CN1487178A - air pump drive - Google Patents

Abstract

The invention discloses an air pump driving device. In an air pump driving device that drives an air pump with an engine, the number of components can be reduced to downsize the entire engine, and it can be easily mounted on a vehicle or the like, and the degree of freedom in setting the gear ratio of the air pump can be increased. The engine has a camshaft (41) that constitutes a part of the valve device (38) and is arranged on the cylinder group (13), and constitutes four strokes, and an air pump (61) that transmits power from the camshaft (41) The pump housing (63) is integrated with the cylinder block (13).

Description

air pump drive

technical field

The present invention relates to an improvement of an air pump driving device which utilizes an engine to drive the air pump.

Background technique

Related air pump driving devices have been known in the past, for example, from Patent Document 1, Patent Document 2, Patent Document 3, and the like.

[Patent Document 1]

Japanese Patent Laid-Open Publication No. 11-44216

[Patent Document 2]

Patent No. 2820782

[Patent Document 3]

Japanese Patent Application Publication No. 2000-170501

In the content disclosed in the above-mentioned Patent Document 1, the double-acting piston air pump with a pump casing independent of the cylinder head is constructed in a manner driven by the camshaft on the cylinder head. Since the air pump is installed in the volume Since the center of gravity of the engine is shifted to the side of the cylinder head due to the high mass of the cylinder head, it may be difficult to mount it on a vehicle.

Furthermore, in the content disclosed in the above-mentioned Patent Document 2, the pump housing of the air pump which is independent of the clutch cover is attached to the clutch cover in the crankcase, which not only increases the number of components, but also leads to an increase in the overall size of the engine. possibility. In addition, a structure in which power is transmitted from the engine crankshaft to the air pump via a dedicated gear train may result in an increase in the number of components and an increase in the size of the engine.

Furthermore, in the content disclosed in the above-mentioned Patent Document 3, the pump casing of the air pump is integrated with the cylinder block, and the air pump is directly driven by the crankshaft, so that the engine is enlarged in the direction extending along the axis of the crankshaft, and it is impossible to freely Set the gear ratio of the air pump.

In view of the above problems, an object of the present invention is to provide an air pump driving device capable of reducing the number of components and downsizing the entire engine, which is easy to mount on a vehicle, and which increases the degree of freedom in setting the air pump transmission ratio.

Contents of the invention

In order to achieve the above objects, the invention according to the first aspect of the present invention is an air pump driving device that drives an air pump by using an engine having a camshaft that constitutes a part of the valve device and is arranged in the cylinder group, and constitutes 4 strokes, the pump casing of the air pump that transmits the power from the camshaft is integrated with the cylinder group.

According to the invention described in the first aspect of the present invention, since the pump casing is integrally formed on the cylinder block whose outer shape is smaller than the cylinder head or the crankcase which is formed to coordinate with the engine main body, the number of components is reduced, and it is possible to Realize the miniaturization of the whole engine, because the camshaft driving the air pump is also arranged in the cylinder group, so the power transmission mechanism that transmits the power from the camshaft to the air pump can be compactly constituted, and the air pump gear ratio The degree of freedom of setting is also improved.

In the invention according to the second aspect of the present invention, on the basis of the structure of the invention described in the first aspect of the present invention, between the pump drive shaft connected to the air pump and the camshaft, there is an annular The power transmission mechanism of the drive belt adopts such a structure that the distance between the camshaft and the pump drive shaft is not affected, and the enlargement of the cylinder block can be prevented and the number of components can be reduced.

In the invention according to claim 3 of the present invention, in addition to the structure of the invention described in claim 2 above, the plane perpendicular to the pump drive shaft that includes the cylinder axis of the engine faces each other. The air pump and the auxiliary machine connected to both ends of the pump drive shaft are arranged at a symmetrical position. With such a structure, the number of components can be reduced by using the pump drive shaft connected to the air pump to drive the auxiliary machine. and reduced weight, can reduce costs by simplifying machining and assembly. Furthermore, the protrusion of the cylinder group to the auxiliary machine is prevented, and the overall size of the cylinder group is avoided.

In the invention described in the fourth aspect of the present invention, on the basis of the structure of the invention described in the third aspect of the present invention, the engine is water-cooled, and the auxiliary machine is a water pump. The water pump is arranged near the cylinder block and the cylinder head, which shortens the water piping, avoids the complexity of the piping, and reduces the pressure loss in the piping.

The invention according to claim 5 of the present invention is based on the structure of the invention according to any one of the first to fourth aspects of the present invention, wherein the air pump is configured such that the piston is in a direction parallel to the cylinder axis of the engine. The reciprocating type of the upper reciprocating motion, the pump drive shaft that transmits the power from the camshaft is connected to the piston through the crank of the yoke type. With this structure, a higher air pressure can be obtained. The air pump The axis of motion is parallel to the cylinder axis of the engine, and the miniaturization of the engine can be realized by adopting a yoke-type crank without using a connecting rod.

In the invention according to claim 6 of the present invention, on the basis of the structure of the invention described in claim 5, the pump housing of the air pump has an axis parallel to the cylinder axis of the engine, and at the same time, forms a side of the cylinder head Open bottomed cylindrical shape, and integrated with the cylinder block, the cover member for air-sealing the cylinder head side opening of the pump casing is bonded to the cylinder block and the cylinder head in the same plane as the bonding surface of the cylinder block and the cylinder head. On the above-mentioned pump casing, adopting this structure can reduce the processing steps of the cylinder group.

Furthermore, in the invention according to claim 7 of the present invention, in addition to the structure of any one of the inventions described in claims 1 to 6, the fuel is directly injected into the air together with the compressed air supplied from the air pump. The injector in the combustion chamber is arranged on the cylinder head. With this structure, since the air pump is not arranged on the cylinder head, the design freedom can be increased and the engine can be downsized, and the injector and its piping can be arranged on the cylinder head. In particular, when the pump chamber of the air pump is arranged on the side of the cylinder head, the distance between the pump chamber and the injector is short, which avoids the complicated structure of the pipeline connected between the air pump and the injector, and can reduce the Pressure loss in the pipeline structure described above.

