JP2018017232A - Internal combustion engine - Google Patents

Abstract

An object of the present invention is to suppress an increase in the weight of an internal combustion engine and a load on an actuator. An internal combustion engine having a cylinder block that can move relative to a crankcase includes a block moving mechanism that is disposed only on one side of the internal combustion engine, and a pair of crankcases. Guide walls 40 a and 40 b, a support member 41 that supports the side surface of the cylinder block 2, and a pressing member 42 that presses the side surface of the cylinder block 2. The support member 41 is attached to the guide wall 40a on the arrangement side of the block moving mechanism 3 above the attachment position of the other end of the connecting member 31, and the pressing member 42 is attached to the other end of the connecting member 31. The support member 41 is disposed below the pressing member 42 at a predetermined interval (on the bottom side of the cylinder block 2) on the guide wall 40b opposite to the arrangement side of the block moving mechanism 3. ). [Selection] Figure 4

Description

  The present invention relates to an internal combustion engine.

  In Patent Document 1, as a conventional internal combustion engine having a cylinder block that can move relative to a crankcase, two eccentric shafts (cam shafts) and eccentric shafts arranged on both sides of the internal combustion engine are connected to each other. An actuator provided with one drive shaft for rotating the cylinder block relative to each other by rotating in the reverse direction and an actuator for rotating the drive shaft is disclosed. Further, in this conventional internal combustion engine, in order to prevent the cylinder block from being inclined in a direction different from the relative movement direction, one side surface of the cylinder block is pressed by a pressing member (biasing mechanism), thereby The other side surface is supported by a support member.

JP 2012-219745 A

  As described above, in the conventional internal combustion engine, it is necessary to dispose the eccentric shafts on both sides of the internal combustion engine, and to dispose the drive shaft so that the eccentric shafts can be rotated in opposite directions. For this reason, there is a problem that the internal combustion engine becomes larger overall and the weight of the internal combustion engine increases.

  Further, when one side surface of the cylinder block is pressed by the pressing member and the other side surface is supported by the support member, when the cylinder block is moved, the pressure that makes contact with the side surface of the cylinder block and the side surface of the cylinder block Resistance (sliding resistance) is generated between the contact surfaces of the member and the support member.

  Here, in order to suppress the increase in the size of the internal combustion engine and suppress the increase in weight, for example, in the conventional internal combustion engine, if one eccentric shaft is arranged and the eccentric shaft is arranged only on one side of the internal combustion engine, the cylinder block When moving the cylinder block, the cylinder block tends to tilt in a direction different from the relative movement direction. In order to prevent the cylinder block from tilting in a direction different from the relative movement direction, the cylinder block is pressed by the pressing member with a pressing force greater than the load input to the pressing member from the cylinder block side during operation of the internal combustion engine. It is necessary to keep. However, as the pressing force by the pressing member is increased, the force for sandwiching the cylinder block between the pressing member and the support member is increased. Therefore, there is a problem that the sliding resistance when moving the cylinder block increases, and the load when moving the cylinder block, that is, the load applied to the actuator increases.

  The present invention has been made paying attention to such problems, and suppresses an increase in weight by suppressing an increase in the size of an internal combustion engine including a cylinder block that can move relative to a crankcase. An object of the present invention is to suppress the load when moving the cylinder block while suppressing tilting in a direction different from the relative movement direction.

  In order to solve the above-described problems, according to an aspect of the present invention, an internal combustion engine including a cylinder block that can move relative to a crankcase and a cylinder head that is attached to the top of the cylinder block is provided in the crankcase. A block moving mechanism that is disposed only on one side of the internal combustion engine and moves the cylinder block relative to the crankcase when the internal combustion engine is viewed from the axial direction of the crankshaft that is rotatably supported; Are attached to a pair of guide walls provided on the crankcase, a guide wall on the arrangement side of the block moving mechanism, and a guide wall on the opposite side thereof so as to face the side surfaces of the cylinder block. The supporting member to be supported, the guide wall on the arrangement side of the block moving mechanism, and the guide wall on the opposite side Each mounted, comprising a pressing member for pressing the side surface of the cylinder block. The block moving mechanism is supported by a crankcase, and includes a main shaft portion, a control shaft having an eccentric portion having a shaft center at a position eccentric from the shaft center of the main shaft portion, and one end portion of the control shaft. Attached to the eccentric part, the other end part is attached to the cylinder block, a connecting member for connecting the control shaft and the cylinder block, and the control shaft is rotated in both directions within a predetermined rotation range, An actuator for causing the shaft center of the eccentric portion to swing in the relative movement direction of the cylinder block about the shaft center of the main shaft portion. Then, on the guide wall on the arrangement side of the block moving mechanism, the support member is attached to the top side of the cylinder block from the attachment position of the other end portion of the connecting member, and the pressing member is attached from the attachment position of the other end portion of the connecting member. Is attached to the bottom side of the cylinder block, and on the guide wall opposite to the arrangement side of the block moving mechanism, the support member is spaced apart from the pressing member by a predetermined distance in the relative movement direction of the cylinder block. It is attached to the bottom side.

  According to this aspect of the present invention, it is possible to suppress an increase in weight by suppressing an increase in the size of an internal combustion engine including a cylinder block that can move relative to a crankcase, and the cylinder block in a direction different from the relative movement direction. The load at the time of moving a cylinder block can be suppressed, suppressing tilting.

