JPH0115881Y2 - - Google Patents
Info
- Publication number
- JPH0115881Y2 JPH0115881Y2 JP12221482U JP12221482U JPH0115881Y2 JP H0115881 Y2 JPH0115881 Y2 JP H0115881Y2 JP 12221482 U JP12221482 U JP 12221482U JP 12221482 U JP12221482 U JP 12221482U JP H0115881 Y2 JPH0115881 Y2 JP H0115881Y2
- Authority
- JP
- Japan
- Prior art keywords
- recess
- pair
- exhaust valve
- piston
- notch
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired
Links
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Description
【考案の詳細な説明】
本考案は、エンジンのピストンに関するもので
ある。[Detailed Description of the Invention] The present invention relates to a piston for an engine.
エンジンのピストン頂部には、トツプクリアラ
ンス（ピストン頂部とシリンダヘツド下面との隙
間）を小さくするために、吸・排気弁が嵌まり込
む凹陥部を形成している。 In order to reduce the top clearance (the gap between the top of the piston and the lower surface of the cylinder head), the top of the piston of the engine is formed with a recess into which the intake and exhaust valves fit.
しかし、４弁式エンジンであると、第１図に示
すように、ピストン１の頂部１ａに一対の吸気弁
が嵌まり込む一対の吸気弁用凹陥部２，２と、一
対の排気弁が嵌まり込む一対の排気弁用凹陥部
３，３とが形成してあると共に、ピストン頂部１
ａの中央部には凹部４が形成してある。 However, in the case of a four-valve engine, as shown in FIG. A pair of exhaust valve recesses 3, 3 into which the piston top 1 fits are formed.
A recess 4 is formed in the center of a.
このために、一対の排気弁用凹陥部３，３間の
ピストン頂部１′ａと凹部４との境界部分５の幅
ｔが狭くなり、高温なる排気ガスが一対の排気ポ
ートより排出される際に、前記の巾狭なる境界部
分５に吹きつけられるから、クラツクが発生して
しまう。 For this reason, the width t of the boundary portion 5 between the piston top 1'a and the recess 4 between the pair of exhaust valve recesses 3, 3 becomes narrower, and when the high temperature exhaust gas is discharged from the pair of exhaust ports. Moreover, cracks occur because the air is blown onto the narrow boundary portion 5 mentioned above.
本考案は上記の事情に鑑みなされたものであ
り、その目的は、４弁式エンジンのピストンにお
いて、相隣接する一対の排気弁用凹陥部の境界部
分にクラツクが発生することを防止できるように
したエンジンのピストンを提供することである。 The present invention was developed in view of the above circumstances, and its purpose is to prevent cracks from occurring at the boundary between a pair of adjacent exhaust valve recesses in the piston of a four-valve engine. The objective is to provide a piston for an engine that is
以下第２図以降を参照して本考案の実施例を説
明する。なお、従来と同一部分は符号を同一とし
て説明を省略する。 Embodiments of the present invention will be described below with reference to FIG. 2 and subsequent figures. In addition, the same parts as the conventional one are given the same reference numerals and the explanation will be omitted.
相隣接する一対の排気弁用凹陥部３，３間のピ
ストン頂部１′ａにおける凹部４側部分には、切
欠部６が形成され、一対の排気弁用凹陥部３，３
の底壁３ａ，３ａが切欠部６で平担面となるよう
に連続してあり、切欠部６とピストン頂部１ａと
の段部７が境界部分となつていると共に、段部７
は滑らかに彎曲している。 A notch 6 is formed in the recess 4 side portion of the piston top 1'a between the pair of adjacent exhaust valve recesses 3, 3.
The bottom walls 3a, 3a are continuous so as to form a flat surface at the notch 6, and the step 7 between the notch 6 and the piston top 1a forms a boundary part, and the step 7
is smoothly curved.
