JPS5941632A - Internal-combustion engine with variable compression ratio - Google Patents

Abstract

PURPOSE:To enable the automatic and stepless change in the compression ratio of an engine, by controlling the axial displacememt of a spiller so that the opened and closed position of a spill port for regulating the quantity of outflow of working oil from a hydraulic chamber behind an auxiliary piston for changing the compression ratio is controlled depending on the rotational frequency of the engine. CONSTITUTION:Working oil is continuously fed to a hydraulic chamber 15 behind an auxiliary piston 9. A spill port 19 provided in a stem 14 extending from the auxiliary piston 9 and projecting out of an auxiliary cylinder 7 is opened and closed by the axial displacement of a spiller 20 caused by an actuator 22, to drain the working oil out of the hydraulic chamber 15 to move the axial position of the auxiliary piston to change the compression ratio. A control circuit 24 regulates the actuator 22 depending on the output of a load detector 25. The opened and closed position of the spill port 19 is controlled depending on the output of a rotational frequency detector 26 so that the opened and closed position is much displaced backward below the rotational frequency of idling and much displaced at the rotational frequency of idling.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable compression ratio internal combustion engine in which the compression ratio is changed in accordance with operating conditions such as engine load.

K, which improves output and reduces fuel consumption in internal combustion engines, increases the compression ratio and is good, but when the compression ratio is increased, a noise occurs in the high load range.For this reason, conventional compression In an internal combustion engine with a constant ratio, the compression ratio must be set to a value that does not cause the high fi range II range (keep) . At the same time, fuel consumption cannot be sufficiently reduced.

Therefore, Japanese Patent Application Laid-Open No. 56-88926 as a prior art proposes to increase the compression ratio in the low load range and lower it in the high load range. When changing the compression ratio by moving the sub-history piston J inserted into the piston back and forth, the tip of the zero protruding outside the piston sub-series 'J should be the same as here. - When the intake negative pressure in the engine is in a low load range where the intake negative pressure in the engine is greater than a certain value, hydraulic pressure is sent to the hydraulic syringe to increase the compression ratio and the intake When the negative pressure is in the high φ11 range where the negative pressure is lower than a certain value, the yuzu oil pressure is released to lower the compression ratio. O where the ratio suddenly changes from high to low or from low to high
It is a N-OFF control, and the compression ratio is proportional to the load and is smooth (C control is not possible, and when the compression ratio suddenly changes, the engine's 1 torque fluctuation becomes large and the dry nozzle S-shield occurs.) Tee gets worse.

In response to this f'l, the inventors of the present invention, in the earlier patent application (Japanese Patent Application No. 57-48295), proposed that the auxiliary histometer, which was inserted into the auxiliary series (connected to the combustion chamber), be used to reduce the load on the engine. In order to slide back and forth accordingly, the rear chamber of the sub-vist system is used as a hydraulic chamber and hydraulic oil is continuously supplied thereto, while a stem is provided so as to protrude from the sub-vist system to the outside of the sub-series J spear. A spill boat is installed at the protruding part of the stem to allow the hydraulic oil in the hydraulic chamber to escape. By providing a spill body that operates so as to be displaced along the axial force direction of the stem, and by associating the spill body to operate in response to changes in engine load, self-help control of the compression ratio can be achieved as the engine load changes. We proposed an invention that allows smoothing in a stepless manner according to changes in .

In addition to automatically controlling the compression ratio in a stepless manner with respect to the load, the present invention relates to other engine operating conditions such as starting and idling. It is controlled by In other words, starting the engine (
By keeping the compression ratio at the lowest level while the engine reaches a certain rotational speed, starting the engine at a high compression ratio will prevent engine damage due to increased torque and abnormal combustion. While preventing deterioration of startability, it also maintains the compression ratio at the highest level during engine engine start-up and 7-g operation, thereby stabilizing idling operation, reducing the number of rotations during engine start-up and 7-g operation, and reducing exhaust gas. Further, the second invention of the present application, in addition to the first invention described above, provides a method for reducing the speed of the engine 5. , by keeping the compression ratio at the lowest level, the mode consumption a is reduced.

