JP4056449B2 - Side feed type fuel injection valve mounting structure - Google Patents

Description

  The present invention relates to a structure for mounting a fuel injection valve in an internal combustion engine, and more particularly to a structure for mounting a side feed type fuel injection valve to a cylinder head cover.

As a mounting of a bottom feed type fuel injection valve in a conventional internal combustion engine, the side surface of the valve body is held by an O-ring which is a seal in a mounting hole provided in the intake pipe of the engine, and the upper and lower sides of the valve body are made of rubber or the like. Attachment made by pressing through an elastic body is known (see, for example, Patent Document 1), and as a side feed type fuel injection valve (device), a fuel composed of a metal pipe fixed to an intake pipe It is known that a fuel injection valve is held in a valve body housing part provided in a gallery through a seal which is an O-ring, and a cap part of the injection valve is attached by pressing from above with a cover via rubber. (See, for example, Patent Document 2), and further, a fuel injection valve is held in a valve body housing portion provided in a similar fuel gallery via a seal that is an O-ring, Fee upper flange of the injection valve is also known mounted fixed by a clamp or bayonet locking member (e.g., see Patent Document 3).
Japanese Utility Model Publication No. 5-3741 (Page 2 to Page 3, Figure 1 to Figure 2) Utility Model Registration No. 2501967 (Pages 2 to 3, FIGS. 2 and 6) Japanese Patent Publication No. 6-501762 (pages 3 to 5, FIGS. 1 and 2)

  As shown in FIG. 9, the bottom feed type fuel injection valve 070 described in Patent Document 1 is inserted into a mounting hole 051 formed in the body 01 disposed in the intake pipe of the engine. The fuel injection valve 070 is pressed from above by the cover 080 and accommodated in the mounting hole 051, and the radial direction thereof is supported by the O-rings OR3, 0R4, and the cover 080 via the elastic body 0R. Is pushed downward and held.

  Further, the side feed type fuel injection valve 070 described in the above-mentioned Patent Document 2 is attached to each of the plurality of intake manifolds 01 and 01 as shown in FIGS. 10 to 11. , 02 are provided, and the injector housing 03 has a substantially cylindrical shape with an open upper surface for holding and holding the fuel injection valve 070 as shown in FIG. In addition, a stepped portion 03a that is further recessed is provided at the opening edge of the cylindrical upper end.

The fuel injection valve 070 is inserted into the housing 03 from the opening on the upper surface thereof and is accommodated in the housing 03 via seals 0R3 and 0R4 which are O-rings. 081 is pressed by the cover 082 via the rubber 0R, and the upper flange portion 070a is brought into contact with the step portion 03a of the upper edge opening portion of the housing 03 and is fixedly held in the housing 03.

Further, as shown in FIG. 12, the side feed type fuel injection valve described in Patent Document 3 described above includes a valve housing opening in a fuel supply passage 01 of a fuel distributor fixed to a suction pipe of an internal combustion engine. A stepped valve accommodating portion 02 is provided, and the fuel injection valve 070 is held in the accommodating portion 02 via seal members 0R3 and 0R4 which are O-rings. A flange 070a above the injection valve 070 is provided. The injection valve 070 is held in the housing portion 02 by being fixed to the upper portion of the housing portion 02 by a clamp or bayonet type locking body 080. Note that 03 is an electrical connector.

By the way, as for attachment of the fuel injection valve of the said patent documents 1 thru | or 3, all are attachment structure where this injection valve is accommodated and hold | maintained via elastic bodies, such as rubber | gum, with respect to the valve body accommodating part which is the accommodating part. It is said that. However, with such an attachment structure, since the fuel injection valve injects high-pressure fuel, shock vibration due to the reaction at the time of fuel injection is transmitted to the housing portion without being sufficiently absorbed.

Since all of the fuel injection valves described in Patent Documents 1 to 3 are housed in a valve body housing portion attached to the intake manifold, the fuel injection valve is shocked by a reaction during fuel injection. Such vibration is transmitted from the valve body housing part to the intake manifold, and vibrates so as to strike the manifold to generate noise.

In particular, in the mounting of the fuel injection valve described in Patent Documents 2 and 3, the flange portion of the valve body is in direct contact with the structure portion of the valve body housing portion. The direct contact structure portion between the housing portions directly transmits the shock vibration in the fuel injection of the fuel injection valve without mitigating at all. Therefore, the suppression of the shock vibration and the generation of noise based on the vibration are effective. It cannot be resolved.

On the other hand, in a direct injection type fuel injection valve, the injection valve is usually attached to the head cover of the cylinder head without being provided in the intake manifold or the like. It is intended to absorb reaction force and vibration at the time of injection by interposing an isoelastic body, and only measures similar to those described above for vibration absorption are taken, especially those in absorption of reaction force by fuel injection. Since no special measures are taken, the vibration and noise due to the reaction force have not been effectively eliminated.

Under such circumstances, in the direct injection type side feed type fuel injection valve attached to the head cover of the cylinder head, the injection reaction force in the fuel injection is effectively absorbed, and the vibration based on the reaction force is reduced. Development of a mounting structure for a fuel injection valve in which noise generation is effectively suppressed is desired.

