JP2009180186A - Multi-cylinder internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve assembling performance and manufacturing easiness when reducing a thrust load of a piston by a planetary gear mechanism composed of an internal gear 5 and a planetary gear 6 engaged therewith in a multi-cylinder internal combustion engine with two cylinders 1, 2 aligned. <P>SOLUTION: In crank arms 13b, 13c, 23b, 23c provided with crank pins 13a, 23a of the respective cylinders, pairs of right and left pin shafts 13d, 23d, 13e, 23e are integrally provided to a region decentered by one fourth dimension of a reciprocating stroke of the piston, and one pair of pin shafts 13e, 23e are rotatably journaled to output rotary shafts 14, 24 of the respective cylinders in a region decentered by one fourth dimension of the reciprocating stroke. On the other hand, the internal gear 5 is arranged between the respective cylinders and the other pair of pin shafts 13d, 23d are fittingly inserted into the planetary gear 6 so as to be positioned on the same axis. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal combustion engine in which a plurality of cylinders are arranged in a line.

  In a conventional internal combustion engine, as is well known, a crank arm is integrally provided on an output rotary shaft of the internal combustion engine, and a piston reciprocating stroke from the center of the rotary shaft of the crank arm is provided. The piston is connected to the crankpin integrally provided in the part eccentric by half the dimension via the connecting rod. According to this configuration, the crankpin is centered on the rotating shaft. Due to the rotation, the piston has a drawback in that a lateral thrust load is generated.

  Therefore, in Patent Documents 1 and 2 as prior arts, a crank arm provided with a crank pin is separated from an output rotating shaft in an internal combustion engine, and 1 of the reciprocating stroke from the center of the crank pin of the crank arm. A pin shaft is integrally provided at a portion eccentric by a dimension of / 4, and this pin shaft can be freely rotated at a portion eccentric by a dimension of 1/4 of the reciprocating stroke to a rotating shaft for output in an internal combustion engine. An planetary gear having a pitch circle with the reciprocating stroke as a pitch circle is arranged in a non-rotating position concentrically with the crankshaft, and the planetary gear has a half dimension of the reciprocating stroke as a pitch circle. A crank mechanism has been proposed in which a gear is fitted and the pin shaft is non-rotatably inserted into the planetary gear.

  According to the crank mechanism of this configuration, the crank pin is rotated in the reverse direction by the planetary gear meshing with the non-rotating internal gear, and the top dead center and the bottom dead center are along a straight line connecting them. Since it reciprocates, it is possible to reduce the thrust in the lateral direction with respect to the piston.

Further, in FIG. 6 of the above-mentioned Patent Document 1, when the crank mechanism is applied to each cylinder in an internal combustion engine in which at least two cylinders are arranged in a row, the two cylinders, that is, It has been proposed to arrange the internal gear and a planetary gear meshing with the internal gear at a portion between the first cylinder and the second cylinder.
Japanese Patent Laid-Open No. 62-182442 Japanese Patent Laid-Open No. 7-305601

  According to the configuration of FIG. 6 of Patent Document 1, there is an advantage that one internal gear disposed in a portion between each cylinder and one planetary gear meshing with the same can be shared by both cylinders.

  However, on the other hand, FIG. 6 of Patent Document 1 shows that the pin shaft in the crank mechanism of the first cylinder and the pin shaft in the crank mechanism of the second cylinder are integrally connected, and in this integrally connected portion, The one planetary gear is configured to be fitted, but a crank arm is integrally provided at both ends of the pin shaft in a portion integrally connected at a portion between the first cylinder and the second cylinder. Therefore, in order to assemble the single planetary gear on the pin shaft in the integrally connected portion, the planetary gear is divided into a plurality of parts along the axis. The plurality of parts must be fitted on the pin shaft and then coupled to each other.

  For this reason, not only the number of parts is greatly increased, but also processing of various parts including the crank mechanism and the planetary gear for each cylinder is extremely difficult, and assembly and disassembly are extremely difficult. The axial length of the gear is increased by the amount that the planetary gear must be provided with a coupling allowance for multiple parts, which increases the distance between the two cylinders, and thus increases the size of the internal combustion engine. There is a problem of doing.

  Furthermore, since the crank mechanism in each cylinder is an integral structure that is connected to the pin shaft, it is difficult to manufacture the crank mechanism and the manufacturing cost is greatly increased.

  It is a technical object of the present invention to solve the above-mentioned problems when the crank mechanism of the prior art is applied to a multi-cylinder internal combustion engine.

In order to achieve this technical problem, claim 1 of the present invention provides:
“In a multi-cylinder internal combustion engine with at least two cylinders arranged in a row,
The crankpin for each cylinder is provided in a crank arm for each cylinder, and a portion of each crank arm that is eccentric from the crankpin by a quarter of the reciprocating stroke of the piston of the cylinder is A pair of left and right pin shafts are integrally provided so as to protrude from the crank arm. Of the pair of pin shafts for each cylinder, the pin shaft on the outside in the cylinder row direction is pivotally supported for each cylinder. The output rotary shaft is rotatably supported at a portion eccentric by a dimension of 1/4 of the reciprocating stroke, while the reciprocating stroke is arranged as a pitch circle between the cylinders. An internal gear is arranged concentrically with the output rotation shaft, and this planetary gear has one planetary gear having a pitch circle half the size of the reciprocating stalk. Together are, in this single planetary gear, the pin shaft inside the cylinder row of the pair of pin shaft in each of said cylinders have been fitted so as to be positioned on the same axis. "
It is characterized by that.

Further, claim 2 in the present invention is
“In the first aspect of the present invention, the output rotary shaft for each cylinder is rotatably supported by a large-diameter journal portion provided integrally therewith. An outward pin shaft is supported on each side. "
It is characterized by that.

  According to the configuration of the first aspect, the crankpin for each cylinder is constituted by one internal gear disposed at a portion between the cylinders and one planetary gear meshing with the same, as in the prior art. , It can reciprocate between the top dead center and the bottom dead center along a straight line connecting them.

  In this case, both the pin shafts of both cylinders are fitted and inserted into the same planetary gear on the same axis, so that the two planet shafts are connected to each other by the one planetary gear, and thus both cylinders Therefore, the one planetary gear can be assembled without dividing the planetary gear into a plurality of parts as in the prior art, and the number of parts can be reduced. In addition, the various parts can be processed extremely easily, and the assembly and disassembly can be greatly improved.

  In addition, the length of the planetary gear in the axial direction can be shortened by an amount not necessary to provide a coupling allowance for the plurality of parts on the planetary gear. The engine can be reduced in size and weight.

  Furthermore, since the crank mechanism in each cylinder has an independent configuration for each cylinder, its manufacture is easy and manufacturing costs can be greatly reduced.

  In particular, according to the configuration described in claim 2, since the output rotary shaft in each cylinder is supported by the large-diameter journal portion, the bearing strength can be greatly improved.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  These drawings show a four-cycle two-cylinder internal combustion engine in which two cylinders, that is, a first cylinder 1 and a second cylinder 2 are arranged in a line.

  Each of the cylinders 1 and 2 in the multi-cylinder internal combustion engine includes a cylinder bore 11 and 21 formed in the cylinder block 3, pistons 12 and 22 that reciprocate within a predetermined stroke L in the cylinder bores 11 and 21, The first and second cylinders 1 and 2 have crank mechanisms 13 and 23 for the pistons 12 and 22 and output rotary shafts 14 and 24 disposed outside the crank mechanisms 13 and 23. The rotation angle of the rotary shafts 13 and 23 is shifted by 360 degrees, such that when one first cylinder 1 is in the explosion stroke, the other second cylinder 2 is in the intake stroke.

  Note that the tops of the cylinder bores 11 and 21 in each of the cylinders 1 and 2 are closed by a cylinder head 4 fastened to the upper surface of the cylinder block 3. As is well known, an intake port with an intake valve, an exhaust port with an exhaust valve, an ignition plug, a fuel injection valve, and the like are provided for each of the cylinders 1 and 2.

  The rotary shafts 14 and 24 for output in each of the cylinders 1 and 2 are located on the same axis, and in the large-diameter journal portions 14a and 24a provided integrally with each of the cylinders 1 and 2, respectively, It is rotatably supported through bearings 14b and 24b.

  Each of the crank mechanisms 13 and 23 in each of the cylinders 1 and 2 includes one crank pin 13a and 23a for each cylinder, and a pair of crank arms 13b, 13c, 23b and 23c for each cylinder. Pistons 12 and 22 in the cylinders 1 and 2 are connected to crankpins 13a and 23a in the crank mechanisms 13 and 23 via connecting rods 15 and 25, respectively.

  Of the two crank arms 13b and 13c in the crank mechanism 13 of the first cylinder 1, an inner crank arm 13b located on the second cylinder 2 side is provided with an inward pin shaft 13d that protrudes toward the second cylinder 2. However, the outer crank arm 13c located on the opposite side to the second cylinder 2 is integrally provided with outward pin shafts 13e that project toward the opposite side of the second cylinder 2, and these two The pin shafts 13d and 13e are located at a portion eccentric from the crank pin 13a by a dimension E1 that is ¼ of the reciprocating stroke L.

