JPH10331744A - Injector-mounting structure having sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injector mounting structure having a sealing device to effect sealing of a through-part as a mounting error and relative displacement are absorbed by arranging an elastic seal member at a through-part between the fuel passage boss of an injector and a head cover. SOLUTION: A fuel passage boss 15 extending from an injector body 14 at a given angle θ is extended through a hole 24 orthogonally to the side wall 23 of a head cover 22. An elastic seal member 28 to seal the hole 24 absorbs the mounting errors of the fuel passage boss 15 and the head cover 22 and also absorbs relative vibration between an injector 1 and the head cover 22 is also absorbed. Since there is no need for the elastic seal member 28 to be arranged at a special angle with the head cover 22 and effect special processing for mounting, a manufacturing cost is reduced and a mounting work is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal for sealing a space between an injector mounted on a cylinder head and a head cover covering the injector in an engine, in particular, a direct injection engine in which fuel is directly injected into a combustion chamber by an injector. The present invention relates to an injector mounting structure provided with a device.

[0002]

2. Description of the Related Art In recent years, mainly small-sized diesel engines are provided with two camshafts per cylinder in consideration of high performance, low fuel consumption and compliance with exhaust gas regulations. DOHC with two intake or exhaust valves on each camshaft and multiple valves (four valves)
Is desired. In this engine, two camshafts are arranged so that one injector per cylinder faces substantially the center of the cylinder with its axis substantially aligned with the axis of the combustion chamber, and two camshafts extending in parallel so as to sandwich the injector. It is located on the head.

[0003] The injector and the valve train are covered by a head cover. Therefore, a fuel supply pipe for supplying fuel from the fuel injection pump to the injector or a fuel return pipe for returning fuel from the injector to a fuel recovery tank such as a fuel tank is disposed through the head cover as a fuel pipe communicating with the injector. Will be done. The fuel supply pipe and the fuel return pipe may be formed in the form of a boss so as to extend integrally from the injector. Examples of such a fuel supply pipe structure in which the fuel passage means of the injector is disposed so as to penetrate the head cover are disclosed in JP-A-6-173817 and JP-A-8-28404.

[0004] Japanese Patent Application Laid-Open No. 6-173817 describes that
A fuel supply pipe structure for an internal combustion engine is disclosed in which a connection portion between a fuel injection nozzle and a fuel supply pipe is disposed outside a cylinder head, and the fuel injection nozzle can be easily attached to and detached from the cylinder head. In detail, this fuel supply pipe structure has a recess formed, for example, in a semicircular notch in a side wall of a cylinder head, a semicircular plug is mounted in the recess, and a through hole formed in the plug is formed. The fuel supply pipe is connected to the tip of the fuel intake pipe projecting out of the cylinder head through a fuel intake pipe integrally connected to the fuel injection nozzle.

In the above-described fuel supply pipe structure, the fuel intake pipe extends out of the cylinder head as a component constituting the fuel injection nozzle, and the connection between the fuel intake pipe and the fuel supply pipe is visually observed even after the pipe assembly is completed. Checked at. Also, since the connecting portion is disposed outside the head cover, even if fuel leaks from the connecting portion due to forgetting to tighten the connecting portion, if the fuel leaks into the head cover, the leaked fuel is returned to the intake system together with blow-by gas. There is no overrun caused by burning in the combustion chamber. Further, at the time of maintenance, the fuel injection nozzle together with the plug and the oil seal is removed from the cylinder head by removing the semicircular plug from the recess formed by the semicircular notch formed in the cylinder head side wall.

Since the space on the cylinder head covered by the head cover is a space through which blow-by gas flows, an oil seal is provided between the fuel intake pipe and the plug to prevent the blow-by gas from flowing out. I have. The oil seal is fixed by being driven into a through hole of the plug or inserted between the plug and the fuel intake pipe. The oil seal is made of rubber, and can absorb a slight displacement when the fuel injection nozzle is attached to the cylinder head within the elastic deformation of the rubber.

Japanese Patent Application Laid-Open No. Hei 8-28404 discloses a sealing device in which an annular boot is disposed between an injection pipe obliquely penetrating a through hole provided in a head cover. The seal between the annular boot and the injection pipe is provided by a seal lip provided on the inner peripheral surface at the inner end located inside the head cover of the annular boot, in close contact with the outer surface of the injection pipe. In addition, the seal between the head cover and the annular boot is formed by overlapping a seal flange formed on the outer peripheral surface of the other end of the annular boot located outside the head cover in correspondence with the seal surface provided on the head cover. This is achieved by: The overlap between the seal surface of the head cover and the seal flange of the annular boot is achieved by pressing a mounting plate that can be mounted and operated by bolts from the outside of the head cover against the surface of the seal flange, and pressing the seal flange against the seal surface of the head cover. This is done by fixing. In addition, a guide sleeve having a non-circular outer peripheral surface protrudes from the seal flange of the annular boot to the outside of the head cover, and the non-circular outer peripheral surface of the guide sleeve engages with a non-circular positioning hole formed in the mounting plate. I have.

