JP2013064354A - Fuel injection pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection pump which can reduce lubricating oil mixed into fuel oil by reducing the lubricating oil reaching a tappet.SOLUTION: In a fuel injection pump 1A which reciprocates a plunger 5 by the rotation of a cam 15 accommodated in a cam chamber 16 via a tappet 30 and pressure-sends fuel, there is arranged a fold 40A for damming the lubricating oil Lo which is pumped up by the rotation of the cam 15 at the wall face 16a of the cam chamber 16. The fold 40A is formed at a face at the upstream side of a cam shaft 19 in the rotation direction at a folding member 41 which is protruded from the wall face 16a of the cam chamber 16 toward the radial inside of the cam shaft 19.

Description

  The present invention relates to a fuel injection pump, and more particularly to a technique for reducing lubricating oil mixed in fuel oil.

  Conventionally, a fuel injection pump that pumps fuel by reciprocating a plunger via a tappet by rotation of a cam housed in a cam chamber is known (for example, see Patent Document 1).

  In such a fuel injection pump, a part of the lubricating oil stored in the cam chamber is rolled up toward the tappet when the cam rotates. A part of the rolled up lubricating oil reaches the tappet, enters the inside of the tappet, adheres to the lower part of the plunger, and may be mixed into the fuel oil along the sliding surface of the plunger. In this case, the blackening of the fuel oil and the deterioration of the engine performance will be caused.

JP 2004-143958 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel injection pump that can reduce the lubricating oil mixed in the fuel oil.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  According to a first aspect of the present invention, in a fuel injection pump that pumps fuel by reciprocating a plunger through a tappet by rotation of a cam housed in a cam chamber, the cam chamber is wound up by rotation of the cam. A return for blocking the lubricating oil is provided.

  According to a second aspect of the present invention, the barb is formed so as to protrude from the wall surface of the cam chamber toward the radially inner side of the cam shaft.

  According to a third aspect of the present invention, the return is formed such that the distance between the wall surface of the cam chamber and the tip of the cam becomes wider toward the upstream side in the rotation direction of the cam.

  According to a fourth aspect of the present invention, a lubricating oil discharge opening is formed in the return, and a discharge pipe communicates with the opening.

  According to a fifth aspect of the present invention, the return is formed to be inclined with respect to the cam shaft.

  According to a sixth aspect of the present invention, in the fuel injection pump that feeds fuel by reciprocating the plunger through the tappet by the rotation of the cam housed in the cam chamber, the wall surface of the cam chamber is in contact with the outer periphery of the cam. A scraping body for scraping off the adhering lubricating oil is provided.

  8. A fuel injection pump that pumps fuel by reciprocating a plunger through a tappet by rotation of a cam housed in a cam chamber, wherein the tappet includes a tappet roller that contacts the cam and the tappet roller. The storage body is provided with a scraping body that scrapes off the lubricating oil adhering to the outer periphery of the tappet roller.

  According to a eighth aspect of the present invention, in the fuel injection pump that pumps the fuel by reciprocating the plunger through the tappet by the rotation of the cam housed in the cam chamber, the fuel injection pump is provided below the urging member that urges the plunger. A lower spring receiver that is inserted into the tappet is provided. The lower spring receiver is substantially disk-shaped, is not provided with a communication hole, and is provided with a seal member on the outer periphery.

  According to a ninth aspect of the present invention, in the fuel injection pump that pumps the fuel by reciprocating the plunger through the tappet by the rotation of the cam housed in the cam chamber, the fuel injection pump is provided below the urging member that urges the plunger. A lower spring receiver inserted into the tappet is provided, and the tappet is configured to be shallow enough to prevent the lower spring receiver from being removed.

  According to a tenth aspect of the present invention, in the fuel injection pump that pumps the fuel by reciprocating the plunger through the tappet by the rotation of the cam housed in the cam chamber, the fuel injection pump is provided below the urging member that urges the plunger. A lower spring support that is inserted into the tappet is provided, and the tappet is not provided with a communication hole in a mounting table on which the lower spring support is mounted.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect, the lubricating oil reaching the tappet can be reduced, and the lubricating oil mixed in the fuel oil can be reduced.

  According to the second aspect of the present invention, the lubricating oil reaching the tappet can be reduced, and the lubricating oil mixed in the fuel oil can be reduced.

  According to the third aspect of the present invention, the lubricating oil reaching the tappet can be reduced, and the lubricating oil mixed in the fuel oil can be reduced.

  According to the fourth aspect of the present invention, the lubricating oil wound up by the cam can be fed from the return to an arbitrary position.

  According to the fifth aspect of the present invention, the lubricating oil that has been dammed by the return flows down along the inclination of the return, so that the lubricating oil can be efficiently removed.

  According to the sixth aspect of the present invention, the lubricating oil that reaches the tappet can be reduced by scraping off the excessive lubricating oil adhering to the cam, so that the lubricating oil mixed in the fuel oil can be reduced.

  According to the seventh aspect of the present invention, the lubricating oil that reaches the tappet can be reduced by scraping off the excessive lubricating oil adhering to the tappet roller, so that the lubricating oil mixed in the fuel oil can be reduced.

