JPS62613A - Scavenged gas pressure utilization type tappet mechanism - Google Patents

Abstract

PURPOSE:To reduce the output loss due to the valve driving by operating the exhaust valve of a 2-cycle engine by a hydraulic pressure in the initial period of opening and carrying out opening operation by utilizing the scavenged-gas pressure afterwards. CONSTITUTION:An exhaust valve 5 installed onto a 2-cycle engine 12 is equipped with a hydraulic cylinder 4 at the upper edge and a pneumatic cylinder 7 in the intermediate part. In the initial period in the opening of said exhaust valve, a solenoid valve 1 is opened to allow the pressurized oil to act onto a piston 5a, and the valve is opened by the high-pressure force against the gas in the cylinder under high pressure. Then, a solenoid valve 9 is opened to introduce the scavenged-gas pressure in a crank chamber into a piston 8 through a hole 10, chamber 15, and a pipe 14, and the opening operation is performed by said pressure. Though the exhaust valve needs a large force in the initial period of opening, only the force for a valve closing spring 6 is necessary afterwards, and a large hydraulic pressure is not needed, and opening operation is performed only by the scavenged-gas pressure only.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scavenging pressure-based valve operating mechanism for driving intake and exhaust valves in a two-stroke engine.

[Conventional technology]

Conventionally, the drive mechanism for the intake valve and exhaust valve in a two-stroke engine is as shown in Figs. 3 and 4. The rotational movement of the cam 19' is taken out through the ? A mechanical valve train as shown in Figure 53 or a hydraulic valve train as shown in Figure 4 8! The signal is transmitted to the exhaust valve 5' by the mechanism to open and close the exhaust valve 5'. In Figure 3.4, only the case where the exhaust valve 5' is driven to open and close is shown, and the case where the intake valve is driven to open and close is not shown.

In other words, as shown in FIG. 3, in the Iso Ten Commandments type valve train, the combustion inside the cylinder 12' exhausts gas as the piston 13' fitted in the cylinder 12' reciprocates. An exhaust pipe 11', which is opened and closed by an exhaust valve 5', is connected to the cylinder 12'. Also,
In the airtight chamber 24' above the exhaust valve 5', the exhaust well 5
A spring holder 18' is attached to the exhaust valve shaft 5'+1, and a spring 6' is interposed between the spring holder 18' and the lower surface of the airtight chamber 24'. ', the exhaust valve 5' is moved in the direction of closing the trachea 11'. − has been done.

A part of the output of the two-cycle ennon, which is taken out as the rotational movement of the cam 19', is transmitted to the exhaust valve shaft 5'b via the conrod rod 17'' and the camshaft 7) 16', and is transmitted to the exhaust valve shaft 5'b. Opening/closing drive is performed.In other words,
When the cam 19' pushes up the connecting rod 17',
The exhaust valve 5' is opened against the urging force of the spring 6.

On the other hand, as shown in FIG. 4, even in the case of a hydraulic valve control groove, as with the above-mentioned one, as the piston 13' fitted in the cylinder 12' reciprocates, the inside of the cylinder 12' moves. In order to exhaust the combustion bus, there is a
An exhaust pipe 11' opened and closed by an exhaust valve 5' is shown *a. Further, an oil-tight chamber 4' connected to a pump 21' is provided above the exhaust valve 5', and a piston 5'a formed at the upper end of the exhaust valve 5' is fitted into the oil-tight chamber 4'. Hydraulic pressure is applied to the lower surface of the piston 5'a by a pump 21' so that the exhaust valve 5' opens and closes the exhaust pipe 11'. Furthermore, the cam 19' is adapted to come into contact with the lower surface of the piston 22' fitted in the cylinder 23', and the cam 19' is in contact with the lower surface of the piston 22' fitted in the cylinder 23', and is inside the cylinder 23' above the piston 22' and in the oil-tight chamber above the piston 5'a. What is within 4'?
Filled with hydraulic oil 3'a, hydraulically connected to each other? 20'.

A part of the output of the two-stroke engine, which is taken out as the rotational movement of the cam 19', is converted into the hydraulic pressure of the hydraulic oil 3'a through the piston 22', and the hydraulic oil 3'a is converted into hydraulic pressure through the hydraulic pipe 20'. By feeding the gas into the chamber 4', the exhaust valve 5' is driven to open and close. That is, when the cam 19' pushes up the piston 22', the exhaust valve 5' opens against the hydraulic pressure from the pump 21'.

