JP2005061301A - Scotch yoke type engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scotch york type engine which contributes to the miniaturization of an engine, and in which a crank shaft and a cylinder block do not require an excessive rigidity. <P>SOLUTION: An engine 1 has yokes 2, 3 to which four pistons 15-18 is provided. A crank shaft 21 is rotated by the reciprocating motion of the yokes 2, 3. A balancer shaft 41 of a balancer 4 is rotated with rotation of the crank shaft 21. An inertial force accompanying the movement of the yokes 2, 3 is canceled by centrifugal force of balance weights 43, 44 mounted in the balancer shaft 41 and counter weights 23, 27 provided to the yokes 2, 3. The separated distance L1 between the first balance weight 43 and the first yoke 2 matches with the separated distance L2 between the second balance weight 44 and the second yoke 3 so as to offset a moment applied to the crank shaft 21. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a scotch yoke engine, and more particularly, to a scotch yoke engine that can suitably suppress vibration generated during driving.

  As an engine used for automobiles and the like, there is a scotch yoke type engine using a scotch yoke mechanism, in addition to a general piston and a piston connected by a connecting rod. This Scotch yoke engine has a pair of connecting rods (hereinafter referred to as “yoke elements”), and has a yoke in which a long hole perpendicular to the extending direction of the yoke element is formed. An eccentric crankshaft is inserted into the long hole, and a mechanism for reciprocating the crankpin while rolling in the long hole is provided. In this Scotch yoke type engine, since the yoke connected to the crankshaft only reciprocates, there is no interference between the yoke and the cylinder bore wall skirt, so that the distance between the crankshaft and the piston can be shortened. Among such Scotch-yoke engines, there are those provided with four yokes, for example, those disclosed in German Patent Application Publication No. 10107921 (Patent Document 1).

  This Scotch-yoke engine has two cylinders that are adjacent to each other and provided in parallel, and two cylinders that are provided adjacent to each other and parallel to each other at a position facing the two cylinders. Further, the Scotch yoke engine has a yoke having four yoke elements to which four pistons, which are provided so as to be reciprocally movable, are respectively attached to these four cylinders. In addition, a long hole is formed in the yoke, and a crankshaft serving as an output shaft is inserted into the long hole in an eccentric state. Then, each cylinder sequentially goes through a normal engine cycle to reciprocate the yoke and rotate the crankshaft.

  Some types of Scotch-yoke engines have a balancer provided with a balance weight in order to suppress vibration associated with movement of a piston provided on the yoke. The balancer has a balancer shaft that is arranged in parallel to the crankshaft and rotates in a direction opposite to the rotation direction of the crankshaft, and a balance weight is provided at a position corresponding to a yoke attached to the crankshaft. Is. In this Scotch Yoke type engine, the balancer shaft rotates as the crankshaft rotates, and the force due to the balance weight works in the direction opposite to the inertial force accompanying the piston movement, canceling the inertial force accompanying the piston movement. To do.

However, even if such a balancer is provided, the balancer shaft and the crankshaft cannot be matched, and an unbalanced moment due to the balance weight is generated. In order to cancel such an unbalanced moment, a two-throw crankshaft provided with two crankpins is used, a yoke is attached to each crankpin, and a balancer provided with a balance weight for each is used. The yoke is reciprocated by setting the phase difference of the yoke in each of the two throws to 180 degrees. In this way, the unbalanced moment generated by each of the two balance weights is cancelled.
German Patent Application Publication No. 10107921

  However, in the Scotch yoke engine disclosed in Patent Document 1, the point of canceling the inertial force due to the movement of the piston is not particularly considered.

  Further, in a Scotch yoke type engine in which a balancer is provided on the crankshaft, the positions of the crankpin and the balancer are shifted as seen from the side surface in the axial direction of the crank. For this reason, due to the movement of the balance weight, a moment is generated at the position where the crankpin is provided on the crankshaft, and this moment causes the generation of vibration.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a scotch yoke engine that suitably suppresses vibration due to a moment accompanying rotation of a balancer.

  A scotch yoke engine according to the present invention that has solved the above-described problems is provided in a first cylinder and a second cylinder that are provided in parallel to each other at opposing positions, and to each of the first cylinder and the second cylinder so as to be able to reciprocate. A Scotch yoke type having a first piston and a second piston, and two yoke elements each provided with the first piston and the second piston, and having a yoke for transmitting the reciprocating motion of each piston to the crank pin of the crankshaft. The engine has a first yoke and a second yoke that are spaced apart in the axial direction of the crankshaft as the yoke, and a balancer having a balancer shaft disposed along the axial direction of the crankshaft is provided. The balancer shaft includes a first balance weight and a second balance way that are spaced apart in the axial direction. Is provided, spaced a distance crankshaft direction of the first balance weight and the first yoke, in which are made to coincide with the direction of the crankshaft distance between the second balance weight and a second yoke.

  Further, the Scotch yoke engine according to the present invention that has solved the above problems is provided at a position facing the first cylinder and the second cylinder, and a first cylinder and a second cylinder that are adjacent to and parallel to each other, A third cylinder and a fourth cylinder that are provided adjacent to each other in parallel, and a first piston, a second piston, a third piston, and a fourth piston that are reciprocally movable from the first cylinder to the fourth cylinder. A scotch yoke engine having four yoke elements each provided with a first piston to a fourth piston and transmitting a reciprocating motion of each piston to a crank pin of the crankshaft. A first yoke and a second yoke that are spaced apart in the axial direction of the crankshaft. A balancer having a balancer shaft arranged along the direction is provided, and the balancer shaft is provided with a first balance weight and a second balance weight that are arranged apart from each other in the axial direction. The distance in the crankshaft direction from the first yoke is the same as the distance in the crankshaft direction between the second balance weight and the second yoke.

  The Scotch yoke engine according to the present invention includes a first balance weight and a second balance weight, and has a balancer that suppresses vibration due to the reciprocating motion of the piston. Here, the distance in the crankshaft direction between the first balance weight and the first yoke is made to coincide with the distance in the crankshaft direction between the second balance weight and the second yoke. For this reason, the moments applied to the crankshaft can be of the same magnitude with different rotational directions, so that these moments can be offset. Therefore, it is possible to suppress the vibration due to the moment accompanying the rotation of the balancer.