In the sealing device using the above annular boot, the boot and the mounting plate are accurately positioned by the engagement between the non-circular outer peripheral surface of the guide sleeve and the non-circular positioning hole of the mounting plate. This prevents deterioration of the sealing performance due to the vibration of the head cover and the injection pipe. The seal between the injection pipe and the annular boot is sealed by a seal lip, and the space between the annular boot and the head cover is sealed by a seal flange.
In the sealing device, the respective vibrations of the injection pipe and the head cover are absorbed by the elastic action of the annular boot, so that the injection pipe and the head cover are not cracked even if the sealing pressure at each sealing portion is increased. Things.

[0009]

However, in the fuel supply pipe structure described in Japanese Patent Application Laid-Open No. 6-173817, the fuel supply boss extends in a direction perpendicular to the axis of the injector. Is applied to a DOHC engine, the fuel supply boss will be located below the camshaft. In such an arrangement, the camshaft must be removed when attaching and detaching the injector for maintenance and replacement of the injector. In order to attach the camshaft once removed from the cylinder head to the cylinder head again, adjustment such as matching the relative phases of both camshafts is required.
On the other hand, the replacement frequency of the camshaft is generally less than that of the injector. Therefore, the camshaft which does not need to be replaced in order to remove the injector is removed, and the workability is extremely deteriorated, including the necessity of reattaching and adjusting the camshaft.

Conversely, if the fuel supply boss is arranged above the camshaft, the overall length of the injector will be increased, the overall height of the engine will be increased, and the mountability on the vehicle will be impaired, thus hindering the downsizing of the engine. Furthermore, since a structure is used in which the fuel supply boss penetrates the cylinder head side wall using a semicircular plug, special parts that constitute the fuel supply piping structure like a semicircular plug are required, and the number of parts is reduced. To increase. Further, a specially shaped processing step of forming a semicircular notch in the side wall of a cylinder head made of metal such as cast iron or aluminum is required, and the number of processing steps is increased as a whole. As a result, the fuel supply pipe structure described in the above publication has a problem that the manufacturing cost of the engine is increased.

On the other hand, in the injection pipe sealing device described in JP-A-8-28404, a fuel supply boss (sleeve nut) is obliquely penetrated with respect to a head cover, and is sealed by a guide sleeve and a positioning hole. Restricts device orientation. In order to comply with the regulations, the number of processing steps for processing each component of the sealing device is increased, and it is necessary to maintain the processing accuracy of the direction of the sealing device at a certain level or more, which results in an increase in engine manufacturing costs. ing. Further, it is necessary to dispose the seal device at a specific angle, and the workability of attaching the seal device to the head cover is deteriorated.

Therefore, in the injector in which the upper part of the cylinder head to which the injector is attached is covered with a head cover, a fuel passage boss connected to a fuel supply pipe or the like extending from the body of the injector is provided as a lubrication valve for a valve mechanism. Sealing between the inside and outside of the head cover through which the fuel passage boss penetrates to prevent oil etc. from leaking to the outside from the inside of the head cover where the oil is scattered, or to prevent fuel other than lubricating oil from entering from outside, for example. Processing accuracy is strictly required, such as preparing a semicircular plug as in the above-described conventional technology or preparing a boot that penetrates a through hole formed in a head cover in an oblique direction. In order to obtain an inexpensive and simple upper structure of the cylinder head without adopting the special structure Issues to be determined are left.

[0013]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and an elastic seal for sealing between a fuel passage boss extending from an injector body and a hole formed in a head cover. By adopting the member and utilizing the error absorbing action of the elastic deformation of the elastic sealing member, strict accuracy is not required for the manufacture of the injector and the head cover and for the assembly of the injector and the head cover to the cylinder head, and As a component of the sealing device, a component having a simple structure can be adopted, the number of processing steps for manufacturing the component is reduced, the processing accuracy is reduced, and the mounting operation is simplified, and the manufacturing cost is reduced. It is to provide an injector mounting structure with a reduced sealing device.

