JP2009013935A - Hollow valve for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hollow valve for an internal combustion engine having good cooling properties. <P>SOLUTION: The hollow valve 10A for the internal combustion engine provided with a stem part Vs, a head part Vh provided on one end of the stem part Vs, a sealed hollow part 4 communicating with the inside between the head part Vh and the stem part Vs, and refrigerant 5 filled in the hollow part 4. The head part Vh includes a wall surface section (lower cap 3) having a combustion chamber wall surface 3a forming a part of a wall surface of a combustion chamber CC of the internal combustion engine and a hollow part wall surface 3b forming a part of a wall surface of the hollow part 4. At least one high heat conduction member 6A performing high heat conduction between the wall surface section and at least either of heat conduction objects of refrigerant 5 and the stem part Vs is provided on the hollow part wall surface 3b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hollow valve for an internal combustion engine used for an intake / exhaust valve operating mechanism in the internal combustion engine.

  In the valve mechanism for intake / exhaust in an internal combustion engine, a valve for communicating or blocking between the intake port and the combustion chamber or between the exhaust port and the combustion chamber is provided. In general, this valve is roughly divided into an umbrella part and a shaft part, and a reciprocating motion of the shaft part in the axial direction creates a communication or blocking state between the intake port and the combustion chamber or between the exhaust port and the combustion chamber. .

  Here, since the umbrella part of this valve, especially the part which comprises a part of wall surface of a combustion chamber, is exposed to the combustion gas of a combustion chamber, the heat | fever generated by combustion becomes easy to be transmitted. In particular, in recent years, the amount of heat generated in the combustion chamber has increased due to not only the high output of the internal combustion engine but also the combustion mode performed to reduce the amount of fuel consumed and harmful substances (hydrocarbons, etc.) in the exhaust gas. There is a tendency to increase the heat transmitted to the umbrella.

  Therefore, conventionally, there is a valve that makes it easy to release heat transmitted to the umbrella. For example, in Patent Document 1 below, there is a hollow valve for an internal combustion engine in which a sealed hollow portion connected from an umbrella portion to a shaft portion is formed in a valve, and a green compact serving as a heat conduction medium is sealed in the hollow portion. It is disclosed. In this hollow valve for an internal combustion engine, the hollow portion is not filled with the heat conduction medium, so that the heat conduction medium is swung in the hollow portion as the valve reciprocates and flows between the umbrella portion and the shaft portion. To do. Therefore, in this hollow valve for an internal combustion engine, the heat of the umbrella part transmitted from the combustion chamber can be transferred to the shaft part by the heat conduction medium, and the excessive temperature rise of the umbrella part can be suppressed. .

  The following Patent Document 2 relates to a heat radiating base material of a semiconductor device unrelated to a hollow valve for an internal combustion engine. However, the rod has a higher thermal conductivity than the base material in a direction perpendicular to the base material. A technique for embedding (made of at least one of a carbon fiber reinforced composite material, a carbon-based metal composite material, a highly heat conductive metal material, etc.) to obtain good heat conduction characteristics is described.

Japanese Patent Laid-Open No. 5-113113 JP 2003-188324 A

  However, there are many types of internal combustion engines, but in almost all types of internal combustion engines, the axial direction of the hollow valve for internal combustion engines does not match the direction of gravity. The heat conduction medium (refrigerant) does not necessarily come into uniform contact with the wall surfaces of the umbrella part and the shaft part in the hollow part, and each of them may not be cooled uniformly. For example, since a so-called serial internal combustion engine is generally mounted on a vehicle with an inclination, it is unlikely that the axial direction of the hollow valve for the internal combustion engine coincides with the direction of gravity. In addition, since the so-called V-shaped (including horizontally opposed) internal combustion engine is provided with a bank angle, it is also unlikely that the axial direction of the hollow valve for internal combustion engine coincides with the direction of gravity. Further, in the first place, since the hollow valve for an internal combustion engine is generally tilted and mounted on the internal combustion engine, the axial direction and the gravity direction do not match.

  In other words, in a conventional hollow valve for an internal combustion engine, for example, heat is transmitted to a heat transfer medium in a certain part of the umbrella portion in the hollow portion, and the heat can be released to a heat transfer target such as a shaft portion. However, it is also possible that the heat conduction medium cannot touch the wall surface in other parts, and it is impossible to take the heat there, which makes it particularly effective for cooling the umbrella part that requires cooling. Spots may appear. In order to improve such inconvenience, the amount of the heat conduction medium (generally metallic sodium) may be increased. However, most of the heat conduction medium moves in the direction opposite to the movement direction of the valve. Further, since the inertia force of the valve increases with the increase, the smooth reciprocation of the hollow valve for the internal combustion engine may be hindered.

  Accordingly, an object of the present invention is to provide a hollow valve for an internal combustion engine that improves the disadvantages of the conventional example and has good cooling performance.

  In order to achieve the above object, according to the first aspect of the present invention, a shaft portion, an umbrella portion provided at one end of the shaft portion, and a sealed hollow that communicates internally between the umbrella portion and the shaft portion. In the hollow valve for an internal combustion engine comprising a portion and a refrigerant sealed in the hollow portion, the umbrella portion is a part of a wall surface of the combustion chamber of the internal combustion engine and a wall surface of the hollow portion. And a hollow portion having a wall portion formed with a hollow portion, and a high heat conduction member that conducts high heat conduction between the wall portion and at least one of the heat transfer target of the refrigerant or the shaft portion. At least one is arranged with respect to the part wall surface.