  Of the two crank arms 23b, 23c in the crank mechanism 23 of the second cylinder 2, an inner crank arm 23b located on the first cylinder 1 side is provided with an inward pin shaft 23d that protrudes toward the second cylinder 1. However, the outer crank arm 23c located on the opposite side to the first cylinder 1 is integrally provided with an outward pin shaft 23e that projects toward the opposite side of the first cylinder 1, and both The pin shafts 23d and 23e are located at a portion eccentric from the crank pin 23a by a dimension E1 that is ¼ of the reciprocating stroke L.

  The crank arms 13b, 13c, 23b, 23c in the crank mechanisms 13, 23 of the cylinders 1, 2 are integrally provided with balance weights on the opposite side of the crank pins 13a, 23a.

  On the other hand, in the region between the first cylinder 1 and the second cylinder 2, one internal gear 5 having the reciprocating stroke L as a pitch circle D1 is concentric with the output rotary shafts 14 and 24. It is disposed and supported by the cylinder block 3.

  Inside the internal gear 5, one planetary gear 6 having a half of the reciprocating stroke L as a pitch circle D <b> 2 is disposed so as to mesh with the internal gear 5.

  The inward pin shaft 13d in the crank mechanism 13 of the first cylinder 1 and the inward pin shaft 23d in the crank mechanism 23 of the second cylinder 2 are aligned in a straight line in the one planetary gear 6. Further, it is configured such that it is inserted by spline fitting or the like and detachably connected to each other via the one planetary gear 6.

  On the other hand, the outward pin shaft 13e in the crank mechanism 13 of the first cylinder 1 and the outward pin shaft 23e in the crank mechanism 23 of the second cylinder 2 are respectively journals on the output rotating shafts 14 and 24. The parts 14a and 24a are rotatably supported at portions eccentric from the output rotary shafts 14 and 24 by a dimension E2 that is ¼ of the reciprocating stroke L.

  In this configuration, the crank pin 13a in the crank mechanism 13 of the first cylinder 1 and the crank pin 23a in the crank mechanism 23 of the second cylinder 2 correspond to the reciprocating motion of the pistons 12 and 22 in the cylinders 1 and 2, respectively. The reciprocating motion between the top dead center TDC and the bottom dead center BDC at the same time along the straight line 7 connecting between the top dead center TDC and the bottom dead center BDC by the reverse rotation by the planetary gear 6 meshing with one internal gear 5 Thrust in the lateral direction with respect to the pistons 12 and 22 can be reduced.

  In this case, both the inward pin shafts 13d and 23d in the crank mechanisms 13 and 23 of the two cylinders 1 and 2 are fitted and inserted into the one planetary gear 6 on the same axis line. 6, both the inward pin shafts 13 d and 23 d are connected to each other, so that the one planetary gear 6 can be assembled without being divided into a plurality of parts as in the prior art. .

  The above embodiment is applied to a four-cycle multi-cylinder internal combustion engine. However, the present invention is not limited to this, and the present invention can be similarly applied to a two-cycle multi-cylinder internal combustion engine. The present invention is not limited to the ignition type multi-cylinder internal combustion engine, but can be similarly applied to a compression ignition type multi-cylinder internal combustion engine such as a diesel engine.

1 is a longitudinal front view of a multi-cylinder internal combustion engine showing an embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st cylinder 2 2nd cylinder 3 Cylinder block 4 Cylinder head 5 Internal gear 6 Planetary gear 11, 12 Cylinder bore 12, 22 Piston 13, 23 Crank mechanism 14, 24 Output rotating shaft 13a, 23a Crank pin 13b, 13c, 23b , 23c Crank arm 13d, 23d Pin shaft 13e, 23e Pin shaft 14a, 24a Journal part

Claims (2)

In a multi-cylinder internal combustion engine in which at least two cylinders are arranged in a row,
The crankpin for each cylinder is provided in a crank arm for each cylinder, and a portion of each crank arm that is eccentric from the crankpin by a quarter of the reciprocating stroke of the piston of the cylinder is A pair of left and right pin shafts are integrally provided so as to protrude from the crank arm. Of the pair of pin shafts for each cylinder, the pin shaft on the outside in the cylinder row direction is pivotally supported for each cylinder. The output rotary shaft is rotatably supported at a portion eccentric by a dimension of 1/4 of the reciprocating stroke, while the reciprocating stroke is arranged as a pitch circle between the cylinders. An internal gear is disposed concentrically with the output rotary shaft, and the internal gear includes a planetary gear having a pitch circle that is half the reciprocating stroke. The multiple planetary gears are inserted into the planetary gear so that the pin shafts inside the cylinder row of the pair of pin shafts for each cylinder are located on the same axis. Cylinder internal combustion engine.   In the first aspect of the present invention, the output rotation shaft for each cylinder is rotatably supported by a large-diameter journal portion provided integrally therewith, and the large-diameter journal portion is provided for each cylinder. An in-line multi-cylinder internal combustion engine characterized in that an outward pin shaft is supported on the shaft.

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