JPS60206932A - Intake device for 2-cycle engine - Google Patents

Abstract

PURPOSE:To obtain a sufficient mixer without increasing the volume of crank chamber by opening a window for assembling a valve box through one sidewall at the opposite side from the other sidewall for pivoting the crank shaft of crankcase then inserting the valve box of a check valve system and securing. CONSTITUTION:A cantilever crankshaft 2 is pivoted through a bearing 37 at one sidewall of crankcase 35 while the pin section 3 at the inner end of crankshaft 2 and the piston 4 are coupled through a conrod 5. While a mixer 30 for mixing the air and fuel is coupled through a check valve system 20 to the crank chamber 7. A valve box assembling window 6 for inserting and securing a valve box 10 is made through the other sidewall 38 at the opposite side of said sidewall 36 for pivoting said crank 2. The valve box 10 is constructed with a tubular outer frame section 11 to be fitted in said window 6, an outerboard 14 having an inlet 12 communicated to the mixer 30 and a flange 13 and an innerboard 16 having a valve chamber outlet 15.

Description

[Detailed Description of the Invention] Technical Field> The present invention relates to an intake system for a two-stroke engine, and more specifically, the present invention relates to an intake system for a two-stroke engine. This invention relates to an intake system for a two-stroke engine that allows different engines to be manufactured.

<Prior art> In a two-stroke engine, the air-fuel mixture has traditionally flowed in from the intake port, filled the crank chamber, and then been introduced into the cylinder via the scavenging port, but due to the shape of the crank chamber, , the intake port was opened on the peripheral wall of the crankcase.

For example, FIG. 3 is a schematic diagram showing the arrangement of intake ports in a conventional two-stroke engine.
1 and 21 are supported by the crankshaft 2, and the crank pin between the disc-shaped crank arms 21 and 21 and the piston 4 are connected by a connecting rod 5. And intake port 2
0 is provided with an opening between the disc-shaped crank arms 21 and 21.

Such a two-stroke engine is also required to have high output, and in this case, as shown in FIGS. It is also conceivable that the case 20' be installed horizontally to open and close a plurality of intake boats 22 each having a valve body of 1°7, thereby reducing the intake resistance and supplying a large amount of fuel (mixture).

However, in this case, the volume of the crank chamber 7 is substantially increased by the addition of the intake port case 20', and in the above-mentioned engine that handles compressible fluid, the mixture flowing from the scavenging boat into the combustion chamber is This structure is inconvenient for high-output two-stroke engines because the air flow rate is low.

In addition, with conventional 2-stroke engines, when manufacturing engines for different uses, for example, it is necessary to design them separately for high-speed rotation or low-speed rotation and assemble them using production lines appropriate for each. This was inconvenient in terms of improving production efficiency.

In other words, in high-speed rotation ennons, it is necessary to reduce the volume of the crank chamber in order to increase scavenging efficiency, and conversely, in low-speed rotation ennons, it is necessary to increase the crank chamber volume in order to reduce the blow-through of the combustion chamber. This is because there is.

<Objective of the Invention> The present invention provides a two-stroke engine which solves the problem mentioned in item 1 above, and is capable of supplying sufficient air-fuel mixture without actually increasing the volume of the crank chamber. To provide an intake device suitable for a high-output two-stroke engine;
Furthermore, the present invention makes it possible to reduce manufacturing costs by forming the crankcase so that the volume of the crank chamber can be changed as appropriate, and by making the crank case common to multiple types of engines with different volumes of crank chambers. The purpose is to

<Structure of the Invention> The present invention has been made as a result of intensive research by the inventor of the present invention in order to achieve the object "1. A cantilevered crankshaft 2 is pivotally supported via a bearing 37, and the pin portion 3 at the inner end of the crankshaft 2 and the piston 1 are connected by a rod 5, and the air and fuel mixer 30 is reversely connected. Stop valve device 2
In the intake system of a two-stroke engine, which communicates with the crank chamber 7 through the crank case 35, a former T1 window hole of the valve box 3 is formed in the other side wall 38 of the crankcase 35, which is opposite to the one side wall 36 that pivotally supports the crankshaft 2. 6, the valve box 10 of the check valve device 2 () is inserted into the window hole 6 and fixed.

<Example> Embodiments according to the present invention will be described below based on the drawings.

FIG. 1 is a sectional view of a two-stroke engine incorporating an intake device according to the present invention.

A cantilevered crankshaft 2 is supported by 41 supports via a bearing 37 on one side wall 3G of the base frame 1 constituting the crankcase 35 . An inner end pin portion 3 of a crankshaft 2 and a piston 4 are connected by a rod 5.

111j: A valve box assembly window hole 6 for inserting and fixing a valve box 1 ( ), which will be described later, is opened in the other side wall 38 that is opposite to the one side wall 36 that pivotally supports the crankshaft 2 .

The valve box 10 includes a cylindrical outer frame 11 fitted into the window hole 6, an outer plate 111 having an inlet 12 communicating with the mixer 30, and a collar 13. and valve chamber exit []
15 and an inner plate 16 having a diameter of 15.