FIG. 1 is a schematic perspective view of an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a schematic exploded perspective view of the internal combustion engine shown in FIG. 3 is a schematic exploded perspective view of the internal combustion engine shown in FIG. FIG. 4 is a schematic cross-sectional view of an internal combustion engine according to an embodiment of the present invention. FIG. 5 is a diagram for explaining the operation of the block moving mechanism. FIG. 6 is a diagram for explaining the operation of the block moving mechanism, and schematically shows the block moving mechanism. FIG. 7 is a diagram illustrating a problem when the block moving mechanism is provided only on one side of the internal combustion engine. FIG. 8 is a diagram showing the force acting on the support member and the pressing member of the guide mechanism during the operation of the internal combustion engine by arrows. FIG. 9A is a diagram for explaining the reason why opposing support members and pressing members are arranged at the same height in the cylinder axial direction. FIG. 9B is a diagram illustrating the reason why the opposing support member and pressing member are arranged at the same height in the cylinder axial direction. FIG. 10 is a view showing a modification of the internal combustion engine according to one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are assigned to similar components.

  FIG. 1 is a schematic perspective view of an internal combustion engine 100 according to an embodiment of the present invention. 2 and 3 are schematic exploded perspective views of the internal combustion engine 100 shown in FIG.

  As shown in FIGS. 1 to 3, the internal combustion engine 100 includes a crankcase 1, a cylinder block 2, a block moving mechanism 3, and a guide mechanism 4.

  The crankcase 1 rotatably supports the crankshaft 10 and includes a block accommodating portion 11 for accommodating the cylinder block 2 therein.

  The cylinder block 2 is separated from the crankcase 1 so as to be movable relative to the crankcase 1, and a part of the cylinder block 2 is accommodated in the block accommodating portion 11 of the crankcase 1. A cylinder 20 is formed in the cylinder block 2. In the present embodiment, four cylinders 20 are formed in series along the longitudinal direction of the cylinder block 2 (hereinafter referred to as “block longitudinal direction”).

  Hereinafter, the internal configuration of the internal combustion engine 100 and the details of the block moving mechanism 3 and the guide mechanism 4 will be described with reference to FIG. 4 in addition to FIGS.

  FIG. 4 is a schematic sectional view of the internal combustion engine 100. 1 to 3, some components are omitted from the internal combustion engine 100 shown in FIG. 4 in order to prevent the drawing from being complicated.

  As shown in FIG. 4, a cylinder head 5 is attached to the top of the cylinder block 2, and an oil pan 6 is attached to the bottom of the crankcase 1.

  A piston 21 that reciprocates inside the cylinder 20 in response to combustion pressure is housed inside the cylinder 20. The piston 21 is connected to the crankshaft 10 via a connecting rod 22, and the reciprocating motion of the piston 21 is converted into rotational motion by the crankshaft 10. A space defined by the cylinder head 5, the cylinder 20, and the piston 21 is a combustion chamber 7.

  The crankshaft 10 includes a crank journal 10a, a crankpin 10b, and a crank arm 10c.

  The crank journal 10 a is a portion that is rotatably supported by the crankcase 1. The axis P1 of the crank journal 10a is the rotation center of the crankshaft 10.

  The crank pin 10b is a part to which the large end of the connecting rod 22 is attached. The axis P2 of the crank pin 10b is eccentric from the axis P1 of the crank journal 10a by a predetermined amount. Therefore, when the crankshaft 10 rotates, the axis P2 of the crankpin 10b rotates around the axis P1.

  The crank arm 10c is a part that connects the crank journal 10a and the crank pin 10b. In this embodiment, in order to smoothly rotate the crankshaft 10, a balance weight 10d is provided on the crank arm 10c.

  The block moving mechanism 3 is a mechanism for moving the cylinder block 2 relative to the crankcase 1, and as shown in FIGS. 2 to 4, one control shaft 30, a connecting member 31, And an actuator 32.

  The block moving mechanism 3 according to the present embodiment is configured such that the relative position of the cylinder block 2 relative to the crankcase 1 in the cylinder axial direction can be changed by moving the cylinder block 2 in the cylinder axial direction. Only the volume of the combustion chamber 7 can be changed without changing the top dead center position of the piston 21 by moving the cylinder block 2 relative to the crankcase 1 in the cylinder axial direction. Thus, the mechanical compression ratio of the internal combustion engine 100 can be changed by changing only the volume of the combustion chamber 7 without changing the top dead center position of the piston 21. Therefore, the block moving mechanism 3 according to the present embodiment functions as a variable compression ratio mechanism of the internal combustion engine 100. The mechanical compression ratio is a compression ratio mechanically determined from the stroke volume of the piston 21 and the volume of the combustion chamber 7 during the compression stroke, and is represented by (combustion chamber volume + stroke volume) / combustion chamber volume. .

  The control shaft 30 extends in parallel with the crankshaft 10 and is rotatably supported by two sets of control bearings 12 (see FIG. 2) provided in the crankcase 1, and an axis of the main shaft portion 30a. And an eccentric portion 30b (see FIG. 4) having a shaft center P4 (see FIG. 4) at a position eccentric from the P3 (see FIG. 4) by a predetermined amount. Therefore, if the control shaft 30 is rotated once, the shaft center P4 of the eccentric portion 30b rotates once around the shaft center P3 of the main shaft portion 30a. As shown in FIGS. 2 and 3, in the present embodiment, one eccentric portion 30b is provided on each of one end side and the other end side in the block longitudinal direction.

