JP3143564B2 - Cam type engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cam engine in which a crankshaft and a connecting rod in a conventional reciprocating internal combustion engine are eliminated, and a reciprocating motion of a piston is directly converted to a rotational motion of a cam.

[0002]

2. Description of the Related Art In a conventional gasoline engine or diesel engine, a reciprocating motion of a piston sliding in a cylinder is converted into a rotational motion of a crankshaft via a connecting rod. In the case of a four-stroke cycle engine, the crankshaft rotates twice for two reciprocations of the piston, during which suction, compression, expansion,
A four-stroke cycle of exhaust is performed.

[0003] A rotary type engine is known separately from such a reciprocating type internal combustion engine. This is a triangular rotor corresponding to a reciprocating piston, and three combustion chambers are formed between this rotor and a cocoon-shaped rotor housing. In each combustion chamber, four cycles of suction, compression, expansion, and exhaust are performed. Therefore, in the case of this rotary engine, neither a crankshaft nor a connecting rod is required, and the rotation of the rotor is transmitted to the output shaft via an eccentric shaft, a planetary gear, or the like, and 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 is performed only once while the piston reciprocates twice. Further, since the penetrating force of the connecting rod acts on the piston as a side pressure in addition to the reaction force of the output torque, the maximum value of the side pressure increases, and wear and impact on the cylinder increase. In addition, since forces in different directions are constantly applied to the connecting portion between the connecting rod and the piston or the crankshaft, high quality is required for their strength, rigidity and finish, and it has been difficult to realize low cost. Furthermore, there is a limit in reducing the size and weight of the engine due to the use of a connecting rod and a crankshaft. On the other hand, rotary engines are not widely used as reciprocating engines because they are slightly disadvantageous in terms of fuel economy, and there is a problem that reciprocating engines cannot use the superior technology cultivated up to now. Was. An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a low-cost cam-type engine which is small and lightweight and which can obtain a large output.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a casing in which two cylinders which are radially opposed to each other at 180 degrees around a cam case are integrally provided, A positive-acting cam having an output shaft extending into the cam case at the center, having two or more even-numbered cam ridges at equal intervals in the circumferential direction, and having a rim protruding laterally along the cam curve; A piston provided in each of the cylinders so as to be capable of reciprocating sliding; a circumscribed cam follower rotatably provided on each of the pistons and circumscribing a rim of the positive cam; An inscribed cam follower that is provided so as to be inscribed in the rim, and an air supply means and an ignition means provided in each of the cylinders, wherein the shape of the rim of the positive cam is the same as that of each of the pistons. The so as to move in the opposite direction in the period in which 該確 movement cam while within each cylinder for reciprocating sliding is a configuration that has become such as to enable it to rotate in one direction.

[0006] The present invention also relates to a cam case around a cam case.
A casing in which a plurality of cylinder pairs each of which are two cylinders facing each other in the radial direction and separated by 0 degrees are provided integrally, and an output shaft extending into the cam case is provided at a central portion, and is provided at equal intervals in a circumferential direction. It has two or more even cam ridges,
A positive cam having a rim protruding laterally along a cam curve; a piston provided in each of the cylinders so as to be capable of reciprocating sliding; and a rim of the positive cam provided rotatably provided in each of the pistons An outer cam follower circumscribing the circumscribed cam follower, an inner cam follower rotatably provided on each of the pistons opposed to the outer circumscribed cam follower, and an inscribed cam follower provided on each of the cylinders; and Each pair of cylinders is located at a predetermined distance around the periphery of the cam case, and the shape of the rim of the positive cam is such that two pistons sliding in the cylinders constituting each pair of cylinders are the same. The positive cam is rotated in one direction while all pistons reciprocate in each of the cylinders by moving in opposite directions at the same time. It is obtained by the Configurations.

[0007]

According to the present invention, since the reciprocating motion of the piston is converted into the rotational motion of the positive cam via the cam follower, a small, lightweight and low-cost engine with good mechanical efficiency can be realized. . Further, since the piston performs at least two reciprocations during one rotation of the positive cam to perform four strokes of suction, compression, expansion, and exhaust, and performs explosion a plurality of times in accordance with the number of cylinders and cam ridges, a large explosion occurs. Output torque is obtained. 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. Furthermore, since the cam follower is in rolling contact with the cam, the mechanical efficiency is good, and the cylinder arrangement and the cam shape are 180 degrees symmetric, so that the dynamic balance is good and the vibration is small. Furthermore, the desired movement and displacement can be given in all strokes of intake, compression, expansion, and exhaust, so that energy conversion efficiency can be improved and the engine can be optimized. Characteristics can be optimized. Furthermore, in the cam type engine of the present invention, no side pressure other than the reaction force of the output torque does not act on the piston, and therefore, the above-mentioned disadvantages in the conventional reciprocating engine in which the penetrating force of the connecting rod acts as the side pressure. Can be eliminated.

