JPH0751881B2 - Piston lateral pressure reduction mechanism - Google Patents

Description

The present invention relates to a reciprocating internal combustion engine, an air compressor, and the like.
The present invention relates to a motion conversion device for converting the reciprocating motion of a piston into a rotary motion of an output shaft or the rotary motion of an input shaft into a reciprocating motion of a piston, and more specifically, an engine for improving the balance of a motion system and reducing vibration. The present invention relates to a mechanism devised to further reduce the lateral pressure of a piston in a motion conversion device such as the one described above.

[Prior Art and Problems to be Solved by the Invention] The basic invention of the present invention has already been applied for as a “motion conversion device in an engine or the like” in Japanese Patent Application No. 60-259336, and a related invention is “opposed piston engine”. There are already patent applications such as Sho 61-046753. Although these inventions are described in detail in the specification, they are basically excellent in balance and vibration and noise are significantly reduced as compared with the conventional reciprocating machine. Further, conventionally, the kinetic energy applied to the piston was not output torque because the efficiency of the crank mechanism was poor near the bottom dead center, and most of it was vibration or heat. Since it is directly recovered as the compression work of the adjacent cylinder, the energy efficiency becomes very high. Further, considering the movement of the piston, the piston speed of the conventional crank mechanism becomes faster near the top dead center and slower near the bottom dead center as compared with the sine movement. On the other hand, this mechanism is completely opposite to the conventional one: it becomes slower near top dead center and faster near bottom dead center. This is very advantageous in terms of combustion mechanism, which improves combustion efficiency and reduces exhaust loss. Further, the difference in the piston movement mechanism makes the torque fluctuation extremely smooth, and the vibration and noise can be further reduced.

In a motion conversion device such as an engine that has many advantages as described above, the mechanism that generates the torque is that the pressure of the piston obtained by the explosion causes the swing torque to the cross arm directly connected to the swing shaft via the link. , Which is converted into the rotational torque of the Z crankshaft via the orthogonal bearing.
At that time, the reaction force from the load applied to the Z crankshaft generates a lateral pressure on the piston of the exploded cylinder. When pressure is applied to opposite cylinders at the same time, for example in a compressor or a 2-cycle engine, when the same torque is generated for 4 cycles, the side pressure of the piston is halved and distributed to the two opposed cylinders, which is a guide for lubrication conditions. The PV value is reduced by half, which is advantageous in terms of life due to vibration and wear. In the 4-cycle engine described in the above-mentioned application example, the side pressure of the piston due to the reaction force from the load concentrates on the exploded cylinder, which is disadvantageous with respect to the PV value. However, near the top dead center where the piston side pressure increases, the piston speed is much slower than in the conventional reciprocating machine, so even if the piston side pressure increases, it will be almost the same as the conventional PV value.

The present invention further reduces the side pressure of the piston of a four-cycle engine by adding a device mainly to the mechanism of the bearing portion of the cross arm in Japanese Patent Application No. 60-259336 “Motion Converter for Engine etc.” by the above-mentioned applicant. , With reduced vibration and wear.

[Means for Solving the Problems] Considering the generation mechanism of the lateral pressure of the piston of the 4-cycle engine seen in the application example of the basic patent, the rhombic link mechanism above the swing shaft, the cross arm and the cylinder are completely If the clearance of each sliding part is zero in a rigid body,
The side pressure of the piston is equally divided into two parts, that is, the cylinder under the explosion pressure and the cylinder facing the explosion pressure, because the structure is geometrically symmetrical with respect to the center line of the swing axis. Considering this, each part is asymmetrical and slightly elastically deformed by the explosion pressure, and each sliding part also has a minute clearance because an oil film is required. Further, due to an error in machining, most of the reaction force from the load applied to the Z crankshaft becomes the side pressure of the piston toward the explosion cylinder.

In the basic invention described above, at the intersection of the central axes of the cylinders intersecting with each other in a cross shape, the bearings are supported so that the swinging centers of the two cross arms intersecting with the straight line orthogonal to the central axes coincide with each other in the X shape. However, in the case where a pressure is applied to the opposite cylinders at the same time, for example, in the case of a compressor or a two-cycle engine, elastic strain or the like becomes symmetrical, so that the above structure can be applied.

