JPH01190901A - Variable capacity type reciprocating piston device - Google Patents

Abstract

PURPOSE:To reduce the pumping loss and reduce fuel consumption drastically by setting the shift locus of the revolution center so that the inclination of the line connecting the revolution centers increases more as the reciprocation stroke reduces further. CONSTITUTION:When the first or second main shaft 12 or 18 is revolution-driven from outside, a piston 3 performs a rectilinear movement in reciprocation, accompanied with the revolution of the revolution center O3. The angle formed by the lines M3 and M2 for connecting the points O1 and O2' is set to phi. The shift locus A of the revolution center O2 is set so that the angle phi becomes larger as the reciprocation stroke S reduces. Therefore, the pumping loss can be reduced, and fuel consumption can be reduced drastically.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a variable displacement reciprocating piston device used as a reciprocating internal combustion engine or a reciprocating compressor.

A typical example of a conventional reciprocating piston device is a reciprocating internal combustion engine. This is configured so that the linear motion of a piston that reciprocates due to combustion pressure is transmitted to the crankshaft via a connecting rod and converted into rotational motion of the crankshaft.

Reciprocating piston devices are also used as compressors. In this case, conversely, the rotational motion of the crankshaft is converted into reciprocating linear motion of the piston via the connecting rod, thereby suctioning and compressing the fluid.

Problems to be Solved by the Invention However, in the conventional reciprocating piston device using the piston crank mechanism as described above, the reciprocating stroke of the piston is fixedly determined only by the amount of eccentricity of the crank pin in the crankshaft. As a result, the capacity of the piston device, that is, the displacement as an internal combustion engine and the discharge amount as a compressor, is always constant.
cannot be changed.

Therefore, for example, in a gasoline engine, it is necessary to adjust the output by throttling a throttle valve in the intake passage during low-load operation, and there is a problem in that fuel consumption deteriorates due to the accompanying pumping loss.

Furthermore, when used as a compressor, it was necessary to turn on and off the compressor and to variably control the driving rotation speed in order to adjust the flow rate and pressure of fluid.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a variable displacement reciprocating piston device that can variably control the reciprocating stroke of a piston and hence its displacement with an extremely simple configuration, and can maintain a compression ratio substantially constant regardless of changes in displacement. It is an object.

Means for Solving the Problems A variable displacement reciprocating piston device according to the present invention includes a pin portion connected to a reciprocating piston via a connecting rod, and sliders or guide grooves are arranged orthogonally to each other on both end surfaces. an intermediate joint member formed along the direction of the intermediate joint member, and a guide groove or slider is formed in the radial direction on the joint surface that is in close contact with one end surface of the intermediate joint member, and the rotation center O2 is fixed. a first main shaft, which is in close contact with the other surface of the intermediate section member, and a second main shaft having a guide groove or a slider formed on the joint surface; A movable bearing member movable along a predetermined trajectory so that the rotation center O1 can approach and move away from the rotation center O9 of the first main shaft, and the distance between the two rotation centers 0+ and Ot is 0 as the decrease. ．． 0. It is characterized in that the locus of movement of the rotation center O1 is set so that the slope of the line connecting them increases.

Operation In the above configuration, the first main shaft, the second main shaft, and the intermediate joint member between them constitute a so-called Oldham joint, and the piston is connected to the intermediate joint member, which is the intermediate joint.

Therefore, the reciprocating stroke of the piston is between the rotation center 01 of the first main shaft and the rotation center 0.1 of the second main shaft. It is approximately equal to the distance between In other words, if the distance between the self-rotation center 0+ and Ot increases due to movement of the movable bearing, the capacity increases, and conversely, if the distance decreases, the capacity decreases.

On the other hand, when the distance between both rotation centers Ot and Ot is maximum, 01. The line connecting Of has a small slope and is substantially along the piston movement direction (that is, the cylinder axis).

And when the capacity decreases, that is 0+.

0. When the distance between 0. ．． 0. The slope of the line connecting them will be large. As a result, the top dead center position of the piston in the latter case is higher than the top dead center position in the former case. Therefore, fluctuations in the compression ratio due to capacity reduction are reduced.

