WO2015170384A1 - Hollow poppet valve - Google Patents

Hollow poppet valve Download PDF

Info

Publication number
WO2015170384A1
WO2015170384A1 PCT/JP2014/062374 JP2014062374W WO2015170384A1 WO 2015170384 A1 WO2015170384 A1 WO 2015170384A1 JP 2014062374 W JP2014062374 W JP 2014062374W WO 2015170384 A1 WO2015170384 A1 WO 2015170384A1
Authority
WO
WIPO (PCT)
Prior art keywords
valve
diameter hollow
hollow portion
diameter
small
Prior art date
Application number
PCT/JP2014/062374
Other languages
French (fr)
Japanese (ja)
Inventor
基治 鈴木
Original Assignee
日鍛バルブ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日鍛バルブ株式会社 filed Critical 日鍛バルブ株式会社
Priority to PCT/JP2014/062374 priority Critical patent/WO2015170384A1/en
Publication of WO2015170384A1 publication Critical patent/WO2015170384A1/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
    • F01L3/12—Cooling of valves
    • F01L3/14—Cooling of valves by means of a liquid or solid coolant, e.g. sodium, in a closed chamber in a valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
    • F01L3/20—Shapes or constructions of valve members, not provided for in preceding subgroups of this group

Definitions

  • the present invention relates to a hollow poppet valve in which a coolant is loaded in a hollow portion formed from the umbrella portion to the shaft portion of the poppet valve.
  • a hollow part is formed from the umbrella part of the poppet valve integrally formed on one end side of the shaft part to the shaft part, and has a higher thermal conductivity than the base material of the valve.
  • a hollow poppet valve is described in which a coolant (eg, metallic sodium, melting point about 98 ° C.) is loaded into the hollow portion with an inert gas.
  • the thermal conductivity of the valve (hereinafter referred to as the heat extraction effect of the valve) can be improved. it can.
  • the combustion chamber becomes hot due to the driving of the engine, but if the temperature of the combustion chamber is too high, knocking occurs and a predetermined engine output cannot be obtained, leading to deterioration of fuel consumption (deterioration of engine performance). Therefore, as a method of actively conducting heat generated in the combustion chamber through the valve in order to lower the temperature of the combustion chamber (a method for increasing the heat-sucking effect of the valve), the coolant is hollowed together with the inert gas.
  • Various hollow valves loaded in the box have been proposed.
  • the communication portion between the disk-shaped large-diameter hollow portion in the umbrella portion and the linear small-diameter hollow portion in the shaft portion is a smooth curved region (the inner diameter gradually increases).
  • This transition area is configured to be smoothly continuous, so that the coolant (liquid) fills the gas when the valve opens and closes (the valve reciprocates in the axial direction).
  • the large-diameter hollow portion and the small-diameter hollow portion can move smoothly, and the heat-drawing effect of the valve is improved.
  • the coolant (liquid) moves smoothly between the large-diameter hollow part and the small-diameter hollow part according to the opening / closing operation of the valve.
  • the coolant (liquid) in the hollow portion moves in the axial direction in a state where the upper layer portion, the middle layer portion, and the lower layer portion are maintained in a vertical relationship without being stirred.
  • Patent Document 3 by providing stepped irregularities on the inner peripheral surface of the smooth communication portion between the large-diameter hollow portion and the small-diameter hollow portion, the contact area of the coolant (liquid) with the valve increases. Further, since the coolant is stirred by the unevenness, the heat transfer property is improved.
  • the inner peripheral surface of the communication part has a shape in which the inner diameter gradually changes due to the stepped irregularities, so that when the valve reciprocates in the axial direction, the coolant in the large-diameter hollow part is positively It is not agitated, and it cannot be said that the heat pulling effect (thermal conductivity) is sufficiently exhibited.
  • Patent Document 4 (WO2104 / 054113, published on April 10, 2014) was proposed.
  • the large-diameter hollow portion in the umbrella portion in communication with the small-diameter hollow portion in the shaft portion is formed into a truncated cone shape, and the opening peripheral portion of the small-diameter hollow portion constituting the top surface of the large-diameter hollow portion is defined as the center of the valve.
  • a circulating flow (convection) in the longitudinal direction is formed around the central axis of the valve in the coolant (liquid) in the large-diameter hollow portion of the valve that reciprocates in the axial direction.
  • the entire coolant in the large-diameter hollow portion is actively stirred, and the heat-drawing effect (thermal conductivity) is improved.
  • the inventor has focused on the maximum temperature (Tmax) point appearing in the fillet portion that curves between the umbrella portion and the shaft portion. That is, in the prior art document 4, the small-diameter hollow portion on the shaft portion side and the large-diameter hollow portion on the umbrella portion side communicate at right angles in the fillet portion, and the fillet portion is thicker than the shaft portion and the umbrella portion, In particular, when used as an exhaust valve, it is considered that the highest temperature point comes to the fillet portion because heat tends to accumulate in the thick fillet portion that is the most exposed portion to the high-temperature exhaust gas.
  • the maximum temperature appearing in the fillet portion may be lowered, that is, the heat of the fillet portion is efficiently
  • the fillet portion forming wall should be made thin and the coolant corresponding to the fillet portion of the hollow portion should be actively stirred.
  • a frustoconical large-diameter hollow part is provided in the umbrella part, and the small-diameter hollow part in the shaft part communicates perpendicularly to the ceiling surface of the large-diameter hollow part (conical frustum).
  • the peripheral edge of the opening to the valve section is a plane perpendicular to the central axis of the valve, and the coolant in the large-diameter hollow part of the valve that reciprocates in the axial direction circulates inward in the vertical direction around the central axis of the valve.
  • a hollow part with a medium-diameter hollow part with an enlarged inner diameter is provided at the communicating part of the hollow part with the large-diameter hollow part, and the peripheral edge of the opening to the medium-diameter hollow part of the small-diameter hollow part is substantially perpendicular to the central axis of the valve.
  • the cooling inside the hollow inner diameter of the valve that reciprocates in the axial direction We considered a new structure that "form longitudinal circulation stream (convection) in wood.
  • the present invention has been made in view of the above-described problems of the prior art, and its purpose is to promote the stirring of the coolant in the hollow portion when the valve reciprocates in the axial direction, thereby improving the heat-drawing effect. It is to provide a hollow poppet valve.
  • the hollow portion is formed from the umbrella portion of the poppet valve integrally formed at the shaft end portion to the shaft portion,
  • the hollow poppet valve in which the hollow portion is filled with a coolant In the umbrella part, a frustoconical large-diameter hollow part having a tapered outer peripheral surface following the outer shape of the umbrella part is provided,
  • a linear small-diameter hollow portion that communicates with the large-diameter hollow portion is provided in the shaft portion, and a medium-diameter hollow whose inner diameter is increased at the communicating portion of the small-diameter hollow portion with the large-diameter hollow portion.
  • a first circulating flow (convection) in the longitudinal direction around the central axis of the valve is formed in the coolant (liquid) of the large-diameter hollow portion, and the medium diameter
  • a second circulating flow (convection) in the vertical direction is formed in the coolant in the hollow portion.
  • the opening periphery to the large-diameter hollow portion and the opening periphery to the medium-diameter hollow portion of the small-diameter hollow portion are each configured by a plane orthogonal to the central axis of the valve, but the medium-diameter hollow of the small-diameter hollow portion
  • the peripheral edge of the opening to the portion may be formed of a tapered surface inclined at a predetermined angle with respect to the central axis of the valve, and the inclination of the tapered surface is in the range of 60 degrees or less (30 degrees or less with respect to the plane perpendicular to the central axis).
  • a valve constituting a valve mechanism for an automobile is driven by a cam that rotates in synchronization with a crankshaft (reciprocating operation in the axial direction).
  • inertia forces Wa and Wb act on the liquid.
  • the coolant in the hollow portion is strongly influenced by the inertial force acting when the valve is seated, and as shown in FIGS. 3 (a), 3 (b), and FIG.
  • a circulation flow (convection) T1 and a second circulation flow (convection) T2 are formed, and the inside of the hollow portion is actively stirred.
  • the upward inertia force Wa acts on the coolant in the hollow portion as shown in FIG. F1 occurs.
  • the ceiling surface of the large-diameter hollow part (the peripheral edge of the opening of the medium-diameter hollow part in the large-diameter hollow part) and the ceiling surface in the medium-diameter hollow part (the peripheral edge of the opening of the small-diameter hollow part) are, for example, orthogonal to the central axis of the valve Therefore, unlike the conventional hollow valve in which the communication part between the hollow parts is formed in a smooth shape, the coolant cannot move smoothly upward.
  • the coolant in the large-diameter hollow portion includes the center (radially inner side) of the communication portion P1 from the tapered outer peripheral surface along the annular step portion (the ceiling surface of the large-diameter hollow portion) and the medium-diameter hollow portion.
  • the coolant in the medium-diameter hollow portion is communicated with the small-diameter hollow portion from the outer peripheral surface of the medium-diameter hollow portion along the annular stepped portion (the ceiling surface of the medium-diameter hollow portion).
  • a flow F5 toward the center (radially inward) of the part P2 is generated.
  • the coolant in the hollow portion has a downward inertia as shown in FIG. Since the force Wb acts, a flow F3 is generated that is directed downward and radially outward along the bottom surface in the large-diameter hollow portion.
  • the coolant in the large-diameter hollow portion is combined with the flows F2 and F3, and the first circulation in the longitudinal direction around the central axis of the valve.
  • a flow (convection) T1 is formed.
  • the valve reciprocates in the axial direction, whereby a first circulating flow (convection) T1 in the longitudinal direction around the central axis of the valve is formed in the coolant in the large-diameter hollow portion, A second circulating flow (convection) T2 in the vertical direction is formed in the coolant in the medium-diameter hollow portion, and the coolant in the hollow portion is actively agitated, so that the heat drawing effect of the valve (thermal conductivity) ) Is significantly improved.
  • the medium-diameter hollow portion is provided at a position corresponding to the fillet portion between the umbrella portion and the shaft portion.
  • an inner diameter of the small-diameter hollow portion near the valve shaft end portion is formed larger than an inner diameter of the small-diameter hollow portion near the valve umbrella portion.
  • An annular step portion is provided at a predetermined axial position in the small-diameter hollow portion, and the coolant is loaded to a position beyond the step portion.
  • the turbulent flow generated in the vicinity of the stepped portion when the coolant moves in the axial direction in the small-diameter hollow portion in accordance with the opening / closing operation (vertical reciprocating operation) of the valve is caused by the coolant in the small-diameter hollow portion.
  • the opening / closing operation vertical reciprocating operation
  • the stepped portion in the small-diameter hollow portion when the stepped portion in the small-diameter hollow portion is disposed in an exhaust passage or an intake passage where the valve opens to a combustion chamber of an engine, It is configured to be provided at a predetermined position that does not fall within the exhaust passage or the intake passage.
  • the fatigue strength does not decrease in the region near the shaft end in the valve shaft portion than in the region near the valve umbrella portion, even if it is formed thinly (the inner diameter of the small-diameter hollow portion is increased), the strength (due to fatigue) There is no problem in durability such as breakage.
  • the inner diameter of the small-diameter hollow portion near the shaft end is increased, firstly, the surface area (contact surface area with the coolant) of the entire small-diameter hollow portion increases, and the heat transfer efficiency in the valve shaft portion increases. Second, the volume of the entire small-diameter hollow portion increases, and the total weight of the valve can be reduced. Third, by increasing the charging amount of the coolant, the heat drawing effect (thermal conductivity) of the valve shaft portion is increased. And the heat-drawing effect of a valve
  • the stepped portion in the small-diameter hollow portion is substantially at a predetermined position that is not at least in the exhaust passage or the intake passage when the valve is fully opened (for example, at the end of the valve guide facing the exhaust passage or the intake passage). It is most desirable to provide at the corresponding position.
  • the amount of coolant charged in the hollow portion increases, and the contact area with the coolant on the inner peripheral surface of the hollow portion also increases, so the heat drawing effect (thermal conductivity) of the valve is improved. As a result, engine performance is improved.
  • a circulation flow is formed in the longitudinal direction around the central axis of the valve, and in the medium-diameter hollow portion, a longitudinal circulation flow is also formed in the hollow portion. Since the coolant in the entire section is actively agitated, the heat-sucking effect (thermal conductivity) of the valve is improved, and the engine performance is improved.
  • the heat transfer action in the fillet portion is surely enhanced, the heat drawing effect (heat conductivity) of the valve is further improved, and the engine performance is further improved.
  • turbulent flow is generated in the vicinity of the stepped portion in the small-diameter hollow portion along with the opening / closing operation (reciprocating operation in the vertical direction) of the valve, and at least the upper layer of the coolant in the hollow portion Since the middle layer part is stirred from the part, the heat transfer by the coolant in the hollow part becomes active, the heat drawing effect (thermal conductivity) of the valve is further improved, and the engine performance is further improved.
  • the hollow poppet valve of the fourth aspect since the inner diameter of the small-diameter hollow portion near the shaft end portion in the valve shaft portion is increased within a range that does not affect the durability, the heat drawing effect of the valve shaft portion (heat (Conductivity) is further improved, and the total weight of the valve is reduced, further improving the engine performance.
  • FIG. 1 It is a longitudinal cross-sectional view of the hollow poppet valve which is the 1st Example of this invention. It is a figure which shows the inertial force which acts on the coolant in a hollow part at the time of the same hollow poppet valve reciprocatingly, (a) is sectional drawing which shows the inertial force which acts on the coolant at the time of valve seating, (b) ) Is a cross-sectional view showing the inertial force acting on the coolant when the valve shifts from the valve opening operation to the valve closing operation (from falling to rising).
  • (A) is an enlarged view showing the movement of the coolant in the hollow portion when the hollow poppet valve opens and closes (reciprocates in the axial direction), and (a) shows that the engine starts and the valve shifts from the seated state to the valve open state. It is a figure which shows the motion of the coolant at the time of carrying out, (b) is a figure which shows the motion of the coolant at the time of a valve
  • FIGS. 4A and 4B are diagrams showing a manufacturing process of the hollow poppet valve, wherein FIG. 4A shows a hot forging process for forging a shell which is an intermediate product of the valve, and FIG. 4B shows a hole corresponding to a small-diameter hollow portion formed in a shaft portion.
  • (C) shows a hole drilling process for drilling a hole corresponding to the medium-diameter hollow part in the fillet part, and (d) shows a hole corresponding to the small-diameter hollow part near the shaft end part.
  • (E) shows an axial contact process for axially contacting the shaft end member,
  • (f) shows a process for filling the small-diameter hollow portion with a coolant, and
  • (g) shows an inert gas.
  • the process of welding a cap to the opening part of the recessed part (large diameter hollow part) of an umbrella outer shell under atmosphere (large diameter hollow part sealing process) is shown. It is a longitudinal cross-sectional view of the hollow poppet valve which is the 2nd Example of this invention.
  • FIG. 1 to 4 show a hollow poppet valve for an internal combustion engine according to a first embodiment of the present invention.
  • reference numeral 10 denotes a heat-resistant alloy in which an umbrella portion 14 is integrally formed on one end side of a shaft portion 12 that extends straight through an R-shaped fillet portion 13 that gradually increases in outer diameter.
  • a tapered face portion 16 is provided on the outer periphery of the umbrella portion 14.
  • a shaft-integrated shell (hereinafter simply referred to as a shell) 11 (see FIGS. 1 and 6), which is a valve intermediate product in which an umbrella outer shell 14a is integrally formed on one end of a cylindrical shaft portion 12a;
  • the shaft end member 12b axially contacted with the shaft portion 12a of the shell 11 and the disc-shaped cap 18 welded to the opening portion 14c in the frustoconical recess 14b of the umbrella outer shell 14a of the shell 11
  • a hollow poppet valve 10 having a hollow portion S is formed from the portion 14 to the shaft portion 12.
  • the hollow portion S is filled with a coolant 19 such as metallic sodium together with an inert gas such as argon gas.
  • a larger amount of the coolant 19 is more excellent in the heat-drawing effect, a difference in heat-drawing effect is small if the amount is larger than a predetermined amount, so that cost-effectiveness (the more the coolant 19 is, the higher the cost). For example, an amount of about 1/2 to about 4/5 of the volume of the hollow portion S may be loaded.
  • reference numeral 2 denotes a cylinder head
  • reference numeral 6 denotes an exhaust passage extending from the combustion chamber 4, and a tapered surface 8 a with which the face portion 16 of the valve 10 abuts the opening peripheral edge of the exhaust passage 6 to the combustion chamber 4.
  • An annular valve seat 8 is provided.
  • Reference numeral 3 denotes a valve insertion hole provided in the cylinder head 2, and an inner peripheral surface of the valve insertion hole 3 is constituted by a valve guide 3 a with which the shaft portion 12 of the valve 10 is slidably contacted.
  • Reference numeral 9 is a valve spring for urging the valve 10 in the valve closing direction (upward in FIG. 1)
  • reference numeral 12c is a cotter groove provided at the end of the valve shaft.
  • the shell 11 and the cap 18 that are exposed to the high temperature gas in the combustion chamber 4 and the exhaust passage 6 are made of heat-resistant alloy steel.
  • the shaft end member 12b that does not require heat resistance as much as the cap 18 is made of a general steel material.
  • the hollow portion S in the valve 10 includes a truncated cone-shaped large-diameter hollow portion S1 provided in the valve umbrella portion 14 and a linear (rod-shaped) small-diameter hollow portion S2 provided in the valve shaft portion 12. Are communicated so as to be orthogonal to each other via a columnar medium-diameter hollow portion S3 provided at a position corresponding to the fillet portion 13.
  • annular ceiling surface of the large-diameter hollow portion S1 (a bottom surface of the concave portion 14b of the umbrella outer shell 14a that is the opening peripheral portion of the medium-diameter hollow portion S3) 14b1, and a medium-diameter hollow portion that is the opening peripheral portion of the small-diameter hollow portion S1
  • the annular ceiling surface 20 of S ⁇ b> 3 is configured by a plane that is orthogonal to the central axis L of the bulb 10.
  • the communicating portion P1 of the large-diameter hollow portion S1 with the medium-diameter hollow portion S3 is replaced with a smooth shape as in the prior art documents 1 and 2, and a bowl-shaped annular step as viewed from the large-diameter hollow portion S1 side.
  • a portion 15 is formed, and a side (a ceiling surface of the large-diameter hollow portion S1) 14b1 facing the large-diameter hollow portion S1 of the annular step portion 15 is configured by a plane orthogonal to the central axis L of the bulb 10. .
  • the communicating portion P2 of the medium-diameter hollow portion S3 with the small-diameter hollow portion S2 is replaced with a smooth shape as in the prior patent documents 1 and 2, and has a bowl-like shape when viewed from the large-diameter hollow portion S1 side.
  • a step portion 15 a is formed, and the ceiling surface 20 in the medium-diameter hollow portion S ⁇ b> 3 (opening peripheral edge portion of the small-diameter hollow portion S ⁇ b> 2 in the medium-diameter hollow portion S ⁇ b> 3) 20 is also configured by a plane orthogonal to the central axis L of the valve 10. ing.
  • the small-diameter hollow portion S2 includes a small-diameter hollow portion S21 having a relatively large inner diameter near the valve shaft end portion and a small-diameter hollow portion S22 having a relatively small inner diameter near the valve umbrella portion 14.
  • the annular stepped portion 17 is formed between the small-diameter hollow portion S21 and the small-diameter hollow portion S22, and the coolant 19 is loaded up to a position beyond the stepped portion 17.
  • the coolant (liquid) 19 in the large-diameter hollow portion S1 and the medium-diameter hollow portion S3 has a longitudinal circulation flow (convection) T1 as shown in FIG. , T2 are formed, and at the same time, as shown in FIGS. 3A and 3B, turbulent flows F9a and F9b are formed in the coolant (liquid) 19 in the small-diameter hollow portion S2.
  • the lower layer portion, the middle layer portion, and the upper layer portion of the coolant 19 in the hollow portion S are positively stirred, so that the heat drawing effect (thermal conductivity) in the valve 10 is greatly improved.
  • the valve 10 is driven (reciprocating in the axial direction) by a cam (not shown) that rotates in synchronization with the crankshaft. Therefore, as shown in FIGS. 2A and 2B, inertial forces Wa and Wb act on the coolant 19 in the hollow portion S of the valve 10, and particularly when the valve 10 is seated.
  • the first circulation flow (convection) T1 and the second circulation flow (convection) T2 are formed in the hollow portion S by being strongly influenced by the inertial force Wa (see FIGS. 2 and 4). The inside of S is actively stirred.
  • the coolant in the hollow portion S has an upward inertial force Wa as shown in FIG.
  • an upward flow F1 is generated.
  • the ceiling surface of the large-diameter hollow portion S1 (opening peripheral edge portion of the medium-diameter hollow portion S3 in the large-diameter hollow portion S) 14b1 and the ceiling surface of the medium-diameter hollow portion S3 (opening of the small-diameter hollow portion S2 in the medium-diameter hollow portion S3) (Peripheral part) 20 is constituted by a plane perpendicular to the central axis L of the valve, so that the communication parts P1, P2 between the hollow parts S1, S2, S3 are formed in a smooth shape.
  • the coolant 19 cannot move upward smoothly.
  • the coolant 19 in the large-diameter hollow portion S1 includes the center (radially inner side) of the communicating portion P1 along the annular stepped portion 15 (the ceiling surface 14b1 of the large-diameter hollow portion S1) from the tapered outer peripheral surface 14b2.
  • the coolant 19 in the medium-diameter hollow portion S3 is radially directed from the cylindrical outer peripheral surface along the annular stepped portion 15a (the ceiling surface 20 of the medium-diameter hollow portion S3).
  • An inward flow F5 is generated.
  • valve 10 is switched from the valve opening operation to the valve closing operation (the valve 10 changes from lowering to rising) and is further seated, as shown in FIG. Since the downward inertia force Wb acts, the coolant 19 flows downward, and further a flow F3 is generated radially outward along the bottom surface in the large-diameter hollow portion S1.
  • the coolant 19 in the large-diameter hollow portion S1 has a flow inward in the longitudinal direction around the central axis L of the valve where the flows F2 and F3 are synthesized.
  • a longitudinal circulation flow (convection) T2 in which the flows F5 and F3 are combined is formed in the coolant 19 in the medium-diameter hollow portion S3.
  • the coolant 19 in the large-diameter hollow portion S1 has a circulating flow (convection) T1 in the longitudinal direction around the central axis L of the valve.
  • a longitudinal circulation flow (convection) T2 is formed in the coolant 19 in the medium diameter hollow portion S3, and further, turbulent flows F9a and F9b are formed in the vicinity of the stepped portion 17 of the small diameter hollow portion S2.
  • the annular ceiling surface (the upper surface of the truncated cone) 14b1 and the outer peripheral surface (the outer circumferential surface of the truncated cone) 14b2 of the large-diameter hollow portion S1 form an obtuse angle. Furthermore, the flow of the coolant 19 (F2 in FIG. 3 (a)) from the radially outer side of the large-diameter hollow portion S1 toward the communication portion P1 along the ceiling surface of the large-diameter hollow portion S1 becomes smooth.
  • the medium-diameter hollow portion S3 is located at a position corresponding to the fillet portion 13 between the umbrella portion 14 and the shaft portion 12, which is a portion most exposed to high-temperature exhaust gas when used as an exhaust valve.
  • FIG. 5 shows the temperature distribution characteristics in the axial direction of the surface temperature of the hollow poppet valve 10 of the present embodiment, the hollow valve B in which the coolant is loaded in the hollow portion formed in the shaft portion, the hollow formed from the shaft portion to the umbrella portion.
  • the temperature distribution characteristic of the valve 10 of this embodiment is estimated to be as shown by a one-point difference line in comparison with the temperature distribution characteristics of each of the peripheral portions (configured with a plane perpendicular to the central axis of the valve).
  • the In FIG. 5, the shape (outer shape) of the hollow poppet valve 10 is indicated by hatching.
  • the entire coolant in the hollow portion is agitated by the circulating flow formed in the large-diameter hollow portion, so that the valve surface temperature including the maximum temperature Tmax is Compared to the maximum temperature (Tmax) position of the valves B and C, the maximum temperature (Tmax) position is closer to the valve umbrella than the valve B and C. It can be seen that the heat drawing effect (heat dissipation) is superior to C.
  • the whole coolant 19 in the hollow part S is more active by the circulation flow T1 formed in the large diameter hollow part S1, and the circulation flow T2 formed in the medium diameter hollow part S3.
  • the maximum temperature (Tmax) position is closer to the umbrella side as shown in FIG. Presumed to be gentle.
  • the stepped portion 17 in the small-diameter hollow portion S2 is provided at a position substantially corresponding to the end portion 3b facing the exhaust passage 6 of the valve guide 3a, and has a shaft end portion having a large inner diameter.
  • the stepped portion 17 in the small-diameter hollow portion S has a predetermined position (in the valve shaft portion 12) that does not enter the exhaust passage 6 when the valve 10 is fully opened (lowered).
  • a thin-walled small-diameter hollow portion S21 forming wall is provided at a predetermined position that is not easily affected by heat in the exhaust passage 6.
  • Reference numeral 17X in FIG. 1 indicates the position of the stepped portion 17 in a state where the valve 10 is fully opened (lowered).
  • the region near the valve umbrella portion 14 in the valve shaft portion 12 that is always in the exhaust passage 6 and exposed to high heat reduces the fatigue strength. It must be formed to a thickness that can withstand.
  • heat from the combustion chamber 4 and the exhaust passage 6 is transmitted via the coolant 19.
  • the transmitted heat is immediately radiated to the cylinder head 2 through the valve guide 3a, the temperature does not become as high as that near the valve umbrella portion 14.
  • the fatigue strength does not decrease in the region near the shaft end in the valve shaft portion 12 than in the region near the valve umbrella portion 14, the strength is improved even if it is formed thin (the inner diameter of the small-diameter hollow portion S 21 is increased). There is no problem in the target (durability such as breakage due to fatigue).
  • the position of the stepped portion 17 is a position substantially corresponding to the lower end portion 3b of the valve guide 3 that is as low as possible and does not enter the exhaust passage 6 when the valve 10 is fully opened (lowered).
  • the inner diameter of the small-diameter hollow portion S21 is increased, and first, the surface area (contact area with the coolant 19) of the entire small-diameter hollow portion S2 is increased, so that the heat transfer efficiency in the valve shaft portion 12 is increased. Has been enhanced.
  • the total weight of the valve 10 is reduced by increasing the volume of the entire small-diameter hollow portion S21.
  • a shell 11 in which an umbrella outer shell 14a provided with a truncated cone-shaped concave portion 14b and a shaft portion 12a are integrally formed is formed by a hot forging process.
  • the bottom surface 14b1 of the concave portion 14b of the umbrella outer shell 14a is formed by a plane orthogonal to the shaft portion 12 (the central axis L of the shell 11).
  • the hot forging process is extrusion forging in which the dies are sequentially replaced, extrusion forging in which the shell 11 is manufactured from a heat-resistant alloy steel metal block, or a spherical portion is installed at the end of the heat-resistant alloy steel rod with an upsetter.
  • any of upsetting forging may be used in which the shell 11 (the umbrella outer shell 14a) is forged using a mold.
  • an R-shaped fillet portion 13 is formed between the umbrella outer shell 14a and the shaft portion 12a of the shell 11, and a tapered face portion is formed on the outer peripheral surface of the umbrella outer shell 14a. 16 is formed.
  • the shell 11 is arranged so that the concave portion 14b of the umbrella outer shell 14a faces upward, and the shaft portion 12 extends from the bottom surface 14b1 of the concave portion 14b of the umbrella outer shell 14a.
  • the hole 14e corresponding to the small-diameter hollow portion S22 is drilled by drilling (first hole drilling step).
  • a hole 14e ′ corresponding to the medium-diameter hollow portion S3 is drilled from the bottom surface 14b1 of the concave portion 14b of the umbrella outer shell 14a (second hole drilling step). ).
  • bowl-shaped annular step portions 15 and 15a are formed in the communication portion between the recess 14b and the hole 14e ′ and the communication portion between the hole 14e ′ and the hole 14e as viewed from the recess 14b side. .
  • a hole 14f corresponding to the small-diameter hollow portion S21 is drilled from the shaft end side of the shell 11 (third hole drilling step).
  • the shaft end member 12b is axially contacted with the shaft end portion of the shell 11 (shaft end member axial contact step).
  • a predetermined amount of coolant (solid) 19 is inserted into the hole 14 e of the recess 14 b of the umbrella outer shell 14 a of the shell 11 (coolant loading step).
  • a cap 18 is welded (for example, resistance welding) to the opening 14c of the recess 14b of the umbrella outer shell 14a of the shell 11 under an argon gas atmosphere, and the valve 10
  • the hollow portion S is sealed (hollow portion sealing step).
  • the welding of the cap 18 may employ electron beam welding, laser welding, or the like instead of resistance welding.
  • FIG. 7 shows a hollow poppet valve according to a second embodiment of the present invention.
  • the shaft end member 12b is axially contacted with the shaft portion 12a of the shaft-integrated shell 11 which is a valve intermediate product, whereby the shaft portion 12 of the valve 10 is configured.
  • the shaft portion 12 of the valve 10A is integrally configured in advance with the umbrella portion 14 (umbrella portion outer shell 14a).
  • the ceiling surface of the medium-diameter hollow portion S3 (opening peripheral edge portion of the small-diameter hollow portion S2 in the medium-diameter hollow portion S3) 20 is configured by a plane orthogonal to the central axis L of the valve 10.
  • the ceiling surface of the medium-diameter hollow portion S3 ′ (the opening peripheral edge of the small-diameter hollow portion S2 ′ in the medium-diameter hollow portion S3 ′) 20a and a predetermined angle with respect to the central axis L
  • the tapered surface is inclined at 60 to 90 degrees (tapered at 30 to 0 degrees with respect to a plane perpendicular to the central axis L).
  • the inner diameter of the small-diameter hollow portion S21 near the valve shaft end is formed larger than the inner diameter of the small-diameter hollow portion S22 near the valve umbrella portion 14, so that the inside of the small-diameter hollow portion S2
  • the second annular stepped portion 17 is provided at a predetermined position in the axial direction, and the coolant 19 is loaded up to a position beyond the second stepped portion 17.
  • the inside diameter of the small-diameter hollow portion S2 ′ is formed to have a constant size in the axial direction.

