KR20120004522A - Fuel injection pump - Google Patents

Abstract

Droplets of lubricating oil on the gear case side connected to the pump housing are less likely to enter the inside of the pump housing, so that lubricating oil generated due to the lubricating oil droplets is prevented from entering the fuel. The fuel injection pump 1 includes a pump housing 3 connected to the gear case 50, a lubricant discharge hole 3j connecting the inside of the pump housing 3 and the gear case 50, and the lubricant discharge. The pump housing 3 is provided with a groove portion connected to the ball 3j, a cover 60 mounted to the pump housing 3 and covering a lubricating oil discharge hole 3j and a part of the groove portion at the gear case 50 side. The lubricating oil discharge hole 3j, the groove portion, and the cover 60 constituted a curved communication path communicating the inside of the pump housing 3 with the gear case 50.

Description

Fuel Injection Pump {FUEL INJECTION PUMP}

The present invention relates to a fuel injection pump of a fuel injection device mounted on an engine.

Background Art Conventionally, a fuel injection pump having a configuration in which a camshaft bearing supported by a pump housing is driven by a crankshaft of an engine, and a plunger is reciprocated in the vertical direction by a cam provided on the camshaft, and the fuel is pumped by the plunger is known. (For example, refer patent document 1). This fuel injection pump stores lubricating oil in a cam chamber formed in the lower part of the pump housing, and lubricates drive system components such as cams stored in the cam chamber.

The fuel injection pump is configured to form a lubricant discharge hole in the pump housing, and to discharge the lubricant oil from the cam chamber into the gear case connected to the pump housing through the lubricant discharge hole. On the other hand, the lubricating oil discharged to the gear case is used to lubricate the power transmission means for transmitting power from the crankshaft of the engine to the camshaft of the fuel injection pump in the gearcase, or to lubricate the crankshaft, piston and the like in the engine.

Further, in such a fuel injection pump, the plunger barrel is fitted into a hydraulic head on the pump housing, and the plunger is inserted into the plunger barrel so as to be vertically slidable. Inside the plunger barrel, a pressure chamber (fuel pressure chamber) is formed above the plunger. Below the plunger barrel, a spring for biasing the plunger downward is wound on the lower part of the plunger and at the same time the tappet is connected. The tappet is inserted into the tappet chamber so as to slide up and down and press-fits with the cam. The tappet chamber is formed above the cam chamber of the pump housing and communicates with the cam chamber.

Patent Document 1: Japanese Patent Application Laid-Open No. 2008-106780

In the conventional configuration as disclosed in Patent Document 1, the lubricating oil is scattered through the lubricating oil discharge hole formed in the pump housing to enter the cam chamber inside the pump housing from the gear case, and the amount of droplets of lubricating oil in the cam chamber increases. there was.

When the amount of splash droplets of lubricating oil in a cam chamber increases, as shown in FIG. 22, the splash droplets of the lubricating oil 82 reach the lower part of the plunger 81, and is attached to the reciprocating motion of the plunger 81 in the up-down direction. As a result, the lubricating oil 82 may move upward through the gap between the plunger 81 and the plunger barrel 80 to be mixed into the fuel 83 through the leak return groove 80a of the fuel 83. Or the lubricating oil 82 may raise further, it may enter the pressurization chamber, and may be mixed in the fuel 83. FIG. For this reason, the amount of the lubricating oil 82 mixed in the fuel 83 increases, which may cause problems such as blackening of the fuel 83 and deterioration of engine performance.

Therefore, the present invention provides a fuel injection pump which makes it possible for droplets of lubricant oil on the gear case side connected to the pump housing to be less likely to enter the pump housing, thereby preventing the lubricant oil generated due to the droplets of lubricant oil from entering the fuel. It aims to provide.

The present invention provides a fuel injection pump having a pump housing connected to a gear case, wherein the pump housing is provided with a communication hole communicating with an interior of the pump housing and an interior of the gear case, a groove portion connected to the communication hole, and mounted on the pump housing. And a cover for covering the communication hole and a part of the groove part at the gear case side, wherein the communication hole, the groove part, and the cover constitute a bent communication path communicating the inside of the pump housing with the gear case. did.

In the present invention, a through hole constituting a part of the communication path is formed in the cover, and is disposed so as to be displaced at a position facing the communication hole.

The present invention provides a lubricating oil storage unit which is in the middle of the communication path and which can store lubricating oil between the pump housing and the cover.

The present invention forms a cam chamber for storing a cam in the pump housing, and forms a tappet chamber for receiving a tappet in contact with the cam so as to communicate with the cam chamber, and has a plunger side than the tappet of the cam chamber and the tappet chamber. In between, a stopper was formed to prevent these communication.

The present invention uses the communication hole as the first lubricating oil discharge passage, the through hole as the third lubricating oil discharge passage, and uses a portion excluding the communication hole and the through hole of the communication passage as the second lubricating oil discharge passage. And a lubricating oil discharge passage for discharging the lubricating oil from the inside of the pump housing to the inside of the gear case by passing through the first lubricating oil discharge passage, the second lubricating oil discharge passage, and the third lubricating oil discharge passage. The passage area of the lubricating oil discharge passage and the passage area of the third lubricating oil discharge passage were respectively smaller than the passage area of the first lubricating oil discharge passage.

The present invention made the passage area of the third lubricant discharge passage smaller than the passage area of the second lubricant discharge passage.

The present invention has provided the third lubricant discharge passage below the first lubricant discharge passage.

The present invention provides a concave portion or a convex portion that can be coupled to a convex portion or a concave portion formed in the pump housing, and the cover is mounted to be positionable on the pump housing.

According to the present invention, since the communication path is connected so as to be bent with respect to the communication hole, the flow direction of the lubricating oil between the communication path and the communication hole is changed so that droplets of lubricating oil from the gear case side are communicated through the communication hole. It becomes difficult to get into. Further, the pulsation pressure is attenuated when propagated from the gear case side to the fuel injection pump, so that the pulsation pressure of the fuel injection pump is reduced. Therefore, the present invention can reduce the amount of splash droplets of lubricating oil inside the pump housing, and can suppress the mixing of lubricating oil generated due to the splash droplets of the lubricating oil into the fuel.

According to the present invention, since the communication path is bent by the through hole, the flow direction of the lubricating oil is changed in the middle of the communication path, and it is difficult for the droplets of lubricant oil on the gear case to enter the pump housing through the communication hole. Therefore, the present invention can reduce the amount of splash droplets of lubricating oil inside the pump housing, and can suppress the mixing of lubricating oil generated due to the splash droplets of the lubricating oil into the fuel. It is also possible to mount the end of the cover to the pump housing using a fastener. Therefore, this invention can aim at the improvement of the shockproof of a cover.

According to the present invention, the pulsating pressure accompanying the vertical motion of the piston of the diesel engine is attenuated by the lubricating oil accumulated in the lubricating oil storage part, and it is difficult to propagate to the pump housing from the gear case side. Therefore, the present invention can reduce the amount of splash droplets of lubricating oil inside the pump housing, and can suppress the mixing of lubricating oil generated due to the splash droplets of the lubricating oil into the fuel.

According to the present invention, the droplets of lubricating oil inside the pump housing are less likely to enter the plunger side than the tappet of the tappet chamber with the pressurized chamber supplied with fuel from the cam chamber. Therefore, the present invention can suppress the mixing of the lubricating oil generated due to the droplets of lubricating oil inside the pump housing into the fuel.

According to the present invention, the gear case side passage area of the lubricating oil discharge passage becomes smaller than the pump housing side passage area, so that the lubricant easily accumulates in the third lubricant discharge passage. For this reason, the pulsation pressure accompanying the vertical motion of the piston of a diesel engine is attenuated by the lubricating oil accumulated in the 3rd lubricating oil discharge channel | path, and it becomes difficult to propagate to the pump housing from the gear case side. Therefore, the present invention can reduce the amount of splash droplets of lubricating oil inside the pump housing, and can suppress the mixing of lubricating oil generated due to the splash droplets of the lubricating oil into the fuel.

According to the present invention, the gear case side passage area of the lubricating oil discharge passage decreases in steps toward the gear case, so that the lubricating oil is easily accumulated by the third lubricating oil discharge passage. For this reason, the pulsation pressure accompanying the vertical motion of the piston of a diesel engine is attenuated by the lubricating oil accumulated in the 3rd lubricating oil discharge channel | path, and it becomes difficult to propagate to the pump housing from the gear case side. Therefore, the present invention can reduce the amount of splash droplets of lubricating oil inside the pump housing, and can suppress the mixing of lubricating oil generated due to the splash droplets of the lubricating oil into the fuel.

According to the present invention, when the lubricating oil is discharged from the inside of the pump housing into the gear case, the lubricating oil discharge passage flows down from above. Therefore, the present invention can improve the lubrication performance of the fuel injection pump by smoothly flowing the lubricating oil.

According to the present invention, the mounting work of the cover becomes easy. Therefore, this invention can make it possible to perform the assembly work of a fuel injection pump efficiently.

1 is a right side cross-sectional view showing the overall configuration of a fuel injection pump according to an embodiment of the present invention.
2 is a front sectional view showing an overall configuration of a fuel injection pump according to an embodiment of the present invention.
(A) is a front view which shows the plunger which concerns on 1st Embodiment, (b) is a front view which shows the state which attached the cover of the plunger which concerns on 1st Embodiment.
FIG. 4A is a perspective view of the plunger and the cover according to the first embodiment, and FIG. 4B is a perspective view illustrating a state where the cover of the plunger according to the first embodiment is mounted.
(A) is a front view which shows a cover, (b) is a right side view which shows a cover.
(A) is a figure which shows the flow of lubricating oil in a 1st lubricating oil discharge hole and a 1st communication path, (b) is a figure which shows the flow of lubricating oil in a 2nd lubricating oil discharge hole and a 2nd communication path. .
FIG. 7: (a) is a front view which shows the plunger which concerns on 2nd embodiment, (b) is a front view which shows the state which attached the cover of the plunger which concerns on 2nd embodiment.
(A) is a front view which shows a cover, (b) is a right side view which shows a cover.
(A) is a graph which shows the pulsating pressure of each lubricating oil in the fuel injection pump which has a plunger which concerns on 1st embodiment, and the inside of a gear case, (b) is a fuel which has a plunger which concerns on 2nd embodiment. It is a graph which shows the pulsating pressure of each lube oil in an injection pump and a gear case.
10 is a right side cross-sectional view showing a configuration near the tappet.
11 is a side sectional view showing a fuel injection pump according to another embodiment of the present invention.
12 is a front sectional view showing a fuel injection pump according to another embodiment of the present invention.
It is a front view which shows a plunger part and a cover.
It is an exploded perspective view which shows a plunger part and a cover.
It is a front view which shows the groove part of a plunger part.
16 is a perspective view of the cover;
17 is a front view illustrating the cover.
FIG. 18 is a view along arrow A of FIG. 17.
(A) is a figure which shows the lubricating oil discharge channel of the left side, (b) is a figure which shows the lubricating oil discharge channel of the right side.
20 is a diagram illustrating a second lubricant oil discharge passage.
21 is a right side cross-sectional view showing another configuration near the tappet.
It is a figure which shows the mixing route in the fuel of lubricating oil.

