JP2012097627A - Metallic-sodium-filled engine valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic-sodium-filled engine valve capable of further achieving reduction in weight, even while suppressing heat transfer to a stem seal.SOLUTION: In the metallic-sodium-filled engine valve 100 including a stem 112 and an umbrella part 111 and having a hollow part inside the stem 112, wherein metallic-sodium 101 is filled in the hollow part, the stem 112 is composed of: a lower member 112A in which a hollow part 112Aa is formed over the entire length in the axial direction, which is connected to the umbrella part 111, and in which the metallic-sodium 101 is filed in the hollow part 112Aa; an upper member 112B in which a hollow part 112Ba is formed over the entire length in the axial direction; and a blocking member 112C provided between the lower member 112A and the upper member 112B so as to block a gap between the hollow part 112Aa of the lower member 112A and the hollow part 112Ba of the upper member 112B.

Description

  The present invention relates to a metallic sodium-enclosed engine valve having a stem portion and an umbrella portion, having a hollow portion inside the stem portion, and having metallic sodium sealed in the hollow portion.

  A schematic configuration of a main part of an example of an engine including a conventional metal sodium-enclosed engine valve having a stem portion and an umbrella portion and having a hollow portion inside the stem portion and metal sodium is enclosed in the hollow portion. As shown in FIG.

  As shown in FIG. 5, an exhaust port 4 communicating with the exhaust port 2 and the combustion chamber 3 is opened and closed on the combustion chamber 3 side of the exhaust port 2 formed in a substantially horizontal direction in the cylinder head 1 of the engine. An exhaust engine valve 10 is provided. The engine valve 10 is incorporated in a direct acting valve mechanism 20 disposed in the cylinder head 1. The direct acting valve mechanism 20 includes a valve lifter 22 that reciprocates the engine valve 10 and a cam 21 that rotates in accordance with engine rotation and opens the engine valve 10.

  The valve lifter 22 includes a projection 23 that contacts the stem portion 12 of the engine valve 10, a shim 23 a that contacts the cam 21 above the projection 23 and adjusts the clearance, and the cylinder head 1. A valve guide 24 that is press-fitted and fixed to the stem portion 12 of the engine valve 10 so as to be slidable in the axial direction, and between the upper end portion of the valve guide 24 and the stem portion 12 of the engine valve 10. A stem seal 25 made of a polymer material that seals the valve, a valve spring 26 that opens the engine valve 10 against the pressing force of the cam 21, and upper seats provided at the upper and lower ends of the valve spring 26 27, the lower seat 28, the stem 12 of the engine valve 10 and the valve spring 26, etc. And a Bukotta 29.

  The engine valve 10 is supported in a slidable manner with respect to the valve guide 24 so as to be slidable with respect to the valve guide 24 and is connected to the umbrella portion 11 and has an upper end at the protrusion 23. Between the stem portion 12 of the shaft portion brought into contact with the hollow portion 11, the hollow portion 11 a formed inside the umbrella portion 11, and the hollow portion 11 a of the umbrella portion 11 and the middle in the axial direction of the stem portion 12. A hollow portion 12a formed in the stem portion 12 so as to communicate with each other, and a metallic sodium 101 enclosed in the hollow portion 11a and the hollow portions 11a and 12a of the stem portion 12. Reference numeral 13 denotes a cotter groove portion engaged with the valve cotter 29.

  In such an engine having the engine valve 10 in which the metallic sodium 101 is sealed in the hollow portions 11a and 12a, the cam 21 of the direct acting valve mechanism 20 rotates in response to the rotation of the engine, and the valve lifter The engine valve 10 is moved up and down (valve lift) via the valve 22 so that the exhaust valve 4 is opened when the exhaust gas in the combustion chamber 3 is discharged to the outside of the combustion chamber 3. The engine valve 10 is raised so that the combustion exhaust gas is sent down to the exhaust port 2 and the exhaust port 4 is closed at other times.

  At this time, the metallic sodium 101 having high thermal conductivity in the hollow portions 11a and 12a of the engine valve 10 vibrates in the hollow portions 11a and 12a as the engine valve 10 moves up and down (valve lift). By efficiently transferring the heat of the umbrella portion 11 (about 800 ° C.) that is in contact with the high-temperature combustion exhaust gas to the valve guide 24 through the stem portion 12 (oscillation heat transport) ), The heat is efficiently transmitted to the cylinder head 1 and can be efficiently cooled by the coolant flowing through the coolant flow passage formed in the cylinder head 1.

JP 2007-032465 A

  By the way, in an engine valve, in order to improve fuel consumption and the like, it is strongly demanded to reduce the weight as much as possible. For this reason, in the metallic sodium-enclosed engine valve as described above, for example, it is conceivable to extend the hollow portion to the vicinity of the upper end of the stem portion. However, when the hollow portion is extended to the vicinity of the upper end of the stem portion in this way, the metal sodium 101 enclosed in the hollow portion is oscillated and transported to the upper end side of the stem portion by the vibration flow. There is a possibility that high-temperature heat is transferred from the stem portion to the stem seal 25 made of a polymer material, and the life of the stem seal 25 is greatly reduced.

  In view of the above, an object of the present invention is to provide a metal sodium-enclosed engine valve that can achieve further weight reduction while suppressing heat transfer to the stem seal.

  In order to solve the above-described problem, a metal sodium-enclosed engine valve according to the present invention has a stem portion and an umbrella portion, and has a hollow portion inside the stem portion, and metal sodium is enclosed in the hollow portion. In the metallic sodium-enclosed engine valve, the stem part is formed with the hollow part over the entire length in the axial direction and is connected to the umbrella part, and the hollow part extends in the axial direction with the lower member into which the metallic sodium can be placed. And a blocking member disposed between the lower member and the upper member so as to block between the hollow portion of the lower member and the hollow portion of the upper member. It is comprised from these.

  Further, the metal sodium-enclosed engine valve according to the present invention is the above-described metal sodium-enclosed engine valve, with respect to the length La between the bottom surface of the umbrella portion and the upper end surface of the upper member of the stem portion, The length Lc between the bottom surface of the umbrella portion and the surface adjacent to the lower member of the blocking member of the stem portion is a size in a range of 0.4 to 0.7 times (0.4 La ≦ Lc ≦ 0.7 La).

  Further, the metal sodium sealed engine valve according to the present invention is the above-described metal sodium sealed engine valve, wherein when the stem portion is supported by a valve guide attached to a cylinder head of the engine, the blocking of the stem portion is performed. A surface of the member adjacent to the lower member is set so as to be always located inside the valve guide.

  Further, the metal sodium sealed engine valve according to the present invention is the above-described metal sodium sealed engine valve, wherein the blocking member of the stem portion is fitted into the hollow portion so as to face the hollow portion of the lower member. It has a lower fitting part and an upper fitting part fitted to the hollow part facing the hollow part of the upper member.

  According to the metallic sodium-enclosed engine valve according to the present invention, since the upper member has the hollow portion, the blocking member is interposed between the hollow portion of the lower member and the hollow portion of the upper member. Even if metallic sodium generates an oscillating flow with the up-and-down movement, the metallic sodium can be prevented from flowing into the hollow portion of the upper member, and the heat of the umbrella portion that becomes high temperature in contact with the high-temperature combustion exhaust gas. Most of the heat can be transmitted to the outside via the valve guide, so the heat of the stem seal can be greatly suppressed by reducing the high temperature heat while reducing the weight of the stem seal. Can be suppressed.

It is a schematic block diagram of the principal part of main embodiment of the engine provided with the metal sodium enclosure engine valve which concerns on this invention. It is an extraction enlarged view of the metallic sodium-enclosed engine valve of FIG. FIG. 3 is an exploded view of the metallic sodium filled engine valve of FIG. 2. It is an extraction expanded sectional view of the important section of other embodiments of a metal sodium enclosure engine valve concerning the present invention. It is a schematic block diagram of the principal part of an example of the engine provided with the conventional metal sodium enclosure engine valve.

  Embodiments of a metal sodium filled engine valve according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to only the following embodiments described with reference to the drawings.

<Main embodiment>
A main embodiment of a metallic sodium filled engine valve according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, an exhaust port 4 communicating with the exhaust port 2 and the combustion chamber 3 is opened and closed on the combustion chamber 3 side of the exhaust port 2 formed in a substantially horizontal direction in the cylinder head 1 of the engine. A metal sodium filled engine valve 100 according to the present invention for exhaust is provided. This metallic sodium-enclosed engine valve 100 is incorporated in a direct acting valve mechanism 20 disposed in the cylinder head 1. The direct acting valve mechanism 20 includes a valve lifter 22 that reciprocates the metal sodium-enclosed engine valve 100, and a cam 21 that rotates according to engine rotation to open the metal sodium-enclosed engine valve 100. Yes.

  The valve lifter 22 includes a projection 23 that contacts the stem portion 112 of the engine valve 100, a shim 23a that contacts the cam 21 and adjusts the clearance above the projection 23, and the cylinder head. A valve guide 24 that is press-fitted and fixed to 1 and supports the stem portion 112 of the engine valve 100 so as to be slidable along the axial direction; and an upper end portion of the valve guide 24 and the stem portion 112 of the engine valve 100 A stem seal 25 made of a polymer material that seals the gap, a valve spring 26 that opens the engine valve 100 against the pressing force of the cam 21, and uppers provided at the upper and lower ends of the valve spring 26 A seat 27, a lower seat 28, a stem portion 112 of the engine valve 100, and the valve sp. And a valve cotter 29 for fixing the ring 26 and the like.

  The engine valve 100 includes a bowl-shaped umbrella portion 111 that opens and closes the exhaust port 4, and a stem portion 112 that is supported by the valve guide 24 so as to be slidable and connected to the umbrella portion 111. It has. Reference numeral 113 denotes a cotter groove that engages with the valve cotter 29.

  As shown in FIGS. 1 and 2, the engine valve 100 according to the present embodiment has hollow portions inside the umbrella portion 111 and the stem portion 112, and metal sodium 101 is sealed in the hollow portions, and the stem The portion 112 is formed with a hollow portion 112Aa over the entire length in the axial direction and communicates with the hollow portion 111a of the umbrella portion 111, and the lower member 112A in which the metallic sodium 101 can be put in the hollow portions 111a and 112Aa, The lower member 112A and the upper member 112B so as to block between the upper member 112B formed with the hollow portion 112Ba and the hollow portion 112Aa of the lower member 112A and the hollow portion 112Ba of the upper member 112B. It is comprised from the interruption | blocking member 112C arrange | positioned between.

  Further, the engine valve 100 has a length La between the bottom surface of the umbrella portion 111 and the upper end surface of the upper member 112B of the stem portion 112, and the bottom surface of the umbrella portion 111 and the stem portion 112. The length Lc between the lower member 112A and the adjacent surface of the blocking member 112C is in the range of 0.4 to 0.7 times (0.4La ≦ Lc ≦ 0.7La). Is set to

  In other words, the engine valve 100 is adjacent to the lower member 112A of the blocking member 112C of the stem portion 112 when the stem portion 112 is supported by the valve guide 24 attached to the cylinder head 1 of the engine. In other words, when the engine valve 100 is in the open state, the lower member of the blocking member 112C of the stem portion 112 is set so that the surface to be operated is always located inside the valve guide 24. When the surface adjacent to 112A is positioned above the lower end surface of the valve guide 24 and is closed, the surface adjacent to the lower member 112A of the blocking member 112C of the stem portion 112 is It is set so as to be positioned below the upper end surface of the guide 24.

  In such an engine valve 100, for example, the hollow portion 112Aa is formed by a punch with a cylindrical material (for example, heat resistant steel SUH35, etc.), and forging and drawing are performed, so that the umbrella portion 111 and the lower portion are formed. The side member 112A is integrally formed and the metal sodium 101 is injected into the hollow portion 112Aa, while the hollow portion 112Ba is formed by drilling a rod-shaped material (for example, heat-resistant steel SUH35). The upper member 112B is formed of a pipe-shaped material having 112Ba (for example, heat-resistant steel SUH11), and the lower side is interposed through the blocking member 112C made of a disk-shaped material (for example, heat-resistant steel SUH11, SUH35, etc.). By joining the member 112A and the upper member 112B integrally by friction welding, laser welding, etc., it is easy. It can be granulated (see FIG. 3).

  In the engine provided with the engine valve 100 according to this embodiment, the cam 21 of the direct acting valve mechanism 20 rotates in response to the rotation of the engine, and the engine valve is connected via the valve lifter 22. By moving the valve 100 up and down (valve lift), the engine valve 100 is lowered to open the exhaust port 4 when the combustion exhaust gas in the combustion chamber 3 is discharged to the outside of the combustion chamber 3, and the combustion exhaust gas is removed. The engine valve 100 is raised so as to send to the exhaust port 2 and close the exhaust port 4 at other times.

  At this time, the metallic sodium 101 having high thermal conductivity in the umbrella portion 111 of the engine valve 100 and the hollow portions 111a and 112Aa of the lower member 112A is accompanied with the up-and-down movement (valve lift) of the engine valve 100. Then, an oscillating flow is generated in the hollow portions 111a and 112Aa, and the heat of the umbrella portion 111 (about 800 ° C.) that is in contact with the high-temperature combustion exhaust gas and is heated to the valve guide 24 through the stem portion 112 efficiently. By transmitting (oscillation heat transport), the heat is efficiently transmitted to the cylinder head 1 and can be efficiently cooled by the coolant flowing through the coolant flow passage formed in the cylinder head 1. it can.

  Here, the engine valve 100 has a hollow portion 112Ba in the upper member 112B, and at the same time, between the hollow portion 112Aa of the lower member 112A and the hollow portion 112Ba of the upper member 112B. Since the blocking member 112C is interposed, the weight can be reduced as compared with the conventional case, and even if the metallic sodium 101 generates the vibration flow as the engine valve 100 moves up and down, the upper member 112B can be prevented from flowing into the hollow portion 112Ba, and most of the heat of the umbrella portion 111 (about 800 ° C.) that comes into contact with the high-temperature combustion exhaust gas is heated via the valve guide 24. It can be transmitted to the outside of the engine valve 100.

  For this reason, it is possible to largely suppress the transfer of high-temperature heat to the stem seal 25 made of a polymer material, and it is possible to suppress a decrease in the life of the stem seal 25.

  Therefore, according to the engine valve 100 according to the present embodiment, further weight reduction can be achieved while suppressing heat transfer to the stem seal 25.

<Other embodiments>
In the above-described embodiment, the engine valve 100 is manufactured by joining the lower member 112A and the upper member 112B via the disc-shaped blocking member 112C. As an embodiment, for example, as shown in FIG. 4, a lower fitting portion 212Ca that fits into the hollow portion 112Aa facing the hollow portion 112Aa of the lower member 112A, and the hollow of the upper member 112B. The lower member 112A and the upper member 112B are friction welded via a disc-shaped blocking member 212C having an upper fitting portion 212Cb that fits into the hollow portion 112Ba facing the portion 112Ba on the corresponding end surface. If the metallic sodium-encapsulated engine valve 200 is manufactured by integrally joining by laser welding or the like, the lower member 112 is manufactured. The so align the upper member 112B can be easily performed and, preferably.

  Further, in the above-described embodiment, the metal sodium-enclosed engine valve 100 having the hollow portion inside both the umbrella portion 111 and the stem portion 112 has been described, but the present invention is not limited thereto, and as other embodiments, For example, if it is a metal sodium sealed engine valve having a hollow part at least inside the stem part, such as a metal sodium sealed engine valve having a hollow part only inside the stem part, the same action as in the above-described embodiment An effect can be obtained.

  Further, in the above-described embodiment, the case where it is incorporated in the direct acting valve mechanism 20 has been described. However, the present invention is not limited to this. As a matter of course, it is possible to obtain the same operational effects as in the case of the above embodiment.

  Further, in the above-described embodiment, the case where the present invention is applied as the engine valve 10 for exhaust that opens and closes the exhaust port 4 that connects the exhaust port 2 formed in the cylinder head 1 of the engine and the combustion chamber 3 has been described. As another embodiment, for example, the present invention can be applied as an intake engine valve that opens and closes an intake port communicating with an intake port formed in a cylinder head of an engine and a combustion chamber.

  The metal sodium-enclosed engine valve according to the present invention can suppress the reduction in the life of the stem seal by largely suppressing the transfer of high-temperature heat to the stem seal while reducing the weight of the engine valve. It can be used extremely beneficially in the automobile industry and the like.

DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Exhaust port 3 Combustion chamber 4 Exhaust port 20 Direct acting valve mechanism 21 Cam 22 Valve lifter 23 Protruding part 23a Shim 24 Valve guide 25 Stem seal 26 Valve spring 27 Upper seat 28 Lower seat 29 Valve cotter 100 Metal-enclosed engine valve 101 Metal sodium 111 Umbrella part 111a Hollow part 112 Stem part 112A Lower side member 112Aa Hollow part 112B Upper side member 112Ba Hollow part 112C Blocking member 113 Cotta groove part 200 Metal sodium sealed engine valve 212C Blocking member 212Ca Lower side fitting part 212Cb Upper side fitting Part

Claims (4)

In a metal sodium sealed engine valve having a stem portion and an umbrella portion and having a hollow portion inside the stem portion and metal sodium sealed in the hollow portion,
The stem portion is
A lower member which is formed over the entire axial length and is connected to the umbrella portion and into which the metallic sodium is put in the hollow portion;
An upper member formed with the hollow portion in the axial direction;
A blocking member disposed between the lower member and the upper member so as to block between the hollow portion of the lower member and the hollow portion of the upper member. Features a metallic sodium filled engine valve. The metallic sodium filled engine valve according to claim 1,
With respect to the length La between the bottom surface of the umbrella portion and the upper end surface of the upper member of the stem portion, the bottom surface of the umbrella portion and the surface adjacent to the lower member of the blocking member of the stem portion; The length Lc is set to a size in the range of 0.4 to 0.7 times (0.4La ≦ Lc ≦ 0.7La). . In the metal sodium filled engine valve according to claim 1 or 2,
When the stem portion is supported by a valve guide attached to a cylinder head of an engine, the surface of the stem portion adjacent to the lower member of the blocking member is always located inside the valve guide. Metal sodium filled engine valve characterized by being set to. The metallic sodium-enclosed engine valve according to any one of claims 1 to 3,
The blocking member of the stem portion is
A lower fitting part that fits into the hollow part facing the hollow part of the lower member;
A metal sodium-enclosed engine valve, comprising: an upper fitting portion that fits into the hollow portion so as to face the hollow portion of the upper member.

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