[0008]

FIG. 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 engine. 1 and 2, reference numeral 1 denotes a casing, which is formed integrally with a cam case 2 on both sides thereof in a 180-degree direction.
(In the present embodiment, it is symmetric with respect to the cam case 2 by 180 degrees, and therefore, only one of the elements is denoted by a reference numeral). A cocoon-shaped cam 4 which is a positive cam is accommodated in the cam case 2, and this cam 4 has two cam ridges 4a and 4b in the 180-degree direction.
Rim 4 protruding on both sides along the cam curve on its outer peripheral surface
The output shaft 5 is formed integrally at the center. The output shaft 5 has a bearing 6
Are supported rotatably. In case of multiple structure,
The output shaft 5 is supported on both sides by bearings. The output shaft 5 may be formed separately from the cam 4 and integrated later. A piston 7 having a hollow interior is provided in each cylinder 3 so as to be slidable.
A piston ring 8 is fitted on the outer periphery of the upper part, and a roller-shaped outer cam follower 10 is rotatably mounted in the lower part by a piston pin 9, and the roller-shaped inner cam follower 1 is further mounted by pins 11 and 12.
3, 14 are rotatably mounted. One outer cam follower 10 rolls by contacting the outer peripheral surface of the rim 4c of the cam 4, and two inner cam followers 13 and 14 roll by contacting the inner peripheral surface of the rim 4c of the cam 4. I do. An intake passage 1 connected to an intake pipe is provided above each cylinder 3.
5 and an exhaust passage 16 connected to the exhaust pipe are formed,
Portions of the intake passage 15 and the exhaust passage 16 that open at the top inside the cylinder are provided with an intake valve 17 and an exhaust valve 18 respectively.
A spark plug 19 serving as ignition means is mounted between the intake valve 17 and the exhaust valve 18 so as to face into the cylinder 3. Other parts not shown have the same configuration as the conventional four-stroke cycle gasoline engine.

In the first embodiment, the shape of the rim 4c of the cam 4 is such that the cam 4 moves one time during the reciprocating sliding in each cylinder 3 so that each piston 7 moves the same amount in the opposite direction at the same time. It is such that it can rotate in the direction. As the positive cam, in addition to the above embodiment, a guide groove is provided on at least one side surface of the cam, and a roller-shaped cam follower rotatably held on a piston is fitted into the guide groove. Is also good.

Next, the operation of the above embodiment will be described.
Although the following description focuses on the upper piston 7, the lower piston 7 performs the same movement as shown in FIG. First, the output shaft 5 starts rotating by the starter, and when the cam 4 rotates counterclockwise, the cam followers 10 and 13 and 14 circumscribe and inscribe the rim 4c.
The piston 7 descends from the state shown in FIG. 1 along the cam ridge 4a, and the mixture of gasoline and air is sucked into the cylinder 3 through the opened intake valve 17, and reaches the bottom dead center as shown in FIG. When the cam 4 further rotates, the piston 7 moves up the cam peak 4b, and the air-fuel mixture in the cylinder 3 is compressed by the piston 7, ignited by the ignition plug 19 at the position of the top dead center, exploded and expanded, and again the piston 7 Goes down the cam mountain 4b to reach the bottom dead center. When the piston moves up the cam 4a again from this state, the exhaust gas in the cylinder 3 is exhausted through the opened exhaust valve 18 and returns to the state of FIG. Thus, while the cam 4 makes one rotation, the two pistons 7 make two reciprocations, and perform a four-stroke cycle of suction, compression, expansion, and exhaust,
One explosion is made for each cylinder 3.

