JPH0596404U - Valve mechanism - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] In a roller rocker arm type valve train of an engine, when fixing the roller bearing shaft by crimping, strengthen the fixing of the bearing shaft without impairing the bearing function. [Structure] The roller 20 is provided at the end of the rocker arm on the cam side.
The bearing shaft 21 is passed through the hole 19 of the arm 16 and fixed by caulking, and the roller outer 23 is fitted and mounted on the bearing shaft 21 via the needle 22.
Further, there is no crimping in the range of the actual contact rolling portion of the end of the bearing shaft 21 on the cam side of the cam, which ensures the bearing function when a larger load is applied to the mountain portion of the cam, and the other wide range is deepened by the large crimping load. Caulking to form the caulking groove 24, the bearing shaft 2
Strengthen the fixation of 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a valve mechanism of a roller rocker arm type in a vehicle engine, and more particularly, to a caulking method for fixing a roller bearing shaft to a rocker arm by caulking.

[0002]

[Prior Art]

 Generally, in a roller rocker arm type valve mechanism, a roller is attached to one end of a rocker arm supported by a rocker shaft. A bearing shaft of the roller is fixed to the rocker arm by caulking, and the roller outer is fitted to the bearing shaft through a needle so that the roller can roll. Therefore, in order to strengthen the fixing of the bearing shaft, it is effective to increase the deformation of the shaft end due to the caulking and increase the tightening force with the hole of the arm. As a method of increasing the deformation due to caulking, it is considered that the caulking load is increased or the shape of the caulking jig is optimized. However, if the caulking load is increased and the deformation of the shaft end is increased, the needle rolling surface is also deformed, which may shorten the bearing life or make rolling uncomfortable. For this reason, it is required to devise to enhance the fixing by increasing the deformation due to the crimping of the shaft end without impairing the bearing function.

Conventionally, as for the caulking fixing of the bearing shaft of the roller rocker arm type valve operating mechanism, there is, for example, the prior art of Japanese Utility Model Laid-Open No. 63-133851. It is shown here that, at the end of the shaft that is caulked and fixed to the rocker arm, a wide area on the cam side is locally caulked except for a predetermined narrow area on the opposite side of the cam to which the load from the cam is applied. There is.

[0004]

[Problems to be solved by the device]

 By the way, in the above-mentioned prior art, since the wide area on the cam side is caulked at the end of the shaft, if the caulking load is increased and the needle rolling surface is deformed, the direct bearing function is deteriorated. There is a problem such as doing.

The present invention has been made in view of this point, and in a roller rocker arm type, when fixing the bearing shaft of the roller by caulking, it is possible to strengthen the fixing of the bearing shaft without impairing the bearing function. To aim.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, according to the present invention, a roller is mounted on a cam side end of a rocker arm by passing a bearing shaft through a hole of the arm and caulking and fixing the roller outer through a needle to the bearing shaft. In the roller rocker arm type valve mechanism to be mounted, the caulking groove is formed in a wide range excluding the range of the actual needle contact rolling part on the end surface of the bearing shaft, and the shaft in the area extending from the end surface to the needle rolling surface is modified. It forms deeply.

[0007]

[Action]

 Based on the above configuration, in the roller mounted on the rocker arm, the range of the actual contact rolling portion on the cam side is not crimped, so that the bearing shaft is not deformed and a good bearing function is secured. In the bearing shaft of the roller, a caulking groove is deeply formed by a large caulking load in a range other than this range where a gap is created in the needle portion, and the caulking is performed so as to cause shaft deformation. Will be firmly fixed to.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 3, the outline of the roller rocker arm type valve mechanism will be described. Reference numeral 1 is a valve, and a valve spring 3 is biased to a retainer 2 at the stem end of the valve 1. In the valve mechanism 10, a rocker arm 12 is swingably fitted to a rocker shaft 11, an adjusting screw 13 is attached to one end of the rocker arm 12 by a lock nut 14, and the other end of the adjusting screw 13 is a stem end of the valve 1. Connected to. At the other end of the rocker arm 12, an arm 16 is formed in a bifurcated shape by a groove 15 and a roller 20 is mounted inside the groove 15. A cam 18 of a cam shaft 17 is disposed below the roller 20, and the rocker arm 12 is swung with a small friction while the valve 1 rolls due to the crests of the cam when the valve 1 is lifted. It is designed to make a stroke.

