JP2008184953A - Fuel supply pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply pump improving seizure resistance of a driving shaft or a cam. <P>SOLUTION: This fuel supply pump 1 has a first plunger 35 and a second plunger 45 reciprocated by the cam 83 rotating together with the driving shaft 80. The first and second plungers 35, 45 are arranged in the peripheral direction on an outer peripheral side of the cam 83 at a predetermined sandwiching angle. The driving shaft 80, the cam 83, and the first and second plungers 35, 45 are stored in housings 20, 30, 40, 50. Shaft holes 51, 52 supporting the driving shaft 80 and first lubricating oil passages 60, 70 for supplying lubricating oil to the driving shaft 80 are formed in the housings. The first lubricating oil passages 60, 70 have first opening parts 61, 71 opened on side walls of the shaft holes 51, 52 within a scope in the peripheral direction corresponding to a small angle side between the first and second plungers 35 and 45. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel supply pump that pumps fuel.

  Conventionally, a cam that is arranged between a fuel tank and an internal combustion engine, rotates inside with a drive shaft inside, is arranged in a circumferential direction on the outer peripheral side of the cam, and a plunger that pressurizes fuel by reciprocating and pumps it to the internal combustion engine And a fuel supply pump having a housing that rotatably supports a drive shaft and supports a plunger so as to reciprocate (see Patent Documents 1 and 2).

  In the fuel supply pump of Patent Document 1, a groove for flowing fuel as lubricating oil is formed on the inner wall surface of the housing that supports the drive shaft in order to suppress seizure between the drive shaft and the housing. By causing the fuel to flow through the groove, an oil film is formed on the surface of the drive shaft, and seizure of the drive shaft is suppressed.

Further, in the fuel supply pump of Patent Document 2, a passage having an opening whose one end opens on the surface of the drive shaft and the cam is formed inside the drive shaft and the cam. By allowing fuel as lubricating oil to flow through this passage, an oil film is formed on the surfaces of the drive shaft and cam, and seizure of the drive shaft and cam is suppressed.
JP 2003-172231 A Japanese Patent Laid-Open No. 2002-4978

  In a fuel supply pump including a plunger that reciprocates by rotating a cam and pressurizes and pumps fuel as described in Patent Documents 1 and 2, the cam and the drive shaft and the cam that rotate the cam are Each time the plunger reciprocates, it receives a radial force from the plunger.

  As described above, in Patent Documents 1 and 2, in order to suppress seizure of the drive shaft and the cam, the drive shaft and the cam are driven in a groove that circulates fuel on the inner wall surface of the housing that supports the drive shaft. Fuel as lubricating oil is supplied to the surfaces of the drive shaft and the cam by forming a passage having an opening opening on the surface of the shaft and the cam.

  In order to improve seizure resistance, it is conceivable to increase the amount of fuel supplied to the surface of the drive shaft or cam. However, if the groove width is increased or the opening area of the opening is increased in order to increase the amount of fuel supplied, the drive shaft or cam receives the radial force generated when the plunger reciprocates. When the site and the location of the groove or the opening coincide with each other, the surface pressure between the drive shaft and the housing or the surface pressure between the cam and the site supporting the cam increases. When the surface pressure increases, the oil film may be cut off even if a large amount of fuel is supplied. Therefore, there are limits to increasing the width of the groove or increasing the opening area of the opening.

  The present invention has been made in view of such problems, and an object thereof is to provide a fuel supply pump capable of improving the seizure resistance of a drive shaft or a cam.

In order to achieve the above object, according to the first aspect of the present invention, a fuel pressurizing chamber is provided by a plurality of cams that rotate together with the drive shaft, and a plurality of cams that are disposed on the outer peripheral side of the cams and reciprocate as the cams rotate. A fuel supply comprising: a plunger that pressurizes and pumps fuel sucked into the chamber; a cam chamber that houses the cam; a shaft hole that rotatably supports the drive shaft; and a housing that has a cylinder that reciprocally supports the plunger. A pump,
The plunger has first and second plungers arranged circumferentially on the outer peripheral side of the cam at a predetermined clamping angle, and a first lubricating oil passage for supplying lubricating oil to the surface of the drive shaft is formed in the housing. The first lubricating oil passage has a first opening that opens in a side wall of the shaft hole within a circumferential range corresponding to a narrow angle side between the first plunger and the second plunger. .

  In the fuel supply pump in which the first and second plungers are arranged in the circumferential direction on the outer peripheral side of the cam at a predetermined sandwich angle, when the drive shaft is rotated and the first and second plungers are reciprocated, the cam A force along the axial direction of the plunger is received from the first and second plungers.

  Since the drive shaft connected to the cam tends to move in the same direction as the direction in which the cam is pressed, the surface pressure between the drive shaft and the housing supporting the drive shaft is between the first and second plungers. It increases in the circumferential range corresponding to the wide angle side, and decreases in the circumferential range corresponding to the narrow angle side between the first and second plungers.

  In the first aspect of the present invention, the first opening is formed in the side wall of the shaft hole within the circumferential range corresponding to the portion where the surface pressure is reduced, that is, the narrower angle between the first and second plungers. Therefore, the opening area of the first opening can be increased while suppressing the occurrence of the problem of running out of the oil film, which has been a problem in the prior art. Thereby, since the supply amount of the lubricating oil to the surface of the drive shaft increases, the seizure resistance of the drive shaft can be improved.

  According to the second aspect of the present invention, fuel that is not pumped from the fuel pressurizing chamber is accumulated in the cam chamber, and the first lubricating oil passage has a second opening that opens into the cam chamber. It is a feature. According to this configuration, the fuel accumulated in the cam chamber can be used as lubricating oil, and the cam chamber and the drive shaft are formed close to each other, so that the first lubricating oil passage that is processed into the housing is formed. Becomes easy.

  According to the third aspect of the present invention, the first lubricating oil passage has a first opening at a position facing the bottom and a direction along the axial hole having the second opening at the axial end. It is characterized by an extending groove. According to this configuration, since the shape of the first lubricating oil passage is a very simple structure of a concave groove, it is easy to process the first lubricating oil passage into the housing.

  According to a fourth aspect of the present invention, the housing has a bearing having an axial hole formed on the inner peripheral surface, and the first opening is formed only at the axial center of the bearing. It is said.