In the two-stroke engine shown in Fig. 3.4, scavenging gas is sent into the cylinder 12' from a scavenging chamber (not shown), thereby performing air supply and exhaust simultaneously.

[Problem that the invention seeks to solve]

However, in the conventional valve mechanism as described above, a part of the output of the two-stroke engine is directly transmitted to the intake valve or exhaust valve 5'.
Since it is used as the valve driving force for the engine, the output loss of the two-stroke engine itself becomes extremely large (3 to 3 of the engine output).
5%).

In addition, in a two-stroke engine, the exhaust energy is enormous, reaching about 1/3 of the energy released when the fuel is combusted, but some of it is used as scavenging air by a supercharger etc. Indeed, the two-stroke engine is operated with a considerable amount of scavenging pressure left.

The present invention aims to solve the above-mentioned problems, and improves the efficiency of the two-stroke engine by making it possible to use the scavenging pressure in a two-stroke engine as the driving force for valves such as intake valves and exhaust valves. The purpose of the present invention is to provide a valve train using scavenging pressure.

[Means for solving problems]

For this reason, the scavenging pressure utilization type valve [+ff] of the present invention is designed to drive the supply and exhaust valves mounted on the cylinders of a two-stroke engine, and is equipped with an auxiliary piston attached to the valve shaft of the supply and exhaust valves. An auxiliary cylinder fitted with a piston is provided, and a conduit for introducing scavenging pressure from the scavenging system of the Ennon is connected to the auxiliary cylinder via an on-off valve that opens and closes in synchronization with the operation of the engine. It is said that

[For production]

In the above-described valve operating mechanism using scavenging pressure of the present invention, scavenging pressure is introduced into the auxiliary cylinder from the scavenging system of the two-stroke engine through the conduit and the on-off valve, and drives the auxiliary piston in the cylinder. The supply and exhaust valves are driven in synchronization with the operation of the engine.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
FIG. 1 shows a scavenging pressure-utilizing valve train 8 as a first embodiment of the present invention! It is a vertical cross-sectional view showing the structure, and in a two-stroke engine, it is fitted into the cylinder 12. piston 13
A tracheal pipe 11 that is opened and closed by an exhaust valve 5 is connected to the upper part of the cylinder 12 in order to exhaust the combustion gas in the cylinder 12 as the cylinder 12 reciprocates.

Further, an auxiliary piston 8 is attached to an intermediate portion of the exhaust valve shaft 51 of the exhaust valve 5, and this auxiliary piston 8 is fitted in an airtight chamber 7 as an auxiliary cylinder. In order to guide the scavenging pressure above the auxiliary piston 8, a scavenging chamber 15 as the ennon scavenging system is connected to the upper part of the airtight chamber 7 via a solenoid valve 9 as a 1m closed valve and a scavenging pressure pipe 14 as a conduit. It is connected to the.

The solenoid valve 9 is provided with two solenoid valve passages 9a and 9b, and by opening the solenoid valve passage 9a and closing the solenoid valve passage 9b, the airtight chamber 7 and the scavenging chamber 15 are cleaned. A state of communication is established through the pressure pipe 14 and the electromagnetic valve passage 9a, and scavenging pressure is introduced into the airtight chamber 7. Further, by opening the solenoid valve passage 9b and closing the solenoid valve passage 9a, the airtight chamber 7 and the outside air are brought into communication via the solenoid valve passage 9b, and the scavenging pressure in the airtight chamber 7 is released. It has become so.

The scavenging chamber 15 communicates with the cylinder 12 through the scavenging hole 10, and the scavenging hole 10 is opened and closed from within the cylinder 12 by the piston 131, and as the scavenging hole 10 opens and closes, air is supplied into the scavenging chamber 15 from a supercharger (not shown). The scavenging air is sent into the cylinder 12 from the scavenging air chamber 15.

An oil-tight chamber 4 is provided above the exhaust valve 5, and a piston 5 is formed in the oil-tight chamber 4 at the upper end of the exhaust valve shaft 51J.
A is fitted.

A spring 6 is interposed between the piston 5a and the lower surface of the oil-tight chamber 4, and this spring 6 causes the exhaust valve 5 to
11 is biased in the direction of closing. In addition, the oil-tight chamber 4 above the piston 5a is connected to the pump 2 and the solenoid valve passage 11.
．． By operating the pump 2 with the solenoid valve passage 1a open and the solenoid valve passage 1b closed,
Hydraulic oil 3a is supplied into oil-tight chamber 4 through electromagnetic valve passage 1u, and piston 5a is driven downward to open exhaust gas l-5.

