Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
  • G01L23/22—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines
  • G01L23/221—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines for detecting or indicating knocks in internal combustion engines
  • G01L23/222—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines for detecting or indicating knocks in internal combustion engines using piezoelectric devices
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
  • G01L23/22—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L1/00—Measuring force or stress, in general
  • G01L1/18—Measuring force or stress, in general using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material

Definitions

• the invention relates to a knock sensor of an internal combustion engine with an electronically evaluable vibration sensor.
• the vibration sensor is designed, among other things, as a ceramic piezo element.
• Knock sensors of this type are known, for example, from EP 0 47 22 19 B1, EP 0 844 470 B1 and DE 195 39 919 C2.
• the invention is concerned with the problem of designing a generic, electronically evaluable vibration sensor of a simpler design and of more rational application than can be used within a knock sensor. In addition to the 'measuring signals to achieve a simplified . réelle.
• the generic vibration sensor is primarily designed as a piezoresistive amorphous carbon layer firmly applied to a surface area of a base body, which can be, in particular, a DLC layer (diamond-like carbon layer).
• a base body which can be, in particular, a DLC layer (diamond-like carbon layer).
• a DLC layer diamond-like carbon layer.
• Such layering ten the type of application of which can be carried out, for example, by a PVD (physical vapor deposition) or CVD (chemical vapor deposition) method, and sensors made from these layers for determining the condition of parameters on mechanical components are described in DE 199 54 164 AI described.
• washers are known from DE 19 831 372 AI with measuring layers for checking non-positive connections.
• a plate spring present in a knock sensor as a tensioning means can serve as the base body to which the measuring layer is to be applied.
• the invention is based on the general idea that, in the case of a knock sensor of the generic type, by applying a thin measuring layer directly to the surface of a component which does not exclusively perform a vibration sensor function, an additional component, which usually represents the vibration sensor, can be saved compared to the prior art.
• Application of the measuring layer to a disc spring contained in a knock sensor as a tensioning element is particularly advantageous.
• the plate spring can in particular be designed such that the usual seismic mass of the knock sensor, which is tensioned within the knock sensor via a plate spring, is an integral part of the plate spring.
• the vibrations of the internal combustion engine when they act, for example, on the plate spring, produce voltage changes in the layer which can be electronically evaluated in a manner which is conventional per se.
• the deformation of the disc spring is used to generate electrically detectable changes in tension in the layer.
• the high measuring sensitivity of the measuring layer according to the invention is particularly well suited for telemetric signal evaluation.
• the prior art refers, for example, to DE 40 34 019 Cl, EP 0 533 709 B1 and DE 37 14 195 AI.
• each in a longitudinal section 1 shows a knock sensor with a plate spring in a first embodiment between a seismic mass and an abutment that can be fixedly mounted on an internal combustion engine
• FIG. 2 shows a knock sensor according to FIG. 1 with a washer or plate spring in the flat state according to FIG. 1,
• FIG 3 shows a knock sensor with a DLC layer between a seismic mass and an abutment that can be fixedly mounted on an internal combustion engine
• FIG. 4 shows a knock sensor with a seismic mass which is clamped with a screw and in which DLC layers are located on the underside of the screw head and the fastening body,
• FIG. 5 shows a knock sensor according to FIG. 1 with a diaphragm spring which is preloaded in a defined manner by means of a special screw,
• FIG. 6 shows a knock sensor with a plate spring and a special screw which is exciting and can be screwed directly to the internal combustion engine
• Fig. 7 shows a knock sensor with a seismic mass clamped between two disc springs.
• 1 comprises a fastening body 1 for firmly screwing onto the housing of an internal combustion engine and a screw 2 anchored in the fastening body 1, with the head of which a seismic mass 3 is braced against the fastening body 1 with the interposition of a plate spring 4.
• the end face of the plate spring 4 facing the head of the screw 2 is partially provided with a DLC layer as a piezoresistive amorphous carbon splint, from which electrical lines 6 lead to an electronic evaluation unit, not shown in the drawing.
• the thickness of the layer is preferably in a range between 1 to 10 ⁇ m.
• the seismic mass 3 which is acted upon by the plate spring 4 and is designed as an annular component, is excited and exerts a corresponding load on the plate spring 4.
• the DLC layer 5 attached to the plate spring 4 experiences a corresponding change in voltage, which is fed via the electrical lines 6 to an electronic evaluation unit and evaluated there.
• a transponder can be provided on the relevant component for telemetric transmission for the transmission of the measurement signals originating from the layer 5.
• the plate spring is replaced by a washer 7, which can optionally also be a flat-tensioned plate spring 4.
• a DLC layer 5 according to the invention can be applied on both sides of the plate spring 4 or the washer 7.
• the electronically evaluable voltages in the DLC layer 8 are generated via essentially tangential tensile and / or compressive stresses within the washer 7.
• DLC layers 9, 10 are provided on the seismic mass 3 on both opposite clamping areas, which layers can be firmly connected on the one hand to the fastening body 1 and on the other hand firmly to the head of the screw 2.
• 5 shows a knock sensor in which a special screw 11 is used as a screw for tensioning the plate spring 4, with which a defined tensioning of the plate spring 4 can be achieved in a simple manner by providing a stop collar 12 integrated in the screw 11.
• a seismic mass 3 ⁇ is clamped between two plate springs 4, 4. In this way, in particular a smaller seismic mass can be used, if such a mass is still required.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
• Measuring Fluid Pressure (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=31724280

Family Applications (1)

Country Status (9)

Cited By (2)

Families Citing this family (4)

Citations (3)

Family Cites Families (11)

• 2002
  • 2002-09-04 DE DE10240671A patent/DE10240671A1/de not_active Withdrawn
• 2003
  • 2003-06-07 US US10/526,211 patent/US7146847B2/en not_active Expired - Fee Related
  • 2003-06-07 JP JP2004534951A patent/JP4488209B2/ja not_active Expired - Fee Related
  • 2003-06-07 WO PCT/DE2003/001895 patent/WO2004025238A1/de not_active Ceased
  • 2003-06-07 CN CNB038209616A patent/CN100385222C/zh not_active Expired - Fee Related
  • 2003-06-07 AU AU2003296643A patent/AU2003296643A1/en not_active Abandoned
  • 2003-06-07 KR KR1020057003653A patent/KR20050040932A/ko not_active Ceased
  • 2003-06-07 DE DE10393179T patent/DE10393179D2/de not_active Expired - Fee Related
  • 2003-06-07 EP EP03740065A patent/EP1535036B1/de not_active Expired - Lifetime
  • 2003-06-07 ES ES03740065T patent/ES2277090T3/es not_active Expired - Lifetime
  • 2003-06-07 DE DE50305780T patent/DE50305780D1/de not_active Expired - Lifetime

Patent Citations (3)

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