The present invention has been made in order to solve the above-mentioned object.
It is configured as follows. That is, the present invention provides an injector body provided with an injection hole for injecting fuel into a combustion chamber and attached to a cylinder head, and a passage extending from the injector body and supplying or discharging the fuel to or from the injector body. An injector having a fuel passage boss provided with: and a head cover attached to the cylinder head so as to cover the injector and having a hole formed through the fuel passage boss. The head cover covers the periphery of the fuel passage boss and the hole at a predetermined inclination angle with respect to the axis, and an assembling error between the fuel passage boss and the head cover and a relative error. A sealing device including an elastic seal member capable of absorbing displacement is provided. On the injector mounting structure.

According to the injector mounting structure provided with the seal device of the present invention, the seal between the fuel passage boss extending from the injector body mounted on the cylinder head and the head cover mounted on the cylinder head is elastic. Since the sealing is performed by the seal member, there is an error in the assembly in which the fuel passage boss of the injector penetrates the hole of the head cover due to a manufacturing error of the injector or the head cover or an error in mounting the injector and the head cover to the cylinder head. Even if it occurs, that is, even if the penetration position or penetration angle deviates from the original design, the assembly error is absorbed by the elastic deformation of the elastic seal member. During operation of the engine, static relative displacement between the head cover and the fuel passage boss caused by heat or the like, and dynamic relative displacement due to the difference between the vibration of the injector and the vibration of the head cover occur. The displacement is also absorbed by the elastic sealing member. Therefore, it is not necessary to strictly control the manufacturing accuracy of the injector, the head cover, and the elastic seal member and the mounting accuracy to the cylinder head, and the manufacturing cost and the mounting cost can be reduced.

Further, in the injector mounting structure provided with the seal device, the injector is mounted on the cylinder head in a state where the axis of the injector body is substantially coincident with the axis of the combustion chamber. For example, even in a small direct-injection diesel engine, if the axis of the injector body is substantially aligned with the axis of the combustion chamber, a total of four intake and exhaust valves can be arranged in a well-balanced manner around the injector. In addition, it is possible to achieve DOHC with improved output and improved combustion characteristics despite its small size.

In the injector mounting structure provided with the seal device, a fuel pipe for supplying or discharging fuel to or from the injector is connected to a tip of a fuel passage boss protruding outside the head cover. With this configuration, the completion of the connection between the fuel passage boss and the fuel pipe can be visually confirmed without removing the head cover, and it is possible to avoid a fuel leak caused by forgetting to connect or insufficient connection. In addition, when the connection is made in the head cover, when the connection is not good, the situation that the fuel leaks into the head governor and the fuel is mixed with the blow-by gas, which may cause a problem, can be avoided in advance.

In the injector mounting structure provided with the sealing device, a hole through which the fuel passage boss passes is formed in a side wall of the head cover, and the fuel passage boss passes through the hole at a substantially right angle to the side wall. doing. As described above, since the fuel passage boss is arranged orthogonally to the head cover, there is no need to prepare a sealing component having a special angle as a sealing device around the through hole, and the manufacturing cost is reduced. Since there is no need to assemble in a special direction, the work of assembling the seal component into the through hole is simplified.

In the injector provided with the sealing device, the elastic sealing member has a flange mounted on a mounting surface formed on an outer surface of the head cover by a tightening bolt, and a peripheral portion of the fuel passage boss mounted on the flange. An elastic seal lip for sealing engagement with the surface, wherein a fitting hole for inserting the elastic seal lip and a tightening bolt are inserted into the flange and the mounting position of the flange with respect to the mounting surface can be adjusted. A bolt hole having a diameter larger than the diameter of the fastening bolt is formed. By dividing such an elastic seal member into a flange that plays a role of attaching to the head cover and an elastic seal lip that plays a role of sealingly engaging the peripheral surface of the fuel passage boss, the tightening force of the tightening bolt is elastically increased. Since there is no engagement with the parts, the life of the elastic seal lip can be extended. Also, since the inner diameter of the bolt hole formed in the flange is made larger than the diameter of the tightening bolt, a flange is formed in the elastic seal lip in a state where the elastic seal lip is sealingly engaged with the peripheral surface of the fuel passage boss. After being moved to a position showing a natural state where the stress is minimized, it can be mounted on the mounting surface of the head cover with a tightening bolt. Since the elastic seal member is attached to the head cover in the minimum stress state as described above, even if vibration occurs in the elastic seal lip due to the difference between the mode of the injector vibration and the mode of the head cover vibration during engine operation, the vibration deformation occurs. Can be minimized.