An embodiment of the fuel injection pump of the present invention will be described.

<1st embodiment>

First, the whole structure of the fuel injection pump 1 which concerns on one Embodiment of this invention is demonstrated.

In the following description, the direction indicated by the arrow F in FIG. 1 is defined as the front and rear direction as the front of the fuel injection pump 1, and the direction indicated by the arrow U in FIG. 1 is the upper and lower direction as the upper side of the fuel injection pump 1. The left and right directions of the fuel injection pump 1 are defined as the direction indicated by the arrow L in FIG. 2.

The fuel injection pump 1 is a component part of the fuel injection apparatus mounted in a diesel engine, and presses the fuel supplied from the fuel tank, and presses a predetermined amount of fuel to a fuel injection valve through an injection pipe at a predetermined timing. As shown in FIG. 1 and FIG. 2, the fuel injection pump 1 is a distribution type fuel injection pump which distributes and delivers fuel to several fuel injection valves.

The fuel injection pump 1 is constructed by joining a hydraulic head 2 and a pump housing 3 up and down.

The plunger barrel 4 is inserted into the hydraulic head 2. The plunger 5 is built in the plunger barrel 4 so that it can slide up and down. In the hydraulic head 2, a low temperature start timer mechanism 6 is provided in front of the left side of the plunger barrel 4, and an accumulator 7 is provided in the right side with the plunger barrel 4 interposed therebetween. The pressurizing chamber 8 is formed between the plunger barrel 4 and the upper end of the plunger 5.

The leak return groove 4a is formed in the plunger barrel 4 in order to reduce the phenomenon (fuel leak) in which fuel leaks from the clearance with the plunger 5 and mixes in lubricating oil. The leak return groove 4a is connected to a fuel tank (not shown).

The tappet chamber 20 is formed in the upper front part of the pump housing 3, and the lower end part of the plunger barrel 4 is inserted. The plunger 5 protrudes downward toward the tappet chamber 20 from the lower end of the plunger barrel 4.

An upper spring bearing 21 is fixed around the lower end of the plunger barrel 4. The lower spring support 22 is fixed to the lower end of the plunger 5. Between the upper surface of the lower spring support 22 and the lower surface of the upper spring support 21, a spring 23 for imparting a biasing force downward to the plunger 5 is interposed. At the lower end of the plunger 5, the tappet 24 is provided to reciprocally slide the tappet chamber 20 in the vertical direction.

The tappet 24 is a cylindrical shape opened upwards. The lower spring support 22 is fixed inside the tappet 24. The tappet 24 is biased downwardly with the plunger 5 by the spring 23 via the lower spring bearing 22. The lower portion of the tappet 24 is supported by a rotating material through the roller shaft 26. An adjusting shim 27 is provided between the upper surface of the tappet 24 and the lower surface of the lower spring support 22.

A rack chamber 30 is formed at the rear upper portion of the pump housing 3. The rack room 30 houses a rack. In the rear part of the hydraulic head 2, the distribution shaft 31 is inserted in an up-down direction. The lower end of the distribution shaft 31 protrudes into the rack room 30. The transmission shaft 32 is fixed to the lower end of the distribution shaft 31 via the joint 33 on the same shaft center as the distribution shaft 31. The transmission shaft 32 is installed in the pump housing 3 in the vertical direction and is rotatably supported. The upper end of the transmission shaft 32 is rotatably supported by the bearing portion 34 of the pump housing 3, and the position in the axial direction (up and down direction) is determined by the positioning member 35.

The inside of the distribution shaft 31 and the pressurizing chamber 8 are communicated by the flow path 9 formed in the hydraulic head 2 inside. The delivery valve 10 is provided through the holder 11 at the back of the distribution shaft 31 in the hydraulic head 2. The delivery valve 10 prevents the fuel inside the injection pipe from flowing into the pressure chamber 8 at the end of the injection of the fuel injection pump 1.

The cam chamber 40 is formed in the lower part of the pump housing 3. The camshaft 41 is constructed in the cam chamber 40 so that the axial direction may be front-back direction. The camshaft 41 is rotatably supported by the pump housing 3 via the 1st cam bearing 42 and the 2nd cam bearing 43. FIG. The cam chamber 40 is filled with lubricating oil. The cam 44 on the camshaft 41 is lubricated by the lubricating oil of the cam chamber 40. The cam 44 is disposed in front of the cam chamber 40 and abuts against the front roller portion 25.

Bevel gears 45 fixed to the camshaft 41 are accommodated in the rear of the cam chamber 40. From the upper surface of the cam chamber 40, the transmission shaft 32 protrudes downward toward the cam chamber 40. A bevel gear 46 that engages with the bevel gear 45 on the cam shaft 41 is fixed to the lower end of the transmission shaft 32.

The camshaft 41 projects rearward from the rear of the pump housing 3 toward the outside of the pump housing 3. The rear protrusion part of the camshaft 41 is provided with the governor sleeve 12 and the governor weight 13 which comprise a governor mechanism.

The plunger 3a is formed in the front part of the pump housing 3 (front of the cam chamber 40). The camshaft 41 projects forward from the plunger 3a toward the gear case 50. The gear case 50 is disposed in front of the pump housing 3, connected to the pump housing 3, and mounted to the engine body of the diesel engine. Inside the gear case 50, the camshaft fixing plunger 52 is fixed to the front end of the camshaft 41. The cam gear 51 is fixed to the camshaft fixed plunger 52 by the bolt 53. Then, power from the crankshaft of the diesel engine can be transmitted to the power transmission means inside the gear case 50, the camshaft 41 via the cam gear 51, and the like.

In addition, two lubricating oil discharge holes 3i · 3j are formed in the plunger 3a, which is a communication hole communicating the inside of the pump housing 3, that is, the cam chamber 40 and the gear case 50. The lubricating oil of the cam chamber 40 is discharged into the gear case 50 through the two lubricating oil discharge holes 3i and 3j. The cover 60 mentioned later is attached to the outer side of the plunger 3a so that it may oppose these lubricating oil discharge holes 3i * 3j.

In the fuel injection pump 1 according to such a configuration, when power is transmitted from the crankshaft of the diesel engine to the camshaft 41 and the camshaft 41 rotates, the cam 44 is rotated with the rotation of the camshaft 41. Rotate The tappet 24 reciprocates in the vertical direction as the cam 44 rotates, and the plunger 5 reciprocates in the vertical direction via the lower spring support 22 fixed to the tappet 24.

Then, by the reciprocating motion of the plunger 5, the intake stroke of the fuel entering the pressurizing chamber 8 and the discharge stroke of the fuel exiting the pressurizing chamber 8 are alternately performed. That is, when the plunger 5 is pushed down by the biasing force of the spring 23 in the suction stroke, the fuel is sucked into the pressurizing chamber 8 from the fuel pump. In the discharge stroke, when the plunger 5 is pushed up by the biasing force of the spring 23 and ascended, the fuel sucked into the pressurizing chamber 8 is pressurized and passed to the distribution shaft 31 through the flow path 9. do. The fuel pumped to the distribution shaft 31 is distributed to the delivery valve 10 by the distribution shaft 31, and is injected from the fuel injection valve through the injection pipe.

Next, the structure of the plunger 3a which concerns on 1st Embodiment is demonstrated.

As shown in FIG. 1, FIG. 3, and FIG. 4, the plunger 3a is formed in substantially triangular shape when seen from the front. In the center of the plunger 3a, the through hole 3d is formed in a substantially circular shape when viewed from the front. As described above, the camshaft 41 is inserted into the through hole 3d and supported by the second cam bearing 43. In the front surface which is the outer surface of the plunger 3a, the ring-shaped boss part 3b is formed so that the outer periphery outer side of the through hole 3d may protrude forward. The boss portion 3b is coupled to the through hole 50a drilled on the rear surface of the gear case 50. Then, in a state where the boss portion 3b is engaged with the through hole 50a so as to face the inside of the gear case 50, the bolt is fitted to the mounting hole 3c or the like drilled on the outer circumference outer side of the boss portion 3b and the plunger 3a. ) Is fixed to the gear case 50.

As shown in FIGS. 3A and 4A, the groove portion 3e extends along the circumferential direction of the boss portion 3b on the front surface of the boss portion 3b, and when viewed from the front, the ring It is formed into an approximately C shape when viewed from the front in which a part of the incision is cut open to the right. The groove portion 3e opens toward the front of the gear case 50. In the groove portion 3e, a plurality of convex partitions 3f, 3f, ... are arranged at predetermined intervals in the circumferential direction of the boss portion 3b. The groove portion 3e is divided into a first groove portion, a second groove portion, a third groove portion, a fourth groove portion, and a fifth groove portion by the plurality of partitions 3f 3f... These groove portions are arranged in the order of the first groove portion, the second groove portion, the third groove portion, the fourth groove portion, and the fifth groove portion in the clockwise direction when viewed from the front from one end located at the upper right portion of the groove portion 3e. 3 g of mounting holes of the cover 60 are formed in the uppermost part (1st groove part) of the groove part 3e. The mounting hole 3h of the cover 60 is formed in the lowest part (fourth groove part) of the groove part 3e.

