JPS626289Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil leak passage connection structure for a fuel injection valve mainly used in a diesel engine.

As a conventional oil leakage passage connection structure, for example, the fifth
As shown in the figure, an oil leakage pipe 71 is connected to the upper end of the fuel injection valve 3, that is, the inner part of the valve arm chamber 8 via a joint 70, or an injection valve is inserted into the cylinder head 13 as shown in FIG. There is one in which a lateral hole 74 is formed facing the hole 73, and leaked oil is guided to the outside of the cylinder head 13 through this lateral hole 74.

However, in the structure shown in FIG. 5, when removing the injection valve 3, the joint 70 and oil leak pipe 71 must be disassembled, which takes time and effort. In addition, there is a high possibility that oil leakage will enter the valve arm chamber 8 from the joint 70, and if oil leaks into the valve arm chamber 8, it will dilute the lubricating oil in the valve arm chamber 8 and cause engine operation. This may cause defects.

Further, in the structure shown in FIG. 6, fuel leakage accumulated in the side hole 74 flows into the combustion chamber through the insertion hole 73 when the injection valve is taken out, causing a starting failure of the engine.

The applicant of this application previously applied for a structure as shown in FIG.
57-57895). That is, the one in FIG. 7 shows the downward oil leakage outlet hole 75 of the injection valve 3 and the cylinder head 1.
In this structure, the upper oil leakage inlet hole 76 of No. 3 is fitted and connected by a substantially vertical joint 78 within the injection valve chamber 20 . However, the structure shown in FIG. 7 requires extremely accurate positioning accuracy of the outlet hole 75, etc., so there is a problem in that it takes time and effort to process.

The present invention is an attempt to improve the structure shown in Fig. 7 to make it easier to process, and also to make it easier to attach and detach the injection valve. is as stated in the claims for utility model registration. The present invention will be explained below based on the drawings.

In FIG. 1, an injection valve chamber 20 is formed in the cylinder head 13, and the fuel injection valve 3 is inserted into the valve chamber 20 from the valve arm chamber 8 side. The lower end nozzle portion 21 of the injection valve 3 faces the combustion chamber 22, and the lock nut 6 and cap nut 7 for the injection pressure adjusting screw 5 protrude upward from the upper surface 13a of the cylinder head. The valve chamber lid 1 consists of a lid body 1a and a bottomed cylindrical portion 1b, and is formed in a shape that can completely isolate the valve chamber 20 from the valve arm chamber 8 and completely cover both the nuts 6 and 7. ing. That is, the outer peripheral end portion of the lower surface of the lid 1 is in contact with the upper surface 13a of the cylinder head via a generally annular rubber packing 24, and the bottomed cylinder portion 1b that opens downward and covers the cap nut 7 is press-fitted into the inner peripheral hole 23 of the lid body 1a. It is fixed. The lower surface portion 1c of the lid body 1a on the valve center side is in contact with the upper surface of the valve body 4.

The valve holding fitting 11 is fixed to the cylinder head upper surface 13a with bolts 25 and nuts 26, and the tip fork portion 27 of the fitting 11 is in contact with the upper surface of the lid body 1a. This compresses the rubber gasket 24 and presses the injection valve 3 (main body 4) downward via the lid main body 1a. Copper gaskets 9 are arranged on both upper and lower surfaces of the lock nut 6, respectively.

Therefore, the lid 1 completely isolates the entire injection valve 3 including both nuts 6 and 7 from the valve arm chamber 8, and even if the gaskets 9 on both the upper and lower sides of the nut 6 are damaged, the valve arm chamber There is no need to worry about oil leaking into 8.

Note that "oil leakage" refers to fuel oil leaking from the nozzle part 21 into the valve body 4, which fills the gap on the outer circumferential side of the adjustment screw 5 and prevents oil leakage passages 51 and 4, which will be described later.
This refers to the oil that is returned to the fuel tank via the 1st class.