In the injector provided with the sealing device, the flange is mounted on the mounting surface via a gasket portion formed integrally with the elastic sealing lip. Since the flange is attached to the head cover with such a gasket part interposed, even if there is minute unevenness between the contact surface between the head cover and the flange due to the elastic deformation of the gasket part, uniform sealing surface pressure is achieved. As a result, the sealing is ensured, and the sealing performance for blocking the flow of the fluid between the inside and the outside of the head cover is improved. Furthermore,
Since the gasket portion has an integral structure with the elastic seal lip, an increase in the number of parts is suppressed, and the workability of attaching and detaching the elastic seal lip is improved.

In the injector provided with the sealing device, the elastic sealing lip is provided in a lip portion for sealingly contacting the peripheral surface of the fuel passage boss, a fitting portion fitted to the flange, and a lip portion and a fitting portion. And a corrugated connecting portion for increasing the relative displacement between the fuel passage boss and the head cover that can be connected by the elastic seal lip. Since the elastic seal lip has a corrugated connection, even if there is a mismatch between the fuel passage boss of the injector and the hole of the head cover, the corrugated connection elastically deforms with low stress and absorbs the deviation It is possible to do.

In the injector provided with the sealing device, a spring member for increasing a sealing force on a peripheral surface of the fuel passage boss is fitted around an outer periphery of the lip portion. The spring member is preferably a coil spring.
The contraction force of the spring member increases the tightening force of the lip portion acting on the peripheral surface of the fuel passage boss, so that the sealing performance of the elastic seal lip on the fuel passage boss is improved.

Further, in the injector provided with the sealing device, two camshafts disposed in parallel with each other with the injector interposed therebetween on the cylinder head, and an intake / exhaust valve for opening / closing an intake / exhaust port of a combustion chamber. A valve operating mechanism comprising two cams provided at positions interposing the injector with respect to each camshaft to operate the
The fuel passage boss is located directly above one camshaft and 2
A plurality of cams extend from the injector body at a predetermined angle with respect to the body axis. When the engine to which the injector equipped with the sealing device is applied is a DOHC type engine and such an injector mounting structure is used, the fuel passage boss is different from the cam shaft and the cam provided on the cam shaft. Will not interfere, but will be located closest to the camshaft, as a result
The height position of the fuel passage boss extending from the injector standing upright at the center position surrounded by the four intake / exhaust valves is sufficiently lowered, so that the overall height of the engine can be reduced. Further, the axes of the valves such as the intake and exhaust valves driven by the cam provided on the camshaft can be further approached to each other while being parallel to the axis of the injector. Therefore, the upper structure of the cylinder head does not adversely affect the characteristics of the DOHC engine.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an injector mounting structure provided with a sealing device according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view showing an embodiment of an injector mounting structure provided with a sealing device according to the present invention, and FIG. 2 is a state in which a head cover and a sealing device are removed from a cylinder head in the injector mounting structure provided with a sealing device shown in FIG. 3 is a plan view of an elastic seal member used in the injector mounting structure provided with the seal device shown in FIG. 1, and FIG. 4 is a sectional view of the elastic seal member shown in FIG. FIG.

The injector mounting structure provided with the seal device shown in FIG. 1 is applied to a multi-cylinder small diesel engine in which a plurality of injectors 1 are arranged in series. Injector 1
FIG. The other injectors 1 have the same structure and mutual relationship between the fuel passage boss and the elastic seal member. Injector 1 with valve operating mechanism and clamp member viewed from top view of top surface of cylinder head 2
2 is shown in FIG. 2 with the head cover removed.

The injector 1 is inserted into a mounting hole 3 formed in the cylinder head 2 and mounted by a clamp member 4. The clamp member 4 is made of an elastic metal material and has a flat plate-like shape as a whole, and has the same structure at both ends to be shared with the adjacent injector 1. Only one is shown. The clamp member 4 has a bifurcated fork portion 5 in which the abutting portion with the injector 1 sandwiches the injector 1, and the fork portion 5 abuts on the shoulder 6 as a clamp pressure receiving surface on both upper sides of the injector body 14. In contact. The shoulder portion 6 is formed by cutting an unnecessary thickness of the injector 1 and processing it into a flat surface. The central part of the clamp member 4 is fixed to the cylinder head 2 by a fixing bolt 7.
, The injector 1 is attached to the cylinder head 2.

