JP2011220317A - Compressed air reciprocating engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reciprocating engine that uses compressed air and can be mechanically controlled by partially modifying an existing four-cycle engine to solve the following problems of conventional reciprocating engines: there is concern about pollution due to exhaust gas generated when fuel is combusted or depletion of oil resources due to fuel consumption;or when inflow/discharge of air is controlled by an electrovalve and computer in a reciprocating engine that uses compressed air, advanced knowledge on electricity and equipment are required.SOLUTION: The reciprocating engine that uses compressed air as an energy source is provided with an inflation chamber for inflating the compressed air, a piston to be stored in the inflation chamber so as to reciprocate freely, and a camshaft which rotates along with a crankshaft installed through a connecting rod. An air inlet valve and an air release valve are located in the inflation chamber. The camshaft is set so that the air inlet valve is opened and the air release valve is closed near a top dead point and the air inlet valve is closed and the air release valve is opened near a bottom dead point at each turn of the crankshaft, to electrically control the air and to obtain power.

Description

The present invention relates to a reciprocating engine, and relates to a compressed air reciprocating engine in which a part of an existing four-cycle engine in practical use is remodeled and compressed air is used as an energy source.

  As a conventional reciprocating engine, for example, there is a gasoline engine that uses gasoline as fuel, converts thermal energy from combustion into pressure energy in a combustion chamber, and converts reciprocating motion of a piston into rotational motion by a crank mechanism to obtain power ( Patent Document 1). Also, there is a steam engine that burns biomass fuel in an adjacent boiler, converts water into steam with the generated heat, supplies the steam into the cylinder, and converts the reciprocating motion of the piston into rotational motion via a transmission mechanism. Yes (see Patent Document 2). Both use thermal energy from fuel combustion.

Examples of engines that use compressed air include:
The present invention relates to a method for injecting compressed secondary air into a combustion chamber and recovering thermal energy around an engine having a storage device for high-pressure compressed air. The high-pressure compressed air in the storage device is in a variable capacity system such as a piston in a cylinder. It is characterized by generating work used by mechanical means or the like (see Patent Document 3).

  In addition, instead of a boiler for generating steam, compressed air is generated by an air compressor that uses a diesel engine as a drive source, and a pressure vessel for storing the compressed air is provided, and a port is opened and closed by a piston valve in a valve chamber outside the engine. Provided is a compressed air locomotive that mechanically controls compressed air instead of steam to enable travel (see Patent Document 4).

  A rotary engine that uses the repulsive force of compressed air as a power source, and obtains rotational output by pressurizing the pressure doubled by the pressure booster to the engine piston portion like alternating pulses (see Patent Document 5).

  A drive device by circulating a filled air in which a pair of air-filled cylinders and a pair of pressure concentration cylinders are provided and a rotational force proportional to the filling pressure is obtained by moving and circulating the filling air pressure (see Patent Document 6), etc. It is.

  A steam engine is provided with a boiler chamber outside the engine to burn fuel and change water to steam. Steam is sent to the valve chamber, and the flow is switched by a piston valve linked to the movement of the connecting rod and supplied to the engine.

  As a principle of operation, the 4-cycle engine completes one cycle in four strokes of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. Gas intake / exhaust is performed by controlling the intake / exhaust valves using the camshaft cam.

  In the present invention, the intake stroke of the 4-cycle engine is replaced with an expansion stroke by inflow of compressed air, the compression stroke is replaced with an exhaust stroke, and an intake valve and an exhaust valve are set so that one cycle is completed only with two strokes of an expansion stroke and an exhaust stroke. Set the camshaft to control. It is therefore considered a two-cycle engine.

  On the other hand, the existing two-cycle engine performs expansion, exhaust, and scavenging during the downward stroke of the piston, and performs compression and intake during the upward stroke. Further, there is no valve found in a four-cycle engine, and the gas is controlled by the piston passing through an exhaust port and a scavenging port provided in the cylinder. Therefore, the compressed air reciprocating engine of the present invention is different from existing two-cycle engines.