  According to the eighth aspect of the present invention, since the communication hole is not provided, the lubricating oil does not enter from the communication hole, and the sealing member prevents the lubricating oil from entering from the gap between the tappet and the lower spring receiver. The lubricating oil mixed in the fuel oil can be reduced.

  According to the ninth aspect of the present invention, since the volume of the storage portion is reduced, the lubricating oil accumulated in the storage portion can be reduced, and the lubricating oil mixed in the fuel oil can be reduced.

  According to the tenth aspect, it is possible to prevent the lubricating oil from entering from the communication hole of the mounting table, and it is possible to reduce the lubricating oil mixed in the fuel oil.

1 is a right side cross-sectional view showing an overall configuration of a fuel injection pump 1A according to a first embodiment. 1 is a front cross-sectional view showing a configuration of a cam chamber 16 of a fuel injection pump 1A according to a first embodiment. Front sectional drawing which shows the structure of the cam chamber 16 of the fuel injection pump 1B which concerns on 2nd embodiment. The right sectional view showing the configuration of the cam chamber 16 of the fuel injection pump 1C according to the third embodiment. Front sectional drawing which shows the structure of the cam chamber 16 of fuel injection pump 1D which concerns on 4th embodiment. Front sectional drawing which shows the structure of the cam chamber 16 of the fuel injection pump 1E which concerns on 5th embodiment. Front sectional drawing which shows the structure of the tappet 30 of the fuel injection pump 1F which concerns on 6th embodiment. Front sectional drawing which shows the structure of the tappet 30 of the fuel injection pump 1G which concerns on 7th embodiment. Front sectional drawing which shows the structure of the tappet 30 of the fuel injection pump 1H which concerns on 8th embodiment. Front sectional drawing which shows the structure of the tappet 30 of the fuel injection pump 1I which concerns on 9th embodiment. Front sectional drawing which shows the structure of the tappet 30 of the fuel injection pump 1J which concerns on 10th embodiment.

  Below, the whole structure of 1 A of fuel-injection pumps which concern on 1st embodiment of this invention is demonstrated using FIG.1 and FIG.2. In the following description, the front-rear direction is defined with the right-hand direction in FIG. 1 as the front direction, the left-right direction is defined with the front direction on the paper as the left direction, and the up-down direction is defined with the upper direction on the page as the upward direction.

  The fuel injection pump 1A is a part of a fuel injection device mounted on the engine, and is for pumping a predetermined amount of fuel at a predetermined timing to a fuel injection valve disposed in a cylinder head of the engine. . The fuel injection pump 1A in the present embodiment is a distribution type fuel injection pump that distributes and pumps fuel to a fuel injection valve. 1 A of fuel-injection pumps are comprised by joining the hydraulic head 2 and the pump housing 3 up and down. In addition, the fuel injection pump may be a line type or an independent type, and does not limit the type of the fuel injection pump.

  A plunger barrel 4 is inserted into the hydraulic head 2, and a plunger 5 is housed in the plunger barrel 4 so as to be slidable up and down. A pressure chamber 6 is formed between the plunger barrel 4 and the upper end of the plunger 5. The plunger 5 projects downward from the lower end of the plunger barrel 4. A cold start timer mechanism 7 is provided in front of the plunger barrel 4.

  An upper spring receiver 8 is fixed to the outer periphery of the lower end of the plunger barrel 4, and a lower spring receiver 9 is fixed to the lower end of the plunger 5, and a biasing member that biases the plunger 5 downward therebetween. A spring 10 is interposed. The lower spring receiver 9 is formed with a communication hole 9a serving as a vent hole. A cylindrical control sleeve 11 is provided between the plunger barrel 4 and the upper spring receiver 8, and the control sleeve 11 engages with the plunger 5 and can rotate integrally.

  A rack chamber 12 for accommodating a control rack (not shown) is formed in the upper part of the pump housing 3. The control rack is connected to the control sleeve 11, and by sliding the control rack, the plunger 5 is rotated in the axial direction together with the control sleeve 11, and the fuel injection amount in the fuel injection valve can be adjusted. The

  A tappet chamber 13 that houses the tappet 30 is formed in the front upper portion of the pump housing 3. The tappet chamber 13 communicates with the rack chamber 12. A tappet 30 is provided in the tappet chamber 13 so as to be reciprocally slidable in the vertical direction. The tappet 30 is fitted with a lower end portion of the plunger 5, a lower spring receiver 9, and a lower portion of the spring 10.

  Specifically, as shown in FIG. 2, the tappet 30 mainly includes a tappet main body 31, a tappet roller 32, and a tappet pin 33. The tappet body 31 is a substantially cylindrical member whose axial direction is the vertical direction, and is in sliding contact with the wall surface of the tappet chamber 13. A mounting table 31 a is provided inside the tappet body 31, and the lower spring receiver 9 is mounted on the upper surface of the mounting table 31 a via the adjustment shim 14. In other words, the upper side from the mounting table 31 a is a storage portion 31 b that stores the lower spring receiver 9.

  The tappet body 31 is a storage body that stores the tappet roller 32. The tappet roller 32 is stored below the mounting table 31 a in the tappet body 31 and is rotatably supported by the tappet pins 33. A keyway 31 c is provided in the lower left part of the tappet body 31. A communication hole 31d is formed on the center side of the mounting table 31a.