Embodiment FIG. 1 is an exploded perspective view of an embodiment of a variable displacement reciprocating piston device according to the present invention.

In the figure, 1 is the spindle case, and this spindle case 1
A cylinder block 2 is mounted and fixed on the upper surface of the cylinder block.

The cylinder block 2 has a cylinder (not shown) therein, into which a piston 3 is slidably fitted. This piston 3 is connected to the small end of a connecting rod 5 via a piston pin 4.

Reference numeral 6 denotes an intermediate joint member corresponding to the intermediate joint in a so-called Oldham joint. Second
It consists of a slider 8.9. The pin portion 7 is attached to the large end of the connecting rod 5 with a cap bolt 1.
It is rotatably held via a cap IO fastened at 1. The first slider 8. The second slider 9 is
They are rod-shaped with a rectangular cross section and are formed along directions perpendicular to each other.

Next, 12 indicates a first main axis corresponding to one node of the Oldham joint. This first main shaft 12 is composed of a disk portion 13 that is in close contact with the end surface of the pin portion 7, and a shaft portion 14 that is formed protrudingly from the back surface of the disk portion 13.
A guide groove 15 along the radial direction is recessed in the surface of 3. This guide groove 15 fits into the first slider 8 of the intermediate node member 6, and restricts the direction of relative movement between the two in only one direction. The shaft portion 14 is supported by a fixed bearing 16 fixed to the main shaft case 1 with a bolt 17.
It is rotatably supported.

Further, I8 indicates a second main shaft corresponding to the other node of the Oldham joint. The second main shaft 18, like the first main shaft 12, is composed of a disc part 19 that is in close contact with the other end surface of the pin part 7, and a shaft part 20 formed on the back surface of the disc part 19, and the surface of the disc part 19 is A guide groove 21 is recessed along the radial direction. The guide groove 21 fits into the second slider 9 of the intermediate node member 6, and also restricts the direction of relative movement between the two in only one direction. The shaft portion 20 of the second main shaft 18 is connected to the bearing portion 2 of a bearing lever 22 which is a movable bearing member.
3, it is rotatably supported by a shaft. This bearing lever 22 has a fulcrum part 24 at one end rotatably supported by a support shaft 25 of the main shaft case I, and an elongated engagement hole 26 is formed in the operating part at the other end. . That is, the bearing portion 2
3 moves in an arc-shaped trajectory,
Correspondingly, an arc-shaped opening 27 is provided in the spindle case l. Note that when the bearing lever 22 is pushed down to the lowest position, the rotation center 0 of the second main shaft 18 is the first main shaft 1.
2, and when the bearing lever 22 is rotated upward from here, both rotation centers 0+ and Ot approach each other.

Further, as a drive mechanism for driving the bearing lever 22, a double-acting hydraulic cylinder 28 is used in this embodiment. The hydraulic cylinder 28 includes a cylinder case 30 attached to the flange portion 29 of the main shaft case 1, a piston 31 that fits into the cylinder case 30 and separates hydraulic chambers from above and below, and one end fixed to the piston 31. and a rod 32 whose other end is connected to the engagement hole 26 of the bearing lever 22. Further, 33 is a spool valve that controls hydraulic pressure supply to the upper and lower hydraulic chambers of the double-acting hydraulic cylinder 28. It is composed of a body 35. A control lever 36 is attached to the lower end of the valve body 35.
The tips of the spool valves 33 are connected to each other, and the spool valve 33 is switched by swinging the control lever 36. Note that a support plate 37 supporting the control lever 36 as a fulcrum is fixed to the main shaft case l.

Now, in the above configuration, as described above, the first main shaft 12
The second main shaft 18 and the intermediate joint member 6 constitute a so-called Oldham joint, and the large end of the connecting rod 5 is connected to the intermediate joint member 6 corresponding to the intermediate joint of the Oldham joint.

As shown in FIG. 2, the rotation center of the first main shaft 12 is 01,
If the rotation center of the second main shaft 18 is O2, and the rotation center of the intermediate node member 6 (pin part 7) is O8, then as is well known, the first main shaft 12 and the second main shaft! 8 and the intermediate node member 6 do not rotate in exactly the same phase, and the center of rotation of the intermediate node member 6 is 0. is the line segment 0. .

