JP2007093396A - Visualization engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve durability of a device by avoiding an influence of a thermal stress at a high-load operation time, in a visualization engine having a structure wherein a cylinder is formed from a transparent material and the inside of a combustion chamber can be viewed. <P>SOLUTION: A lower ring 14 is provided along the inner circumferential surface of the transparent cylinder 9 which is a component of this visualization engine, and an upper ring 15 is provided on the upper outer circumferential surface of a piston crown 7 interfitted with the crown part of an extensible piston 5, and an airtight space S is constituted in a gap between the inner circumferential surface of the transparent cylinder 9 and the outer circumferential surface of the extensible piston 5, and a through hole 5a communicated with the airtight space S is formed on the wall surface of the extensible piston 5. Hereby, when the extensible piston 5 is reciprocated, the volume of the airtight space S is increased/decreased, and the air flows in/out from the through hole 5a. Hereby, the air works as a cooling medium, and the whole inner circumferential surface of the transparent cylinder 9 can be cooled effectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a visualization engine having a structure in which a cylinder of an engine is formed of a transparent material so that the inside of a combustion chamber can be visually observed, and more specifically, by effectively cooling the inner peripheral surface of the transparent cylinder, The present invention relates to a visualization engine that avoids the effects of thermal stress and improves the durability of the apparatus.

Conventionally, a visualization engine in which a cylinder, which is a component of the engine, is formed of a transparent material such as heat-resistant glass, and the actual fuel injection and combustion state in the combustion chamber can be visually recognized from the outside of the transparent cylinder. It has been developed (see Patent Document 1).
JP 2002-139407 A

  Although this conventional visualization engine is less affected by heat load during low-speed operation, the temperature in the combustion chamber increases when operated at high load and high rotation, so the transparent cylinder breaks due to thermal stress or abnormalities from the inside The engine could be damaged by ignition. Therefore, in order to operate the visualization engine at a high load, it was necessary to cool the transparent cylinder. At this time, if a liquid such as oil is used as a cooling medium, the combustion chamber becomes difficult to see. Therefore, in order to avoid such a problem, an air cooling type cooling device has been adopted. As such an air-cooling type cooling device, for example, there are those that blow cool air from the outside of a transparent cylinder, and those that send cool air into the cylinder from below the piston.

  However, the one that blows cool air from the outside of the transparent cylinder cools the outer surface of the transparent cylinder, while the temperature in the combustion chamber rises due to high-load operation, so the temperature difference between the inner and outer surfaces of the transparent cylinder increases. However, the transparent cylinder was damaged by thermal stress. Also, in the case of sending cool air from the bottom of the piston into the cylinder, even if the lower part of the transparent cylinder can be cooled, the upper part of the transparent cylinder that becomes the heat spot in the combustion chamber cannot be cooled sufficiently, and the influence of thermal stress is also avoided. could not.

  Therefore, the present invention addresses such problems and effectively cools the entire inner peripheral surface of the transparent cylinder, thereby avoiding the influence of thermal stress during high-load operation and improving the durability of the apparatus. The purpose is to provide a visualization engine.

  In the visualization engine according to the present invention, a first annular member is provided along an inner peripheral surface of a transparent cylinder made of a material that transmits visible light, and an upper outer peripheral surface of a piston that reciprocates in the transparent cylinder is provided on the upper outer peripheral surface. 2 is provided, and an airtight space sandwiched between the two annular members is formed in a gap between the inner peripheral surface of the transparent cylinder and the outer peripheral surface of the piston, and a through hole is formed in the member constituting the airtight space. Is formed.

  According to the present invention, the air in the airtight space formed in the gap between the transparent cylinder and the piston can flow in and out of the through hole by utilizing the reciprocating motion of the piston in the transparent cylinder. Therefore, the air flowing into and out of the airtight space becomes a cooling medium, and the entire inner peripheral surface of the transparent cylinder can be effectively cooled.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view showing an embodiment of a visualization engine according to the present invention. This visualization engine has a structure in which the combustion chamber of the engine can be seen, and can photograph and measure the influence of parameters such as the performance of the fuel injection device and the air supply / exhaust device, or the type of fuel, engine load, etc. It is what I did.

  A crankshaft 2 is rotatably supported in the crankcase 1 at the bottom of the visualization engine, and a connecting rod 3 is connected to the crankshaft 2. A lower piston assembly 4 is interposed at the upper end of the connecting rod 3, and an extension piston 5 is attached to the upper surface of the lower piston assembly 4. The lower piston assembly 4 is a cylindrical member housed in the cylinder body 6 and reciprocates while being in close contact with the inner wall of the cylinder body 6. The extension piston 5 is a cylindrical member that receives a force generated by the explosion of fuel in a combustion chamber 10 to be described later, and a part of its wall surface is cut off and its internal space is opened to the atmosphere. Yes. The force received by the extension piston 5 is transmitted to the lower piston assembly 4 and the connecting rod 3 to rotate the crankshaft 2. A piston crown 7 constituting the bottom surface of the combustion chamber 10 is fitted to the upper end portion of the extension piston 5.