The present invention relates to a fuel injection valve mounting structure for solving the above-mentioned problems, and relates to a cylinder head cover of an internal combustion engine, a valve body housing hole for a fuel injection valve provided in the cylinder head cover, and the valve body housing. In a mounting structure of a side-feed type fuel injection valve provided with a fuel injection valve accommodated in the hole, the cylinder head in contact with the cylinder head cover is positioned in the axial direction of the valve body accommodation hole of the fuel injection valve. An air-fuel mixture injection valve accommodating hole for the air-fuel mixture injection valve is formed, and the accommodation of the air-fuel mixture injection valve in the air-fuel mixture injection valve accommodation hole is elastic with respect to the inner wall in the air-fuel mixture injection valve accommodation hole. The fuel injection valve is held in the mixture injection valve accommodation hole through an elastic body such as a seal, and the injection port of the mixture injection valve is exposed in the fuel chamber, and the fuel injection valve into the valve body accommodation hole Containment of the valve body A flange portion is provided on the head side of the fuel injection valve while being held in the valve body accommodation hole portion via an elastic body such as an elastic seal with respect to the inner wall in the hole portion, and the fuel injection of the flange portion The head side with respect to the axial direction of the valve is positioned by an annular presser plate that abuts against the flange portion, and the injection port side of the flange portion with respect to the axial direction of the fuel injection valve holds the cylinder head cover with a gap. The crankcase side valve body portion is inserted into the diameter-reduced hole portion of the cylinder head from the diameter-enlarged valve body portion of the mixture injection valve, and the head end surface of the diameter-enlarged valve body portion of the mixture injection valve Is in contact with the end face of the outer peripheral wall that holds the thin shaft diameter portion of the fuel injection valve in the cylinder head cover.

Further, the presser plate is brought into contact with the outer surface of the flange portion through an elastic body such as a spring .

  According to a first aspect of the present invention, there is provided a cylinder head cover of an internal combustion engine, a valve body accommodating hole portion for a fuel injection valve provided in the cylinder head cover, and a fuel injection valve accommodated in the valve body accommodating hole portion. In the side feed type fuel injection valve mounting structure provided, the fuel injection valve is housed in the valve body housing hole through an elastic body such as an elastic seal with respect to the inner wall in the valve body housing hole. The flange portion is provided on the head side of the fuel injection valve, and one side surface side of the flange portion is positioned by an annular presser plate abutting against the flange portion, and the flange portion Since the other side surface is held with a gap with respect to the cylinder head cover, the fuel injection valve accommodated in the valve body accommodating hole portion has a predetermined gap portion in the accommodating hole portion. Yield Since the direct contact with the cylinder head cover is avoided, the impact force due to the movement of the valve body due to the reaction force at the time of fuel injection of the injection valve is not directly transmitted to the cylinder head cover. Is reduced, and the generation of noise due to the vibration is suppressed.

According to a second aspect of the present invention, the holding of the fuel injection valve on the head side by the annular pressing plate surrounds the outer periphery of the valve body on the outer side of the flange portion in an annular manner with a predetermined gap. Since the presser plate arranged so as to be in contact with the outer surface of the flange portion, the outer surface of the flange portion is evenly supported by the presser plate over the entire circumference. The injection valve is held in a very stable state.

  This is implemented as a side feed type fuel injection valve mounting structure that is mounted on a cylinder head cover of an internal combustion engine.

A first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 shows a motorcycle on which an internal combustion engine E according to an embodiment of the present invention is mounted. The motorcycle includes a head pipe 2 that rotatably supports a front fork 1, and the head pipe 2. A basic frame structure comprising a main frame 3 extending rearward and downward and a pair of left and right rear frames 4 connected to the rear portion of the frame 3 and extending rearward and upward.

A front wheel 5 is pivotally supported at the lower end of the front fork 1, and a traveling handle 6 is connected to the upper portion of the front fork 1. A front fender 7 that covers the upper side of the front wheel 5 is supported by the front fork 1, and a rear wheel 10 is pivotally supported at the rear of the rear fork 9 whose front end is rotatably supported by the pivot plate 8. A seat 11 is provided on the rear frame 4.

A hanger plate 12 is fixed to both side surfaces of the intermediate portion of the main frame 3, and a pivot plate 8 is fixed to both rear side surfaces of the main frame 3, and the hanger plate 12 and the pivot plate 8 are interposed therebetween. The internal combustion engine E is suspended at a position below the main frame 3, and the internal combustion engine E has the cylinder head 40 side in front of the vehicle, the crank chamber 20 side in the rear, and an intake port as shown in the figure. It is mounted horizontally on the vehicle with the side up. In FIG. 1, 13 is an air cleaner, 14 is a leg shield, and 15 is a drive chain.

The internal combustion engine E according to the embodiment of the present invention is a single-cylinder four-cycle engine, and its structure will be briefly described below with reference to FIGS.

The internal combustion engine E main body includes a crankcase 20, a cylinder block 30, a cylinder head 40, a cylinder head cover 50, and the like having a divided structure, and the internal combustion engine E is mounted on a vehicle as shown in FIG. Each of these structural portions has an arrangement structure in which a cylinder block 30 is mounted in front of the crankcase 20, a cylinder head 40 is mounted in front of the cylinder block 30, and a cylinder head cover 50 is mounted in front of the cylinder head 40. .

