JPH0342281Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a reed valve device for a two-stroke engine that controls opening and closing of an intake passage.

[Technical background of the invention and its problems]

An example of a reed valve device for controlling intake air in a two-stroke engine is shown in FIGS. 7 and 8. Box-shaped valve housing 1 with two opposing faces converging at an angle
is set in the intake passage 5 so that its convergent tip faces downstream, and a reed valve 3 with a free end on the downstream side is brought into elastic contact with the outer surface of the valve port 2 provided on the inclined surface. 4 indicates a stopper plate. The intake passage 5 opens into a cylinder 7 through an intake port 6, and communicates with a crank chamber 9 through a branched intake hole 8. Due to negative pressure in the crank chamber 9 caused by the vertical movement of the piston, fuel gas in the intake passage 5 pushes open the reed valve 3 and is drawn into the crank chamber 9 through the intake port 6 and the intake hole 8. When the crank chamber 9 becomes a positive pressure, the reed valve 3 closes and acts to confine the sucked fuel gas into the crank chamber 9.

The reed valve 3 is forcibly opened and closed according to the engine speed. For this reason, the reed valve 3 is required to have good responsiveness, good sealing performance, and excellent durability. Although metal plates and synthetic resin plates are used as materials, synthetic resin reed valves are molded from a composite of glass fibers, carbon fibers, and the like. In this case, as shown in FIG. 5, it is common to use plain-woven fibers, but they have the disadvantage of being weak in the twist direction. In order to improve this point, there is an idea to use plain weave fibers for the bias as shown in FIG. 6, but the elasticity in the longitudinal direction is insufficient and there is a risk of causing a fluttering phenomenon, leading to an increase in board thickness. Furthermore, resin reed valves hit the valve seat when closing, and the periphery tends to chip, causing cracks to grow and breakage, resulting in poor durability; however, the above-mentioned fibers do not take into account reinforcement in this respect.

[Purpose of invention]

In view of the above points, this idea aims to obtain mechanical properties suitable for the action of a reed valve by improving the pattern of composite fibers such as glass and carbon contained within the synthetic resin reed valve. purpose.

[Summary of the idea]

In order to achieve the above object, this invention uses a reed valve device that controls the opening and closing of the intake passage of a two-stroke engine, in which the reed valve that is elastically installed at the valve port is made of synthetic resin composited with fibers such as glass and carbon. , is characterized in that the flow of the composite fibers forms a pattern in which single-crested waveforms are arranged in the longitudinal direction.

[Example of idea]

FIG. 1 is a plan view of three reed valves showing an embodiment of this invention.

The reed valve 3 is molded from synthetic resin,
Composite fibers inside (glass, carbon) 10
The waveforms are arranged in a pattern in which a waveform of one mountain flowing in the left-right direction is drawn, and many of these waveforms are overlapped in the longitudinal direction. The patterns are laminated as appropriate depending on the thickness of the reed valve 3.

With the above configuration, the reed valve 3 becomes strong in the torsional direction and also in the longitudinal direction. When this is incorporated into the reed valve device, the lift posture is stabilized and the intake air flow is not disturbed, resulting in improved engine intake efficiency. will improve. Furthermore, since the fiber distribution has a higher density at the peripheral edge, it prevents chipping of the peripheral edge, which is a weak point of this type of resin reed valve, and greatly improves durability.

In the above pattern, a blank 12 is made by half-mounting the material 11 (Fig. 2), which is made by winding fibers into a rod shape and hardening them with resin.
(FIG. 3) and obliquely crush this blank 12 to form the reed valve 3. In the triple series shown in the first figure, three reed valves 3 are connected in parallel. Material 11
may have a hollow shape, or may be formed from a blank obtained by dividing the material 11 into three or more pieces.

[Effect of idea]

As described above, the reed valve device for a two-stroke engine according to this invention uses a reed valve made of synthetic resin that forms a pattern in which composite fibers form a single mountain waveform arranged in the longitudinal direction. The valve has mechanical properties suitable for reed valves, such as elasticity, strength, and lift posture, and can be made thinner, resulting in less intake resistance and response than reed valve devices incorporating conventional resin reed valves. It has excellent performance, reliability, and durability, and is therefore highly effective in increasing the intake efficiency and output performance of two-stroke engines.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a synthetic resin reed valve showing an embodiment of this invention, Figs. 2, 3, and 4 are perspective views showing the molding process of the same reed valve, Figs. The figure is a plan view of a synthetic resin reed valve showing a conventional fiber pattern, Figure 7 is a longitudinal sectional view of a two-cycle engine intake passage illustrating a reed valve device, and Figure 8 is a perspective view of the same reed valve device alone. be. 1... Valve housing, 2... Valve port, 3...
Reed valve, 5...Intake passage, 10...Fiber.

Claims (1)

[Scope of utility model registration request] In a reed valve device that controls the opening and closing of the intake passage of a two-stroke engine, the reed valve that is elastically installed at the valve port is made of a synthetic resin composite of fibers such as glass and carbon, and the flow of the composite fibers is made from a single mountain. A reed valve device for a two-stroke engine, characterized in that the waveforms are arranged in a pattern in the longitudinal direction.