Accelerometer

Abstract

The invention relates to an acceleration sensor (1), comprising: a substrate (12), the substrate having tangential side surfaces (12.1, 12.2, 12.3, 12.4) and normal side surfaces (12.6, 12.7), the tangential side surfaces being arranged tangentially relative to a vertical axis (z), and the normal side surfaces being arranged normal relative to the vertical axis; at least one piezoelectric element being fastened to the tangential side surfaces; at least one test block being fastened to the piezoelectric element; a housing (1.2) and a signal output end (1.4), which is fastened to the housing and has a signal conductor; wherein the tangential side surface to which no piezoelectric element is fastened is arranged spaced apart from the signal conductor across an assembly gap (1.24) extending perpendicularly to the vertical axis; a first normal side surface (12.7) or a bracket (13.7) fastened to the first normal side surface has a substrate output conductor; and the substrate output conductor is in direct contact with the signal conductor across the assembly gap perpendicular to the vertical axis.

Description

Technical Field

[0001] The invention relates to an acceleration sensor. Background Art

[0002] In many very different applications, such as robotics, power generation, transportation, etc., it is necessary to detect the acceleration of physical objects. Here, the impact acting on the physical object and the vibration of the physical object are detected as acceleration. The acceleration is based on the acceleration of gravity g = 9.81msec -2 In the measuring range of 2 Hz to 10 kHz, the typical magnitude of the detected acceleration is + / -500 g. To detect the acceleration, the accelerometer is fastened to the physical object.

[0003] Patent document CH399021A1 shows such an acceleration sensor, which has a test block, a piezoelectric system and a matrix. In order to prevent harmful environmental influences, the acceleration sensor has a housing, in which the test block, the piezoelectric system and the matrix are arranged. The acceleration sensor is fastened to the physical object through the housing. When accelerating, the test block exerts a force proportional to its acceleration on the piezoelectric system. The piezoelectric system has a plurality of flat disks made of piezoelectric material with high sensitivity to the piezoelectric longitudinal effect. Under the action of force, the piezoelectric material generates piezoelectric charges, and the number of piezoelectric charges generated is proportional to the magnitude of the force. Under the piezoelectric longitudinal effect, piezoelectric charges are generated on the same end face of the disk, and the force as the normal force also acts on the end face. Each disk has two end faces, on which piezoelectric charges with opposite polarities are generated. The piezoelectric system also has thin electrodes made of conductive material to intercept the piezoelectric charges from the two end faces. Each electrode has a surface of the size of an end face. The electrode is directly and completely attached to the end face through this surface. In addition, the piezoelectric system is mechanically preloaded between the test block and the base body by means of a preload sleeve. This mechanical preload closes the tiny holes between the end face and the electrode, so that all generated piezoelectric charges can be intercepted, which is important for the linearity of the acceleration sensor, which is the ratio of the number of piezoelectric charges to the magnitude of the force. The piezoelectric charges can be electrically derived as an acceleration signal. The electrically derived acceleration signal can be electrically converted in the converter unit.

[0004] Patent document DE69405962T2 also describes an acceleration sensor having a test block and a piezoelectric system on a printed circuit board. The acceleration sensor detects acceleration as a shear force along an axis based on a transverse shear effect. The piezoelectric system is arranged between the test block and the printed circuit board. The converter unit is located on the printed circuit board.

[0005] The piezoelectric system of patent document CH399021A1 is only sensitive to normal forces along the axis. The piezoelectric system of patent document DE69405962T2 is only sensitive to shear forces along the axis. However, what is desired is an acceleration sensor that can simultaneously detect accelerations along multiple axes of a rectangular coordinate system.

[0006] Patent document RU1792537C1 discloses an acceleration sensor that can detect acceleration in three physical dimensions. A piezoelectric system having six flat disks made of piezoelectric material and six test blocks is assembled on a cubic substrate having six surfaces. Every two surfaces are oriented normally relative to one of three mutually perpendicular axes, which are referred to as normal axes in the following text. On each of the six surfaces, a flat disk is arranged between the surface and the test block. These disks are mechanically preloaded on the substrate by an external preload housing. Therefore, the piezoelectric system has a pair of disks for each of the three normal axes. These disks are highly sensitive to transverse shear effects. In the case of transverse shear effects, piezoelectric point charges are generated on the same end faces of the disks where the shear force acts tangentially on the normal axis, which are referred to as the main tangential axes in the following text. The piezoelectric system also has electrodes made of conductive material for intercepting piezoelectric charges from the end faces of the disks.

[0007] According to document RU1792537C1, the piezoelectric system has, for each of the three normal axes, a pair of disks made of piezoelectric material which have a high sensitivity to shear forces along the main tangential axis.

[0008] Unfortunately, it is inevitable that piezoelectric materials have more or less sensitivity to shear forces along different axes. Thus, a piezoelectric material that has a high sensitivity to shear forces along the main tangential axis has a low sensitivity to shear forces along an axis perpendicular to the main tangential axis and perpendicular to the normal, which axis is referred to as the secondary tangential axis in the following. Both shear forces, the shear force along the main tangential axis and the shear force along the secondary tangential axis, generate piezoelectric charges on the end faces of the disk. For example, quartz as a piezoelectric material has a high sensitivity to shear forces along the main tangential axis, which is 7 times higher than the low sensitivity to shear forces along the secondary tangential axis.

[0009] Therefore, the low sensitivity of the piezoelectric material to the shear forces along the secondary tangential axis may distort the detection of the shear forces along the primary tangential axis, the corresponding piezoelectric charges being referred to below as piezoelectric interference charges. In order to avoid this distortion, according to document RU1792537C1, a pair of disks with opposite polarity are connected in series for each of the three normal axes. This has the advantage that the shear forces acting along the secondary tangential axes generate the same number of piezoelectric interference charges on the end faces of the two disks, but these piezoelectric interference charges have opposite polarities and are neutralized by the series tapping.

[0010] Patent document EP054680A1 also describes an acceleration sensor which uses a piezoelectric system to detect acceleration as shear force along three mutually perpendicular main tangential axes with high sensitivity based on the transverse shear effect. Figure 8 In an embodiment of the invention, the piezoelectric system consists of six disks made of piezoelectric material, a pair of disks with opposite polarity being connected in series for each of the three main tangential axes. The acceleration sensor requires only three test blocks, one for each of the three main tangential axes. By such a series tapping, the piezoelectric interference charge originating from the shear force along the secondary tangential axis is neutralized for each of the three main tangential axes.

[0011] Patent document US5539270A1 also relates to an acceleration sensor for detecting acceleration in three physical dimensions. A piezoelectric system is configured for each dimension, and each piezoelectric system has two plates made of piezoelectric material. The two plates are connected to each other by material fit through the end faces facing each other. The material fit connection is electrically insulating. Electrodes are assembled on the end faces of the plates facing away from each other, and these electrodes intercept the piezoelectric charge generated under the action of the normal force. The three piezoelectric systems are mechanically fastened to a bracket. The bracket has an electrical conductor, which conducts the piezoelectric charge from the electrode. No test block is provided.