Patent Publication 2007-192231 Registered utility model 312335 Special table 2000-514901 Patent Publication 2010-12929 Patent Publication 2003-343201 Patent Publication 2008-57420

  In conventional reciprocating engines with fuel combustion, such as Patent Document 1 and Patent Document 2, there are concerns about pollution problems due to exhaust gas generation and oil resource depletion problems due to fuel consumption.

  Further, in the reciprocating engine using compressed air disclosed in Patent Document 3, inflow / exhaust of air is controlled by an electrovalve and a computer, and advanced electrical knowledge and equipment are required.

  Patent Document 4 uses a steam engine to control the supply of compressed air instead of steam. The engine is large and is not suitable for operation with heavy load fluctuations or high-speed operation.

  Patent Document 5 is a rotary engine using compressed air, and the air is controlled by a rotary valve type mechanism in which a sheath tube is rotatably inserted in a hermetically sealed outer diameter of a wheel shaft having a fluid supply path. There is a problem with the characteristics, and it is not suitable for high-speed driving.

  In Patent Document 6, the piston is provided with an intake / exhaust valve that opens and closes by vertical movement, and the air is controlled. Therefore, the structure is complicated and it is not suitable for a small engine.

  None of the above-described engines using compressed air is a system that controls the intake and exhaust valves using a simple and compact camshaft that is employed in existing four-cycle engines.

  The present invention has been made to solve these problems.

  In order to solve the above problems, compressed air is used as an energy source as a first problem solving means. The reciprocating engine further includes an expansion chamber for expanding compressed air, reciprocally accommodates a piston in the expansion chamber, and is provided with a camshaft that rotates in conjunction with a crankshaft attached via a connecting rod. An intake valve and an exhaust valve are arranged, and the camshaft is set so that the intake valve opens and closes near the top dead center and the exhaust valve opens and closes near the bottom dead center for each rotation of the crankshaft. In this way, air inflow / exhaust is controlled, and rotation is sustained by the inertia of the flywheel attached to the crankshaft to obtain power.

  The camshaft has the same shape with a phase difference of 180 degrees, and a shape in which a pair of intake valve cams and a pair of exhaust valve cams having the same specifications are axially separated from each other and offset by 90 degrees.

  Furthermore, as a second problem solving means, a side hole is provided in the expansion chamber wall near the bottom dead center of the lower expansion chamber.

  The operation of the first problem solving means is as follows. That is, since compressed air is used as an energy source, there is no need to worry about exhaustion of petroleum resources, etc., and no pollution such as exhaust gas occurs, so the global environment is not affected.

  Although a compressor is used as a means for obtaining compressed air, electric power such as wind power, hydraulic power or sunlight can be used directly or indirectly as an energy source, and it is not always necessary to use petroleum resources.

  Furthermore, it is possible to replace it with a compressed air reciprocating engine by changing the design of only the camshaft of a conventional four-cycle gasoline engine, and almost no new development costs are required. In addition, high-level electrical knowledge and equipment are not required, and air can be mechanically controlled by a simple method.

Further, as a function of the second problem solving means, by providing a side hole in the expansion chamber wall near the bottom dead center at the lower portion of the expansion chamber, it is possible to easily increase the rotation speed and improve the performance. Using a 50cc4 cycle engine for a motorcycle made from a Honda motorcycle, nine side holes with a diameter of 4.5mm were provided on the same circumference of the expansion chamber wall at a position 2mm above the bottom dead center. An increase in engine speed approximately twice that of 9584 was obtained.

  Furthermore, the pressure of the expansion chamber by compressed air is 8.38 atm as a maximum experimental value, which is about 1/10 or less of the combustion pressure of the conventional 4-cycle engine, about 90 atm, and there is no thermal influence. Therefore, a compact, lightweight, and compact structure can be achieved in terms of strength.

  Further, high-pressure gas such as nitrogen can be used instead of compressed air.