本考案は以上の様になり、一対の排気弁用凹陥
部３，３間のピストン頂部１′ａと凹部４との境
界部分７は、切欠部６を設けたことによつて従来
よりも巾広くなつており、しかも切欠部６は排気
弁用凹陥部３と同一深さで、かつ一対の排気弁用
凹陥部３，３間に亘つて形成されているので、そ
の切欠部６によつて一対の排気弁用凹陥部３，３
の底壁３ａ，３ａが平担面で連接される通路が形
成されるから、その部分に排気ガスが吹きつけら
れてもガス流及び熱が一対の排気用凹陥部３，３
に分散して熱スポツトが発生せず、両者が相候つ
て境界部分７にクラツクが発生することが防止で
きる。 The present invention is as described above, and the boundary portion 7 between the piston top 1'a and the recess 4 between the pair of exhaust valve recesses 3, 3 is wider than the conventional one by providing the notch 6. In addition, the notch 6 has the same depth as the exhaust valve recess 3 and is formed between the pair of exhaust valve recesses 3, 3. A pair of exhaust valve recesses 3, 3
Since a passage is formed in which the bottom walls 3a, 3a are connected by a flat surface, even if exhaust gas is blown to that part, the gas flow and heat are transferred to the pair of exhaust recesses 3, 3.
It is possible to prevent the occurrence of cracks in the boundary portion 7 due to the combination of the two.
また、切欠部６は排気弁用凹陥部３と同一深さ
であるから、燃焼室の無駄容積を最小限にとどめ
ることができる。 Moreover, since the notch 6 has the same depth as the exhaust valve recess 3, the waste volume of the combustion chamber can be kept to a minimum.
第１図は従来例の平面図、第２図は本考案の実
施例を示す平面図、第３図は第２図の−線断
面図である。
１はピストン、１ａは頂部、２は吸気弁用凹陥
部、３は排気弁用凹陥部、４は凹部、６は切欠
部、７は段部。
FIG. 1 is a plan view of a conventional example, FIG. 2 is a plan view showing an embodiment of the present invention, and FIG. 3 is a sectional view taken along the line -- in FIG. 1 is a piston, 1a is a top, 2 is an intake valve recess, 3 is an exhaust valve recess, 4 is a recess, 6 is a notch, and 7 is a step.
Claims (1)
円形となつた一対の吸気弁用凹陥部２，２と略円
形となつた一対の排気弁用凹陥部３，３とを形成
し、かつ中央部には略円形の凹部４を形成すると
共に、前記相隣接する一対の排気弁用凹陥部３，
３間のピストン頂部１′ａにおける凹部４側に、
排気弁用凹陥部３と同一深さの切欠部６を、相隣
接する一対の排気弁用凹陥部３，３間に亘つて形
成することで凹部４と離隔した段部７を形成し、
その段部７を境界部分としたことを特徴とするエ
ンジンのピストン。 A pair of substantially circular concave portions 2, 2 for intake valves and a pair of substantially circular concave portions 3, 3 for exhaust valves are formed near the outer periphery of the top portion 1a of the piston 1; A substantially circular recess 4 is formed in the pair of adjacent exhaust valve recesses 3,
On the recess 4 side in the piston top 1'a between 3 and 3,
A notch 6 having the same depth as the exhaust valve recess 3 is formed between a pair of adjacent exhaust valve recesses 3 to form a step 7 separated from the recess 4,
An engine piston characterized in that the stepped portion 7 is a boundary portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12221482U JPS5927141U (en) | 1982-08-13 | 1982-08-13 | engine piston |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12221482U JPS5927141U (en) | 1982-08-13 | 1982-08-13 | engine piston |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5927141U JPS5927141U (en) | 1984-02-20 |
| JPH0115881Y2 true JPH0115881Y2 (en) | 1989-05-11 |
Family
ID=30279435
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12221482U Granted JPS5927141U (en) | 1982-08-13 | 1982-08-13 | engine piston |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5927141U (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07103818B2 (en) * | 1983-11-29 | 1995-11-08 | ヤマハ発動機株式会社 | 4 cycle engine piston |
| DE102005060547A1 (en) * | 2005-12-17 | 2007-06-28 | Mahle International Gmbh | Automotive piston for fuel-injected engine has profiled central combustion cavity with rounded edges |
-
1982
- 1982-08-13 JP JP12221482U patent/JPS5927141U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5927141U (en) | 1984-02-20 |
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