[0012] Usually, there is only a small space available for fastening the accelerometer to a physical object. Therefore, the accelerometer should have small external dimensions, less than 50 cm. 3 The desired measurement frequency is over 10kHz. And since the resonance frequency of an accelerometer is inversely proportional to its weight, the accelerometer should be lightweight.

[0013] Patent document CN201152880Y shows an acceleration sensor having a piezoelectric system, a test block and a substrate. The substrate is cylindrical and terminates at a normal end face along a vertical axis. The piezoelectric system is mechanically preloaded along a normal axis perpendicular to the vertical axis between the substrate and the test block through a preload sleeve. The preload sleeve is hollow cylindrical and terminates in a plane of the normal end face of the substrate with a side. The test block is disc-shaped and also terminates in a plane of the normal end face of the substrate with a side. The converter unit in the embodiment of the charge amplifier is arranged in this plane, on the sides of the preload sleeve and the test block and on the normal end face of the substrate, which saves space.

[0014] The disadvantage of arranging the converter unit on the side surfaces of the preload sleeve and the test block and on the normal end surface of the base body is that a force shunt is formed between the test block and the base body. The test block can no longer vibrate freely under the influence of acceleration, so that the force exerted on the piezoelectric system due to the inertia of the test block is suppressed, so that the force is no longer proportional to the acceleration, and the piezoelectric charge generated by the piezoelectric material is also no longer proportional to the acceleration to be detected. This force shunt therefore distorts the detection of the acceleration. Summary of the invention

[0015] A first object of the present invention is to provide an acceleration sensor that can detect acceleration in multiple physical dimensions simultaneously. A second object of the present invention is to provide an acceleration sensor that detects acceleration as distortion-free as possible. A third object of the present invention is that the acceleration sensor should have small external dimensions and low weight. A fourth object of the present invention is to provide an acceleration sensor for high measurement frequencies greater than 10 kHz. A fifth object of the present invention is that the acceleration sensor should be able to be manufactured at low cost.

[0016] At least one of the above purposes is achieved by the features of the technical solution of the present invention.

[0017] The present invention relates to an acceleration sensor, comprising:

[0018] - a base body, the base body having a tangential side surface and a normal side surface, the tangential side surface being arranged tangentially with respect to the vertical axis, and the normal side surface being arranged normally with respect to the vertical axis;

[0019] - at least one piezoelectric element, which is fastened on the tangential side surface;

[0020] - at least one test mass fastened to the piezoelectric element; and

[0021] - a housing and a signal output terminal, wherein the signal output terminal is fastened to the housing and has a signal conductor;

[0022] wherein the tangential side surface to which no piezoelectric element is fastened is arranged spaced apart from the signal conductor by an assembly gap extending perpendicularly to the vertical axis;

[0023] The first normal side surface or the bracket fastened to the first normal side surface has a base output conductor; and the base output conductor directly contacts the signal conductor across an assembly gap perpendicular to the vertical axis.

[0024] The invention has the following advantages: All side surfaces of the base body are optimally used in a space-saving manner. At least one piezoelectric element and a test block are fastened to a tangential side surface. In order to detect acceleration in three physical dimensions, two further piezoelectric elements and two further test blocks can be fastened to two further tangential side surfaces. Therefore, the base body can be prefabricated and stored together with the piezoelectric element and the test block as an intermediate product, whereby the acceleration sensor can be manufactured at low cost. If necessary, the intermediate product can be fastened in the housing via the normal side surface. The housing will protect the piezoelectric element from harmful environmental influences. For this purpose, the housing preferably has a housing opening so that the intermediate product can be placed inside the housing. In order to derive the acceleration signal of the acceleration sensor from the inside of the housing, the signal output end has a signal conductor. According to the invention, one tangential side surface remains empty so that the base body is arranged as close as possible to the signal conductor in space, separated only by an assembly gap.

[0025] The base output conductor is arranged on the other normal side or on the support. For the contact tool, the other normal side and the signal conductor are easily accessible through the housing opening. Therefore, the intermediate product can be directly contacted with the signal conductor via the base output conductor, and the base output conductor only needs to cross the assembly gap for this purpose, which can be carried out simply and quickly, thereby also reducing the assembly costs.

[0026] Further advantageous embodiments of the invention are the subject of the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be described in detail below with reference to the accompanying drawings in exemplary embodiments.

[0028] Figure 1 A view of a portion of a first embodiment of an acceleration sensor having a sensor unit;

[0029] Figure 2 A view of a portion of a second embodiment of an acceleration sensor having a sensor unit;

[0030] Figure 3 To have basis Figure 1 A view of a sensor unit of a converter unit of an acceleration sensor;

[0031] Figure 4 To have basis Figure 2 A view of a sensor unit of a converter unit of an acceleration sensor;

[0032] Figure 5 Based on Figures 1 to 4 an exploded view of a portion of a sensor unit;

[0033] Figure 6 Based on Figures 1 to 5 A top view of the sensor unit under the action of acceleration;

[0034] Figure 7 Based on Figures 1 to 5 A first view of a first embodiment of a piezoelectric element of a sensor unit;

[0035] Figure 8 Based on Figure 7 A second view of an embodiment of a piezoelectric element;

[0036] Fig. 9 Based on Figures 1 to 5 A first view of a second embodiment of a piezoelectric element of a sensor unit;

[0037] Fig.10 Based on Fig. 9 A second view of a second embodiment of a piezoelectric element;

[0038] Fig.11 To export based on Figures 1 to 5 Schematic diagram of the piezoelectric charge of the sensor unit;

[0039] Fig.12 Based on Fig.11 Schematic diagram of a high pass filter of a converter unit of a sensor unit;

[0040] Fig.13 Based on Fig.11 A schematic diagram of a low pass filter of a converter unit of a sensor unit;

[0041] Fig.14 For assembly according to Figure 2 A view of a first step of an acceleration sensor, wherein a signal conductor is guided into the housing;

[0042] Fig.15 For assembly according to Figure 2 A view of a second step of the acceleration sensor, wherein the signal conductor in the housing is potted with a potting material;

[0043] Fig.16 For assembly according to Figure 2A view of a third step of the acceleration sensor, wherein the signal conductor potted with the potting material is exposed regionally in the housing;

[0044] Fig.17 For assembly according to Figure 2 A view of a fourth step of the acceleration sensor, wherein the sensor unit is placed into the housing; and

[0045] Fig.18 For assembly according to Figure 2 FIG. 5 is a view of a fifth step of an acceleration sensor, in which the converter unit electrically contacts the sensor unit.