In addition to the valve box 10, the check valve device 20 includes the inner plate 16.
A check valve body 17 is provided outside the valve chamber outlet 15 of the crank chamber 7. When the crank chamber 7 becomes negative pressure, the valve body 17 opens the valve chamber outlet 15 and the air-fuel mixture in the valve chamber 18 is turned off when the crank chamber 7 becomes negative pressure. It is configured to flow into the chamber 7.

When assembling the valve box 10 of the check valve device 20 into the valve box assembly window hole 6, a shim 9 having a required thickness is interposed between the collar 13 and the outer frame portion 8 of the window hole, and the crank chamber 7 Select and adjust the volume appropriately.

Or, as shown in Figure 2,
A seat 6' is provided in the hole 6, and the inner plate 1G is held in a predetermined position by a plurality of annular washers 19, and the outer plate 14', the inner plate 16, and the washers 19 constitute a valve body 10.

In this case, the volume of the crank chamber 7 is appropriately selected and adjusted by changing the position at which the inner plate 16 is held.

In FIGS. 1 and 2, 20 is a lubricating oil supply nozzle, and a mist of lubricating oil is supplied from this nozzle 2 ( ) into the valve chamber 18 and included in the air-fuel mixture.

When the crank chamber 7 becomes negative pressure, the valve body 17 opens and the internal &
The mixture flows into the crank chamber 7 through the valve chamber outlet 15 of 16, or the mist-like lubricating oil contained in the mixture directly adheres to the crank rod 5, and as the crank rod 5 is cranked, the mixture flows into the crank chamber 7. It penetrates into the inner end pin part 3 of 2 and the connection part between the piston 4 and the funnel rod 5. The mist-like lubricating oil contained in the air-fuel mixture that has flowed into the crank chamber 7 is
While lubricating the sliding surface of the piston 4 through the scavenging passages 2...1, the positive pressure of the crank chamber 7 is used to lubricate the sliding surface of the piston 4 (because there is a small pipe 25 communicating between the bearing and the scavenging passage 2/l-). It lubricates a force vane device 2G and a ball bearing 23, which will be described later.

In FIG. 1, the crankshaft 2 is supported in a cantilever manner by integral ball bearings 23, and a governor device 26 is assembled between the ball bearings 23 and 23.

The gas burner device 26 is composed of a weight 27, a slide 28, and a co-moving member 26 that is rotated by the slide 28, and ultimately automatically adjusts the amount of air-fuel mixture supplied according to the rotational speed of the engine. Configure it as follows. Note 3
1 is an air cleaner, 32 is a fuel pressure regulator (zero governor), and 33 is a lubricating oil supply pump.

<Effects of the Invention> The present invention is configured as described above, and provides the following effects.

(b) Window holes for assembling the valve box are created in the side walls of the crankcase on the crankshaft support side and the opposite side, and an intake device is installed in these holes, so the volume of the crank chamber is actually increased. It becomes possible to supply sufficient air-fuel mixture even without
It should be possible to adapt it to high output 2-stroke engines.

(b) According to the configuration described in -1-, the assembly of the valve box selects the position and rJrJ! This makes it possible to select and adjust the capacity of the crank chamber (ri) as appropriate, making it possible to share the crankcase. Since it is easy to organize and publish, it contributes to improving production efficiency.

(c) Furthermore, the mist of lubricating oil contained in the air-fuel mixture flowing into the crank chamber can easily reach the connecting rod directly, and the lubricating oil can be applied to the large and small ends of the connecting rod as the crank moves. It is easy to configure the structure so that the lubrication performance can be improved by smoothly penetrating the oil.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a two-cycle ennon to which the intake device of the present invention is applied, Fig. 2 is a side sectional view of the main part similarly showing another embodiment, and Fig. 3 is an intake of a conventional two-cycle ennon. FIG. 1 is a schematic view of the pond, and FIG. 5 is a sectional view of the intake port shown in FIG. 4. 1... Crankcase base frame, 2... Crankshaft, 3
...Inner end bottle part, 4...Piston, 5...Fun rod, 6...Valve box assembly window hole, 7...Crank chamber, 1
0...Valve box, 20...Check valve device, 3()...Mixer.

Claims (1)

[Claims] A cantilevered crankshaft 2 is pivotally supported on one side wall 36 of a crankcase 35 of a 1st and 2nd cycle engine via a bearing 37, and a pin part 3 at the inner end of the crankshaft 2 and a piston 4 are connected by a connecting rod 5. In a two-cycle engine intake system in which the air and fuel mixer 30 is connected to the crank chamber 7 via the check valve device 20, one side wall 36 that pivotally supports the crankshaft 2 of the crankcase 35; A two-stroke engine characterized in that a valve box assembly window hole 6 is formed in the other side wall 38 on the opposite side, and a valve box 10 of a check valve device 20 is inserted and fixed into the valve box assembly window hole 6. intake device