JPH0893597A - Fuel injection pump - Google Patents

Abstract

PURPOSE: To keep the oil surface in a pump higher than an oil dropping hole even after the stoppage of an engine in order to improve lublicity at the time of starting the engine in a fuel injection pump having an oil supply course for introducing an lubricating oil to the pump into a cam chamber and a plunger chamber, and an oil dropping hole for returning the lubricating oil gathering in the cam chamber to the engine side. CONSTITUTION: A cover 15 for enclosing an oil dropping hole 13 in a space to open upward to the position of a fixed height outside a cam chamber is provided. As a means in place of the cover 15, a pipe for extending the oil dropping hole 13 upward to the position of a fixed height is provided outside the cam chamber 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an engine fuel injection pump.

[0002]

2. Description of the Related Art A fuel injection pump for a diesel engine is an important part of a fuel injection device, and various improvements have been proposed in order to lubricate sliding parts inside the pump (Actual Publication No. Hei 3-123921). Gazette, Jitsukaihei 3-1145
No. 72 gazette, actual Kaihei 4-1233367 gazette, actual Kaihei 4
-57670 gazette).

In many of these cases, the lubricating oil for the pump is taken out from the oil gallery of the engine block through the oil supply pipe and is supplied to the clearance between the tappet and the oil supply hole opened on the tappet sliding surface of the pump housing. As can be seen, a lubrication system in which lubricating oil is directly introduced into the cam chamber by an oil supply pipe is often adopted.

[0004]

By the way, the surplus of the lubricating oil accumulated in the cam chamber is returned to the engine side through the oil drop hole. For example, in the case of a lubrication method that introduces lubricating oil directly into the cam chamber, the oil level rises from the cam chamber to the plunger chamber during engine operation, and the plunger chamber is also lubricated, but when the engine is stopped, the oil drop hole opening position The oil level will decrease. Therefore, even if refueling of the cam chamber is started when the engine is started, it takes time for the oil level to rise to the plunger chamber again, which may cause a temporary deterioration of the lubricating condition of the plunger chamber.

Even in the lubrication system in which the lubricating oil to the pump is supplied to the clearance of the tappet, a part of the lubricating oil is sent from the clearance to the plunger chamber and naturally flows down to the cam chamber while lubricating each sliding portion. When the cam chamber is equipped with an oil drain hole that regulates the oil level in the pump, the lubricating oil in the plunger chamber drops into the cam chamber and remains almost completely when the engine stops. As with the direct delivery method to, the lubrication failure of the plunger chamber could occur.

The present invention has been made in consideration of such problems, and it is possible to keep the oil level of the cam chamber higher than the opening position of the oil drop hole even after the engine is stopped.

[0007]

According to the first aspect of the present invention, an oil supply path for introducing lubricating oil to the pump into the cam chamber and the plunger chamber and an oil drop hole for returning the lubricating oil collected in the cam chamber to the engine side are provided. In the fuel injection pump, a cover is provided to surround the oil drop hole in a space that opens upward to a predetermined height position outside the cam chamber.

According to the second aspect of the invention, in the fuel injection pump provided with an oil supply path for introducing lubricating oil to the pump into the cam chamber and the plunger chamber, and an oil drop hole for returning the lubricating oil collected in the cam chamber to the engine side, A pipe is provided to extend the oil drain hole upward to a predetermined height outside the chamber.

[0009]

According to the first aspect of the present invention, by adding the cover that surrounds the outside of the oil drop hole, the substantial opening position can be easily increased without changing the processing position of the oil drop hole. Therefore, the oil level drop after the engine is stopped is suppressed,
Good lubricity can be secured even when the engine is started.

According to the second aspect of the invention, by adding the pipe for extending the oil drop hole, the substantial opening position can be easily increased without changing the processing position of the oil drop hole. Therefore, it is possible to suppress a decrease in the oil level after the engine is stopped and to secure good lubricity even when the engine is started.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 1 is a pump housing, 2 is a plunger mechanism for pumping fuel, and lubricating oil for the pump is taken out from an oil gallery of an engine block through an oil supply pipe 3, and an oil supply port 4 of the pump housing is used. Through the cam chamber 5. The camshaft 6 drives the plunger mechanism 2 in synchronization with the engine rotation, and is supported in front of and behind the cam chamber 5 via bearings 9a and 9b, respectively. The lubricating oil may be supplied from the oil supply port 4 of the pump housing 1 to the cam chamber 5 and the plunger chamber 8 via the clearance of the tappet 7.

A timer 10 is provided at the front end of the camshaft 6,
Since the governor 11 is attached to the rear end portion and returns the excess oil to the engine side, the bearing cover 12a on the governor 11 side (in this case, also serves as a part of the governor housing 12) is used as shown in FIGS. An oil drop hole 13 is formed to open the upper portion of the cam chamber 5 into the governor housing 12.

A cover 15 is attached to the rear surface of the bearing cover 12a (on the side of the governor housing 12) to enclose the oil drain hole 13 in a space that opens upward at a predetermined position higher than this, and the lubricating oil in the cam chamber 5 is used as the oil drain hole 13
Over the cover 15 into the governor housing 12,
It is designed to be returned to the engine side through an overflow pipe. 18 is an oil seal on the outer circumference of the camshaft 6,
Reference numeral 19 is a mounting bolt for the governor housing, and the cover 15 is fastened to the pump housing 1 together with a bolt 19a.

Then, while the engine is operating, the oil level rises to the plunger chamber 8 by the oil supply to the cam chamber 5, and the oil level is maintained at a predetermined level that is in balance with the overflow amount. When the oil level rises above the second roll from below the plunger spring 16, the expansion and contraction of the spring 16 splashes the oil supply in all directions, so that the plunger chamber 8 is efficiently lubricated in a favorable environment.

When the engine stops, refueling also stops, so the oil level inside the pump lowers to the regulated position of the cover 15. However, the substantial opening position of the oil drop hole 13 is increased by the cover 15, so that the pump is lower than before. The amount of oil remaining inside increases. When the opening position of the cover 15 is high enough to reach the plunger chamber 8, the lubricating oil remains at the bottom of the plunger chamber 8 even after the engine is stopped.

Therefore, when oil supply to the pump is started when the engine is started, the oil level quickly rises from the cam chamber 5 to a predetermined level in the plunger chamber 8. Therefore, not only the cam chamber 5 but also the plunger chamber immediately after the engine is started. Good lubrication of No. 8 can be secured. In this case, the lubrication of the pump can be easily improved by a simple configuration in which the cover 15 of the oil drop hole 13 is added without changing the processing position of the oil drop hole 13 or increasing the amount of oil supplied to the pump. .

FIG. 4 shows another embodiment in which the pipe 20 is used in place of the cover 15 for the oil drop hole 13.
Is connected to the oil dropping hole 13 of the bearing cover 12a outside the cam chamber 5 and extends upward to a predetermined height position. As a result, the oil level in the pump can be maintained at the opening position of the pipe 20 higher than the oil drop hole 13 even after the engine is stopped, as in the above embodiment.

[0018]

According to the first aspect of the present invention, the fuel injection is provided with an oil supply path for introducing lubricating oil to the pump into the cam chamber and the plunger chamber, and an oil drop hole for returning the lubricating oil collected in the cam chamber to the engine side. In the pump, a cover was provided to enclose the oil drop hole outside the cam chamber in a space that opens upward to a predetermined height position. The opening position can be easily increased. Therefore, a decrease in the oil level after the engine is stopped can be suppressed, and good lubricity can be secured even when the engine is started.

According to the second aspect of the invention, in a fuel injection pump having an oil supply path for introducing lubricating oil to the pump into the cam chamber and the plunger chamber and an oil drop hole for returning the lubricating oil collected in the cam chamber to the engine side. Since the pipe for extending the oil drop hole upward to the predetermined height position is provided outside the cam chamber, the engine can be stopped by increasing the substantial opening position of the oil drop hole by adding the pipe as in the first invention. After that, the oil level can be prevented from lowering and good lubricity can be secured even when the engine is started.

[Brief description of drawings]

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

FIG. 2 is a sectional view of a main part thereof.

FIG. 3 is a rear view of the bearing cover.

FIG. 4 is a rear view and a sectional view of a bearing cover showing another embodiment.

[Explanation of symbols]

 1 Pump Housing 2 Plunger Mechanism 3 Oil Supply Pipe 4 Oil Supply Port 5 Cam Chamber 6 Cam Shaft 8 Plunger Chamber 9a, 9b Bearing 11 Governor 12 Governor Housing 12a Bearing Cover 13 Oil Drop Hole 15 Cover 20 Pipe

Claims (2)

[Claims] 1. A fuel injection pump having an oil supply path for introducing lubricating oil to a pump into a cam chamber and a plunger chamber, and an oil dropping hole for returning lubricating oil collected in the cam chamber to the engine side. A fuel injection pump, characterized in that a cover is provided to surround a space that opens upward to a predetermined height position on the outside of the. 2. A fuel injection pump having an oil supply path for introducing lubricating oil to the pump into the cam chamber and the plunger chamber, and an oil drop hole for returning the lubricating oil collected in the cam chamber to the engine side, outside the cam chamber. A fuel injection pump, characterized in that a pipe is provided for extending the oil drop hole upward to a predetermined height position.