JP3218236B2 - Valve lifter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct-acting valve lifter used for a valve train of an internal combustion engine.

[0002]

2. Description of the Related Art As shown in FIG. 8, a conventional valve lifter 100 has a cylindrical side wall 101 and a disk-shaped end wall 102 closing the upper end thereof.
Are integrally formed by forging or the like to form an inverted cup. In recent years, there has been a tendency to reduce the thickness of the side wall portion 101 in order to reduce the weight of the valve lifter corresponding to the high rotation speed of the internal combustion engine, and the rigidity of the side wall portion 101 is insufficient,
The following problems may occur.

During heat treatment (carburizing and quenching) after forging, the side wall portion 101 having insufficient rigidity is deformed by thermal stress.
In particular, since the dent-deformed portion is not ground during the grinding after the heat treatment, a black scale residue 103 is generated. Side wall 1 with insufficient rigidity due to the force received during grinding
No. 01 is deformed, the roundness and the cylindricity are reduced, and burns are generated. During the heat treatment, not only the outer peripheral surface but also the inner peripheral surface of the side wall portion 101 are carburized and quenched, so that the hardness is increased, but the toughness is reduced and the impact load is weakened. When used in an internal combustion engine, the side wall portion 101 having insufficient rigidity vibrates and generates noise.

Further, since the outer peripheral surface of the side wall portion 101 is a uniform cylindrical surface as a whole, the following problem may occur. When used in an internal combustion engine, especially when used at a low temperature where the viscosity of the oil increases, the oil film formed on the entire outer peripheral surface of the side wall portion 101 causes the pulp lid to malfunction.

As shown in FIG. 9, a lower end portion 111a of a side wall portion 111 is formed on a microfilm of Japanese Utility Model Application No. 61-147622 (Japanese Utility Model Application Laid-Open No. 63-54806).
Lifter 110 which is thicker inward than other parts
As shown in FIG. 10, the lower end portion 121 of the side wall portion 121 is formed.
a is bent so as to form an obtuse angle inward, and a concave portion 122 in which a middle portion in the height direction of the side wall portion 121 is concaved inward.
The valve lifter 120 described above is disclosed. As described above, the lower end portion 11 which is the opening side of the side wall portions 111 and 121 is provided.
When the thickness of 1a, 121a is increased or bent inward, the section modulus increases, and thus the side wall portions 111, 121a are increased.
The rigidity can be maintained even if the wall thickness is reduced.
Therefore, the above problem can be solved. Further, when the concave portion 122 is provided on the side wall portion 121, the oil can escape to the concave portion 122 and cut the oil film, so that the above problem can be solved.

However, these valve lifters 110, 1
Even with 20, the above problem could not be solved. In addition, although the above-mentioned problem is alleviated to some extent, there is still a case where noise that can be heard is generated.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, not only to reduce the deformation during heat treatment and grinding, but also to prevent the rigidity from being reduced even if the thickness of the side wall is reduced. Heat treatment does not act on the lower end of the side wall so much that it increases the toughness and can withstand impact loads.It also reduces the vibration of the side wall that occurs during use in internal combustion engines, and attaches the frequency to the ears. An object of the present invention is to provide a valve lifter that can be changed so as not to be moved.

[0008]

In order to achieve the above object, a valve lifter according to the present invention is a valve lifter having a cylindrical side wall and an end wall closing an upper end of the side wall. The lower end is bent or curved inward, and the bent or curved edge is formed on the inner peripheral surface of the side wall by a material different from the side wall along the inner peripheral surface of the side wall. The side walls are substantially in contact with each other via a separate member formed in a bulging shape, and a middle portion in the height direction of the side wall portion includes a concave shape concaved inward.