Hereinafter, the present invention will be explained with reference to the drawings of the embodiments. (4) Histoscope that slides back and forth inside, f5
11-j Each shows a combustion chamber formed by four stacking the lower surface of the cylinder head (2) in a spherical or polyspherical shape, and the combustion chamber f5) K has a cylinder head mark 2 approximately at the center thereof.
), and an intake boat and an exhaust boat (not shown) are open.

(7) is a secondary syringe installed in the above-mentioned cylinder: 7 cylinders (21 kg), and the lower side of the secondary cylinder (2) is in the combustion chamber (5), and the upper side is in the cylinder and in the royal chamber of lid (2). Open,
A cover plate (8) is provided at the opening to the two series heads of the sub-series J (7) to close the openings.

(9) is an auxiliary piston fitted slidably into the auxiliary piston (7), and the auxiliary piston (9) is provided with a histosiliary (9) I on the outer periphery of the auxiliary piston (9). When the combustion chamber (5) advances twice (6), the volume of the combustion chamber decreases and the compression ratio increases, and the secondary histograph (9) retreats in the nof direction away from the combustion chamber (5). This increases the volume of the combustion chamber and lowers the compression capacity, and this secondary piston (9)
The secondary histonia f91 K u is biased in the backward direction by the spring (10), and the secondary piston (9
) is advanced toward the combustion chamber (5) to the maximum, a stepped portion (11) is provided on the cylinder lid (2) side so as to prevent it from moving forward. Jis I・'
It is configured to define the position of the highest [1: 箭#+It] in 11'' base of J(9). In this case, the top surface (121) of the minor histone (9) looking into the combustion chamber (5) is a spherical shape with the same curvature as that of the spherical inner wall surface (13) of the combustion chamber (5). A recess is formed in the concave spherical top surface (12), and the auxiliary screw (9) is connected to the stepped portion (12).
It is configured to be continuous with the inner wall surface (13) of the combustion chamber (5) without any step when i↑ is changed to one in the position change of the maximum compression ratio according to the provisions of 1).

The secondary piston (
A stem (141) extending in the axial direction from the center of the stem (141) is integrally provided, and the stem (141) can be slid freely through the cover plate (8) and protrudes outward. h :J(
A hydraulic chamber (15) is formed between the back surface of the holder (9) and the lid (and (8)) 1-5 The hydraulic oil from the hydraulic source is supplied to the hydraulic chamber (15) through the check valve (16) and the port (1) Continuously supplied via force.The broken stem (14) has a hydraulic chamber (15).
The hydraulic chamber (18) is provided with a passageway (18) that communicates with the hydraulic chamber (
15) Drill a spill hole 1-f19+ to drain the hydraulic oil inside the cylinder into the silicator cylinder.

(20) shows a spill rig which is one embodiment of the spill body, and the spill rig (20) is attached to the stem (
14) (by slidingly fitting the spill link (20)
) is moved forward in the direction of the combustion chamber (5), the spill port 1- (19+ is closed by the relevant Schillishig (20), and when the Schillishig (20) is moved backward in the direction away from the combustion chamber (5), the spill boat (19) is closed. [21+ is a lever provided in the upper chamber of the Scilly J Yuhe Lido with its midway part pivoted on a shaft (23), and the lever (21) is One end of the above
(19) while Leverage 1) ITJ% asthma K
, an actuator <2 operated by a control circuit (24)
w, and the engine load detector (2) is connected to the control circuit (24).
5) is input, and the actuator 21 is configured to move the tifI-noted shifter (20) in the direction of the backward force in proportion to the increase in engine load CC. Furthermore, the eleventh control circuit (24) includes an engine rotation speed detector (
26) and throttle valve opening detector for intake air adjustment (input the confidence from 2 forces, 1-1, engine start switch is ON, and engine speed is lower than idling speed) When the rotation speed is not reached, the Spirley Jl
The spill ring (20) is moved backward by the actuator (221) to a greater extent than the actuator (221), and when the opening of the spill valve is at the idle position and the rotational speed is the same as that at idle, the spill ring (20) is moved backward by the actuator (221 When the throttle valve is moved forward significantly, and the opening degree of the throttle valve is at the idle position and the rotational speed is higher than a certain rotational speed, which is higher than the rotational speed at the time of fit 1, the above-mentioned Schiller
2+, it is configured to give priority to the control based on the load and move backward significantly.

