JP2010216262A - Fuel injection pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection pump which can suppress the deterioration of sliding surface in an axial direction even when the rotation speed of a cam is increased. <P>SOLUTION: The fuel injection pump 1 includes a camshaft 5, a cam 6 rotating eccentrically and integrally with respect to the camshaft 5, a housing 2 including a cam chamber 20 freely rotatably accommodating the cam 6 and a fuel pressurization chamber therein, a movable member driven by the cam 6 to pressurize and force-feed fuel sucked in the fuel pressurization chamber, and a bearing member 8 interposed between the wall surface 201 of the cam chamber 20 and an end surface 61 in an axial direction in the cam 6 and receiving an axial load F from the end surface 61 to produce a slide between the end surface 61 and wall surface 201. The bearing member 8 includes a first bearing member 81 mounted to the wall surface 201 so as to prevent co-rotate with the cam 6 and a second bearing member 82 freely rotatable with respect to both the first bearing member 81 and the end surface 61 and interposed therebetween. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel injection pump for an internal combustion engine.

  Conventionally, a camshaft, a cam provided eccentrically with respect to the camshaft, a housing in which a cam chamber and a fuel pressurizing chamber are rotatably accommodated, and a cam driven by the cam. 2. Description of the Related Art There is known a fuel injection pump that includes a plunger that pressurizes and pumps fuel sucked into a fuel pressurizing chamber by reciprocating (see Patent Document 1).

  In this fuel injection pump, a disc portion having a larger diameter than the cam is formed integrally with the cam shaft between the axial end surface of the cam and the wall surface of the cam chamber, and between the wall surface and the disc portion. A washer (bearing member) is attached to the wall surface. The cam, the disc part, and the bearing member are accommodated in the cam chamber and are immersed in fuel as lubricating oil filled in the cam chamber.

  Here, in a fuel injection pump that receives a driving force from an engine with a large driving force, the camshaft is generally received by a gear, but in order to reduce the backlash and flatten the driving force transmitted to the cam. It is desirable to receive a driving force with a helical gear. When receiving a driving force with a helical gear, an axial load acts on the camshaft.

  For this reason, the rotating disk part is pressed against the bearing member, and the sliding surface between the disk part and the bearing member, which is the sliding surface in the axial direction, has a problem of deterioration such as wear and seizure. Become. On the other hand, since the disk portion has a larger diameter than the cam, the surface pressure of the sliding surface between the disk portion and the bearing member can be reduced, and deterioration of the sliding surface can be suppressed. I can do it.

JP 2001-227426 A

  Since the disk portion and the bearing member are immersed in the lubricating oil, if the oil film on the sliding surface can be held, deterioration on the sliding surface between the disk portion and the bearing member can be suppressed. However, since the oil film on the sliding surface cannot be maintained when the cam rotation speed increases, it is difficult to suppress deterioration on the sliding surface even if the surface pressure of the sliding surface can be reduced by the above-described conventional technology. ing.

  The present invention has been made in view of such circumstances, and provides a fuel injection pump capable of suppressing deterioration of the sliding surface in the axial direction even when the rotational speed of the cam increases. Objective.

  In order to achieve the above object, the present invention employs the following technical means.

  According to the first aspect of the present invention, the camshaft, the cam provided eccentrically with respect to the central axis of the camshaft, rotating integrally with the camshaft, the cam chamber for rotatably accommodating the cam, and the fuel A housing in which a pressurizing chamber is formed; a movable member that is driven by a cam and reciprocates to pressurize and pump fuel sucked into the fuel pressurizing chamber; and an axial end surface of the cam and the cam chamber A bearing member that receives an axial load from the end surface and generates a slip between the end surface and the wall surface, and the bearing member is attached to the wall surface so that it does not rotate with the cam. And a second bearing member that is rotatable with respect to both the first bearing member and the end face and interposed between the first bearing member and the end face. .

  According to this configuration, the bearing member interposed between the axial end surface of the cam and the wall surface of the cam chamber is provided with the first bearing member attached to the wall surface of the cam chamber so as not to rotate with the cam. And a second bearing member that is rotatable with respect to both the first bearing member and the end face and is interposed between the first bearing member and the end face. For this reason, the second bearing member that is rotatable with respect to both the first bearing member and the end surface forms an axial first sliding surface with the first bearing member, and the axial end surface of the cam A second sliding surface in the axial direction is formed between the two.

