JP2007231738A - Cooling structure of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide cooling structure of an internal combustion engine which can suppress excessive local cooling of a combustion chamber peripheral wall part. <P>SOLUTION: The cooling structure 20 of an engine 10 has a water jacket 14, an opening part 22, and a second cooling water passage 40. The opening part 22 is formed in a side wall part 11a of a cylinder block 11. The opening part 22 has a first cooling water passage 41 guiding cooling water L from the outside of the cylinder block 11 into the water jacket 14. The second cooling water passage 40 guides the cooling water L from the outside of the cylinder block 11 to the first cooling water passage 41. A cross-section 41a of the first cooling water passage 41 opposed to the second cooling water passage 40 is larger than a cross-section 40a of the second cooling water passage 40 opposed to the opening part 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an internal combustion engine cooling structure, and more particularly to a refrigerant passage through which a refrigerant formed from a water pump to a cylinder block flows.

  For example, in an automobile engine, as an engine cooling structure, a water jacket is formed around a peripheral wall portion that forms a combustion chamber inside a cylinder liner or the like. Cooling water discharged from the water pump flows into the water jacket from an inlet formed in the cylinder block of the engine, cools the engine, and is then guided to the radiator.

  However, since the water jacket is disposed around the cylinder, the relatively vigorous cooling water discharged by the water pump comes into contact with the peripheral wall of the cylinder after flowing into the water jacket. The part where the cooling water hits on the peripheral wall of the cylinder is supercooled as compared with the surrounding area. In other words, the peripheral wall of the cylinder liner is locally cooled.

  As described above, when the peripheral wall of the cylinder is locally cooled, the lubricating oil in the cylinder is cooled, and therefore, it is considered that the friction between the piston and the peripheral wall of the cylinder liner increases. Furthermore, it is considered that the deformation of the peripheral wall of the cylinder liner due to thermal expansion is difficult to adjust due to the local supercooling of the peripheral wall of the cylinder liner, and therefore the friction between the peripheral wall of the cylinder and the piston increases. It is done.

Therefore, in order to solve the above problems, the thickness of the portion of the peripheral wall of the cylinder liner where the coolant hits is increased, and the flowing cooling water is equally divided into the water jacket by the thickness portion. (For example, refer to Patent Document 1).
JP-A-7-127520

  However, as disclosed in Patent Document 1, even when the shape of the peripheral wall is increased, it is difficult to suppress thermal deformation because the portion of the peripheral wall is supercooled when it hits the cooling water. I think that the. Furthermore, since the shape of the peripheral wall becomes complicated by increasing the portion of the peripheral wall of the cylinder liner where the refrigerant hits, it seems difficult to adjust the shape deformation due to thermal expansion.

  Accordingly, an object of the present invention is to provide a cooling structure for an internal combustion engine that can suppress local overcooling of the peripheral wall of the combustion chamber.

  The cooling structure for an internal combustion engine of the present invention includes a water jacket, an opening, and a second refrigerant passage. The water jacket is provided around a combustion chamber peripheral wall defining a combustion chamber in the internal combustion engine. The opening is formed in a side wall portion of the internal combustion engine. The opening has a first refrigerant passage that guides the refrigerant into the water jacket from the outside of the cylinder block. The second passage guides the refrigerant from the outside of the cylinder block to the first refrigerant passage. The cross section of the first refrigerant passage that faces the second refrigerant passage is larger than the cross section of the second refrigerant passage that faces the opening.

  According to this structure, when the refrigerant guided to the opening is moved from the second refrigerant passage to the opening, the passage cross-section rapidly expands and the flow velocity is reduced. A joint portion between the opening and the second refrigerant passage functions as a relaxation portion that reduces the flow rate of the refrigerant.

  When the second refrigerant passage has a bent portion, in a preferred embodiment of the present invention, the second refrigerant passage is located on the outer peripheral portion side of the bent portion at the peripheral edge of the cross section of the first passage facing the second refrigerant passage. 1 edge part is located outside the 2nd edge part located in the outer peripheral part side of the said bending part in the periphery of the cross section of the said 2nd refrigerant path facing the said opening part.