[0046] The reference numerals are listed as follows:

[0047] 1 Accelerometer

[0048] 1.1 Sensor unit

[0049] 1.2 Housing

[0050] 1.20 Shell opening

[0051] 1.21 Housing cover

[0052] 1.22 Signal output opening

[0053] 1.23 Shell bottom

[0054] 1.24 Assembly clearance

[0055] 1.3 Converter unit

[0056] 1.4 Signal output terminal

[0057] 10, 10′, 10″ piezoelectric element

[0058] 11, 11′, 11″ test blocks

[0059] 12 Matrix

[0060] 12.1, 12.2, 12.3, 12.4 Tangential side

[0061] 12.6, 12.7 Normal side

[0062] 13.01, 13.01′, 13.01″ first piezoelectric element contact

[0063] 13.02, 13.02′, 13.02″ Second piezoelectric element contact

[0064] 13.03, 13.03′, 13.03″ First substrate input contact

[0065] 13.04, 13.04′, 13.04″ Second base input contact

[0066] 13.08, 13.08′, 13.08″ first base output contact

[0067] 13.09 Second base output contact

[0068] 13.1, 13.1′, 13.1″ first piezoelectric element conductor

[0069] 13.2, 13.2', 13.2" conductor of the second piezoelectric element

[0070] 13.3, 13.3′, 13.3′ first base conductor

[0071] 13.4, 13.4′, 13.4″ Second base conductor

[0072] 13.5, 13.5′, 13.5″ first resistor

[0073] 13.6, 13.6′, 13.6″ Second resistor

[0074] 13.7 Bracket

[0075] 13.8, 13.8′, 13.8″ first base output conductor

[0076] 13.9 Second Matrix Output Conductor

[0077] 13.10, 13.10′, 13.10″ Transimpedance Converter

[0078] 14.1, 14.1′, 14.1″ first signal conductor

[0079] 14.2 Second signal conductor

[0080] 14.3 Protective cover

[0081] 14.4 Shield flange

[0082] 14.5 Electrical insulation

[0083] 14.6 Potting materials

[0084] 14.7 Exposed parts

[0085] 15, 15′, 15″ internal connection device

[0086] 16, 16′, 16″ external connection device

[0087] 17, 17′, 17″ low pass filter

[0088] 18, 18′, 18″ high pass filter

[0089] 101 First Conductive Coating

[0090] 102 Second conductive coating

[0091] 110, 120 end face

[0092] 111, 111' first conductive end surface coating

[0093] 112, 112', 112" first uncoated end surface area

[0094] 121-121″′ Second conductive end surface coating

[0095] 122, 122', 122" second uncoated end surface area

[0096] 130, 140, 150, 160 side

[0097] 131, 131' first conductive side coating

[0098] 132, 132'-132"" first uncoated side area

[0099] 133, 133' Additional first conductive side coating

[0100] 141 Second conductive side coating

[0101] 142, 142', 142" second uncoated side area

[0102] 151, 151' third conductive side coating

[0103] 161 Fourth conductive side coating

[0104] a Normal axis

[0105] F-Force

[0106] h Main tangential axis

[0107] n Secondary tangential axis

[0108] S1, S2 acceleration signal

[0109] x horizontal axis

[0110] y vertical axis

[0111] z vertical axis DETAILED DESCRIPTION

[0112] Figure 1 and Figure 2Parts of two embodiments of an acceleration sensor 1 according to the invention are shown. The acceleration sensor 1 has a sensor unit 1.1, a housing 1.2, a converter unit 1.3 and a signal output 1.4. The acceleration sensor 1 is arranged in a rectangular coordinate system with three axes x, y, z, which are also referred to as the horizontal axis x, the longitudinal axis y and the vertical axis z.

[0113] The housing 1.2 protects the acceleration sensor 1 from harmful environmental influences such as pollutants (dust, moisture, etc.) and electromagnetic interference in the form of electromagnetic radiation. The housing 1.2 is made of a mechanically resistant material, such as a pure metal, a nickel alloy, a cobalt alloy, an iron alloy, etc. The housing 1.2 has a rectangular cross section, the width of which along the transverse axis x is preferably less than 5 cm, the length along the longitudinal axis y is preferably less than 5 cm, and the height along the vertical axis z is preferably less than 2 cm, so that the housing has a width of less than 50 cm. 3 The housing 1.2 is can-shaped and has a housing opening 1.20 and a housing bottom 1.23. The size of the housing opening 1.20 is determined so that the sensor unit 1.1 can be placed in the housing 1.2 through the housing opening 1.20, can be fixed through the housing bottom 1.23, and can be in contact with the signal output terminal 1.4. In the present invention, the term "contact" refers to electrical connection and mechanical connection. The housing opening 1.20 can be closed by a housing cover 1.21. Preferably, the closing is performed by material matching such as welding, brazing, bonding, etc. The acceleration sensor 1 is fastened to a physical object whose acceleration is to be detected through the housing 1.2. The type and method of fastening are arbitrary.

[0114] The sensor unit 1.1 comprises a first, a second and a third piezoelectric element 10, 10', 10", a first, a second and a third test block 11, 11', 11" and a base body 12. The first, the second and the third piezoelectric element 10, 10', 10" and the first, the second and the third test block 11, 11', 11" are fastened to the base body 12. The base body 12 is in turn fastened to the housing 1.2. The base body 12 is preferably fastened to the housing 1.2 by material bonding (e.g. bonding, soldering, etc.).

[0115] The first, second and third piezoelectric elements 10, 10', 10" are made of piezoelectric materials, such as quartz (SiO2 single crystal), calcium gallium germanate (Ca3Ga2Ge4O 14 or CGG), lanthanum gallium silicate (La3Ga5SiO 14 or LGS), tourmaline, gallium phosphate, piezoelectric ceramics, etc. The first, second and third piezoelectric elements 10, 10', 10" have high sensitivity to the received force. The cross-section of the first, second and third piezoelectric elements 10, 10', 10" is rectangular, and its area is preferably less than 1cm 2And its thickness is preferably less than 2 mm. With the knowledge of the present invention, those skilled in the art can realize piezoelectric elements with different shapes and other cross-sectional shapes (such as round, etc.).

[0116] The first, second and third test blocks 11, 11', 11" are preferably made of a high-density material, such as iridium, platinum, tungsten, gold, etc. Due to the small outer dimensions of the acceleration sensor 1, the first, second and third test blocks 11, 11', 11" preferably have a density greater than 19 g / cm 3 The cross-sections of the first, second and third test blocks 11, 11', 11" are rectangular, and their areas are preferably less than 1 cm 2 And its thickness is preferably less than 5 mm. Under the understanding of the present invention, those skilled in the art can realize test blocks with different shapes and other cross-sectional shapes (such as round, etc.). Those skilled in the art can also use test blocks made of low-density materials (such as steel, ceramics, etc.).

