JP6275516B2 - Oil injection device for piston cooling of internal combustion engine - Google Patents

Description

  The present invention relates to an oil injection device for cooling a piston in an internal combustion engine.

  During high-speed operation or high-load operation, the piston top is heated abnormally and thermally expands, resulting in an increase in frictional force between the cylinder inner peripheral surface and the piston top outer periphery. In order to avoid this phenomenon, there has been a piston cooling oil injection device that injects oil toward the inner surface of the piston top and cools the piston top with this injection oil (see Patent Document 1).

Japanese Patent Laid-Open No. 08-068322

  In the invention described in Patent Document 1, in a single-cylinder internal combustion engine 1 (hereinafter referred to as the reference described in the publication) mounted on a motorcycle or the like, it is orthogonal to a crankshaft 16 oriented in the vehicle width direction. In addition, the crankcase 2 is divided into a thick portion 36 of the right crankcase and a pressing portion 37 of the left crankcase on a plane passing through the cylinder hole center line.

  A cylindrical recess 38 is formed in the thick part 36 of the right crankcase from its end surface toward the back of the thick part 36, and the cylindrical nozzle base 42 of the injection nozzle 41 is provided with a right crankcase thickness. The injection nozzle 41 is fitted into the recess 38 of the portion 36, and the left crankcase pressing portion 37 is brought into contact with the outer end surface of the cylindrical nozzle base 42, so that the injection nozzle 41 has the right crankcase thick portion 36. It comes to be attached to.

  Thus, since the injection nozzle 41 is inserted and mounted in the recess 38 formed on the end face of the crankcase 2, it is restricted to be disposed at the end face position of the crankcase 2, and the inside of the crankcase 2 is also limited. The crankshaft 16 and the transmission 24 are arranged in the layout, and in order to circulate the oil passage to the injection nozzle 21 and arrange the injection nozzle 21 at a predetermined position to inject oil in a desired direction, a layout is used. The above restrictions were great.

  Further, since the cylindrical nozzle base 42 fitted in the recess 38 of the right crankcase thick part 36 is pushed by the left crankcase pressing part 37 thinner than the right crankcase thick part 36, The injection nozzle 41 having a large moment of inertia inclined obliquely upward reciprocally swings in the hour hand direction and the counter hour hand direction around the center line of the oil supply passage 39 due to vertical vibration of the internal combustion engine, and the O-ring 46 is worn. There is a problem that oil leakage is likely to occur.

  In this case, the left crankcase pressing portion 37 is thinner than the right crankcase thick portion 36, and the left crankcase pressing portion 37 cannot contact the right crankcase thick portion 36 over the entire surface. Therefore, there is a drawback that oil leakage cannot be prevented as a result that the recess 38 cannot be liquid-tightly sealed with an O-ring or packing between both end faces of the right crankcase thick part 36.

  Furthermore, if the left crankcase pressing portion 37 is made thicker in order to improve this drawback, there arises a problem in that the weight of the entire crankcase 2 and the manufacturing cost increase.

  The present invention relates to an improvement in an oil injection device for cooling a piston of an internal combustion engine that has overcome such difficulties, and reduces the restrictions on the layout of the oil injection device and the oil supply oil passage to the oil injection device, and has a simple structure. An object of the present invention is to provide a piston cooling oil injection device that can cool the piston and prevents oil leakage and is lightweight and inexpensive.

The invention according to claim 1 is a piston cooling oil injection device that cools the top inner surface of the piston by injecting oil into the top inner surface of the piston of the internal combustion engine from an oil injection port at the tip of the oil jet pipe. The oil jet pipe includes a pipe oil supply port opened on an outer peripheral surface of a base portion of the oil jet pipe, an oil injection port opened on a front end surface of the oil jet pipe, and the pipe oil supply port inside the oil jet pipe. And an oil passage in the pipe that communicates with the oil injection port, and a jet pipe that penetrates the crankcase from the outer peripheral surface to the inner peripheral surface of the internal combustion engine. An insertion hole and an oil supply path that opens to the inner peripheral surface of the jet pipe insertion hole and is connected to an oil supply source are formed. The oil jet pipe maintains the direction in which the oil injection direction injected from the oil injection port is directed to the top inner surface of the piston at a position where the pipe oil supply port and the oil supply path of the crankcase communicate with each other. As described above, the positioning member mounted on the crankcase 11a is integrally fixed to the crankcase. The base of the oil jet pipe has an enlarged diameter portion at a distance in the longitudinal direction of the oil jet pipe. A plurality of tip end portions having a diameter smaller than the diameter-expanded portion of the oil jet pipe are formed in the jet pipe insertion hole at the back side in the oil jet pipe insertion direction, and the pipe oil supply port of the oil jet pipe is formed. Are opened at least one in a portion sandwiched between the plurality of enlarged diameter portions, and the pipe filler opening is opened. A space between the outer peripheral surface of the oil jet pipe and the inner peripheral surface of the jet pipe insertion hole of the crankcase is defined by the oil supply path of the crankcase, the oil jet The oil jet pipe is composed of a straight pipe, and the tip of the oil jet pipe is formed with a smaller diameter than the tip of the jet pipe insertion hole. The diameter portion has a bowl-like shape, and the oil jet pipe is centered and positioned in the jet pipe insertion hole and seals between the outer surface of the jet pipe and the jet pipe insertion hole. Is an oil injection device for cooling a piston.