Reference numeral 29 is a fuel high pressure pipe, which is connected to the fuel injection pump and inserted into the cylinder head 13 from the cylinder head side surface 13b, and is directly connected to the protrusion 4a of the valve body 4 without using an intermediate joint or the like. It is connected. That is, as shown in FIG.
A female threaded hole 31 is formed in the same center as the conical seat part 30, and a tapered conical part 32 is formed at the tip of the high pressure pipe 29, and the conical part 32 is connected to the seat part 30. is in contact with. A tightening tube 33 is fitted into the outer circumferential side of the high-pressure tube 29, and a male thread 3 is attached to the tip of the tightening tube 33 on the valve chamber side.
4 is formed, and this male thread 34 is inserted into the female threaded hole 3.
It is screwed into 1. The distal end edge of the clamping pipe 33 is connected to the flange portion 3 of the high pressure pipe 29 via the annular spacer 38.
2a. The tightening tube 33 extends outward from the cylinder head side surface 13b (FIG. 1), and the outer end of the cylinder head of the tightening tube 33 has a head 36 (with which a tightening tool can be engaged). For example, a hexagonal head) is formed. The head 36 contacts the cylinder head side surface 13b via an annular packing 37. That is, the clamping pipe 33 is connected to the cylinder head 13.
By tightening from the outside, the valve chamber side edge of the tightening pipe 33 presses the conical part 32 against the seat part 30 via the annular spacer 38, and both parts 32, 3
0 is connected in a liquid-tight manner, and the inside of the high pressure pipe 29 and the fuel oil passage 40 are communicated with each other. Further, by tightening the packing 37 between the head 36 and the cylinder head side surface 13b, the high pressure pipe insertion hole 39 in the head 13 is closed in a liquid-tight state.

Reference numeral 41 in FIG. 1 is a fuel oil leak passage, which is formed in a portion of the cylinder head 13 below the high-pressure pipe 29, and extends laterally from the cylinder head side surface 13b to the vicinity of the valve body 4. The end of the oil leakage passage 41 on the side of the cylinder head side surface 13b is
For example, it is connected to a fuel tank via a pipe joint bolt 42. The end of the oil leak passage 41 on the side of the valve body 4 communicates with an oil leak inlet hole 43 extending upward, and the oil leak inlet hole 43 has a structure as described below to prevent leakage of the valve body 4 as shown in FIG. It is connected to the oil outlet hole 45.

That is, in FIG. 3, the oil leakage outlet hole 45 is formed in the protruding portion 4a of the valve body 4 and opens downward, and its lower end has a stepped diameter and includes a horizontal annular flat sheet portion 46. ing. On the other hand, a joint pipe 47 is press-fitted into the oil leakage inlet hole 43 of the cylinder head 13, and a horizontal flat sheet portion 48 is formed at the upper end of the joint pipe 47. An annular rubber packing 49 is fitted into the enlarged diameter portion at the lower end of the oil leakage outlet hole 45. The packing 49 has a cross-sectional shape such that the lower end on the inner peripheral side thereof protrudes a certain amount _L1 below the lower surface 50 of the valve body projecting portion 4a in the free state (solid line). The amount of protrusion L ₁ is larger than the amount of compression of the packing L ₂ . Further, the upper end portion of the inner peripheral side of the gasket 49 is slightly lower than the seat portion 46 in the free state. In addition, oil leakage outlet hole 4
5 is the first through the horizontal oil leakage passage 51 of the valve body 4.
It communicates with the outer peripheral gap of the adjusting screw 5 shown in the figure.

When the injection valve is tightened, the gasket 49 is compressed between the two flat seat portions 46 and 48, as shown by the imaginary line in FIG. That is, even if there is some dimensional error in the horizontal formation position of the oil leakage outlet hole 45, for example, the distance from the center line of the injection valve, the two holes 45 and 43 can be reliably and easily connected.

