JPS58126434A - Smoothing device of torque in internal-combustion engine - Google Patents

Abstract

PURPOSE:To form a smoothing device of torque to small size and light weight in a single cylinder engine, by connecting a DC motor, which can be operated also as a generator, to a crankshaft and selecting action of the motor through a control circuit in accordance with each stroke. CONSTITUTION:A DC motor 2 of large diametrical flat type capable of operating as a motor and generator is directly connected to a crankshaft 1a of a single cylinder engine 1. While on the basis of crank angle data, throttle valve opening data, etc., a control circuit 4 detects each stroke of compression, explosive expansion, intake and exhaust in 1 cycle, in accordance with the detection result, electric power is supplied to the motor 2 from a capacitor 5 to operate the motor 2 as a motor reversely supply of the power is stopped to operate the motor 2 as a generator rotated by the crankshaft 1a and accumulate power from the motor 2 in the capacitor 5. In this way, a change of torque can be decreased while a device itself can be formed to small size and light weight further a quick response at transient time of acceleration and deceleration or the like can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for smoothing torque fluctuations in, for example, a single cylinder or 2 to 3 cylinder internal combustion engine.

Conventional torque smoothing devices of this type include, for example, those in which a large flywheel is attached to the rear end of the crankshaft of an internal combustion engine (hereinafter referred to as "Engine J"), and those in "Machine Research J Vol. 25, No. 1 As described on page 116 of No. (1973), there are also those using balun 1-thwaite.

However, in such a conventional torque smoothing device, the moment of inertia IP of the flywheel or balance weight is used, and the accumulated energy is used to
Since the torque is smoothed, in order to increase the smoothing effect, the moment of inertia IPi must be increased, which increases the weight of the device and worsens the response to acceleration and deceleration of the engine. There were some problems.

It should be noted that although balance weighters are highly effective in reducing vibration, they are not as effective as flywheels in absorbing torque fluctuations.

This invention was made by focusing on such conventional problems, and it solves the above-mentioned problem by using an active flywheel that absorbs and releases energy using electromagnetic force. An object of the present invention is to provide a torque smoothing device for an internal combustion engine that eliminates the problem.

Therefore, the torque extinguisher for an internal combustion engine according to the present invention has an electric machine that can operate as an electric motor and a generator connected to the crankshaft of a reciprocating (reciprocating) internal combustion engine, and a The internal combustion engine is configured with a control circuit that reduces torque fluctuations of the internal combustion engine by switching between electric motor operation and engine operation of the electric machine according to the compression, explosion, and intake/exhaust strokes of the internal combustion engine.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, the crankshaft 1a of the single-cylinder engine 1 includes:
A large-diameter flat DC motor 2, which is an electric machine that can operate as an electric motor and a generator, is directly connected to a position where a flywheel is normally attached.

That is, the crankshaft 1a of the engine 1 and the output shaft 6 of the motor 2 rotate together.

The control circuit 4 controls compression, explosion (expansion), etc. during one cycle of the engine '1 based on crank angle data, throttle valve opening data, etc. input from a crank angle sensor, throttle valve opening sensor, etc. (not shown). Each intake and exhaust stroke is detected, and depending on the detection result, power is supplied from the capacitor 5 to the motor 2 to operate the motor 2 as an electric motor, or conversely, the power supply is stopped and the motor is rotated by the crankshaft 12. The electric power generated from the motor 2, which operates as a generator, is transferred to a power storage device 5.
I store it in.

In a normal single-cylinder engine, the angular velocity ω of the crankshaft fluctuates greatly during one cycle (2 revolutions of the crankshaft at 720° in a 4-cycle engine), as shown by the solid line in Figure 2 (A) (4 strokes/1 cycle). In the engine, the crankshaft 1a rotates twice during one cycle).

That is, in the compression stroke, the gas in the cylinder is compressed while consuming the energy of the flywheel, so the angular velocity of the crankshaft continues to decrease during this period.

