JP3213078U - Engine valve and engine equipped with the same - Google Patents

Abstract

An engine valve capable of further improving the cooling effect of a valve portion of an engine valve without causing a decrease in strength and an engine including the same are provided. An engine valve includes a valve head and a valve stem with which the valve head is integrated, and metallic sodium Na is sealed in a hollow portion provided therein. Here, the valve stem 64 includes a base portion 72 integrated with the valve head 62 and a stem end portion 74 connected to the base portion 72. The concave portions 62b and 72a constituting the hollow portion 66 are provided in the upper portion. Further, the stem end portion 74 is provided with a conical portion 78 protruding into the hollow portion 66. Accordingly, the contact area between the metallic sodium Na and the valve stem 64 is increased without causing a decrease in strength, and the heat of the valve head 62 can be effectively radiated through the valve stem 64. [Selection] Figure 12

Description

  The present invention relates to an engine valve configured to open and close a communication opening between an intake passage and an exhaust passage provided in a cylinder head and a combustion chamber, and an engine including the engine valve.

  Japanese Patent Laying-Open No. 2012-87620 (Patent Document 1) includes a shaft portion that is slidably supported by a valve guide, and a valve portion that is integrally formed with the shaft portion, and a hollow portion is provided therein. And an engine valve in which metallic sodium is sealed in the hollow portion.

  In the engine valve, when the metallic sodium sealed in the hollow portion flows in the hollow portion in accordance with the opening / closing operation (axial movement) of the engine valve, the upper surface of the metallic sodium is always located inside the valve guide. The amount of the sealed portion, in other words, the amount of sealed sodium that is always in contact with the valve guide via the shaft, is set so that the heat of the valve portion that is exposed to high-temperature combustion gas and becomes hot. Can be efficiently conducted to the valve guide through the metallic sodium and the shaft portion.

JP 2012-87620 A

  By the way, the amount of heat transfer from metallic sodium to the shaft part of the engine valve is proportional to the contact area between metallic sodium and the inner peripheral surface of the shaft part (the inner surface of the hollow part). The cooling effect can be further improved. To increase the contact area, it is possible to increase the diameter (inner diameter) of the inner peripheral surface (hollow part) of the shaft part of the engine valve, or to extend the hollow part to the shaft end of the engine valve. This is a trade-off with reduced engine valve strength. The above-mentioned publication does not mention anything about these points, and there is still room for improvement in terms of improving the cooling effect of the valve part without causing a decrease in strength.

  The present invention has been made in view of the above, and an object thereof is to provide a technique capable of further improving the cooling effect of the valve portion of the engine valve without causing a decrease in strength.

  The engine valve of the engine of the present invention and the engine including the same employ the following means in order to achieve the above-described object.

  According to a preferred embodiment of the engine valve according to the present invention, an engine valve configured to open and close a communication opening between an intake passage and an exhaust passage provided in a cylinder head and a combustion chamber is configured. The engine valve includes a shaft portion having a hollow portion therein, a valve portion integrated with the shaft portion, and a heat transfer medium sealed in the hollow portion. The shaft portion includes a first shaft portion connected to the valve portion, and a second shaft portion connected to an end portion of the first shaft portion opposite to the side to which the valve portion is connected. ing. The first shaft portion is provided with a recess that forms a hollow portion. The said recessed part is opened in the edge part by the side of the 1st axial part to which the 2nd axial part is connected. The second shaft portion has an extending portion that extends in the axial direction of the second shaft portion. The extension portion is configured to protrude into the recess when the second shaft portion is connected to the first shaft portion. Here, “integrated with the shaft portion” suitably includes a mode in which the shaft portion and the valve portion are integrally molded, and a mode in which the shaft portion and the valve portion are formed separately and then integrated.

  According to the present invention, since the extending portion of the second shaft portion protrudes into the recess of the first shaft portion, the contact area with the shaft portion of the heat transfer medium increases by the surface integral of the extending portion. . As a result, the amount of heat transferred from the heat transfer medium to the shaft portion increases, so that the heat of the valve portion that has been exposed to high-temperature combustion gas and becomes hot is effectively radiated from the shaft portion through the heat transfer medium. be able to. In addition, since only the extending part which protrudes in a recessed part is provided, a structure is simple and the strength reduction of engine valve itself is not caused. Thereby, the cooling effect of a valve part can be improved further, without causing a strength fall.

