JP3823727B2 - Parallel multi-cylinder engine for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular parallel multi-cylinder engine provided with a balancer device for vibration reduction.
[0002]
[Prior art]
A parallel multi-cylinder engine mounted on a vehicle, particularly a motorcycle, has a structure in which a crankcase is divided into upper and lower parts, and a crankshaft is pivotally supported on the divided surface. Some of such parallel multi-cylinder engines are equipped with a balancer device to alleviate secondary vibrations generated due to their structure.
[0003]
This balancer device is preferably placed near the extension of the cylinder bore shaft in order to avoid the influence of couples and obtain the maximum vibration damping effect. In many models, the balancer device is placed near the lower part of the crankshaft. It is supported.
[0004]
On the other hand, a main oil gallery (main oil passage) formed inside the crankcase for supplying oil discharged from the oil pump to each lubricating portion inside the engine is also arranged substantially in the vicinity of the lower part of the crankshaft, A plurality of journal oil passages extending from the main oil gallery communicate with a plurality of crank journal receivers that support the crankshaft.
[0005]
[Problems to be solved by the invention]
However, since the balancer device and the main oil gallery are both installed near the lower part of the crankshaft in this way, it is necessary to shift the balancer device forward or the main oil gallery backward to prevent mutual interference. As a result, various problems occur.
[0006]
For example, if the main oil gallery is shifted rearward from near the lower portion of the crankshaft, the journal oil passage cannot be formed at a right angle to the split surface of the crankcase. For this reason, it becomes impossible to cast and form each journal oil passage at the same time as the casting of the crankcase, and a difficult post-process such as a drilling process is required, resulting in a great increase in cost.
[0007]
In addition, when the balancer device is shifted forward from near the lower part of the crankshaft, it is necessary to provide a protruding portion on the front surface of the crankcase to accommodate the balancer device, and the formation of the protruding portion enlarges the crankcase, As a result, the entire engine is increased in size and weight.
[0008]
In addition, since the balancer device is separated from the cylinder bore shaft extension line, it becomes susceptible to couples, and not only the maximum vibration control effect is obtained, but also the balancer device is supported at an unstable position. Therefore, it is necessary to improve the strength of the crankcase and other related parts, which also increases the cost and weight.
[0009]
The present invention has been made in order to solve the above-described problems. The balancer device and the main oil gallery can be arranged in the vicinity of the lower part of the crankshaft without interfering with each other, and the formation of the journal oil passage is facilitated. A parallel multi-cylinder engine for vehicles that reduces engine manufacturing costs, improves the damping effect by stably supporting the balancer device, and reduces the size and weight of the engine while preventing noise and damage. The purpose is to provide.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a parallel multi-cylinder engine for a vehicle according to the present invention includes a crankcase having an upper case and a lower case, and is divided into upper and lower parts. A crankshaft is pivotally supported by a plurality of crank journal receivers provided on the dividing surface, and a main oil gallery is formed in the lower case and substantially parallel to the crankshaft below the crankshaft and extends from the main oil gallery. A parallel multi-cylinder engine for a vehicle, in which a plurality of journal oil passages communicate with each of the crank journal receivers and are further driven to rotate by the crankshaft so as to reduce vibrations. In the above section, a part of the main oil gallery is cut and both ends of the cut part The bypass pipe is connected by a bypass pipe, and the bypass pipe is provided with a substantially U-shape that enters into the lower part. At least a part of the balancer device is disposed inside the substantially U-shape, and the crankshaft shaft The main oil gallery and the balancer device are overlapped in the direction view.
[0011]
With the above configuration, since the balancer device is arranged in the cut section of the main oil gallery, both the balancer device and the main oil gallery can be arranged near the lower part of the crankshaft without interfering with each other. As a result, the balancer device is arranged in the vicinity of the cylinder bore shaft extension line to improve the vibration damping effect, and the journal oil passage extending from the main oil gallery is formed at right angles to the split surface of the crankcase so that the crankcase is cast. At the same time, casting can be formed, and the manufacturing cost of the engine can be reduced.
