JPH0515524Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to the structure of a valve lifter that is installed directly above the intake and exhaust valves of an internal combustion engine that has a direct-acting valve system that directly transmits the amount of cam lift caused by the rotation of a camshaft to the valves. [Prior Art] The structure of the vicinity of a valve lifter provided directly above the intake and exhaust valves of an internal combustion engine having a conventional direct-acting valve system is as shown in FIG. That is, the upper ends of the intake and exhaust valves 1, which are urged upward by the valve springs 2, slide into contact with the valve lifter 3, and the valve lifter 3 has its upper surface slidably contacted by the cam 4 via the shim 5. Driven. The valve lifter 3 slides on the inner peripheral surface of a bore 7 provided in the cylinder head 6 and is driven in the vertical direction, and can also rotate in the circumferential direction. In this type of direct-acting valve lifter,
In high-speed, high-output engines, wear resistance is particularly required on the outer circumferential surface of the lifter. Conventionally, this type of valve lifter has often been made of chromium, molybdenum steel, etc., which have good heat resistance and wear resistance. but,
Valve lifters made of cast iron or steel have good wear resistance on the outer circumferential surface, but their specific gravity is large and heavy, so they are not sufficient in terms of friction torque and response (engine speed). In order to improve the performance of internal combustion engines, it is desirable to reduce the weight of valve train parts as much as possible to reduce inertia mass and reduce friction in the valve train. has been considered for some time. In order to reduce the weight of the valve lifter, although the application has not yet been published, the applicant has previously proposed constructing the valve lifter from resin such as fiber reinforced plastic (hereinafter also referred to as FRP). Application No. 111095 (Sho 60-111095 (see Utility Model Application No. 62-20102)). [Problems to be solved by the invention] However, in the structure of the above proposal, from the point of view of moldability, injection molding or compression molding using short fibers is not possible.
Since FRP valve lifters are mainly used, the wall thickness must be increased in order to secure the strength and rigidity required for a valve lifter, and the problem remained that the contribution to weight reduction was not very high. Further, the orientation direction of the short fibers on the outer circumferential surface of the valve lifter is random, and there remains a problem that the effect of suppressing wear on the outer circumferential surface of the lifter cannot be obtained as much as expected. The present invention particularly improves the wear resistance of the outer circumferential surface of the valve lifter, and provides a valve lifter structure that can ensure sufficient strength and rigidity without significantly increasing the wall thickness. The purpose is to ensure smooth operation and reduce weight through prevention. [Means for Solving the Problems] The valve lifter of the present invention that meets this objective is a valve lifter that is a bottomed cylindrical body that is installed directly above a valve of an internal combustion engine and that is composed of a top surface and a cylindrical portion. The surface portion is made of fiber-reinforced metal, the cylindrical portion is made of continuous long fiber reinforced resin, and at least the outermost layer of the cylindrical portion is made of continuous long fiber reinforced resin with fibers oriented in a direction 90° to the sliding direction of the valve lifter. Become. [Function] In such a valve lifter, the material constituting the valve lifter varies from entirely steel to FRM and
The weight is reduced because it is combined with FRP. Since the top surface of the valve lifter is made of FRM, it is thinner than a top surface made of FRP, ensuring sufficient strength and rigidity for the cam and the valve top surface. Compared to conventional FRP with oriented short fibers, the long fibers are oriented at 90 degrees to the sliding direction of the valve lifter, especially on the outer peripheral surface of the valve lifter cylinder.
With respect to sliding with the valve lifter hole of the cylinder head, the wear resistance is improved as shown in the test results described below. As a result, a certain minute clearance necessary for smooth sliding is secured between the cylinder head and the valve lifter hole, and the valve lifter is prevented from tilting, thereby ensuring smooth operation of the valve lifter. Further, by orienting continuous long fibers extending in the circumferential direction in the outermost layer of the cylindrical portion, radial deformation of the valve lifter is efficiently suppressed from the outer circumferential side, and the strength and rigidity of the cylindrical portion are particularly improved. [Embodiments] Preferred embodiments of the valve lifter of the present invention will be described below with reference to FIGS. 1 to 11. 1 and 2 show a valve lifter according to an embodiment of the present invention. In the figure, 11
1 shows the entire valve lifter, and the valve lifter 11 is provided directly above the valve as shown in FIG. In the embodiment of the present invention, the valve lifter 11 is a bottomed cylindrical body consisting of a top surface portion 12 and a cylindrical portion 13. The base material of the top surface portion 12 of the valve lifter 11 is steel;
It is composed of fiber reinforced metal (FRM) 13 made of aluminum alloy, magnesium, or aluminum alloy. The cylindrical part 14 is formed by a filament winding method as shown in FIG. Resin bathed with thermosetting resin such as ester or polyester, or thermoplastic resin,
As shown in FIG. 3, the valve lifter 11 made of FRM 13 is wound around a cylindrical molding jig 18 having an outer diameter of approximately 24±0.2 mm, and the top surface 12 of the valve lifter 11 made of FRM13 is attached to the tip thereof, and heat treatment or pressure treatment is performed. After that, it is pulled out from the molding jig 18 and molded. As shown in FIG. 2, the inner layer 16 of the cylindrical portion 14 is composed of continuous long fibers 15 impregnated with resin and desirably has a diameter of approximately 45 to 45 cm in the sliding direction of the valve lifter 11.
It consists of windings wound at a 55° angle and oriented perpendicular to each other. The outermost layer 17 of the cylindrical portion 14 is
As shown in the figure, continuous long fibers 15 impregnated with resin
is wound so as to extend in a direction 90° to the sliding direction of the valve lifter 11. The cylindrical portion 14 is also formed on the outer periphery of the top surface portion 12 made of FRM. The operation of the embodiment device configured as described above will be explained. Due to sliding contact with the cam as the cam rotates, the valve lifter 11 moves up and down together with the valve. At this time, the top surface portion 12 receives a thrusting force from the top of the valve and a force from the cam, but the top surface portion 12
Since it is constructed from FRM13, its strength is increased, and the necessary strength and rigidity are ensured without increasing the wall thickness of this part. Since the cylindrical portion 14 of the valve lifter 11 controls the attitude of the valve lifter 11, force is applied to the valve lifter cylindrical portion 14 from the wall of the valve lifter hole in the cylinder head during sliding. In this embodiment, the cylindrical portion 14 is the valve lifter 1.
Continuous long fiber 1 extending in a direction 90° to the sliding direction of 1
5 and an inner layer 16 of continuous fiber-reinforced resin that extends in a direction of approximately 45 degrees with respect to the top surface portion 12 and has orthogonal orientation to each other. The strength and rigidity are improved both in the vertical direction and in the radial direction, and the deformation of the cylindrical portion 14 that extends downwardly from the top surface portion 12 and the deformation in the radial direction are suppressed to a small level. Therefore, the valve lifter 11 is prevented from tilting or twisting, the posture of the valve lifter 11 is maintained at a predetermined posture, and smooth vertical movement (sliding) of the valve lifter 11 is ensured. Therefore, the strength of the cylindrical part,
In order to ensure rigidity, there is no need to increase the wall thickness as in the case of FRP with oriented short fibers, and the necessary strength and rigidity can be maintained even with a thin wall. Continuous long fibers 15 are provided in the outermost layer 17 of the cylindrical portion 14.
is oriented at 90 degrees to the sliding direction of the valve lifter 11, so the wear resistance of the outer periphery is improved.
Smooth sliding between the valve lifter hole and the valve lifter hole is maintained. In order to confirm the effect of improving the wear resistance of the outer peripheral surface of the cylindrical part of the valve lifter due to the 90° orientation of continuous long fibers, the following test was conducted. In the test, the type of long fibers to be oriented in the outermost layer of the cylindrical part was varied, and the angle θ between the orientation direction of the continuous long fibers impregnated with resin such as epoxy or vinyl ester and the sliding direction of the valve lifter was Various changes were made. When θ=0 degrees, the orientation is in the same direction as the sliding direction of the valve lifter, and when θ=90°, the orientation is perpendicular to the sliding direction. A prepreg block test piece with each long fiber oriented was prepared with a thickness of 6.5 mm.
mm, size 15mm x 10mm, and the mating member for the wear test was a ring-shaped test with an outer diameter of 35mm, an inner diameter of 20mm, and a width of 6mm made of aluminum alloy (JIS standard AC2) used for the material of the valve lifter hole. Created as a piece. A wear test was conducted using the block-shaped test piece and the ring-shaped test piece. The test conditions are load
The weight was 100Kg, the sliding speed was 1μ/sec, the wear time was 1 hour, the oil was Castle 10W oil, and the oil temperature was 120℃. Table 1 shows each test condition.