Thus, according to the above embodiment, the cam 4
Each rotation of the piston 7 makes two reciprocations in one rotation, and a four-stroke cycle of suction, compression, expansion, and exhaust is performed. Since one explosion is performed for each cylinder 3, a large output can be obtained with a small size and light weight. In addition, since the cam 4 makes one rotation for each reciprocating motion of each piston 7, the rotation of the output shaft 5 is reduced, the output rotation speed, heat generation and vibration are suppressed, and the energy conversion efficiency is good. Further, since the cam followers 10, 13 and 14 are used, the number of sliding corners can be reduced, and the mechanical efficiency is high. Furthermore, the pistons 7 and the cylinders 3 are arranged 180 degrees symmetrically, the cam 4 is also formed 180 degrees symmetrical, and the reciprocating motion of each piston 7 is also symmetrical, so that dynamic balance is good and vibration is small.

In the above embodiment, the pistons 7 in the two opposing cylinders 3 are operated in the same process as shown in FIG. 4, but are shifted by two strokes, that is, one is suction, compression and expansion. When exhaust is performed, the other may be controlled to perform expansion, exhaust, suction, and compression.

FIG. 5 is a schematic sectional front view of a gasoline type four-stroke cycle engine showing a second embodiment of the present invention, and FIG. 6 is a schematic sectional side view of the engine. FIG.
6, reference numeral 21 denotes a casing, and a cam case 22 and two cylinders 23 integrally formed on both sides thereof in the 180-degree direction (in the present embodiment, the cam case 2
Since it is symmetrical about 180 with respect to 2, only one of the elements is denoted by a reference numeral. ). Cam case 2
2, a curved cam 24, which is a positive cam, is accommodated.
a, 24b, 24c, and 24d, and the cam curves of the pair of cam ridges 24a and 24c and the pair of cam ridges 24b and 24d that are opposed to each other are different. That is, cam mountain 2
The set of 4a, 24c has an angle from valley to valley of 100 degrees, and the set of cam ridges 24b, 24d has an angle of 80 degrees from valley to valley. The cam 24 also has a rim 24 protruding on both sides along a cam curve on an outer peripheral surface thereof.
e is formed, and the output shaft 25 is integrally formed at the center. The output shaft 25 is rotatably supported by the cam case 22 by bearings 26. In the case of a multiple structure, the output shaft 25 is supported by bearings on both sides. Further, the output shaft 25 may be formed separately from the cam 24 and integrated later. A piston 27 having a hollow interior is slidably provided in each cylinder 23, and each piston 27 has a piston ring 2 on its upper outer peripheral portion.
8, a roller-shaped external cam follower 30 is rotatably mounted in the lower portion by a piston pin 29, and roller-shaped internal cam followers 33 and 34 are rotatably mounted by pins 31 and 32. I have.
One circumscribed cam follower 30 is a rim 24c of the cam 24.
Rolls by contacting the outer peripheral surfaces of the two cam followers 3
The rollers 34 contact the inner peripheral surface of the rim 24c of the cam 24 and roll. An intake passage 35 connected to the intake pipe and an exhaust passage 36 connected to the exhaust pipe are formed in the upper part of each cylinder 23. The intake passage 35 and the exhaust passage 36
An intake valve 37 and an exhaust valve 38 are respectively provided at portions opened to the upper part of the cylinder, and a spark plug 39 serving as ignition means is provided between the intake valve 37 and the exhaust valve 38.
Are attached toward the inside of the cylinder 23. Other parts not shown have the same configuration as the conventional four-stroke cycle gasoline engine. In the second embodiment, the shape of the rim 24e of the cam 24 is
7, so that the cam 24 can rotate in one direction while reciprocatingly sliding in each cylinder 23 by moving the same amount in the opposite direction at the same time. In addition,
As the positive cam, in addition to the above embodiment, a configuration may be used in which a guide groove is provided on at least one side surface of the cam, and a roller-like cam follower rotatably held on a piston is fitted into the guide groove. .

Next, the operation of the above embodiment will be described.
Although the following description focuses on the upper piston 27, the lower piston 27 performs the same movement as shown in FIG. First, the output shaft 25 starts rotating by the starter,
When the cam 24 rotates counterclockwise, the cam peak 24a
The piston 7 descends from the state shown in FIG. 5 by the cam followers 30 and 33, 34 which are circumscribed and inscribed in the rim 24e of the portion of FIG. Mountain 24a is 50
By rotating the piston 27 degrees, the piston 27 reaches the bottom dead center as shown in FIG. Next, when the cam 24 rotates by 40 degrees, the piston 27 moves up the cam ridge 24b, and the air-fuel mixture in the cylinder 23 is compressed by the piston 27.
9 ignites and explodes and expands, the cam peak 24b rotates 40 degrees, the piston 27 descends again, and reaches the bottom dead center. In this state, when the cam 24 rotates by 50 degrees and the piston 27 moves up the cam peak 24c, the exhaust gas in the cylinder 23 is exhausted through the opened exhaust valve 38. Similarly, the piston 27 descends the cam peak 24c to perform the suction stroke,
The compression stroke is performed by ascending the cam ridge 24d,
d, the expansion stroke is performed, the cam peak 24a is raised, the exhaust stroke is performed, and the state returns to the state shown in FIG. In this manner, while the cam 24 makes one rotation, the two pistons 27 reciprocate four times, and perform four stroke cycles of suction, compression, expansion, and exhaust twice, and two explosions are performed for each cylinder 23. It is.

