JP2005009336A - Engine piston cooling structure - Google Patents

Abstract

An object of the present invention is to provide a cylinder block having a cylinder bore provided with an insertion cylinder part forming a part of the cylinder bore, and in a state where the insertion cylinder part is inserted into the crankcase in a crankcase separate from the cylinder block. In an engine piston cooling structure in which an oil jet for jetting oil for cooling a piston that is slidably fitted to a cylinder bore is provided in the crankcase, the crankcase is positioned at a position closer to the piston. So that the cooling efficiency of the piston is improved.
An opening 45 is provided in an insertion cylinder portion 42 of a cylinder block 14 to allow oil ejected from an oil jet 44 fixed to a crankcase 11 to pass through the insertion cylinder portion 42 toward the piston 17 side. Provided.
[Selection] Figure 3

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a cylinder block having a cylinder bore is provided with an insertion cylinder portion that forms a part of the cylinder bore, and the insertion cylinder portion is inserted into the crankcase in a crankcase that is separate from the cylinder block. The cylinder block is coupled to the piston cooling structure of the engine in which an oil jet for ejecting oil for cooling a piston slidably fitted in a cylinder bore is provided in the crankcase.
[0002]
[Prior art]
For example, Patent Document 1 and Patent Document 2 have already been known in which an oil jet is provided in a crankcase and the piston is cooled by injecting oil from the oil jet toward the piston.
[0003]
[Patent Document 1]
Japanese Utility Model Publication No. 61-31134 [Patent Document 2]
JP-A-9-68042 [0004]
[Problems to be solved by the invention]
By the way, an insertion cylinder part to be inserted into the crankcase is provided in the cylinder block, and in the above-mentioned conventional one, in order to avoid interference with the insertion cylinder part, the oil jet is at a position facing the tip of the insertion cylinder part. It is provided in the crankcase, and the distance between the oil jet and the piston is relatively long, and it is difficult to say that the cooling efficiency of the piston is high.
[0005]
The present invention has been made in view of such circumstances, and provides an engine piston cooling structure in which an oil jet is provided in a crankcase at a position closer to the piston to improve piston cooling efficiency. Objective.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is provided with a cylinder case having a cylinder bore provided with an insertion cylinder portion that forms a part of the cylinder bore, and a crankcase that is separate from the cylinder block. An engine in which the cylinder block is coupled in a state in which the insertion cylinder portion is inserted into the crankcase, and an oil jet for ejecting oil for cooling a piston slidably fitted in the cylinder bore is provided in the crankcase. In this piston cooling structure, an opening for allowing the oil jetted from an oil jet fixed to the crankcase to pass through the insertion cylinder and toward the piston is provided in the insertion cylinder of the cylinder block. It is characterized by being able to.
[0007]
According to the configuration of the invention described in claim 1, the oil jet can be provided in the crankcase at a position closer to the piston side than the tip of the insertion cylinder portion provided in the cylinder block. Can be shortened, and the cooling efficiency of the piston can be improved.
[0008]
According to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, the opening is formed in a substantially U-shape that opens toward the inside of the crankcase, so that the distal end of the insertion tube portion is formed. The oil jet, which is a member different from the crankcase, is fixed to the crankcase so that a part of the oil jet is disposed in the opening. For example, the oil jet can be brought closer to the piston side, and the insertion cylinder portion does not interfere with the oil jet when the insertion cylinder portion is inserted into the crankcase to connect the cylinder block to the crankcase. It can contribute to the improvement of assembly.
[0009]
According to a third aspect of the present invention, in addition to the configuration of the second aspect of the present invention, an insertion hole for inserting the insertion tube portion and a mounting hole opened on the inner surface of the insertion hole are provided in the crankcase. The oil jet fitted in the mounting hole is integrally provided with a flange portion adjacent to and opposed to the outer surface of the insertion tube portion around the opening portion. Since the part abuts against the outer surface of the insertion tube part, the oil jet is prevented from detaching from the mounting hole, eliminating the need for dedicated equipment for fixing the oil jet to the crankcase, reducing the number of parts. In addition, the oil jet can be securely fixed to the crankcase.
