JPS5910755A - Variable compression ratio internal-combustion engine - Google Patents

Abstract

PURPOSE:To correct the compression ratio automatically in accordance to the temperature by moving a sub-piston inserted into a sub-cylinder conducting to the combustion chamber while providing a mechanism for displacing the sub- piston in accordance to the engine temperature on an internal-combustion engine having variable compression ratio. CONSTITUTION:A sub-piston 9 is inserted into a sub-cylinder 7 conducted to a combustion chamber 5 then the operating oil is fed through a check valve into a hydraulic chamber 12 on the rear face and flowed out through a spill port 16 of the stem 11a. An actuator 23 will slide a spill ring 17a on the stem 11a through a lever 27 in accordance to the load thus to stop the sub-piston at the position where the pressure oil flow through the spill port 16 will balance with the oil supply. The stem 11a is splitted into two and connected through a bimetal and constructed such that the entire length will be shortened as the engine temperature rise, then the compression ratio is corrected automatically to the lower level resulting in prevention of knocking under high temperature.

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 the load and/or operating condition of the engine.

1 To increase output and reduce fuel consumption in internal combustion engines
Should I just increase the compression ratio? If I increase the compression ratio, knocking will occur in the high load range and/or low rotation range. For this reason, in a conventional internal combustion engine with a constant compression ratio, the compression ratio must be set to a value that does not cause sagging in the high load and/or low rotation range, so the output is higher in the low load and/or high rotation range. In addition to being unable to produce
It is not possible to sufficiently reduce fuel consumption.

Therefore, Japanese Patent Application Laid-open No. 56-88926 as a prior art proposes to increase the compression ratio in the low rotation/low load range, lower it in the low rotation/high load range, and increase it in the high rotation range. When changing the compression ratio by moving the sub-piston inserted into the sub-cylinder communicating with the combustion chamber back and forth, the cylindrical cylinder protrudes from the sub-screw 1 to the outside of the sub-syringe. The tip is in contact with the planar gloss in the oil linter installed on the same axis as this, and the intake negative pressure in the engine is greater than a certain value in the low load range. At this time, hydraulic pressure is sent to the hydraulic syringe to increase the compression ratio, and when the intake negative pressure is lower than a certain value in the high load range and the rotation speed is lower than a certain value at low rotations, the hydraulic pressure of the hydraulic syringe is released to increase the compression ratio. Therefore, the control of the compression ratio is an ON-OFF type control in which the compression ratio suddenly changes from high to low or from low to high after a certain load value and rotation speed. cannot be controlled smoothly in proportion to the load and/or rotational speed, and when the compression ratio suddenly changes, the engine's one-herk fluctuation becomes large and the triverility deteriorates.

In contrast, the present inventors filed an earlier patent application (Japanese Patent Application No. 57
-48295), when the sub-piston inserted into the sub-cylinder communicating with the combustion chamber is slid after MiJ according to the engine load and/or rotation speed, the sub-screw 1-
The right side chamber of the stem is the curved chamber 11, and hydraulic oil is continuously supplied to this chamber. A spill boat is installed to prevent the hydraulic oil from escaping in the oil storage chamber, and the spill boat from the spill boat 1 is placed in the protruding part of the housing. d
A spill body is provided that operates to open and close in a manner such that the load and/or rotation speed of the engine changes, and to displace the opening and closing position along the axial direction of the stem. Alternatively, the present invention relates to a system that operates in response to changes in engine speed, so that the automatic control of the compression ratio can be performed steplessly and smoothly in response to changes in engine load and/or engine speed. Proposed.

The present invention is based on the prior invention by the present inventors, in which correction for engine temperature is added to the automatically controlled compression ratio.

In other words, engine knocking is more likely to occur as engine and engine temperatures rise, so the compression ratio value by the automatic control of the prior invention is adjusted to prevent knocking when the engine temperature is high. If you set this, there will be too much margin for knocking when the engine temperature is low, and if you set it according to when the engine temperature is low, knocking will occur when the engine temperature becomes high. In view of this, the present invention is configured to displace the secondary piston in the backward direction in response to the opening/closing position IN of the spill bow 1 to the opening/closing position IN of the engine by the spill body rising by M degrees. The compression ratio is automatically controlled or adjusted so that it gradually decreases as the engine temperature rises.

Hereinafter, the present invention will be explained with reference to the first embodiment shown in FIGS. 1 to 3. In the figures, (1) is a cylinder block, (
2) is the Noritsuta head (3) is the cylinder block (1)
), a screw 1 that slides back and forth within the pore (4) of the
(5) indicates a combustion chamber formed by recessing the lower surface of the Noritsuta head (2), and the combustion chamber (5) has an ignition column (6) screwed onto the Noritsuta head (2) approximately in the center thereof.
At the same time, the intake boat and exhaust boat (not shown) are open.

