FI105231B - Fuel injection pump for machines with piston combustion engine - Google Patents

Description

, 105231

Fuel injection pump for percussion piston engine engines

The invention relates to a fuel injection pump for percussion internal combustion engine machines having at least one cylinder containing a supply chamber, a piston moving in longitudinal direction therewith and a suction chamber communicating with the supply chamber, the connection to the supply chamber being cut off during the feeding step.

In hitherto known injection pumps of this type, it was common to place a hole in the wall of the pump cylinder which connects the supply chamber to the suction chamber 10. This connection is interrupted when the piston feed chamber facing end has bypassed the hole during the feed stroke to begin the feed phase. The end of the feed phase is effected by a slanting guide edge disposed on the piston which, as the piston continues to move, passes said hole and thereby connects the feed and suction chambers again. The oblique guide edge was obtained by rotating the plunger to go to the 15 holes sooner or later, which varied the end of feed and thus also the amount of feed. With this structure, the feed rate change is always associated with the feed start time. Therefore, it is not possible to optimally adapt the fuel injection at different times of use to the needs of the internal combustion engine.

It is an object of the invention to initially improve such a spraying pump so that the start of the spraying can be arbitrarily adjusted to achieve optimal fitting.

The objective is achieved by a pump characterized by what · ·. : Notation in day 1 character section.

Exemplary embodiments of the invention will be illustrated in the following description in greater detail with reference to the drawings, in which Figure 1 schematically illustrates a longitudinal section of a fuel injection pump according to the invention: V Figure 2 likewise illustrates modifications of a longitudinal section injection pump: 30, Fig. 3 is a perspective view of the skate used in the pump of Fig. 2, and Figs. 4a-d show four different operating positions of the skate.

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According to Fig. 1, the fuel injection pump has a body 1, the upper part of which, in Fig. 1, forms a cylinder 2 in which the piston 3 moves upwards and downwards. The cylinder 2 comprises an inlet chamber 4 associated with an upwardly extending pressure line 5 in Fig. 1, which leads to a schematically illustrated spray nozzle 6 disposed on a cylinder head not shown on a diesel-type piston combustion engine whose bottom end extends to the cylinder 5 of the machine cylinder. In Figure 1, the piston 3 extends downwardly through the suction chamber 7 and then through the lower part of the body 1. The lower end of the piston 3, not shown, is wheel-supported on the camshaft cam. The suction chamber 7 is connected to a source of diesel fuel (arrow A) not shown on at least one channel 8.

A piston 3 is provided on the suction chamber 7 with a sleeve-like slide 9, 10 which can slide with the piston 3. In the figure 1, the slide 9 has a guide edge 10 which runs at right angles to the movement direction of the piston 3 (double arrow B). At the upper end of the slide 9 is a second guide edge 11 which runs obliquely with respect to the direction of movement of the piston 3.

The guide edges 10 and 11 interact with a long-hole transverse channel 15 which starts at the center of the piston 3 and extends radially outward to the peripheral surface of the piston 3. The transverse channel 12 communicates with the longitudinal channel 13 extending in the center of the piston 3. The channel 13 starts from the front face 3 'facing the piston 3 supply chamber 4 and thereby connects the suction chamber 7 with the transverse channel 12 to the supply chamber 4. extends into the suction chamber 7 and comprises an eccentric pin 15. The pin 15 extends into the annular groove 16 of the slide 9 extending parallel to the guide edge 10. In order to prevent the slide 9 from rotating as it is moved longitudinally, a stick 19 'extending into the longitudinal groove 19' of the slide is attached to the frame 1.

Under the suction chamber 7, a toothed bar, «17, is mounted on the body 1, which acts on the toothed rim 18, which is pivotally mounted on the piston 3 but still allows longitudinal movement of the piston 3. Ham · · ·: The cam blade 18 and piston 3 can be rotated about their axis 20 by moving the rack 17 ·· · 1: V at right angles to the drawing plane of Figure 1.

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The spray pump 7 illustrates the following: The suction chamber 7 is in the position shown in section 1 through the transverse channel 12 and the longitudinal channel 13 in communication with the supply chamber 4, the latter being filled with fuel. Said, not shown beak moves the piston 3 upwards.