  According to the further form of the engine valve which concerns on this invention, the extension part is formed in the cone shape.

  According to this embodiment, it is possible to increase the contact area between the heat transfer medium and the shaft portion without reducing the fluidity of the heat transfer medium in the hollow portion.

  According to the further form of the engine valve which concerns on this invention, the valve part is comprised so that it may connect to the recessed part of a 1st axial part, and may have the 2nd recessed part which comprises a hollow part.

  According to this form, since a heat transfer medium can be made to flow inside the valve part exposed to high temperature combustion gas, the cooling effect of a valve part can be improved more effectively.

  According to a preferred embodiment of the engine according to the present invention, the engine includes a cylinder head, a cylinder block, a piston, and the engine valve according to any one of the above-described aspects of the present invention. The cylinder head has an intake passage and an exhaust passage, and a combustion chamber constituting recess that forms a combustion chamber. The cylinder block has a cylinder bore. The piston is accommodated in the cylinder bore so as to be slidable in the cylinder bore. The combustion chamber is composed of a combustion chamber constituting recess, a cylinder bore, and a piston. The intake and exhaust passages and the combustion chamber are configured to communicate with each other through a communication opening. Then, by opening and closing the communication opening using an engine valve, air is introduced from the intake passage to the combustion chamber, and combustion gas is discharged from the combustion chamber to the exhaust passage.

  According to the present invention, air is introduced from the intake passage to the combustion chamber by opening and closing the communication opening using the engine valve according to any one of the above-described aspects of the present invention, and the combustion gas from the combustion chamber to the exhaust passage. Therefore, the engine valve according to the present invention has the same effect as the engine valve, for example, the effect of further improving the cooling effect of the valve portion of the engine valve without reducing the strength. be able to. As a result, knocking can be suppressed and fuel consumption can be improved.

  According to the present invention, the cooling effect of the valve portion of the engine valve can be further improved without causing a decrease in strength.

It is a block diagram which shows the outline of a structure of the engine 1 which concerns on embodiment of this invention. It is sectional drawing which shows the cross section which cut the cylinder head 2 with the plane orthogonal to a cylinder row direction. It is explanatory drawing which shows a mode that the valve mechanism 20 was assembled | attached to the cylinder head 2. FIG. 3 is an exploded view of the valve mechanism 20. FIG. It is an external view which shows the external appearance of the engine valve 28 which concerns on embodiment of this invention. It is a disassembled perspective view of the engine valve 28 which concerns on embodiment of this invention. It is an external view which shows the external appearance of the base part 72 with which the valve head 62 was united. It is sectional drawing which shows the AA cross section of FIG. 3 is an external view showing an external appearance of a stem end portion 74. FIG. It is a disassembled perspective sectional view which shows the cross section of the state which decomposed | disassembled the engine valve 28 which concerns on embodiment of this invention. It is a perspective sectional view showing a section of engine valve 28 concerning an embodiment of the invention. It is explanatory drawing which shows the state by which metal sodium Na was enclosed in the hollow part.

  Next, the best mode for carrying out the present invention will be described with reference to examples.

  As shown in FIG. 1, the engine 1 according to the present embodiment includes a cylinder head 2, an intake camshaft 4 and an exhaust camshaft 6 that are rotatably supported by the cylinder head 2, and a cylinder head 2. The valve mechanism 20 arranged, the rocker cover 8 attached to the upper part of the cylinder head 2, the cylinder block 10 attached to the lower part of the cylinder head 2, and the cylinder bore 10a of the cylinder block 10 are slidably accommodated. A piston 12, a crankshaft 16 coupled to the piston 12 via a connecting rod 14 and rotatably supported by the cylinder block 10, and an oil pan 18 attached to the lower portion of the cylinder block 10. .

  As shown in FIG. 2, the cylinder head 2 includes bearing portions 42a and 42b for supporting the intake camshaft 4 and the exhaust camshaft 6, valve lifter guide bosses 44a and 44b, an intake passage 46, and an exhaust passage. It has a passage 48 and a combustion chamber constituting recess 50. As shown in FIG. 1, a combustion chamber CC is constituted by the combustion chamber constituting recess 50, the cylinder bore 10 a, and the piston 12. The cylinder head 2 is formed with through holes 47a and 47b penetrating from the upper deck 2a to the intake passage 46 and the exhaust passage 48, respectively.