[0012]
In addition, the parallel multi-cylinder engine for a vehicle according to the present invention, as described in claim 2, has a configuration between the journal tightening bolts of the crank journal receiver as viewed in the axial direction of the crankshaft. The axis of the balancer device was disposed in the sandwiched area. As a result, the balancer device is pivotally supported in the most rigid part of the crankcase, improving the balancer device's vibration damping effect and increasing the strength of the crankcase and other related parts as the balancer device is supported. Therefore, it is possible to reduce the manufacturing cost and reduce the size and weight of the engine.
[0013]
Further, the parallel multi-cylinder engine for a vehicle according to the present invention is, as described in claim 3, in the configuration of claim 1 or claim 2, at substantially both ends of the cut section of the main oil gallery, respectively. Opening connection ports are provided, and both ends of the bypass pipe are provided with insertion portions that are liquid-tightly inserted into the connection ports, while pipe receiving portions are formed in an oil pan that is joined below the lower case, By making this pipe receiving part abut on the bypass pipe from below, the insertion part of the bypass pipe was prevented from being pulled out from the connection port of the main oil gallery. In this way, the bypass pipe can be prevented from being pulled out without providing a dedicated fixing member or the like, so that the number of components and assembly man-hours of the engine can be reduced and the manufacturing cost can be reduced.
[0014]
In addition, the parallel multi-cylinder engine for a vehicle according to the present invention, as described in claim 4, has an eccentric support in which the intermediate portion is eccentric with respect to both ends in the configuration of claims 1-3. A shaft and a balancer rotating body rotatably supported at an intermediate portion of the eccentric support shaft, and both ends of the eccentric support shaft are supported by the crankcase and at one end of the eccentric support shaft. The provided pivot adjustment part is exposed on one side of the crankcase, and the pivot adjustment part is pivoted to adjust the inter-shaft distance between the intermediate part of the eccentric support shaft and the crankshaft. . With the above configuration, it is possible to adjust the backlash at the gear meshing portion between the crankshaft and the balancer rotor, so that it is possible to prevent the occurrence of gear meshing noise.
[0015]
Furthermore, the parallel multi-cylinder engine for a vehicle according to the present invention, as described in claim 5, in the configuration of claims 1 to 4, both ends of the cut section of the main oil gallery and both ends of the bypass pipe. the connection position between parts, said plurality of crank journal receives a vicinity below the receiving two adjacent crank journals except crank journal receiving the ends of the oil to be joined bypass pipe below the lower case Placed inside the bread. With this configuration, since the bypass pipe is concealed inside the crankcase and the oil pan, it is possible to avoid damage to the bypass pipe due to external force and improve the appearance of the engine.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a left side view of a motorcycle showing an example of a vehicle equipped with a parallel multi-cylinder engine according to the present invention. In the motorcycle 1, a front fork 3 is provided on a front head of a vehicle body frame 2 so as to be rotatable left and right. A front wheel 4 is pivotally supported at a lower end portion of the front fork 3. 5 is fixed together with the headlamp 6 and the instrument 7. Reference numeral 8 denotes a front fender.
[0018]
On the other hand, a pivot shaft 10 is installed at the center lower portion of the vehicle body frame 2 in the vehicle width direction, and a rear wheel 12 is pivotally supported at a rear end portion of a swing arm 11 rotatably provided on the pivot shaft 10. ing.
[0019]
The parallel multi-cylinder engine 13 is mounted on the front half of the body frame 2, and its output is transmitted to the rear wheel 12 via the chain 14. An intake device such as a carburetor 15 is disposed at the rear of the parallel multi-cylinder engine 13, and an exhaust pipe 16 is connected to the front of the parallel multi-cylinder engine 13, and the exhaust pipe 16 is connected to the parallel multi-cylinder engine 13. Extends backward through the bottom of the.
[0020]
A fuel tank 18 is installed in the upper half of the vehicle body frame 2, a seating seat 19 is placed in the upper half of the vehicle body frame 2, and a rear cover 20 and a rear fender 21 are provided in the lower part thereof. Further, an oil cooler 22 is installed in front of the parallel multi-cylinder engine 13.