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When the lower edge 12 'of the transverse channel 12 has passed the guide edge 10, 10; 35 of the slide 9, the feed step of the piston 3 begins, since the slide 9 then completely covers the transverse opening of the transverse channel 12. . The fuel penetrates through the pressure line 5 to the jet nozzle 6, which opens when the jet pressure is reached and allows the fuel to flow into the combustion chamber. The feeding step of the piston 3 ends at the moment when the upper edge 12 "of the transverse channel 12 passes the second guide edge 11 of the slide 9.

Thus again a connection is made between the feed chamber 4 and the suction chamber 3, so that the pressure of the fuel in the feed chamber 4 decreases. The start of the feed can be varied by the axis 14 such that the pin 15 moves the slide 9 slightly up or down as the shaft 14 rotates so that the relative position of the transverse channel 12 with respect to the guide edges 10 and 11 is changed. Downward movement 10 of the slide 9 causes feed and spraying to start earlier and upward movement accordingly later. Irrespective of this adjustment option, the injection pump can also adjust the feed rate such that the tooth ring 18 and piston 3 are rotated by a rack 17 so that the transverse channel 12 moves to the right or left in FIG. Moving to the right ai-15 causes a decrease in the feed rate as the transverse channel 12 travels faster along the longitudinal distance between the guide edges 10 and 11, i.e. the feed start and end times are closer together. Moving the transverse channel to the left increases the feed rate because the ridge 3 requires a longer time for the transverse channel to travel between the guide edges 10 and 11; the feed start and end times are thus further apart.

Instead of being mounted on the piston 3, it is possible to fasten the toothed rim 18 to the slide 9, which is correspondingly longer, and toothed tooth 17 respectively. The stick 19 and the longitudinal groove 19 'are excluded from this embodiment. Here, too, the start and amount of the feed can be adjusted independently,

In the injection pump of Figure 2, the body 21 again comprises a supply chamber 24 and controls a piston 23 on its cylinder 22. A suction cup 29 is disposed in the suction chamber 27 with a toothed rim 48 at its lower end in contact with a toothed bar. The slide 29 can be rotated on the axis 40 of the piston v: 30 23 by means of a gear ring 48. The guide edges of the skate 29 are designated by numbers 30 and 31. The skate 29 is displaced longitudinally by a ring 49 surrounding the piston 23, the upper surface of which is the lower surface of the skate 29 in FIG. The lower surface is provided with an oblique sliding surface 50. The sliding surface 50 extends approximately half the circumference of the ring 49 and rests on the stop 51 formed by the pin: 35 attached to the body 21. The ring 49 (· ft. • «4 105231 also has a toothed ring 52 which is toothed with a not shown tooth bar.

Figure 2 further shows that the coil spring 53 presses the slide 29 and the ring 49 downwardly against the stop 51. The spring rests on the lower end 5 of the cylinder 22 on the one hand and the upper end of the slide 29 on the other hand. In the embodiment of Figure 2, instead of one transverse channel 12, there are two transverse channels 62 and 63 which are longitudinally spaced apart and further extend across the plunger 23.

Figure 3 shows more clearly than Figure 2 a symmetrical structure 10 of the slide 29, comprising two guide edges 30 and two second guide edges 31. The guide guide edges 30 form the upper edge of a window-shaped hole which could be open downwards. Due to the symmetrical arrangement of the guide edges and the transverse passageways 62 and 63 passing through the piston, the slider 29 generates a uniform pressure.