In this configuration, when the spill port (19) is moved in the forward direction from the position shown by the solid line to the position shown by the two-dot chain line in FIG. ) Stops hydraulic oil from flowing out.
f II), reverse + h * f16) port (1η), the pressure in the hydraulic chamber (19) that is constantly supplied with hydraulic oil increases by -1, so the secondary hysteresis 1-near (91 is the combustion chamber (5
When the iT7 base advances to the opening of the port (19), the spill boat f1
Hydraulic oil starts to leak from 9+, and this leakage amount and hydraulic chamber (1
At the point when the supply amount to 5) is equal to 177, the sub-piston (9) stops moving. Spill link (2)
0) in the backward direction from the position of the double-dashed line to the position of the solid line, the spill bowl 1'' (19) is fully opened, the amount of flow from the spill port increases, and the pressure in the hydraulic chamber (15) decreases. Therefore, the secondary piston (9) is moved back away from the combustion chamber by the pressure of the combustion chamber (5) and/or the spring (10), and this retreat causes the spill boat (19) to close at When the progress is reached, the spillover occurs.
!・When the outflow amount from 09) decreases and the outflow amount becomes balanced with the supply amount, the sub piston (9) retreats.
] is stopped, the position of the sub-piston (9) can be changed arbitrarily by moving the Subirri-Jri C20+, and in turn the compression ratio can be changed arbitrarily. By connecting the lever (21) and actuator (22) to the engine load via the control circuit (24) so as to move backward as the load increases, the compression ratio is This is a force that can be automatically and steplessly controlled so that it gradually decreases as the engine load increases and gradually increases as the engine load decreases. In this case, the higher the engine speed is, the less likely engine knots are to occur, and the lower the engine speed is, the more likely they are to occur. It is also possible to modify the value of
In engines, atmospheric pressure and intake air temperature are adjusted so that as the atmospheric pressure or temperature of the intake air decreases, and as the humidity of the intake air increases, it becomes more difficult to generate It is related to intake conditions such as air temperature and humidity, and
The control circuit (24
), signals from the intake air condition detector (28) such as atmospheric pressure, intake air temperature and humidity, and/or engine temperature detectors such as 2 types of engine cooling water, lubricating oil temperature or shirifu lock temperature, etc. (29), and the value of the compression ratio is adjusted according to the intake condition and/or the engine temperature. It is also possible to modify it.

Next, when the engine is started, when the engine speed is about to reach a certain speed lower than the engine speed when idling, the spill valve 7 (20) is in the most retracted position, and therefore the secondary piston (9) Since the compression ratio is maintained at the lowest compression ratio at the most retracted position h', the required voltage at the spark plug can be lowered compared to when starting at a high compression ratio, and the crank This makes it possible to reduce the rotational torque of the crankshaft during the so-called uran+shiji rotation of the shaft.

When the throttle valve of the engine is at the idle position and the engine speed is at the idle speed, the engine throttle (20) is at its most advanced position, and therefore the secondary histone (9) is also at its most advanced position. Since it is in the most advanced position and is held at the highest compression ratio, ignition combustion at 7:00 is significantly affected by the temperature of the soil layer due to the high compression ratio, and the idle IJ is at 15 hours of operation. is stabilized, and the rotational speed can be set to a correspondingly lower value.Furthermore, unburned harmful components in the exhaust gas are reduced. the top surface of the sub-piston (9) (
] 2) is formed into a spherical recess so as to be continuous with the spherical inner wall surface ( ] 3) of the combustion chamber (5) without any step, the air-fuel mixture flow 7'1 in the combustion chamber (5) can be improved. It is more effective because it becomes extremely smooth and does not cover blind spots.

