JP2010059799A - Internal combustion engine having piston balancer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine having a piston balancer capable of securing a sufficient oil capacity while meeting the requirement of the good mountability thereof on a vehicle. <P>SOLUTION: This internal combustion engine includes: a balancer piston 36 operating while facing a cylinder piston 14; a balancer liner 38 which allows the balancer piston 36 to be inserted therein and is closed at the bottom part 38a; an oil falling passage 52 formed in such a manner that the oil circulated in the internal combustion engine 10 is led into the inner space 38b of the balancer liner; a one-way valve 70 for restricting the flow of oil only in the direction from the oil falling passage 52 toward the inner space 38b of the balancer liner; an oil discharge pipe 60 connecting an oil tank 40 to the inner space 38b of the balancer liner; and a one-way valve 72 for restricting the flow of oil only in the direction from the inner space 38b of the balancer liner toward the oil discharge pipe 60. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an internal combustion engine including a piston type balancer.

  Conventionally, for example, Patent Document 1 discloses an engine with a reciprocating balancer. In this conventional engine, the reciprocating motion of a rod (balancer piston) that reciprocates in a guide cylinder (balancer liner) is used as an oil pump or a fuel pump. In this conventional technique, the reciprocating balancer mechanism is applied to an inclined engine in which a cylinder protrudes obliquely upward from a crank chamber.

JP 2004-293363 A JP 2002-21932 A JP 2002-21933 A JP 62-52236 A JP 2004-301316 A JP 2004-301272 A JP 2006-194108 A

  By the way, in an internal combustion engine equipped with a piston type balancer, in the configuration in which the oil pan is disposed below the balancer piston, a sufficient gap is provided between the balancer piston and the oil surface of the oil to avoid interference with the oil. It is necessary to ensure. As a result, it is necessary to ensure a certain oil capacity for the oil pan, so the bottom of the oil pan must be set low (deep), the overall height of the internal combustion engine becomes long, and there is a problem with vehicle mountability. Will occur. Further, in the internal combustion engine provided with the conventional piston type balancer, a sufficient oil capacity cannot be ensured unless the internal combustion engine is greatly inclined, and mounting on a vehicle becomes difficult.

  The present invention has been made to solve the above-described problems. In an internal combustion engine equipped with a piston-type balancer, a configuration capable of ensuring a sufficient oil capacity while satisfying a good mounting property on a vehicle. The purpose is to provide.

1st invention is an internal combustion engine provided with a piston type balancer,
A balancer piston that moves in opposition to an in-cylinder piston disposed in a cylinder of the internal combustion engine;
A balancer liner that has been inserted into the balancer piston and closed at the bottom;
An oil introduction path formed so that oil circulated inside the internal combustion engine is led to a balancer liner inner space surrounded by a top surface of the balancer piston and an inner peripheral surface of the balancer liner;
A first oil flow restriction means provided between the oil introduction path and the balancer liner inner space, and restricts the flow of the oil only in a direction from the oil introduction path toward the balancer liner inner space;
An oil discharge path connecting the oil tank for storing the oil and the balancer liner internal space;
A second oil flow restricting means provided between the oil discharge passage and the balancer liner inner space and restricting the flow of the oil only in a direction from the balancer liner inner space toward the oil discharge passage;
It is characterized by providing.

The second invention is the first invention, wherein
The first oil flow restricting means includes a reciprocating motion of the balancer piston at a connection port of the oil introduction path provided on a side closer to the crankshaft than a connection port with the oil discharge path in a side wall portion of the balancer liner. It is realized by opening and closing by the balancer piston using.

The third invention is the first or second invention, wherein
The oil tank is formed in a crankcase around the balancer;
At least a part of the balancer liner is arranged so as to be immersed in the oil stored in the oil tank.

According to a fourth invention, in any one of the first to third inventions,
At least the balancer liner of the balancer liner and the balancer piston is provided with a guide portion for guiding the oil introduced from the oil introduction path into the balancer liner inner space to be discharged to the oil discharge path. It is characterized by.