  When the bearing is press-fitted into the housing and the drive shaft is supported by the bearing, when the first lubricating oil passage is formed in the housing and the bearing in order to open the first opening in the side wall of the bearing, The drop load between the bearings is reduced.

  According to this configuration, the first opening is formed so that the lubricating oil can be supplied only to the axial central portion of the drive shaft, which is the place where seizure is most likely to occur. While suppressing the drop load, seizure of the drive shaft can be suppressed.

According to the fifth aspect of the present invention, a plurality of cams that rotate together with the drive shaft, and a plurality of cams arranged on the outer peripheral side of the cams, pressurize the fuel sucked into the fuel pressurizing chamber by reciprocating with the rotation of the cams, A fuel supply pump comprising a plunger for pumping, a cam chamber for accommodating a cam, a shaft hole for rotatably supporting a drive shaft, and a housing having a cylinder for reciprocally supporting the plunger,
The plunger has first and second plungers arranged circumferentially on the outer peripheral side of the cam at a predetermined clamping angle, and a first cam ring that revolves around the rotation shaft of the drive shaft is between the cam and the plunger. Fuel that is not pumped from the fuel pressurizing chamber is accumulated in the cam chamber, and the first cam ring has an outer periphery within a circumferential range corresponding to a wide angle side between the first plunger and the second plunger. A second lubricating oil passage that communicates between the wall and the inner peripheral wall is formed.

  When the drive shaft is rotated to reciprocate the first and second plungers, the cam receives a force along the axial direction of the plunger from the first and second plungers. The surface pressure between the cam and the first cam ring is increased in the circumferential range corresponding to the narrow angle side between the first and second plungers, and on the wide angle side between the first and second plungers. The corresponding surface pressure in the circumferential direction is reduced.

  According to the fifth aspect of the present invention, the outer peripheral wall and the inner peripheral wall of the first cam ring are within a circumferential range corresponding to a portion where the surface pressure is reduced, that is, a wide angle side between the first and second plungers. Is formed, the opening area of the second lubricating oil passage can be increased while suppressing the occurrence of the problem of oil film breakage, which has been a problem in the prior art. Thereby, since the supply amount of fuel as lubricating oil to the surface of the cam is increased, the seizure resistance of the cam can be improved.

According to the invention described in claim 6, a plurality of cams that rotate together with the drive shaft, and a plurality of cams arranged on the outer peripheral side of the cams, pressurize the fuel sucked into the fuel pressurizing chamber by reciprocating with the rotation of the cams, A fuel supply pump comprising a plunger for pumping, a cam chamber for accommodating a cam, a shaft hole for rotatably supporting a drive shaft, and a housing having a cylinder for reciprocally supporting the plunger,
The plunger has third and fourth plungers arranged in the circumferential direction on the outer peripheral side of the cam so as to substantially face each other, and a third lubricating oil passage for supplying lubricating oil to the surface of the drive shaft is formed in the housing. The third lubricating oil passage has a third opening that opens in the side wall of the shaft hole within a corresponding circumferential range between the third plunger and the fourth plunger.

  In the fuel supply pump disposed in the circumferential direction on the outer peripheral side of the cam so that the third and fourth plungers are substantially opposed to each other, when the drive shaft is rotated to reciprocate the third and fourth plungers, The force along the axial direction of the plunger is received from the fourth plunger.

  Since the drive shaft connected to the cam tends to move in the same direction as the cam is pushed, the surface pressure between the drive shaft and the housing supporting the drive shaft is just below the third and fourth plungers. In the circumferential direction range between the third and fourth plungers does not increase as much as the part corresponding to just below the third and fourth plungers.

  In the invention according to claim 6, since the third opening is opened on the side wall of the shaft hole in the region where the surface pressure is not increased, that is, in the circumferential range between the third and fourth plungers, The opening area of the third opening can be increased while suppressing the occurrence of the problem of oil film breakage, which has been a problem in the prior art. Thereby, since the supply amount of the lubricating oil to the surface of the drive shaft increases, the seizure resistance of the drive shaft can be improved.

  According to the seventh aspect of the present invention, fuel that is not pumped from the fuel pressurizing chamber is accumulated in the cam chamber, and the third lubricating oil passage has a fourth opening that opens to the cam chamber. It is a feature. The fuel accumulated in the cam chamber can be used as lubricating oil, and the cam chamber and the drive shaft are formed close to each other, so that it is easy to form the third lubricating oil passage processed into the housing.

  According to the eighth aspect of the present invention, the third lubricating oil passage has a third opening at a position facing the bottom and a direction along the axial hole having the fourth opening at the axial end. It is characterized by an extending groove. According to this configuration, since the shape of the third lubricating oil passage is a very simple structure of a concave groove, the processing of the third lubricating oil passage into the housing is facilitated.

  According to a ninth aspect of the present invention, the housing has a bearing having an axial hole formed on the inner peripheral surface, and the third opening is formed only in the axial center portion of the bearing. It is said.

  In the case where the bearing is press-fitted into the housing and the drive shaft is supported by the bearing, when the third lubricating oil passage is formed in the housing and the bearing so as to open the third opening in the side wall of the bearing, The drop load between the bearings is reduced.

  According to this configuration, the third opening is formed so that the lubricating oil can be supplied only to the axial central portion of the drive shaft, which is the place where seizure is most likely to occur. While suppressing the drop load, seizure of the drive shaft can be suppressed.

According to the invention described in claim 10, a plurality of cams that rotate together with the drive shaft, and a plurality of cams arranged on the outer peripheral side of the cams, pressurize the fuel sucked into the fuel pressurizing chamber by reciprocating with the rotation of the cams, A fuel supply pump comprising a plunger for pumping, a cam chamber for accommodating a cam, a shaft hole for rotatably supporting a drive shaft, and a housing having a cylinder for reciprocally supporting the plunger,
The plunger has third and fourth plungers arranged circumferentially on the outer peripheral side of the cam so as to substantially face each other, and a second cam ring that revolves around the rotation shaft of the drive shaft is between the cam and the plunger. Fuel that is not pumped from the fuel pressurizing chamber is accumulated in the cam chamber, and the outer peripheral wall and the inner peripheral wall communicate with each other in the circumferential range between the third plunger and the fourth plunger in the second cam ring. The fourth lubricating oil passage is formed.

  When the drive shaft is rotated to reciprocate the third and fourth plungers, the cam receives a force along the axial direction of the plunger from the third and fourth plungers. The surface pressure between the cam and the second cam ring increases in a portion located directly below the third and fourth plungers, and does not increase as much as the above portion in the circumferential range between the third and fourth plungers.

