JPH084552A - Cam type engine - Google Patents

Abstract

PURPOSE:To reduce size and weight and to increase an output by providing a casing formed integrally with two cylinders positioned radially facing each other, a positive motion cam having the odd number of cam crests, being three or more cam crests, arranged at equal intervals in a peripheral direction, a cam follower making rolling contact with a cam surface, and a coupling rod to intercouple pistons. CONSTITUTION:An output shaft is rotated by a starter and when a cam 4 is rotated counterclockwise, a piston 7 climbs a cam crest 4a for rise by a driven cam follower 10, air-fuel mixture of gasoline and air sucked in a cylinder 3 is compressed and the piston ascends to a top dead center. In this position, the air-fuel mixture is ignited for explosion and expansion through which the piston 7 is forcibly pressed down and during re-rise, combustion gas is exhausted. During lowering of the piston 7, the fuel-air mixture is sucked, the piston climbs a cam crest 4c for compression, and the piston descends owing to explosion and expansion and is restored to an initial state. Since, as noted above, six full stroke cycles per one full turn of the cam 4 are carried out. When explosion is effected at least two times, high output torque is generated by reduced size and weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cam type engine which eliminates a crankshaft and a connecting rod in a conventional reciprocating internal combustion engine and directly converts the reciprocating motion of a piston into a rotary motion of a cam.

[0002]

2. Description of the Related Art In a conventional gasoline engine or diesel engine, the reciprocating motion of a piston sliding in a cylinder is converted into a rotary motion of a crankshaft via a connecting rod. In the case of a four-stroke cycle engine, the crankshaft makes two revolutions with respect to two reciprocating motions of the piston, during which a four-stroke cycle of intake, compression and expansion exhaust is performed.

In addition to such a reciprocating internal combustion engine, a rotary engine is known. The part corresponding to the reciprocating piston is a triangular rotor, and three combustion chambers are formed between this rotor and the cocoon-shaped rotor housing. In each combustion chamber, four cycles of intake, compression, expansion and exhaust are performed. Therefore, in the case of this rotary type engine, neither the crankshaft nor the connecting rod is required, and the rotation of the rotor is transmitted to the output shaft via the eccentric shaft, the planetary gear, etc. and is rotated. That is, since the rotation output is obtained from the rotation of the rotor, the rotation is smooth and the noise is small.

[0004]

However, in the above-mentioned conventional reciprocating engine, there is a limit in obtaining a large output because the explosion occurs only once while the piston reciprocates twice. Further, in addition to the reaction force of the output torque, the penetrating force of the connecting rod acts on the piston as a lateral pressure, so that the maximum value of the lateral pressure becomes large and wear and impact on the cylinder become large. Further, since the force of different directions is constantly applied to the connecting portion of the connecting rod and the piston or the crankshaft, high quality is required for strength, rigidity and finish of these, and it is difficult to realize low cost. Furthermore, there is a limit in reducing the size and weight of the engine because of the use of the connecting rod and the crankshaft.

On the other hand, the rotary engine is not so popular as the reciprocating engine because it is slightly disadvantageous in terms of fuel consumption, and the reciprocating engine cannot utilize the excellent technology cultivated up to now. There was a problem. The present invention
SUMMARY OF THE INVENTION It is an object of the present invention to solve such a conventional problem, and to provide a low-cost cam type engine that is compact and lightweight and can obtain a large output.

[0006]

In order to achieve the above object, the present invention provides a casing in which two cylinders, which are 180 degrees apart from each other and are opposed to each other in a radial direction, are integrally provided around a cam case, and A positive cam having an output shaft extending in the cam case in the center and having an odd number of cam peaks of three or more at equal intervals in the circumferential direction, and a piston reciprocally slidably provided in each cylinder. A cam follower that is rotatably provided on each piston and is in rolling contact with the cam surface of the positive cam, a connecting rod that integrally connects the pistons, and an air supply means and an ignition means provided on each cylinder. And the shape of the positive-moving cam is such that the positive-moving cam can rotate in one direction when the pistons reciprocally slide in the cylinder. Things That. Further, according to the present invention, a casing in which a plurality of cylinder pairs, which are two cylinders that are opposed to each other in the radial direction and are separated by 180 degrees around the cam case, are integrally provided, and an output shaft extending in the cam case are central portions. And a positive cam having an odd number of cam ridges of three or more at equal intervals in the circumferential direction, a piston provided reciprocally slidably in each cylinder, and rotatably provided to each piston. A cam follower that comes into rolling contact with the cam surface of the positive cam and an air supply means and an ignition means provided in each cylinder, and each cylinder pair is located at a predetermined distance around the cam case. And two pistons that slide in the cylinders forming each cylinder pair are integrally connected by a connecting rod, and the shape of the positive cam is such that each piston is It is 該確 movement cam when the inside cylinder reciprocating sliding is obtained by the configuration makes it possible to rotate the position.

[0007]

Therefore, according to the present invention, since the reciprocating motion of the piston is converted into the rotary motion of the positive cam through the cam follower, it is possible to realize an engine which is excellent in mechanical efficiency, small in size, light in weight and low in cost. . Further, during one rotation of the positive cam, each piston reciprocates according to the number of cylinders and cam lobes, and at least four strokes of suction, compression, expansion, and exhaust are performed, and a plurality of explosions are performed. A large output torque can be obtained. Further, since the opposed pistons reciprocate in the same direction, the pressure at the time of explosion of one piston can be used for compression or exhaust of the other piston. That is, in the conventional reciprocating engine, the force at the time of explosion in one cylinder is transmitted to the crankshaft via the connecting rod, and in the other cylinders, the force required in the compression stroke is transmitted from the crankshaft to the piston via the connecting rod. By propagating to the, the condition for effectively using energy is satisfied to some extent, but the energy loss increases due to the long propagation path. On the other hand, in the cam type engine of the present invention,
The explosive force in the two cylinders is used to rotate the positive cam via the cam follower, and the force is
Through the connecting rod, a force for compression in a cylinder radially opposite to the one cylinder is directly transmitted to a piston in the latter cylinder. By configuring this ideal propagation path, energy loss can be reduced. Further, since the output shaft is decelerated with respect to the reciprocating motion of the piston, the output rotation speed, heat generation and vibration are suppressed, and the energy conversion efficiency is improved. Also, inhalation,
Although there is a condition that compression, expansion, and exhaust all have the same displacement and kinematic characteristics, it is possible to optimize the engine by changing one kinetic characteristic related to all strokes, and energy conversion efficiency. And the dynamic characteristics such as vibration and driving performance can be optimized. Further, in the cam type engine of the present invention, the side pressure other than the reaction force of the output torque does not act on the piston, so that the penetrating force of the connecting rod acts as the side pressure as described above in the conventional reciprocating engine. Can be resolved.

[0008]

1 is a schematic sectional front view of a gasoline type four-stroke cycle engine showing a first embodiment of the present invention, and FIG. 2 is a schematic sectional side view of the same engine. In FIGS. 1 and 2, reference numeral 1 is a casing, which is integrally formed on the cam case 2 and both eyes in a direction of 180 degrees.
Cylinders 3 (in the present embodiment, they are 180 degrees symmetrical with respect to the cam case 2, and therefore, the same reference numerals are used for the same elements). A curved cam 4, which is a positive-moving cam, is housed in the cam case 2. The cam 4 includes three cam ridges 4a at 120 ° intervals in the circumferential direction.
4b and 4c, and an output shaft 5 is integrally formed at the center. The output shaft 5 is rotatably supported by the cam case 2 by the bearing 6, but in the case of the multiple structure,
It is supported by bearings on both sides. Output shaft 5
May be formed separately from the cam 4 and integrated later. Inside each cylinder 3, there is a hollow piston 7.
Each of the pistons 7 is slidably provided with a piston ring 8 fitted on an outer peripheral portion of an upper portion thereof, and a piston pin 9 is provided inside a lower portion thereof by a roller-shaped cam follower 10
Is rotatably mounted, and a plurality of connecting rods 11
Are connected and integrated by. In addition, an intake passage 12 connected to the intake pipe and an exhaust passage 13 connected to the exhaust pipe are formed in the upper portion of each cylinder 3, and the portions of the intake passage 12 and the exhaust passage 13 that open in the upper portion of the cylinder are formed. An intake valve 14 and an exhaust valve 15 are provided respectively, and an ignition plug 16 which is an ignition means is attached between the intake valve 14 and the exhaust valve 15. Other parts not shown have the same structure as the conventional four-stroke cycle gasoline engine. Cam 4
The shape has a valley in the middle between two adjacent cam peaks, allowing the cam 4 to rotate in one direction as each piston 7 slides back and forth in each cylinder 3. It looks like this.

Next, the operation of the above embodiment will be described.
Although the following description focuses on the upper piston 7, the lower piston 7 is assumed to move one stroke ahead as shown in FIG. First, when the output shaft 5 starts rotating by the starter and the cam 4 rotates counterclockwise, the cam follower 10 driven by the cam 4 causes the piston 7 to move up from the state shown in FIG. The mixture of gasoline and air sucked into the cylinder 3 is compressed through the intake valve 14 opened in the intake stroke to reach the top dead center.
It becomes the state of. At this position, the ignition plug 16 ignites and explodes and expands, and the piston 7 moves down the cam lobe 4a and is pushed down to the valley between the cam lobes 4a and 4b. When the piston 7 climbs up the cam crest 4b again from this state, the exhaust gas in the cylinder 3 is exhausted through the open exhaust valve 15. Next, while the piston 7 is pushed down into the valley between the cam peaks 4b and 4c, the intake valve 14 is opened and the air-fuel mixture is sucked into the cylinder 3, and the piston 7 goes up the cam peak 4c and moves to the cylinder 3c. The air-fuel mixture inside is compressed, and then descends due to explosive expansion, returning to the state of FIG. 1 and one rotation of the cam 4 is completed. As a result, the piston 7 reciprocates 3 times while the cam 4 makes one rotation, and a 6-stroke cycle including suction, compression, expansion and exhaust is performed. During this time, the lower piston 7, which is connected to the upper piston 7 by the connecting rod 11, performs the preceding stroke, so that when the upper piston 7 performs the expansion stroke, the lower piston 7 moves in the compression stroke. Since the pressure at the time of the explosion of the upper piston 7 can be used for the compression of the lower piston 7, and the force at the time of the explosion can be used as the force for rotating the cam 4, the energy can be used efficiently. can do.

Thus, according to the above embodiment, the cam 4
Each piston 7 reciprocates three times in one rotation to perform a six-stroke cycle including four strokes of suction, compression, expansion, and exhaust, and at least two explosions are performed. Therefore, a small size and a large output torque can be obtained. Also, the cam 4 has three mountains 4
a, 4b, 4c, the cylinders 3 are arranged 180 degrees symmetrically, and the opposing pistons 7 reciprocate in the same direction, so that the pressure at the time of explosion of the upper piston 7 is It can be used as a force to rotate the cam 4, and energy loss is small. Also, the piston 7
Since the cam 4 makes one rotation with respect to three reciprocating motions, the rotation of the output shaft 5 is decelerated, the output rotation speed and heat generation and vibration are suppressed, and the energy conversion efficiency is good. Further, since the cam follower 10 makes rolling contact with the cam 4, mechanical efficiency is good. In addition, in the intake, compression, expansion, and exhaust strokes, although there is a condition that the pistons and the like all have the same displacement and motion characteristics, by optimizing the engine by changing one motion characteristic related to all strokes. Therefore, dynamic characteristics such as vibration and driving performance can be optimized.

FIG. 5 shows a second embodiment of the present invention, in which the cam 41 has five cam ridges 41a, 41b, at equal intervals in the circumferential direction.
It has only 41c, 41d, 41e different from the above-mentioned embodiment. Therefore, in this example,
One rotation of the cam 41 results in 2.5 strokes of 10 stroke cycles including suction, compression, expansion, and exhaust, so that each piston 7 has 2.5 explosions, which is a total of 5 times. The output can be further improved.