FIG. 1 is a partial cross-sectional view of a compressed air reciprocating engine. FIG. 2 is a perspective view of the camshaft. FIG. 3 is a perspective view of the camshaft as seen from the axial direction. FIG. 4 is an explanatory diagram showing opening and closing timings of the intake valve and the exhaust valve. FIG. 5 is an explanatory view of a side hole provided in the expansion chamber wall. FIG. 6 is a schematic diagram showing a reverse rotation method of the engine. FIG. 7 is a state diagram during normal rotation of the engine. FIG. 8 is a state diagram at the time of reverse rotation of the engine.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a partial cross-sectional view of a compressed air reciprocating engine, showing a state where a piston is located at a top dead center. A camshaft 1, a rocker arm 9, an intake valve 2, and an exhaust valve 3 that rotate in conjunction with a crankshaft attached to the expansion chamber head 10 via a connecting rod 8 are disposed.

  When the intake valve is open near the top dead center, the compressed air flows in from the intake pipe 4 and expands in the expansion chamber 6 through the intake valve 2. The piston 7 is pushed down by the expansion and heads to the bottom dead center.

Due to the inertia of the flywheel attached to the crankshaft, the piston 7 goes to the top dead center after passing through the bottom dead center. The expanded air is discharged from the exhaust pipe 5 to the outside because the exhaust valve 3 is open.

  FIG. 2 is a perspective view of the camshaft. An intake valve cam 11 and an exhaust valve cam 12 are provided on the camshaft 1. FIG. 3 is a perspective view of the intake valve cam 11 and the exhaust valve cam 12 when the camshaft 1 is viewed from the axial direction.

  The camshaft axially separates a pair of intake valve cams and a pair of exhaust valve cams having the same shape and specifications with a phase difference of 180 degrees and offset by 90 degrees. This is because the rotation of the camshaft is decelerated to half of the rotation of the crankshaft in the four-cycle engine and the intake valve is opened and closed 180 degrees earlier than the exhaust valve at the crank angle. Therefore, the intake valve and the exhaust valve are opened and closed once for each rotation of the crankshaft.

  FIG. 4 shows the opening / closing timing of the intake valve and the exhaust valve. The intake valve 2 is opened before the top dead center 13 (intake valve open 15) and closed after the bottom dead center 14 (intake valve closed 16). The compressed air expands in the expansion chamber during the intake valve opening period 19. When the exhaust valve 3 opens before the bottom dead center 14 (exhaust valve open 17), the expanded air passes through the top dead center 13 and closes (exhaust valve closed 18) within the exhaust valve opening period 20 until the exhaust valve 3 is closed. Discharge to the outside through.

  A valve overlap 21 is provided to sufficiently perform intake and exhaust using the inertia of air, and to release the pressure remaining in the intake pipe to the exhaust pipe side when the engine is started, and to easily position the piston immediately after top dead center.

  FIG. 5 shows the position of the side hole 22 provided in the expansion chamber wall. In the 50cc4 cycle engine for a Honda motorcycle used in the experiment, as shown in the figure, three side holes with a diameter of 4.5 mm and an interval of 7 mm are provided in a row on the same circumference at a position of 2 mm above the bottom dead center. A total of nine were made, with three each in three directions shifted by 90 degrees.

  FIG. 6 is a schematic diagram showing the engine reverse rotation method. It consists of an intake side switching valve 24, an exhaust side switching valve 25, an intake port 26, an exhaust port 27, an air intake 28 and a switching handle 29. The intake port 26 is connected to the intake pipe 4 and the exhaust port 27 is connected to the exhaust pipe 5. Compressed air flows from the air intake 28. The A direction of the switching handle 29 indicates normal rotation, and the B direction indicates reverse rotation.

  FIG. 7 shows a state A during normal rotation of the engine. When the switching handle 29 in FIG. 6 is set to the direction A, the compressed air flowing from the air intake port 28 passes through the intake side switching valve 24, travels from the intake port 26 to the intake pipe 4, and flows into the expansion chamber 6 from the intake valve 2. To do. The air discharged from the exhaust valve 3 after expansion passes through the exhaust side switching valve 25 from the exhaust port 27 connected to the exhaust pipe 5 and is discharged to the outside.

