DE102006059581B4 - Acquisition of a load signal for controlling an exhaust gas recirculation system - Google Patents

Abstract

An internal combustion engine having an exhaust gas recirculation system, comprising an electrical exhaust gas recirculation valve in the exhaust gas recirculation line, which is controlled in dependence on the control rod position of an injection pump, wherein a pickup determines the position of the control rod without contact and at predetermined positions a signal to a switch that initiates the opening or closing of the Exhaust gas recirculation valve causes, characterized in that the tapping device consists of at least one on the control rod (1) directly or indirectly fixed magnet (3) whose magnetic field of a crankcase (6) fixed Hall sensor (5) is detectable and the Hall Sensor (5) for adjustment in control rod movement direction is displaceable and the Hall sensor (5) on a displaceable carriage (13) is arranged, wherein the carriage (13) is subjected to force in its leadership by a spring and on its outside a toothing (15 ), in a worm of a rotatable adjusting bolt (16) engages so that by rotating the adjusting bolt (16) of the carriage (13) is displaceable.

Description

The invention relates to an internal combustion engine with an exhaust gas recirculation system, comprising an electrical exhaust gas recirculation valve in the exhaust gas recirculation line, which is controlled in response to the control rod position of an injection pump, wherein a pickup device determines the position of the control rod contactless and at predetermined positions a signal to a switch passes, the Opening or closing the exhaust gas recirculation valve causes.

Modern exhaust gas recirculation systems are usually controlled by an electronic injection, for which purpose a control device is present on the internal combustion engine. The exhaust gas recirculation amount is controlled via a map which corresponds to the load conditions of the internal combustion engine.

In today's "mechanical" internal combustion engines with a series injection pump completely lacks such electronics. The only load signal in these "mechanical" internal combustion engines is the position of the control rod on the injection pump.

From the WO 2006/066737 A1 an exhaust gas recirculation control is known, which has a Hall sensor as a pick-off and cooperates with integrated into the control rod magnet. The DE 44 13 496 C1 discloses an adjustable mounting of a Hall sensor. Wieter is known an actuator for the exhaust overflow valve of a diesel engine.

The generic DE 10 2004 060 841 A1 describes such an internal combustion engine, wherein in the exhaust gas recirculation line, an electrically controlled exhaust gas recirculation valve for controlling the effective cross section of the exhaust gas recirculation line is arranged and an electrical pickup determines the position of the control rod contactless and then controls the exhaust gas recirculation valve.

The invention has for its object to provide an internal combustion engine with a controlled exhaust gas recirculation system, in which a secure and accurate detection of the rack position is done and with simple means an adjustment of the pickup device is possible.

According to the invention, this object is achieved in that the pickup device consists of at least one directly or indirectly fixed to the control rod magnet whose magnetic field is detected by a mounted on the crankcase Hall sensor and the Hall sensor for adjustment in control rod movement direction is displaceable. With the magnets on the control rod and the Hall sensor an extremely accurate and absolutely reliable detection of the rack position is achieved. With the displaceability of the Hall sensor in control rod movement direction adjustment is possible and can compensate for tolerances and set different switching points depending on the engine type.

In an embodiment of the invention, the Hall sensor is arranged on a displaceable slide. By moving the carriage, the adjustment can be made.

In a further embodiment, a holding device is attached to the control rod, which has arranged in alignment in the direction of movement of the control rod magnets. Advantageously, the holding device, a plastic clip which is introduced into a recess of the control rod. The magnets are in development of the invention bar magnets.

In an inventive embodiment, the magnets are molded flush with an outer edge of the plastic of the holding device so that only one end face of the magnets is free of plastic. Of course, all magnets are the same polarity. Due to the plastic sheathing disturbing effects can be avoided by the metallic control rod and you get a sharply demarcated magnetic field.

In a further embodiment, a metal pin is arranged in each case at the beginning and at the end of the row of magnets. As a result, the magnetic field is stabilized.

An embodiment of the adjustment is characterized in that a toothing is arranged in the carriage, which is guided on a fixed in its longitudinal direction rotatable adjusting screw with a thread.

In a further development, the toothing consists of a bent plate with a toothed recess, which engages in the thread of the adjusting screw.

The curved plate presses in inventive development at the same time the slide in his leadership.

An alternative embodiment of the adjustment is characterized in that the carriage is subjected to a force in its guide via a spring and on its outer side has a toothing in which engages a screw of a rotatable adjusting bolt so that by rotating the adjusting bolt, the carriage is displaceable.

In a further development, the spring is a bent sheet, which is supported on a pin fixed with respect to its position.

In a further development of the invention, the carriage is located in a sensor housing attached to the crankcase.

In an inventive embodiment, the adjusting screw and the adjusting bolt are secured after adjustment of the carriage by a locking plate or a cap from unauthorized adjustment.