As described above, according to the above embodiment, the cam 2
Each revolution of piston 4 makes four reciprocations in one rotation of 4, and performs four stroke cycles of suction, compression, expansion, and exhaust twice,
Since two explosions are performed for each cylinder 23, a large output can be obtained with a small size and light weight. Further, since the cam 24 makes one rotation for each reciprocating motion of each piston 27, the rotation of the output shaft 25 is reduced, the output rotation speed, heat generation and vibration are suppressed, and the energy conversion efficiency is good. Further, since the cam followers 30 and 33 and 34 are used, the number of sliding corners can be reduced, and the mechanical efficiency is high. Furthermore, the pistons 27 and the cylinders 23 are arranged 180 degrees symmetrically, and the reciprocating movements of the opposed pistons 27 are also symmetrical, so that dynamic balance is good and vibration is small. Furthermore, since the time spent in the intake stroke and the exhaust stroke can be taken longer than the time spent in the compression stroke and the expansion stroke, the intake of the air-fuel mixture and the discharge of the exhaust gas can be sufficiently performed. Therefore, energy conversion efficiency can be improved, and dynamic characteristics such as vibration and driving performance can be optimized.

FIG. 9 shows the first embodiment in which the pins 11 and 12 for supporting the inscribed cam followers 13 and 14 are extended outwardly, and rollers 40 and 41 are rotatably supported at both ends thereof. On the wall of the cam case 2 opposed to the rollers 40 and 41, guide grooves 42 and 43 are provided in the same direction as the piston 7 to guide the rollers 40 and 41 in rolling. In the example shown in FIG. 9, each piston 7 has a roller 4 that rolls in guide grooves 42 and 43.
Since the rotation in the circumferential direction is restricted by 0 and 41, the reciprocating motion in the cylinder 3 can be ensured. It is of course possible to adopt the configuration shown in FIG. 9 in the second embodiment.

In each of the above embodiments, when the cam-type engine shown in each embodiment has a multiple structure, the dynamic balance and the dynamic balance and the explosion timing of the adjacent engines are appropriately arranged so as not to overlap. Vibration control can be improved. In addition, a balancer or a flywheel can be provided for absorbing vibration and noise.

In each of the above embodiments, two cylinders 3 and 23 are provided around the cam cases 2 and 22 at 180 degrees and are opposed to each other in the radial direction, and two pistons 7 and 27 are provided correspondingly. However, it is also possible to increase the number of these cylinders and pistons. That is, it is possible to provide a plurality of cylinder pairs composed of two radially opposed cylinders 180 degrees apart from each other around the cam case so that each cylinder pair is separated by a predetermined distance around the cam case. is there. The number of cam ridges of the cam is two in the first embodiment and four in the second embodiment. However, if the cam curve is 180 degrees symmetric with a different cam curve, six or more even numbers are used. A plurality of cam ridges can be provided, and the characteristics of the engine can be changed by variously setting cam curves.

FIG. 10 shows a modification of the first embodiment shown in FIG. 1 in which the number of cylinders and pistons is increased. That is, in the configuration shown in FIG. 10, two cylinders 3 that are 180 degrees apart from each other and are radially opposed to each other around the cam case form one cylinder pair, and the other two cylinders 3
A is another one cylinder pair, and two cylinder pairs are provided. In this case, one cylinder pair 3 and another cylinder pair 3A are provided around the cam case at a predetermined interval, that is, at an angle α, and the pistons 7, 7A slide in each cylinder. The shape of the rim of the cam 4 is 1
Two pistons 7 sliding in the cylinder 3 forming one cylinder pair move the same amount in the opposite direction at the same time, and two pistons 7A sliding in the cylinder 3A forming another cylinder pair. Move the same amount in the opposite direction at the same time to allow the cam 4 to rotate in one direction while all pistons slide back and forth in each cylinder.