  In the fifth aspect of the present invention, the fourth cam which communicates the outer peripheral wall and the inner peripheral wall of the second cam ring within a region where the above-described surface pressure does not increase, that is, within a circumferential range between the third and fourth plungers. Since the lubricating oil passage is formed, it is possible to increase the opening area of the fourth lubricating oil passage while suppressing the occurrence of the oil film breakage problem that has been a problem in the prior art. Thereby, since the supply amount of fuel as lubricating oil to the surface of the cam is increased, the seizure resistance of the cam can be improved.

  Hereinafter, a plurality of embodiments in which the present invention is applied to a fuel supply pump used in a common rail fuel injection device will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
1 and 2 show a fuel supply pump 1 according to a first embodiment of the present invention. The fuel supply pump 1 is a fuel supply pump of a type in which two plungers 35 and 45 are arranged at a predetermined sandwich angle on the outer periphery of a cam 83 that rotates together with a drive shaft 80. FIG. 1 shows the configuration of the fuel supply pump 1 taken along the line II in FIG. 2, that is, the configuration of the fuel supply pump 1 viewed from the direction of viewing the axial cross section of one plunger 35. FIG. 2 shows the configuration of the fuel supply pump 1 taken along the line II-II in FIG.

  As shown in FIGS. 1 and 2, the pump housing of the fuel supply pump 1 includes a housing body 20, first and second cylinder heads 30 and 40, and a bearing cover 50. As shown in FIG. 1, the 1st cylinder head 30 has the 1st cylinder 31 inside, and is supporting the 1st plunger 35 by this 1st cylinder 31 so that a reciprocation is possible. A first pressurizing chamber 32 as a fuel pressurizing chamber is formed by the inner wall surface of the first cylinder 31, the end surface of the valve member 37 a of the check valve 37, and the end surface of the first plunger 35.

  As shown in FIG. 2, the second cylinder head 40 has a second cylinder 41 inside, and the second cylinder 41 supports a second plunger 45 so as to be able to reciprocate. A second pressurizing chamber 42 as a fuel pressurizing chamber is formed by the inner wall surface of the second cylinder 41, the end surface of the valve member 47 a of the check valve 47, and the end surface of the second plunger 45.

  The bearing cover 50 is fixed to the housing body 20 with bolts or the like (not shown), and accommodates a large-diameter bearing 51 that is a bearing of the large-diameter portion 81 of the drive shaft 80. A small diameter bearing 52 that is a bearing of the small diameter portion 82 of the drive shaft 80 is accommodated in the housing body 20. The large-diameter bearing 51 is press-fitted and fixed to the bearing cover 50, and constitutes a part of the housing according to the claims. The small-diameter bearing 52 is press-fitted and fixed to the housing body 20, and a part of the housing according to the claims is arranged. It is composed. The large-diameter bearing 51 and the small-diameter bearing 52 correspond to the shaft holes recited in the claims. The bearing cover 50 and the drive shaft 80 are sealed with an oil seal 53.

  The drive shaft 80 includes a large-diameter portion 81, a small-diameter portion 82, and a cam 83, and is accommodated in the housing body 20 and the bearing cover 50. The large-diameter portion 81 is the large-diameter bearing 51 and the small-diameter portion 82 is the small-diameter bearing 52. Is rotatably supported. The cam 83 is formed between the large diameter portion 81 and the small diameter portion 82 so that the cam contour is circular and is eccentric with respect to the central axes of the large diameter portion 81 and the small diameter portion 82.

  On the inner wall of the housing body 20 and the side wall of the bearing cover 50, annular washers 92 and 93 that are in sliding contact with the axial end surface of the cam 83 are provided. Around the cam 83, first and second plungers 35 and 45 are arranged at a predetermined sandwich angle. A cam ring 90 as a first cam ring is provided between the cam 83 and the first and second plungers 35 and 45.

  The cam ring 90 is formed in a special trapezoidal shape whose outer peripheral wall is composed of a straight line and a circular arc curve, and the inner peripheral wall is formed in a circular shape. An annular bush 91 is provided on the inner peripheral wall of the cam ring 90 so as to be slidable with the cam 83. The bush 91 is press-fitted and fixed to the inner peripheral wall of the cam ring 90.

  The cam 83, the cam ring 90, and the bush 91 are accommodated in a cam chamber 21 formed by the housing body 20, the first and second cylinder heads 30 and 40, and the bearing cover 50. The cam chamber 21 is filled with fuel.

  The cam ring 90 and the bush 91 are fitted into the cam 83 so as to be rotatable. The outer peripheral surface of the cam ring 90 facing the first and second plungers 35 and 45 and the end surfaces of the first and second plungers 35 and 45 are formed in a planar shape and are in contact with each other in a plane.

  The cam ring 90 orbits around the central axis of the drive shaft 80 according to the movement of the cam 83 caused by the rotation of the drive shaft 80, that is, revolves. The cam ring 90 is rotatable relative to the cam 83, but is always pressed against the first and second plungers 35 and 45, so the cam ring 90 itself does not rotate and only the cam 83 is cam ring 90. Rotate within.

  As shown in FIG. 2, between the end of the first cylinder head 30 on the cam 83 side and the first plunger 35 and between the end of the second cylinder head 40 on the cam 83 side and the second plunger 45, respectively. First and second springs 36 and 46 are provided. The first and second springs 36 and 46 always urge the first and second plungers 35 and 45 toward the cam ring 90. Thereby, the first and second plungers 35 and 45 follow the revolution of the cam ring 90. When the cam ring 90 revolves with the rotation of the drive shaft 80, the first and second plungers 35 and 45 reciprocate along the first and second cylinders 31 and 41.

  As shown in FIGS. 1 and 2, the first cylinder head 30 is formed with a first fuel inflow passage 33 and a first fuel discharge passage 34 connected to the first pressurizing chamber 32. A connection member 27 connected to a fuel pipe connected to a common rail (not shown) is provided on the downstream side of the first fuel discharge passage 34. A check valve 37 that allows only fuel flow to the first pressurizing chamber 32 is provided in the middle of the first fuel inflow passage 33, and fuel to the connection member 27 is provided in the middle of the first fuel discharge passage 34. A check valve 38 that allows only circulation is provided.