  The connecting member 31 is a member for connecting the eccentric portion 30 b of the control shaft 30 and the cylinder block 2. One end of the connecting member 31 on the lower side in the cylinder axial direction (the bottom side of the cylinder block 2, that is, the crankshaft 10 side) is attached to the eccentric part 30b of the control shaft 30, and the upper side in the cylinder axial direction (on the cylinder block 2). The other end of the top side (ie, the cylinder head 5 side) is attached to the connecting pin 33 supported by the cylinder block 2. As shown in FIGS. 2 and 3, in the present embodiment, the two connecting members 31 allow the eccentric portion 30 b on one end side in the block longitudinal direction and the cylinder block 2, and the eccentric portion 30 b on the other end side in the block longitudinal direction. And cylinder block 2 are connected.

  In the present embodiment, the control shaft 30 has a so-called crank shape, but an eccentric cam whose shaft center is eccentric from the axis P3 of the main shaft part 30a is fixed to the outer periphery of the main shaft part 30a, and is connected to the outer periphery of the eccentric cam. One end of the member 31 may be attached.

  The connecting pin 33 is a support portion 23 provided on a side surface on one end side in the short direction of the cylinder block 2 (a direction intersecting at right angles to the block longitudinal direction and the cylinder axial direction, hereinafter referred to as “block short direction”). Supported by. As shown in FIG. 2, in the present embodiment, one support portion 23 is provided on each of the one end side and the other end side in the block longitudinal direction so as to correspond to the eccentric portion 30b.

  The actuator 32 is a drive device that applies drive torque to the control shaft 30 and rotates the control shaft 30 in both directions within a predetermined rotation angle range. In the present embodiment, an electric motor is used as the actuator 32.

  As described above, when the internal combustion engine 100 is viewed from the axial direction of the crankshaft 10 that substantially matches the longitudinal direction of the block, the block moving mechanism 3 has left and right sides of the internal combustion engine 100 (in this embodiment, in the block short direction). The cylinder block 2 is arranged relative to the crankcase 1 so as to move relative to the crankcase 1.

  The guide mechanism 4 is a mechanism for suppressing the cylinder block 2 from tilting in a direction different from the moving direction, and includes a guide wall 40, a support member 41, and a pressing member 42.

  The guide wall 40 is a wall provided in the crankcase 1 so as to face the side surface of the cylinder block 2, and is arranged around the cylinder block 2 with a predetermined gap with respect to the side surface of the cylinder block 2. In the following description, when it is particularly necessary to distinguish, the guide wall 40 on one end side in the block short direction of the internal combustion engine 100 is referred to as a “guide wall 40a”, and the other end side in the block short direction. The guide wall 40 is referred to as “guide wall 40b”.

  The support member 41 is a member for supporting the side surface of the cylinder block 2. In the present embodiment, two support members 41 are attached to each of the guide walls 40 a and 40 b as shown in FIGS. 2 and 3. As shown in FIG. 4, the support member 41 is attached to the guide walls 40 a and 40 b so that a contact surface 411 formed at one end thereof is in contact with the side surface of the cylinder block 2.

  The pressing member 42 is a member for pressing the side surface of the cylinder block 2 toward the support member 41. In this embodiment, two pressing members 42 are provided on each of the guide walls 40a and 40b as shown in FIGS. It is attached one by one. As shown in FIG. 4, the pressing member 42 according to the present embodiment includes a body 421 having an opening, a contact plate 422 attached to the opening of the body 421 so as to be movable in both directions of the block short side, 421 and a spring 423 that applies a pressing force that always presses the contact plate 422 toward the side surface of the cylinder block 2 against the contact plate 422. The pressing member 42 is attached to the guide walls 40a and 40b so that the side surface of the cylinder block 2 can be pressed toward the support member 41 by the contact plate 422.

  Thus, in this embodiment, the cylinder block 2 is supported by pressing the side surface of the cylinder block 2 on the opposite side with the pressing member 42 while supporting the side surface of the cylinder block 2 on one side of the internal combustion engine 100 with the support member 41. Inclination in a direction different from the cylinder axis direction is suppressed. Further, it is possible to prevent the cylinder block 2 from being inclined in a direction different from the cylinder axis direction due to vibration generated during the operation of the internal combustion engine 100.

  As shown in FIGS. 2 to 4, in this embodiment, the support member 41 attached to the guide wall 40 a on one end side in the short side direction of the block, which is the arrangement side of the block moving mechanism 3, is connected to the connecting member 31. The pressing member 42 disposed on the upper side in the cylinder axial direction from the attachment position of the end portion (position of the support portion 23) and also attached to the guide wall 40a is connected to the attachment position (support portion 23) of the other end portion of the connecting member 31. It is arranged on the lower side in the cylinder axial direction than the position (1). Further, the support member 41 attached to the guide wall 40b on the other end side in the short side direction of the block, which is the side opposite to the arrangement side of the block moving mechanism 3, is made to be more cylinder than the pressing member 42 also attached to the guide wall 40b. It is arranged on the lower side in the axial direction. The reason for this will be described later with reference to FIG.

  Moreover, as shown in FIG. 4, in this embodiment, the supporting member 41 and the pressing member 42 which oppose are arrange | positioned at the same height in the cylinder axial direction. That is, the support member 41 attached to the guide wall 40a on the arrangement side of the block movement mechanism 3 and the pressing member 42 attached to the guide wall 40b on the opposite side to the arrangement side of the block movement mechanism 3 are connected to the cylinder. They are arranged at the same height in the axial direction. Further, the pressing member 42 attached to the guide wall 40a on the arrangement side of the block movement mechanism 3 and the support member 41 attached to the guide wall 40b on the opposite side to the arrangement side of the block movement mechanism 3 are connected to the cylinder shaft. It is arranged at the same height in the direction. The reason for this will be described later with reference to FIG.

  Next, the operation of the block moving mechanism 3 will be described with reference to FIGS.

  FIG. 5 shows an internal combustion engine 100 in a state in which the volume of the combustion chamber 7 is minimized when the piston 21 is located at the compression top dead center by the block moving mechanism 3, that is, in a state in which the mechanical compression ratio is maximized. The control shaft 30 is rotated clockwise by a predetermined rotation angle so that the volume of the combustion chamber 7 is maximized when the piston 21 is located at the compression top dead center, that is, the mechanical compression ratio is minimized. It is the figure which showed the internal combustion engine 100 in comparison.

  FIG. 6 is a diagram comparing the internal combustion engine 100 with the mechanical compression ratio maximized and the internal combustion engine 100 with the mechanical compression ratio minimized, similar to FIG. FIG. 2 is a diagram schematically showing a block moving mechanism 3 in order to facilitate understanding of A broken line A in FIG. 6 is a locus of the axis P4 of the eccentric portion 30b when the control shaft 30 is rotated once. P5 is the axis of the connecting pin 33.

  As shown in FIG. 6, in the present embodiment, the locus A of the axis P4 of the eccentric portion 30b is divided into two semicircular regions by parallel lines Q passing through the axis P3 of the main shaft portion 30a and parallel to the cylinder axis direction. Then, the actuator 32 rotates the control shaft 30 in both directions so that the shaft center P4 moves in both directions in the range of either one of the semicircle regions (the semicircle region on the left side in the drawing in the present embodiment). It is rotating in the direction.

  When the mechanical compression ratio on the left side in the drawing is maximized compared to the state in which the mechanical compression ratio on the right side in the drawing is minimized, the block moving mechanism 3 has the axis P4 of the eccentric portion 30b in the cylinder axial direction. It is comprised so that it may be located in the lower side (bottom part side of the cylinder block 2, ie, the crankshaft 10 side).

  Therefore, for example, when the control shaft 30 is rotated clockwise by the actuator 32 from the state where the mechanical compression ratio on the left side in the drawing is maximized, the shaft center P4 of the eccentric portion 30b moves on the locus A on the upper side in the cylinder axial direction ( It moves toward the top of the cylinder block 2, that is, the cylinder head 5 side. Accordingly, the connecting pin 33 is linearly pushed upward toward the upper side in the cylinder axial direction via the connecting member 31 connected to the eccentric portion 30b, so that the cylinder block 2 is relatively moved with respect to the crankcase 1. Pushed upward in the cylinder axis direction. As a result, the volume of the combustion chamber 7 when the piston 21 is located at the compression top dead center is gradually increased, and the mechanical compression ratio is gradually decreased.

  On the other hand, for example, when the control shaft 30 is rotated counterclockwise by the actuator 32 from the state where the mechanical compression ratio on the right side in the drawing is minimized, the shaft center P4 of the eccentric portion 30b moves on the locus A in the cylinder axial direction. Move down. Accordingly, the connecting pin 33 is linearly pulled downward toward the lower side in the cylinder axial direction via the connecting member 31 connected to the eccentric portion 30 b, so that the cylinder block 2 is relative to the crankcase 1. To the lower side in the cylinder axial direction. As a result, the volume of the combustion chamber 7 when the piston 21 is located at the compression top dead center is gradually reduced, and the mechanical compression ratio is gradually increased.

  As described above, the block moving mechanism 3 according to the present embodiment rotates the control shaft 30 including the main shaft portion 30a and the eccentric portion 30b, and uses the axis P4 of the eccentric portion 30b as a cylinder around the axis P3 of the main shaft portion 30a. By swinging up and down in the axial direction, the cylinder block 2 is moved up and down in the axial direction of the cylinder by the connecting member 31 connected to the eccentric portion 30b.

  By the way, in this embodiment, by providing such a block moving mechanism 3 only on one side of the internal combustion engine 100, an increase in the size of the internal combustion engine 100 and an increase in weight are suppressed. However, when the block moving mechanism 3 is provided only on one side of the internal combustion engine 100, the cylinder block 2 is operated during the operation of the internal combustion engine 100 as compared with the case where the block moving mechanism 3 is provided on both sides of the internal combustion engine 100. There is a problem in that a block rotational force is applied to rotate the motor in a constant rotational direction. Hereinafter, this problem will be described with reference to FIG.

  FIG. 7 is a diagram illustrating a problem when the block moving mechanism 3 is provided only on one side of the internal combustion engine 100 (in this example, one end side in the block short direction). FIG. 7 schematically shows the block moving mechanism 3 in order to facilitate understanding of the invention.

  During the operation of the internal combustion engine 100, combustion occurs in the combustion chambers 7 of the respective cylinders 20, so that an upward combustion load F is applied to the cylinder head 5 as shown in FIG. At this time, when the control shaft 30 is arranged only on one side of the internal combustion engine 100 and the control shaft 30 and the cylinder block 2 are connected by the connecting member 31 as in the present embodiment, the cylinder head 5 is added. Due to the combustion load F, a block rotational force that causes the cylinder block 2 to rotate clockwise in the drawing mainly around the other end of the connecting member 31 is generated. That is, a clockwise moment M is generated around the axis P5 in the drawing.

