JP2556142Y2 - Lubricating device in diesel engine fuel injection system - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for a fuel injection device of a diesel engine.

[0002]

2. Description of the Related Art FIG . 4 shows a prior art of a fuel injection device for a diesel engine. Specifically, a fuel injection pump case 102 is attached to a crankcase 101, a fuel injection pump 103 is accommodated in the fuel injection pump case 102, and a fuel injection camshaft 104 is provided below the fuel injection pump 103. A tappet 106 of a fuel injection pump 103 is mounted on a fuel injection cam 105 of a fuel injection cam shaft 104.

In this prior art, in order to lubricate the fuel injection device, a wide communication port 107 facing the inside of the crankcase 101 is provided at the bottom of the fuel injection pump case 102.
Is open. According to such a configuration, the lubricating oil mist generated in the crankcase 101 flows into the fuel injection pump case 102 from the communication port 107, adheres to the cam surface 108 of the fuel injection cam 105, and condenses. The rotation of the injection cam 105 causes the cam surface 108 and the tappet 106 to rotate.
And is lubricated.

[0004]

In the above-mentioned prior art, the lubricating portion between the cam surface 108 and the tappet 106 is lubricated by only a small amount of lubricating oil mist in contact with the cam surface 108. The amount of lubricating oil supplied to the sliding portion is relatively small. Therefore, if the high-speed operation is continued for a long time, the sliding portion may be seized.

Therefore, in order to solve this problem, as shown by a chain line, lubricating oil is supplied from a lubricating oil injection hole 109 provided below the fuel injection cam 105 toward a cam surface 108 of the fuel injection cam 105 as indicated by an arrow 110. So that the cam surface 10
It is also conceivable to bring a large amount of lubricating oil into contact with 8. However, in this case, since the lubricating oil is intensively supplied to a narrow area of the cam surface 108, the lubricating oil forms a large oil droplet on the cam surface 108, and during high-speed operation in which the fuel injection cam 105 rotates at high speed. Oil droplets having a large mass are scattered around by the centrifugal force, and the amount of lubricating oil supplied to a sliding portion between the cam surface 108 and the tappet 106 becomes insufficient. For this reason, even in this case, if the high-speed operation is continued for a long time, the sliding portion may be seized.

On the other hand, the inner wall of the fuel injection pump case 102
Part of the oil swells to form an oil sump.
Lubricating oil is collected in the oil sump and fuel is injected into the lubricating oil in the oil sump.
It is conceivable to immerse a part of the shooting cam 105. This
In the case of, the lubricating oil
Can be lifted and splashed on the lift projection on cam surface 108
And slides between the cam surface 108 and the tappet 106.
A large amount of lubricating oil is caught in the moving parts. Because of this, high speed
Even if the operation is continued for a long time, the cam surface 108
The sliding portion with the pet 106 does not burn.

However, lubricating oil is stored in the oil sump.
If the lubricating oil is left as it is,
8 is continuously exposed to the sliding heat of the sliding portion of the tappet 106.
Deteriorated early. And when the engine starts
Means that the lubricating oil in the oil reservoir is
Resistance to rotation and smooth start of the engine
It may not be possible.

In the present invention, during normal operation, fuel injection
Apply a large amount of lubricating oil to the sliding part between the cam surface of the cam and the tappet.
When the engine is started, the lubricating oil burns
It is an object of the present invention to provide a lubricating device for a fuel injection device of a diesel engine, which does not cause resistance to rotation of a fuel injection cam .

[0009]

According to the present invention, a fuel injection pump case 2 is mounted on a crankcase 1 as illustrated in FIG.
A fuel injection pump 3 is accommodated in the fuel injection pump case 2, a fuel injection cam shaft 4 is provided below the fuel injection pump 3, and the fuel injection cam 5 of the fuel injection cam shaft 4 is mounted on the fuel injection cam 5. A fuel injection device for a diesel engine, in which the tappet 6 of the fuel injection pump 3 is mounted, is characterized as follows, for example, as shown in FIG .

