JP2003269218A - Device for operating internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a labor and a cost for manufacture by incorporating various types of sensors as a module in a device. <P>SOLUTION: This device for operating an internal combustion engine comprises a casing 5, and the casing 5 supports one additional sensor element 15 in addition to a function unit 10 for operating the internal combustion engine. A sensor casing 20 for storing the sensor element 15 therein is installed in the device, and the casing 5 of the device 1 supports the sensor casing 20. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an apparatus for operating an internal combustion engine, which is provided with a casing,
In addition to the functional unit for operating the internal combustion engine, the housing is of the type that additionally supports one sensor element.

[0002]

2. Description of the Related Art German Patent Publication No. 324
A sensor is already known from 3743 specification which detects the pressure in the combustion chamber of an internal combustion engine by means of the resistance value of an electrical conductor mounted on the spark plug, which changes under pressure. The electrical conductors are in this case attached to the insulating legs of the spark plug.

[0003]

[Patent Document 1] German Patent Application Publication No. 324
3743 Specification

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to improve an apparatus for operating an internal combustion engine of the type mentioned at the outset so that a wide variety of sensors can be integrated into the apparatus as modules. This reduces manufacturing effort and cost.

[0005]

In order to solve this problem, in the configuration of the present invention, a sensor casing for accommodating the sensor element is provided, and the casing of the device supports the sensor casing. I chose

[0006]

According to the present invention having the features of claim 1,
The device for operating an internal combustion engine has the advantage that a sensor casing for accommodating the sensor element is provided, which sensor casing is supported by the casing of the device. In this way various types of sensors can be integrated into the device as modules. The device can thus be provided, for example, with a standardized mounting space for such a sensor casing. Depending on the type of sensor used, it is not necessary to provide different device geometries for mounting the respective sensor. Therefore, the device according to the present invention is uniform in a large number and is inexpensive and can be manufactured at low cost.

Furthermore, by using the sensor casing, it is possible to easily realize a shield against environmental influences, electric fields and electromagnetic disturbance radiation, and the sensor element is protected from such influences. .

Claims 2 and the following provide advantageous further developments and improvements of the device according to claim 1.

Particularly advantageously, the sensor housing is arranged in the region of the support, in particular in the region of the shoulder or flange shoulder of the functional unit, for fixing to the casing of the device. In this way, when fixing the functional unit to the casing of the device, the sensor casing can be firmly clamped between the functional unit and the casing of the device, so that it can be stably supported on the device. . Instead of a support, the sensor casing serves for fixing the functional unit to the casing. For this purpose, the casing of the device need only be somewhat extended to accommodate the sensor casing, otherwise no structural modification of the device is necessary.

Such an advantage is realized especially when the sensor casing is mounted on the support of the functional unit.

Particularly preferably, at least the sensor element is preloaded and mounted on the sensor housing. In this way, the pressure sensor can also measure negative pressure. Moreover, the reaction characteristics of the sensor element are improved. If the sensor element and the connecting contact are preloaded and arranged in the sensor housing, the contact between the sensor element and the connecting contact is ensured by the preload.

A further advantage is obtained if the sensor casing is made of metal. In this way, the sensor element is protected from electrical fields and electromagnetic disturbance radiation.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings.

In the drawings, reference numeral 1 designates a device according to the invention, which device is provided for the operation of an internal combustion engine. In this case, the device 1 may be arranged, for example, in the cylinder head of an internal combustion engine. This device 1
May in this case be, for example, a spark plug, a glow plug, an inflow valve, an outflow valve or a fuel injection valve. The device 1 has a casing 5. The casing 5 is fixed in the cylinder head and has threads for this purpose, which threads are not shown. Casing 5
Supports a functional unit 10 provided for operating the internal combustion engine. Only a part of the functional unit 10 is shown in the drawing. The casing 5 further has a sensor casing 20, in which the sensor element 15 is arranged. The sensor housing 20 may have, for example, standardized geometric dimensions, and thus various different types of sensor elements may be provided in the device 1.
The geometrical dimensions of the device 1 can be incorporated as a module without having to be adapted to the particular type of sensor element. Therefore, the sensor casing 20
The sensor element 15 arranged therein can be realized in various ways without affecting the geometry of the device 1. Because the sensor element 15 is a sensor housing 2 having an invariably defined geometrical dimension.
This is because it is incorporated into 0. The sensor element 15 can thus be, for example, piezoceramic or piezoelectrically or inductively or capacitively.
Alternatively, it may be designed as a strain cage or the like.