Abstract

Provided is a hollow poppet valve having improved heat conductivity. A hollow poppet valve (10) has an umbrella section (14) formed integrally at a shaft end of the valve. A hollow section (S) is formed in the valve so as to extend from the umbrella section (14) to a shaft section (12) and is filled with a cooling material (19). A rectilinear small-diameter hollow section (S2) within the shaft section (12) communicates with a circular truncated cone-shaped large-diameter hollow section (S1) through a medium-diameter hollow section (S3) provided at a position corresponding to a fillet section (13), the large-diameter hollow section (S1) being located within the umbrella section (14). The opening peripheral edge (14b1) of the medium-diameter hollow section (S3), the opening peripheral edge (14b1) facing the large-diameter hollow section (S1), and the opening peripheral edge (20) of the small-diameter hollow section (S2), the opening peripheral edge (20) facing the medium-diameter hollow section (S3), are respectively constituted by planes perpendicular to the center axis (L) of the valve. When the valve (10) reciprocates axially, a vertically inward circulation flow (T1) is formed in the hollow section (S1), and a vertical circulation flow (T2) is formed in the hollow section (S3). Consequently, the cooling material (19) is positively stirred to enhance the heat conductivity of the valve (10).

Description

中空ポペットバルブHollow poppet valve
　ポペットバルブの傘部から軸部にかけて形成された中空部に冷却材が装填された中空ポペットバルブに関する。 The present invention relates to a hollow poppet valve in which a coolant is loaded in a hollow portion formed from the umbrella portion to the shaft portion of the poppet valve.
　下記特許文献１、２等には、軸部の一端側に傘部を一体的に形成したポペットバルブの傘部から軸部にかけて中空部が形成され、バルブの母材よりも熱伝導率の高い冷却材（例えば、金属ナトリウム、融点約９８℃）が不活性ガスとともに中空部に装填された中空ポペットバルブが記載されている。 In the following Patent Documents 1, 2, etc., a hollow part is formed from the umbrella part of the poppet valve integrally formed on one end side of the shaft part to the shaft part, and has a higher thermal conductivity than the base material of the valve. A hollow poppet valve is described in which a coolant (eg, metallic sodium, melting point about 98 ° C.) is loaded into the hollow portion with an inert gas.
　バルブの中空部は、傘部内から軸部内に延びており、それだけ多くの量の冷却材を中空部に装填できるので、バルブの熱伝導性（以下、バルブの熱引き効果という）を高めることができる。 Since the hollow portion of the valve extends from the inside of the umbrella portion into the shaft portion, and so much coolant can be loaded into the hollow portion, the thermal conductivity of the valve (hereinafter referred to as the heat extraction effect of the valve) can be improved. it can.
　即ち、エンジンの駆動によって燃焼室は高温になるが、燃焼室の温度が高すぎると、ノッキングが発生して所定のエンジン出力が得られず、燃費の悪化（エンジンの性能の低下）につながる。そこで、燃焼室の温度を下げるために、燃焼室で発生する熱をバルブを介して積極的に熱伝導させる方法（バルブの熱引き効果を上げる方法）として、冷却材を不活性ガスとともに中空部に装填した種々の中空バルブが提案されている。 That is, the combustion chamber becomes hot due to the driving of the engine, but if the temperature of the combustion chamber is too high, knocking occurs and a predetermined engine output cannot be obtained, leading to deterioration of fuel consumption (deterioration of engine performance). Therefore, as a method of actively conducting heat generated in the combustion chamber through the valve in order to lower the temperature of the combustion chamber (a method for increasing the heat-sucking effect of the valve), the coolant is hollowed together with the inert gas. Various hollow valves loaded in the box have been proposed.
ＷＯ2010／041337WO2010 / 041337 特開2011-179328JP2011-179328 実開平4-769074-76907 PCT/JP2012/075452（ＷＯ2104/054113）PCT / JP2012 / 075452 (WO2104 / 054113)
　特許文献１，２のように、従来の冷媒入り中空ポペットバルブでは、傘部内の円盤状大径中空部と軸部内の直線状小径中空部間の連通部が滑らかな曲線領域（内径が徐々に変わる遷移領域）で構成されているが、この連通部が滑らかに連続する形状であることで、バルブの開閉動作（バルブの軸方向への往復動作）の際に冷却材（液体）が封入ガスとともに大径中空部と小径中空部間をスムーズに移動できて、バルブの熱引き効果が上がると考えられている。 As in Patent Documents 1 and 2, in the conventional refrigerant-containing hollow poppet valve, the communication portion between the disk-shaped large-diameter hollow portion in the umbrella portion and the linear small-diameter hollow portion in the shaft portion is a smooth curved region (the inner diameter gradually increases). This transition area is configured to be smoothly continuous, so that the coolant (liquid) fills the gas when the valve opens and closes (the valve reciprocates in the axial direction). At the same time, it is considered that the large-diameter hollow portion and the small-diameter hollow portion can move smoothly, and the heat-drawing effect of the valve is improved.
　然るに、大径中空部と小径中空部間の連通部が滑らかに連続する形状であるため、バルブの開閉動作に合わせて大径中空部と小径中空部間で冷却材（液体）がスムーズに移動できるが、中空部内の冷却材（液体）は上層部，中層部，下層部が攪拌されることなく互いに上下関係を保持したままの状態で軸方向に移動している。 However, since the communication part between the large-diameter hollow part and the small-diameter hollow part is smoothly continuous, the coolant (liquid) moves smoothly between the large-diameter hollow part and the small-diameter hollow part according to the opening / closing operation of the valve. However, the coolant (liquid) in the hollow portion moves in the axial direction in a state where the upper layer portion, the middle layer portion, and the lower layer portion are maintained in a vertical relationship without being stirred.
　このため、熱源に近い側の冷却材下層部における熱が冷却材中層部，上層部に積極的に伝達されず、熱引き効果（熱伝導性）が十分に発揮されない、ということが分かった。 For this reason, it was found that heat in the coolant lower layer near the heat source was not actively transmitted to the coolant middle layer and upper layer, and the heat-drawing effect (thermal conductivity) was not sufficiently exhibited.
　一方、特許文献３では、大径中空部と小径中空部間の滑らかな連通部の内周面に階段状の凹凸を設けることで、冷却材（液体）のバルブとの接触面積が増加し、また、凹凸により冷却材が攪拌されるので、熱伝達性が上がる、というものである。 On the other hand, in Patent Document 3, by providing stepped irregularities on the inner peripheral surface of the smooth communication portion between the large-diameter hollow portion and the small-diameter hollow portion, the contact area of the coolant (liquid) with the valve increases. Further, since the coolant is stirred by the unevenness, the heat transfer property is improved.
　しかし、連通部の内周面はその内径が階段状の凹凸によって徐々に少しづつ変化する形状であるため、バルブが軸方向に往復動作する際に、大径中空部内の冷却材が積極的に攪拌されるものではなく、熱引き効果（熱伝導性）が十分に発揮されるとはいえない。 However, the inner peripheral surface of the communication part has a shape in which the inner diameter gradually changes due to the stepped irregularities, so that when the valve reciprocates in the axial direction, the coolant in the large-diameter hollow part is positively It is not agitated, and it cannot be said that the heat pulling effect (thermal conductivity) is sufficiently exhibited.
　そこで、特許文献４（ＷＯ2104/054113、2014年4月10日公開）が提案された。この特許文献４は、軸部内の小径中空部が連通する傘部内の大径中空部を円錐台形状にして、大径中空部の天上面を構成する小径中空部の開口周縁部をバルブの中心軸線に対し直交する平面で構成することで、軸方向に往復動作するバルブの大径中空部内の冷却材（液体）に、バルブの中心軸線の周りに縦方向内回りの循環流（対流）が形成されて、大径中空部内の冷却材全体が積極的に攪拌され、熱引き効果（熱伝導性）が改善される、というものである。 Therefore, Patent Document 4 (WO2104 / 054113, published on April 10, 2014) was proposed. In this Patent Document 4, the large-diameter hollow portion in the umbrella portion in communication with the small-diameter hollow portion in the shaft portion is formed into a truncated cone shape, and the opening peripheral portion of the small-diameter hollow portion constituting the top surface of the large-diameter hollow portion is defined as the center of the valve. By configuring the plane perpendicular to the axis, a circulating flow (convection) in the longitudinal direction is formed around the central axis of the valve in the coolant (liquid) in the large-diameter hollow portion of the valve that reciprocates in the axial direction. Thus, the entire coolant in the large-diameter hollow portion is actively stirred, and the heat-drawing effect (thermal conductivity) is improved.
　この先行特許文献４の中空ポペットバルブの表面温度の軸方向の温度分布を先行特許文献１，２と比較（先行特許文献４の図４参照）すると、確かに、Ｒ形状のフィレット部に出現する最高温度（Ｔｍａｘ）点が傘部寄りに移動するとともに、温度分布特性も緩やか、即ち、最高温度を含む表面温度が全体的に低くなっていることがわかる。 When the axial temperature distribution of the surface temperature of the hollow poppet valve of the prior patent document 4 is compared with the prior patent documents 1 and 2 (see FIG. 4 of the prior patent document 4), it certainly appears in the R-shaped fillet portion. It can be seen that the maximum temperature (Tmax) point moves closer to the umbrella, and the temperature distribution characteristics are also gentle, that is, the surface temperature including the maximum temperature is lowered as a whole.
　発明者は、傘部と軸部間の湾曲するフィレット部に出現している最高温度（Ｔｍａｘ）点に着目した。即ち、先行特許文献４では、軸部側の小径中空部と傘部側の大径中空部がフィレット部において直交して連通し、フィレット部が軸部や傘部よりも厚肉となって、特に、排気バルブとして使用される場合は、高温の排気ガスに最もさらされる部位である厚肉のフィレット部に、熱がこもりやすいため、最高温度点がフィレット部にくると考えられる。そこで、先行特許文献４の構造を前提として、熱引き効果（熱伝導性）をさらに改善するには、フィレット部に出現する最高温度を低下させればよい、即ち、フィレット部の熱を効率的に軸端部や傘部側に伝達すればよく、そのためには、フィレット部形成壁を薄くするとともに、中空部のフィレット部に対応する冷却材を積極的に攪拌させればよいと考えた。 The inventor has focused on the maximum temperature (Tmax) point appearing in the fillet portion that curves between the umbrella portion and the shaft portion. That is, in the prior art document 4, the small-diameter hollow portion on the shaft portion side and the large-diameter hollow portion on the umbrella portion side communicate at right angles in the fillet portion, and the fillet portion is thicker than the shaft portion and the umbrella portion, In particular, when used as an exhaust valve, it is considered that the highest temperature point comes to the fillet portion because heat tends to accumulate in the thick fillet portion that is the most exposed portion to the high-temperature exhaust gas. Therefore, on the premise of the structure of the prior art document 4, in order to further improve the heat drawing effect (thermal conductivity), the maximum temperature appearing in the fillet portion may be lowered, that is, the heat of the fillet portion is efficiently In order to achieve this, it was considered that the fillet portion forming wall should be made thin and the coolant corresponding to the fillet portion of the hollow portion should be actively stirred.
　詳しくは、「傘部内に円錐台形状の大径中空部を設け、軸部内の小径中空部が大径中空部（円錐台）の天井面に直交して連通し、小径中空部の大径中空部への開口部周縁部をバルブの中心軸線に対し直交する平面で構成し、軸方向に往復動作するバルブの大径中空部内の冷却材に、バルブの中心軸線の周りに縦方向内回りの循環流（対流）を形成する」という先行特許文献４の構造を前提として、更なる改良を検討する過程で、発明者は、中空バルブのフィレット部の表面温度をさらに下げるための構造として、「小径中空部の大径中空部との連通部にその内径を拡径した中径中空部を設け、小径中空部の中径中空部への開口部周縁部をバルブの中心軸線に対しほぼ直交する平面で構成し、軸方向に往復動作するバルブの中径中空部内の冷却材にも縦方向の循環流（対流）を形成する」という新たな構造を考えた。 For details, refer to “A frustoconical large-diameter hollow part is provided in the umbrella part, and the small-diameter hollow part in the shaft part communicates perpendicularly to the ceiling surface of the large-diameter hollow part (conical frustum). The peripheral edge of the opening to the valve section is a plane perpendicular to the central axis of the valve, and the coolant in the large-diameter hollow part of the valve that reciprocates in the axial direction circulates inward in the vertical direction around the central axis of the valve. In the process of studying further improvements on the premise of the structure of the prior patent document 4 that “forms a flow (convection)”, the inventor, as a structure for further lowering the surface temperature of the fillet portion of the hollow valve, A hollow part with a medium-diameter hollow part with an enlarged inner diameter is provided at the communicating part of the hollow part with the large-diameter hollow part, and the peripheral edge of the opening to the medium-diameter hollow part of the small-diameter hollow part is substantially perpendicular to the central axis of the valve The cooling inside the hollow inner diameter of the valve that reciprocates in the axial direction We considered a new structure that "form longitudinal circulation stream (convection) in wood.
　そして、この新たな構造の中空バルブが開閉動作（軸方向に往復動作）する際の中空部内の冷却材の動きをコンピュータを用いてシミュレーション解析したところ、大径中空部内の冷却材に、バルブの中心軸線の周りに縦方向内回りの循環流（対流）が形成され、同時に、中径中空部内の冷却材にも、縦方向の循環流（対流）が形成されて、中空部内の冷却材の拡散作用がいっそう促進されることが確認されたことで、この度の特許出願にいたったものである。 The simulation of the movement of the coolant in the hollow part when the hollow valve of this new structure opens and closes (reciprocates in the axial direction) using a computer revealed that the coolant in the large-diameter hollow part A circulation flow (convection) inward in the longitudinal direction is formed around the central axis, and at the same time, a circulation flow (convection) in the longitudinal direction is also formed in the coolant in the medium-diameter hollow portion, so that the coolant in the hollow portion is diffused. Since it was confirmed that the action was further promoted, this was the result of the patent application.
　本発明は、前記した従来技術の問題点に鑑みてなされたもので、その目的は、バルブが軸方向に往復動作する際の中空部内の冷却材の攪拌を促進して、熱引き効果を改善する中空ポペットバルブを提供することにある。 The present invention has been made in view of the above-described problems of the prior art, and its purpose is to promote the stirring of the coolant in the hollow portion when the valve reciprocates in the axial direction, thereby improving the heat-drawing effect. It is to provide a hollow poppet valve.
　前記目的を達成するために、本発明（請求項１）に係る中空ポペットバルブにおいては、軸端部に傘部を一体的に形成したポペットバルブの傘部から軸部にかけて中空部が形成され、前記中空部に冷却材が装填された中空ポペットバルブにおいて、
　前記傘部内に、該傘部の外形に倣うテーパ形状の外周面を備えた円錐台形状の大径中空部を設け、
　一方、前記軸部内に、前記大径中空部に連通する直線状の小径中空部を設けるとともに、前記小径中空部の前記大径中空部との連通部に、その内径を拡径した中径中空部を設け、
　前記大径中空部の天井面を形成する、前記中径中空部の前記大径中空部への開口周縁部を、前記バルブの中心軸線に対し直交する平面で構成し、
　前記中径中空部の天井面を形成する、前記小径中空部の前記中径中空部への開口周縁部を、前記バルブの中心軸線に対し直交する平面または所定角度傾斜するテーパ面で構成して、
　前記バルブが軸方向に往復動作する際に、前記大径中空部の冷却材（液体）に前記バルブの中心軸線周りに縦方向内回りの第１の循環流（対流）が形成され、前記中径中空部の冷却材に縦方向の第２の循環流（対流）が形成されるように構成した。 In order to achieve the object, in the hollow poppet valve according to the present invention (Claim 1), the hollow portion is formed from the umbrella portion of the poppet valve integrally formed at the shaft end portion to the shaft portion, In the hollow poppet valve in which the hollow portion is filled with a coolant,
In the umbrella part, a frustoconical large-diameter hollow part having a tapered outer peripheral surface following the outer shape of the umbrella part is provided,