According to a second aspect of the present invention, the cross-sectional shape of the base end of the oil jet pipe is formed in a deformed shape different from a circle, and the fitting of the positioning member that fits into the base end of the deformed shape of the oil jet pipe The joint is formed in the same shape as the cross-sectional shape of the base end of the oil jet pipe, and the positioning member is fitted to the crankcase in a state where the fitting port of the positioning member is fitted to the base end of the oil jet pipe. The oil injection device for cooling a piston according to claim 1, wherein are integrally coupled .

According to a third aspect of the present invention, the jet pipe insertion hole is provided on the side where the chain tensioner is disposed, at a position covered by a crankcase cover outside the crankcase, and is integrally attached to the crankcase. 3. The piston cooling oil injection device according to claim 2 , wherein the positioning member is located farther from the cylinder sleeve end of the cylinder block and is positioned inward in the width direction than the chain tensioner . 4.

According to a fourth aspect of the present invention, there is provided the piston cooling oil injection device for cooling the top inner surface of the piston by injecting oil into the top inner surface of the piston of the internal combustion engine from the oil injection port at the tip of the oil jet pipe. The oil jet pipe includes a pipe oil supply port opened on an outer peripheral surface of a base portion of the oil jet pipe, an oil injection port opened on a front end surface of the oil jet pipe, and the pipe oil supply port inside the oil jet pipe. And an oil passage in the pipe that communicates with the oil injection port, and a jet pipe that penetrates the crankcase from the outer peripheral surface to the inner peripheral surface of the internal combustion engine. An insertion hole and an oil supply path that opens to the inner peripheral surface of the jet pipe insertion hole and is connected to an oil supply source are formed. The oil jet pipe maintains the direction in which the oil injection direction injected from the oil injection port is directed to the top inner surface of the piston at a position where the pipe oil supply port and the oil supply path of the crankcase communicate with each other. Thus, the jet pipe insertion hole is fixed to the crank case cover on the outer side of the crank case on the side where the chain tensioner is arranged. The piston cooling unit provided at a position to be covered and mounted integrally with the crankcase is spaced apart from a cylinder sleeve end of a cylinder block and is positioned inward in the width direction with respect to the chain tensioner. Oil injection device.

According to a fifth aspect of the present invention, a plurality of enlarged-diameter portions are formed at a base portion of the oil jet pipe in the longitudinal direction of the oil jet pipe with a space therebetween in the longitudinal direction of the oil jet pipe. 5. The piston cooling oil injection device according to claim 4, wherein a tip end portion having a smaller diameter than the enlarged diameter portion of the oil jet pipe is formed on the back side in the insertion direction of the jet pipe .

  According to the oil injection device for cooling a piston according to claim 1, the oil jet pipe includes a pipe oil supply port opened on an outer peripheral surface of a base portion of the oil jet pipe, and an oil injection port opened on a front end surface of the oil jet pipe. And an oil passage in the pipe communicating with the pipe oil supply port and the oil injection port inside the oil jet pipe, and the crankcase of the internal combustion engine extends from the outer peripheral surface of the crankcase to the inner peripheral surface. A jet pipe insertion hole penetrating through the crankcase and an oil supply path that opens to an inner peripheral surface of the jet pipe insertion hole and is connected to an oil supply source are formed. The direction in which the oil injection direction from the oil injection port is directed to the inner surface of the top of the piston at a position where the opening and the oil supply passage of the crankcase communicate with each other As a result, the positioning member mounted on the crankcase is integrally fixed to the crankcase so that the oil injection device and the layout of the oil supply oil passage to the oil injection device are reduced, and the structure is simple. It becomes possible to cool the piston.

  Also, the oil sent from the oil supply source flows in the oil supply passage and passes through the pipe feed hole on the outer peripheral surface of the base of the oil jet pipe from the inner peripheral surface opening of the jet pipe insertion hole to the inside of the pipe in the oil jet pipe. The oil that flows into the oil passage and the oil that flows into the oil passage in the pipe is jetted from the oil injection port at the tip of the oil jet pipe toward the piston top inner surface, and the piston top inner surface is cooled by the injection oil. In the oil circuit that reaches the oil injection port from the oil supply source, there is no oil leaking part that causes oil leakage, so the oil that has reached the oil injection port at the tip of the oil jet pipe from the oil supply source is placed on the inner surface of the piston top. Reaching reliably, the piston top is effectively cooled.

