JPS6050268A - Fuel jet pump for internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fuel injection pump for an internal combustion engine, which has a pump piston having a stroke disk and driven by a shaft, the stroke disk being aligned with the axis. The pump piston runs along a roller supported in the direction, in which case the pump piston performs an additional stroke movement, and is provided with a return spring which brings the stroke disk into contact with the roller, until the end of the discharge of the pump piston. A fuel injection pump for an internal combustion engine, which is provided with a device for preventing the stroke disk from separating from the roller after the stroke, and a fuel injection pump for an internal combustion engine, which has a stroke disk and a pump piston driven by a shaft. The stroke disk runs along an axially supported roller, in which case the pump piston is arranged to perform an additional stroke movement, and a return spring that brings the stroke disk into contact with the roller moves the pump The pump casing is supported by a spring support of the casing and the pump piston, and a device is provided to prevent the stroke disk from separating from the roller after the pump piston has finished discharging. Relates to a type that passes through a guide pin or spring receiver guided within.

2. Prior Art An injection pump of the above type is disclosed, for example, in West German Patent Application No. 314.
4277, in which a device for preventing the displacement of the stroke disk from the rollers consists of a damping chamber filled with fuel and formed by a pump piston and a cylinder section in contact with the pump piston. . Although the known device can be retrofitted to existing types of injection pumps, in addition to the injection function of the pump piston, additional auxiliary functions must always be provided, which cannot be achieved without problems.

Problem to be Solved by the Invention The object of the invention is to improve a fuel injection pump of the type mentioned at the outset, to eliminate the drawbacks of the known technology and to make it technically inexpensive.

Means for Solving the Problems In order to solve the above problems, the first configuration of the present invention includes:
A device for preventing separation of the stroke disk from the rollers is provided by a spring fg ((material) with no difference between the pump casing and the stroke disk of the IF piston, preferably the pump piston. In one embodiment of the invention, as a device for preventing the stroke disk from separating from the rollers, a spring element and a sleeve, which are inserted between the engine casing and the pump piston, are arranged on the guide pin one behind the other in the direction of action. Ori,
The spacing between the sleeve and the spring receiver is determined so that the spring receiver is pressed against the spring member via the sleeve at the latest at the end of the discharge stroke.

Effects of the Invention] Based on the first invention, the drawbacks of the above-mentioned known techniques have been eliminated technically at low cost and without impairing functionality. The invention provides that the device for preventing the displacement of the stroke disk from the rollers is placed not in the pump piston, where the function would be impaired in any case, but in the area of the return spring, where the function is only slightly impaired. It is based on doing.

The device according to the invention is easily adjusted by providing the spring member with different spring characteristics or by varying the spring travel using cover plates of different thicknesses.

Furthermore, according to the second aspect of the invention, the device, ie the spring element, can be provided in an advantageous area in a simple manner.

Advantageous embodiments of the invention are set out in the subclaims. By prestressing the rest spring according to the embodiment claimed in claim 5, the leaf spring is loaded only at the time of the speed change during the delivery stroke, so that the service life of the leaf spring is increased.

According to the embodiment according to claim 6, stepless adjustment of the spring stroke of the disc spring is possible. The embodiment according to claim 7 is particularly suitable for fuel injections with a maximum discharge velocity such that the spring is easily loaded during the suction and discharge processes.

Embodiment As shown in FIG. 1, in a casing 1o of a distribution type fuel injection pump for an internal combustion engine, there is a pump piston driven in the direction indicated by an arrow 9 through a shaft (not shown). 1
1 is accepted. Pump piston 11 is stroke disk 1
2, the cam surface 11j of the stroke disk runs on the rollers 14 of the axially supported roller ring 15, and thereby the pump piston] 1 is shown by the double arrow 8. A stroke motion is additionally provided.

Due to the rotational and stroke movements of the pump piston 11, fuel is sucked from the inner chamber 16 of the injection pump into a high-pressure chamber (not shown) and then via the line 17, which is controlled by means of the adjusting lever 18. The individual cylinders of the internal combustion engine are supplied until the opening of the boreholes 19 towards the interior chamber 16 is controlled.

The first and second (not shown) return springs 20 are constructed as helical compression springs, which are supported on the one hand in a spring receiver 21 of the pump piston ]-], and on the other hand in a spring receiver 21 of the pump piston ]-]. The ring shoulder 22 abuts against the axially outer flange 23 of the sleeve 24.
The sleeve is arranged slidably along a guide pin 25 inserted into a hole 26 of the casing 10, the guide pin is arranged parallel to the pump piston 11 and the spring receiver 21 It engages with play in the opening 27 of.