When the throttle valve is suddenly closed at the idle position while the engine is running, the spill ring (20) The sub-piston (9) moves backward significantly, and therefore the sub-piston (9) also moves back further, resulting in a lower compression ratio. When the compression ratio is related to the load, the compression ratio is highest when the engine decelerates, so the volume of the combustion chamber is minimized, and the pressure in the combustion chamber increases toward the vacuum side when the engine is descending, reducing the suction mixture. 13- The air flow rate increases, but when the engine decelerates, the compression ratio takes priority over the load and becomes lower, increasing the volume of the combustion chamber (5). Room (
5) It is possible to prevent the pressure from increasing significantly toward the vacuum side, and the amount of intake air mixture can be reduced.

In the explosion process of the engine, the sub-histo, If9)
When it receives a large explosive force, this 'explosive force causes the side hist-/ (9) to retreat slightly and the spillover 1'' f]
9) closes, while the hydraulic oil in the hydraulic chamber 05) becomes trapped within the hydraulic chamber (15), thereby bearing a large explosive force against the secondary piston (9). In this case, there is a secondary hysteresis caused by the leakage of hydraulic oil during the time when Spill Hole 1- (191 closes) and the subsequent pressure rise/soaking of the hydraulic oil, resulting in explosive combustion of the air-fuel mixture in the combustion chamber (5). It absorbs and softens the impact on the 1-n (9).

In addition, in the above example of harmful interference, the hydraulic oil that is constantly supplied to the hydraulic chamber (15) is lubricating oil in the engine or engine oil.
Car power steering wheel? Operation in the 7-wheel mechanism 14- Oil or hydraulic oil used in automatic transmissions of automobiles can be used, and the above embodiment is an example of the spill link ++7 as an embodiment of the 7-wheel mechanism. ), but as shown in Figure 3, the stems (1, 4a,
') is formed into a hollow shaft, and a spill rod (20a,) is slidably inserted into the stem (14a), and the spill rod (2 (20a) is slidably inserted into the stem (14a).
11'3,) may be configured to open and close the spill port 1-f''19a) by sliding with an actuator related to the load of the engine, as shown in Figures 4 and 5. As shown in the figure, the stylus ball at (1, 4b)
1 to 1 are formed on the slanted sprue 1- (19b) that is inclined with respect to the axis of the stem (14b), while a tooth-type spirulisic (20) is formed on the outer periphery of the stem (4b).
b) is rotatably and slidably fitted to the spirulli'J (
20b] with a bearing (not shown).
On the other hand, the pivot support 15, this Suhi 11/Rishiji (201))
When the stem (14tl) slides back and forth, one VCl-filled relief port (30) is drilled so that it matches the inclined spill port (19b). Gear 1 on the outer periphery of the stem (20b)
The stem (20b) is rotated by sliding the force (2) in the longitudinal direction with the actuator (24) related to the load of the engine. 1
The compression pressure may be fully automatically controlled by shifting the relief port 1-(30) to the (11 position or tn+ position) with respect to the inclined spill port 1-(19b) of 4b). (In this case, the stem (14b) is slidable,
It is held in a non-rotatable manner, and it is twisted here.
The mechanism for rotating the lever (20b) is not limited to the mechanism shown in the embodiment, but may also be a mechanical mechanism.

Although one embodiment has been described above, the present invention has a structure in which a sub piston is slidably inserted into a sub cylinder (J) which communicates with a combustion chamber, and a hydraulic chamber is formed on the back surface of the sub cylinder. While supplying hydraulic oil to the hydraulic chamber, a stem is provided in the axial direction of the sub-piston so as to protrude from υ to the sub-series 'J'2 to the sub-hysteresis 1 indicated by li, and the protruding end of the stem is provided with a stem. 1. Creation of the hydraulic chamber e+Drill a spill port for oil to flow out,
At the protruding end of the stem, the sonospill port is opened and closed to adjust the outflow from the spill ports 1 to 1, and its opening and closing position is displaced along the axial force direction of the stem. A spill rod that operates is provided, and the spill rod is configured to operate according to the load of the engine, and the opening/closing position of the spill port by the spill rod is controlled according to the load of the engine.
When the engine speed is below a certain speed, which is lower than the engine speed when the engine is idling, it is largely displaced in the backward direction, and when the engine is idling, it is significantly displaced in the forward direction. The compression ratio can be automatically controlled steplessly and smoothly, so you can control the compression ratio automatically! + There is no sudden torque fluctuation when changing the position, and therefore the driver's grip tee does not worsen.Furthermore, the present invention uses the rear side of the secondary histone in the secondary silicitor as a hydraulic chamber, and sends hydraulic oil to this to supply the secondary piston. It moves back and forth, and as in the prior art mentioned above, there is a hydraulic cylinder on the outside of the secondary cylinder, and a separate 7 cylinder cylinder (
Since there is no need to provide a
This makes it possible to reduce the weight.