Description of drawings

Fig. 1 is a partial longitudinal sectional side view of the engine;

Fig. 2 is a 2-2 line view of Fig. 1 with the end cover removed;

Fig. 3 is the 3-3 line sectional view of Fig. 2;

Fig. 4 is a sectional view of line 4-4 of Fig. 3;

Fig. 5 is the 5-5 line sectional view of Fig. 2;

Fig. 6 is a sectional view of line 6-6 of Fig. 5;

Fig. 7 is the 7-7 line sectional view of Fig. 5;

Fig. 8 is a longitudinal sectional view of the engine along line 8-8 in Fig. 2 .

Detailed ways

Hereinafter, an embodiment of the present invention will be described based on one embodiment of the invention shown in the drawings.

Fig. 1～Fig. 8 shows an embodiment of the present invention, and Fig. 1 is the partial longitudinal sectional side view of engine, and Fig. 2 is the 2-2 line view of Fig. 1 under the state that end cover is removed, Fig. 3 is 3-3 line sectional view of Fig. 2, Fig. 4 is 4-4 line sectional view of Fig. 3, Fig. 5 is 5-5 line sectional view of Fig. 2, Fig. 6 is 6-6 line sectional view of Fig. 5, Fig. 7 is Fig. 5 7-7 line sectional view, Fig. 8 is a longitudinal sectional side view of the engine along line 8-8 in Fig. 2 .

First, in Fig. 1, the engine body 11 of the four-stroke water-cooled single-cylinder engine of the overhead valve type is equipped with: a crankcase 12, a cylinder group 13 combined with the crankcase 12, The cylinder head 14 connected to the cylinder block 13 on the opposite side and the end cover 15 bonded to the cylinder head 14 on the opposite side to the cylinder block 13 are attached to a vehicle such as a motorcycle with the cylinder head 14 side slightly upward. .

Referring to Fig. 2 ~ Fig. 4 at the same time, the piston 17 that slidably cooperates with the cylinder bore 16 provided in the cylinder group 13 is connected to the crankcase 12 freely via the connecting rod 18 and the crank pin (not shown). A combustion chamber 19 facing the top of the piston 17 is formed between the cylinder group 13 and the cylinder head 14 on a rotatably supported crankshaft 10 (see FIG. 1 ).

The cylinder head 14 is provided with: first and second intake valve ports 20, 22 opened on the top surface of the combustion chamber 19, communicated with these intake valve ports 20, 21 and on the upper side of the cylinder head 14 The suction pump 23 of opening, the single exhaust valve port 22 of opening on the top surface of combustion chamber 19, communicate with this exhaust valve port 22 and the exhaust hole 24 of the bottom side opening of cylinder head 14; Simultaneously, with The injector 25 , which compresses the air and simultaneously injects fuel directly into the combustion chamber 19 , is arranged on the axis of the cylinder bore 16 , that is, the cylinder axis C.

On the figure projected on a plane orthogonal to the cylinder axis C, the first intake valve port 20 and the exhaust valve port 22 are arranged on both sides of the cylinder axis C, that is, the injector 25, and are approximately connected to the first On another straight line L2 perpendicular to the straight line L1 between the intake valve port 20 and the exhaust valve port 22 , the second intake valve port 21 is arranged on the side of the cylinder axis C, that is, the injector 25 . And, a spark plug 26 is attached to the cylinder head 14 facing the combustion chamber 19 at a position avoiding the first intake valve port 20 , the second intake valve port 21 , and the exhaust valve port 22 .

On the cylinder head 14, the first and second suction valves 27, 28, which can open and close the first and second suction valve ports 20, 21 respectively, can be opened and closed, and can be opened and closed. Close the exhaust valve 29 of the exhaust valve port 22. The first and second suction valves 27, 28 are respectively slidably fitted into guide cylinders 30 ... Between the seat rings 31... on the upper ends of 27 and 28 and the cylinder head 14, valve springs 32... are arranged respectively, and the spring force exerted by these valve springs 32... , 28 is loaded in the direction to make the valve close. And, the exhaust valve 29 is slidably fitted into the guide cylinder 33 fixed on the cylinder head 14, between the seat ring 34 fixed on the upper end portion of the exhaust valve 29 protruding from the guide cylinder 33 and the cylinder head 14 A valve spring 35 is provided, and the exhaust valve 29 is biased in a direction to close the valve by a spring force exerted by the valve spring 35 .

Referring to Figs. 5 to 7 at the same time, the first and second suction valves 27, 28 and exhaust valve 29 are driven to open and close by an air valve device 38. The air valve device 38 is equipped with: a suction side and an exhaust side cam 39, 40 and rotating camshaft 41, the suction side first rocker arm 42 driven by the suction side cam 39 and the exhaust side first rocker arm 42 driven by the exhaust side cam 40 The rocker arm 43, the suction-side second rocker arm 44 having a pair of pressing arm portions 44a, 44b in contact with the first and second suction valves 27, 28, and the second rocker arm 44 on the suction side having a pressing arm portion in contact with the exhaust valve 29 The second rocker arm 45 on the exhaust side of 45a transmits the swing motion of the first rocker arm 42 on the suction side to the second rocker arm 44 on the suction side and is arranged between the first and second rocker arms 42 and 44 on the suction side. between the suction side push rod 46, the swing motion of the exhaust side first rocker arm 43 is transmitted to the exhaust side second rocker arm 45 and is arranged between the exhaust side first and second rocker arms 43, 45 Exhaust side push rod 47.

An air valve chamber 48 is formed between the cylinder head 14 and the end cover 15, and the air valve chamber 48 is used to accommodate and configure the second rocker arms 44, 45 on the suction side and the exhaust side in the air valve device 38, and the suction The upper parts of the air-side and exhaust-side push rods 46 , 47 are provided with oil injection holes 36 in the end cover 15 in order to lubricate the portion of the air valve device 38 housed in the air valve chamber 48 .