  According to the first invention, the oil introduction path is configured so that the oil circulated through each part of the internal combustion engine is guided to the balancer liner inner space, and the reciprocating motion of the balancer piston is used to enter the balancer liner inner space. The introduced oil is discharged toward the oil tank. According to such a configuration, the reciprocating motion of the balancer piston can be made to function as a scavenge pump for actively discharging oil (and further blow-by gas) from the inside of the internal combustion engine. As a result, in an internal combustion engine in which a piston-type balancer is arranged below the crankshaft, a space for oil circulation (such as an oil pan) is not required further below the balancer liner, that is, the overall height of the internal combustion engine is increased. Without this, it is possible to construct a system that can circulate oil inside the internal combustion engine.

  According to the second aspect of the invention, the opening / closing function of the connection port of the oil introduction path can be realized by using the reciprocating motion of the balancer piston, and the number of parts can be reduced (cost reduction).

  According to the third aspect of the invention, the oil recovered from each part of the internal combustion engine can be stored in the crankcase around the balancer liner using the reciprocating motion of the balancer piston functioning as the scavenge pump. For this reason, the oil capacity can be secured without the need to lower the bottom surface of the crankcase functioning as an oil pan. Therefore, in the internal combustion engine in which the piston balancer is disposed below the crankshaft, the overall height of the internal combustion engine is increased. Therefore, it is possible to construct a system that can circulate oil inside the internal combustion engine. In addition, since it is not necessary to install the oil tank separately from the internal combustion engine, the number of parts can be reduced (cost reduction).

  According to the fourth aspect of the invention, the oil or the like flowing into the balancer liner inner space from the oil introduction path can be smoothly guided to the oil discharge path side by the guide portion. Thereby, the pump efficiency when the reciprocating motion of the balancer piston is caused to function as a scavenge pump can be improved, and the friction of the internal combustion engine can be further reduced.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view for explaining the configuration of an internal combustion engine 10 including a piston balancer according to Embodiment 1 of the present invention.
In the present invention, the number of cylinders of the internal combustion engine is not particularly limited. Here, it is assumed that the internal combustion engine 10 shown in FIG. 1 is an inline two-cylinder engine. An in-cylinder piston 14 is slidably disposed inside each cylinder 12 of the internal combustion engine 10. The in-cylinder piston 14 is connected to a crankpin 20 provided on the crankshaft 18 via a connecting rod 16. Here, it is assumed that the crankpins 20 provided in each of the two cylinders of the internal combustion engine 10 are set to have the same phase. That is, the internal combustion engine 10 is configured such that the explosion strokes are equally spaced.

  The direction of the internal combustion engine 10 in FIG. 1 corresponds to the mounting direction when the internal combustion engine 10 is actually mounted on a vehicle. That is, here, the internal combustion engine 10 is mounted on the vehicle so that the axial direction of the in-cylinder piston 14 (and the axial direction of the balancer piston 36 described later) is perpendicular to the ground. To do. In the following specification, the method of mounting the internal combustion engine 10 on the vehicle in such a direction may be simply referred to as “vertical mounting”.

  A cylinder head 24 is attached above a cylinder block 22 which is a member constituting each cylinder 12 of the internal combustion engine 10. A combustion chamber 26 of the internal combustion engine 10 is formed as a space surrounded by the cylinder 12, the in-cylinder piston 14, and the cylinder head 24 in the cylinder block 22.

  A crankcase 28 is attached below the cylinder block 22. A crank chamber 30 is formed inside the crankcase 28 as an internal space of the internal combustion engine 10 opposite to the combustion chamber 26 with the in-cylinder piston 14 interposed therebetween.

  Further, the crankshaft 18 is provided with a balancer crankpin 32 at a position symmetrical to the crankpin 20 with the axis center of the crankshaft 18 as the center. The balancer crank pin 32 is connected to a balancer piston 36 via a balancer connecting rod 34.

  A balancer liner 38 that receives the insertion of the balancer piston 36 is provided around the balancer piston 36. As shown in FIG. 1, the balancer liner 38 includes a bottom 38 a that faces the top surface of the balancer piston 36, and the bottom 38 a is closed. Here, a space surrounded by the top surface of the balancer piston 36 and the inner peripheral surface of the balancer liner 38 is referred to as a “balancer liner internal space 38b”.

  More specifically, the balancer piston 36 is configured to move in opposition to the in-cylinder piston 14 as the crankshaft 18 rotates while being slidably guided by the balancer liner 38. . The balancer piston 36 is a force that balances the inertial force of the in-cylinder piston 14, and its mass is adjusted so that a reverse inertial force is generated. The balancer crankpin 32, the balancer connecting rod 34, the balancer piston 36, and the balancer liner 38 as described above realize the piston type balancer mechanism of the internal combustion engine 10 of the present embodiment.