(7) is a sub-printer installed in the cylinder cylinders 1 to (2), and the sub-cylinder (7) is located on the lower side or in the combustion chamber (5).
1" open each on the two Noritsuta heads (2) on the upper surface of the Noritsuta head (2), and the sub-slicers (7)
) is provided with a cover plate (8) for closing the opening to the two cylinder heads 1-''. (9) is a sub-screw that is slidably inserted into the sub-cylinder (7). When the sub-piston (9) moves in the direction of the combustion chamber (5), the combustion chamber volume The bond decreases, the compression ratio increases, and the secondary screw 1
-No (9) When moving back in the direction away from the combustion chamber, the breeding of the combustion chamber increases and the compression ratio becomes lower.
The auxiliary piston (9) at the center of the eye is pushed in the backward direction at 10, and the auxiliary piston (9) is attached to the rear side of the auxiliary piston (on the back side of the combustion chamber (5)). The relevant sub-screws 1 to 1 (
A stem l-(+1) extending in the axial direction from the center of the stem l-(+1) is integrally provided, and the stem l-(+1) extends slidably through the cover plate (8) and protrudes outward. Piston (9)
An oil well chamber (121) is formed between the back surface of the engine and the cover plate (8), and a check valve (13
Continuously supplied via the hydraulic pressure supply port h (14). Furthermore, the stem (1]) is equipped with an Mt FJ chamber (passage Q5 communicating with the stem), and the stem (1]) or lid plate (
8) In the part that protrudes in the opposite direction, there is a hydraulic chamber a marked MiJ.
Grooved spill holes 1 to (16) are drilled to release the lubricating oil inside the cylinder into the upper chamber of the cylinder head 1, and these grooved spill holes 1 and 0fi) are located on the right side of the stem (1υ).
It is tilted at an appropriate angle (0).

(I) is a spill link which is an example of a slot body rotatably and slidably fitted on the protruding end of the stem (11), and the spill link (171 includes the stem 1,
(11) When moving forward in the direction of the combustion chamber (5), it communicates with the spill port (Je) and the stem (1) is connected to the spill port (Je) that moves backward in the direction away from the combustion chamber (5). A relief port 08) is provided so that the

Then, on the outside of the spill link (lη), a ring body having a gear (241) on the outer peripheral surface, and a spill ring θ
The link bodies are arranged concentrically with an annular gap between them and the outer circumferential surface of the cover plate (8), and the link bodies are rotatably connected to the shaft by a bearing frame Qυ formed integrally with the cover plate (8). The link body θ and the spill ring Oη are supported by an annular gap between them (
b) Connected by a bimetal plate (21) provided so as to extend in the circumferential direction within the bimetal plate I
21) When the temperature expands in the N circumferential direction as the temperature rises to -, the spill link 0 or the arrow (
In the case where the bearing 7 is configured to rotate clockwise in the A) direction, the bearing 7 has a gear c! on the outer periphery of the link body (1!1). The rack rod (,!j) that meshes with 4, the rack rod (!
The rack rod (
2 Connect the actuator (23) related to the engine load, and as the engine load increases, rotate the link body θ9 clockwise in the direction of arrow (B), and as the engine load decreases, the link body (One is configured to rotate counterclockwise in the direction of arrow (C).

In this configuration, the link body 0 is shown as a solid line in the diagram t-<
<t When both sides rotate to the left in the direction of arrow (C), the spill link (17) connected to the link body 09 by the bimetal plate Qυ also rotates to the left, and the escape ball 1-081 becomes (
1) The opening/closing position of the relief port θ8) to the spill port 1 is moved in the direction away from the auxiliary screw 1, and the spill boat (IQ is the relief port 08) is closed in a disconnected state. The lubricating oil leaks out or stops, reverse 1 (-valve (1: () (= J port Q4
) The pressure in the hydraulic chamber (a), which is supplied with lubricating oil (
) towards OiJ and Kono forward or Spielbo 1-Oe
When the lubricating oil from the hydraulic chamber θ begins to flow out from the spill port 1-00 and the relief port 1-08), this outflow flows into the hydraulic chamber. (Amount of supply to gong, etc.) <At the moment of lancing, the sub-piston (9) moves forward or stops. Also, when the link body 01) is rotated clockwise in the direction of the arrow (B) from the position of the solid line in the figure, the escape port 08) of the spill link 0 connected to this ring body θ via the bimetal plate (21) or (It ) position i
When the fd is reached, the opening/closing position of the spill port 1- (relative to lfi) is moved so that the opening/closing position of the relief bow 1- (1g) approaches the secondary screw line. Since the outflow amount from 161 increases, the LI force of the hydraulic chamber α force decreases, so the secondary piston (9) is moved away from the combustion chamber (5) by the T1 force and/or spring 01 of the combustion chamber (5). When this retreat progresses to a point where there is partial communication between the spill boat (If) and the relief port 0 at position (II), it is difficult to determine the amount of outflow from these, and the amount of outflow and supply is different. At this point, the secondary screw ((1) will either move backward or stop. In this case, the ring body (+i) will be rotated clockwise by the actuator (c) related to the engine load as the engine load increases. Since the engine is configured to rotate to the left as the load decreases, it is possible to automatically control the compression ratio so that it gradually decreases as the engine load increases, and gradually increases as the load decreases. Yes, and instead of being related to this load, it is related to the engine speed; -1: The compression is automatically controlled to become gradually higher as the rotation speed increases, or it is related to both the load and the rotation speed. It is also possible to automatically control the compression ratio.