Part -I - The present invention lowers the compression ratio at the beginning of starting the engine to reduce the engine torque by 1-1. Arrival 17- Since it stabilizes fire combustion, it is possible to start the engine from the start to the end of the start very smoothly, and at the same time, it is possible to downsize the Tanabata for starting the engine, and it is possible to This makes it possible to reduce fuel consumption by lowering the set rotational speed during engine cleaning, and also to make exhaust residue cleaner.

In addition to the first invention, the second Fl# of the present application has the following features:
By lowering the compression ratio when the engine is decelerating, it is possible to reduce the fuel consumption rate of the intake air-fuel mixture.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal sectional front view of the main parts of the engine, Fig. 2 is a sectional view taken from -0 in Fig. 1, and Fig. 3 and 4 are a spill rod and spill port. Another example diagram, Figure 5 1-
j: A plan view of FIG. 4. f1+-°° series J cylinder head, (2)... syringe head, (5)... combustion chamber, (6)... ignition plug, (7)... auxiliary cylinder head, ( 9)...Sub-piste y
, 115) - Hydraulic chamber, (141 (14a) (14b
) ・” Stem, [191 (19a) (19b)
- Spill port, (201 (20a) 1'20b)・
・・Spill rod, (2”;!I−°° actuator,
+241...Control 18- circuit, Ko...Load detector, Q motor °°° throttle opening degree detector, (26)...Rotation speed detector. Patent applicant Taihatsu Kogyo Co., Ltd. Representative Patent attorney Akio Ishii 19- Figure 4

Claims (2)

[Claims] (1). An auxiliary piston is slidably inserted into an auxiliary series communicating with the combustion chamber, and a hydraulic chamber is formed on the back surface of the auxiliary piston to supply hydraulic oil to the hydraulic chamber. A stem is provided in the axial direction of the secondary histone so as to protrude outside the secondary series J/2 from The protruding end of the stem is provided with a spill body that operates to open and close the spill port so as to adjust the amount of outflow from the spill port and to displace the opening and closing position along the axial direction of the stem. The spill body is configured to operate according to the load of the engine, and the opening/closing position of the spill port by the spill body is changed significantly in the backward direction when the rotation speed is below a certain rotation speed that is lower than the rotation speed during idling. A variable compression ratio internal combustion engine characterized by being configured to be displaced significantly in the forward direction during idle link. (2) A sub-piston is slidably inserted into a sub-piston that communicates with the combustion chamber, a hydraulic chamber is formed on the back surface of the sub-piston, and hydraulic oil is supplied to the hydraulic chamber; A spill port is provided in the axial direction of the sub-piston so as to protrude from the sub-histon to the outside of the sub-piston, and the hydraulic oil in the hydraulic chamber flows out from the protruding end of the stem. and the protruding end vC1l'i of the stem:, the spill port is opened and closed so as to adjust the outflow 1'' from the spill port, and the opening and closing position is displaced along the axial direction of the stem. A spill body is provided, and the spill body is configured to operate according to the load of the engine, and the opening/closing position of the spill port by the spill body is set at a certain rotation speed lower than the rotation speed at the time of rotation. 1. A variable compression ratio internal combustion engine, characterized in that it is configured to be largely displaced in the backward direction when the engine speed is below 500 mph or when the engine is decelerating, and to be significantly displaced in the forward direction when the engine is idle.