  Here, if the block moving mechanism 3 is provided on both sides of the internal combustion engine 100, for example, one end side and the other end side in the block short direction, the cylinder block 2 on one end side in the block short direction of the internal combustion engine 100. A block rotational force that causes the cylinder block 2 to rotate clockwise is generated around the other end of the coupling member 31 disposed along the side surface. On the other hand, the cylinder block 2 is rotated counterclockwise around the other end portion of the connecting member 31 disposed along the side surface of the cylinder block 2 on the other end side in the block short direction of the internal combustion engine 100. The block rotational force that tries to rotate is generated. Therefore, the block rotational force for rotating the cylinder block 2 in the clockwise direction and the block rotational force for rotating in the counterclockwise direction are balanced and offset, and apparently the block rotational force is applied to the cylinder block 2. It will not occur.

  However, when the block moving mechanism 3 is provided only on one side of the internal combustion engine 100, the block rotational force is not canceled as in the case where it is provided on both sides. Therefore, when the block moving mechanism 3 is provided only on one side of the internal combustion engine 100, a block rotational force that attempts to rotate the cylinder block 2 in a constant rotational direction with respect to the cylinder block 2 during operation of the internal combustion engine 100 is provided. As a result, the block rotational force acts on the guide mechanism 4.

  FIG. 8 is a diagram showing the force acting on the support member 41 and the pressing member 42 of the guide mechanism 4 during operation of the internal combustion engine 100 by arrows.

  In the example shown in FIG. 8, due to the combustion load F, a block rotational force is applied to the cylinder block 2 to rotate the cylinder block 2 clockwise. That is, a force is applied to the cylinder block 2 to incline the cylinder block 2 to the right side in the drawing. Therefore, as shown in FIG. 8, with respect to the support member 41 and the pressing member 42 attached to the guide wall 40 a on one end side in the short side of the block, which is the arrangement side of the block moving mechanism 3, the other end of the connecting member 31 is mainly used. The block rotational force F1 resulting from the combustion load F acts on the support member 41 attached to the upper side in the cylinder axial direction from the portion. Further, with respect to the support member 41 and the pressing member 42 attached to the guide wall 40b on the other end side in the short side of the block, which is the side opposite to the arrangement side of the block moving mechanism 3, the lower side in the cylinder axial direction is mainly used. A block rotational force F1 ′ caused by the combustion load F acts on the attached support member 41.

  Further, during the operation of the internal combustion engine 100, due to the inclination of the connecting rod 22 during the reciprocating motion of the piston 21, a force in the block short direction (piston thrust force) acts on the cylinder block 2. Specifically, the piston anti-thrust force F2 that pushes the cylinder block 2 toward one end side in the block short direction with respect to the cylinder block 2, and the piston positive thrust force F2 that pushes the cylinder block 2 toward the other end side in the block short direction. 'Is added from the piston 21. Therefore, as shown in FIG. 8, the piston anti-thrust force F <b> 2 acts on the support member 41 and the pressing member 42 attached to the guide wall 40 a on one end side in the block short direction. Further, the piston positive thrust force F2 'acts on the support member 41 and the pressing member 42 attached to the guide wall 40b on the other end side in the block short direction.

  Further, when the cylinder block 2 is moved in the cylinder axial direction, due to the inclination of the connecting member 31 of the block moving mechanism 3, the force in the block short direction from the connecting member 31 to the cylinder block 2 (moving mechanism anti-thrust) The force F3 and the moving mechanism positive thrust force F3 ′) act.

  As described above, in the present embodiment, the support member 41 is arranged at a portion where the block rotational forces F1 and F1 'caused by the combustion load F act. In other words, the pressing member 42 is not disposed in the portion where the block rotational forces F1 and F1 'caused by the combustion load F act. The reason will be described below.

  As described above, in the present embodiment, the cylinder block 2 is supported by pressing the side surface of the cylinder block 2 on the opposite side with the pressing member 42 while supporting the side surface of the cylinder block 2 on one side of the internal combustion engine 100 with the support member 41. Is prevented from tilting in a direction different from the cylinder axis direction.

  At this time, the support member 41 is fixed to the guide wall 40 a and does not move, but the pressing member 42 presses the contact plate 422 against the side surface of the cylinder block 2 by the pressing force of the spring 423. Therefore, when a force larger than the pressing force of the spring 423 is applied from the cylinder block 2 side, the cylinder block 2 may be inclined toward the pressing member 42 side. In order to prevent this, the pressing force of the spring 423 may be increased.

  However, since the pressing force by the spring 423 is always a force acting on the side surface of the cylinder block 2, the larger the pressing force of the spring 423 is, the more the cylinder block 2 is supported by the pressing member 42 and the support member 41. The force to pinch is increased. Therefore, when the cylinder block 2 is moved, resistance in the cylinder axial direction (hereinafter referred to as “sliding resistance”) generated between the support member 41 and the pressing member 42 and the cylinder block increases.

  When the sliding resistance increases, the load when moving the cylinder block 2 in the cylinder axis direction, that is, the driving torque for rotating the control shaft 30 increases. Therefore, for example, when the actuator 32 is an electric motor, the power consumption increases, resulting in a deterioration in fuel consumption. Further, since it is necessary to increase the maximum drive torque of the actuator 32, the actuator 32 is increased in size and capacity, and as a result, the internal combustion engine 100 is increased in size and weight.