  Moreover, it can be set as the aspect which consists of an 8-cylinder engine which has 8 sets of cylinders and pistons.

  In such an 8-cylinder engine having 8 sets of cylinders and pistons, vibration due to the moment accompanying the rotation of the balancer can be suppressed.

  Furthermore, a crank gear that rotates together with the crankshaft is attached to the crankshaft, and a balancer gear that transmits the rotation of the crank gear to the balancer shaft is attached to the balancer shaft, so that the crankshaft and the balancer shaft are relatively It is preferable to adopt a mode that rotates in the opposite direction.

  In this way, by applying rotation of the crankshaft to the balancer shaft via the gear, it is not necessary to separately provide power for rotating the balancer shaft. Further, the rotation of the crankshaft and the rotation of the balancer shaft can be reliably synchronized.

  According to the Scotch yoke type engine according to the present invention, it is possible to suitably suppress the vibration due to the moment accompanying the rotation of the balancer.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each embodiment, portions having the same function are denoted by the same reference numerals, and redundant description may be omitted. FIG. 1 is a perspective view of a main part of a Scotch yoke type engine according to a first embodiment of the present invention.

  As shown in FIG. 1, a Scotch yoke engine (hereinafter referred to as “engine”) 1 according to this embodiment is a so-called 8-cylinder engine, and the engine 1 includes two yokes 2 and 3. The configuration of the yokes 2 and 3 is the same, and the configuration of the first yoke 2 will be described below.

  The first yoke 2 is provided with four yoke elements 11, 12, 13, and 14. Of these, the first yoke element 11 and the second yoke element 12 are adjacent to each other and provided in parallel. ing. The third yoke element 13 and the fourth yoke element 14 are provided adjacent to each other and in parallel. Further, the third yoke element 13 and the fourth yoke element 14 are provided at positions facing the first yoke element 11 and the second yoke element 12.

  Pistons 15 to 18 are provided at the tip portions of the yoke elements 11 to 14, respectively. Among these, the 1st piston 15 and the 2nd piston 16 are each provided in the 1st cylinder and the 2nd cylinder which are provided in parallel with the mutually opposing position so that reciprocation is possible, respectively. Furthermore, the third piston 17 and the fourth piston 18 are respectively provided in a third cylinder and a fourth cylinder (not shown) provided in parallel to each other at opposite positions so as to be able to reciprocate. Thus, the engine 1 has four sets of cylinders and pistons.

  A rail 19 is formed between the first yoke element 11 and the second yoke element 12 and the third yoke element 13 and the fourth yoke element 14. The rail 19 is formed along a direction orthogonal to the reciprocating direction of the first yoke 2, and the first slider 20 is inserted into the rail 19.

  The first slider 20 is rotatably attached to a first crank pin 22 formed on the crankshaft 21. The crankshaft 21 is rotatably attached to a cylinder block (not shown). The first crank pin 22 is formed at a position deviated from the axis of the crankshaft 21, and the first slider 2 moves along the rail 19 as the first yoke 2 reciprocates. As the first crank pin 22 moves up and down as the slider 20 moves, the crankshaft 21 rotates.

  The crankshaft 21 is provided with a first counterweight 23 at a position facing the first crankpin 22 via the crankshaft 21. The first counterweight 23 is in a position symmetrical to the first crankpin 22 with respect to the crankshaft 21 and applies centrifugal force in a direction to cancel the inertial force generated by the movement of the first yoke 2 and the pistons 15 to 18. Giving. Here, the weight of the first counterweight 23 is half (1/2) that of the first yoke 2, and the centrifugal force by the first counterweight 23 is half of the maximum value of the inertial force due to the movement of the first yoke 2. It has been adjusted to be.

  Auxiliary drive pulleys (crank pulleys) and valve drive chain sprockets (not shown) are attached to the front side of the crankshaft 21, and a flywheel 25 is attached to the rear side. Further, the crankshaft 21 rotates to the position on the front side of the position where the first yoke 2 is provided as the crankshaft 21 rotates. A crank gear 24 that is coaxially arranged with the crankshaft 21 and rotates with the rotation of the crankshaft 21 is attached to the crankshaft 21 at a position behind the auxiliary drive pulley.

  Similarly, the second yoke 3 has yoke elements 30 to 33 and pistons 34 to 37. A second rail 38 is formed between the first yoke element 30 and the second yoke element 31 and the third yoke element 32 and the fourth yoke element 33. The second rail 38 is formed along a direction orthogonal to the reciprocating direction of the second yoke 3, and a second slider 39 is inserted into the second rail 38.

  The second slider 39 is rotatably attached to a second crank pin 26 formed on the crankshaft 21. The second crankpin 26 is formed at a position eccentric from the axis of the crankshaft 21, and the second slider 39 moves along the second rail 38 as the second yoke 3 reciprocates. As the second slider 39 moves, the second crank pin 26 moves up and down to rotate the crankshaft 21. The second crankpin 26 is provided with a 90 ° crank angle phase difference with respect to the first crankpin 20.

  The crankshaft 21 is provided with a second counterweight 27 at a position facing the second crankpin 26 via the crankshaft 21. The second counterweight 27 is located symmetrically with the second crankpin 26 with respect to the crankshaft 21 and applies centrifugal force in a direction to cancel the inertial force generated by the movement of the second yoke 3 and the pistons 34 to 37. Giving. Here, the weight of the second counterweight 27 is adjusted so that the centrifugal force generated by the second counterweight 27 is half (1/2) the maximum value of the inertial force generated by the movement of the second yoke 3.

  A balancer 4 is provided above the crankshaft 21. The balancer 4 has a balancer shaft 41 disposed along the axial direction of the crankshaft 21. The balancer shaft 41 is rotatably attached to a cylinder block (not shown), and a balancer gear 42 is attached to a front end portion thereof. The balancer gear 42 meshes with a crank gear 24 provided on the crankshaft 21, and the rotation of the crankshaft 21 is transmitted to the balancer shaft 41 via the crank gear 24 and the balancer gear 42. The gear ratio (rotational speed ratio) between the crank gear 24 and the balancer gear 42 is set to 1: 1, and the balancer shaft 41 rotates in synchronization with the rotation of the crankshaft 21. Thus, the balancer shaft 41 rotates in synchronization with the crankshaft 21 in the opposite direction.

  Further, a first balance weight 43 is provided at the front end of the balancer shaft 41, and a second balance weight 44 is provided at the rear end of the balancer shaft 41. The first balance weight 43 and the second balance weight 44 have the same weight. The first balance weight 43 and the second balance weight 44 are arranged with a phase difference of 180 degrees with respect to the balancer shaft 41 as schematically shown in FIG.

  When the balancer 4 rotates on the crankshaft 21, the inertial force generated by the movement of the yokes 2 and 3 causes the centrifugal force generated by the rotation of the balance weights 43 and 44 and the centrifugal force generated by the rotation of the counterweights 23 and 27. Canceled by force. The weights of both balance weights 43 and 44 are the same. Further, the centrifugal force generated by the rotation of the balance weights 43 and 44 of the balancer 4 is adjusted to be one half (1/2) of the maximum value of the inertial force due to the movement of the first yoke 2.

  Further, as shown in FIG. 2, the distance between the first balance weight 43 and the first yoke 2 in the balancer 4 (hereinafter referred to as “first separation distance”) is L1, and the second balance weight 44 and the second yoke 3 are The distance (hereinafter referred to as “second separation distance”) is L2. At this time, the first separation distance L1 and the second separation distance L2 are adjusted to be the same. In FIG. 2, the position of the cylinder is indicated by a virtual line.

  The operation and action of the engine 1 according to this embodiment having the above configuration will be described.

  In the engine 1 according to the present embodiment, in each of the first yoke 2 and the second yoke 3, the engine processes of the four cylinders, ie, the intake process, the compression process, the combustion process, and the exhaust process, are circulated to the first yoke 2. The pistons 15 to 18 attached and the pistons 34 to 37 attached to the second yoke enter and exit each cylinder, whereby the first yoke 2 and the second yoke 3 reciprocate. When the first yoke 2 reciprocates, the first slider 20 and the first crank pin 22 attached to the first yoke 2 move up and down relatively with respect to the crankshaft 21. When the second yoke 3 reciprocates, the second slider 39 and the second crank pin 26 attached to the second yoke 3 move up and down. The crankshaft 21 rotates as the first crankpin 22 and the second crankpin 26 move up and down.

  The rotation of the crankshaft 21 is supplied as power through a crank pulley. The rotation of the crankshaft 21 is transmitted to the balancer shaft 41 via the crank gear 24 balancer gear 42. Thus, the balancer shaft 41 rotates in the direction opposite to the rotation direction of the crankshaft 21.

  As the balancer shaft 41 rotates, the balance weights 43 and 44 also rotate. Of these, the first yoke 2 is caused by the centrifugal force generated by the rotational movement of the first balance weight 43 and the centrifugal force of the first counterweight 23 disposed at a symmetrical position with respect to the first crankpin 22 via the crankshaft 21. The inertial force due to the movement of the pistons 15 to 18 attached to is canceled. Also, the second balance weight 44 is attached to the second yoke 3 by the centrifugal force generated by the rotational movement of the second balance weight 44 and the force of the second counterweight 27 arranged at a symmetrical position with respect to the second crankpin 26 via the crankshaft 21. The inertial force due to the movement of the pistons 34 to 37 is canceled. This point will be described with reference to FIGS.

  3A is a schematic view of the first yoke portion of the engine as viewed from the axial direction of the crankshaft, and FIG. 3B is a schematic view of the second yoke portion of the engine as viewed from the axial direction of the crankshaft. ) Is a schematic view of the engine viewed from a direction orthogonal to the crankshaft. In FIG. 3A, the crankshaft 21 rotates counterclockwise, and the balancer shaft 41 rotates clockwise. In the following description, the state where the first crank pin 22 is at the uppermost end is defined as a state where the crank angle is 0 °. FIG. 2 shows a state where the crank angle is 0 °. FIG. 4 shows a state where the crank angle is 90 °.

  Looking at the relationship between the forces in the horizontal direction when the crank angle is 0 °, as shown in FIG. 3A, the first yoke 2 is located at the center of the reciprocating motion. There is no inertial force in the reciprocating direction. The inertial force accompanying the movement of the yokes 2 and 3 always acts only in the reciprocating direction (horizontal direction) of the yokes 2 and 3 and does not act in the vertical direction (vertical direction).

  At this time, the first balance weight 43 is located at the uppermost part, and the first counterweight 23 is located at the lowermost part. For this reason, neither the centrifugal force of the first balance weight 43 nor the centrifugal force of the first counterweight 23 is generated in the reciprocating direction of the first yoke 2. Therefore, in this state, the force that causes the vibration in the horizontal direction is not acting on the first yoke 2.

  Further, as shown in FIG. 3B, the pistons 34 to 37 attached to the second yoke 3 are located in the center of the reciprocating motion, and an inertial force is exerted in the reciprocating motion direction of the pistons 34 to 37. It has not occurred. The second balance weight 44 is located at the lowermost part, and the second counterweight 27 is located at the lowermost part. For this reason, neither the centrifugal force of the second balance weight 44 nor the centrifugal force of the second counterweight 27 is generated in the reciprocating direction of the second yoke 3. Therefore, in this state, the force that causes the vibration in the horizontal direction is not acting on the second yoke 3.

  Next, regarding the relationship between the forces in the vertical direction, as shown in FIG. 3A, the first balance weight 43 is located at the uppermost position, and the centrifugal force FB1 faces upward in the vertical direction. . The first counterweight 23 is located at the lowermost position, and the centrifugal force FC1 is directed vertically downward. Here, the masses of the first balance weight 43 and the first counterweight 23 are the same, and the centrifugal force FB1 generated by the first balance weight 43 and the centrifugal force FC1 generated by the first counterweight 23 are the same. For this reason, both centrifugal forces FB1 and FC1 can be canceled out to cause vibrations.

  Further, as shown in FIG. 3B, the second balance weight 44 is positioned at the lowermost position, and the centrifugal force FB2 faces downward in the vertical direction. Further, the second counterweight 27 is located at the uppermost position, and the centrifugal force FC2 is directed vertically upward. Here, the masses of the second balance weight 44 and the second counterweight 27 are the same, and the centrifugal force FB2 due to the second balance weight 44 and the centrifugal force FC2 due to the second counterweight 27 are the same. For this reason, both centrifugal forces FB2 and FC2 can be prevented from canceling each other and causing vibration.

  At this time, as shown in FIG. 3C, the position of the first crank pin 22 and the position of the first balance weight 43 are shifted as seen from the side of the crankshaft 21. Further, the centrifugal force FB1 due to the first balance weight 43 works upward in the vertical direction, and the centrifugal force FB2 due to the second balance weight 44 works downward in the vertical direction. For this reason, a moment MS1 in the clockwise direction is applied to a position where the first crank pin 22 is formed on the crankshaft 21 (hereinafter referred to as “first throw”). Further, the position of the second crank pin 26 and the position of the second balance weight 44 viewed from the side of the crankshaft 21 are also shifted. For this reason, a counterclockwise moment MS2 is applied to the portion of the crankshaft 21 where the second crankpin is formed (hereinafter referred to as “second throw”).

  Here, in the present embodiment, the first separation distance L1 and the second separation distance L2 are the same. Further, since the masses of the balance weights 43 and 44 are the same, the two moments MS1 and MS2 have the same magnitude. Therefore, these moments MS1 and MS2 cancel each other, so that they can be prevented from generating vibration.

  Further, as shown in FIG. 4A, when the crank angle is 90 °, the pistons 15 to 18 attached to the first yoke 2 are moved to the leftmost side, and the crank pin 22 is connected to the crankshaft. 21 on the left side. At this time, the inertial force FX1 accompanying the movement of the first yoke 2 acts on the left side.

  Furthermore, the centrifugal force FC1 due to the first counterweight 23 and the centrifugal force FB1 due to the first balance weight 43 provided on the balancer 4 both act on the right side in the horizontal direction of FIG. Here, the centrifugal force FC1 due to the first counterweight 23 is half of the inertial force FX1 accompanying the movement of the first yoke 2, and the centrifugal force FB1 due to the first balance weight 43 is both the movement of the first yoke 2. Is half of the inertial force FX1 associated therewith. Therefore, the centrifugal forces FC1 and FB1 due to the first counterweight 23 and the first balance weight 43 cancel the inertial force FX1 accompanying the movement of the first yoke 2, and the vibration due to the reciprocating motion of the pistons 15 to 18 is suppressed. .

  On the other hand, as shown in FIG. 4B, the pistons 34 to 37 attached to the second yoke 3 have moved to the rightmost side, and the crank pin 22 is located on the right side with respect to the crankshaft 21. Yes. At this time, the inertial force FX2 accompanying the movement of the second yoke 3 acts on the right side of FIG.

  Further, the centrifugal force FC2 due to the second counterweight 27 and the centrifugal force FB2 due to the second balance weight 44 provided on the balancer 4 both act on the left side in the horizontal direction of FIG. Here, the centrifugal force FC2 due to the second counterweight 27 is half of the inertial force FX2 accompanying the movement of the second yoke 3, and the centrifugal force FB2 due to the second balance weight 44 is the movement of the second yoke 3. Is half of the inertial force FX2. For this reason, the inertial force FX2 accompanying the movement of the second yoke 3 is canceled out by the centrifugal forces FC2 and FB2 due to the second counterweight 27 and the second balance weight 44, and vibration due to the reciprocating motion of the pistons 34 to 37 is suppressed. .

  Further, as shown in FIG. 4C, the centrifugal force generated by the balance weights 43 and 44 does not work in the vertical direction, so that no moment is applied to the crankshaft 21. However, as shown in FIG. 4A, with respect to the resultant force of the centrifugal force FB1 between the centrifugal force FC1 by the first counterweight 23 and the first balance weight 43, the inertial force FX1 accompanying the movement of the first yoke 2 is It is offset. For this reason, the clockwise moment MF1 is applied to the first throw.

  Similarly, as shown in FIG. 4B, the inertial force FX2 accompanying the movement of the second yoke 3 with respect to the resultant force of the centrifugal force FC2 caused by the second counterweight 27 and the centrifugal force FB2 caused by the second balance weight 44. Is offset. For this reason, the counterclockwise moment MF2 is applied to the second throw.

  In this respect, these moments MF1 and MF2 have the same magnitude, and their directions are opposite to each other. For this reason, these moments MF1 and MF2 work as torsional moments with respect to the crankshaft 21, and do not cause vibration.

  Thus, in the engine 1 according to this embodiment, the separation distance L1 between the first balance weight 43 and the first yoke 2 in the crankshaft direction is such that the second balance weight 44 and the second yoke 3 are in the crankshaft direction. It is made to correspond with the separation distance L2. For this reason, the moments applied to the crankshaft 21 can be of the same magnitude with different rotational directions, so that these moments can be offset. Therefore, it is possible to suitably suppress the vibration due to the moment accompanying the rotation of the balancer 4.

  Next, a second embodiment of the present invention will be described. The present embodiment is mainly different from the first embodiment in that there are three yokes.

  FIG. 5 is a schematic view of the engine according to the second embodiment of the present invention viewed from a direction orthogonal to the crankshaft.

  As shown in FIG. 5, the engine 50 according to the present embodiment includes three yokes 51 to 53. These yokes 51 to 53 have the same configuration as the yoke shown in the first embodiment, and include four yoke elements and a piston attached thereto.

  These yokes 51 to 53 are respectively provided at positions of crank pins 55 to 57 provided on the crankshaft 54, and the cranks are moved via a slider (not shown) by reciprocation of the first yoke 51 to the third yoke 53. The shaft 54 is rotated. A crank gear 58 is provided at one end of the crankshaft 54, and a flywheel 59 is provided at the other end of the crankshaft 54.

  Regarding the positional relationship between the yokes 51 to 53, the first yoke 51 is disposed at a position closest to the crank gear 58, and the second yoke 52 is disposed at a position closest to the flywheel 59. A third yoke 53 is disposed between the two yokes 52, and a third yoke 53 is disposed between the first yoke 51 and the second yoke 52. The first yoke 51 to the third yoke 53 are arranged with a phase difference of 120 ° with respect to the adjacent yokes.

  A first counterweight 60 is provided on the crankshaft 54 at a position having a phase difference of 60 ° with respect to a position facing the first crankpin 55 via the crankshaft 54. The first counterweight 60 is in a position symmetrical to the first crankpin 55 with respect to the crankshaft 54 and applies a centrifugal force in a direction to cancel the inertial force generated by the movement of the first yoke 51. Here, the centrifugal force by the first counterweight 60 is adjusted to be half of the maximum value of the inertial force due to the movement of the first yoke 51.

  Similarly, a second counterweight 61 is provided on the crankshaft 54 at a position having a phase difference of 60 ° with respect to a position facing the second crankpin 56 via the crankshaft 54. The second counterweight 61 is located at a position symmetrical to the second crankpin 56 with respect to the crankshaft 54 and applies a centrifugal force in a direction to cancel the inertial force generated by the movement of the second yoke 52. Here, the centrifugal force by the second counterweight 61 is adjusted to be half of the maximum value of the inertial force due to the movement of the second yoke 52.

  A balancer 70 is provided above the crankshaft 54. The balancer 70 includes a balancer shaft 71 disposed in parallel to the axial direction of the crankshaft 54, and a balancer gear 72 that meshes with the crank gear 58 is provided at one end of the balancer shaft 71. The balancer gear 72 rotates in the opposite direction to the crank gear 58 as the crank gear 58 rotates. For this reason, the crankshaft 54 and the balancer shaft 71 rotate in directions opposite to each other.

  Furthermore, balance weights 73 and 74 are provided on both ends of the balancer shaft 71, respectively. These balance weights 73 and 74 are arranged around the balancer shaft 71 with a phase difference of 180 °. The distance L1 between the first yoke 51 and the first balance weight 73 in the crankshaft 54 direction is the same as the distance L2 between the second yoke 52 and the second balance weight 74 in the crankshaft 54 direction. Here, the separation distance L <b> 1 between the first yoke 51 and the first balance weight 73 in the direction of the crankshaft 54 coincides with the separation distance between the first counterweight 60 and the first balance weight 73. Further, the distance L2 between the second yoke 52 and the second balance weight 74 in the direction of the crankshaft 54 coincides with the distance between the second counterweight 61 and the second balance weight 74.

  The operation and action of the engine 50 according to the present embodiment having the above configuration will be described.

  In the engine 50 according to the present embodiment, the pistons provided in the yokes 51 to 53 move in and out of the cylinder, so that the yokes 51 to 53 reciprocate. The crankshaft 54 is rotated by the reciprocating motion of the yokes 51 to 53. The rotation of the crankshaft 54 is transmitted to the balancer shaft 71 via the crank gear 58 and the balancer gear 72, and the balancer shaft 71 rotates in the direction opposite to the rotation direction of the crankshaft 54.

  The balance weights 73 and 74 are also rotated by the rotation of the balancer shaft 71, and the inertial force accompanying the movement of the yokes 51 to 53 is canceled by the balance weights 73 and 74 and the counter weights 60 and 61. This point will be described with reference to FIG.

  6A is a schematic diagram of the first yoke portion of the engine as viewed from the axial direction of the crankshaft, and FIG. 6B is a schematic diagram of the third yoke portion of the engine as viewed from the axial direction of the crankshaft. ) Is a schematic diagram of the second yoke portion of the engine as viewed from the axial direction of the crankshaft, and (d) is a schematic diagram of the engine as viewed from the direction orthogonal to the crankshaft. In the present embodiment, the state where the first crank pin 55 is at the uppermost end is defined as a state where the crank angle is 0 °. FIG. 6 shows a state where the crank angle is 0 °.

  Looking at the force relationship in the horizontal direction when the crank angle is 0 °, as shown in FIG. 6 (a), the first yoke 51 is located at the center in the reciprocating direction. No inertial force is generated in the reciprocating direction 51. The inertial force accompanying the movement of the yokes 51 to 53 always acts only in the reciprocating direction (horizontal direction) of the yokes 51 to 53, and does not act in the vertical direction (vertical direction).

  At this time, the first balance weight 73 is at a position of 60 °, and the first counterweight 60 is at a position of 150 °. For this reason, the centrifugal force FB1 of the first balance weight 73 and the centrifugal force FC1 of the first counterweight 60 act in the left direction.

  Further, as shown in FIG. 6B, the third yoke 53 moves to the left in the reciprocating direction, and the inertial force FX1 accompanying the movement acts on the right. The inertial force FX2 due to the third yoke 53 coincides with the resultant force FS1 obtained by adding the centrifugal force FB1 of the first balance weight 73 and the centrifugal force FC1 of the first counterweight 60. Therefore, both forces are canceled out, and the force that causes the vibration in the horizontal direction by the first yoke 51 and the third yoke 53 does not work.

  Further, as shown in FIG. 6C, the second yoke 52 is positioned on the right side of the reciprocating motion, and the inertial force FX2 accompanying the movement of the second yoke 52 acts on the right side. The second balance weight 74 is at a position of 240 °, and the second counterweight 61 is at a position of 300 °. For this reason, the centrifugal force FB2 of the second balance weight 74 and the centrifugal force FC2 of the second counterweight 61 act in the right direction in the horizontal direction. The inertial force FX2 accompanying the movement of the second yoke 52 coincides with the resultant force FS2 obtained by adding the centrifugal force FB2 of the second balance weight 74 and the centrifugal force FC2 of the second counterweight 61. Therefore, both forces are canceled out, and the force that causes the horizontal vibration by the second yoke 52 does not work.

  Next, regarding the force relationship in the vertical direction, as shown in FIG. 6 (d), the vertical component of the centrifugal force FB 1 of the first balance weight 73 and the vertical direction of the centrifugal force FC 1 of the first counterweight 60. Is consistent with the components of Further, the vertical component of the centrifugal force FB2 of the second balance weight 74 and the vertical component of the centrifugal force FC2 of the second counterweight 61 coincide with each other. For this reason, since these mutually cancel the force, it can prevent that a vibration arises.

  At this time, as shown in FIG. 6 (d), the position of the first counterweight 60 and the position of the first balance weight 73 are shifted from the side of the crankshaft 54. This gives a clockwise moment MS1. Further, since the position of the second counterweight 61 and the position of the second balance weight 74 are deviated, a counterclockwise moment MS2 is applied to the crankshaft 54.

  In contrast, in the engine 50 according to this embodiment, the separation distance L1 between the first counterweight 60 and the first balance weight 73 and the separation distance L2 between the second counterweight 61 and the second balance weight 74 are as follows. Match. For this reason, the moments MS1 and MS2 are moments facing in opposite directions having the same magnitude, and become a force for twisting the entire engine 50. Therefore, by making the cylinder block high in rigidity, these moments MS1, MS2 can be prevented from causing vibration.

  Further, as shown in FIG. 7A, when the crank angle is 300 °, the first yoke 51 is moved to the left side, and the inertial force FX1 accompanying the movement of the first yoke 51 is generated on the left side. . Further, as shown in FIG. 7B, the third yoke 53 is located at the center, and no inertial force is generated as the third yoke 53 moves. Further, as shown in FIG. 7C, the second yoke 52 is moved to the left side, and the inertial force FX2 accompanying the movement of the second yoke 52 is acting on the right side.

  In this state, as shown in FIG. 7A, the centrifugal force FC1 of the first counterweight 60 and the centrifugal force FB1 of the first balance weight 73 are both directed to the right side. Further, the resultant force FS1 of the centrifugal forces FC1 and FB1 is the same as the inertial force FX1 accompanying the movement of the first yoke 51, and both are in opposite directions. Therefore, the resultant force FS1 and the inertial force FX1 cancel each other, and can be prevented from causing vibration.

  Further, as shown in FIG. 7B, since the third yoke 53 is located at the center, inertial force accompanying the movement does not occur. Furthermore, as shown in FIG. 7C, the centrifugal force FC2 of the second counterweight 61 and the centrifugal force FB2 of the second balance weight 74 are directed to the left side. The second yoke 52 is positioned on the right side of the center, and the inertial force FX2 accompanying the movement of the second yoke 52 faces the left side, and is the same as the resultant force FS2 of the centrifugal forces FC2 and FB2. For this reason, the resultant force FS2 and the inertial force FX2 accompanying the movement of the second yoke 52 are canceled out, and it is possible not to cause vibration.

  At this time, as shown in FIG. 7 (d), no moment is generated as viewed from the axial direction of the crankshaft 54, so that no factor of vibration due to torsion occurs.

  FIG. 8 shows a state where the crank angle is 240 °. When the crank angle is 240 °, as shown in FIG. 8A, the first yoke 51 is located on the left side, and as shown in FIG. 8B, the third yoke 53 is located on the right side. Yes. Further, as shown in FIG. 8C, the second yoke 52 is located at the center. Thus, the inertial force FX1 associated with the movement of the first yoke 51 acts on the left side, and the inertial force FX3 associated with the movement of the third yoke 53 acts on the right side, and inertial force due to the movement of the second yoke 52 does not occur.

  Further, the horizontal component of the centrifugal force FB1 of the first counterweight 60 acts on the right side, and the horizontal component of the centrifugal force FB1 of the first balance weight 73 also acts on the right side. The resultant force FS1 of the centrifugal forces FC1 and FB1 coincides with the inertial force FX1 accompanying the movement of the first yoke 51, and both cancel each other, so that it does not cause vibration.

  Further, the inertial force FX3 accompanying the movement of the third yoke 53 acts on the right side. Further, the horizontal component of the centrifugal force FC2 of the second counterweight 61 and the horizontal component of the centrifugal force FB2 of the second balance weight 74 both act on the left side, and the resultant force FS2 acts on the movement of the third yoke 53. This coincides with the accompanying inertial force FX3. Therefore, the resultant force FS2 and the inertial force FX3 cancel each other, and can be prevented from causing vibration.

  On the other hand, when viewed in the vertical direction, as shown in FIG. 8 (d), the vertical component of the centrifugal force FC1 of the first counterweight 60 and the vertical component of the first balance weight 73 are the same. It faces the opposite direction. For this reason, both cancel each other. In addition, the vertical component of the second counterweight 61 and the vertical component of the second balance weight 73 are the same, and both match. For this reason, both cancel each other. In this way, it is possible to prevent the occurrence of vibration in the vertical direction.

  Further, when viewed from the axial direction of the crankshaft 54, a clockwise moment MS1 and a counterclockwise moment MS2 are generated, and these moments MS1 and MS2 have the same magnitude. Therefore, these serve as a force for twisting the entire engine 50, and by making the cylinder block highly rigid, these moments MS1, MS2 can be prevented from causing vibration.

  Next, FIG. 9 shows a state where the crank angle is 180 °. In the state where the crank angle is 180 °, as shown in FIG. 9A, the first yoke 51 is located at the center, and as shown in FIG. 9B, the third yoke 53 is located on the right side. As shown in FIG. 9C, the second yoke 52 is located on the left side. Thus, the inertial force FX3 associated with the movement of the third yoke 53 acts on the right side, and the inertial force FX2 associated with the movement of the second yoke 52 acts on the left side.

  Further, the horizontal component of the centrifugal force FC1 of the first counterweight 60 and the horizontal component of the centrifugal force FB1 of the second balance weight 73 both act on the left side, and the resultant force FS1 also acts on the left side. The resultant force FS1 is the same as the inertial force FX3 accompanying the movement of the third yoke 53, and the directions thereof are contradictory to each other, so that they can be canceled out to cause no vibration.

  Further, the horizontal component of the centrifugal force FC2 of the second counterweight 61 and the horizontal component of the centrifugal force FB2 of the second balance weight 74 both act on the right side, and the resultant force FS2 also acts on the right side. The resultant force FS2 is the same as the inertial force FX2 that accompanies the movement of the second yoke 52, and since the directions thereof are contradictory to each other, they can be canceled out and cause no vibration.

  When viewed in the vertical direction, as shown in FIG. 9D, the vertical component of the centrifugal force FC1 of the first counterweight 60 and the vertical component of the first balance weight 73 are the same, and It faces the opposite direction. For this reason, both cancel each other. In addition, the vertical component of the second counterweight 61 and the vertical component of the second balance weight 73 are the same, and both match. For this reason, both cancel each other. In this way, it is possible to prevent the occurrence of vibration in the vertical direction.

  Furthermore, a clockwise moment MS1 and a counterclockwise moment MS2 are generated when viewed from the axial direction of the crankshaft 54, and these moments MS1 and MS2 have the same magnitude. Therefore, these serve as a force for twisting the entire engine 50, and by making the cylinder block highly rigid, these moments MS1, MS2 can be prevented from causing vibration.

  Next, FIG. 10 shows a state where the crank angle is 120 °. When the crank angle is 120 °, as shown in FIG. 10A, the first yoke 51 is located on the right side, and as shown in FIG. 10B, the third yoke 53 is located in the center. Yes. Further, as shown in FIG. 10C, the second yoke 52 is located on the left side. In this way, the inertial force FX1 accompanying the movement of the first yoke 51 acts on the right side and the inertial force FX2 accompanying the movement of the second yoke 52 acts on the right side, and no inertial force due to the movement of the third yoke 53 occurs.

  Further, the horizontal component of the centrifugal force FB1 of the first counterweight 60 acts on the left side, and the horizontal component of the centrifugal force FB1 of the first balance weight 73 also acts on the left side. The resultant force FS1 of the centrifugal forces FC1 and FB1 coincides with the inertial force FX1 accompanying the movement of the first yoke 51, and both cancel each other, so that it does not cause vibration.

  In addition, the horizontal component of the centrifugal force FC2 of the second counterweight 61 and the horizontal component of the centrifugal force FB2 of the second balance weight 74 both act on the right side, and the resultant force FS2 acts on the movement of the second yoke 52. This coincides with the accompanying inertial force FX2. Therefore, the resultant force FS2 and the inertial force FX2 can be canceled out so as not to cause vibration.

  At this time, as shown in FIG. 10 (d), no moment is generated as viewed from the axial direction of the crankshaft 54, so that no factor of vibration due to torsion occurs.

  Next, FIG. 11 shows a state where the crank angle is 60 °. When the crank angle is 60 °, as shown in FIG. 11A, the first yoke 51 is located on the right side, and as shown in FIG. 9B, the third yoke 53 is located on the left side. As shown in FIG. 9 (c), the second yoke 52 is located at the center. Thus, the inertial force FX1 associated with the movement of the first yoke 51 acts on the right side, and the inertial force FX3 associated with the movement of the third yoke 53 acts on the left side.

  Further, the horizontal component of the centrifugal force FC1 of the first counterweight 60 and the horizontal component of the centrifugal force FB1 of the first balance weight 73 both act on the left side, and the resultant force FS1 also acts on the left side. The resultant force FS1 is the same as the inertial force FX1 accompanying the movement of the first yoke 51, and the directions thereof are contradictory to each other, so that they can be canceled out to cause no vibration.

  Further, the horizontal component of the centrifugal force FC2 of the second counterweight 61 and the horizontal component of the centrifugal force FB2 of the second balance weight 74 both act on the right side, and the resultant force FS2 also acts on the right side. The resultant force FS2 is the same as the inertial force FX3 accompanying the movement of the third yoke 53, and the directions thereof are contradictory to each other, so that they can be canceled out and cause no vibration.

  When viewed in the vertical direction, as shown in FIG. 11D, the vertical component of the centrifugal force FC1 of the first counterweight 60 and the vertical component of the first balance weight 73 are the same, and It faces the opposite direction. For this reason, both cancel each other. In addition, since the vertical component of the second counterweight 61 and the vertical component of the second balance weight 74 are the same and coincide with each other, they cancel each other. In this way, it is possible to prevent the occurrence of vibration in the vertical direction.

  Furthermore, a clockwise moment MS1 and a counterclockwise moment MS2 are generated when viewed from the axial direction of the crankshaft 54, and these moments MS1 and MS2 have the same magnitude. Therefore, these serve as a twisting force for the entire engine 50, and the moments MS1 and MS2 can be prevented from causing vibrations by keeping the rigidity of the cylinder block high.

  Thus, in the engine 50 according to the present embodiment, it is possible to prevent the occurrence of vibration due to the inertial force of the yoke and the centrifugal force of the counterweight or balancer weight, regardless of the crank angle. The distance L1 between the first balance weight 73 and the first yoke 51 in the direction of the crankshaft 54 and the distance L2 between the second balance weight 74 and the second yoke 52 in the direction of the crankshaft 54 are matched. Yes. For this reason, the vibration by the moment concerning the crankshaft 54 can be suppressed suitably.

  Further, in the engine 50 according to the present embodiment, the counterweight is provided only at positions corresponding to the first crankpin and the second crankpin, so that the number of parts can be reduced. In addition, a counterweight and a balance weight corresponding to each of the positions corresponding to the first to third crankpins may be provided.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, although two balance weights are provided on both balancers in the above-described embodiment, it is possible to adopt a mode in which more balance weights are provided. Moreover, in the said embodiment, although the balancer axis | shaft is rotated via a gear, it can also be set as the aspect which rotates a balancer using another motive power. Furthermore, although the balance weight has the same weight, the balance weight and the counter weight having different weights can be used by adjusting the distance relationship of the yoke 2.