By opening the solenoid valve passage 1b and opening the solenoid valve passage 1a, the hydraulic oil 3. The supply of oil into the oil-tight chamber 4 is stopped, and the oil 3a above the piston 5a is discharged to the oil sump tank 3 via the electromagnetic valve passage 1b in accordance with the movement of the piston 511.

Note that the solenoid valves 1 and 9 are opened and closed in synchronization with the operation of the two-stroke engine.

In addition, in this 2-stroke engine, the scavenging chamber 15
By sending scavenging air from the cylinder 12 through the scavenging hole 10 into the cylinder 12, air is supplied and exhausted at the same time.

Since the scavenging pressure utilization type valve locking structure of Embodiment 10 of R51 of the present invention is configured as described above, when the exhaust valve 5 is driven to open, the electromagnetic The electromagnetic fr-path 1a of the valve 1 is opened, and the pump 2 is driven to supply hydraulic oil 3a from the oil sump tank 3 to above the piston 5a in the oil-tight chamber 4. The piston 5a receives the hydraulic pressure of the hydraulic oil 3a, and the exhaust valve 5 is also pushed down against the biasing force of the spring 6, so that the exhaust pipe 11
will be released.

In this way, first, when the exhaust valve 5 is driven slightly open, the combustion gas pressure in the cylinder 12 acting on the lower surface of the exhaust valve 5 decreases, and in order to open the exhaust valve 5, the hydraulic oil 3a is applied. No need for high oil pressure. at this point
The solenoid valve passage 1a of the solenoid valve 1 is closed and the solenoid valve passage 1b is opened to return the high-pressure hydraulic oil 3a from the oil-tight chamber 4 to the oil sump tank 3. At the same time, the solenoid valve passage 9a of the solenoid valve 9 is opened to perform cleaning. The scavenging air in the scavenging chamber 15 is sent into the airtight chamber 7 through the atmospheric pressure W14. Therefore, instead of the hydraulic oil 3a,
Due to the large scavenging pressure, the auxiliary piston 8 attached to the exhaust valve shaft 5b is driven downward, and the exhaust valve 5 is further pushed down, and the slightly open exhaust valve 5 is completely opened. State is preserved.

In this state, the combustion gas in the cylinder 12 is exhausted through the exhaust pipe 11.

7l: π line 1'x he is ending 73 - Regular valve of thunder nose 9; Close the m paste 9a and open the solenoid valve passage 9b to exhaust the scavenging gas in the airtight chamber 7. The exhaust valve 5 is driven to close by the biasing force of the spring 6 with no pressure acting on the auxiliary piston 8 inside.

The opening and closing of the exhaust valve 5 by the opening and closing of the electromagnetic valves 1 and 9 as described above is performed in conjunction with the 11th stroke of the two-stroke engine.

Note that the solenoid valve passage 9b of the solenoid valve 9 is closed only when the solenoid valve passage 9a is open, and is always open at other times.

In this way, scavenging pressure, which has not been used effectively in the past, can now be used to open and close the exhaust valve 5.
This can significantly improve energy efficiency.

FIG. 2 is a longitudinal sectional view showing a scavenging pressure utilizing type valve operating mechanism as a second embodiment of the present invention, and the second embodiment of the present invention is also similar to the first embodiment.
The structure is almost the same as that of the first embodiment, but in this second embodiment, the scavenging pressure pipe 14 is connected to the lower part of the airtight chamber 7 via the solenoid valve 9, and the scavenging pressure from the scavenging chamber 15 is applied to the auxiliary piston 8.
In addition, a spring 6 is placed in the oil-tight chamber 4 and interposed between the piston 5a and the upper surface of the oil-tight chamber 4, and this spring 6 causes the exhaust valve 5 to The tube 11 is biased in the direction of opening. In addition, hydraulic oil 3
a is the oil sump tank 3 by the same hydraulic system as in the first embodiment.
is supplied downward from the piston 5a.

Therefore, in this second embodiment, with the solenoid valve passage 1a of the solenoid valve 1 in an open state and the solenoid valve passage 1b in a closed state, and the hydraulic pressure of the hydraulic oil 3a in the oil-tight chamber 4 being increased by the pump 2, The closed state of the exhaust valve 5 is maintained.