  As shown in FIG. 1, a cam chamber 16 that houses a cam 15 is formed in the lower portion of the pump housing 3. The cam chamber 16 is formed in a substantially cylindrical shape whose longitudinal direction is the front-rear direction. A cam shaft 19 is installed in the cam chamber 16 via bearings 17 and 18 in the front-rear direction and is rotatably supported. The front end portion of the cam shaft 19 is connected to power transmission means in a gear case (not shown) connected to the flange 3 a of the pump housing 3.

  As shown in FIG. 2, the cam shaft 19 is configured to rotate counterclockwise when viewed from the front. A substantially rectangular cam 15 is disposed on the cam shaft 19. Lubricating oil Lo is stored in the cam chamber 16, and the cam 15 and gears are lubricated by the lubricating oil Lo. Further, as shown in FIG. 1, the cam 15 is disposed so as to contact the tappet roller 32 in the longitudinal direction of the cam shaft 19.

  The hydraulic head 2 is provided with a delivery valve 20 and a distribution shaft 21, and a transmission shaft 22 on the same axis as the distribution shaft 21 is connected to a lower end portion of the distribution shaft 21. A bevel gear 24 that meshes with the bevel gear 23 is fixed to the lower end portion of the transmission shaft 22. A governor weight 25 and a governor sleeve 26 are attached to the rear end portion of the cam shaft 19.

  In such a fuel injection pump 1A, when power from the crankshaft of the engine is transmitted to the camshaft 19 via power transmission means or the like in the gear case, the cam 15 is rotated together with the camshaft 19, and the tappet. The plunger 5 is reciprocated up and down via 30. Then, by the reciprocating motion of the plunger 5, the fuel suction stroke into the pressurizing chamber 6 and the fuel discharge stroke from the pressurizing chamber 6 are alternately performed.

  That is, in the intake stroke, when the plunger 5 is pushed down by the urging force of the spring 10 and descends, the fuel from the fuel tank (feed pump) is drawn into the pressurizing chamber 6. In the discharge stroke, when the plunger 5 rises against the urging force of the spring 10, the fuel sucked into the pressurizing chamber 6 is pressurized and fed to the distribution shaft 21. Thereafter, the fuel pumped to the distribution shaft 21 is distributed to the delivery valve 20 by the distribution shaft 21 and injected from the fuel injection nozzle through the injection pipe.

  Next, the fuel injection pump 1A according to the first embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1 </ b> A, the wall surface 16 a of the cam chamber 16 is provided with a return 40 </ b> A that is a surface for blocking the lubricating oil Lo wound up by the rotation of the cam 15. The return 40A is upstream in the rotational direction of the cam 15 with respect to the position where the cam 15 and the tappet roller 32 abut, and is downstream in the rotational direction of the cam 15 with respect to the oil surface position of the lubricating oil Lo stored in the cam chamber 16. The cam shaft 16 is provided on the wall surface 16a at the upper right side of the cam chamber 16 because the rotation direction of the cam shaft 19 is counterclockwise when viewed from the front. 2 indicates the rotation direction of the cam shaft 19 (the same applies to the arrow α shown in FIGS. 3 and 5 to 11).

  Specifically, a return member 41 having a substantially arc shape when viewed from the front centered on the cam shaft 19 is formed so as to protrude from the wall surface 16 a of the cam chamber 16 toward the axial center side of the cam shaft 19. The position of the return member 41 is outside the rotational locus of the tip of the cam 15 and from the lower end on the right side (upstream in the rotational direction) of the tappet chamber 13 to the upstream side in the rotational direction of the cam 15 by a predetermined length. It is composed integrally with. The predetermined length of the arc-shaped portion may be a length that can remove the lubricating oil Lo from the tip of the cam 15.

  One end surface of the return member 41 on the upstream side in the rotation direction of the cam shaft 19 is set as a return 40A, and the return 40A is an inclined surface that gradually approaches the wall surface 16a of the cam chamber 16 toward the upstream side in the rotation direction. The width of the return 40A in the front-rear direction (axial center direction of the cam 15) is formed to be longer than the width of the cam 15 in the front-rear direction (see FIG. 1). It is also possible to form a plurality of barbs 40A by providing a plurality of barb members 41 on the wall surface 16a at the upper right side of the cam chamber 16.

  In such a fuel injection pump 1A, the rotation of the cam 15 causes the lubricating oil Lo to be wound up along the wall surface 16a of the cam chamber 16, and the wound up lubricating oil Lo is blocked at the return 40A. Thus, the lubricating oil Lo can be prevented from flowing into the tappet chamber 13 side, the lubricating oil Lo reaching the tappet roller 32 can be reduced, and the lubricating oil Lo mixed in the fuel oil can be reduced. Note that the black arrow shown in FIG. 2 indicates the lubricating oil Lo that has been dammed up by the return 40A and has flowed down.

  In this embodiment, the gap between the cam shaft 19 side surface 41a of the return member 41 and the tip of the cam 15 is made as small as possible to reduce the lubricating oil Lo passing through this gap. Thereby, the effect of reducing the lubricating oil Lo reaching the tappet roller 32 can be enhanced.

  Further, the barb 40A can be formed by providing a barb member 41 with respect to the conventional cam chamber 16. In this case, the turning back 40A can be formed by simple processing with respect to the conventional cam chamber 16.

