JPS6135681Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rocker arm shaft fixing device for an engine, and an object of the present invention is to securely hold the rocker arm shaft while eliminating permanent distortion.

Conventionally, as shown in FIG. 3, by inserting a mounting bolt 56 into the upper and lower parts of the rocker arm bracket 52 and tightening a nut 61 that is screwed into the bolt, a deformation relief is formed halfway into the mounting hole 54 of the mounting bolt. The groove 60 is distorted and the rocker arm shaft 55 is held in the shaft support hole 53 in a non-rotatable manner, but since the deformation release groove is short, sufficient deflection is not applied, so the rocker arm shaft 55 cannot be held securely. However, flapping often occurred.

In addition, if the nut is tightened strongly, since this deformation relief groove is small, its flexibility is small and permanent distortion will remain in this part, causing damage to the bracket itself, as shown in Figure 4. Due to the length of the relief groove and the position of the axis of the mounting bolt, there was a risk that the bracket 52 would bend from the shaft support hole toward the bolt 56, causing the mounting bolt to bend (the symbol A indicates this angle of inclination). .

Therefore, prior to the present invention, the present inventor planned the proposal shown in FIG. 2. That is, a deformation relief groove 80 is provided on the mounting bolt 76 side of the shaft support hole 73, and the mounting hole 74
By passing through the bracket 72 to one end of the bracket 72, tighten the nut 81 that is screwed to the mounting bolt, and press the top and bottom of the relief hole 80 while opening the shaft support hole 7.
Locker arm shaft 7 to be inserted into the relevant part by squeezing 3
5, but the bracket 7
The rigidity of No. 2 is significantly reduced.

The present invention solves the above-mentioned drawbacks by providing a deformation relief to facilitate the deformation of the mounting hole of the rocker arm shaft toward the tightening side by the pressing force of the mounting bolt that fixes the rocker arm bracket to the cylinder head. By forming a groove from the rear surface of the shaft support hole across the mounting hole to the middle of the wall at the rear of the mounting hole, the flexibility of the deformation relief groove is increased while ensuring the rigidity of the bracket itself. The rocker arm shaft is securely held in the bracket by the tightening force of the mounting bolt.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional side view of the cylinder head and head cover of an overhead valve engine. A lock arm bracket 2 is placed on a support 12 formed on the cylinder head 8 of the engine 1. Lock arms 14 are pivotally supported on the left and right sides of the bracket 2 so that they can swing freely. The receivers 14b at the rear ends of the brackets 2 are pushed up by push rods 15 linked to the crankshaft.
The pressing portion 14a at the front end presses the intake/exhaust valve 16 to open the intake/exhaust port 17.

Shaft support holes 3 are provided on the left and right sides of the rocker arm bracket 2, and mounting holes 4 are provided on the upper and lower sides of the rocker arm bracket 2 so as to be shifted back and forth.A rocker arm shaft 5 is inserted into the shaft support hole 3, and a mounting bolt is inserted into the mounting hole 4. Insert 6 and
The leg portion 7 is screwed into a screw hole 9 of a cylinder head 8 of the engine 1.

Then, by tightening the nut 11 that is threaded onto the head of the mounting bolt 6, the rocker arm bracket 2 is pressed and fixed to the cylinder head 8, and the mounting hole 4 is inserted from the position corresponding to the rear surface of the shaft support hole 3.
A small deformed relief hole 10 is formed halfway through the wall at the rear of the mounting hole, and the width of this relief hole is narrowed by the tightening force of the nut, resulting in the diameter of the shaft support hole 3 being reduced. , the rocker arm shaft 5 is securely held on the bracket 2.

The effects of the present invention will be described below.The deformation relief hole formed at one end of the shaft support hole is provided across the mounting hole to the middle of the rear wall of the bracket. The deformation relief hole is sufficiently bent in response to the tightening force of the mounting bolt, efficiently narrowing down the diameter of the shaft support hole, and firmly holding the rocker arm shaft inserted through the hole.

Next, since the rear end of the deformation relief hole remains within the wall of the bracket, the rigidity of the bracket is maintained high, and since the deformation relief hole is long,
This eliminates permanent distortion due to the large amount of elastic deformation of the upper wall, and the deflection is evenly distributed throughout the relief hole, so the axis of the mounting bolt deviates from the vertical direction and bends. It will no longer be attached to the bracket while it is still attached.

In addition, since the structure is simple in that the deformation escape hole is formed halfway up the wall at the rear of the mounting bolt, it can be implemented at low cost.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional side view of the cylinder head and head cover of a head valve engine, Fig. 2 is a side view of a rocker arm bracket showing a prior example of the present invention, Fig. 3 is a view equivalent to Fig. 2 showing a conventional example, FIG. 4 is a side view of a bracket showing a modification of a conventional mounting bolt. 1... Engine, 2... Locker arm bracket, 3... Shaft support hole, 4... Mounting hole, 5... Locker arm shaft, 6... Mounting bolt, 7... Mounting bolt leg, 8... Cylinder. Head, 9...Screw hole, 10...Deformation relief groove, 11...Nut head.

Claims (1)

[Scope of utility model registration request] A shaft support hole 3 penetrating left and right through the rocker arm bracket 2 of the engine 1 and a mounting hole 4 penetrating vertically
The rocker arm shaft 5 is inserted into the shaft support hole 3, the mounting bolt 6 is inserted into the mounting hole 4, and the leg part 7 is screwed into the screw hole 9 of the cylinder head 8 of the engine 1. At the same time, the head 1
1, the upper surface of the rocker arm bracket 2 is pressed against the cylinder head 8, and this pressing force causes the shaft support hole 3 to open.
A deformation relief groove 10 is formed from the rear surface of the shaft support hole 3, across the mounting hole 4, to the middle of the rear wall of the mounting hole 4 to facilitate deformation to the tightening side. An engine locking arm shaft fixing device featuring: