JP6014458B2 - Multi-cylinder engine - Google Patents

Description

  The present invention relates to a multi-cylinder engine such as a horizontally opposed four-cylinder engine that has improved vibration generated in a crankshaft or the like.

  In general, in a four-cylinder engine, as shown in the schematic diagram of the horizontally opposed four-cylinder engine in FIG. 5, the first cylinder 101, the second cylinder 102, the third cylinder 103, and the fourth cylinder from one end side. A flywheel 105 is provided at the other end, which is arranged in order with the cylinder 104. In the four-cylinder engine 100, the crankshaft 110 supports the first pin 101b that rotatably supports the connecting rod 101a of the first cylinder 101 and the connecting rod 104a of the fourth cylinder 104 that is rotatably supported. The direction of the force acting on the fourth pin 104b, the second pin 102b that rotatably supports the connecting rod 102a of the second cylinder 102, and the third pin 103b that rotatably supports the connecting rod 103a of the third cylinder 103 The direction of the working force acts in the opposite direction. In the figure, reference numerals 111, 112, 113, 114, and 115 denote a first journal, a second journal, a third journal, a fourth journal, and a fifth journal that support the crankshaft 110, respectively. Thus, in the four-cylinder engine 100, because of the structure, inertial force is always input in the reverse direction to the first pin 101b, the fourth pin 104b, the second pin 102b, and the third pin 103b. The crankshaft 110 is deformed like a bow due to inertial force. Due to the bow deformation generated by this inertial force, the first journal 111, the third journal 113, and the fifth journal 115 are always located on the explosion cylinder side at the top dead center (TDC) timing of each cylinder. When a larger in-cylinder pressure input is received, the crankshaft 110 is pushed back and crossing behavior occurs (FIG. 4 shows the crossing behavior of the axis of the fifth journal 115). When crossing behavior occurs in the moderate acceleration region of medium loads and medium rotations such as city riding, the fifth journal 115 has a large vibration during the crossing behavior due to the weight of the flywheel 105 and the clutch fastened in the vicinity. Therefore, if the crossing behavior of the fifth journal 115 occurs at the explosion timing of the fourth cylinder 104, the driver may feel uncomfortable or uncomfortable due to the cranking sound using this as the excitation source. In order to improve such bending vibration of the crankshaft, for example, in Japanese Patent Application Laid-Open No. 2003-227548 (hereinafter referred to as Patent Document 1), in an in-line four-cylinder engine, cranks are provided at portions corresponding to the first and fourth cylinders. The counterweight included in the shaft is lighter than the counterweight included in the crankshaft at the portions corresponding to the second and third cylinders, and the crank pulley and the flywheel have portions corresponding to the second and third cylinders. A technique for providing an additional weight for generating an inertial force in phase with the inertial force applied to the crankshaft is disclosed.

JP 2003-227548 A

  However, in the technology of the in-line four-cylinder engine disclosed in Patent Document 1 described above, it is necessary to reshape the counterweight according to the engine characteristics, and a common crankshaft is used in various engines. There is a problem that it is difficult to adopt from the viewpoint of sharing parts, cost and design time.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a multi-cylinder engine that can suppress the deterioration of vibration associated with the crossing behavior of the crankshaft without changing the shape of the crankshaft.

A multi-cylinder engine according to an aspect of the present invention includes a first cylinder, a second cylinder, a third cylinder, and a fourth cylinder arranged in this order from one end side, and a flywheel at the other end. One of the disk members of the drive plate is provided, and the force acting on the first pin that rotatably supports the connecting rod of the first cylinder and the fourth pin that rotatably supports the connecting rod of the fourth cylinder is provided. A crankshaft having a direction opposite to a direction of a force acting on a second pin rotatably supporting the connecting rod of the second cylinder and a third pin rotatably supporting the connecting rod of the third cylinder; In the multi-cylinder engine, between the crankshaft and the disk member, the axis of the third pin passes through the center of rotation of the crankshaft substantially perpendicular to a straight line extending in the direction of the disk member. Over the direction , Provided a weight member which centrifugal force is the weight on the outside of the disc member which acts on the axis side of the third pin extending in the direction of the disc member is formed heavily generated by rotation of the crankshaft, The inclination of the crankshaft side end of the crankshaft toward the fourth pin direction was suppressed, and the crossing behavior of the journal at the explosion timing of the fourth cylinder was suppressed.

  According to the multi-cylinder engine of the present invention, it is possible to suppress the deterioration of vibration associated with the crossing behavior of the crankshaft without particularly changing the shape of the crankshaft.

1 is a schematic diagram illustrating a structure of a horizontally opposed four-cylinder engine according to an embodiment of the present invention. It is attachment explanatory drawing of the flywheel and weight member which concern on one Embodiment of this invention. It is explanatory drawing of the effect which concerns on one Embodiment of this invention. It is explanatory drawing of the crossing behavior of the shaft center of the 5th journal by a prior art. It is a schematic diagram explaining the structure of the horizontally opposed 4-cylinder engine by a prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a horizontally opposed four-cylinder engine as a multi-cylinder engine. From one end side, a first cylinder 11, a second cylinder 12, a third cylinder 13, and a fourth cylinder 14 are shown. A flywheel 15 is provided as a disk member at the other end in order. In the case of an automatic transmission vehicle, a drive plate is provided as a disk member.

  In the horizontally opposed four-cylinder engine 1, the crankshaft 10 has a first pin 11 b that rotatably supports the connecting rod 11 a of the first cylinder 11 and a connecting rod 14 a of the fourth cylinder 14 that is rotatably supported. The direction of the force acting on the fourth pin 14b, the second pin 12b that rotatably supports the connecting rod 12a of the second cylinder 12, and the third pin 13b that rotatably supports the connecting rod 13a of the third cylinder 13 The direction of the working force acts in the opposite direction. In FIG. 1, reference numerals 21, 22, 23, 24, and 25 denote a first journal, a second journal, a third journal, a fourth journal, and a fifth journal that support the crankshaft 10.

  Here, in the present embodiment, as shown in the front view of the flywheel in FIG. 2 (front view seen from the fourth cylinder 14 side), the fifth journal 25 of the crankshaft 10 and the flywheel 15 are interposed between them. (Specifically, the surface of the flywheel 15 on the fifth journal 25 side) is substantially perpendicular to the straight line extending the axis of the third pin 13b in the direction of the flywheel 15 and the rotation center Pc of the crankshaft. A weight member 16 acting on the axial center side of the third pin 13b in which the centrifugal force generated by the rotation of the crankshaft 10 extends in the direction of the flywheel 15 is fixed along the straight line Lh. . The weight member 16 is formed to be heavier on the rotation outer side (the outer end side of the flywheel 15) than on the rotation center Pc side of the crankshaft 10.

  Next, the operation of the horizontally opposed four-cylinder engine 1 configured as described above will be described. First, in a state where the horizontally opposed four-cylinder engine 1 is stopped (stationary), the crankshaft 10 is not bowed as shown in FIG.

  From such a state, when the horizontally opposed four-cylinder engine 1 is operated and enters a moderately accelerated state of medium load and medium rotation such as city riding, as described above, the horizontally opposed four-cylinder engine 1 is structurally first. Since the inertia force is always input in the reverse direction to the pin 11b, the fourth pin 14b, the second pin 12b, and the third pin 13b, the crankshaft 10 is deformed like a bow by the inertia force as described above. To do.

  Conventionally, due to the bow deformation generated by this inertial force, the first journal 21, the third journal 23, and the fifth journal 25 are always located on the explosion cylinder side at each cylinder top dead center (TDC) timing. When an in-cylinder pressure input larger than the inertia force is received, the crankshaft 10 is pushed back, and a crossing behavior occurs. In particular, since the fifth journal 25 has a large vibration during the crossing behavior due to the weight of the flywheel 15 and the clutch fastened in the vicinity, the crossing behavior of the fifth journal 25 occurs at the explosion timing of the fourth cylinder 14. Then, there is a possibility that the driver may feel uncomfortable or uncomfortable due to a cranking sound using this as a vibration source.