The lubricating oil 8 in the oil pan 7 is pumped and supplied into the fuel injection pump case 2 by the pumping force of the oil pump 9, and the fuel injection pump case 2 is provided with a bottom wall 10. The fuel injection cam 5 on the bottom wall 10
Ri opened lubricating oil return hole 11 to a position below the lubricating
Through the oil return hole 11 and inside the fuel injection pump case 2
By communicating with the inside of the crankcase 1, the upper
Lubricant 8 is circulated between via the serial lubricating oil return hole 11 of the oil pan 7 and the <br/> fuel injection pump casing 2
And the fuel passing through the lubricating oil return hole 11
Flow from the injection pump case 2 into the crankcase 1
The amount of the lubricating oil 8 to be discharged is determined in the fuel injection pump case 2.
Lubricating oil less than the amount of lubricating oil 8
As the oil 8 is accumulated in the inner bottom of the fuel injection pump casing 2
And a part of the fuel injection cam 5 is immersed in the lubricating oil 8.

[0011]

[Function] The present invention is configured as described above,
For example, as shown in FIG. Normal
During operation, the lubricating oil 8 in the oil pan 7 is
Pumping into the fuel injection pump case 2 by the pumping force of the pump 9
The fuel is supplied and accumulates on the inner bottom of the fuel injection pump case 2. You
That when, by the fuel injection portion of the fuel injection cam 5 on Jun <br/> Namerayu 8 waiting reservoir in the inner bottom of the pump casing 2 is immersed, it rotated 39 of the fuel injection cam 5, the lubricating oil 8 cam In addition to being lifted as an oil film on the surface 14,
5, a large amount of lubricating oil 8 is entrained in the sliding portion between the cam surface 14 and the tappet 6. Therefore, even if high-speed operation is continued for a long time, the cam surface 1
The sliding portion between the tappet 4 and the tappet 6 does not burn.

[0012] The lubricating oil 8 which waited reservoir in the inner bottom of the fuel injection pump casing 2 is always discharged from the lubricating oil return hole 11
Is returned to the oil pan 7 so that the fuel injection pump
The lubricating oil 8 in the case 2 is replaced in a relatively short time, and the same lubricating oil is not continuously exposed to the sliding heat of the sliding portion between the cam surface 14 and the tappet 6. Therefore , compared with the case where the lubricating oil 8 stagnates on the inner bottom of the fuel injection pump case 2,
This early deterioration of the lubricating oil 8 is prevented, and the performance of preventing the seizure of the sliding portion between the cam surface 14 and the tappet 6 by the lubricating oil 8 can be maintained for a long period of time.

On the other hand, when the engine stops, the fuel injection port
The lubricating oil 8 accumulated on the inner bottom of the pump case 2
After being discharged from the return hole 11, the fuel injection cam 5
No longer immersed in. Therefore, when starting the engine
The lubricating oil 8 in the fuel injection pump case 2 is
The start of the engine is smooth without the resistance of the rotation of the cam 5.
Can be done

[0014]

[Effect of the Invention] The present invention is constructed and operated as described above.
Therefore, the following effects are obtained. Normal engine operation
Lubricating oil collects on the inner bottom of the fuel injection pump case.
On the other hand, the oil always returns to the oil pan through the lubricating oil return hole.
The lubricating oil in the fuel injection pump case is relatively
In a short period of time, the cam surface of the fuel injection cam and the fuel
Lubricating oil is applied to the sliding heat of the sliding part of the injection pump with the tappet.
There is no continuous exposure. Therefore, the fuel injection pump
Compared to the case where lubricating oil is stored in the inner bottom of the case
Prevents early deterioration of the lubricating oil and prevents the cam surface
Long-term anti-seizure performance of the sliding part between
Can be maintained over time.

In addition, when the engine stops,
Lubricating oil accumulated on the inner bottom of the fuel injection pump case
The fuel is discharged from the lubrication oil return hole and the fuel injection cam is
When the engine starts, the fuel
The lubricating oil in the injection pump case
Resistance can be prevented and the engine starts smoothly
I can do it.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.
First, a first embodiment will be described. FIG. 1 is a vertical sectional front view of a fuel injection device for a diesel engine according to a first embodiment of the present invention. FIG. 2 is a longitudinal sectional side view of FIG.

The structure of the fuel injection device of the first embodiment is as follows. As shown in FIG. 1, a fuel injection pump case 2 is attached to the upper left side of a crankcase 1, a fuel injection pump 3 is housed in the fuel injection pump case 2, and a fuel injection cam is provided below the fuel injection pump 3. A shaft 4 is provided, and a tappet 6 of a fuel injection pump 3 is mounted on a fuel injection cam 5 of the fuel injection cam shaft 4. A Bosch type pump is used for the fuel injection pump 3 and a flat tappet is used for the tappet 6. As shown in FIG. 2, a gear case 37 is provided in front of the fuel injection pump case 2, and a distal end portion 18 of the fuel injection camshaft 4 protrudes into the gear case 37. The gear 19 is fitted outside. The camshaft input gear 19 is linked to a crank gear (not shown) via an idle gear 20.