In the present invention, in order to disperse the lateral pressure of the piston in the case of a 4-cycle engine or the like, at each intersection O of the central axes X-X and Y-Y of the cylinders arranged in a cross shape, as in each embodiment described later,
It is possible to decenter in the direction in which there is the swing center of some or all of the cross arms that swing in mutually opposite directions at the central portion of the rhomboid link mechanism with respect to the straight line ZZ or XZ plane orthogonal to the central axis. The bearing support structure is such that the side pressure of the piston is applied to the cylinder opposite the explosion side cylinder, and the reaction force from the load is dispersed and received by the two cylinders.

[Embodiment 1] FIG. 1 shows a main mechanism of an upper half of a motion converting mechanism which is a basic patent of the present invention.

Piston pins p1 to p4 are arranged at respective connecting portions of a diamond-shaped link mechanism composed of links L1 to L4 of equal sides, and are connected to the piston. At the center of the piston pin of each link, the cross arm A1 is connected via the joints j1 and j3, and the cross arms A1 and A2 are connected via the joints j2 and j4.

Now, assume that the cylinder of piston P1 explodes and pushes down the piston with the force of F. The transmission path of the force that gives the swinging torque T to the cross arm A1 is p1 → L1 in the thick line portion of FIG. 3 (a).
→ j1. The other transmission path is p1 → L4 → j4 → A2 → j2 → L2 → p3 → L3 → j3 in the bold line portion of FIG. 3 (b). Comparing these two transmission paths, (a) has much higher link rigidity than (b). Furthermore, since the number of sliding parts is small, the cumulative gap of the sliding parts is very small. The cross arm A1 and cross arm A2 are the central axes of the cylinder X-X, Y-
When the bearing is supported so that the straight line ZZ orthogonal to the central axis at the intersection point O of Y and the swing center of the cross arm A1 and the cross arm A2 overlap, when the force F is applied to the piston, In the diagram (b), a slight transmission delay occurs as compared with the diagram (a). Therefore, if the rigidity is designed and the clearance between the sliding parts is designed, all the force F is transmitted to the yoke 3 through the transmission path (a). The reaction force coming from the load applied to the Z crankshaft (not shown) goes backward in the transmission path of (a) and generates the side pressure of the piston P1. At this time, the force passing through the transmission path of (b) does not contribute to the generation of the torque due to the transmission delay, so that it does not receive the reaction force, and accordingly, the side pressure of the piston P2 coming from the reaction force does not exist either.

In order to simplify the idea of FIG.
It can be replaced with the simulated mechanism in the figure.

Assume that the input is transmitted from the top to the bottom in FIG. 4 (C), and the rigidity of the gap of the sliding portion and the link of the transmission path in FIGS. 3 (a) and 3 (b) are compared with springs, δ1, δ2 and S1 respectively. , S2. When the force F is transmitted downward in FIG. 4 (d), the members 5 and 6 and 7 and 8 are fixed to each other so that they are not tilted even by an eccentric load. The force F is transmitted downward via the right transmission path. At that time, S1 causes elastic deformation proportional to the force. Third
Figure (b) is likened to the transmission path on the left side, where no force is transmitted under normal load. Now, as shown in FIG. 4 (e), if the members 7 and 8 are allowed to freely tilt by the pin 9, when the force F is applied, the member 8 is tilted until the left and right forces are balanced, and the force F is dispersed left and right. It is transmitted to the bottom.

2 shows the AA cross section of FIG. 1, and the swing shaft 2 is ZZ
It has a floating structure that can be eccentric to. Therefore, the cross arm A1 is a straight line W- connecting the centers of the pin holes of the yoke 3.
It can move in a conical shape with the intersection P with W as the apex.
On the other hand, the cross arms A2 and A2 are supported by the pin 4 and the flange 11 so that the swing center is a straight line ZZ.

Now, when the force F is applied to the rhomboid link mechanism, first, the cross arm A1 is pushed through the link L1, but the cross arm floats, so the force is transmitted to the opposite joint j3, while FIG. 3 (b).
The force from the path of is transmitted to the joint j3, the force compensates the accumulated gap and elastic deformation of each other, and the cross arm A1 moves to a position where the forces are balanced. There, a couple is generated in the cross arm A1 and is transmitted to the yoke 3. This principle can be explained as FIG. 4 (e). In this way, the reaction force from the load is dispersed as the side pressure of the pistons P1 and P3, and the side pressure per unit is reduced.

