JPH084550A - Cam type engine - Google Patents

Abstract

PURPOSE:To provide a low-cost engine which is constituted to reduce size and weight and generate a high output by converting reciprocating movement of a piston into rotational movement of a positive motion cam through a cam follower. CONSTITUTION:An output shaft 5 is started to rotate by a starter and when a cam 4 is rotated counterclockwise, a piston 7 is lowered from a state in a figure along a cam crest by cam followers 10 and 13, 14 making external and internal contact with a rim 4c. Air-fuel mixture of gasoline and air is sucked in a cylinder 3 through an intake valve 17 and the piston is lowered to a bottom dead center. When the cam 4 is further rotated, the piston 7 is raised along a cam rib 4b and air-fuel mixture in a cylinder 3 is compressed by the piston 7. In the position of a top dead center, ignition is effected by an ignition plug 19 to effect explosion expansion. The piston 7 is lowered along the cam crest 4b again to the bottom dead center. When, with this state, the piston 7 is raised along the cam crest 4a exhaust gas in the cylinder 3 is exhausted through an opened exhaust valve 18 and the piston is returned to a state in the figure.

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 4-stroke cycle engine, the crankshaft makes two revolutions with respect to two reciprocating motions of the piston, during which suction, compression, expansion,
A four-stroke cycle of 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 there is a problem that the reciprocating engine cannot utilize the excellent technology cultivated up to now. It was The present invention solves such a conventional problem, and an object of the present invention is to provide a low-cost cam-type engine that is small and lightweight, and can obtain a large output.

[0005]

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 at the center, an even number of two or more cam ridges at equal intervals in the circumferential direction, and a rim protruding laterally along the cam curve; Reciprocatingly slidable pistons in each cylinder, an external cam follower rotatably provided on each piston and circumscribing the rim of the positive cam, and a piston rotating opposite the external cam follower. An inner cam follower that is inscribed in the rim, and an air supply unit and an ignition unit that are provided in each of the cylinders, and 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.

Further, according to the present invention, there is provided 18
A casing integrally provided with a plurality of cylinder pairs composed of two cylinders which are spaced apart by 0 degree and are opposed to each other in the radial direction, and an output shaft extending in the cam case at the center portion thereof and equidistantly in the circumferential direction. Has an even number of cams of 2 or more,
A positive cam having a rim protruding laterally along a cam curve, a piston reciprocally slidably provided in each cylinder, and a rim of the positive cam rotatably provided on each piston. An external cam follower circumscribing to and an internal cam follower rotatably provided on each piston facing the external cam follower and inscribed in the rim, and an air supply means and an ignition means provided on each cylinder, Each cylinder pair is located at a predetermined distance around the cam case, and the rim of the positive movement cam has a shape such that two pistons that slide in the cylinders that form each cylinder pair have the same shape. So that the positive cams can rotate in one direction while all pistons reciprocally slide in the cylinders. It is obtained by the Configurations.

[0007]