In the crankcase 20, a crankshaft 21 and a main shaft and a countershaft of a transmission 22 in which only a part thereof is illustrated are rotatably supported (see FIG. 3). As is well known, a piston P is attached to the crank portion 21 a of 21 via a connecting rod 23, and this piston P is configured to reciprocate in the cylinder hole 31 of the cylinder block 30.

A combustion chamber 40a is provided in a space formed by the front portion of the cylinder hole 31 (the upper portion in FIGS. 3 and 4) of the cylinder block 30 and the concave portion of the rear surface of the cylinder head 40, and an ignition plug 40b is provided in the combustion chamber 40a. Further, an injection port 60g of an injection valve 60 for air-fuel mixture injection, which will be described in detail later, faces the combustion chamber 40a and a valve opening 40c for intake / exhaust and an intake / exhaust valve. 40d is disposed (see FIG. 2).

The cylinder head 40 is provided with a passage portion 40e for intake / exhaust communicating with the intake / exhaust valve opening 40c, and a structure portion 40f for mounting the valve 40d and an air-fuel mixture injection later described. The air-fuel mixture injection valve 60 and the like are provided, and the cylinder head cover 50 attached to the cylinder head 40 is provided with a valve operating mechanism such as an air pressure regulator 50a and a rocker arm 50b, and a fuel injection valve 70 described in detail later. (See Fig. 2, 4 etc.)

Although the schematic structure of the internal combustion engine E is as described above, FIG. 4 shows a view of the horizontal section of the front portion of the internal combustion engine E mounted horizontally on the vehicle as seen from above. In this figure, the peripheral structure of the mounting portion of the mixture injection valve 60 and the fuel injection valve 70 in the cylinder head 40 and the cylinder head cover 50 of the internal combustion engine E is particularly shown enlarged.

In the drawing, the above-described cylinder block 30 and the cylinder hole 31 of the cylinder block 30 are also illustrated. In addition, a piston P is disposed in the cylinder hole 31, and the spark plug 40b and the mixture injection valve 60 are provided. The above-described state in which the injection port portion 60g faces the combustion chamber 40a is also illustrated.

The cylinder head 40 has a receiving hole 41 for mounting the air-fuel mixture injection valve 60 penetrating from the front surface 40A (upper surface in FIG. 4) to the rear surface 40B (lower surface in FIG. 4). The air-fuel mixture injection valve 60 is accommodated in the hole 41 with mounting means described in detail later. As described above, the cylinder head cover 50 is attached to the front surface 40A of the cylinder head 40 via a fixing means such as a bolt B, and the spark plug 40b is substantially attached to the cylinder head 40. It has been.

The cylinder head cover 50 attached to the cylinder head 40 is provided with a housing hole 51 for mounting the fuel injection valve 70. The housing hole 51 is formed on the front surface 50A of the cylinder head cover 50 (upper portion in FIG. 4). Surface) to the rear surface 50B (the lower surface in FIG. 4), the head cover 50 is penetrated, and the fuel injection valve 70 is accommodated in the accommodation hole 51 with mounting means described in detail later.

In the state where the cylinder head cover 50 is attached to the cylinder head 40, the above-described two injection valves 60, 70, that is, the air-fuel mixture injection valve 60 and the fuel injection valve 70 have their longitudinal axes aligned with each other, Further, the cylinder head 40 and the cylinder head cover 50 are mounted by mounting means described later in the receiving holes 41 and 51 of the cylinder head 40 and the cylinder head cover 50 so as to partially overlap each other.

Further, as shown in FIG. 4, the accommodation hole 51 for accommodating the fuel injection valve 70 is supplied to supply fuel to the fuel injection valve 70 at a relatively front position (upward in FIG. 4). An opening 52 is opened, and a supply port 53 for supplying compressed air to the air-fuel mixture injection valve 60 is opened at a lower position thereof. Further, a part of a passage for supplying these fuel and compressed air is provided. 54 and 55 are formed on the cylinder head cover 50 (see FIG. 5). The fuel supply to the two injection valves 60 and 70 and the supply of compressed air will be described later.

Incidentally, although the details of the structure of the mixture injection valve 60 accommodated in the accommodation hole 41 of the mixture injection valve 60 of the cylinder head 40 are not shown, the injection valve 60 is a direct injection type. There is a type in which the air-fuel mixture is directly injected into the combustion chamber by compressed air. That is, the valve body is provided with a through-center hole (not shown), and a poppet valve that opens and closes the rear (lower part in the figure) opening of the hole is controlled by a solenoid so that the compression described later is performed through an air passage. The compressed air supplied to the air chamber 57 is mixed with the fuel supplied from the fuel injection valve 70 and injected into the combustion chamber 40a.

FIG. 4 shows only the external appearance of the air-fuel mixture injection valve 60. According to the figure, the outer shape of the valve body of the injection valve 60 is substantially unevenly distributed forward from the central part of the valve body. A large-diameter valve body portion 60a, a valve body portion 60b extending from the front portion of the large-diameter valve body portion 60a, and a valve body portion 60c extending from the rear portion of the large-diameter valve body portion 60a. It is.