In addition, the oil jet pipe is formed outside the crankcase where the structure is constrained, the outer part of the crankcase can be easily machined and drilled by processing the required parts of the oil jet pipe that are easy to process. By attaching the pipe, the piston cooling oil injection device can be obtained efficiently and reliably, and the oil jet pipe can be attached by a positioning member having a simple shape, so that the width of the base portion of the internal combustion engine can be reduced. Furthermore, a plurality of enlarged diameter portions are formed at intervals in the longitudinal direction of the oil jet pipe at the base portion of the oil jet pipe, and a plurality of enlarged diameter portions of the oil jet pipe are formed in the jet pipe insertion hole. A large-diameter portion that can be fitted and a small-diameter portion that is thinner than the base enlarged-diameter portion are formed, and a plurality of enlarged-diameter portions of the oil jet pipe are fitted into the large-diameter portion of the insertion hole of the jet pipe. The jet pipe is fixed in the vertical and horizontal directions without causing shaft runout, and the tip surface of the enlarged diameter portion of the oil jet pipe is in contact with the step surface of the large diameter portion and the small diameter portion of the jet pipe. As a result of firmly positioning the location where the oil injected from the pipe reaches the piston top inner surface, the oil can reach the portion of the piston top inner surface that needs to be cooled. It is.
A space between the outer peripheral surface of the oil jet pipe and the inner peripheral surface of the jet pipe insertion hole of the crankcase is sandwiched between the plurality of enlarged diameter portions, and the oil supply path of the crankcase and the pipe of the oil jet pipe Since it communicates with the oil passage, the oil can smoothly flow into the oil passage in the oil jet pipe from the oil supply passage of the crankcase.

According to the oil injection device for cooling a piston according to claim 2, the cross section shape of the base end of the oil jet pipe and the fitting port of the positioning member are both different from the circular shape and formed in the same shape. Since the positioning member is integrally coupled to the crankcase with the positioning member fitting port being fitted to the base end, the jet oil injected from the oil jet injection port at the tip of the oil jet pipe is required. Without deviating from the injection direction, it is possible to reach the required position on the inner surface of the piston top surface, and the piston top surface is cooled.

According to the piston cooling oil injection device of the third aspect , the jet pipe insertion hole is provided at the position where the chain tensioner is disposed and at the position covered by the crank case cover outside the crank case. In addition, the positioning member that is integrally mounted on the crankcase is located farther away from the cylinder sleeve of the cylinder block and on the inner side in the width direction than the chain tensioner, so the small dead space between the chain tensioner and the crankcase side wall is utilized. Thus, the piston cooling oil injection device can be arranged, the width around the crankcase of the internal combustion engine is shortened, and the internal combustion engine can be downsized.

According to the oil injection device for cooling a piston according to claim 4, the oil jet pipe includes a pipe oil supply port opened on an outer peripheral surface of a base portion of the oil jet pipe and an oil injection port opened on a front end surface of the oil jet pipe. And an oil passage in the pipe communicating with the pipe oil supply port and the oil injection port inside the oil jet pipe, and the crankcase of the internal combustion engine extends from the outer peripheral surface of the crankcase to the inner peripheral surface. A jet pipe insertion hole penetrating through the crankcase and an oil supply path that opens to an inner peripheral surface of the jet pipe insertion hole and is connected to an oil supply source are formed. The direction in which the oil injection direction from the oil injection port is directed to the inner surface of the top of the piston at a position where the opening and the oil supply passage of the crankcase communicate with each other As a result, the positioning member mounted on the crankcase is integrally fixed to the crankcase so that the oil injection device and the layout of the oil supply oil passage to the oil injection device are reduced, and the structure is simple. It becomes possible to cool the piston.
Also, the oil sent from the oil supply source flows in the oil supply path and passes through the pipe oil supply port on the base outer peripheral surface of the oil jet pipe from the inner peripheral surface opening of the jet pipe insertion hole to The oil that flows into the oil passage and the oil that flows into the oil passage in the pipe is jetted from the oil injection port at the tip of the oil jet pipe toward the piston top inner surface, and the piston top inner surface is cooled by the injection oil. In the oil circuit that reaches the oil injection port from the oil supply source, there is no oil leaking part that causes oil leakage, so the oil that has reached the oil injection port at the tip of the oil jet pipe from the oil supply source is placed on the inner surface of the piston top. Reaching reliably, the piston top is effectively cooled.
In addition, the oil jet pipe is formed outside the crankcase where the structure is constrained, the outer part of the crankcase can be easily machined and drilled by processing the required parts of the oil jet pipe that are easy to process. By attaching the pipe, the piston cooling oil injection device can be obtained efficiently and reliably, and the oil jet pipe can be attached by a positioning member having a simple shape, so that the width of the base portion of the internal combustion engine can be reduced.
Furthermore, on the side where the chain tensioner is arranged, a jet pipe insertion hole is provided at a position covered by the crankcase cover outside the crankcase outside the crankcase, and further positioned integrally with the crankcase. Since the member is located farther away from the cylinder sleeve of the cylinder block and inside the chain tensioner, the piston cooling oil injection device can be arranged by utilizing a small dead space between the chain tensioner and the crankcase side wall. The width around the crankcase of the internal combustion engine is shortened, and the internal combustion engine can be downsized.