  As shown in FIG. 2, similarly to the first cylinder head 30, the second cylinder head 40 is also formed with a second fuel inflow passage 43 and a second fuel discharge passage (not shown). A check valve 47 that allows only fuel to flow into the second pressurizing chamber 42 is provided in the middle of the second fuel inflow passage 43, and fuel to the second pressurizing chamber is provided in the middle of the second fuel discharge passage. A check valve (not shown) is provided to prevent the backflow.

  As a result, when the cam ring 90 revolves and the first and second plungers 35 and 45 reciprocate, fuel flows into the first pressurizing chamber 32 from the first fuel inflow passage 33 through the check valve 37. The fuel flows into the second pressurizing chamber 42 from the second fuel inflow passage 43 through the check valve 47. The first and second plungers 35 and 45 pressurize the fuel that has flowed into the pressure chambers 32 and 42. The pressurized fuel passes through the first fuel discharge passage 34 and the second fuel discharge passage, and is supplied from the connection member 27 to the common rail via a fuel pipe (not shown).

  As shown in FIG. 2, a feed pump 22 that sucks fuel in a fuel tank (not shown) and sends it to the first and second pressurizing chambers 32 and 42 at the end on the small diameter portion 82 side of the drive shaft 80. Is provided. The feed pump 22 has an inner rotor 23, an outer rotor 24, and a cover 26 that houses both the rotors 23, 24. As shown in FIG. 2, a washer 25 is provided between the housing body 20 and the feed pump 22.

  The washer 25 has a suction port and a discharge port (not shown). A fuel passage (not shown) for supplying fuel from a fuel tank (not shown) to the fuel supply pump 1 is connected to the suction port, and fuel pressurized by the feed pump 22 is first and first supplied to the discharge port. 2 First and second fuel inflow passages 33 and 43 for feeding to the pressurization chambers 32 and 42 are connected. The housing body 20 is formed with a fuel passage (not shown) for feeding a part of the fuel fed from the discharge port to the first and second pressurizing chambers 32 and 42 to the cam chamber 21.

  A return passage 28 a connected to the cam chamber 21 is formed in the housing body 20. A connection member 28 connected to a fuel pipe connected to a fuel tank (not shown) is provided on the downstream side of the return passage 28a.

  The inner rotor 23 and the outer rotor 24 are provided so as to be relatively rotatable. When the inner rotor 23 rotates together with the drive shaft 80, fuel in a fuel tank (not shown) is sucked, and the sucked fuel is in the first and second pressurizing chambers. 32, 42.

  As shown in FIG. 2, a metering valve 29 is provided in the middle of the first and second fuel inflow passages 33 and 43. The metering valve 29 adjusts the flow rate of the fuel fed from the feed pump 22 to the first and second pressurizing chambers 32 and 42.

  Next, the lubrication of the drive shaft 80 will be described in detail. The large diameter portion 81 of the drive shaft 80 is supported by the large diameter bearing 51. In order to ensure the lubricity of the large-diameter portion 81, as shown in FIG. 1, the bearing cover 50 serves as a first lubricating oil passage according to claim for supplying lubricating oil to the surface of the large-diameter portion 81. A large-diameter side lubricating oil passage 60 is formed.

  The large-diameter-side lubricating oil passage 60 is a passage that connects the cam chamber 21 and the large-diameter bearing 51, and supplies the fuel accumulated in the cam chamber 21 to the large-diameter bearing 51 as lubricating oil. As shown in FIG. 1, the large-diameter side lubricating oil passage 60 extends along the axial direction of the large-diameter bearing 51 so that the opening portion opens in the inner wall of the large-diameter bearing 51 and the bottom portion faces the opening portion. It is a groove. The opening that opens in the inner wall of the large-diameter bearing 51 is an outlet opening 61 that communicates the fuel flowing through the large-diameter-side lubricating oil passage 60 to the large-diameter portion 81, and corresponds to the first opening according to claim To do. The large-diameter side lubricating oil passage 60 extends from the cam chamber 21 to the vicinity of the oil seal 53.

  The inlet opening 62 as the second opening according to claim 2, wherein the fuel in the cam chamber 21 is supplied to the large-diameter side lubricating oil passage 60 on the side surface of the large-diameter side lubricating oil passage 60 on the cam chamber 21 side. Has been. The end portion on the cam chamber 21 side of the outlet opening 61 and the end portion on the large diameter portion 81 side of the inlet opening 62 are connected. For this reason, since the large-diameter side lubricating oil passage 60 has a simple concave groove shape, the formation of the large-diameter side lubricating oil passage 60 in the bearing cover 50 is facilitated.

  FIG. 3 shows a cross section taken along line III-III in FIG. As shown in FIG. 3, the outlet opening 61 of the large-diameter side lubricating oil passage 60 opens in the inner wall of the large-diameter bearing 51 within a predetermined range in the circumferential direction. The outlet opening 61 has a narrower side within the angle between the central axis of the first plunger 35 and the central axis of the second plunger 45 as shown by the broken line in FIG. 3, that is, the circumferential direction corresponding to the angle α. It opens to the inner wall of the large diameter bearing 51 within the range.

  The housing body 20 is also formed with a small-diameter side lubricating oil passage 70 that supplies fuel as lubricating oil to the small-diameter portion 82 of the drive shaft 80. The shape of the small-diameter-side lubricating oil passage 70 is the same concave groove shape as that of the large-diameter-side lubricating oil passage 60, and an outlet opening 71 that opens in the inner wall of the small-diameter bearing 52 and an inlet opening that opens in the cam chamber 21. 72.

  Further, the circumferential direction range of the outlet opening 71 that opens to the inner wall of the small diameter bearing 52 is the same as that of the outlet opening 71 formed on the inner wall of the large diameter bearing 51, between the first plunger 35 and the second plunger 45. It is the range of the circumferential direction corresponding to the narrow side among the angles between.

  Here, the operation of the fuel supply pump 1 will be described. As the drive shaft 80 rotates, the inner rotor 23 of the feed pump 22 rotates, and the inner rotor 23 and the outer rotor 24 rotate relatively to drive the feed pump 22. When the feed pump 22 is driven, fuel stored in a fuel tank (not shown) flows into the feed pump 22 via the fuel passage.