Referring to FIG. 1, a portion of the roller 20 will be described. A hole 19 is provided in the arm 16 of the rocker arm 12, and a hollow bearing shaft 21 is inserted into the hole 19 and its end portion is fixed by caulking. It Inside the groove 15, a large number of needles 22 are directly arranged in contact with the entire circumference of the bearing shaft 21, and a roller outer 23 is fitted on the outer side of the needles 22 so as to be rollable.

Here, a description will be given of how the load is applied to the roller 20 by the peak portion 18a of the cam 18 at the time of valve lift. First, the range of the load F applied to the roller 20 by the peak portion 18a of the cam 18 is a range β of, for example, 30 degrees corresponding to the angle α of the peak portion 18a as shown in FIG. 3, and in this range β, as shown in FIG. Further, the needle 22 is strongly pressed against the bearing shaft 21 by the roller outer 23. For this reason, it is necessary to prevent the shaft from being deformed in the actual rolling portion range β of the needle in order to properly secure the bearing function. In the wide range γ on the opposite side of the cam 18 excluding the range β, the load F does not act directly, so that a gap d is formed between the bearing shaft 21 and the needle 22, and the like. Therefore, in this range γ, it is possible to increase the crimping load so that the shaft is deformed within the range of the gap d.

Therefore, as shown in FIG. 2, on the end surface 21 a of the bearing shaft 21, the caulking groove 24 is provided by the caulking jig in the wide area γ on the side opposite to the cam 18, and the caulking is performed. In this case, the caulking load is increased and the caulking groove 24 is deeply formed. As shown in FIG. 1, the bearing shaft 21 is deformed so that a bulged portion 21c is formed in the region A extending from the end surface 21a to the needle rolling surface 21b. To be done. As a result, the bulging portion 21c of the bearing shaft 21 is engaged with the hole 19 of the arm 18 with a large tightening force and is firmly fixed without affecting the actual rolling of the needle.

Further, in the bearing shaft 21, the range β of the actual needle contact rolling portion has no caulking, so that the outer shape of the range β, that is, the needle rolling surface 21b becomes a perfect circle as shown in FIG. Therefore, when the cam 18 rotates during engine operation and a large load F acts on the roller 20 due to the crest portion 18a, the bearing shaft 21 and the needle 22 and the like are in uniform contact with each other in the axial direction and satisfactorily rolls. Come to do.

Referring to FIG. 4, another embodiment of the present invention will be described. A protrusion 31 is provided at the front end of the caulking jig 30, and a protrusion amount in the actual needle contact rolling portion range β is small, and other ranges γ are provided. Is formed in a tapered shape so as to increase the amount of protrusion, and the caulking jig 30 caulks the bearing shaft 21 of the roller 20. Therefore, in this embodiment, the depth of the caulking groove 24 on the end surface 21a of the bearing shaft 21 is gradually changed to ensure a good bearing function and increase the caulking load as described above.

The embodiments of the present invention have been described above, but the present invention is not limited thereto.

[0015]

[Effect of the device]

 As described above, according to the present invention, in the roller rocker arm type valve mechanism, when the bearing shaft of the roller is crimped and fixed in the hole of the arm, the needle actual rolling portion of the end face of the bearing shaft is contacted. Since the range of is not crimped, a good bearing function can be secured to improve roller rolling, and the bearing life is extended. Since the range where a gap is created in the needle part on the opposite side of the cam from the bearing shaft is crimped, it is also possible to increase the crimping load and deform the needle rolling surface, thereby strengthening the fixing of the bearing shaft. You can Since the caulking range of the end surface of the bearing shaft is specified, the structure is simple.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of an embodiment of a valve mechanism according to the present invention.

FIG. 2 is a side view showing a crimped state of the embodiment.

FIG. 3 is a side view showing a roller rocker arm type valve mechanism in a partial cross section.

FIG. 4 is a cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 10 Valve Mechanism 12 Rocker Arm 16 Arm 18 Cam 19 Hole 20 Roller 21 Bearing Shaft 22 Needle 23 Roller Outer 24 Caulking Groove

Claims (2)

[Scope of utility model registration request] 1. A roller is provided at a cam side end of a rocker arm,
In a roller rocker arm type valve mechanism that is installed by inserting the bearing shaft through the hole of the arm and crimping and fixing it, and then fitting the roller outer to this bearing shaft through the needle, the needle actual rolling part of the end surface of the bearing shaft A valve mechanism in which a caulking groove is deeply formed in a wide range excluding the range so as to deform the shaft in a region extending from the end surface to the needle rolling surface. 2. The valve mechanism according to claim 1, wherein a caulking groove that is shallower than the caulking groove is formed on the end surface of the bearing shaft corresponding to the actual rolling contact area of the needle.