With this structure, it is difficult to transmit the vibration of the upper cylinder block to the lower Z crankshaft, and it is not necessary to set the positional relationship with each other strictly.

[Embodiment 2] FIG. 5 shows a rhombic link mechanism of "Claim 2" viewed from the cross arm A1.

FIG. 6 shows a cross section taken along the line BB of FIG. 5, and FIG. 7 shows a cross section of FIG.
It is a C cross section.

The round hole of the flange 11a in FIG. 7 is located concentrically with the straight line ZZ, and the bush 12a is swingably fitted therein. The upper portion 2a of the swing shaft 2 is machined into a flat surface and slidably fitted in the processed hole of the bush 12a. Swing shaft 2a is the joint position of cross arm A1
It is designed to move in a direction perpendicular to a straight line JJ connecting the centers of j1 and j3. The swing shaft 2 can move in a fan shape with an apex at an intersection point P of a straight line WW and a line ZZ connecting the centers of the pin holes of the yoke 3a. The cross arms A2, A2 have their swing centers fluctuated following the action of the swing shaft 2 and swing in the opposite direction to the swing shaft 2 at the same swing center.

Now, when a force F is applied to the piston pin p1 from above in FIG. 5Y-Y, the piston P1 slides on the left wall of the cylinder Y-.
Go down along Y. Here, due to the above-mentioned bearing structure, the entire rhomboid link mechanism tries to move from the intersection point O in a direction perpendicular to the straight line JJ (obliquely lower right direction). Piston pin p1 is Y
-The entire rhomboid link mechanism tries to rotate counterclockwise around the piston pin p1 because it moves down along -Y, but when it rotates slightly, the piston p3 hits the right wall of the cylinder and stops.
Then, the side pressure of the piston is generated. Therefore, the force F is
At the same time as being transmitted to j1, the reaction force coming from the side pressure of the piston P3 is transmitted to the joint j3, so that the two forces are combined and converted into the swing torque of the swing shaft 2.

This swing torque exchanging method can be likened to FIG. 4 (f). When the diamond-shaped link mechanism is the driving side and the swing shaft 2 is the driven side, the driving side and the driven side simultaneously make minute movements, which causes cumulative gaps and elastic strains in the transmission path of FIG. 3A and the transmission path of FIG. Compensating for, and stopping at a position where the forces applied to the joints on both ends of the cross arm A1 are balanced, and a swing torque is generated. In FIG. 4 (f), the members 5 and 6 and the members 7 and 8 are pins 10
If a mechanism that can freely rotate by and 9 is used, it is similar to the automatic adjustment so that when the force F is transmitted from the driving side of the upper part to the driven side of the lower part, the members 6 and 8 are inclined and the left and right forces are balanced. There is. However, the movements of the upper and lower members are not related and move independently, but the embodiment is different in that they move with certain restrictions.

With the above mechanism, the lateral pressure of the piston is applied to the upper and lower cylinders, and the lateral pressure of each piston can be reduced to further reduce wear and vibration.

In this embodiment, the force F is supported by the flange 11a shown in FIG. 6 and the Z flank shaft bearing (not shown). The bearing that supported the shaft can be omitted.

[Embodiment 3] FIG. 8 shows a rhombus link mechanism portion of claim 3, FIG. 9 is a sectional view taken along line EE of FIG. 8, and FIG. 10 is D of FIG.
The -D cross section is shown.

As can be seen from FIG. 10, the upper part 2b of the swing shaft 2 is the bush 12.
The bush 12b is slidably fitted in a, and the bush 12b is fitted in the flange 11b so as to be slidable at an angle of 45 degrees (MM direction) with respect to the central axis X-X or Y-Y of the cylinder.

Therefore, the swing shaft 2 can move in a fan shape in the MM direction with the intersection P of the line WW and ZZ connecting the centers of the pin holes of the yoke 3b as the apex. Cross arms A2 and A2 are swing axis 2
Is fitted so as to swing in the opposite direction at the same center as the swing shaft 2.