  Here, the total value of the first rotational speed difference of the second bearing member relative to the first bearing member on the first sliding surface and the second rotational speed difference of the cam relative to the second bearing member on the second sliding surface is: The cam rotation speed. For this reason, the first rotational speed difference on the first sliding surface and the second rotational speed difference on the second sliding surface are both kept lower than the rotational speed of the cam. Deterioration can be suppressed. Therefore, deterioration of the sliding surface in the axial direction can be suppressed even if the rotational speed of the cam increases.

  According to the second aspect of the present invention, the through hole for inserting the camshaft, and the limiting portion for limiting the rotation region of the second bearing member to the outer peripheral side from the camshaft inserted through the through hole, It forms in the 1st bearing member, It is characterized by the above-mentioned.

  According to this configuration, the rotation region of the second bearing member is limited to the outer peripheral side with respect to the camshaft inserted through the through hole by the limiting portion. For this reason, it can prevent that the 2nd bearing member rotatable with respect to both the 1st bearing member and the end surface of a cam interferes with a cam shaft. Therefore, even if the rotational speed of the cam increases, it is possible to suppress the deterioration of the sliding surface in the axial direction while preventing the interference between the second bearing member and the camshaft.

  According to the third aspect of the present invention, the limiting portion is a ring-shaped recess formed concentrically with the through hole on the outer peripheral side of the through hole, and the second bearing member is fitted into the recess. It is formed in the ring shape which can contact with both a 1st bearing member and the end surface of a cam, It is characterized by the above-mentioned.

  According to this configuration, the second bearing member can contact both the first bearing member and the end face of the cam while being fitted in the recess. For this reason, a 1st sliding surface can be formed between a 2nd bearing member and a 1st bearing member in the state which the 2nd bearing member fitted in the recessed part, and the end surface of the axial direction of a 2nd bearing member and a cam Since the second sliding surface can be formed between the two, the deterioration of the sliding surface in the axial direction can be suppressed.

  Furthermore, according to this configuration, since the ring-shaped second bearing member is fitted in the ring-shaped recess, the second bearing member is guided by the recess on both the outer peripheral side and the inner peripheral side. For this reason, the rotation area | region of a 2nd bearing member can be more reliably restrict | limited to the outer peripheral side rather than a cam shaft.

  Therefore, even if the rotational speed of the cam is increased, it is possible to suppress the deterioration of the sliding surface in the axial direction while more reliably preventing the interference between the second bearing member and the camshaft.

  According to a fourth aspect of the present invention, the second bearing member is composed of a plurality of plates arranged in a stacked manner and rotatable relative to each other.

  According to this configuration, the sliding surface in the axial direction is also formed between the plurality of plates. For this reason, the total value of the first and second rotational speed differences on the first and second sliding surfaces and the rotational speed differences on the sliding surfaces formed between the plurality of plates is the rotational speed of the cam. It has become. For this reason, the first and second rotational speed differences on the first and second sliding surfaces and the rotational speed differences on the sliding surfaces are suppressed to be lower than the rotational speed of the cam. Deterioration of the sliding surface can be further suppressed.

  Therefore, even if the rotational speed of the cam increases, the deterioration of the sliding surface in the axial direction can be further suppressed.

  According to the fifth aspect of the present invention, the sliding surface that rotates while being in contact with each other in each plate is coated with a solid lubricant for reducing wear of the sliding surface.

  According to this configuration, since the wear of each sliding surface of the plurality of plates can be reduced, it is possible to further suppress deterioration of the sliding surface in the axial direction formed by the sliding surfaces contacting each other. For this reason, even if the rotational speed of the cam increases, the deterioration of the sliding surface in the axial direction can be further suppressed.

  According to the sixth aspect of the present invention, the first and second sliding surfaces of the second bearing member that rotate while being in contact with the first bearing member and the second sliding surface that is rotated while being in contact with the end surface are first and second. It is characterized by being coated with a solid lubricant for reducing sliding surface wear.

