JP2543020B2 - Fuel injection pump for internal combustion engine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection pump for an internal combustion engine, which includes a pump housing and a pumping amount adjusting member operated by an electrically controlled adjuster. And a pumping amount adjusting member having an adjusting rod having a shaped cross section supported in the pump housing, the adjusting rod being of a type in which the end on the adjusting side is guided outside the pump housing. Regarding things.

2. Description of the Prior Art In known fuel injection pumps of this kind, the bearing of the adjusting rod with an angled cross section has a sliding guide which is retained in the end walls of the pump housing and adapted to the chevron section of the adjusting rod. It is done through two bushes. The bushing, which is located at the end of the adjusting rod opposite the regulator, is liquid-tightly closed by means of a cap screwed into the pump housing. It is difficult to seal the penetrating guide part of the adjusting rod by the bush on the side, and it is not reliable in terms of long-term service life. Moreover, fuel leakage must be absolutely prevented, especially if electromagnetic regulators are used. Furthermore, the sealing property of the penetration guide portion of the adjusting rod and the non-smooth movement of the adjusting rod itself pose problems.

Advantages of the Invention Compared to the above-mentioned known examples, the fuel injection pump of the invention having the structure shown in claim 1 has an advantage that the sealability is ensured for a long time.
According to the cylindrical slide bearing sleeve having the cylindrical slide portion or the guide portion for guiding the adjusting rod, the good sliding performance of the guide portion and the sufficient sliding bearing performance with only a slight friction loss in the slide bearing sleeve are provided. Allows for small manufacturing tolerances that guarantee good sealing. It is not necessary to make any changes to the chevron section, which is already well established as an advantageous construction of the adjusting rod. Even if the chevron section is modified in any way, it does not impair the sealing property of the adjusting rod outlet from the pump pusing.

Embodiment One advantageous embodiment is shown in claim 2. According to the constitution of the second term, even if the unavoidable displacement of the adjusting rod and the slight inclination of the adjusting rod occur, all the performance and sealing performance of the guide ring of the adjusting rod in the slide bearing sleeve are affected. There is no such thing.

An advantageous embodiment is also possible with the configuration of claim 5. According to this structure, for example, the guide ring can be easily connected to the adjusting rod on one side while the structural adjustment is made to the adjusting rod having the chevron cross section, and the action of the adjuster and the return spring can be performed on the other side. One connecting member can be provided for transmission to the adjusting rod.

According to the structure of claim 6, based on the cardan type connection between the holding pin and the guide ring which penetrates the inside of the guide ring with a large radial play, particularly, according to claim 11 and 12, When the entrainment pin itself of the holding pin according to the configuration is supported in a cardan manner, the tilting of the adjusting rod and the holding pin relative to the slide bearing axis is possible over a relatively large range. In this case, the Cardan connection is the connection between the retaining pin and the guide ring,
It is a connection that allows the holding pin and the adjusting rod to be tilted with respect to the plain bearing axis, the axis of the holding pin and the adjusting rod forming a solid cone shape.

The elasticity of the drive disk according to the seventh aspect also makes a kind of cardan connection for a small displacement of at least one of the holding pin and the adjusting rod. I mean,
This is because the entrainment disc can be compressed from one side and thus allows a slight degree of tilting of the retaining pin and / or the adjusting rod.

Claims 14, 15, 15 as a measure for a more complete slide bearing guide that seals the interior of the pump housing against the regulator, especially because of the stop position occupied by the regulator rod when the internal combustion engine is stopped. Additional sealing means according to the provision of paragraph 17 is provided, which prevents the fuel oil from leaking slowly to the regulator once but slowly.

According to the structure of claim 16, the diameter of the adjusting rod bearing can be reduced, and the leakage of the adjusting rod can be better prevented.

Embodiment The fuel injection pump, which is only partially shown in FIG. 1, is a generally known fuel injection pump, as described, for example, in DE 2149362. At least one barrel is arranged in the pump housing 10 in which a plunger having an oblique control edge is guided. The rotation for changing the effective pumping stroke of the plunger is performed by a so-called pumping amount adjusting member 11. For this reason
11 has an adjusting rod 12 of chevron cross section, which on the one hand engages the plunger for its rotation,
On the other hand, it is acted upon by the regulator 13. In response to the control signal sent by the governor to the adjuster 13, the adjuster 13 causes the adjusting rod 12 to axially slide against the force of the return spring 14 and to rotate the plunger. Make adjustments.