Now, when the explosive force is applied to the piston pin p1, the piston pin p1
Lowers along YY, but the upper part 2b of the swing shaft 2 is MM
The entire rhomboid link mechanism tries to rotate counterclockwise about the piston pin p1 because it lowers in the lower right direction along with, but if it makes a minute rotation, the piston 3 on the opposite side (not shown) hits the right cylinder wall and becomes the side pressure of the piston. The reaction force of this side pressure is applied to the smooth joint j3 and is combined with the force directly applied to the smooth joint j1 from the link L1 to generate the swinging torque of the cross arm A1.

This torque generating mechanism can be compared with that in FIG. 4 (f), and the same explanation as in the second embodiment can be made. However, Example 2
In contrast, the direction of minute movement of the swing shaft 2 changes according to the piston displacement, whereas in the present embodiment, the moving direction is always constant in the MM direction.

With the above mechanism, the lateral pressure of the piston can be reduced, and wear and vibration can be reduced.

[Embodiment 4] FIG. 12 is an embodiment according to claim 4, FIG. 13 is its FF cross section, and FIG. 11 is a GG cross section of FIG.

The present embodiment is a piston side pressure reduction mechanism when only one pair facing each other is used as an engine, but this engine has excellent characteristics such as low vibration as medium horsepower, and if the other pair is used as a compressor, The direct rhombus link mechanism pushes the piston of the compressor, resulting in a highly efficient conversion mechanism. Also, in the "opposed piston engine" of the related invention, the gap volume at the bottom dead center of the piston is very small, which is used for this. As a supercharger, it can be a compact, lightweight engine with a very high specific output.
In this embodiment, the side pressure of the piston of the opposed piston engine applicable to them is reduced.

In FIG. 11, the upper portion 2c of the swing shaft 2 is swingably fitted in the bush 12c, and the bush 12c is slidably fitted in the flange 11c only in the XX direction.

Now, when an explosive force is applied to the piston pin p1, first, the joint j1 is pushed via the link L1, but when there is a load on the cross arm A1, the reaction force causes the piston P1 to push the left wall of the cylinder. At that time, the rocking shaft 2 moves to the right along XX by the bearing structure of FIG. 11, and the rhombus link mechanism moves the piston pin p1.
However, the piston P3 hits the right wall of the cylinder and becomes the side pressure of the piston. From this state, as shown in FIGS. 3 (a) and 3 (b), the accumulated clearance and elastic strain of the sliding portions of the two transmission paths are compensated, and the piston pin p1 and
When the force of p2 is balanced, it becomes the couple torque of the swing shaft 2 and Z
It is transmitted to the crankshaft. At that time, the side pressure of the piston is not concentrated on the piston P1 and is distributed to the upper and lower pistons, so that the side pressure of each piston is halved.

The pair of cross arms A2, A2 arranged so as to sandwich the cross arm A1 from above and below in Examples 1 to 4 have different shapes from the cross arm A1, and the both sides of the syllable are wide. This causes angular vibration when the rocking shaft 2 and the yoke 3 rock, but the cross arms A2 and A2 that rock in the opposite direction are made wider, and the polar inertia ratio is higher than that of the cross arm A1. There is an effect of reducing the vibration by increasing the value and canceling out some or all of the angular vibration. If necessary, a swing balance weight can be appropriately added. Further, FIG. 14 shows that in the four-cylinder engine of Embodiments 1 to 3, when the piston P1 is near the top dead center, the piston pins p2 and p4 sometimes protrude from the lower part of the cylinder. At this time, when an explosive force is applied to the piston P1, the rhombus link mechanism may elastically deform, or in the second and third embodiments, the lozenge link mechanism may slightly lower due to a slight downward displacement component of the swing shaft. That is, the piston pins p2 and p4 are Y
-Pistons P2 and P4 slightly tilt down from -Y as shown in the figure. At this time, if the clearance between the lower part of the cylinder and the piston is very small, excessive friction will occur and damage the piston and cylinder. Therefore, by expanding the lower part of the cylinder as shown by the dotted line, it is possible to avoid problems due to excessive friction.