  According to this configuration, since the wear of the first and second sliding surfaces can be reduced, the deterioration of the first sliding surface formed by contacting the first sliding surface and the first bearing member, and the second sliding surface And the deterioration of the second sliding surface formed by contact between the cam and the axial end surface of the cam can be further suppressed. For this reason, even if the rotational speed of the cam increases, the deterioration of the sliding surface in the axial direction can be further suppressed.

It is a longitudinal section showing a fuel injection pump by one embodiment of the present invention. 1 is a cross-sectional view showing a fuel injection pump according to an embodiment of the present invention. It is a schematic diagram of the camshaft periphery shown in FIG. FIG. 4 is a schematic enlarged view around a cam and a thrust bearing shown in FIG. 3. FIG. 5 is an enlarged plan view of the thrust bearing shown in FIG. 4. It is a plane enlarged view which shows the modification of FIG. It is sectional drawing of the VII-VII line in FIG. It is a plane enlarged view which shows the modification of FIG.

  Embodiments of the present invention will be described below with reference to the drawings, taking as an example a fuel injection pump used in a vehicle common rail fuel injection system. In addition, the same code | symbol is attached | subjected to the mutually same or equivalent part in a figure.

(Constitution)
A fuel injection pump 1 shown in FIG. 1 is a single cylinder fuel injection pump including a housing 2 in which one cylinder 221 and one fuel pressurizing chamber 222 are formed, and one plunger 3. The fuel injection pump 1 further includes a cam 6 that rotates together with the camshaft 5 and a cam ring 7 provided on the outer peripheral side of the cam 6, and a cam that rotatably houses the cam 6 inside the housing 2. A chamber 20 is formed.

  The housing 2 formed of an aluminum-based material includes a housing main body 21, a cylinder head 22 in which a cylinder 221 is formed, and a bearing cover 23, and the fuel pressurizing chamber 222 has a check and an inner surface of the cylinder 221. The end face of the check valve member of the valve 41 and the end face of the plunger 3 are formed. The bearing cover 23 is fixed to the housing main body 21 with bolts, and the bearing cover 23 and the camshaft 5 are sealed with an oil seal. The camshaft 5 is attached to the housing main body 21 and the bearing cover 23 via a metal bush. It is supported rotatably.

  The camshaft 5 together with the cam 6 is made of an iron-based material, and a helical gear 51 is attached to the right end of the camshaft 5 in the figure. The helical gear 51 receives driving force from the crankshaft of the engine and rotates with the camshaft 5 in the direction of arrow R. As the helical gear 51 rotates in the direction of the arrow R, an axial load F acts on the camshaft 5.

  In the cam 6, a thrust bearing 8 is interposed between the axial end surface 61 and the wall surface 201 of the cam chamber 20 to ensure sliding between them, and the shaft 6 extends from the end surface 61 of the rotating cam 6. The load F in the direction is received and the slip is generated between the end surface 61 and the wall surface 201. Note that the thrust bearing 8 on the left side in the drawing receives an axial load opposite to the load F from the end surface 61 and causes slippage between the end surface 61 and the wall surface 201.

  As shown in FIG. 2, the thrust bearing 8 has a circular shape, and the cross section of the cam 6 has a circular shape. As shown in FIG. 1, the cam 6 is integrally formed eccentrically with respect to the central axis of the camshaft 5, and is slidable between the cam ring 7 and the cam 6 between the cam ring 7 and the cam 6 having a rectangular outer shape. A metal bush 9 is interposed. The plunger 3 is slidably in contact with the upper surface of the cam ring 7.

  In FIG. 2, according to the movement of the cam 6 due to the rotation of the camshaft 5, the cam ring 7 orbits, that is, revolves around the shaft central axis of the camshaft 5. The plunger 3 is biased toward the cam ring 7 by a spring 31. For this reason, the cam ring 7 can rotate relative to the cam 6, but the cam ring 7 does not rotate when pressed against the plunger 3, and the cam 6 rotates in the cam ring 7.