  The flow rate of the refrigerant flowing in the outer peripheral portion of the bent portion is faster than the flow velocity of the refrigerant flowing in the inner peripheral portion of the bent portion. According to this structure, since the flow path leading to the outer peripheral portion where the flow rate of the refrigerant is high is rapidly expanded, the flow rate of the portion where the flow rate is high in the refrigerant is relaxed.

  In addition, the outer peripheral part said by this invention is the vicinity of the wall part which faces the outer side of bending among the surrounding walls of a bending part in the flow path formed in a bending part.

  Or the cooling structure of the internal combustion engine of this invention is equipped with a water jacket, an opening part, a 2nd refrigerant path, and a mitigation apparatus. The water jacket is provided around a combustion chamber peripheral wall defining a combustion chamber in the internal combustion engine. The opening is formed in a side wall portion of the internal combustion engine. The opening has a first refrigerant passage that guides the refrigerant into the water jacket from the outside of the cylinder block. The second refrigerant passage guides the refrigerant from the outside of the cylinder block to the first refrigerant passage. The relaxation device is interposed between the opening and the second refrigerant passage to relieve the flow of the refrigerant.

  According to this structure, the flow rate of the refrigerant is alleviated only by interposing the relaxation device.

  In a preferred embodiment of the present invention, the mitigation device has a third refrigerant passage that communicates with the first and second refrigerant passages and guides the refrigerant to the first refrigerant passage. The cross section of the third refrigerant passage that faces the second refrigerant passage is smaller than the cross section of the second refrigerant passage that faces the relaxation device.

  According to this structure, when the refrigerant hits the edge of the third refrigerant passage, the contact becomes resistance, and the flow velocity of the refrigerant is reduced.

  When the second refrigerant passage has a bent portion that bends, in a preferred embodiment of the present invention, the outer peripheral side of the bent portion in the peripheral edge of the cross section of the third refrigerant passage facing the second refrigerant passage. The edge part located in is located inside the edge part located in the outer peripheral part side of the said bending part among the peripheral edges of the cross section of the said 2nd refrigerant path facing the said mitigation apparatus.

  The flow rate of the refrigerant flowing in the outer peripheral portion of the bent portion is faster than the flow velocity of the refrigerant flowing in the inner peripheral portion of the bent portion. According to this structure, the refrigerant flowing in the outer peripheral portion of the bent portion where the flow rate of the refrigerant is fast comes into contact with the edge portion of the relaxation device. This contact becomes resistance, and the flow velocity at a portion where the flow velocity is high in the refrigerant is relaxed.

  In addition, the outer peripheral part said by this invention is the vicinity of the wall part which faces the outer side of bending among the surrounding walls of a bending part in the flow path formed in a bending part.

  In a preferred embodiment of the present invention, the relaxation device is a gasket.

  According to this structure, it is not necessary to separately provide a gasket that makes the first and second end faces liquid-tight.

  In a preferred embodiment of the present invention, a cross section of the first refrigerant passage facing the mitigation device is larger than a cross section of the third refrigerant passage facing the opening.

  According to this configuration, the flow rate of the refrigerant is reduced by rapidly expanding the cross section of the flow path of the refrigerant that has passed through the relaxation device.

  According to the present invention, since the flow rate of the refrigerant is relaxed when flowing into the water jacket, it does not strike the combustion chamber peripheral wall portion vigorously. Therefore, local overcooling of the combustion chamber peripheral wall is suppressed.

  A cooling structure for an internal combustion engine according to a first embodiment of the present invention will be described with reference to FIG. The internal combustion engine used in the present embodiment is, for example, an automobile engine 10.

  FIG. 1 is a cross-sectional view showing a cooling structure 20 of the engine 10. As shown in FIG. 1, the cooling structure 20 includes a cylinder block 11 constituting a part of the engine 10 and a water pump 21. The engine 10 includes a cylinder block 11, a cylinder head (not shown), an oil pan, and the like.