Therefore, according to the present invention, the reciprocating motion of the piston is converted into the rotary motion of the positive cam through the cam follower, so that a compact, lightweight, low-cost engine having high mechanical efficiency can be realized. . Further, while the positive motion cam makes one rotation, the piston reciprocates at least two times to perform four strokes of suction, compression, expansion, and exhaust, and a plurality of explosions are performed depending on the number of cylinders and cam lobes, so that a large 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 makes rolling contact with the cam, the mechanical efficiency is good, and the cylinder arrangement and the cam shape are 180 degrees symmetrical, so that the dynamic balance is good and the vibration is small. Furthermore, since the desired motion and displacement can be given in all strokes of intake, compression, expansion, and exhaust, it is possible to improve energy conversion efficiency and optimize the engine, and it is possible to improve vibration and driving performance. The characteristics 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 with the cam case 2 on both sides thereof in a direction of 180 degrees.
And a cylinder 3 (in this embodiment, the cam case 2 is symmetrical with respect to the cam case 2 by 180 degrees, so that only one of the elements has a reference numeral). A cocoon-shaped cam 4, which is a positive-moving cam, is housed in the cam case 2. The cam 4 has two cam ridges 4a and 4b in a 180-degree direction,
A rim 4 protruding on both sides along the cam curve on its outer peripheral surface
c is formed, and the output shaft 5 is integrally formed at the center. The output shaft 5 has a bearing 6 on the cam case 2.
It is rotatably supported by. In case of multiple structure,
The output shaft 5 is supported by bearings on both sides thereof. Further, the output shaft 5 may be formed separately from the cam 4 and integrated later. Inside each cylinder 3, a piston 7 having a hollow inside is slidably provided.
Each has a piston ring 8 fitted on the outer periphery of the upper part, a roller-shaped outer cam follower 10 is rotatably mounted inside the lower part by a piston pin 9, and further, a roller-shaped inner cam follower 1 by pins 11 and 12.
3, 14 are rotatably mounted. One external contact cam follower 10 rolls by contacting the outer peripheral surface of the rim 4c of the cam 4, and two internal contact cam followers 13, 14 roll by contacting the inner peripheral surface of the rim 4c of the cam 4. To do. In addition, 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,
An intake valve 17 and an exhaust valve 18 are respectively provided in portions of the intake passage 15 and the exhaust passage 16 which are open in the upper portion of the cylinder.
A spark plug 19 as an ignition means is attached between the intake valve 17 and the exhaust valve 18 toward the inside of the cylinder 3. Other parts, not shown, have the same structure 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 each cam 7 moves reciprocally in the opposite direction at the same time and reciprocally slides in each cylinder 3 so that the cam 4 moves in one direction. It is designed to allow it to rotate in any direction. In addition to the above embodiment, a guide groove is provided on at least one side surface of the cam as the positive cam, and a roller-like cam follower rotatably held by the piston is fitted into the guide groove. 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 also moves in the same manner as shown in FIG. First, when the output shaft 5 starts to rotate by the starter and the cam 4 rotates in the counterclockwise direction, the cam followers 10 and 13 and 14 that are inscribed in and out of the rim 4c
The piston 7 descends from the cam ridge 4a from the state shown in FIG. 1, sucks the mixture of gasoline and air 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 lobe 4b, the air-fuel mixture in the cylinder 3 is compressed by the piston 7, is ignited by the ignition plug 19 at the position of the top dead center, explodes and expands, and the piston 7 again. Descends on Cam Mountain 4b to reach bottom dead center. When the piston ascends 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. In this way, 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 performed for each cylinder 3.

As described above, according to the above embodiment, the cam 4
Each piston 7 reciprocates two times in one rotation, and performs a four-stroke cycle of intake, compression, expansion, and exhaust. Since each cylinder 3 is exploded once, a large output can be obtained with a small size and light weight. Further, since the cam 4 makes one rotation with respect to the two reciprocating motions of each piston 7, 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 followers 10 and 13 and 14 are used, the sliding corners can be reduced and the mechanical efficiency is good. Furthermore, the pistons 7 and the cylinders 3 are arranged 180 degrees symmetrically, the cams 4 are also formed 180 degrees symmetrically, and the reciprocating motions of the pistons 7 are also symmetrical, so that the dynamic balance is good and the vibration is small.