The injection pump according to Figures 2 and 3 operates as follows: With the plunger 23 in the position of Figure 2, the supply chamber 24 communicates with the intake chamber 27 through the longitudinal passage 33 and the transverse channels 62 and 63 so that the intake chamber 24 is filled with pressurized fuel. As the piston 23 moves upward, the feeding step begins when the lower edge of the lower transverse hub 62 has passed past the guide edge 30 (Fig. 4a). The feeding step continues until the upper edge of the upper transverse channel 63 passes the second guide edge 31 (Fig. 4b), since there is again a connection between the supply chamber 24 and the suction chamber 27. The start of the feed can be adjusted by the ring 49 by means of the gear ring 52, •,: by rotating, because the slanting surface 50 sliding on the stop 51 of the ring 49 moves the ring • · * ''. ' 25 and slides 29 in the longitudinal direction. It has already been found in connection with Figure 1 that the beginning of the feed can be brought forward by moving the slide 29 downwards in Figure 2 and vice versa. Regardless of this adjustment, the feed rate can also be adjusted by rotating the slide 29 by means of the gear ring 48 to change the relative position of the second guide edge 31 relative to the transverse channels 62 and 63. The relative position of the slide 29 relative to the piston 23 is shown in the figure when the injection pump supplies the maximum amount of fuel. Fig. 4d shows another extreme situation, that is, the injection pump feed rate is zero because the slider 29 is rotated so far that the distance between the guide edges 30 and 31 is smaller than the distance between the lower edge of transverse channel 62 and upper 35 of transverse channel 63. In this position, the slide in this position therefore does not break the connection between the suction chamber 27 and the feed chamber I (· 5 105231 chamber 24).

In contrast to the illustrated example of Figure 2, it is possible to place the gear ring 48 on the piston 23 instead of the slide 29, as shown in the embodiment of Figure 1. Further, it is possible to move the window-shaped holes delimiting the guide edge 5 of the slide 29 in Figure 3 to the left. This may prove to be appropriate if the distance between the guide edge 30 and the guide edge 31 at the right edge of Figure 3 is too small to provide sufficient strength anymore. When moving the window-shaped holes, the lower transverse channel 63 should be moved accordingly to the left.

In both embodiments, it is further possible to place at least one transverse passage at the lower end of the supply chamber 4, 24 of the cylinder 2, 22 in connection with the suction chamber 7, 27 to allow rapid filling of the supply chamber 4, 24. There is no effect on controlling the start of the feed through the holes.

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Claims (5)

A fuel injection pump for machines with a piston combustion engine, said pump having at least one cylinder containing a feed chamber (4; 24), a piston (3; 23) moving longitudinally in the cylinder (2; 22) and a suction chamber (7; 27) which is in communication with the feeding chamber, which connection with the feeding chamber is broken during the feeding phase, the cowling exiting from the end surface (3 ') which touches the feeding chamber within the area which touches the periphery has at least one channel (13; 33) in the longitudinal direction and at least one transverse channel (12; 62, 63) exiting from this channel which opens in the region which touches the periphery of the piston and in the region of the transverse channel there is arranged a longitudinally adjustable slide (9; 19), which exhibit at least a first guide edge 15 (10; 30) acting together with the transverse channel to affect the starting time of the feed and to act on the feed end time at least one second together with the transverse channel acting in relation to the piston (3; 23) direction of movement oblique guide edge (11; 31) and wherein the slide or cowl can be adjusted about its axis relative to the cowl or slide, characterized in that the first guide edge (10; 30) is arranged at right angles to the relationship. in the direction of movement of the piston (3; 23) and that the second guide edge (11; 31) is arranged between the first guide edge (10; 30) and the feeding chamber (4; 24). 2. Pump according to claim 1, characterized in that the transverse can consists of two longitudinal pistons at a distance apart from each other existing heels (62, 63), which both act together with a guide edge (30, 31). Pump according to claim 1 or 2, characterized in that: ···, to move the slide (9) in the longitudinal direction, on the shaft (14) a pin (15) is eccentrically arranged to engage a lock (16), which runs circumferentially to the slide. Pump according to Claim 1 or 2, characterized in that in order to move the slide (19) in the longitudinal direction, a ring (49) is arranged on the slide (49), which has a ring (49). relative to the direction of movement of the piston (23) towards; oblique sliding surface (50), and which ring rests on an abutment fixed to the cylinder. . Pump according to any one of claims 1-4, characterized in that for a relative movement of the cow (3) or the slide (19) around the shaft, a chain ring (18; 48) is arranged to pivot together with the cow (3) or the slide (19) and it is connected to a rack (17).