JP2016089627A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine having an oil jet which injects a lubricant at necessary timing, and is stabilized in an injection position.SOLUTION: An internal combustion engine has: an internal combustion engine main body 2 in which at least one cylinder 11 is formed; at least one piston 15 which is reciprocally accommodated in the cylinder; at least one oil jet 44 which is attached to the internal combustion engine main body in response to the piston, and injects a lubricant toward a rear face of the corresponding piston; oil passages 41, 43 which extend from an oil pump 35 to the oil jet; and changeover valves 42 which are arranged at the oil passages, and switch communication and disconnection between the oil pump and the oil jet. The changeover valve is driven by receiving power from a crankshaft, and connects the oil jet corresponding to an arbitrary piston to the oil pump when the arbitrary piston is located within a prescribed moving range.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an internal combustion engine, and more particularly, to a cooling device for a piston including an oil jet.

  In a reciprocating internal combustion engine, a device for cooling a piston by spraying lubricating oil pressurized by an oil pump from an oil jet onto the back surface of the piston is known (for example, Patent Document 1). The piston cooling device according to Patent Document 1 is connected to an oil pump, and has an upstream oil passage opened on a sliding contact surface of a crankshaft bearing, and one end opened on an outer peripheral surface of a journal of the crankshaft. A downstream oil passage having the other end opened on the protruding end surface of the weight. In this cooling device, when the piston is near bottom dead center, the upstream oil passage and the downstream oil passage are connected to each other, and the injection port (oil oil formed by the counterweight side opening end of the downstream oil passage) From the jet) toward the back of the piston. In such a piston cooling device, the connection and disconnection of the upstream oil passage and the downstream oil passage are switched according to the rotation of the crankshaft, and the lubricating oil is intermittently injected, so the injection amount of the lubricating oil is reduced. As a result, the load on the oil pump is reduced. Further, when the injection port and the piston are closest to each other, the upstream oil passage and the downstream oil passage are connected and the lubricating oil is injected from the injection port, so that the lubricating oil is reliably supplied to the back surface of the piston. The

JP 2002-256835 A

  However, in the piston cooling device according to the cited document 1, since the injection port is formed in the counterweight, the position and direction of the injection port change according to the rotation of the crankshaft, and the position where the lubricant is sprayed on the back surface of the piston Is not constant. Therefore, when a cooling channel that allows the lubricating oil to flow is formed inside the piston and a part of the cooling channel is open on the back surface of the piston, the piston cooling device according to the cited document 1 applies the lubricating oil to the cooling channel. The problem that it cannot supply efficiently arises.

  In view of the above background, it is an object of the present invention to provide an internal combustion engine including an oil jet that injects lubricating oil at a necessary timing and has a fixed injection position.

  In order to solve the above-mentioned problems, an internal combustion engine of the present invention includes an internal combustion engine body (2) having at least one cylinder (11) formed therein, and is accommodated in each of the cylinders so as to be able to reciprocate, and a connecting rod (18). At least one piston (15) connected to the crankshaft (20) via the cylinder, and attached to the internal combustion engine main body corresponding to each of the pistons, and injecting lubricating oil toward the back surface of the corresponding piston At least one oil jet (44), an oil passage (41, 43) extending from the oil pump (35) to each of the oil jets, and communication between the oil pump and the oil jet provided in the oil passage And a switching valve (42) for switching cutting, and the switching valve is driven by receiving power from the crankshaft. Characterized by connecting the oil jet corresponding to any of said piston when any of said piston is positioned in a predetermined moving range in the oil pump.

  According to this configuration, since the oil jet is attached to the internal combustion engine body, the lubricating oil can be sprayed to a fixed position on the back surface of the piston. Further, since the oil jet injects the lubricating oil at a predetermined timing by the switching valve, the load of the oil pump is reduced as compared with the case of always injecting.

  In the above invention, the switching valve is rotatably received in the valve case (46) and the valve case, and is connected to the crankshaft through the power transmission mechanism (51). A valve body (47) that rotates at the same speed, and the valve case is disposed on an inner peripheral surface (46A) that is in sliding contact with an outer peripheral surface (47A) of the valve body, and on an upstream side (41) of the oil passage. An inlet port (54) that communicates and opens to the inner peripheral surface, and at least one outlet port (55) that communicates with the downstream side (43) of the oil passage and opens to the inner peripheral surface; The valve body has a connection passage (58) opened in the outer peripheral surface, and the connection passage corresponds to the arbitrary piston when the arbitrary piston is located in a predetermined movement range. The outlet port may be connected to the inlet port that.

  According to this configuration, since the valve body is driven by the crankshaft synchronized with the piston position, the switching valve can open and close the oil passage at a predetermined timing corresponding to the piston position.

  Further, in the above invention, the valve body is formed in a cylindrical shape, and at least one of the outlet ports opens to the inner peripheral surface of the valve case, and an opening end on the inner peripheral surface side of the outlet port. Should extend in the circumferential direction.

  According to this configuration, it is possible to extend the period during which the connection between the connection passage and the outlet port continues. Moreover, the oil jet injection period can be easily set by arbitrarily changing the circumferential direction of the opening end on the inner peripheral surface side of the outlet port.

  In the above invention, the valve body is formed in a cylindrical shape, and at least one of the outlet ports opens to the inner peripheral surface of the valve case and is an open end facing the outlet port of the connection passage. Should extend in the circumferential direction.

  According to this configuration, it is possible to extend the period during which the connection between the connection passage and the outlet port continues. Moreover, the oil jet injection period can be easily set by arbitrarily changing the circumferential direction of the opening end facing the outlet port of the connection passage.

  In the above invention, the valve body may have a center of gravity that is deviated with respect to the rotation axis of the valve body.

  According to this configuration, the valve body can function as a primary balancer shaft that reduces primary vibrations of the internal combustion engine. Therefore, the switching valve can also serve as the primary balancer device, and the internal combustion engine can be downsized.

  In the above invention, the valve body is formed in a cylindrical shape, and at least one of the outlet ports has an opening in a thrust surface (46B) that is in sliding contact with an axial end surface (47C) of the valve body of the valve case. And the said connection channel | path is good to open to the said thrust surface corresponding to the said exit port.