During the engine's explosion stroke, when the secondary piston (() receives a large explosive force, this explosive force causes the secondary piston (9) to explode.
) moves back a little, and at the same time, the stem (11) also moves back a little, and the spill port 1- (lfil's escape port 0
8) is closed, the pressure in the hydraulic chamber (121) momentarily increases, the check valve (1) closes, and the oil in the oil tapping chamber (0) is trapped within the hydraulic chamber (121). In this case, a small amount of oil spills until the spill boat closes against the escape boat 08), and the subsequent It absorbs and softens the explosion impact on the hydraulic upper pipe or the sub-piston (9).

On the other hand, the occurrence of knocking increases as the engine temperature rises, so the compression ratio value is automatically controlled in relation to the engine load and/or rotational speed when the engine temperature is low. If the engine temperature is set to 1, knocking will occur frequently when the engine temperature becomes high. (4) is provided with a bimetal plate (QI) that connects the two, and this bimetal plate (21) is warmed by the lubricating oil flowing out from the relief port 1-08), while the lubricating oil is heated by the engine's cylinder flock and Since the temperature is approximately proportional to the engine temperature when passing through the oil passages of the cylinder △ and soto, the bimetal plate Qυ thermally expands in the circumferential direction as the engine temperature increases, and the spill ring 07 ) to the ring body (]!J and in the direction of arrow (A) with respect to stem 0υ, that is, stem (11)
Spill Poe 1~(It's Spill Poe 1~(1
Since the area of the column i1 of 81 rotates in the direction of increasing, the amount of outflow from the spill boat (10) increases, and the sub-piston (9) rotates in the direction of increasing the area of the column i1 (the amount of outflow from one frame is (
J (the compression ratio decreases as it retreats to the point where it balances with the feed amount).

In other words, the compression ratio is automatically adjusted by the bimetal plate (21) so that it gradually becomes 1 as the engine temperature rises, thereby preventing the occurrence of knocking when the engine temperature is high. Yes, and when the compression ratio value by automatic control in relation to the engine load and/or rotation speed is set to match when the engine temperature is high, the compression ratio when the engine temperature is low is set at that time. It can be easily adjusted to suit.

In addition, in the above embodiment, the lubricating oil in the engine was used as the hydraulic oil to the oil H-chamber (12), or the hydraulic oil in the hydraulic chamber a
As the hydraulic oil for b, it is possible to use the hydraulic oil in the power steering link mechanism of the automobile or the automatic transmission of the automobile. When using this power-steering link mechanism or the hydraulic oil that flows between O1 and the automatic transmission, the hydraulic oil that has entered the hydraulic chamber
), then lead them to the empty stabbing room (c) inside Spielbo 1- (
16), the deviation is good enough to make the temperature of ('
In addition, inclined spill bow 1- (+6) and relief port 1
-08) is provided in the opposite position to that of the previous embodiment, and the spill link (1-08) is attached to the stem (11).
17) may be provided with an inclined spill port 1 (16J), and if necessary, the shape of the spill port oQ may be made into an arbitrary shape as shown by the two-dot chain line in FIG.

4 and 5 show a second embodiment, in which the stem (1, 1a) projects from the sub-piston (9) in the sub-ribber (7). A spill ring (17a) for opening and closing the spill, +4-l- (16a), which is provided at the protruding end, is rotatably and slidably fitted, and the spill ring (17a) is pivoted at the midpoint (A). The 01J spill ring (17a) is moved by the arrow (D
) direction to increase the compression ratio, and as the load of the engine increases and/or the rotational speed decreases, the compression ratio decreases by sliding in the direction of the arrow In this second embodiment, when the temperature of the hydraulic oil passing through the stem (Ila), that is, the temperature of the engine, increases, the shaft temperature increases. Thermal expansion occurs in the direction of the opening of the spill boat (16a), and the amount of flow from the spill boat (16a) decreases, resulting in a flow from the sub-viston (9) to the hydraulic chamber. Since the compression ratio increases as the engine advances to a point where the amount and supply amount are balanced, knocking becomes more likely to occur as the engine temperature increases than in the case of the first embodiment described in Section 11.