Since the scavenging pressure utilization type valve operating mechanism as the second embodiment of the present invention is configured as described above, when the exhaust valve 5 is driven to open, the solenoid valve 1 is opened with the start of the exhaust stroke of the two-stroke engine. While closing the solenoid valve passage 1a, the solenoid valve passage 1
b is opened, and the hydraulic oil 3a in the oil-tight chamber 4 is discharged into the oil sump tank 3. As a result, no oil pressure acts on the piston 5a, the piston 5a is driven downward by the biasing force of the spring 6, and the exhaust valve 5 is also pushed down via the exhaust valve shaft 5b, opening the exhaust v11.

On the other hand, when the exhaust stroke is completed and the exhaust valve 5 is driven to close, the solenoid valve passages 1a and 9a in the solenoid valves 1 and 9 are
By opening each and operating pump 2,
Hydraulic oil 3a is supplied below the piston 5a in the oil-tight chamber 4, and scavenging gas is guided from the scavenging chamber 15 to below the piston 8 in the air-tight chamber 7 via the scavenging pressure pipe 14. In this way, the hydraulic pressure acting on the piston 5a and the piston 8
The scavenging pressure acting on the exhaust valve 5 pushes up the exhaust valve 5 against the biasing force of the spring 6, thereby driving the exhaust valve 5 to close.

The opening/closing operation of the exhaust valve 5 by the opening/closing operations of the electromagnetic valves 1 and 9 as described above is performed in conjunction with the exhaust stroke of the two-stroke engine, as in the first embodiment.

Note that the solenoid valve passage 9b of the solenoid valve 9 is closed only when the solenoid valve passage 9a is open, and is always open at other times.

In this way, the piles 2 and 1 and 1 of the present invention can be combined with n kincompensation pressure utilization system 8! In this structure, as in the first embodiment, the scavenging pressure, which has not been effectively utilized in the past, can now be used to open the exhaust valve 5, thereby significantly improving energy efficiency.

It should be noted that the above-described valve operating mechanisms as the first and second embodiments are both applied to open and close the exhaust valve 5, but the scavenging pressure-based valve operating mechanism of the present invention It can also be applied to a two-stroke engine that has an air supply pipe that is opened and closed by a valve and exhausts combustion gas from a scavenging chamber, and the opening and closing of the air intake valve is performed in conjunction with the air intake stroke. Accordingly, the same effect as described above can be obtained. In this case, scavenging air is supplied into the cylinder from the air supply pipe, and scavenging pressure is guided into the auxiliary cylinder through a conduit branched from the air supply pipe.

〔Effect of the invention〕

As described in detail above, according to the scavenging pressure utilization type valve operating mechanism of the present invention, in order to drive the supply and exhaust valve mounted on the cylinder of a two-stroke engine, The engine is equipped with an auxiliary piston and an auxiliary cylinder fitted with the piston, and a conduit for introducing scavenging pressure from the scavenging system of the engine is connected to the auxiliary cylinder via an on-off valve that opens and closes in synchronization with the operation of the ennon. With a simple configuration, the scavenging pressure, which was not used effectively in the past, is used to open and close the intake valve and exhaust valve.
It is now possible to reduce engine output loss, greatly improving the energy efficiency of the entire Ennon.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a scavenging pressure-utilizing valve mechanism as a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing a scavenging pressure-utilizing valve mechanism as a second embodiment of the present invention. Figures 3 and 4 both show conventional valve train mechanisms;
FIG. 3 is a longitudinal sectional view showing a mechanical valve operating mechanism, and FIG. 4 is a longitudinal sectional view showing a hydraulic valve operating mechanism. 1. Solenoid valve, 1b. Solenoid valve passage, 2. Pump, 3. Oil sump tank, 3a. Hydraulic oil, 4. Oil tight chamber.
5... Exhaust valve, 5a... Piston, 5b... Exhaust valve shaft,
6. Spring, 7. Airtight chamber as auxiliary cylinder, 8.
・Auxiliary piston, 9...Solenoid valve as σa on/off valve, 9a
, 9b...Solenoid valve passage, 10...Scavenging hole, 11...Exhaust pipe, 12...Cylinder, 13...Piston, 14...Scavenging pressure pipe as conduit, 15...Scavenging air as engine scavenging system Room. Sub-Agent Patent Attorney Yoshihiko Iinuma Figure 1

Claims (1)

[Claims] In order to drive the supply and exhaust valves installed in the cylinders of a two-stroke engine, the system is equipped with an auxiliary piston attached to the valve shaft of the supply and exhaust valve, and an auxiliary cylinder fitted with the same piston. A scavenging pressure utilization type valve operating mechanism, characterized in that a conduit for guiding scavenging pressure from the system is connected to the auxiliary cylinder via an on-off valve that opens and closes in synchronization with the operation of the engine.