[0010]
In addition to the configuration of the invention described in claim 3, the crankcase comprises a pair of case members coupled to each other on a plane parallel to the axis of the cylinder bore. An oil passage for supplying oil to the cylinder head side, which is coupled to the cylinder block on the opposite side of the case, extends in a direction parallel to the axis of the cylinder bore and is provided in one case member and the cylinder block. The connecting hole that communicates is provided in the one case member so that the axis line is arranged on a plane orthogonal to the axis line of the cylinder bore, and according to such a configuration, an oil passage is easily provided in the crankcase and the cylinder block. In addition to improving the workability, the oil passage dedicated to the oil jet is not required and the oil passage structure is simplified. It can be of.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.
[0012]
1 to 5 show a first embodiment of the present invention. FIG. 1 is a longitudinal side view of an engine, FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, and FIG. FIG. 4 is an enlarged view taken along line 4-4 of FIG. 3, and FIG. 5 is a sectional view taken along line 5-5 of FIG.
[0013]
First, in FIG. 1, this engine is a four-cycle V-type two-cylinder engine having first and second banks BA and BB. The first and second banks BA and BB are rotatable by a crankcase 11. Cylinder blocks 14 each having a cylinder bore 13... That is individually coupled to the crankcase 11 on the projection onto a plane orthogonal to the axis of the crankshaft 12 to be supported, each having a cylinder bore 13. Combustion chambers 18 that face the tops of pistons 17 that are slidably fitted into the cylinder bores 13 are formed between the cylinder blocks 14 and opposite to the crankcase 11. A cylinder head 15 coupled to each cylinder block 14 and a cylinder head 15 on the opposite side of each cylinder block 14. Each consists of the head cover 16 ... city that is coupled.
[0014]
Each cylinder block 14 is cast with a cylindrical cylinder liner 19. The cylinder bores 13 are formed by inner surfaces of the cylinder liners 19.
[0015]
Referring also to FIG. 2, the cylinder head 15 on the first bank BA side has a pair of intake valve ports 20 that can communicate with the combustion chamber 18 and both intake valve ports 20. An intake port 21 that opens to the side of the cylinder head 15 on the bank BB side, a single exhaust valve port 22 that can communicate with the combustion chamber 18, and a cylinder head that communicates with the exhaust valve port 22 and on the opposite side of the second bank BB. 15 is provided with an exhaust port 23 that opens on the side surface of the engine 15, a pair of intake valves 24 that open and close each intake valve port 20, and a single exhaust valve 25 that opens and closes the exhaust valve port 22. It is arranged so that it can be opened and closed so that the operating axis intersects in a V shape on the projection onto the plane orthogonal to the axis of the shaft 12.
[0016]
Between the cylinder head 15 and the head cover 16, a single camshaft 26 that is common to both the intake valves 24... And the exhaust valve 25, and both intake valves are configured to swing following the rotation of the camshaft 26. 24 and a pair of intake side rocker arms 27 interposed between the camshaft 26 and the exhaust valve 25 and the camshaft 26 so as to swing as the camshaft 26 rotates. A valve operating device 29 including an exhaust side rocker arm 28 is accommodated, and rotational power from the crankshaft 12 is transmitted to one end portion of the camshaft 26 through a timing transmission device 30 with a reduction ratio of 1/2. The
[0017]
The timing transmission device 30 includes a driving sprocket 31 fixed to the crankshaft 12, a driven sprocket 32 fixed to one end of the camshaft 26, and an endless timing wound around the driving and driven sprockets 31 and 32. A chain running chamber 34 for running the timing chain 33 is formed in the cylinder block 14 and the cylinder head 15. In addition, a pair of spark plugs 35 and 36 are attached to the cylinder head 15 so that the tip faces the combustion chamber 18.
[0018]
Also on the second bank BB side, a pair of intake valves and exhaust valves (not shown) are arranged in the cylinder head 15 in the same manner as the first bank BA side, and the valve operating apparatus (FIG. (Not shown) is accommodated between the cylinder head 15 and the head cover 16, and an intake device 37 disposed between the first and second banks BA and BB is connected to the intake ports 21 of the cylinder heads 15.
[0019]
The crankcase 11 includes first and second case members 40 and 41 which are coupled to each other in a plane parallel to the axis of the cylinder bores 13 in the first and second banks BA and BB. Both case members 40 and 41 are rotatably supported.
