JPH06323159A - Reciprocating engine - Google Patents

Abstract

PURPOSE:To provide a reciprocating engine capable of performing explosion of one time or more per one turn of a crankshaft, increasing expansion work volume and improving an output and thermal efficiency. CONSTITUTION:An engine has a rotatably arranged output shaft 12, connecting member 13 fixedly formed in the output shaft 12, cocoon-shaped guide groove 21 having a pair of small diametric guide grooves 21c, 21d and a pair of large diametric guide grooves 21a, 21b formed in the connecting member 13 and opposed by interposing the output shaft 12 and connecting rods 11 of relatively movable connecting big end parts 11b to the guide groove 21. The engine is provided with pistons 10 fixedly connected to small end parts 11a of the connecting rods 11 and cylinders 3 of inserting the pistons 10 in a direction at a right angle to the output shaft 12. A minimum distance S' from an axial line of the output shaft 12 to the one small diametric guide groove 21d is set smaller than a minimum distance S to the other small diametric guide groove 21c, and further in explosion and exhaust strokes, the one small diametric guide groove 21d passes through the big end part 11a of the connecting rod 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating engine for converting reciprocating motion of a piston into rotational motion of an output shaft.

[0002]

2. Description of the Related Art As a reciprocating engine, a 4-cycle engine is generally used. In this 4-cycle engine, a large end of a connecting rod is rotatably connected to a crank arm of a crankshaft and a piston is attached to a small end of the connecting rod. Is rotatably connected, the piston is inserted into the cylinder, and a combustion chamber is formed by the cylinder inner surface, the piston upper end surface, and the cylinder head inner surface.

[0003]

In the reciprocating engine, it is advantageous to increase the number of explosions in one revolution of the crankshaft in order to increase the output, and it is possible to increase the expansion work amount in the explosion / exhaust stroke. It is advantageous. However, the conventional 4-cycle engine explodes once every two revolutions of the crankshaft, and the two-cycle engine explodes once every revolution of the crankshaft, and the number of explosions cannot be increased any further. There is also a limit to increase the work of expansion.

The present invention has been made in view of the above-mentioned conventional circumstances, and can explode once or more per one revolution of the crankshaft, increase the work of expansion, improve output and improve thermal efficiency. It is intended to provide a reciprocating engine.

[0005]

According to a first aspect of the present invention, an output shaft rotatably arranged, a connecting member fixed to the output shaft, and a connecting member formed on the connecting member sandwiching the output shaft. A guide part having a plurality of small-diameter guide parts and a plurality of large-diameter guide parts facing each other, a connecting rod whose large end is movably connected to the guide part, and a connecting part fixedly connected to the small end of the connecting rod. And a cylinder into which the piston is slidably inserted in a direction perpendicular to the output shaft. Note that the connecting member also includes one integrally formed with the output shaft.

According to a second aspect of the present invention, in the reciprocating engine according to the first aspect, the guide portion is formed into an eyebrow shape having a pair of small diameter guide portions and a pair of large diameter guide portions, and one side from the output shaft axis line. The minimum distance to the small-diameter guide part is set smaller than the minimum distance to the other small-diameter guide part, and the one small-diameter guide part is configured to pass the large end part of the connecting rod during the explosion / exhaust stroke. It is characterized by

[0007]

According to the reciprocating engine of the first aspect of the present invention, the connecting rod reciprocates in the cylinder axial direction as the piston reciprocates. The large end of the connecting rod moves on the guide portion of the connecting member to rotate the connecting member and thus the output shaft, whereby the reciprocating motion of the piston is converted into the rotating motion of the output shaft.