  In the hollow valve for an internal combustion engine according to the first aspect, the heat of the wall surface portion is taken away by the high heat conductive member, so that the wall surface portion can be cooled. Further, since the heat taken away by the high heat conducting member is transmitted to a heat transfer target such as a refrigerant, it is finally transferred from the heat transfer target to the cylinder head. For this reason, the hollow valve for an internal combustion engine can efficiently cool the umbrella portion that is likely to be the highest temperature.

  In order to achieve the above object, according to a second aspect of the present invention, in the hollow valve for an internal combustion engine according to the first aspect, the one end brought into contact with the wall surface of the hollow portion and the other end brought into contact with the heat transfer object. A highly heat-conductive member having a heat conduction direction between them is prepared. For example, as this type of high thermal conductive member, a carbon fiber reinforced metal can be considered as in the third aspect of the invention.

  In the hollow valve for an internal combustion engine according to claim 2 or 3, the heat of the wall surface portion can be reliably transmitted to a desired heat transfer target.

  In order to achieve the above object, according to a fourth aspect of the present invention, in the hollow valve for an internal combustion engine according to the first, second, or third aspect of the present invention, a high heat capable of transferring the heat of the wall surface portion to the refrigerant. A plurality of conductive members are arranged so as to protrude in substantially the same direction as the axial direction of the shaft portion so that convex portions are formed.

  In the hollow valve for an internal combustion engine according to claim 4, since the refrigerant splashed up by the convex portion along with the reciprocating motion is delivered to the upper side of the shaft portion, the heat taken by the refrigerant from the high heat conductive member is It is transmitted to the upper part of the section. Therefore, this hollow valve for an internal combustion engine can obtain a particularly high cooling effect of the umbrella portion.

  In order to achieve the above object, according to a fifth aspect of the present invention, in the hollow valve for an internal combustion engine according to the first, second, or third aspect, the other end of the hollow portion wall surface and the shaft portion opposite to the umbrella portion. A high heat conduction member is disposed so that heat conduction is performed between the wall surface and the wall.

  In the hollow valve for an internal combustion engine according to claim 5, whether or not it is inclined and arranged, but even when the valve lift amount is small and the refrigerant does not significantly jump, Since heat is directly transmitted to the wall surface near the other end of the shaft portion, the wall surface portion can be reliably cooled.

  In order to achieve the above object, according to a sixth aspect of the present invention, in the hollow valve for an internal combustion engine according to any one of the first to fifth aspects, the central portion of the wall surface of the hollow portion and the heat transfer target High heat conduction member is arranged so that heat conduction is performed between the peripheral part of the wall surface of the hollow part and the vicinity of the valve seat of the umbrella part in the hollow part. is doing.

  In the hollow valve for an internal combustion engine according to the sixth aspect, the heat of the wall surface part is transmitted not only to the heat transfer target (refrigerant or shaft part) but also to the vicinity of the valve seat of the umbrella part. Therefore, for example, if the intake air temperature rises and you do not want to increase the temperature of the shaft, a highly heat-conductive member is arranged near the valve seat to increase the heat dissipation, and the intake air temperature rises. Try to be suppressed.

  The hollow valve for an internal combustion engine according to the present invention has a high heat dissipation property of the high heat conduction member itself, and heat is transmitted from the high heat conduction member to the heat transfer target, so that a good cooling performance is ensured particularly in the umbrella portion. Will be able to.

  Embodiments of a hollow valve for an internal combustion engine according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

  A first embodiment of a hollow valve for an internal combustion engine according to the present invention will be described with reference to FIGS.

  1 denotes a hollow valve for an internal combustion engine according to the first embodiment. The hollow valve 10A for an internal combustion engine according to the first embodiment is used for an intake or exhaust valve mechanism (a mechanism including a valve lifter 101 or the like) in an internal combustion engine (not shown), and a combustion chamber CC of the internal combustion engine. The communication is made between the intake ports P (or between the combustion chamber CC and the exhaust port P) by reciprocating in the axial direction.

  First, the hollow valve 10A for the internal combustion engine of the first embodiment is roughly divided into a shaft portion (so-called valve stem) Vs and an umbrella portion Vh provided at an end portion of the shaft portion Vs, and these are opened at both ends. A cylindrical valve main body 1, a first closing member (hereinafter referred to as “upper cap”) 2 that closes an opening at one end of the valve main body 1, and a first closing member that closes an opening at the other end of the valve main body 1. 2 occlusion member (hereinafter referred to as “lower cap”) 3.

  The valve main body 1 includes a cylindrical portion 1a having both ends opened, and a truncated cone portion 1b formed in a substantially truncated cone shape having an inner space connecting the upper bottom opening and the lower bottom opening. , And is integrally formed by combining one open end of the cylindrical portion 1a and the open end on the upper bottom side of the truncated cone portion 1b. The inner space in the truncated cone part 1b is formed in a shape close to a truncated cone substantially the same as the outer shape. Accordingly, in the valve main body 1, a hollow portion 4 having a shape in which a columnar space in the cylindrical portion 1a and a substantially frustoconical space in the truncated cone portion 1b are connected is formed. That is, in the valve main body 1, the hollow portion 4 has a shape substantially equivalent to the outer shape.

