JPH109092A - Fixture for injection valve used in dohc type internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely dispose a glow plug, and enhance startability and durability by firmly fixing the pedestal part of an injection valve to a cylinderhead bolts, stabilizing the bearing-pressure of a nozzle gasket while vibration from the injection valve is being lowered, and providing one end fixing the injection valve for the washer part of the cylinderhead. SOLUTION: A mounting hole 2 for an injection valve 5 is provided for the center part of a cylinderhead 1a, and counter sunk holes for vertical female screws and cylinderhead bolts are also provided for an upper deck 19. A counter sunk hole approximately 20mm deep from the upper surface of the cylinderhead is also provided while being offcentered afterward. When a bolt 8 is fastened, a spherical washer 9 is lowered down, a nozzle retainer 11 allows its forked curved surface to be lowered down while its curved surface leg 12 is being made as a fulcrum in a nozzle gasket interposed between the injection valve 5 and the cylinderhead 1a, and the bearing pressure of the nozzle gasket is thereby insured. Other five cylinderhead bolts are fastened via plain washers 17 onto a cylinder block so as to be fixed thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a fixture for an injection valve for a DOHC internal combustion engine.

[0002]

2. Description of the Related Art In a conventional injection valve fixing method, a fixed seat surface of an injection valve is provided on the upper deck of an upper deck of a cylinder head, so that a mounting angle of a glow plug cannot be increased, and starting performance and durability are insufficient. I was

A conventional method for fixing an injection valve (FIGS. 9 and 10 are views showing a conventional example) is to provide a mounting hole 20 for the injection valve substantially at the center of the cylinder of the cylinder head 1 and to provide an upper deck 19. A female screw boss is provided vertically. Further, the boss 3 protrudes inside the side wall 33 of the cylinder head.
2 and a pin 14 pressed into the hole.

The cylinder head 1 has a mounting hole 2 for an injection valve.
A glow plug 16 for starting, which is arranged in a horizontal direction with 0, is attached. On the left and right sides of the injection valve, camshafts 4, 3
0 is arranged and pressed by the cam cap.

[0005] In the lateral direction of the injection valve 5, an inlet 3 for high-pressure fuel is provided.
The needle valve lift sensor 6 and the spill tube 39 are screwed to the main body 8 in the upward direction. Further, a two-sided cut surface 34 for providing a pressure receiving portion of the nozzle retainer 11 is formed at the center.

On the upper surface of the cylinder head 1, a rocker cover 10 is fixed with screws via a rocker cover gasket 13. The outer cylinder of the lip seal 3 is press-fitted into the rocker cover 10, and the inner surface elastically supports the inlet 38.

The nozzle gasket 70 provided between the injection valve 5 and the cylinder head 1 lowers the spherical washer 9 when the bolt 8 is tightened, and the nozzle retainer 11
The bifurcated curved surface 7 is lowered downward at the fulcrum, and the surface pressure of the nozzle gasket 70 can be secured. Further, the six cylinder head bolts 15 are fastened and fixed to the cylinder block via washers 18.

[0008]

However, in the above-mentioned conventional fixture for an injection valve for a DOHC type internal combustion engine,
The following problems occurred. (1) When the bolt 8 is tightened, the curved foot 12 and the pin 14 are lowered with the bifurcated curved surface 7 as a fulcrum, and the side wall of the head is deformed, so that the sealing property of the rocker cover gasket is deteriorated and oil leakage occurs. Further, when the pin 14 is lowered, the surface pressure of the nozzle gasket 70 is reduced, so that gas leaks in the cylinder. (2) When the nozzle holder receives the in-cylinder pressure, the pin 15 vibrates up and down, deforming the side wall of the head and causing radiation noise. (3) Since a pedestal pin and a boss for the nozzle retainer 11 are provided, the machining cost of the cylinder head and the cost of parts are required, which has been a factor of cost increase. (4) If the pedestal pin or the boss for the nozzle retainer 11 is lowered, the glow plug cannot be set up, thus deteriorating the low-temperature startability. The present invention has been proposed in view of the problems of the prior art described above, in which the base part of the injection valve is firmly fixed with a cylinder head bolt, and the surface pressure of the nozzle gasket 70 is reduced while reducing the vibration from the injection valve. Stabilized. Another object of the present invention is to solve the above-mentioned problems by providing the one end for fixing the injection valve in the cylinder head washer so that the glow plug can be freely arranged and the startability and durability are improved.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a fixture for a fuel injection valve of a DOHC type diesel engine, comprising: a nozzle holder having a pivot at a center; Is used.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following description, the same parts and members as those described in the related art will be described using the same reference numerals.

FIG. 1 and FIG. 2 are diagrams showing a first embodiment of the present invention. First, the configuration of the first embodiment will be described. A mounting hole 20 for an injection valve is provided in the center of the cylinder head 1a, and a vertical female screw and a counterbore 48 for a cylinder head bolt 43 are provided in the upper deck 19. Provided. A counterbore 47 is formed eccentrically rearward and approximately 20 mm deep from the upper surface of the cylinder head. The nozzle base 50 shown in FIGS. 3 and 4 is integrated with a hole 63 coaxial with the hole of the head bolt 43 and the outer cylinder 60 is integrated with the cylindrical portion 41 eccentric by Y. The slope 68 is omitted for weight reduction.

When the bolt 8 is tightened, the spherical washer 9 of the nozzle gasket 70 provided between the injection valve 5 and the cylinder head 1a is lowered, and the nozzle retainer 11 has the bifurcated curved surface 7 lowered with the curved foot 12 as a fulcrum. The surface pressure of the nozzle gasket 70 can be secured. The other five cylinder head bolts are fastened and fixed to the cylinder block via flat washers 17.