  As shown in FIG. 2, the lifter guides 45a and 45b are formed in the valve lifter guide bosses 44a and 44b, and a later-described valve lifter 22 is slidably accommodated in the lifter turbos 45a and 45b. The lift turbo 45a is configured coaxially with the through hole 47a, and the lift turbo 45b is configured coaxial with the through hole 47b.

  As shown in FIG. 2, the intake passage 46 and the exhaust passage 48 communicate with the combustion chamber constituting recess 50 through communication openings 52 a and 52 b, respectively. The communication opening 52a is coaxial with the riff turbo door 45a and the through hole 47a, and the communication opening 52b is coaxial with the riff turbo door 45b and the through hole 47b. Valve seats 54a and 54b are installed in the communication openings 52a and 52b.

  The valve mechanism 20 is configured as a mechanism that operates in accordance with the rotation of the intake camshaft 4 and the exhaust camshaft 6 to connect and disconnect the communication between the intake passage 46 and the exhaust passage 48 and the combustion chamber CC. Yes. As shown in FIGS. 3 and 4, the valve mechanism 20 includes a valve lifter 22 configured in a bottomed cylindrical shape, a valve guide 24 configured in a cylindrical shape, an oil seal 26, and an embodiment of the present invention. The engine valve 28, the valve spring 30, the spring seat 32, the spring retainer 34, and the cotter 36 are configured. In the present embodiment, the valve mechanism 20 has basically the same configuration for intake and exhaust.

  As shown in FIG. 4, the valve lifter 22 is configured such that the intake cam 4a and the exhaust cam 6a provided on the intake camshaft 4 and the exhaust camshaft 6 are in contact with the bottom wall. The valve lifter 22 is configured as a member that converts the rotational motion of the intake cam 4a and the exhaust cam 6a into linear motion.

  As shown in FIG. 3, the valve guide 24 is press-fitted into the through holes 47a and 47b of the cylinder head 2 so that the upper part protrudes into the lift turbo-lowers 45a and 45b of the valve lifter guide bosses 44a and 44b. Here, the through holes 47a and 47b are formed adjacent to a water jacket WJ provided in the cylinder head 2, as shown in FIG. In other words, the valve guide 24 is installed at a position adjacent to the water jacket WJ, as shown in FIG. The valve guide 24 is preferably formed so that its axial length is as long as possible from the viewpoint of improving the slidability of the valve stem 64 described later.

  The engine valve 28 according to the embodiment of the present invention is made of, for example, heat-resistant steel (SUH35). As shown in FIGS. 3 and 4, the valve head 62 and the valve head 62 are integrated. And a valve stem 64. As shown in FIGS. 5, 11, and 12, the engine valve 28 has a hollow portion 66 provided therein, and metallic sodium Na is sealed in the hollow portion 66. Metal sodium Na is an example of the implementation structure corresponding to the "heat transfer medium" in this invention.

  As shown in FIG. 5, the valve head 62 has a valve face 62a. Further, as shown in FIGS. 8 and 12, a concave portion 62b constituting a part of the hollow portion 66 (see FIG. 12) is formed inside the valve head 62. As shown in FIG. 3, the valve face 62 a is configured as a contact surface that contacts valve seats 54 a and 54 b installed in the communication openings 52 a and 52 b of the cylinder head 2. By contacting the valve face 62a with the valve seats 54a and 54b, the communication between the intake passage 46 and the exhaust passage 48 and the combustion chamber CC is reliably blocked. The valve head 62 is an example of the implementation structure corresponding to the “valve part” in the present invention. Moreover, the recessed part 62b is an example of the implementation structure corresponding to the "2nd recessed part" in this invention.

  The valve stem 64 is configured as a shaft portion that is inserted into the valve guide 24, and as shown in FIG. 6, a base portion 72 to which the valve head 62 is integrally connected, and the base portion 72. And a stem end portion 74. The valve stem 64 corresponds to the “shaft portion” in the present invention, the base portion 72 corresponds to the “first shaft portion” in the present invention, and the stem end portion 74 corresponds to the “second shaft portion” in the present invention. It is an example of the corresponding implementation structure.

