JPH0849632A - Oil feeder of fuel injection pump - Google Patents

Abstract

PURPOSE:To secure the appropriate supplying amount of lubricating oil without increasing the number of parts in an oil feeder of a fuel injection pump for introducing lubricating oil to a pump through an oil feeding pipe, and for supplying it into an oil feeding hole opened to a tappet sliding surface. CONSTITUTION:The opening position of an oil feeding hole 17 is set off from the stroke center (p) of a tappet sliding surface 16 to one side, and the valve opening range of the oil feeding hole 17 taking a tappet 11 as a valve is provided on the top dead center side or the bottom dead center side of the tappet 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil supply device for a fuel injection pump.

[0002]

2. Description of the Related Art A fuel injection pump for a diesel engine is an important part that is the center of the fuel injection device, and various lubrication devices have been proposed in order to lubricate the sliding parts inside the pump well (actually, the actual fuel injection pump 3). -123921 publication, actual Kaihei 3
No. 114572, Japanese Utility Model Application No. 2-13347, No. 4-1233367, No. 4-57670.

Of these, as shown in FIG. 3, the lubricating oil for the pump is taken out from the oil gallery of the engine block through the oil supply pipe 1, and is supplied to the clearance between the tappet 4 and the oil supply hole 3 formed in the tappet sliding surface 2. There are many examples of doing this. Reference numeral 5 is a cam that drives the plunger 6 via the tappet 4, and 7 is an eyebolt that forms a connection portion (introduction portion) with the oil supply pipe 1 on the outer surface of the pump housing 8. Lubricating oil for the pump is supplied to the cam chamber 9 It collects, but is returned to the engine side through the overflow pipe.

[0004]

However, in such a conventional example, since the supply amount of the lubricating oil depends on the clearance of the tappet 4, there is a possibility that poor lubrication may occur due to variations in the clearance. for that reason,
It is conceivable to directly pass the oil supply hole 3 to the side of the cam chamber 9 or the side of the plunger 6 instead of the clearance with the tappet 4. However, in this case, means for controlling the flow rate such as an orifice is provided in order to avoid excessive supply of lubricating oil. There was a problem that it was necessary and increased the cost.

The present invention has been made in consideration of such problems, and provides a device capable of appropriately controlling the supply amount of lubricating oil by increasing the number of parts by making the tappet function as a valve. To aim.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an oil supply device for a fuel injection pump in which lubricating oil is introduced into a pump through an oil supply pipe and is supplied to an oil supply hole opened on a sliding surface of a tappet. The opening position of the hole is offset to one side from the stroke center of the tappet sliding surface, and the valve opening region of the oil supply hole having the tappet as a valve is provided at the top dead center side or the bottom dead center side of the tappet.

[0007]

According to this, since the tappet functions as a valve for the oil supply hole, it is possible to secure an appropriate amount of oil supply to the pump by adjusting the valve opening region. In this case, since it is only necessary to open the oil supply hole at an offset position where the amount of oil supply is appropriate, good lubrication of the pump can be realized at low cost without increasing the number of parts.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 10 is a cam for driving a plunger 12 via a tappet 11 and 13 is an oil supply pipe for introducing lubricating oil from an oil gallery of an engine block to a pump. An eyebolt 15 that forms a connection portion (introduction portion) with the pipe 13 is attached, and the lubricating oil from the oil supply pipe 13 is fed to the tappet sliding surface 16
The oil is supplied to the oil supply hole 17 that opens in the.

In this case, the opening position of the oil supply hole 17 is the stroke center p of the tappet sliding surface 16 (the tappet sliding surface 16).
By offsetting a predetermined amount upward from a boundary line that bisects the upper and lower parts, a valve opening region is provided in which the tappet 11 is used as a valve for the fueling hole 17 and the fueling hole 17 directly communicates with the plunger 12 side at the bottom dead center side. To be

When the cam does not lift (bottom dead center position), the tappet 11 opens the oil supply hole 17 above it.
When the cam is lifted, the oil supply hole 17 is closed at the offset position on the top dead center (represented by the chain double-dashed line) side. 1
Reference numeral 8 indicates a cam chamber of the pump.

With such a structure, when the valve-closing region facing the clearance with the tappet 11 moves to the valve-opening region in which the oil supply hole 17 directly communicates with the plunger 12, the supply amount of the lubricating oil increases, so that the oil supply is increased. By adjusting the valve opening area of the hole 17, it is possible to secure an appropriate amount of oil supply to the pump.

In this case, since it is only necessary to open the oil supply hole 17 at the offset position where the amount of oil supply is appropriate on the tappet sliding surface 16, good pump lubrication can be realized at low cost without increasing the number of parts. .

FIG. 2 shows another embodiment, which is an oil supply hole 1
By offsetting the opening position of 7a downward from the stroke center p of the tappet sliding surface 16 by a predetermined amount, a valve opening region is provided at the top dead center side of the tappet 11 so that the oil supply hole 17a directly communicates with the cam chamber 18. The same parts as those in FIG. 1 are designated by the same reference numerals, and the duplicated description will be omitted.

According to this, the amount of oil supplied is increased not to the plunger 12 side but to the cam chamber 18 side. However, as in the previous embodiment, by adjusting the valve opening area of the oil supply hole 17a, the appropriate amount of oil can be supplied to the pump. The amount of refueling can be secured.

[0015]

As described above, according to the present invention, the lubricating oil is introduced into the pump through the oil supply pipe and is supplied to the oil supply hole opened on the sliding surface of the tappet. The opening position of the tappet is offset to one side from the stroke center of the sliding surface, and the valve opening area of the lubrication hole with the tappet as the valve is provided at the top dead center side or bottom dead center side of the tappet. By adjusting the valve area with the offset amount, it is possible to secure an appropriate amount of oil supply to the pump without adding any parts.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a pump showing an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a pump showing another embodiment.

FIG. 3 is a cross-sectional view of a main part of a pump illustrating a conventional technique.

[Explanation of symbols]

 10 Cam 11 Tappet 12 Plunger 13 Oil Supply Pipe 16 Tappet Sliding Surface 17, 17a Oil Supply Hole 18 Cam Chamber

Claims (1)

[Claims] 1. An oil supply device for a fuel injection pump, wherein lubricating oil is introduced into a pump through an oil supply pipe and is supplied to an oil supply hole opened on a tappet sliding surface. A refueling device for a fuel injection pump, characterized in that a valve opening region of a refueling hole having a tappet as a valve is provided on the top dead center side or a bottom dead center side of the tappet, offset from the stroke center of the moving surface to one side.