Further, in the present invention, since the guide portion of the connecting member is composed of the plurality of small diameter guide portions and the plurality of large diameter guide portions, the piston corresponds to the small diameter and large diameter guide portions every one rotation of the output shaft. It strokes a number of times, which allows one or more explosions per revolution of the output shaft. For example, claim 1
When a pair of the small-diameter guide portion and the large-diameter guide portion are provided in pairs, that is, when the small-diameter groove portion and the large-diameter groove portion are provided every 90 degrees, the piston has four strokes in one rotation of the output shaft. 1 for every revolution of the output shaft
It can be detonated twice. Further, for example, when the small-diameter and large-diameter groove portions are provided at every 45 degrees, the explosion can occur twice in one rotation of the output shaft. As described above, according to the present invention, it is possible to explode once or more for each rotation of the output shaft depending on the shape of the guide portion, which is advantageous in increasing the output.

Further, in the present invention, the stroke of each stroke, the piston speed, etc. can be freely set depending on the shape of the guide portion. For example, in the invention of claim 2, a small diameter,
A pair of large-diameter guides is provided, and the minimum distance of one small-diameter guide to the output shaft is set smaller than the minimum distance of the other small-diameter guide. -Because it passes through in the exhaust stroke, the stroke during the explosion / exhaust stroke becomes longer than the stroke during the other strokes, the expansion work amount increases correspondingly, and the thermal efficiency improves.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 5 are views for explaining a star-type four-cycle engine according to an embodiment of the present invention. FIG. 1 is a sectional front view, FIG. 2 is a sectional side view, and FIG. Is a PV diagram and FIG. 5 is a characteristic diagram showing the relationship between the rotation angle of the output shaft and the stroke.

In the figure, reference numeral 1 is a star-type four-cycle four-cylinder engine. The engine 1 includes a crankcase 2 and
It is provided with four cylinder blocks 3 attached to the crankcase 2 at intervals of 90 degrees, a cylinder head 4 connected to each cylinder block 3, and a head cover 5 attached to each cylinder head 4. The cylinder heads and head covers of three of the four cylinder blocks 3 are not shown.

A combustion recess 4a is formed on the block-side mating surface of each cylinder head 4, and the combustion recess 4a constitutes a combustion chamber with the bore 3a of the cylinder block 3 and the piston 10. The intake port 4b and the exhaust port 4c opening to the combustion recess 4a are led out to the outer wall of the cylinder through an intake passage 4d and an exhaust passage 4e. The intake port 4b and the exhaust port 4c are opened and closed by an intake valve 6 and an exhaust valve 7, and the intake valve 6 and the exhaust valve 7 are opened and closed by an intake cam shaft 8 and an exhaust cam shaft 9.

The piston 10 is slidably inserted in the cylinder bore 3a of the cylinder block 3. The piston 10 has a small end 11 a of a connecting rod 11.
Is integrally formed, and the large end portion 11 of the connecting rod 11 is formed.
b is connected to a connecting member 13 fixedly connected to the output shaft 12 via a connecting mechanism 14.

The connecting mechanism 14 includes the connecting rod 11
The connecting pin 16 is inserted into the large end 11b of the connecting pin 16 via the needle roller 15, and the connecting bearings 17 and 18 are attached to both ends of the connecting pin 16. A ridge 11c is provided so as to protrude from the large end 11b on the side opposite to the piston. The ridge 11c is slidably inserted into a ring groove 12a that is annularly recessed in the output shaft 12, whereby the connecting rod 11 is restricted from moving in the axial direction of the output shaft 12.

The connecting member 13 is composed of disk-shaped left and right plates 19 and 20 arranged to face each other. The left plate 19 is integrally formed with the output shaft 12, and the right plate 20 has a boss portion 20.
a is fitted and fixed to the output shaft 12. A guide groove 21 is annularly formed in the opposing end surfaces of the left and right plates 19 and 20. The connecting bearings 17 and 18 of the connecting pin 16 are rotatably inserted in the guide groove 21. In this way, the reciprocating movement of the piston 10 causes the large end portion 11b of the connecting rod 11 to rotate the connecting member 13 and thus the output shaft 12.