  Inside the cylinder block 11, a plurality of wet cylinder liners 12 that form the combustion chamber 13 inside are incorporated. Each cylinder liner 12 accommodates a piston (not shown), and a space defined by the piston, the inner surface 12a of the cylinder liner 12 and the cylinder head is a combustion chamber.

  The peripheral wall portion 12b of the cylinder liner 12 is an example of a combustion chamber peripheral wall portion that defines a combustion chamber in the present invention. Note that the combustion chamber 13 is not limited to the structure formed by using the cylinder liner 12 as described above. For example, the combustion chamber may be formed integrally with the cylinder block 11 by directly boring the cylinder block 11. In this case, the peripheral wall portion defining the combustion chamber on the inner side in the cylinder block 11 is the combustion chamber peripheral wall portion referred to in the present invention.

  A water jacket 14 is formed around the cylinder liner 12 in the cylinder block 11. In the water jacket 14, cooling water L flows as an example of a refrigerant, and the cylinder liner 12 is cooled. In this embodiment, since the cylinder liner 12 is wet, the cooling water L is in direct contact with the outer surface 12 c of the cylinder liner 12.

  An opening 22 is formed in the side wall 11 a of the cylinder block 11. The side wall portion 11a is a side wall portion of the internal combustion engine referred to in the present invention. A first cooling water passage 41 that communicates with the water jacket 14 and communicates with the outside of the cylinder block 11 is formed in the opening 22. A mounting seat 22a to which a cooling water passage tube body 24 of a water pump 21, which will be described later, is mounted is formed around the opening 22.

  The water pump 21 is assembled to the cylinder block 11. The water pump 21 includes a pump body 23 and a cooling water passage tube 24.

  The pump body 23 includes a pump housing 25, a pump shaft 26, an impeller 27, a bearing portion 28, a pump pulley 29, and the like.

  The pump shaft 26 is attached to the pump housing 25 via a bearing portion 28. A pump pulley 29 is attached to one end of the pump shaft 26. A driving force is transmitted from the crankshaft of the engine 10 to the pump pulley 29 by a V belt (not shown) or the like. An impeller 27 is attached to the other end of the pump shaft 26.

  The pump housing 25 is attached to the cooling water passage tube body 24. More specifically, the cooling water passage tube body 24 has a shape that opens toward the pump housing 25. The pump housing 25 is fastened to the cooling water passage tube body 24 by bolts 35 so as to cover the opening of the cooling water passage tube body 24 in a liquid-tight manner. A pump chamber 30 for accommodating the impeller 27 is formed between the pump housing 25 and the cooling water passage tube body 24.

  A cooling water introduction passage portion 31 is provided in the cooling water passage tube body 24. The coolant introduction passage 31 communicates the pump chamber 30 with a radiator (not shown), and guides the coolant L cooled by the radiator to the pump chamber 30.

  An attachment seat 24 a that is attached to the attachment seat 22 a of the cylinder block 11 is formed at one end of the cooling water passage tube body 24. The mounting seats 22a and 24a are fastened to each other by bolts 33, for example.

  A second cooling water passage 40 that guides the cooling water L discharged from the pump chamber 30 as the impeller 27 rotates to the opening 22 is formed inside the cooling water passage tube body 24. Therefore, the cooling water passage tube 24 constitutes a part of the water pump 21. The second cooling water passage 40 is a second refrigerant passage referred to in the present invention.

  The portion of the cooling water passage tube 24 where the second cooling water passage 40 is formed is substantially linear. Therefore, the second cooling water passage 40 is also substantially linear.

  The first cross section 41 a of the first cooling water passage 41 that opens to the first end face 22 b that faces the cooling water passage tube body 24 in the opening 22 is the first cross section that faces the opening 22 in the cooling water passage tube body 24. It is larger than the 2nd cross section 40a of the 2nd cooling water channel 40 opened to the end surface 42 of 2. The entire area of the peripheral edge 41b of the first cross section 41a is located outside the entire area of the peripheral edge 40b of the second cross section 40a. The first cross section 41a is a cross section of the first refrigerant passage facing the second refrigerant passage in the present invention. The 2nd cross section 40a is a cross section of the 2nd refrigerant path facing the opening part said by this invention.