  In addition, an oil tank 40 for storing oil that lubricates each part of the internal combustion engine 10 is installed separately from the internal combustion engine 10 around the internal combustion engine 10. The crankcase 28 is provided with a feed pump 46 for pumping the oil in the oil tank 40 through the oil strainer 42 and the oil supply pipe 44 and supplying it to each part of the internal combustion engine 10. The feed pump 46 operates using the driving force of the internal combustion engine 10.

  The oil pressurized by the feed pump 46 is introduced into the main oil hole 50 formed in the cylinder block 22 through the oil passage 48. Then, oil is supplied from the main oil hole 50 toward each part (cylinder head 24 and the like) of the internal combustion engine 10.

  Further, as shown in FIG. 1, an oil dropping passage 52 is formed in the cylinder block 22 and the crankcase 28. The oil dropping passage 52 is a passage for returning the oil supplied to the cylinder head 24 toward the oil tank 40. The crankcase 28 also includes oil (such as oil scraped off by the piston ring and oil discharged from the clearance of the crank bearing) or blow-by gas (clearance between the piston ring and the cylinder inner wall) in the crank chamber 30. A crank communication passage 54 is formed to guide the blow-by gas leaked from the oil passage 52 to the oil drop passage 52.

  The oil drop passage 52 is connected to the balancer liner internal space 38b via an oil introduction port 56 provided in a side wall portion (a reciprocating section portion of the balancer piston 36) in the vicinity of the bottom 38a of the balancer liner 38. As described above, the internal combustion engine 10 of the present embodiment is configured such that the oil circulated through each part of the internal combustion engine 10 is guided to the balancer liner internal space 38b through the oil dropping passage 52.

  An oil discharge port 58 is provided in a side wall portion (a reciprocating section portion of the balancer piston 36) facing the oil introduction port 56 in the vicinity of the bottom 38a of the balancer liner 38. One end of an oil discharge pipe 60 is connected to the oil discharge port 58. The other end of the oil discharge pipe 60 is connected to a gas-liquid separator 62 installed in the oil tank 40. Inside the gas-liquid separator 62, oil and blow-by gas are separated. More specifically, the liquid oil is stored in the oil tank 40 through the oil passage 64, and the blow-by gas, which is a gas, is connected to an intake passage (not shown). Through the passage 66, it is introduced into the intake passage by intake negative pressure. A PCV valve 68 for adjusting the amount of blow-by gas introduced is provided in the intake communication passage 66.

  The oil introduction port 56 is provided with a one-way valve 70 that restricts the flow of oil and blow-by gas only in the direction from the oil dropping passage 52 toward the balancer liner internal space 38b. The oil discharge port 58 is provided with a one-way valve 72 that restricts the flow of oil and blow-by gas only in the direction from the balancer liner inner space 38b toward the oil tank 40. More specifically, here, the one-way valves 70 and 72 are configured to open and close by utilizing a pressure change in the balancer liner inner space 38b accompanying the reciprocating motion of the balancer piston 36. Note that the valve responsible for opening and closing the balancer liner inner space 38b and its surroundings is not limited in its configuration, for example, controls the internal combustion engine 10 as long as the valve realizes the same function as the one-way valves 70 and 72 described above. It may be an electromagnetic valve that is opened and closed based on a command from the ECU.

  FIG. 2 is a view for explaining an operation that occurs as the balancer piston 36 reciprocates. More specifically, FIG. 2A shows the operation during the “intake stroke” in which the balancer liner internal space 38b expands as the balancer piston 36 rises, and FIG. FIG. 2C shows the “discharge completion state” in which the balancer piston 36 has reached the top dead center, respectively.

  As shown in FIG. 2A, during the “intake stroke”, the one-way valve 70 is opened and the one-way valve 72 is closed by the action of the negative pressure generated in the balancer liner inner space 38b. As a result, oil in the cylinder head 24 is sucked into the balancer liner inner space 38b via the oil drop passage 52 communicating with the introduction port 56, and oil and blow-by gas in the crankcase 28 are also introduced into the crank communication passage 54 and The oil is drawn into the balancer liner internal space 38b through the oil drop passage 52.