  According to this configuration, since at least one of the outlet ports opens in the thrust surface, the number of outlet ports arranged corresponding to the outer peripheral surface of the valve body can be reduced. As a result, the axial length of the valve body can be shortened, the valve body can be reduced in size and weight, and the sliding contact area between the valve body and the valve case can be reduced. Thereby, the power required to rotate the valve body is reduced, and the load on the internal combustion engine is reduced.

  Further, in the above invention, a plurality of the pistons are provided, and the outlet port corresponding to the piston that reciprocates in the same phase gathers a portion that opens in the thrust surface, and a common collecting passage (101, 102) may be formed.

  According to this configuration, the length and volume of the entire outlet port are reduced by the collecting passage, so that the valve case and the valve body can be reduced in size.

  In the above invention, the switching valve includes a journal (202) of the crankshaft and a bearing (211) that rotatably supports the journal, and the upstream side and the downstream side (213, 214) of the oil passage. ) Are opened to the inner peripheral surface of the bearing independently of each other, the journal has a connection passage (215) opened to the outer peripheral surface of the journal, and the connection passage is free from a predetermined piston. The upstream side and the downstream side of the oil passage corresponding to the arbitrary piston may be connected to each other when located in the movement range.

  According to this configuration, since the switching valve is configured by the crankshaft and its bearing, it is not necessary to provide a separate part to configure the switching valve, and the internal combustion engine can be reduced in size and weight.

  Moreover, in the said invention, it is good for the opening end which opposes the downstream of the said oil path of the said connection channel | path to extend in the circumferential direction.

  According to this configuration, it is possible to extend the period during which the connection between the connection passage and the outlet port continues. Moreover, the oil jet injection period can be easily set by arbitrarily changing the circumferential direction of the opening end facing the outlet port of the connection passage.

  In the above invention, the connection passage may be a groove extending in the circumferential direction on the outer peripheral surface of the journal.

  According to this configuration, processing of the connection passage is facilitated.

  Further, in the above invention, the piston has a cooling channel (16) formed inside the piston, a part of which is open on the back surface of the piston, and the oil jet injection port is a reciprocating direction of the piston. It is good to arrange | position so that it may oppose the opening (16B) of the said cooling channel.

  According to this configuration, since the injection port of the oil jet always faces the opening of the cooling channel, the injected lubricating oil is efficiently supplied to the cooling channel.

  According to the above configuration, it is possible to provide an internal combustion engine including an oil jet that is injected at a necessary timing and has a fixed injection position.

1 is a longitudinal sectional view of an internal combustion engine according to a first embodiment. Explanatory drawing which shows the lubrication system of the internal combustion engine which concerns on 1st Embodiment. III-III sectional view of FIG. IV-IV sectional view of FIG. Diagram showing oil jet injection period Sectional drawing of the switching valve which concerns on the modification of 1st Embodiment. Sectional drawing of the switching valve which concerns on the modification of 1st Embodiment. (A) Cross-sectional view of switching valve according to second embodiment, (B) BB cross-sectional view of FIG. 8 (A), (C) CC cross-sectional view of FIG. 8 (A). Sectional drawing of the valve case at the time of setting the internal combustion engine which concerns on 2nd Embodiment to 3 cylinders Sectional drawing of the valve case at the time of making the internal combustion engine which concerns on 2nd Embodiment into a single cylinder Sectional drawing which shows the internal combustion engine which concerns on 3rd Embodiment. XII-XII sectional view of FIG. Sectional drawing which shows the internal combustion engine which concerns on 4th Embodiment XIV-XIV cross section of Fig. 13 XV-XV sectional view of FIG.

  Embodiments in which the present invention is applied to an internal combustion engine for automobiles will be described below with reference to the drawings.

(First embodiment)
As shown in FIGS. 1 and 2, the internal combustion engine 1 according to the first embodiment is an in-line four-cylinder reciprocating engine. The internal combustion engine 1 includes, as an internal combustion engine body 2, a cylinder block 3, an oil pan 4 coupled to the lower part of the cylinder block 3, and a cylinder head 5 coupled to the upper part of the cylinder block 3. The cylinder block 3 includes an upper block 7 and a lower block 8 provided at a lower portion of the upper block 7. On the upper portion of the upper block 7, first to fourth cylinders 11 (11A to 11D) are formed in parallel to each other and in a line. A crankcase 12 is formed by the lower portion of the upper block 7 and the lower block 8. Each cylinder 11 has an upper end opened to the upper end surface of the cylinder block 3 and a lower end opened to a crank chamber 13 formed inside the crankcase 12. The cylinder head 5 is coupled to the upper end surface of the cylinder block 3 and closes the upper end of each cylinder 11.

  The first to fourth cylinders 11 receive the first to fourth pistons 15A to 15D so as to be capable of reciprocating. As shown in FIG. 1, a cooling channel 16 is formed inside the crown portion of each piston 15. The cooling channel 16 is an oil passage formed inside the crown portion. The cooling channel 16 has an annular portion 16A formed in an annular shape around the axis of the piston 15, and the back surface of the crown portion from the annular portion 16A, that is, the back surface of the piston 15. A pair of openings 16B extending and opening. The openings 16 </ b> B are formed at positions that are symmetric with respect to each other about the axis of the piston 15, and each point downward along the axial direction of the piston 15.

  Each piston 15 is connected to a crankshaft 20 via a connecting rod 18. In the present embodiment, the first and fourth pistons 15A and 15D are arranged in the same phase with respect to the crank angle, and the second and third pistons 15B and 15C are shifted by 180 ° with respect to the first piston 15A. Is arranged. The crankshaft 20 is rotatably supported by a bearing formed at the boundary between the upper block 7 and the lower block 8.

  As shown in FIG. 1, a secondary balancer device 23 is coupled to the lower part of the lower block 8. The secondary balancer device 23 includes an upper housing 24 coupled to the lower block 8, a lower housing 25 coupled to the upper housing 24, and two rotatably supported between the upper housing 24 and the lower housing 25. And balancer shafts 26, 26. Each balancer shaft 26, 26 has a center of gravity deviated from the rotation axis. The balancer shafts 26 and 26 are arranged in parallel to each other, are connected to each other by a gear (not shown), and rotate in opposite directions. One of the two balancer shafts 26 and 26 is connected to the crankshaft 20 by a chain transmission mechanism (not shown), and rotates at twice the rotational speed of the crankshaft 20.

