1. An air intake device for an internal combustion engine, comprising:
an intake air path for supplying air from a surge tank to a combustion chamber of the internal combustion engine; and
an exhaust gas path for supplying exhaust gas from an exhaust gas distribution header to the combustion chamber,
wherein the length of the exhaust gas path measured along the centerline of the exhaust gas path is set to be in the range from 75% to 125%, inclusive, of the length of the intake air path measured along the centerline of the intake air path,
the intake air path includes an upstream intake air path section and a downstream intake air path section,
the exhaust gas path includes an upstream exhaust gas path section and a downstream exhaust gas path section,
the downstream exhaust gas path section and the downstream intake air path section form a common path,
the upstream exhaust gas path section and the upstream intake air path section of the intake air path positioned upstream of the common path are arranged parallel with each other,
the surge tank comprises a lower body and an upper body, the lower body being an integral unit combining a half lower intake air path wall section and a half lower surge tank wall section, the upper body being an integral unit combining a half upper intake air path wall section and a half upper surge tank wall section, and
the upstream exhaust gas path section and the exhaust gas distribution header are formed on a top surface of the upper body.
2. The air intake device according to claim 1, wherein the length of the exhaust gas path is the same as the length of the intake air path.
3. The air intake device according to claim 2, wherein a ratio LcD of the length of the upstream exhaust gas path Lc measured along the centerline of the upstream exhaust gas path section to a path diameter D is set to 3 or greater.
4. The air intake device according to claim 2, wherein the upstream exhaust gas path section and the common path are connected to each other to allow the centerline of the upstream exhaust gas path section to cross the centerline of the intake air path with an angle smaller than 90 degrees.
5. The air intake device according to claim 1, wherein the upstream exhaust gas path section and the upstream intake air path section are sectioned by a common path wall to be arranged parallel with each other.
6. The air intake device according to claim 2, wherein the upstream exhaust gas path section communicates with an intermediate portion of the intake air path.
7. The air intake device according claim 2, wherein the unit of the upstream exhaust gas path section and the exhaust gas distribution header comprises a body forming the exhaust gas path and a body forming the surge tank.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An optical recording medium comprising an essentially flat recording layer having a first reflectivity at a wavelength specified for a reading or recording light beam, and a guide track having a second reflectivity different from the first reflectivity at the specified wavelength, wherein the guide track is an alloyed guide track formed by alloying of the material of the essentially flat recording layer.
2. The optical recording medium according to claim 1, wherein the essentially flat recording layer includes a CuSi composition, a PdTe composition, or a PdOTe composition.
3. The optical recording medium according to claim 1, wherein the guide track is formed by laser irradiation or a thermal process.
4. The optical recording medium according to claim 1, wherein it is a DVD-like medium.
5. A method for manufacturing an optical recording medium, the method comprising the steps of:
forming at least an essentially flat recording layer on a substrate; and
forming a guide track within the essentially flat recording layer by alloying the material of the recording layer.
6. The method according to claim 5, wherein alloying is performed by irradiating the essentially flat recording layer with an intense light beam along the desired guide track, or by applying a thermal process to the area of the desired guide track.
7. The method according to claim 5, wherein the essentially flat recording layer includes a CuSi composition, a PdTe composition, or a PdOTe composition.
8. The method according to claim 5, wherein the optical recording medium is a DVD-like medium.
9. The method according to claim 5, comprising the step of applying at least a cover layer on the essentially flat recording layer.
10. An apparatus for manufacturing an optical recording medium, the apparatus comprising:
means for applying at least an essentially flat recording layer on a substrate; and
means for forming a guide track within the essentially flat recording layer by alloying the material of the recording layer.
11. The apparatus according to claim 10, wherein the means for forming the guide track is a light source for irradiating the essentially flat recording layer with an intense light beam along the desired guide track, or a thermal processing means for applying a thermal process to the area of the desired guide track.
12. The apparatus according to claim 10, comprising means for applying at least a cover layer on the essentially flat recording layer.