  However, in the present embodiment, as shown in FIGS. 2 and 3, when the crankshaft 10 is rotated and the crankshaft 10 is rotated at a rotation speed higher than a predetermined speed, the weight member 16 is thereby caused to move to the crankshaft. Centrifugal force generated by rotation of 10 acts on the axial center side (arrow A side in the figure) of the third pin 13 b extending in the direction of the flywheel 15. The force acting on the end of the crankshaft 10 on the flywheel 15 side suppresses the inclination of the end of the crankshaft 10 on the flywheel 15 side in the direction of the fourth pin 14b (α2 in FIG. 3 <FIG. 5). Α1). As a result, the crossing behavior of the fifth journal 25 can be suppressed at the timing of the explosion of the fourth cylinder 14 as has occurred in the prior art. It is possible to prevent the user from feeling uncomfortable.

  Thus, according to the embodiment of the present invention, the first cylinder 11, the second cylinder 12, the third cylinder 13, and the fourth cylinder 14 are arranged in this order from one end side, and the other In the horizontally opposed four-cylinder engine 1 provided with the flywheel 15 at the end portion, the axis of the third pin 13 b extends in a straight line extending in the direction of the flywheel 15 between the crankshaft 10 and the flywheel 15. A weight member that acts on the axial center side of the third pin 13b in which the centrifugal force generated by the rotation of the crankshaft 10 extends in the direction of the flywheel 15 in a direction substantially perpendicular to the rotation center Pc of the crankshaft 10. 16 was provided. For this reason, without changing the shape of the crankshaft in particular, it is possible to suppress the deterioration of vibration caused by the crossing behavior of the crankshaft by using a common crankshaft in various engines. It is possible to prevent the driver from feeling uncomfortable or uncomfortable due to the hitting sound.

  In the embodiment of the present invention, the example in which the present invention is applied to the horizontally opposed four-cylinder engine 1 as a multi-cylinder engine has been described.

DESCRIPTION OF SYMBOLS 1 Horizontally opposed 4 cylinder engine 10 Crankshaft 11 1st cylinder 11a Connecting rod 11b 1st pin 12 2nd cylinder 12a Connecting rod 12b 2nd pin 13 3rd cylinder 13a Connecting rod 13b 3rd pin 14 4th cylinder 14a connecting rod 14b fourth pin 15 flywheel (disk member)
16 Weight member 21 First journal 22 Second journal 23 Third journal 24 Fourth journal 25 Fifth journal

Claims (4)

The first cylinder, the second cylinder, the third cylinder, and the fourth cylinder are arranged in this order from one end side, and a disk member of either a flywheel or a drive plate is provided at the other end. The direction of the force acting on the first pin that rotatably supports the connecting rod of the first cylinder and the fourth pin that rotatably supports the connecting rod of the fourth cylinder and the connecting rod of the second cylinder rotate. In a multi-cylinder engine provided with a crankshaft in which the direction of the force acting on the second pin that freely supports and the third pin that rotatably supports the connecting rod of the third cylinder is reversed,
Between the crankshaft and the disk member, the crankshaft extends in a direction passing through the center of rotation of the crankshaft substantially perpendicular to a straight line extending in the direction of the disk member with the axis of the third pin. A weight member formed with a heavy weight is provided on the outer side of the disk member acting on the axial center side of the third pin in which centrifugal force generated by the rotation of the third pin extends in the direction of the disk member ; The multi-cylinder engine characterized by suppressing the inclination of the disk member side end portion in the direction of the fourth pin and suppressing the crossing behavior of the journal at the explosion timing of the fourth cylinder.   The multi-cylinder engine according to claim 1, wherein the weight member is formed to be heavier on the outer side than the center of rotation of the crankshaft.   3. The multi-cylinder engine according to claim 1, wherein the multi-cylinder engine is configured as a horizontally opposed four-cylinder type.   The multi-cylinder engine according to any one of claims 1 to 3, wherein the weight member is provided on a surface of the disk member on the crankshaft side.

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