  Here, if the pressing member 42 is disposed in a portion where the block rotational forces F1 and F1 ′ caused by the combustion load F act, the pressing force of the spring 423 is blocked with respect to the pressing member 42 on the guide wall 40a side. It is necessary to set the pressing force to be equal to or greater than the resultant force of the rotational force F1, the piston anti-thrust force F2, and the moving mechanism anti-thrust force F3. For the pressing member 42 on the guide wall 40b side, it is necessary to set the pressing force of the spring 423 to a pressing force equal to or greater than the resultant force of the block rotational force F1 ′, the piston positive thrust force F2 ′, and the moving mechanism positive thrust force F3 ′. There is. That is, if the pressing member 42 is disposed at a portion where the block rotational forces F1 and F1 ′ caused by the combustion load F act, a force exceeding these three combined forces is always applied to the side surface of the cylinder block 2. 42 will act.

  On the other hand, as in the present embodiment, the support member 41 is disposed at the portion where the block rotational forces F1 and F1 ′ caused by the combustion load F act, and the pressing member 42 is not disposed, thereby the guide wall 40a side. With respect to the pressing member 42, the pressing force of the spring 423 may be set to a pressing force equal to or greater than two resultant forces of the piston anti-thrust force F2 and the moving mechanism anti-thrust force F3. Further, with respect to the pressing member 42 on the guide wall 40b side, the pressing force of the spring 423 may be set to a pressing force equal to or greater than two resultant forces of the piston positive thrust force F2 'and the moving mechanism positive thrust force F3'.

  In other words, in this embodiment, since the block rotational forces F1 and F1 'do not act on the pressing member 42, the pressing force of the spring 423 can be set to a lower value accordingly. In particular, the block rotational forces F1 and F1 ′ caused by the combustion load F are much higher than the piston anti-thrust force F2, the piston positive thrust force F2 ′, the moving mechanism anti-thrust force F3, and the moving mechanism positive thrust force F3 ′. Since it is large, the pressing force of the spring 423 can be significantly reduced by preventing the block rotational forces F1 and F1 ′ from acting on the pressing member 42.

  Thus, by disposing the support member 41 in the portion where the block rotational forces F1 and F1 ′ act and not placing the pressing member 42, the portion where the block rotational forces F1 and F1 ′ act is applied by the pressing member 42. Compared to the case of pressing, the pressing force of the spring 423 of the pressing member 42 can be reduced. Therefore, sliding resistance when moving the cylinder block 2 in the cylinder axial direction can be reduced. As a result, it is possible to suppress deterioration in fuel consumption, increase in size of the actuator, and increase in capacity. Therefore, the increase in size and weight of the internal combustion engine 100 can be further suppressed.

  Next, the reason why the supporting member 41 and the pressing member 42 facing each other are arranged at the same height in the cylinder axial direction will be described with reference to FIGS. 9A and 9B.

  FIG. 9A shows the force acting on the cylinder block 2 by the pressing force of the pressing member 42 when the opposing support member 41 and the pressing member 42 are arranged at the same height in the cylinder axial direction as in this embodiment. FIG. On the other hand, FIG. 9B differs from the present embodiment in that when the opposing support member 41 and the pressing member 42 are arranged at different heights in the cylinder axial direction, the pressing force of the pressing member 42 acts on the cylinder block 2. It is the figure which showed an example of the force to do.

  As shown in FIGS. 9A and 9B, the cylinder block 2 is subjected to the pressing force F4 from the pressing member 42 and the reaction force F4 '(= F4) from the support member 41.

  At this time, as shown in FIG. 9A, when the supporting member 41 and the pressing member 42 facing each other are arranged at the same height in the cylinder axial direction, the center of gravity C of the cylinder block 2 is caused by the pressing force F4 of the pressing member 42. The length of the moment arm r1 of the generated clockwise moment M1 is equal to the length of the moment arm r2 of the counterclockwise moment M2 generated around the center of gravity C of the cylinder block 2 by the reaction force F4 ′. Therefore, the magnitudes of the moment M1 (= F4 × r1) and the moment M2 (= F4 ′ × r2) are equal to each other. There will be no moment.

  On the other hand, for example, as shown in FIG. 9B, when the opposing support member 41 and the pressing member 42 are arranged at different heights in the cylinder axial direction, the length of the moment arm r1 is different from the length of the moment arm r2. . 9B, the moment M1 (= F4 × r1) is larger than the moment M2 (= F4 ′ × r2), and a moment is generated around the center of gravity C of the cylinder block 2. As a result, since the force resulting from this moment acts on the support member 41 or the pressing member 42, sliding resistance will increase.

  Therefore, in the present embodiment, the supporting member 41 and the pressing member 42 facing each other are arranged at the same height in the cylinder axial direction. As a result, it is possible to prevent a moment around the center of gravity C of the cylinder block 2 from being generated, and thus an increase in sliding resistance can be suppressed.