On the other hand, a linear small-diameter hollow portion that communicates with the large-diameter hollow portion is provided in the shaft portion, and a medium-diameter hollow whose inner diameter is increased at the communicating portion of the small-diameter hollow portion with the large-diameter hollow portion. Set up a section,
Forming a ceiling surface of the large-diameter hollow portion, and forming an opening peripheral edge portion of the medium-diameter hollow portion to the large-diameter hollow portion by a plane orthogonal to the central axis of the valve;
The opening peripheral edge portion of the small-diameter hollow portion to the medium-diameter hollow portion that forms the ceiling surface of the medium-diameter hollow portion is configured by a plane orthogonal to the central axis of the bulb or a tapered surface inclined at a predetermined angle. ,
When the valve reciprocates in the axial direction, a first circulating flow (convection) in the longitudinal direction around the central axis of the valve is formed in the coolant (liquid) of the large-diameter hollow portion, and the medium diameter A second circulating flow (convection) in the vertical direction is formed in the coolant in the hollow portion.
　なお、バルブが軸方向に往復動作する際に、大径中空部，中径中空部の冷却材に第１の循環流，第２の循環流が形成されるためには、中径中空部の大径中空部への開口周縁部，小径中空部の中径中空部への開口周縁部がそれぞれバルブの中心軸線に対し直交する平面で構成されることが望ましいが、小径中空部の中径中空部への開口周縁部は、バルブの中心軸線に対し所定角度傾斜するテーパ面で構成してもよく、テーパ面の傾斜は６０度以下（中心軸線と直交する平面に対し３０度以下)の範囲で有効であることが確認されている。
（作用）自動車用の動弁機構を構成するバルブは、クランクシャフトと同期して回転するカムによって駆動（軸方向に往復動作）するが、バルブの往復動作に伴って、中空部内の冷却材（液体）には、図２（ａ），（ｂ）に示すように、慣性力Ｗａ，Ｗｂが作用する。特に、中空部内の冷却材は、バルブが着座する際に作用する慣性力の影響を強く受けて、図３（ａ），（ｂ），図４に示すように、中空部内には第１の循環流（対流）Ｔ１や第２の循環流（対流）Ｔ２が形成されて、中空部内が積極的に攪拌される。 In addition, when the valve reciprocates in the axial direction, in order to form the first circulation flow and the second circulation flow in the coolant of the large-diameter hollow portion and the medium-diameter hollow portion, It is desirable that the opening periphery to the large-diameter hollow portion and the opening periphery to the medium-diameter hollow portion of the small-diameter hollow portion are each configured by a plane orthogonal to the central axis of the valve, but the medium-diameter hollow of the small-diameter hollow portion The peripheral edge of the opening to the portion may be formed of a tapered surface inclined at a predetermined angle with respect to the central axis of the valve, and the inclination of the tapered surface is in the range of 60 degrees or less (30 degrees or less with respect to the plane perpendicular to the central axis). It is confirmed that it is effective.
(Operation) A valve constituting a valve mechanism for an automobile is driven by a cam that rotates in synchronization with a crankshaft (reciprocating operation in the axial direction). As shown in FIGS. 2A and 2B, inertia forces Wa and Wb act on the liquid. In particular, the coolant in the hollow portion is strongly influenced by the inertial force acting when the valve is seated, and as shown in FIGS. 3 (a), 3 (b), and FIG. A circulation flow (convection) T1 and a second circulation flow (convection) T2 are formed, and the inside of the hollow portion is actively stirred.
　詳しくは、バルブが着座した状態から開弁 (下降) する際は、図３（ａ）に示すように、中空部内の冷却材には、上向きの慣性力Ｗａが作用するので、上方に向う流れＦ１が発生する。しかし、大径中空部の天井面（大径中空部における中径中空部の開口周縁部）および中径中空部内の天井面（小径中空部の開口周縁部）が例えばバルブの中心軸線に対し直交する平面でそれぞれ構成されているので、各中空部間の連通部が滑らかな形状で形成されている従来の中空バルブのように、冷却材はスムーズに上方に移動できない。 Specifically, when the valve is opened (lowered) from the seated state, the upward inertia force Wa acts on the coolant in the hollow portion as shown in FIG. F1 occurs. However, the ceiling surface of the large-diameter hollow part (the peripheral edge of the opening of the medium-diameter hollow part in the large-diameter hollow part) and the ceiling surface in the medium-diameter hollow part (the peripheral edge of the opening of the small-diameter hollow part) are, for example, orthogonal to the central axis of the valve Therefore, unlike the conventional hollow valve in which the communication part between the hollow parts is formed in a smooth shape, the coolant cannot move smoothly upward.
　このため、大径中空部内の冷却材には、テーパ形状の外周面から環状段差部（大径中空部の天井面）に沿って中径中空部との連通部Ｐ１の中心（半径方向内側）に向かう流れＦ２が発生し、同時に、中径中空部内の冷却材には、該中径中空部の外周面から環状段差部（中径中空部の天井面）に沿って小径中空部との連通部Ｐ２の中心（半径方向内側）に向かう流れＦ５が発生する。 Therefore, the coolant in the large-diameter hollow portion includes the center (radially inner side) of the communication portion P1 from the tapered outer peripheral surface along the annular step portion (the ceiling surface of the large-diameter hollow portion) and the medium-diameter hollow portion. At the same time, the coolant in the medium-diameter hollow portion is communicated with the small-diameter hollow portion from the outer peripheral surface of the medium-diameter hollow portion along the annular stepped portion (the ceiling surface of the medium-diameter hollow portion). A flow F5 toward the center (radially inward) of the part P2 is generated.
　そして、バルブが開弁動作から閉弁動作に切り替わり（バルブが下降から上昇に転じ）、さらに着座するまでは、図３（ｂ）に示すように、中空部内の冷却材には、下向きの慣性力Ｗｂが作用するので、下方に向かい、さらに大径中空部内の底面に沿って半径方向外方にかう流れＦ３が発生する。 Then, until the valve switches from the valve-opening operation to the valve-closing operation (the valve changes from descending to ascending) and is further seated, the coolant in the hollow portion has a downward inertia as shown in FIG. Since the force Wb acts, a flow F3 is generated that is directed downward and radially outward along the bottom surface in the large-diameter hollow portion.
　そして、バルブが着座する際には、図４に示すように、大径中空部内の冷却材には、流れＦ２，Ｆ３が合成された、バルブの中心軸線周りに縦方向内回りの第１の循環流（対流）Ｔ１が形成され、一方、中径中空部内の冷却材には、流れＦ５，Ｆ３が合成された縦方向の第２の循環流（対流）Ｔ２が形成される。 When the valve is seated, as shown in FIG. 4, the coolant in the large-diameter hollow portion is combined with the flows F2 and F3, and the first circulation in the longitudinal direction around the central axis of the valve. A flow (convection) T1 is formed. On the other hand, a second circulation flow (convection) T2 in the vertical direction, in which the flows F5 and F3 are combined, is formed in the coolant in the medium-diameter hollow portion.
　このように、バルブが軸方向に往復動作することで、大径中空部内の冷却材には、バルブの中心軸線周りに縦方向内回りの第１の循環流（対流）Ｔ１が形成されるとともに、中径中空部内の冷却材には、縦方向の第２の循環流（対流）Ｔ２が形成されて、中空部内の冷却材が積極的に攪拌されるので、バルブの熱引き効果（熱伝導性）が著しく改善される。 As described above, the valve reciprocates in the axial direction, whereby a first circulating flow (convection) T1 in the longitudinal direction around the central axis of the valve is formed in the coolant in the large-diameter hollow portion, A second circulating flow (convection) T2 in the vertical direction is formed in the coolant in the medium-diameter hollow portion, and the coolant in the hollow portion is actively agitated, so that the heat drawing effect of the valve (thermal conductivity) ) Is significantly improved.
　また、バルブが軸方向に往復動作する際に、中空部内の冷却材は上下方向に移動（図３（ａ），（ｂ）のＦ１，Ｆ３参照）するが、大径中空部と中径中空部の連通部Ｐ１および中径中空部と小径中空部の連通部Ｐ２では、流路の断面積が急変するため、連通部の下流側に乱流(渦)が形成されて、これらの乱流(渦)が中空部内の冷却材の上層部、中層部、下層部をより積極的に攪拌し、バルブの熱引き効果（熱伝導性）がさらに改善される。 When the valve reciprocates in the axial direction, the coolant in the hollow portion moves in the vertical direction (see F1 and F3 in FIGS. 3A and 3B). In the communication part P1 of the part and the communication part P2 of the medium-diameter hollow part and the small-diameter hollow part, since the cross-sectional area of the flow path changes suddenly, a turbulent flow (vortex) is formed on the downstream side of the communication part. (Vortex) stirs the upper layer, middle layer, and lower layer of the coolant in the hollow portion more positively, and the heat drawing effect (thermal conductivity) of the valve is further improved.
　請求項２においては、請求項１に記載の中空ポペットバルブにおいて、前記中径中空部を、前記傘部と軸部間のフィレット部に対応する位置に設けるように構成した。 According to Claim 2, in the hollow poppet valve according to Claim 1, the medium-diameter hollow portion is provided at a position corresponding to the fillet portion between the umbrella portion and the shaft portion.
　(作用)　先行特許文献４では、フィレット部が軸部や傘部よりも厚肉に形成されているため、特に、排気バルブとして用いた場合は、高温の排気ガスに最もさらされる部位である厚肉のフィレット部に熱がこもり易いが、請求項２では、バルブの開閉動作の際に、フィレット部に対応する位置に設けられた中径中空部に縦方向の循環流(対流)が形成されて、中空部内全体の冷却材がいっそう積極的に攪拌されるので、特にフィレット部における熱伝達作用が高められ、その結果、フィレット部における最高温度が低下するなど、バルブの熱引き効果（熱伝導性）がいっそう改善される。 (Operation) In the prior art document 4, since the fillet portion is formed thicker than the shaft portion and the umbrella portion, particularly when used as an exhaust valve, the thickness is the portion most exposed to high-temperature exhaust gas. Heat tends to be trapped in the fillet portion of the meat, but in claim 2, when the valve is opened and closed, a vertical circulation flow (convection) is formed in the medium-diameter hollow portion provided at a position corresponding to the fillet portion. In addition, since the coolant in the entire hollow portion is more actively agitated, the heat transfer effect, particularly in the fillet portion, is enhanced, and as a result, the maximum temperature in the fillet portion is reduced. Sex) is further improved.
　請求項３においては、請求項１または２に記載の中空ポペットバルブにおいて、前記バルブ軸端部寄りの小径中空部の内径を、前記バルブ傘部寄りの小径中空部の内径よりも大きく形成して、前記小径中空部内の軸方向所定位置に円環状の段差部を設けるとともに、前記段差部を越えた位置まで前記冷却材を装填するように構成した。 According to a third aspect of the present invention, in the hollow poppet valve according to the first or second aspect, an inner diameter of the small-diameter hollow portion near the valve shaft end portion is formed larger than an inner diameter of the small-diameter hollow portion near the valve umbrella portion. An annular step portion is provided at a predetermined axial position in the small-diameter hollow portion, and the coolant is loaded to a position beyond the step portion.
　（作用）特に、バルブ着座時およびバルブ開弁動作(下降)の際に、冷却材（液体）は慣性力(上向き)の影響を受けて小径中空部内を上方に移動するが、内径の小さいバルブ傘部寄りの小径中空部から内径の大きいバルブ軸端部寄りの小径中空部に移動する際に、図３（ａ）に示すように、小径中空部内の円環状段差部の下流側で乱流Ｆ９ａが発生し、小径中空部内の冷却材が攪拌される。 (Operation) Especially when the valve is seated and when the valve opens (lowers), the coolant (liquid) moves upward in the small-diameter hollow under the influence of inertia (upward), but the valve has a small inner diameter. When moving from the small-diameter hollow portion near the umbrella portion to the small-diameter hollow portion near the valve shaft end portion having a large inner diameter, as shown in FIG. 3A, turbulent flow downstream of the annular stepped portion in the small-diameter hollow portion F9a is generated and the coolant in the small-diameter hollow portion is agitated.
　一方、バルブが開弁動作から閉弁動作に切り替わる（バルブが下降から上昇に転じる）際は、小径中空部内をいったん上方に移動した冷却材（液体）が慣性力（下向き）の影響を受けて下方に移動するが、内径の大きいバルブ軸端部寄りの小径中空部から内径の小さいバルブ傘部寄りの小径中空部に移動する際に、図３（ｂ）に示すように、小径中空部内の円環状段差部の下流側で乱流Ｆ９ｂが発生し、小径中空部内の冷却材が攪拌される。 On the other hand, when the valve switches from valve opening to valve closing (the valve changes from descending to ascending), the coolant (liquid) once moved upward in the small-diameter hollow is affected by inertial force (downward). When moving from a small-diameter hollow portion near the end of the valve shaft having a large inner diameter to a small-diameter hollow portion near the valve umbrella portion having a small inner diameter, as shown in FIG. Turbulent flow F9b is generated downstream of the annular stepped portion, and the coolant in the small-diameter hollow portion is agitated.
　このように、バルブの開閉動作(上下方向の往復動作)に伴って、冷却材が小径中空部内を軸方向に移動する際に段差部の近傍に発生する乱流が、小径中空部内の冷却材を攪拌し、これによって中空部内全体の冷却材の少なくとも上層部が攪拌されて、中空部内の冷却材による熱伝達が活発となる。 As described above, the turbulent flow generated in the vicinity of the stepped portion when the coolant moves in the axial direction in the small-diameter hollow portion in accordance with the opening / closing operation (vertical reciprocating operation) of the valve is caused by the coolant in the small-diameter hollow portion. As a result, at least the upper layer portion of the coolant in the entire hollow portion is stirred, and heat transfer by the coolant in the hollow portion becomes active.
　請求項４においては、請求項３に記載の中空ポペットバルブにおいて、前記小径中空部内の段差部を、前記バルブがエンジンの燃焼室に開口する排気通路または吸気通路に配設された際に、前記排気通路または吸気通路内とならない所定位置に設けるように構成した。 According to a fourth aspect of the present invention, in the hollow poppet valve according to the third aspect, when the stepped portion in the small-diameter hollow portion is disposed in an exhaust passage or an intake passage where the valve opens to a combustion chamber of an engine, It is configured to be provided at a predetermined position that does not fall within the exhaust passage or the intake passage.
　（作用）金属の疲労強度は高温になるほど低下するため、常に排気通路（または吸気通路）内にあって高熱にさらされる部位である、バルブ軸部におけるバルブ傘部寄りの領域は、疲労強度の低下に耐え得る程度の肉厚に形成する必要がある。一方、熱源から離れ、しかも常にバルブガイドに摺接する部位である、バルブ軸部における軸端部寄りの領域は、冷却材を介して燃焼室や排気通路（または吸気通路）の熱が伝達されるものの、伝達された熱はバルブガイドを介して直ちにシリンダヘッドに放熱されるため、バルブ傘部寄りの領域ほどの高温となることがない。したがって、バルブ軸部における軸端部寄り領域は、バルブ傘部寄りの領域よりも疲労強度が低下しないため、薄肉に形成（小径中空部の内径を大きく形成）しても、強度的（疲労により折損する等の耐久性）には問題がない。 (Action) Since the fatigue strength of metal decreases as the temperature rises, the region near the valve umbrella in the valve shaft, which is always in the exhaust passage (or intake passage) and is exposed to high heat, has fatigue strength. It is necessary to form a thickness that can withstand the decrease. On the other hand, in the region near the shaft end in the valve shaft, which is a portion that is away from the heat source and is always in sliding contact with the valve guide, heat from the combustion chamber and the exhaust passage (or intake passage) is transmitted via the coolant. However, since the transmitted heat is immediately radiated to the cylinder head via the valve guide, it does not become as high as the region near the valve umbrella. Accordingly, since the fatigue strength does not decrease in the region near the shaft end in the valve shaft portion than in the region near the valve umbrella portion, even if it is formed thinly (the inner diameter of the small-diameter hollow portion is increased), the strength (due to fatigue) There is no problem in durability such as breakage.