Next, the operation of the first embodiment will be described.

In the nozzle base 50, when the head bolt 43 is assembled, the cylinder head counterbore holes 47, 48 are positioned by the eccentric cylindrical portions 41, 60, respectively, so that there is no problem that the nozzle base 50 rotates when the head bolt is tightened. . In addition, the nozzle base 50 and the head bolts 43 firmly fix the upper deck 19 and the deformation of the upper deck can be reduced because the upper deck 19 is close to the female screw boss 18.
Furthermore, since the mounting surface of the nozzle base 50 can be lowered,
Gas leakage due to excessive surface pressure of the nozzle gasket due to thermal expansion of the cylinder head (aluminum) can be prevented.

Since the nozzle retainer seat and the cylinder head bolt seat are shared, four valves, oil drop holes, blow-by passages, and the like can be freely installed on the upper deck.

Since the glow plug 65 can be set upright on the stepped portion of the nozzle base 50 shown in FIG. 4, the tip heating section can be efficiently projected into the combustion chamber, so that the engine startability at low temperatures is improved.

Even if the nozzle holder receives the reaction force of the in-cylinder pressure, the force can be quickly released from the nozzle base to the cylinder head bolt seat, so that deformation and vibration of the cylinder head side wall can be prevented.

Since the nozzle base is firmly fixed to the cylinder head bolt seat, the surface pressure of the nozzle gasket 70 is stabilized, and the gas sealing performance is improved.

The cost is reduced because the nozzle base and the cylinder head bolt seat are shared.

Next, a second embodiment of the present invention will be described with reference to FIGS.

Nozzle base 9 in the second embodiment
2 is a cylinder head bolt seat and a female screw 8 for nozzle fixing
3. The receiving base 84 is integrated.

First, the structure will be described. The holes 89 and 93 are coaxially opened in the bolt seat cylindrical portion 91, the eccentric receiving base 84 is provided on the upper part, and the nozzle fixing screw boss 82 which protrudes in the middle part. Consists of Therefore, the second embodiment has the following advantages. (A) Since the screw boss for fixing the nozzle is not required in the upper deck 81, the deck thickness can be reduced by 8 mm to 5 mm. In addition, since the screw back boss is also eliminated, the water jacket can be expanded, reducing the heat load. (B) The weight can be reduced and the equipment cost can be reduced by eliminating the processing of the nozzle fixing screw of the cylinder head, so that the cost can be reduced. (C) Since the nozzle base 92 and the nozzle fixing female screw 83 are integrated, the support rigidity of the nozzle retainer 87 can be increased.
The seal surface pressure of the nozzle gasket can be stabilized, and gas leakage can be eliminated. (D) Since there is no screw boss for fixing the nozzle from the upper deck 81, even if the bolt for fixing the nozzle is tightened, the deformation of the valve lifter hole or the cam journal that has been precisely machined can be prevented.

[0023]

As described above, according to the present invention, gas leakage due to excessive surface pressure of the nozzle gasket due to thermal expansion of the cylinder head (aluminum) can be prevented, and four valves, oil drop holes, Blow-by passages can be installed freely.

Further, according to the present invention, the startability of the engine at a low temperature is improved, the deformation and vibration of the side wall of the cylinder head can be prevented, the surface pressure of the nozzle gasket is stabilized, and the gas sealing performance is improved. In addition, since the nozzle base and the cylinder head bolt seat are shared, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

FIG. 3 is a detailed view of a nozzle base.

FIG. 4 is a detailed view of a nozzle base.

FIG. 5 is a configuration diagram showing another embodiment of the present invention.

FIG. 6 is a configuration diagram showing another embodiment of the present invention.

FIG. 7 is a configuration diagram showing another embodiment of the present invention.

FIG. 8 is a configuration diagram showing another embodiment of the present invention.

FIG. 9 is a configuration diagram showing a conventional example.

FIG. 10 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 1, 1a Cylinder head 3 Lip seal 4 Cam shaft 5 Injection valve 6 Needle valve lift sensor 7 Bifurcated surface 8 Bolt 9 Spherical washer 10 Rocker cover 11 Nozzle retainer 12 Curved surface 13 Rocker cover gasket 14 Pin 15 Cylinder head bolt 16 Glow plug 17 Flat washer 18 Female thread boss 19 Upper deck 20 Injection valve mounting hole 30 Cam shaft 32 Overhang boss 33 Side wall of cylinder head 34 Two-side cut surface 38 High-pressure fuel inlet 39 Spill tube 41 Cylindrical part 43 Cylinder head bolt 47, 48 Cylinder head seat Counterbore 50 Nozzle base 60 Cylindrical part 63 Hole 65 Glow plug 68 Slope 70 Nozzle gasket 81 Upper deck 82 Nozzle fixing screw boss 83 Nozzle fixing female screw 84 Receiving stand 87 Zururiteina 89,93 hole 91 bolt bearing cylindrical section 92 nozzle base

Claims (3)

[Claims] 1. A fuel injection valve fixing device for a DOHC type diesel engine, wherein a cylinder head washer is used for one of pedestals in a nozzle holder having a pivot at a center. Valve fixture. 2. The injection valve for a DOHC internal combustion engine according to claim 1, wherein in the cylinder head washer, a cylinder head bolt seat and a nozzle base are eccentrically positioned with respect to a cylinder head. Utensils. 3. In the cylinder head washer, a cylinder head bolt seat and a nozzle base are formed eccentrically, and a female thread portion of a bolt for fixing an injection valve is integrated to position the cylinder head washer and the cylinder head. The DOH of claim 1, wherein
A fixture for an injection valve for a C-type internal combustion engine.