  In the feed pump 22, the fuel is pressurized by the relative rotation of the inner rotor 23 and the outer rotor 24. The pressurized fuel flows out to the first and second fuel inflow passages 33 and 43 connected to the discharge ports, and is fed to the first and second pressurization chambers 32 and 42. The flow rate of the fuel fed from the feed pump 22 and flowing into the first and second pressurizing chambers 32 and 42 is adjusted by the metering valve 29. A part of the pressurized fuel flowing out from the discharge port is supplied to the cam chamber 21.

  The fuel that has passed through the metering valve 29 is moved into the first and second pressurizing chambers as the first and second plungers 35 and 45 descend in the first and second cylinders 31 and 41 as the drive shaft 80 rotates. 32, 42 is inhaled. At this time, the fuel opens the check valves 37 and 47 and flows into the first and second pressurizing chambers 32 and 42.

  As the first and second plungers 35 and 45 rise in the first and second cylinders 31 and 41, the fuel in the first and second pressurizing chambers 32 and 42 is pressurized. When the fuel in the first and second pressurizing chambers 32 and 42 reaches a predetermined pressure, the check valve 38 of the first fuel discharge passage 34 connected to the first and second pressurizing chambers 32 and 42, The check valve of the second fuel discharge passage is opened, and the fuel in the first and second pressurizing chambers 32 and 42 is discharged to a common rail (not shown). In the common rail, the fuel including the pressure fluctuation supplied from the fuel supply pump 1 is held at a constant pressure in an accumulated state.

  On the other hand, fuel supplied from the feed pump 22 to the cam chamber 21 passes through the large-diameter side lubricating oil passage 60 formed in the bearing cover 50 and is supplied to the surface of the large-diameter portion 81 and is formed in the housing body 20. The small-diameter side lubricating oil passage 70 is supplied to the surface of the small-diameter portion 82. An oil film is formed on the surfaces of the large-diameter portion 81 and the small-diameter portion 82 by the supplied fuel, thereby smoothing the rotation of the large-diameter portion 81 and the small-diameter portion 82 and suppressing seizure.

  In the present embodiment, since the fuel is used as the lubricating oil for the large diameter portion 81 and the small diameter portion 82, it is not necessary to prepare the lubricating oil separately.

  When the fuel supply pump 1 is operated, the cam ring 90 receives a force in a direction indicated by an arrow in FIG. 1 from the first and second plungers 35 and 45. Then, since the drive shaft 80 tends to move in the direction indicated by the arrow in FIG. 1, the range on the wider side, that is, the range of the angle β, among the angles between the first and second plungers 35 and 45 shown in FIG. The surface pressure between the large diameter portion 81 and the inner wall of the large diameter bearing 51 and the surface pressure between the small diameter portion 82 and the inner wall of the small diameter bearing 52 are increased. On the contrary, the surface pressure between the large diameter portion 81 and the inner wall of the large diameter bearing 51 in the range of the angle α described above and the surface pressure between the small diameter portion 82 and the inner wall of the small diameter bearing 52 are reduced.

  When the fuel supply pump 1 is operated, the surface pressure between the drive shaft 80 and the bearing supporting it within the range of the angle α decreases, so even if the area supporting the drive shaft 80 decreases within this range, There is little risk of causing a problem of oil film breakage on the surface of the drive shaft due to increased surface pressure.

  In the first embodiment, the outlet opening 61 of the large-diameter side lubricating oil passage 60 and the outlet opening 71 of the small-diameter side lubricating oil passage 70 are placed in a place where there is little possibility of causing a problem of oil film breakage, that is, within the range of the angle α. Since it formed, the length of the axial direction of the outlet opening parts 61 and 71 and the circumferential direction can be lengthened, suppressing the generation | occurrence | production of the problem of the oil film cutting | disconnection which was a problem in the prior art, and an opening area can be enlarged. Thereby, the amount of fuel supplied to the surface of the drive shaft 80 can be increased, and the seizure resistance of the drive shaft 80 can be improved.

  Further, as shown in FIG. 4, the large-diameter side lubricating oil passage 60 has a narrow formation angle in the circumferential direction of the outlet opening 61, as in FIG. 3, on the narrow angle side between the first and second plungers 35 and 45. A large-diameter lubricating oil passage 60 in which the width of the bottom facing the outlet opening 61 is larger than the width of the outlet opening 61 may be used. FIG. 4 shows only the large-diameter side lubricating oil passage 60, but the small-diameter side lubricating oil passage 70 may of course have the same shape as that in FIG.

(Second Embodiment)
A fuel supply pump 1 according to a second embodiment of the present invention will be described below with reference to FIG.

  In the fuel supply pump 1 according to the first embodiment, the large-diameter side lubricating oil passage 60 is formed in the bearing cover 50 in a concave groove shape, and the small-diameter side lubricating oil passage 70 is formed in the housing body 20 in a concave groove shape. Yes. On the other hand, in the fuel supply pump 1a according to the second embodiment, the outlet opening 611 formed in the large-diameter side lubricating oil passage 601 has a large-diameter bearing 51 in which the fuel flowing through the large-diameter side lubricating oil passage 601 flows. The outlet opening 711 formed in the small-diameter side lubricating oil passage 701 is formed so as to open only in the central portion in the axial direction of the small-diameter side lubricating oil passage 701. It is formed so as to open only.

  In the first embodiment, since the outlet openings 61 and 71 are formed along the axial direction of the large-diameter bearing 51 and the small-diameter bearing 52, a very large opening area can be ensured. A large amount of fuel can be supplied to the small diameter portion 82, and the seizure resistance of the drive shaft 80 can be remarkably improved.

  However, if the opening areas of the outlet openings 61 and 71 are increased, there is a possibility that the loosening load between the large diameter bearing 51 and the bearing cover 50 and between the small diameter bearing 52 and the housing body 20 may be reduced. The second embodiment is characterized in that the outlet openings 611 and 711 are formed at optimum locations in consideration of the removal load.

  The feature is that the axial position of the outlet opening 611 of the large-diameter side lubricating oil passage 601 is set only in the axial center portion of the large-diameter bearing 51, and the axis of the outlet opening 711 of the small-diameter side lubricating oil passage 701. The direction position is to be formed only in the central portion of the small diameter bearing 52 in the axial direction. An inlet opening 612 of the large-diameter side lubricating oil passage 601 and an inlet opening 712 of the small-diameter side lubricating oil passage 701 are open to the cam chamber 21.