  Here, in the valve main body 1, the cylindrical portion 1a forms the main portion of the shaft portion Vs, and the remaining opening end of the cylindrical portion 1a (that is, the opening end on the opposite side to the truncated cone portion 1b). ) Is provided with an upper cap 2. That is, the shaft portion Vs of the internal combustion engine hollow valve 10 </ b> A exemplified here is composed of the cylindrical portion 1 a of the valve main body 1 and the upper cap 2. For example, the upper cap 2 is integrated with the cylindrical portion 1a using a technique such as welding, thereby closing the opening end of the valve main body 1 on the cylindrical portion 1a side.

  Further, in the valve main body 1, the truncated cone part 1b forms the main part of the umbrella part Vh, and a lower cap is attached to the remaining opening end of the truncated cone part 1b (that is, the opening end on the lower bottom side). 3 is disposed. That is, the umbrella portion Vh of the internal combustion engine hollow valve 10 </ b> A exemplified here is constituted by the truncated cone portion 1 b of the valve main body 1 and the lower cap 3. For example, the lower cap 3 is shown in FIG. 1 forming a part of the wall surface of the combustion chamber CC when the port P (referring to an intake port or an exhaust port) P and the combustion chamber CC are in a disconnected state. The combustion chamber wall surface 3a and the hollow portion wall surface 3b shown in FIG. 2 forming a part of the wall surface of the hollow portion 4 are wall surfaces formed in an opposing state. Then, the lower cap 3 is integrated with the truncated cone portion 1b by using a technique such as welding with the hollow portion wall surface 3b on the inside, whereby the opening end of the valve main body 1 on the truncated cone portion 1b side is integrated. Occlude.

  The internal combustion engine hollow valve 10A thus formed reciprocates in the axial direction of the shaft portion Vs by the action of the valve mechanism. For example, the internal combustion engine hollow valve 10A is pressed through the valve lifter 101 by the operation of a cam or a rocker arm (not shown). Accordingly, in the internal combustion engine hollow valve 10A, the inclined surface of the umbrella portion Vh is a boundary portion between the port P (referring to the intake port or the exhaust port) P and the combustion chamber CC (that is, in FIG. 1). The two are separated from the illustrated annular valve seat 102) and communicated between the two.

  On the other hand, here, in conjunction with the pressing operation of the internal combustion engine hollow valve 10A, the annular retainer 103 fixed to the upper cap 2 compresses the elastic member (winding spring) 104 with, for example, the cylinder head 105. ing. Therefore, the elastic force of the elastic member 104 acts on the internal combustion engine hollow valve 10A via the retainer 103 in accordance with the operation of the cam or the like. For this reason, this internal combustion engine hollow valve 10A is moved in the direction opposite to the pressing operation, and the inclined surface of the umbrella portion Vh abuts against the valve seat 102 to block the two.

  The hollow valve 10A for the internal combustion engine has a shaft portion Vs surrounded by a cylindrical valve stem guide 106, and the valve stem guide 106 smoothly guides the reciprocating motion.

  Furthermore, the internal combustion engine hollow valve 10A is provided with a cooling means for releasing heat transferred from the combustion chamber CC (particularly, heat of a portion exposed to the combustion gas such as the lower cap 3).

  In the first embodiment, as the cooling means, first, a coolant 5 such as metallic sodium is enclosed in the hollow portion 4. At least when the internal combustion engine is in operation, if the refrigerant 5 is metallic sodium, it is in a liquid state exceeding the melting point. The refrigerant 5 is shaken with the reciprocating motion of the internal combustion engine hollow valve 10 </ b> A and is caused to flow in the hollow portion 4. And the refrigerant | coolant 5 which contact | connected the wall surface of the hollow part 4 whose temperature is higher than itself takes heat from the wall surface, and flows further each time the reciprocating motion is repeated, and contacts the wall surface of the hollow part 4 whose temperature is lower than itself. When passing heat to the wall. For example, in the internal combustion engine hollow valve 10A, the heat of the umbrella portion Vh that is likely to become the highest temperature is received by the refrigerant 5, and the refrigerant 5 moves to the shaft portion Vs as the internal combustion engine hollow valve 10A reciprocates. By doing so, the heat received from the umbrella part Vh is transmitted from the refrigerant 5 to the shaft part Vs, and the umbrella part Vh is cooled.

  In the first embodiment, as another cooling means, at least one high heat conductive member 6A having high thermal conductivity and heat conduction direction is disposed on the hollow portion wall surface 3b of the lower cap 3. For example, carbon fiber reinforced metal (CFRM) can be used as this type of high thermal conductive member 6A. In other words, the carbon fiber reinforced metal is a metal using a metal as a base material and a carbon fiber as a reinforcing material. By exposing the metal of the base material at both ends, the high heat conductive member 6A Heat can be transferred from the high temperature side to the low temperature side between the exposed metal surface at one end and the exposed metal surface at the other end.

  In the first embodiment, a highly heat conductive member 6A formed into a linear shape having a substantially equal length and a small diameter (for example, about 10 μm) covers the entire circular hollow wall surface 3b as shown in FIGS. Arrange multiple lines as you like. In FIG. 2, a clear gap is formed between the high heat conductive members 6A, but the gap is for convenience of illustration. One end of each of these high heat conductive members 6A is bonded to the hollow wall surface 3b using a technique such as metal plating so that the heat transfer efficiency with the lower cap 3 is not hindered.