FIG. 11 shows a configuration in which the shape of the cam of the first embodiment is changed. That is, the cam 54 in FIG.
Two 180 ° symmetrical cam ridges 54 having different cam curves
a, 54b, each rotation of the cam 54 causes each piston 7 to reciprocate two times to perform the same suction, compression, expansion, and exhaust strokes as in the first embodiment. However, in the configuration of FIG. 11, the two pistons 7 move in the opposite directions at the same time, but the movement amounts of the two pistons in the opposite directions at the same time are not the same. in this way,
The characteristics of the engine can be changed by changing the amount of movement of the piston.

In each of the above embodiments, a gasoline engine has been exemplified. However, only air rather than air-fuel mixture is sucked into the cylinders 3 and 23 from the intake passages 15 and 35, and fuel is injected as ignition means instead of a spark plug. By providing the nozzle, a diesel engine can be configured.

Further, the present invention provides various techniques for reducing exhaust gas and improving fuel efficiency, which are recent achievements in a conventional four-stroke cycle engine, such as air-fuel ratio control, ignition control, fuel injection control, EGR control, and supply. Electronic control technology such as exhaust control, sub-chamber combustion technology, vortex chamber combustion technology, and the like can be applied as appropriate.

[Brief description of the drawings]

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

FIG. 6 is a schematic side sectional view of the engine.

FIG. 7 is a schematic front sectional view for explaining the operation of the engine.

FIG. 8 is a schematic cam diagram for explaining the operation of the engine.

FIG. 9 is a view similar to FIG. 2, showing a modification of the configuration of the first embodiment.

FIG. 10 is a schematic front sectional view showing a configuration example in which the engine of the first embodiment is changed so as to increase the number of cylinders and pistons.

FIG. 11 is a schematic front sectional view showing an example in which the shape of a cam in the engine of the first embodiment is changed.

[Explanation of symbols]

1, 21 casing 2, 22 cam case 3, 23 cylinder 4, 24, 54 cam 4a, 4b; 24a, 24b, 24c, 24d; 54
a, 54b Cam ridge 4c, 24e Rim 5 Output shaft 7, 27 Piston 10, 30 Outer cam follower 13, 14; 33, 34 Inner cam follower 15, 35 Intake passage 16, 36 Exhaust passage 17, 37 Intake valve 18, 38 Exhaust Valve 19, 39 Spark plug 40, 41 Roller 42, 43 Guide groove

Claims (3)

(57) [Claims] 1. A casing in which two cylinders which are 180 degrees apart from each other and are radially opposed to each other around a periphery of a cam case are integrally provided, and an output shaft extending into the cam case is provided at a center portion in a circumferential direction. A positive cam having two or more even-numbered cam ridges at equal intervals, and having a rim protruding laterally along the cam curve; a piston provided in each of the cylinders so as to be capable of reciprocating sliding; An outer cam follower rotatably provided on each of the pistons and circumscribing a rim of the positive cam, and an inner cam follower rotatably provided on each of the pistons opposed to the outer cam follower and inscribed on the rim; An air supply means and an ignition means provided in the cylinder are provided, and the shape of the rim of the positive cam is such that each piston moves in the opposite direction at the same time in each cylinder. A cam engine adapted to allow the positive cam to rotate in one direction during a reverse slide. 2. A casing in which a plurality of pairs of two cylinders, which are radially opposed to each other and are 180 degrees apart from each other around a cam case, are integrally provided, and an output shaft extending into the cam case is provided at a center portion. A positive cam having two or more even-numbered cam ridges at equal intervals in the circumferential direction and having a rim protruding sideways along a cam curve, and reciprocally slidable into each of the cylinders. A piston provided, a circumscribed cam follower rotatably provided on each of the pistons and circumscribing the rim of the positive cam, and an inner cam rotatably provided on each of the pistons opposed to the circumscribed cam follower and inscribed in the rim. A cam follower, and an air supply unit and an ignition unit provided in each of the cylinders, wherein each of the cylinder pairs is located at a predetermined distance around the cam case; The shape of the rim of the positive cam is such that all the pistons reciprocate in each of the cylinders so that the two pistons sliding in the cylinders constituting each of the cylinder pairs move in opposite directions at the same time. A cam engine adapted to allow the positive cam to rotate in one direction while sliding. 3. The cam-type engine according to claim 1, wherein each piston is provided with a rotation preventing means in a circumferential direction.