According to the oil injection device for cooling a piston according to claim 5 , a plurality of enlarged diameter portions are formed at intervals in the longitudinal direction of the oil jet pipe at the base portion of the oil jet pipe. A large-diameter portion into which a plurality of base-diameter enlarged portions of the oil jet pipe can be fitted and a small-diameter portion thinner than the base-diameter enlarged portion; Since the oil jet pipe is fitted in the large diameter part, the oil jet pipe is fixed in the vertical and horizontal directions without causing shaft runout, and the end face of the enlarged part of the oil jet pipe is the large diameter part and the small diameter part of the jet pipe. As a result, the location where oil injected from the oil jet pipe reaches the inner surface of the piston top is firmly positioned. As a result, cooling of the inner surface of the piston top is required. And reach the oil to the portion, part thereof is cooled.

1 is a left side view illustrating an internal combustion engine supported by a body frame of an off-road vehicle according to an embodiment of the present invention and a peripheral portion of the internal combustion engine. FIG. 2 is a left side view illustrating a left crankcase and a cylinder block with the left crankcase cover removed in the internal combustion engine illustrated in FIG. 1. It is a crankcase crossing plane of the state which attached the oil jet pipe to the left crankcase. FIG. 4 is a left side view of the crankcase in the state illustrated in FIG. 3. It is a longitudinal cross-sectional view of an oil jet pipe.

  Hereinafter, an embodiment for carrying out the present invention illustrated in FIGS. 1 to 5 will be described.

  In the description and claims of the present specification, the front-rear, top-bottom, and left-right orientations are in accordance with a normal standard in which the straight traveling direction of the motorcycle 1 that is an off-road vehicle for rough terrain travel according to this embodiment is the front. .

  As shown in FIG. 1, in the body frame 2 of the motorcycle 1 that is an off-road vehicle for running on rough terrain, as shown in FIG. 1, the main frame 4 extends rearward and obliquely downward from the head pipe 3. At the same time, the down frame 5 extends further downward from the main frame 4 from the head pipe 3, and the lower end of the center frame 6 extending downward from the rear end of the main frame 4 and the lower end of the down frame 5 are connected by the connecting frame 7. Has been.

  The upper part of the down frame 5 and the rear part of the main frame 4 are connected by a reinforcing frame 8 to reinforce the vehicle body frame 2.

  The internal combustion engine 10 is a water-cooled single-cylinder four-scroll cycle internal combustion engine, and a cylinder block 12, a cylinder head 13, and a cylinder head cover 14 are superimposed on a pair of left and right left and right crankcases 11 divided into left and right parts. A front bolt 16a and a rear bolt 16b that pass through the front bolt insertion hole 15a and the rear bolt insertion hole 15b of the cylinder head cover 14, the cylinder head 13, and the cylinder block 12 and are screwed to the left and right crankcases 11 (FIG. 3, FIG. 4), the left and right crankcase 11, the cylinder block 12, the cylinder head 13, and the cylinder head cover 14 are integrally connected to each other to assemble the internal combustion engine. A crankcase cover (not shown) is detachably attached to the cover attachment edge 11c.

  As shown in FIG. 1, the left and right crankcases 11 of the internal combustion engine 10 shown in FIG. 3 protrude to the lower part of the down frame 5 and the lowermost part of the connecting frame 7. The support bracket 21 is attached to and supported by the support bolt 20a and the support bolt 21a, and the rear portion of the cylinder head 13 is attached to the support bracket 22 projecting from the upper end of the center frame 6 by the support bolt 22a. It is supported by the body frame 2 at three places.

  As shown in FIG. 4, a piston 17 is slidably fitted in the cylinder sleeve 12 a, and the piston 17 and the crankshaft 23 are connected by a connecting rod 18. A combustion chamber (not shown) is formed in the cylinder head 13, and the combustion energy in the combustion chamber of the internal combustion engine E10 is converted into the kinetic energy of the piston 17 so that the piston 17 moves up and down. 7 is rotationally driven.

