JPH0622551U - Engine head structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an engine head structure for preventing a disturbance of intake air in an intake chamber caused by a cylinder head bolt and extending a substantial intake port length. [Structure] A frame-shaped rocker cover 4 for accommodating a rocker arm 3 is attached to a cylinder head 2 having a plurality of intake ports 1 opened on the upper surface, and the rocker cover 4 covers the rocker arm 3 and the intake port 1 and has a lid shape. In a head structure of an engine in which a head cover 5 is attached and an intake chamber 9 is formed therein, a partition wall for partitioning each intake port 1 opened in the cylinder head upper surface 2a inside the rocker cover 4 that constitutes the intake chamber 9 is provided. The feature is that the member 16 is integrally provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an engine head structure in which a frame-shaped rocker cover and a lid-shaped head cover are mounted on a cylinder head so as to overlap each other and an intake chamber is formed therein.

[0002]

[Prior art]

 FIG. 4 shows a head structure of an OHV engine previously developed by the applicant, FIG. 5 is a perspective view of the rocker cover, and FIG. 6 is a sectional view taken along line VI-VI of FIG.

As shown in the figure, a frame-shaped rocker cover 4 for housing a rocker arm 3 is attached to a cylinder head 2 having a plurality of intake ports 1 opened on the upper surface. A lid-shaped head cover 5 is attached to the rocker cover 4 so as to cover the rocker arm 3 and the intake port 1.

A partition wall 6 is provided inside the rocker cover 4 along the crankshaft direction, and the partition wall 6 surrounds the rocker chamber 4 a accommodating the rocker arm 3 and the suction port 1. It is partitioned into an intake chamber 4b. On the other hand, inside the head cover 5, a partition rib 7 is formed so as to be continuous with the partition wall 6.

According to this configuration, the intake air sucked from the intake port 8 of the head cover 5 is guided into the intake chamber 9 defined by the partition rib 7 and the partition wall 6, and the intake chamber 9 is inhaled with each intake port. 1 will be introduced into each cylinder.

[0006]

[Problems to be solved by the device]

 However, the following problems occur in the above-described head structure.

[0007] Intake air flowing from the intake chamber 9 to each cylinder through each intake port 1 is prevented from flowing smoothly by the cylinder head bolt 10 protruding into the intake chamber 9 when flowing into the intake port 1. Therefore, the intake resistance increases and the intake efficiency significantly decreases. The cylinder head bolt 10 is attached from above to attach the cylinder head 2 to the cylinder body 11, and is forced to project to the upper surface 2a of the cylinder head 2 in the intake chamber 9.

[0008] Generally, it is known that the length of the intake port 1 is increased in order to improve the intake efficiency in the middle and low speed range of the engine, but no consideration is given to the above structure. That is, in the above configuration, there is still room for further increasing the intake port 1 to increase intake efficiency in the medium and low speed regions.

The object of the present invention, which was devised in consideration of the above circumstances, is to prevent the disturbance of the intake air due to the cylinder head bolt protruding into the intake chamber and to extend the substantial intake port length of the engine head part. To provide the structure.

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, according to the present invention, a cylinder-shaped rocker cover for accommodating a rocker arm is attached to a cylinder head having a plurality of intake ports opened on its upper surface, and the rocker cover covers the rocker arm and the intake port. In a head structure of an engine in which a lid-shaped head cover is attached and an intake chamber is formed inside, a partition wall member that partitions each intake port opened on the upper surface of the cylinder head is provided inside the rocker cover that constitutes the intake chamber. It is characterized by being provided integrally.

[0011]

[Action]

 Since a partition wall member that partitions each intake port is provided inside the rocker cover that constitutes the intake chamber, the substantial length of the intake port is extended by the amount of the partition wall member, and the intake efficiency in the middle and low speed range is improved.

Further, since the partition wall member covers the cylinder head bolt projecting to the upper surface of the cylinder head, the disturbance of the flow of intake air flowing from the intake chamber to each intake port is prevented.

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, a cylinder head 2 having a plurality of intake ports 1 opened on its upper surface is attached to a cylinder body 11 by a cylinder head bolt 10. A frame-shaped rocker cover 4 for accommodating and supporting the rocker arm 3 and the rocker shaft 12 is mounted on the cylinder head 2 as shown in FIG. A lid-shaped head cover 5 is mounted on the rocker cover 4, covering the rocker arm 3, the rocker shaft 12, and the intake port 1, and an intake chamber 9 is formed therein.

More specifically, a partition wall 6 for partitioning the inside of the rocker cover 4 in the crankshaft direction is provided. As shown in FIG. 2, the inside of the cover 4 includes a rocker chamber 4 a for housing the rocker arm 3. It is partitioned into an intake chamber 4b surrounding the intake port 1. Ribs 13 are provided at intervals in the rocker chamber 4a in the direction orthogonal to the crankshaft, and the rocker shafts 12 are inserted and supported in the support holes 14 formed in the ribs 13. The rocker arm 3 is housed in the room 15 partitioned into. On the other hand, inside the head cover 5, a partition rib 7 is formed so as to be continuous with the partition wall 6. According to this configuration, the intake air sucked from the intake port 8 of the head cover 5 is introduced into each cylinder through the intake port 9 through the intake chamber 9 defined by the partition rib 7 and the partition wall 6. It

The feature of this embodiment is that a partition member 16 for partitioning each intake port 1 opened on the upper surface 2a of the cylinder head 2 is integrally provided inside the rocker cover 4 on the intake chamber 4b side. There is a point. As shown in FIG. 1, these partition members 16 are formed so as to be smoothly continuous with the respective intake ports 1 in order to extend the substantial length of the intake ports 1. The suction port 17 opened on the upper surface 4a of the rocker cover 4 by these partition members 16 has an edge formed in an R shape as shown in FIG. 3 (b), and has an edge shape as shown in FIG. 3 (a). It prevents the contraction phenomenon that occurs when it is shaped, and prevents the effective port cross-sectional area from being reduced (φd <φD). Further, as shown in FIG. 1, these partition members 16 are formed in the shape of a thin inverted container whose lower surface is open, and are attached so as to cover the cylinder head bolts 10 projecting on the upper surface of the cylinder head 2. There is.

The operation of this embodiment having the above configuration will be described.

Since the partition member 16 for partitioning each intake port 1 opened on the upper surface of the cylinder head is integrally provided inside the rocker cover 4, the substantial length of the intake port 1 can be achieved without increasing the number of constituent parts. Becomes longer by the height of the partition member 16. Therefore, the effect of inertial supercharging in the middle and low speed range is enhanced.

Further, the partition member 16 is formed in an upside-down container shape with an open lower surface, which covers the cylinder head bolt 10 protruding to the upper surface 2 a of the cylinder head 2. Therefore, the cylinder head bolt 10 does not project into the intake chamber 9, the disturbance of the flow of intake air caused by the head bolt 10 is prevented, the intake resistance is reduced, and intake is performed smoothly.

Further, since the edge portion of the intake port 17 opened on the upper surface 4a of the rocker cover 4 by the partition member 16 is formed into an R shape, the contraction phenomenon that occurs when the edge shape is formed is prevented, and the intake resistance is reduced. Is further reduced and intake efficiency is improved.

[0021] As a related technique, the Japanese Patent Application No. 3-96506 "Rocker bracket structure", which the applicant of the present invention filed earlier (within one year and six months), is known.

[0022]

As described above, according to the present invention, the partition member is integrally provided in the rocker cover, so that the intake port length can be substantially extended without increasing the number of components, and the inertia can be increased. The supercharging effect can be enhanced and the intake resistance can be reduced by covering the cylinder head bolt protruding into the intake chamber.

[Brief description of drawings]

FIG. 1 is an explanatory view of a structure of a head portion of an engine showing an embodiment of the present invention, and is a cross-sectional view taken along line II in FIG.

FIG. 2 is a perspective view of a rocker cover that constitutes the head structure.

FIG. 3 is a cross-sectional view of an intake port opened on the upper surface of the rocker cover.

FIG. 4 is a cross-sectional view showing a head structure of an engine previously developed by the applicant.

FIG. 5 is a perspective view of a rocker cover previously developed by the applicant.

6 is a sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

 1 Intake Port 2 Cylinder Head 2a Cylinder Head Top Surface 3 Rocker Arm 4 Rocker Cover 5 Head Cover 9 Intake Chamber 16 Partition Member

Claims (1)

[Scope of utility model registration request] 1. A cylinder-shaped rocker cover for accommodating a rocker arm is attached to a cylinder head having a plurality of intake ports opened on its upper surface, and a lid-shaped head cover is attached to the rocker cover to cover the rocker arm and the intake port. In a structure of a head portion of an engine in which an intake chamber is formed, a partition wall member for partitioning each intake port opened on an upper surface of a cylinder head is integrally provided inside a rocker cover forming the intake chamber. The engine head structure.