  By forming the outlet openings 611 and 711 in this way, it is possible to suppress the above-described reduction in the drop load. The axial lengths of the outlet openings 611 and 711 are shorter than the axial lengths of the outlet openings 61 and 71 of the first embodiment, and the opening area is reduced, but the circumferential length is longer than that of the prior art. Since the length can be increased, the amount of fuel supplied to the large diameter portion 81 and the small diameter portion 82 can be sufficiently secured. In addition, since each of the outlet openings 611 and 711 is formed only in the central portion in the axial direction of the large-diameter bearing 51 and the small-diameter bearing 52, fuel can be supplied to a place where seizure is most likely to occur. The seizure resistance of the shaft 80 can be improved as compared with the prior art.

(Third embodiment)
A fuel supply pump 1b according to a third embodiment of the present invention will be described below with reference to FIG. FIG. 6 shows a cross section taken along line II-II in FIG.

  In the third embodiment, a through passage 94 as a second lubricating oil passage is formed in the cam ring 901. The through passage 94 is a passage that connects the outer peripheral wall and the inner peripheral wall of the cam ring 901 and supplies the fuel accumulated in the cam chamber 21 to the surface of the cam 83.

  As shown in FIG. 6, the through-passage 94 is formed within the circumferential range corresponding to the wide side, that is, within the range of the angle γ, among the angles between the first plunger 35 and the second plunger 45. Yes.

  When the fuel supply pump 1b operates and the first and second plungers 35 and 45 reciprocate, the cam ring 901 receives a force in the direction indicated by the arrow in FIG. 6 from the first and second plungers 35 and 45. Therefore, the surface pressure between the cam ring 901 and the cam 83 in the range of the angle γ decreases.

  When the fuel supply pump 1b is operated, the surface pressure between the cam ring 901 and the cam 83 within the range of the angle γ decreases. Therefore, even if the area of the cam ring 901 that supports the cam 83 decreases within this range, There is little risk of causing a problem of oil film breakage on the surface of the cam 83 due to an increase in surface pressure.

  In the third embodiment, since the through passage 94 penetrating the outer peripheral wall and the inner peripheral wall of the cam ring 901 is formed in a place where there is little possibility of causing the problem of oil film breakage, that is, within the range of the angle γ, The opening area of the through-passage 94 can be increased while suppressing the occurrence of the problem of running out of the oil film. As a result, the amount of fuel supplied to the surface of the cam 83 can be increased, and the seizure resistance of the cam 83 can be improved.

(Fourth embodiment)
A fuel supply pump 1c according to a fourth embodiment of the present invention will be described below with reference to FIGS.

  The fuel supply pump 1 according to the first embodiment is of a type in which the first and second plungers 35 and 45 are circumferentially arranged on the outer periphery of the cam 83 at a predetermined clamping angle. In the fuel supply pump 1c according to the fourth embodiment, as shown in FIG. 7, the third and fourth plungers 351 and 451 are approximately 180 °, that is, the third and fourth plungers 351 and 451 are opposed to each other. Arranged circumferentially on the outer periphery. Since the functions of other components are the same as those in the first embodiment, detailed description thereof is omitted.

  FIG. 8 shows a cross section of only the housing body 201 taken along line VIII-VIII in FIG. As shown in FIG. 8, the housing body 201 has a through hole 202 through which one end surface and the other end surface penetrate. The through hole 202 is formed so that the diameter decreases from the upper side to the lower side in FIG. A bearing cover accommodating portion 203 that accommodates the bearing cover 50 is formed at one end side of the through-hole 202, an upper end portion in FIG. 8, and a cam chamber 21 that accommodates the cam 83 is formed below the bearing cover accommodating portion 203. Further, a small diameter bearing 52 is provided on the lower side. A feed pump attachment surface 203 to which the feed pump 22 is attached is formed on the end surface on the side where the small diameter bearing 52 is provided.

  A cylinder hole 204 is formed on the side wall of the cam chamber 21 on the back side in FIG. The third cylinder head 302 is inserted into the cylinder hole 204. Although only one cylinder hole 204 is disclosed in FIG. 8, a cylinder hole is also formed on the opposite side of the cylinder hole 204, and the fourth cylinder head 402 is inserted there. ing.

  As shown in FIG. 8, the housing main body 201 is formed with a small-diameter side lubricating oil passage 702 as a third lubricating oil passage that communicates the cam chamber 21 and the small-diameter bearing 52, and the fuel accumulated in the cam chamber 21 is supplied to the housing main body 201. The lubricating oil is supplied to the small diameter bearing 52. As shown in FIG. 8, the small-diameter side lubricating oil passage 702 is formed in a concave groove shape, and has an outlet opening 712 as a third opening that opens in the inner wall of the small-diameter bearing 52 and a fourth opening that opens in the cam chamber 21. And an inlet opening 722 as an opening.

  In the fuel supply pump 1c of the type in which the third and fourth plungers 352 and 452 are arranged to face each other, when the third and fourth plungers 352 and 452 reciprocate with the rotation of the drive shaft 80, the cam ring 902 The third and fourth plungers 352 and 452 receive a force in the direction indicated by the arrow in FIG. Then, since the drive shaft 80 tries to move in the direction indicated by the arrow in FIG. 7, that is, the direction along the reciprocating direction of the third and fourth plungers 352 and 452, the large-diameter portion 81 and the large-diameter portion in that direction are moved. The surface pressure between the bearing 51, the small diameter portion 82 and the small diameter bearing 52 increases. On the other hand, the surface pressure between the large-diameter portion 81 and the large-diameter bearing 51 between the third plunger 352 and the fourth plunger 452 and between the small-diameter portion 82 and the small-diameter bearing 52 is not as high as the above-described portion.

  When the fuel supply pump 1c is operated, the surface pressure between the drive shaft 80 and the bearing supporting it within the corresponding range between the third plunger 352 and the fourth plunger 452 is not so high as to cause an oil film breakage. Even if the area supporting the drive shaft 80 decreases within this range, there is little possibility of causing the problem of the oil film running out on the surface of the drive shaft 80 due to the increase in surface pressure.

  In the present embodiment, as shown in FIG. 8, the outlet opening 712 of the small-diameter-side lubricating oil passage 702 is placed at a place where there is little risk of causing a problem of oil film breakage, that is, between the third plunger 352 and the fourth plunger 452. Therefore, the length of the outlet opening 712 in the axial direction and the circumferential direction can be increased while suppressing the occurrence of a problem of oil film breakage, which has been a problem in the prior art, and the opening area can be reduced. Can be bigger. Thereby, the amount of fuel supplied to the surface of the drive shaft 80 can be increased, and the seizure resistance of the drive shaft 80 can be improved.