  After that, as shown in FIG. 2B, during the “discharge stroke”, the one-way valve 70 is closed and the one-way valve 72 is opened by the pressure in the balancer liner internal space 38b that is increased by the lowering of the balancer piston 36. As a result, the oil introduction port 56 communicating with the oil dropping passage 52 is blocked, and the oil and blow-by gas that have lost their destination are discharged to the oil discharge pipe 60 through the one-way valve 72.

  Thereafter, as shown in FIG. 2C, when the balancer piston 36 reaches the top dead center, the one-way valves 70 and 72 are both closed, and the discharge of oil and blow-by gas in the balancer liner inner space 38b is completed. Every time the internal combustion engine 10 rotates once and the balancer piston 36 reciprocates once, the above operation is repeated. Further, as described above, the oil and blow-by gas discharged to the oil discharge pipe 60 are separated by the gas-liquid separator 62, the oil is stored in the oil tank 40, and the blow-by gas is recirculated to the intake passage. .

  As described above, in the internal combustion engine 10 of the present embodiment, the oil drop passage 52 is configured so that oil and blowby gas circulated through each part of the internal combustion engine 10 is guided to the balancer liner internal space 38b, and the balancer piston The oil and blow-by gas introduced into the balancer liner inner space 38 b are discharged toward the oil tank 40 by using the reciprocating motion 36. According to such a configuration, the reciprocating motion of the balancer piston 36 can be functioned as a scavenge pump for positively discharging oil and blow-by gas from the inside of the internal combustion engine 10.

  Thereby, in the internal combustion engine 10 in which the piston type balancer is arranged below the crankshaft 18, a space (oil pan or the like) for oil circulation is not required further below the balancer liner 38, that is, the internal combustion engine 10 It is possible to construct a system that can circulate oil inside the internal combustion engine 10 without enlarging the overall height of the internal combustion engine 10. Further, according to the configuration of the present embodiment, since the oil pan is not provided below the balancer piston 36, it is possible to avoid the deterioration of the friction caused by the interference between the balancer piston 36 that reciprocates and the oil in the oil pan. Furthermore, it is possible to prevent bubbles from being generated in the oil due to such interference.

  Further, since the oil and blow-by gas in the crank chamber 30 are sucked using the crank communication passage 54 communicating with the oil dropping passage 52, the inside of the crank chamber 30 can be decompressed, and friction (pump loss) ) Can also be reduced. Furthermore, since the gas-liquid separation device 62 is provided in the oil tank 40, it is possible to separate oil and blow-by gas at an early stage, thereby preventing oil deterioration and sludge generation.

  Further, in an in-line two-cylinder engine in which explosions occur at regular intervals, such as the internal combustion engine 10 of the present embodiment, the engine vibrates in the vertical direction of the piston due to the inertial force when the in-cylinder piston moves up and down. On the other hand, since the internal combustion engine 10 of the present embodiment includes the balancer piston 36 configured to move in opposition to the in-cylinder piston 14, the inertial force of the in-cylinder piston 14 is used as the inertia of the balancer piston 36. The force can be canceled out by force, and the rotation balance of the internal combustion engine 10 (crankshaft 18) can be secured satisfactorily. Furthermore, as described above, the internal combustion engine 10 of the present embodiment is mounted vertically on the vehicle. For this reason, according to the internal combustion engine 10, the rotation balance in an internal combustion engine provided with a piston type balancer can be ensured better. As described above, the total height of the internal combustion engine 10 can be effectively lowered when the internal combustion engine 10 including the piston balancer is vertically mounted to obtain a good rotational balance.

  In the first embodiment described above, the oil dropping passage is used as the “oil introduction passage” in the first invention, and the one-way valve 70 is used as the “first oil flow regulating means” in the first invention. The pipe 60 corresponds to the “oil discharge passage” in the first invention, and the one-way valve 72 corresponds to the “second oil flow restricting means” in the first invention.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIG. 3 and FIG.
FIG. 3 is a cross-sectional view for explaining the configuration of an internal combustion engine 80 including the piston balancer according to the second embodiment of the present invention. In FIG. 3, the same components as those shown in FIG.