Further, the first lubricating oil discharge hole 3i extends linearly in the front-rear direction at the bottom of the upper right side (first groove) of the inside of the groove 3e, facing the cam chamber 40 from the rear end side, and the front end side. Is formed to face inside the gear case 50 connected to the pump housing (3). On the left side (third groove portion) inside the groove portion 3e, the second lubricating oil discharge hole 3j extends linearly in the front-rear direction, faces the cam chamber 40 at the rear end side, and the pump housing 3 at the front end side. It is formed to face inside the gear case 50 connected to. The first lubricating oil discharge hole 3i and the second lubricating oil discharge hole 3j respectively pass through the plunger 3a in the front-rear direction to communicate with the cam chamber 40 and the gear case 50 inside the pump housing 3. . That is, the cam chamber 40 inside the pump housing 3 communicates with the gear case 50 by these 1st lubricating oil discharge hole 3i and the 2nd lubricating oil discharge hole 3j.

The first lubricating oil discharge hole 3i and the second lubricating oil discharge hole 3j pass through the axis of the camshaft 220 when the fuel injection device is mounted on the diesel engine, respectively, when the fuel injection pump 1 is viewed from the front. It is arrange | positioned above the horizontal line, or in the height position which the lower part hangs on the said horizontal line. In this way, the first lubricant oil discharge hole 3i and the second lubricant oil discharge hole 3j are supplied with lubricant from the pump housing 3 to the gear case 50 in accordance with the amount of lubricant in the pump housing 3. It can be discharged properly.

As shown in (b) of FIG. 3, FIG. 4, and FIG. 5, the cover 60 has the flow direction of the lubricating oil in the 1st lubricating oil discharge hole 3i and the 2nd lubricating oil discharge hole 3j, ie, the front-back direction. It is a board | plate material made of resin or metal which has a plane extended in the orthogonal direction with respect to it, and is formed in substantially C shape when seen from the front part which cut off a part of ring. The cover 60 has a shape similar to the groove portion 3e when viewed from the front, and the surface area is set slightly smaller than the groove portion 3e. The length of the circumferential direction of the cover 60 is set shorter than the circumferential length of the groove part 3e.

The cover 60 has a concave-convex shape by the first flat portion 60a, the first concave portion 60b concave backward, the second flat portion 60e, and the second concave portion 60f concave backward. It is composed. In the cover 60 having a substantially C-shape when viewed from the front, each part is first planar portion 60a, the first in the clockwise direction when viewed from the front from one end located at the upper right of the cover 60. It arrange | positions in order of the recessed part 60b, the 2nd planar part 60e, and the 2nd recessed part 60f.

The cover 60 is coupled to the groove portion 3e such that the first recessed portion 60b is positioned at the top thereof, the second recessed portion 60f is positioned at the bottom thereof, and the second flat portion 60e is positioned at the left side thereof. do. At the time of engagement, the first lubricant oil discharge hole 3i and the second lubricant oil discharge hole 3j are covered by the cover 60 at the gear case 50 side when viewed from the front. In detail, the 1st lubricating oil discharge hole 3i is covered by the 1st flat part 60a of the cover 60 at the gear case 50 side, and the 2nd lubricating oil discharge hole 3j is the 2nd flat part 60e. ) Is covered on the gear case 50 side.

Mounting holes 60c and 60g are formed in the front-back direction at the top, bottom, left, and right centers of the recesses 60b and 60f. The mounting holes 60c and 60g are used for mounting to the plunger 3a when the cover 60 is coupled to the groove portion 3e. In addition, a discharge hole 60h, which is a through hole, is formed in the front and rear directions below the second flat part 60e.

The cover 60 matches the two mounting holes 60c and 60g with the mounting holes 3g and 3h of the grooves 3e, respectively, and is then engaged with the grooves 3e of the plunger 3a as described above. The cover 60 is attached to the plunger 3a by inserting the bolts 61 and 61 as fasteners into the mounting holes 60c and 60g from the front and screwing into the mounting holes 3g and 3h (Fig. 3). (b) and (b) of FIG. 4). In this case, the cover 60 is disposed to face the first lubricating oil discharge hole 3i and to face the inside of the gear case 50.

When the cover 60 is mounted on the plunger 3a in this manner, as shown in FIG. 3B, the first flat portion 60a of the cover 60 is formed by the first groove portion of the groove portion 3e and It is arrange | positioned in the position which faces the 1st lubricating oil discharge hole 3i. In other words, the first groove portion and the first plane portion 60a of the groove portion 3e are overlapped when viewed from the front, and the first lubricant oil discharge hole 3i and the first plane portion 60a are viewed from the front side. When duplicated. As a result, the first lubricant oil discharge hole 3i and the second lubricant oil discharge hole 3j and the gear case 50 do not communicate linearly.

At this time, the cover 60 comes into contact with the partitions 3f and 3f... And a space is formed between the cover 60 except for the contact portion and each groove portion of the groove portion 3e. Among these spaces, the first space formed between the first flat portion 60a of the cover 60 and the first groove portion of the groove 3e constitutes a part of the first communication path 3m. The 1st space is arrange | positioned so that it may extend in the direction (approximately up-down direction) orthogonal to the direction (front-back direction) which the 1st lubricating oil discharge hole 3i extends.

At the same time, the discharge hole 60d as a through hole constituting a part of the first communication path 3m is formed in the front-rear direction on the lower right side of the first flat portion 60a of the cover 60. The discharge hole 60d is a cut-out hole, and is disposed shifted downward rightward from the position facing the second lubricating oil discharge hole 3j. A gap is formed between the plunger 3a and the cover 60 by the discharge hole 60d, so that the first space communicates with the inside of the gear case 50 through the discharge hole 60d.

In this way, the 1st communication path 3m consists of the said 1st space and the discharge hole 60d, and is bent with respect to the 1st lubricating oil discharge hole 3i via the cover 60 and the pump housing 3. Is connected. As a result, the first communication path 3m communicates with the cam chamber 40 inside the pump housing 3 via the first lubricant oil discharge hole 3i, and the first lubricant oil discharge hole 3i is connected to the first communication path ( 3m) communicates with the gear case 50 inside. That is, the cam chamber 40 and the gear case 50 in the pump housing 3 communicate with each other through the first lubricant oil discharge hole 3i and the first communication path 3m.

Therefore, as shown by the white arrow in FIG. 6A, the lubricating oil flows from the cam chamber 40 inside the pump housing 3 to the first lubricating oil discharge hole 3i and from the first lubricating oil discharge hole 3i to the first. After exiting the communication path 3m, the first flat portion 60a of the cover 60 is brought into contact with each other to change the flow direction from the front-rear direction to the up-down direction, and the first communication path 3m is the first lubricant discharge hole. It flows downward to the right of (3i). When the lubricating oil reaches the front of the discharge hole 60d, the lubricating oil abuts against the inner circumferential surface of the first groove portion, changes the flow direction from the up and down direction to the front and rear direction, and flows from the discharge hole 60d into the gear case 50.

That is, as shown to Fig.6 (a), the 1st lubricating oil discharge hole 3i and the 1st communication path 3m, ie, the discharge path (communication path) of lubricating oil, are comprised in a crank shape, and a lubricating oil discharge path In the middle of the bent portion (3x) is formed. For this reason, when lubricating oil is discharged | emitted from the 1st lubricating oil discharge hole 3i, it does not flow linearly toward the gear case 50, but changes a flow direction, flows to the 1st communication path 3m, and changes a flow direction again. After flowing through the discharge hole (60d) toward the gear case 50. In short, while the lubricating oil changes the flow direction between the first lubricating oil discharge hole 3i and the first communication path 3m, and also changes the flow direction in the middle of the first communication path 3m, The cam chamber 40 is discharged into the gear case 50 via the first lubricating oil discharge hole 3i and the first communication path 3m in order.

For this reason, in the gear case 50, as shown by the black arrow shown in FIG. 6 (a), when lubricating oil splashes to the 1st lubricating oil discharge hole 3i side of the pump housing 3, the flying droplets of lubricating oil are In the vicinity of the position facing the first lubricating oil discharge hole 3i, the first flat portion 60a of the cover 60 is hit and the intrusion into the first lubricating oil discharge hole 3i is prevented. In addition, even when the splash droplets of the lubricating oil reach the discharge hole 60d, the discharge passage of the lubricating oil must flow through the bent portion 3x in the opposite direction to the flow direction of the lubricating oil, that is, the discharge direction, that is, the first communication. Since the flow direction must flow between the furnace 3m and the 1st lubricating oil discharge hole 3i, it becomes difficult to penetrate into the 1st lubricating oil discharge hole 3i.

Similarly, when the cover 60 is mounted to the plunger 3a, the position where the second flat portion 60e of the cover 60 faces the third groove portion and the second lubricant discharge hole 3j of the groove portion 3e Will be placed in. In other words, when the 3rd groove part and the 1st flat part 60a of the groove part 3e are overlapped when it sees from the front, the 2nd lubricating oil discharge hole 3j and the 2nd flat part 60e are seen from the front. When duplicated.

In addition, the third space formed between the second planar portion 60e of the cover 60 and the third groove portion of the groove portion 3e constitutes a part of the second communication path 3n. The third space is arranged to extend in a direction (approximately up and down direction) orthogonal to the direction (front and rear direction) in which the first lubricating oil discharge hole 3i extends.

A discharge hole 60h as a through hole constituting a part of the second communication path 3n is formed in the front-rear direction in the lower portion of the second flat portion 60e of the cover 60. The discharge hole 60h is disposed to be shifted downward from the position facing the second lubricant oil discharge hole 3j. The third space communicates with the gear case 50 through the discharge hole 60h.

In this way, the 2nd communication path 3n is comprised from the said 3rd space and the discharge hole 60h, and is bent with respect to the 2nd lubricating oil discharge hole 3j via the cover 60 and the pump housing 3. Is connected. As a result, the second communication passage 3n communicates with the cam chamber 40 inside the pump housing 3 via the second lubricant discharge hole 3j, and the second lubricant discharge hole 3j communicates with the second communication passage ( It communicates with the inside of the gear case 50 via 3n). That is, the cam chamber 40 and the gear case 50 in the pump housing 3 communicate with each other through the second lubricant oil discharge hole 3j and the second communication path 3n.

Accordingly, as shown by the white arrow in FIG. 6B, the lubricant flows from the cam chamber 40 inside the pump housing 3 to the second lubricant discharge hole 3j and from the second lubricant discharge hole 3j to the second. After exiting the communicating passage 3n, the second planar portion 60e of the cover 60 abuts, changes the flow direction from the front-rear direction to the substantially vertical direction, and changes the second communication passage 3n to the second lubricant discharge hole. It flows downward of (3j). When the lubricating oil reaches the front of the discharge hole 60h, the lubricating oil abuts against the inner circumferential surface of the third groove portion, changes the flow direction from the up and down direction to the front and rear direction, and flows from the discharge hole 60h into the gear case 50.

That is, as shown to Fig.6 (b), the 2nd lubricating oil discharge hole 3j and the 2nd communication path 3n, ie, the discharge path (communication path) of lubricating oil, are comprised in a crank shape, and a lubricating oil discharge path In the middle of the bent portion (3y) is formed. For this reason, when lubricating oil is discharged | emitted from the 2nd lubricating oil discharge hole 3j, it does not flow linearly toward the gear case 50, but changes a flow direction, flows into the 2nd communication path 3n, and changes a flow direction again. After flowing through the discharge hole (60h) toward the gear case 50. In short, while the lubricating oil changes the flow direction between the second lubricating oil discharge hole 3j and the second communication path 3n, and also changes the flow direction even in the middle of the second communication path 3n, From the cam chamber 40, it is discharged | emitted into the gear case 50 via the 2nd lubricating oil discharge hole 3j and the 2nd communication path 3n in order.

Here, as shown in FIG. 6 (b), when the lubricating oil flows through the second communication path 3n, the lubricating oil passes through the discharge hole 60h while being accumulated below the discharge hole 60h of the third space. It flows toward the gear case 50. In this way, the lubricating oil reservoir 3p is provided between the pump housing 3 and the cover 60 while being in the middle of the discharge passage connecting the cam chamber 40 and the gear case 50 inside.

For this reason, as shown by the black arrow in FIG. 6 (b), even when lubricating oil splashes inside the gear case 50 to the second lubricating oil discharge hole 3j side of the pump housing 3, the lubricating oil splashes. In the vicinity of the position facing the small second lubricant oil discharge hole 3j, the first flat portion 60a of the cover 60 is hit, and the intrusion into the second lubricant oil discharge hole 3j is prevented. In addition, even when the flying droplets of the lubricating oil reach the discharge hole 60h, the discharge passage of the lubricating oil must flow through the bent portion 3y in the opposite direction to the flow direction of the lubricating oil, that is, the discharge direction, that is, the second communication. Since the flow direction must flow between the furnace 3n and the 2nd lubricating oil discharge hole 3j, it becomes difficult to invade the 2nd lubricating oil discharge hole 3j.

With this configuration, the splash droplets of the lubricating oil are transferred from the gear case 50 to the cam chamber 40 inside the pump housing 3, the first communication path 3m and the first lubricating oil discharge hole 3i, and It becomes difficult to penetrate while passing through the 2 communicating paths 3n and the 2nd lubricating oil discharge hole 3j. Therefore, the fuel injection pump 1 can reduce the amount of splash droplets of lubricating oil in the cam chamber 40. As a result, the fuel injection pump 1 has the droplets of lubricating oil reaching and attaching to the lower part of the plunger 5, and the lubricating oil is plunged by the plunger 5 and the plunger barrel 4 by the reciprocating motion of the plunger 5 in the vertical direction. It is possible to suppress the inflow into the leak return groove 4a and the pressurizing chamber 8 through the gap between the gaps) and into the fuel.

Next, the structure of the plunger 103a which concerns on 2nd Embodiment is demonstrated. However, about the member similar to the member of the structure of 1st Embodiment, the same code | symbol is attached | subjected and it demonstrates centering around a different part from 1st Embodiment.

As shown in Fig. 7A, the plunger 103a is formed in a substantially triangular shape when viewed from the front. In the front center portion of the plunger 103a, a ring-shaped boss portion 103b is formed to protrude forward. An approximately C-shaped groove 103e is formed in the outer circumferential outer side of the through hole 3d when viewed from the front concave backward. The cover support part 103k formed in the step shape is formed in the outer peripheral part inside the groove part 103e. 103 g of mounting holes of the cover 70 are formed in the lower right part of the groove part 103e.

Further, two lubricating oil discharge holes 103i 占 103i, which are through holes, extend linearly in the front-rear direction at the lower right side inside the groove part 103e, face the cam chamber 40 at the rear end side, and the pump housing at the front end side. It is formed to face inside the gear case 50 connected to (3). The two lubricating oil discharge holes 103i and 103i are disposed with the mounting hole 103g interposed therebetween. The cam chamber 40 inside the pump housing 3 is connected to the gear case 50 by these lubricating oil discharge holes 103i and 103i.

As shown in FIGS. 7B and 8, the cover 70 is made of resin or metal having a plane extending in the direction perpendicular to the flow direction of the lubricant oil in each lubricant discharge hole 103i, that is, the front-rear direction. It is a plate material, and is formed in a substantially C shape when viewed from the front. The cover 70 has a shape similar to a portion of the groove portion 103e when viewed from the front, and the surface area is set slightly smaller than the portion of the groove portion 103e. The length of the circumferential direction of the cover 70 is set shorter than the length of the circumferential direction of the groove part 103e.

The cover 70 is composed of a flat portion 70a and a cutout 70c. In the cover 70, the flat part 70a is arrange | positioned throughout the circumferential direction of the cover 70, and the cutout 70c is arrange | positioned at the outer peripheral side of the middle part of the circumferential direction of the cover 70. As shown in FIG.

The cover 70 is coupled to the lower portion of the groove 103e so that the cutout 70c is located at the bottom thereof. At the time of joining, two lubricating oil discharge holes 103i 占 103i are covered by the cover 70 on the gear case 50 side when viewed from the front. A mounting hole 70b for mounting the cover 70 to the plunger 103a is formed at the center of the flat portion 70a in the front-rear direction.

The cover 70 is made to fit the mounting hole 70b with the mounting hole 103g, and is then engaged with the groove portion 103e of the plunger 103a as described above. The cover 70 is attached to the plunger 103a by inserting the bolt 61 · 61 into the mounting hole 70b from the outside of the pump housing 3 and screwing to the mounting hole 103g. At this time, the cover 70 is disposed to face the two lubricating oil discharge holes 103i and 103i and faces the inside of the gear case 50.

When the cover 70 is mounted on the plunger 103a in this manner, the flat portion 70a of the cover 70 is partially recessed in the groove 103e and the two lubricant oil discharge holes 103i and 103i of the plunger 103a. Will be placed in the facing position. In other words, the part of the groove part 103e and the flat part 70a are overlapped when it sees from the front, and the two lubricating oil discharge holes 103i * 103i and the flat part 70a are overlapping when it sees from the front. Will be. As a result, the respective lubricant oil discharge holes 103i and the gear case 50 do not communicate linearly.

At this time, the cover 70 comes into contact with the cover support 103k, and a space is formed between the flat portion 70a and the groove 103e of the cover 70 except for the contact portion. This space constitutes part of the communication path 103n. This space is arrange | positioned so that it may extend in the direction (approximately up-down direction) orthogonal to the direction (front-back direction) which the lubricating oil discharge hole 103i extends.

At the same time, discharge holes 70d and 70d as through holes constituting a part of the communication path 103n are formed in the front-rear direction at both left and right ends of the planar portion 70a of the cover 70. Each discharge hole 70d is an incision hole, and is disposed to be shifted left or right upward in a position facing the respective lubricant discharge holes 103i. These discharge holes 70d and 70d generate a gap between the plunger 103a and the cover 70, and the space communicates with the inside of the gear case 50 through each discharge hole 70d.

In this way, the communication path 103n is comprised with the said space and two discharge hole 70d * 70d, and is bent with respect to each lubricating oil discharge hole 103i via the cover 70 and the pump housing 3. Connected. As a result, the communication path 103n communicates with the cam chamber 40 inside the pump housing 3 through each lubricant discharge hole 103i, and each lubricant discharge hole 103i communicates with the gear case via the communication path 103n. (50) In communication with the inside. That is, the cam chamber 40 and the gear case 50 in the pump housing 3 communicate with each other through two lubricant discharge holes 103i and 103i and a communication path 103n.

Therefore, the lubricating oil flows from the cam chamber 40 inside the pump housing 3 to the two lubricating oil discharge holes 103i and 103i, and out of the two lubricating oil discharge holes 103i and 103i into the communication path 103n, and then covers the cover ( In contact with the flat portion 70a of 70, the flow direction is changed from the front-rear direction to the substantially up-down direction, and the communication path 103n flows upward of the respective lubricating oil discharge holes 103i from the discharge holes 70d and 70d. It flows into the gear case 50. Here, the discharge hole 70d is disposed to be offset from the position facing the lubricant discharge holes 103i and 103i.

That is, the two lubricating oil discharge holes 103i and 103i communicating with the cam chamber 40 inside the pump housing 3 and the gear case 50 and the communication path, that is, the discharge passage of the lubricating oil have a crank shape. A bend is formed in the middle of the discharge passage. For this reason, the lubricating oil discharged | emitted from each lubricating oil discharge hole 103i does not flow linearly toward the gear case 50, but changes the flow direction, flows into the communication path 103n, and passes through the discharge hole 70d and the gear case 50 To flow. In other words, while the lubricating oil changes the flow direction between the respective lubricating oil discharge holes 103i and the communicating path 103n, the lubricating oil discharge holes 103i and the communicating path 103n are removed from the cam chamber 40 inside the pump housing 3. In turn, the gas is discharged into the gear case 50.

Here, when lubricating oil flows through the communication path 103n, it flows toward the gear case 50 via the discharge hole 70d, accumulating in the space formed between the planar parts 70a of the cover 70. In this way, the lubricant reservoir 103p is provided between the pump housing 3 and the cover 70 while being in the middle of the discharge passage connecting the cam chamber 40 and the gear case 50 inside. In this embodiment, the lubricating oil of the lubricating oil storage part 103p may flow toward the gear case 50 through the gap formed between the cutout 70c of the cover 70 and the groove part 103e.

For this reason, even when the lubricating oil splashes inside the gear case 50 toward each of the lubricating oil discharge holes 103i of the pump housing 3, the droplets of lubricating oil are covered near the position facing the respective lubricating oil discharge holes 103i. It hits the flat part 70a of 70, and an invasion to each lubricating oil discharge hole 103i is prevented. In addition, even when the splash droplets of the lubricating oil reach the discharge hole 70d, the discharge passage of the lubricating oil must flow through the bent portion in the direction opposite to the flow direction of the lubricating oil, that is, the discharge direction, that is, the communication path 103n Since the flow direction must be changed between the 1 lubricant oil discharge holes 3i, it becomes difficult to penetrate into each lubricant oil discharge hole 103i.

With such a configuration, it is difficult for the droplets of lubricant oil to enter the cam chamber 40 inside the pump housing 3 from the gear case 50 while passing through the communication path 103n and the two lubricant discharge holes 103i. Lose. Therefore, the fuel injection pump 1 can reduce the amount of splash droplets of lubricating oil in the cam chamber 40. As a result, the fuel injection pump 1 has the droplets of lubricating oil reaching and attaching to the lower part of the plunger 5, and the lubricating oil is plunged by the plunger 5 and the plunger barrel 4 by the reciprocating motion of the plunger 5 in the vertical direction. It is possible to suppress the inflow into the leak return groove 4a and the pressurizing chamber 8 through the gap between the gaps) and into the fuel.

In addition, in the fuel injection pump 1, when the through-hole 22a * 27a of the up-down direction is provided in the lower spring support 22 and the adjustment shim 27, respectively, as shown in FIG. Since the roller part 25 of the 24 contacts the cam 44 and rotates at the time of its rotation, the lubricating oil supplied to the cam 44 is lifted by the rotation of the roller part 25, and the through hole 22a. 27a flows into the plunger 5 side from the tappet 24 of the tappet chamber 20 and from the gap between the plunger 5 and the plunger barrel 4 to the leak return groove 4a or the pressurizing chamber 8. There is a risk of mixing in the fuel.

Therefore, in the fuel injection pump 1, as shown in FIG. 10, the through-hole of the up-down direction was not provided in the lower spring support 22 and the adjustment shim 27. As shown in FIG. As a result, the fuel injection pump 1 forms a blocking portion 28 between the roller portion 25 of the tappet 24 and the lower spring support 22 so that the lubricating oil attached to the roller portion 25 of the tappet is tappeted. (24) It can prevent entering inside, and can reduce the amount of lubricating oil transfer in fuel.

As described above, the fuel injection pump 1 includes a pump housing 3 connected to the gear case 50. In the fuel injection pump 1, the pump housing 3 includes a first lubricant oil discharge hole 3i and a second lubricant oil discharge hole 3j communicating with the pump housing 3 and the gear case 50. Two lubricating oil discharge holes 103i and 103i, a groove portion connected to the first lubricating oil discharge hole 3i and a groove portion connected to the second lubricating oil discharge hole 3j, and attached to the pump housing 3 to form a first Cover 60 (cover 70) covering the lubricant discharge hole 3i and the second lubricant discharge hole 3j (two lubricant discharge holes 103i and 103i) and a part of each groove portion at the gear case 50 side. And a first lubricant oil discharge hole 3i and a second lubricant oil discharge hole 3j (two lubricant discharge holes 103i and 103i), respective groove portions, and a cover 60 (cover 70). As a result, a curved communication path connecting the inside of the pump housing 3 and the gear case 50, that is, the first lubricant oil discharge hole 3i and the first communication path 3m, and the second lubricant oil discharge hole 3j. ) And second communication path 3n (two lubricating oil vessels) Formed a hole (103i · 103i) and (103n)) to communicate with each other.

Accordingly, the first communication path 3m and the second communication path 3n (communication path 103n) are respectively the first lubricant oil discharge hole 3i and the second lubricant oil discharge hole 3j (each lubricant discharge hole ( 103i), the first communication path 3m and the second communication path 3n (communication path 103n), the first lubricant oil discharge hole 3i, and the second lubricant oil discharge hole 3j are connected. The flow direction of the lubricating oil between (the respective lubricating oil discharge holes 103i) is changed, so that droplets of lubricating oil on the gear case 50 side are first lubricant discharge holes 3i and second lubricant discharge holes 3j ( It is difficult to enter the pump housing 3 through each lubricant oil discharge hole 103i). In addition, the pulsation pressure accompanying the up-down movement of the piston of the diesel engine is attenuated by the cover 60 when propagated from the gear case 50 side to the fuel injection pump 1, so that the pulsation pressure of the fuel injection pump 1 is reduced. Will be reduced. Therefore, the fuel injection pump 1 can reduce the amount of the droplets of lubricating oil in the pump housing 3 inside, and can suppress that the lubricating oil which arises due to the droplets of lubricating oil mixes into fuel.

On the other hand, when the cover 60 is attached to the plunger 3a according to the first embodiment, the pulsation pressure inside the pump housing 3 is, for example, as shown in FIG. 9 (a). The damping is approximately 60% compared with the pulsation pressure inside the gear case 50 of the engine.

In addition, when the cover 70 is attached to the plunger 103a which concerns on 2nd Embodiment, the pulsation pressure inside the pump housing 3 is a concrete example, as shown to FIG. 9 (b), for example. The damping is almost zero compared to the pulsation pressure inside the gear case 50 of the diesel engine.

The fuel injection pump 1 has a discharge hole 60d and a discharge hole 60h (two holes) that constitute part of the first communication path 3m and the second communication path 3n (communication path 103n). Discharge holes 70d and 70d are formed in the cover 60, and they are shifted from the position facing the first lubricant oil discharge hole 3i and the second lubricant oil discharge hole 3j (each lubricant discharge hole 103i). do.

As a result, the first communication path 3m and the second communication path 3n (communication path 103n) are bent by the discharge hole 60d and the discharge hole 60h (each discharge hole 70d). The flow direction of the lubricating oil is changed in the middle of the first communication path 3m and the second communication path 3n (communication path 103n), so that droplets of lubricating oil on the gear case 50 side are first lubricant discharge holes. It becomes difficult to enter inside the pump housing 3 via 3i and the 2nd lubricating oil discharge hole 3j (each lubricating oil discharge hole 103i). Therefore, the fuel injection pump 1 can reduce the amount of droplets of lubricating oil in the pump housing 3 inside, and can suppress that the lubricating oil which arises from the droplets of lubricating oil mixes into fuel. In addition, the end portion of the cover 60 (cover 70) can be attached to the pump housing 3 using bolts 61 and 61. Therefore, the fuel injection pump 1 can aim at the improvement of the shockproof of the cover 60 (cover 70).

The fuel injection pump 1 is in the middle of the second communication path 3n (communication path 103n), and the plunger 3a (plunger 103a) and cover 60 (cover 70) of the pump housing 3. Between)), the lubricating oil storage part 3p (lubricating oil storage part 103p) which can store a lubricating oil is provided.

Thereby, the pulsating pressure accompanying the up-down movement of the piston of a diesel engine is attenuated by the lubricating oil accumulating in the lubricating oil storage part 3p (lubricating oil storage part 103p), and the pump housing 3 by the gear case 50 side. It becomes difficult to propagate. Therefore, the fuel injection pump 1 can reduce the amount of droplets of lubricating oil in the pump housing 3 inside, and can suppress that the lubricating oil which arises from the droplets of lubricating oil mixes into fuel.

The fuel injection pump 1 forms a cam chamber 40 for accommodating the cam 44 in the pump housing 3, and the cam tap chamber 20 for accommodating the tappet 24 in contact with the cam 44. A blocking portion 28 formed so as to communicate with the 40 and preventing the communication between the plunger 5 side and the cam chamber 40 than the tappet 24 of the cam chamber 40 and the tappet chamber 20. To form.

As a result, droplets of lubricating oil in the pump housing 3 are less likely to enter the pressure chamber 8 side from which fuel is supplied from the cam chamber 40. Therefore, the fuel injection pump 1 can suppress mixing of the lubricating oil which arises from the droplets of lubricating oil in the pump housing 3 inside fuel.

<2nd embodiment>

Next, the fuel injection pump 201 which concerns on other embodiment of this invention is demonstrated.

In the following description, the direction indicated by the arrow F in FIG. 11 is defined as the front and rear direction as the front of the fuel injection pump 201, and the direction indicated by the arrow U in FIG. 11 is the upper and lower direction as the upper side of the fuel injection pump 201. The direction indicated by the arrow R in FIG. 12 is defined as the right side of the fuel injection pump 201.

The fuel injection pump 201 is a component of a fuel injection device mounted in a diesel engine. The fuel injection pump 201 presses a fuel supplied from a fuel tank and presses a predetermined amount of fuel to a fuel injection valve through an injection pipe at a predetermined timing. As shown in FIG. 11 and FIG. 12, the fuel injection pump 201 is a distribution type fuel injection pump which distributes and delivers fuel to several fuel injection valves.

In the fuel injection pump 201, the plunger 210 is provided in the plunger barrel 211 to vertically reciprocately slide. The plunger barrel 211 is inserted into the hydraulic head 213 provided on the pump housing 212. The pressure chamber 214 is formed between the upper end of the plunger 210 and the plunger barrel 211. In addition, a thermoelectric element 215 serving as a low temperature start timer mechanism is provided on the right side of the plunger barrel 211 in the hydraulic head 213. On the other hand, an accumulator 238 is provided on the left side of the plunger barrel 211.

The lower end of the plunger barrel 211 is inserted into the tappet chamber 121 formed on the upper portion of the pump housing 212. The plunger 210 protrudes downward toward the tappet chamber 121 from the lower end of the plunger barrel 211. An upper spring support 216 is fixed to a lower outer circumference of the plunger barrel 211. The lower spring support 217 is fixed to the lower end of the plunger 210. Springs 218 for biasing the plunger 210 downward are interposed between the upper spring bearing 216 and the lower spring bearing 217. In addition, the tappet 219 is provided at the lower end of the plunger 210 so as to vertically reciprocate the tappet chamber 121.

The tappet 219 is a substantially cylindrical member having a bottom opening upward. The lower spring support 217 is fixed inside the tappet 219. The tappet 219 is biased downward with the plunger 210 via the lower spring bearing 217 by the spring 218. In addition, the roller 191 is supported by the rotating material through the roller shaft 192 in the lower part of the tappet 219. The roller 191 abuts the cam 221 on the camshaft 220. In addition, the adjustment shim 222 is provided between the upper and lower portions of the lower spring support 217 and the tappet 219. The adjustment shim 222 adjusts the clearance between the cam 221 and the tappet 219 to an appropriate value.