Here, the shape of the "bend or curve" is not particularly limited, and may have both the bend and the curve. The "separate material" may have a shape along the inner peripheral surface of the side wall portion. The material of the separate material is not particularly limited, and may be metal or non-metal. However, using a material different from that of the side wall has a higher effect of reducing vibration or changing the frequency. "Almost contact" means a state in which the gap between the bent or curved edge and the inner peripheral surface of the side wall portion is reduced to the extent that the cooling liquid for heat treatment is difficult to immediately enter. There may be a slight gap left to allow the coolant to enter if time is required.

The shape and number of the "concave shape" are not particularly limited, and the following embodiments can be exemplified. Cylindrical concave shape: A concave shape in which the middle part in the height direction of the side wall portion is depressed inward so as to be one or two or more (preferably 2 to 5) diameter-reduced cylinders. The two or more reduced diameter cylinders are arranged in the direction of the lifter center axis. Corrugated concave shape (No. 1): A concave shape in which the middle part in the height direction of the side wall portion is depressed inward so as to form one or two or more (preferably 2 to 10) annular grooves. The two or more annular grooves are arranged in the direction of the center axis of the lifter. The sectional shape of the annular groove is not particularly limited, and examples thereof include a U-shape and a V-shape. Spiral concave shape: A concave shape in which the middle part in the height direction of the side wall portion is depressed inward such that one or more parallel spiral grooves (preferably 2 to 5) are formed. The cross-sectional shape of the spiral groove is not particularly limited, and examples thereof include a U-shape and a V-shape. Frame concave shape: The middle part of the side wall in the height direction is 2 or more (2
(Preferably 10 to 10). The two or more frame-shaped concave portions are arranged in the circumferential direction of the valve lifter. The shape of the picture frame is not particularly limited,
Examples include a quadrangle, an oval, an ellipse, and a circle. Corrugated concave shape (No. 2): A concave shape in which the middle part in the height direction of the side wall portion is depressed inward so as to form two or more (preferably 4 to 20) vertical grooves. The two or more vertical grooves are arranged in the circumferential direction of the lifter. The cross-sectional shape of the vertical groove is not particularly limited.
And V-shape.

Although the area of the “concave shape” is not particularly limited,
1/12 to 3/4 of the area of the entire side wall is preferable, and 1 /
6 to 2/3 are more preferred. The concave depth of the “concave shape” is not particularly limited, but is preferably 0.5 to 5 mm,
4 mm is more preferred. The method for forming the “concave shape” is not particularly limited, and examples thereof include spinning, rolling, and pressing.

In addition, a through-hole may be provided at the concave bottom of the “concave shape”. For example, the through-holes can be provided in any of the above-described concave-shaped aspects. In particular, the through-holes are easily provided in the cylindrical concave shape of the aspect and the frame-shaped concave shape of the aspect. The shape of the through hole is not particularly limited, and examples thereof include a square, a circle, and the like.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings.

A valve lifter 1 according to the first embodiment shown in FIG.
Reference numeral 0 denotes an inverted cup shape in which a cylindrical side wall portion 11 and a disk-shaped end wall portion 12 closing the upper end thereof are integrally formed from a steel material by forging or the like. The lower end 11a of the side wall 11 is bent inward by about 180 degrees, and the bent edge 11b almost directly contacts the inner peripheral surface of the side wall 11. The middle part in the height direction (substantially the center part in this example) of the side wall part 11 includes a cylindrical concave shape 13 which is depressed inward so that the part becomes, for example, one reduced diameter cylinder.

In order to manufacture the valve lifter 10, first, the side wall portion 11 and the end wall portion 12 are integrally cold forged from a rod-shaped or coil-shaped steel material (not shown). The thickness of the side wall 11 is made as thin as possible.

Next, while rotating the side wall portion and the end wall portion 12 around the lifter center axis by a rotation mechanism (not shown),
A roller jig (not shown) is pressed against the outer peripheral surface of the side wall portion 11 to indent a middle portion of the side wall portion 11 inward.
The two reduced-diameter cylinders are spinned to form a cylindrical concave shape 13. Since the cylindrical concave shape 13 increases the section modulus, the rigidity is not impaired even if the thickness of the side wall portion 11 is small, and deformation during the next heat treatment or grinding can be reduced.