　また、軸端部寄り小径中空部の内径を大きくすれば、第１には、小径中空部全体の表面積（冷却材との接触表面積）が増え、バルブ軸部における熱伝達効率が上がる。第２には、小径中空部全体の容積が増え、バルブの総重量を軽量化できる。第３には、冷却材の装填量を増やすことで、バルブ軸部の熱引き効果（熱伝導性）が上がる。そして、小径中空部内の段差部がバルブ傘部寄りとなるほど、バルブの熱引き効果が高くなる。 Also, if the inner diameter of the small-diameter hollow portion near the shaft end is increased, firstly, the surface area (contact surface area with the coolant) of the entire small-diameter hollow portion increases, and the heat transfer efficiency in the valve shaft portion increases. Second, the volume of the entire small-diameter hollow portion increases, and the total weight of the valve can be reduced. Third, by increasing the charging amount of the coolant, the heat drawing effect (thermal conductivity) of the valve shaft portion is increased. And the heat-drawing effect of a valve | bulb becomes high, so that the level | step-difference part in a small diameter hollow part becomes near a valve | bulb umbrella part.
　このため、小径中空部内の段差部は、バルブが開弁しきった状態で、少なくとも排気通路または吸気通路内とならない所定位置（例えば、バルブガイドの排気通路または吸気通路に臨む側の端部に略対応する位置）に設けることが最も望ましい。 For this reason, the stepped portion in the small-diameter hollow portion is substantially at a predetermined position that is not at least in the exhaust passage or the intake passage when the valve is fully opened (for example, at the end of the valve guide facing the exhaust passage or the intake passage). It is most desirable to provide at the corresponding position.
　本願発明に係る中空ポペットバルブによれば、中空部における冷却材の装填量が増えるとともに、中空部内周面の冷却材との接触面積も増えるので、バルブの熱引き効果（熱伝導性）が改善されて、エンジンの性能が向上する。 According to the hollow poppet valve according to the present invention, the amount of coolant charged in the hollow portion increases, and the contact area with the coolant on the inner peripheral surface of the hollow portion also increases, so the heat drawing effect (thermal conductivity) of the valve is improved. As a result, engine performance is improved.
　また、バルブの開閉動作に伴って、大径中空部ではバルブの中心軸線周りに縦方向内回りの循環流が形成されるとともに、中径中空部においても縦方向の循環流が形成されて、中空部内全体の冷却材が積極的に攪拌されるので、バルブの熱引き効果（熱伝導性）が改善されて、エンジンの性能が向上する。 In addition, along with the opening and closing operation of the valve, in the large-diameter hollow portion, a circulation flow is formed in the longitudinal direction around the central axis of the valve, and in the medium-diameter hollow portion, a longitudinal circulation flow is also formed in the hollow portion. Since the coolant in the entire section is actively agitated, the heat-sucking effect (thermal conductivity) of the valve is improved, and the engine performance is improved.
　請求項２に係る中空ポペットバルブによれば、フィレット部における熱伝達作用が確実に高められるので、バルブの熱引き効果（熱伝導性）がいっそう改善されて、エンジンの性能がいっそう向上する。 According to the hollow poppet valve according to claim 2, since the heat transfer action in the fillet portion is surely enhanced, the heat drawing effect (heat conductivity) of the valve is further improved, and the engine performance is further improved.
　請求項３に係る中空ポペットバルブによれば、バルブの開閉動作(上下方向の往復動作) に伴って、小径中空部内の段差部近傍に乱流が発生して、中空部内の冷却材の少なくとも上層部から中層部が攪拌されるので、中空部内の冷却材による熱伝達が活発となって、バルブの熱引き効果（熱伝導性）がいっそう改善されて、エンジンの性能がいっそう向上する。 According to the hollow poppet valve according to claim 3, turbulent flow is generated in the vicinity of the stepped portion in the small-diameter hollow portion along with the opening / closing operation (reciprocating operation in the vertical direction) of the valve, and at least the upper layer of the coolant in the hollow portion Since the middle layer part is stirred from the part, the heat transfer by the coolant in the hollow part becomes active, the heat drawing effect (thermal conductivity) of the valve is further improved, and the engine performance is further improved.
　請求項４に係る中空ポペットバルブによれば、耐久性に影響を与えない範囲で、バルブ軸部における軸端部寄りの小径中空部の内径を大きくしたので、バルブ軸部の熱引き効果（熱伝導性）がいっそう改善されるとともに、バルブ総重量が軽量化されて、エンジンの性能がさらにいっそう向上する。 According to the hollow poppet valve of the fourth aspect, since the inner diameter of the small-diameter hollow portion near the shaft end portion in the valve shaft portion is increased within a range that does not affect the durability, the heat drawing effect of the valve shaft portion (heat (Conductivity) is further improved, and the total weight of the valve is reduced, further improving the engine performance.
本発明の第１の実施例である中空ポペットバルブの縦断面図である。It is a longitudinal cross-sectional view of the hollow poppet valve which is the 1st Example of this invention. 同中空ポペットバルブが軸方向に往復動作する際の中空部内の冷却材に作用する慣性力を示す図で、（ａ）はバルブ着座時の冷却材に作用する慣性力を示す断面図、（ｂ）はバルブが開弁動作から閉弁動作に移行する（下降から上昇に転じる）際の冷却材に作用する慣性力を示す断面図である。It is a figure which shows the inertial force which acts on the coolant in a hollow part at the time of the same hollow poppet valve reciprocatingly, (a) is sectional drawing which shows the inertial force which acts on the coolant at the time of valve seating, (b) ) Is a cross-sectional view showing the inertial force acting on the coolant when the valve shifts from the valve opening operation to the valve closing operation (from falling to rising). 同中空ポペットバルブが開閉動作（軸方向に往復動作）する際の中空部内の冷却材の動きを拡大して示す図で、（ａ）はエンジンが始動しバルブが着座状態から開弁状態に移行する際の冷却材の動きを示す図で、（ｂ）はバルブが開弁動作から閉弁動作に移行する（下降から上昇に転じる）際の冷却材の動きを示す図である。(A) is an enlarged view showing the movement of the coolant in the hollow portion when the hollow poppet valve opens and closes (reciprocates in the axial direction), and (a) shows that the engine starts and the valve shifts from the seated state to the valve open state. It is a figure which shows the motion of the coolant at the time of carrying out, (b) is a figure which shows the motion of the coolant at the time of a valve | bulb changing from a valve opening operation | movement to a valve closing operation | movement (it changes from a fall to a raise). 同中空ポペットバルブが開閉動作（軸方向に往復動作）する際の大径中空部および中径中空部内の冷却材に形成される循環流(対流)を示す図（図２（ａ）に対応する図）である。The figure (the figure corresponding to Drawing 2 (a)) which shows the circulation flow (convection) formed in the cooling material in the large diameter hollow part and the medium diameter hollow part when the hollow poppet valve opens and closes (reciprocates in the axial direction) Figure). 同中空ポペットバルブの表面温度の軸方向における温度分布を先行特許文献と比較して示す図である。It is a figure which shows the temperature distribution in the axial direction of the surface temperature of the hollow poppet valve compared with a prior patent document. 同中空ポペットバルブの製造工程を示す図で、（ａ）はバルブ中間品であるシェルを鍛造する熱間鍛造工程を示し、（ｂ）は小径中空部に相当する孔を軸部に穿設する孔穿設工程を示し、（ｃ）は中径中空部に相当する孔をフィレット部に穿設する孔穿設工程を示し、（ｄ）は軸端部寄りの小径中空部に相当する孔を穿設する孔穿設工程を示し、（ｅ）は軸端部材を軸接する軸接工程を示し、（ｆ）は小径中空部に冷却材を充填する工程を示し、（ｇ）は不活性ガス雰囲気下で傘部外殻の凹部（大径中空部）の開口部にキャップを溶接する工程（大径中空部密閉工程）を示す。FIGS. 4A and 4B are diagrams showing a manufacturing process of the hollow poppet valve, wherein FIG. 4A shows a hot forging process for forging a shell which is an intermediate product of the valve, and FIG. 4B shows a hole corresponding to a small-diameter hollow portion formed in a shaft portion. (C) shows a hole drilling process for drilling a hole corresponding to the medium-diameter hollow part in the fillet part, and (d) shows a hole corresponding to the small-diameter hollow part near the shaft end part. (E) shows an axial contact process for axially contacting the shaft end member, (f) shows a process for filling the small-diameter hollow portion with a coolant, and (g) shows an inert gas. The process of welding a cap to the opening part of the recessed part (large diameter hollow part) of an umbrella outer shell under atmosphere (large diameter hollow part sealing process) is shown. 本発明の第２の実施例である中空ポペットバルブの縦断面図である。It is a longitudinal cross-sectional view of the hollow poppet valve which is the 2nd Example of this invention.
　次に、本発明の実施の形態を実施例に基づいて説明する。 Next, embodiments of the present invention will be described based on examples.
　図１～図４は、本発明の第１の実施例である内燃機関用の中空ポペットバルブを示す。 1 to 4 show a hollow poppet valve for an internal combustion engine according to a first embodiment of the present invention.
　これらの図において、符号１０は、真っ直ぐに延びる軸部１２の一端側に、外径が徐々に大きくなるＲ形状のフィレット部１３を介して、傘部１４が一体的に形成された耐熱合金製の中空ポペットバルブで、傘部１４の外周には、テーパ形状のフェース部１６が設けられている。 In these drawings, reference numeral 10 denotes a heat-resistant alloy in which an umbrella portion 14 is integrally formed on one end side of a shaft portion 12 that extends straight through an R-shaped fillet portion 13 that gradually increases in outer diameter. In the hollow poppet valve, a tapered face portion 16 is provided on the outer periphery of the umbrella portion 14.
　詳しくは、円筒形状の軸部１２ａの一端側に傘部外殻１４ａが一体的に形成されたバルブ中間品である軸一体型シェル（以下、単にシェルという）１１（図１，６参照）と、シェル１１の軸部１２ａに軸接された軸端部材１２ｂと、シェル１１の傘部外殻１４ａの円錐台形状の凹部１４ｂにおける開口部１４ｃに溶接された円盤形状のキャップ１８とによって、傘部１４から軸部１２にかけて中空部Ｓが設けられた中空ポペットバルブ１０が構成されている。中空部Ｓには、金属ナトリウム等の冷却材１９がアルゴンガスなどの不活性ガスとともに装填されている。冷却材１９の装填量は、多い方が熱引き効果に優れるものの、所定量以上では熱引き効果としての差が僅かとなるため、費用対効果（冷却材１９が多ければ、コストもかかること）を考慮して、例えば、中空部Ｓの容積の約１／２～約４／５の量が装填されていればよい。 Specifically, a shaft-integrated shell (hereinafter simply referred to as a shell) 11 (see FIGS. 1 and 6), which is a valve intermediate product in which an umbrella outer shell 14a is integrally formed on one end of a cylindrical shaft portion 12a; The shaft end member 12b axially contacted with the shaft portion 12a of the shell 11 and the disc-shaped cap 18 welded to the opening portion 14c in the frustoconical recess 14b of the umbrella outer shell 14a of the shell 11 A hollow poppet valve 10 having a hollow portion S is formed from the portion 14 to the shaft portion 12. The hollow portion S is filled with a coolant 19 such as metallic sodium together with an inert gas such as argon gas. Although a larger amount of the coolant 19 is more excellent in the heat-drawing effect, a difference in heat-drawing effect is small if the amount is larger than a predetermined amount, so that cost-effectiveness (the more the coolant 19 is, the higher the cost). For example, an amount of about 1/2 to about 4/5 of the volume of the hollow portion S may be loaded.
　なお、図１における符号２はシリンダヘッド、符号６は燃焼室４から延びる排気通路で、排気通路６の燃焼室４への開口周縁部には、バルブ１０のフェース部１６が当接するテーパ面８ａを備えた円環状のバルブシート８が設けられている。符号３は、シリンダヘッド２に設けられたバルブ挿通孔で、バルブ挿通孔３の内周面は、バルブ１０の軸部１２が摺接するバルブガイド３ａで構成されている。符号９は、バルブ１０を閉弁方向（図１上方向）に付勢するバルブスプリング、符号１２ｃは、バルブ軸端部に設けたコッタ溝である。 In FIG. 1, reference numeral 2 denotes a cylinder head, and reference numeral 6 denotes an exhaust passage extending from the combustion chamber 4, and a tapered surface 8 a with which the face portion 16 of the valve 10 abuts the opening peripheral edge of the exhaust passage 6 to the combustion chamber 4. An annular valve seat 8 is provided. Reference numeral 3 denotes a valve insertion hole provided in the cylinder head 2, and an inner peripheral surface of the valve insertion hole 3 is constituted by a valve guide 3 a with which the shaft portion 12 of the valve 10 is slidably contacted. Reference numeral 9 is a valve spring for urging the valve 10 in the valve closing direction (upward in FIG. 1), and reference numeral 12c is a cotter groove provided at the end of the valve shaft.
　また、燃焼室４や排気通路６の高温ガスにさらされる部位である、シェル１１およびキャップ１８は、耐熱合金鋼で構成されているのに対し、機械的強度が要求されるものの、シェル１１およびキャップ１８ほどの耐熱性が要求されない軸端部材１２ｂは、一般的な鋼材で構成されている。 In addition, the shell 11 and the cap 18 that are exposed to the high temperature gas in the combustion chamber 4 and the exhaust passage 6 are made of heat-resistant alloy steel. The shaft end member 12b that does not require heat resistance as much as the cap 18 is made of a general steel material.
　また、バルブ１０内の中空部Ｓは、バルブ傘部１４内に設けられた円錐台形状の大径中空部Ｓ１と、バルブ軸部１２内に設けられた直線状（棒状）の小径中空部Ｓ２とが、フィレット部１３に対応する位置に設けられた円柱状の中径中空部Ｓ３を介して直交するように連通して構成されている。大径中空部Ｓ１の円環状天井面（中径中空部Ｓ３の開口周縁部である傘部外殻１４ａの凹部１４ｂの底面）１４ｂ１、および小径中空部Ｓ１の開口周縁部である中径中空部Ｓ３の円環状天井面２０は、バルブ１０の中心軸線Ｌに対しそれぞれ直交する平面で構成されている。 The hollow portion S in the valve 10 includes a truncated cone-shaped large-diameter hollow portion S1 provided in the valve umbrella portion 14 and a linear (rod-shaped) small-diameter hollow portion S2 provided in the valve shaft portion 12. Are communicated so as to be orthogonal to each other via a columnar medium-diameter hollow portion S3 provided at a position corresponding to the fillet portion 13. An annular ceiling surface of the large-diameter hollow portion S1 (a bottom surface of the concave portion 14b of the umbrella outer shell 14a that is the opening peripheral portion of the medium-diameter hollow portion S3) 14b1, and a medium-diameter hollow portion that is the opening peripheral portion of the small-diameter hollow portion S1 The annular ceiling surface 20 of S <b> 3 is configured by a plane that is orthogonal to the central axis L of the bulb 10.
　即ち、大径中空部Ｓ１における中径中空部Ｓ３との連通部Ｐ１には、先行文献１，２のような滑らかな形状に代えて、大径中空部Ｓ１側から見て庇状の環状段差部１５が形成されており、この環状段差部１５の大径中空部Ｓ１に臨む側（大径中空部Ｓ１の天井面）１４ｂ１がバルブ１０の中心軸線Ｌに対し直交する平面で構成されている。さらには、中径中空部Ｓ３における小径中空部Ｓ２との連通部Ｐ２にも、先行特許文献１，２のような滑らかな形状に代えて、大径中空部Ｓ１側から見て庇状の環状段差部１５ａが形成されており、中径中空部Ｓ３における天井面（中径中空部Ｓ３における小径中空部Ｓ２の開口周縁部）２０も、バルブ１０の中心軸線Ｌに対し直交する平面で構成されている。 That is, the communicating portion P1 of the large-diameter hollow portion S1 with the medium-diameter hollow portion S3 is replaced with a smooth shape as in the prior art documents 1 and 2, and a bowl-shaped annular step as viewed from the large-diameter hollow portion S1 side. A portion 15 is formed, and a side (a ceiling surface of the large-diameter hollow portion S1) 14b1 facing the large-diameter hollow portion S1 of the annular step portion 15 is configured by a plane orthogonal to the central axis L of the bulb 10. . Further, the communicating portion P2 of the medium-diameter hollow portion S3 with the small-diameter hollow portion S2 is replaced with a smooth shape as in the prior patent documents 1 and 2, and has a bowl-like shape when viewed from the large-diameter hollow portion S1 side. A step portion 15 a is formed, and the ceiling surface 20 in the medium-diameter hollow portion S <b> 3 (opening peripheral edge portion of the small-diameter hollow portion S <b> 2 in the medium-diameter hollow portion S <b> 3) 20 is also configured by a plane orthogonal to the central axis L of the valve 10. ing.