Here, attachment of the air-fuel mixture injection valve 60 to the accommodation hole 41 of the cylinder head 40 will be described.
The air-fuel mixture injection valve 60 is attached to the receiving hole 41 at a stage before the cylinder head cover 50 is attached to the cylinder head 40 and penetrates from the front surface 40A to the rear portion 40B of the cylinder head 40. This is done by inserting the injection port portion 60g of the injection valve 60 from the enlarged diameter hole portion 41a, which is the opening of the front surface 40A of the hole portion 41, into the accommodating hole portion 41 to be formed.

The insertion of the air-fuel mixture injection valve 60 into the accommodation hole 41 is performed for sealing the annular groove 60d of the valve body 60c extending from the rear of the large-diameter valve body 60a of the injection valve 60. The O-ring R1 is inserted, and in this state, the valve body portion 60c is inserted into the diameter-reduced diameter-reduced hole portion 41b connected to the enlarged-diameter hole portion 41a that is the opening of the front surface 40A of the accommodating hole portion 41, The injection port 60g slightly protrudes from the rear opening 41c of the hole 41b that opens to the wall forming surface of the combustion chamber 40a so as to face the combustion chamber 40a. When the injection valve 60 is mounted in the housing hole 41, the front surface of the large-diameter valve body 60a is the opening of the front 40A of the housing hole 41 of the cylinder head 40. It is the same surface as the edge of the diameter hole 41a.

Therefore, in the mounting state of the air-fuel mixture injection valve 60 in the accommodation hole 41, the valve body portion 60 b extending from the front portion of the large-diameter valve body portion 60 a of the injection valve 60 is the front surface of the cylinder head 40. It will protrude from 40A. When the cylinder head cover 50 is attached to the cylinder head 40, the projecting valve body 60b has a reduced diameter hole 51c (see FIG. 5) that is a rear hole of the accommodation hole 51 of the fuel injection valve 70 of the cylinder head cover 50. 6).

Insertion of the valve body portion 60b of the air-fuel mixture injection valve 60 protruding from the front surface 40A of the cylinder head 40 into the reduced diameter hole portion 51c of the accommodation hole portion 51 is formed on the outer periphery of the valve body portion 60b. It is made by press-fitting into the diameter-reduced hole 51c in a state where an O-ring R2 for sealing is fitted in the two annular grooves 60e, and a front portion (upper part in the drawing) of the fitting position of the O-ring R2 will be described later. When the fuel injection valve 70 is mounted, it is configured as a compressed air chamber 57 for supplying compressed air to the front portion 60A of the air-fuel mixture injection valve 60, that is, the head of the valve. An opening 53 of the wall surface of the reduced diameter hole 51c communicating with the passage is provided so as to face (see FIG. 5).

The air-fuel mixture injection valve 60 is fitted into the annular grooves 60d and 60e of the O-rings R1 and R2 of the valve body parts 60b and 60c extending from the front part and the rear part of the large-diameter valve body part 60a, respectively. A constant holding force is obtained by the elastic force generated by the respective press-fitting into the receiving hole portions 41 and 51 via the, thereby maintaining a stable state. In this state, the injection port portion 70g at the rear end of the fuel injection valve 70 and the concave portion, which is the substantial head portion of the front portion 60A of the air-fuel mixture injection valve 60, will be described later. An insertion relationship is established (see FIG. 4).

On the other hand, the fuel injection valve 70 is a so-called side feed type injection valve having a fuel intake port 70f on the side surface of a so-called injection valve body. The fuel injection valve 70 is opened and closed by a solenoid (not shown) mounted in the valve body. The fuel injection is controlled by the operation of the poppet valve, and its specific internal structure is not shown in the figure and description thereof is omitted.

4 to 6 show only the external view of the fuel injection valve 70. As can be understood from these drawings, the external shape of the injection valve 70 is substantially the front of the valve body of the injection valve 70. A large-diameter bowl-shaped flange portion 70a is provided at a position near 70A (upward in the drawing), a valve body portion 70b extending from the front portion of the flange portion 70a, and a valve extending from the rear portion of the flange portion 70a. It consists of a body part 70c.

The valve body portion 70c extending from the rear portion of the flange portion 70a has a structure in which the valve body shaft diameter changes in a plurality of stages. An opening 70f for the valve body portion 70c, a slightly thicker shaft diameter portion 70d in the vicinity of the flange portion 70a of the valve body portion 70c, and an injection port portion 70g at the rear of the valve body portion 70c that is separated from the flange portion 70a. The annular shaft grooves 70h and 70i are formed in the narrow shaft diameter portion 70e at a relatively close position, respectively, and O-rings R3 and R4, which are seal members, are fitted in the annular grooves 70h and 70i, respectively. Yes.

  A receiving hole 51 for the fuel injection valve 70 provided in the cylinder head cover 50 has an enlarged front opening for receiving the flange portion 70a of the injection valve 70 as shown in FIGS. A diameter-enlarged hole 51a, a hole 51b having a slightly larger inner diameter connected to the diameter-enlarged hole 51a that receives the valve body 70c in which the valve body shaft diameter of the injection valve 70 changes, and the slightly larger The diameter-expanded hole 51c is a hole having a sufficient depth and a sufficient inner diameter for receiving the flange part 70a with a margin when the injection valve 70 is mounted. is there.