  The plunger 3 follows the revolution of the cam ring 7 by sliding on the upper surface of the cam ring 7 and converts the revolution of the cam ring 7 into a reciprocating movement (a movement in the vertical direction in the figure). As a result, the plunger 3 reciprocates vertically in the cylinder 221 and pressurizes and pumps the fuel sucked into the fuel pressurizing chamber 222 from a fuel tank (not shown) via the check valve 41. The check valve 41 prevents the fuel from flowing backward from the fuel pressurizing chamber 222 to the fuel tank side.

  The fuel pressurized in the fuel pressurizing chamber 222 is supplied from a fuel discharge passage 223 to a common rail (not shown) via a fuel pipe. A check valve 42 is provided in the fuel discharge passage 223, and the check valve 42 prevents fuel from flowing back from the fuel discharge passage 223 to the fuel pressurizing chamber 222.

  In FIGS. 1 and 2, the cam 6, the cam ring 7, the thrust bearing 8, and the like are housed in a cam chamber 20 in the housing 2 and are immersed in fuel as lubricating oil filled in the cam chamber 20.

  The basic configuration of the fuel injection pump 1 has been described above. Hereinafter, the thrust bearing 8 that is a characteristic configuration of the fuel injection pump 1 will be described with reference to FIGS.

(Characteristic configuration)
The thrust bearing 8 is formed of an iron-based material, and as shown in FIG. 3, the fixed plate 81 attached to the wall surface 201 so as not to rotate together with the cam 6, and the end surface 61 of the fixed plate 81 and the cam 6. And a rotating plate 82 interposed between the fixed plate 81 and the end surface 61.

  As described above, when the helical gear 51 rotates in the direction of the arrow R, an axial load F acts on the camshaft 5, and the right thrust bearing 8 shown in FIG. The axial load F is received from the end surface 61 of the inner surface, and slippage is generated between the end surface 61 and the wall surface 201. This slip is generated by rotating the rotary plate 82 with respect to the fixed plate 81. When an axial load opposite to the load F is generated on the camshaft 5, this load is received by the thrust bearing 8 on the left side from the end surface 61 of the cam 6 between the end surface 61 and the wall surface 201. A slip is generated.

  The fixing plate 81 is attached to the wall surface 201 by a fixing pin 202 that is driven and fixed to the housing 2 by the wall surface 201. As shown in FIGS. 4 and 5, the fixing plate 81 is formed with a shaft hole 811 through which the camshaft 5 is inserted, a ring step 812, and two fixing holes 813. The fixing plate 81 is attached to the wall surface 201 by inserting the fixing pins 202 into the two fixing holes 813.

  As shown in FIG. 5, the ring step 812 is a ring-shaped step, guides the outer periphery of the rotating plate 82, and rotates the rotating plate 82 on the outer peripheral side of the camshaft 5 inserted through the shaft hole 811. Is limiting. This limited rotation region is a region between the outer periphery of the camshaft 5 and the ring step 812.

  The rotating plate 82 is formed in a ring shape that fits into the concave portion of the ring step 812 and can contact both the fixed plate 81 and the end surface 61 of the cam 6. Specifically, in FIG. 4, the second sliding surface 823 of the rotating plate 82 is in contact with the sliding surface 814 of the fixed plate 81 while the first sliding surface 822 of the rotating plate 82 is in contact with the sliding surface 814 of the fixed plate 81. The fixed plate 81 and the rotating plate 82 are formed so that the height of the second sliding surface 823 protrudes from the upper surface 816 to the left in the drawing. Further, the rotary plate 82 is also formed with a shaft hole 821 through which the camshaft 5 is inserted.

  The first sliding surface 822 of the rotating plate 82 is a sliding surface that rotates while being in contact with the sliding surface 814 of the fixed plate 81, and the first sliding surface 822 and the sliding surface 814 are in contact with each other to contact the first sliding surface in the axial direction. 824 is formed. The second sliding surface 823 of the rotating plate 82 is a sliding surface that rotates while being in contact with the end surface 61 of the cam 6, and the second sliding surface 823 and the end surface 61 are in contact with each other to contact the second sliding surface 825 in the axial direction. Is formed.

