JP5473771B2 - Manufacturing method of engine valve filled with sodium metal - Google Patents

Description

  The present invention relates to a method for manufacturing an engine valve in which metallic sodium is enclosed.

  In engine valves for automobiles, etc., in order to cope with high performance and low fuel consumption of the engine, a hollow portion is provided inside the engine valve and metal sodium is enclosed to reduce weight and increase heat transfer. Has been done.

  Such an engine valve has, for example, (1) solid metal sodium extruded into a cylindrical shape and cut into a predetermined length with respect to a stem portion having a hollow portion formed inside and an opening formed at the upper end. Then, it is inserted into the hollow part from the opening, or (2) solid metal sodium is heated and melted (about 120 to 300 ° C.) to form a liquid, and a predetermined amount is injected into the hollow part from the opening. After the metal sodium is put into the hollow portion, the opening is sealed (for example, see Patent Documents 1 to 3 below).

JP-A-3-018605 JP-A-4-232318 JP-A-4-272413 Japanese Patent No. 4390291

  However, the conventional method for manufacturing a metal sodium filled engine valve as described above has the following problems.

(1) Since columnar metallic sodium must be cut into a predetermined length for each engine valve and inserted, workability is poor.
(2) When liquid metallic sodium is injected into the hollow portion, if the metallic sodium adheres to the inner wall of the elongated hollow portion (about 2 to 4 mm in diameter), it immediately cools and solidifies to close the hollow portion. Therefore, the liquid metal sodium had to be injected while heating the whole stem part (98 ° C. or higher), and the workability for the injection was poor.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a metal sodium-enclosed engine valve that can easily add metal sodium into the engine valve. There is.

  In order to solve the above-described problem, a method for manufacturing a metal sodium-enclosed engine valve according to the first aspect of the present invention includes an engine valve having a hollow portion inside the stem portion and the umbrella portion and having an opening at the upper end of the stem portion. In the method for manufacturing a metal sodium-encapsulated engine valve in which metal sodium is sealed by sealing the opening after putting metal sodium into the hollow portion from the opening of the stem portion of the stem portion, the temperature at which the metal sodium is melted The metal sodium is supplied while being liquefied in the hollow portion by feeding the wire-shaped metal sodium into the hollow portion from the opening of the stem portion while holding the umbrella portion.

  According to a second aspect of the present invention, there is provided a method for manufacturing a metal sodium-enclosed engine valve according to the first aspect, wherein the stem portion is sequentially drawn so as to gradually reduce the outer diameter and the inner diameter of the stem portion. In order to manufacture the engine valve by molding the stem part into a desired size, after performing the drawing process on the stem part until the inner diameter of the hollow part of the stem part reaches a specified size, While holding the umbrella portion at a temperature at which the metallic sodium is melted, the metallic sodium in a wire shape is fed into the hollow portion from the opening of the stem portion, thereby supplying the metallic sodium while liquefying in the hollow portion. Later, by further cold-drawing the stem part, the stem part is formed into a target size. And features.

  According to a third aspect of the present invention, there is provided a method for manufacturing a metal sodium-enclosed engine valve according to the first aspect, wherein the stem portion is sequentially drawn so as to gradually reduce the outer diameter and the inner diameter of the stem portion. In making the engine valve by forming the stem portion into a desired size, before performing the drawing process on the stem portion, while holding the umbrella portion at a temperature at which metal sodium is melted, By feeding the metallic sodium into the hollow part from the opening of the stem part into the hollow part, supplying the metallic sodium while liquefying in the hollow part, and then performing cold drawing on the stem part The stem portion is formed into a desired size.

  According to a fourth aspect of the invention, there is provided a method for manufacturing a metal sodium-enclosed engine valve according to the second or third aspect, wherein a protective agent made of solid paraffin or naphthalene is supplied together with the supply of the metal sodium into the hollow portion. After shielding between the metallic sodium and the atmosphere by supplying into the hollow portion, the cold-drawing process is performed on the stem portion, and the stem portion is formed into a target size. .