FIG. 4 shows another embodiment, in which a joint pipe 47' is fitted into the oil leak inlet hole 43 via an O-ring 53 so as to be movable in the vertical direction, and a coil spring 5
2 is biased upward. Oil leakage outlet hole 45
Horizontal flat sheet portions 46 and 48 are formed at the lower end and the upper end of the joint tube 47', respectively. An annular packing 49 is attached to a counterbore at the upper end of the joint pipe 47'.

In the structure shown in FIG. 4, not only can horizontal dimensional errors such as the outlet hole 45 be absorbed, but also the spring 52
Accordingly, even large dimensional errors in the vertical direction can be reliably absorbed, and the manufacturing process and disassembly and assembly of the injection valve 3 are further facilitated.

As explained above, the present invention provides a downward oil leakage outlet hole 45 in the fuel injection valve 3 in the cylinder head 13.
The outlet hole 45 is formed in the cylinder head 13.
An oil leak inlet hole 43 facing upward is formed, and approximately horizontal flat sheet portions 46 and 48 are formed at the lower end periphery of the outlet hole 45 and the upper end periphery of the inlet hole 43, respectively. By disposing a packing 49 made of an elastic material and pressing this packing 49 in the vertical direction, an oil leak passage communicating between both holes 45 and 43 is formed, which has the following advantages.

(1) Since the gasket 49 is pressed between the substantially horizontal flat sheet portions 46 and 48, there may be some difference in the horizontal formation position of the outlet hole 45, etc., for example, the distance from the center line of the injection valve 3. Even if there is a dimensional error, the two holes 45 and 43 can be reliably and easily connected by simply inserting the injection valve 3 into the valve chamber 20 from above. Therefore, the machining of the outlet hole 45 and the like does not take much time, and the installation and removal operations of the injection valve 3 are also extremely simple. Also, the cost will be lower.

(2) Since the oil leakage inlet hole 43 of the cylinder head 13 is formed upward, there is no fear that oil leakage will flow into the valve chamber 20 and combustion chamber 22 from the inlet hole 43 when the injection valve is removed, and the engine can be started. There is no risk of defects occurring.

(3) Since both holes 45 and 43 are connected within the cylinder head 13, there is no risk of oil leakage entering the valve arm chamber 8, and therefore there is no risk of lubricant dilution occurring within the valve arm chamber 8. No malfunctions occur due to lubricant dilution.

Note that as the packing 49, synthetic resin can also be used in addition to rubber. Further, in FIG. 3, the flat sheet portion 48 on the upper end side of the inlet hole 43 is connected to the joint 47.
Although the seat portion 48 is formed at the upper end portion, the seat portion 48 may be formed directly at the cylinder head 13 portion at the upper end periphery of the inlet hole 43 without using the joint 47.

[Brief explanation of the drawing]

Fig. 1 is a partial vertical cross-sectional side view of a diesel engine to which the present invention is applied, Figs. 2 and 3 are a partial view of Fig. 1 and an enlarged view of the part, respectively, and Fig. 4 is Fig. 3 showing another embodiment. Corresponding enlarged cross-sectional views, 5th, 6th,
FIG. 7 is a partially vertical side view showing a conventional example. 3...Fuel injection valve, 13...Cylinder head,
43... Oil leak inlet hole, 45... Oil leak outlet hole, 4
6, 48...Flat sheet part, 49...Putskin.

Claims (1)

[Scope of utility model registration request] A downward oil leakage outlet hole 45 is formed in the fuel injection valve 3 in the cylinder head 13.
An upward oil leakage inlet hole 43 is formed opposite to the outlet hole 45, and approximately horizontal flat sheet portions 46 and 48 are formed at the lower end periphery of the outlet hole 45 and the upper end periphery of the inlet hole 43, respectively. Seat part 46, 4
A gasket 49 made of an elastic material is disposed between the holes 43 and 45, and by pressing the gasket 49 in the vertical direction, an oil leakage passage communicating between the two holes 43 and 45 is formed. Oil passage connection structure.