  The plunger 3 corresponds to the movable member recited in the claims, the thrust bearing 8 corresponds to the bearing member recited in the claims, and the fixed plate 81 corresponds to the first bearing member recited in the claims. The shaft hole 811 corresponds to the through hole recited in the claims, the ring step 812 corresponds to the restricting portion recited in the claims, and the rotating plate 82 corresponds to the second bearing member recited in the claims.

(Function and effect)
Next, the operation of the fuel injection pump 1 of this embodiment will be described with reference to FIGS.

  In the fuel injection pump 1 according to this embodiment, as a characteristic configuration, the thrust bearing 8 interposed between the axial end surface 61 of the cam 6 and the wall surface 201 of the cam chamber 20 does not rotate with the cam 6. As described above, the fixed plate 81 attached to the wall surface 201 of the cam chamber 20 and the rotation interposed between the fixed plate 81 and the end surface 61 are rotatable with respect to both the fixed plate 81 and the end surface 61 of the cam 6. A plate 82. For this reason, the rotary plate 82 that is rotatable with respect to both the fixed plate 81 and the end surface 61 forms a first sliding surface 824 in the axial direction between the fixed plate 81 and the end surface 61 of the cam 6. Thus, a second sliding surface 825 in the axial direction is formed.

  Here, the total value of the first rotational speed difference of the rotating plate 82 relative to the fixed plate 81 on the first sliding surface 824 and the second rotational speed difference of the cam 6 relative to the rotating plate 82 on the second sliding surface 825 is: The rotational speed of the cam 6 is obtained. For this reason, the first rotational speed difference on the first sliding surface 824 and the second rotational speed difference on the second sliding surface 825 are both suppressed to be lower than the rotational speed of the cam 6, and as a result, the first And deterioration of the 2nd sliding face 824,825 can be suppressed.

  Therefore, even if the rotational speed of the cam 6 is increased, deterioration of the sliding surfaces 824 and 825 in the axial direction can be suppressed.

  Further, the rotation region of the rotation plate 82 is limited to the outer peripheral side with respect to the camshaft 5 inserted through the shaft hole 811 by the ring step 812. For this reason, it is possible to prevent the rotating plate 82 that is rotatable with respect to both the fixed plate 81 and the end surface 61 of the cam 6 from interfering with the camshaft 5.

  Further, the rotating plate 82 is formed in a ring shape that can come into contact with both the fixed plate 81 and the end surface 61 of the cam 6 while being fitted in the concave portion of the ring step 812. Therefore, the first sliding surface 824 can be formed between the rotating plate 82 and the fixed plate 81 in a state where the rotating plate 82 is fitted in the concave portion of the ring step 812, and the end surface 61 of the rotating plate 82 and the cam 6 is formed. The second sliding surface 825 can be formed between the two.

  Therefore, even if the rotational speed of the cam 6 is increased, it is possible to suppress the deterioration of the sliding surfaces 824 and 825 in the axial direction while preventing interference between the rotating plate 82 and the camshaft 5.

(Modification)
In the above-described example, the rotation region of the rotation plate 82 is limited to the outer peripheral side with respect to the camshaft 5 inserted through the shaft hole 811 by the ring step 812. On the other hand, in the thrust bearing 80 according to the modified example shown in FIGS. 6 and 7, the camshaft 5 inserted through the shaft hole 811 in the rotation region of the rotary plate 820 is formed by the ring groove 815 formed in the fixed plate 810. It is limited to the outer peripheral side.

  As shown in FIGS. 6 and 7, the ring groove 815 is a ring-shaped recess and is formed concentrically with the shaft hole 821 on the outer peripheral side of the shaft hole 821. The ring groove 815 guides both the outer periphery and the inner periphery of the rotating plate 820 and restricts the rotation region of the rotating plate 82 to the outer peripheral side of the camshaft 5 inserted through the shaft hole 811. This limited rotation region is the region of the ring groove 815 itself.

  The rotating plate 820 is formed in a ring shape that can contact both the fixed plate 810 and the end surface 61 of the cam 6 while being fitted in the ring groove 815. Specifically, in FIG. 7, the second sliding surface 823 of the rotating plate 820 is the upper surface 816 of the fixed plate 810 while the first sliding surface 822 of the rotating plate 820 is in contact with the sliding surface 814 of the fixed plate 810. The fixed plate 810 and the rotating plate 820 are formed such that the height of the second sliding surface 823 protrudes from the upper surface 816 to the left in the drawing.