[0117] The substrate 12 is made of a low-density mechanically rigid material, such as Al2O3, ceramic, Al2O3 ceramic, sapphire, etc. The substrate 12 is mechanically rigid so as to transfer the acceleration to be detected from the housing 1.1 to the first, second and third test blocks 11, 11', 11" in an inelastic manner. For the high mechanical rigidity of the acceleration sensor 1, the substrate 12 has a high elastic modulus of preferably 350 GPa to 470 GPa. Due to the light weight of the acceleration sensor 1, the substrate 12 has a modulus of preferably less than 4 g / cm 3 The substrate 12 is preferably a cube with six sides 12.1, 12.2, 12.3, 12.4, 12.6, 12.7. The four tangential sides 12.1, 12.2, 12.3, 12.4 are arranged tangentially with respect to the vertical axis z. The two normal sides 12.6, 12.7 are arranged normally with respect to the vertical axis z. The sides 12.1, 12.2, 12.3, 12.4, 12.6, 12.7 are largely of the same size. Each side 12.1, 12.2, 12.3, 12.4, 12.6, 12.7 has a diameter of less than 1 cm. 2 In the sense of the present invention, the adjective "to a large extent" has the meaning of "+ / -10%". Each axis x, y, z is normal to the two side faces. With the knowledge of the present invention, a person skilled in the art can realize differently formed substrates with other surface shapes (e.g., circular, etc.).

[0118] The first test block 11 and the first piezoelectric element 10 are fastened to a first tangential side surface 12.1 of the base body 12. The second test block 11' and the second piezoelectric element 10' are fastened to a second tangential side surface 12.2 of the base body 12. The third test block 11" and the third piezoelectric element 10" are fastened to a third tangential side surface 12.3 of the base body 12. Here, a piezoelectric element 10, 10', 10" is arranged between the tangential side surfaces 12.1, 12.2, 12.3 and the test blocks 11, 11', 11", respectively. The fourth tangential side surface 12.4 is free.

[0119] The fastening of the first, second and third test blocks 11, 11′, 11″ and the first, second and third piezoelectric elements 10, 10′, 10″ on the base 12 is achieved by first, second and third internal connecting devices 15, 15′, 15″ and first, second and third external connecting devices 16, 16′, 16″. The fastening is achieved by material matching such as bonding, thermocompression bonding, etc. Such mechanical fastening of the first, second and third test blocks 11, 11′, 11″ and the first, second and third piezoelectric elements 10, 10′, 10″ by the first, second and third internal connecting devices 15, 15′, 15″ and first, second and third external connecting devices 16, 16′, 16″ makes the acceleration sensor 1 easy to assemble and can be implemented quickly and at low cost.

[0120] The first, second and third internal connecting means 15, 15', 15" and the first, second and third external connecting means 16, 16', 16" are chemically hardened adhesives or physically curable adhesives, or a combination of chemically hardened adhesives and physically curable adhesives. Preferably, the first, second and third internal connecting means 15, 15', 15" and the first, second and third external connecting means 16, 16', 16" are made of adhesives, such as epoxy resin, polyurethane (Polyurethan), cyanoacrylate (Cyanacrylat), methyl methacrylate (Methylmethacrylat) and the like. The first, second and third internal connecting means 15, 15', 15" and the first, second and third external connecting means 16, 16', 16" are adhesives having a strength of more than 10 12 Ωmm 2 An electrical insulator with a specific resistance of / m.

[0121] like Figure 5As shown, the first piezoelectric element 10 is fastened to the first tangential side 12.1 by means of the first internal connection means 15. The first test block 11 is fastened to the first piezoelectric element 10 by means of the first external connection means 16. The second piezoelectric element 10' is fastened to the second tangential side 12.2 by means of the second internal connection means 15'. The second test block 11' is fastened to the second piezoelectric element 10' by means of the second external connection means 16'. The third piezoelectric element 10" is fastened to the third tangential side 12.3 by means of the third internal connection means 15". The third test block 11" is fastened to the third piezoelectric element 10" by means of the third external connection means 16".

[0122] Preferably, the first, second and third piezoelectric elements 10, 10', 10" are fastened together with the first, second and third test blocks 11, 11', 11" and the base 12 in a shear-resistant manner by first, second and third internal connecting devices 15, 15', 15" and first, second and third external connecting devices 16, 16', 16".

[0123] Each of the first, second and third internal connecting means 15, 15', 15" and each of the first, second and third external connecting means 16, 16', 16" is rectangular in cross section, preferably having a diameter of less than 1 cm. 2 The area and preferably the thickness of less than 0.1 mm. With the knowledge of the present invention, those skilled in the art can realize the internal and external connecting means of different shapes and with other cross-sectional shapes (such as circular, etc.).

[0124] The first, second and third piezoelectric elements 10, 10', 10" have high sensitivity to transverse shear effects along the main tangential axis h, low sensitivity to transverse shear effects along the secondary tangential axis n, and low sensitivity to piezoelectric transverse effects along the normal axis a. For each of the three piezoelectric elements 10, 10', 10", the main tangential axis h is a different one of the three axes x, y, z. For each of the three piezoelectric elements 10, 10', 10", the secondary tangential axis n is a different one of the three axes x, y, z. For each of the three piezoelectric elements 10, 10', 10", the normal axis a is a different one of the three axes x, y, z.

[0125] In the case of a lateral shear effect along the main tangential axis h or the secondary tangential axis n, piezoelectric charges are generated on the same end faces of the first, second and third piezoelectric elements 10, 10', 10", and shear forces act on these end faces along the main tangential axis h or the secondary tangential axis n.

[0126] In the case of the piezoelectric lateral effect, piezoelectric charges are generated on the side surfaces of the first, second and third piezoelectric elements 10, 10', 10", which are perpendicular to the end surfaces of the first, second and third piezoelectric elements 10, 10', 10", on which the normal force acts along the normal axis a.

[0127] The higher the sensitivity, the more piezoelectric charge is generated for a given force. In the sense of the invention, the terms "high sensitivity" and "low sensitivity" are related to each other. Each of the three piezoelectric elements 10, 10', 10" generates at least five times more piezoelectric charge per unit force with a high sensitivity to shear forces along the main tangential axis h than with a low sensitivity to shear forces along the secondary tangential axis n or to normal forces along the normal axis a.

[0128] Therefore, the piezoelectric material is selected to mainly consider the piezoelectric charge from the transverse shear effect along the main tangential axis h to detect acceleration. In the following, the piezoelectric charge due to the transverse shear effect along the secondary tangential plane and due to the piezoelectric transverse effect along the normal axis a are called piezoelectric interference charges.