  FIG. 2 shows the lubrication system 30 of the internal combustion engine 1. The lubrication system 30 is a device that supplies the lubricating oil stored in the oil pan 4 to the sliding contact portion and the high temperature portion of the internal combustion engine 1 and performs lubrication and cooling with the lubricating oil. As shown in FIG. 2, the lubrication system 30 includes an oil suction port 31 disposed at the bottom of the oil pan 4, a main gallery 32 that is a passage for lubricating oil formed inside the cylinder block 3, and an oil suction port. 31 and an oil passage 33 that connects the main gallery 32, and an oil pump 35, an oil filter 36, and an oil cooler 37 that are arranged on the oil passage 33 in this order from the upstream side. The oil pump 35 is a known pump, and may be a trochoid pump, for example. The oil pump 35 is driven by receiving power from the crankshaft 20. By driving the oil pump 35, the lubricating oil in the oil pan 4 is sucked from the oil suction port 31, passes through the oil pump 35, the oil filter 36, and the oil cooler 37 in order, and is pumped to the main gallery 32.

  A plurality of oil passages branched from the main gallery 32 are connected to the main gallery 32. One of the oil passages supplies lubricating oil to the sliding contact portion between the crankshaft 20 and its bearing 211, and the other one lubricates the sliding contact portion of the valve mechanism 39 that opens and closes the intake valve and the exhaust valve. Supply. The other oil passage supplies lubricating oil to the piston cooling device 40 for cooling the piston 15.

  The piston cooling device 40 includes an upstream oil passage 41 connected to the main gallery 32, a switching valve 42 connected to the upstream oil passage 41, and first to fourth downstream oil passages connected to the switching valve 42. 43 (43A to 44D) and first to fourth oil jets 44 (44A to 44D) connected to the first to fourth downstream oil passages 43 (43A to 44D), respectively.

  As shown in FIGS. 2 to 4, the switching valve 42 includes a valve case 46 formed in a cylindrical shape and a shaft-shaped (columnar) valve body 47 that is rotatably received in the valve case 46. The valve body 47 has half-shaped case halves coupled to each other. Both case halves are connected to each other so as to sandwich the valve body 47, whereby the valve body 47 is received inside the valve case 46. In the present embodiment, one of the case halves of the valve case 46 is formed integrally with the upper housing 24 of the secondary balancer device 23, and one of the case halves is formed integrally with the lower housing 25. In other embodiments, the valve case 46 may be formed as a separate member from the housings 24 and 25 and may be coupled thereto by welding, bolt fastening, or the like.

  The valve body 47 is formed in an axial shape having a circular cross section, and is disposed in parallel with the crankshaft 20. One end of the valve body 47 penetrates the valve case 46 and protrudes outside the valve case 46. One end of the valve body 47 is connected to the crankshaft 20 via the power transmission mechanism 51. The power transmission mechanism 51 includes, for example, sprockets provided on the crankshaft 20 and the valve body 47, and endless chains spanned over the sprockets. The power transmission mechanism 51 rotates the valve body 47 at the same rotational speed as the crankshaft 20.

  An outer peripheral surface 47 </ b> A of the valve body 47 is formed on a circumferential surface and is in sliding contact with an inner peripheral surface 46 </ b> A of the valve case 46. The valve case 46 is formed with an inlet port 54 and first to fourth outlet ports 55 (55A to 55D) that are passages extending from the outer surface to the inner peripheral surface 46A. The inlet port 54, the first outlet port 55A, the second outlet port 55B, the third outlet port 55C, and the fourth outlet port 55D are spaced apart from each other in the described order in the axial direction of the valve case 46. Yes. Further, on the inner peripheral surface 46A of the valve case 46, a groove portion 56 that extends in the circumferential direction and has an annular shape is formed in a portion where the inlet port 54 is opened.

  A connection passage 58 is formed in the valve body 47. The connection passage 58 includes a main passage 59 extending in the axial direction inside the valve body 47, and first to fifth passages 60 (60A to 60E) extending radially from the main passage 59 to the outer peripheral surface 47A of the valve body 47. ). The first to fourth passages 60A to 60D have a predetermined width in the circumferential direction. In the present embodiment, the first to fourth passages 60A to 60D have the same angular width in each part in the radial direction, but in other embodiments, the outer end side (outer peripheral surface 47A side) is the inner end side (main passage). 59 side), the angular width may be larger in the circumferential direction.

  When the rotation range of the valve body 47 with respect to the valve case 46 is within a predetermined first rotation range, the first passage 60A and the first outlet port 55A are connected, and the fourth passage 60D and the fourth outlet port 55D are connected. When the rotation range of the valve body 47 with respect to the valve case 46 is within a predetermined second rotation range, the second passage 60B and the second outlet port 55B are connected and the third passage 60C and the third outlet port 55C are connected. And are connected. The fifth passage 60E is always connected to the inlet port 54 because it always faces the groove 56 regardless of the rotational position of the valve body 47 with respect to the valve case 46. A plurality of fifth passages 60 </ b> E may be formed at positions that always face the groove 56.

  On the outer surface side of the valve case 46, the inlet port 54 is connected to the upstream oil passage 41, the first outlet port 55A is connected to the first downstream oil passage 43A, and the second outlet port 55B is the second downstream oil passage. 43B, the third outlet port 55C is connected to the third downstream oil passage 43C, and the fourth outlet port 55D is connected to the fourth downstream oil passage 43D.

  As shown in FIG. 2, first to fourth oil jets 44 (44 </ b> A to 44 </ b> D) with corresponding numbers are connected to the downstream ends of the first to fourth downstream oil passages 43 (43 </ b> A to 44 </ b> D). Yes. As shown in FIG. 1, each oil jet 44 includes a base portion 63 having an oil passage formed therein, and a nozzle 64 protruding from the base portion 63 and connected to the oil passage in the base portion 63. The base 63 of the oil jet 44 is coupled to the inner surface (crank chamber 13 side) of the cylinder block 3. Specifically, each base 63 is coupled to the lower surface of the portion of the upper block 7 that forms the upper wall of the crank chamber 13. Further, the base 63 of each oil jet 44 is coupled to the periphery of the opening on the lower end side (crank chamber 13 side) of the cylinder 11 having a corresponding number. That is, the base 63 of the first oil jet 44A is coupled around the opening on the lower end side of the first cylinder 11A. Each nozzle 64 extends laterally from the base 63, then bends upward, and enters the inside of the cylinder 11 having a corresponding number. The injection port of each nozzle 64 is parallel to the cylinder axis and faces upward, and faces the opening 16B of the cooling channel 16 of the piston 15 of the corresponding number. Thereby, the lubricating oil injected from each oil jet 44 jumps upward along the cylinder axial direction and can reach the opening 16B of the cooling channel 16 of the corresponding piston 15.