  An intake valve and an exhaust valve (not shown) and a valve operating mechanism (not shown) are provided in the cylinder block 12 and the cylinder head 13, and as shown in FIG. The camshaft 24 spanned between the sprocket 23a and a driven sprocket (not shown) provided on the camshaft (not shown) of the valve mechanism so that the rotational driving force from the crankshaft 23 is transmitted to the camshaft. It is opened and closed by a valve cam (not shown) formed on the camshaft by rotation of the crankshaft 23 or a valve mechanism. The cam chain 24 is provided with a cam chain guide 25 in contact with the front side of the cam chain 24 and a tension slipper 27 in contact with the front side and the tension slipper 27 in order to prevent the cam chain 24 from slackening due to a change in the rotational speed of the crankshaft 23. A chain tensioner that presses 27 is provided.

  A crankshaft 23 oriented in the vehicle width direction is rotatably supported in the front half of the left and right crankcases 11a and 11b, and a transmission (not shown) is provided in the rear half of the left and right crankcases 11a and 11b. A countershaft 50 is provided, and an endless chain 52 is bridged between a drive sprocket 51 integral with the countershaft 50 and a driven sprocket behind the vehicle body (not shown), and is not shown in conjunction with the rotation of the drive sprocket 51. The wheels are driven to rotate.

  The internal combustion engine 10 of the present embodiment is provided with a piston cooling oil injection device 60 that cools the piston 17 by injecting oil onto the top inner surface 17a of the piston 17. As shown in FIG. 3, the oil injection device 60 for cooling the piston includes an oil jet pipe 30 inserted into a jet pipe insertion hole 40 formed in the left crankcase 11a, and the oil stored in the crankcase 11. Oil is supplied from an oil pump 47, which is a supply source, through an oil supply passage 61 formed in the crankcase 11, and oil is injected from the oil jet pipe 30 to the top internal combustion surface of the piston to cool the piston. It is supposed to be.

  As shown in FIG. 5, the oil jet pipe 30 includes a base end portion 31, a base portion 32 having a larger outer diameter, and a base end portion 31 and a tip portion 33 having a smaller outer diameter than the base portion 32. In the oil jet pipe 30, an in-pipe oil passage 35 is formed.

  The boundary between the base end 31 and the base 32 and the boundary between the base 32 and the tip 33 have two outer diameters larger than the base 32 so that there is a gap in the longitudinal direction of the oil jet pipe 30. Expanded diameter portions 34a and 34b are formed. The base portion 32 is provided with a plurality of oil supply ports 32c that open to the outer peripheral surface 32d of the base portion 32 so that the base portion interior 32a communicates with the oil sump space 32b located outside the base portion.

  Plugs 36a and 36b are fitted to the base end portion 31 and the tip end portion 33 of the oil jet pipe 30 in a liquid-tight manner, respectively. On the side surface of the distal end portion 33 of the oil jet pipe 30, an oil jet injection port 37 for injecting oil is formed closer to the base end portion 31 than the plug 36b in the axial direction of the oil jet pipe 30. The oil jet injection port 37 opens in a direction of 90 degrees or less with respect to the center line from the base end portion 31 to the tip end portion 33 of the oil jet pipe 30 and injects oil onto the top inner surface 17a of the piston 17. It is like that. The oil supply port 32 c and the oil jet injection port 37 are communicated with each other through an oil passage 35 in the oil jet pipe 30.

  The cross-sectional shape of the base end portion 31 of the oil jet pipe 30 is formed in an irregular shape different from a circle, and is fitted into a fitting port 38a of a positioning member 38 to be described later.

  As shown in FIG. 3, the left crankcase 11a is formed with a jet pipe insertion hole 40 penetrating through the crankcase 11a from the outer peripheral surface 11e to the inner peripheral surface 11f of the crankcase 11a. The jet pipe insertion hole 40 has a diameter smaller than that of the enlarged diameter portions 34a and 34b of the oil jet pipe 30 on the back side in the insertion direction of the oil jet pipe 30, and a tip portion through which the tip portion 33 of the oil jet pipe 30 is inserted. 40a is formed.

The jet pipe insertion hole 40 is below the lower end of the cylinder sleeve 12a of the cylinder block 12 and is behind the tension slipper 27 in a side view on the side of the left crankcase 11a where the chain tensioner 26 is disposed. Te, positioned outside the rotational locus 23b of crank-wait provided on the crankshaft 23 is provided at a position outside of the crankcase 11a is covered with the crankcase cover (not shown).

  Further, as shown in FIG. 3, the left crankcase 11a has an oil supply passage 41 that communicates with the jet pipe insertion hole 40 from a position located in front of the jet pipe insertion hole 40 on the left side surface of the left crankcase 11a. The outer end of the oil supply passage 41 is sealed with a stopper 42 in a liquid-tight manner.