  Regarding the relationship between the size of the first cross section 41a and the size of the second cross section 40a, for example, the size of the first cross section 41a may be increased based on the size of the second cross section 40a. Or conversely, the second cross section 40a may be made smaller with reference to the size of the first cross section 41a.

  Next, the operation of the cooling structure 20 will be described. The cooling water L discharged from the pump chamber 30 by the rotation of the impeller 27 is guided to the opening 22 through the second cooling water passage 40.

  When the cooling water L guided to the opening 22 moves from the cooling water passage tube body 24 to the opening 22 (on the cylinder block 11 side), the passage cross section rapidly expands, that is, the cooling water L. As the cross section of the passage through which the cross section changes from the second cross section 40a to the first cross section 41a, the flow velocity is reduced. That is, the joint A between the opening 22 and the cooling water passage tube 24 functions as a relaxation portion that reduces the flow rate of the cooling water L.

  The cooling water L that has flowed into the water jacket 14 through the opening 22 corresponds to a portion P facing the opening 22 on the outer surface 12c of the cylinder liner 12 because the second cooling water passage 40 is substantially linear.

  However, since the flow rate of the cooling water L is sufficiently relaxed when the cooling water L flows into the opening 22, the cooling water L does not strike the part P vigorously. Thereafter, the cooling water L gradually flows in the water jacket 14.

  In the cooling structure 20 of the engine 10 formed in this way, the flow rate of the cooling water L is alleviated by the relaxing portion constituted by the joint A of the first and second cross sections 41a and 42a. The abutting against the outer surface 12c of the liner 12 is suppressed. As a result, it is possible to suppress the supercooling of the temperature of the portion P where the coolant L hits the outer surface 12c of the cylinder liner 12.

  Therefore, since the cylinder liner 12 is not locally subcooled, an increase in friction between the piston and the cylinder liner 12 due to cooling of the lubricating oil in the cylinder liner 12 is suppressed.

  Furthermore, since the cylinder liner 12 is not locally subcooled, it becomes easy to adjust the deformation of the cylinder liner 12 due to thermal expansion. Therefore, an increase in friction between the cylinder liner 12 and the piston due to thermal deformation is suppressed.

  Next, a cooling structure for an internal combustion engine according to a second embodiment of the present invention will be described with reference to FIGS. In addition, the structure which has a function similar to 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description. This embodiment is different from the first embodiment in that the second cooling water passage 40 is bent. In this embodiment, this point will be specifically described.

  FIG. 2 is a cross-sectional view of the cooling structure 20 of the present embodiment. As shown in FIG. 2, in the present embodiment, the cooling water passage tube body 24 is provided with first and second bent portions 50 and 51. The cooling water passage tube body 24 is bent approximately 90 degrees at the first and second bent portions 50 and 51.

  The first bent portion 50 is provided at a portion of the cooling water passage tube body 24 that is immediately before the opening 22. The second bent portion 51 is provided upstream of the first bent portion 50. Therefore, the second cooling water passage 40 is also bent at the first and second bent portions 50 and 51.

  FIG. 3 is an enlarged view of the range of F3 shown in FIG. FIG. 3 shows the first bent portion 50 and the joint portion A in an enlarged manner. As shown in FIG. 3, the first edge located on the outer peripheral portion 50 a side of the first bent portion 50 at the peripheral edge 41 b of the first cross section 41 a of the first cooling water passage 41 that opens to the first end surface 22 b. The second edge portion located on the outer peripheral portion 50a side of the first bent portion 50 at the peripheral edge 40b of the second cross section 40a of the second cooling water passage 40 that opens to the second end face 42. It arrange | positions outside 40c.

  In addition, the outer peripheral part 50a is the vicinity of the wall part 53a which faces the outer side of bending among the peripheral walls 53 of the first bending part 50 in the second cooling water passage 40.

  This point will be specifically described. When the second cooling water passage 40 is bent at the first bent portion 50 as in the present embodiment, the flow rate of the cooling water L at the outer peripheral portion 50a of the first bent portion 50 is the inner peripheral portion 50b side. It tends to be larger than the flow velocity at.

