A RECIPROCATING INTERNAL COMBUSTION ENGINE WITH A CAM GROOVE- CONNECTING ROD TYPE TRANSMISSION MECHANISM
Technical Field of the invention
This invention relates to a reciprocating internal combustion engine.
Background of the invention
A various types of the internal combustion engines are invented and actually used today. For example, a reciprocating internal combustion engine with a crankcase-connecting rod type transmission mechanism (referred to as a crankcase-connecting rod engine) for imparting a power is widely used in a plurality of vehicles such as automobile, motorcycle, diesel locomotive, ship, aircraft, etc. Furthermore, it is known several engines, for example a Baladin engine which is a reciprocating type with a crankcase but is not provided with a connecting rod having a compact size and a high technical properties but the structure of the crankcase of Baladin engine is too complex; a rotary piston engine (referred to as Wankel rotary engine) which is provided with a compact mechanism but there are too many differences in the lubricating and cooling of the engine as well as the sealing of the combustion chamber thereof, in addition the parts of the engine are hardly manufactured. The types of the rotary engine use a rotary unit having a plurality of cylinders and pistons disposed in a radial fashion in which the outer ends are relatively displaced in relation to the guiding grooves. Further, the types of the rotary engine with the cylinder-piston units disposed in parallel along the drive shafts are bulky in structure, the formation of the parts are significantly complicated, the assembly thereof is substantially difficult.
The crankshaft-connecting rod engine is type having the transmission mechanism which the most equivalent to the engine of the present invention. However, the crank-connecting rod like transmission mechanism of the engine is bulky and complicated in structure, the manufacture of the parts is difficult; one working cycle of the engine corresponds to times of rotation of the crank so that
the engine is not stably and evenly operated, the flywheel is a large in size resulting in the weight of the engine, the acceleration of the engine is low, the vibration of the engine is high; in particular, since the stroke of the engine is constant, the speed and acceleration of the piston are occurred in an unchanged manner, a various requirements of each of the separated strokes (intake, compression, combustion and exhaust) of the operating cycle are not satisfied so that several disadvantages are not overcame such as the intake stroke is not completely performed due to an amount of the residual gases are present in the cylinder, the compression stroke is not presented in optimal manner, the combustion stroke is not completely performed, the pressure of the combustion gases at the end of the expansion is not utilized in a optimal manner, the exhaust stroke is not completely performed.
Summary of the invention
The present invention is made to overcome or diminish the problems of the prior types of the engine and a first object of the invention is to provide a new transmission mechanism which have the higher performances including: the technology, the power, economic as well as the lower fuel consuming.
A second object of the invention is to provide a new transmission mechanism which is simply, compact structure and it is easily manufactured.
A third object of the invention is to provide an engine in which each stroke of the working cycle can be changed so as to adapt to the various requirements itself.
A fourth object of the invention is to provide an engine which is capable of controlling the movement state of the piston in relation to the cylinder of the engine at any required time so as to reduce the losses of the power and increase the thermal performances.
A fifth object of the invention is to provide an engine which is used to replace the most present engines in a simple, economic, more effect manner. In addition, the objects and advantages of the invention can be clearly found below.
With the above objects and others, the present invention relates to a reciprocating internal combustion engine with a cam groove- connecting rod type transmission mechanism. This mechanism changes back and forth movement of the piston into the rotation of a drive shaft in the expansion stroke for generating the power and changes the rotation of the drive shaft into the back and forth movement of the piston in intake, compression and exhaust strokes; the mechanism of the invention is characterized in that: the drive shaft penetrates through the engine and is perpendicular to the axis of the cylinder, is not provided with webs as the conventional crank-connecting rod type engine; it is also characterized in that: in the drive shaft, a pair of cam groove plates which is corresponding to each of the cylinders is secured to the shaft, is located in a plane perpendicular to the shaft and is disposed symmetrical to both sides of the connecting rod and embraced close to the rod so as to prevent the axial movement of the connecting rod; furthermore, a pair of cam grooves with the profile symmetrically matched together via the connecting rod is formed in the surfaces of each of cam groove plates facing to each other, the connecting rod is coaxially mounted to the axis of the cylinder, a small end of the rod is provided with a hole through which a piston pin is inserted, the rod is connected to the piston by the piston pin and the piston serves as the guiding portion of back and forth movement of the small end of the rod; in addition a big end is formed a elongated slot called as the connecting rod groove which is attached perpendicular to the drive shaft, secured close to both sides of the shaft via an intermediate boss or a ball bearing so that it functions as the guide to cause back and forth movement of the connecting rod in the axial direction thereof; it is also characterized in that the big end of the rod is provided with a hole through which a connecting rod pin is inserted, the connecting rod pin and the connecting rod are linked in rotation and slide joint form or are linked together via an intermediate boss or a ball bearing so as to maintain the state that the connecting rod pin can be rotated about the axis thereof without any gaps in the hole for the connecting rod pin; furthermore, both ends of the connecting rod pin are mounted in the cam groove of pair of relative cam plates
so as to assure that the connecting rod pin is relatively moved along the cam groove; in addition, the profile of the cam groove is shaped in a curved line located in the plane thereof, this curved line is a set of a plurality of points from which the distances to a center of the drive shaft are the same or different from each other.
With the above described characterized features of the mechanism as compared to that of the other types of the engine, the working cycle of the reciprocating internal combustion engine with a cam groove- connecting rod type transmission mechanism is occurred as follows: a) intake (induction) stroke: the piston moves from point 1 to point 2, the intake valve 10 opens, the exhaust valve 11 closes, the drive shaft rotates from angle a=0° to angle b. In the intake stroke, the power is consumed for descending of the piston, the volume within the cylinder is increased from Vl to V2, the pressure within the cylinder is decreased, the air-fuel mixture is drawn from the carburetor via the intake valve into the cylinder. It is characterized in that the volume Vl can be or substantially zero since the prior exhaust stroke is nearly completely performed for the purposes of essentially removing the residual gases of the combustion and expansion strokes. b) compression stroke: the piston moves from point 2 to point 3, both intake and exhaust valves are closed, the drive shaft rotates from angle b to angle c, the volume within the cylinder is decreased from V2 to V3, the pressure within the cylinder is increased. At the end of the compression stroke, the spark plug is ignited to burn the air-fuel mixture. c) combustion and expansion stroke: the piston moves from point 3 to point 4, both intake and exhaust valves are closed, the drive shaft rotates from angle c to angle d, the volume within the cylinder is increased from V3 to V4. In this stroke, the pressure created in the combustion and expansion process of the air-fuel mixture forces the piston downward and generates the power. Here, the characterizing features are: the volume V4 is significantly greater
than the volume V2, this results in that the pressure at the end of combustion and expansion process is utilized in a maximum manner, d) exhaust stroke: the piston moves from point 4 to point 1, the exhaust valve is opened, the intake valve is closed, the drive shaft is rotated from angle d to angle e=360°, the volume within the cylinder is decreased from V4 to Vl. In the exhaust stroke, the piston ascends and forces the exhaust gases out, this significantly consumes the power. Furthermore, since the volume Vl can be or substantially zero, the entire burned mixture can be completely pushed out through exhaust port.
The above working cycle of the reciprocating internal combustion engine with a cam groove- connecting rod type transmission mechanism is described. In is noted that, with other profile as shown in Fig.4, the cam groove- connecting rod type engine has two working cycles corresponding to one rotation of the drive shaft. Similarly, with various relative profiles, the cam groove- connecting rod type engine can be provided with several working cycles corresponding to one rotation of the drive shaft.
In addition, other systems of the cam groove- connecting rod type engine such as the fuel supplying, gas distributing, exhaust, combustion, lubricating, cooling systems etc., are the same as those of the conventional engines (gasoline, diesel engines). The cam groove- connecting rod type engine may be included 1, 2, 3, 4, 6, 8 ,12, 16 etc., cylinders, can be arranged in one row of cylinders (I- shaped), two rows of cylinders (V-shaped), three rows of cylinders (W-shaped), four rows of cylinders (H-shaped or X-shaped) or five rows of cylinders (star- shaped).
Brief description of the drawings
Fig.1/5 is schematically cross section view of the main members of one type of the engine according to the invention;
Fig.2/5 is similar to Fig.1/5 in which the structural diagram and the power graph of one type of the engine according to the invention are illustrated;
Fig.3/5 is a principle operating diagram of one type of the engine according to the invention; and
Figs.4/5 and 5/5 are schematically cross section views of the main members of the other type of the engine according to the invention.
Description of the preferred embodiments
A common structure of the engine is clearly shown in Figs.1/5 and 2/5, in which a cylinder 1, a piston 2, a timing valve system of an intake vale and an exhaust valve, a spark plug 12 are the same as parts of a conventional engine. Here, a special characterizing feature is a transmission mechanism of the engine.
As shown in Fig.1/5, a drive shaft 3 is a straight one or is composed of several shafts which are coaxially connected to each other. One or several pairs of grooved plates 4 which are corresponding to a number of cylinders in the engine assembly can be mounted and disposed in series in the drive shaft. The pairs of the grooved plates 4 are attached to the drive shaft 3 by press-fitting or by a key means so that a correct relative position between the pairs of the grooved plates and the drive shaft are secured. The drive shaft can be a hollow one in which a plurality of passages of a lubricating system supplied by a oil pump are formed for the purposes of lubricating and cooling.
The pairs of the grooved plates 4 are a circular shape or a special shape as shown in Fig.1/5, a pair of cam grooves 5 of which the profiles are symmetrical together through a plane of the connecting rod 7 are formed in these pairs of the grooved plates, the profiles are calculated so that when a unit of the drive shaft and pair of the grooved plates is rotated, a connection between the cam grooves 5 and a connecting rod pin 9 changes a rotation of the unit of the drive shaft and pair of the grooved plates into a back and forth movement of the connecting rod 7, further this back and forth movement of the rod conforms to a predetermined manner which is decided by the profiles of the recesses.
A structure of a unit of a connecting rod — piston pin - connecting rod pin is clearly shown in Fig.1/5. A connecting rod is constructed of three main parts, in
particular: a hole for a piston pin is formed at one end of the rod, a hole for a connecting rod pin is formed at a intermediate position of the rod, at the other end of the rod a elongated slot called as a connecting rod slot 8 is formed. The piston pin 6 is inserted in the piston pin hole by rotatably slidably fitting or by means of an intermediate boss or a ball bearing so as to maintain that the piston pin can be rotated without a gap about the axis itself in the piston pin hole. The connecting rod pin is inserted in the connecting rod pin hole by rotatably slidably fitting or by means of an intermediate boss or a ball bearing so as to maintain that the connecting rod pin can be rotated without a gap about the axis itself in the connecting rod pin hole. The connecting rod slot is coaxially formed with the connecting rod, is elongated shaped of which a wide is adapted to a diameter portion of the drive shaft, and of which a length is corresponding to a running stroke of the piston.
The piston is connected to the connecting rod unit by the piston pin which is inserted via the pin holes in the piston and the connecting rod, the pin is fixed in place by two retaining rings located at two ends of the pin hole of the piston. With this link, back and forth movement of the piston in the cylinder is changed into back and forth movement of the connecting rod and vice versa.
The connecting rod slot is mounted so as to substantially contact with two sides of the drive shaft, two other sides of the connecting rod are sandwiched between the pair of the grooved plates. Therefore, the connecting rod is forced to move in reciprocating manner along the axis of the cylinder. Other embodiment of the mechanism is shown in Fig.5, in which the connecting rod is not positioned by the connecting rod slot but is positioned by a pair of guide bases which are fixedly attached to the crankcase and the connecting rod is slid in a gap which is formed by the pair of guide bases.
While connecting rod pin is inserted through the connecting rod pin hole by rotatably slidably fitting or by means of an intermediate boss or a ball bearing, two ends of the pin is positioned in the cam grooves of pair of the grooved plates. The axial movement of the connecting rod pin is blocked by the bottom surface of the
cam grooves or by two balls which are provided at two ends of the connecting rod pin, or by two retaining rings which are respectively positioned at two relative positions in two sides of the connecting rod pin. Thus, the rotation of the unit of the drive shaft and pair of the cam groove plates is changed into the relative movement between the connecting rod pin and the cam grooves. With such a link of the connecting rod pin and the cam grooves, the rotation of the unit of the drive shaft and pair of the cam groove plates is changed into back and forth movement of the unit of the piston and the connecting rod and vice versa.
Since the mechanism is described above, the constant rotation of the drive shaft is changed into back and forth special movement of the piston as it depends on the profile of the pairs of the cam grooves. For each of strokes of the cycle, the initial and finished points of this movement are different, the speed and acceleration thereof are correctly defined at each time and position of the piston within the cylinder in order to obtain the best effects with regard to the power, performance, economic property, etc. of the engine.