The adjusting rod 12 is a pump housing due to its sliding motion.
Within 10, it is also supported axially and slidably at both ends of the pump housing. At the bearing point facing the adjuster 13, the adjusting rod 12 is guided out of the pump housing 10 and at the end is actuated by an operating tapette 15 of the adjuster 13, which in the present case is electromagnetic. Is loaded.

A cylindrical plain bearing sleeve 16 is fixed in the pump housing 10 for supporting the adjusting rod 12 at the pump housing outlet. In the case of the present embodiment, the sliding bearing sleeve 16 is screwed to the end face side of the pump housing 10 via the outer thread. A cylindrical guide ring 17 for the adjusting rod 12 is arranged in the plain bearing sleeve 16 so as to be slidable with a minimum of play. This guide ring 17 is fixedly connected to the adjusting rod 12 and
Is used as a guide portion of the adjusting rod 12 by closely surrounding the.

In the case of the embodiment of the adjusting rod 12 shown in FIGS. 1, 2 and 2a, one leg side portion 18 of the chevron cross section is cut off at the end of the adjusting rod on the adjuster side, and the other leg is formed. The side portion 19 is bent. An angle piece-shaped connecting member is provided at the free end of the leg portion 19.
20 is riveted, and this connecting member 20 is provided with a screw pin 21 extending in the moving direction of the adjusting rod. The operating tape 15 of the adjuster 13 acts on the tip of the screw pin 21. A support cap 23 for the return spring 14 is further fixed to the screw pin 21 via a nut 22. Return spring 14
Is supported on the bottom of the support cap 23 on the one hand, and on the ring end surface of the slide bearing sleeve 16 on the other hand,
The screw pin 21 is pushed toward the operating tape 15 once.

The guide ring 17 is closely and immovably fitted on the leg portion 19. The guide ring 17 is supported on one side by one end face 20a of the connecting member 20, and on the other side by the upper and lower shoulder portions 24, 25 (FIG. 1) of the leg portion 19.

According to the embodiment of FIG. 3, a plain bearing sleeve is also provided.
116 is screwed into the end wall of pump housing 10. A guide ring 117, which is guided in this plain bearing sleeve 116 with a minimum of play, has a screw pin 1 fixed to the end of the adjusting rod 12 by means of a hole pin connection 127.
Located on 26. The guide ring 117 is fitted onto the screw pin 126 without radial play and is crimped onto the end of the adjusting rod by a nut 128 screwed onto the screw pin 126. A seal disk 129 is arranged between the end surface of nut 128 and guide ring 117. The axial length of the guide ring 117 is selected so that the guide ring 117 is not tightened in the slide bearing sleeve 116 even when the adjusting rod 12 and the screw pin 126 are inclined.

In the embodiment of FIGS. 4 and 5, the plain bearing sleeve 216 is fixed via one union nut-shaped cap 230 screwed into the pump housing 10, which cap 230 is intended for the retaining pin 232. It has an opening 231. The retaining pin 232 is connected to the end of the adjusting rod 12 via a hole pin connection 227, the adjusting rod 12 additionally having a U-shape extending into the pump housing 10, as can be seen in FIG. Guided in the guide rail 233. A guide ring 217, which slides in the plain bearing sleeve 216 with little play, surrounds the retaining pin 232 with a relatively large radial play, in this case between the retaining pin 232 and the guide ring 217. An elastic sealing member 234 is arranged. The guide ring 217 and the holding pin 232 are connected in a cardan manner, that is, the adjusting rod 12 is inclined with respect to the axis of the holding pin 232 so that the axis of the adjusting rod 12 can draw a virtual conical surface. You can Same thing for adjusting rod
The same can be said for the inclined position of the holding pin 232 relative to 12. This cardan connection is provided by side hole 235 and side hole 2
It is made by a lateral pin 236 which is loosely located within 35. The lateral hole 235 has an extremely narrow ring web 237 protruding from the central hole wall, with which the lateral pin 236 contacts, the lateral pin 236 being free in the radial direction in the other lateral hole areas. It is movable. Both end sections of the lateral pin 236 projecting from the lateral hole 235 come into contact with one side surface section of the ring web 217a projecting from the inner wall of the guide ring 217 toward the holding pin 232. The elastic sealing member 234 is constituted by an elastic entrainment disc 238. This encircling disc 238 is a ring groove 23 of the retaining pin 232.
By means of the retaining ring 239 held in 2a, the guide rig 2
The ring web 217a of 17 is crimped to the other side surface. Thus, the guide ring 217 is connected to the holding pin 232 by the lateral pin 236 and the entrainment disc 238. Gear up 230
Is set to a value such that the entraining disc 238 seals the through opening 231 at one end position of the adjusting rod 12, that is, the stop position. The size of the through opening 231 is
One support ring 2 arranged between the stop ring 239 and the driving disc 238 and fitted on the peripheral surface of the holding pin 232.
40 is selected to fit into the through opening 231.

The simplified embodiment of the Cardan connection between the retaining pin and the guide ring is shown in the embodiment of FIG. In this case, the plain bearing sleeve 316 is cap-shaped and has a central through opening 331 for a retaining pin 332 which is connected to the adjusting rod 12. This slide bearing sleeve 316 is clamped via a clamp fixing member 341, which is also engaged with a peripheral groove 316a of the slide bearing sleeve 316 and fixed to the end wall surface of the pump housing 10 by a screw 346. Retained in the housing 10. The connection between the retaining pin 332 and the guide ring 317 which is axially movable in the plain bearing sleeve 316 without radial play is connected on the one hand by one elastic entrainment disc 338 and on the other hand. Is formed by one ring projection 344 on the outer peripheral portion of the holding pin 332. The elastic entrainment disc 338 is immovably positioned on the holding pin 332, and constitutes the seal member 334, and the ring-shaped seal bead 342 of the ring pin groove of the holding pin 332.
It fits in 343. The ring groove 343 is limited by the ring shoulder 345. The drive disc 338 is a guide ring 317.
, And the ring protrusion 344 is in contact with the bottom 317a of the guide ring 317 of the bowl. The elasticity of the entrainment disc 338 allows a limited tilting of the adjusting rod axis in any direction relative to the axis of the retaining pin 332 according to a Cardan connection. In this case, the length of the slide bearing sleeve 316 is such that the elastic encircling disc 338 is located at one end position of the adjusting rod 12.
Covers the through opening 331, and the seal bead 342
It is set to go into 1.

According to the embodiment of FIG. 7, the adjusting rod guide portion is
It consists of a cylindrical guide section 450 of a retaining pin 432 fixed to the twelve adjuster end 12a. Pump housing 1
One closure cap 4 screwed into the end wall from inside 4
51 has at its surprising end facing the adjuster 13 a bottom which once projects inwardly towards the guide section 450 of the retaining pin 432, which holds a plain bearing sleeve 416. This slide bearing sleeve 416 is the same as the guide ring in the above-mentioned embodiment, and has the minimum axial length in which there is no fear of tightening due to tilting. The plain bearing sleeve 416 has a through opening 431 in the center, which is based on the inner slide bearing and which allows the internal chamber 10a of the pump housing 10 accommodating at least the adjusting rod 12 to be located in the adjuster 13. A guide section 450 that seals against and guides the adjusting rod 12 in the through opening 431 during its adjusting movement.
To guide you through. As in the case of the previously described embodiment, the adjusting rod 12 configured as an adjusting rod having a chevron cross section has an end portion 12a on the adjuster side, and is provided with both leg portions 18 and 19 of the chevron shape of the adjusting rod 12. It has a fixing projection 454 of the holding pin 432 that is gripped. This fixing projection 454 is riveted to the end 12a of the adjusting rod 12 and possibly additionally welded for safety reasons. In this case, the fixing protrusion 454 and the guide section 450
One ring collar 452 located between and one shoulder 452 of
a is in contact with the end surface of the adjusting rod end 12a.

In the case of the embodiment of FIG. 7 above, the slide bearing sleeve 416, which is designed as the bottom of the closure cap 451, is manufactured as a separate member and is joined by an edge bending connection. This slide bearing sleeve 416 is a ring-shaped sealing member 453 manufactured as a lip packing in a ring groove 455.
Accepts a beaded retaining ring. Holding pin 432
A sealing lip 453a, which slopes once towards the guide section 450 and extends from the plain bearing sleeve 416 towards the inner chamber 10a of the pump housing 10, together with the other shoulder 452b of the ring collar 452, for example when the engine is stopped, It provides an additional seal against oil leakage from the internal chamber 10a of the pump housing 10 to the regulator 13. That is, when the engine is stopped, the adjusting rod 12 moves toward the adjuster 13 and occupies the stop position, that is, one end position (not shown), and the shoulder portion 452b closely contacts the seal lip 453a at this end position. This prevents any leakage of oil into the regulator even when the injection pump is full of oil or when the injection pump is tilted. The relatively small guide diameter of the through opening 431 in this embodiment ensures a good seal against oil leakage even during operation of the pump.

For all the embodiments described above, plain bearing sleeves
16: 116; 216; 316; 416 axially movable guide part 1
The radial play of 7; 117; 217; 317; 450 is kept as small as possible, but at the same time a satisfactory sliding of the guide part in the plain bearing sleeve is guaranteed. Fig. 4 ~
The radial play in the embodiment of FIG. 6 is less than a few hundredths of a millimeter, whereas the radial play in the embodiment of FIGS. 1 to 3 and 7 is up to 0.1 mm. You may

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a pump housing part shown together with an electromagnetic type adjuster, FIG. 2 is a plan view of an adjusting rod part shown in the direction of an arrow in FIG. 1, and FIG. Fig. 3 is a horizontal sectional view taken along the line II-II, Fig. 3 is a vertical sectional view showing the adjusting rod penetrating guide portion in the pump housing of the second embodiment, and Fig. 4 is an adjusting rod in the pump housing of the third embodiment. FIG. 5 is a vertical cross-sectional view showing the penetration guide portion, FIG. 5 is a cross-sectional view taken along the line VV in FIG. 4, and FIG. 6 is a vertical cross-sectional view showing the adjustment rod penetration guide portion in the pump housing of the fourth embodiment. FIG. 7 is a vertical sectional view showing an adjusting rod penetrating guide portion in a pump housing of the fifth embodiment. 10 …… Pump housing, 12 …… Adjusting rod, 13 …… Adjuster, 14 …… Return spring, 15 …… Operating tapette, 16 …… Sliding bearing sleeve, 17 …… Guide ring, 18,19 …… Legs Part, 20 ... connecting member, 21 ... screw pin, 22 ... nut,
23 …… Support cap, 24,25 …… Shoulder, 116,216,316,416
...... Slide bearing sleeve, 117,217,317 …… Guide ring, 126 …… Screw pin, 128 …… Nut, 129 …… Seal disc, 230 …… Cap, 231,331,431 …… Through opening, 23
2,332,432 …… Holding pin, 233 …… Guide rail, 234…
… Seal member, 235 …… Horizontal hole, 236 …… Horizontal pin, 237 ……
Ring web, 238, 338 ... Entrainment disk, 239 ... Stop ring, 240 ... Support ring, 342 ... Seal bead, 343 ...
… Ring groove, 344… Ring protrusion, 345… Ring shoulder, 450… Guide segment, 451… Closure cap, 452…
… Ring collar, 453 …… Ring-shaped sealing member, 454… Fixed protrusion.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Peter Knolek, Federal Republic of Germany, Vuacezha Bou Hengsyutrase 29 (56) References JP-A-56-98563 (JP, A) JP-A-58-28587 (JP, A) JP-A-48-42224 (JP, A) Actual opening 55-14065 (JP, U) Actual opening 51-85118 (JP, U) Actual opening 55-146865 (JP, U)

Claims (17)