  The inner peripheral portion 50b is in the vicinity of the wall portion 53b facing the inner side of the bend among the peripheral walls 53 of the first bent portion 50 in the second cooling water passage 40.

  Therefore, by arranging the first edge portion 41c on the outer peripheral portion 50a side on the outer periphery 41b of the first cross section 41a on the outer side than the second edge portion 40c of the second cross section 40a, a portion having a high flow velocity. Since the passage cross section of this is rapidly enlarged at the joint A, the flow rate of the cooling water L is effectively relaxed at the joint A.

  The third edge portion 41d of the portion located on the inner peripheral portion 50b side of the first bent portion 50 on the peripheral edge 41b (entire circumference) of the first cross section 41a is on the inner peripheral portion 50b side in the second cross section 40a. It may be arranged at a position substantially overlapping with the fourth edge portion 40d located at.

  Or as shown in FIG. 4, the peripheral edge 40b (entire periphery) of the 1st cross section 41a may be arrange | positioned outside the peripheral area 40b of the 2nd cross section 40a over the whole region. In the present embodiment, in addition to the same effects as in the first embodiment, when the second cooling water passage 40 is bent, the flow rate of the cooling water L can be effectively reduced. 4 shows that the peripheral edge 41b of the first cross section 41a is arranged outside the peripheral edge 40b of the second cross section 40a in the joint portion A between the opening 22 and the cooling water passage tube 24 over the entire area. It is sectional drawing which shows the state performed.

  Next, a cooling structure for an internal combustion engine according to a third embodiment of the present invention will be described with reference to FIGS. In addition, the structure which has a function similar to 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  The present embodiment is different from the first embodiment in that a gasket 60 is interposed between the cooling water passage tube body 24 and the opening 22. This point will be specifically described.

  FIG. 5 is an enlarged cross-sectional view of the joint portion A between the opening 22 and the coolant passage tube 24 in the cooling structure 20 of the engine 10 of the present embodiment. As shown in FIG. 5, a gasket 60 is interposed between the cooling water passage tube 24 and the opening 22. The gasket 60 provides a liquid-tight seal between the cooling water passage tube body 24 and the opening 22. The gasket 60 is an example of a relaxation device as referred to in the present invention.

  In the present embodiment, the shape of the first cross section 41a and the shape of the second cross section 40a are substantially equal to each other, and the peripheral edge 41b of the first cross section 41a and the peripheral edge 40b of the second cross section 40a are mutually overlapping.

  A through hole 61 that connects the second cooling water passage 40 and the first cooling water passage 41 is formed in the gasket 60. The through hole 61 functions as a third cooling water passage referred to in the present invention.

  FIG. 6 is a cross-sectional view of the cooling water passage tube body 24 taken along the line F6-F6 shown in FIG. FIG. 6 shows the cylinder block 11 side from the cooling water passage tube 24 side.

  As shown in FIGS. 5 and 6, the third cross-section 61 a of the through-hole 61 that opens in the end surface 62 of the gasket 60 facing the cooling water passage tube body 24 facing the cooling water passage tube body 24 is formed in the second cooling water passage 40. It is smaller than the second cross section 40a. The peripheral edge 61b of the third cross section 61a of the through hole 61 is located on the inner side over the entire area than the peripheral edge 40b of the second cross section 40a. The cooling water passage tube side end surface 62 is a passage portion side end surface referred to in the present invention. The third cross section 61a is a cross section of the third refrigerant passage opposed to the second refrigerant passage in the present invention.

  Since the third cross section 61 a of the through hole 61 of the gasket 60 is smaller than the second cross section 40 a of the second cooling water passage 40, the cooling water L passes around the periphery 61 b of the gasket 60 when passing through the gasket 60. I hit it. By hitting the periphery of the peripheral edge 61b, this contact becomes resistance, and the flow rate of the cooling water L is relaxed. The 2nd cross section 40a is a cross section of the 2nd refrigerant path facing the mitigation device said by this invention.