  Next, the fuel injection pump 1B according to the second embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1B, similarly to the fuel injection pump 1A, the wall surface 16a of the cam chamber 16 is provided with a barb 40B that is a surface for blocking the lubricating oil Lo wound up by the rotation of the cam 15. The return 40B is upstream in the rotational direction of the cam 15 relative to the position where the cam 15 and the tappet roller 32 abut, and downstream in the rotational direction of the cam 15 relative to the oil level position of the lubricating oil Lo stored in the cam chamber 16. The cam shaft 16 is provided on the wall surface 16a on the right side of the cam chamber 16 because the rotation direction of the cam shaft 19 is counterclockwise when viewed from the front.

  Specifically, in the wall surface 16a, the upper portion 16b of the wall 15a is configured as an arc having a short distance (radius) from the axis of the cam 15 to the wall surface 16a, and the lower portion 16c is formed from the axis of the cam 15 to the wall surface 16a. It is configured as a long arc. That is, the interval between the wall surface 16a of the cam chamber 16 and the tip of the cam 15 is made wider toward the upstream side in the rotational direction of the cam 15 with reference to the position where the cam 15 and the tappet roller 32 abut. And the boundary part of these upper part 16b and the lower part 16c is formed in a step shape, and this step part is provided as return 40B. The front-rear width of the barb 40B is longer than the front-rear width of the cam 15. It is also possible to form a plurality of barbs 40B on the wall surface 16a on the right side of the cam chamber 16.

  In such a fuel injection pump 1B, the rotation of the cam 15 causes the lubricating oil Lo to be wound up along the wall surface 16a of the cam chamber 16, and the wound up lubricating oil Lo is blocked by the return 40B. Thus, the lubricating oil Lo can be prevented from flowing into the tappet chamber 13 side, the lubricating oil Lo reaching the tappet roller 32 can be reduced, and the lubricating oil Lo mixed in the fuel oil can be reduced. In addition, the black arrow shown in FIG. 3 has shown the lubricating oil Lo which was dammed up by the return 40B and flowed down.

  Further, the barb 40B can be formed by notching the conventional cam chamber 16 (for example, providing a notch 42 on the lower right side of the wall surface 16a of the cam chamber 16). In this case, the return 40B can be formed by simple processing with respect to the conventional cam chamber 16 without increasing the number of parts.

  Further, the return 40B is formed with a lubricating oil discharge opening 16d. The lubricating oil discharge opening 16 d is formed to have a wide front-rear width, and the upper portion communicates with a lubricating oil discharge passage 3 b formed in the pump housing 3. A discharge pipe 43 is inserted into the lubricating oil discharge passage 3b. That is, the discharge pipe 43 communicates with the lubricant discharge opening 16d. As a result, part of the lubricating oil Lo wound up by the cam 15 flows into the lubricating oil discharge opening 16 d and can be sent to any position (for example, an oil pan) through the discharge pipe 43. 3 indicates the lubricating oil Lo discharged through the lubricating oil discharge opening 16d.

  Next, the fuel injection pump 1C according to the third embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1C, similarly to the fuel injection pumps 1A and 1B, the wall surface 16a of the cam chamber 16 is provided with a barb 40C that is a surface for blocking the lubricating oil Lo wound up by the rotation of the cam 15. The return 40C is upstream in the rotational direction of the cam 15 relative to the position where the cam 15 and the tappet roller 32 abut, and downstream in the rotational direction of the cam 15 relative to the oil level position of the lubricating oil Lo stored in the cam chamber 16. It is provided on the wall surface 16a of the cam chamber 16 on the side. The barb 40C is formed in an inclined shape (slope shape) with respect to the cam shaft 19. In the present embodiment, the cam shaft 19 is provided on the right wall surface 16 a of the cam chamber 16 because the rotation direction of the cam shaft 19 is counterclockwise when viewed from the front.

  Specifically, the barb 40C has a stepped shape in which the upper part protrudes toward the axial center of the camshaft 19 and the lower part is recessed outwardly on the right wall surface 16a of the cam chamber 16, and the shape of the stepped part that becomes the barb 40C. Is inclined so as to gradually fall from the rear upper part to the front lower part in a side view, and the rear end of the return 40C is located at the rear side of the rear end of the cam 15 at the height below the tappet chamber 13, and the return 40C The front end of the cam shaft 19 is at a position substantially in front of the cam 15 at the height of the approximate axis of the cam shaft 19. However, the inclination direction may be reversed, and may be a straight line or a curved line.

  In such a fuel injection pump 1 </ b> C, the rotation of the cam 15 causes the lubricating oil Lo to be wound up along the wall surface 16 a of the cam chamber 16, but from the front side of the cam 15 to the rear side during the upward rotation of the cam 15. The lubricating oil Lo is dammed up gradually by the return 40C, and the dammed lubricating oil Lo sequentially flows down to the front and lower. Therefore, when the weir is stopped on the horizontal plane, the droplet may remain attached to the return 40C. However, in this embodiment, the return 40C is inclined downward, so that the blocked lubricating oil is returned to the return 40C. The lubricating oil Lo adhering to the cam 15 can be efficiently removed. In addition, the black arrow shown in FIG. 4 has shown the lubricating oil Lo which was dammed up by the return 40C and flowed down.

  Next, the fuel injection pump 1D according to the fourth embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1D, a scraping body 50D that scrapes off the lubricating oil Lo that comes in contact with the outer periphery 15a of the cam 15 is provided. The scraping member 50D is upstream of the cam 15 and the tappet roller 32 in the rotational direction of the cam 15, and in the rotational direction of the cam 15 than the oil surface position of the lubricating oil Lo stored in the cam chamber 16. It is provided on the wall surface 16 a of the cam chamber 16 on the downstream side. In the present embodiment, the cam shaft 19 is provided on the wall surface 16 a at the upper right side of the cam chamber 16 because the rotation direction of the cam shaft 19 is counterclockwise when viewed from the front.

  Specifically, the scraper 50D is mainly configured by a support base 51 fixed to the wall surface 16a at the upper right side of the cam chamber 16, and a blade 52 protruding from the support base 51 toward the cam 15 side. The The support base 51 is fixed so as to protrude from the wall surface 16a so that the tip of the support base 51 does not contact when the cam 15 rotates. The blade 52 is made of an elastic member such as rubber, and protrudes toward the center of the camshaft 19 with such a length that the tip of the blade 52 is always in contact with the outer periphery 15 a of the cam 15. The front-rear width of the support base 51 and the front-rear width of the blade 52 are approximately the same as the front-rear width of the cam 15. The blade 52 can also be constituted by a brush.

  In such a fuel injection pump 1D, excess lubricating oil Lo adhering to the outer periphery 15a of the cam 15 is scraped off by the blade 52, so that the tappet 30 maintains the lubricity of the contact surface between the cam 15 and the tappet 30. The lubricating oil Lo reaching to can be reduced, and the lubricating oil Lo mixed in the fuel oil can be reduced. Furthermore, since the support base 51 acts as a return member (return) of the first embodiment, the lubricating oil Lo reaching the tappet 30 can be further reduced. A black arrow shown in FIG. 5 indicates the lubricating oil Lo scraped off by the scraping body 50D.

  Next, the fuel injection pump 1E according to the fifth embodiment of the present invention will be described in detail with reference to FIG.

  The fuel injection pump 1E is provided with a scraping body 50E that scrapes off the lubricating oil Lo that comes into contact with the outer periphery 15a of the cam 15 and adheres thereto. The scraping body 50E is upstream of the cam 15 and the tappet roller 32 in the rotational direction of the cam 15, and in the rotational direction of the cam 15 than the oil surface position of the lubricating oil Lo stored in the cam chamber 16. It is provided on the wall surface 16 a of the cam chamber 16 on the downstream side. In the present embodiment, the cam shaft 19 is provided on the wall surface 16 a at the upper right side of the cam chamber 16 because the rotation direction of the cam shaft 19 is counterclockwise when viewed from the front.

  Specifically, a groove-like mounting hole 16 e disposed in parallel with the cam shaft 19 is recessed in the wall surface 16 a at the upper right side of the cam chamber 16. The scraper 50E is inserted into the mounting hole 16e. The scraper 50E includes a cylindrical roller 53, a support 54 that slides in the radial direction of the cam shaft 19 with respect to the mounting hole 16e, and supports the roller 53 via a support pin 55, and the support And a spring 56 for urging 54 in the camshaft 19 direction. The front-rear width of the roller 53 is approximately the same as the front-rear width of the cam 15.

  In such a fuel injection pump 1E, the roller 53 moves together with the support 54 in the direction of the cam shaft 19 due to the biasing force of the spring 56, and the roller 53 is always in contact with the outer periphery 15a of the cam 15. The excess lubricating oil Lo adhering to the outer periphery 15a of the cam 15 is scraped off by the roller 53, so that the lubricating oil Lo reaching the tappet 30 is reduced while maintaining the lubricity of the contact surface between the cam 15 and the tappet 30. Thus, the lubricating oil Lo mixed in the fuel oil can be reduced. Since the roller 53 rolls when the cam 15 rotates, the surface of the cam 15 is not worn, and generation of dust due to wear can be suppressed. The black arrow shown in FIG. 6 indicates the lubricating oil Lo that has been scraped off by the scraper 50E.

  Next, the fuel injection pump 1F according to the sixth embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1F, there is provided a scraping body 60F that contacts the outer periphery 32a of the tappet roller 32 and scrapes off the adhering lubricating oil Lo. The scraper 60F is downstream of the tappet roller 32 in the rotational direction from the position where the cam 15 and the tappet roller 32 are in contact, and is further upstream of the tappet roller 32 in the rotational direction than the communication hole 31d provided in the mounting table 31a. The tappet body 31 is provided. In the present embodiment, the rotation direction of the tappet roller 32 is clockwise when viewed from the front, which is the opposite direction to the rotation direction of the camshaft 19, and is provided on the left side of the lower end of the tappet body 31. 7 indicates the direction of rotation of the tappet 30 (the same applies to the arrow β shown in FIGS. 8 to 11).