The slightly larger inner diameter hole 51b is fitted with an O-ring R3 for sealing in an annular groove 70h of a slightly thicker shaft diameter portion 70d of the valve body 70c when the fuel injection valve 70 is mounted. Since it is inserted and fitted, it has a larger inner diameter than the shaft diameter portion, and the diameter-reduced hole portion 51c is sealed in the annular concave groove 70i of the shaft portion 70e having a narrow valve body portion 70c when mounted. Since an O-ring R4 for insertion is inserted and fitted, it has a larger inner diameter than the shaft diameter portion 70e, and the rear opening 51d of the reduced diameter hole portion 51c is chamfered to expand in a tapered shape. Thus, when the cylinder head cover 50 is attached to the cylinder head 40, the extension valve of the front portion of the mixture injection valve 60 to the reduced diameter hole portion 51c which is the rear hole portion of the aforementioned accommodation hole portion 51 is described. So that the body part 60b can be inserted easily. There.

Here, attachment of the fuel injection valve 70 to the accommodation hole 51 provided in the cylinder head cover 50 will be described.
The fuel injection valve 70 is installed in the accommodation hole 51 of the cylinder head cover 50 in such a manner that the mixture injection valve 60 is installed in the accommodation hole 41 for the mixture injection valve 60 of the cylinder head 40, and the cylinder The cylinder head cover 50 is attached to the head 40, and eventually, the valve body portion 60 b protruding from the front portion of the air-fuel mixture injection valve 60, that is, the head portion of the injection valve 60 is behind the receiving hole portion 51 of the cylinder head cover 50. This is done in a state of being inserted into the reduced diameter hole 51c which is a hole (see FIGS. 4 and 6).

The fuel injection valve 70 is mounted by pushing the valve body of the injection valve 70 from the enlarged diameter hole portion 51a which is the front opening of the accommodation hole portion 51 with the injection port portion 70g side of the fuel injection valve 70 first. Two annular grooves 70h and 70i formed at different portions of the shaft diameter of the valve body portion 70c extending from the rear portion of the flange portion 70a of the injection valve 70 are inserted at the time of insertion for this mounting. O-rings R3 and R4, which are the aforementioned sealing members, are inserted in advance.

When the fuel injection valve 70 is mounted, the flange portion 70a is housed in the enlarged hole portion 51a, which is the front opening of the housing hole portion 51, with a gap in the periphery thereof, and forward (upward in FIGS. 4 to 6). ) From the rear portion of the flange portion 70a, and the annular groove 70h of the shaft portions 70d and 70e having two different shaft diameters spaced apart from each other. , 70i are inserted into O-rings R3 and R4, respectively, and are inserted into the rear hole 51b and the diameter-reduced hole 51c following the diameter-expanded hole 51a of the receiving hole 51, and injected at the rear end of the valve body. The opening 70g is in the recess of the valve body 60b head 60A, which is a front protrusion of the air-fuel mixture injection valve 60 that has already been inserted into the reduced diameter hole 51c, which is the rear hole of the receiving hole 51. It is made by being inserted into.

In the mounted state, the fuel is separated by O-rings R3 and R4 fitted in annular grooves 70h and 70i of different shaft diameter portions 70d and 70e of the valve body portion 70c extending from the rear portion of the flange portion 70a, and the fuel. The fuel supply port 52 is opened in the wall surface of the hole 51 in the space in the accommodation hole 51 where the fuel intake port 70f of the injection valve 70 opens, that is, the fuel chamber 56.

An annular groove in the front valve body 60b of the air-fuel mixture injection valve 60 that has been inserted into the O-ring R4 of the valve body 70c and the reduced diameter hole 51c that is already a hole behind the housing hole 51. The compressed air supply port 53 is inserted into a rear space portion of the accommodation hole portion 51, that is, the compressed air chamber 57, which is partitioned by an O-ring R 2 fitted in 60 e and where the compressed air intake port 53 of the air-fuel mixture injection valve 60 opens. Is opened in the wall surface of the hole 51, and the fuel supply to the fuel injection valve 70 and the compressed air to the front part 60A of the mixture injection valve 60, that is, the head of the valve, as will be described later. Supply is made.

Push-in insertion of the valve body portion 70c extending from the rear portion of the flange portion 70a into the hole portion 51b and the reduced-diameter hole portion 51c is performed by an O-ring R3 fitted in the annular grooves 70h and 70i of the valve body portion 70c. , R4 is pressed against the elastic deformation, so that the injection valve 70 is accommodated by the holding force due to the frictional force between the hole 51b and the inner wall of the reduced diameter hole 51c due to the elastic deformation of the O-rings R3, R4. The injection valve 70 is stably held in combination with the holding action by the contact between the presser plate 80 and the flange portion 70a, which will be described later.

In this state, the substantial head portion 70A of the injection valve 70, which is the valve body portion 70b extending from the front portion 70a of the flange portion, protrudes through the central opening 80a of the presser plate 80. Therefore, the injection valve 70 The head 70 </ b> A protrudes outward from the front surface 50 </ b> A of the cylinder head cover 50.