[0129] Figure 6 1 is a top view of the sensor unit 1.1 under acceleration. Depending on the acceleration, a force F is exerted on the end faces of the first, second and third piezoelectric elements 10, 10', 10" by the first, second and third test blocks 11, 11', 11". This force F acts, for example, parallel to the longitudinal axis y, as indicated by the arrow.

[0130] The first piezoelectric element 10 has a high sensitivity to shear forces along the longitudinal axis y as the main tangential axis h. Since the force F acts along the longitudinal axis y, the first piezoelectric element 10 generates piezoelectric charges on the end face according to the transverse shear effect in response to this force. The first piezoelectric element 10 has a low sensitivity to shear forces along the vertical axis z as the secondary tangential axis n, and has a low sensitivity to normal forces along the transverse axis x as the normal axis a. The force F acts along the longitudinal axis y and applies a torque along the vertical axis z. The first piezoelectric element 10 generates piezoelectric interference charges on the end face according to the transverse shear effect in response to this torque.

[0131] The second piezoelectric element 10' has a high sensitivity to shear forces along the transverse axis x as the main tangential axis h. However, since the force F acts along the longitudinal axis y, the second piezoelectric element 10' does not generate piezoelectric charges for it on the end face. The second piezoelectric element 10' has a low sensitivity to shear forces along the vertical axis z as the secondary tangential axis n, and has a low sensitivity to normal forces along the longitudinal axis y as the normal axis a. Since the force F acts along the longitudinal axis y, the second piezoelectric element 10' generates piezoelectric interference charges for it on the side according to the piezoelectric transverse effect.

[0132] The third piezoelectric element 10″ has high sensitivity to shear force along the vertical axis z as the main tangential axis h. However, since the force F acts as a shear force along the longitudinal axis y, the third piezoelectric element 10″ does not generate piezoelectric charge on the end face thereof. The third piezoelectric element 10″ has low sensitivity to shear force along the longitudinal axis y as the secondary tangential axis n, and has low sensitivity to normal force along the transverse axis x as the normal axis a. The force F acts along the longitudinal axis y and applies a torque along the vertical axis z. The third piezoelectric element 10″ generates piezoelectric interference charge on the end face in response to the torque according to the lateral shear effect.

[0133] Figure 7 and Figure 8 A first embodiment of a first, second or third piezoelectric element 10 , 10 ′, 10 ″ of sensor unit 1 . 1 is shown in detail. Fig. 9 and Fig.10 A second embodiment of first, second or third piezoelectric element 10 , 10 ′, 10 ″ of sensor unit 1 . 1 is shown in detail. First, second or third piezoelectric element 10 , 10 ′, 10 ″ has two end faces 110 , 120 and four side faces 130 , 140 , 150 , 160 .

[0134] Each of the three piezoelectric elements 10, 10', 10" has a first end face 110 and a second end face 120. Each end face 110, 120 is located in a plane extended by a main tangential axis h and a secondary tangential axis n. In the plane, the secondary tangential axis n is perpendicular to the main tangential axis h. And the normal axis a is in the normal direction of the plane. Under the action of the shear force along the main tangential axis h, each of the three piezoelectric elements 10, 10', 10" generates piezoelectric charges on the two end faces 110, 120. And under the action of the shear force along the secondary tangential axis, each of the three piezoelectric elements 10, 10', 10" generates piezoelectric interference charges on the two end faces 110, 120. Each of the three piezoelectric elements 10, 10', 10" has side faces 130, 140, 150, 160. These side faces 130, 140, 150, 160 are parallel to the normal axis a. These side surfaces 130, 140, 150, 160 include a first side surface 130, a second side surface 140, a third side surface 150 and a fourth side surface 160. The first side surface 130 and the fourth side surface 160 are normal to the secondary tangential axis n of the piezoelectric element 10, 10', 10". The second side surface 140 and the third side surface 150 are normal to the primary tangential axis h of the piezoelectric element 10, 10', 10".

[0135] Under the action of the normal force along the normal axis, each of the three piezoelectric elements 10 , 10 ′, 10 ″ generates piezoelectric interference charges on the four side surfaces 130 , 140 , 150 , 160 .

[0136] Therefore, the piezoelectric charge for the shear force to be detected is generated only on the two end faces 110 , 120 of the piezoelectric element, whereas the piezoelectric interference charge is generated both on the two end faces 110 , 120 and on the four side faces 130 , 140 , 150 , 160 .

[0137] The end faces 110, 120 partially have at least one conductive end face coating 111, 121. The size of the area of ​​the conductive end face coating 111, 121 may be between 90% and 100% of the end faces 110, 120. The side faces 130, 140, 150, 160 partially have at least one conductive side face coating 131, 141, 151, 161. The size of the area of ​​the conductive side face coating 131, 141, 151, 161 may be between 0% and 100% of the side faces 130, 140, 150, 160. The conductive end face coating 111, 121 and the conductive side face coating 131, 141, 151, 161 may be formed by thermal lamination using a metal foil or by metal deposition. The metal may use copper, copper alloy, gold, gold alloy, aluminum, aluminum alloy, silver, silver alloy, etc. The thickness of the conductive end coatings 111, 121 and the conductive side coatings 131, 141, 151, 161 is preferably less than 0.1 mm.

[0138] Therefore, the acceleration sensor 1 no longer has physical electrodes ( Instead of an electrically conductive coating 111 , 121 , the acceleration sensor 1 has only electrically conductive end face coatings 111 , 121 and electrically conductive side surface coatings 131 , 141 , 151 , 161 . As a result, fewer components are present, which saves space and simplifies the assembly of the acceleration sensor 1 .

[0139] Due to the conductive end face coating 111, 121 and the conductive side face coating 131, 141, 151, 161, mechanical prestressing of the first, second or third piezoelectric element 10, 10', 10" is not necessary. This is because the conductive end face coating 111, 121 and the conductive side face coating 131, 141, 151, 161 are materially fitted on the end faces 110, 120 and the side faces 130, 140, 150, 160 and close the tiny holes in the end faces 110, 120 and the side faces 130, 140, 150, 160. By closing these tiny holes, the acceleration sensor 1 no longer requires any independent prestressing device, such as the prestressing sleeve described in patent document CH399021A1 or the prestressing housing described in patent document RU1792537C1. Therefore, there are fewer components, thereby saving space and weight and simplifying the assembly of the acceleration sensor 1.

[0140] according to Figure 7 and Figure 8 In the first embodiment of the first, second or third piezoelectric element 10, 10′, 10″ shown, the first end face 110 partially has two first conductive end face coatings 111, 111′, and partially has two first uncoated end face areas 112, 112′. And the second end face 120 partially has more than two conductive end face coatings 121, 121′, 121″. The first side surface 130 partially has a first conductive side coating 131, partially has another first conductive side coating 133, and partially has multiple uncoated first side areas 132, 132′, 132″, 132″′, 132″″. The second side surface 140 partially has a second conductive side coating 141, and partially has a second uncoated side area 142. The third side surface 150 partially has a third conductive side coating 151, and partially has two uncoated third side areas 152, 152′. The fourth side surface 160 partially has a fourth conductive side surface coating 161 .