  Specifically, the scraping body 60F is mainly configured by a support base 61 fixed to the lower end of the tappet body 31 and a blade 62 attached to the support base 61 and protruding toward the tappet roller 32 side. . The front and rear widths of the support base 61 and the blade 62 are approximately the same as those of the tappet roller 32. Further, a scraping body 60F having the same configuration is also provided on the right side of the lower end of the tappet body 31. These two scraping bodies 60F and 60F are arranged so as to cover the gap between the tappet roller 32 and the lower end of the tappet body 31. Instead of the blade 62, a brush may be used.

  In such a fuel injection pump 1F, excess lubricating oil Lo adhering to the outer periphery 32a of the tappet roller 32 is scraped off by the left and right scraping bodies 60F and 60F, so that the lubricating oil Lo reaching the tappet 30 is reduced. Thus, the lubricating oil Lo mixed in the fuel oil can be reduced. Furthermore, since the two scrapers 60F and 60F cover the gap between the tappet roller 32 and the lower end of the tappet body 31, the lubricating oil Lo wound up by the cam 15 can be prevented from flowing in from the gap. 7 indicates the lubricating oil Lo that has been scraped off by the scraping body 50F.

  Next, the fuel injection pump 1G according to the seventh embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1G, there is provided a scraping body 60G that scrapes off the lubricating oil Lo that comes into contact with the outer periphery 32a of the tappet roller 32 and adheres thereto. The scraping body 60G is downstream in the rotation direction of the tappet roller 32 with respect to the position where the cam 15 and the tappet roller 32 contact each other, and is further upstream in the rotation direction of the tappet roller 32 than the communication hole 31d provided in the mounting table 31a. The tappet body 31 is provided. In the present embodiment, since the rotation direction of the tappet roller 32 is clockwise when viewed from the front, it is provided on the upper left side of the tappet body 31.

  Specifically, a groove-like mounting hole 31e is provided in parallel with the tappet pin 33 on the upper left side of the mounting table 31a, and a scraping body 60G having the same configuration as the scraping body 50E shown in FIG. 6 is inserted into the mounting hole 31e. Is done.

  In such a fuel injection pump 1G, excess lubricating oil Lo adhering to the outer periphery 32a of the tappet roller 32 is scraped off by the rollers constituting the scraping body 60G, so that the lubricating oil Lo reaching the tappet 30 is reduced. Thus, the lubricating oil Lo mixed in the fuel oil can be reduced. A black arrow shown in FIG. 8 indicates the lubricating oil Lo that has been scraped off by the scraping body 60G.

  Next, the fuel injection pump 1H according to the eighth embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1H, the lower spring receiver 9 has a substantially disk shape, and an O-ring 70H serving as a seal member is fitted on the outer periphery thereof. The O-ring 70H is disposed above the key groove 31c. Further, the lower spring receiver 9 is not provided with the communication hole 9a shown in FIG. The communication hole serving as a vent hole is provided at another position (for example, in the pump housing 3 behind the tappet chamber 13), and the rack chamber 12 and the cam chamber 16 are communicated with each other. The internal pressure of the cam chamber 16 is made the same.

  In such a fuel injection pump 1H, since the communication hole 9a is not provided in the lower spring receiver 9, the lubricating oil Lo does not enter from the communication hole 9a, and the O-ring 70H allows the inside of the tappet body 31 to be in contact. The lubricating oil Lo can be prevented from entering through the gap between the peripheral surface and the lower spring receiver 9, and the lubricating oil Lo accumulated on the upper part of the lower spring receiver 9 can be reduced. Thereby, the lubricating oil Lo adhering to the lower part of the plunger 5 can be reduced, and the lubricating oil Lo mixed in the fuel oil along the sliding surface of the plunger 5 can be reduced. A black arrow in FIG. 9 indicates the lubricating oil Lo that has been prevented from entering by the O-ring 70H.

  Next, the fuel injection pump 1I according to the ninth embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1I, the tappet 30 is configured so that the depth H of the storage portion 31b for storing the lower spring receiver 9 is shallow enough to prevent the lower spring receiver 9 from being removed. In the present embodiment, the depth H of the storage portion 31 b is configured to be slightly higher than the combined height of the lower spring receiver 9 and the adjustment shim 14.

  In such a fuel injection pump 1I, since the volume of the storage part 31b of the tappet 30 becomes small, the lubricating oil Lo collected in the storage part 31b can be reduced. Thereby, the lubricating oil Lo adhering to the lower part of the plunger 5 can be reduced, and the lubricating oil Lo mixed in the fuel oil along the sliding surface of the plunger 5 can be reduced.

  Next, the fuel injection pump 1J according to the tenth embodiment of the present invention will be described in detail with reference to FIG.

  In the fuel injection pump 1J, the tappet 30 is configured such that the mounting base 31a on which the lower spring receiver 9 is placed is not provided with the communication hole 31d shown in FIG. 2, but the partition 90J is provided on the center side of the tappet body 31. . In the present embodiment, the partition 90 </ b> J is formed in a stepped concave portion in a side sectional view, and a convex portion that fits into the concave portion is formed in the lower portion of the lower spring receiver 9.

  In such a fuel injection pump 1I, the lubricating oil Lo is prevented from entering the housing portion 31b of the lower spring receiver 9 from the communication hole 31d of the mounting table 31a without changing the vertical height of the conventional tappet. be able to. Thereby, the lubricating oil Lo adhering to the lower part of the plunger 5 can be reduced, and the lubricating oil Lo mixed in the fuel oil along the sliding surface of the plunger 5 can be reduced. Note that the tappet 30 may be configured without the tappet roller 32.