In the sensor casing 20, together with the sensor element 15, connection contacts 30, 35 are arranged. The connection contacts 30 and 35 are respectively in contact with the sensor element 15 in order to transmit the measurement signal of the sensor element 15 to the outside. The sensor casing 20 connects the sensor element 15 to the contact 3
0, 35 are protected from the influence of the environment such as combustion gases from the combustion chamber of the cylinder of the internal combustion engine. Since the sensor housing 20 is preferably made of metal, the sensor element 15 is further protected from electrical fields and electromagnetic disturbance radiation. Therefore, the sensor casing 15 allows the sensor element 15
The measurement results sent from the instrument are prevented from being influenced by ambient influences, electric fields or electromagnetic disturbance radiation.

If the sensor housing 20 is made of metal, it can also be used as a reference potential for connecting one of the two connecting contacts 30, 35. Therefore, by coupling the sensor casing 20 with the casing 5 of the device, which is screwed into the cylinder head, the sensor casing 20 is located on the vehicle ground.

Of the two connecting contacts 30, 35, the other connecting contact which is not connected to the sensor casing 20 is led out of the sensor casing 20 via a connecting cable (not shown) and is likewise not shown. Connected to the circuit. This evaluation circuit evaluates the measured value sent from the sensor element 15. In order to transmit the measurement result, of course, the sensor element 15 must be electrically conductively connected to both connection contacts 30, 35, respectively. For this purpose, the connecting contacts 30, 35 project into the sensor element 15, respectively, as shown. In this case, the first connecting contact 30 projects into the sensor element 15 from above and the second connecting contact 35 projects from below into the sensor element 15.

For contact with the outside, contact layers 40 and 45 are used.
Done through. Therefore, the sensor element 15
It is embedded between the upper contact layer 40 and the lower contact layer 45. The upper contact layer 40 is in contact with the first connecting contact 30 and the lower contact layer 45 is in contact with the second connecting contact 35. Both contact layers 40, 45 are galvanically separated from the sensor casing 20 by an insulating layer 50, 55, respectively, and are therefore electrically insulated from the sensor casing 20. In this case, one of the two contact layers 40, 45, for example the lower contact layer 45, is placed directly on the sensor casing 20 in order to ensure the connection between the second connection contact 35 and the reference potential. It may be done. The upper contact layer 40 ensures that the first connecting contact 30 is not conductively connected by contact with the sensor casing 20.
It must be insulated from the sensor casing 20 by the upper insulating layer 50. The connection cable insulated from the sensor casing 20 can be guided from the upper contact layer 40 to the evaluation circuit via the notches provided in the upper insulating layer 50 and the sensor casing 20.

If the lower insulating layer 55 is also provided, the contact between the lower contact layer 45 and the reference potential or the sensor casing 20 is also made via the connecting cable extending in the sensor casing 20.

In an advantageous configuration of the invention, the components of the sensor are preloaded and mounted in the sensor casing 20 as indicated by the double-headed arrows in the drawing. This means that, after the insulating layers 50 and 55, the contact layers 40 and 45, and the sensor element 15 are attached to the sensor casing 20, the cover 60 is pressed and mounted on the sensor casing 20 by, for example, a pusher. It is realized by doing. Thereby, the component parts 15, 30, 35, 40, 45, 50, 55 are preloaded in the sensor casing 20. By preloading the sensor element 15, the sensor element 15 can also detect a negative pressure in the combustion chamber of the internal combustion engine, for example, which occurs in the intake stroke. Furthermore, the reaction characteristics of the sensor element 15 are improved. In particular, when the contact layers 40, 45, the connecting contacts 30, 35, the sensor element 15 are preloaded and mounted in the sensor casing 20, the connecting contacts 30, 35 and the contact layers 40, 4
It is ensured via 5 and 5 that the sensor element 15 makes a good, almost error-free contact.

The cover 60 can be applied to the sensor casing 20 under pressure as described, and is then welded to the sensor casing 20, for example. In this case, the cover 60 is also made of metal, for example.