  The base portion 72 is configured as a guide sliding contact portion that is in sliding contact with the inner peripheral surface of the valve guide 24. As shown in FIGS. 7 and 8, a recess 72 a that constitutes a part of the hollow portion 66 is formed inside the base portion 72. The concave portion 72a is opened at one end side in the axial direction of the base portion 72 (the side opposite to the side to which the valve head 62 is connected), and the other end side in the axial direction of the base portion 72 (to which the valve head 62 is connected). And communicated with the recess 62b of the valve head 62.

  As shown in FIGS. 6 and 9, the stem end portion 74 is integrated with a cylindrical portion 76 in which an annular groove 76 a for engaging the cotter 36 is formed, and one axial end portion of the cylindrical portion 76. A conical portion 78 having a conical shape. As shown in FIG. 11, the stem end portion 74 is integrally connected to the valve stem 64 in a state where the conical portion 78 protrudes into the recess 72 a of the base portion 72. Thereby, a hollow portion 66 is formed in the engine valve 28. The conical part 78 is an example of the implementation structure corresponding to the "extension part" in this invention.

  Next, a state in which the valve head 62 of the engine valve 28 that opens and closes the communication openings 52a and 52b of the cylinder head 2 as the engine 1 configured as described above is cooled will be described. When the operation of the engine 1 is started, the intake camshaft 4 and the exhaust camshaft 6 are rotated, and the rotational force of the intake cam 4a and the exhaust cam 6a acts on the valve lifter 22.

  The rotational motion of the intake cam 4a and the exhaust cam 6a is converted into a linear motion by the valve lifter 22, and the engine valve 28 slides along the axial direction of the valve stem 64. As a result, the valve head 62 opens the communication opening 52a and the communication opening 52b of the cylinder head 2, and the air-fuel mixture from the intake passage 46 is supplied to the combustion chamber CC via the communication opening 52a. The combustion gas is discharged to the exhaust passage 48 through the communication opening 52b.

  At this time, the metallic sodium Na sealed in the hollow portion 66 of the engine valve 28 flows in the hollow portion 66 as the engine valve 28 slides along the axial direction. Due to the flow of the metallic sodium Na, the heat of the valve head 62 exposed to the high-temperature combustion gas in the combustion chamber CC is transferred to the metallic sodium Na, and the heat transferred to the metallic sodium Na is the valve stem. The heat is dissipated through 64.

  Here, in this embodiment, since the conical portion 78 of the stem end portion 74 protrudes into the hollow portion 66, the area where the metallic sodium Na flowing in the hollow portion 66 contacts the valve stem 64 is increased. Therefore, heat conduction from the metallic sodium Na to the valve stem 64 is performed more effectively.

  In addition, the heat from the metal sodium Na which contacted the inner peripheral surface of the hollow part 66 among the metal sodium Na flowing in the hollow part 66 is radiated mainly through the base part 72 of the valve stem 64. Since the base portion 72 slides in the valve guide 24 disposed adjacent to the water jacket WJ, the base portion 72 is well cooled by the cooling water flowing through the water jacket WJ. Thereby, the heat dissipation via the base part 72 can be accelerated | stimulated.

  In addition, the heat from the metal sodium Na that contacts the surface of the conical portion 78 protruding into the hollow portion 66 out of the metal sodium Na flowing in the hollow portion 66 is mainly radiated through the stem end portion 74. Since the stem end portion 74 is indirectly cooled by lubricating oil that lubricates the sliding contact portion between the intake cam 4a and the exhaust cam 6a and the valve lifter 22, heat dissipation through the stem end portion 74 is promoted. Can be done.

  According to the engine valve 28 according to the embodiment of the present invention described above, the hollow portion 66 is provided inside, the metallic sodium Na is enclosed in the hollow portion 66, and the conical portion protruding into the hollow portion 66 is provided. 78 is provided to increase the contact area between the metallic sodium Na to which heat is transferred from the high temperature valve head 62 and the valve stem 64, so that the heat from the valve head 62 is effectively transmitted through the valve stem 64. Can dissipate heat. Since the conical portion 78 is only projected into the hollow portion 66 in which the metallic sodium Na is sealed, the structure is simple and the strength of the engine valve 28 itself is not reduced. Thereby, the cooling effect of a valve part can be improved further, without causing a strength fall.

  In the present embodiment, the conical conical portion 78 protrudes into the hollow portion 66, but the present invention is not limited to this. For example, a configuration in which a triangular pyramid-shaped triangular pyramid portion protrudes into the hollow portion 66 or a configuration in which a cylindrical columnar column portion protrudes may be employed.