  A check valve (not shown) is provided in the oil passage of each base 63. The check valve allows the flow from the base 63 side to the nozzle 64 side, while preventing the reverse flow. The check valve is configured to open when the pressure difference between the upstream side (downstream oil passage 43 side) and the downstream side (nozzle 64 side) exceeds a predetermined value.

  At least a part of the upstream oil passage 41 and the downstream oil passage 43 is formed in the cylinder block 3. A part of the upstream oil passage 41 and the downstream oil passage 43 may be formed by a pipe member coupled to the cylinder block 3. In the present embodiment, the upstream oil passage 41 and the downstream oil passage 43 are connected to the pipe member coupled to the outer surface of the valve case 46, the upper block 7, the lower block 8, and the housings 24, 25 of the secondary balancer device 23. And a passage formed inside. In another embodiment, the inlet port 54 and the outlet port 55 extend in the valve case 46 to the housings 24 and 25 of the secondary balancer device 23, and the upstream oil passage 41 and the downstream side formed inside the housings 24 and 25. You may make it connect directly to the oil path 43. FIG.

  In the switching valve 42, the timing at which each passage 60 and each outlet port 55 communicate is set according to the position of the corresponding piston 15. FIG. 5 is a diagram illustrating a relationship between a period during which the passage 60 and the outlet port 55 corresponding to each other of the switching valve 42 communicate with each other and a piston position (crank angle). In the figure, the piston position is represented by the crank angle, and when it is at top dead center (TDC), 0 ° is used as a reference, the rising period before top dead center is expressed as a negative value, and the falling period after top dead center is Expressed as a positive value. The piston speed has a positive value in the upward direction (rise period) and a negative value in the downward direction (down period). Similarly, the inertia force generated in the lubricating oil in the cooling channel 16 has a positive value for the upward direction and a negative value for the downward direction. In the present embodiment, the speed of the lubricating oil injected from each oil jet 44 is upward, and is set to a value smaller than the maximum value of the upward speed of the piston 15.

  The greater the value (speed difference) obtained by subtracting the speed of the piston 15 from the speed of the lubricating oil injected from the oil jet 44, the greater the relative speed of the lubricating oil in the direction approaching the piston 15; It becomes easy for the lubricating oil to enter the cooling channel 16. Further, the greater the inertia force generated in the lubricating oil in the cooling channel 16 is, the easier the lubricating oil injected from the oil jet 44 enters the cooling channel 16. When the inertial force generated in the lubricating oil in the cooling channel 16 is large downward, the lubricating oil in the cooling channel 16 flows in the outflow direction, so that the lubricating oil injected from the oil jet 44 is difficult to enter. Further, the closer the distance between the oil jet 44 and the piston 15 is, the easier it is to maintain the kinetic energy of the lubricating oil when it reaches the back surface of the piston. Therefore, the lubricating oil injected from the oil jet 44 easily enters the cooling channel 16. Become. Considering the above factors, for example, the oil jet 44 injects oil in the movement range of the piston position from −30 ° to 130 °, that is, the passage 60 and the outlet port 55 corresponding to each piston 15 of the switching valve 42. Should be connected. The first rotation range defines the above range with respect to the first piston 15A, and the second rotation range defines the above range with respect to the second piston 15B. It should be noted that the first rotation range and the second rotation range are appropriately changed according to the dimensions of the reciprocating motion system of the internal combustion engine.

  In the present embodiment, since the first piston 15 and the fourth piston 15 have the same phase, the connection between the first passage 60A and the first outlet port 55A and the connection between the fourth passage 60D and the fourth outlet port 55D are as follows. Performed at the same timing. Since the second piston 15 and the third piston 15 have the same phase and are 180 degrees out of phase with respect to the first piston 15, the connection between the second passage 60B and the second outlet port 55B and the third passage 60C are provided. The connection of the third outlet port 55C and the connection of the third outlet port 55C are the same timing, and are performed at a timing shifted by 180 ° from the connection of the first passage 60A and the first outlet port 55A.

  In the internal combustion engine 1 according to the first embodiment, since the piston cooling device 40 has the switching valve 42 that opens and closes the oil passage in synchronization with the crankshaft 20, the oil jet 44 supplies the lubricating oil to the piston 15 according to the piston position. It sprays intermittently toward the back side. Therefore, the amount of lubricating oil injected is reduced compared to the case where the oil jet 44 always injects, and the load on the oil pump 35 is reduced. As described above, since the ease with which the lubricant injected from the oil jet 44 enters the cooling channel 16 changes according to the position of the piston 15, the injected lubricant tends to enter the cooling channel 16. Only during the period, the piston 15 can be efficiently cooled by the oil jet 44 injecting the lubricating oil.

  In the internal combustion engine 1 according to the first embodiment, since the oil jet 44 is fixed to the cylinder block 3 that is the internal combustion engine main body 2, the position and the injection direction of the oil jet 44 are always constant. Therefore, by making the injection direction of the oil jet 44 parallel to the reciprocating direction of the piston 15, the lubricating oil injected from the oil jet 44 is always injected toward the opening 16 </ b> B of the cooling channel 16.

  Since the valve body 47 of the switching valve 42 is connected to the crankshaft 20 via the power transmission mechanism 51 and rotates at the same rotational speed as the crankshaft 20, each passage is synchronized with the reciprocating motion of the piston 15 at a predetermined timing. 60 and each outlet port 55 are connected. The period during which each oil jet 44 continues to be injected can be easily set by changing the circumferential length of the opening end of each passage 60 on the outer peripheral surface 47A side (outlet port 55 side). Further, as shown in FIG. 6, the period in which each oil jet 44 continues to inject is also changed by changing the circumferential length of the opening end of the outlet port 55 on the inner peripheral surface 46 </ b> A side (each passage 60 side). It can be set easily.