The cam 221 is fixed to the camshaft 220 and is accommodated in the front part of the cam chamber 122 formed in the lower part of the pump housing 212. The camshaft 220 is temporarily installed in the cam chamber 122 in the front-back direction, and is rotatably supported by the pump housing 212 via the bearing 240. The cam chamber 122 is filled with lubricating oil. Drive system components such as the cam 221 are lubricated by lubricating oil.

In addition, a plunger 234 is formed in front of the pump housing 212. The plunger 234 is equipped with a gear case 223. The camshaft 220 protrudes toward the inside of the gear case 223 from the front surface of the plunger 234. The gear case 223 is disposed in front of the pump housing 212 and connected to the pump housing 212, and is mounted to the engine body of the diesel engine. In the gear case 223, the cam gear 224 is fixed to the front end of the cam shaft 220. Then, the power from the crankshaft of the diesel engine can be transmitted to the power transmission means inside the gear case 223, the camshaft 220 through the cam gear 224 and the like.

On the other hand, the cam shaft 220 protrudes rearward from the rear of the pump housing 212. Outside the pump housing 212, the rear end of the camshaft 220 is provided with a governor sleeve 225 and a governor weight 226, which are components constituting the governor mechanism. The governor mechanism is embedded in the governor chamber 125 formed behind the pump housing 212. The governor chamber 125 and the cam chamber 122 communicate with each other by a vent hole.

In addition, a bevel gear 227 fixed to the camshaft 220 is accommodated in the rear part of the cam chamber 122. The bevel gear 227 is fixed to the camshaft 220. The transmission shaft 228 projects downward from the upper surface of the cam chamber 122 toward the cam chamber 122. The bevel gear 229 is fixed to the lower end of the transmission shaft 228. Bevel gear 229 meshes with bevel gear 227 on camshaft 220. The transmission shaft 228 is hypothesized in the up and down direction and is rotatably supported by the pump housing 212. The position of the up-down direction (axial direction) of the transmission shaft 228 is fixed by the stopper 230.

The rack chamber 124 is formed above the transmission shaft 228 in the pump housing 212. The rack chamber 124 incorporates a rack which is a component constituting the injection amount adjusting mechanism of the fuel injection pump 201. The rack chamber 124 and the cam chamber 122 are communicated by the vent hole.

In addition, the distribution shaft 231 is fixed to the same shaft center as the transmission shaft 228 via the joint 232 at the upper end of the transmission shaft 228. In addition, a delivery valve 233 is provided at the rear of the distribution shaft 231 in the hydraulic head 213 through the holder 331. The delivery valve 233 prevents the fuel inside the injection pipe from flowing into the pressure chamber 214 at the end of the injection of the fuel injection pump 201.

With this configuration, when the cam 221 rotates in the fuel injection pump 201, the tappet 219 reciprocates up and down by the rotation of the cam 221, and at the same time, the lower portion fixed to the tappet 219. The plunger 210 also reciprocates up and down through the spring receiver 217. And the suction stroke of the fuel to the pressurizing chamber 214 and the discharge stroke of the fuel from the pressurizing chamber 214 are performed by the up-down reciprocating motion of the plunger 210 alternately. That is, when the plunger 210 is pressed down by the biasing force of the spring 218 in the suction stroke, the fuel is sucked from the fuel tank into the pressure chamber 214, while the plunger 210 is the spring 218 in the discharge stroke. When it is pushed up and raised by the biasing force of the fuel, the fuel sucked in the pressurizing chamber 214 is pressurized and it is conveyed to the distribution shaft 231 through a flow path. Thereafter, the fuel pumped to the distribution shaft 231 is distributed to the delivery valve 233 by the distribution shaft 231, and is injected from the fuel injection valve through the injection pipe.

The plunger 234 shown to FIG. 13 and FIG. 14 is formed in substantially inverted triangle shape when seen from the front. A boss portion 341 supporting the camshaft 220 is provided at the center of the plunger 234. And the groove part 342 is provided on the front surface of the boss part 341. The cover 251 is disposed to cover the opening of the groove portion 342 on the gear case 223 side, and is attached to the boss portion 341 by bolts 236 and 236.

In addition, three bolt holes 343, 343, and 343 in which bolts for mounting the pump housing 212 to the gear case 223 are inserted are provided in the outer peripheral portion of the plunger 234. These three bolt holes 343, 343, and 343 are respectively disposed at three corner portions of the plunger 234 formed in an approximately inverted triangle shape, and have approximately equal angles (about 120 degrees) about the boss portion 341. Are provided at intervals.

The plunger 234 is provided with two lubricating oil discharge passages 370L and 370R. Each of the lubricating oil discharge passages 370L and 370R communicates with the inside of the pump housing 212 and the gear case 223. Lubricant oil is discharged from the cam chamber 122 inside the pump housing 212 to the gear case 223 through the respective lubricant discharge passages 370L and 370R. In addition, in the following description about lubricating oil discharge channel | path 370L * 370R, the pump housing 212 side is called "upstream side" in the flow direction of lubricating oil, and the gear case 223 side is called "downstream side."

As shown in FIG. 19 (a) and FIG. 19 (b), the two lubricating oil discharge passages 370L and 370R are both formed to be bent in a substantially crank shape when viewed in cross section. The two lubricating oil discharge passages 370L and 370R are arranged at the left and right sides with the camshaft 220 interposed therebetween when viewed from the front (see FIG. 13). That is, the lubricating oil discharge passage 370L (hereinafter referred to simply as the “left lubricating oil discharge passage 370L”) is disposed on the left side of the cam shaft 220, and the lubricating oil discharge passage 370R (hereinafter simply referred to as “left lubricant discharge passage 370L”) is provided. &Quot; right lubricant discharge passage 370R "

The left lubricant discharge passage 370L is constituted by the first lubricant discharge passage 371L, the second lubricant discharge passage 372L and the third lubricant discharge passage 373L. In the left lubricant discharge passage 370L, the first lubricant discharge passage substantially perpendicular to the second lubricant discharge passage 372L on the upstream side of the second lubricant discharge passage 372L provided on the front surface of the boss portion 341 ( 371L communicate with each other, and a third lubricant discharge passage 373L approximately orthogonal to the second lubricant discharge passage 372L communicates with the downstream side of the second lubricant discharge passage 372L.

On the other hand, the right lubricant discharge passage 370R is constituted by the first lubricant discharge passage 371R, the second lubricant discharge passage 372R and the third lubricant discharge passage 373R. In the right lubricant discharge passage 370R, a first lubricant discharge passage 371R substantially orthogonal to the second lubricant discharge passage 372R on an upstream side of the second lubricant discharge passage 372R provided on the front surface of the boss portion 341. ) Communicate with each other, and a third lubricant discharge passage 373R approximately orthogonal to the second lubricant discharge passage 372R communicates with the downstream side of the second lubricant discharge passage 372R.

As shown in Fig. 15, the groove portion 342 extends along the circumferential direction of the boss portion 341, and is formed in a substantially C shape that cuts a part of the ring and opens to the left when viewed from the front. The groove 342 opens forward. The inside of the groove part 342 is divided into the 1st groove part 342A, the 2nd groove part 342B, and the 3rd groove part 342C by a partition. The positional relationship of the groove part 342 with respect to each of these 1st-3rd groove parts 342A, 342B, and 342C is as follows.

Specifically, in the groove portion 342 formed in a substantially C shape when viewed from the front, the first groove portion 342A is located at one end (upper end) of the opening portion of the groove portion 342. The third groove 342C is located at the other end of the opening 342 (lower end). The second groove portion 342B is located between the first groove portion 342A and the second groove portion 342B. In other words, the first groove portion 342A is located above the outer periphery of the boss portion 341. The 2nd groove part 342B is located in the side part of the outer periphery of the boss part 341, and in the right part of the outer periphery of the boss part 341 in this embodiment. The third groove portion 342C is located at the lower outer circumference of the boss portion 341.

In addition, a pair of bolt holes 344 占 345 are provided in the groove 342. The pair of bolt holes 344 占 345 are holes into which the bolts 236 占 236 (see FIGS. 13 and 14) for mounting the cover 251 are inserted, so as to penetrate the plunger 234 in the front-rear direction. Prepared. One bolt hole 344 of the pair of bolt holes 344 and 345 is provided inside the first groove 342A, specifically, in the center of the left and right approximately inside the first groove 342A, and the other bolt hole 345. ) Is provided inside the third groove 342C. The pair of bolt holes 344 占 345 are disposed substantially symmetrically (line symmetry) with respect to the center of the boss portion 341.

A pair of recessed parts 342D and 342E are provided in the outer edge of the groove part 342. The pair of recesses 342D and 342E are formed such that the outer edge of the groove 342 is cut off. The pair of recesses 342D and 342E can be easily processed by, for example, cutting the outer edge of the groove 342. One of the recesses 342D of the pair of recesses 342D and 342E is provided at the outer edge of the first groove 342A, and the other recess 342E is at the outer edge of the third groove 342C. Prepared. The pair of recesses 342D and 342E are disposed substantially symmetrically (line symmetry) with respect to the center of the boss portion 341. The pair of recesses 342D and 342E and the pair of bolt holes 344 and 345 are disposed on one line (diameter) passing through the center of the boss portion 341.

In the left side of the bolt hole 344 in the inside of the first groove 342A, a first lubricant oil discharge passage 371L constituting an upstream side passage of the lubricant lubricant discharge passage 370L on the left side is provided. Further, a first lubricant oil discharge passage 371R constituting an upstream side passage of the lubricant lubricant discharge passage 370R on the right side is provided at an end portion of the second groove portion 342B toward the first groove portion 342A.