It revolves around a circle R whose diameter is 0.

Therefore, for example, if the first main shaft 12 or the second main shaft 18 is rotationally driven from the outside as a compressor, the piston 3 will reciprocate linearly as the rotation center O1 revolves. Conversely, if the piston 3 moves linearly in a reciprocating manner as an internal combustion engine, the first main shaft 12 and the second main shaft 18 will rotate as the pin portion 7 revolves.

As is clear from FIG. 2, the reciprocating stroke S during the reciprocating linear movement of the piston 3 is the diameter of the circle R, that is, the first. The distance is approximately equal to the distance between the rotation centers O1 and O2 of the second main shaft 12.18.

Therefore, by rotating the bearing lever 22 upward in FIG.
．． ．． 0. If the distance between Or and Or is made small, the reciprocating stroke S becomes shorter, and conversely, if the bearing lever 22 is rotated downward to increase the distance between Or and Or, the reciprocating stroke S becomes shorter.
becomes longer. This changes the capacity of the piston device, that is, the displacement amount as an internal combustion engine and the discharge amount as a compressor.

In the embodiment shown in FIG. 1, movement of the bearing lever 22 is effected by a hydraulic control mechanism using a spool valve 33 and a hydraulic cylinder 28. That is, a predetermined hydraulic pressure is guided from a hydraulic pump (not shown) to the supply boat 38 of the spool valve 33, and the spool valve 33 is switched by operating the control lever 36 to move the double-acting hydraulic cylinder 28 upward or downward. By operating the capacitance, variable control of the capacity is achieved. This variable control of the capacity can be performed at any timing without stopping the operation of the piston device.

Therefore, for example, when this is used as a gasoline engine, it is possible to adjust the engine output without using an upstream throttle valve for variable displacement control. Therefore, the pumping loss is reduced, and fuel efficiency can be significantly improved, especially during low-load operation.

Furthermore, when used as a compressor, it becomes possible to control the flow rate and pressure without controlling the device on/off or controlling the rotation speed of the drive shaft.

By the way, in FIG. 2, if both rotation centers O1 and Ot
Assuming that is located on the cylinder axis M1, the center of the circle R is always above the cylinder axis M, so the top dead center position of the piston 3 is located when the rotation center O0 of the pin portion 7 is the point O.
The piston will be in position 3 when it matches 1. In other words,
The top dead center position of the piston 3 will be fixed, which means that even if the overall capacity of the device changes, the remaining capacity at top dead center will not change, and fluctuations in the compression ratio will not be affected. It's coming. Therefore, in this embodiment, the top dead center position is changed at the same time to suppress fluctuations in the compression ratio. This will be further explained with reference to the explanatory diagram of FIG.

First, let the respective rotation centers when the bearing lever 22 is pushed down to the lowest position be Or and Ox, the inside of the revolution at that time be R9, and the center of the inside of the revolution Rt be 04. In this state, the reciprocating stroke S of the piston 3 is the maximum stroke S
1, which is approximately equal to the diameter of circle R+. In addition, in this embodiment, in order to use a so-called offset crank type,
The rotation center O1゜0 is slightly away from the cylinder axis M, and the line M connecting 0+ and Os has an angle of θ with respect to the line M, and intersects near the center 04 of the revolution R1. There is. Of course, if the offset crank type is not used, θ may be 0.

In the case of the above maximum stroke S, the top dead center position of the piston 3 is defined when the center O2 of the bottle part 7 comes to the cylinder axis M, the upper point T+, and the bottom dead center position is defined as the point 03
is defined when it reaches point B on line M. In the diagram,
The center of the piston pin 4 at this top dead center and bottom dead center is P
+, indicated as Pg.

On the other hand, when the bearing lever 22 is rotated upward, the rotation center O2 of the second main shaft 18 moves along an arcuate trajectory A. In the figure, the rotation center at a certain rotation position is shown as Ot-, but the revolution inside R, at this time is point 01 and point O
Since it is drawn as a circle whose diameter is the line segment connecting t-, as is clear from the figure, the shape extends beyond the initial revolution R1 into the force on the figure. In this case, the top dead center position of the piston 3 is defined when the center O2 of the pin portion 7 comes to point T, and the bottom dead center position is defined when the point 03 comes to point B2. Ru. Also, the reciprocating stroke S of the piston 3
, has a value approximately equal to the diameter of R2 within the revolution. Note that the center of the piston pin 4 at the top dead center position is shown as P1''.

