JP3005893U - Rocker arm adjust screw - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] A two-body adjust screw for a rocker arm, which is composed of a screw body and a tip body. It is easy to manufacture the tip body, and the tip body is assembled to the screw body. To provide an adjusting screw which can be easily carried out and in which the tip body does not fall off. [Structure] A rocker arm in which a holding hole is formed at the lower end of a screw body 7 having a rotating portion at the upper end, and the shaft portion of a chip body 11 having a contact portion formed at one end of the shaft portion is press-fitted into the hole. A two-body type adjusting screw, characterized in that a twill-shaped knurling is engraved on the side surface of the shaft portion of the tip body 11, whereby the tip body 11 can be easily manufactured and assembled to the screw body 7. It can be performed easily, and the chip body 11 does not fall off.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an adjust screw used for a rocker arm of an engine, and more particularly to improvement of a two-body adjust screw.

[0002]

[Prior art]

 The adjusting screw is screwed to the opposite end of the rocker arm (for example, roller type) 3 driven by the cam 2 of the engine to the roller 4 as is well known and shown by 1 in FIG. The adjusting screw 1 is fixed and presses the valve 6 at its lower end. The adjusting screw 1 has a holding hole 7b at the lower end of the screw main body 7 having a rotating portion 7a at the upper end as shown in FIG. There is a two-body type adjusting screw in which the shaft portion 8a of the chip body 8 in which the contact portion 8b is formed at one end of the shaft portion 8a having a smooth surface as shown in FIG. 8 is press-fitted into the hole 7b.

[0003]

[Problems to be solved by the device]

 However, in the conventional adjusting screw 1, during operation of the engine, the shaft portion 8a of the tip body 8 press-fitted into the holding hole 7b of the screw main body 7 is inserted into the valve 6 through the contact portion 8b which comes into contact with the valve 6. There is a risk of the tip body 8 falling off from the holding hole 7b of the screw body 7 because it may be moved or rotated by. In order to solve this problem, it is conceivable to use the screw main body 7 integrated with the tip body 8, but in order to increase the wear resistance of the contact portion 8b in contact with the valve 6. It is necessary to use a material having high strength and high wear resistance as a whole, which causes an increase in cost. Further, although the two-body type is used as described above, it is conceivable that the tip body 8 is fixed to the screw main body 7 by pressure contact or welding, but even if this secures the fixation, the tip body 8 comes into contact with the valve 6. There is a possibility that quality problems such as decrease in surface hardness and peeling may occur. The object of the present invention is to solve all of the above problems, the chip body can be easily manufactured, and such a chip body can be easily assembled to the screw main body, and the chip body may fall off. Not intended to provide an adjust screw.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention forms a holding hole at the lower end of a screw main body having a rotating portion at the upper end, and the above-mentioned shaft portion of a chip body having a contact portion formed at one end of the shaft portion in the hole. This is a two-piece adjuster screw for a rocker arm that is press-fitted. It is a device of the adjuster screw for a rocker arm, characterized in that a twill-shaped knurl is engraved on the side surface of the shaft part of the tip body.

[0005]

[Work]

 According to the adjust screw of the present invention having the above-described structure, when the shaft portion of the tip body of the present invention is press-fitted into the holding hole of the screw body, the tip body is moved or rotated from the valve side in the removal direction during engine operation. Even if a force is applied, the knurled knurls engraved on the shaft of the chip body bite into the inner surface of the holding hole to suppress the movement or rotation.

[0006]

【Example】

 The present invention will be described in detail with reference to FIGS. Since the screw main body 7 has the same structure as that of the conventional example, its description is omitted. The chip body 11 according to the present invention is basically the same as the conventional one shown in FIG. 8, and is made of a hard material including ceramics, and a contact portion 11b is formed at one end of a shaft portion 11a as shown in FIG. However, a twill-shaped knurl 12 is engraved on the peripheral surface of the shaft portion 11a by a known method. As shown in detail in FIGS. 4 to 6, the twill-shaped knurl 12 has a pair of opposed diamond-shaped eyes 12c having an acute angle 12a, 12a 'and an obtuse angle 12b, 12b'. The rhombus 12c has a steep slope 12d that rises at a steep angle from the section line L that sandwiches one of the acute angles 12a and a gentle slope that rises at a gentle angle from the section line L'that sandwiches the other acute angle 12a '. 12e and the flat surface 12f on the steep slope 12d and the gentle slope 12e. In the present embodiment, the diamond-shaped eye 12c forms an angle a of 15 ° to 45 ° between the section lines L and L'and the line S connecting the vertices of the acute angles 12b and 12b ', as shown in FIG. Further, as shown in FIG. 5, an angle b between a ridgeline 12d 'of the steep slope 12d and a vertical line (a line perpendicular to the shaft portion 11a of the chip body 11) is 5 ° to 15 °, and the ridgeline 12e of the gentle slope 12e. And a horizontal line (a line parallel to the shaft portion 11a of the chip body 11) form a range of 20 ° to 40 °. The twill-shaped knurl 12 as described above is engraved with the steep slope 12d side being the contact portion 11b side of the chip body 11.

