JP3119908B2 - Fuel injection pump for internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The invention relates to a fuel injection pump for an internal combustion engine of the type defined in the preamble of claim 1.

[0002]

2. Description of the Related Art German Patent Application Publication No. 3805033.
A fuel injection pump of the above-mentioned type, which is known from the specification, has a pump piston which can be reciprocated simultaneously with a rotary movement by means of a cam drive. The cam drive comprises a stationary part configured as a roller ring and a rotating part configured as a stroke disk driven by a drive shaft. The stationary part is rotatable with respect to the rotating part by means of the injection regulating device, whereby the relevance of the stroke movement of the pump piston to the rotation angle of the drive shaft is variable. The pump piston limits the pump working chamber which is depressurized via an electrically controlled valve during the pump piston stroke to control the pump piston stroke available for injection. It is possible. The stationary part of the cam drive is engaged radially by a pin, which at the other end is supported by a piston via a sliding element. The piston is arranged in a fuel-filled cylinder and is tangentially shiftable, in this case pivotable, with respect to the stationary part under the pressure of the fuel. However, it is also desired that the injection adjustment in relation to the various operating parameters is likewise realized by electrically controlled valves, so that adjustment of the stationary part is no longer necessary.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to further improve a fuel injection pump.

[0004]

According to the invention, the above-mentioned object has been achieved by a fuel injection pump having the features of claim 1.

[0005]

An advantage of the fuel injection pump according to the present invention having the features described in claim 1 is that the stationary part of the cam drive device uses the components of a known fuel injection pump having an injection adjusting device. In that known fuel injection pumps can be modified slightly.

[0006] Advantageous refinements of the fuel injection pump according to the invention are described in the further claims. With the construction of the receiving part according to claim 2, the receiving part does not require any additional sealing points in the pump housing. With the configuration according to claim 3, the sliding element can be shifted for tolerance compensation. However, the displacement of the receiving part due to the impact acting on the sliding member is prevented. With the configuration of the receiving part according to the fifth aspect, the sliding member can be mounted from the outside of the pump casing.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to two illustrated embodiments.

The distribution type fuel injection pump shown in FIG.
It has a pump piston 13 working in a cylinder hole 10 of a bush 12 inserted into a pump casing 11. The pump piston 13 can be reciprocated simultaneously with the rotational movement by the cam driving device 14. The cam driving device 14 includes a stroke disk 17 as a rotating part connected to a driving shaft 16 of the fuel injection pump, and a roller ring 18 as a stationary part. The stroke disk 17 has a cam track with an end cam ridge 19 which contacts a roller 20 held in a roller ring 18. Pump piston 13
In addition, the electrically controlled valve 22 inserted into the pump casing 11 has the pump working chamber 2 in the cylinder bore 10.
3 are limited. The inner chamber 24 of the fuel injection pump is filled with fuel by a feed pump 25 incorporated in the fuel injection pump and used as a suction chamber, from which fuel is supplied to a pump working chamber.

The roller ring 18 has a cylindrical outer peripheral surface 26, through which the roller ring 18 is supported radially in a hole 27 of the pump casing 11. A pin 30 is engaged with the roller ring 18 in a radial direction, and the pin 30 is secured by a rod 31 in the roller ring. The end of the pin 30 protruding from the roller ring 18 is connected to a slider 3 used as a sliding member.
Three radial holes 32 are supported. The slide 33 is
The drive shaft 1 provided on the inner surface side of the pump casing 11
6 or a longitudinal groove 36 extending parallel to the longitudinal axis 34 of the fuel injection pump and opening towards the inner chamber 24.
Is arranged so as to be shiftable in the axial direction. Slider 3
3 is guided with a slight play between the bottom 37 of the longitudinal groove 36 and the outer peripheral surface 26 of the roller ring 18. Slider 33 tangential to roller ring 18
Are arranged in the longitudinal groove 36 with as little play as possible, so that the rotational movement of the roller ring is locked and the impact-based longitudinal force acting on the roller ring and supported via the slide is provided. The deflection of the slide in the directional groove is prevented. The pin 30 is pivotally arranged with slight play in the bore 32 of the slide 33 and is shiftable along its longitudinal axis 38.

This makes it possible to correct errors in the distance and angle between the roller ring 18 and the slider 33 without tightening the pin 30. The roller ring 18 and the pins 30 can be inherited without modification from known fuel injection pumps with adjustable roller rings. If the roller ring is locked, no additional sealing is required.

The connection between the inner chamber 24 and the pump working chamber 23 is controlled by a valve 22. During the suction stroke of the pump piston 13, the valve 22 is opened and fuel flows from the inner chamber 24 through the passage 40 and the valve 22 to the pump working chamber 23. During the compression stroke of the pump piston 13, the valve 2
2 is closed during the selected high-pressure delivery of the pump piston, and the fuel under high pressure is indicated by a dotted line via a distribution opening 41 on the outer circumference of the pump piston 13 with a corresponding rotation of the pump piston. It is fed to the illustrated feeding passage 42,
The passage 42 is connected via an injection conduit to the injection point of the internal combustion engine. The closing period, and thus the high-pressure injection quantity and the closing time of the valve 22, which defines the start of the high-pressure injection phase, are determined by a control unit (not shown). A rotation transmitter 43 is provided for detecting the rotation speed and rotation position of the drive shaft 16 of the fuel injection pump, and the transmitter 43 is connected to a control device. With this control device, other parameters of the internal combustion engine driven by the fuel injection pump, such as, for example, load, temperature, etc., can be taken into account.