Therefore, as is clear from the positional relationship between points T1 and T, which define the top dead center, when the reciprocating stroke is S, the top dead center position of the piston 3 is the top dead center position when the reciprocating stroke is Sl. It will move above the dead center position.

In other words, the remaining capacity at top dead center decreases accordingly. In other words, a decrease in compression ratio due to a decrease in total capacity is suppressed.

The above movement amount α of the top dead center position approximates the distance of points T, , T, along the cylinder axis M1 direction, so if the influence of angle θ is ignored, the line connecting points 0+ and Ot- M, and line M,
It can be determined as α#5(1-cosφ)/2, where φ is the angle formed by .

In short, the reciprocating stroke S (that is, the diameter of the public circle R)
The center of rotation O becomes larger as the angle φ becomes smaller.
By setting the movement trajectory A of No. 2, the top dead center, where the capacity becomes smaller, moves upward, making it possible to suppress fluctuations in the compression ratio within a small range.

Note that the ideal movement trajectory A varies depending on the shape of the upper part of the cylinder, the compression ratio, etc. Therefore, in the above embodiment, the locus is arcuate, but it goes without saying that the locus is not limited to this.

Further, in the above embodiment, a 1° second slider 8.9 is provided protruding from the intermediate node member 6 side, and the first main shaft 12. Although the guide grooves 15 and 21 are recessed on the second main shaft 18 side, this relationship can be changed as appropriate.

In other words, the intermediate section member 6 and the first section member 6. It is only necessary that the movement directions with respect to the second main shafts 12 and 18 can be restricted to one direction.

Further, in the above embodiment, an embodiment of a single cylinder piston device has been described, but it goes without saying that this can be used by connecting a plurality of cylinders.

Effects of the Invention As is clear from the above explanation, according to the variable displacement reciprocating piston device according to the present invention, the reciprocating stroke of the piston can be changed while the operation continues, and the displacement can be changed at any timing. can be controlled. Therefore, by applying the present invention to, for example, an internal combustion engine, it is possible to reduce the pumping loss, and in particular, it is possible to significantly reduce fuel consumption during low-load operation. Furthermore, if applied to a compressor, it becomes possible to control the flow rate and pressure while continuing smooth operation.

When the reciprocating stroke of the piston decreases, the top dead center position of the piston changes upward at the same time, so it is possible to suppress fluctuations in the compression ratio due to changes in displacement.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing one embodiment of a variable displacement reciprocating piston device according to the present invention, Fig. 2 is an explanatory diagram for explaining its operating principle, and Fig. 3 is an explanation of the operating principle in further detail. FIG. 3...Piston, 5...Connecting rod, 6
... intermediate node member, 7 ... pin part, 8 ... first slider, 9 ... second slider, 12 ... first main shaft, 1
5... Guide groove, 16... Fixed bearing, 18... Second main shaft, 21... Guide groove, 22... Bearing lever,
28...Double-acting hydraulic cylinder.

Claims (1)

[Claims] (1) An intermediate node member having a pin portion connected to a reciprocating piston via a connecting rod, and having sliders or guide grooves formed on both end faces along directions orthogonal to each other; A first main shaft that is in close contact with one end surface of the member, a guide groove or a slider is formed in the radial direction on the joint surface thereof, and whose rotation center O_1 is fixed, and a first main shaft that is in close contact with the other surface of the intermediate joint member. and a second main shaft having a guide groove or a slider formed on its joint surface, and the second main shaft is rotatably supported, and its rotation center O_2 approaches and moves away from the rotation center O_1 of the first main shaft. and a movable bearing member that is movable along a predetermined trajectory, and as the distance between the two rotation centers O_1, O_2 decreases, O_1,
Center of rotation O_ so that the slope of the line connecting O_2 increases
A variable displacement reciprocating piston device characterized in that two movement trajectories are set.