JPH0481524A - Internal combustion engine - Google Patents

Abstract

PURPOSE:To improve efficiency and output of an engine and reduce a fuel consumption ration by setting input/output characteristics of a variable angular velocity ratio transmission mechanism so as to generate the change of the angular velocity of a crankshaft for increasing a volume variation ratio in cylinders in an initial period of a stroke, and decreasing it in latter periods of the stroke. CONSTITUTION:A transformation gear transmission mechanism 8 is used as a variable angular velocity ratio transmission mechanism 8. In the case that a changing pattern of the angular velocity shown in the figure is executed to a crankshaft 2, pistons 4 to 7 of cylinders I to IV of a four-cycle four-cylinder internal combustion engine 1 correspond to periods between points A and B in the figure in former half periods of intake and expansion stroke during descending from a top dead center, while they correspond to periods between points C and D in former half periods compression and exhaust stroke during rising from a bottom dead center. In any case, the angular velocity of the crankshaft 2 is higher than that of an output shaft having a constant velocity, so that the pistons 4 to 7 move with a higher speed. Contrarily, the pistons correspond to periods between points B and C in latter half periods of the intake and expansion stroke, and correspond to periods between points D and A in latter half periods of the compression and exhaust stroke. The angular velocity of the crankshaft 2 is thus lower than that of the output shaft having a constant velocity, so that the pistons 4 to 7 move slowly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to internal combustion engines, and in particular to internal combustion engines that operate in a completely different manner than conventional internal combustion engines, thereby achieving higher engine efficiency than conventional internal combustion engines. The invention relates to a new type of internal combustion engine.

[Conventional technology]

In general, internal combustion engines are machines that perform work by exploding and expanding intermittently, so the crankshaft is driven intermittently, and if left as is, the rotational fluctuations would be large, causing discomfort when the engine is installed in a car. Normally, efforts are made to make the angular velocity of the crankshaft as constant as possible by utilizing the inertia of a flywheel attached to the crankshaft. (For example, see Japanese Utility Model Application No. 47-590.) [Problem to be solved by the invention] It is no exaggeration to say that conventional technology has been directed toward making the rotation of the crankshaft of an internal combustion engine as similar as possible. However, if we change our way of thinking and reconsider this problem from the perspective of engine efficiency, we can see that due to the inertia of the flywheel, the rotation changes in a -like manner, and the piston moves in a -like manner during each stroke, which increases efficiency. I realized once again that this is not necessarily the case if good results are obtained in terms of this.

Therefore, the inventor came up with the idea of actively applying rotational fluctuations to the crankshaft, which is completely contrary to the conventional technology of making the rotation of the crankshaft uniform.
As a result of various studies on how various factors related to engine efficiency change when various types of rotational fluctuations are applied, and as a result of numerous simulations and experiments, the results shown in Figure 2 ( As shown in a), we will compare the case where the crankshaft rotates at a constant angular velocity from start to finish during every stroke (conventional style), as in the past, and look at the trends in the changes in characteristics. first for
The way in which this changes occurs is by increasing the angular velocity of the crankshaft at the beginning of each of the intake, compression, expansion, and exhaust strokes to make the piston move faster. One method is to reduce the angular velocity to slow the movement of the piston (hereinafter referred to as the first method), and the second method is to reduce the angular velocity of the crankshaft at the beginning of each stroke to slow the movement of the piston. There are three cases: one is to slow down the piston, and the other is to increase the angular velocity of the crankshaft at the end of each stroke to speed up the movement of the piston (hereinafter referred to as the second mode). , an attempt was made to analyze the internal state of the engine during each stroke.

The results are shown in FIGS. 2(b) to (e). Figure 2(b)
shows the change in the amount of intake air inflow per unit time during the intake stroke, that is, the intake flow rate.In the second mode, the piston moves gently at the beginning of the stroke, so the intake air follows well, and when compared at the same piston position, The flow rate is temporarily larger than in the other modes, but it soon reaches a plateau and tends to decrease, becoming smaller at the end of the stroke than before, whereas in the first mode, the piston moves quickly and reaches a large stroke position quickly, so the differential pressure between the cylinder pressure and atmospheric pressure is large from beginning to end, and the flow rate does not reach a plateau and does not decrease even towards the end of the stroke. As a result, according to the first method, the largest amount of intake air can be drawn into the cylinder compared to other methods.