  The internal combustion engine 80 shown in FIG. 3 is the same as the internal combustion engine 10 of the first embodiment described above except that the method for opening and closing the oil introduction port 86 that is a connection port between the oil drop passage 82 and the balancer liner internal space 84b is different. It has the composition of.

  As shown in FIG. 3, the configuration of the present embodiment is characterized by the location of the oil inlet 86 provided in the balancer liner 84 inside the crankcase 88. That is, the oil introduction port 86 is disposed on the side closer to the crankshaft 18 than the oil discharge port 58 disposed in the vicinity of the bottom portion 84a, which is a portion facing the oil introduction port 86 in the side wall portion of the balancer liner 84. Yes. The reciprocating motion of the balancer piston 36 is used to open and close the oil introduction port 86 by the side wall of the balancer piston 36.

FIG. 4 is a diagram for explaining an operation that occurs as the balancer piston 36 reciprocates.
As shown in FIG. 4C, when the balancer piston 36 is located at the top dead center, the oil introduction port 86 is closed by the side wall of the balancer piston 36. During the “intake stroke”, a negative pressure is generated in the balancer liner inner space 84b as the balancer piston 36 rises from the top dead center, and the one-way valve 72 on the oil discharge port 58 side is closed by the negative pressure. . Thereafter, when the balancer piston 36 is further raised, the oil introduction port 86 is opened. As a result, as shown in FIG. 4A, the oil in the cylinder head 24 is sucked into the balancer liner inner space 84b through the oil drop passage 82 communicating with the introduction port 86, and the inside of the crankcase 28 Oil or blow-by gas is sucked into the balancer liner inner space 84b through the crank communication passage 54 and the oil dropping passage 82.

  Thereafter, as shown in FIG. 4B, during the “discharge stroke”, the oil introduction port 86 is closed (shut off) again by the lowering of the balancer piston 36 and the increased pressure in the balancer liner internal space 84b increases. Valve 72 is opened. As a result, the oil and blow-by gas that have lost their destination are discharged to the oil discharge pipe 60 through the one-way valve 72. Since the subsequent operation is the same as that of the first embodiment, detailed description thereof is omitted here.

  Also with the configuration of the internal combustion engine 80 of the present embodiment described above, the reciprocating motion of the balancer piston 36 can function as a scavenge pump for actively discharging oil and blow-by gas from the inside of the internal combustion engine 80. become. As a result, in the internal combustion engine 80 in which the piston type balancer is disposed below the crankshaft 18, it is possible to construct a system that can circulate oil inside the internal combustion engine 80 without enlarging the overall height of the internal combustion engine 80. Become. Further, according to the configuration of the present embodiment, the opening / closing function of the oil introduction port 86 can be realized by utilizing the reciprocating motion of the balancer piston 36, and the number of parts can be reduced (cost reduction). .

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIG.
FIG. 5 is a cross-sectional view for explaining the configuration of an internal combustion engine 90 including the piston balancer according to the third embodiment of the present invention. In FIG. 5, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  In the first and second embodiments described above, the oil tank 40 is provided separately from the internal combustion engines 10 and 80. On the other hand, in the internal combustion engine 90 of the present embodiment, as shown in FIG. 5, the space in the crankcase 92 around the balancer liner 38 is used as an oil tank. In other words, in this embodiment, the balancer liner 38 is arranged so that most of the balancer liner 38 is submerged in the oil stored in the crankcase 92 that also functions as an oil pan.

  In addition, one end of an oil discharge pipe 94 is connected to the oil discharge port 58 of the present embodiment. The other end of the oil discharge pipe 94 is open to the crank chamber 30 at a position higher than the oil level of the oil in the crankcase 92. The feed pump 46 is configured to pump up oil using an oil strainer 96 inserted into the oil in the crankcase 92.

  Also in the internal combustion engine 90 of the present embodiment, the reciprocating motion of the balancer piston 36 functions as a scavenge pump. Since the operation is the same as that of the first and second embodiments, detailed description thereof is omitted here. Further, the oil and blow-by gas recovered from each part of the internal combustion engine 90 by the function of such a scavenge pump is discharged into the crank chamber 30 above the oil level of the oil by the oil discharge pipe 94. Thereby, oil and blow-by gas can be separated more reliably, and deterioration of oil and generation of sludge can be satisfactorily prevented.