  According to the present embodiment described above, the internal combustion engine 100 including the cylinder block 2 that can move relative to the crankcase 1 is viewed from the axial direction of the crankshaft 10 that is rotatably supported by the crankcase 1. Is disposed only on one side of the internal combustion engine 100, and the block moving mechanism 3 for moving the cylinder block 2 relative to the crankcase 1 and the side surface of the cylinder block 2 are opposed to each other. A pair of guide walls 40a, 40b provided on the left and right sides of the crankcase 1, a guide wall 40a on the arrangement side of the block moving mechanism 3, and a guide wall 40b on the opposite side are respectively attached to the cylinder block 2. The support member 41 that supports the side surface, the guide wall 40a on the arrangement side of the block moving mechanism 3, and the guide on the opposite side And 40b, the attached each comprise a pressing member 42 for pressing the side surface of the cylinder block 2, a.

  The block moving mechanism 3 is supported by the crankcase 1 and has a main shaft portion 30a and an eccentric portion 30b having a shaft center P4 at a position eccentric from the shaft center P3 of the main shaft portion 30a by a predetermined amount. The control shaft 30, one end portion is attached to the eccentric portion 30b, the other end portion is attached to the cylinder block 2, and a connecting member 31 for connecting the control shaft 30 and the cylinder block 2 is provided. An actuator 32 for rotating in both directions within a predetermined rotation range to swing the shaft center of the eccentric portion 30b in the relative movement direction of the cylinder block 2 about the shaft center of the main shaft portion 30a. It is configured.

  The relative movement direction of the cylinder block 2 with respect to the guide wall 40a on the arrangement side of the block moving mechanism 3 is greater than the attachment position of the other end of the connecting member 31 (the position of the support 23, the axis P5). Is attached to the upper side of the cylinder block 2 (the top side of the cylinder block 2), and the pressing member 42 is located on the lower side in the relative movement direction of the cylinder block 2 relative to the attachment position of the other end of the connecting member 31 It is attached. In addition, the support member 41 is spaced below the pressing member 42 in the relative movement direction of the cylinder block 2 (at the bottom of the cylinder block 2) with a predetermined interval on the guide wall 40 b opposite to the arrangement side of the block moving mechanism 3. Side).

  Thereby, according to the internal combustion engine 100 according to the present embodiment, the cylinder block 2 can be moved relative to the crankcase 1 via the connecting member 31 only by rotating one control shaft 30. Therefore, one control shaft 30 may be disposed only on one side of the internal combustion engine 100 in parallel with the crankshaft 10, for example, and as a result, the block moving mechanism 3 can be disposed only on one side of the internal combustion engine. Therefore, there is no need for the eccentric shafts on both sides of the internal combustion engine 100 as in the above-described conventional internal combustion engine, and there is no need to arrange a drive shaft for rotating the two eccentric shafts. In contrast, an increase in weight of the internal combustion engine 100 including the cylinder block 2 that can move relative to the cylinder block 2 can be suppressed.

  Further, when the block moving mechanism 3 having such a configuration is arranged only on one side of the internal combustion engine 100, a moment M mainly around the axis P <b> 5 is generated by the combustion load F, and the cylinder block 2 with respect to the cylinder block 2. Block rotational forces F1 and F1 ′ are applied to rotate the block toward the block moving mechanism 3 side. Therefore, as in the present embodiment, the support member 41 is placed on the guide wall 40a on the arrangement side of the block moving mechanism 3 in the relative movement direction of the cylinder block 2 relative to the attachment position (axial center P5) of the other end of the connecting member 31. The pressure member 42 is attached to the upper side and attached to the lower side in the relative movement direction of the cylinder block 2 with respect to the attachment position (axial center P5) of the other end portion of the connecting member 31, while being opposite to the arrangement side of the block moving mechanism 3 A cylinder block 2 on which block rotational forces F1 and F1 ′ are applied by attaching a support member 41 to the lower guide wall 40b with a predetermined interval below the pressing member 42 in the relative movement direction of the cylinder block 2 These side surfaces can be supported by the support member 41.

  Therefore, the pressing force of the spring 423 of the pressing member 42 can be reduced as compared with the case where the pressing member 42 presses the portion where the large block rotational forces F1 and F1 'due to the combustion load F act. Therefore, the sliding resistance when moving the cylinder block 2 in the cylinder axial direction can be reduced. As a result, it is possible to suppress deterioration in fuel consumption, increase in size of the actuator, and increase in capacity. Therefore, the increase in size and weight of the internal combustion engine 100 can be further suppressed.

  In particular, according to the internal combustion engine 100 according to the present embodiment, the support member 41 attached to the guide wall 40a on the arrangement side of the block moving mechanism 3 and the guide wall 40b on the opposite side to the arrangement side of the block movement mechanism 3 are attached. The pressing member 42 is disposed at the same height in the relative movement direction of the Linder block. Further, the pressing member 42 attached to the guide wall 40a on the arrangement side of the block moving mechanism 3 and the support member 41 attached to the guide wall 40b on the opposite side to the arrangement side of the block moving mechanism 3 are a cylinder block. They are arranged at the same height in the relative movement direction.

  Therefore, it is possible to suppress the moment from being generated around the center of gravity C of the cylinder block 2 due to the pressing force of the pressing member 42, and thus it is possible to suppress an increase in sliding resistance. As a result, it is possible to further suppress deterioration in fuel consumption, increase in size and capacity of the actuator, and further suppress increase in size and weight of the internal combustion engine 100.

  Although the embodiments of the present invention have been described above, the above embodiments only show a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. It is not the purpose.

  For example, in the above embodiment, the pressing member 42 configured to press the contact plate 422 against the side surface of the cylinder block 2 by the biasing force of the spring 423 is used, but the configuration of the pressing member 42 is limited to such a configuration. It is not a thing.

