JPH078802Y2 - Rocker arm holding device for four-cycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a rocker arm holding device for a four-cycle engine.

[Conventional technology and its problems]

In a four-cycle engine, a rocker arm is rocked by the rotation of a cam of a cam shaft that is interlocked with a crankshaft, and an intake valve and an exhaust valve are pushed down against a spring to open and close. And, the rocker arm is one that is pivotally attached to the rocker shaft, and the pivot provided at the base of the rocker arm is held by the pivot metal fitting of the cylinder head, and the dedicated holding spring presses the pivot against the pivot metal fitting so as not to separate. There is something held in. See, for example, JP-A-59-168208. Such a pivot type rocker shaft has a large number of parts, is expensive to manufacture, and is inconvenient to assemble.

[Purpose of device]

In this invention, a rocker shaft of one rocker arm is provided with a pivot seat, the pivot of the other rocker arm is inserted, and the pivot of the other rocker arm is clamped by a coil spring that axially urges the rocker arm of the other rocker arm. An object of the present invention is to obtain a rocker arm holding device for a four-cycle engine that can be held, has a simple structure, can reduce the number of parts, can be made inexpensive, and is easy to assemble.

[Constitution of device]

 Hereinafter, the present invention will be described with reference to the embodiments shown in the drawings.

As shown in FIGS. 1 to 4, the rocker shaft 1 is
The seesaw-type rocker arm 3 is inserted through the lateral hole of the cylinder head 2 and pivotally attached thereto. The seesaw-type rocker arm 3 swings by the rotation of the cam 5 of the camshaft 4 and pushes the exhaust valve 6 against the spring 7 to open and close it. The seesaw-type rocker arm 3 is biased by the coil spring 8 inserted into the rocker shaft 1 so as to be pressed against the bearing 9 side. Swing type rocker arm
No. 10 has a pivot 11 screwed on the base,
Is inserted into the pivot seat 12 provided on the rocker shaft 1. Then, the neck portion of the pivot 11 is sandwiched between the coil springs 8 and stopped so as not to come off the pivot seat, and the swing type rocker arm 10 is held at the regular position. The swing-type rocker arm 10 includes the cam 5 of the camshaft 4.
Rotation of the intake valve causes the intake valve 14 to swing about the pivot 11.
Is pressed against the spring 15 to open and close.

[Function of device]

Since the rocker shaft 1 on which the seesaw-type rocker arm 3 is pivotally mounted is provided with the pivot seat 12, and the pivot 11 of the swing-type rocker arm 10 is inserted and held, it is not necessary to separately attach the pivot seat to the cylinder head 2. ,
The number of parts can be reduced and the cost can be reduced. Further, the neck portion of the pivot 11 of the swing-type rocker arm 10 is clamped between the coil springs 8 inserted into the rocker shaft 1 for urging the seesaw-type rocker arm 3 toward the bearing 9 for positioning, and the pivot 11 Since it is prevented from coming off from the pivot seat 12, it is possible to omit the parts for preventing the pivot 11 from coming off and to reduce the cost. Thus, the number of parts is small, the structure is simple, the cost is low, and the assembling is good.

[Effect of device]

As described above, according to the present invention, the intake valve and the exhaust valve are each opened and closed by rocking the rocker arm, and the rocker shaft inserted into the cylinder head has the rocker shaft of the seesaw type rockable. The swing-type rocker arm pivot into the rocker shaft pivot seat, insert the swing-type rocker arm pivot through the rocker shaft, and insert the seesaw-type rocker arm into the bearing side between the coil springs. Since the coil spring for positioning the seesaw-type rocker arm can also be used for positioning the swing-type rocker arm, it is not necessary to separately provide the pivot seat and the pivot retainer separately.
The number of parts can be reduced, the structure can be simplified, the cost can be reduced, and the assemblability can be improved.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a plan view, FIG. 2 is a vertical sectional side view, FIG. 3 is an enlarged plan view of essential parts, and FIG. 1 ... rocker shaft, 2 ... cylinder head, 3
...... Seesaw type rocker arm, 6 ... Exhaust valve, 8 ...
… Coil spring, 9… Bearing, 10… Swing type rocker arm, 11… Pivot, 12… Pivot seat, 14…
... intake valve.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An intake valve and an exhaust valve each of which opens and closes by rocking a rocker arm, wherein a seesaw-type rocker arm is pivotally mounted on a rocker shaft inserted through a cylinder head, and at the same time, a rocker. Insert the swing-type rocker arm pivot into the pivot seat of the shaft, and insert the swing-type rocker arm pivot between the coil springs that are inserted through the rocker shaft and urge the seesaw-type rocker arm toward the bearing side. A rocker arm holding device for a four-cycle engine, which is characterized in that