  In the present embodiment, since there are two places where the above-described surface pressure is reduced, as shown in FIG. 8, a small-diameter side lubricating oil passage 702 can be formed at each place. According to this, the amount of fuel supplied to the surface of the drive shaft 80 can be further increased. Further, the bearing cover 50 provided with the large-diameter bearing 51 can also be formed with the large-diameter side lubricating oil passage in the same shape and the same position as the small-diameter side lubricating oil passage 702 described above.

(Fifth embodiment)
A fuel supply pump 1d according to a fifth embodiment of the present invention will be described below with reference to FIG. FIG. 9 shows a cross section of only the housing body 201 taken along line VIII-VIII in FIG. A small-diameter side lubricating oil passage 703 is formed in the housing body 201 at the same position (see FIG. 8) as the housing body 201 of the fuel supply pump 1c according to the fourth embodiment. The configuration of the other parts not shown in FIG. 9 is the same as that of the fuel supply pump shown in FIGS.

  The small-diameter side lubricating oil passage 703 in the fifth embodiment is not a concave groove like the small-diameter side lubricating oil passage 702 in the fourth embodiment, and the outlet opening 713 formed in the small-diameter side lubricating oil passage 703 has a small diameter. The fuel flowing in the side lubricating oil passage 703 is formed so as to open only at the axially central portion of the small diameter bearing 52. An inlet opening 723 that opens to the cam chamber 21 is formed on the cam chamber 21 side of the small-diameter side lubricating oil passage 703.

  By forming the outlet opening 713 in this way, the area of the outlet opening 713 can be made smaller than the opening area of the outlet opening 712 in the fourth embodiment, so that the reduction of the dropout load of the small diameter bearing 52 is suppressed. be able to. Although the axial length of the outlet opening 713 is shorter than the axial length of the outlet opening 712 of the fourth embodiment and the opening area is small, the circumferential length can be longer than that of the prior art, so the small diameter A sufficient amount of fuel is supplied to the portion 82 (see FIG. 7). Further, since the outlet opening 713 is formed only in the central portion in the axial direction of the small-diameter bearing 52, fuel can be supplied to a place where seizure is most likely to occur, and the seizure resistance of the drive shaft 80 is conventionally improved. It can be improved over technology.

  In the present embodiment, only the small-diameter side lubricating oil passage 703 formed in the housing main body 201 is shown, but the cam chamber 21 and the large-diameter bearing 51 are connected to the bearing cover in the same way as the small-diameter side lubricating oil passage 703. Of course, a communicating lubricating passage may be formed.

(Sixth embodiment)
A fuel supply pump 1e according to a sixth embodiment of the present invention will be described below with reference to FIG. FIG. 10 shows a cross section taken along line XX of FIG. About the structure of the other part which is not shown by FIG. 10, since it is the same as the fuel supply pump shown in FIG. 7, description is abbreviate | omitted.

  Unlike the cam ring 90 of the first embodiment, the cam ring 903 as the second cam ring of the fuel supply pump 1e according to the sixth embodiment is formed in a substantially square shape having an outer peripheral wall having four planes, and the inner peripheral wall is circular. Is formed. An annular bush 91 is provided on the inner peripheral wall of the cam ring 903 so as to be slidable with the cam 83. The bush 91 is press-fitted and fixed to the inner peripheral wall of the cam ring 903.

  The cam 83, the cam ring 903, and the bush 91 are accommodated in a cam chamber 21 formed by the housing body 201, the third and fourth cylinder heads 302, 402, and a bearing cover (not shown). The cam chamber 21 is filled with fuel. The cam ring 903 and the bush 91 are fitted into the cam 83 so as to be rotatable. The third and fourth plungers 352 and 452 are in contact with two opposing surfaces of the cam ring 903.

  The cam ring 903 revolves around the central axis of the drive shaft 80 according to the movement of the cam 83 caused by the rotation of the drive shaft 80. The cam ring 903 can rotate relative to the cam 83, but is always pressed against the third and fourth plungers 352 and 452, so the cam ring 903 itself does not rotate, and only the cam 83 is the cam ring 903. Rotate within.

  In the sixth embodiment, the cam ring 903 is formed with a through passage 941 as a fourth lubricating oil passage. The through passage 941 is a passage that connects the outer peripheral wall and the inner peripheral wall of the cam ring 901 and supplies the fuel accumulated in the cam chamber 21 to the surface of the cam 83. As shown in FIG. 10, the through passage 941 is formed in a circumferential range between the third plunger 352 and the fourth plunger 452.

  When the fuel supply pump 1e operates and the third and fourth plungers 352 and 452 reciprocate, the cam ring 903 receives a force in the direction indicated by the arrow in FIG. 10 from the third and fourth plungers 352 and 452. The surface pressure between the cam ring 903 and the cam 83 in the range between the third and fourth plungers 352 and 452 is the surface between the cam ring 903 and the cam 83 located immediately below the third and fourth plungers 352 and 452. Not as high as pressure.

  When the fuel supply pump 1e is operated, the surface pressure between the cam ring 903 and the cam 83 is changed between the third and fourth plungers 352 and 452 within the circumferential range between the third and fourth plungers 352 and 452. Since the portion located directly below does not rise, even if the area of the cam ring 903 that supports the cam 83 decreases within this range, there is little possibility of causing a problem of oil film breakage on the surface of the cam 83 due to increased surface pressure.

  In the sixth embodiment, the through passage 941 that penetrates the outer peripheral wall and the inner peripheral wall of the cam ring 903 is formed in a place where there is little possibility of causing the problem of oil film breakage, that is, in the range between the third and fourth plungers 352 and 452. Therefore, the opening area of the through-passage 941 can be increased while suppressing the occurrence of the problem of the oil film breakage that has been a problem in the prior art. As a result, the amount of fuel supplied to the surface of the cam 83 can be increased, and the seizure resistance of the cam 83 can be improved.

  In the present embodiment, since there are two places as described above, that is, the range between the third and fourth plungers 352 and 452, as shown in FIG. 10, a through-passage 941 is formed at each place. be able to. According to this, the amount of fuel supplied to the surface of the cam 83 can be further increased.