The guide groove 21 has a pair of large-diameter groove portions 21a and 21b facing each other with the output shaft 12 interposed therebetween, and a pair of small-diameter groove portions 21c, 2 having a large diameter groove portions 21c facing each other with the output shaft 12 interposed therebetween.
It has a cocoon shape consisting of 1d. In addition, the output shaft 1
The distances from the axis of 2 to the large diameter groove portions 21a and 21b are both set to L, while the small diameter groove portions 21c and 21b are set.
The distance to d is set to S, S'and S> S '. And in the explosion and exhaust stroke, the connecting rod 1
The small-diameter groove portion 21d passes through the large end portion 11a of No. 1.

Next, the function and effect of this embodiment will be described. In the engine 1 of this embodiment, the connecting rod 11 rotates the connecting member 13 and thus the output shaft 12 as the piston 10 moves in the axial direction. This operation will be described focusing on the upper cylinder in FIG.

In the suction stroke, the piston 10 is located at the top dead center and the connecting pin 16 of the connecting rod 11 is located in the large-diameter groove portion 21b of the guide groove 21 of the connecting member 13 (see FIG. 3 (a)). Therefore, the connecting member 13 lowers the piston 10 by rotation due to inertia, and the connecting pin 16 is positioned in the small-diameter groove portion 21c of the guide groove 21. The stroke in this suction stroke is L-S.

In the compression stroke, the guide member 13 raises the piston 10 by rotation due to inertia, and the connecting pin 16
Will be located in the large-diameter groove portion 21a of the guide groove 21. The stroke in this compression stroke is L as in the suction stroke.
-S.

In the explosion stroke, the high pressure combustion gas causes the piston 10 to descend from the substantially top dead center position to the bottom dead center position, and the connecting pin 16 of the connecting rod 11 is located in the small diameter groove portion 21d. The stroke in this explosion stroke is L-S ',
Since S'is set to be smaller than S, it is larger than the stroke in the suction / compression stroke.

In the exhaust stroke, the guide member 13 moves the output shaft 1
By the rotation due to the inertia of 2, the piston 10 is raised to the top dead center by the same stroke as the above-described explosion stroke.

As described above, in the engine 1 of this embodiment, the guide groove 21 of the connecting member 13 is formed into a pair of large-diameter groove portions 21a, 21.
b, and the pair of small-diameter groove portions 21c and 21d, the piston 10 makes four strokes for each rotation of the output shaft 12, and it is possible to explode once for each rotation of the output shaft 12 and increase the output. Can be achieved. Also, in order to obtain the same output, a rotation speed of 1/2 is sufficient, and friction loss, pumping loss, etc. can be reduced.

Further, in this embodiment, the distance from the axis of the output shaft 12 to the small diameter groove portion 21d on the explosion / exhaust side is set smaller than the distance to the small diameter groove portion 21c on the suction / compression side. Is greater than L-S 'and the stroke L-S during suction / compression (see FIG. 5). As a result, the work of expansion is increased by the shaded area in FIG. 4, and the thermal efficiency can be improved.

Further, in this embodiment, since the piston and the connecting rod are fixed, both of them move only in the cylinder axis direction, and it is difficult for the piston to swing. As a result, the behavior of the piston is stable, and the amount of blow-by gas and lubrication are large. Oil consumption can be reduced.

Furthermore, in this embodiment, since the four cylinders are combined in a cross shape, the vibrations can be canceled by each other, and a quiet engine can be obtained.

In the above embodiment, the guide groove has been described as consisting of a pair of small-diameter groove portions and a pair of large-diameter groove portions, but the shape of the guide groove is not limited to this.
For example, the small-diameter groove portion and the large-diameter groove portion may be formed every 45 degrees. In this case, the piston makes one stroke with the rotation of the output shaft by 45 degrees.
Explosion can be performed twice per revolution.