  As described above, in the fuel injection pumps 1A, 1B, and 1C according to the first to third embodiments of the present invention, the plunger 5 is reciprocated via the tappet 30 by the rotation of the cam 15 accommodated in the cam chamber 16. In the fuel injection pumps 1A, 1B, and 1C that pump the fuel, the return 40A, 40B, and 40C that serve as surfaces for blocking the lubricating oil Lo wound up by the rotation of the cam 15 on the wall surface 16a of the cam chamber 16 are provided. It is provided. Thereby, the lubricating oil Lo reaching the tappet 30 can be reduced, and the lubricating oil Lo mixed in the fuel oil can be reduced.

  In the fuel injection pump 1A according to the first embodiment of the present invention, the return 40A is located on the upstream side in the rotational direction of the return member 41 that protrudes from the wall surface 16a of the cam chamber 16 toward the radially inner side of the cam shaft 19. It is formed on the surface. Thereby, the lubricating oil reaching the tappet 30 can be reduced by the return 40A, and the lubricating oil mixed in the fuel oil can be reduced. Further, the barb 40A can be formed by providing a barb member 41 by welding or the like to the conventional cam chamber 16, and in this case, the barb 40A is returned to the conventional cam chamber 16 only by simple processing. Can be formed.

  In the fuel injection pump 1B according to the second embodiment of the present invention, in the return 40B, the interval between the wall surface 16a of the cam chamber 16 and the tip of the cam 15 becomes wider toward the upstream side in the rotation direction of the cam 15. In this way, the cutout 42 is formed on the downstream surface in the rotation direction. Thereby, the lubricating oil Lo reaching the tappet 30 can be reduced by the return 40B, and the lubricating oil Lo mixed in the fuel oil can be reduced. Further, the barb 40B can be formed by notching the conventional cam chamber 16, and in this case, the barb 40B can be formed by simple machining with respect to the conventional cam chamber 16 without increasing the number of parts. Can be formed.

  In the fuel injection pump 1B according to the second embodiment of the present invention, the return 40B is formed with a lubricating oil discharge opening 16d, and the discharge pipe 43 is communicated with the opening 16d. . Thereby, the lubricating oil Lo wound up by the cam 15 can be returned and fed from the 40B to an arbitrary position.

  In the fuel injection pump 1 </ b> C according to the third embodiment of the present invention, the return 40 </ b> C is formed to be inclined with respect to the cam shaft 19. Thereby, the lubricating oil Lo dammed up by the return 40C flows down along the inclination of the return 40C, so that the lubricating oil Lo can be efficiently removed.

  In the fuel injection pumps 1D and 1E according to the fourth and fifth embodiments of the present invention, the fuel that pumps fuel by reciprocating the plunger 5 via the tappet 30 by the rotation of the cam 15 housed in the cam chamber 16. In the injection pumps 1D and 1E, scrapers 50D and 50E are provided on the wall surface 16a of the cam chamber 16 to scrape off the lubricating oil Lo that comes into contact with the outer periphery 15a of the cam 15. Thereby, by scraping off the excessive lubricating oil Lo adhering to the cam 15, the lubricating oil Lo reaching the tappet 30 can be reduced, and the lubricating oil Lo mixed in the fuel oil can be reduced.

  In the fuel injection pumps 1F and 1G according to the sixth and seventh embodiments of the present invention, the fuel that pumps fuel by reciprocating the plunger 5 through the tappet 30 by the rotation of the cam 15 housed in the cam chamber 16. In the injection pumps 1 </ b> F and 1 </ b> G, the tappet 30 includes a tappet roller 32 that contacts the cam 15 and a tappet main body 31 that serves as a storage body for storing the tappet roller 32, and the tappet main body 31 includes the tappet roller 32. Scraping bodies 60F and 60G are provided for scraping off the lubricating oil Lo that has come into contact with the outer periphery 32a. Thereby, by scraping off the excessive lubricating oil Lo adhering to the tappet roller 32, the lubricating oil Lo reaching the tappet 30 can be reduced, and the lubricating oil Lo mixed in the fuel oil can be reduced.

  In the fuel injection pump 1H according to the eighth embodiment of the present invention, in the fuel injection pump 1H in which the plunger 5 is reciprocated through the tappet 30 by the rotation of the cam 15 accommodated in the cam chamber 16, and the fuel is pumped. The lower spring receiver 9 is provided in a lower part of a spring 10 which is an urging member for urging the plunger 5 and is fitted into the tappet 30. The lower spring receiver 9 is substantially disc-shaped and has a communication hole. 9a is not provided, and an O-ring 70H serving as a seal member is provided on the outer periphery. Thereby, since the communication hole 9a is not provided, the lubricating oil Lo does not enter from the communication hole 9a, and the O-ring 70H allows the lubricating oil Lo to pass through the gap between the inner peripheral surface of the tappet 30 and the lower spring receiver 9. Can be prevented from entering, and the lubricating oil Lo mixed in the fuel oil can be reduced.