It is sectional drawing of the fuel supply pump by 1st Embodiment. It is sectional drawing of the II-II line | wire in FIG. It is sectional drawing of the III-III line | wire in FIG. It is principal part sectional drawing which shows the modification of the fuel supply pump by 1st Embodiment. It is sectional drawing of the fuel supply pump by 2nd Embodiment. It is sectional drawing of the fuel supply pump by 3rd Embodiment. It is sectional drawing of the fuel supply pump by 4th Embodiment. It is sectional drawing of the housing main body of the fuel supply pump by 4th Embodiment. It is sectional drawing of the housing main body of the fuel supply pump by 5th Embodiment. It is sectional drawing of the fuel supply pump by 6th Embodiment.

Explanation of symbols

1 Fuel supply pump 20 Housing body (housing)
21 Cam chamber 22 Feed pump 27 Connecting member 28 Connecting member 29 Metering valve 30 First cylinder head (housing)
31 1st cylinder (cylinder)
32 First pressurizing chamber (fuel pressurizing chamber)
33 First fuel inflow passage 35 First plunger (plunger)
36 First spring 37 Check valve 37a Valve member 40 Second cylinder head (housing)
41 Second cylinder (cylinder)
42 Second pressurizing chamber (fuel pressurizing chamber)
43 Second fuel inflow passage 45 Second plunger (plunger)
46 Second spring 47 Check valve 47a Valve member 50 Bearing cover (housing)
51 Large diameter bearing (shaft hole)
52 Small-diameter bearing (shaft hole)
60 Large-diameter side lubricating oil passage (first lubricating oil passage)
61 Exit opening (first opening)
62 Entrance opening (second opening)
70 Small-diameter side lubricating oil passage (first lubricating oil passage)
71 Exit opening (first opening)
72 Entrance opening (second opening)
80 Drive shaft 81 Large diameter portion 82 Small diameter portion 83 Cam 90 Cam ring (first cam ring)
91 Bush 94 Through-passage (second lubricating oil passage)

Claims (10)

A cam that rotates with the drive shaft;
Plurally arranged on the outer peripheral side of the cam, a plunger that pressurizes and pumps the fuel sucked into the fuel pressurizing chamber by reciprocating with the rotation of the cam;
A fuel supply pump comprising: a cam chamber that houses the cam; a shaft hole that rotatably supports the drive shaft; and a housing that has a cylinder that reciprocally supports the plunger;
The plunger has first and second plungers arranged circumferentially on the outer peripheral side of the cam at a predetermined sandwich angle;
The housing is formed with a first lubricating oil passage for supplying lubricating oil to the surface of the drive shaft,
The first lubricating oil passage has a first opening that opens in a side wall of the shaft hole within a circumferential range corresponding to a narrow angle side between the first plunger and the second plunger. And fuel supply pump. The cam chamber stores fuel that is not pumped from the fuel pressurizing chamber,
2. The fuel supply pump according to claim 1, wherein the first lubricant passage has a second opening that opens into the cam chamber. 3.   The first lubricating oil passage is a concave groove extending in a direction along the axial hole having the first opening at a position facing the bottom and the second opening at an axial end. The fuel supply pump according to claim 2, wherein The housing has a bearing in which the shaft hole is formed on an inner peripheral surface,
3. The fuel supply pump according to claim 1, wherein the first opening is formed only in an axially central portion of the bearing. A cam that rotates with the drive shaft;
Plurally arranged on the outer peripheral side of the cam, a plunger that pressurizes and pumps the fuel sucked into the fuel pressurizing chamber by reciprocating with the rotation of the cam;
A fuel supply pump comprising: a cam chamber that houses the cam; a shaft hole that rotatably supports the drive shaft; and a housing that has a cylinder that reciprocally supports the plunger;
The plunger has first and second plungers arranged circumferentially on the outer peripheral side of the cam at a predetermined sandwich angle;
A first cam ring that revolves around the rotation shaft of the drive shaft is provided between the cam and the plunger;
In the cam chamber, fuel that is not pumped from the fuel pressurizing chamber is accumulated,
The first cam ring is formed with a second lubricating oil passage that communicates the outer peripheral wall and the inner peripheral wall within a circumferential range corresponding to the wide angle side between the first plunger and the second plunger. A fuel supply pump. A cam that rotates with the drive shaft;
A plurality of plungers arranged on the outer peripheral side of the cam, pressurizing and pumping the fuel sucked into the fuel pressurizing chamber by reciprocating as the cam rotates;
A fuel supply pump comprising: a cam chamber that houses the cam; a shaft hole that rotatably supports the drive shaft; and a housing that has a cylinder that reciprocally supports the plunger.
The plunger has third and fourth plungers arranged circumferentially on the outer peripheral side of the cam so as to substantially face each other,
The housing is formed with a third lubricating oil passage for supplying lubricating oil to the surface of the drive shaft,
The third lubricating oil passage has a third opening that opens in a side wall of the shaft hole within a corresponding circumferential range between the third plunger and the fourth plunger. . The cam chamber stores fuel that is not pumped from the fuel pressurizing chamber,
The fuel supply pump according to claim 6, wherein the third lubricant passage has a fourth opening that opens into the cam chamber.   The third lubricating oil passage is a concave groove extending in the direction along the axial hole having the third opening at a position facing the bottom and the fourth opening at an axial end. 8. The fuel supply pump according to claim 7, wherein The housing has a bearing in which the shaft hole is formed on an inner peripheral surface,
The fuel supply pump according to claim 6 or 7, wherein the third opening is formed only in an axially central portion of the bearing. A cam that rotates with the drive shaft;
Plurally arranged on the outer peripheral side of the cam, a plunger that pressurizes and pumps the fuel sucked into the fuel pressurizing chamber by reciprocating with the rotation of the cam;
A fuel supply pump comprising: a cam chamber that houses the cam; a shaft hole that rotatably supports the drive shaft; and a housing that has a cylinder that reciprocally supports the plunger;
The plunger has third and fourth plungers arranged circumferentially on the outer peripheral side of the cam so as to substantially face each other,
A second cam ring that revolves around the rotation shaft of the drive shaft is provided between the cam and the plunger;
In the cam chamber, fuel that is not pumped from the fuel pressurizing chamber is accumulated,
The second cam ring is formed with a fourth lubricating oil passage that communicates the outer peripheral wall and the inner peripheral wall within a circumferential range between the third plunger and the fourth plunger. Supply pump.

Images