[0141] according to Figure 7 and Figure 8 In the first embodiment of the first, second or third piezoelectric element 10, 10′, 10″ shown, the two first conductive end face coatings 111, 111′, the additional first conductive side coating 133 and the third conductive side coating 151 form a first continuous conductive coating 101. Multiple second conductive end face coatings 121, 121′, 121″, the first conductive side coating 131, the second conductive side coating 141 and the fourth conductive side coating 161 form a second continuous conductive coating 102.

[0142] In the sense of the present invention, the characteristic word "continuous" has the meaning of "connected to each other in an electrically conductive manner". The first continuous conductive coating 101 intercepts the first piezoelectric charge generated on the surface of the first, second or third piezoelectric element 10, 10', 10" below the first continuous conductive coating 101 as a first acceleration signal S1. The second continuous conductive coating 102 intercepts the second piezoelectric charge generated on the surface of the first, second or third piezoelectric element 10, 10', 10" below the second continuous conductive coating 102 as a second acceleration signal S2. The first piezoelectric charge and the second piezoelectric charge have different signs. Either the first piezoelectric charge has a negative sign and the second piezoelectric charge has a positive sign, or the first piezoelectric charge has a positive sign and the second piezoelectric charge has a negative sign.

[0143] Preferably, the first conductive end face coating 111 and the first conductive side coating 131 form a first continuous conductive coating 101. Preferably, the second conductive end face coating 121 and the further first conductive side coating 133 form a second continuous conductive coating 102. Preferably, at least one second, third or fourth conductive side coating 141, 151, 161 is part of the first continuous conductive coating 101 or part of the second continuous conductive coating 102.

[0144] according to Figure 7 and Figure 8 In the first embodiment of the first, second or third piezoelectric element 10, 10′, 10″ shown, the first continuous conductive coating 101 and the second continuous conductive coating 102 are electrically insulated from each other by two first uncoated end surface areas 112, 112′, a plurality of first uncoated side areas 132, 132′, 132″, 132″′, 132″″, a second uncoated side area 142 and two third uncoated side areas 152, 152′.

[0145] according to Fig. 9 and Fig.10In the second embodiment of the first, second or third piezoelectric element 10, 10′, 10″ shown, the first end face 110 partially has a first conductive end face coating 111 and partially has a plurality of first uncoated end face regions 112, 112′, 112″. The second end face 120 partially has a plurality of second conductive end face coatings 121, 121′, 121″ and partially has a second uncoated end face region 122. The first side surface 130 partially has a first conductive side surface coating 131, partially has two additional first conductive side surface coatings 133, 133′, and partially has a plurality of first uncoated side surface regions 132, 132′, 132″. The second side 140 partially has a second conductive side coating 141 and partially has a plurality of second uncoated side regions 142 , 142 ′, 142 ″. The third side 150 partially has a third conductive side coating 151 and partially has third uncoated side regions 152 , 152 ′. The fourth side 160 partially has a fourth conductive side coating 161 .

[0146] according to Fig. 9 and Fig.10 In the second embodiment of the first, second or third piezoelectric element 10, 10′, 10″ shown, the multiple first conductive end face coatings 112, 112′, 112″ and the two first conductive side coatings 131, 131′ form a first continuous conductive coating 101. The multiple second conductive end face coatings 121, 121′, 121″, the two additional first conductive side coatings 133, 133′, the second conductive side coating 141, the third conductive side coating 151 and the fourth conductive side coating 161 form a second continuous conductive coating 102.

[0147] according to Fig. 9 and Fig.10 In the second embodiment of the first, second or third piezoelectric element 10, 10′, 10″ shown, the conductive side coating 131, 131′ of the first continuous conductive coating 101 intercepts piezoelectric interference charges for the normal force along the normal axis a, and the polarity of the piezoelectric interference charge is opposite to the polarity of the piezoelectric interference charge intercepted by the first conductive end face coating 111 of the first continuous conductive coating 101 for the shear force along the secondary tangential axis n. And the conductive side coating 133, 141, 151, 161 of the second continuous conductive coating 102 intercepts piezoelectric interference charges for the normal force along the normal axis a, and the polarity of the piezoelectric interference charge is opposite to the polarity of the piezoelectric interference charge intercepted by the second conductive end face coating 121, 121′, 121″ of the second continuous conductive coating 102 for the shear force along the secondary tangential axis n.

[0148] according to Fig. 9 and Fig.10In the second embodiment of the first, second or third piezoelectric element 10, 10′, 10″ shown, the first conductive coating 101 and the second conductive coating 102 are electrically insulated from each other by a plurality of first uncoated end face regions 112, 112′, 112″, a second uncoated end face region 122, a plurality of first uncoated side regions 132, 132′, 132″, a plurality of second uncoated side regions 142, 142′, 142″ and a third uncoated side region 152.

[0149] The ratio of the size of the first conductive coating 131 to the size of the further first conductive coating 133 can be adjusted by the relative position and / or size of the first uncoated side areas 132, 132′, 132″, 132″′, 132″″ of the first side 130. In the sense of the present invention, the conjunction “and / or” means that either only one of the conjunctions occurs or both conjunctions occur.

[0150] The size ratio of the first conductive coating 131 to the size of the additional first conductive coating 133 can be adjusted by the relative positions of the first uncoated side regions 132, 132′, 132″, 132″′, 132″″ of the first side 130 with respect to the second and third sides 140, 150. According to the relative positions of the first uncoated side regions 132, 132′, 132″, 132″′, 132″″ of the first side 130 in the direction of the second side 140 or in the direction of the third side 150, the size ratio of the first conductive coating 131 to the size of the additional first conductive coating 133 can be reduced or increased accordingly. Figure 7 and Figure 8 In the first embodiment of the first, second or third piezoelectric element 10, 10', 10", the first uncoated side area 132, 132', 132", 132"', 132"" is relatively close to the second side 140. Fig. 9 and Fig.10 In the second embodiment of the first, second or third piezoelectric element 10 , 10 ′, 10 ″ shown, the first uncoated side regions 132 , 132 ′, 132 ″ are relatively equidistant from the second and third side regions 140 , 150 .

[0151] However, the size ratio of the first conductive coating 131 to the size of the further first conductive coating 133 can also be adjusted by increasing or decreasing the size of the first coating-free side regions 132, 132', 132", 132'", 132"" of the first side 130. Figure 7 and Figure 8In the first embodiment of the first, second or third piezoelectric element 10, 10', 10" shown, the first coating-free side area 132, 132', 132", 132"', 132"" is to a large extent twice as large as the additional first conductive coating 133, and the first coating-free side area 132, 132', 132", 132"', 132"" is to a large extent five times smaller than the first conductive coating 131. Fig. 9 and Fig.10 In the second embodiment of the first, second or third piezoelectric element 10 , 10 ′, 10 ″ shown, the first coating-free side regions 132 , 132 ′, 132 ″ and the first electrically conductive coating 131 , 131 ′ and the further first electrically conductive coating 133 are largely of the same size.