As shown to Fig.19 (a), the 1st lubricating oil discharge path 371L is comprised by the communication hole which penetrates the plunger 234 in the front-back direction. The upstream end of the first lubricant discharge passage 371L communicates with the cam chamber 122 (see FIGS. 11 and 12) of the pump housing 212. The downstream end of the first lubricant oil discharge passage 371L communicates with the inside of the first groove 342A. The first lubricant oil discharge passage 371L is above the horizontal line passing through the axis of the camshaft 220 when viewed from the front of the fuel injection pump 1 when the fuel injector is mounted on the diesel engine, or the lower end portion on the horizontal line. It is arranged at the height position of the catch. In addition, the hole shape of the 1st lube oil discharge path 371L becomes substantially elliptical shape when seen from the front. The hole width (length in the elliptic short side direction) of the first lubricant oil discharge passage 371L substantially coincides with the groove width of the first groove portion 342A. In addition, below, the passage area (cross-sectional area of the direction orthogonal to the flow direction of lubricating oil. Hereinafter, the same) of the 1st lubricating oil discharge channel 371L is represented by AL1.

As shown to FIG. 19B, the 1st lubricating oil discharge path 371R is comprised by the communication hole which penetrates the plunger 234 forward and backward. The upstream end of the first lubricant discharge passage 371R communicates with the cam chamber 122 (see FIGS. 11 and 12) of the pump housing 212. The downstream end of the first lubricating oil discharge passage 371R communicates with the inside of the second groove 342B. When the fuel injection device is mounted on the diesel engine, the first lubricant discharge passage 371R is located above the horizontal line passing through the axis of the camshaft 220 when viewed from the front of the fuel injection pump 1, or the lower end portion thereof on the horizontal line. It is arranged at the height position of the catch. In addition, the hole shape of the 1st lubricating oil discharge path 371R becomes substantially elliptical shape when seen from the front. The hole width (length in the elliptical short side direction) of the first lubricant oil discharge passage 371R substantially coincides with the hole width of the first groove portion 342A. In addition, below, the passage area of the 1st lubricating oil discharge path 371R is represented by AR1.

13 and 16 to 18, the cover 251 is a substantially C-shaped plate-like member, and is disposed on the groove portion 342 of the plunger 234 in an open state to the left. The cover 251 is a plate-like structure consisting of a plurality of concave portions having a first attachment plate 351 or a second attachment plate 352 and a plurality of planar portions having a left passage plate 353 or a right passage plate 354. to be. The cover 251 is provided with a pair of bolt holes 351A and 352A and a pair of convex portions 351B and 352B.

In the cover 251 formed in a substantially C-shape, one end (upper end) of the opening of the cover 251 becomes the left passage plate 353. The first mounting plate 351 is connected to the left passage plate 353. On the other hand, the other end of the opening (lower end) of the cover 251 becomes the second attachment plate 352. The right passage plate 354 is connected to the second attachment plate 352. In the cover 251, the first mounting plate 351 and the second mounting plate 352 are disposed on the same plane (Z1 shown in FIG. 18), and the left passage plate 353 and the right passage plate 354 are provided. Is disposed on the same plane (Z2 shown in FIG. 18) which is substantially parallel to the plane Z1 and whose height is different from the plane Z1.

As also shown in FIG. 13, the width | variety of the 1st attachment plate 351 is comprised slightly narrower than the groove width inside the 1st groove part 342A. That is, the first mounting plate 351 is configured to couple inside the first groove 342A. And the back surface (surface of the plunger 234) of the 1st attachment plate 351 is comprised so that the bottom surface (front surface of the plunger 234) of the 1st groove part 342A may be followed. The first mounting plate 351 is provided with one bolt hole 351A among the pair of bolt holes 351A and 352A. The bolt hole 351A is a hole passing through the first mounting plate 351 and passes through the bolt 236 together with the bolt hole 344 inside the first groove 342A. In addition, one convex portion 351B of the pair of convex portions 351B and 352B is provided on the outer edge of the first mounting plate 351. The convex part 351B is a part which protrudes outward from the outer edge of the 1st attachment plate 351, and is comprised so that it may engage with the recessed part 342D of the 1st groove part 342A.

The width of the second attachment plate 352 is configured to be slightly narrower than the groove width inside the third groove 342C. That is, the second attachment plate 352 is configured to couple inside the third groove 342C. And the back surface (side surface of the plunger 234) of the 2nd attachment plate 352 is comprised so that the bottom surface (front surface of the plunger 234) of the 2nd groove part 342B may be followed. The second mounting plate 352 is provided with the other bolt hole 352A among the pair of bolt holes 351A and 352A. The bolt hole 352A is a hole penetrating the second attachment plate 352 and passes the bolt 236 together with the bolt hole 345 inside the third groove 342C. Moreover, the other convex part 352B among a pair of convex parts 351B and 352B is provided in the outer edge of the 2nd attachment plate 352. As shown in FIG. The convex part 352B is a part which protrudes outward from the outer edge of the 2nd attachment plate 352, and is comprised so that it may engage with the recessed part 342E of the 3rd groove part 342C.

Then, the left passage plate 353 is formed by bending so that the opening end (upper end) of the cover 251 is substantially parallel to the first attachment plate 351 (see FIG. 18). The width of the left passage plate 353 is set slightly wider than the groove width inside the first groove portion 342A. That is, the left passage plate 353 is configured to cover the first groove portion 342A on the gear case 223 side. Accordingly, as shown in FIGS. 19A and 20, the passage having a predetermined cross-sectional area by the first groove portion 342A and the left passage plate 353, that is, the second lubricant oil discharge passage on the left side ( 372L).

In addition, below, the passage area of the 2nd lubricating oil discharge channel | path 372L is represented by AL2. The passage area AL2 of the second lubricant oil discharge passage 372L is smaller than the passage area AL1 of the first lubricant oil discharge passage 371L (AL2 <AL1).

An upstream end of the second lubricant oil discharge passage 372L communicates with the first lubricant oil discharge passage 371L. The downstream end of the second lubricant oil discharge passage 372L communicates with the third lubricant discharge passage 373L. The passage width of the second lubricant oil discharge passage 372L substantially coincides with the opening width (ellipse short side) of the first lubricant oil discharge passage 371L at the upstream end in the radial direction of the boss portion 341. A narrow portion 372La is formed at the downstream end of the second lubricant discharge passage 372L. The passage width (groove width inside the first groove portion 342A) of the narrow portion 372La is narrower than the passage width at the upstream end in the radial direction of the boss portion 341.

As shown to Fig.19 (a), the 3rd lubricating oil discharge path 373L is comprised by the through-hole which penetrates the left channel board 353 of the cover 251. As shown to FIG. The third lubricant oil discharge passage 373L is an incision hole and is configured along the outer edge end surface 353A of the left passage plate 353 of the cover 251. Specifically, the third lubricant discharge passage 373L is constituted by a gap generated between the outer edge end surface 353A of the left passage plate 353 and the inner circumferential surface of the first groove portion 342A (narrow portion 372La). The outer edge cross section 353A is a cross section of the opening tip portion of the cover 251 and is configured to traverse the first groove portion 342A (the direction crossing the flow direction of the lubricating oil). The upstream end of the third lubricant oil discharge passage 373L communicates with the second lubricant oil discharge passage 372L. The downstream end of the third lubricant discharge passage 373L is opened toward the front of the plunger 234 to communicate with the inside of the gear case 223. That is, the third lubricant discharge passage 373L forms a communication path together with the second lubricant discharge passage 372L to communicate the inside of the gear case 223 and the first lubricant discharge passage 371L outside the plunger 234. Let's do it. In addition, the third lubricant oil discharge passage 373L is provided below the first lubricant oil discharge passage 371L.

In addition, below, the passage area of the 3rd lubricant discharge path 373L is represented by AL3. The passage area AL3 of the third lubricant oil discharge passage 373L is smaller than the passage area AL1 of the first lubricant oil discharge passage 371L (AL3 <AL1). In addition, the passage area AL3 of the third lubricant oil discharge passage 373L is smaller than the passage area AL2 of the second lubricant oil discharge passage 372L (AL3 <AL2). In other words, the passage area AL3 of the third lubricant discharge passage 373L is the smallest in the left lubricant discharge passage 370L, and the passage area AL1 of the first lubricant discharge passage 371L is the largest (AL3 <AL2 <AL1). In other words, the lubricating oil discharge passage 370L on the left side has a passage area of the three lubricating oil discharge passages 371L, 372L, and 373L facing the gear case 223 from the upstream side, that is, the pump housing 212 side. It is configured to be smaller step by step.

In the right passage plate 354, a portion between the first mounting plate 351 and the second mounting plate 352 in the cover 251 is provided with respect to the first mounting plate 351 and the second mounting plate 352. It is formed so that it may be bent in substantially parallel (refer FIG. 18). The width of the right passage plate 354 is set slightly wider than the groove width of the second groove portion 342B. That is, the right passage plate 354 is configured to cover the second groove portion 342B on the gear case 223 side. Accordingly, as shown in FIGS. 19B and 20, the passage having a predetermined cross-sectional area by the second groove portion 342B and the right passage plate 354, that is, the second lubricant discharge passage 372R on the right side. ) Is configured.

In addition, below, the passage area of the 2nd lubricating oil discharge channel | path 372R is represented by AR2. The passage area AR2 of the second lubricant oil discharge passage 372R is smaller than the passage area AR1 of the first lubricant oil discharge passage 371R (AR2 <AR1).

The upstream end of the second lubricant discharge passage 372R communicates with the first lubricant discharge passage 371, and the downstream end of the second lubricant discharge passage 3372R communicates with the third lubricant discharge passage 373R. In addition, the passage width of the second lubricant discharge passage 372R substantially coincides with the opening width (ellipse short side) of the first lubricant discharge passage 371R at the upstream end in the radial direction of the boss portion 341. The narrow part 372Ra is formed in the middle flow part of the 2nd lubricating oil discharge channel | path 372R. The passage width (groove width inside the second groove portion 342B) of the narrow portion 372Ra is narrower than the passage width at the upstream end in the radial direction of the boss portion 341.

As shown in FIG. 19B, the third lubricant discharge passage 373R is formed of a through hole passing through the right passage plate 354 of the cover 251. The hole shape of the third lubricant discharge passage 373R is substantially circular. The upstream end of the third lubricant oil discharge passage 373R communicates with the second lubricant oil discharge passage 372R. The downstream end of the third lubricant discharge passage 373R is opened toward the front of the plunger 234 to communicate with the inside of the gear case 223. That is, the third lubricant discharge passage 373R forms a communication path together with the second lubricant discharge passage 372R to connect the inside of the gear case 223 and the first lubricant discharge passage 371R outside the plunger 234. Let's do it. The third lubricant oil discharge passage 373R is provided below the first lubricant oil discharge passage 371R. In other words, the third lubricant oil discharge passage 373R is provided at an end opposite to the side covering the first lubricant oil discharge passage 371R in the right passage plate 354.