In each of the above embodiments, two cylinders 3 and two pistons 7 are provided on both sides of the cam case 2 in the direction of 180 degrees, but these are four in the circumferential direction of the cam case 2.
An even number such as six can be provided, and the number of explosions can be increased accordingly. That is, the cylinder 3
Two cylinders, which are 180 degrees apart from each other and are opposed to each other in the radial direction around the cam case, may be provided as one cylinder pair, and the cylinder pair may be provided in plural. In this case, each pair of cylinders is provided around the cam case at a predetermined interval, and two pistons sliding in the cylinders forming each pair of cylinders are integrally connected by a connecting rod. Further, the number of peaks of the cam 4 may be an odd number of 3 or more at equal intervals in the circumferential direction.

Further, when the cam type engine of each of the above-described embodiments has a multiple structure, it is preferable to set the explosion order of the pistons 7 in consideration of the dynamic balance and the vibration control effect. Also, a balancer or a flywheel can be provided to absorb vibration and noise. Further, in each of the above-described embodiments, only the air is sucked into the cylinder 3 from the intake passage 12 and not the air-fuel mixture, and the fuel injection nozzle is provided as the ignition means instead of the spark plug 16, thereby making the gasoline engine a diesel engine. Can be changed to

The present invention is also applicable to various techniques for improving exhaust gas and improving fuel efficiency, which are the recent achievements of conventional four-stroke cycle engines, such as air-fuel ratio control, ignition control, fuel injection control, EGR control, and fuel supply. Electronic control technology such as exhaust control, sub-chamber combustion technology, swirl chamber combustion technology, etc. can be appropriately applied.

[Brief description of drawings]

FIG. 1 is a schematic front sectional view of a cam type engine showing a first embodiment of the present invention.

FIG. 2 is a schematic side sectional view of the engine.

FIG. 3 is a schematic front cross-sectional view for explaining the operation of the engine.

FIG. 4 is a schematic cam diagram for explaining the operation of the engine.

FIG. 5 is a schematic front sectional view of a cam type engine showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Casing 2 Cam Case 3 Cylinder 4 Cam 4a, 4b, 4c Cam Mountain 5 Output Shaft 6 Bearing 7 Piston 8 Piston Ring 9 Piston Pin 10 Outer Cam Follower 11 Connecting Rod 12 Intake Passage 13 Exhaust Passage 14 Intake Valve 15 Exhaust Valve 16 Spark Plug 41 Cam 41a, 41b, 41c, 41d, 41e Cam mountain

Claims (2)

[Claims] 1. A casing in which two cylinders that are 180 degrees apart from each other and are opposed to each other in the radial direction are integrally provided around the cam case, and an output shaft extending into the cam case is provided at a central portion in a circumferential direction. A positive cam having an odd number of cam ridges of three or more at equal intervals, a piston reciprocally slidably provided in each cylinder, and a rotatably provided piston provided on each piston. A cam follower that comes into rolling contact with the cam surface, a connecting rod that integrally connects the pistons, and an air supply means and an ignition means provided in each of the cylinders are provided. A cam type engine adapted to allow the positive cam to rotate in one direction as it slides back and forth in a cylinder. 2. A casing in which a plurality of cylinder pairs, which are two cylinders that are opposed to each other in the radial direction and are separated by 180 degrees around the cam case, are integrally provided, and an output shaft extending in the cam case is centered. And a positive cam having an odd number of cam ridges of three or more at equal intervals in the circumferential direction, a piston reciprocally slidably provided in each cylinder, and rotatably provided to each piston. And a cam follower that comes into rolling contact with the cam surface of the positive cam, and an air supply means and an ignition means that are provided in each of the cylinders, and each of the pair of cylinders is positioned at a predetermined distance around the cam case. Yes, each two pistons that slide in the cylinders forming each cylinder pair are integrally connected by a connecting rod, and the positive cam shape is such that each piston has each cylinder. A cam type engine that is adapted to allow the positive cam to rotate in one direction as it slides back and forth in the housing.