The magnets are in a preferred embodiment bar magnets.

The internal combustion engine is in an embodiment of the invention, a self-igniting internal combustion engine.

Further advantageous embodiments of the invention are described in the drawings, are described in more detail in the embodiments illustrated in the figures of the invention.

• 1 in einem Schnitt eine erste erfindungsgemäße Ausführungsform im Bereich der Regelstange und der Abgreifvorrichtung,
• 2 einen Schnitt nach B-B in 1,
• 3 in einem Schnitt eine zweite erfindungsgemäße Ausführungsform im Bereich der Regelstange und der Abgreifvorrichtung und
• 4 einen Schnitt nach B-B in 3.

Show it:

• 1 in a section a first embodiment according to the invention in the region of the control rod and the pick-off device,
• 2 a cut to BB in 1 .
• 3 in a section, a second embodiment according to the invention in the region of the control rod and the pick-off device and
• 4 a cut to BB in 3 ,

1 shows a section of a self-igniting internal combustion engine in the control rod 1 , By the arrangement described below, an exhaust gas recirculation valve in response to the position of the control rod 1 be switched (black and white circuit).

This is done in a recess of the control rod 1 a plastic clip 2 brought in. This includes in an escape in the direction of movement of the control rod 1 attached magnets 3 whose pole ends (all magnets 3 are the same polarity or mounted accordingly) flush with an outer edge with a plastic sheath 21 are overmoulded so that only one of the front sides 3a is free of material. In the embodiment shown here are the magnets 3 Bar magnets.

Furthermore, each at the beginning and at the end of this series is a metal pin 4 attached to stabilize the magnetic field. this shows 2 in which a cut to BB from 1 is shown. Through the plastic coating 21 can cause interference by the metallic control rod 1 be avoided and thus obtains a sharply demarcated magnetic field.

This magnetic field can now be controlled by a Hall sensor 5 , on the crankcase 6 is fastened, be detected. The Hall sensor 5 - shown is just the case - is now attached so that the edge of the plastic clip 2 on which the magnets 3 are flush mounted, slides in engine operation close to him over. The Hall sensor 5 causes, depending on whether he detects a magnetic field or not, the opening or closing of a switch. This switch is used to switch an exhaust gas recirculation valve by means of a solenoid (not shown). Thus, the exhaust gas recirculation valve becomes dependent on the position of the control rod 1 connected.

To compensate for tolerances and to display different switching points depending on the type of internal combustion engine, the position of the Hall sensor 5 be finely adjustable. Two concepts are presented here. Both concepts have in common that the Hall sensor 5 on a carriage (in the embodiment of the 1 and 2 this is by the reference numeral 7 is fixed), which via a guide in the sensor housing 8th which also includes the switch, is movable only in control rod movement direction.

In Concept I is in the sleigh 7 a bent sheet metal 9 attached, in the middle of a recess with a toothing 20 having. The teeth of this gearing 20 grab into a thread 19 an adjusting screw 10 one in the sensor housing 8th is rotatably mounted and fixed in its longitudinal direction. The curved and tensioned sheet metal 9 pushes the sledge 7 in a guide in the sensor housing 8th so that the hall sensor 5 always at a defined distance to the plastic clip 2 located. Due to the interlocking toothing between sheet metal 9 and adjusting screw 10 can be done by turning the adjusting screw 10 , which for this purpose at your end a slot 22 and accessible from outside, the position of the carriage 7 to be changed.

The live sheet 9 also creates a self-locking, so that the adjustment of the carriage 7 not changed by vibrations. To a later adjustment of the carriage 7 to prevent by the customer is a barb-trained locking plate 11 into the sensor housing 8th , which is made of plastic, flush or recessed, allowing access to the slot 22 the adjusting screw 10 is covered.

Furthermore, the sensor housing 8th with special screws, whose heads are sunk to avoid twisting with pliers, on the crankcase 6 attached. These special screws (eg Torx-Temper-Plus) can only be assembled and disassembled with tools that are not commercially available.

In the 3 and 4 an alternative concept II is shown, which will be described below. 3 shows in a section this second embodiment according to the invention or this concept II in the region of the control rod 1 and the pick-off device. 4 shows a section to BB in 3 ,

The arrangement of the magnets 3 - again bar magnets - in the plastic clip 2 at the control rod 1 is with that of the embodiment according to the 1 and 2 identical.

In this embodiment is in the carriage 13 a bent sheet metal 12 attached to the sledge 13 due to its montagebedingte bias and the support on a pin 14 in the sensor housing 8th is mounted, presses into its guide in the sensor housing 8, so that the Hall sensor 5 always at a defined distance to the plastic clip 2 located.