Here, further explanation will be given on the pushing insertion of the valve 70 into the accommodation hole 51 for mounting the fuel injection valve 70 described above.
As described above, the fuel injection valve 70 inserted through the injection port portion 70g through the enlarged diameter hole portion 51a that is the opening of the front surface 51A of the accommodation hole portion 51 is inserted from the rear portion of the flange portion 70a. O-rings R3 and R4 are fitted into two annular concave grooves 70h and 70i of the extending valve body part 70c, respectively, and the O-rings R3 and R4 push the injection valve 70 into the pressure so that the pressure on the inner wall of the receiving hole 51 is increased. It is slid along the inner wall while being elastically deformed into an elliptical shape so as to be received and crushed.

The pushing insertion for inserting the valve body is continued until the protruding amount of the flange portion 70a of the injection valve 70 from the front surface 50A of the cylinder head cover 50 reaches a predetermined amount, and the protruding amount of the flange portion 70a is predetermined. When the protruding amount is reached, the push-in insertion is stopped. Thereafter, the presser plate 80 is covered with the outer surface of the flange portion 70a, and the presser plate 80 is fixed to the cylinder head cover 50 by tightening the bolt B, so that the injection valve 70 is attached together with the fixing of the presser plate 80. Completely made.

In other words, the crown on the outer surface of the flange portion 70a of the presser plate 80 is such that the central opening 80a of the presser plate 80 is the front portion of the flange portion 70a of the fuel injection valve 70 as shown in FIGS. Is loosely fitted to the valve body portion 70b extending from the center, that is, the center opening 80a of the presser plate 80 is aligned with the positioning recess 80b provided in the opening 80a. This is done by fitting into the convex portion 70j and loosely fitting into the valve body head portion 70A of the injection valve 70 in this state.

After the crowning to the outer side surface of the flange portion 70a of the presser plate 80, the cylinder head cover 50 is tightened by tightening the bolt B through the bolt hole 80d opened in the ear portion 80c extending to the both sides of the presser plate 80. When the flange portion 70a is fixed to the front surface 50A, the outer surface of the flange portion 70a is pressed by the press plate 80, and the injection valve 70 is further pressed and inserted as the press plate 80 is pressed, and tightening for fixing the press plate 80 is completed. At the same time, the push-in insertion of the injection valve 70 is completed, and the installation of the injection valve 70 is completed.

The mounting of the fuel injection valve 70 is achieved in the above-described state. The mounting state of the injection valve 70 is a state in which the pressing force to the flange portion 70a by the presser plate 80 is maintained as it is, and the two O-rings R3, R4 remains in a state in which the elastic deformation reaction force due to the push-in remains, and the reaction force acts to push back the flange portion 70a, and the flange portion 70a presses the presser plate 80 to press it. Therefore, the injection valve 70 has a contact pressure due to the elastic pressure of the flange portion 70a to the holding plate 80, a hole portion 51b of the receiving hole portion 51 and an inner wall surface of the reduced diameter hole portion 51c due to elastic deformation of the O-rings R3 and R4. It is mounted and held by the holding action by frictional contact.

The characteristic structure in mounting the fuel injection valve 70 is that the injection valve 70 elastically supports the flange portion 70a on the holding plate 80, and the valve body portion 70c extending from the rear portion of the flange portion 70a has an O-ring. The fuel injection valve 70 is in direct contact with the cylinder head cover 50 by being substantially held by the friction force pressed against the hole 51b of the accommodation hole 51 and the inner wall surface of the reduced diameter hole 51c through elastic deformation of R3 and R4. Without having a structure portion to be accommodated, it is accommodated and mounted in the accommodation hole portion 51 with its surrounding space.

The mounting of the fuel injection valve 70 described above exhibits a characteristic action in the absorption of the reaction force in the fuel injection of the injection valve 70. That is, the reaction force at the time of fuel injection of the injection valve 70 instantaneously moves the injection valve body backward, and the impact force due to this movement is applied to the presser plate 80 that is in a press-contact relationship in advance through the flange portion 70a of the valve body. Immediately communicated. Of course, the impact force transmitted to the presser plate 80 is transmitted to the head cover 50 via the bolt B fastening portion and the contact portion between the presser plate 80 and the cover 50, and the O-rings R 3 and R 4 are applied to the cover 50. A part of the impact force of the injection valve 70 is transmitted through the contact portion by insertion.

However, the transmission of the impact force due to the reaction at the time of fuel injection to the cylinder head cover 50 is indirect via the presser plate 80 because the injection valve 70 and the head cover 50 do not have a structure part that directly contacts, Transmission of vibration due to the impact force caused by the reaction in the fuel injection of the injection valve 70 to the head cover 50 is quite limited, and generation of noise in the cover 50 due to the vibration is effectively suppressed.

Next, the supply of fuel and the supply of compressed air in the fuel injection valve 70 and the air-fuel mixture injection valve 60 will be briefly described with reference to FIG.