  In the fuel injection pump 1I according to the ninth embodiment of the present invention, in the fuel injection pump 1I in which the plunger 5 is reciprocated through the tappet 30 by the rotation of the cam 15 accommodated in the cam chamber 16, and the fuel is pumped. A lower spring receiver 9 is provided at a lower portion of a spring 10 serving as an urging member for urging the plunger 5 and is fitted into the tappet 30, and the tappet 30 stores a lower spring receiver 9. The depth H of 31b is so shallow that the lower spring support 9 is not removed. Thereby, since the volume of the storage part 31b becomes small, the lubricating oil Lo accumulated in the storage part 31b can be reduced, and the lubricating oil Lo mixed in the fuel oil can be reduced.

  In the fuel injection pump 1J according to the tenth embodiment of the present invention, in the fuel injection pump 1J in which the plunger 5 is reciprocated through the tappet 30 by the rotation of the cam 15 housed in the cam chamber 16, and the fuel is pumped. A lower spring receiver 9 is provided at a lower portion of a spring 10 serving as an urging member for urging the plunger 5 and is fitted into the tappet 30, and the tappet 30 mounts the lower spring receiver 9. The mounting base 31a is not provided with the communication hole 31d. Thereby, it is possible to prevent the lubricating oil Lo from entering from the communication hole 31d of the mounting table 31a, and to reduce the lubricating oil Lo mixed in the fuel oil.

1A Fuel injection pump according to the first embodiment 1B Fuel injection pump according to the second embodiment 1C Fuel injection pump according to the third embodiment 1D Fuel injection pump according to the fourth embodiment 1E Fuel injection pump according to the fifth embodiment 1F Fuel Injection Pump According to Sixth Embodiment 1G Fuel Injection Pump According to Seventh Embodiment 1H Fuel Injection Pump According to Eighth Embodiment 1I Fuel Injection Pump According to Ninth Embodiment 1J Fuel Injection Pump According to Tenth Embodiment 5 Plunger 9 Lower spring support 9a Communication hole 10 Spring (biasing member)
DESCRIPTION OF SYMBOLS 15 Cam 15a Outer periphery 16 Cam chamber 16a Wall surface 16d Lubricating oil discharge opening 18 Cam shaft 30 Tappet 31 Tappet body (housing body)
31a Mounting base 31b Storage portion 31d Communication hole 32 Tappet roller 32a Outer circumference 40A Return 40B Return 40C Return 41 Return member 42 Notch 43 Discharge pipe 50D Scraping body (blade)
50E scraped body (roller)
60F scraped body (blade)
60G scraped body (roller)
70H O-ring (seal member)
90J Partition Lo Lubricant

Claims (10)

In a fuel injection pump that pumps fuel by reciprocating a plunger via a tappet by rotation of a cam housed in a cam chamber,
A fuel injection pump characterized in that a return for blocking the lubricating oil wound up by rotation of the cam is provided on the wall surface of the cam chamber.   2. The fuel injection pump according to claim 1, wherein the return is formed to protrude from a wall surface of the cam chamber toward a radially inner side of the cam shaft.   2. The fuel injection pump according to claim 1, wherein the return is formed such that an interval between a wall surface of the cam chamber and a tip of the cam becomes wider toward an upstream side in a rotation direction of the cam.   The fuel injection pump according to any one of claims 1 to 3, wherein a lubricating oil discharge opening is formed in the return, and a discharge pipe communicates with the opening. .   The fuel injection pump according to any one of claims 1 to 4, wherein the return is formed to be inclined with respect to the camshaft. In a fuel injection pump that pumps fuel by reciprocating a plunger via a tappet by rotation of a cam housed in a cam chamber,
A fuel injection pump characterized in that a scraping body for scraping off the lubricating oil adhering in contact with the outer periphery of the cam is provided on a wall surface of the cam chamber. In a fuel injection pump that pumps fuel by reciprocating a plunger via a tappet by rotation of a cam housed in a cam chamber,
The tappet includes a tappet roller that comes into contact with the cam and a storage body that stores the tappet roller.
The fuel injection pump according to claim 1, wherein the storage body is provided with a scraping body that scrapes off the attached lubricant oil in contact with the outer periphery of the tappet roller. In a fuel injection pump that pumps fuel by reciprocating a plunger via a tappet by rotation of a cam housed in a cam chamber,
A lower spring receiver provided at a lower portion of a biasing member for biasing the plunger and inserted into the tappet;
The fuel injection pump according to claim 1, wherein the lower spring receiver has a substantially disk shape, is not provided with a communication hole, and is provided with a seal member on an outer periphery. In a fuel injection pump that pumps fuel by reciprocating a plunger via a tappet by rotation of a cam housed in a cam chamber,
A lower spring receiver provided at a lower portion of a biasing member for biasing the plunger and inserted into the tappet;
The fuel injection pump according to claim 1, wherein the tappet is configured so that a depth of a storage portion for storing the lower spring receiver is shallow enough to prevent the lower spring receiver from being removed. In a fuel injection pump that pumps fuel by reciprocating a plunger via a tappet by rotation of a cam housed in a cam chamber,
A lower spring receiver provided at a lower portion of a biasing member for biasing the plunger and inserted into the tappet;
In the tappet, a communication hole is not provided in a mounting table on which the lower spring receiver is mounted.

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