water temperatures (maximum) of the other two cooling water passages 4a and 4c. Temperature) cancel each other by heat conduction, and the leftmost branch pipe 21 is cooled at a uniform temperature.

  Similarly, in the branch pipe 21 arranged at the right end in the figure, the cooling water temperature (maximum temperature) of the central cooling water passage 4b and the cooling water temperatures (minimum temperature) of the other two cooling water passages 4a and 4c. ) Are offset by heat conduction, and the rightmost branch pipe 21 is cooled at a uniform temperature.

  Note that the branch pipes 21 arranged at both ends are also made uniform by the same principle as described above, and the branch pipes 21 are cooled.

  Therefore, the exhaust gas temperature passing through the branch pipe 21 provided side by side is cooled by the uniform cooling water temperature, and the cooling water temperature in the cooling water passage 4 differs depending on the position of the cooling water passage 4. There is no fear and uneven cooling can be prevented.

  Then, the cooled cooling water after receiving heat is discharged from the respective water discharge ports 42a, 42b, 42c, sent to a cooling device such as a radiator, and re-cooled. It is supplied again from the water supply ports 41a, 41b, 41c.

  As described above, according to the exhaust manifold A of the present embodiment, it is possible to eliminate uneven cooling of the temperature of the cooling water flowing through the plurality of cooling water passages 4a, 4b, and 4c.

  FIG. 4 is an overall plan view schematically illustrating an exhaust manifold according to another embodiment, and FIG. 5 is an enlarged cross-sectional view of a part of FIG.

  In addition, the same code | symbol is attached | subjected to the site | part which is common in FIGS. 1-3, and the overlapping description is abbreviate | omitted, and only the characteristic of this embodiment is demonstrated below.

  The exhaust manifold A of the present embodiment is characterized in that ribs 5 are installed between outer walls of adjacent cooling water passages 4.

  That is, for example, the three cooling water passages 4a, 4b, and 4c in the exhaust manifold A of the present embodiment are connected to the adjacent cooling water passages 4a and 4b and the cooling water passages 4b and 4c. The ribs 5 are respectively constructed.

  By installing such ribs 5 between the outer walls of the adjacent cooling water passages 4, not only the strength of the exhaust manifold A is increased, but the respective cooling water passages 4 a, 4 b, 4 c are retained. Heat is transferred from the high temperature side (for example, the cooling water passages 4a and 4c side) to the low temperature side (for example, the cooling water passage 4b side) through the ribs 5.

  Therefore, according to the exhaust manifold A of the present embodiment, the heat held by the plurality of cooling water passages 4a, 4b, and 4c can be made uniform, cooling unevenness can be further prevented, and the ribs 5 are installed. By doing so, heat dissipation is also improved, and cooling efficiency can also be improved.

  FIG. 6 is an enlarged cross-sectional view of a main part schematically illustrating an exhaust manifold according to still another embodiment.

  In addition, the same code | symbol is attached | subjected to the site | part which is common in FIGS. 1-5, and the overlapping description is abbreviate | omitted, and only the characteristic of this embodiment is demonstrated below.

  The exhaust manifold A according to the present embodiment is characterized in that a plurality of protrusions 6 protrude outwardly on the outer wall of the cooling water passage 4.

  For example, as the plurality of protrusions 6, as shown in FIGS. 1 to 5, as shown in FIG. 1, fins are further protruded radially on the outer wall of the cooling water passage 4 as shown in FIG. 6. Although what was provided etc. can be considered, the point can be employ | adopted if the heat radiation area of the said outer wall is enlarged and the said cooling water channel | path 4 can be cooled efficiently.

  As described above, according to the exhaust manifold A of the present embodiment, since the plurality of protrusions 6 protrude outwardly on the outer wall of the cooling water passage 4, the heat dissipation is further improved and the cooling is performed. Efficiency can be further increased.

  Moreover, if the protrusion 6 shown in the present embodiment has a structure projecting outward, the radiation area can be improved, and as a synergistic effect with the rib 5 shown in FIGS. , Can be obtained as a follow-up effect.

A Exhaust manifold E Engine 1 Flange 2 Exhaust pipe 3 Connection flange 4 (4a to 4c) Cooling water passages 41a to 41c Water supply port 5 Rib 6 Projection

Claims (4)

In the exhaust manifold provided with a cooling water passage along the cylinder arrangement direction of the engine mounted on the vehicle,
A plurality of the cooling water passages are provided, and each of the plurality of cooling water passages is provided with an individual water supply port.
An exhaust manifold characterized in that the cooling water flowing in at least one of the plurality of cooling water passages flows in the opposite direction to the cooling water flowing in the other cooling water passages. . In the exhaust manifold according to claim 1,
Among the plurality of cooling water passages, the cooling water flowing in one cooling water passage flows in the opposite direction to the cooling water flowing in the other adjacent cooling water passages. exhaust manifold. In the exhaust manifold according to claim 1 or 2,
An exhaust manifold characterized in that ribs are installed between the outer walls of adjacent cooling water passages. In the exhaust manifold according to any one of claims 1 to 3,
An exhaust manifold characterized in that a plurality of protrusions project outward from the outer wall of the cooling water passage.

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