It is a principal part perspective view of the Scotch yoke type engine which concerns on 1st Embodiment. It is the schematic diagram of the engine seen from the direction orthogonal to a crankshaft. It is a figure which shows the state where a crank angle is 0 degree, (a) is a schematic diagram of the 1st yoke part of the engine seen from the axial direction of a crankshaft, (b) is an engine seen from the axial direction of the crankshaft. (C) is the schematic diagram of the engine seen from the direction orthogonal to a crankshaft. It is a figure which shows the state where a crank angle is 90 degrees, (a) is a schematic diagram of the 1st yoke part of the engine seen from the axial direction of the crankshaft, (b) is an engine seen from the axial direction of the crankshaft. (C) is the schematic diagram of the engine seen from the direction orthogonal to a crankshaft. It is a schematic diagram of the state which looked at the engine which concerns on 2nd Embodiment from the direction orthogonal to a crankshaft. It is a figure which shows the state where a crank angle is 0 degree, (a) is a schematic diagram of the 1st yoke part of the engine seen from the axial direction of a crankshaft, (b) is an engine seen from the axial direction of the crankshaft. FIG. 4C is a schematic diagram of the second yoke portion of the engine as viewed from the axial direction of the crankshaft, and FIG. 4D is a schematic diagram of the engine as viewed from the direction orthogonal to the crankshaft. It is. It is a figure which shows the state whose crank angle is 300 degrees, (a) is a schematic diagram of the 1st yoke part of the engine seen from the axial direction of a crankshaft, (b) is an engine seen from the axial direction of the crankshaft. FIG. 4C is a schematic diagram of the second yoke portion of the engine as viewed from the axial direction of the crankshaft, and FIG. 4D is a schematic diagram of the engine as viewed from the direction orthogonal to the crankshaft. It is. It is a figure which shows the state whose crank angle is 240 degrees, (a) is a schematic diagram of the 1st yoke part of the engine seen from the axial direction of a crankshaft, (b) is an engine seen from the axial direction of the crankshaft. FIG. 4C is a schematic diagram of the second yoke portion of the engine as viewed from the axial direction of the crankshaft, and FIG. 4D is a schematic diagram of the engine as viewed from the direction orthogonal to the crankshaft. It is. It is a figure which shows the state where a crank angle is 180 degrees, (a) is a schematic diagram of the 1st yoke part of the engine seen from the axial direction of a crankshaft, (b) is an engine seen from the axial direction of the crankshaft. FIG. 4C is a schematic diagram of the second yoke portion of the engine as viewed from the axial direction of the crankshaft, and FIG. 4D is a schematic diagram of the engine as viewed from the direction orthogonal to the crankshaft. It is. It is a figure which shows the state whose crank angle is 120 degrees, (a) is a schematic diagram of the 1st yoke part of the engine seen from the axial direction of a crankshaft, (b) is an engine seen from the axial direction of the crankshaft. FIG. 4C is a schematic diagram of the second yoke portion of the engine as viewed from the axial direction of the crankshaft, and FIG. 4D is a schematic diagram of the engine as viewed from the direction orthogonal to the crankshaft. It is. It is a figure which shows the state whose crank angle is 60 degrees, (a) is a schematic diagram of the 1st yoke part of the engine seen from the axial direction of a crankshaft, (b) is an engine seen from the axial direction of the crankshaft. FIG. 4C is a schematic diagram of the second yoke portion of the engine as viewed from the axial direction of the crankshaft, and FIG. 4D is a schematic diagram of the engine as viewed from the direction orthogonal to the crankshaft. It is.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,50 ... Engine, 2 ... 1st yoke, 3 ... 2nd yoke, 4,70 ... Balancer, 11-14, 30-33 ... Yoke element, 15-18, 34-37 ... 1st piston, 16 ... 1st Two pistons, 17 ... third piston, 18 ... fourth piston, 19 ... rail, 20 ... first crank pin, 20 ... first slider, 21 ... crank shaft, 22 ... first crank pin, 23 ... first counterweight 24, 58 ... crank gear, 25, 59 ... flywheel, 26 ... second crank pin, 27 ... second counterweight, 38 ... second rail, 39 ... second slider, 41, 71 ... balancer shaft, 42, 72 ... Balancer gear, 43, 73 ... First balance weight, 44, 74 ... Second balance weight, 51 ... First yoke, 52 ... Second yoke, 53 ... Third yoke, 54 ... Class Shaft, 55 ... first crankpin, 56 ... second crankpin, 57 ... third crankpin, 60 ... first counterweight, 61 ... second counterweight, L1 ... first separation distance, L2 ... second separation distance.

Claims (4)

A first cylinder and a second cylinder provided in parallel to each other at opposite positions; a first piston and a second piston provided in each of the first cylinder and the second cylinder so as to be capable of reciprocating; the first piston and the A scotch yoke engine having two yoke elements each provided with a second piston and having a yoke for transmitting the reciprocating motion of each piston to a crankpin of a crankshaft;
As the yoke, it has a first yoke and a second yoke that are spaced apart in the axial direction of the crankshaft,
A balancer having a balancer shaft arranged along the axial direction of the crankshaft is provided, and the balancer shaft is provided with a first balance weight and a second balance weight arranged separately in the axial direction. And
The distance between the first balance weight and the first yoke in the crankshaft direction is the same as the distance between the second balance weight and the second yoke in the crankshaft direction. Expression engine. A first cylinder and a second cylinder provided adjacent to each other in parallel, and a third cylinder and a fourth cylinder provided at positions opposed to the first cylinder and the second cylinder, provided adjacent to each other and in parallel. A first piston, a second piston, a third piston, and a fourth piston that are reciprocally provided to each of the cylinder, the first cylinder to the fourth cylinder, and the fourth piston to the fourth piston. A scotch yoke type engine having four yoke elements and having a yoke for transmitting the reciprocating motion of each piston to a crank pin of a crankshaft;
As the yoke, it has a first yoke and a second yoke that are spaced apart in the axial direction of the crankshaft,
A balancer having a balancer shaft arranged along the axial direction of the crankshaft is provided, and the balancer shaft is provided with a first balance weight and a second balance weight arranged separately in the axial direction. And
The distance between the first balance weight and the first yoke in the crankshaft direction is the same as the distance between the second balance weight and the second yoke in the crankshaft direction. Expression engine.   The scotch-yoke engine according to claim 1, comprising an eight-cylinder engine having eight cylinders and pistons. A crank gear that rotates with the crankshaft is attached to the crankshaft,
A balancer gear that transmits rotation of the crank gear to the balancer shaft is attached to the balancer shaft,
The scotch yoke engine according to any one of claims 1 to 3, wherein the crankshaft and the balancer shaft rotate in opposite directions.

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