  According to the manufacturing method of the metallic sodium filled engine valve according to the present invention, the metallic sodium is fed into the hollow portion from the opening of the stem portion while holding the umbrella portion at a temperature at which the metallic sodium is melted. Is supplied while being liquefied in the hollow portion, so that it is not necessary to cut and insert the metallic sodium into a predetermined length for each engine valve, but only by adjusting the feeding length of the metallic metallic sodium. The engine valve can be easily adjusted for the amount supplied to the inside, and can be prevented from clogging with metallic sodium in the hollow portion of the stem by simply holding the umbrella at a temperature that melts metallic sodium. It is possible to greatly improve the workability of putting metallic sodium into the interior of the container to facilitate the work.

  In addition, since the metallic sodium is once melted in the hollow portion and solidified again, the gap between the metallic sodium and the wall surface of the hollow portion can be eliminated, and the contact area between the metallic sodium in the hollow portion and the atmosphere is minimized. Therefore, the reaction of the metallic sodium accompanying the contact with moisture, oxygen, etc. in the atmosphere can be more reliably suppressed.

It is explanatory drawing of 1st embodiment of the manufacturing method of the metal sodium enclosure engine valve which concerns on this invention. It is procedure explanatory drawing of 2nd embodiment of the manufacturing method of the metal sodium enclosure engine valve which concerns on this invention. It is procedure explanatory drawing of the other example of 2nd embodiment of the manufacturing method of the metal sodium enclosure engine valve which concerns on this invention.

  Embodiments of a method for manufacturing a metal sodium-enclosed engine valve according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments described with reference to the drawings.

[First embodiment]
1st Embodiment of the manufacturing method of the metal sodium enclosure engine valve which concerns on this invention is described based on FIG.

  As shown in FIG. 1, the engine valve according to the present embodiment has a hollow portion H inside the stem portion S and the umbrella portion A, and an opening at the upper end of the stem portion S.

  A method according to this embodiment in which metallic sodium is placed inside such an engine valve will be described.

  First, by placing the engine valve on a heating table T disposed in a dry inert gas atmosphere such as dry nitrogen gas and operating the heating table T, the umbrella A is heated to form a metal. It is kept at a temperature (98 ° C. or higher) at which sodium Na is melted.

  Next, metallic sodium Na, which has been processed into a wire shape and wound in a reel shape, is fed out in the atmosphere, and is fed into the hollow portion H from the opening of the stem portion S. When abutting against the bottom surface of the hollow portion H inside the umbrella portion A, the metallic sodium Na is melted and liquefied from the tip side and stored in the hollow portion H.

  And if the said metallic sodium Na is drawn out by regulation length, the regulation amount of metallic sodium Na will be supplied in the said hollow part H by unwinding the said metallic sodium Na.

  Finally, the engine valve in which a prescribed amount of metallic sodium Na is sealed can be obtained by retracting from the heating table T and closing the opening.

  That is, in the present embodiment, the wire-shaped metal sodium Na is fed into the hollow portion H from the opening of the stem portion S while holding the umbrella portion A at a temperature (98 ° C. or higher) at which the metal sodium Na is melted. Thus, the metallic sodium Na is supplied while being liquefied in the hollow portion H.

  For this reason, in this embodiment, it can be made to melt and liquefy from the front end side of the wire-shaped metal sodium Na which contacted the bottom face of the hollow part H in the umbrella part A, and metal sodium Na can be supplied in the said hollow part H. Therefore, (1) Even if the metallic sodium Na is not cut into a predetermined length for each engine valve and inserted, it is only necessary to adjust the feeding length of the metallic metallic Na to supply the metallic sodium Na to the inside. The amount can be easily adjusted, and (2) the metal in the hollow portion H of the stem portion S can be obtained simply by holding the umbrella portion A at a temperature (98 ° C. or higher) at which the metallic sodium Na is melted. Blockage by sodium can be prevented.

  Therefore, according to this embodiment, the workability | operativity which puts sodium metal Na into the inside of an engine valve can be improved significantly, and work can be facilitated.