[0020]
In addition, the cylinder blocks 14 of the first and second banks BA, BB are provided with insertion cylinder portions 42 that form part of the cylinder bores 13 respectively, and a pair of crankcases 11 are provided. The cylinder blocks 14 of both banks BA and BB are coupled to the crankcase 11 in a state where the insertion cylinder portions 42 are inserted into the insertion holes 43.
[0021]
By the way, in the crankcase 11, oil is ejected from the crankcase 11 side toward the pistons 17 slidably fitted in the cylinder bores 13 of the two cylinder blocks 14. The oil jets 44 are provided individually corresponding to the pistons 17.
[0022]
Referring also to FIGS. 3 to 5, in the insertion cylinder portion 42 of the cylinder block 14, the oil jetted from the oil jet 44 fixed to the crankcase 11 penetrates the insertion cylinder portion 42 and moves toward the piston 17 side. An opening 45 is provided to allow it to go, and the opening 45 is formed in a substantially U shape that opens toward the inside of the crankcase 11 and is provided at the distal end portion of the insertion tube portion 42.
[0023]
On the other hand, an oil jet 44, which is a separate member from the crankcase 11, is fixed to the crankcase 11 so that a part of the oil jet 44 is disposed in the opening 45. A mounting hole 46 for mounting the oil jet 44 is provided in the first case member 40 of the crankcase 11 so as to open to the inner surface of the insertion hole 43 into which the insertion tube portion 42 is inserted.
[0024]
The oil jet 44 includes a bottomed cylindrical large-diameter cylindrical portion 44a with one end closed, and a small-diameter cylindrical portion 44b formed smaller in diameter than the large-diameter cylindrical portion 44a and coaxially connected to the other end of the large-diameter cylindrical portion 44a. , And a flange portion 44c that projects outward from the outer surface of the intermediate portion of the large-diameter cylindrical portion 44a.
[0025]
The large-diameter cylindrical portion 44a of the oil jet 44 is fitted into the mounting hole 46 from the insertion hole 43 side, for example, by light press-fitting until the flange portion 44c contacts the first case member 40. An annular path 47 is formed between the outer surface of 44 b and the inner surface of the mounting hole 46. Moreover, the flange portion 44c is formed in a non-circular shape, and an engagement groove 48 for receiving and engaging the flange portion 44c is provided on the inner surface of the insertion hole 43, and the engagement of the flange portion 44c is achieved. Due to the engagement with the groove 48, the position of the oil jet 44 around the axis of the mounting hole 46 is fixed.
[0026]
After the crankcase 11 is attached to the first case member 40, the cylinder block 14 is coupled to the crankcase 11 so that the insertion cylinder portion 42 is inserted into the insertion hole 43. One end of the diameter cylindrical portion 44 a is disposed in the opening 45, and the flange portion 44 c is close to and faces the outer surface of the insertion tube portion 42 around the opening 45.
[0027]
In the oil jet 44, the large-diameter cylindrical portion 44a and the small-diameter cylindrical portion 44b are coaxially provided with an oil passage 49 whose one end is closed on one end side of the large-diameter cylindrical portion 44a. The part is closed by a steel ball 50 that is press-fitted into the other end of the small diameter cylindrical part 44b. In addition, the small-diameter cylindrical portion 44 b is provided with a plurality of communication holes 51 that allow the oil passage 49 to communicate with the annular passage 47.
[0028]
Thus, when the other end of the oil passage 49 is closed with the steel ball 50 and the oil in the oil passage 49 is guided through the annular passage 47 and the communication hole 51..., Impurities in the oil are clogged with a part of the annular passage 47. Even if it is, the oil passage 49 can be reliably guided. On the other hand, if the steel ball 50 is omitted and the other end of the oil passage 49 is opened directly to the mounting hole 46, a sufficient amount of oil is supplied to the oil passage 49 when the other end of the oil passage 49 is clogged. The oil jet 44 needs to be replaced.
[0029]
A slope 52 facing the piston 17 side fitted to the cylinder bore 13 is formed at one end of the large-diameter cylindrical portion 44 a at a portion located in the opening 45 of the insertion cylinder portion 42, and the oil passage 49. An ejection hole 53 having an inner end passed through one end and an outer end opened to the inclined surface 52 is provided at one end of the large-diameter cylindrical portion 44 a so as to eject oil toward the piston 17.