[Table] After each test shown in Table 1 was conducted, the amount of wear on the block-shaped specimen after the test was measured using a surface roughness meter, and the amount was evaluated as the wear volume. The results are shown in Figure 5. As can be seen from Table 1 and FIG. 5, carbon fibers are particularly excellent as long fibers, and those whose direction is 90° to the sliding direction are much better than other fibers. Next, FIGS. 6 to 8 show an embodiment different from the embodiments shown in FIGS. 1 and 2. In FIGS. 6 and 7, 21 indicates the entire valve lifter, and the valve lifter 21 includes:
Similar to the one shown in FIG. 12, it is provided directly above the valve. The valve lifter 21 is a bottomed cylindrical body consisting of a top portion 23 made of fiber reinforced metal (FRM) 22 of steel, aluminum alloy, magnesium, or aluminum alloy, and a cylindrical portion 25 made of continuous long fiber reinforced resin. . Cylindrical portion 25 of valve lifter 21
The outermost layer 26 is aligned with the sliding direction of the valve lifter 21.
It is made up of resin-impregnated continuous fibers 24 extending in a 90° direction, that is, in the circumferential direction of the cylindrical portion 25. In the device of this embodiment, the inner layer 27 of the cylindrical portion 25 of the valve lifter 21 is formed by continuous long fibers 24 impregnated with resin on the top surface 27 of the valve lifter 21, similar to the device of the embodiment shown in FIGS. It consists of windings extending at an angle of approximately 45° to the winding surface and oriented perpendicularly to each other. The difference between this embodiment and the embodiment shown in FIGS. 1 and 2 is that the top surface portion 23 and the cylindrical portion 25 of the two-part valve lifter 21 are bonded together. Even in the type in which the top surface portion 23 and the cylindrical portion 25 of the valve lifter 21 are bonded, the wall thickness of the top surface portion 23 of the valve lifter 21 is not increased, similar to the embodiment shown in FIGS. 1 and 2. The strength and rigidity required for the cylindrical portion 25 are ensured.
Continuous long fibers 24 are oriented in the direction perpendicular to the sliding direction of the valve lifter 21 in the outermost layer 26 of the valve lifter 21, so the wear resistance of the outer periphery is improved and smooth sliding with the valve lifter hole is achieved. is maintained. Moreover, since the valve lifter 21 is made of long fibers 24 impregnated with FRM and resin, it is lighter than a steel valve lifter. In this example as well, in order to confirm the effect of improving the wear resistance of the outer circumferential surface of the valve lifter cylindrical part in this example, the tests were carried out in accordance with the test conditions shown in Table 2 in the example shown in Figures 1 and 2. Tests were conducted in a similar manner. The preparation of prepreg block test pieces, setting values, etc. have been described in the examples shown in FIGS. 1 and 2, and will therefore be omitted. Table of each test condition
Shown in 2.