As shown, the sensor casing 20 can be arranged, for example, between the functional unit 10 and the casing 5. According to the drawing, in this case the sensor casing 20 is arranged in the region of the support 25 of the functional unit 10. In this case, the support 25 serves to fix the functional unit 10 to the casing 5 of the device 1. The support 25 may be, for example, a shoulder of the functional unit 10 or a so-called “flange shoulder”. In this case, in an advantageous configuration, the sensor housing 20 is mounted on the support 25 of the functional unit 10 as shown. In this case, the casing 5 of the device 1 is usually bent to secure it to the support 25 of the functional unit 10. In order to mount the sensor casing 20, the casing 5 may be extended and curled onto the support 70 above the sensor casing 20 instead of on the support 25. If the sensor casing 20 has an invariably defined geometrical dimension, the casing 5 is also extended by an invariably defined length and the sensor casing 20 can be assembled to the device 1. In this case, the casing 5 of the device 1 must be geometrically adapted regardless of the type of sensor element 15. The functional unit 10 is now fixed to the casing 5 of the device 1 not directly but via the sensor casing 20.

Sensor casing 2 of functional unit 10
On the side different from 0, the functional unit 10 is mounted on the support 75 of the casing 5 of the device 1 and is thereby firmly fixed to the casing 5 of the device 1. The edging of the casing 5 of the device 1 on the support 70 of the sensor casing 20 is designated by the numeral 75 in the drawing.

The sensor element 15 may be embodied as a pressure sensor, for example. Therefore, the sensor element 1
5 is able to detect the gas pressure in the combustion chamber of the internal combustion engine and send a signal indicative of this gas pressure as a measurement value to the evaluation unit. Due to the gas pressure in the combustion chamber, a gas force 65 is applied to the functional unit 10 from the combustion chamber side, in the drawing from below. The gas force 65 also presses the sensor element 15 and is converted into an electrical signal proportional to the gas pressure in the combustion chamber. This signal is further sent to the evaluation circuit. The edging portion 75 applies a counter force in the direction opposite to the gas force 65. This counterforce firmly holds the functional unit 10 and the sensor casing 20 in the casing 5 of the device 1 screwed into the cylinder head.

The edging portion 75 allows the sensor casing 20.
The counter-force applied to is designated by the numeral 80 in the drawings.

The sensor element 15 can be designed, for example, as a piezoceramic. The gas force 65 is proportional to the gas pressure in the combustion chamber and acts on the ceramic of the piezoelectric ceramic sensor element as a sliding force. The sliding force on the ceramic is converted into an electric signal proportional thereto, so that the electric signal is also proportional to the gas pressure in the combustion chamber. The electrical signal is supplied to the evaluation circuit as a measurement signal. Further suitable cutouts must be provided in the bend 75 so that the connecting line leads to the evaluation circuit. The connecting cable is provided, for example, with a plastic insulator and therefore the sensor casing 20.
And electrically isolated from the casing 5 of the device 1. The casing 5 of the device 1 is likewise preferably made of metal and, as mentioned above, lies above the reference potential or the vehicle ground. The sensor element 15 as a pressure sensor is thus based on the principle of force measurement, as described, here of the gas force 65.

The sensor element 15 is optionally piezoelectrically or inductively as described.
Alternatively, it may be formed capacitively, as a strain cage, or the like.

As shown, the sensor casing 20 can be formed in a ring shape, for example. In this case, the inner diameter of the ring is larger than the outer diameter of the functional unit 10 above the support portion 25. Therefore, the sensor casing 20 can be pushed from above into the support 25 via the functional unit 10 and thus surround the functional unit 10. The functional unit 10 thus projects above and below the sensor casing 20 as shown.

However, the functional unit 10 may be closed upward by the support portion 25, and the sensor casing 20 may be mounted on the functional unit 10 upward. In this case, the inner diameter of the sensor casing 20 may be almost zero. Even when the sensor casing 20 is formed in a ring shape as shown in the drawing, the functional unit 10 does not need to project upward beyond the sensor casing 20.

As mentioned, the device 1 may be designed as a spark plug, a glow plug, an inlet valve, an outlet valve or an injection valve. If the device 1 is formed as a spark plug, the functional unit 10 may be formed as an insulator, whereby the sensor casing 20 is arranged between the casing 5 of the spark plug and the insulator 10. The insulator, in this case preferably made of ceramic, serves for accommodating the connecting pin and the center electrode.
This center electrode is necessary to ignite the fuel-air mixture in the combustion chamber.

The sensor casing 20 can be formed with small dimensions, so that the space required for the construction within the casing 5 of the device 1 is small. Furthermore, this increases the natural frequency of the sensor casing 20 with the sensor element 15. In particular, when a piezoceramic or piezoelectric sensor element is used, it can be manufactured inexpensively due to its simple structure. The geometrical dimensions of the sensor casing 20 can be adapted to the installation space of the device 1, which can be realized by extension of the casing 5 of the device 1. Sensor element 1
By mounting 5 and the sensor casing 20 in the casing 5 of the device 1, no additional holes to the combustion chamber for mounting a separate sensor element therein are required. Components 15, 30, 35, 40, 45, 50, 5
The sensor casing 20 with 5 can be manufactured as an integrated part.