On the side facing away from the crankcase 6 of the carriage 13 is a plate with a toothing 15 attached. In this gearing 15 engages a worm on the face of an adjusting bolt 16 is shaped. On the opposite end 3a of the adjusting bolt 16 which is rotatable in the sensor housing 8th is stored, a hexagon socket is introduced. By turning with the help of a suitable screwdriver can now on the worm gear slide 13 be positioned. A self-locking, which is to avoid the adjustment by vibration, is through a sealing ring 17 between adjusting bolts 16 and sensor housing 8th achieved, which also has a sealing function.

To prevent subsequent adjustment by the customer, a cap 18 so in the adjustment of the housing 8th struck that it can only be removed by destruction. Furthermore, the sensor housing 8th fastened with special screws whose heads are countersunk to avoid twisting with pliers. These special screws (eg Torx-Temper-Plus) can only be assembled and disassembled with tools that are not commercially available.

During assembly, the control rod 1 fixed in a defined position. The position is chosen to match the desired switching point of the Hall sensor 5 equivalent. Turn the adjusting screw 10 or the adjusting bolt 16 becomes the Hall sensor 5 now adjusted so that it switches exactly in this position. The signal used for this purpose is a lamp temporarily connected to the switch or an integrated light-emitting diode. Subsequently, the locking plate 11 or the cap 18 assembled.

By the described embodiments is a simple adjustment of the carriage 7 . 13 and thus the Hall sensor 5 reached. In addition, the switching points are extremely accurate and secure.

LIST OF REFERENCE NUMBERS

1

control rod

2

Plastic clip

3

magnets

3a

front

4

metal pin

5

Hall sensor

6

crankcase

7

carriage

8th

sensor housing

9

bent sheet metal

10

adjustment

11

Locking plate

12

bent sheet metal

13

carriage

14

pen

15

gearing

16

adjusting

17

seal

18

cap

19

thread

20

gearing

21

Plastic sheathing

22

slot

Claims (10)

Internal combustion engine with an exhaust gas recirculation system, comprising an electrical exhaust gas recirculation valve in the exhaust gas recirculation line, which is controlled in dependence on the control rod position of an injection pump, wherein a pickup device determines the position of the control rod without contact and at predetermined positions, a signal to a switch which causes the opening or closing of the exhaust gas recirculation valve, characterized in that the tapping device consists of at least one of the control rod (1) directly or indirectly fixed magnet (3) whose magnetic field of an am Cage housing (6) mounted Hall sensor (5) is detectable and the Hall sensor (5) for adjustment in control rod movement direction is displaceable and the Hall sensor (5) on a displaceable carriage (13) is arranged, wherein the carriage (13 ) is force-loaded in its guide by a spring and on its outside a toothing (15) into which a screw of a rotatable adjusting bolt (16) engages so that by rotating the adjusting bolt (16) of the carriage (13) is displaceable. Internal combustion engine after Claim 1 , characterized in that the spring is a bent plate (12), which is supported on a pin (14) fixed with respect to its position. An internal combustion engine with an exhaust gas recirculation system, comprising an electrical exhaust gas recirculation valve in the exhaust gas recirculation line, which is controlled in dependence on the control rod position of an injection pump, wherein a pickup device determines the position of the control rod without contact and at predetermined positions a signal to a switch that initiates the opening or closing of the Exhaust gas recirculation valve causes, characterized in that the tapping device consists of at least one on the control rod (1) directly or indirectly fixed magnet (3) whose magnetic field of a crankcase (6) fixed Hall sensor (5) is detectable and the Hall Sensor (5) for adjustment in control rod movement direction is displaceable, wherein the Hall sensor (5) on a displaceable carriage (7, 13) is arranged, and wherein in the carriage (7) a toothing (20) is arranged on one in their Longitudinally fixed rotatable Einstellschraub e (10) with a thread (19) is guided. Internal combustion engine after Claim 3 , characterized in that the toothing (20) consists of a bent plate (9) with a toothed recess which engages in the thread (19) of the adjusting screw (10). Internal combustion engine after Claim 4 , characterized in that the bent sheet metal (9) at the same time pushes the carriage (7) in his leadership. Internal combustion engine after Claim 1 to 5 , characterized in that on the control rod (1) has a holding device is fixed, which in alignment in the direction of movement of the control rod (1) arranged magnets (3). Internal combustion engine after Claim 6 , characterized in that the magnets (3) are encapsulated flush with an outer edge of the plastic of the holding device so that only one end face (3a) of the magnets (3) is free of plastic. Internal combustion engine according to one of Claims 6 or 7 , characterized in that in each case at the beginning and at the end of the row of magnets (3), a metal pin (4) is arranged. Internal combustion engine according to one of the preceding claims, characterized in that the magnets (3) are bar magnets. Internal combustion engine according to one of the preceding claims, characterized in that the internal combustion engine is a self-igniting internal combustion engine.

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