[0021]
2 is a longitudinal sectional view of the parallel multi-cylinder engine 13 as viewed from the left, and FIG. 3 is a longitudinal sectional view of the parallel multi-cylinder engine 13 taken along the line III-III in FIG. 4 is an enlarged view of a portion IV in FIG. 2, and FIG. 5 is an enlarged view of a portion V in FIG.
[0022]
The parallel multi-cylinder engine 13 is, for example, a parallel 4-cylinder engine, and a cylinder assembly 26 is installed on a crankcase 25 so as to be inclined forward. The crankcase 25 includes an upper case 27 and a lower case 28 and is divided into upper and lower parts. An oil pan 29 is joined to the lower surface of the lower case 28 and formed on a split surface of the upper case 27 and the lower case 28. A crankshaft 37 extending in the vehicle width direction is supported by the six crank journal receivers 31 to 36. Each of the crank journal receivers 31 to 36 is fastened by a pair of journal fastening bolts 38 and 39 (see FIG. 4) provided so as to sandwich the crankshaft 37, and holds the crankshaft 37 rotatably with high rigidity. .
[0023]
The cylinder assembly 26 is configured by placing a cylinder block 41, a cylinder head 42, and a head cover 43 in order from the bottom, and four cylinder bores 44 are formed in the cylinder block 41 in parallel in the vehicle width direction. In addition, four combustion chambers 45 aligned with the respective cylinder bores 44 are formed on the lower surface of the cylinder head 42. Further, an intake port 46 communicating with the combustion chamber 45 from the rear and an exhaust port 47 communicating with the combustion chamber 45 from the front are formed inside the cylinder head 42. The above-described carburetor 15 and exhaust pipe 16 are connected to the intake port 46 and the exhaust port 47, respectively.
[0024]
Pistons 48 are slidably inserted into the cylinder bores 44, and the pistons 48 and the crank pins 49 of the crankshaft 37 are connected by connecting rods 50, and the reciprocating motion of the pistons 48 in the cylinder bores 44 is performed. It is converted into the rotational motion of the crankshaft 37 and taken out as the output of the parallel multi-cylinder engine 13.
[0025]
In the lower case 28, a main oil gallery (main oil passage) 52 is formed below the crankshaft 37 in parallel with the crankshaft 37, and six journal oil passages 53 to 58 extending from the main oil gallery 52 are formed. And one head oil passage 59 and one transmission oil passage 60 are respectively accommodated in the respective crank journal receivers 31 to 36, the cylinder head 42, and the crankcase 25 (not shown). ). Here, each of the journal oil passages 53 to 58 is formed at right angles to the dividing surfaces of the upper case 27 and the lower case 28.
[0026]
Further, as shown in FIG. 2, an oil pump 62 is installed inside the crankcase 25. The oil pump 62 is driven by a counter shaft (not shown) to store oil stored in the oil pan 29 with a strainer 63. The water is pumped up and discharged to the main oil gallery 52. Therefore, oil is supplied from the main oil gallery 52 to the crank journal receivers 31 to 36, the inside of the cylinder head 42, and the transmission to lubricate each part. An oil filter 64 is provided on the front surface of the crankcase 25 and in the center in the vehicle width direction. The oil discharged from the oil pump 62 first passes through the oil filter 64 to filter out impurities, and then the main oil. It flows to the gallery 52.
[0027]
By the way, a part of the oil discharged from the oil pump 62 is supplied to the inside of the cylinder head 42 and the inside of the cylinder block 41 as cooling oil by the cooling oil pipe 65 disposed at the rear part of the cylinder assembly 26. The oil spent for cooling flows to the oil cooler 22 through a cooler inlet hose (not shown), and after heat exchange there, the oil formed on the cooler outlet hose 66 (see FIG. 4) and the bottom surface of the oil pan 29 It returns to the inside of the oil pan 29 through the return passage 67. The oil return passage 67 is formed to extend below the main oil gallery 52 in the front-rear direction.