  As described above, in the internal combustion engine 90 of the present embodiment, the reciprocating motion of the balancer piston 36 functions as a scavenge pump, and oil recovered from each part of the internal combustion engine 90 by the scavenge pump is used in the balancer liner 38. It is made to collect in the surrounding crankcase 92. As a result, the oil capacity can be ensured without having to lower the bottom surface of the crankcase 92 that functions as an oil pan. Therefore, in the internal combustion engine 90 in which the piston balancer is disposed below the crankshaft 18, the internal combustion engine 90 It is possible to construct a system that can circulate oil inside the internal combustion engine 90 without enlarging the overall height. In addition, since it is not necessary to install the oil tank separately from the internal combustion engine 90, the number of parts can be reduced (cost reduction).

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described with reference to FIG. 6 and FIG.
FIG. 6 is a view for explaining a characteristic configuration (guide portion of the present invention) in an internal combustion engine including the piston type balancer according to the fourth embodiment of the present invention. In FIG. 6, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  6A is a view showing the internal shape of the balancer liner 100 as viewed from the oil discharge port 58 side, and FIG. 6B is a view showing the internal shape of the balancer liner 100 from the oil introduction port 56 side. FIG. 6C is a view of the bottom portion 100a of the balancer liner 100 as viewed from the top surface side of the balancer piston 102. FIG.

  As shown in each drawing of FIG. 6, an oil guide groove 104 is formed in the bottom 100 a of the balancer liner 100 from the oil introduction port 56 toward the oil discharge port 58. More specifically, the oil guide groove 104 is formed so that the oil introduction port 56 and the oil discharge port 58 are located inside the oil guide groove 104. Furthermore, the top portion 102a of the balancer piston 102 is formed in a convex shape at the center thereof in accordance with the bottom portion 100a of the balancer liner 100 formed in a concave shape. In the balancer liner 100, a surface 100 c positioned between the side wall portion 100 b and the oil guide groove 104 is provided with an oil oil so that the oil dripping the side wall portion 100 b of the balancer liner 100 can easily flow into the oil discharge port 58. It is formed so as to be inclined toward the guide groove 104.

  Unlike the configuration shown in FIG. 6 above, if the balancer liner has a flat bottom that is perpendicular to the side wall and the top of the balancer piston is also flat, when the balancer piston is lowered, Then, the flow of oil or the like in the left-right direction in FIG. When such a flow of oil or the like occurs, the oil or the like from the balancer liner inner space to the oil discharge port will not be discharged well.

  On the other hand, according to the configuration shown in FIG. 6 described above, the oil or the like flowing into the balancer liner internal space 100d from the oil introduction port 56 can be smoothly guided to the oil discharge port 58 side by the oil guide groove 104. become able to. Thereby, the pump efficiency when the reciprocating motion of the balancer piston 102 is caused to function as a scavenge pump can be improved, and the friction of the internal combustion engine 90 can be further reduced. Further, since the top portion 102a of the balancer piston 102 has a shape along the oil guide groove 104, it is possible to avoid creating a useless volume in the balancer liner 100, and this also improves the discharge performance of oil and the like. Can be secured.

  By the way, in Embodiment 4 described above, the balancer is used as the guide portion of the present invention for guiding the oil and blow-by gas introduced from the oil introduction port 56 to the balancer liner inner space 100d to be discharged to the oil discharge port 58. The bottom portion 100 a of the liner 100 and the top portion 102 a of the balancer piston 102 are provided with an oil guide groove 104 in the bottom portion 100 a, and the top portion 102 a is shaped along the oil guide groove 104. However, the guide portion in the present invention is not limited to the above-described configuration as long as it guides the oil or the like so as to prompt the oil discharge to the oil discharge port. That is, for example, a configuration as shown in FIG.

FIG. 7 is a diagram for explaining another configuration of the guide portion of the present invention. More specifically, FIG. 7 is a diagram showing the internal shape of the balancer liner 110 viewed from the same direction as FIG.
As shown in FIG. 7, the bottom 110a of the balancer liner 110 is inclined in the downward direction of FIG. 7 (the direction from the crankshaft 18 toward the bottom 110a) from the oil introduction port 112 side to the oil discharge port 114 side. Is formed. Then, as shown in FIG. 7, the top portion 116a of the balancer piston 116 is inclined downward from the oil inlet 112 side toward the oil outlet 114 side at a gentler inclination angle than the bottom portion 110a. Is formed.