  Further, as shown in FIG. 4, the left crankcase 11a communicates with the oil supply passage 41 and is directed upward in parallel with the cylinder axis, and is opened up and down at the front and rear portions of the upper end surface of the left crankcase 11a. A directed front oil passage 43 and a rear oil passage 44 are formed. As shown in FIG. 3, the upper end surface of the left crankcase 11 a communicates with the upper end openings 43 a and 44 a of the front oil passage 43 and the rear oil passage 44, and from the front of the cylinder around the cylinder center line. An arcuate groove 45 having a shallow transverse cross section is formed toward the rear.

  Further, as shown in FIGS. 1 and 3, the upper end portion 46 a of the oil passage 46 is connected to the lower end of the front oil passage 43, and the lower end portion 46 b of the oil passage 46 is connected to the oil pump 47. The suction port 47b of the oil pump 47 is connected to an oil reservoir 49 through an oil strainer 48. The oil supply passage 41, the front oil passage 43, the rear oil passage 44, the arc-shaped groove 45, and the oil passage 46 serve as an oil passage from the oil pump 47 that is the oil supply source to the oil jet pipe 30. 61.

  When the oil jet pipe 30 is inserted into the jet pipe insertion hole 40, the outer peripheral surface 32d of the base portion 32 of the oil jet pipe 30 with the oil supply port 32c opened, and the inner peripheral surface of the jet pipe insertion hole 40 of the left crankcase 11a The space between 40b and the two enlarged diameter portions 34a, 34b becomes an oil reservoir space 32b, which communicates with the oil supply passage 41 of the crankcase 11a and the oil passage 35 in the pipe of the oil jet pipe 30. Has been.

  As shown in FIG. 3, after inserting the oil jet pipe 30 into the jet pipe insertion hole 40 of the left crankcase 11a, the oil jet pipe 30 communicates with the oil supply port 32c and the oil supply path 41 of the crankcase 11a. In the position where the oil jet is injected from the oil jet injection port 37, the direction of the oil injection directed to the top inner surface 17a of the piston 17 is maintained so as to be integrated with the crankcase 11a by the positioning member 38 attached to the crankcase 11a. Fixed.

  The positioning member 38 is a gourd-shaped plate member having two circular arcs, and a fitting port 38a that fits into the deformed base end 31 of the oil jet pipe 30 is formed in the center of one arc. A bolt hole 38b through which a mounting bolt 38c for mounting to the right crankcase 11a is inserted is formed at the center of the other arc. Yes. The positioning member 38 is integrally coupled to the left crankcase 11a in a state where the fitting port 38a of the positioning member 38 is fitted to the base end portion 31 of the oil jet pipe 30. The positioning member 38 that is integrally attached to the crankcase 11 a is positioned away from the cylinder sleeve 12 a of the cylinder block 12 and on the inner side in the width direction than the chain tensioner 26.

  Since the embodiment of the present invention is configured as described above, when the internal combustion engine 10 is in an operating state, the oil pump 47 is operated, and the oil present on the bottom surfaces of the left and right crankcases 11 is removed from the oil strainer 48. The oil is sucked into the suction port 47b of the oil pump 47 and flows into the front oil passage 43 through the oil passage 46, and the oil flowing into the front oil passage 43 rises to form an arcuate groove 45 on the top surface of the left crankcase 11a. The oil that has flowed into the rear oil passage 44 and descended in the rear oil passage 44 flows into the base inside 32a of the jet pipe insertion hole 40 through the oil supply passage 41 and is formed in the base portion 32 of the oil jet pipe 30. The oil jet pipe 30 flows into the pipe oil passage 35 in the oil jet pipe 30 through the plurality of oil supply ports 32c and moves up and down in the cylinder sleeve 12a toward the lower surface of the top of the piston (not shown). From the oil jet injection port 37 formed on the side surface of the front end portion 33, the oil is injected accurately along the required jet injection direction, and is cooled effectively and appropriately.

  Further, the oil jet pipe 30 includes an oil supply port 32c that is open on the outer peripheral surface of the base portion 32 of the oil jet pipe 30, an oil jet injection port 37 that is formed on the side surface of the tip 33 of the oil jet pipe 30, A pipe oil passage 35 communicating with the oil supply port 32c and the oil jet injection port 37 is formed inside the oil jet pipe 30, and the left crankcase 11a of the internal combustion engine 10 has an outer peripheral surface of the left crankcase 11a. To the inner peripheral surface of the jet pipe insertion hole 40 passing through the left crankcase 11 across the a and the inner peripheral surface of the jet pipe insertion hole 40, and connected to an oil pump 47 which is an oil supply source. An oil passage 46, a front oil passage 43, an arc-shaped groove 45, a rear oil passage 44, and an oil supply passage 41 are formed as oil supply passages, and an oil jet pipe 30 serves as an oil supply port 32c and the oil in the crankcase 11a. At a position where the supply passage 41 communicates, the positioning member 38 attached to the left crankcase 11a keeps the oil injection direction from the oil jet injection port 37 so that the oil injection direction is directed toward the inner surface of the top of the piston. Since it is integrally fixed to the crankcase 11a, the layout restriction of the oil jet pipe 30 and the oil supply oil passage to the oil jet pipe 30 is reduced, and the piston can be cooled with a simple structure.