[0028]
Further, the parallel multi-cylinder engine 13 is provided with a balancer device 70 for mitigating secondary vibration that occurs as the crankshaft 37 rotates. The balancer device 70 has a crank journal receiver 31 so that its axis is parallel to the crankshaft 37 and in the vicinity of the cylinder bore shaft extension C when viewed in the axial direction of the crankshaft 37 (see FIG. 2). To 36 journal fastening bolts 38 and 39 (see FIG. 4).
[0029]
The balancer device 70 includes an eccentric support shaft 71 and a balancer rotating body 72, and both ends of the eccentric support shaft 71 are closely inserted into standing wall portions of two adjacent crank journal receivers 32 and 33. The balancer rotating body 72 is rotatably supported via a roller bearing 73 at an intermediate portion of the eccentric support shaft 71. A balancer weight 74 is integrally formed at the right end portion of the balancer rotating body 72, while a balancer third gear 76 is provided at the left end portion of the balancer rotating body 72 via a buffer damper 75, and this gear 76 is attached to the crankshaft 37. It meshes with the formed balancer drive gear 77.
[0030]
Since the balancer drive gear 77 has twice the number of teeth as the balancer third gear 76, when the crankshaft 37 rotates, the balancer rotating body 72 (balancer weight 74) rotates at twice the rotational speed of the crankshaft 37. The secondary vibration accompanying the rotation of the shaft 37 is canceled out. The balancer rotator 72 is prevented from being submerged under the liquid level of the oil stored in the oil pan 29 by a saucer-shaped oil separator 78 (see FIG. 4) installed immediately below the balancer rotator 72. Rotation resistance is reduced.
[0031]
An intermediate portion of the eccentric support shaft 71 is slightly eccentric with respect to both end portions, and a rotation adjusting portion 81 (see FIG. 5) is provided at the left end of the eccentric support shaft 71, for example. The rotation adjusting portion 81 is exposed on the left side surface of the lower case 28, and the lock plate 82 is fastened to this portion with a lock bolt 83, thereby preventing the eccentric support shaft 71 from rotating naturally. The distance between the balancer rotating body 72 and the crankshaft 37 can be adjusted by loosening the lock bolt 83 and accessing the rotation adjusting unit 81 with a tool such as a screwdriver to rotate the eccentric support shaft 71. .
[0032]
For this reason, the backlash in the meshing part of the balancer reven gear 76 and the balancer drive gear 77 can be removed to prevent the meshing noise of the gear, and the quietness during operation of the parallel multi-cylinder engine 13 can be improved.
[0033]
By the way, the main oil gallery 52 formed inside the lower case 28 is partially cut off, and both ends of the cut-off section are closed, and a separate bypass pipe is formed between the closed parts. 85 is connected. The bypass pipe 85 is curved and formed in a substantially U shape that enters the bottom, and the connection positions of the main oil gallery 52 and both ends of the bypass pipe 85 are six cranks formed inside the crankcase 25. there is a two crank journals received in the vicinity of the lower adjacent excluding crank journal receiver 31 and 36 at both ends of the journal receiving 31 to 36.
[0034]
In this embodiment, as shown in an enlarged view in FIG. 5, the connection position of the left end portion of the bypass pipe 85 is the lower portion of the crank journal receiver 32, and the connection position of the right end portion of the bypass pipe 85 is the crank journal receivers 33 and 34. The bottom is between.
[0035]
At both ends of the cut section of the main oil gallery 52, cylindrical connection ports 86 and 87 that open downward are provided. On the other hand, the bypass pipe 85 has a three-piece structure in which cylindrical insertion portions 89 and 90 each having a thick outer diameter are fixed to both ends of a pipe member 88 curved in a substantially U shape. 89 and 90 are inserted into the connection ports 86 and 87 of the main oil gallery 52 from below. Since the O-ring 91 is provided around the insertion portions 89 and 90, the space between the connection ports 86 and 87 and the insertion portions 89 and 90 is sealed in a liquid-tight manner. The bypass pipe 85 does not necessarily have a three-piece structure, and the pipe member 88 and the insertion portions 89 and 90 may be configured integrally.