A disk spring 28, which is configured as a spring set, coaxially surrounds the guide pin 25 and contacts the second ring shoulder 29 of the outer flange 23 on the one hand and the standard plate 30 on the other hand, itself in the recess 31 in the casing 10
, in which case the recess 31 receives the end spring 28 .

In the embodiment shown in FIG. 2, the same parts as in the embodiment shown in FIG. 1 are given the same reference numerals. The guide pin 35 inserted into the bore 26 of the casing 10 has an axial shoulder 36 formed by reducing its diameter and a ring groove 37 with a snap plate 38. A first axial surface 39 of the snap plate carries a disc spring 28, and a second axial surface 40 of the snap plate contacts the bottom 32 of the recess 3. The spacing between the axial shoulder 36 and the first axial surface 39 is such that the disc spring 28 has a pre-low I? It is stipulated that it can be given.

The edge 42 of the recess 31, which receives the book spring 28, is covered by a plate with holes 41, in which case with play the hole 3, which receives the sleeve 34, as a whole 1111, and the spring of the spring 28, are covered. The diameter is defined to be formed.

In the embodiment shown in FIG. 3, the same parts as in the previous embodiment are given the same reference numerals. In contrast to the previous embodiments, the guide pin 45 has a coaxial thread l? The external thread of the threaded bolt is adapted to cooperate with the internal thread of a threaded sleeve 47, which threaded sleeve has as an integral part an outer flange 23 and a blind hole in the casing 10. 4
A Belleville spring 28, guided in 8 and preloaded in this case, holds the outer flange ) 23 against the bottom 32.

By pivoting the threaded sleeve 47, the screw pin 46 cooperating with the threaded sleeve is moved in one direction or the other as indicated by the double arrow Φ9, in which case the sleeve 34 is moved correspondingly in the axial direction, thereby The preload of the disc spring 28 is increased or decreased.

In the embodiment shown in FIG. 4, the disk spring is tensioned to the preload of the return spring.

In the diagram shown in the upper part of FIG. 5, the horizontal direction is l? It represents the rotation angle α of the pump piston (FIG. 1) and the vertical direction represents the stroke. In an injection pump with a normal displacement, the stroke disk 2 is always in contact with the roller 14 during the suction and discharge strokes of the pump piston 11, so that the pump piston 11 moves along the stroke curve 50. do.

In injection pumps with a large delivery velocity, the stroke disk 12 is at the instant 5 of the velocity reduction 51a of the pump piston 11.
1, the pump piston moves along the partial curve 52 and contacts the roller 14 again at a time 53 displaced from the bottom dead center UT in the discharge direction to the top dead center, so that the contact is not an impact. It is carried out according to

Although the device according to the invention does not completely avoid the above-mentioned separation of the pump piston 11, the dashed line 54. ”
: the sea urchin presses down the pump piston 11, and the pump piston contacts the roller 14 again at time 55, either before reaching the bottom dead center UT or just after the bottom dead center, depending on the rotational speed.

In the diagram shown at the bottom of FIG. 5, in the horizontal direction, I? The rotation angle α of the [Nzopiston] 1 is plotted, and the velocity is plotted in the vertical direction. The speed curve 56 belonging to the stroke curve 50 has its highest height at the instant 51a, from which point I? The stroke sequence of the pump piston 1.1 shown in FIGS. 1 to 4, in which the pump piston speed is reduced to top dead center and converted in a similar manner into a negative speed range, is as follows: No. 5 As shown in the figure, the pump piston 11 moves from the bottom dead center position to the stroke curve 5.
0 to the maximum speed at point 50;
By doing so, the disc spring is compressed, and as a result, the pump piston 11 draws a partial curve indicated by the broken line 54, and reaches the bottom dead center UTO.
The stroke curve 50 is reached immediately after the front or bottom dead center UT.

