JPH10196396A - Variable stroke device for miller cycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable stroke device for increasing an expansion ratio by being an expansion stroke and an exhaust stroke larger than a suction stroke and a compression stroke without providing an operation mechanism of an intake valve and a supercharger. SOLUTION: A crankshaft pinion gear 5 is rotated by vertically reciprocating motion of a piston 1 via a crankshaft 8. By the rotation of the crankshaft pinion gear 5, a rotation is transmitted to a sun gear 4 as output while the crankshaft pinion gear 5 rotates twice along a ring gear 6 incorporated into and fixed to a cylinder block, to thereby rotate the ring gear 6 once. Accordingly, it is possible to be an expansion stroke and an exhaust stroke larger than a suction stroke and a compression stroke.

Description

Description: TECHNICAL FIELD The present invention relates to a variable stroke device for a Miller cycle engine.

[Technical Background and Problems of the Invention] As an outline of the theory of the Miller cycle, in order to efficiently convert heat energy into mechanical energy, the expansion stroke and the exhaust stroke are made larger than the suction stroke and the compression stroke. That is, the idea is to increase the expansion ratio. As a method, there are an early closing type in which the intake valve is closed before the bottom dead center and a late closing type in which the intake valve is closed after the bottom dead center. In the early closing type, an output that is expected cannot be obtained because the intake air amount at a high rotation is extremely reduced. For this reason, it has not been put to practical use only in theory. In addition, although the other type of late closing has been put to practical use, the air-fuel mixture once sucked in the intake stroke is pushed back from the cylinder through the intake valve to the intake system after the bottom dead center, reducing the amount of intake air that can be taken in. I do. Therefore, since the torque is proportional to the amount of the air-fuel mixture taken in, there is a problem that the torque becomes insufficient. To overcome this problem, the Miller cycle engine must be supercharged. Making the turbocharger an absolutely necessary condition is difficult and impractical in terms of cost, small size, light weight, efficiency, mountability and the like.

[Object of the Invention] In view of the above, the present invention does not provide an intake valve operating mechanism and a supercharger, and the crankshaft pinion gear rotates twice along a ring gear fixedly incorporated in a cylinder block. By transmitting rotation as output to the sun gear and making one revolution of the ring gear, the expansion stroke and the exhaust stroke are made larger than the suction stroke and the compression stroke. That is, in order to efficiently convert the thermal energy of the engine into mechanical energy, it is an object to obtain a variable stroke device for increasing the expansion ratio by the movement of the piston itself.

[Construction of the Invention] The present invention will be described below with reference to embodiments shown in the drawings. The vertical reciprocating motion of the piston 1 is changed into a rotary motion by a crankshaft 8 which is independent for each cylinder. This rotational movement is the rotation of two left and right crankshaft pinion gears 5 integrally formed at both ends of the cran shaft 8. The rotation of the crankshaft pinion gear 5 transmits the rotation as an output to the sun gear 4 while rotating twice, and revolves the ring gear 6 once, along a ring gear 6 fixed in the cylinder block. FIG. 3 is a diagram showing a state of a suction stroke. The position of the crankshaft pinion gear 5 is located directly above the sun gear 4, and the crankshaft arm 9 is in a state of facing downward. FIG. 4 is a view showing a state of a compression stroke. From the bottom dead center of inhalation in FIG.
This is a state in which the crankshaft pinion gear 5 is rotated right by 180 °. The position of the crankshaft pinion gear 5 exists at a position immediately to the left of the sun gear, and the crankshaft arm 9 is in an upward state. FIG. 5 is a diagram showing an expansion stroke. 4, the crankshaft arm 9 faces downward with the crankshaft pinion gear 5 further rotated clockwise by 180 °, and the crankshaft pinion gear 5 is located immediately below the sun gear. FIG. 6 shows the exhaust stroke, and shows a state in which the crankshaft pinion gear 5 is further rotated by 180 ° clockwise than in FIG. The crack shaft arm 9 faces upward, and the crankshaft pinion gear 5 is located right next to the sun gear. As mentioned above,
The expansion stroke in FIG. 5 and the exhaust stroke in FIG. 6 are larger than the intake stroke and the compression stroke in FIG. 4, and as a result, the expansion ratio is increased and the thermal efficiency is improved.