  As described above, in the hollow valve 10A for the internal combustion engine of the first embodiment, the plurality of high heat conductive members 6A are erected on the entire hollow wall surface 3b of the lower cap 3. Is taken away by all the high thermal conductivity members 6A, and the lower cap 3 can be cooled. Further, in the hollow valve 10A for the internal combustion engine, the heat is transmitted to the refrigerant 5 in contact with the free end (that is, the other end opposite to the hollow portion wall surface 3b) of each high heat conducting member 6A.

  And in this hollow valve 10A for internal combustion engines, each high heat conduction member 6A will be in the state which raised the refrigerant | coolant 5 which is heat transfer object, and it is the same amount of refrigerant | coolants 5 as what is not provided with the high heat conduction member 6A. If there is, even if the internal combustion engine hollow valve 10A is tilted, the reciprocating movement of the refrigerant 5 more reliably reaches the upper side of the shaft portion Vs (the valve lifter 101 side). For this reason, most of the heat (that is, the heat of the lower cap 3) received by the refrigerant 5 from the high heat conducting member 6A is almost the shaft portion Vs {the cylindrical portion 1a of the valve main body 1 and the lower surface of the upper cap 2 (that is, the hollow portion). 4), and is radiated from the shaft portion Vs to the cylinder head 105 through the valve stem guide 106, the valve lifter 101, the cam, and the like. Accordingly, the hollow valve 10A for the internal combustion engine according to the first embodiment can efficiently cool the lower cap 3, thereby increasing the temperature of the valve seat 102 and the valve face surface of the umbrella portion Vh that contacts the valve seat 102. Further, it is possible to effectively suppress the wear of the valve seat 102 and the valve face, and it is possible to improve the durability and the air tightness of the combustion chamber CC.

  On the other hand, when the cooling effect can be sufficiently obtained by the hollow valve for the internal combustion engine in which the high heat conduction member 6A is not provided, the high heat conduction member 6A is provided and the hollow for internal combustion engine of the first embodiment is provided. By using the valve 10A, the amount of the refrigerant 5 enclosed can be reduced, and the inertia mass when reciprocating can be reduced. Therefore, the hollow valve 10A for the internal combustion engine of the first embodiment in this case can reciprocate easily and responsively, and the accuracy of the valve opening timing and the valve closing timing can be improved.

  As described above, the hollow valve 10A for the internal combustion engine according to the first embodiment can effectively cool the umbrella portion Vh that is likely to be the highest temperature. Further, it is possible to improve the airtightness of the combustion chamber CC and the accuracy of the valve opening timing and the valve closing timing. For this reason, the hollow valve 10A for an internal combustion engine can improve the accuracy with respect to the command value of the excess air ratio (that is, the air-fuel ratio, particularly the theoretical air-fuel ratio) of the combustion chamber CC, and can increase the in-cylinder pressure. High output and low fuel consumption are possible. Further, the hollow valve 10A for an internal combustion engine can sufficiently secure heat resistance and durability even if the valve seat 102 is formed by itself and a low-cost material having lower heat resistance and durability than conventional ones. The cost of itself and its peripheral parts can be reduced. Furthermore, this internal combustion engine hollow valve 10A significantly cools the umbrella portion Vh (particularly, the portion forming the wall surface of the combustion chamber CC such as the combustion chamber wall surface 3a of the lower cap 3). Therefore, knocking can be suppressed more than before. Therefore, the internal combustion engine hollow valve 10A can advance the ignition timing associated with the knocking suppression effect, and can improve the output performance.

  Here, in the hollow valve 10A for the internal combustion engine of the first embodiment, the degree of cooling of the umbrella portion Vh can be adjusted by increasing or decreasing the number of high heat conducting members 6A to be arranged. Therefore, when this internal combustion engine hollow valve 10A is applied to the exhaust side, which is easily exposed to high heat, more heat conductive members 6A are disposed than when applied to the intake side to ensure a sufficient cooling effect. You can make it possible. And since the hollow valve 10A for internal combustion engines of the present Example 1 can change a cooling degree only by adjusting the number of the high heat conductive members 6A in this way, it is common to all components at the exhaust side and the intake side. The exhaust valve and the intake valve can be manufactured at low cost.

  Next, a second embodiment of the hollow valve for an internal combustion engine according to the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view taken along the central axis of the valve main body 1 and shows the same shape even if it is cut at any angle of 360 degrees around the central axis.

  3 indicates a hollow valve for an internal combustion engine according to the second embodiment. In the hollow valve 10B for the internal combustion engine of the second embodiment, a plurality of high heat conduction members 6A in the hollow valve 10A for the internal combustion engine of the first embodiment described above are replaced with a plurality of high heat conduction members 6B shown in FIG. Is.

  Specifically, each of the high heat conductive members 6 </ b> B of the second embodiment is arranged in a shape in which the central portion of each high heat conductive member 6 </ b> A of the first embodiment protrudes inward of the hollow portion 4. That is, in the second embodiment, for example, a plurality of linear high heat conductive members 6B having substantially the same length and diameter as those of the first embodiment are arranged in an annular shape on the peripheral portion of the hollow wall surface 3b of the lower cap 3. A plurality of high heat conductive members 6B that are longer than the peripheral portion are arranged so that the convex portion 7 is formed inside the peripheral portion.

  Here, the convex portion 7 of the second embodiment is provided with a high heat conductive member 6B which is formed to have a length gradually increased from the outside so as to gradually increase in height toward the central axis of the hollow valve 10B for the internal combustion engine. Has been.