In the crankcase 12, the cylinder block 13 and the cylinder head 14 in the engine main body 11, an oil return passage 49 is provided extending parallel to the cylinder axis C on the side of the cylinder bore 16, and the oil return passage 49 is used to make the The oil lubricating the part of the valve device 38 accommodated in the valve chamber 48 is returned to the oil pan 12a (see FIG. 1 ) formed in the lower part of the crankcase 12 .

The camshaft 41 in the valve device 38 is arranged in the cylinder group 13 so as to avoid the valve chamber 48 between the cylinder head 14 and the end cover 15 and to be accommodated in the oil return passage 49, and the axis is parallel to the crankshaft. Both ends of the camshaft 41 are rotatably supported by the cylinder group 13 via ball bearings 51 , 51 , and by a cover 50 connected to the cylinder group 13 so as to form the outer surface of the oil return passage 49 .

Also, an oil supply path 37 is provided on the camshaft 41 for sliding contact with the intake-side and exhaust-side cams 39, 40, and the first main arm 42 on the intake side and the first rocker arm 43 on the exhaust side. Supply of lubricating oil.

In the oil return passage 49, the first driven sprocket 52, the first driving sprocket 60 (see FIG. 1 ) and the endless cam chain are accommodated in order to reduce the power from the crankshaft 10 by 1/2 and transmit it. 53, the first driven sprocket 53 is connected to the camshaft 41 in a non-rotatable manner, the first driving sprocket 60 is connected to the crankshaft 10 in a non-rotatable manner, and the cam chain 53 is wound around the first driving sprocket 60 and the second driving sprocket 60 On a driven sprocket 52.

Intake-side and exhaust-side first rocker arms 42, 43, respectively having rollers 54, 55 in rolling contact with the intake-side and exhaust-side cams 39, 40 from the side of the cylinder head 14, are arranged parallel to said camshafts. 41 and first rocker shafts 56 , 57 on the intake side and exhaust side provided between the cylinder bank 13 and the head 50 are swingably supported. Bowl-shaped pressing portions 42a, 43a located on opposite sides of the rollers 54, 55 are integrally provided on these suction-side and exhaust-side first rocker arms 42, 43 in such a manner as to open on the cylinder head 14 side. superior.

On the other hand, on the cylinder head 14 in the valve chamber 48 , the intake-side and exhaust-side second valves having axes parallel to the camshaft 41 are supported so as to be arranged on both sides of the injector 25 . The rocker shafts 58, 59 are the second rocker arm 44 on the suction side, which has a pair of pressing arm parts 44a, 44b branched into two strands, and is swingably supported by the rocker shaft 58 on the suction side, and the second rocker arm 44 on the exhaust side. The two rocker arms 45 are swingably supported by an exhaust-side rocker shaft 59 .

And, on the side opposite to the two push arm portions 44a, 44b with respect to the second rocker shaft 58 on the suction side, on the second rocker arm 44 on the suction side, a bowl that is opened on the side of the cylinder group 13 is integrally provided. The pressure receiving portion 44c is integrally provided on the second rocker arm 45 on the exhaust side on the side opposite to the pressing arm portion 45a with respect to the second rocker arm shaft 59 on the exhaust side, and is opened on the side of the cylinder group 13. Bowl-shaped pressure receiving portion 45b.

The suction side and exhaust side push rods 46, 47 pass through the valve chamber 48 and extend between a part of the oil return passage 49, and the spherical ends of the suction side and exhaust side push rods 46, 47 on one end side The part can be swung to fit on the pressing parts 42a, 43a of the first rocker arms 42, 43 on the suction side and the exhaust side, and the spherical ends on the other end sides of the push rods 46, 47 on the suction side and the exhaust side The pressure receiving parts 44c, 45b of the suction-side and exhaust-side second rocker arms 44, 45 are fitted so as to be swingable.

In the valve device 38, according to the rotation of the camshaft 41 that transmits the rotational force from the crankshaft at a reduction ratio of 1/2, the intake side push rod is moved by swinging the intake side first rocker arm 42 by the intake side cam 39. 46 moves in its axial direction, and by correspondingly swinging the second rocker arm 44 on the suction side, the first and second suction valves 27, 28 are driven to open and close, and by using the cam 40 on the exhaust side to swing The exhaust-side first rocker arm 43 moves the exhaust-side push rod 47 in its axial direction, and accordingly swings the exhaust-side second rocker arm 45 to open and close the exhaust valve 29 .

The injector 25 serves to supply compressed air from a reciprocating air pump 61 that reciprocates a piston 66 in a direction parallel to the cylinder axis C to the exhaust hole 24 provided in the cylinder head 14 The corresponding side is arranged in the lower part of the cylinder bank 13 . In addition, in the cylinder group 13, in a plane perpendicular to the cylinder axis C, a working chamber 62 connected to the oil return passage 49 in a substantially L-shape and arranged below the cylinder bore 16 is formed. The pump 61 is disposed below the oil return passage 49 at the connecting portion between the oil return passage 49 and the working chamber 62 .

Referring to FIG. 8 , the pump casing 63 of the air pump 61 is formed into a bottomed cylindrical shape with an axis parallel to the cylinder axis C and the cylinder head 14 side is open, and is integrated with the cylinder block 13, and the pump casing 63 is airtightly closed. The cover member 64 of the side opening of the cylinder head 14 is connected to the cylinder block 13 . Also, the cover member 64 is joined to the pump housing 63 on the same plane as the joining face 87 of the cylinder block 13 and the cylinder head 14 .

A piston 66 is slidably fitted into the pump housing 63, and between one end of the piston 66 and the cover member 64, a pump chamber 65 arranged on the side of the cylinder head 14 is formed to generate compressed air corresponding to volumetric contraction. Between the other end of the pump housing 63 and the closed end of the pump housing 63, an atmospheric pressure chamber 88 is formed on the oil pan 12a side.