  The thrust bearing 80 corresponds to the bearing member described in the claims, the fixing plate 810 corresponds to the first bearing member described in the claims, and the ring groove 815 corresponds to the limiting portion and the recess described in the claims. The rotating plate 820 corresponds to the second bearing member described in the claims.

  According to this modification, the rotating plate 820 can contact both the fixed plate 810 and the end surface 61 of the cam 6 while being fitted in the ring groove 815. Therefore, the first sliding surface 824 can be formed between the rotating plate 820 and the fixed plate 810 in a state where the rotating plate 820 is fitted in the ring groove 815, and the rotation plate 820 and the end surface 61 of the cam 6 Since the second sliding surface 825 can be formed in between, the deterioration of the sliding surfaces 824 and 825 in the axial direction can be suppressed.

  Further, since the ring-shaped rotating plate 820 is fitted in the ring-shaped ring groove 815, the rotating plate 820 is guided by the ring groove 815 on both the outer peripheral side and the inner peripheral side. For this reason, the rotation area | region of the rotating plate 820 can be restrict | limited more reliably to the outer peripheral side rather than the cam shaft 5.

  Therefore, even if the rotational speed of the cam 6 is increased, the deterioration of the axial sliding surfaces 824 and 825 can be suppressed while more reliably preventing the rotation plate 820 and the camshaft 5 from interfering with each other.

  In the above-described example, the rotation bearings 82 and 820 are provided in the thrust bearings 8 and 80. On the other hand, the thrust bearing 800 according to the modification shown in FIG. 8 includes two plates 831 and 832. A rotating plate 83 is provided.

  The rotating plate 83 includes two plates 831 and 832 that are arranged in a stacked manner and are rotatable with respect to each other. The rotating plate 83 can contact both the fixed plate 810 and the end surface 61 of the cam 6 while being fitted in the ring groove 815. It is formed in a simple ring shape. Specifically, in FIG. 8, the second sliding surface 823 of the rotating plate 83 is the upper surface 816 of the fixed plate 810 in a state where the first sliding surface 822 of the rotating plate 83 is in contact with the sliding surface 814 of the fixed plate 810. The fixed plate 810 and the rotating plate 83 are formed so that the height of the second sliding surface 823 protrudes from the upper surface 816 to the left in the drawing.

  Between the two plates 831 and 832, an axial sliding surface 835 is formed by contacting the sliding surface 833 of the plate 831 and the sliding surface 834 of the plate 832.

  According to this modification, since the axial sliding surface 835 is also formed between the two plates 831 and 832, the first and second rotational speeds of the first and second sliding surfaces 824 and 825 are provided. The total value of the difference and the rotational speed difference on the sliding surface 835 formed between the two plates 831 and 832 is the rotational speed of the cam 6. For this reason, the first and second rotational speed differences between the first and second sliding surfaces 824 and 825 and the rotational speed difference between the sliding surfaces 835 are suppressed to be lower than the rotational speed of the cam. The deterioration of the sliding surfaces 824, 825, and 835 can be further suppressed.

  Therefore, even if the rotational speed of the cam 6 increases, the deterioration of the sliding surfaces 824, 825, and 835 in the axial direction can be further suppressed.

  Further, the first sliding surface 822 and the second sliding surface 823 of the rotary plates 82, 820, 83 are coated with a solid lubricant such as molybdenum disulfide (MoS2) for reducing wear of the sliding surfaces 822, 823. Is possible. Thereby, since wear of the first and second sliding surfaces 822 and 823 can be reduced, the first sliding surface 824 formed by contact between the first sliding surface 822 and the sliding surfaces 814 of the fixed plates 81 and 810 can be reduced. Deterioration and deterioration of the second sliding surface 825 formed by the contact between the second sliding surface 823 and the end surface 61 of the cam 6 can be further suppressed. For this reason, even if the rotational speed of the cam 6 increases, the deterioration of the sliding surfaces 824 and 825 in the axial direction can be further suppressed.