  Thus, in the hollow valve 10B for the internal combustion engine of the second embodiment, the high heat conductive member 6B is arranged in a shape where the central portion is raised. In other words, according to the space close to the truncated cone shape. Since the length of the high heat conductive member 6B in the center portion is longer than that of the surrounding area, heat from the lower cap 3 is more easily taken away by the convex portion 7 than in the first embodiment. Further, in the hollow valve 10B for an internal combustion engine, the refrigerant 5 that is a heat transfer target in contact with the convex portion 7 during the reciprocating motion can be splashed higher than in the first embodiment, and the refrigerant can be more reliably supplied. 5 reaches the upper side of the shaft portion Vs (the valve lifter 101 side). Accordingly, the internal combustion engine hollow valve 10B can exhibit a higher cooling effect than the internal combustion engine hollow valve 10A of the first embodiment.

  Further, when the cooling effect can be sufficiently obtained by the internal combustion engine hollow valve 10A of the first embodiment, the amount of the refrigerant 5 enclosed can be reduced by providing the convex portion 7 as in the second embodiment. Thus, the inertial mass when reciprocating can be reduced as compared with the first embodiment.

  As described above, the hollow valve 10B for the internal combustion engine of the second embodiment can more effectively cool the umbrella portion Vh that is likely to reach the highest temperature, thereby improving its durability and the valve seat 102. It is possible to further improve the durability, the air tightness of the combustion chamber CC, and the accuracy of the valve opening timing and the valve closing timing. For this reason, the internal combustion engine hollow valve 10B further improves the accuracy with respect to the command value of the excess air ratio of the combustion chamber CC (that is, the air-fuel ratio, particularly the stoichiometric air-fuel ratio), and further increases the in-cylinder pressure. This enables more effective high output and low fuel consumption. Further, the hollow valve 10B for an internal combustion engine has sufficient heat resistance and durability even when the valve seat 102 is formed by itself and a low-cost material having lower heat resistance and durability as in the first embodiment. Therefore, the cost of itself and its peripheral parts can be reduced. Furthermore, this internal combustion engine hollow valve 10B has an umbrella portion Vh (particularly, the portion forming the wall surface of the combustion chamber CC such as the combustion chamber wall surface 3a of the lower cap 3) as in the first embodiment. Compared with the prior art, knocking can be suppressed more than before, so that the ignition timing can be advanced and the output performance can be improved.

  Here, also in the hollow valve 10B for the internal combustion engine of the second embodiment, as in the first embodiment, the degree of cooling of the umbrella portion Vh is adjusted by increasing / decreasing the number of high heat conductive members 6B to be arranged. Can do. Therefore, when this internal combustion engine hollow valve 10B is applied to the exhaust side, which is easily exposed to high heat, more heat conductive members 6B are arranged than when applied to the intake side to ensure a sufficient cooling effect. You can make it possible. The hollow valve 10B for the internal combustion engine of the second embodiment can change the degree of cooling only by adjusting the number of the high heat conducting members 6B in this way, so that most parts are common on the exhaust side and the intake side. The exhaust valve and the intake valve can be manufactured at low cost.

  Further, when a sufficient cooling effect can be obtained with the hollow valve 10B for the internal combustion engine of the second embodiment described above, the high heat conduction member 6B at the peripheral portion is removed, and the central portion (that is, the convex portion 7) is removed. You may comprise only the high heat conductive member 6B, and even if it does in this way, there can exist the same effect. In such a case, a high heat conductive member 6B disposed on the entire hollow portion wall surface 3b having a high cooling effect for the umbrella portion Vh is manufactured as an exhaust valve, and the high heat conductive member at the center portion where the cooling effect for the umbrella portion Vh is lower than this. Only 6B may be manufactured as an intake valve.

  Next, a third embodiment of the hollow valve for an internal combustion engine according to the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view taken along the central axis of the valve main body 1 and shows the same shape even if it is cut at any angle of 360 degrees around the central axis.

  4 indicates a hollow valve for an internal combustion engine according to the third embodiment. The hollow valve 10C for the internal combustion engine of the third embodiment is obtained by replacing the plurality of high heat conduction members 6A with the plurality of high heat conduction members 6C shown in FIG. 4 in the hollow valve 10A for the internal combustion engine of the first embodiment described above. Is.

  Specifically, each of the high heat conductive members 6C of the third embodiment has a central portion extending to the upper cap 2 in each of the high heat conductive members 6A of the first embodiment, in other words, the convex portion of the second embodiment. It can be said that the central portion of the portion 7 extends to the upper cap 2. That is, in the third embodiment, for example, a plurality of linear high heat conductive members 6C having substantially the same length and diameter as those of the first embodiment are arranged in an annular shape on the peripheral portion of the hollow wall surface 3b of the lower cap 3. A plurality of high heat conductive members 6C having one end abutting against the lower surface of the upper cap 2 (that is, the surface forming the wall surface of the hollow portion 4) are disposed inside the peripheral edge portion. The high heat conductive member 6C and the upper cap 2 are bonded using a technique such as metal plating in the same manner as the lower cap 3.