On the other hand, in the working chamber 62, a cylindrical bearing member 69 having an axis parallel to the axis of the camshaft 41 and passing through the axis of the piston 66 is arranged, and the bearing members 69 are respectively connected to Protrudingly arranged on a plurality of, for example, four connecting bosses 70 . . . on the cylinder group 13 . Also, a cover 72 forming the outer side of the working chamber 62 is connected to the cylinder group 13, and when the cover 72 is opened, the fastening and loosening operation of the bolts 71... can be performed.

The pump drive shaft 73 is coaxially inserted through the bearing member 69 , a roller bearing 74 is inserted between one end of the bearing member 69 and the pump drive shaft 73 , and the other end of the bearing member 69 is connected to the pump drive shaft 73 Ball bearing 75 is sandwiched between. That is, the pump drive shaft 73 is rotatably supported by the bearing member 69 connected to the cylinder group 13 .

The pump drive shaft 73 in the protruding part of one end of the bearing member 69 transmits the power from the camshaft 41 through the power transmission mechanism 89, which is driven by the second pump drive shaft 73 fixed on the power transmission mechanism 89. A driven sprocket 78, a second drive sprocket 79 integrated with the first driven sprocket 52 coupled to the camshaft 41, and wound around the second driven and drive sprockets 78, 79 as an endless drive belt The chain 80 constitutes.

The pump drive shaft 73 is connected to the piston 66 of the air pump 61 via a yoke crank 84, which connects the front end of the eccentric shaft 73a protruding from an eccentric position at one end of the pump drive shaft 73 to a slidably fitted to the member on the sliding plate 68 on the piston 66 . Also, corresponding to the rotation of the pump drive shaft 73 by the power transmitted from the camshaft 41, the eccentric shaft 73a rotates around the axis of the pump drive shaft 73, reciprocatingly drives the piston of the air pump 61 in the axial direction within the pump housing 63. 66, to increase or decrease the volume of the pump chamber 65.

In the piston 66, there is provided a slide hole 67 whose axis is arranged on a plane extending along one diameter line thereof and perpendicular to the axis of the camshaft 41, to which the slide piece 68 is slidably fitted. middle. Also, an eccentric shaft 73 a is integrally protrudingly provided on one end of the pump drive shaft 73 .

In addition, an opening 76 through which one end of the pump drive shaft 73 is inserted is provided in the pump casing 63, and an insertion hole 77 is provided in the piston 66 to pass through the longitudinal center of the sliding hole 67, and the eccentric shaft 73a is inserted into the insertion hole 77. In the hole 77 , the eccentric shaft 73 a is allowed to move in a direction along the axis of the slide hole 67 corresponding to the rotation of the pump drive shaft 73 .

At the central portion between the ball bearing 75 and the roller bearing 74, through-holes 81, 82 are provided on both side portions of the bearing member 69, respectively, and at positions corresponding to one through-hole 81, formed on the bearing member 69. An oil guide 83 for guiding a part of the oil dropped into the working chamber 62 between the bearing member 69 and the pump drive shaft 73 is integrally provided. That is, a passage 134 provided in the cylinder head 14 so as to guide part of the oil accumulated in the lower part of the valve chamber 48 is provided in the cylinder head 14, and a passage 135 opened on the working chamber 62 through the passage 134 is provided in the cylinder head 14. In the group 13 , an oil guide 83 is integrally provided on the bearing member 69 so as to guide the oil falling from the passage 135 into the through hole 81 . In addition, part of the oil introduced between the bearing member 69 and the pump drive shaft 73 is used to lubricate the roller bearing 74 and the ball bearing 75, and the rest falls from the through hole 82 into the working chamber 62 and is stored in the working chamber. The oil in the lower portion of the working chamber 62 is returned to the oil pan 12 a side from the return passage 136 provided in the cylinder group 13 through the lower portion of the working chamber 62 .

On the opposite side of the air pump 61 with respect to the bearing member 69, on the cylinder group 13, a water pump 90 as an auxiliary machine having a rotation axis coaxial with the pump drive shaft 73 is mounted on the side including the cylinder axis C with respect to The air pump 61 and the water pump 90 are disposed at positions symmetrical to the plane PL perpendicular to the pump drive shaft 73 .

The pump casing 91 of the water pump 90 is composed of a casing main body 92 formed by integrally connecting the disk-shaped portion 92b to the open end of the bottomed cylindrical portion 92a on the side of the closed pump drive shaft 73, and the open end of the closed casing main body 92. The pump cover 93 at the end is formed, and the pump cover 93 is connected to the cylinder group 13, and the outer peripheral part of the open end of the casing main body 92 is clamped between it and the cylinder group 13.

On the central part of the closed end of the bottomed cylindrical part 92a and the central part of the pump cover 93, both ends of the pump shaft 94 coaxial with the pump drive shaft 73 are freely rotatably supported, and a plurality of magnets 96.. . It is fixed to the rotor 95 inserted into the bottomed cylindrical portion 92a so as to rotate integrally with the pump shaft 94 . On the other hand, on the other end of the pump drive shaft 73 protruding from the other end of the bearing member 69, a rotating member having a cylindrical portion 97a around the same axis as the bottomed cylindrical portion 92a of the casing main body 92 is fixed. 97, a plurality of magnets 98 are fixed on the inner surface of the cylindrical part 97a. This causes the rotor 95 to rotate together with the pump shaft 94 corresponding to the rotation of the rotating member 97 together with the pump drive shaft 73 .

A vortex chamber 99 is formed between the casing main body 92 and the pump cover 93 , and the impeller 100 housed in the vortex chamber 99 is provided on the rotor 95 .