In the above embodiment, the pistons 7 in the two opposed cylinders 3 are operated in the same process as shown in FIG. 4, but they are shifted by two strokes, that is, one of them is suction, compression, expansion. When exhausting, the other can 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 same engine. Figure 5
In FIG. 6 and FIG. 6, reference numeral 21 denotes a casing, which is a cam case 22 and two cylinders 23 integrally formed on both sides thereof in the 180 degree direction (in this embodiment, the cam case 2
Since it is symmetrical about 180 degrees around 2, only one element is labeled. ). Cam case 2
A curved cam 24, which is a positive-moving cam, is housed inside the camshaft 2. The cam 24 includes four cam ridges 24 at 90-degree intervals.
The cam curves of the set of cam ridges 24a, 24c and the set of cam ridges 24b, 24d that have a, 24b, 24c, 24d and are opposed to each other are different. That is, Kam mountain 2
The set of 4a and 24c is formed with a valley-to-valley angle of 100 degrees, and the set of cam peaks 24b and 24d is formed of a valley-to-valley angle of 80 degrees. The cam 24 also has a rim 24 on its outer peripheral surface that projects to both sides along the cam curve.
e is formed, and the output shaft 25 is integrally formed in the central portion. 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 thereof. Alternatively, the output shaft 25 may be formed separately from the cam 24 so as to be integrated later. Inside each cylinder 23, a piston 27 having a hollow inside is slidably provided, and each piston 27 has a piston ring 2 on an outer peripheral portion of an upper portion.
8, a roller-shaped external cam follower 30 is rotatably attached by a piston pin 29 inside the lower portion, and further roller-shaped internal cam followers 33, 34 are rotatably attached by pins 31 and 32. There is.
One circumscribing cam follower 30 is a rim 24c of the cam 24.
2 inner contact cam followers 3
The rollers 3, 34 roll by contacting the inner peripheral surface of the rim 24c of the cam 24. In addition, an intake passage 35 connected to the intake pipe and an exhaust passage 36 connected to the exhaust pipe are formed in the upper portion of each cylinder 23, and the intake passage 35 and the exhaust passage 36 are formed.
An intake valve 37 and an exhaust valve 38 are respectively provided at portions of the cylinder that open to the upper part of the cylinder, and an ignition plug 39 serving as an ignition means is provided between the intake valve 37 and the exhaust valve 38.
Are mounted toward the inside of the cylinder 23. Other parts, not shown, have the same structure as the conventional four-stroke cycle gasoline engine. In the second embodiment, the shape of the rim 24e of the cam 24 is the same as that of each piston 2
The cams 7 are allowed to rotate in one direction while reciprocatingly sliding in each cylinder 23 by moving the same amount in opposite directions at the same time. In addition,
In addition to the above-described embodiment, a guide groove may be provided on at least one side surface of the cam as the positive-moving cam, and a roller-like cam follower rotatably held by a piston may be 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 also performs the same movement as shown in FIG. First, the output shaft 25 starts to rotate by the starter,
When the cam 24 rotates counterclockwise, the cam crest 24a
The cam followers 30 and 33, 34, which are inscribed in and out of the rim 24e of the portion, cause the piston 7 to descend from the state shown in FIG. 5, and the mixture of gasoline and air is sucked into the cylinder 23 via the open intake valve 37, and the cam Mountain 24a is 50
The piston 27 reaches the bottom dead center as shown in FIG. Next, when the cam 24 rotates 40 degrees, the piston 27 moves up the cam crest 24b, the mixture in the cylinder 23 is compressed by the piston 27, and the spark plug 3 is placed at the position of the top dead center.
9 ignites and explodes and expands, the cam crest 24b rotates 40 degrees, the piston 27 descends again, and reaches the bottom dead center. When the cam 24 rotates 50 degrees from this state and the piston 27 moves up the cam crest 24c, the exhaust gas in the cylinder 23 is exhausted through the open exhaust valve 38. Similarly, the piston 27 descends the cam crest 24c to perform the suction stroke,
The cam mountain 24d is raised to perform the compression stroke, and the cam mountain 24d
d is lowered to perform the expansion stroke, the cam lobe 24a is raised to perform the exhaust stroke, and the state returns to the state of FIG. In this way, the two pistons 27 reciprocate four times while the cam 24 makes one rotation, and the four stroke cycles of suction, compression, expansion, and exhaust are performed twice, and two explosions are performed for each cylinder 23. Be done.

Thus, according to the above embodiment, the cam 2
Each piston 27 reciprocates four times in one rotation of 4, and performs a four-stroke cycle of suction, compression, expansion, and exhaustion 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 with respect to four reciprocating movements of each piston 27, the rotation of the output shaft 25 is decelerated, the output rotation speed and heat generation and vibration are suppressed, and the energy conversion efficiency is good. Further, since the cam followers 30 and 33, 34 are used, the sliding corners can be reduced and the mechanical efficiency is good. Furthermore, the pistons 27 and the cylinders 23 are arranged symmetrically with respect to each other by 180 degrees, and the reciprocating motions of the opposed pistons 27 are also symmetrical, so that the dynamic balance is good and the vibration is small. Furthermore, since the time spent on the intake stroke and the exhaust stroke can be set longer than the time spent on 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, so that the engine can be optimized. The energy conversion efficiency can be improved and the dynamic characteristics such as vibration and driving performance can be optimized.