  Further, in the internal combustion engine 10 in which the split surface of the crankcase is oriented along the surface oriented toward the front rear of the vehicle body, the piston cooling composed of the oil jet pipe 30 and the jet pipe insertion hole 40 is provided at a position located below the cylinder sleeve 12a. Even if the oil injection device is provided, the tension slipper 27 of the chain tensioner 26 does not protrude laterally, and the width direction dimension of the internal combustion engine 10 can be shortened.

  Further, since the injection direction of the oil injected from the oil jet injection port 37 of the jet pipe insertion hole 40 is firmly fixed by the positioning member 38, the twisting force around the center line of the jet pipe insertion hole 40 is applied to the jet pipe insertion hole 40. Even if it works on 40, oil is sprayed on the piston top inner surface, and the piston top is reliably cooled.

  Furthermore, if the positioning member 38 whose position of the flat surface of the fitting port 38a of the positioning member 38 is changed, the adjustment of the oil injection direction can be easily and appropriately changed.

  Further, since the distal end portion 33 of the jet pipe insertion hole 40 is thinner than the base portion 32, the bending deformation acting on the jet pipe insertion hole 40 is not affected even when the jet pipe insertion hole 40 is subjected to longitudinal and vertical excitation forces. Few.

  As mentioned above, although the hydraulic control valve structure of the internal combustion engine of the embodiment according to the present invention has been described, the aspect of the present invention is not limited to the above-described embodiment, and is implemented in various ways within the scope of the gist of the present invention. Is also included.

10 ... engine, 11 ... Crankcase, 11a ... Left crank case, 11e ... outer peripheral surface, 11f ... inner peripheral surface, 12 ... cylinder block, 12a ... cylinder sleeve 17 ... piston, 17a ... top inner surface, 26 ... Chen tensioner, 30 ... oil jet pipe 31 ... base end, 32 ... base, 32c ... oil supply port, 32d ... outer peripheral surface, 34a ... diameter portion, 34b ... expanded diameter section, 35 ... pipe oil passage, 37 ... oil Jet injection port, 38 ... positioning member, 38a ... fitting port, 40 ... jet pipe insertion hole, 40b ... inner peripheral surface, 41 ... oil supply path, 47 ... oil pump.

Claims (7)