  In the first embodiment, the form in which the valve case 46 is formed integrally with the upper housing 24 and the lower housing 25 of the secondary balancer device 23 is illustrated. However, in the other embodiments, the valve case 46 may be the lower block 8 or the upper block. It may be directly coupled to the block 7 or may be integrally formed with the lower block 8 or the upper block 7. Further, since the secondary balancer device 23 is not an essential configuration, it may be omitted in other embodiments. Further, the valve body 47 may be coupled to the rotation shaft of the oil pump 35 that rotates in synchronization with the crankshaft 20.

  A partial modification of the configuration of the switching valve 42 according to the first embodiment will be described below. As shown in FIG. 7, the valve body 47 of the switching valve 42 protrudes outward from the valve case 46 in addition to one end where the power transmission mechanism 51 is provided. An unbalanced weight 71 is coupled to the other end of the valve body 47 so as to protrude in the radial direction of the valve body 47. As a result, the center of gravity of the valve body 47 including the unbalanced weight 71 is displaced in the radial direction with respect to the rotational axis of the valve body 47. The position of the center of gravity of the valve body 47 is set so as to cancel the primary inertial force of the piston 15 and the crankshaft 20 and constitutes a primary balancer device. Thus, the switching valve 42 also serves as the primary balancer device.

  When the switching valve 42 also serves as the primary balancer device, the secondary balancer device 23 is omitted, and the valve case 46 is directly coupled to the lower block 8 or the upper block 7, or is integrated with the lower block 8 or the upper block 7. It is good to form. Moreover, the switching valve 42 that also serves as the primary balancer device can be applied to an internal combustion engine having various numbers of cylinders and phase differences between the pistons. The switching valve 42 that also serves as the primary balancer device is suitable, for example, for a three-cylinder in-line internal combustion engine in which each piston has a phase difference of 120 ° between each other.

(Second Embodiment)
In the second embodiment, only the configuration of the switching valve 42 of the internal combustion engine 1 according to the first embodiment is different, and the other configurations are the same. In the second embodiment, the description of the same configuration as that of the internal combustion engine 1 is omitted.

  As shown in FIG. 8, the switching valve 42 has a valve case 46 and a valve body 47 received in the valve case 46. The valve body 47 is formed in a disc shape (cylinder) having a predetermined thickness, and has an outer circumferential surface 47A formed on a circumferential surface centering on the axis, and at both ends in the axial direction so as to be orthogonal to the axis. The first end surface 47B and the second end surface 47C are provided. The valve body 47 is formed such that the length in the axial direction is smaller than the diameter. The valve body 47 is received in the valve case 46 so as to be rotatable about an axis as a rotation axis, and the outer peripheral surface 47A and the first and second end surfaces 47B, 47C are in sliding contact with the inner surface of the valve case 46. A cylindrical shaft 47D protrudes from the center of the first end face 47B. The shaft 47 </ b> D penetrates the valve case 46 and projects outward from the valve case 46. The distal end portion of the shaft 47 </ b> D is connected to the crankshaft 20 through the power transmission mechanism 51.

  One end of the first collecting passage 101 and the second collecting passage 102 is opened on the thrust surface 46B that is in sliding contact with the second end surface 47C of the valve case 46. The first and second collecting passages 101 and 102 extend from the thrust surface 46B in parallel to each other in the valve case 46 in the axial direction of the valve body 47, and the other end is closed. In the present embodiment, the first and second collecting passages 101 and 102 are holes formed directly in the valve case 46. In another embodiment, two pipe members may be inserted into a valve case 46 formed in a bottomed cylindrical shape, and the first and second collecting passages 101 and 102 may be formed by the inner walls of the pipe members.

  The valve case 46 includes an inlet port 54 extending from the outer surface to the inner peripheral surface 46A, first and fourth outlet ports 55A and 55D extending from the outer surface to the first collecting passage 101, and a second extending from the outer surface to the second collecting passage 102. 2 and third outlet ports 55B and 55C are formed. In the axial direction of the valve body 47, the inlet port 54, the first outlet port 55A, the second outlet port 55B, the third outlet port 55C, and the fourth outlet port 55D are spaced from each other in the order shown in the valve case 46. Is formed. Further, on the inner peripheral surface 46A of the valve case 46, a groove portion 56 that extends in the circumferential direction and has an annular shape is formed in a portion where the inlet port 54 is opened. The inlet port 54 is connected to the upstream oil passage 41, the first outlet port 55A is connected to the first downstream oil passage 43A, the second outlet port 55B is connected to the second downstream oil passage 43B, and the third outlet The port 55C is connected to the third downstream oil passage 43C, and the fourth outlet port 55D is connected to the fourth downstream oil passage 43D.

  A connection passage 58 is formed in the valve body 47. In the connection passage 58, a first end 58A as one end opens to the outer peripheral surface 47A, and a second end 58B as the other end opens to the second end surface 47C. The first end 58 </ b> A of the connection passage 58 is formed at a position that always faces the groove 56 regardless of the rotational position of the valve body 47. The second end 58B of the connection passage 58 is connected to the first collecting passage 101 when the valve body 47 is in a predetermined first rotation range, and is connected to the second set 58 when the valve body 47 is in a predetermined second rotation range. It is formed so as to be connected to the passage 102. The first rotation range is set based on the position of the first piston 15, and is set in a range in which the lubricating oil injected from the oil jet 44 can easily enter the cooling channel 16 of the first piston 15. Similarly, the second rotation range is set based on the position of the second piston 15, and is set in a range in which the lubricating oil injected from the oil jet 44 can easily enter the cooling channel 16 of the second piston 15. The method for setting the first and second rotation ranges is the same as that in the first embodiment. The connection period between the second end 58B of the connecting passage 58 and the first and second collecting passages 101 and 102 is changed by the circumferential length of the first and second collecting passages 101 and 102 around the axis of the valve body 47. Can be done by changing. In another embodiment, in order to change the connection period of the first and second collecting passages 101 and 102, the circumferential length of the second end 58B of the connection passage 58 around the axis of the valve body 47 is set. It may be changed.

  In the switching valve 42 according to the second embodiment, the first to fourth outlet ports 55A to 55D do not need to correspond to the outer peripheral surface 47A of the valve body 47, as compared with the switching valve 42 according to the first embodiment. The length of the valve body 47 in the axial direction can be shortened, the valve body 47 can be reduced in size and weight, and the sliding contact area between the valve body 47 and the valve case 46 is reduced. Thereby, the power required for rotating the valve body 47 is reduced, and the fuel efficiency of the internal combustion engine 1 is improved.