Next, without processing the lower edge of the side wall portion 11 or press-cutting or cutting as necessary, the lower end portion 11a of the side wall portion 11 is bent inward by about 180 degrees, The bent edge 11 b is brought into direct contact with the inner peripheral surface of the side wall 11. Since the section modulus is increased by this bending, the rigidity is not impaired even if the thickness of the side wall portion 11 is thin, and deformation during the next heat treatment or grinding can be reduced.

Next, the valve lifter 10 is heat-treated (here, carburized and quenched). At this time, the side wall portion 11 having high rigidity is not easily deformed. In addition, there is almost no gap between the bent edge 11b and the inner peripheral surface of the side wall portion 11, and it is difficult for the cooling liquid for quenching to enter immediately, so that quenching hardly enters the lower end portion 11a. For this reason, the lower end 11a
Has a high toughness and can withstand an impact load.

Next, the valve lifter 10 is finished by grinding. At this time, since the side wall portion 11 is not deformed by the heat treatment as described above, no black scale remains unlike the conventional case. Further, the rigidity of the side wall portion 11 is not easily deformed by the force received during the grinding, so that the roundness and the cylindricity do not decrease.

The valve lifter 10 has a side wall 11 inserted into the guide hole 1 of the cylinder head so as to be slidable up and down.
The end wall portion 12 that has received the sliding contact of the cam 2 is used so as to press the valve 3 downward. At this time, since the bent edge 11b is almost in contact with the inner peripheral surface of the side wall 11, the vibration of the side wall 11 is reduced or the frequency is changed, so that noise is not heard.

Further, even when the oil is used at a low temperature where the viscosity of the oil becomes high, the oil escapes to the cylindrical concave shape 13 and the oil film formed on the outer peripheral surface of the side wall portion 11 can be cut. 10 can be prevented from malfunctioning.

The valve lifter 1 of the second embodiment shown in FIG.
0 is a corrugated concave shape 14 in which a portion in the height direction of the side wall portion 11 is concaved inward so as to form, for example, four annular grooves 14a.
Only in that the first embodiment is included.
The four annular grooves 14a are arranged in the direction of the center axis of the lifter.

A valve lifter 1 according to a third embodiment shown in FIG.
Reference numeral 0 differs from the first embodiment only in that a halfway portion in the height direction of the side wall portion 11 includes a spiral recessed shape 15 that is recessed inward so as to form, for example, one spiral groove.

A valve lifter 1 according to a fourth embodiment shown in FIG.
Reference numeral 0 differs from the first embodiment only in that the side wall portion 11 includes a frame recessed shape 16 that is recessed inward so as to form, for example, four frame-shaped recesses 16a in the height direction. The four frame-shaped concave portions 16a are arranged in the circumferential direction of the lifter. Although not shown in FIG. 4, the lower end of the side wall 11 is bent or the like as in the first embodiment.

A valve lifter 1 according to a fifth embodiment shown in FIG.
0 is different from the first embodiment only in that the middle part in the height direction of the side wall portion 11 includes a wavy concave shape 17 which is depressed inward so as to form, for example, eight vertical grooves 17a. 8
The two vertical grooves 17a are arranged in the circumferential direction of the lifter. Although not shown in FIG. 5, the lower end of the side wall 11 is bent or the like as in the first embodiment.

The valve lifter 1 of the sixth embodiment shown in FIG.
0 represents four through holes 1 in the concave bottom of the cylindrical concave shape 13, for example.
Only the point provided with 8 is different from the first embodiment. The through hole has the concave shape 1 in the second to fourth embodiments.
4, 15, 16, and 17 may be provided at the concave bottoms.