　また、小径中空部Ｓ２は、図１に示すように、バルブ軸端部寄りの、内径が比較的大きい小径中空部Ｓ２１と、バルブ傘部１４寄りの、内径が比較的小さい小径中空部Ｓ２２で構成されて、小径中空部Ｓ２１と小径中空部Ｓ２２間には、円環状の段差部１７が形成されるとともに、段差部１７を越えた位置まで冷却材１９が装填されている。 Further, as shown in FIG. 1, the small-diameter hollow portion S2 includes a small-diameter hollow portion S21 having a relatively large inner diameter near the valve shaft end portion and a small-diameter hollow portion S22 having a relatively small inner diameter near the valve umbrella portion 14. The annular stepped portion 17 is formed between the small-diameter hollow portion S21 and the small-diameter hollow portion S22, and the coolant 19 is loaded up to a position beyond the stepped portion 17.
　このため、バルブ１０が開閉動作する際に、大径中空部Ｓ１，中径中空部Ｓ３内の冷却材（液体）１９には、図４に示すように、縦方向の循環流（対流）Ｔ１，Ｔ２が形成され、同時に、図３（ａ），（ｂ）に示すように、小径中空部Ｓ２内の冷却材（液体）１９には、乱流Ｆ９ａ，Ｆ９ｂが形成される。 For this reason, when the valve 10 is opened and closed, the coolant (liquid) 19 in the large-diameter hollow portion S1 and the medium-diameter hollow portion S3 has a longitudinal circulation flow (convection) T1 as shown in FIG. , T2 are formed, and at the same time, as shown in FIGS. 3A and 3B, turbulent flows F9a and F9b are formed in the coolant (liquid) 19 in the small-diameter hollow portion S2.
　この結果、中空部Ｓ内の冷却材１９の下層部，中層部，上層部が積極的に攪拌されることとなって、バルブ１０における熱引き効果（熱伝導性）が大幅に改善されている。 As a result, the lower layer portion, the middle layer portion, and the upper layer portion of the coolant 19 in the hollow portion S are positively stirred, so that the heat drawing effect (thermal conductivity) in the valve 10 is greatly improved. .
　次に、バルブ１０の開閉動作に伴って、中空部Ｓに循環流（対流）Ｔ１，Ｔ２や乱流Ｆ９ａ，Ｆ９ｂが形成されて、中空部Ｓ内の冷却材１９全体が攪拌される作用を、図２,３，４に基づいて説明する。 Next, with the opening / closing operation of the valve 10, circulating flows (convections) T1, T2 and turbulent flows F9a, F9b are formed in the hollow portion S, and the entire coolant 19 in the hollow portion S is agitated. This will be described with reference to FIGS.
　バルブ１０は、クランクシャフトと同期して回転するカム（図示せず）によって駆動（軸方向に往復動作）する。このため、バルブ１０の中空部Ｓ内の冷却材１９には、図２（ａ），（ｂ）に示すように、慣性力Ｗａ，Ｗｂが作用し、特に、バルブ１０が着座する際に作用する慣性力Ｗａ（図２，４参照）の影響を強く受けて、中空部Ｓ内には第１の循環流（対流）Ｔ１や第２の循環流（対流）Ｔ２が形成されて、中空部Ｓ内が積極的に攪拌される。 The valve 10 is driven (reciprocating in the axial direction) by a cam (not shown) that rotates in synchronization with the crankshaft. Therefore, as shown in FIGS. 2A and 2B, inertial forces Wa and Wb act on the coolant 19 in the hollow portion S of the valve 10, and particularly when the valve 10 is seated. The first circulation flow (convection) T1 and the second circulation flow (convection) T2 are formed in the hollow portion S by being strongly influenced by the inertial force Wa (see FIGS. 2 and 4). The inside of S is actively stirred.
　詳しくは、エンジンが始動し、バルブ１０が着座した状態から開弁 (下降) する際は、図３（ａ）に示すように、中空部Ｓ内の冷却材には、上向きの慣性力Ｗａが作用するので、上方に向う流れＦ１が発生する。しかし、大径中空部Ｓ１の天井面（大径中空部Ｓにおける中径中空部Ｓ３の開口周縁部）１４ｂ１および中径中空部Ｓ３の天井面（中径中空部Ｓ３における小径中空部Ｓ２の開口周縁部）２０がバルブの中心軸線Ｌに対し直交する平面でそれぞれ構成されているので、各中空部Ｓ１，Ｓ２，Ｓ３間の連通部Ｐ１，Ｐ２が滑らかな形状に形成されている従来の中空バルブ（先行特許文献１，２）のように、冷却材１９はスムーズに上方に移動できない。 Specifically, when the engine is started and the valve 10 is seated, when the valve is opened (lowered), the coolant in the hollow portion S has an upward inertial force Wa as shown in FIG. As a result, an upward flow F1 is generated. However, the ceiling surface of the large-diameter hollow portion S1 (opening peripheral edge portion of the medium-diameter hollow portion S3 in the large-diameter hollow portion S) 14b1 and the ceiling surface of the medium-diameter hollow portion S3 (opening of the small-diameter hollow portion S2 in the medium-diameter hollow portion S3) (Peripheral part) 20 is constituted by a plane perpendicular to the central axis L of the valve, so that the communication parts P1, P2 between the hollow parts S1, S2, S3 are formed in a smooth shape. Like the valve (prior patent documents 1 and 2), the coolant 19 cannot move upward smoothly.
　このため、大径中空部Ｓ１内の冷却材１９には、テーパ形状の外周面１４ｂ２から環状段差部１５（大径中空部Ｓ１の天井面１４ｂ１）に沿って連通部Ｐ１の中心（半径方向内側）に向かう流れＦ２が発生し、同時に、中径中空部Ｓ３内の冷却材１９には、円筒形状の外周面から環状段差部１５ａ（中径中空部Ｓ３の天井面２０）に沿って半径方向内側に向う流れＦ５が発生する。 For this reason, the coolant 19 in the large-diameter hollow portion S1 includes the center (radially inner side) of the communicating portion P1 along the annular stepped portion 15 (the ceiling surface 14b1 of the large-diameter hollow portion S1) from the tapered outer peripheral surface 14b2. At the same time, the coolant 19 in the medium-diameter hollow portion S3 is radially directed from the cylindrical outer peripheral surface along the annular stepped portion 15a (the ceiling surface 20 of the medium-diameter hollow portion S3). An inward flow F5 is generated.
　その後、バルブ１０が開弁動作から閉弁動作に切り替わり（バルブ１０が下降から上昇に転じ）、さらに着座するまでは、図３（ｂ）に示すように、中空部Ｓ内の冷却材１９には、下向きの慣性力Ｗｂが作用するので、冷却材１９は、下方に向かい、さらに大径中空部Ｓ１内の底面に沿って半径方向外方にかう流れＦ３が発生する。 Thereafter, until the valve 10 is switched from the valve opening operation to the valve closing operation (the valve 10 changes from lowering to rising) and is further seated, as shown in FIG. Since the downward inertia force Wb acts, the coolant 19 flows downward, and further a flow F3 is generated radially outward along the bottom surface in the large-diameter hollow portion S1.
　そして、バルブ１０が着座する際には、図４に示すように、大径中空部Ｓ１内の冷却材１９には、流れＦ２，Ｆ３が合成された、バルブの中心軸線Ｌ周りに縦方向内回りの循環流（対流）Ｔ１が形成され、一方、中径中空部Ｓ３内の冷却材１９には、流れＦ５，Ｆ３が合成された縦方向の循環流（対流）Ｔ２が形成される。 When the valve 10 is seated, as shown in FIG. 4, the coolant 19 in the large-diameter hollow portion S1 has a flow inward in the longitudinal direction around the central axis L of the valve where the flows F2 and F3 are synthesized. On the other hand, a longitudinal circulation flow (convection) T2 in which the flows F5 and F3 are combined is formed in the coolant 19 in the medium-diameter hollow portion S3.
　また、バルブ着座時およびバルブ開弁動作(下降)の際に、冷却材１９は慣性力(上向き)の影響を受けて小径中空部Ｓ２内を上方に移動するが、内径の小さいバルブ傘部１４寄りの小径中空部Ｓ２２から内径の大きいバルブ軸端部寄りの小径中空部Ｓ２１に移動する際に、図３（ａ）に示すように、小径中空部Ｓ２内の円環状段差部１７の下流側で乱流Ｆ９ａが発生し、小径中空部Ｓ２内の冷却材１９が攪拌される。 Further, when the valve is seated and during the valve opening operation (lowering), the coolant 19 is moved upward in the small-diameter hollow portion S2 due to the influence of inertia force (upward), but the valve umbrella portion 14 having a small inner diameter is used. When moving from the small-diameter hollow portion S22 closer to the small-diameter hollow portion S21 closer to the valve shaft end portion having the larger inner diameter, as shown in FIG. 3A, the downstream side of the annular stepped portion 17 in the small-diameter hollow portion S2. As a result, a turbulent flow F9a is generated, and the coolant 19 in the small-diameter hollow portion S2 is agitated.
　一方、バルブ１０が開弁動作から閉弁動作に切り替わる（バルブ１０が下降から上昇に転じる）際は、小径中空部Ｓ２内をいったん上方に移動した冷却材１９が慣性力（下向き）の影響を受けて下方に移動するが、内径の大きいバルブ軸端部寄りの小径中空部Ｓ２１から内径の小さいバルブ傘部寄りの小径中空部Ｓ２２に移動する際に、図３（ｂ）に示すように、小径中空部Ｓ２内の円環状段差部１７の下流側で乱流Ｆ９ｂが発生し、小径中空部Ｓ２内の冷却材１９が攪拌される。 On the other hand, when the valve 10 is switched from the valve-opening operation to the valve-closing operation (the valve 10 turns from descending to ascending), the coolant 19 once moved upward in the small-diameter hollow portion S2 is affected by the inertial force (downward). As shown in FIG. 3 (b), when moving from the small-diameter hollow portion S21 near the end of the valve shaft having a large inner diameter to the small-diameter hollow portion S22 near the valve umbrella portion having a small inner diameter, A turbulent flow F9b is generated downstream of the annular stepped portion 17 in the small-diameter hollow portion S2, and the coolant 19 in the small-diameter hollow portion S2 is agitated.
　このように、バルブの開閉動作(上下方向の往復動作)に伴って、大径中空部Ｓ１内の冷却材１９には、バルブの中心軸線Ｌ周りに縦方向内回りの循環流（対流）Ｔ１が形成されるとともに、中径中空部Ｓ３内の冷却材１９には、縦方向の循環流（対流）Ｔ２が形成され、さらには、小径中空部Ｓ２の段差部１７近傍に乱流Ｆ９ａ，Ｆ９ｂが発生して、中空部Ｓ内の冷却材１９の上層部、中層部、下層部が積極的に攪拌されることで、バルブ１０の熱引き効果（熱伝導性）が著しく改善される。 Thus, along with the opening / closing operation (vertical reciprocation) of the valve, the coolant 19 in the large-diameter hollow portion S1 has a circulating flow (convection) T1 in the longitudinal direction around the central axis L of the valve. In addition, a longitudinal circulation flow (convection) T2 is formed in the coolant 19 in the medium diameter hollow portion S3, and further, turbulent flows F9a and F9b are formed in the vicinity of the stepped portion 17 of the small diameter hollow portion S2. When the upper layer portion, the middle layer portion, and the lower layer portion of the coolant 19 in the hollow portion S are positively stirred, the heat-drawing effect (thermal conductivity) of the valve 10 is remarkably improved.
　特に、本実施例では、大径中空部Ｓ１の円環状の天井面（円錐台の上面）１４ｂ１とその外周面（円錐台の外周面）１４ｂ２が鈍角をなすので、バルブ１０が開閉動作する際に、大径中空部Ｓ１の半径方向外方から大径中空部Ｓ１の天井面に沿って連通部Ｐ１に向かう冷却材１９の流れ（図３（ａ）のＦ２）の発生がスムーズとなる分、大径中空部Ｓ１内の冷却材１９に形成される縦方向内回りの循環流（対流）Ｔ１が活発になるので、中空部Ｓ内の冷却材１９の攪拌がそれだけ促進されて、バルブ１０における熱引き効果（熱伝導性）が著しく改善されることになる。 In particular, in this embodiment, the annular ceiling surface (the upper surface of the truncated cone) 14b1 and the outer peripheral surface (the outer circumferential surface of the truncated cone) 14b2 of the large-diameter hollow portion S1 form an obtuse angle. Furthermore, the flow of the coolant 19 (F2 in FIG. 3 (a)) from the radially outer side of the large-diameter hollow portion S1 toward the communication portion P1 along the ceiling surface of the large-diameter hollow portion S1 becomes smooth. Since the circulating flow (convection) T1 formed in the coolant 19 in the large-diameter hollow portion S1 is activated in the longitudinal direction, the stirring of the coolant 19 in the hollow portion S is promoted accordingly, and the valve 10 The heat drawing effect (thermal conductivity) will be remarkably improved.
　また、バルブ１０が軸方向に往復動作する際に、中空部Ｓ内の冷却材１９は上下方向に移動（図３（ａ），（ｂ）のＦ１，Ｆ３参照）するが、大径中空部Ｓ１と中径中空部Ｓ３の連通部Ｐ１および中径中空部Ｓ３と小径中空部Ｓ２の連通部Ｐ２では、流路の断面積が急変するため、連通部Ｐ１，Ｐ２の下流側に乱流(渦) Ｆ６ａ，Ｆ７ａ（Ｆ６ｂ，Ｆ７ｂ）が形成されて、これらの乱流(渦) Ｆ６ａ，Ｆ７ａ（Ｆ６ｂ，Ｆ７ｂ）が中空部Ｓ内の冷却材１９の上層部、中層部、下層部をより積極的に攪拌し、バルブ１０の熱引き効果（熱伝導性）がさらに改善される。 When the valve 10 reciprocates in the axial direction, the coolant 19 in the hollow portion S moves in the vertical direction (see F1 and F3 in FIGS. 3A and 3B). In the communication part P1 between S1 and the medium-diameter hollow part S3 and the communication part P2 between the medium-diameter hollow part S3 and the small-diameter hollow part S2, the cross-sectional area of the flow path changes suddenly, and therefore turbulent flow downstream of the communication parts P1 and P2 ( Vortex) F6a, F7a (F6b, F7b) are formed, and these turbulent (vortex) F6a, F7a (F6b, F7b) form the upper, middle and lower layers of the coolant 19 in the hollow portion S. Agitation is positively performed, and the heat drawing effect (thermal conductivity) of the valve 10 is further improved.
　また、本実施例では、排気バルブとして用いた場合に高温の排気ガスに最もさらされる部位である、傘部１４と軸部１２間のフィレット部１３に対応する位置に、中径中空部Ｓ３が設けられることで、フィレット部１３形成壁の厚さがそれだけ薄くなることに加えて、排気ガスにさらされて高温となったフィレット部１３の熱が、中径中空部Ｓ３内の冷却材１９に形成される循環流Ｔ２を介して軸端部側に積極的に伝達されるので、フィレット部１３表面に熱がこもらず、フィレット部１３における最高温度も低下するなど、バルブ１０の熱引き効果（熱伝導性）が著しく改善される。 Further, in this embodiment, the medium-diameter hollow portion S3 is located at a position corresponding to the fillet portion 13 between the umbrella portion 14 and the shaft portion 12, which is a portion most exposed to high-temperature exhaust gas when used as an exhaust valve. By being provided, in addition to the thickness of the fillet portion 13 forming wall being reduced accordingly, the heat of the fillet portion 13 that has been exposed to the exhaust gas and heated to the coolant 19 in the medium-diameter hollow portion S3. Since the heat is actively transmitted to the shaft end portion side through the formed circulation flow T2, heat is not accumulated on the surface of the fillet portion 13, and the maximum temperature at the fillet portion 13 is also reduced. Thermal conductivity) is significantly improved.
　図５は、本実施例の中空ポペットバルブ１０の表面温度の軸方向における温度分布特性を、軸部に形成した中空部に冷却材を装填した中空バルブＢ、軸部から傘部にかけて形成した中空部（連通部が滑らかな形状の中空部）に冷却材を装填した中空バルブＣ、先行特許文献４の中空バルブＤ（円錐台形状の大径中空部の天上面を構成する小径中空部の開口周縁部がバルブの中心軸線に対し直交する平面で構成）のそれぞれの温度分布特性と比較して示す図で、本実施例のバルブ１０の温度分布特性は、一点差線のようになると推定される。なお、図５中、中空ポペットバルブ１０の形状（外形）を斜線で示す。 FIG. 5 shows the temperature distribution characteristics in the axial direction of the surface temperature of the hollow poppet valve 10 of the present embodiment, the hollow valve B in which the coolant is loaded in the hollow portion formed in the shaft portion, the hollow formed from the shaft portion to the umbrella portion. A hollow valve C in which a coolant is charged in a portion (a hollow portion having a smooth communicating portion), a hollow valve D of Prior Patent Document 4 (an opening of a small-diameter hollow portion constituting a top surface of a large-diameter hollow portion having a truncated cone shape) The temperature distribution characteristic of the valve 10 of this embodiment is estimated to be as shown by a one-point difference line in comparison with the temperature distribution characteristics of each of the peripheral portions (configured with a plane perpendicular to the central axis of the valve). The In FIG. 5, the shape (outer shape) of the hollow poppet valve 10 is indicated by hatching.
　図５から明らかなように、中空バルブＤでは、大径中空部に形成される循環流により中空部内の冷却材全体が攪拌されるため、最高温度Ｔｍａｘを含むバルブ表面温度が、バルブＢ，Ｃと比べて全体的に低く、かつなだらかになっており、また最高温度（Ｔｍａｘ）位置も、バルブＢ，Ｃの最高温度（Ｔｍａｘ）位置と比べてバルブ傘部寄りとなって、中空バルブＢ，Ｃよりも熱引き効果（放熱性）に優れていることがわかる。 As is clear from FIG. 5, in the hollow valve D, the entire coolant in the hollow portion is agitated by the circulating flow formed in the large-diameter hollow portion, so that the valve surface temperature including the maximum temperature Tmax is Compared to the maximum temperature (Tmax) position of the valves B and C, the maximum temperature (Tmax) position is closer to the valve umbrella than the valve B and C. It can be seen that the heat drawing effect (heat dissipation) is superior to C.
　そして、本実施例のバルブ１０では、大径中空部Ｓ１に形成される循環流Ｔ１および中径中空部Ｓ３に形成される循環流Ｔ２により、中空部Ｓ内の冷却材１９全体がより積極的に攪拌されるため、中空バルブＤの温度特性と比較すると、図５の一点差線で示すように、最高温度（Ｔｍａｘ）位置がより傘部側になるとともに、表面温度が全体的に低く、かつなだらかになるものと、推定される。 And in the valve | bulb 10 of a present Example, the whole coolant 19 in the hollow part S is more active by the circulation flow T1 formed in the large diameter hollow part S1, and the circulation flow T2 formed in the medium diameter hollow part S3. Compared with the temperature characteristics of the hollow valve D, the maximum temperature (Tmax) position is closer to the umbrella side as shown in FIG. Presumed to be gentle.