(57) [Claims] 1. A fuel injection pump for an internal combustion engine, comprising a pump housing and a pumping amount adjusting member operated by an electrically controlled regulator, the pumping amount adjusting member being inside the pump housing. In the pump housing (10), there is an adjusting rod having a molded cross section which is supported on the pump housing, and the adjusting rod end is guided to the outside of the pump housing. A cylindrical plain bearing sleeve (16; 116; 216; 316; 416) is fixed to the pump housing outlet of the adjusting rod (12) having a cross section, and this plain bearing sleeve (16; 116; 216; 316; 4
In the inside of 16), one cylindrical adjusting rod guide member is fixed to the adjusting rod (12) having a chevron cross section and guides the adjusting rod (12) by sealing it to the adjuster (13). (17; 11
7; 217; 317; 450) is arranged so as to be slidable on the inner peripheral surface of the slide bearing sleeve with a minimum radial play, and a fuel injection pump for an internal combustion engine. 2. The adjusting rod guide member comprises one guide ring (17; 1).
17. The fuel injection pump according to claim 1, wherein the guide ring has a minimum axial length that is free from tilting tightening. 3. The leg portion (18) of the adjusting rod (12) having a chevron cross section is cut away at the end of the adjusting rod on the adjuster side, and the guide ring (17) is within this cutting range. 3. The fuel injection according to claim 2, wherein the leg side portion (19) is fixedly mounted on the leg side portion (19) that is not cut off so as to closely surround the leg side portion (19). pump. 4. A rivet at one end of the leg portion (19) for transmitting an adjusting force to the adjusting rod (12) within the range of the leg portion (18) being removed. The guide ring (17) is supported on one side by one end surface (20a) of the connecting member (20), and on the other side by the adjusting rod (12) by the shoulders (24, 25). The fuel injection pump according to claim 3. 5. A guide ring (117) having a screw pin (126) fixed to the adjuster-side end of the adjusting rod (12).
Is fitted on this screw pin (126), and the nut (128) screwed on the screw pin (126) with the guide ring (117) sandwiching the seal disc (129). The second aspect of the present invention is crimped to the end of the adjusting rod via
A fuel injection pump according to item. 6. A holding pin (232; 332) is fixed to the end of the adjusting rod (12) on the adjuster side, and the adjusting rod guide portion is formed of one guide ring (217; 317). Cage,
The guide ring (217; 317) surrounds the retaining pin (232; 332) under radial play and is connected to the retaining pin (232; 332) in a cardan manner without axial play. The fuel injection pump according to claim 1, wherein one elastic sealing member (234: 334) is arranged between the pin (232; 332) and the guide ring (217; 317). 7. The cardan-type coupling, on the one hand, projects radially from the retaining pin (232; 332) and comes into contact with one end face of the guide ring (217; 317), the entrainment member (236; 3).
44) and, on the other hand, the retaining pin (232; 332)
The guide ring (217; 317) fitted on top
Of the entrainment member (23; 338; 338) contacting the other end surface of the entrainment disc (238; 338).
6; 344) and fixed in position, and at the same time constitutes a sealing member (234; 334) between the holding pin (232; 332) and the guide ring (217; 317). The fuel injection pump according to item 6. 8. The entrainment disc (338) has one ring-shaped seal bead (342) located in the ring groove (343) on the retaining pin (332), which seal bead (34).
The fuel injection pump according to claim 7, wherein 2) is in contact with a ring shoulder portion (345) of a holding pin (332) that axially defines the ring groove (343). 9. The fuel injection pump according to claim 7, wherein the entrainment member comprises one ring-shaped projection (344) of the holding pin (332). 10. The entrainment member is a lateral hole (2) of the holding pin (232).
Fuel injection pump according to claim 7, consisting of a lateral pin (236) held in the lateral hole (235) and projecting from the lateral hole (235) on both sides. 11. The fuel injection pump according to claim 10, wherein the lateral pin (236) in the holding pin (232) is supported in a cardan manner substantially on the axis of the holding pin. 12. The lateral pin (236) has an extremely narrow ring web (23) protruding from the hole wall at the center of the lateral hole (235).
12. The fuel injection pump according to claim 11, which is in contact with 7) and is located loosely with radial play in the other lateral hole areas. 13. The entraining disc (238) and both ends of the lateral pin are
One ring web (217a) that protrudes from the inner wall of the guide ring toward the holding pin (232) is in contact with the diametrically opposed side surfaces, and the entrainment disc (238) is one support ring (240). One stop ring sandwiched (239)
By holding pin (232) by the ring web (217a)
The fuel injection pump according to any one of claims 10 to 12, which is fixed in position against the fuel injection pressure. 14. The plain bearing sleeve (316) is cap-shaped and has a central opening (331) for a retaining pin (332), the length of the plain bearing sleeve (316) being the adjusting rod. The encircling disc (338) is set to a value that seals the central opening (331) at one end position of the (12), according to any one of claims 7 to 13. The fuel injection pump described. 15. A plain bearing sleeve (216) is fixed in a pump housing (10) by means of a screw-capable union nut-shaped cap (330), which cap (330) is a retaining pin (330). Central opening (23)
1), and the length of the cap (230) is such that the encircling disc (238) covers the central opening (231) at one end position (stop position) of the adjusting rod (12). The fuel injection pump according to any one of claims 7 to 13 that is set. 16. The adjusting rod guide portion comprises a cylindrical guide section (450) of one holding pin (432) fixed to the end of the adjusting rod (12) on the adjuster side, and a slide bearing is provided. The sleeve (416) has a minimum axial length that does not cause tightening due to tilting, and this slide bearing sleeve (416)
Consists of the bottom of one closing cap (451) fixed to the pump housing (10) at the pump housing outlet of the adjusting rod (12), which projects inwardly towards said guide section (450). The fuel injection pump according to claim 1. 17. The retaining pin (432) has its guide section (45).
(0) has a ring collar (452) protruding in the radial direction at the end of the adjusting rod side, which ring collar (452) moves toward the adjuster (13) of the adjusting rod (12). At the one end position (stopper position), the closing cap (45
Pump housing (1) receiving the adjusting rod (12) in contact with one ring-shaped sealing member (453) fixed in the region of the transition from 1) to the plain bearing sleeve (416).
Fuel injection pump according to claim 16, characterized in that the internal chamber (10a) of (0) is additionally sealed to the regulator (13).