  FIG. 8 shows a state B during reverse rotation of the engine. When the switching handle 29 in FIG. 6 is in the direction B, the compressed air flowing in from the air intake port 28 passes through the exhaust side switching valve 25, travels from the exhaust port 27 toward the exhaust pipe 5, and flows into the expansion chamber 6 from the exhaust valve 3. To do. The air discharged from the intake valve 2 after expansion passes through the intake side switching valve 24 from the intake port 26 connected to the intake pipe 4 and is discharged to the outside. In this way, the switching handle 29 switches the inflow path from the intake pipe side to the exhaust pipe side, so that the crankshaft can be easily reversed.

  In addition, it is easy to connect the exhaust pipe and the intake pipe of each engine, and provide a 180-degree phase difference on the crankshaft so that the top dead center of one engine becomes the bottom dead center of the adjacent engine, and arrange them coaxially. It is also possible to increase the number of cylinders.

  As for the start of the compressed air reciprocating engine, in the case of manual operation, the piston is positioned immediately after the top dead center, and the compressed air is introduced from the intake pipe. In the case of automatic, a starter motor is provided, and the motor is started regardless of the position of the piston. Further, in order to control the rotation speed after starting, the intake pressure is adjusted by a pressure adjusting valve provided upstream of the intake pipe.

  Actually, the camshaft of a 50cc 4-cycle engine for a motorcycle of a Honda motorcycle was set for the present invention and assembled to the engine body, and it was confirmed that the engine alone was operated by compressed air. As a result of the performance test, 1.8 horsepower was obtained at a maximum of 7084 revolutions per minute.

  Furthermore, it was mounted on its own cart (wheelbase 1.04m, total weight 190Kg, tire diameter 38cm), confirmed that it was able to run, and at the same time, performance data was acquired. The results were as follows: one air tank (capacity 12 liters, filling pressure 200 atm), 3886 revolutions per minute, maximum speed of 14.8 Km, and travel distance of 400 m.

  The calculation result of the efficiency of the cart with one air tank (capacity 12 liters, filling pressure 200 atm) filled in 30 minutes by a 3.7 kw compressor is about 3.0%.

  The distance traveled is expected to increase due to the weight reduction of the engine and vehicle body, the increase in the filling amount of the air tank, and the installation of the compressor. For the time being, it may be used for transportation in parks and theme parks and transportation of goods.

  In the future, the range of use is expected to expand due to the improvement of infrastructure such as a compressed air filling station.

1 camshaft 2 intake valve 3 exhaust valve 4 intake pipe 5 exhaust pipe 6 expansion chamber 7 piston 8 connecting rod 9 rocker arm 10 expansion chamber head 11 intake valve cam 12 exhaust valve cam 13 top dead center 14 bottom dead center 15 intake valve Open 16 Inlet valve closed 17 Exhaust valve open 18 Exhaust valve closed 19 Intake valve opening period 20 Exhaust valve opening period 21 Valve overlap 22 Side hole 23 Crank 24 Intake side switching valve 25 Exhaust side switching valve 26 Intake port 27 Exhaust port 28 Air Intake 29 Switching handle

Claims (2)

  A camshaft that uses compressed air as an energy source, has an expansion chamber for expanding the compressed air, reciprocally accommodates a piston in the expansion chamber, and rotates in conjunction with a crankshaft attached via a connecting rod. In the provided reciprocating engine, an intake valve and an exhaust valve are disposed in the expansion chamber, and the intake valve is opened and closed near the top dead center and the exhaust valve is opened and closed near the bottom dead center every rotation of the crankshaft. Compressed air characterized in that the camshaft is set so that the intake valve is closed to control the inflow / exhaust of air and the rotation is maintained by the inertia of the flywheel attached to the crankshaft to obtain power Reciprocating engine.   The compressed air reciprocating engine according to claim 1, wherein a side hole is provided in an expansion chamber wall near a bottom dead center of the lower expansion chamber.

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