　また、小径中空部Ｓ２内の段差部１７は、図１に示すように、バルブガイド３ａの排気通路６に臨む側の端部３ｂに略対応する位置に設けられて、内径の大きい軸端部寄りの小径中空部Ｓ２１を軸方向に長く形成することで、バルブ１０の耐久性を低下させることなく、バルブ軸部１２の冷却材１９との接触面積が増えて、バルブ軸部１２の熱伝達効率が上がり、小径中空部Ｓ２１形成壁が薄肉となって、バルブ１０も軽量となる。 Further, as shown in FIG. 1, the stepped portion 17 in the small-diameter hollow portion S2 is provided at a position substantially corresponding to the end portion 3b facing the exhaust passage 6 of the valve guide 3a, and has a shaft end portion having a large inner diameter. By forming the closer small-diameter hollow portion S21 in the axial direction, the contact area between the valve shaft portion 12 and the coolant 19 is increased without reducing the durability of the valve 10, and heat transfer of the valve shaft portion 12 is achieved. Efficiency increases, the small-diameter hollow portion S21 forming wall becomes thin, and the valve 10 is also lightweight.
　また、小径中空部Ｓ内の段差部１７は、図１の仮想線に示すように、バルブ１０が開弁(下降)しきった状態で、排気通路６内とならない所定位置（バルブ軸部１２における薄肉の小径中空部Ｓ２１形成壁が排気通路６内の熱の影響を受け難い所定位置）に設けられている。図１の符号１７Ｘは、バルブ１０が開弁(下降)しきった状態での段差部１７の位置を示す。 Further, as shown by an imaginary line in FIG. 1, the stepped portion 17 in the small-diameter hollow portion S has a predetermined position (in the valve shaft portion 12) that does not enter the exhaust passage 6 when the valve 10 is fully opened (lowered). A thin-walled small-diameter hollow portion S21 forming wall is provided at a predetermined position that is not easily affected by heat in the exhaust passage 6. Reference numeral 17X in FIG. 1 indicates the position of the stepped portion 17 in a state where the valve 10 is fully opened (lowered).
　詳しくは、金属の疲労強度は高温になるほど低下するため、常に排気通路６内にあって高熱にさらされる部位である、バルブ軸部１２におけるバルブ傘部１４寄りの領域は、疲労強度の低下に耐え得る程度の肉厚に形成する必要がある。一方、熱源から離れ、しかも常にバルブガイド３ａに摺接する部位である、バルブ軸部１２における軸端部寄りの領域は、冷却材１９を介して燃焼室４や排気通路６の熱が伝達されるものの、伝達された熱はバルブガイド３ａを介して直ちにシリンダヘッド２に放熱されるため、バルブ傘部１４寄りの領域ほどの高温となることがない。 Specifically, since the fatigue strength of the metal decreases as the temperature increases, the region near the valve umbrella portion 14 in the valve shaft portion 12 that is always in the exhaust passage 6 and exposed to high heat reduces the fatigue strength. It must be formed to a thickness that can withstand. On the other hand, in the region near the shaft end portion of the valve shaft portion 12 that is away from the heat source and is always in sliding contact with the valve guide 3 a, heat from the combustion chamber 4 and the exhaust passage 6 is transmitted via the coolant 19. However, since the transmitted heat is immediately radiated to the cylinder head 2 through the valve guide 3a, the temperature does not become as high as that near the valve umbrella portion 14.
　即ち、バルブ軸部１２における軸端部寄りの領域は、バルブ傘部１４寄りの領域よりも疲労強度が低下しないため、薄肉に形成（小径中空部Ｓ２１の内径を大きく形成）しても、強度的（疲労により折損する等の耐久性）には問題がない。 That is, since the fatigue strength does not decrease in the region near the shaft end in the valve shaft portion 12 than in the region near the valve umbrella portion 14, the strength is improved even if it is formed thin (the inner diameter of the small-diameter hollow portion S 21 is increased). There is no problem in the target (durability such as breakage due to fatigue).
　そこで、本実施例では、段差部１７の位置を、バルブ１０が開弁(下降)しきった状態で排気通路６内とならない、できるだけ下方の、バルブガイド３の下端部３ｂに略対応する位置とするとともに、小径中空部Ｓ２１の内径を大きく形成して、第１には、小径中空部Ｓ２全体の表面積（冷却材１９との接触面積）を増やすことで、バルブ軸部１２における熱伝達効率が高められている。第２には、小径中空部Ｓ２１全体の容積を増やすことで、バルブ１０の総重量が軽量化されている。 Therefore, in the present embodiment, the position of the stepped portion 17 is a position substantially corresponding to the lower end portion 3b of the valve guide 3 that is as low as possible and does not enter the exhaust passage 6 when the valve 10 is fully opened (lowered). In addition, the inner diameter of the small-diameter hollow portion S21 is increased, and first, the surface area (contact area with the coolant 19) of the entire small-diameter hollow portion S2 is increased, so that the heat transfer efficiency in the valve shaft portion 12 is increased. Has been enhanced. Secondly, the total weight of the valve 10 is reduced by increasing the volume of the entire small-diameter hollow portion S21.
　次に、中空ポペットバルブ１０の製造工程を、図６に基づいて説明する。 Next, the manufacturing process of the hollow poppet valve 10 will be described with reference to FIG.
　まず、図６（ａ）に示すように、熱間鍛造工程により、円錐台形状の凹部１４ｂを設けた傘部外殻１４ａと軸部１２ａとを一体的に形成したシェル１１を成形する。傘部外殻１４ａの凹部１４ｂの底面１４ｂ１は、軸部１２（シェル１１の中心軸線Ｌ）に対し直交する平面で形成されている。 First, as shown in FIG. 6A, a shell 11 in which an umbrella outer shell 14a provided with a truncated cone-shaped concave portion 14b and a shaft portion 12a are integrally formed is formed by a hot forging process. The bottom surface 14b1 of the concave portion 14b of the umbrella outer shell 14a is formed by a plane orthogonal to the shaft portion 12 (the central axis L of the shell 11).
　熱間鍛造工程としては、金型を順次取り替える押し出し鍛造で、耐熱合金鋼製金属ブロックからシェル１１を製造する押し出し鍛造、またはアップセッタで耐熱合金鋼製棒材の端部に球状部を据え込んだ後に、金型を用いてシェル１１（の傘部外殻１４ａ）を鍛造する据え込み鍛造のいずれであってもよい。なお、熱間鍛造工程において、シェル１１の傘部外殻１４ａと軸部１２ａとの間には、Ｒ形状フィレット部１３が形成され、傘部外殻１４ａの外周面には、テーパ形状フェース部１６が形成される。 The hot forging process is extrusion forging in which the dies are sequentially replaced, extrusion forging in which the shell 11 is manufactured from a heat-resistant alloy steel metal block, or a spherical portion is installed at the end of the heat-resistant alloy steel rod with an upsetter. After that, any of upsetting forging may be used in which the shell 11 (the umbrella outer shell 14a) is forged using a mold. In the hot forging process, an R-shaped fillet portion 13 is formed between the umbrella outer shell 14a and the shaft portion 12a of the shell 11, and a tapered face portion is formed on the outer peripheral surface of the umbrella outer shell 14a. 16 is formed.
　次に、図６（ｂ）に示すように、例えば、傘部外殻１４ａの凹部１４ｂが上向きとなるようにシェル１１を配置し、傘部外殻１４ａの凹部１４ｂの底面１４ｂ１から軸部１２にかけて小径中空部Ｓ２２に相当する孔１４ｅをドリル加工により穿設する（第１の孔穿設工程）。 Next, as shown in FIG. 6B, for example, the shell 11 is arranged so that the concave portion 14b of the umbrella outer shell 14a faces upward, and the shaft portion 12 extends from the bottom surface 14b1 of the concave portion 14b of the umbrella outer shell 14a. The hole 14e corresponding to the small-diameter hollow portion S22 is drilled by drilling (first hole drilling step).
　引き続き、図６（ｃ）に示すように、傘部外殻１４ａの凹部１４ｂの底面１４ｂ１から中径中空部Ｓ３に相当する孔１４ｅ’をドリル加工により穿設する（第２の孔穿設工程）。 Subsequently, as shown in FIG. 6C, a hole 14e ′ corresponding to the medium-diameter hollow portion S3 is drilled from the bottom surface 14b1 of the concave portion 14b of the umbrella outer shell 14a (second hole drilling step). ).
　第２の孔穿設工程により、凹部１４ｂと孔１４ｅ’の連通部，孔１４ｅ’と孔１４ｅの連通部には、凹部１４ｂ側から見て庇状の環状段差部１５，１５ａが形成される。 By the second hole drilling step, bowl-shaped annular step portions 15 and 15a are formed in the communication portion between the recess 14b and the hole 14e ′ and the communication portion between the hole 14e ′ and the hole 14e as viewed from the recess 14b side. .
　次に、図６（ｄ）に示すように、シェル１１の軸端部側から、小径中空部Ｓ２１に相当する孔１４ｆをドリル加工により穿設する（第３の孔穿設工程）。 Next, as shown in FIG. 6 (d), a hole 14f corresponding to the small-diameter hollow portion S21 is drilled from the shaft end side of the shell 11 (third hole drilling step).
　次に、図６（ｅ）に示すように、シェル１１の軸端部に軸端部材１２ｂを軸接する（軸端部材軸接工程）。 Next, as shown in FIG. 6E, the shaft end member 12b is axially contacted with the shaft end portion of the shell 11 (shaft end member axial contact step).
　次に、図６（ｆ）に示すように、シェル１１の傘部外殻１４ａの凹部１４ｂの孔１４ｅに冷却材（固体）１９を所定量挿入する（冷却材装填工程）。 Next, as shown in FIG. 6 (f), a predetermined amount of coolant (solid) 19 is inserted into the hole 14 e of the recess 14 b of the umbrella outer shell 14 a of the shell 11 (coolant loading step).
　最後に、図６（ｇ）に示すように、アルゴンガス雰囲気下で、シェル１１の傘部外殻１４ａの凹部１４ｂの開口部１４ｃにキャップ１８を溶接（例えば、抵抗溶接）して、バルブ１０の中空部Ｓを密閉する（中空部密閉工程）。なお、キャップ１８の溶接は、抵抗溶接に代えて、電子ビーム溶接やレーザー溶接等を採用してもよい。 Finally, as shown in FIG. 6G, a cap 18 is welded (for example, resistance welding) to the opening 14c of the recess 14b of the umbrella outer shell 14a of the shell 11 under an argon gas atmosphere, and the valve 10 The hollow portion S is sealed (hollow portion sealing step). Note that the welding of the cap 18 may employ electron beam welding, laser welding, or the like instead of resistance welding.
　図７は、本発明の第２の実施例である中空ポペットバルブを示す。 FIG. 7 shows a hollow poppet valve according to a second embodiment of the present invention.
　前記した第１の実施例では、バルブ中間品である軸一体型シェル１１の軸部１２ａに軸端部材１２ｂが軸接されることで、バルブ１０の軸部１２が構成されているが、この第２の実施例では、バルブ１０Ａの軸部１２が傘部１４（傘部外殻１４ａ）に予め一体的に構成されている。 In the first embodiment described above, the shaft end member 12b is axially contacted with the shaft portion 12a of the shaft-integrated shell 11 which is a valve intermediate product, whereby the shaft portion 12 of the valve 10 is configured. In the second embodiment, the shaft portion 12 of the valve 10A is integrally configured in advance with the umbrella portion 14 (umbrella portion outer shell 14a).
　また、前記した第１の実施例では、中径中空部Ｓ３の天井面（中径中空部Ｓ３における小径中空部Ｓ２の開口周縁部）２０がバルブ１０の中心軸線Ｌに対し直交する平面で構成されているが、この第２の実施例では、中径中空部Ｓ３’の天井面（中径中空部Ｓ３’における小径中空部Ｓ２’の開口周縁部）２０ａ、中心軸線Ｌに対し所定角度（６０度～９０度）傾斜するテーパ面（中心軸線Ｌと直交する平面に対し３０度～０度傾斜するテーパ面）で構成されている。 In the first embodiment described above, the ceiling surface of the medium-diameter hollow portion S3 (opening peripheral edge portion of the small-diameter hollow portion S2 in the medium-diameter hollow portion S3) 20 is configured by a plane orthogonal to the central axis L of the valve 10. However, in the second embodiment, the ceiling surface of the medium-diameter hollow portion S3 ′ (the opening peripheral edge of the small-diameter hollow portion S2 ′ in the medium-diameter hollow portion S3 ′) 20a and a predetermined angle with respect to the central axis L ( The tapered surface is inclined at 60 to 90 degrees (tapered at 30 to 0 degrees with respect to a plane perpendicular to the central axis L).
　また、前記した第１の実施例では、バルブ軸端部寄りの小径中空部Ｓ２１の内径が、バルブ傘部１４寄りの小径中空部Ｓ２２の内径よりも大きく形成されて、小径中空部Ｓ２内の軸方向所定位置に第２の円環状の段差部１７が設けられるとともに、第２の段差部１７を越えた位置まで冷却材１９が装填された構造であるが、この第２の実施例では、小径中空部Ｓ２’の内径が軸方向に一定の大きさに形成されている。 Further, in the first embodiment described above, the inner diameter of the small-diameter hollow portion S21 near the valve shaft end is formed larger than the inner diameter of the small-diameter hollow portion S22 near the valve umbrella portion 14, so that the inside of the small-diameter hollow portion S2 The second annular stepped portion 17 is provided at a predetermined position in the axial direction, and the coolant 19 is loaded up to a position beyond the second stepped portion 17. In this second embodiment, The inside diameter of the small-diameter hollow portion S2 ′ is formed to have a constant size in the axial direction.
　その他の構成は、前記した第１の実施例のバルブ１０と同一であり、同一の符号を付すことで、その重複した説明は省略する。 Other configurations are the same as those of the valve 10 of the first embodiment described above, and the same reference numerals are given to omit redundant description.
　この中空ポペットバルブ１０Ａにおいても、前記した第１の実施例の中空ポペットバルブ１０と同様、バルブ１０Ａの開閉動作(上下方向の動作)に伴って大径中空部Ｓ１，中径中空部Ｓ３’内の冷却材（液体）１９には、縦方向内回りの循環流（対流）Ｔ１，Ｔ２（図４参照）が形成され、同時に、大径中空部Ｓ１，中径中空部Ｓ３’，小径中空部Ｓ２’内の冷却材（液体）１９には、乱流Ｆ６ａ，Ｆ６ｂ，Ｆ７ａ，Ｆ７ｂ（図３（ａ），（ｂ）参照）が形成されて、中空部Ｓ’内の冷却材１９全体が積極的に攪拌されて、バルブ１０Ａにおける熱引き効果（熱伝導性）が大幅に改善されている。 Also in this hollow poppet valve 10A, in the same way as the hollow poppet valve 10 of the first embodiment described above, the inside of the large-diameter hollow portion S1 and the medium-diameter hollow portion S3 ′ in accordance with the opening / closing operation (vertical operation) of the valve 10A. In the coolant (liquid) 19, circulation flows (convection) T 1 and T 2 (see FIG. 4) inward in the vertical direction are formed, and at the same time, a large diameter hollow portion S 1, a medium diameter hollow portion S 3 ′, and a small diameter hollow portion S 2. In the 'coolant (liquid) 19', turbulent flows F6a, F6b, F7a, and F7b (see FIGS. 3A and 3B) are formed, and the entire coolant 19 in the hollow portion S 'is positive. The heat absorption effect (thermal conductivity) in the valve 10A is greatly improved.
１０，１０Ａ　中空ポペットバルブ
１１　傘部外殻と軸部を一体的に形成したシェル
１２　バルブ軸部
１２ａ　軸部
１２ｂ　軸端部材
１３　フィレット部
１４　バルブ傘部
１４ａ　傘部外殻
１４ｂ　傘部外殻の凹部
１４ｂ１　大径中空部の天井面(中径中空部の大径中空部への開口周縁部）
１４ｂ２　傘部外殻の円錐台形状の凹部内周面
１４ｃ　傘部外殻の開口部
１５　庇状の環状段差部
１５ａ　庇状の環状段差部
１７　小径中空部内の円環状の段差部
１８　キャップ
１９　冷却材
２０　中径中空部の天井面(小径中空部の中径中空部への開口周縁部）
Ｌ　バルブの中心軸線
Ｓ，Ｓ’　中空部
Ｓ１　大径中空部
Ｓ２，Ｓ２’　直線状の小径中空部
Ｓ２１　軸端部寄りの小径中空部
Ｓ２２　傘部寄りの小径中空部
Ｓ３，Ｓ３’　中径中空部
Ｐ１　大径中空部と中径中空部の連通部
Ｐ２　中径中空部と小径中空部の連通部
Ｔ１　縦方向内回りの循環流
Ｔ２　縦方向の循環流 DESCRIPTION OF SYMBOLS 10,10A Hollow poppet valve 11 Shell in which umbrella part outer shell and shaft part are integrally formed 12 Valve shaft part 12a Shaft part 12b Shaft end member 13 Fillet part 14 Valve umbrella part 14a Umbrella part outer shell 14b Recess 14b1 The ceiling surface of the large-diameter hollow part (the peripheral edge of the opening of the medium-diameter hollow part to the large-diameter hollow part)
14b2 Frustum-shaped recessed inner peripheral surface 14c of umbrella-shaped outer shell 14c Opening 15 of umbrella-shaped outer shell 庇 -shaped annular stepped portion 15a 庇 -shaped annular stepped portion 17 Annular stepped portion 18 in small-diameter hollow portion Cap 19 Cooling Material 20 Ceiling surface of medium-diameter hollow part (peripheral edge of opening to medium-diameter hollow part of small-diameter hollow part)
L Valve center axis S, S 'Hollow part S1 Large diameter hollow part S2, S2' Linear small-diameter hollow part S21 Small-diameter hollow part near shaft end S22 Small-diameter hollow part near umbrella part S3, S3 'Medium-diameter hollow Portion P1 Communication portion P2 between the large-diameter hollow portion and the medium-diameter hollow portion Communication portion T1 between the medium-diameter hollow portion and the small-diameter hollow portion Circulating flow T2 in the longitudinal direction Circulating flow in the longitudinal direction