  For example, as shown in FIG. 10, an oil passage (not shown) communicating with the first hydraulic chamber 53 is provided inside the guide wall 40, and a contact plate 422 using a hydraulic lash adjuster 50 as the pressing member 42. May be pressed against the side surface of the cylinder block 2 so that the gap between the contact plate 422 and the side surface of the cylinder block 2 is always kept at zero.

  The lash adjuster 50 is formed in the plunger 51 integrated with the contact plate 422, the body 52 that accommodates the plunger 51, the first hydraulic chamber 53 formed in the plunger 51, and the body 52. The second hydraulic chamber 54, the check ball 56 that seals the communication passage 55 that communicates the first hydraulic chamber 53 and the second hydraulic chamber 54, and the plunger 51 that is disposed in the second hydraulic chamber 54 are connected to the cylinder block 2. And a spring 57 that always presses to the side.

  When a load from the cylinder block 2 side is not applied, the lash adjuster 50 pushes the plunger 51 by the spring force of the spring 57 to bring the abutment plate 422 into contact with the side surface of the cylinder block 2. The gap between the plate 422 and the side surface of the cylinder block 2 is always kept at zero. On the other hand, when a load from the cylinder block 2 side is applied to the contact plate 422, the plunger 51 is pushed down and the second hydraulic chamber 54 is sealed by the check ball 56 to become a high pressure. As a result, the position of the plunger 51 is fixed at a predetermined position by the hydraulic pressure of the second hydraulic chamber 54, and the contact plate 422 is pressed against the side surface of the cylinder block 2.

  When the pressing member 42 is configured to press the contact plate 422 against the side surface of the cylinder block 2 by the urging force of the spring 423 as in the above embodiment, the pressing force by the spring 423 is always applied to the cylinder block 2. Act on.

  On the other hand, when the lash adjuster 50 is used as the pressing member 42, only the spring force of the spring 57 acts on the cylinder block 2 when no load is applied from the cylinder block 2 side. Since the lash adjuster 50 applies a hydraulic pressure corresponding to the load when a load is applied from the cylinder block 2 side and suppresses the tilt of the cylinder block 2, the spring force of the spring 57 of the lash adjuster 50 is as described above. The spring force of the spring 423 of the embodiment can be made smaller. Therefore, by using the lash adjuster 50 as the pressing member 42, the sliding resistance when a large load is not applied from the cylinder block 2 side can be reduced.

  In the above-described embodiment, the connecting member 31 is tilted outward from the block. However, the connecting member 31 faces the block inward so that the other end of the connecting member 31 is positioned on the cylinder block 2 side. You can tilt it.

  In the above embodiment, the eccentric portion 30b of the control shaft 30 and the cylinder block 2 are connected by the two connecting members 31. However, the number of the connecting members 31 is not limited to two, and may be increased or decreased as necessary. You may let them.

DESCRIPTION OF SYMBOLS 1 Crankcase 2 Cylinder block 3 Block moving mechanism 10 Crankshaft 30 Control shaft 30a Main shaft part 30b Eccentric part 31 Connecting member 32 Actuator 40 Guide wall 41 Support member 42 Pressing member 100 Internal combustion engine

Claims (3)

An internal combustion engine comprising a cylinder block movable relative to a crankcase, and a cylinder head attached to the top of the cylinder block,
When the internal combustion engine is viewed from the axial direction of the crankshaft rotatably supported by the crankcase, the cylinder block is disposed only on one side of the internal combustion engine to move the cylinder block relative to the crankcase. A block moving mechanism;
A pair of guide walls provided in the crankcase so as to face the side surface of the cylinder block;
A support member attached to each of the guide wall on the arrangement side of the block moving mechanism and the guide wall on the opposite side to support the side surface of the cylinder block;
A pressing member that is attached to each of the guide wall on the arrangement side of the block moving mechanism and the guide wall on the opposite side, and presses a side surface of the cylinder block;
With
The block moving mechanism is
A single control shaft supported by the crankcase and having a main shaft portion, and an eccentric portion having a shaft center at a position eccentric from the shaft center of the main shaft portion by a predetermined amount;
One end is attached to the eccentric part and the other end is attached to the cylinder block, and a connecting member for connecting the control shaft and the cylinder block;
An actuator for rotating the control shaft in both directions within a predetermined rotation range and swinging the shaft center of the eccentric portion in the relative movement direction of the cylinder block about the shaft center of the main shaft portion;
With
The support member is attached to the guide wall on the arrangement side of the block moving mechanism on the top side of the cylinder block with respect to the attachment position of the other end of the connection member, and the pressing member is connected to the other of the connection member. It is attached to the bottom side of the cylinder block from the attachment position of the end, and the support member is spaced from the pressing member by a predetermined interval on the guide wall opposite to the arrangement side of the block moving mechanism. It is attached to the bottom side of the cylinder block in the relative movement direction of the cylinder block.
Internal combustion engine. The support member attached to the guide wall on the arrangement side of the block movement mechanism and the pressing member attached to the guide wall on the side opposite to the arrangement side of the block movement mechanism are relative to the cylinder block. Arranged at the same height in the direction of movement,
The internal combustion engine according to claim 1. The pressing member attached to the guide wall on the arrangement side of the block movement mechanism and the support member attached to the guide wall on the side opposite to the arrangement side of the block movement mechanism are relative to the cylinder block. Arranged at the same height in the direction of movement,
The internal combustion engine according to claim 1 or 2.

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