[Second Embodiment]
2nd Embodiment of the manufacturing method of the metal sodium enclosure engine valve which concerns on this invention is described based on FIG. However, the same parts as those in the first embodiment described above are denoted by the same reference numerals as those in the first embodiment described above, thereby overlapping the descriptions in the first embodiment described above. Description to be omitted is omitted.

  The method according to the present embodiment forms an umbrella portion by forging or the like on a solid round bar-shaped material as described in Patent Document 4 and the like, and is provided inside a portion that becomes a stem portion. After forming the hollow part with a punch or the like, the size of the outer diameter and the inner diameter of the stem part is reduced stepwise and the length of the stem part is extended stepwise. This is an application example in the case where an engine valve is manufactured by forming a stem portion having a target size by sequentially inserting a stem portion into the inside and sequentially performing drawing processing.

  Specifically, as shown in FIG. 2, first, a solid round bar-shaped material M (for example, a diameter of about 16 to 20 mm, a length of about 35 to 50 mm) is prepared (step S11), and an umbrella is formed by forging or the like. While forming the part A, the hollow part H (for example, internal diameter about 15-19 mm) is formed by a punch etc. (step S12). Next, the stem portion S is inserted into a cylindrical die D1 having an inner diameter smaller than the outer diameter of the stem portion S (peripheral portion of the hollow portion H) (for example, about −0.5 to −1.5 mm). Then, drawing is performed to reduce the size of the outer diameter and the inner diameter and extend the length (step S13).

  Then, the stem portion S is inserted again into a cylindrical die D2 having an inner diameter smaller than the die D1 (for example, about −0.5 to −1.5 mm), and further drawing processing is performed. The size of the inner diameter is further reduced and the length is further extended (step S14). Hereinafter, the outer diameter and the inner diameter of the stem portion S are set to a prescribed size (sequentially using a plurality of dice Dx having different sizes whose inner diameters are gradually reduced (for example, about 0.5 to 1.5 mm). For example, the drawing is sequentially performed so that the inner diameter is reduced to about 4 to 15 mm (preferably about 10 to 15 mm) and the length is extended stepwise (step S15).

  After drawing and reducing the stem S to the specified size, a dry inert gas atmosphere (for example, dry nitrogen gas) is used, as in the first embodiment described above. , The sodium A placed on the heating table T and held at a temperature (98 ° C. or higher) at which the umbrella part A is heated to melt the metallic sodium Na, and the metallic sodium Na ( For example, a diameter of about 1 to 14 mm (preferably about 7 to 14 mm) is drawn out in the atmosphere, and is drawn into the hollow portion H from the opening of the stem portion S, and the tip of the metallic sodium Na is placed in the umbrella. The metal sodium Na is melted and liquefied from the tip side by being brought into contact with the bottom surface of the hollow part H inside the part A, and is stored in the hollow part H. At the time of feeding prescribed length, by unwinding the metallic sodium Na, it supplies a predetermined amount of metallic sodium Na in the hollow portion H (step S16).

  When a prescribed amount of metallic sodium Na is supplied to the inside of the hollow portion H in this manner, it is smaller than the die Dx (for example, about −0) in a dry inert gas atmosphere (for example, dry nitrogen gas). .5--1.5 mm) The above-mentioned stem portion S is inserted into a cylindrical die Dx + 1 having an inner diameter, and cold drawing is performed to further reduce the size of the outer diameter and the inner diameter and further extend the length. (Step S17). At this time, the metallic sodium Na supplied to the hollow portion H is deformed following the deformation of the hollow portion H along with the cold drawing.

  Hereinafter, similarly, the outer diameter and the inner diameter of the stem portion S are used by sequentially using a plurality of dice Dn having different sizes whose inner diameters are gradually decreased (for example, by about 0.5 to 1.5 mm). Cold squeeze to gradually reduce to a size (for example, an outer diameter of about 5 to 7 mm, an inner diameter of about 2 to 4 mm) and to a desired length (for example, about 55 to 90 mm). Processing is performed sequentially (step S18).

  When the outer diameter and the inner diameter of the stem S have the desired size and the desired length in this way, the end of the stem portion S is axially joined and sealed (step S19). The engine valve V in which the metallic sodium Na is sealed in the hollow part H of the stem part S can be obtained.