[Effects of the Invention] As described above, according to the present invention, the vertical reciprocating motion of the piston can be changed into the rotary motion by the independent crankshaft for each cylinder. This rotational movement is the rotation of two crankshaft pinion gears, one on the left and one on the left, which are integrally formed at both ends of the clan shaft. The rotation of the crankshaft pinion gear transmits rotation as output to the sun gear while rotating twice, and revolves the ring gear once, along a ring gear incorporated and fixed in the cylinder block. As a result, the expansion stroke and the exhaust stroke can be made longer than the intake stroke and the compression stroke without operating the intake valve. That is, since the expansion ratio can be increased, the thermal efficiency is high, and a high-efficiency engine with a small displacement can be realized. The magnitude of the torque is determined by the length of the arm of the crankshaft if the expansion force is constant. It is better to increase the length of the arm of the crankshaft in order to obtain high torque. However, it is limited by the compression ratio. Accordingly, comparing FIG. 3 with FIG. 4, the crankshaft pinion gear is lowered to a position horizontal to the sun gear in FIG. 4, so that the crankshaft pinion gear of FIG. If the value obtained by subtracting the length from the center point of the position to the center point of the sun gear is doubled, the length of the suction and compression strokes is obtained. That is, the length of the actual crankshaft arm is not twice the length of the suction and compression strokes, but a shorter suction stroke and compression stroke can be achieved. Therefore, a high torque can be obtained with a small displacement.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a variable stroke device of a Miller cycle engine.

FIG. 2 is a side view taken along the line AA of FIG. 1;

FIG. 3 is a cross-sectional view showing an embodiment of a suction stroke.

FIG. 4 is a cross sectional view showing an embodiment of a compression stroke.

FIG. 5 is a cross-sectional view showing an embodiment of an expansion stroke.

FIG. 6 is a cross-sectional view showing an example of an exhaust stroke.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piston 2 Conlot 3 Pinion gear 4 Sun gear 5 Crankshaft pinion gear 6 Ring gear 7 Carrier plate 8 Crankshaft 9 Crankshaft arm

Claims (3)

[Claims] 1. The vertical reciprocating motion of the piston (1) is changed into a rotary motion by an independent crankshaft (8) for each cylinder. This rotational movement is rotation of two left and right crankshaft pinion gears (5) integrally formed at both ends of the crankshaft (8). The rotation of the crankshaft pinion gear (5) is transmitted along the ring gear (6) incorporated in the cylinder block and fixed to the sun gear (4) while rotating twice, and the ring gear (6) is rotated once. Revolve. Thus, a variable stroke device for a Miller cycle engine characterized in that the expansion stroke and the exhaust stroke can be made larger than the intake stroke and the compression stroke. 2. The bearing portion at both ends of the kunk shaft (8) includes a ring gear (6) incorporated and fixed in a cylinder block, a crankshaft pinion gear (5),
It is composed of components such as a pinion gear (3), a sun gear (4), and a carrier plate (7). The impact load from the piston (1) is directly applied to the carrier plate (7) and each gear (3, 4, 5, 6). For this reason, it is necessary to reduce the impact load by increasing the contact area of each gear (3, 4, 5, 6). For this purpose, helical gears are used for the respective gears (3, 4, 5, 6) at both ends of the bearing. However, if a helical gear is used, thrust may be caused. Therefore, the right and left tooth profiles of both ends of the bearing are reversed. Further, the carrier plate (7) is divided and replenished for convenience in assembling the shaft of each gear (3, 4, 5). Therefore, the divided carrier plate (7) is assembled by abutting the shaft of each gear (3, 4, 5) so as to be axially attached thereto, and interlocked with the revolving direction of the shaft of each gear (3, 4, 5). A crankshaft bearing device for a variable stroke device of a Miller cycle engine, characterized in that the gears (3, 4, 5) are positioned and a part of the impact load from the piston (1) is received. 3. The setting of the number of cylinders and the ignition sequence is based on the arrangement in which the crankshaft pinion gear (5) is incorporated in the carrier plate (7) with the sun gear (4) as the center point. Cylinders are 90 ゜, 3 cylinders and 6 cylinders
A device for setting the number of cylinders and the ignition sequence by means of a carrier plate (7) of a Miller cycle engine, characterized in that the cylinders are mounted at equal intervals, for example at 120 °.