  Thus, in the hollow valve 10C for the internal combustion engine of the third embodiment, the hollow portion wall surface 3b of the lower cap 3 and the lower surface of the upper cap 2 are connected at both ends of the high heat conductive member 6C. The heat taken from the lower cap 3 can be reliably transmitted to the lower surface of the upper cap 2 that is a direct heat transfer target, and the transmitted heat is transmitted to the cylinder head 105 via the valve lifter 101, the valve stem guide 106, and the like. Heat can be dissipated. Moreover, in this internal combustion engine hollow valve 10C, since the length of the high thermal conductive member 6C at the center is extended, the heat dissipation effect is enhanced. In the hollow valve 10C for an internal combustion engine illustrated here, the refrigerant 5 as a heat transfer target to which heat is transferred from the high heat conduction member 6C at the peripheral portion of the wall surface 3b of the hollow portion accompanies the reciprocating motion of the shaft portion Vs. Delivered to. Therefore, the hollow valve 10C for the internal combustion engine according to the third embodiment, whether or not it is tilted, is sure to be used even when the valve lift amount is small and the refrigerant 5 does not jump significantly. Since the heat of the lower cap 3 is transmitted to the upper side of the shaft portion Vs (the lower surface of the upper cap 2), the lower cap 3 can be reliably cooled.

  As described above, the hollow valve 10C for the internal combustion engine of the third embodiment can more effectively cool the umbrella portion Vh that is likely to be the highest temperature, thereby improving its durability and the valve seat 102. It is possible to further improve the durability, the air tightness of the combustion chamber CC, and the accuracy of the valve opening timing and the valve closing timing. For this reason, the internal combustion engine hollow valve 10C further improves the accuracy with respect to the command value of the excess air ratio (that is, the air-fuel ratio, particularly the stoichiometric air-fuel ratio) of the combustion chamber CC, and further increases the in-cylinder pressure. This enables more effective high output and low fuel consumption. Further, the hollow valve 10C for an internal combustion engine has sufficient heat resistance and durability even when the valve seat 102 is formed by itself and a low-cost material having lower heat resistance and durability than the conventional one, as in the first embodiment. Therefore, the cost of itself and its peripheral parts can be reduced. Furthermore, this internal combustion engine hollow valve 10C has an umbrella portion Vh (particularly, a portion forming the wall surface of the combustion chamber CC such as the combustion chamber wall surface 3a of the lower cap 3) as in the first embodiment. Compared with the prior art, knocking can be suppressed more than before, so that the ignition timing can be advanced and the output performance can be improved.

  Here, also in the hollow valve 10C for the internal combustion engine of the third embodiment, the degree of cooling of the umbrella portion Vh is adjusted by increasing / decreasing the number of the high heat conducting members 6C to be arranged as in the first embodiment. Can do. Therefore, when the internal combustion engine hollow valve 10C is applied to the exhaust side, which is easily exposed to high heat, more heat conductive members 6C are arranged than in the case of application to the intake side to ensure a sufficient cooling effect. You can make it possible. Since the hollow valve 10C for the internal combustion engine of the third embodiment can change the degree of cooling only by adjusting the number of the high heat conducting members 6C as described above, it is common to most parts on the exhaust side and the intake side. The exhaust valve and the intake valve can be manufactured at low cost.

  Further, when a sufficient cooling effect can be obtained with the hollow valve 10B for the internal combustion engine of the second embodiment described above, the high heat conduction member 6B at the peripheral portion is removed, and the central portion (that is, the convex portion 7) is removed. You may comprise only the high heat conductive member 6B, and even if it does in this way, there can exist the same effect. In such a case, a high heat conductive member 6B disposed on the entire hollow portion wall surface 3b having a high cooling effect for the umbrella portion Vh is manufactured as an exhaust valve, and the high heat conductive member at the center portion where the cooling effect for the umbrella portion Vh is lower than this. Only 6B may be manufactured as an intake valve.

  Further, when a sufficient cooling effect can be obtained with the hollow valve 10C for the internal combustion engine of the third embodiment described above, the high thermal conductivity member 6C at the peripheral portion is removed and the high thermal conductivity member 6C at the center portion (that is, It may be configured only by connecting the hollow wall surface 3b of the lower cap 3 and the lower surface of the upper cap 2). Even in this case, the same effect can be obtained. In this case, if the desired cooling effect can be obtained, it is not always necessary to enclose the refrigerant 5 in the hollow portion 4, thereby further reducing the inertial mass. Thus, the hollow valve 10C for an internal combustion engine can be reciprocated more easily and responsively. For example, in such a case, a high heat conductive member 6C arranged on the entire hollow portion wall surface 3b having a high cooling effect for the umbrella portion Vh is manufactured as an exhaust valve, and the high heat in the central portion where the cooling effect for the umbrella portion Vh is lower than this. Only the conductive member 6C may be manufactured as an intake valve. Moreover, what enclosed the refrigerant | coolant 5 may be manufactured as an exhaust valve, and what does not have the refrigerant | coolant 5 may be manufactured as an intake valve.

  Next, a fourth embodiment of the hollow valve for an internal combustion engine according to the present invention will be described with reference to FIGS.

5 indicates a hollow valve for an internal combustion engine according to the fourth embodiment. The internal combustion engine hollow valve 10D of the fourth embodiment, a plurality of high thermal conductivity member 6D ₁ showing a plurality of high thermal conductivity member 6A in Figures 5 and 6 in the hollow valve 10A for an internal combustion engine of the first embodiment described above , 6D ₂ .