The camshaft 8 is provided at the position sandwiching the injector 1 with respect to the injector 1, for driving the intake / exhaust valve.
A plurality of cams 10 and 11 are provided. Further, the camshaft 9 is also provided with the injector 1 relative to the injector 1.
Two cams 12 and 13 for driving the intake and exhaust valves
Are provided at positions corresponding to the cams 10 and 11.
Therefore, each of the cams 10 to 13
The injector 1 is located upright at the center surrounded by the four intake and exhaust valves. The camshafts 8 and 9 and the cams 10 to 13 provided on the camshafts 8 and 9
The above-mentioned valve mechanism is constituted. The distance between the camshafts 8 and 9 is set such that the distance between the camshafts 8 and 9 is
However, since the operation timings of the intake and exhaust valves between the cams 10 and 11 and the cams 12 and 13 are different, the camshafts 8 and
9 rotates while maintaining a constant rotational angle relationship with each other, so that the cams 10, 11 and the cams 12, 13 do not interfere with each other during rotation of the camshafts 8, 9.

The injector 1 has an injector body 14.
And a fuel passage boss 15 that extends integrally with the upper part of the injector body 14. Fuel passage boss 15
Are shown as fuel supply passage bosses in this embodiment. Axis line of injector body 14 (body axis) AA
Is fixed to the cylinder head 2 in a state substantially coincident with the axis of the combustion chamber into which fuel is injected from the injection hole 19 of the injector 1. The clamping force of the clamp member 4 shown in FIG. 2 presses the distal end side of the injector 1 against the tapered surface of the mounting hole 3 via the nozzle packing 20, and the nozzle packing 20 causes the cylinder head 2 to have the combustion chamber and the mounting hole. 3 is sealed. An injection nozzle 18 formed at the tip of the injector 1 faces the combustion chamber.

A fuel supply passage 16 extends in the injector body 14 in parallel with the axis AA.
6 is connected to the fuel supply passage 17 of the fuel supply boss 15. The fuel passage boss 15 is located immediately above the camshaft 8 and disposed between the cams 10 and 11, and extends obliquely upward so as to intersect the camshaft 8. The axis CC of the fuel passage boss 15 is aligned with the axis A- of the injector 1.
A is at a predetermined angle θ. Fuel passage boss 1
5 is arranged so as to be as close as possible to the camshaft 8 to narrow the gap with the camshaft 8. Therefore, the installation position of the fuel passage boss 15 is
And the connection of the fuel line to the injector 1 is not at the upper end of the injector 1 shaft,
It can be performed from the side of the injector 1 and suppresses the overall height of the injector 1. Further, the injector body 14 includes the layout of the fuel pipe 26 from the fuel pump.
At a predetermined angle with respect to the axis A-A of the camshaft 8.
The space-saving structure can be achieved by arranging them close to each other.

Since the distance between the valve ports of the intake and exhaust valves and the like is determined according to the scale of the engine, an increase in the distance between the camshafts 8 and 9 means that the valve shafts of the intake and exhaust valves and the like are connected to the injector. This means that it is inevitable to incline with respect to the first axis A-A, and in such an opening structure of the valve port with respect to the combustion chamber, the performance of the engine deteriorates. However, in the mounting structure of the injector 1, the gap between the camshaft 8 and the fuel passage boss 15 can be narrowed. According to such a structure, the camshafts 8, 9 are arranged close to each other, and the camshafts 8, 9 are arranged.
The intake / exhaust valves driven by the fuel injectors are arranged close to each other while maintaining parallel to the injector 1, in other words, maintaining perpendicular to the combustion chamber. Even a diesel engine does not cause performance degradation.

Further, if the strength of the fuel passage boss 15 permits, the fuel passage boss 15 adjacent to the camshaft 8 is cut into a cylindrical arc-shaped surface to form a relief portion 21 for avoiding interference with the camshaft 8. Thus, the fuel passage boss 15 can be made closer to the camshaft 8.
When such a structure is employed, the height position of the fuel passage boss 15 is further lowered, so that the overall height of the engine is further lowered, and valves such as intake and exhaust valves driven by cams 10 and 11 provided on the camshaft 8. Can be further approached to each other while being parallel to the axis of the injector 1.

The upper surface of the cylinder head 2 including the injector 1, the camshafts 8, 9 and the cams 10 to 13 is entirely covered by a head cover 22. The head cover 22 is attached to the cylinder head 2 by attachment bolts 39 at a peripheral portion thereof. The side wall 23 of the head cover 22 is substantially perpendicular to the axis CC of the fuel passage boss 15. That is, the fuel passage boss 15 penetrates perpendicularly to the side wall 23. In the side wall 23, a through hole 24 that is sufficiently larger than the outer diameter of the fuel passage boss 15 is formed corresponding to the fuel passage boss 15. Since a sufficient gap is formed between the hole wall of the through hole 24 and the peripheral surface of the fuel passage boss 15, a space for accommodating a seal lip of an elastic seal member described later is secured, and the injector 1 and the head cover are formed. 22. Absorbs a relative mounting error relative to 22 and a relative displacement due to vibration. Therefore, the fuel passage boss 15 does not abnormally approach the side wall 23. The outer wall surface of the side wall 23 constitutes a mounting surface 25 to which an elastic seal member 28 described later is mounted.