FIG. 7 shows a modified example of the lower end portion 11a of the side wall portion 11. (A) is an example in which the lower end portion 11a of the side wall portion 11 is rounded inward and the curved edge 11b is almost directly in contact with the inner peripheral surface of the side wall portion 11. 3B, the lower end portion 11a of the side wall portion 11 is bent inward by about 180 degrees, and the bent edge 11b is almost in contact with the inner peripheral surface of the side wall portion 11 via the separate material 20. It is an example. (C) is an example in which the lower end portion 11a of the side wall portion 11 is rounded inward and the curved edge 11b is almost in contact with the inner peripheral surface of the side wall portion 11 via the separate material 20. The separate material 20 is formed of a metal material (preferably a metal material different from the side wall portion 11) in a thin ring shape along the inner peripheral surface of the side wall portion 11. The reduction effect increases.

According to the second to sixth embodiments and the modified examples described above, the same operation and effect as those of the first embodiment can be obtained.

The present invention is not limited to the above-described embodiments and modified examples. For example, as described below, the present invention can be appropriately modified and embodied without departing from the spirit of the invention. (1) The lower end of the side wall is bent inward into a triangular or quadrangular shape, and the bent edge substantially contacts the inner peripheral surface of the side wall. (2) When a space is formed between the lower end portion of the side wall portion and the inner peripheral surface of the side wall portion as shown in FIG. 7A, the space is filled with members for reducing vibration. (3) Heat treatment other than carburizing and quenching (for example, carbonitriding and quenching) should be adopted. (4) A shim (not shown) is replaceably fitted to the end wall portion 12.

[0030]

As described in detail above, according to the valve lifter of the present invention, it is possible to reduce the deformation during heat treatment and grinding so that the rigidity is not impaired even if the thickness of the side wall is reduced. In addition to being able to do it, heat treatment does not act much on the lower end of the side wall to increase toughness, it is possible to increase the impact load, and it is also possible to reduce the vibration of the side wall that occurs during use in an internal combustion engine. It has an excellent effect that the frequency can be changed so as not to be heard.

[Brief description of the drawings]

FIG. 1 is a front view of a valve lifter according to a first embodiment, partially cut away.

FIG. 2 is a front view showing a valve lifter according to a second embodiment, partially cut away;

FIG. 3 is a front view showing a valve lifter according to a third embodiment, partially cut away;

FIG. 4 is a perspective view showing a valve lifter according to a fourth embodiment in a partially broken manner.

FIG. 5 is a perspective view showing a valve lifter according to a fifth embodiment with a part cut away.

FIG. 6 is a front view showing a valve lifter according to a sixth embodiment, partially cut away;

FIG. 7 is a partial cross-sectional view showing a modification of the lower end of the side wall in the valve lifters of the first to sixth embodiments.

FIG. 8 is a front view showing a conventional valve lifter with a part cut away.

FIG. 9 is a front view of another conventional valve lifter, partially cut away.

FIG. 10 is a partially cutaway front view of another conventional valve lifter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Valve lifter 11 Side wall part 11a Lower end part 11b Edge 12 End wall part 13 Cylindrical concave shape 14 Corrugated concave shape 14a Annular groove 15 Spiral concave shape 16 Frame concave shape 16a Frame concave part 17 Wave concave shape 17a Vertical groove 18 Through hole 20 Separate material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-173621 (JP, A) JP-A 63-54806 (JP, U) JP-A 62-18304 (JP, U) (58) Investigation Field (Int.Cl. ⁷ , DB name) F01L 1/14

Claims (2)

(57) [Claims] 1. A valve lifter having a cylindrical side wall and an end wall closing an upper end of the side wall, wherein a lower end of the side wall is bent or curved inward, and is bent or bent. The edge is substantially in contact with the inner peripheral surface of the side wall portion via a separate material formed in a ring shape along the inner peripheral surface of the side wall portion using a material different from the side wall portion, and the height direction of the side wall portion A valve lifter characterized in that a middle portion includes a concave shape that is concave inward. 2. The valve lifter according to claim 1, wherein a through hole is provided in the concave bottom of the concave shape.