Specifically, in the fourth embodiment, the respective free ends of the peripheral portions of the respective high thermal conductive members 6A of the first embodiment are brought into contact with the wall surface of the hollow portion 4 in the vicinity of the valve face of the umbrella portion Vh. . That is, in the fourth embodiment, for example, as shown in FIG. 6, a linear high thermal conductive member 6D ₁ having the same length and diameter as the first embodiment is provided at the central portion of the hollow wall surface 3b of the lower cap 3. A plurality of circularly arranged, and a plurality of high heat conductive members 6D ₂ that radially connect the hollow portion wall surface 3b and the wall surface near the valve face at both ends are arranged radially. In FIG. 6, there is a clear gap between the high heat conductive members 6D ₁ and 6D ₂ , but this gap is for convenience of illustration. As between the high thermal conductivity member 6D ₂ and the valve face surface wall in the vicinity is bonded using techniques metal plating as well as between the lower cap 3.

Thus, in the internal combustion engine for a hollow valve 10D of the fourth embodiment, between the peripheral portion and the valve face surface wall in the vicinity of the hollow portion wall 3b of the lower cap 3 is connected by both ends of the high thermal conductivity member 6D ₂ Therefore, the heat taken from the lower cap 3 can be radiated to the cylinder head 105 via the valve seat 102 from the wall surface in the vicinity of the valve face which is the heat transfer target. Here, in the hollow valve 10D for an internal combustion engine is illustrated, the shaft portion with high thermal conductivity member 6D ₁ heat transfer target serving coolant 5 which is transferring heat from the central portion to the reciprocating motion in the hollow portion wall 3b Delivered to the upper side of Vs. That is, the internal combustion engine hollow valve 10D according to the fourth embodiment can radiate the heat of the lower cap 3 by dividing it into the shaft portion Vs side and the valve seat 102. And even if comprised in this way, the hollow valve 10D for internal combustion engines of the present Example 4 can cool the lower cap 3 reliably like Example 1. FIG.

  By the way, when the internal combustion engine hollow valve 10D is applied to the exhaust side, the entire body may be exposed to high-temperature exhaust gas as in the exhaust stroke, so that the cooling is larger than that applied to the intake side. An effect is needed. On the other hand, when the internal combustion engine hollow valve 10D is applied to the intake side, if a large amount of heat is radiated to the shaft portion Vs that is always in contact with the intake air, the temperature of the intake air rises and is increased in the combustion chamber CC. Since the volumetric efficiency of the battery deteriorates, the thermal efficiency may decrease.

Therefore, when this internal combustion engine hollow valve 10D is applied to the exhaust side, where high cooling performance is required, high heat conduction at the peripheral portion is ensured so that the heat radiation to the wall surface near the valve face surface is larger than the shaft portion Vs. It is arranged defining a respective number of the high thermal conductivity member 6D ₁ member 6D ₂ and the central portion. In other words, since the valve face surface directly contacts the valve seat 102 fitted in the cylinder head 105 to transfer heat, the heat transfer efficiency of the cylinder head 105 is better when the heat is radiated to the wall surface near the valve face than the shaft portion Vs. The hollow valve 10D for an internal combustion engine can enhance the cooling performance by increasing the amount of heat radiation to the wall surface.

On the other hand, when this internal combustion engine hollow valve 10D is applied to the intake side where appropriate cooling performance is required so that volume efficiency does not deteriorate, high heat conduction at the peripheral portion is reduced so that the amount of heat released to the shaft portion Vs is reduced. The number of each of the member 6D ₂ and the high thermal conductive member 6D _{1 at} the center is determined and arranged. Then, the situation where the intake air is warmed by the heat of the shaft portion Vs and the volumetric efficiency is deteriorated can be avoided. Therefore, the internal combustion engine hollow valve 10D is configured to prevent internal combustion while suppressing unnecessary supercooling. A decrease in the thermal efficiency of the engine can be prevented.

As described above, the hollow valve 10D for the internal combustion engine according to the fourth embodiment can change the degree of cooling only by adjusting the number of high heat conducting members 6D ₁ and 6D _{2 to be} arranged. All parts can be shared, and exhaust valves and intake valves can be manufactured at low cost.

Further, the high heat conducting member 6D ₂ of the fourth embodiment can make the heat of the valve main body 1 and the lower cap 3 near the welded portion 8 shown in FIG. Function as. Further, since the high heat conductive member 6D ₂ is disposed so as to cover the welded portion 8, it also functions as a reinforcing material for the welded portion 8. That is, since the carbon fiber reinforced metal which is the high heat conductive member 6D ₂ has high rigidity, the twist and distortion of the welded portion 8 can be suppressed. Therefore, the hollow valve 10D for the internal combustion engine of the fourth embodiment can prevent the occurrence of cracks and the like at the welded portion 8 and the surroundings thereof.

Here, the high heat conductive member 6D ₁ at the center may be replaced with the high heat conductive member 6B forming the convex portion 7 of the above-described second embodiment, and the hollow portion wall surface of the lower cap 3 in the above-described third embodiment. You may replace with 6 C of high heat conductive members which connect between 3b and the lower surface of the top cap 2. FIG.

  Next, a fifth embodiment of the hollow valve for an internal combustion engine according to the present invention will be described with reference to FIGS.

  7 denotes a hollow valve for an internal combustion engine according to the fifth embodiment. The hollow valve 10E for the internal combustion engine of the fifth embodiment is changed from the plurality of high heat conduction members 6A to the plurality of high heat conduction members 6E shown in FIGS. 7 and 8 in the hollow valve 10A for the internal combustion engine of the first embodiment. Is replaced.

  Specifically, each of the high thermal conductive members 6E of the fifth embodiment is obtained by connecting the peripheral portion of the hollow portion wall surface 3b of the lower cap 3 and the wall surface of the hollow portion 4 near the valve stem guide 106 at both ends. Yes, and arranged radially as shown in FIG. 8 around the central axis of the hollow valve 10E for the internal combustion engine. In FIG. 8, there is a clear gap between the high heat conductive members 6E, but this gap is for convenience of illustration. The high heat conducting member 6E and the wall surface in the vicinity of the valve stem guide 106 are bonded using a technique such as metal plating in the same manner as with the lower cap 3.

  Thus, in the internal combustion engine hollow valve 10E of the fifth embodiment, the peripheral portion of the hollow wall surface 3b of the lower cap 3 and the wall surface in the vicinity of the valve stem guide 106 are connected at both ends of the high heat conductive member 6E. Therefore, the heat taken from the lower cap 3 can be reliably transmitted to the wall surface in the vicinity of the valve stem guide 106 that is the target of direct heat transfer, and the transmitted heat can be transferred to the cylinder head via the valve stem guide 106. 105 can dissipate heat. Moreover, in this hollow valve 10E for internal combustion engines, since the high heat conductive member 6E is long, the heat dissipation effect is enhanced. In the hollow valve 10E for an internal combustion engine illustrated here, the refrigerant 5 that has taken heat from the central part of the wall surface 3b of the hollow part is delivered to the shaft part Vs along with the reciprocating motion. Accordingly, the hollow valve 10E for the internal combustion engine of the fifth embodiment, whether or not it is tilted, is sure to be used even when the amount of valve lift is small and the refrigerant 5 does not jump significantly. Since the heat of the lower cap 3 is transmitted to the wall surface in the vicinity of the valve stem guide 106, the lower cap 3 can be reliably cooled.

  In the fifth embodiment, since a large number of high heat conduction members are not in contact with each other as in the first to fourth embodiments described above, the cross sectional area of the high heat conduction member 6E (that is, the cross sectional area of the metal that is the base material) is increased. Since it can be molded, the amount of heat radiation can be increased.

  As described above, the hollow valve for an internal combustion engine according to the present invention is useful for a technique for improving the cooling performance, particularly the cooling performance of the umbrella portion.

It is sectional drawing which shows the structure of Example 1 of the hollow valve for internal combustion engines which concerns on this invention. It is a perspective view shown about the shape and arrangement | positioning of the high heat conductive member of Example 1. FIG. It is sectional drawing which shows the structure of Example 2 of the hollow valve for internal combustion engines which concerns on this invention. It is sectional drawing which shows the structure of Example 3 of the hollow valve for internal combustion engines which concerns on this invention. It is sectional drawing which shows the structure of Example 4 of the hollow valve for internal combustion engines which concerns on this invention. It is the top view seen from the hollow part shown about arrangement | positioning of the high heat conductive member of Example 4. FIG. It is sectional drawing which shows the structure of Example 5 of the hollow valve for internal combustion engines which concerns on this invention. It is sectional drawing cut | disconnected by the XX line of FIG. 7 shown about arrangement | positioning of the high heat conductive member of Example 5. FIG.

Explanation of symbols

1 valve main 1a cylindrical portion 1b frustoconical portion 2 upper cap 3 lower cap 3a combustion chamber wall surface 3b hollow section wall 4 hollow portion 5 refrigerant _{6A, 6B, 6C, 6D 1} , 6D 2, 6E high thermal conductivity member 7 projecting portion 10A, 10B, 10C, 10D, 10E Internal combustion engine hollow valve 101 Valve lifter 102 Valve seat 103 Retainer 104 Elastic member 105 Cylinder head 106 Valve stem guide CC Combustion chamber P port (intake port, exhaust port)
Vh Umbrella Vs Shaft

Claims (6)

A shaft portion, an umbrella portion provided at one end of the shaft portion, a sealed hollow portion that communicates internally between the umbrella portion and the shaft portion, and a refrigerant sealed in the hollow portion. In the internal combustion engine hollow valve provided,
The umbrella portion has a wall surface portion in which a combustion chamber wall surface forming a part of a wall surface of a combustion chamber of an internal combustion engine and a hollow wall surface forming a part of a wall surface of the hollow portion are formed,
At least one high heat conductive member that conducts high heat between the wall surface portion and at least one of the refrigerant and the heat transfer target of the shaft portion is disposed on the wall surface of the hollow portion. A hollow valve for an internal combustion engine.   The said high heat conductive member has the directionality of heat conduction between the one end made to contact with the said hollow part wall surface, and the other end made to contact with the said heat transfer object, The Claim 1 characterized by the above-mentioned. Hollow valve for internal combustion engine.   The hollow valve for an internal combustion engine according to claim 1, wherein the high heat conductive member is a carbon fiber reinforced metal.   A plurality of the high heat conductive members capable of transmitting heat of the wall surface portion to the refrigerant are arranged so as to protrude in substantially the same direction as the axial direction of the shaft portion so that a convex portion is formed. A hollow valve for an internal combustion engine according to claim 1, 2 or 3.   The high heat conductive member is disposed so that heat conduction is performed between the wall surface of the hollow portion and the wall surface of the shaft portion near the other end opposite to the umbrella portion. 2. A hollow valve for an internal combustion engine according to 2 or 3.   The high heat conductive member is disposed so that heat conduction is performed between a central portion of the wall surface of the hollow portion and the heat transfer target, and a peripheral portion of the wall surface of the hollow portion and the umbrella portion in the hollow portion The hollow valve for an internal combustion engine according to any one of claims 1 to 5, wherein heat conduction is performed between the valve seat and the vicinity of the valve seat.

Images