[0030]
By the way, the oil path 54 which supplies oil to the cylinder head 15 side to the 1st case member 40 and the cylinder block 14 among the 1st and 2nd case members 40 and 41 which comprise the crankcase 11 in cooperation. Is provided so as to extend in a direction parallel to the axis of the cylinder bore 13, and the mounting hole 46 in which the axis is arranged in a plane orthogonal to the axis of the cylinder bore 13 communicates the inner end thereof with the oil passage 54. In this way, the first case member 40 is provided.
[0031]
Next, the operation of the first embodiment will be described. In the first and second banks BA and BB, the cylinder block 14 having the insertion cylinder portion 42 inserted into the insertion hole 43 provided in the crankcase 11 is a crankcase. 11 is provided in the crankcase 11 for ejecting oil for cooling the piston 17 slidably fitted into the cylinder bore 13 provided in the cylinder block 14. The insertion cylinder portion 42 is provided with openings 45 that allow oil ejected from an oil jet 44 fixed to the crankcase 11 to pass through the insertion cylinder portion 42 toward the piston 17 side.
[0032]
Accordingly, the oil jet 44 can be provided in the crankcase 11 at a position closer to the piston 17 side than the tip of the insertion cylinder portion 42 provided in the cylinder block 14, and the distance between the oil jet 44 and the piston 17 is shortened. The cooling efficiency of 17 can be improved.
[0033]
In addition, the opening 45 is formed in a substantially U shape that opens into the crankcase 11 and is provided at the distal end portion of the insertion cylinder portion 42, and an oil jet 44, which is a separate member from the crankcase 11, Since part of the oil jet 44 is fixed to the crankcase 11 so as to be disposed in the opening 45, the oil jet 44 can be brought closer to the piston 17. In addition, when the insertion cylinder part 42 is inserted into the crankcase 11 so as to couple the cylinder block 14 to the crankcase 11, the insertion cylinder part 42 does not interfere with the oil jet 44, which contributes to an improvement in assemblability. it can.
[0034]
Further, the crankcase 11 is provided with an insertion hole 43 for inserting the insertion cylinder portion 42 and an attachment hole 46 opened on the inner surface of the insertion hole 43, and oil fitted into the attachment hole 46 by light press fitting or the like. The jet 44 is integrally provided with a flange portion 44c that is close to and opposed to the outer surface of the insertion tube portion 42 around the opening 45, so that the flange portion 44c comes into contact with the outer surface of the insertion tube portion 42 so that the oil The detachment of the jet 44 from the mounting hole 46 is prevented, and no dedicated equipment for fixing the oil jet 44 to the crankcase 11 is required, and the oil jet 44 is attached to the crankcase 11 while reducing the number of parts. It can be fixed securely.
[0035]
Further, the crankcase 11 is formed by connecting the first and second case members 40 and 41 to each other in a plane parallel to the axis of the cylinder bores 13 and an oil passage 54 for supplying oil to the cylinder head 15 side. However, the mounting hole 46 extending in a direction parallel to the axis of the cylinder bore 13 is provided in the first case member 40 and the cylinder block 14 and communicates with the oil passage 54 so that the axis is arranged on a plane perpendicular to the axis of the cylinder bore 13. Thus, the first case member 40 is provided. Accordingly, the oil passage 54 can be easily formed in the crankcase 11 and the cylinder block 14 to improve workability, and the oil passage 44 can be simplified by eliminating the oil passage dedicated to the oil jet 44. it can.
[0036]
FIG. 6 shows a second embodiment of the present invention, and parts corresponding to the first embodiment are given the same reference numerals.
[0037]
A recess 57 provided at the end of the insertion hole 43 on the cylinder block 14 side is provided at an intermediate portion in the axial direction of the insertion cylinder portion 42 provided in the cylinder block 14 so as to be inserted into the insertion hole 43 of the crankcase 11. An opening 55 is provided to allow the oil jetted from the oil jet 56 fixed to the first case member 40 of the crankcase 11 to pass through the insertion tube portion 42 toward the piston 17 side.
[0038]
The first case member 40 is provided with an attachment hole 58 having one end opened in the recess 57 so as to have an axis that obliquely intersects the plane including the axis of the cylinder bore 13, and the other end of the attachment hole 58. Communicates with the oil passage 54 provided in the first case member 40 and the cylinder block 14.