  In the present embodiment, in addition to the effects of the first embodiment, the flow velocity of the cooling water L can be easily achieved simply by interposing the gasket 60 without changing the size of the first and second sections 40a and 41a. Can be provided.

  Further, by using the gasket 60 as a relaxation device for reducing the flow rate, a separate member for liquid-tight sealing between the first and second passages 40 and 41 is not required, so that the number of parts can be reduced. it can.

  Further, since it is only necessary to form the through hole 61 in the gasket 60, the gasket 60 can be used as a relaxation device with a simple shape without making the gasket 60 into a complicated shape.

  Next, a cooling structure for an internal combustion engine according to a fourth embodiment of the present invention will be described with reference to FIGS. In addition, the structure which has the same function as 2nd, 3rd embodiment attaches | subjects the same code | symbol, and abbreviate | omits description. In the present embodiment, the gasket 60 described in the third embodiment is interposed between the cooling water passage tube body 24 and the opening 22 described in the second embodiment. , 3 is different from the third embodiment. This point will be specifically described.

  FIG. 7 is an enlarged cross-sectional view of the joint A between the opening 22 and the cooling water passage tube 24 in the cooling structure 20 of the engine 10 of the present embodiment.

  As shown in FIG. 7, the fifth edge 61 c located on the outer peripheral portion 50 a side of the first bent portion 50 among the peripheral edge 61 b of the third cross section 61 a of the through hole 61 is the second cooling water passage 40. Of the peripheral edge 40b of the second cross section 40a, the second edge 40c is located on the inner side of the second edge 40c. The 5th edge part 61c is an edge part located in the outer peripheral part side of a bending part among the peripheral edges of the cross section of the 3rd refrigerant path facing the 2nd refrigerant path said by this invention. The 2nd edge 40c is an edge located in the outer peripheral part side of a bending part among the peripheral edges of the cross section of the 2nd refrigerant path facing the relaxation apparatus said by this invention.

  Therefore, the cooling water L passing through the outer peripheral portion 50a of the first bent portion 50 having a relatively high flow velocity hits the fifth edge 61c, so that the flow velocity of the cooling water L is effectively reduced. Become.

  In the present embodiment, the shape of the first cross section 41a and the shape of the second cross section 40a are substantially equal to each other, and the peripheral edge 40b of the first cross section 41a and the peripheral edge 41b of the first cross section 41a are mutually overlapping.

  The sixth edge portion 61d located on the inner peripheral portion 50b side of the first bent portion 50 among the peripheral edge 61b of the third cross section 61a of the through-hole 61 that opens to the cooling water passage tube body 24 side is Of the peripheral edge 40b of the second cross section 40a of the cooling water passage 40, it may be arranged so as to substantially overlap the fourth edge 40d located on the inner peripheral part 50b side.

  Alternatively, as shown in FIG. 8, the entire area of the third cross section 61 a peripheral edge 61 b of the through hole 61 is located inside the entire area of the peripheral edge 40 b of the second cross section 40 a of the second cooling water passage 40. Good. FIG. 8 is a cross-sectional view showing a state in which the peripheral edge 61b of the third cross section 61a of the gasket 60 is arranged on the inner side over the entire area from the peripheral edge 40b of the second cross section 40a.

  In the present embodiment, in addition to the effects of the third embodiment, even when the second cooling water passage 40 is bent, the flow rate of the cooling water L is effectively reduced at the joint A.

  Next, a cooling structure for an internal combustion engine according to a fifth embodiment of the present invention will be described with reference to FIG. In addition, the structure which has the same function as 3rd Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  In this embodiment, the magnitude | size of the 1st cross section 41a of the 1st cooling water channel | path 41 differs from 3rd Embodiment. This point will be specifically described.

  FIG. 9 is an enlarged cross-sectional view of the joint A between the opening 22 and the cooling water passage tube 24 in the cooling structure 20 of the present embodiment. As shown in FIG. 9, in the present embodiment, the first cross section 41 a of the first cooling water passage 41 has a through hole 61 that opens to an opening side end surface 65 that is an end surface facing the opening 22 in the gasket 60. The fourth cross section 69 is larger. The first cross section 41a is a cross section of the first refrigerant passage facing the mitigation device referred to in the present invention. The fourth cross section 69 is a cross section of the third refrigerant passage facing the opening referred to in the present invention.

