JP2011058474A5

JP2011058474A5 -

Info

Publication number: JP2011058474A5
Application number: JP2009211814A
Authority: JP
Filing date: 2009-09-14
Publication date: 2012-08-09
Anticipated expiration: 2029-09-14

Description

前記の課題を解決するため本発明の実施形態に係る４サイクルエンジンは、燃焼室を有するシリンダヘッドと、前記シリンダヘッドに軸支された排気カムシャフトと、前記排気カムシャフトに一体に形成された排気カムと、前記排気カムシャフトの軸方向に沿って配置され前記排気カムにより開閉される２つの排気バルブと、前記排気バルブの一方を開いて前記燃焼室内を減圧する遠心ウェイト式の第一デコンプレッション装置と、前記排気バルブの他方を開いて前記燃焼室内を減圧するワンウェイクラッチ式の第二デコンプレッション装置と、を備え、前記第一デコンプレッション装置および前記第二デコンプレッション装置は、２つの前記排気バルブを挟んでその両端にそれぞれ配置されたことを特徴とする。 In order to solve the above problems, a four-cycle engine according to an embodiment of the present invention is formed integrally with a cylinder head having a combustion chamber, an exhaust camshaft supported by the cylinder head, and the exhaust camshaft. An exhaust cam, two exhaust valves disposed along the axial direction of the exhaust cam shaft and opened and closed by the exhaust cam, and a centrifugal weight type first depressurizing unit that opens one of the exhaust valves to decompress the combustion chamber. A compression device, and a one-way clutch type second decompression device that opens the other of the exhaust valves to depressurize the combustion chamber, wherein the first decompression device and the second decompression device are It is characterized by being arranged at both ends of the exhaust valve, respectively.

また、前記の課題を解決するため本発明に係る４サイクルエンジンは、燃焼室を有するシリンダヘッドと、前記シリンダヘッドに軸支された排気カムシャフトと、前記排気カムシャフトに一体に形成された排気カムと、前記排気カムシャフトの軸方向に沿って配置され前記排気カムにより開閉される少なくとも１つの排気バルブと、前記排気バルブを開いて前記燃焼室内を減圧させるワンウェイクラッチ式のデコンプレッション装置と、を備え、前記デコンプレッション装置は、前記排気カムシャフトの端部に穿孔された孔に収容され前記排気カムシャフトが逆転されたときトルクを伝達するワンウェイクラッチと、前記ワンウェイクラッチに軸支されたデコンプカムと、前記排気カムシャフトが正転したとき前記デコンプカムの回転を規制する回転規制機構と、を備えたことを特徴とする。 In order to solve the above problems, a four-cycle engine according to the present invention includes a cylinder head having a combustion chamber, an exhaust camshaft supported by the cylinder head, and an exhaust gas integrally formed with the exhaust camshaft. A cam, at least one exhaust valve disposed along the axial direction of the exhaust camshaft and opened and closed by the exhaust cam, a one-way clutch type decompression device that opens the exhaust valve and depressurizes the combustion chamber; The decompression device is housed in a hole drilled in an end of the exhaust camshaft and transmits a torque when the exhaust camshaft is reversed, and a decompression cam pivotally supported by the one-way clutch And the rotation of the decompression cam when the exhaust camshaft rotates forward A rotation regulating mechanism that, characterized by comprising a.

Claims

A cylinder head having a combustion chamber;
An exhaust camshaft supported by the cylinder head;
An exhaust cam integrally formed with the exhaust camshaft;
At least one exhaust valve disposed along the axial direction of the exhaust camshaft and opened and closed by the exhaust cam;
A one-way clutch type decompression device that opens the exhaust valve and depressurizes the combustion chamber;
The decompression device is
A one-way clutch that transmits torque when the exhaust camshaft is reversely accommodated in a hole drilled in an end of the exhaust camshaft;
A decompression cam pivotally supported by the one-way clutch;
A four-cycle engine comprising: a rotation restricting mechanism that restricts rotation of the decompression cam when the exhaust camshaft rotates forward.

Two exhaust valves,
A centrifugal weight type first decompression device that opens one of the exhaust valves to depressurize the combustion chamber,
The decompression device opens the other of the exhaust valves to depressurize the combustion chamber,
The first decompression device and the decompression device are disposed at both ends of the two exhaust valves, respectively.
The first decompression device is
A first decompression cam that opens one of the exhaust valves;
A decompression camshaft formed integrally with the first decompression cam and extending toward one end of the exhaust camshaft;
2. A decompression arm connected to the decompression camshaft and swinging due to a decrease in centrifugal force accompanying a decrease in the rotational speed of the exhaust camshaft to actuate the first decompression cam. 4 cycle engine.

The rotation restricting mechanism is
A pin holder portion having an apertured holes is integrally formed radially on the front Kide Konpukamu,
A stopper pin accommodated in the hole of the pin holder part so as to be able to appear and retract,
A biasing member that biases the stopper pin in a radially outward direction of the pin holder portion;
A stopper provided on the cylinder head,
Claim 1, characterized in that taking relatively rotatable state and the exhaust camshaft as before Kide Konpukamu by said stopper pin on the stopper when the exhaust camshaft rotates forward is abutted or 4-cycle engine according to 2.

The stopper pin has an inclined surface portion formed at the tip,
Rotation restriction before Kide Konpukamu said stopper pin against the urging force of the urging member and the inclined surface portion is brought into contact with the stopper when the exhaust camshaft is reversed is retracted into the hole of the pin holder portion 4-cycle engine according to claim 3 but in which the said exhaust camshaft and before Kide Konpukamu is released, characterized in that a rotatable state integrally.

A snap ring fitted to partially cover the hole of the pin holder portion;
The stopper pin has a retaining surface that faces a protruding direction formed by cutting out a part of a side surface, and when the retaining surface comes into contact with the snap ring, dropping of the stopper pin is restricted. The four-cycle engine according to claim 4 .

The stopper pin has a detent surface along a protruding direction formed by cutting out a part of a side surface, the detent surface is in contact with a side surface of the snap ring, and the stopper pin is detented. The four-cycle engine according to claim 5 .