The tip of the fuel passage boss 15 projects outside the head cover 22. As shown in FIG. 1, a fuel pipe 26 is connected to the fuel passage boss 15 by tightening a connecting nut 27 outside the head cover 22. In this example, the fuel pipe 26 is shown as a fuel supply pipe for supplying fuel to the injector 1. High-pressure fuel from a fuel pump provided outside the cylinder head is supplied to the injector 1 through a fuel pipe 26.
Supplied to The fuel supplied to the injector 1 is burned from the injection hole 19 of the nozzle 18 through the fuel supply passage 16 in the body 14 of the injector 1 from the fuel supply passage 17 of the fuel passage boss 15 at the timing when the fuel pressure reaches a predetermined fuel pressure. It is injected indoors.

Since the connection between the fuel passage boss 15 and the fuel pipe 26 is made outside the head cover 22, the connection failure such as fuel leakage is more likely to occur in the head cover 22 than in the case where the above connection is made inside the head cover 22. Confirmed visually externally. Therefore, the fuel passage boss 15 and the fuel pipe 2
6 can be reliably attached and detached, and a major failure can be prevented. Also, even if fuel leaks from the connection between the fuel passage boss 15 and the fuel pipe 26, the fuel leaks outside the head cover 22, so that the leaked fuel enters the head cover 22 and mixes with the blow-by gas. Never.

The fuel passage boss 15 penetrating through a hole 24 formed in the side wall 23 of the head cover 22 and the head cover 22
An elastic seal member 28 is disposed between the two. The inside of the head cover 22 in which the lubricating oil for the valve mechanism is scattered is sealed by the elastic seal member 28 from the outside. The elastic seal member 28 includes a flange 29 attached to the attachment surface 25 of the head cover 22 and an elastic seal lip 30. Flange 29
A fitting hole 31 for fitting the elastic seal lip 30 inside is formed in the center of the
Tightening bolt 40 for attaching to head cover 22
A bolt hole 32 is formed to pass through. The bolt hole 32 is formed such that its inner diameter is sufficiently larger than the outer diameter of the tightening bolt 40.

The elastic seal lip 30 is disposed in the fitting hole 31 of the flange 29. Elastic seal lip 30
Is formed of an elastic member such as rubber which is easily deformed, and has a lip portion 33 abutting on the peripheral surface of the fuel passage boss 15,
The fitting portion 34 is attached to a wall surface of the fitting hole 31 of the ninth, and a connecting portion 35 having a cross-sectional waveform for connecting the lip portion 33 and the fitting portion 34 is provided. A coil spring 36 urged in the contraction direction is fitted on the outer periphery of the lip 33. The coil spring 36 tightens the lip portion 33 against the peripheral surface of the fuel passage boss 15 to make contact with a necessary sealing force.

Further, a flat annular gasket portion 37 extends outward from the connecting portion 35 integrally.
The gasket portion 37 occupies a position along the side surface of the flange 29 when the elastic seal lip 30 is attached to the flange 29. Further, when the elastic seal member 28 is attached to the head cover 22, the gasket portion 37 is compressed between the mounting surface 25 of the head cover 22 and the flange 29. That is, the flange 29 is attached to the attachment surface 25 of the side wall 23 of the head cover 22 via the gasket portion 37.

Even if there are minute irregularities on the opposing surface between the mounting surface 25 and the flange 29, a sufficient surface pressure and sealing force can be secured over the entire opposing surface by the elastic deformation of the gasket portion 37. The gasket 37 has a solid projection 3
8 is formed in an annular shape, so that when the projection 8 is compressed and attached between the attachment surface 25 and the flange 29, the projection 3
8, the annular portion having a high surface pressure is obtained, and the head cover 22 and the fuel passage boss 15 by the elastic seal member 28 are formed.
And high sealing performance can be secured between them. The passage of oil or gas from inside to outside or from outside to inside of the head cover 22 is prevented between the mounting surface 25 of the head cover 22 and the flange 29 and between the fitting hole 31 and the fitting portion 34. . In addition, since the gasket portion 37 is formed integrally with the elastic seal lip 30, the number of components constituting the elastic seal member 28 is reduced, and furthermore,
The elastic seal member 28 is attached to the head cover 22 by sandwiching the gasket portion 37 integrally formed with the elastic seal lip 30 between the flange 29 and the mounting surface 25 of the head cover 22.
Does not come out of the flange 29 carelessly.