  Furthermore, the peripheral edge 41b of the first cross section 41a is located outside the peripheral edge 69a of the fourth cross section 69 over the entire region. When the cooling water L moves from the gasket 60 to the opening 22, the flow path of the cooling water L expands rapidly, that is, the flow path cross-sectional area changes from the fourth cross section 69 to the first cross section 41a. The flow rate of the cooling water L is relaxed.

  In the present embodiment, the action of the gasket 60 and the action of the sudden expansion of the flow path of the cooling water L between the first and fourth cross sections 41a and 69, in addition to the effects of the third embodiment, The flow rate is further relaxed.

  Next, a cooling structure for an internal combustion engine according to a sixth embodiment of the present invention will be described with reference to FIG. In addition, the structure which has a function similar to 4th Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description. In this embodiment, the magnitude | size of the 1st cross section 41a of the 1st cooling water channel | path 41 differs from 4th Embodiment. This point will be specifically described.

  FIG. 10 is an enlarged view of the joint A between the opening 22 of the cooling structure 20 and the cooling water passage tube 24 of the present embodiment. As shown in FIG. 10, the first cross section 41 a of the first cooling water passage 41 is a fourth cross section of the through hole 61 that opens to the opening side end face 65 that is the end face facing the opening 22 in the gasket 60. Greater than 69. And the 1st edge 41c of the 1st cross section 41a of the 1st cooling water channel | path 41 is the 7th edge located in the outer peripheral part 50a side among the peripheral edges 69a of the 4th cross section 69 of the through-hole 61. It is located outside of 69b.

  When the cooling water L moves from the gasket 60 to the opening 22, the flow path on the outer peripheral portion 50 a side where the speed of the cooling water L is relatively high rapidly expands, that is, the flow path cross-sectional area changes from the fourth cross section 69 to the second cross section. By changing to one cross section 41a, the flow rate of the cooling water L is relaxed.

  In FIG. 10, the third edge 41 d of the peripheral edge 41 b of the first cross section 41 a is on the inner peripheral part 50 b side of the first bent part 50 of the peripheral edge 69 a of the fourth cross section 69 of the gasket 60. Although it substantially overlaps with the positioned eighth edge 69c, the present invention is not limited to this. For example, as shown in FIG. 4, the entire area of the peripheral edge 41 b of the first cross section 41 a may be located outside the entire area of the peripheral edge 69 a of the fourth cross section 69.

  In the present embodiment, in addition to the effects of the fourth embodiment, the cooling water L is added by the action of the gasket 60 and the action of the sudden expansion of the flow path of the cooling water L between the gasket 60 and the first cross section 41a. The flow rate of the gas is further relaxed.