  In the present embodiment, the single conical portion 78 protrudes into the hollow portion 66, but the present invention is not limited to this. For example, it is good also as a structure which makes the several cone part 78 protrude in the hollow part 66. FIG. According to the said structure, since the area which metal sodium Na can contact can be increased more, the cooling effect of the valve head 62 can be improved further.

  In the present embodiment, the concave portion 62b is provided in the valve head 62 and the hollow portion 66 is formed from the base portion 72 to the valve head 62. However, the present invention is not limited to this. For example, the concave portion 62 b is not provided in the valve head 62, and the hollow portion 66 may be formed only in the base portion 72.

  In the present embodiment, the metallic sodium Na is sealed in the hollow portion 66. However, as long as the heat of the valve head 62 can be transmitted to the valve stem 64, the medium is not limited to the metallic sodium Na, and any medium is sealed. Also good.

  In the present embodiment, the entire engine valve 28 is made of the same material (heat resistant steel (SUH35)), but is not limited thereto. For example, the base portion 72 and the stem end portion 74 of the valve stem 64 may be made of different materials. In this case, a material having a thermal conductivity of the stem end portion 74 higher than that of the base portion 72 can be used.

  This embodiment shows an example for carrying out the present invention. Therefore, the present invention is not limited to the configuration of the present embodiment.

1 Engine (Engine)
2 Cylinder head (cylinder head)
2a Upper deck 4 Intake camshaft 4a Intake cam 6 Exhaust camshaft 6a Exhaust cam 8 Rocker cover 10 Cylinder block
10a Cylinder bore (cylinder bore)
12 Piston
14 Connecting rod 16 Crankshaft 18 Oil pan 20 Valve mechanism 22 Valve lifter 24 Valve guide 26 Oil seal 28 Engine valve (engine valve)
30 valve spring 32 spring seat 34 spring retainer 36 cotter 42a bearing portion 42b bearing portion 44a valve lifter guide boss 44b valve lifter guide boss 45a lift turbo door 45b lift turbo door 46 intake passage (intake passage)
47a Through hole 47b Through hole 48 Exhaust passage (exhaust passage)
50 Combustion chamber configuration recess
52a Communication opening (communication opening)
52b Communication opening (communication opening)
54a Valve seat 54b Valve seat 62 Valve head (valve part)
62a Valve face 62b Recess (second recess)
64 Valve stem (shaft)
66 Hollow part (hollow part)
72 Base part (first shaft part)
72a Concave part (concave part)
74 Stem end (second shaft)
76 Cylindrical part 76a Annular groove 78 Conical part (extension part)
CC combustion chamber (combustion chamber)
WJ Water jacket Na Metal sodium (Heat transfer medium)

Claims (4)

An engine valve configured to be able to open and close a communication opening between an intake passage and an exhaust passage provided in a cylinder head and a combustion chamber,
A shaft portion having a hollow portion inside,
A valve unit integrated with the shaft unit;
A heat transfer medium enclosed in the hollow portion;
With
The shaft portion includes a first shaft portion connected to the valve portion, a second shaft portion connected to an end portion of the first shaft portion opposite to the side to which the valve portion is connected, and Have
The first shaft portion is provided with a recess that constitutes the hollow portion,
The recess is opened at an end of the first shaft portion to which the second shaft portion is connected,
The second shaft portion has an extending portion extending in the axial direction of the second shaft portion,
The extension portion is configured to project into the recess when the second shaft portion is connected to the first shaft portion. The engine valve according to claim 1, wherein the extension portion is formed in a conical shape. The engine valve according to claim 1 or 2, wherein the valve portion is configured to have a second recess that is connected to the recess and forms the hollow portion. A cylinder head having an intake passage and an exhaust passage, and a combustion chamber constituting concave portion constituting a combustion chamber;
A cylinder block having a cylinder bore;
A piston accommodated in the cylinder bore slidably in the cylinder bore;
The engine valve according to any one of claims 1 to 3,
With
The combustion chamber is constituted by the combustion chamber constituting concave portion, the cylinder bore, and the piston.
The intake passage, the exhaust passage, and the combustion chamber are configured to communicate with each other through a communication opening;
An engine configured to open and close the communication opening using the engine valve to introduce air from the intake passage to the combustion chamber and to discharge combustion gas from the combustion chamber to the exhaust passage.

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