In the injector mounting structure having a structure in which the fuel passage boss 15 of the injector 1 extends obliquely upward, a hole through which a piping system having a fuel passage to the injector 1 penetrates is formed at some position of the head cover 22. In this embodiment, however, the fuel passage boss 15 of the injector 1 is penetrated through the head cover 22,
The diameter of the hole 24 formed in the head cover 22 is made sufficiently larger than the outer diameter of the fuel passage boss 15, and the gap between the hole 24 and the fuel passage boss 15 is closed by an elastic seal member 28. Therefore, a sufficient clearance is formed between the hole 24 and the fuel passage boss 15 only by removing the fastening bolt 40 from the head cover 22 and pulling out the elastic seal member 28 from above the fuel passage boss 15. as a result,
At the time of work such as inspection and maintenance of the valve operating mechanism and the injector 1, the head cover 22 is quickly moved from the cylinder head 2 without interfering with the fuel passage boss 15 of the injector 1 which is fixed to the cylinder head 2. Can be detached. Further, with respect to the fuel passage boss 15, a seal portion is set on the peripheral surface at a position corresponding to the hole 24.
5 only needs to be secured in a necessary range, and the sealing device can be made compact.

Further, since the fuel passage boss 15 penetrates the hole 24 having a diameter larger than the outer diameter of the fuel passage boss 15, an assembly error due to accumulation of machining errors can be sufficiently absorbed. There is no need for precise processing of each component. Also, since the fuel passage boss 15 penetrates the hole 24 at right angles to the hole 24, the diameter of the through hole increases, as seen when the fuel passage boss 15 obliquely penetrates the hole 24, and the sealing device Does not increase in size. The elastic seal member 28 is also a symmetrical part, and does not require special processing, thereby reducing manufacturing costs. Furthermore, if the component is asymmetric, it is necessary to attach the elastic seal member 28 while paying attention to the attachment state such as the attachment direction and the attachment position. The elastic seal member 28 can be attached without paying special attention to the mounting angle with respect to the angle and the angle around the axis CC of the fuel passage boss 15, and the sealing performance of the attached elastic seal member 28 also maintains a high level. can do.

The bolt hole 32 for the tightening bolt 40 is formed such that its inner diameter is sufficiently larger than the outer diameter of the tightening bolt 40, so that the elastic seal member 2
8 can be finally positioned with respect to the head cover 22 when the elastic seal member 28 is attached, and a reliable seal can be achieved. When attaching the elastic seal member 28 to the head cover 22, first, the elastic seal lip 30 of the elastic seal member 28 is attached to the fuel passage boss 1.
The elastic seal member 28 is roughly positioned with respect to the fuel passage boss 15 by being fitted on the outer periphery of the fuel passage 5. In this state, the tightening bolt 40 is inserted into the bolt hole 3 of the flange 29.
2 and screwed into the screw hole 41 of the mounting surface 25.
Since the inner diameter of the bolt hole 32 for the tightening bolt 40 of the flange 29 is loosened with respect to the diameter of the tightening bolt 40, the positioning of the flange 29 with respect to the mounting surface 25 is adjusted before the tightening bolt 40 is screwed into the screw hole 41. And the flange 29 can be screwed into the elastic seal member 28, so that the load acting on the elastic seal member 28, particularly on the connecting portion 35, can be minimized. Further, even if the mode of the vibration of the injector 1 and the mode of the vibration of the head cover 22 during the operation of the engine are different, the relative vibration displacement between the two is absorbed by the elasticity of the connecting portion 35, so that compared with the hard seal. In addition, the durability of the seal by the elastic seal member 28 is improved.

The embodiment of the injector mounting structure for an engine according to the present invention has been described above as an injector mounting structure for a small diesel engine. However, in the case of an injector type engine, a diesel engine having various injection systems or an in-cylinder engine can be used. Obviously, it is applicable to an injection type gasoline engine.