Sectional drawing of the cooling structure of the engine which concerns on the 1st Embodiment of this invention. Sectional drawing of the cooling structure of the engine which concerns on the 2nd Embodiment of this invention. The enlarged view of the range of F3 shown in FIG. Sectional drawing which shows the state by which the periphery of the 1st cross section is arrange | positioned outside the periphery of the 2nd cross section over the whole region in the 2nd Embodiment of this invention. Sectional drawing which expands and shows the junction part of an opening part and a cooling water passage pipe body in the cooling structure of the engine which concerns on the 3rd Embodiment of this invention. Sectional drawing of the cooling water channel | tube pipe body shown along F6-F6 line shown by FIG. Sectional drawing which expands and shows the junction part of an opening part and a cooling water passage pipe body in the cooling structure of the engine which concerns on the 4th Embodiment of this invention. Sectional drawing which shows the state by which the peripheral edge of the cross section of a gasket is arrange | positioned inside covering the whole region rather than the peripheral edge of a 2nd cross section in 4th Embodiment. Sectional drawing which expands and shows the junction part of an opening part and a cooling water channel pipe body in the cooling structure of the engine which concerns on the 5th Embodiment of this invention. Sectional drawing which expands and shows the junction part of an opening part and a cooling water channel | path in the engine cooling structure which concerns on the 6th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Engine (internal combustion engine), 11a ... Side wall part (side wall part of internal combustion engine), 12b ... Peripheral wall part (combustion chamber peripheral wall part), 13 ... Combustion chamber, 14 ... Water jacket, 22 ... Opening part, 40 ... Second Cooling water passage (second refrigerant passage), 40a ... second cross section (second refrigerant passage facing the opening, cross section of second refrigerant passage facing the mitigation device), 40c ... second (The edge located on the outer peripheral side of the bent portion of the peripheral edge of the cross section of the second refrigerant passage facing the mitigating device), 41... First cooling water passage (first refrigerant passage), 41a ... 1st cross section (cross section of 1st refrigerant path which opposes 2nd refrigerant path, cross section of 2nd refrigerant path which opposes mitigation device), 41c ... 1st edge part, 42 ... 2nd end surface (End surface facing the relaxation device in the refrigerant passage), 50... First bent portion (bent portion), 60. Ket (relaxation device), 61 ... through hole (third refrigerant passage), 61a ... third cross section (cross section of the third refrigerant passage facing the second refrigerant passage), 61c ... fifth edge ( Out of the peripheral edges of the cross section of the third refrigerant passage facing the second refrigerant passage, the edge located on the outer peripheral side of the bent portion), 69... Fourth cross section (of the third refrigerant passage facing the opening) Cross section), L ... Cooling water (refrigerant).

Claims (7)

A water jacket provided around the peripheral wall of the combustion chamber defining the combustion chamber in the internal combustion engine;
An opening formed in a side wall of the internal combustion engine, the opening having a first refrigerant passage that guides the refrigerant into the water jacket from the outside of the cylinder block;
A second refrigerant path for guiding the refrigerant from the outside of the cylinder block to the first refrigerant path;
Comprising
A cooling structure for an internal combustion engine, wherein a cross section of the first refrigerant passage facing the second refrigerant passage is larger than a cross section of the second refrigerant passage facing the opening. The second refrigerant passage has a bent portion that bends;
The first edge located on the outer peripheral side of the bent portion at the peripheral edge of the cross section of the first passage facing the second refrigerant passage is a cross section of the second refrigerant passage facing the opening. 2. The cooling structure for an internal combustion engine according to claim 1, wherein the cooling structure is located outside a second edge portion located on an outer peripheral portion side of the bent portion at a peripheral edge of the internal combustion engine. A water jacket provided around a combustion chamber peripheral wall defining a combustion chamber in the internal combustion engine;
An opening formed in a side wall of the internal combustion engine, the opening having a first refrigerant passage that guides the refrigerant into the water jacket from the outside of the cylinder block;
A second refrigerant path for guiding the refrigerant from the outside of the cylinder block to the first refrigerant path;
A relaxation device that is interposed between the opening and the second refrigerant passage and relaxes the flow of the refrigerant;
A cooling structure for an internal combustion engine, comprising: The relaxation device has a third refrigerant passage that communicates with the first and second refrigerant passages and guides the refrigerant to the first refrigerant passage,
4. The internal combustion engine according to claim 3, wherein a cross section of the third refrigerant path facing the second refrigerant path is smaller than a cross section of the second refrigerant path facing the mitigation device. 5. Cooling structure. The second refrigerant passage has a bent portion that bends;
Of the peripheral edge of the cross section of the third refrigerant passage facing the second refrigerant passage, the edge located on the outer peripheral side of the bent portion is the cross section of the second refrigerant passage facing the relaxation device. 5. The cooling structure for an internal combustion engine according to claim 4, wherein the cooling structure is located on an inner side of an edge located on an outer peripheral portion side of the bent portion.   The cooling structure for an internal combustion engine according to claim 4, wherein the relaxation device is a gasket.   The cooling structure for an internal combustion engine according to claim 4, wherein a cross section of the first refrigerant passage facing the relaxation device is larger than a cross section of the third refrigerant passage facing the opening.

Images