Claims (4)

  1. 　軸端部に傘部を一体的に形成したポペットバルブの傘部から軸部にかけて中空部が形成され、前記中空部に冷却材が装填された中空ポペットバルブにおいて、
    　前記傘部内には、該傘部の外形に倣うテーパ形状の外周面を備えた円錐台形状の大径中空部が設けられ、
    　一方、前記軸部内には、前記大径中空部に連通する直線状の小径中空部が設けられるとともに、前記小径中空部の前記大径中空部との連通部にその内径を拡径した中径中空部が設けられ、
    　前記大径中空部の天井面を形成する、前記中径中空部の前記大径中空部への開口周縁部が前記バルブの中心軸線に対し直交する平面で構成され、
    　前記中径中空部の天井面を形成する、前記小径中空部の前記中径中空部への開口周縁部が前記バルブの中心軸線に対し直交する平面または所定角度傾斜するテーパ面で構成されて、
    　前記バルブが軸方向に往復動作する際に、前記大径中空部の冷却材に前記バルブの中心軸線周りに縦方向内回りの第１の循環流（対流）が形成され、前記中径中空部の冷却材に縦方向の第２の循環流（対流）が形成されることを特徴とする中空ポペットバルブ。     In the hollow poppet valve in which a hollow portion is formed from the umbrella portion of the poppet valve integrally formed at the shaft end portion to the shaft portion, and a coolant is loaded in the hollow portion,
    In the umbrella portion, a frustoconical large-diameter hollow portion having a tapered outer peripheral surface following the outer shape of the umbrella portion is provided,
    On the other hand, a linear small-diameter hollow portion that communicates with the large-diameter hollow portion is provided in the shaft portion, and a medium diameter whose inner diameter is increased at the communicating portion of the small-diameter hollow portion with the large-diameter hollow portion. A hollow part is provided,
    Forming a ceiling surface of the large-diameter hollow portion, an opening peripheral edge to the large-diameter hollow portion of the medium-diameter hollow portion is constituted by a plane perpendicular to the central axis of the valve;
    The opening peripheral edge of the small-diameter hollow part to the medium-diameter hollow part, which forms the ceiling surface of the medium-diameter hollow part, is configured by a plane orthogonal to the central axis of the bulb or a tapered surface inclined at a predetermined angle,
    When the valve reciprocates in the axial direction, a first circulation flow (convection) inward in the longitudinal direction is formed around the central axis of the valve in the coolant of the large-diameter hollow portion, A hollow poppet valve characterized in that a second circulating flow (convection) in the vertical direction is formed in the coolant.
  2. 　前記中径中空部は、前記傘部と軸部間のフィレット部に対応する位置に設けられたことを特徴とする請求項１に記載の中空ポペットバルブ。 The hollow poppet valve according to claim 1, wherein the medium-diameter hollow portion is provided at a position corresponding to a fillet portion between the umbrella portion and the shaft portion.
  3. 　前記バルブ軸端部寄りの小径中空部の内径が、前記バルブ傘部寄りの小径中空部の内径よりも大きく形成されて、前記小径中空部内の軸方向所定位置に円環状の段差部が設けられるとともに、前記段差部を越えた位置まで前記冷却材が装填されたことを特徴とする請求項１または２に記載の中空ポペットバルブ。 An inner diameter of the small-diameter hollow portion near the valve shaft end is formed larger than an inner diameter of the small-diameter hollow portion near the valve umbrella, and an annular step portion is provided at a predetermined axial position in the small-diameter hollow portion. The hollow poppet valve according to claim 1, wherein the coolant is loaded up to a position beyond the stepped portion.
  4. 　前記小径中空部内の段差部は、前記バルブがエンジンの燃焼室に開口する排気通路または吸気通路に配設された際に、前記排気通路または吸気通路内とならない所定位置に設けられたことを特徴とする請求項３に記載の中空ポペットバルブ。 The step portion in the small-diameter hollow portion is provided at a predetermined position that does not enter the exhaust passage or the intake passage when the valve is disposed in the exhaust passage or the intake passage that opens to the combustion chamber of the engine. The hollow poppet valve according to claim 3.
PCT/JP2014/062374 2014-05-08 2014-05-08 Hollow poppet valve WO2015170384A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2014/062374 WO2015170384A1 (en) 2014-05-08 2014-05-08 Hollow poppet valve