In addition, below, the passage area of the 3rd lubricant discharge path 373R is represented by AR3. The passage area AR3 of the third lubricant oil discharge passage 373R is smaller than the passage area AR1 of the first lubricant oil discharge passage 371R (AR3 <AR1). In addition, the passage area AR3 of the third lubricant oil discharge passage 373R is smaller than the passage area AR2 of the second lubricant oil discharge passage 372R (AR3 <AR2). In other words, the passage area AR3 of the third lubricant discharge passage 373R is the smallest in the lubricant discharge passage 370R on the right side, and the passage area AR1 of the first lubricant discharge passage 371R is the largest (AR3 <AR2 <AR1). In other words, the lubricating oil discharge passage 370R on the right side has a passage area of the three lubricating oil discharge passages 371R, 372R, and 373R facing the gear case 223 from the upstream side, that is, the pump housing 212 side. It is configured to be smaller step by step.

As described above, the fuel injection pump 201 mounts the gear case 223 to the plunger 234 of the pump housing 212, and the cam shaft 220 protruding from the plunger 234 into the gear case 223. Insert it. The fuel injection pump 201 provides the cam gear 224 on the cam shaft 220 in the gear case 223, and discharges the lubricant oil passage through which the lubricant oil in the pump housing 212 is discharged into the gear case 223. 370L and 370R are provided in the plunger 234. In the fuel injection pump 201, the lubricating oil discharge passages 370L and 370R are formed to be bent in a substantially crank shape, and the first lubricating oil discharge passages 371L and 371R and the second lubricating oil discharge passages 372L and 372R are formed. It is comprised by the 3rd lubricant oil discharge path 373L * 373R. The second lubricant oil discharge passages 372L and 372R are provided on one side of the plunger 234 of the pump housing 212. The first lubricant oil discharge passage 371L and 371R is substantially orthogonal to the second lubricant oil discharge passage 372L and 372R and communicates with the upstream side of the second lubricant oil discharge passage 372L and 372R. The third lubricant oil discharge passage 373L and 373R is substantially orthogonal to the second lubricant oil discharge passage 372L and 372R and communicates with the downstream side of the second lubricant discharge passage 372L and 372R. Grooves 342 constituting a part of the lubricating oil discharge passages 370L and 370R are provided on one side surface of the plunger 234 of the pump housing 212. The first lubricant oil discharge passages 371L and 371R are holes passing through the plunger 234 of the pump housing 212 inside the groove 342. An upstream end of the first lubricant discharge passage communicates with the inside of the pump housing 212. The downstream end of the first lubricating oil discharge passage 371L · 371R communicates with the inside of the groove portion 342 and is covered by the cover 251. The 2nd lubricating oil discharge channel | path 372L * 372R is comprised by the groove part 342 and the cover 251. As shown in FIG. The third lubricant oil discharge passages 373L and 373R are configured along the cross section of the cover 251. The passage areas AL2 and AR2 of the second lubricant discharge passages 372L and 372R and the passage areas AL3 and AR3 of the third lubricant discharge passages 373L and 373R are respectively passages of the first lubricant discharge passage 371L and 371R. It is smaller than the area AL1 / AR1.

Accordingly, the lubricating oil passes from the cam chamber 122 inside the pump housing 212 to the first lubricating oil discharge passage 371L · 371R, the second lubricating oil discharge passage 372L.372R, and the third lubricating oil discharge passage 371L · 373R. In turn, the gas is discharged into the gear case 223. And the passage area on the gear case 223 side of the lubricating oil discharge passage 370L and 370R is smaller than the passage area on the pump housing 212 side, and the lubricant is likely to accumulate in the third lubricant discharge passage 373L and 373R. Lose. For this reason, the pulsation pressure accompanying the up-down motion of the piston of a diesel engine is attenuated by the lubricating oil accumulated in the 3rd lubricant discharge path 373L * 373R, and it is hard to propagate to the pump housing 3 from the gear case 223 side. Lose. Therefore, the fuel injection pump 201 can reduce the amount of the droplets of lubricating oil in the pump housing 3 inside, and can suppress the mixing of lubricating oil which arises from the droplets of lubricating oil in fuel.

The fuel injection pump 201 makes the passage area AL3 * AR3 of the 3rd lubricating oil discharge path 373L * 373R smaller than the passage area AL2 * AR2 of the 2nd lubricating oil discharge channel 372L * 372R.

As a result, the passage area on the gear case 223 side of the lubricant discharge passage 370L · 370R decreases in stages toward the gear case 223 side, whereby the lubricant is discharged by the third lubricant discharge passage 373L · 373R. It becomes easy to collect. For this reason, the pulsation pressure accompanying the up-down movement of the piston of a diesel engine is attenuated by the lubricating oil accumulated in the 3rd lubricant discharge path 373L * 373R, and it is hard to propagate to the pump housing 3 from the gear case 223 side. Lose. Therefore, the fuel injection pump 201 can reduce the amount of the droplets of lubricating oil in the pump housing 3 inside, and can suppress the mixing of lubricating oil which arises from the droplets of lubricating oil in fuel.

In addition, the passage area of the lubricating oil discharge passages 370L and 370R can be easily adjusted by only processing the end surface of the cover 251. Therefore, the processing cost of the lubricating oil discharge passages 370L and 370R can be reduced, and the manufacturing cost of the fuel injection pump 201 can be reduced.

The third lubricant oil discharge passage 373L and 373R is provided below the first lubricant oil discharge passage 371L and 371R.

Accordingly, when the lubricant is discharged from the pump housing 212 into the gear case 223, the lubricant flows down the lubricant discharge passages 370L and 370R from above. Therefore, the lubricating performance can be improved by smoothly discharging the lubricating oil.

The fuel injection pump 201 provides the cover 251 with a convex portion 351B and 352B that can be coupled to the recessed portions 342D and 342E formed in the plunger 234 of the pump housing 212. It is attached to the pump housing 3 so that positioning is possible.

As a result, the mounting work of the cover 251 becomes easy. Therefore, the assembling work of the fuel injection pump 201 can be performed efficiently.

That is, when the fuel injection pump 201 mounts the cover 251 to the plunger 234 of the pump housing 212, the pair of convex portions 351B and 352B of the cover 251 are respectively plunger 234. The cover 251 can be easily positioned on the plunger 234 (groove 342) by engaging the pair of recesses 342D and 342E of the top surface.

And the convex part 351B is provided in the outer edge of the middle part of the 1st attachment plate 351, while the convex part 352B is provided in the outer edge of the front-end | tip part of the 2nd attachment plate 352 (in other words, convex) Since the part 351B and the convex part 352B are asymmetrically provided with respect to the center of the boss part 341, the mounting position of the cover 251 can be easily recognized at the time of assembly. As a result, the pair of convex portions 351B and 352B can be easily coupled to the pair of concave portions 342D and 342E, respectively, and the mounting work of the cover 251 is further facilitated.

<Industrial availability>

The present invention can be used for a fuel injection pump of a fuel injection device mounted in a diesel engine.

1, 201 fuel injection pump
2 hydraulic head
3, 212 pump housing
3a, 103a plunger
3i First lubricant drain hole (communication hole)
3j Second lubricant discharge hole (communication hole)
3n first communication path
3m 2nd communication path
3p lubricant reservoir
28 Jersey
50, 223 gear case
60, 235 covers
60d, 60h, 70d outlet hole (through hole)
103i Lubricant Drain Hole (Communication Hole)
103n communication path
103p lubricant reservoir
220 camshaft
224 cam gear
234 plunger section
370L left lubricant drain passage
370R right lubricating oil drain passage
342 groove
342D, 342E recesses
351B, 352B Convex
371L left first lubricant discharge passage
371R right first lubricating oil drain passage
372L left second lubricant discharge passage
372R right second lubricating oil discharge passage
373L Left Third Lubricant Drainage Path
373R Right Third Lubricant Drainage Path

Claims (8)

A fuel injection pump having a pump housing connected to a gear case,
The pump housing,
A communication hole communicating between the pump housing and the gear case;
A groove portion connected to the communication hole,
A cover mounted to the pump housing and covering a portion of the communication hole and the groove portion at the gear case;
The fuel injection pump which comprised the said communication hole, the said groove part, and the said cover, the curved communication path which communicates inside the pump housing and inside of the gear case. The method of claim 1,
A fuel injection pump in which a through hole constituting a part of the communication path is formed in the cover, and is displaced from a position facing the communication hole. The method according to claim 1 or 2,
A fuel injection pump provided in the middle of the communication path and provided with a lubricating oil storage unit capable of storing lubricating oil between the pump housing and the cover. 4. The method according to any one of claims 1 to 3,
A cam chamber for housing the cam is formed in the pump housing, and a tappet chamber for housing the tappet in contact with the cam is formed to communicate with the cam chamber.
A fuel injection pump provided with a stopper for preventing communication between the cam chamber and the plunger side than the tappet of the tappet chamber. The method of claim 2,
Lubricating oil is used by using the communication hole as the first lubricant oil discharge passage, the through hole as the third lubricant oil discharge passage, and using the portion of the communication passage except the communication hole and the through hole as the second lubricant oil discharge passage. A lubricant discharge passage for discharging into the gear case through the first lubricant discharge passage, the second lubricant discharge passage, and the third lubricant discharge passage in order from the inside of the pump housing;
A fuel injection pump in which the passage area of the second lubricant oil discharge passage and the passage area of the third lubricant discharge passage are smaller than the passage area of the first lubricant discharge passage, respectively. The method of claim 5,
A fuel injection pump in which the passage area of the third lubricant discharge passage is smaller than the passage area of the second lubricant discharge passage. The method according to claim 5 or 6,
The fuel injection pump provided with the said 3rd lubricating oil discharge channel | path below the said 1st lubricating oil discharge channel | path. The method according to any one of claims 1 to 7,
And a concave portion or convex portion that is engageable with the convex portion or the concave portion formed in the pump housing, and the cover is mounted to the pump housing so that the cover can be positioned in the pump housing.

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