In FIG. 9, in the first embodiment, the pins 11 and 12 for supporting the inscribed cam followers 13 and 14 are extended outward, and the rollers 40 and 41 are rotatably supported at both ends thereof. The guide grooves 42 and 43 in the same direction as the piston 7 are provided on the wall surface of the cam case 2 facing the rollers 40 and 41 to guide the rollers 40 and 41 to roll. In the example shown in FIG. 9, each piston 7 has a roller 4 that rolls in the 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-mentioned embodiments, when the cam type engine shown in each embodiment has a multiple structure, the dynamic balance and the dynamic balance can be improved by appropriately arranging the adjacent engines so that the explosion timings do not overlap. The vibration damping property can be improved. Also, a balancer or flywheel can be provided for vibration and noise absorption.

In each of the above-described embodiments, two cylinders 3 and 23, which are 180 degrees apart and are opposed to each other in the radial direction, are provided around the cam cases 2 and 22, 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 cylinders that are opposed to each other in the radial direction by 180 degrees around the cam case, with each cylinder pair being separated by a predetermined distance around the cam case. is there. Further, the number of cam peaks of the cam is two in the first embodiment and four in the second embodiment, but if the cam curve is different and 180 ° symmetry, an even number of six or more is provided. Individual cam peaks can be provided and various cam curves can be set to change engine characteristics.

FIG. 10 shows a structure in which the number of cylinders and pistons is increased by modifying the first embodiment shown in FIG. That is, in the configuration of FIG. 10, the two cylinders 3 which are 180 degrees apart from each other and are opposed to each other in the radial direction around the cam case are set as one cylinder pair, and the other two cylinders 3 are arranged.
Two cylinder pairs are provided, where A is another cylinder pair. In this case, one cylinder pair 3 and the other cylinder pair 3A are provided around the cam case at a predetermined distance, that is, at an angle α, and the pistons 7 and 7A slide in each cylinder. The shape of the rim of the cam 4 is 1
Two pistons 7A sliding in the cylinders 3 forming one cylinder pair move in the same direction in opposite directions at the same time, and two pistons 7A sliding in the cylinders 3A forming another cylinder pair. Is moved in the opposite direction at the same time, and the cam 4 can rotate in one direction while all the pistons reciprocate 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-degree symmetric cam peaks 54 with different cam curves
Each piston 7 has two reciprocations with one rotation of the cam 54, and performs the same intake, compression, expansion and exhaust strokes as in the first embodiment. However, in the configuration of FIG. 11, the two pistons 7 move in opposite directions at the same time, but the amounts of movement of both pistons in opposite directions at the same time are not the same. in this way,
The characteristics of the engine can be changed by changing the moving amount of the piston.

In each of the above embodiments, the gasoline engine is illustrated, but only air is sucked from the intake passages 15 and 35 into the cylinders 3 and 23, not the air-fuel mixture, and fuel is injected as ignition means instead of the spark plug. A diesel engine can be constructed by providing the nozzle.

Further, the present invention provides various techniques for exhaust gas countermeasures and fuel consumption improvement, 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.

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

FIG. 7 is a schematic front cross-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 modified 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 the cam is changed in the engine of the first embodiment.

[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 mountain 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)

[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 even number of cam ridges of two or more at equal intervals and having a rim protruding laterally along a cam curve; and a piston reciprocally slidably provided in each cylinder, An external cam follower rotatably provided on each piston and circumscribing the rim of the positive cam, and an internal cam follower rotatably provided on each piston facing the external cam follower and inscribed in the rim, and The cylinder includes an air supply means and an ignition means provided in the cylinder, and the shape of the rim of the positive movement cam is such that the pistons move in the respective cylinders at the same time in opposite directions. A cam type engine adapted to allow the positive cam to rotate in one direction while sliding back. 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. A positive cam having two or more even number of cam ridges at equal intervals in the circumferential direction and a rim protruding laterally along the cam curve, and reciprocally slidable in each cylinder. A piston provided, an external cam follower rotatably provided on each piston and circumscribing the rim of the positive cam, and an internal cam rotatably provided on each piston facing the external cam follower and inscribed in the rim. A contact cam follower, and an air supply means and an ignition means provided in each of the cylinders, wherein each of the pair of cylinders is at a position separated by a predetermined distance around the cam case, The shape of the rim of the positive movement cam is such that all two pistons sliding in the cylinders forming the cylinder pairs move in opposite directions at the same time and all the pistons reciprocate in the cylinders. 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 stopping means in the circumferential direction.