  In the second embodiment, the first and fourth pistons 15A, 15D are arranged in the same phase, and the second and third pistons 15B, 15C are arranged in the same phase. Therefore, the first and fourth outlet ports 55A, The upstream side of 55D can be used as the first collecting passage 101, and the upstream side of the second and third outlet ports 55B and 55C can be used as the second collecting passage 102.

  As a modification of the second embodiment, FIG. 9 and FIG. 10 show examples of collective passages of the switching valve 42 corresponding to an in-line three-cylinder internal combustion engine having a piston phase interval of 120 ° and a single-cylinder internal combustion engine. . 9 and 10 are views corresponding to FIG. 8C and show a cross section of the valve case 46. As shown in FIG. 9, in the in-line three-cylinder internal combustion engine having piston phases of 120 ° intervals, the first to third outlet ports 55A to 55C may be directly opened on the thrust surface 46B that is in sliding contact with the second end surface 47C. As shown in FIG. 10, in the single cylinder internal combustion engine, the first outlet port 55A may be directly opened on the thrust surface 46B that is in sliding contact with the second end surface 47C. In the case of an in-line two-cylinder internal combustion engine with piston phases of 180 ° intervals, a switching valve 42 shown in FIG. 8 can be used.

(Third embodiment)
The internal combustion engine 200 according to the third embodiment is different in the configuration of the switching valve 42 from the internal combustion engine 1 according to the first embodiment. In the first embodiment, the switching valve 42 is disposed between the upstream oil passage 41 and the downstream oil passage 43, whereas in the third embodiment, the switching valve 42 is provided with an upstream oil passage. It is provided in each downstream oil passage 43 after branching from the passage 41. The other configuration of the third embodiment is the same as that of the first embodiment, and the description of the same configuration is omitted.

  As shown in FIGS. 11 and 12, the crankshaft 20 has first to fourth crank throws 201 (201 </ b> A to 201 </ b> D) corresponding to the first to fourth pistons 15 </ b> A to 15 </ b> D, and both sides of each crank throw 201. The first to fifth crank journals 202 (202 </ b> A to 202 </ b> E) that are provided and form the rotation axis of the crankshaft 20. Each crank throw 201 includes a pair of crank webs 203 (203 </ b> A to 203 </ b> D) projecting in the same direction in the radial direction from opposite ends of adjacent crank journals 202, and a crank spanned between the pair of crank webs 203. Pins 204 (204A to 204D). Each crank pin 204 is connected to the piston 15 via a connecting rod 18.

  The upper block 7 includes first to fifth bearing walls 206 (206A to 206E) that divide the crankcase 12 so as to correspond to the cylinders 11. An upper bearing portion 207 (207A to 207E) having a halved circumferential surface is formed on the lower end surface of each bearing wall 206. The lower block 8 includes bearing caps 208 (208 </ b> A to 208 </ b> E) that are coupled to the lower end surfaces of the respective bearing walls 206, and the lower bearing portions 209 that form a halved circumferential surface on the upper end surface of each bearing cap 208. (209A to 209E) are formed. The upper bearing portion 207 and the lower bearing portion 209 cooperate to form a hole having a circular cross section, and receive a cylindrical slide bearing 211 (211A to 211E) (metal bearing). Each of the sliding bearings 211 is formed in a half shape, and is mounted on the upper bearing portion 207 and the lower bearing portion 209 so as not to rotate. The first to fifth crank journals 202 are rotatably supported by the corresponding numbered plain bearings 211.

  In the third embodiment, the switching valve 42 is formed by the crank journal 202 and the sliding bearing 211. The upstream oil passage 41 extends from the main gallery 32 and is connected to the first to third downstream oil passages 43 </ b> A to 43 </ b> C in the upper block 7. The upstream oil passage 41 may be configured as a part of the main gallery 32. In this case, each downstream oil passage 43 is configured to extend from the main gallery 32.

  The first downstream oil passage 43A extends from the upstream oil passage 41 toward the first sliding bearing 211A in the first bearing wall 206A and penetrates the first sliding bearing 211A in the radial direction to the first sliding bearing 211A. A first upstream portion 213A that opens to the inner peripheral surface of the first sliding bearing 211A, an opening that opens to the inner peripheral surface of the first sliding bearing 211A, and penetrates the first sliding bearing 211A in the radial direction, and the first bearing cap 208A and the first bearing wall The interior of 206A has a first downstream portion 214A that extends toward the first oil jet 44A and is connected to the first oil jet 44A.

  The second downstream oil passage 43B extends from the upstream oil passage 41 toward the third sliding bearing 211C in the third bearing wall 206C, and penetrates the third sliding bearing 211C in the radial direction to pass through the third sliding bearing 211C. The second upstream portion 213B that opens to the inner peripheral surface of the first sliding portion 211C and the third sliding bearing 211C that opens to the inner peripheral surface and radially penetrates the third sliding bearing 211C, and the third bearing cap 208C and the third bearing wall The interior of 206C has a second downstream portion 214B that branches and extends toward the second and third oil jets 44B and 44C and is connected to the second and third oil jets 44B and 44C.

  The third downstream oil passage 43C extends from the upstream oil passage 41 toward the fifth sliding bearing 211E inside the fifth bearing wall 206E and penetrates the fifth sliding bearing 211E in the radial direction to pass through the fifth sliding bearing 211E. A third upstream portion 213C that opens to the inner peripheral surface of the first bearing portion, and an inner peripheral surface of the fifth sliding bearing 211E that passes through the fifth sliding bearing 211E in the radial direction, and includes a fifth bearing cap 208E and a fifth bearing wall. The interior of 206E extends toward the fourth oil jet 44D, and has a third downstream portion 214C connected to the fourth oil jet 44D.

  On the inner peripheral surface of each sliding bearing 211, the opening ends of the respective upstream portions 213A, 213B, and 213C and the opening ends of the respective downstream portions 214A, 214B, and 214C are arranged offset from each other in the axial direction of each sliding bearing 211. ing.