[0036]
On the other hand, the oil pan 29 is formed with a pipe receiving portion 93 positioned immediately below the bypass pipe 85. This pipe receiving portion 93 is formed in a clamp shape (see FIG. 4) having a substantially U-shaped cross section and is provided near the upper portion of the oil return passage 67. When the oil pan 29 is joined below the lower case 28, Since the pipe receiving portion 93 comes into contact with the intermediate portion of the bypass pipe 85 (pipe material 88) from below, the insertion portions 89 and 90 of the bypass pipe 85 can be removed from the connection ports 86 and 87 of the main oil gallery 52. Is prevented.
[0037]
Thus, the insertion parts 89 and 90 at both ends of the bypass pipe 85 are inserted into the connection ports 86 and 87 of the main oil gallery 52 from below, and the pipe receiving part 93 formed on the oil pan 29 side is inserted into the bypass pipe 85 from below. By adopting the abutting structure, it is possible to prevent the insertion portions 89 and 90 of the bypass pipe 85 from being removed from the connection ports 86 and 87 without providing a dedicated fixing member or the like. For this reason, the number of component parts and assembly man-hours of the parallel multi-cylinder engine 13 can be reduced and the manufacturing cost can be reduced.
[0038]
By the way, the balancer device 70 has an axial center height substantially the same as that of the main oil gallery 52, and its front-rear position is set several centimeters ahead of the main oil gallery 52. As shown in FIG. 5, the balancer rotor 72 is arranged so as to be positioned inside the substantially U shape of the bypass pipe 85, and as shown in FIGS. 2 and 4, the crankshaft 37 is viewed in the axial direction. The main oil gallery 52 and the balancer rotating body 72 overlap. If the eccentric support shaft 71 is not eccentric, it is also conceivable that the axis of the balancer device 70 is arranged substantially coaxially with respect to the main oil gallery 52.
[0039]
As described above, since the balancer device 70 is arranged so as to overlap the portion where the main oil gallery 52 is cut off, the balancer device 70 and the main oil gallery 52 are both located near the lower part of the crankshaft 37 without interfering with each other. Can be arranged.
[0040]
As a result, the balancer device 70 is disposed in the vicinity of the cylinder bore shaft extension line C to exhibit the maximum vibration damping effect, and at the same time, the plurality of journal oil passages 53 to 58 extending from the main oil gallery 52 are all crankcase 25. The journal oil passages 53 to 58 can be formed at the same time when the lower case 28 is cast, so that the manufacturing cost of the parallel multi-cylinder engine 13 can be greatly reduced.
[0041]
Further, the balancer device 70 is arranged so that its axial center is located in a region between the journal fastening bolts 38 and 39 of the crank journal receivers 31 to 36 as viewed in the axial direction of the crankshaft 37. Since this is the most rigid portion in the crankcase 25, the damping effect of the balancer device 70 can be improved in this respect as well. In addition, since the balancer device 70 is installed in this highly rigid portion, it is not necessary to improve the strength of the crankcase 25 and other related portions in accordance with the support of the balancer device 70, so the cost of the parallel multi-cylinder engine 13 can be reduced. You can avoid ups and weight increases.
[0042]
On the other hand, since the bypass pipe 85 connecting the both ends of the cut section of the main oil gallery 52 is completely hidden inside the crankcase 25 and the oil pan 29, the bypass pipe 85 is prevented from being damaged by an external force. The appearance of the multi-cylinder engine 13 can be improved.
[0043]
The parallel multi-cylinder engine according to the present invention can be applied not only to a motorcycle but also to other vehicles.
[0044]
【The invention's effect】
As described above, the parallel multi-cylinder engine for a vehicle according to the present invention cuts off a section of the main oil gallery formed inside the lower case constituting the crankcase, and The bypass pipes are connected by a bypass pipe, and the bypass pipe is provided with a substantially U-shape that enters into the lower part, and at least a part of the balancer device that is rotationally driven by the crankshaft is disposed inside the substantially U-shape. The main oil gallery and the balancer device are overlapped when viewed from the axial direction of the crankshaft. According to this configuration, the balancer device and the main oil gallery are not interfered with each other. Both can be placed near the lower part of the crankshaft, facilitating the formation of journal oil passages and reducing engine manufacturing costs. Both supports the balancer device stably improve the damping effect, it can be made compact lightweight engine together.