The pump cover 93 is provided with a plurality of suction ports 101... which are opened at the central part of the vortex chamber 99, and the cooling water sucked into the vortex chamber 99 from these suction ports 101... Pressurize. Further, the cooling water discharged from the water pump 90 is supplied to the head side water jacket 103 provided in the cylinder head 14 through the group side water jacket 102 provided in the cylinder group 13 and the water jacket 102 provided in the cylinder group side. According to the temperature of the cooling water, the state of guiding the cooling water discharged from the head side water jacket 103 to the radiator, etc. not shown in the figure is switched by the thermostat 104, and the state of guiding the cooling water discharged from the head side water jacket 103, and returning to the suction port by detouring in the radiator, etc. 101 . . . , the thermostat housing 105 of the thermostat 104 is integrated with the pump cover 93 of the water pump 90 .

In the upper side wall of the pump casing 63 in the air pump 61, an oil introduction hole 85 for introducing a part of the oil flowing in the oil return passage 49 into the pump is provided through the oil return passage 49. Shell 63 for lubrication. By rotating in the oil return passage 49, the suction side cam 39 and the exhaust side cam 40 of the camshaft 41 agitate and raise a part of the oil flowing in the oil return passage 49, and separate it by centrifugal force. , scattering, and use the centrifugal force to separate and scatter a part of the oil supplied from the oil supply path 37, and set the camshaft 41 and the oil introduction hole 85 in such a way that the separated oil droplets are guided into the oil introduction hole 85 relative position.

The portion of the oil return passage 49 corresponding to the valve device 38 is formed wider than the rest, and surrounds the portion of the camshaft 41 corresponding to the intake cam 39 and the exhaust cam 40 in a substantially semicircular shape. The convex wall 86 of the oil return passage 49 is opposed to the oil flow direction 137 in the oil return passage 49 and protrudes integrally on the cylinder block 13. The oil introduction hole 85 of the air pump 61 is arranged on the cylinder block 13 along the oil flow direction 137 Just upstream of the convex wall 86 . That is, the convex wall 86 is used to introduce the oil circulating in the oil return passage 49 into the oil introduction hole 85 .

Also, the oil introduction hole 85 is provided in the pump casing 63 on the inner periphery of the pump casing 63 on the side of the atmospheric pressure chamber 88 larger than the piston ring 138 mounted on the outer periphery of the piston 66 and in sliding contact with the inner periphery of the pump casing 63. Regardless of the movement of the piston 66 in the axial direction, the oil introduction hole 85 always communicates with one end of the sliding hole 67 provided on the piston 66 . Also, on the outer periphery of the piston 66, a pair of grooves 139... are provided between the end of the piston 66 on the atmospheric pressure chamber 88 side and both ends of the slide hole 67, and are introduced into the pump housing 63 from the oil introduction hole 85. Part of the oil in the pump is used to lubricate between the piston 66 and the pump casing 63, and the rest flows to the atmospheric pressure chamber 88 side through the groove 139.... Moreover, the grooves 139 . . . have the effect of preventing the oil from being extracted from the sliding piece 68 in the yoke crank 84 through the selection of the oil in the sliding hole 67 .

Then, the oil that has flowed into the atmospheric pressure chamber 88 flows from the opening 76 to the working chamber 62 side, and further flows from the return passage 136 to the oil pan 12 a side.

7, the injector 25 is composed of an air fuel injection valve 107 having a nozzle 106 protruding into the combustion chamber 19 and mounted on the cylinder head 14, and is connected to the air fuel injection valve 107 so as to inject the air fuel from the rear. The fuel injection valve 108 that injects fuel in the valve 107 constitutes, and the air fuel injection valve 107 injects fuel directly into the combustion chamber 19 together with the compressed air.

In the cylinder head 14, coaxially with the cylinder axis C, a fitting hole 109 that is hermetically fitted to the nozzle 106 and a fitting hole 109 coaxially connected to the fitting hole 109 having an inner diameter larger than the diameter of the fitting hole 109 are provided. Inserting the barrel 110, the nozzle 106 of the air fuel injection valve 107 is hermetically fitted to the fitting hole 109 while being inserted into the inserting barrel 110 until it comes into contact with the annular step portion 111 formed between the fitting hole 109 and the inserting barrel 110 . Moreover, the wire connecting portion 107a arranged at the rear of the air fuel injection valve 107 is arranged on the notch 110a provided on the rear end of the insertion cylinder 110, and a pair of wires 112 drawn out from the wire connection portion 107a outside the insertion cylinder 110. . . , penetrate the gasket 113 clamped between the overlapping surfaces of the cylinder head 14 and the end cover 15 and lead out to the outside.

On the other hand, the fuel injection valve 108 is fitted and held on the end cover 15, and a cylindrical injector case sandwiching the air fuel injection valve 107 and the cylinder head 14 is integrally formed. 114 , when the end cover 15 is coupled to the cylinder head 14 , the front end of the injector housing 114 is in contact with the rear end of the air-fuel injection valve 107 . Furthermore, a clamping plate 115 for clamping the rear end portion of the fuel injection valve 108 between the injector housing 114 and the rear end of the injector housing 114 is connected.

Between the injector housing 114 and the fuel injection valve 108, an annular fuel chamber 116 passing through the inside of the fuel injection valve 108 is formed, and a pair of sealing members 117, 118 sandwiching the fuel chamber 116 from both sides are sandwiched by the fuel injection valve. 108 and jet housing 114.

Moreover, a fuel supply passage 119 passing through the fuel chamber 116 is directly provided on the end cover 15 , and a hose 120 leading in fuel from a fuel supply source not shown in the figure is connected to the fuel supply passage 119 via a joint 121 .

And, between the front end portion of the fuel injection valve 108, the rear end portion of the air fuel injection valve 107, and the injector housing 114, an annular air chamber 122 passing through the inside of the air fuel injection valve 107 is formed to transfer air from the air pump 61. Incoming compressed air is supplied into the air chamber 122 .

2 and FIG. 8, on the cover member 64 in the air pump 61, there is provided a suction pipe 124 connected to a hose that introduces air from an air filter not shown in the figure, and the suction pipe 124 passes through the cover built into the cover. A reed valve (not shown) in member 64 is connected to pump chamber 65 .

Also, a poppet valve 125 that opens the valve in response to an increase in the pressure of the pump chamber 65 is built in the cover member 64 , and the compressed air discharged from the air pump 61 is supplied through the poppet valve 125 and the compressed air supply path 126 . Give the air chamber 122.

The compressed air supply path 126 is formed by a tubular member 127 connected at one end to the cover member 64 in such a manner as to be connected to the poppet valve 125 and at the other end to the cylinder head 14. A passage 128 connected to the cylinder head 14 and a passage 129 directly connected to the end cover 15 so as to pass through the passage 128 and pass through the air chamber 122 are constituted.

In addition, a part of the passage 128 directly provided on the cylinder head 14 passes through the vicinity of the exhaust hole 24. In particular, in the vicinity of the exhaust hole 24, the cylinder head side water jacket 103 is arranged between the exhaust hole 24 and the cylinder group 13. On the other hand, the passage 128 is set so as to pass through the side opposite to the head side water jacket 103 with respect to the exhaust hole 24 .

And, both ends of the cylindrical positioning pin 130 straddling the overlapping surfaces of the cylinder head 14 and the end cover 15 are inserted into the cylinder head 14 and the end cover 15 to form a part of the compressed air passage 126 and are directly arranged on the cylinder head 14 and the end cover. The passages 128 and 129 on the cover 15 are connected through the positioning pin 130 . Also, an O-ring 133 surrounding the dowel pin 130 is sandwiched between the coincident surfaces of the cylinder head 14 and the end cover 15 .

Also, a hole 131 is formed in the positioning pin 130 , and a relief valve 132 connected to the passage 128 on the upstream side of the hole 131 is attached to the cylinder head 14 .

The effect of this embodiment will be described below. Between the cylinder head 14 and the end cover 15, which is a part of the engine body 11 in the engine that constitutes the four-stroke overhead valve type, an air valve chamber 48 is formed. 48 accommodates and configures the upper parts of the intake side and exhaust side second rocker arms 44, 45 and the intake side and exhaust side push rods 46, 47 as at least a part of the valve device 38, in the engine main body 11 In the crankcase 12, the cylinder block 13, and the cylinder head 14, an oil return passage 49 is formed so as to extend parallel to the cylinder axis C on the side of the cylinder bore 16, and the oil return passage 49 is used to make the valve unit 38 The lubricating oil contained in the valve chamber 48 is returned to the oil pan 12 a formed at the lower part of the crankcase 12 . Furthermore, in the pump housing 63 of the air pump 61 arranged below the oil return passage 49, an oil introduction hole 85 is provided to pass through the oil return passage 49, and the oil introduction hole 85 is used to pass the oil flowing through the oil return passage 49 Part of it is used for lubrication and is introduced into the pump casing.

Therefore, a part of the oil that lubricates a part of the air valve device 38 and returns to the oil pan 12a is reliably introduced into the oil introduction hole 85 of the air pump 61, and the air pump 61 can be reliably lubricated with a simple structure. .

Furthermore, since the pump housing 63 is integrally formed in the cylinder block 13 having an outer shape smaller than the cylinder head 14 and the crank case 12 which are formed to coordinate with the engine main body 11, the number of components can be reduced and the overall size of the engine can be reduced. , It is easy to communicate with the oil return passage 49 and the oil introduction hole 85, and the oil supply structure to the air pump 61 can be simplified.

Also, the first driven sprocket 52, the first driving sprocket 60, and the cam chain 53 for transmitting power from the crankshaft 10 to the camshaft 41 of the valve device 38 are housed in the oil return passage 49, and The first driven sprocket 52 , the first driving sprocket 60 and the cam chain 53 serve as the oil return passage 49 , whereby downsizing of the engine and simplification of the oil supply structure to the air pump 61 can be achieved.

In addition, the camshaft 41 is accommodated and disposed in the oil return passage 49, and the cam chain 41 is set so that the oil droplets separated by the centrifugal force accompanying the rotation of the camshaft 41 are guided to the oil introduction hole 85 side. Therefore, the camshaft 41 can be well lubricated by the oil circulating in the oil return passage 49, and at the same time, the oil droplets scattered by the rotation of the camshaft 41 can be effectively introduced. To the air pump 61, to carry out good lubrication to the air pump 61.

Between the pump drive shaft 73 connected to the air pump 61 and the camshaft 41, a power transmission mechanism 89 that transmits the power of the camshaft 41 to the pump drive shaft 73 is provided, and the camshaft 41 that drives the air pump 61 is arranged near the air pump 61 , to simplify the structure of the power transmission mechanism 89, the miniaturization of the engine can be realized.

Moreover, since the camshaft 41 is also disposed in the cylinder group 13 having a relatively small external shape, the engine can be further downsized, and the power transmission mechanism 89 that transmits power from the camshaft 41 to the air pump 61 can be compactly configured. , At the same time, the degree of freedom in setting the gear ratio of the air pump 61 is also improved. In addition, since the power transmission mechanism 89 is configured to transmit power by the endless chain 80, regardless of the distance between the camshaft 41 and the pump drive shaft 73, it is possible to prevent the cylinder block 13 from being enlarged and reduce the number of components.

And, in the cylinder group 13, protrudingly set the convex wall 86 opposite to the oil flow direction 137 in the oil return passage 49, so that the oil in the lower part of the oil return passage 49 is guided to the oil introduction hole 85, and the convex wall 86 can be used to effectively The oil is directed to the oil inlet hole 85 to lubricate the air pump 61 better.

The air pump 61 is configured in a reciprocating manner, and can obtain relatively high air pressure. Also, a pump drive shaft 73 for transmitting power from the camshaft 41 reciprocating the piston 66 in a direction parallel to the cylinder axis C is connected to the piston 66 via a yoke crank 84 , Therefore, parallel to the working axis of the air pump 61 and the cylinder axis C and adopting the block yoke crank 84, no connecting rod is required, and the engine can be miniaturized.