[0152] Preferably, the conductive side coating of the first conductive coating 101 intercepts a piezoelectric interference charge for a normal force along the normal axis a, the polarity of which is opposite to the polarity of the piezoelectric interference charge intercepted by the first conductive end coating of the first conductive coating 101 for a shear force along the secondary tangential axis n. And the conductive side coating of the second conductive coating 102 intercepts a piezoelectric interference charge for a normal force along the normal axis, the polarity of which is opposite to the polarity of the piezoelectric interference charge intercepted by the second conductive end coating of the second conductive coating 102 for a shear force along the secondary tangential axis n.

[0153] Preferably, the conductive side coating of the first continuous conductive coating 101 is sized such that the conductive side coating intercepts substantially as much piezoelectric disturbance charge for normal forces along the normal axis a as the first conductive end face coating of the first continuous conductive coating 101 intercepts for shear forces along the minor tangential axis n. And the conductive side coating of the second continuous conductive coating 102 intercepts substantially as much piezoelectric disturbance charge for normal forces along the normal axis a as the second conductive end face coating of the second interconnected conductive coating 102 intercepts for shear forces along the minor tangential axis n.

[0154] Unlike patent document RU1792537C1, according to the present invention, only one piezoelectric element 10, 10', 10" is used for detecting shear force in each axis. Therefore, there is no longer the option of connecting two piezoelectric elements in series on each axis so that the piezoelectric interference charges of the shear force along the secondary tangential axis n have opposite polarities and are neutralized, which would cause distortion in the detection of the shear force along the main tangential axis h. Therefore, the acceleration sensor 1 of the present invention implements another technical solution. Because the piezoelectric material will also generate piezoelectric interference charges on the side surfaces 130, 140, 150, 160 for the normal force along the normal axis a. These piezoelectric interference charges will also distort the detection of the shear force along the main tangential axis h. Therefore, These piezoelectric interference charges are also generally not intercepted by the side faces 130, 140, 150, 160. It is now recognized that the occurrence of shear forces along the secondary tangential axis n is accompanied by normal forces along the normal axis a. The former generates piezoelectric interference charges on the end faces 110, 120 and the latter generates piezoelectric interference charges on the side faces 130, 140, 150, 160. Both piezoelectric interference charges distort the detection of the shear forces along the main tangential axis h. However, by means of suitable first and second continuous conductive coatings 101, 102, the end faces 110, 120 and the side faces 130, 140, 150, 160 can be electrically connected in series and the piezoelectric interference charges that distort the detection of the shear forces along the main tangential axis h are neutralized.

[0155] Fig.11 Schematic diagram of the derivation of the piezoelectric charge of sensor unit 1.1. A portion of first, second or third piezoelectric element 10, 10', 10" with first side surface 130 can be seen as well as a portion of converter unit 1.3 and a portion of signal output 1.4.

[0156] The converter unit 1.3 can convert a first acceleration signal S1. The converter unit 1.3 has at least one first and second piezoelectric element conductor 13.1, 13.1′, 13.1″, 13.2, 13.2′, 13.2″, at least one first and second base conductor 13.3, 13.3′, 13.3″, 13.4, 13.4′, 13.4″, at least one transimpedance transformer (Transimpedanzwandler) 13.10, 13.10′, 13.10″, and at least one first and second signal output conductor 13.8, 13.8′, 13.8″, 13.9. The converter unit 1.3 also has at least one first resistor 13.5, 13.5′, 13.5″ and / or at least one second resistor 13.6, 13.6′, 13.6″.

[0157] In accordance with Figure 1 and Figure 3In a first embodiment of the acceleration sensor 1, the converter unit 1.3 is arranged only and directly on the base body 12. Preferably, the converter unit 1.3 is arranged only and directly on the first normal side surface 12.7 of the base body 12. Figure 2 and Figure 4 In a second embodiment of the acceleration sensor 1, the converter unit 1.3 is arranged only on the bracket 13.7. The bracket 13.7 is made of an electrically insulating material, such as Al2O3, ceramic, Al2O3 ceramic, fiber reinforced plastic, etc. The bracket 13.7 is fastened to the substrate 12. Preferably, the bracket 13.7 is fastened to the first normal side surface 12.7 of the substrate 12 by material matching such as bonding, brazing, etc.

[0158] The first and second piezoelectric element conductors 13.1, 13.1′, 13.1″, 13.2, 13.2′, 13.2″, the first and second base conductors 13.3, 13.3′, 13.3″, 13.4, 13.4′, 13.4″, the first resistors 13.5, 13.5′, 13.5″, the second resistors 13.6, 13.6′, 13.6″ and the transimpedance converters 13.10, 13.10′, 13.10″ are fastened to the first normal side surface 12.7 (according to Figure 1 and Figure 3 The first embodiment of the acceleration sensor 1) or fastened to the bracket 13.7 (according to Figure 2 and Figure 4 A second embodiment of the acceleration sensor 1).

[0159] The first and second piezoelectric element conductors 13.1, 13.1′, 13.1″, 13.2, 13.2′, 13.2″, the first and second base conductors 13.3, 13.3′, 13.3″, 13.4, 13.4′, 13.4″ and the first and second signal output end conductors 13.8, 13.8′, 13.8″, 13.9 are made of conductive materials such as copper, copper alloy, gold, gold alloy, aluminum, aluminum alloy, etc., have a diameter of 0.02 mm to 0.10 mm, and are mechanically flexible.

[0160] The first and second piezoelectric element conductors 13.1, 13.1′, 13.1″, 13.2, 13.2′, 13.2″, the first and second base conductors 13.3, 13.3′, 13.3″, 13.4, 13.4′, 13.4″ and the first and second signal output conductors 13.8, 13.8′, 13.8″, 13.9 conduct the first and second acceleration signals S1, S2 in a manner insulated from ground. In the sense of the present invention, the term “insulated from ground” means electrically insulated from the ground of the acceleration sensor 1. Preferably, the housing 1.2 of the acceleration sensor 1 is grounded, and the housing 1.2 has the same potential as the local ground. Therefore, the acceleration signals S1, S2 are conducted in an electrically insulated manner relative to the potential of the acceleration sensor 1. As a result, the detection of the acceleration will not be distorted by fluctuations in the potential of the acceleration sensor 1, for example fluctuations between the housing 1.2 and the converter unit 1.3.