  The cylinder body 6 is provided with an attachment member 8, and a transparent cylinder 9 is attached to the upper portion of the attachment member 8. The transparent cylinder 9 is a cylindrical member that forms the peripheral surface of the combustion chamber 10, and the extension piston 5 reciprocates inside the transparent cylinder 9. The transparent cylinder 9 is formed of a transparent member that transmits visible light, such as heat resistant glass, and the inside of the combustion chamber 10 can be seen from the outside.

Note that the piston crown 7 fitted to the upper end of the extension piston 5 can also be visually observed from below by forming it with a transparent material such as heat-resistant glass. Although not shown in the drawing, a mirror is arranged inside the extension piston 5 and the inside of the combustion chamber 10 can be photographed by using this mirror.
A cylinder head 11 is provided above the transparent cylinder 9. The cylinder head 11 is an assembly constituting the upper surface of the combustion chamber 10, and components such as an injector 12 and a spark plug 13 are disposed. Although not shown, the cylinder head 11 is provided with an intake port for sucking the air-fuel mixture into the combustion chamber 10, an exhaust port for discharging the combustion gas in the combustion chamber 10, and corresponding intake / exhaust means. Has been.

  Here, in the present invention, a mechanism for cooling the inner peripheral surface of the transparent cylinder 9 using the reciprocating motion of the extension piston 5 is provided. Specifically, as shown in FIG. 2, a lower ring 14 is provided along the inner peripheral surface of the transparent cylinder 9, and an upper ring is provided on the upper outer peripheral surface of the piston crown 7 fitted to the upper end portion of the extension piston 5. 15 is provided to form an airtight space S sandwiched between the lower ring 14 and the upper ring 15 in the gap between the inner peripheral surface of the transparent cylinder 9 and the outer peripheral surface of the extension piston 5.

  The lower ring 14 is a first annular member, and is fixed to the inner peripheral end surface of a cylindrical dowel member 16 that attaches the transparent cylinder 9 to the attachment member 8. Sealed to prevent leakage. Further, the upper ring 15 is a second annular member, and is attached to a groove formed on the outer periphery of the piston crown 7, and has an appropriate elasticity so as to slide while maintaining the airtightness of the airtight space S. It is. In FIG. 2, the lower ring 14 and the upper ring 15 are one annular member. However, the present invention is not limited to this, and in order to make the airtight space S completely airtight and reduce wear, You may use more than this.

A through hole 5 a is formed in the vicinity of the bottom surface of the piston crown 7 on the wall surface of the extension piston 5. The through hole 5 a communicates the airtight space S formed in the gap between the transparent cylinder 9 and the extension piston 5 and the open space inside the extension piston 5.
With such a configuration, as shown in FIG. 2, when the extension piston 5 rises, the volume of the airtight space S formed in the gap between the transparent cylinder 9 and the extension piston 5 increases. As shown by the arrow B, the air in the open space inside 5 flows into the airtight space S through the through hole 5a.

On the other hand, as shown in FIG. 4, when the extension piston 5 descends, the volume of the airtight space S decreases, so that the air inside the extension piston 5 passes through the through hole 5a as shown by the arrow D. It flows out into the internal open space.
Thus, the air inside the airtight space S flows in and out of the through hole 5a with the reciprocating motion of the extension piston 5 in the transparent cylinder 9. When the extension piston 5 rises, the airtight space S extends to the upper part of the transparent cylinder 9, so that it can be sufficiently cooled to the upper part of the inner peripheral surface of the transparent cylinder 9 that becomes a heat spot in the combustion chamber 10. At this time, when the visualization engine is operated at a high speed, the amount of air flowing into and out of the airtight space S increases, so that the inner peripheral surface of the transparent cylinder 9 can be effectively cooled.

Here, according to the present embodiment, as shown in FIG. 3, a plurality of, for example, four through holes 5 a are formed in the circumferential direction of the extension piston 5. Thereby, air is taken in over the whole inner peripheral surface of the transparent cylinder 9, and the inner peripheral surface of the transparent cylinder 9 is cooled by the air taken into the airtight space S.
In addition, according to the present embodiment, as shown in FIG. 3, the through hole 5 a is formed in an oblique direction with respect to the radial direction of the airtight space S in the horizontal cross section of the extension piston 5. Thereby, when the extension piston 5 rises, as shown in FIG. 3, the air flowing into the airtight space S rotates clockwise in the drawing. On the other hand, when the extension piston 5 descends, as shown in FIG. 5, the air flow in the airtight space S is reversed and rotates counterclockwise in the drawing. As described above, the reciprocating motion of the extension piston 5 causes the air flow direction in the airtight space S to be reversed and air turbulence occurs, so that the heat transfer coefficient on the inner peripheral surface of the transparent cylinder 9 is increased and the efficiency is increased. Cooling can be performed.