FIG. 7 is a fuel supply system diagram of the internal combustion engine E, and shows paths in which fuel and air are pressure-adjusted and supplied to the fuel injection valve 70 and the mixture injection valve 60, respectively. The air is sent out as compressed air by an air pump 90 and sent into a compressed air chamber 57 partitioned by O-rings R2 and R4 which are seal members connected to the front part of the air-fuel mixture injection valve 60 in the accommodation hole 51. On the other hand, the compressed air branched from the path toward the air-fuel mixture injection valve 60 goes to the air pressure regulator through the orifice.

The compressed air traveling to the air-fuel mixture injection valve 60 increases in pressure as the piston 90a of the air pump 90 (see also FIG. 5) rises to become high temperature and pressure, and moisture in the air is fed into the air passage as water vapor. . The orifice is configured to prevent the reference pressure of the fuel pressure regulator from being affected by the pulsation wave of the air pump 90 and to maintain the high pressure for using the high pressure compressed air for the injection of the air-fuel mixture in the air-fuel mixture injection valve 60. A device provided for two purposes.

The above-mentioned orifice prevents a sudden pressure rise and the compressed air pressure-adjusted by the air pressure regulator is sent from the air pressure regulator to the fuel pressure regulator as a reference pressure to the back pressure chamber. Excess air exceeding the set pressure applied to the air pressure regulator is returned as return air to the suction system such as the air cleaner 13 and supplied to the air pump 90 again. The entire air passage 55 is formed in the internal combustion engine E portion where the temperature is high, and the water vapor in the compressed air is not cooled, so the water vapor is sent to the air pressure regulator without condensation and passes there Can do.

Further, the fuel is supplied from the fuel injection valve 70 according to the embodiment of the present invention as a side feed type fuel injection valve 70 as follows. That is, the fuel sent from the fuel tank to the fuel pump through the filter is discharged at a high pressure by the pump, passes through the fuel supply opening 52 on the inner wall of the accommodation hole 51 of the fuel injection valve 70 through the pulsation damper, and The fuel is fed into a fuel chamber 56 which is a space defined by O-rings R3 and R4 which are sealing members connected to the fuel intake port 70f.

A part of the fuel branched from the path toward the fuel injection valve 70 is directed to the fuel pressure regulator. Here, the pressure of the fuel is adjusted so that the pressure difference is higher than the reference pressure and the pressure difference is constant with reference to the compressed air whose pressure is adjusted downstream of the orifice. In this way, the fuel is fed into the fuel chamber 56 in the accommodation hole 51 at a pressure higher than the air pressure in the compressed air chamber 57. Excess fuel that exceeds the set pressure applied to the fuel pressure regulator is returned to the fuel tank again as return fuel and supplied to the fuel pump again.

Then, compressed air pressure is applied to the compressed air chamber 57 in the housing hole 51 in the joint portion between the fuel injection valve 70 and the mixture injection valve 60, whereby high pressure fuel is measured in the fuel chamber 56. When the poppet valve is opened, the high-pressure fuel in the fuel chamber 56 is injected into the air-fuel mixture injection valve 60 through the fuel injection valve 70. Mixed with compressed air. When the poppet valve (not shown) of the air-fuel mixture injection valve 60 is opened as the next stage, the air-fuel mixture is pushed out into the compressed air and injected into the combustion chamber 40a.

  The first embodiment shown in FIGS. 1 to 7 of the present invention has the above-described configuration. Therefore, the fuel injection valve 70 has two valve body portions 70c protruding from the rear portion of the flange portion 70a of the valve body. The O-rings R3 and R4 are frictionally held in the receiving hole 51 by elastic deformation, and the outer surface of the flange 70a is elastically contacted with the presser plate 80. As a result, the valve body of the injection valve 70 is a cylinder head cover. Thus, the cover 50 is securely mounted and held in the receiving hole 51 of the cover 50 without having a direct contact structure with the cover 50.

Therefore, the impact force caused by the reaction in fuel injection by the fuel injection valve 70 is not directly transmitted to the cylinder head cover 50, and the impact force is transmitted through the elastic contact between the flange portion 70 a of the injection valve 70 and the presser plate 80. Since the applied pressure which is indirectly transmitted to the head cover 50 and the flange portion 70a elastically contacts the pressing plate 80 acts as a force against the impact force due to the reaction, a part of the reaction force is offset. Weakened. Therefore, the transmission of the impact force due to the reaction to the presser plate 80 is mitigated, and the occurrence of impact vibration and the generation of noise due to the vibration in the cylinder head cover 50 are effectively suppressed.

  In Embodiment 1 of the present invention, when the fuel injection valve 70 is mounted in the accommodation hole 51, the flange portion 70a and the presser plate 80 are elastically contacted with each other so as to be in direct contact with each other. As shown in the drawing, an elastic body R such as a spring may be interposed between the flange portion 70a and the presser plate 80. In this case, the reaction caused by the injection of the injection valve 70 is caused via the elastic body R such as the spring. Therefore, the impact force due to the reaction transmitted to the presser plate 80 is absorbed by the buffering effect of the elastic body R such as the spring and is relieved greatly, and the vibration of the cylinder head cover 50 is reduced. Occurrence and resulting noise is greatly suppressed.

  The fuel injection valve mounting structure in the embodiment of the present invention can be applied to other similar valve mounting structures.