[0039]
The oil jet 56 has a jet hole 59 coaxial with the mounting hole 58, and is fixed to the first case member 40 of the crankcase 11 by being screwed to one end of the mounting hole 58.
[0040]
Also according to the second embodiment, the oil jet 56 can be provided in the crankcase 11 at a position closer to the piston 17 side than the tip of the insertion cylinder portion 42 provided in the cylinder block 14, and between the oil jet 56 and the piston 17. , And the cooling efficiency of the piston 17 can be improved.
[0041]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.
[0042]
【The invention's effect】
As described above, according to the first aspect of the present invention, the distance between the oil jet and the piston can be shortened, and the cooling efficiency of the piston can be improved.
[0043]
According to the second aspect of the present invention, the oil jet can be brought closer to the piston side, and the insertion tube portion does not interfere with the oil jet when the insertion tube portion is inserted into the crankcase. It can contribute to improvement of property.
[0044]
According to the third aspect of the present invention, since the flange portion comes into contact with the outer surface of the insertion tube portion, the oil jet is prevented from being detached from the mounting hole, and is dedicated for fixing the oil jet to the crankcase. Therefore, the oil jet can be securely fixed to the crankcase while reducing the number of parts.
[0045]
According to the fourth aspect of the present invention, the oil passage can be easily formed in the crankcase and the cylinder block to improve workability, and the oil passage dedicated to the oil jet is not required. Can be simplified.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of an engine according to a first embodiment.
2 is an enlarged sectional view taken along line 2-2 of FIG.
FIG. 3 is an enlarged view of a portion indicated by an arrow 3 in FIG. 2;
4 is a view taken along line 4-4 in FIG. 3;
5 is a cross-sectional view taken along line 5-5 of FIG.
FIG. 6 is a cross-sectional view corresponding to FIG. 3 of the second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Crankcase 13 ... Cylinder bore 14 ... Cylinder block 15 ... Cylinder head 17 ... Piston 40, 41 ... Case member 42 ... Insertion cylinder part 43 ... Insertion hole 44 56 ... Oil jet 44c ... Hut 45,55 ... Opening 46 ... Mounting hole 54 ... Oil channel

Claims (4)

The cylinder block (14) having the cylinder bore (13) is provided with an insertion cylinder portion (42) that forms a part of the cylinder bore (13), and is a separate crankcase (11) from the cylinder block (14). In addition, the cylinder block (14) is coupled with the insertion tube portion (42) inserted into the crankcase (11), and the piston (17) that is slidably fitted into the cylinder bore (13) is cooled. In an engine piston cooling structure in which oil jets (44, 56) for ejecting oil are provided in the crankcase (11), the crankcase (42) is inserted into the insertion cylinder portion (42) of the cylinder block (14). 11) The oil jetted from the oil jets (44, 56) fixed to the penetrating through the insertion tube portion (42) and the piston (1 ) Of the engine, characterized in that the openings (45, 55) is provided to allow the directed toward the piston cooling structure. The opening (45) is formed in a substantially U shape that opens into the crankcase (11) and is provided at the distal end of the insertion cylinder (42), and is separate from the crankcase (11). The oil jet (44) as a member is fixed to the crankcase (11) such that a part of the oil jet (44) is disposed in the opening (45). The piston cooling structure of the engine according to 1. An insertion hole (43) for inserting the insertion tube portion (42) and a mounting hole (46) opening on the inner surface of the insertion hole (43) are provided in the crankcase (11), and the mounting hole (46 ) Is fitted to an oil jet (44), and the insertion cylinder (44) is formed around the opening (45) so as to prevent the oil jet (44) from being detached from the mounting hole (46). The piston cooling structure for an engine according to claim 2, wherein a flange portion (44c) facing the outer surface of 42) is integrally provided. The crankcase (11) is formed by connecting a pair of case members (40, 41) to each other on a plane parallel to the axis of the cylinder bore (13), and a cylinder block ( 14), an oil passage (54) for supplying oil to the cylinder head (15) side extends in a direction parallel to the axis of the cylinder bore (13), and the one case member (40) and the cylinder block ( 14) and the mounting hole (46) leading to the oil passage (54) is provided in the one case member (40) so that the axis line is arranged on a plane perpendicular to the axis line of the cylinder bore (13). The piston cooling structure for an engine according to claim 3, wherein the piston cooling structure is used.

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