  A first connection passage 215A is formed in the first crank journal 202A, a second connection passage 215B is formed in the third crank journal 202C, and a third connection passage 215C is formed in the fifth crank journal 202E. Each connection passage 215 has one end and the other end opened to the outer peripheral surface of each crank journal 202. One end and the other end of each connection passage 215 are offset from each other in the axial direction of each crank journal 202. When the crankshaft 20 is in the first rotation range, the first connection passage 215A connects the first upstream portion 213A and the first downstream portion 214A opened to the inner surface of the first slide bearing 211A, and the third connection passage 215C. Connects the third upstream portion 213C and the third downstream portion 214C that are open to the inner surface of the fifth sliding bearing 211E. Further, when the crankshaft 20 is in the second rotation range, the second connection passage 215B connects the second upstream portion 213B and the second downstream portion 214B that open to the inner surface of the third sliding bearing 211C. The length of the connection period of the corresponding upstream portion 213 and downstream portion 214 by each connection passage 215 can be adjusted by changing the circumferential length of the opening end. In another embodiment, the length of the connection period of the corresponding upstream portion 213 and downstream portion 214 by each connection passage 215 is equal to the upstream end 213 and the downstream end 214 of the open end of each sliding bearing 211. You may adjust with the circumferential direction length.

  Oil passages 220 extending from the main gallery 32 toward the second and fourth sliding bearings 211B and 211D and passing through the sliding bearings 211 in the radial direction are formed inside the second and fourth bearing walls 206B and 206D. Yes. The oil passage 220 supplies lubricating oil to the sliding contact portion between the second sliding bearing 211B and the second crank journal 202B and the sliding contact portion between the fourth sliding bearing 211D and the fourth crank journal 202D. The crankshaft 20 includes a first shaft oil passage 221 extending from the outer peripheral surface of the second crank journal 202B to the outer peripheral surfaces of the first and second crank pins 204A and 204B, and a third from the outer peripheral surface of the fourth crank journal 202D. And a second in-shaft oil passage 222 extending to the outer peripheral surface of the fourth crank pins 204C, 204D. The sliding contact portion between the first sliding bearing 211A and the first crank journal 202A is lubricated by the lubricating oil supplied from the first upstream portion 213A, and the sliding contact portion between the fifth sliding bearing 211E and the fifth crank journal 202E is the first. 3 Lubricated with lubricating oil supplied from the upstream portion 213C.

  In the internal combustion engine 200 according to the third embodiment, since the switching valve 42 is configured by the crankshaft 20 and the slide bearing 211 that rotatably supports the crankshaft 20, the valve case 46 as in the first and second embodiments. And it is not necessary to provide the valve body 47 separately, and the internal combustion engine 200 can be reduced in size.

(Fourth embodiment)
An internal combustion engine 300 according to the fourth embodiment is an example in which the internal combustion engine 200 according to the third embodiment is changed to an in-line three cylinder. In the following description, the same configuration as that of the internal combustion engine 200 is denoted by the same reference numeral, and the description thereof is omitted.

  In the internal combustion engine 300, the phase difference between the pistons 15 is set to be 120 °. As shown in FIGS. 13 to 15, the crankshaft 20 includes first to third crank throws 201 </ b> A to 201 </ b> C and first to fourth crank journals 202 </ b> A to 202 </ b> D. The upper block 7 and the lower block 8 have first to fourth bearing walls 206A to 206D and first to fourth bearing caps 208A to 208D corresponding to the first to fourth crank journals 202A to 202D. Between the first to fourth bearing walls 206A to 206D and the first to fourth bearing caps 208A to 208D and the first to fourth crank journals 202A to 202D, the first to fourth sliding bearings 211A to 211D are provided. It is intervened.

  The second and fourth bearing walls 206B and 206D are formed with oil passages 220 extending from the main gallery 32 toward the second and fourth sliding bearings 211B and 211D and penetrating the sliding bearings 211 in the radial direction. . The oil passage 220 supplies lubricating oil to the sliding contact portion between the second sliding bearing 211B and the second crank journal 202B and the sliding contact portion between the fourth sliding bearing 211D and the fourth crank journal 202D. The crankshaft 20 includes a first shaft oil passage 221 extending from the outer peripheral surface of the second crank journal 202B to the outer peripheral surfaces of the first and second crank pins 204A and 204B, and a third from the outer peripheral surface of the fourth crank journal 202D. A second shaft oil passage 222 extending to the outer peripheral surface of the crank pin 204C is formed.

  The upstream oil passage 41 extends from the main gallery 32 and is connected to the first and second downstream oil passages 43 </ b> A and 43 </ b> B in the upper block 7. The first downstream oil passage 43A extends from the upstream oil passage 41 toward the first sliding bearing 211A inside the first bearing wall 206A and penetrates the first sliding bearing 211A in the radial direction to form the first sliding bearing 211A. The first upstream portion 213A that opens to the inner circumferential surface of the first sliding bearing 211A, the first sliding bearing 211A that opens to the inner circumferential surface, penetrates the first sliding bearing 211A in the radial direction, and the interior of the first bearing wall 206A is the first. The first downstream portion 214A extends toward the oil jet 44A and is connected to the first oil jet 44A. In the first sliding bearing 211A, the opening ends of the first upstream portion 213A and the first downstream portion 214A are arranged on the same circumference.

  The second downstream oil passage 43B extends from the upstream oil passage 41 toward the third sliding bearing 211C in the third bearing wall 206C, and penetrates the third sliding bearing 211C in the radial direction to pass through the third sliding bearing 211C. The second upstream portion 213B that opens to the inner circumferential surface of the first sliding portion 211C and the third sliding bearing 211C that opens to the inner circumferential surface of the third sliding bearing 211C in the radial direction and passes through the third bearing wall 206C in the second direction. The first branch downstream portion 217A that extends toward the oil jet 44B and is connected to the second oil jet 44B and opens to the inner peripheral surface of the third slide bearing 211C, and penetrates the third slide bearing 211C in the radial direction. The second bearing wall 206C has a second branch downstream portion 217B extending toward the third oil jet 44C and connected to the third oil jet 44C. In the third plain bearing 211C, the opening ends of the second upstream portion 213B, the first branch downstream portion 217A, and the second branch downstream portion 217B are arranged on the same circumference, and the first branch downstream portion 217A and A second upstream portion 213B is disposed between the second branch downstream portions 217B.

  A first connection passage 215A is formed in the first crank journal 202A, and a second connection passage 215B is formed in the third crank journal 202C. Each connection passage 215 is formed as a groove recessed in the outer peripheral surface of each crank journal 202. Each connection passage 215 extends in the circumferential direction of each crank journal 202.