In the second embodiment shown in FIG. 2, the roller ring 18 and the pin 30 are configured in the same manner as in the first embodiment. However, unlike the first embodiment, the slide 46 is arranged in a blind hole 47 in the pump casing 11 extending parallel to the pump longitudinal axis 34. Pin 30
Is the pump casing 11 between the inner chamber 24 and the blind hole 47.
It protrudes into the hole 49 of the slider 46 through the opening 48 inside. The slide 46 is axially displaceable in the blind hole 47 and is arranged with as little play as possible transversely to its longitudinal axis. Blind hole 47
Has a thread section 50 towards the outside of the pump casing 11, into which a closing screw 51 for closing the blind hole 47 is screwed. A seal ring 52 is fastened and fixed between the screw 51. The slider 46 can be inserted into the blind hole 47 from the outside of the pump casing 11. Second
In the embodiment, the roller ring 18, the pin 30, and the slider 46 are used.
Can be inherited almost unchanged from known fuel injection pumps with adjustable roller rings. Advantageously, the location of the blind hole 47 for the slide 46 is selected so that the blind hole 47 can be drilled at a low cost during the automatic production of the pump housing 11. Since the closing screw 51 and the seal ring 52 are standard products, locking of the roller ring 18 can be achieved by simple means.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of a fuel injection pump.

FIG. 2 is a sectional view of a second embodiment of the fuel injection pump illustrating an area II in FIG. 1;

[Explanation of symbols]

10 Cylinder bore, 11 Pump casing, 12
Bush, 13 pump piston, 14 cam drive, 16 drive shaft, 17 stroke disc,
18 roller ring, 19 end cam ridge, 2
0 rollers, 22 valves, 23 pump working chamber, 24
Inner chamber, 25 feed pump, 26 outer peripheral surface, 27
Hole, 30 pin, 31 rod, 32 hole,
33 slider, 34 longitudinal axis, 36 longitudinal groove, 37 bottom, 38 longitudinal axis, 40 passage, 41 distribution opening, 42 feed passage, 43
Rotary transmitter 46 Slider, 47 blind hole, 48 opening, 49 hole, 50 thread section, 51 closing screw, 52 seal ring

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Wolfgang Brown Germany Ditzingen Haldenreinstraße 12 (72) Inventor Wolfgang Fehrmann Germany Stuttgart 80 im Steingarten 25 (72) Inventor Dieter Junger Germany Republic of Stuttgart 50 Ebitzweg 1 (58) Fields studied (Int. Cl. ⁷ , DB name) F02M 41/12-41/14 F02D 1/18

Claims (5)

(57) [Claims] 1. A fuel injection pump for an internal combustion engine, comprising:
Having at least one pump piston (13);
The piston (13) is rotated by the cam drive (14).
Reciprocating motion can be performed simultaneously with rolling motion.
(14) is formed by the stationary part (18) and the drive shaft (16).
And a rotating part (17) driven by
The pivot position of the stationary part (18) is at one end within the stationary part
Can be fixed by a pin (30) that radially engages the
The pin (30) is at the other end, and the sliding member (33; 4)
6) supported by the pump piston (13)
The pump working chamber (23) restricted by
To control the pump piston stroke,
Electrically controlled during pump stroke of Ston (13)
Of a type which can be depressurized via the valve (22)
In addition, the sliding member (33; 46) is provided for the fuel injection pump.
In the receiving part (36; 47) of the casing part (11),
Parallel to the longitudinal axis (34) of the fuel injection pump
It can be shifted in the axial direction, and in addition to the stationary part (18)
Guided and arranged with a slight play in the tangential direction
In order to control the start of injection, the valve
Controlled in relation to engine operating parameters
A fuel injection pump for an internal combustion engine . 2. The receiving part is connected to an inner chamber (2) of the fuel injection pump.
2. The fuel injection pump according to claim 1, wherein the fuel injection pump is formed as a longitudinal groove open toward 4) . 3. The sliding member (33) has a longitudinal groove (3).
6) and the outer peripheral surface (2) of the stationary part (18).
3. The fuel injection pump according to claim 2, wherein the pump is arranged with a slight play between the fuel injection pump and the fuel injection pump. 4. The fuel injection pump according to claim 1, wherein the receiving portion is an inner chamber (2).
2. The fuel injection pump according to claim 1, wherein the fuel injection pump is formed as a blind hole (47) in a casing member having an opening (48) lateral to the 4) . 5. A blind hole (47) is provided in the casing part (1).
It is open towards the outside of 1) and has a thread section (50) in the open area , in which a closing screw (51) can be screwed. The fuel injection pump according to claim 4, wherein