  That is, in the present embodiment, as described in Patent Document 4 and the like, the outer diameter and the inner diameter of the stem portion S are reduced stepwise and the length of the stem portion S is extended stepwise. In addition, an engine valve is manufactured by forming a stem portion S of a desired size by sequentially inserting a stem portion into a plurality of cylindrical dies D1 to Dn of different sizes and performing drawing processing sequentially. In doing so, the stem portion S is once drawn until it reaches a specified size larger than the target size (for example, about 4 to 15 mm (preferably about 10 to 15 mm) inside diameter), and then the umbrella portion A is By heating, the metal sodium Na previously processed into a wire shape and wound in a reel shape is fed into the hollow portion H of the stem portion S, so that the metal sodium Na is contained in the hollow portion H. After the specified amount supplied while liquefied, the stem portion further performs cold-drawn by S, is to the stem portion S was to shape up on the size of interest.

  Therefore, according to the present embodiment, as in the case of the first embodiment described above, the workability of putting metallic sodium Na into the engine valve can be greatly improved and the work can be facilitated. Of course, when the inner diameter of the stem portion S is sufficiently wide (for example, about 4 to 15 mm (preferably about 10 to 15 mm) inside diameter), that is, with respect to the bottom surface of the hollow portion H of the umbrella A. When the metal sodium Na in a wire form is fed when it is easy to contact over a wide range, the metal sodium Na can be melted and liquefied more easily, and the workability can be further improved.

[Other Embodiments]
In the above-described embodiment, as described above, the stem portion S is placed on the stem portion S until a predetermined size larger than the target size (for example, an inner diameter of about 4 to 15 mm (preferably about 10 to 15 mm)) is obtained. Once the drawing process is performed, the umbrella part A is heated, and metal sodium Na previously processed into a wire shape and wound in a reel shape is fed into the hollow part H of the stem part S, so that the metal sodium Na After supplying the specified amount while being liquefied in the hollow portion H, the stem portion S is further subjected to cold drawing to form the stem portion S to the desired size. As an embodiment, for example, as shown in FIG. 3, a material M is prepared (step S11), the umbrella portion A is formed by forging or the like, and the hollow portion H is formed by punching or the like (step S11). S12), a dry inert gas atmosphere (for example, dry nitrogen gas, etc.), the umbrella A is heated, metal sodium Na previously processed into a wire shape and wound in a reel shape is hollowed in the stem portion S By feeding into the part H, after supplying a prescribed amount while liquefying metallic sodium Na in the hollow part H (step S23), the stem part S is inserted into the die D1, and cold drawing is performed. The outer diameter and the inner diameter are reduced and the length is extended (step S24), and subsequently, in the atmosphere, a plurality of dies D2 having different sizes with the inner diameter gradually reduced in the same manner as described above. , Dn, etc. are used successively to reduce the outer diameter and inner diameter of the stem portion S to the desired size in a stepwise manner and cold drawing so as to extend to the desired length in a stepwise manner. After the processing is sequentially performed (steps S25 and S18), the end portion of the stem portion S is axially joined and sealed (step S19), and the engine in which metallic sodium Na is sealed in the hollow portion H of the stem portion S Before obtaining the valve V, that is, before drawing the stem portion S, the umbrella portion A is heated, and the metallic sodium Na previously processed into a wire shape and wound in a reel shape is added to the stem portion. By supplying the metal sodium Na into the hollow portion H by liquefying in the hollow portion H and supplying a specified amount, cold drawing is performed on the stem portion S. It is also possible to mold to the size.

  However, as in the above-described embodiment, the stem portion S is once drawn until it reaches a specified size (for example, an inner diameter of about 10 to 15 mm) larger than the target size, and then the umbrella portion A is heated. The metal sodium Na, which has been processed into a wire shape and wound in a reel shape, is fed into the hollow portion H of the stem portion S, thereby supplying a prescribed amount while liquefying the metal sodium Na in the hollow portion H, If the stem portion S is further subjected to cold drawing to form the stem portion S to the desired size, the number of cold drawing steps performed in a dry inert gas atmosphere is minimized. It can be suppressed to the limit, a decrease in work efficiency can be suppressed, and the contact area between the metallic sodium in the hollow portion H and the atmosphere can be reduced as much as possible, It is possible to more reliably suppress the reaction of the metallic sodium Na accompanying contact with moisture or oxygen that they've been contained even only slightly into the atmosphere, very favorable.

  Further, for example, along with the supply of the metallic sodium Na into the hollow portion H, a protective agent made of solid paraffin or naphthalene is fed into the hollow portion H, and the space between the metallic sodium Na and the atmosphere After shielding with a protective agent, if the stem portion S is subjected to the cold drawing process so that the stem portion S is formed into a target size, contact between the metallic sodium Na and the atmosphere (for example, In addition, the reaction of the metallic sodium Na accompanying contact with moisture, oxygen, etc., which is contained even in a slight amount in the atmosphere, can be further reliably prevented. It is further preferable because the work can be further facilitated.

  Here, as a method of putting the protective agent into the hollow portion H, for example, it is formed in advance in a disk shape or a cylindrical shape according to the diameter size of the hollow portion H, and the metallic sodium Na is put into the hollow portion H. After that, the protective agent is put in and plugged so as to block the hollow portion H above the metallic sodium Na, or after the metallic sodium Na is added, the protective agent is heated and melted. Then, by dropping the protective agent from the opening above the hollow portion H, the protective agent is put inside the hollow portion H so as to cover the surface of the metallic sodium Na.

  The method for manufacturing a metal sodium-enclosed engine valve according to the present invention can be used in an industrially very advantageous manner because metal sodium can be easily put into the engine valve.

V Engine valve A Umbrella part S Stem part H Hollow part D1, D2, Dx, Dx + 1, Dn Die Na Metal sodium

Claims (4)

By sealing the opening after putting sodium metal into the hollow part from the opening of the stem part of the engine valve having a hollow part inside the stem part and the umbrella part and having an opening at the upper end of the stem part. In the manufacturing method of a metal sodium sealed engine valve in which metal sodium is sealed inside,
While holding the umbrella part at a temperature at which the metallic sodium is melted, the metallic sodium is supplied while being liquefied in the hollow part by feeding the metallic sodium into the hollow part from the opening of the stem part. A method for manufacturing a metallic sodium filled engine valve. In the manufacturing method of the metallic sodium enclosure engine valve according to claim 1,
In producing the engine valve by sequentially drawing the stem part so as to reduce the outer diameter and inner diameter of the stem part step by step, and forming the stem part into a desired size,
The stem portion is drawn until the inner diameter of the hollow portion of the stem portion reaches a specified size, and then the umbrella-shaped metal sodium is held in the stem while holding the umbrella portion at a temperature at which the metallic sodium is melted. After the metal sodium is supplied while being liquefied in the hollow part by being fed into the hollow part from the opening of the part, the stem part is further subjected to cold drawing to obtain a desired size for the stem part. A method for manufacturing a metal sodium-enclosed engine valve, characterized by being molded into In the manufacturing method of the metallic sodium enclosure engine valve according to claim 1,
In producing the engine valve by sequentially drawing the stem part so as to reduce the outer diameter and inner diameter of the stem part step by step, and forming the stem part into a desired size,
Before drawing the stem portion, the wire-like metal sodium is fed into the hollow portion from the opening of the stem portion while holding the umbrella portion at a temperature at which the metal sodium is melted. Manufacturing a metallic sodium-enclosed engine valve, wherein sodium is supplied while being liquefied in the hollow portion, and then the stem portion is cold drawn to form the stem portion into a desired size. Method. In the manufacturing method of the metallic sodium filled engine valve according to claim 2 or claim 3,
Along with the supply of the metallic sodium into the hollow portion, a protective agent made of solid paraffin or naphthalene is supplied into the hollow portion, thereby shielding the metallic sodium from the atmosphere, and then the cold to the stem portion. A method for producing a metallic sodium-enclosed engine valve, wherein the stem portion is formed into a target size by drawing.

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