[Advantages of the Invention] The present invention reduces the lateral pressure of the piston of the "motion conversion device in an engine or the like" or the "opposed piston engine" described above. However, in an actual engine, the lateral pressure of the piston is high and Cylinder wear is extremely large near the top dead center where lubrication conditions are poor. Therefore, reducing the lateral pressure of the piston near top dead center reduces wear and friction loss,
Vibration is also reduced. In addition, the structure that is simpler because the bearing that specified the swing shaft in the basic patent can be omitted, and the upper cylinder part and the lower Z crankshaft part are flexibly connected by the flexible bearing support structure. , It is not necessary to set the mutual positional relationship strictly. or,
In Example 1, it is difficult to transmit vibration because the upper part and the lower part are connected only by the syllables.

As described above, by reducing the lateral pressure of the piston with a simple structure, not only the durability is improved but also many advantages can be provided.

[Brief description of drawings]

FIG. 1 is a plan view in which a part of the first embodiment is sectioned, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a simplified view showing a force transmission path. FIG. 4 shows a simulation mechanism showing a force transmission state. FIG. 5 shows a rhomboid link mechanism of the second embodiment, FIG. 6 shows a BB cross section of FIG. 5, and FIG. 7 shows a CC cross section of FIG. FIG. 8 is a rhombic link mechanism of the third embodiment, and FIG. 9 is FIG. 8E.
-E cross section, FIG. 10 shows the DD cross section of FIG. FIG. 12 is a plan view in which a part of the fourth embodiment is shown in section, and FIG.
FIG. 12 is a FF cross section, and FIG. 11 is a GG cross section in FIG. FIG. 14 shows an explanatory view showing a state in which the lower part of the cylinder is enlarged and processed. 1; cylinder block, 2; swing shaft, 3, 3a to 3c; yoke, 4,
9,10; Pin, 5, 6, 8; Member, 11, 11a to 11c; Flange, 2a to 2
c; upper part of swing shaft 2, 12a to 12c; bushes A1 and A2; cross arms L1 to L4; links P1 to P4; pistons p1 to p4; piston pins j1 to j4; skeletons δ1 to δ2; Cumulative gap. S1 to S2; State diagram when elastic deformation of the link is replaced by a spring. XX, YY; central axis of cylinder. ZZ: A straight line orthogonal to the central axis at the intersection O of the central axes. WW: A straight line connecting the centers of the pin holes in the yoke. JJ: A straight line connecting the centers of the joints j1 and j3 of the cross arm A1.

Claims (4)

[Claims] 1. In a motion converting device for an engine or the like, central axes X-X, Y- of cylinders arranged in a cross shape.
At the intersection point O of Y, the straight line ZZ orthogonal to the central axis and the swing center of the pair of upper and lower cross arms A2, A2 of the rhomboid link mechanism are aligned, and the swing center of the cross arm A1 directly connected to the yoke Is a mechanism for reducing the lateral pressure of the piston, which is eccentric with respect to the straight line ZZ. 2. In a motion conversion device for an engine or the like, central axes X-X, Y- of cylinders arranged in a cross shape.
At the intersection point O of Y, the swing center of the cross arm of the rhomboid link mechanism can be eccentric with respect to the straight line ZZ orthogonal to the central axis thereof, and the skeletons at both ends of the cross arm A1 directly connected to the yoke
A piston side pressure reduction mechanism that regulates the eccentric direction so that it is perpendicular to the straight line connecting the centers of j1 and j3. 3. In a motion converting device for an engine or the like, central axes X-X, Y- of cylinders arranged in a cross shape.
At the intersection point O of Y, the swing center of the cross arm of the rhomboid link mechanism can be eccentric to the straight line ZZ orthogonal to the central axis, and the center of the skeleton at both ends of the cross arm A1 directly connected to the yoke A side pressure reduction mechanism for the piston that regulates the eccentric direction at a right angle to the bisector of the swing angle drawn by the straight line connecting the two. 4. In a motion converting device for an engine or the like which uses only a pair of opposed cylinders as an engine, the swing center of a cross arm of a rhomboid link mechanism is XZ which is orthogonal to the central axes YY of the pair of cylinders. A piston side pressure reduction mechanism that is movable on a flat surface.