Further, in the above embodiment, the explosion / exhaust stroke is made larger than the intake / compression stroke by the shape of the guide groove, but the present invention realizes various engine characteristics by appropriately setting the shape of the guide portion. You can For example, in the intake stroke, by increasing the piston speed in the vicinity of the opening of the intake valve, the air flow velocity into the intake passage can be increased and the intake efficiency can be improved. Also, in the compression stroke, by slowly changing the piston rising speed near the top dead center, it is possible to suppress the rise in air temperature due to sudden compression, and to lower the temperature before ignition to prevent knocking. Is also possible.

FIGS. 6 to 8 show examples in which the guide groove shape is appropriately set so that the volume change rate with respect to the crank angle at the time of combustion is made gentler in the explosion stroke than in the conventional reciprocating engine. In this example, as shown in FIG. 6, the bulging portion 2 is formed in the portion of the guide groove 21 corresponding to the explosion stroke.
1e was formed. As a result, as shown in FIGS. 7 and 8,
The expansion work in the explosion stroke is increased and the thermal efficiency is improved.

In the above embodiment, the 4-cycle engine has been described, but the present invention is of course applicable to a 2-cycle engine. Furthermore, the present invention can be applied not only to a reciprocating engine but also to a reciprocating compressor.

[0030]

As described above, according to the reciprocating engine of the first aspect of the present invention, since the guide portion of the connecting member is constituted by the plurality of small diameter guide portions and the plurality of large diameter guide portions, the output shaft 1 There is an effect that the explosion can be performed once or more for each rotation, the output can be increased, or the engine rotation speed can be reduced for the same output.

In the present invention, the stroke of each stroke, the piston speed, etc. can be freely set depending on the shape of the guide portion. For example, in the invention of claim 2, the minimum distance to the output shaft of one small-diameter groove is set smaller than the minimum distance of the other small-diameter groove, so that the stroke during the explosion / exhaust stroke can be made longer than the stroke during the other strokes. Therefore, there is an effect that the expansion work amount can be increased and the thermal efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a sectional front view of a reciprocating engine according to an embodiment of the present invention.

FIG. 2 is a sectional side view of the engine of the embodiment.

FIG. 3 is a schematic diagram for explaining the operation of the engine of the embodiment.

FIG. 4 is a graph for explaining the effect of the engine of the above embodiment.
It is a -V diagram.

FIG. 5 is a characteristic diagram showing a relationship between an output shaft rotation angle and a stroke for explaining the operation of the effect of the engine of the embodiment.

FIG. 6 is a schematic view showing a guide groove of a modified example of the above embodiment.

FIG. 7 is a characteristic diagram showing a relationship between an output shaft rotation angle and a stroke for explaining the operation of the modified example.

FIG. 8 is a P-V diagram for explaining the effect of the modified example.

[Explanation of symbols]

 1 Reciprocating engine 4 Cylinder 10 Piston 11 Connecting rod 12 Output shaft 13 Cam plate 21 Guide groove 21a, 21b Large diameter groove 21c Other small diameter groove 21d One small diameter groove S Minimum distance to the other small diameter groove S'One small diameter groove The minimum distance of

Claims (2)

[Claims] 1. An output shaft rotatably disposed, a connecting member fixed to the output shaft, a plurality of small-diameter guide portions formed on the connecting member and facing each other across the output shaft, and a plurality of small-diameter guide portions. A guide part having a large-diameter guide part, a connecting rod having a large end connected to the guide part so as to be relatively movable, a piston fixedly connected to the small end of the connecting rod, and the piston being the output shaft. A reciprocating engine, comprising: a cylinder that is slidably inserted in a right angle direction. 2. The minimum distance from the output shaft axis line to one of the small diameter guide portions according to claim 1, wherein the guide portion is formed in a cocoon type having a pair of small diameter guide portions and a pair of large diameter guide portions. Is set to be smaller than the minimum distance to the other small-diameter guide section, and the one small-diameter guide section is configured to pass through the large end of the connecting rod in the explosion / exhaust stroke. engine.