[Brief explanation of the drawing]

The drawings show embodiments based on the present invention.
The figure is a partial sectional view of the first embodiment, FIG. 2 is a partial sectional view of the second embodiment, FIG. 3 is a partial sectional view of the third embodiment, and FIG. 4 is a partial sectional view of the fourth embodiment. FIG. 5 is a diagram showing the stroke and speed curves of the pump piston. 10...Casing, 11...Pump piston, 12
... Stroke disk, ]3... Cam surface, 14... Roller, 15... Roller ring, 16... Inner chamber, 17...
Pipe line, 18... Adjustment lever, 19... Control hole, 20
...Return spring, 21...Spring receiver, 22...Ring shoulder, 23...Outer flange, 24...Sleeve,
25... Guide bottle, 26... Hole, 27... Opening,
28... Belleville spring, 29... Ring shoulder, 30...
Standard plate, 31... recess, 32... bottom, 34
... Sleeve, 35 ... Guide pin, 36 ... Axial direction shoulder, 37 ... Ring groove, 38 ... Snap plate, 39 and cow 0 ... Axial direction surface, 41 ... Plate with holes, 42...edge, 43...hole, 45...
Guide bottle, 46... Threaded delt, 47... Threaded sleeve, 48... Blind hole, 50... Stroke curve, 51...
・Time point, 52... Partial curve, 53... Time point, 54.
・Dotted line, 55... Time point, 56... Velocity curve problem, \・ Nobui': D・! Italy - Continued from page 1 0 Inventor Gerhard Höfer Germany j16

Claims (1)

[Claims] 1. A fuel injection pump for an internal combustion engine, comprising a pump piston having a stroke disk and driven by a shaft, the stroke disk extending along a roller supported in the axial direction. In this case, the pump piston carries out an additional stroke movement, and a return spring is provided which brings the stroke disk into contact with the roller, so that after the pump piston has finished discharging, the stroke circle from the roller is removed. In the type equipped with a device for preventing separation of the plate, the device for preventing separation of the stroke disk from the roller includes a pump casing (10),
Fuel injection pump for an internal combustion engine, characterized in that it is a spring member (28) fitted between the IF piston (11). 2. A fuel injection pump for an internal combustion engine, having a pump piston with a stroke disk and driven by a shaft, the stroke disk running along an axially supported roller; The pump piston is adapted to carry out an additional stroke movement, and a return spring which brings the stroke disk into contact with the roller is supported by the pump casing and the spring receiver of the pump piston, so that it is removed from the roller after the pump piston has finished discharging. A device is provided to prevent the stroke disk from separating, and in those of the type passing through a guide pin or spring receiver coaxially guided in the pump casing with respect to the return spring, the stroke disk from the roller is As a device for preventing separation of the plates, a spring member (28) and a sleeve (24, 34), which are fitted differentially between the pump casing (10) and the pump piston (11), move forward and backward in the direction of action through the guide pin (2).
5, 35, 45), and the spring receiver (21) is placed on the sleeve (24, 34) at the latest at the end of the discharge stroke.
) A fuel injection pump for an internal combustion engine, characterized in that the UrI distance between the sleeve (24, 34) and the spring receiver (21) is defined so that the sleeve (24, 34) is pressed against the spring member (28) via the spring member (28). 3. A patent claim in which the spring portion 4 = A is a plane spring (28) that coaxially surrounds the guide pin (25, 35, 45), and the disc spring +1 is configured as a piece 111L, a spring set, or a spring support. The fuel injection pump according to the range 2 above. 4. Fuel injection pump according to claim 3, wherein the disc spring (28) is arranged in a recess (31) of the pump casing (10). 5 The guide pin (35) has a sleeve (34) in the spring side section.
), which has an axial shoulder (36) formed by a diameter reduction of the sump supporting the flange, and a casing-side section protruding from the axial shoulder (38), which
) is in contact with the bottom (32) of the recess (31) and the axial shoulder (
5. A fuel injection pump according to claim 3, wherein the distance between the axial surface (36) and the axial surface (39) is defined. 6 The outer flange, 6. Fuel injection pump according to claim 5, having a threaded thread (46,), the external thread of the threaded thread cooperating with the internal thread of the threaded sleeve (47). 7. Sleeve (24) is the outer flange (23) in the axial direction
one ring shoulder (2) of this outer flange.
2) in which one end section of the return spring (20) is in contact and the other ring shoulder is in contact with one end section of the disc spring (28). Fuel injection pump as described in section. 8. The recess (31) for receiving the disc spring (28) is covered by the holed plate (41), and the holed plate (41) is covered with the holed plate (41).
1) The diameter of the hole (43) in 1) is defined in such a way that it forms a spring plate for a disk spring (28). pump.