In addition, the air pump 61 is a member in which a piston 66 is slidably fitted into the pump housing 63, and the two ends of the piston face each other and are arranged on the cylinder head 14 so as to generate compressed air corresponding to volumetric compression. The pump chamber 65 on the side and the atmospheric pressure chamber 88 disposed on the oil pan 12a side through the oil pan 12a are at a pressure higher than the atmospheric pressure of the piston ring 138 mounted on the outer circumference of the piston 66 and in sliding contact with the inner circumference of the pump casing 63. On one side of the chamber 88, the oil introduction hole 85 is opened on the inner circumference of the pump casing 63, so that the oil that has finished lubricating the air pump 61 is smoothly flowed from the atmospheric pressure chamber 88 to the oil pan by the suction action of the piston 66. 12a side discharge can make the working efficiency and lubrication of the air pump 61 better.

The pump casing 63 of the air pump 61 is formed in a bottomed cylindrical shape open on the cylinder head 14 side, and is integrally formed with the cylinder block 13. The cylinder block 13 is bonded to the pump housing 63 on the same plane as the bonding surface 87 of the cylinder head 14, and thus, the processing steps of the cylinder block 13 can be reduced.

Furthermore, the air pump 61 and the water pump 90 connected to both ends of the pump drive shaft 73 are disposed at positions symmetrical to the plane PL plane perpendicular to the pump drive shaft 73 including the cylinder axis C. The pump drive shaft 73 connected to the air pump 61 drives the water pump 90, which can reduce the number of components, reduce the weight, and reduce the cost by simplifying processing and assembly. In addition, it is possible to prevent the water pump 90 from protruding from the cylinder group, and to prevent the overall size of the cylinder group 13 from being enlarged.

Furthermore, the water pump 90 can be arranged near the cylinder block 13 and the cylinder head 14 which should be water-cooled, the water piping can be shortened, the complexity of the piping can be avoided, and the pressure loss in the piping can be reduced.

Furthermore, the injector 25 that directly injects fuel into the fuel chamber 19 together with the compressed air obtained by the air pump 61 is arranged in the cylinder head 14, and therefore, since the air pump 61 is not arranged in the cylinder head 14, the freedom of design is increased. In addition, the size of the engine can be reduced, and the injector 25 and its piping can be arranged in the cylinder head 14. In particular, since the pump chamber 65 of the air pump 61 is arranged on the side of the cylinder head 14, the distance between the pump chamber 65 and the injector 25 is short, and the compressed air supply that involves guiding the compressed air from the air pump 61 to the injector 25 is avoided. The complexity of the piping structure of the path 126 can reduce the pressure loss in the piping structure.

A part of the compressed air supply path 126 passes through the vicinity of the exhaust hole 24, so the compressed air flowing in the compressed air supply path 126 can be heated by the exhaust heat of the exhaust gas flowing through the exhaust hole 24. Increasing the volume of compressed air increases the efficiency of the pump.

In addition, in the vicinity of the exhaust hole 24, a part of the head side water jacket 103 is arranged between the exhaust hole 24 and the cylinder group 13, while the passage 128 constituting a part of the compressed air supply path 126 is arranged in the vicinity of the exhaust hole 24. On the opposite side of the head side water jacket 103 with respect to the exhaust hole 24, thus, it is possible to prevent the cooling effect caused by the head side water jacket 103 from spreading to the compressed air flowing in the compressed air supply path 126, even for Water-cooled engines also maintain high pump efficiency.

In addition, the air pump 61 is arranged at the lower portion of the cylinder bank 13 on the side corresponding to the exhaust hole 24 , and the air pump 61 can be arranged in an engine arrangement space including an exhaust pipe connected to the exhaust hole 24 .

Also, the fuel injection valve 108 among the injectors 25 is fitted and held in the injector housing 114, but the injector housing 114 is integrally formed with the end cover 15, and therefore, the injector housing 114 does not have to be arranged around the cylinder head 14. The number of components can be reduced, and at the same time, the enlargement of the engine and the complexity of the structure of the engine periphery can be avoided.

Also, the fuel supply passage 119 for respectively supplying fuel and compressed air into the injector housing 114, and the passage 129 as a part of the compressed air supply passage 126 are directly provided on the end cover 15, and thus, it is not necessary Pipelines and the like for separately supplying fuel and compressed air into the injector housing 114 are disposed around the housing 114, thereby reducing the number of components while avoiding enlargement of the engine and complexity of the structure around the engine.

The camshaft 41 constituting a part of the valve device 38 for driving the first intake valve 27 , the second intake valve 28 and the exhaust valve 29 arranged on the cylinder head 14 avoids the cylinder head 14 and the end cover 15 Between them, it is arranged on the cylinder bank 13. Therefore, the camshaft 41 is not disposed between the cylinder head 14 and the end cover 15, the degree of freedom in designing the injector housing 114 can be increased, and the design of the fuel supply passage 119 and the passage 129 directly provided on the end cover 15 can be increased. degrees of freedom.

Furthermore, the injector 25 is arranged on the cylinder axis C, and the first intake valve port 20 and the exhaust valve port 22 are arranged on both sides of the injector 25 in a projected view on a plane perpendicular to the cylinder axis C. At the same time, on another straight line L2 approximately perpendicular to the straight line L1 connecting the first intake valve port 20 and the exhaust valve port 22, the second intake valve port 21 is arranged on the side of the injector 25, thus, By arranging the injector 25 on the central part of the combustion chamber 19, the flame propagation distance in the combustion chamber 19 will not deviate, and the combustion efficiency can be improved. By arranging the first and second intake valve ports 20, 21, it can Improve air filling efficiency and reduce pumping loss, and can easily avoid the mutual interference of two suction valves 27, 28 and one exhaust valve 29, easy to configure spark plug 26, and can configure spark plug 26 close to injector 25 to improve combustion efficiency.