In this fuel injection device, as shown in FIG. 2, the fuel injection camshaft 4 is rotated and linked from a crank gear (not shown) via an idle gear 20 and a camshaft input gear 19 in this order. , The tappet 6 is pushed up, and the fuel injection pump 3 operates.

This fuel injection device is provided with a lubrication device, the configuration of which is as follows. As shown in FIG. 1, lubricating oil 8 is stored in an oil pan 7 attached to the lower side of the crankcase 1, a suction port 21 of an oil pump 9 is immersed in the lubricating oil 8, and a discharge port of the oil pump 9 is A sliding portion 39 such as a bearing portion of a crankshaft is connected to the sliding portion 22 through a lubricating hydraulic pressure passage 23. And, this lubricating hydraulic transmission passage 2
A branch passage 24 is provided in the middle of 3, and a passage end portion 25 of the branch passage 24 is connected to a lubricating oil injection pipe 26 provided below the fuel injection camshaft 4. A lubricating oil injection hole 27 is opened in the lubricating oil injection pipe 26 at a position facing the cam surface 14 of the fuel injection cam 5, and the lubricating oil 8 in the oil pan 7 is injected by the oil pump 9 by the pumping force of the oil pump 9. The fuel is ejected from the hole 27 as indicated by an arrow 28 and supplied into the fuel injection pump case 2.

The fuel injection pump case 2 has a bottom wall 10.
The bottom wall 10 has a lubricating oil return hole 11 facing into the crank chamber 1. The lubricating oil return hole 11 is set to a size such that the amount of the lubricating oil 8 flowing out from the lubricating oil return hole 11 is smaller than the amount of the lubricating oil 8 injected from the lubricating oil injection hole 27.
When the lubricating oil 8 circulates between the inside of the oil pan 7 and the inside of the fuel injection pump case 2, the lubricating oil 8 is stored in the inner bottom of the fuel injection pump chamber 2. Also, the fuel injection camshaft 4
And the front wall 29 of the fuel injection pump case 2
An overflow hole 30 is formed in (see FIG. 2). Therefore, the oil level of the lubricating oil 8 accumulated on the inner bottom of the fuel injection pump case 2 is maintained at substantially the same height as the fuel injection cam shaft 4, and a part of the fuel injection cam 5 is immersed in the lubricating oil 8. It is like that.

In this lubricating device, a part of the fuel injection cam 5 is immersed in the lubricating oil 8 stored in the inner bottom of the fuel injection pump case 2, and the lubricating oil 8 is rotated on the cam surface 14 by the rotation 39 of the fuel injection cam 5. It can be lifted up as an oil film and the cam surface 1
The lubricating oil 8 is splashed up in the form of droplets by the lift projections 15 of 4, and a large amount of lubricating oil 8 is caught in the sliding portion between the cam surface 14 and the tappet 6. Further, since the lubricating oil 8 accumulated on the inner bottom of the fuel injection pump case 2 circulates between the oil pan 7 and the lubricating oil, the same lubricating oil is continuously applied to the sliding heat of the sliding portion between the cam surface 14 and the tappet 6. No exposure. Incidentally, as shown in FIG. 2, the lubricating oil overflowing from the overflow hole 30 flows out into the gear case 37 as shown by an arrow 31, and
As shown in FIG.
It returns to the oil pan 7 from inside.

In this lubricating oil device, when the engine stops, the oil pump 9 stops, and the supply of the lubricating oil from the oil pan 7 into the fuel injection pump case 2 stops. The lubricating oil 8 accumulated in the inner bottom flows out from the lubricating oil return hole 11 into the crankcase 1 as shown by an arrow 33, and the lubricating oil 8 disappears from the fuel injection pump case 2. Therefore, immediately after starting the engine,
Until the lubricating oil 8 accumulates in the inner bottom of the fuel injection pump case 2 in a certain amount or more, a part of the fuel injection cam 5 will not be immersed in the lubricating oil 8. The lubricating oil collides with the cam surface 14 as shown by an arrow 28 to lubricate the cam surface. During this time, low-speed idling operation is usually performed. Therefore, even in this oil jet lubrication system, which is inferior to the oil bath lubrication system, the sliding surface between the cam surface 14 and the tappet 6 is seized. There is no danger of causing. In FIG. 2, reference numeral 34 denotes a mechanical governor device.

Next, a second embodiment of the present invention will be described. FIG. 3 is a diagram corresponding to FIG. 1 of a lubricating device according to a second embodiment of the present invention. This second embodiment is almost the same as the first embodiment.
The fuel injection cam 5 has the same configuration but differs from the cam
The lubricating oil is injected from the surface 14. The structure is as follows.

That is, the branch passage 24 of the lubricating hydraulic transmission passage 23
Is connected to the lubricating oil supply passage 12 opened in the axial center of the fuel injection camshaft 4, and the lubricating oil 8 in the oil pan 7 is supplied to the lubricating oil supply passage 12 by the pumping force of the oil pump 9. It is configured to supply by pressure. Then, a lubricating oil injection passage 13 derived from the lubricating oil supply passage 12 is opened in the flesh portion of the fuel injection cam 5, and the cam surface 14 of the fuel injection cam 5 is provided on the rotation upper base 17 of the lift projection 15. A passage outlet 16 of the lubricating oil injection passage 13 is formed. The other structure is the same as that of the first embodiment shown in FIG.

In this lubricating device, the lubricating oil ejected from the passage outlet 16 of the lubricating oil injection passage 13 is lifted immediately before the lifting projection 15 of the cam surface 14 comes into contact with the tappet 6. 15 and the tappet 6, the lubricating oil that has been jetted at this time is not immediately splashed around by the centrifugal force generated by the rotation of the fuel injection cam 5, and the lubricating oil is ejected between the lift projection 15 and the tappet 6. In the sliding part of
It is surely involved in large quantities.

Then, the passage outlet 1 of the lubricating oil injection passage 13
After that, the lubricating oil squirted from
The cam surface 14 accumulates on the inner bottom of the cam 2 and is lubricated with an oil bath.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of a fuel injection device for a diesel engine according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional side view of FIG.

FIG. 3 is a diagram corresponding to FIG. 1 of a lubricating device according to a second embodiment of the present invention.

FIG. 4 is a diagram corresponding to FIG. 1 of a lubricating device for a diesel engine according to the related art.

[Explanation of symbols]

1 ... Crankcase, 2 ... Fuel injection pump case, 3 ...
Fuel injection pump, 4 ... fuel injection cam shaft, 5 ... fuel injection cam, 6 ... tappet, 7 ... oil pan, 8 ... lubricating oil, 9 ...
Oil pump, 10 ... 2 bottom wall, 11 ... lubricating oil return hole.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinsuke Tsuchiya 64 Ishizu-Kitamachi, Sakai-shi, Osaka, Japan Kubota Sakai Works Co., Ltd. References JP-A 63-130609 (JP, U) JP-A 1-124312 (JP, U) JP-A 63-63514 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A fuel injection pump case (2) is attached to a crankcase (1), and a fuel injection pump (3) is housed in the fuel injection pump case (2).
A fuel injection camshaft (4) is installed below the fuel injection camshaft (4).
In the fuel injection device for a diesel engine, which is configured by mounting the tappet (6), the lubricating oil (8) in the oil pan (7) is pumped by the oil pump (9) using the fuel injection pump case ( The fuel injection pump case (2) is provided with a bottom wall (10) , and a position below the fuel injection cam (5) at the bottom wall (10).
Opening the lubricating oil return hole (11), the lubricating oil return hole (11) through the
And the inside of the fuel injection pump case (2) and the crankcase
The lubricating oil is returned by communicating with the inside of the base (1).
As the hole (11) through the lubricating oil between said oil pan (7) in the above fuel injection pump case (2) in (8) is circulated
Configured, the fuel injection Ponpuke through said lubricating oil return hole (11)
Lubrication flowing out of the crankcase (1)
Pumping the amount of oil (8) into the fuel injection pump case (2)
Lubricate with less than the amount of lubricating oil (8) supplied
(8) accumulates in the inner bottom of the fuel injection pump casing (2)
Uni configured, the fuel injection cam (5) partially lubricating oil (8)
A lubricating device for a fuel injection device of a diesel engine, characterized in that the lubricating device is configured to be immersed in the fuel injection device.