Figure 2 (C) shows the change in the amount of heat that fuel particles in the intake air receive per unit time during the compression stroke. According to the first method, the surrounding air is adiabatically compressed and reaches a high temperature at the earliest stage. At the same time, the piston also moves to the high temperature part of the cylinder (top dead center), so heat flows to the fuel particles from the air around the high temperature and the high temperature part of the cylinder, increasing the amount of heat received. In this way, since the intake air is kept in a highly compressed and high density state for a relatively long period of time, the amount of heat absorbed from the high temperature combustion chamber walls and the like increases. In addition, the maximum temperature of the island cylinder decreases, and high compression becomes possible.

Figure 2 (d) shows the change in the amount of heat lost per hour during the expansion stroke. In the first mode, the high thermal energy of the combustion gas in the combustion chamber is dissipated from the combustion chamber walls, etc. After the piston moves a large distance quickly and performs a large amount of work in a short period of time, the remaining work is extracted over a relatively long period of time by the combustion gas whose temperature has decreased, so there is little heat loss and combustion Gas energy can be converted into work most efficiently.

Finally, Figure 2(e) shows the change in exhaust flow rate per unit time during the exhaust stroke. In this case as well, in the first mode, the piston moves to a position where the exhaust flow rate is large early, and the piston moves to the position where the exhaust flow rate is large. Since a large pressure difference is formed between the internal pressure and the atmosphere, the exhaust gas is discharged at a high speed, a high exhaust flow rate is obtained, and the exhaust gas is completely exhausted.

Therefore, the conclusion was reached that the first mode provides the highest engine efficiency compared to the prior art and the second mode in any of the intake, compression, expansion, and exhaust strokes.

Therefore, the present invention has been developed based on the above considerations and analysis results.
The aim is to utilize it in an actual internal combustion engine and develop a practical means to operate the piston in the first manner.
This is a problem to be solved by the invention.

[Means to solve the problem]

The internal combustion engine of the present invention includes a variable angular speed ratio transmission mechanism between the crankshaft and the output shaft, and at least one of the intake, compression, expansion, and exhaust strokes that the cylinder performs during operation.
The variable angular velocity ratio transmission is configured such that, in one or more strokes, a change in the angular velocity of the crankshaft occurs such that the rate of change in volume within the cylinder is large at the beginning of the stroke and smaller at the end of the stroke. It is characterized by setting the input/output characteristics of the mechanism.

[For production]

A variable angular velocity ratio transmission mechanism is provided between the crankshaft and the output shaft, and the input/output characteristics thereof are adjusted in at least one or more of the intake, compression, expansion, and exhaust strokes.
By setting the volume change rate in the cylinder to be large at the beginning of the stroke, that is, the movement of the piston is relatively fast, and smaller at the end of the stroke, that is, the movement of the piston is relatively slow, Even when the output shaft rotates at a substantially constant angular velocity, the crankshaft is forced to rotate at unequal angular velocities with significant rotational fluctuations.

When the special means of the present invention is applied to the intake stroke, the piston inside the cylinder moves quickly at the beginning of the intake stroke, and a large negative pressure is generated in the cylinder from the beginning of the intake stroke. A large amount of inertia acts on the flow from an early stage.
, the flow rate increases and the intake air filling efficiency becomes significantly higher.

When applied to the compression stroke, the crankshaft quickly rotates from the bottom dead center position at the beginning of the stroke when the compression reaction force acting on the piston is small, causing the piston to rise quickly and the compression reaction force to increase. At the end of the stroke, the piston moves slowly to effectively utilize the relatively small power consumption and slowly compress the intake air to a high pressure. Therefore, abnormal ignition and knocking due to rapid compression are less likely to occur.