[0043]

The injector mounting structure according to the present invention is configured as described above, and has the following effects. That is, since the seal between the fuel passage boss extending from the injector body attached to the cylinder head and the head cover attached to the cylinder head is performed by the elastic seal member, errors in the manufacture of the injector and the head cover and the injector Even if an assembly error occurs between the fuel passage boss and the hole of the head cover through which the fuel passage boss penetrates due to an attachment error of the head cover to the cylinder head or the like, the assembly error is
It is absorbed by the elastic deformation of the elastic seal member. Also,
Even if the fuel passage boss and the head cover are displaced relative to each other due to the difference between the vibration of the injector and the vibration of the head cover generated during operation of the engine, the displacement is absorbed by the elastic seal member. Therefore, it is not necessary to strictly control the manufacturing accuracy of the injector and the head cover and the mounting accuracy of the injector and the head cover to the cylinder head, and it is possible to reduce the manufacturing cost and the mounting cost of the head cover and the injector. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an injector mounting structure provided with a sealing device according to the present invention.

2 is a schematic top view showing an injector mounting structure provided with the sealing device shown in FIG. 1 with a head cover removed.

FIG. 3 is a plan view of an elastic seal member used in the injector mounting structure including the seal device shown in FIG.

FIG. 4 is a cross-sectional view of the elastic seal member shown in FIG. 3 taken along a right-angle cut plane indicated by line BOB.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injector 2 Cylinder head 8, 9 Camshaft 10, 11, 12, 13 Cam 14 Injector main body 15 Fuel passage boss 19 Injection hole 22 Head cover 23 Side wall 24 Hole 25 Mounting surface 26 Fuel pipe 28 Elastic seal member 29 Flange 30 Elastic seal lip 31 Fitting hole 32 Bolt hole 33 Lip part 34 Fitting part 35 Connecting part 36 Coil spring 37 Gasket part 40 Tightening bolt

Claims (9)

[Claims] An injector body, which is provided with an injection hole for injecting fuel into a combustion chamber and is attached to a cylinder head, and a passage extending from the injector body and supplying or discharging the fuel to or from the injector body. An injector having a fuel passage boss provided, and a head cover attached to the cylinder head so as to cover the injector and having a hole formed through the fuel passage boss, wherein the fuel passage boss is a shaft of the injector body. The head cover extends at a predetermined inclination angle with respect to the center, and the head cover seals a gap between the peripheral surface of the fuel passage boss and the hole, and an assembly error and a relative displacement between the fuel passage boss and the head cover. Provided with a sealing device comprising an elastic seal member capable of absorbing Jector mounting structure. 2. The sealer according to claim 1, wherein the injector is attached to the cylinder head in a state where the axis of the injector body is substantially coincident with the axis of the combustion chamber. Injector mounting structure. 3. The fuel pipe according to claim 1, wherein a fuel pipe for supplying or discharging the fuel to or from the injector is connected to a tip of the fuel passage boss protruding outside the head cover. Injector mounting structure provided with a sealing device. 4. The fuel cell system according to claim 1, wherein the hole through which the fuel passage boss penetrates is formed in a side wall of the head cover, and the fuel passage boss penetrates the hole at a substantially right angle to the side wall. An injector mounting structure provided with the seal device according to claim 1. 5. The resilient sealing member is mounted on the flange and a flange attached to a mounting surface formed on an outer surface of the head cover by a tightening bolt, and sealingly engages the peripheral surface of the fuel passage boss. An elastic seal lip, wherein the flange is fitted with a fitting hole for fitting the elastic seal lip and the tightening bolt, and the tightening is performed so that the mounting position of the flange with respect to the mounting surface can be adjusted. An injector mounting structure provided with the seal device according to any one of claims 1 to 4, wherein a bolt hole having a diameter larger than the diameter of the bolt is formed. 6. The injector mounting structure according to claim 5, wherein the flange is mounted on the mounting surface via a gasket portion formed integrally with the elastic seal lip. . 7. The elastic seal lip includes a lip portion that comes into sealing contact with the peripheral surface of the fuel passage boss, a fitting portion fitted to the flange, and a connection between the lip portion and the fitting portion. An injector mounting structure provided with the sealing device according to claim 5 or 6, further comprising a connecting portion formed into a corrugated shape. 8. The injector according to claim 7, wherein a spring member for increasing a sealing force of the fuel passage boss with respect to the peripheral surface is fitted on an outer periphery of the lip portion. Mounting structure. 9. On the cylinder head, two camshafts arranged in parallel with each other with the injector interposed therebetween, and the respective cams for operating intake and exhaust valves for opening and closing intake and exhaust ports of the combustion chamber. A valve mechanism comprising two cams provided at a position sandwiching the injector with respect to a shaft, wherein the fuel passage boss is provided immediately above one of the camshafts and between the two cams. An injector mounting structure provided with the sealing device according to any one of claims 1 to 8, which is extended.