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2014/062374 WO2015170384A1 (en) 2014-05-08 2014-05-08 Hollow poppet valve

Publications (1)

Publication Number Publication Date
WO2015170384A1 true WO2015170384A1 (en) 2015-11-12

Family

ID=54392253

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/062374 WO2015170384A1 (en) 2014-05-08 2014-05-08 Hollow poppet valve

Country Status (1)

Country Link
WO (1) WO2015170384A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190138894A (en) * 2018-03-20 2019-12-16 니탄 밸브 가부시키가이샤 Exhaust Hollow Poppet Valve
CN112752895A (en) * 2018-11-12 2021-05-04 日锻汽门株式会社 Method for manufacturing poppet valve of engine
US11850690B2 (en) 2020-03-30 2023-12-26 Nittan Corporation Method for manufacturing engine poppet valve

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2547383Y2 (en) * 1990-11-19 1997-09-10 フジオーゼックス株式会社 Hollow valves for internal combustion engines
WO2014054613A1 (en) * 2012-10-02 2014-04-10 日鍛バルブ株式会社 Hollow poppet valve

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2547383Y2 (en) * 1990-11-19 1997-09-10 フジオーゼックス株式会社 Hollow valves for internal combustion engines
WO2014054613A1 (en) * 2012-10-02 2014-04-10 日鍛バルブ株式会社 Hollow poppet valve

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190138894A (en) * 2018-03-20 2019-12-16 니탄 밸브 가부시키가이샤 Exhaust Hollow Poppet Valve
EP3667036A4 (en) * 2018-03-20 2020-09-02 Nittan Valve Co., Ltd. Hollow exhaust poppet valve
KR102285017B1 (en) * 2018-03-20 2021-08-04 니탄 밸브 가부시키가이샤 Hollow Poppet Valve for Exhaust
US11300018B2 (en) 2018-03-20 2022-04-12 Nittan Valve Co., Ltd. Hollow exhaust poppet valve
CN112752895A (en) * 2018-11-12 2021-05-04 日锻汽门株式会社 Method for manufacturing poppet valve of engine
US11536167B2 (en) 2018-11-12 2022-12-27 Nittan Valve Co., Ltd. Method for manufacturing engine poppet valve
CN112752895B (en) * 2018-11-12 2023-10-13 日锻株式会社 Method for manufacturing poppet valve of engine
US11850690B2 (en) 2020-03-30 2023-12-26 Nittan Corporation Method for manufacturing engine poppet valve

Similar Documents

Publication Publication Date Title
JP5463439B1 (en) Hollow poppet valve
KR101688582B1 (en) Hollow poppet valve
TWI638092B (en) Hollow poppet valve and method for adjusting relative value of heat insulation effect and heat conduction effect of hollow poppet valve
JP2017535714A (en) piston
JP6033402B2 (en) Hollow poppet valve
WO2015170384A1 (en) Hollow poppet valve
JP6251177B2 (en) Hollow poppet valve
JP6029742B2 (en) Hollow poppet valve
JP6063558B2 (en) Hollow poppet valve
JP6131318B2 (en) Hollow poppet valve
BR112015022247B1 (en) HOLLOW SEAT VALVE

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14891509

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14891509

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP