JP2540243Y2 - Engine valve train - Google Patents

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The invention relates to a valve operating mechanism of an SOHC type engine.

(Prior art) A multi-type OHC with three, four or five valves per cylinder and a single cam type OHC with one camshaft are rotatably supported on the cylinder head. A pair of rocker shafts are juxtaposed on both upper sides of the single camshaft. A rocker arm is rotatably supported on these rocker shafts, and cam followers of these rocker arms are arranged in a row on the cam portion of the camshaft. Therefore,
It is smaller than the cam bearing width of the cylinder head with two valves per cylinder.

In addition, when the cylinder head is a cam thin head type, that is, a cylinder head without a cam cap, the inner diameter of the cam bearing is formed large so that the large diameter portion of the cam can pass, and the cam shaft is inserted from the side of the cylinder head It is configured to be able to. Therefore, the thickness of the cylinder head above the cam bearing, that is, the thickness between the uppermost portion of the cam bearing and the upper surface of the cylinder head cannot be sufficiently ensured.

The rocker shaft is installed on the upper surface of the cylinder head, and the rocker shaft is fastened and fixed to the cylinder head by a mounting bolt penetrating in the radial direction.

(Problems to be Solved by the Invention) As described above, the valve operating mechanism of the conventional engine is such that the thickness of the cylinder head above the cam bearing, that is, the thickness between the top of the cam bearing and the upper surface of the cylinder head. When the load due to the cam lift is applied to the rocker shaft and a force is applied to open the upper part of the cam bearing to the left and right, the cylinder head may be cracked.

This invention has been made in view of the above circumstances, and an object of the invention is to provide an engine valve train that can increase the strength of a cam bearing portion and a rocker shaft with a simple structure. .

[Means and Actions for Solving the Problems] In order to achieve the above object, the present invention provides a camshaft rotatably supported by a cylinder head, and the cylinder head sandwiching the camshaft. A pair of rocker shafts arranged side by side on the upper surface, and a rocker arm rotatably supported by these rocker shafts, having a cam follower at one end contacting the cam of the camshaft, and having the other end contacting the valve stem. In the valve operating mechanism for an engine, a plate-shaped reinforcing plate is erected so as to be supported by the pair of rocker shafts without contacting the cylinder head, and the reinforcing plate is mounted together with the rocker shaft together with the cylinder head by mounting bolts. It has been tightened together.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a cylinder head of a SOHC engine, and the cylinder head 1 is provided with a cam bearing 2. One camshaft 3 is rotatably supported by the cam bearing 2, and cams 4... Are provided on the shaft of the camshaft 3 in correspondence with the respective cylinders. A pair of rocker shafts 5 are provided on the left and right sides of the upper end surface 1a of the cylinder head 1 with the camshaft 3 interposed therebetween.
A plurality of rocker arms 6 are rotatably supported on the rocker shafts 5.
In this embodiment, the rocker arms 6
As shown in the figure, four cylinders are provided for each cylinder. An intermediate portion of the rocker arm 6 is rotatably supported by the rocker shaft 5, and a cam follower 7 composed of a roller is provided at one end of the rocker arm 6 in a state of contact with the cam 4. Further, the other end of the rocker arm 6 is in contact with the valve stems 10 of the intake valves 8, 8 and the exhaust valves 9, 9. Therefore, four valves are arranged for each cylinder, and are independently opened and closed by the cams 4. Reference numeral 11 denotes a spark plug.

The rocker shaft 5 has a hollow cylindrical shape as shown in FIGS. 3 and 4, and is a portion located between both ends and each cylinder, that is, a set of four intake / exhaust valves 8, 9. A flat surface is provided by a notch in the upper and lower portions of the portion located therebetween. That is, 12 ... is the lower flat surface, 13
Are flat upper surfaces, which are provided corresponding to each other. Further, through holes 14 are formed in the upper and lower flat surfaces 12 and 13 so as to penetrate the rocker shaft 5 in the radial direction.
The lower flat surface 12 of the rocker shaft 5 is adapted to fit into the upper end surface 1a of the cylinder block 1 having the bolt holes 1b as shown in FIG. 15 fits.

As shown in FIG. 5, the reinforcing plate 15 is formed of a metal plate, and at both ends in the longitudinal direction, substantially disk-shaped washers 16, 16 are formed. Curved portions 17, 17 are provided. Further, through holes 18 corresponding to the through holes 14 of the rocker shaft 5 are formed in the washer portions 16, 16.

When the pair of rocker shafts 5, 5 are mounted on the upper end surface 1a of the cylinder head 1, the lower flat surfaces of the rocker shafts 5, 5 that support the plurality of rocker arms 6 are provided. Are fitted to the upper end surface 1a of the cylinder head 1 to position the through hole 14 of the rocker shaft 5 in the bolt hole 1b. Next, the reinforcing plates 15 are provided between the pair of rocker shafts 5, 5, and the washer portions 16, 16 at both ends are fitted to the upper flat surfaces 13, 13 of the rocker shafts 5, 5, and the bent portions are formed. 17, 17 with rocker shaft 5,
5 so as to wrap them. At this time, since the bent portions 17 wrap the rocker shafts 5, the positioning between the through hole 14 and the through hole 18 becomes easy. Moreover, both corners 13a of the upper flat surface 13 are processed into R0.3, and both corners 15a of the reinforcing plate 15 are
R0.5, and the upper flat surface 13 has a reinforcing plate 15
The washer 16 is fitted to the upper flat surface 13 in close contact with the upper flat surface 13. In this state, when the mounting bolt 19 is inserted through the through hole 18 of the reinforcing plate 15 and tightened into the bolt hole 1b of the cylinder head 1 through the through hole 14, the reinforcing plate 15 is fastened together with the rocker shaft 5, Rocker shafts 5, 5 are connected by the reinforcing plate 15.

In the embodiment, the bent portions 17 and 17 are provided at both ends of the reinforcing plate 15, and the bent portions 17 and 17 are assembled at the time of assembly.
Although the reinforcing plate 15 is positioned at a predetermined position by engaging the rocker shafts 5 and 17 with the rocker shafts 5 and 5, the bent portions 17 and 17 do not necessarily need to be provided. Good.

[Effect of the invention]

As described above, according to the present invention, in a valve mechanism of an engine, a plate-shaped reinforcing plate is provided between a pair of rocker shafts so as not to be in contact with a cylinder head and to be supported only by a rocker shaft, The reinforcing plate and the rocker shaft are jointly fastened to the cylinder head by mounting bolts. Therefore, by this configuration, not only can the strength of the rocker shaft be improved, but also by using a plate-like plate supported only by the rocker shaft for reinforcement, the plate has the function of a washer, eliminating the need for a washer. There is an operational effect that the weight can be reduced.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention, wherein FIG. 1 is a partially cutaway side view of a valve operating mechanism, FIG. 2 is an exploded perspective view of the valve operating mechanism, FIG. 3 is a plan view of a rocker shaft, FIG. 4 is a side view in which the same portion is cut away, FIG. 5 is a plan view and a side view of the reinforcing plate, and FIG. 6 is a partially cut out side view showing a relationship between the cylinder head, the rocker shaft and the reinforcing plate. DESCRIPTION OF SYMBOLS 1 ... Cylinder head, 3 ... Cam shaft, 5 ... Rocker shaft, 6 ... Rocker arm, 7 ... Cam follower, 10 ... Valve stem, 12, 13 ... Flat surface, 15 ... Reinforcement plate, 19 ... ... Mounting bolts.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuji Tatsumi 1 Mitsui-cho, Uzumasa-ku, Ukyo-ku, Kyoto-shi, Japan Mitsui Automotive Engineering Co., Ltd. Kyoto Office (56) Reference Reference Microfilm (JP, U) photographing the contents of the specification and drawings attached to the application form of Japanese Utility Model Application No. 54-170562 (Japanese Utility Model Application No. 56-86303) Japanese Utility Model Application No. 53-175284 (Japanese Utility Model Application No. 55-86303) 92005) Microfilm (JP, U) photographing the contents of the specification and drawings attached to the application of Japanese Patent Application No. 60-137887 (Japanese Utility Model Application No. 62-45309). Microfilm of contents (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A camshaft rotatably supported by a cylinder head, a pair of rocker shafts juxtaposed on an upper surface of the cylinder head with the camshaft interposed therebetween, and a rotatable shaft mounted on the rocker shafts. An engine valve operating mechanism comprising a cam follower which is rotatably supported and has a cam follower at one end in contact with the cam of the camshaft and a rocker arm at the other end in contact with the valve stem, wherein a plate-shaped reinforcing plate is brought into contact with the cylinder head; An engine valve operating mechanism, wherein the reinforcing plate is mounted together with the rocker shaft together with the rocker shaft and fastened together with the cylinder head by mounting bolts without being supported by the pair of rocker shafts.