Furthermore, according to this embodiment, as shown in FIG. 2, the through hole 5 a is formed so as to face obliquely downward with respect to a direction perpendicular to the wall surface of the extension piston 5 in the vertical cross section of the extension piston 5. Has been. Thereby, it is possible to improve the efficiency of inhaling and discharging air.
FIG. 6 is a cross-sectional view showing a second embodiment of the present invention. In this embodiment, a through-hole 17a is formed on the wall surface of the mounting member 17 to which the transparent cylinder 9 is attached. The through hole 17 a communicates the airtight space S formed in the gap between the inner peripheral surface of the transparent cylinder 9 and the outer peripheral surface of the extension piston 5 and the outside of the transparent cylinder 9.

Here, according to the present embodiment, as shown in FIG. 7, a plurality, for example, four of the attachment members 17 are formed in the circumferential direction.
Moreover, according to this embodiment, each through-hole 17a is formed in the horizontal cross section of the attachment member 17 so that it may face the diagonal direction with respect to the direction orthogonal to the wall surface.
Furthermore, according to this embodiment, as shown in FIG. 6, the through-hole 17a is formed in the perpendicular cross section of the mounting member so as to face obliquely downward with respect to the direction perpendicular to the wall surface.

  Also in this case, when the extension piston 5 in the transparent cylinder 9 reciprocates, air flows into and out of the airtight space S formed in the gap between the transparent cylinder 9 and the extension piston 5 as shown in FIGS. To do. At this time, when the extension piston 5 rises and air flows in (see FIG. 7) and when the extension piston 5 descends and air flows out (see FIG. 9), the direction of air flow in the airtight space S Is reversed and air turbulence occurs, so that the heat transfer coefficient on the inner peripheral surface of the transparent cylinder 9 is increased and efficient cooling can be performed.

  In the above description, the through hole 17a is formed in the wall surface of the mounting member 17. However, the present invention is not limited to this, and any other position can be used as long as the air in the airtight space S can flow in and out. For example, a through hole may be formed in a part of the transparent cylinder 9.

It is sectional drawing which shows embodiment of the visualization engine by this invention. It is a principal part enlarged view which shows the state which the expansion piston of the visualization engine shown in FIG. 1 raises. It is the sectional view on the AA line of FIG. It is a principal part enlarged view which shows the state which the expansion piston of the visualization engine shown in FIG. 2 falls. It is CC sectional view taken on the line of FIG. It is sectional drawing which shows other embodiment of the visualization engine by this invention, and shows the state which an expansion | extension piston raises. It is the EE sectional view taken on the line of FIG. The visualization engine shown in FIG. 6 shows the state where the extension piston descends. It is the GG sectional view taken on the line of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Crankcase, 2 ... Crankshaft, 3 ... Connecting rod, 4 ... Lower piston assembly, 5 ... Elongation piston, 5a ... Through-hole, 6 ... Cylinder trunk, 7 ... Piston crown, 8 ... Mounting member, 9 ... Transparent cylinder, 10 ... Combustion chamber, 11 ... Cylinder head, 12 ... Injector, 13 ... Spark plug, 14 ... Lower ring, 15 ... Upper ring, 16 ... Dowel member, 17 ... Mounting member, 17a ... Through hole, S ... Airtight space

Claims (6)

A transparent cylinder made of a material that transmits visible light; a cylinder head that is provided above the transparent cylinder and that constitutes a part of the combustion chamber; and a piston that reciprocates in the transparent cylinder; In a visualization engine with a visible structure,
A first annular member is provided along the inner peripheral surface of the transparent cylinder, and a second annular member is provided on the upper outer peripheral surface of the piston, and a gap between the inner peripheral surface of the transparent cylinder and the outer peripheral surface of the piston. An airtight space sandwiched between the two annular members
A visualization engine characterized in that a through hole communicating with an external open space is formed in the piston or the transparent cylinder constituting the airtight space.   The visualization engine according to claim 1, wherein the through hole is formed in a wall surface of the piston, and the airtight space communicates with an open space inside the piston.   The visualization engine according to claim 1, wherein the through hole is formed in a wall surface of an attachment member of the transparent cylinder, and the airtight space and an open space outside the transparent cylinder are communicated with each other.   The visualization engine according to claim 2, wherein a plurality of the through holes are formed in a circumferential direction of the airtight space.   The visualization engine according to any one of claims 2 to 4, wherein the through hole is formed in an oblique direction with respect to a radial direction of the airtight space.   The visualization engine according to any one of claims 2 to 5, wherein the through hole is formed in an oblique direction with respect to a vertical direction of the piston or the transparent cylinder.

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