  According to the configuration shown in FIG. 7 described above, when the top portion 116a of the balancer piston 116 approaches the bottom portion 110a of the balancer liner 110, the balancer liner internal space is closer to the oil discharge port 114 than to the oil introduction port 112. 110b becomes wider. Thus, when such consideration is not taken, when oil or the like in the balancer liner internal space 110b is compressed as the balancer piston 116 is lowered, a pressure escape is provided in the direction of the oil discharge port 114. It can be provided. Even with such a configuration, it is possible to configure the guide portion of the present invention that guides oil and the like so as to prompt the discharge of oil and the like to the oil discharge port. Further, the configuration shown in FIG. 7 may be combined with the configuration shown in FIG.

  In the fourth embodiment described above, the oil guide groove 104 formed in the bottom 100a of the balancer liner 100 and the top 102a of the balancer piston 102 formed in a convex shape are the “guide portion” in the fourth invention. It corresponds.

It is sectional drawing for demonstrating the structure of an internal combustion engine provided with the piston type balancer of Embodiment 1 of this invention. It is a figure for demonstrating the operation | movement which arises with the reciprocation of a balancer piston. It is sectional drawing for demonstrating the structure of an internal combustion engine provided with the piston type balancer of Embodiment 2 of this invention. It is a figure for demonstrating the operation | movement which arises with the reciprocation of a balancer piston. It is sectional drawing for demonstrating the structure of an internal combustion engine provided with the piston type balancer of Embodiment 3 of this invention. It is a figure for demonstrating the characteristic structure (guide part of this invention) in an internal combustion engine provided with the piston type balancer of Embodiment 4 of this invention. It is a figure for demonstrating the other structure of the guide part of this invention.

Explanation of symbols

12 cylinder 14 piston in cylinder 16 connecting rod 18 crankshaft 20 crankpin 22 cylinder block 24 cylinder head 26 combustion chamber 28, 88, 92 crankcase 30 crank chamber 32 balancer crank pin 34 balancer connecting rod 36, 102, 116 balancer piston 38 , 84, 100, 110 Balancer liners 38a, 84a, 100a, 110a Balancer liner bottom portions 38b, 84b, 100d, 110b Balancer liner inner space 40 Oil tank 46 Feed pump 50 Main oil holes 52, 82 Oil drop passage 54 Crank communication passage 56, 86, 112 Oil inlet 58, 114 Oil outlet 60, 94 Oil outlet pipe 70, 72 One-way valve 102a, 116a Balancer piston top 104 Le guide groove

Claims (4)

A balancer piston that moves in opposition to an in-cylinder piston disposed in a cylinder of the internal combustion engine;
A balancer liner that has been inserted into the balancer piston and closed at the bottom;
An oil introduction path formed so that oil circulated inside the internal combustion engine is led to a balancer liner inner space surrounded by a top surface of the balancer piston and an inner peripheral surface of the balancer liner;
A first oil flow restriction means provided between the oil introduction path and the balancer liner inner space, and restricts the flow of the oil only in a direction from the oil introduction path toward the balancer liner inner space;
An oil discharge path connecting the oil tank for storing the oil and the balancer liner internal space;
A second oil distribution restriction means provided between the oil discharge passage and the balancer liner inner space, and restricting the flow of the oil only in a direction from the balancer liner inner space toward the oil discharge passage;
An internal combustion engine comprising a piston balancer.   The first oil flow restricting means includes a reciprocating motion of the balancer piston at a connection port of the oil introduction path provided on a side closer to the crankshaft than a connection port with the oil discharge path in a side wall portion of the balancer liner. 2. An internal combustion engine comprising a piston type balancer according to claim 1, wherein the internal combustion engine is realized by opening and closing the balancer piston. The oil tank is formed in a crankcase around the balancer;
3. An internal combustion engine comprising a piston type balancer according to claim 1, wherein at least a part of the balancer liner is disposed so as to be immersed in the oil stored in the oil tank. .   At least the balancer liner of the balancer liner and the balancer piston is provided with a guide portion that guides the oil introduced from the oil introduction path into the balancer liner inner space to the oil discharge path. An internal combustion engine comprising the piston type balancer according to any one of claims 1 to 3.

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