Also, the air fuel injection valve 107 in the injector 25 is supported on the end cover 15, and the passage 129, which is a part of the compressed air supply path 126 that supplies compressed air to the air fuel injection valve 107, is directly provided on the end cover 15. Therefore, there is no need to dispose components for introducing compressed air into the injector 25 around the end cover 15, so that the enlargement of the engine and the complication of the mechanism around the engine can be avoided.

In addition, the two ends of the cylindrical positioning pin 130 straddling the overlapping surface of the cylinder head 14 and the end cover 15 are inserted into the cylinder head 14 and the end cover 15, so that a part of the compressed air passage 126 is formed and directly provided on the cylinder respectively. The passages 128, 129 on the cover 14 and the end cover 15 are connected through the positioning pin 130, whereby the relative position of the cylinder head 14 and the end cover 15 is determined by the positioning pin 130, even if the cylinder head 14 and the cylinder head 14 are connected by the positioning pin 130 In cooperation with supporting the injector 25, excessive pressure is not applied to the injector 25 either. Furthermore, using the positioning pin 130 as a connecting member between the passage 128 of the cylinder head 14 and the passage 129 of the end cover 15 eliminates the need for a dedicated member for connecting the passages, and the number of members can be reduced.

Furthermore, since the hole 131 is formed in the positioning pin 130, the pressure of the compressed air supplied to the injector 25 can be adjusted, and a dedicated member for pressure adjustment is not required, and the number of components can be reduced.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims.

For example, in the above-mentioned embodiment, the power transmission mechanism 89 including the endless chain 80 is provided between the camshaft 41 and the pump drive shaft 73, but it is also possible to arrange the power transmission mechanism 89 including an endless belt between the camshaft 41 and the pump drive shaft 73. between drive shafts 73.

According to the invention described in the first aspect of the present invention, the pump casing is integrally formed on the cylinder block with a small shape, which can reduce the number of components and realize the miniaturization of the whole engine. Since the camshaft driving the air pump is also arranged on the cylinder In combination, the power transmission mechanism that transmits the power from the camshaft to the air pump can be compactly configured, and the degree of freedom in setting the gear ratio of the air pump can be increased.

Furthermore, according to the invention described in the second aspect of the present invention, the increase in size of the cylinder group can be prevented and the number of components can be reduced regardless of the distance between the camshaft and the pump drive shaft.

According to the invention described in claim 3, the auxiliary machine is driven by the pump drive shaft connected to the air pump, the number of components can be reduced, the weight can be reduced, and the cost can be reduced by simplifying processing and assembly. In addition, it is possible to prevent the auxiliary machine from protruding from the cylinder group, thereby avoiding an increase in the overall size of the cylinder group.

According to the invention described in the fourth aspect of the present invention, by arranging the water pump near the cylinder block and the cylinder head which should be water-cooled, the length of the water pipe is shortened, the complexity of the pipe can be avoided, and the pressure loss in the pipe can be reduced.

With the invention described in the fifth aspect of the present invention, higher air pressure can be obtained, the working axis of the air pump is parallel to the axis of the cylinder of the engine, and the crank of the yoke type is adopted to avoid the use of connecting rods, so that the engine can be miniaturized.

According to the invention described in claim 6 of the present invention, the processing steps of the cylinder group can be reduced.

Furthermore, according to the invention described in the seventh aspect of the present invention, the degree of freedom of design can be increased and the size of the engine can be reduced, and the injector and its piping can be arranged on the cylinder head, especially, the pump chamber of the air pump can be arranged When it is arranged on one side of the cylinder head, the distance between the pump chamber and the injector is relatively short, which avoids the complexity of the pipeline structure connected between the air pump and the injector, and can reduce the pressure loss of the pipeline structure. .

Claims (7)

1, a kind of air pump drive unit that utilizes engine-driving air pump (61), it is characterized in that, described motor has the part of formation air valve device (38) and is configured in camshaft (41) in the cylinder block (13), and constitute 4 strokes, transmit from described camshaft (41) and the pump case (63) of the described air pump (61) of the power that comes forms one with described cylinder block (13).

2, air pump drive unit as claimed in claim 1 is characterized in that, between the pump live axle (73) and described camshaft (41) that are connected on the described air pump (61), is provided with the power transmission mechanism (89) that comprises annular driving band (80).

3, air pump drive unit as claimed in claim 2, it is characterized in that, with respect to the cylinder-bore axis that comprises described motor (C) become in the face of the position that claims with described pump live axle (73) plane orthogonal (PL) on, configuration is connected described air pump (61) and the subsidiary engine (90) on the two end part of described pump live axle (73).

4, air pump drive unit as claimed in claim 3 is characterized in that, described motor is a water-cooled, and described subsidiary engine is water pump (90).

5, as each described air pump drive unit in the claim 1～4, it is characterized in that, described air pump (61) constitutes and makes piston (66) reciprocating reciprocating type on the direction parallel with the cylinder-bore axis (C) of described motor, transmits from described camshaft (41) and the pump live axle (73) of the power that comes is connected on the described piston (66) via the crank (84) of scotch yoke formula.

6, air pump drive unit as claimed in claim 5, it is characterized in that, the pump case (63) of described air pump (61), has the parallel axis of cylinder-bore axis (C) with motor, simultaneously, form cylinder head (14) side open the round-ended cylinder shape arranged, and form one with cylinder block (13), the lid member (64) that described cylinder head (14) the side opening portion of this pump case (63) is carried out hermetic seal is in the junction plane (87) of cylinder block (13) and cylinder head (14) and is attached in the same plane on the described pump case (63).

As each described air pump drive unit in the claim 1～6, it is characterized in that 7, the sparger (25) that injects fuel directly into the firing chamber with the pressurized air from described air pump (61) supply is configured on the cylinder head (14).

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