Therefore, for this embodiment, the stem (+-1a) is replaced with two upper and lower stems (lla') (Il) as shown in FIG.
Divided into a′ stem, with both upper and lower stems (I la′) (1
, 1a'') 1111M freely, while the bimetal (21a) is inserted between the two upper stems (11a') (lla'') in the axial direction via the pipe-shaped bimetal (21a). Due to axial thermal expansion, the steno-(
The axial length of lla) may be compressed, and with this configuration, the compression ratio value can be automatically controlled in relation to the engine load and/or rotation speed, depending on the engine temperature. It is possible to correct the value so that it decreases as the value increases.

Incidentally, the spill body is not limited to the link-shaped one in the above two embodiments, but also a rod-shaped spill body (+
, 7b), and this spill body (1, 7b) is slidably inserted into the hollow shaft-like stem (I], b) so as to open and close the spill port 1- (16b), and the spill body ( +7
b) may be configured to slide in response to the load and/or rotational speed of the engine.

Although one embodiment has been described above, the present invention is such that a sub screw 1 is slidably inserted into a sub syringe that communicates with the combustion chamber, and a hydraulic chamber is formed on the back side of the sub screw 1. While supplying hydraulic oil to the hydraulic chamber, a stem is provided in the axial direction of the auxiliary screw 1-in so as to protrude from the auxiliary screw 1-n to the outside of the auxiliary cylinder, and a stem is provided at the protruding end of the stem to provide hydraulic oil for the operation of the hydraulic chamber. A spill boat is installed at the protruding end of the stem to allow oil to flow out, and the spill port I- is opened and closed to adjust the amount of oil flowing out from the spill port I-, and its opening and closing position is adjusted to the axis of the steno shaft. a spill body that is actuated to be displaced along the direction of the engine; In the niI spill body or stem,
The opening/closing position of the spill port 1 is provided with a means for displacing the opening/closing position of the spill port 1 in the axial direction of the stem according to the temperature of the engine, thereby adjusting the compression ratio according to the load and/or rotation speed of the engine. Because it can be automatically controlled steplessly and smoothly,
There is no sudden torque fluctuation when the compression ratio is automatically varied.
Therefore, the problem of 1 to 1b is avoided.Moreover, in the present invention, the rear surface of the auxiliary piston that falls in the auxiliary noritsuta is used as a hydraulic chamber, and hydraulic oil is sent to this chamber, so that the auxiliary screw I-
This system moves the engine back and forth, and there is no need to separately install a hydraulic syringe outside the sub-sleet as in the prior art mentioned above, making it possible to simplify the structure and make the engine smaller and lighter. .

Furthermore, in the present invention, the value of the compression ratio by the automatic control can be corrected with respect to the engine temperature IW, so Ll:
When the engine temperature is high when the engine is automatically controlled by the N-related load and/or rotational speed, the compression ratio may be too high. It has an effective prefecture that can prevent things from happening.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is a vertical cross-sectional view of the main parts of the engine showing the first embodiment, FIG. 2 is an enlarged cross-sectional view of the main parts of FIG. 1, and FIG. FIG. 4 is a degenerate side view of the main parts of the engine showing the second embodiment; FIG.
The figure is an enlarged sectional view of the main part of FIG. 4, and FIG. 6 is a diagram of another embodiment of the spill body and spill port. (1)・Norinta block, (2)・・Nuritsutaheso l', (5)・・Combustion chamber, (7)・・Norinta heso l', (7)・・Norinta heso l', (7)・・Norinta heso l', (9)
)・・Subscrew 1-, (+2-・Hydraulic chamber, (11) (
1la) (1lb) Stem, (+6) (16a)
(], 6b) - ... to Spielbo 1, θη (17a) (
17b) - Spill body, (c)...actuator, 02
1) (21a)...Bimetal.

Claims (1)

[Claims] (1) A sub-piston is slidably inserted into a sub-inverter communicating with the combustion chamber, and an oil (1-chamber is formed on the back side of the sub-piston to supply hydraulic oil to the hydraulic chamber, while the above-mentioned screw 1-
Attach the stem with the secondary screw 1 so that it protrudes from the
A spill boat is provided at the protruding end of the stem to allow the hydraulic oil of the curved pressure chamber to flow out, and the spill boat is provided at the protruding end of the stem. Spill boat spill 1? t
The spill body is connected to the load and/or rotation speed of the engine so that the spill body is operated in accordance with the load and/or rotation speed of the engine, and the spill body or stem is provided with a mechanism for opening and closing the spill boat II1. An internal combustion engine with variable compression ratio oJ, characterized in that it is provided with means for displacing the tea in the axial direction of the stem according to the temperature of the engine.