1 is a side view of a motorcycle equipped with an internal combustion engine equipped with a fuel injection valve of the present invention. It is a figure which shows the state in the horizontal mounting to the vehicle of the internal combustion engine of this invention. It is sectional drawing which shows the main structure part of the internal combustion engine of this invention. It is an enlarged view which shows the cross section of the main structure part of this invention internal combustion engine. FIG. 5 is an enlarged view showing a cross section different from the cross section in FIG. 4 of the main structure of the internal combustion engine of the present invention. It is an enlarged view which shows the attachment structure of the fuel injection valve of this invention, (a) is a side view, (b) is a top view. It is a figure which shows the supply system of the fuel and compressed air to the fuel injection valve of this invention, and a fuel-air mixture injection valve. It is a figure which shows another aspect in the attachment structure of the fuel injection valve of this invention. It is a figure which shows the attachment structure of the conventional fuel injection valve. It is a figure which shows the other aspect of the attachment structure of the conventional fuel injection valve. It is a figure which shows the main structure part of the attachment structure of the fuel injection valve in FIG. 10, (a) is the side view, (b) is the top view. It is a figure which shows the other aspect of the attachment structure of the conventional fuel injection valve, (a) is a side view, (b) is a top view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Front fork, 2 ... Head pipe, 3 ... Main frame, 4 ... Rear frame, 5 ... Front wheel, 6 ... Handle, 7 ... Front fender, 8 ... Pivot plate, 9 ... rear fork, 10 ... rear wheel, 11 ... seat, 12 ... hanger plate, 13 ... air cleaner, 14 ... leg shield, 15 ... drive chain , 20 ... crankcase, 21 ... crankshaft, 21a ... crank part, 22 ... transmission, 23 ... connecting rod, 30 ... cylinder block, 31 ... cylinder hole, 40 ... Cylinder head, 40A ... Front face, 40B ... Rear face, 40a ... Combustion chamber, 40b ... Spark plug, 40c ... Valve opening, 40d ... Intake / exhaust valve, 40e ... Passage part for intake / exhaust, 40f ... structure part for valve mounting, 41 ... accommodating hole part, 50 ... cylinder head cover, 50A ... front face, 50B ... rear face, 50a ... pneumatic regulator, 50b ... rocker arm, 51 ... receiving hole, 51a ... enlarged diameter hole, 51b ... hole, 51c ... reduced diameter hole, 52 ... -Fuel supply port, 53 ... compressed air supply port, 54 ... fuel supply passage, 55 ... compressed air supply passage, 56 ... fuel chamber, 57 ... compressed air chamber, 60 ... Air-fuel mixture injection valve, 60a... Diameter expansion valve body portion, 60b... Front valve body portion, 60c... Rear valve body portion, 60d, 60e. 70, fuel injection valve, 70a ... flange, 70b ... front valve body, 70c ... rear valve body, 70d ... thick Shaft diameter portion, 70e ... thin shaft diameter portion, 70f ... fuel intake port, 70g ... injection port portion, 70h, 70i ... annular groove, 70j ... convex portion, 80 ... · Presser plate, 80a ... Central opening, 80b ... Recess, 80c ... Ear, 80d ... Bolt hole, 90 ... Air pump, 90a ... Piston, E ... Internal combustion engine , P ... piston, R ... elastic body, R1, R2, R3, R4 ... O-ring.

Claims (2)

Side feed type fuel injection valve provided with a cylinder head cover of an internal combustion engine, a valve body accommodating hole for a fuel injection valve provided in the cylinder head cover, and a fuel injection valve accommodated in the valve body accommodating hole In the mounting structure of
An air-fuel mixture injection valve accommodation hole for an air-fuel mixture injection valve is formed in the cylinder head that contacts the cylinder head cover and is positioned in the axial direction of the valve body accommodation hole of the fuel injection valve,
The mixture injection valve is accommodated in the mixture injection valve accommodation hole in the mixture injection valve accommodation hole via an elastic body such as an elastic seal against the inner wall of the mixture injection valve accommodation hole. And the injection port portion of the air-fuel mixture injection valve is exposed in the fuel chamber,
The fuel injection valve is housed in the valve body housing hole, and is held in the valve body housing hole through an elastic body such as an elastic seal with respect to the inner wall in the valve body housing hole.
A flange portion is provided on the head side of the fuel injection valve, and the head side of the flange portion with respect to the axial direction of the fuel injection valve is positioned by an annular presser plate that is in contact with the flange portion, and the fuel in the flange portion The injection port side is held with a gap with respect to the cylinder head cover with respect to the axial direction of the injection valve,
The crankcase side valve body portion is inserted into the diameter-reduced hole portion of the cylinder head from the diameter expansion valve body portion of the mixture injection valve, and the head end surface of the diameter expansion valve body portion of the mixture injection valve is A side feed type fuel injection valve mounting structure, wherein the cylinder head cover is in contact with an end face of an outer peripheral wall that holds a thin shaft diameter portion of the fuel injection valve.   The side feed type fuel injection valve mounting structure according to claim 1, wherein the pressing plate is brought into contact with the outer surface of the flange portion through an elastic body such as a spring.

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