The tip body 11 having the knurled knurls 12 engraved as described above is attached by pressing the shaft portion 11a into the holding hole 7b of the screw body 7 shown in FIG. Since the ridgeline 12e 'of the gentle slope 12e of the eye-shaped knurl 12 faces the shaft end side of the shaft portion 11a, it can be smoothly press-fitted without biting into the inner surface of the holding hole 7b. As in the conventional case, the combination of the screw body 7 and the tip body 11 as described above is screwed to the end of the rocker arm 3 on the valve 6 side as shown in FIG. 1 and fixed by the lock nut 5.

According to the adjusting screw of the present invention having the above-described structure, the force for moving or rotating the tip body 11 from the valve 6 side in the removing direction (downward in the illustrated embodiment) while the engine is operating. Even when receiving, the corners (ridge lines) of the twill-shaped knurl 12 carved on the shaft portion 11a of the tip body 11, especially the steep slope 12d and the plane 12f, bite into the inner surface of the holding hole 7b and move. Alternatively, the rotation is suppressed.

[0009]

[Effect of device]

 The adjusting screw of the rocker arm of the present invention has a holding hole at the lower end of a screw body having a rotating portion at the upper end, and the shaft portion of a chip body having a contact portion at one end of the shaft portion is press-fit into the hole. The two-piece adjuster screw for rocker arm is characterized in that a twill-shaped knurling is engraved on the side surface of the shaft part of the tip body, so that the tip body can be easily manufactured and easily assembled to the screw body. In addition, it is possible to provide an adjusting screw that does not cause the tip body to fall off.

[Brief description of drawings]

FIG. 1 is a front view showing the adjust screw of the present invention mounted on a rocker arm.

FIG. 2 is a front view of the screw body of the adjust screw of the present invention.

FIG. 3 is a front view of the tip body of the adjust screw of the present invention.

FIG. 4 is a partial plan view of a twilled knurl according to the present invention.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a partial perspective view of a twilled knurl according to the present invention.

FIG. 7 is a front view showing a conventional adjust screw attached to a rocker arm together with another valve drive mechanism.

FIG. 8 is a front view of a tip body of a conventional adjust screw. 3; Rocker arm 5; Lock nut 6; Valve 7; Screw body 7b; Holding hole 8; Conventional tip body 8a; Shaft portion of conventional tip body 8b; Contact portion of conventional tip body 11; Chip body 11a of the present invention A shaft portion 11b of the tip body of the present invention; a contact portion 12 of the tip body of the present invention; a knurled twill 12d; a steep slope 12e; a gentle slope 12f;

Claims (3)

[Scope of utility model registration request] 1. A rocker arm comprising a screw body having a rotating portion at its upper end, a holding hole formed in the lower end thereof, and the shaft portion of a chip body having a contact portion formed at one end of the shaft portion. In a two-body type adjusting screw, a twill-shaped knurling is engraved on a side surface of a shaft portion of the tip body, and an adjusting screw of a rocker arm. 2. The cross-shaped knurl is composed of a set of opposed rhombic eyes having a pair of acute angles and a pair of obtuse angles which are adjacent to each other, and the rhombic eyes have a section sandwiching one of the acute angles. 2. The rocker arm according to claim 1, wherein the rocker arm is formed from a steep slope rising from the line at a steep angle, a gentle slope rising from the dividing line sandwiching the other of the acute angles at a gentle angle, and the steep slope and a plane on the gentle slope. Adjust screw. 3. The adjuster screw for a rocker arm according to claim 1, wherein the twill-shaped knurling is arranged with the steep slope being a contact portion side.