When applied to the expansion stroke, in the early stage of the stroke, the high-energy combustion gas immediately after the explosion quickly moves the piston to perform effective work before the high-energy combustion gas loses heat to the combustion chamber walls, etc., and - expands. The residual energy of the cooled combustion gases is slowly absorbed by the piston, whose speed is reduced, and is converted into as much useful work as possible. As an extreme example, even if a large explosion pressure acts on a piston at top dead center, no effective rotational energy can be extracted from the crankshaft, but when the crankshaft has rotated significantly from top dead center, the piston It is clear that when a large explosion pressure is applied to the crankshaft, the energy that can be extracted from the crankshaft as effective torque increases. According to the present invention, since the piston is quickly lowered from the top dead center position at the beginning of the expansion stroke, the proportion of combustion energy converted into effective work increases for the above reasons, and noise and vibration are reduced. It is.

In addition, when applied to the exhaust stroke, the piston moves quickly at the beginning of the stroke, increasing the pressure of exhaust gas in the cylinder from an early stage and giving large inertia to the exhaust flow.
Increase exhaust flow rate to improve exhaust efficiency.

In this way, no matter which stroke the special measures of the invention are applied to, the efficiency of the engine increases, the power increases and: 1. The result is that the fuel efficiency rate decreases.

〔Example〕

FIG. 1 shows an embodiment of the present invention, and is one example in which the present invention is applied to a four-cylinder internal combustion engine 1. In FIG. A small flywheel 3 for adjustment is attached to one end of the crankshaft 2, which provides the minimum inertia force necessary for the engine 1 to continue rotating on its own, It is not provided for smoothing the rotation of 2. Therefore, if the moment of inertia of the crankshaft 2 itself and the members directly connected to it are sufficiently large,
There is no need to provide a flywheel 3 for adjustment.

Normally, in the case of an in-line four-cylinder four-cycle engine, four cylinders 1. I[, III, I''i/ are often divided into two groups with pistons that move in the same way, such as ■ and ■ and ■ and ■, as shown in Figure 1, and each group is They are connected to a common crankshaft 2 at angular intervals of 180°, and are ignited in the order of I-n-r\-III or ■-m-rv-n, and each cylinder is fired every 180° rotation of the crankshaft. The explosions occur sequentially and one cycle is completed in two revolutions.Therefore, in this case, the arrangement is most convenient for the present invention, with pistons 4 and 7 of cylinders ① and ② of the first group When at dead center, pistons 5 and 6 of cylinders (1) and (2) of the second group are at bottom dead center, and the beginnings and ends of all strokes of all cylinders I to (2) are synchronized, respectively. Each stroke is designed to shift in the firing order at 180° intervals.

What is shown as 8 in FIG. 1 is a variable angular velocity ratio transmission mechanism which is the gist of the present invention. It uses a transformation gear transmission mechanism in which gears 9 and 10 and 11 and 12 are meshed together. The variable angular velocity ratio transmission mechanism 8 is a mechanism selected to convert the rotation of the crankshaft 2, which rotates at unequal angular velocity, that is, the rotation is intentionally varied, into rotation having a constant angular velocity. The angular velocity ratio between the input and output shafts changes periodically during rotation. Therefore, the input shaft 13 is connected to the crankshaft 2.
If a thick original flywheel 15 is attached to the output shaft 14 and power is transmitted from the 8-force shaft 14 to a driven body such as a transmission or differential gear (not shown), a large moment of inertia will be generated by them. Since the output shaft 14 attempts to rotate at a constant angular velocity, the crankshaft 2 of the engine 1 is forced to undergo periodic rotational fluctuations due to the predetermined variable angular velocity ratio characteristic of the transmission mechanism 8. .

The variable angular velocity ratio transmission mechanism 8 can be configured by a transformation gear such as an elliptical gear, or can also be configured by a mechanism other than a gear such as a crank mechanism. Even if transformation gears are used, there is no need to use the four transformation gears 9 to 12 and the countershaft 16 as shown in FIG. You can also use it as However, depending on the shape of the transformation gear, it may not be possible to simply use one string due to restrictions on the effective pressure angle and problems with the phase difference.

FIG. 3 shows, as an embodiment of the variable angular velocity ratio transmission mechanism 8, a negative set of transformation gears 17 and 1B (indicated by tooth pitch curves) meshing with each other. The transformed shapes of the transformed gears 17 and 18 can be easily understood by comparing them with virtual perfect circles 19 and 20 drawn by two-dot chain lines overlapping them. For gear cutting of transformation gears, a change pattern of the angular velocity ratio between the input and output shafts 13 and 14 (or 16) is applied to a special gear cutting machine that utilizes NC control, which is currently in practical use. Transformation gears 17, 18, etc. that bring about such a change in angular velocity ratio can be freely manufactured.

