JPS6067762A - Plunger of forced lubrication type fuel injection pump - Google Patents

Abstract

PURPOSE:To prevent any overcomsumption of oil by permitting no communication between a fuel port and an oil inflow port, which is communicated with an oil port opening to the reed part of a plunger while the oil inflow port makes communication with a pressure communication passage through which oil is to be supplied. CONSTITUTION:A fuel injection pump makes a reciprocated plunger 9 compresses fuel oil inside the compression chamber of a barrel 8 so as to squeeze out the fuel oil via a discharge valve 5, a discharge pipe joint 2 and so forth. A reed part 13 for control of fuel injection timing is formed at the upper part of the plunger 9. An oil port 35 opens on the circumferential face of the reed part 13 of the plunger 9 and is communicated by the inner passage 33 of the plunger 9 with an oil inflow port 34 which opens on the circumferential face of the plunger 9. Besides, the oil inflow port 34 is capable of being communicated with a pressure communication passage 28 formed inside a pump body 1 by an intermediate ring groove 29 made on the barrel 8 and other communicating means.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plunger lubricating device in a fuel injection pump for a diesel engine.

-1it, barrel and puller in fuel injection pump +
:; # L rrs F8IW rr +-/-1
y thirstΦ, tqLa m −y J ++, J! Js
Therefore, in terms of the performance of the pump, the smaller the gap and h, the better, but if it is too large, it will cause seizure and wear.In other words, the plunger must move back and forth within the barrel up to 2,200 times for one minute. There are also things to do for exercise,
Since it is necessary to lubricate this sliding TIJJ surface, this lubrication is generally performed by appropriately spacing the gap between the plunger and the barrel and spilling fuel oil. However, recently, engines have become more maintenance-free, and the lubrication method for fuel injection pumps is changing from this method to a forced lubrication method using engine oil. In this case, if there is a lot of spillage in the gap between the plunger and the barrel, the engine oil will become diluted faster, which can cause a major engine accident.
There is a constraint that this spill must be minimized as much as possible.

On the other hand, due to the recent petroleum situation, there is a need for fuel injection pumps that use alternative fuels such as alcohol as fuel for diesel engines, that is, fuels with poor lubricity. L
, jkR17” /-I Lx f b+e!!T
oll a JI4-4-X -1+ f and also,
Regarding the lead part, the balance lead reduces lateral pressure,
Alternatively, the gap between the plunger and the barrel is increased only at the lead portion to prevent seizure.

However, with the forced lubrication method using Kohachi engine oil, as engines gradually improved in fuel efficiency and performance, the fuel injection pump also required high-pressure injection and the reciprocating speed of the plunger. Now you can. As a countermeasure for this, we attempted to drill a centering groove (horizontal groove) around the reed part to supply oil, but in this case, since the centering groove is a horizontal groove, it is necessary to connect the port of the barrel. Each time it passed, engine oil leaked into the fuel oil, causing problems such as increased consumption of lubricating oil.

The present invention was created to solve the problems of the conventional forced lubrication system using engine oil, and the structure of the present invention will be described in detail below with reference to a fifth embodiment shown in the accompanying drawings.

Figure 1 is a cross-sectional view of an improved Bosch PF type fuel injection qXj pump, which is famous as a constant stroke, relief type pump, and can be used not only for high-speed engines but also for general-purpose engines. It is something. In the figure, 1 is a pump body, 2 is a discharge pipe joint, 3 is a tightening flange, and since the tightening flange 3 is provided, this fuel injection q=t pump is housed in one place inside the engine.
Only the fuel intake section (not shown) and the discharge section are exposed from the engine. 4 is a discharge valve spring, 5 is a discharge valve, 7 is a discharge valve seat,
8 is a barrel, 9 is a plunger, and IO and IOU deflectors are arranged symmetrically, and the barrel 81 is connected to a pair of barrel ports 11 and 11 and is provided in the oil reservoir chamber 12. 13, the lead portion 14 is a driving face provided below the plunger 9; 15, a control sleeve that grips the driving face 14 so as to be able to slide vertically; and 16, a control pinion 171, which is carved at the upper end of the control sleeve 16np5, engages with the driving face. Control rack, 18 is rack V-id screw, 19 is upper spring seat, 20 is lower spring seat, 21H plunger spring, 22 is plunger θ° id, 23
indicates a snap ring and a 24,24tri tightening flange mounting bolt.

The above structure is generally the structure of a well-known fuel injection pump, but in this embodiment, in order to use a forced lubrication system, a pipe joint 25 is installed on the side of the pump body 1 [PL, inside the pipe joint 25]. He is holding Le 26 in his hands. A check valve 27 is provided within the pipe joint 25 to prevent fuel oil spills from entering the engine oil in the oil pan.

28 is a pressure communication passage, which is connected to the intermediate ring groove 2 provided in the barrel 8.
It opens at 9. Reference numeral 30 denotes an upper ring groove, which communicates with a communication path 31 for spilling fuel oil.

32 is a lower ring groove, 33 is a passage in the plunger formed by a drilled hole drilled in the center of the granger 9, the upper and lower ends are blank, and an oil inlet port 34 is formed in the middle.
Oil ports 35, 35 are branched at the upper end. The oil port 135 opens at the lead portion 13. 36 indicates a slit through which the inflow port 34 opens to oil.

? ) + Chi / + Tsume rIl - 9 I appeal 90 Wahe Uri
The positions of the engine oil ports 34 and 35 and the slits 36 are designed as follows. The distance from the opening of the oil port 35 to the upper end of the barrel port 11 is l+, and the distance from the upper end of the slit 36 to the lower end of the intermediate ring fM29 is l! 2, then 11 ≦12. That is, first of all, regarding the pressure relationship, during fuel injection, the pressure P on the plunger head side of the fuel
2 Tr! Since the engine oil supply pressure is much higher than 13 degrees, the engine oil will not flow out from the oil port 34, but if it becomes a fuel injection path, the above P2 will be equivalent to the pressure P3 in the oil reservoir chamber 12. , which is smaller than the above-mentioned P1, so that an excessive amount of engine oil flows out from the oil port 34 to the port 11. Therefore,
When the opening of the oil port 35 passes through the barrel port 11, the oil inflow port 34 (and ultimately the toe end of the slit 36) and the intermediate ring groove 29 come into communication, and excess engine oil flows out from the oil port 35. If the lift of the plunger is −L+=L2 in FIG. During the period of VJ, the P1 becomes higher than the P2- or Pl and cannot be performed.

Note that the oil port 35 is provided with two pairs of fuel return grooves 13 and 13 in the lead portion 13 (Fig. 3).
At least 4 side branches are open. 2 is a main part diagram of another embodiment, which is similar to the embodiment shown in FIG. It forms one arm of the river.

In addition, it is provided in the name of 37Vi, and the plunger 9
As a result, the vertical movement of the plunger 9 does not cause a short circuit with the port 11 of the barrel 8, and as shown in FIG. 3, which is a plan view of FIG. In a forced lubrication system for a plunger of a barrel port pump outside the operating range W, an oil port is opened in the lead part drawing of the plunger, and the oil port communicates with an oil inflow port opened on the circumferential surface of the plunger through a passage inside the plunger. However, while the oil inlet port communicates with the pressure communication path for supplying oil, the forced lubrication type fuel injection pump is such that the oil inlet port does not communicate with the barrel port via the oil port. means (17) for preventing the oil inflow port from communicating with the barrel port via the oil port, the plunger (17) for preventing the oil port from communicating with the barrel port even if the adjustment displacement of the plunger occurs; After the port passes through the barrel port, the oil inflow port and the pressure communication path are communicated with each other, so that the problems of the conventional forced lubrication system can be solved. Moreover.

17 between oil port and oil inflow port! There is a passage inside the plunger, and oil is introduced and held in this passage, so as the plunger moves up and down 11 times, its inertia causes it to flow out from the oil port, so the oil is pressurized. Coupled with this, it is possible to effectively flow out to the lead portion.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of 1) Example of the present invention, FIG. 2 is a sectional view of a main part of another embodiment, and FIG. 3 is a plan view of FIG. 2. DESCRIPTION OF SYMBOLS 1... Pump body, 8... Barrel, 9... Plunger, 11... Barrel port), 28... Pressure communication path, 34... Oil inflow port, 35... Oil port. One representative: Yoshihiko Okabe, patent attorney

Claims (1)

[Claims] A forced lubrication device for a plunger of a fuel injection pump of an internal combustion engine, which has an oil port opened on the circumferential surface of a lead part of the plunger, and the oil port is an oil inlet port that is opened on the circumferential surface of the plunger via a passage inside the plunger. The oil inlet port H is in communication with the oil supply barrel and the pressure communication passage provided in the pump body, and at least while the oil inflow port is in communication with the pressure communication passage 1, A forced lubrication type fuel injection pump characterized in that the oil inlet port does not communicate with the barrel port 1 through the oil port.