By injecting oil from the oil injection port (37) at the tip of the oil jet pipe (30) to the top inner surface (17a) of the piston (17) of the internal combustion engine (10), the top inner surface (17a In the piston cooling oil injection device that cools
The oil jet pipe (30) includes a pipe oil supply port (32c) opened on the outer peripheral surface of the base portion (32) of the oil jet pipe (30), and an oil jet opened on the front end surface of the oil jet pipe (30). And an oil passage (35) in the pipe that communicates with the pipe oil supply port (32c) and the oil injection port (37) inside the oil jet pipe (30),
The crankcase (11a) of the internal combustion engine (10) includes a jet pipe that passes through the crankcase (11a) from the outer peripheral surface (11e) to the inner peripheral surface (11f) of the crankcase (11a). An insertion hole (40) and an oil supply path (41) that opens to the inner peripheral surface (40b) of the jet pipe insertion hole (40) and is connected to an oil supply source (47) are formed,
The oil jet pipe (30) injects oil from the oil injection port (37) at a position where the pipe oil supply port (32c) and the oil supply passage (41) of the crankcase (11a) communicate with each other. It is integrally fixed to the crankcase (11a) by a positioning member (38) attached to the crankcase 11a so as to maintain the direction of injection directed to the top inner surface (17a) of the piston (17) ,
The base portion (32) of the oil jet pipe (30) has a plurality of enlarged diameter portions (34a, 34b) formed at intervals in the longitudinal direction of the oil jet pipe (30),
The jet pipe insertion hole (40) has a distal end portion (40a) having a diameter smaller than that of the enlarged diameter portions (34a, 34b) of the oil jet pipe (30) on the back side in the insertion direction of the oil jet pipe (30). Formed,
At least one or more pipe oil supply ports (32c) of the oil jet pipe (30) are opened in a portion sandwiched between the plurality of enlarged diameter portions (34a, 34b),
Between the outer peripheral surface (32d) of the oil jet pipe (30) in which the pipe oil supply port (32c) is opened and the inner peripheral surface (40b) of the jet pipe insertion hole (40) of the crankcase (11a). The space (32b) sandwiched between the plurality of enlarged diameter portions (34a, 34b) includes an oil supply passage (41) of the crankcase (11a) and an oil passage (in-pipe) of the oil jet pipe (30). 35),
The oil jet pipe (30) is a straight pipe,
The tip (40a) of the oil jet pipe (30) is formed with a smaller diameter than the tip (40a) of the jet pipe insertion hole (40),
The enlarged diameter portions (34a, 34b) have a bowl-like shape, and the oil jet pipe (30) is centered and positioned in the jet pipe insertion hole (40), and the jet pipe (30) An oil injection device for cooling a piston , wherein a seal member for sealing between the outer surface of the nozzle and the jet pipe insertion hole (40) is positioned . The cross-sectional shape of the base end portion (31) of the oil jet pipe (30) is formed in an irregular shape different from a circle,
The fitting port (38a) of the positioning member (38) fitted to the odd-shaped base end (31) of the oil jet pipe (30) is formed on the base end (31) of the oil jet pipe (30). Formed in the same shape as the cross-sectional shape,
The positioning member (38) is integrally coupled to the crankcase (11a) in a state in which the fitting port (38a) of the positioning member 38 is fitted to the base end portion (31 of the oil jet pipe (30). The oil injection device for cooling a piston according to claim 1. The jet pipe insertion hole (40) is provided on the side where the chain tensioner (26) is disposed, at a position covered by a crankcase cover outside the crankcase (11a), and the crankcase (11a). The positioning member (38) integrally mounted to the cylinder block (12) is separated from the cylinder sleeve (12a) of the cylinder block (12) and is positioned on the inner side in the width direction than the chain tensioner (26). The oil injection device for piston cooling according to 2. By injecting oil from the oil injection port (37) at the tip of the oil jet pipe (30) to the top inner surface (17a) of the piston (17) of the internal combustion engine (10), the top inner surface (17a In the piston cooling oil injection device that cools
The oil jet pipe (30) includes a pipe oil supply port (32c) opened on the outer peripheral surface of the base portion (32) of the oil jet pipe (30), and an oil jet opened on the front end surface of the oil jet pipe (30). And an oil passage (35) in the pipe that communicates with the pipe oil supply port (32c) and the oil injection port (37) inside the oil jet pipe (30),
The crankcase (11a) of the internal combustion engine (10) includes a jet pipe that passes through the crankcase (11a) from the outer peripheral surface (11e) to the inner peripheral surface (11f) of the crankcase (11a). An insertion hole (40) and an oil supply path (41) that opens to the inner peripheral surface (40b) of the jet pipe insertion hole (40) and is connected to an oil supply source (47) are formed,
The oil jet pipe (30) injects oil from the oil injection port (37) at a position where the pipe oil supply port (32c) and the oil supply passage (41) of the crankcase (11a) communicate with each other. It is integrally fixed to the crankcase (11a) by a positioning member (38) attached to the crankcase 11a so as to maintain the direction of injection directed to the top inner surface (17a) of the piston (17),
The jet pipe insertion hole (40) is provided on the side where the chain tensioner (26) is disposed, at a position covered by a crankcase cover outside the crankcase (11a), and the crankcase (11a). The piston cooling unit is characterized in that the positioning member (38) mounted integrally with the piston is separated from the cylinder sleeve (12a) of the cylinder block (12) and is positioned inward in the width direction of the chain tensioner (26). Oil injection device. The base portion (32) of the oil jet pipe (30) has a plurality of enlarged diameter portions (34a, 34b) formed at intervals in the longitudinal direction of the oil jet pipe (30),
  In the jet pipe insertion hole (40), a distal end portion (40a) having a smaller diameter than the diameter-expanded portion (34a, 34b) of the oil jet pipe (30) on the back side in the insertion direction of the oil jet pipe (30). The oil injection device for cooling a piston according to claim 4, wherein the oil injection device is formed. At least one of the pipe oil supply ports (32c) of the oil jet pipe (30) is opened in a portion sandwiched between the plurality of enlarged diameter portions (34a, 34b),
  Between the outer peripheral surface (32d) of the oil jet pipe (30) in which the pipe oil supply port (32c) is opened and the inner peripheral surface (40b) of the jet pipe insertion hole (40) of the crankcase (11a). The space (32b) sandwiched between the plurality of enlarged diameter portions (34a, 34b) includes an oil supply passage (41) of the crankcase (11a) and an oil passage in the pipe of the oil jet pipe (30) ( 35. The oil injection device for cooling a piston according to claim 5, wherein the oil injection device is communicated with 35). The cross-sectional shape of the base end portion (31) of the oil jet pipe (30) is formed in an irregular shape different from a circle,
  The fitting port (38a) of the positioning member (38) fitted to the odd-shaped base end (31) of the oil jet pipe (30) is formed on the base end (31) of the oil jet pipe (30). Formed in the same shape as the cross-sectional shape,
  The positioning member (38) is integrally coupled to the crankcase (11a) in a state in which the fitting port (38a) of the positioning member 38 is fitted to the base end portion (31 of the oil jet pipe (30). The oil injection device for cooling a piston according to claim 6.

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