During the explosion (expansion) stroke, the combustion gas pushes down the piston and accelerates the flywheel, so the angular velocity ω increases.

In both the exhaust and intake strokes, although there is no significant change in the two strokes mentioned above, the angular velocity ω continues to decrease because energy is lost due to the friction work of the piston, etc. and the pumping work.

Therefore, in the above strokes, in the intake and exhaust strokes and compression strokes in which the angular velocity ω of the crankshaft 1a of the single-cylinder engine 1 shown in FIG. : Operates as an electric motor,
The driving force of the motor 2 suppresses the decrease in the angular velocity ω of the crankshaft 1a, and also prevents the angular velocity ω from decreasing as in the explosion (expansion) stroke.
When the power increases rapidly, the control circuit 4 stops power supply to the motor 2 and causes the motor 2 to operate as a generator.
A part of the rotational energy of the crankshaft 1a is consumed for work for rotating the motor 2.

As a result, an increase in the angular velocity ω can be suppressed, so that the angular velocity ω of the crankshaft 1a becomes approximately constant as shown by the broken line in FIG. 2(A), and the torque generated by the engine 1 also becomes uniform.

In addition, Fig. 2 (b) shows the motor 2 corresponding to the crank position.
shows the generated torque. Here, negative torque means
This shows that the motor 2 operates as a generator and applies braking to the engine 1.

FIG. 3 is a configuration diagram showing another embodiment of the present invention,
Portions corresponding to those in FIG. 1 are designated by the same reference numerals, and explanations of those portions will be omitted.

In this embodiment, the motor 2 is not directly attached to the crankshaft 1a, but is attached to the engine 1, for example, and a large gear 6 and a small gear 7 are attached to the crankshaft 1a and the output shaft B of the motor 2, respectively, and mesh with each other. The two are connected by a speed increaser consisting of.

By doing so, in addition to the same effects as in the previous embodiment, there are the following advantages.

- Since a high-speed motor can be used as the motor 2, the motor 2 can be made smaller and lighter.

(2) Since the generated or absorbed torque of the motor 2 can be reduced, the motor 2 can also be made smaller and lighter, and in particular, the radial dimension of the motor 2 can be made smaller.

However, since the structure is more complicated and heavier than the embodiment shown in FIG. 1 due to the gear mechanism, it is necessary to devise the arrangement of the device.

In addition, since l・lux frequently reverses positive and negative, gear 6.7
It is necessary to pay attention to gear design such as backlash countermeasures.

In the above embodiments, the present invention was applied to a single-cylinder engine, but it can be similarly applied to a two-cylinder or three-cylinder engine.

As has been explained hereafter, the torque smoothing device for an internal combustion engine according to the present invention is capable of reducing the moment of inertia)
rather than passive torque smoothing that relies on motor/
Active torque smoothing using a generator not only makes the device itself smaller and lighter, but also reduces transients such as acceleration and deceleration of internal combustion engines.
Time response is fast.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 (
A) and (B) are diagrams for explaining the operation of FIG. 1, respectively. FIG. 3 is a configuration diagram showing another embodiment of the present invention. 1... Single cylinder engine 1a... Crankshaft 2... Motor (electric machine) 6... Output shaft 4... Control circuit 5・・・・・・Condenser 6, 7・・・・Gear Diagram 1 (A) /' Q (B) Crank angle data Throttle valve opening data City In circuit 4 Part 2 Diagram angular velocity of Kunk shaft ■ crank angle

Claims (1)

[Claims] 1 An electric machine that can operate as a motor and a generator connected to the crankshaft of a reciprocating internal combustion engine, and a motor operation of the electric machine according to each stroke of compression, explosion, intake and exhaust during one cycle of the internal combustion engine. A torque smoothing device for an internal combustion engine, comprising: (c) a control circuit that reduces torque fluctuations of the combustion engine by switching between the generator operation and the generator operation.