[Effect of idea]

As explained above, when using the valve lifter of the present invention, the top surface of the split type valve lifter is
From FRM, the cylindrical part is made of continuous long fiber reinforced resin, and the resin-impregnated long fibers are oriented in at least the outermost layer of the cylindrical part, extending in a direction 90 degrees to the sliding direction of the valve lifter. It improves abrasion resistance and ensures smooth operation of the valve lifter.Also, compared to conventional resin valve lifters, it is possible to ensure the necessary strength and rigidity even with a relatively thin wall. This has the advantage of being lighter in weight than steel valve lifters.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway half-sectional view of a valve lifter according to an embodiment of the present invention, FIG. 2 is a partially cutaway sectional view of the device shown in FIG. 1, and FIG. Fig. 1 is a schematic diagram of the molding process of the valve lifter, Fig. 4 is a perspective view of the molding jig shown in Fig. 3,
Fig. 5 is a diagram showing the relationship between the test number and the amount of wear showing the wear test results, and Fig. 6 is a partially cutaway half cross section of a valve lifter according to an embodiment different from the embodiment device shown in Fig. 1. Figure 7 is a partially cutaway cross-sectional view of the device shown in Figure 6, Figure 8 is a diagram showing the relationship between No. and wear amount showing the wear test results, and Figure 9 is a diagram showing the relationship between the wear test results and the amount of wear. FIG. 10 is a partially cutaway half-sectional view of the valve lifter in a different form from the device shown in FIGS. 7 and 9. 11 is a partially cutaway half-sectional view of a valve lifter in a different form from the device shown in FIGS. 7, 9, and 10, and FIG. 12 is a longitudinal sectional view of the area around the conventional valve lifter. , is. 11, 21, 31, 41, 51...Valve lifter, 12, 23, 32, 42...Top portion, 13,
22...FRM, 14, 25, 33, 43, 52
... Cylindrical part, 15, 24, 54 ... Continuous long fiber,
17, 26, 53...outermost layer.

Claims (1)

[Scope of utility model registration request] A valve lifter is provided directly above a valve of an internal combustion engine and is a bottomed cylindrical body consisting of a top part and a cylindrical part, and the top part of the valve lifter is made of fiber reinforced metal and the cylindrical part is made of continuous long fiber reinforced resin, A valve lifter characterized in that at least the outermost layer of the cylindrical portion is made of continuous long fiber reinforced resin whose fibers are oriented at 90 degrees to the sliding direction of the valve lifter.