When the sensor casing 20 is formed in a ring shape, the sensor element 15, the contact layers 40 and 45, and the insulating layers 50 and 55 are also formed in a ring shape. The connecting contacts 30, 35 for receiving the measuring voltage sent from the sensor element 15 can be formed, for example, as spring contacts, the inner diameter of the sensor element 15 being in contact with the sensor element 15 as shown.

By mounting the sensor element 15 on the sensor casing 20 by preloading it, the sensor element 15 can detect the gas pressure 65 with high accuracy when the shunt of force is small.

The device according to the invention detects the high and low frequency parts of the pressure signal in the combustion chamber, which are formed by the course of the gas pressure and the course of the knocking oscillation, by means of the sensor element 15 inside the apparatus 1. It's an easy and cheap way to do it. Since the casing 5 of the device 1 or the sensor casing 20 is incorporated in the device 1, the device 1 or the cylinder head is necessary, for example, if a sensor element is incorporated between such device and the cylinder head. No structural changes in are needed. As shown, the sensor casing 20
If the outer diameter of the device does not substantially exceed the outer diameter of the functional unit 10, the sensor casing 20 is specially adapted to the casing 5 of the device 1, except for the extension of the casing 5 of the device 1 as described. It can be integrated into the device 1 without being forced. By forming the sensor casing 20 in a ring shape, the sensor casing 20 is further provided with the device 1
There is no need to adapt the geometry of the functional unit 10 for integration into the. This means that the functional unit 10
, Is extended upwardly by the support 25 with a reduced outer diameter, as shown. Other than that, the functional unit 10 does not need to be adapted for the incorporation of the sensor casing 20 into the device 1. In the example shown, a piezoceramic sensor element 15 is described.

[Brief description of drawings]

1 shows a part of a cross-sectional view of a device according to the invention.

[Explanation of symbols]

1 device, 5 casings, 10 functional units,
15 sensor elements, 20 sensor casings, 25 support parts, 30, 35 connection contacts,
40,45 contact layer, 50,55 insulating layer,
60 cover, 65 gas power, 70,75 support, 80 counter force

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Werner Hess             Federal Republic of Germany             Orndorfer Strasse 23 (72) Inventor Uwe Kasner             Germany, Meklingenwe             Lunar-Egg-Strasse 4 F-term (reference) 3G019 KA01 KA28 KD17

Claims (11)

[Claims] 1. A device for operating an internal combustion engine, comprising a casing (5), which casing (5) is a functional unit (1) for operating the internal combustion engine.
0) in addition to one sensor element (15), a sensor casing (20) for accommodating the sensor element (15) is provided and the device (1) Device for operating an internal combustion engine, characterized in that said casing (5) of said carries a sensor casing (20). 2. Device according to claim 1, wherein a sensor casing (20) is arranged between the functional unit (10) and the casing (5). 3. The device as claimed in claim 1, wherein the device (1) is embodied as a spark plug or glow plug, an inflow valve, an outflow valve or an injection valve. 4. The functional unit (10) preferably has a ceramic insulator, the sensor housing (2).
Device according to any one of claims 1 to 3, wherein 0) is arranged between the casing (5) of the device (1) and the insulator. 5. The sensor casing (20) has a support (2).
In the area of 5), in particular in the area of the shoulder or flange shoulder of the functional unit (10), the casing (5) of the device (1).
5. The device according to any one of claims 1 to 4, which is arranged for fixing to. 6. Device according to claim 5, wherein the sensor casing (20) is mounted on a support (25) of the functional unit (10). 7. The device as claimed in claim 1, wherein the sensor housing encloses the functional unit in a ring shape. 8. A sensor casing (20) is additionally provided,
Connecting contact (3) for the sensor element (15)
0, 35), the device according to any one of claims 1 to 7. 9. At least a sensor element (15)
Is preloaded with sensor casing (20)
9. A device according to any one of claims 1 to 8 attached to the. 10. The sensor element according to claim 1, wherein the sensor element (15) is embodied piezoceramic, piezoelectrically, inductively, capacitively or as a strain cage. Or 1
The device according to the item. 11. The device according to claim 1, wherein the sensor housing (20) is made of metal.