  When the crankshaft 20 is in the first rotation range, the first connection passage 215A connects the first upstream portion 213A and the first downstream portion 214A that open to the inner surface of the first sliding bearing 211A. In addition, when the crankshaft 20 is in the second rotation range, the second connection passage 215B connects the second upstream portion 213B and the first branch downstream portion 217A that open to the inner surface of the third sliding bearing 211C. In addition, when the crankshaft 20 is in the third rotation range, the second connection passage 215B connects the second upstream portion 213B and the second branch downstream portion 217B that open to the inner surface of the third sliding bearing 211C. The second connection passage 215B is set to a length that cannot connect the first branch downstream portion 217A and the second branch downstream portion 217B.

  In the fourth embodiment, since the connection passage 215 is a groove formed on the outer surface of the crank journal 202, processing is easy. Further, since the first downstream portion 214A, the first branch downstream portion 217A, and the second branch downstream portion 217B do not pass through the bearing cap 208, the structure of the bearing cap 208 is simplified. Further, since the second connection passage 215B connects the second upstream portion 213B and the second branch downstream portion 217B or the second branch downstream portion 217B, the switching valve 42 can be reduced in size.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, the number of cylinders of the internal combustion engine and the phase of each piston 15 can be arbitrarily selected.

1 ... Internal combustion engine, 2 ... Internal combustion engine body, 3 ... Cylinder block, 4 ... Oil pan, 5 ... Cylinder head, 7 ... Upper block, 8 ... Lower block, DESCRIPTION OF SYMBOLS 11 ... Cylinder, 15 ... Piston, 16 ... Cooling channel, 16A ... Annular part, 16B ... Opening part, 20 ... Crankshaft, 23 ... Secondary balancer apparatus, 24 ... Upper housing, 25 ... Lower housing, 30 ... Lubrication system, 32 ... Main gallery, 35 ... Oil pump, 40 ... Piston cooling device, 41 ... Upstream oil passage , 42 ... Switching valve, 43 ... Downstream oil passage, 44 ... Oil jet, 46 ... Valve case, 46A ... Inner peripheral surface, 46B ... Thrust surface, 47 ... Valve body, 47A ... outer peripheral surface, 47B ... first end face, 47C ... second end face, 51 ... power transmission mechanism, 54 ... inlet port, 55 ... outlet port, 56. .. Groove, 8 ... Connection passage, 58A ... First end, 58B ... Second end, 59 ... Main passage, 60 ... Passage, 101 ... First collective passage, 102 ... First 2 collecting passages, 200 ... internal combustion engine, 202 ... crank journal, 206 ... bearing wall, 208 ... bearing cap, 211 ... slide bearing, 213 ... upstream part, 214 ... Downstream part, 215 ... Connection passage

Claims (11)

An internal combustion engine body formed with at least one cylinder;
At least one piston housed in each of the cylinders in a reciprocable manner and connected to a crankshaft via a connecting rod;
At least one oil jet attached to the internal combustion engine body corresponding to each of the pistons and injecting lubricating oil toward the back surface of the corresponding piston;
An oil passage extending from an oil pump to each of the oil jets;
A switching valve provided in the oil passage, for switching between communication and disconnection between the oil pump and the oil jet;
The switching valve is driven by receiving power from the crankshaft, and connects the oil jet corresponding to the arbitrary piston to the oil pump when the arbitrary piston is located in a predetermined movement range. An internal combustion engine. The switching valve includes a valve case and a valve body that is rotatably received by the valve case and rotates at the same speed as the crankshaft by being connected to the crankshaft via a power transmission mechanism.
The valve case communicates with an inner peripheral surface that is in sliding contact with the outer peripheral surface of the valve body, with an upstream side of the oil passage and with an inlet port that is open to the inner peripheral surface, and with a downstream side of the oil passage. And at least one outlet port opened in the inner peripheral surface,
The valve body has a connection passage opened in the outer peripheral surface,
2. The internal combustion engine according to claim 1, wherein the connection passage connects the outlet port corresponding to the arbitrary piston to the inlet port when the arbitrary piston is located in a predetermined movement range. The valve body is formed in a cylindrical shape,
At least one of the outlet ports opens to the inner peripheral surface of the valve case,
The internal combustion engine according to claim 2, wherein an opening end of the outlet port on the inner peripheral surface side extends in a circumferential direction. The valve body is formed in a cylindrical shape,
At least one of the outlet ports opens to the inner peripheral surface of the valve case,
The internal combustion engine according to claim 2 or 3, wherein an opening end of the connection passage facing the outlet port extends in a circumferential direction.   The internal combustion engine according to any one of claims 2 to 4, wherein the valve body has a center of gravity that is deviated with respect to a rotation axis of the valve body. The valve body is formed in a cylindrical shape,
At least one of the outlet ports has an opening in a thrust surface that is in sliding contact with an axial end surface of the valve body of the valve case, and the connection passage has an opening in the thrust surface corresponding to the outlet port. The internal combustion engine according to claim 2, wherein the engine is an internal combustion engine.   A plurality of the pistons are provided, and the outlet port corresponding to the piston that reciprocates in the same phase forms a common collecting passage by gathering portions that open to the thrust surface. Item 7. The internal combustion engine according to Item 6. The switching valve includes a journal of the crankshaft, and a bearing that rotatably supports the journal,
The upstream side and the downstream side of the oil passage open to the inner peripheral surface of the bearing independently of each other,
The journal has a connection passage opened in the outer peripheral surface of the journal,
2. The connection passage according to claim 1, wherein the upstream side and the downstream side of the oil passage corresponding to the arbitrary piston are connected to each other when the arbitrary piston is located in a predetermined movement range. Internal combustion engine.   The internal combustion engine according to claim 8, wherein an opening end of the connection passage facing the downstream side of the oil passage extends in the circumferential direction.   The internal combustion engine according to claim 8 or 9, wherein the connection passage is a groove extending in a circumferential direction on an outer peripheral surface of the journal. The piston has a cooling channel formed inside the piston, a part of which is open on the back surface of the piston,
11. The internal combustion engine according to claim 1, wherein an injection port of the oil jet is disposed to face an opening of the cooling channel in a reciprocating direction of the piston. organ.

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