  Further, the sliding surfaces 833 and 834 of the plates 831 and 832 can be coated with a solid lubricant such as molybdenum disulfide for reducing wear of the sliding surfaces 833 and 834. Thereby, since wear of the sliding surfaces 833 and 834 can be reduced, deterioration of the sliding surface 835 in the axial direction formed by the sliding surfaces 833 and 834 in contact with each other can be further suppressed. For this reason, even if the rotational speed of the cam 6 increases, the deterioration of the sliding surface 835 in the axial direction can be further suppressed.

  If the rotating plate is composed of three or more plates that are arranged in layers and are rotatable with respect to each other, the rotational speed difference on the sliding surface can be further reduced, and the sliding surface in the axial direction can be reduced. Can be further suppressed.

  In the above-described example, the fuel injection pump 1 is a single cylinder type fuel injection pump including one cylinder 221, one fuel pressurizing chamber 222, and one plunger 3. However, the present invention is not limited to this. Even a two-cylinder fuel injection pump with two cylinders, two fuel pressurization chambers, and two plungers, or with three cylinders, three fuel pressurization chambers, and three plungers The present invention can be applied even to a three-cylinder fuel injection pump.

DESCRIPTION OF SYMBOLS 1 Fuel injection pump, 2 Housing, 20 Cam chamber, 201 Wall surface 202 Fixing pin, 21 Housing main body, 22 Cylinder head, 221 Cylinder 222 Fuel pressurization chamber, 223 Fuel discharge passage, 23 Bearing cover 3 Plunger (movable member), 31 Spring, 41, 42 Check valve 5 Cam shaft, 51 Helical gear, 6 Cam, 61 End face, 7 Cam ring 8, 80, 800 Thrust bearing (bearing member)
81,810 Fixed plate (first bearing member)
811 Shaft hole (through hole), 812 Ring step (restricted portion), 813 Fixing hole 814 Sliding surface, 815 Ring groove (restricted portion, recessed portion), 816 Top surface 82,820 Rotating plate (second bearing member), 821 Shaft hole 822 first sliding surface, 823 second sliding surface, 824 first sliding surface, 825 second sliding surface 83 rotating plate (second bearing member), 831, 832 plate 833, 834 sliding surface, 835 sliding surface, 9 Metal bush

Claims (6)

A camshaft,
A cam that is eccentrically provided with respect to the central axis of the camshaft and rotates integrally with the camshaft;
A housing in which a cam chamber for rotatably accommodating the cam and a fuel pressurizing chamber are formed;
A movable member that is driven by the cam and pressurizes and pumps the fuel sucked into the fuel pressurizing chamber by reciprocating;
A bearing member interposed between the end surface in the axial direction and the wall surface of the cam chamber in the cam, and receiving a load in the axial direction from the end surface to generate a slip between the end surface and the wall surface,
The bearing member is rotatable with respect to both the first bearing member and the end surface, the first bearing member being attached to the wall surface so as not to be rotated together with the cam, and the first bearing member. And a second bearing member interposed between the end faces.   A through hole for inserting the cam shaft and a restricting portion for limiting a rotation region of the second bearing member on the outer peripheral side of the cam shaft inserted through the through hole are formed in the first bearing member. The fuel injection pump according to claim 1, wherein the fuel injection pump is provided. The restricting portion is a ring-shaped recess formed concentrically with the through hole on the outer peripheral side than the through hole.
3. The fuel injection pump according to claim 2, wherein the second bearing member is formed in a ring shape that fits into the recess and is capable of contacting both.   4. The fuel injection pump according to claim 1, wherein the second bearing member includes a plurality of plates arranged in a stacked manner and rotatable with respect to each other. 5.   5. The fuel injection pump according to claim 4, wherein in each of the plates, a sliding surface that rotates while being in contact with each other is coated with a solid lubricant for reducing wear of the sliding surface.   Wear of the first and second sliding surfaces is reduced on the first sliding surface that rotates while contacting the first bearing member and the second sliding surface that rotates while contacting the end surface of the second bearing member. A fuel injection pump according to any one of claims 1 to 5, wherein a solid lubricant for coating is coated.

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