[Brief description of the drawings]
FIG. 1 is a left side view of a motorcycle showing an example of a vehicle equipped with a parallel multi-cylinder engine according to the present invention.
FIG. 2 is a longitudinal sectional view of a parallel multi-cylinder engine as viewed from the left.
FIG. 3 is a view showing an embodiment of the present invention by a longitudinal section along the line III-III in FIG. 2;
4 is an enlarged view of a portion IV in FIG. 2;
FIG. 5 is an enlarged view of a portion V in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Motorcycle 13 Parallel multi-cylinder engine 25 Crankcase 27 Upper case 28 Lower case 29 Oil pan 31-36 Crank journal receptacle 37 Crankshaft 38,39 Journal fastening bolt 52 Main oil gallery 53-58 Journal oil passage 70 Balancer device 71 Eccentric support shaft 72 Balancer rotating body 81 Rotation adjusting portion 85 Bypass pipe 86, 87 Connection port 88 Pipe material 89, 90 Insertion portion 93 Pipe receiving portion

Claims (5)

An upper case and a lower case are provided, and a crankcase that is divided into upper and lower parts is provided. A crankshaft is pivotally supported by a plurality of crank journal receivers provided on the dividing surface of the crankcase, and the main oil gallery is located inside the lower case. Is formed substantially parallel to the crankshaft below the crankshaft, and a plurality of journal oil passages extending from the main oil gallery lead to the respective crank journal receivers , and are further rotationally driven by the crankshaft to reduce vibrations. In a vehicular parallel multi-cylinder engine installed with its axis parallel to the crankshaft, a section of the main oil gallery is cut off and both ends of the cut-off section are connected by a bypass pipe. In addition, the bypass pipe is given a substantially U-shape that enters the bay downward. At least a portion disposed parallel multi-cylinder engine for a vehicle, characterized in that to the main oil gallery and the balancer device and overlap as viewed in the axial direction of the crankshaft of the U-shaped the balancer apparatus on the inside of the. 2. The parallel multi-cylinder engine for a vehicle according to claim 1, wherein the shaft center of the balancer device is arranged in a region sandwiched between journal fastening bolts of the crank journal receiver as viewed in the axial direction of the crankshaft.   At the both ends of the cut section of the main oil gallery, connection ports that open substantially downward are provided, and at the both ends of the bypass pipe, there are provided insertion portions that are inserted into the connection ports in a liquid-tight manner, while the lower case By forming a pipe receiving part in the oil pan joined to the lower part of the oil pipe and bringing the pipe receiving part into contact with the bypass pipe from below, the insertion part of the bypass pipe can be removed from the connection port of the main oil gallery. The parallel multi-cylinder engine for a vehicle according to claim 1 or 2, which is prevented.   The balancer device includes an eccentric support shaft whose intermediate portion is eccentric with respect to both end portions, and a balancer rotating body that is rotatably supported by the intermediate portion of the eccentric support shaft, and has both ends of the eccentric support shaft. The rotation adjustment portion provided at one end of the eccentric support shaft is exposed on one side of the crankcase, and the rotation adjustment portion is rotated so that the intermediate portion of the eccentric support shaft is supported. The parallel multi-cylinder engine for a vehicle according to claim 1, wherein an inter-axis distance between the engine and the crankshaft is adjustable. The main end portions of the oil gallery shredding section and the connection position between the two ends of the bypass pipe, the two adjacent crank journals received lower excluding the crank journal receiving the ends of the plurality of crank journals received 5. The parallel multi-cylinder engine for a vehicle according to claim 1, wherein the parallel multi-cylinder engine for a vehicle according to claim 1, wherein the bypass pipe is disposed in the vicinity of an oil pan joined to the lower case.

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