The variable angular velocity ratio transmission mechanism (transformation gear transmission mechanism) 8 as shown in FIG. 3 brings about a change in the angular velocity ratio in a pattern as shown in FIG. In the figure - perfect circle 21 drawn with a dotted chain line
indicates the rotation of the output shaft 14 (or countershaft 16) that rotates at a constant speed, and since the distance from the center O to each point on the circumference, that is, the radius is constant, it is a constant speed rotation. .

On the other hand, in FIG. 4, the eyebrow-shaped curve 22 is
It represents the angular velocity that changes in response to an arbitrary angle around the center point O, that is, the crank angle. The curve 22 is a point A-
Since the points B and C-D are outside the perfect circle 21, if the countershaft 16, which is the output shaft in this case, is rotating at a constant angular velocity, the input shaft 13 and The angular velocity of the crankshaft 2 connected thereto is greater than that of the output shaft. Also, between points 8 and 6 and within the period between points D and A, the angular velocity of the crankshaft 2 is smaller than that of the output shaft because the curve 22 is inside the perfect circular constant angular velocity curve 21. There is.

Therefore, a transformation gear transmission mechanism 8 as shown in FIG. 3 is used as the variable angular velocity ratio transmission mechanism 8 in FIG. 1, and a pattern of change in angular velocity as shown in FIG. When executed, the pistons 4 to 7 of each cylinder I to ■ of the 4-stroke, 4-cylinder internal combustion engine 1 move to point A in FIG. 4 in the first half of the intake and expansion strokes descending from top dead center.
Corresponding to the period -B, and also in the first half of the compression and exhaust strokes rising from the bottom dead center, corresponding to the period C-D, the angular velocity of the crankshaft 20 is greater than that of the output shaft at a constant speed. , the movement of pistons 4 to 7 becomes faster.

On the contrary, the second half of the intake and expansion strokes corresponds to the period of points B-C in FIG. Since the angular velocity of the crankshaft 2 is smaller than that of the shaft,
The movement of pistons 4 to 7 becomes slow.

In this way, in the internal combustion engine 1 shown in FIG. 1, the pistons 4 to 7 move rapidly during the first half of every stroke, that is, between points A and B and between points C and D in FIG. In the latter half of the stroke, that is, between points B and C and between points D and A, the movement of the piston becomes gradual, and the first mode of operation described with reference to FIG. 2, which is the aim of the present invention, is obtained, and the intake air Improved operation in all strokes of compression, expansion, and exhaust, i.e., intake flow rate, exhaust flow rate, and heat of compression increase, and heat loss decreases compared to conventional internal combustion engines with constant rotation of the crankshaft. As a result, engine efficiency is significantly increased, resulting in lower fuel consumption and higher output.

The variable angular speed ratio transmission mechanism 8 as shown in FIG. 3 which produces the speed change as shown in FIG. 4 can be used almost as is in a two-cylinder two-stroke engine. A two-stroke engine completes its cycle in one revolution and consists of two strokes: a compression stroke in which the piston moves up, and an expansion stroke in which the piston descends.Ignition occurs near top dead center at the end of the compression stroke, and the expansion stroke Scavenging with pressurized fresh air occurs near the bottom dead center from the end of the compression stroke to the beginning of the compression stroke.

Therefore, the two cylinders are connected by a common crankshaft with a 180° phase shift, and the compression stroke of one cylinder is synchronized with the expansion stroke of the other cylinder, and the ignition is performed every 180° of the crank angle. If you do this, like a 4-cylinder 4-cycle engine, each cylinder will alternately explode at 18Q° intervals and perform the expansion stroke, while the other cylinder will perform the compression stroke, so the variable angular velocity ratio transmission mechanism 8 will When a speed change is applied to the crankshaft as shown in 22 in Fig. 4, the angular velocity of the crankshaft increases at the beginning of the stroke (points A-B and C-D) in both the compression stroke and the expansion stroke. The piston speed increases at the end of the stroke (points B-C and D-A).
), the angular velocity of the crankshaft decreases and the speed of the crankshaft decreases. As a result, the aforementioned first mode of operation is achieved and engine efficiency is improved in both compression and expansion strokes.

Thus, it is unnecessary to explain that the present invention can be applied to a two-stroke engine, and for the same reason, can also be applied to a low-pressure engine. In all of the embodiments described above, the strokes of each cylinder in a multi-cylinder engine are conveniently arranged in synchronization with each other at 180° intervals, and in terms of how to give a speed change to the crankshaft, "fast at the beginning of the stroke, There are cases where the common rule "late at the end of the stroke" can be applied as is, but for example, in the case of an inline six-cylinder four-stroke engine with a firing interval of 120 degrees, the "late at the end of the stroke of one cylinder" In multi-cylinder engines where the strokes of the cylinders and other cylinders do not continue in sequence and some of them overlap, the crankshaft It is not possible to decide exactly how to apply velocity changes to the shaft (a pattern like the one shown in Figure 4).

However, the effect of the present invention is mainly produced by increasing the piston speed at the beginning of the intake, expansion, and compression strokes, and therefore, rather than slowing down at the end of the stroke. By placing emphasis on speed and taking that element first, even if parts of each stroke overlap and the demands for increasing and decreasing angular velocity conflict, it is possible to compromise between the two in the design. It is possible to find a point, and even such a multi-cylinder engine can achieve higher engine efficiency than a conventional constant velocity engine. The point is to find the optimal compromise so that the engine as a whole can demonstrate better performance than the conventional one, and this means that the engine has one more point that can be matched, that is, This means that the degree of freedom for finding the optimal point has increased by one.

In the case of a single-cylinder four-stroke engine or two-stroke engine, there is no need to consider the relationship with other cylinders like in a multi-cylinder engine, so the angular velocity of the crankshaft is high at the beginning of each stroke, as per the rules, and The variable angular velocity transmission mechanism 8 may be designed to slow down at the end of .

〔Effect of the invention〕

In the internal combustion engine to which the present invention is applied, the mechanism of action explained in the section above provides better engine efficiency than the conventional internal combustion engine, so the output of one engine increases and the fuel efficiency rate decreases. Effects can be obtained.

Rotation fluctuations are intentionally given to the crankshaft, but since a variable angular velocity ratio transmission mechanism is provided between it and the output shaft, the output shaft can output smooth rotation at a constant angular velocity. The driven body is not adversely affected by rotational fluctuations.

[Brief explanation of drawings]

FIG. 1 is a conceptual vertical cross-sectional view showing the overall configuration of an embodiment of the present invention, and FIGS. 2(a) to (e) compare the analysis results conducted to derive the present invention with the prior art etc. Line diagram shown, 3rd
The figure is a conceptual diagram illustrating the variable angular velocity transmission mechanism that is the main part of the present invention, and FIG. 4 is a diagram illustrating the angular velocity curve that is the Ohata force characteristic of the variable angular velocity ratio transmission mechanism. 1...4 cylinder internal combustion engine, 2...crankshaft, 3...
...Flywheel for adjustment, 4-7...Piston, 8...Variable angular velocity ratio transmission mechanism (transformation gear transmission mechanism),
9-12...Transformation gear, 13...Input shaft, 14
...Output shaft, 15.. Flywheel, 16.. Counter shaft, 17.18.. Transformation gear, 19-21.. Perfect circle, 22.. Angular velocity curve. Fig. 3 Fig. 2... Crankshaft 8... Variable angular speed ratio transmission mechanism 14... Output shaft 15... Flywheel Fig. 4 8... Variable angular speed ratio transmission mechanism 17.18...・Transformation gear 21... Constant angular velocity curve 22... Angular velocity curve diagram

Claims (1)

[Claims] A variable angular speed ratio transmission mechanism is provided between the crankshaft and the output shaft, and the intake, compression, expansion, and
In at least one or more of the exhaust strokes, a change in the angular velocity of the crankshaft occurs such that the volume change rate in the cylinder is large at the beginning of the stroke and becomes smaller at the end of the stroke. An internal combustion engine characterized in that the input/output characteristics of the variable angular speed ratio transmission mechanism are set as follows.