[0161] Preferably, the first and second base conductors 13.3, 13.3', 13.3", 13.4, 13.4', 13.4" are structured in a conductive coating. The conductive coating is achieved by chemical vapor deposition, physical vapor deposition or the like. The conductive coating consists of a conductive material, such as copper, a copper alloy, a gold alloy, platinum, a platinum alloy or the like. The conductive coating is a thin conductive layer. In the sense of the present invention, the term "thin layer" means that the conductive coating has a thickness of preferably less than 0.1 mm in a direction extending perpendicularly to the plane. The conductive coating is applied directly to the first normal side surface 12.7 (according to Figure 1 and Figure 3 The first embodiment of the acceleration sensor 1) or on the bracket 13.7 (according to Figure 2 and Figure 4 In the sense of the invention, the adjective "directly" means "immediately adjacent to". Preferably, the structuring of the first and second base conductors 13.3, 13.3', 13.3", 13.4, 13.4', 13.4" in the conductive coating is achieved by using templates, photolithography and laser ablation.

[0162] Preferably, the converter unit 1.3 has three first piezoelectric element conductors 13.1, 13.1′, 13.1″ and three second piezoelectric element conductors 13.2, 13.2′, 13.2″. Each of the first piezoelectric element conductors 13.1, 13.1′, 13.1″ conducts the first acceleration signal S1 from the first conductive coating 101 of the first, second or third piezoelectric element 10, 10′, 10″ to the converter unit 1.3. Each of the second piezoelectric element conductors 13.2, 13.2′, 13.2″ conducts the second acceleration signal S2 from the second conductive coating 102 of the first, second or third piezoelectric element 10, 10′, 10″ to the converter unit 1.3.

[0163] The first and second piezoelectric element conductors 13.1, 13.1′, 13.1″, 13.2, 13.2′, 13.2″ contact the first side surface 130. Since the first side surface 130 is available and fulfills a specific technical function, namely, piezoelectric element contacts 13.01, 13.01′, 13.01″ are assembled thereon to conduct piezoelectric charges, this saves space. The respective first piezoelectric element conductors 13.1, 13.1′, 13.1″ are in contact with the first conductive side coating 131 via the first piezoelectric element contacts 13.01, 13.01′, 13.01″. The respective second piezoelectric element conductors 13.2, 13.2′, 13.2″ are in contact with the first conductive side coating 131 via the second piezoelectric element contacts 13.02, 13.02′, 13.02″. 02″ is in contact with the second conductive side coating 133. The first and second piezoelectric element contacts 13.01, 13.01′, 13.01″, 13.02, 13.02′, 13.02″ are fastened on the first side 130. The first and second piezoelectric element contacts 13.01, 13.01′, 13.01″13.02, 13.02′, 13.02″ are material combinations such as wire bonding (Drahtbonden), soldering, etc. For wire bonding, methods such as thermocompression bonding, thermosonic ball wedge bonding, ultrasonic wedge-wedge bonding, etc. are applicable. Fig.11 The circular first and second piezoelectric element contacts 13.01, 13.01', 13.01", 13.02, 13.02', 13.02" are molded leads.

[0164] Preferably, the converter unit 1.3 has three first base conductors 13.3, 13.3', 13.3" and three second base conductors 13.4, 13.4', 13.4". The respective first piezoelectric element conductors 13.1, 13.1', 13.1" contact the first base conductors 13.3, 13.3', 13.3" via first base input contacts 13.03, 13.03', 13.03". The respective second piezoelectric element conductors 13.2, 13.2', 13.2" contact the second base conductors 13.4, 13.4', 13.4" via second base input contacts 13.04, 13.04', 13.04". The first and second base input contacts 13.03, 13.03', 13.03", 13.04, 13.04', 13.04" are fastened to the first normal side 12.7 (according to Figure 1 and Figure 3 The first embodiment of the acceleration sensor 1) or fastened to the bracket 13.7 (according to Figure 2 and Figure 4 The first and second substrate input contacts 13.03, 13.03', 13.03", 13.04, 13.04', 13.04" are material combinations such as wire bonding, soldering, etc. For wire bonding, methods such as thermocompression bonding, thermosonic ball wedge bonding, ultrasonic wedge-wedge bonding, etc. are applicable. Fig.11 The circular first and second substrate input contacts 13.03, 13.03', 13.03", 13.04, 13.04', 13.04" are molded leads.

[0165] The first resistors 13.5, 13.5′, 13.5″, the second resistors 13.6, 13.6′, 13.6″ and the transimpedance converters 13.10, 13.10′, 13.10″ are electrically connected to one another via first base conductors 13.3, 13.3′, 13.3″. The second base conductors 13.4, 13.4′, 13.4″ carrying the second acceleration signal S2 of the first, second and third piezoelectric elements 10, 10′, 10″ are electrically short-circuited and are at the reference potential of the converter unit 1.3. The reference potential is stable, i.e., it is a constant DC voltage over time.

[0166] Preferably, the converter unit 1.3 has three transimpedance converters 13.10, 13.10', 13.10". The three transimpedance converters 13.10, 13.10', 13.10" are identically designed. Figure 1 and Figure 2In the embodiment shown, the transimpedance converters 13.10, 13.10', 13.10" are electronic components. The transimpedance converters 13.10, 13.10', 13.10" are connected via an intermediate Fastened with a material fit on the first normal side 12.7 (according to Figure 1 and Figure 3 The first embodiment of the acceleration sensor 1) or fastened to the bracket 13.7 (according to Figure 2 and Figure 4 The second embodiment of the acceleration sensor 1); and / or the transimpedance converters 13.10, 13.10′, 13.10″ are fastened to the first and second base conductors 13.3, 13.3′, 13.3″, 13.4, 13.4′, 13.4″ by an intermediate medium material. The intermediate medium is a chemically hardened adhesive, a physically cured adhesive, a solder, etc. Preferably, the intermediate medium is an adhesive, such as epoxy, polyurethane, cyanoacrylate, methyl methacrylate, etc. The first base conductors 13.3, 13.3', 13.3" contact the transimpedance converters 13.10, 13.10', 13.10". The type and manner of contact are arbitrary. Each first base conductor 13.3, 13.3', 13.3" conducts the first acceleration signal S1 to the input of the transimpedance converter 13.10, 13.10', 13.10". Preferably, the input of the transimpedance converter 13.10, 13.10', 13.10" has a resistance greater than 10 7 The transimpedance converters 13.10, 13.10', 13.10" convert the first acceleration signal S1 into a voltage. The converted first acceleration signal S1 is applied to the output end of the transimpedance converters 13.10, 13.10', 13.10". Preferably, the output end of the transimpedance converters 13.10, 13.10', 13.10" has a voltage less than 10 2 With the knowledge of the present invention, a person skilled in the art can also use a charge amplifier to replace the transimpedance converter, with a low resistance at the input of the charge amplifier.

[0167] Fig.12 A schematic diagram of a high-pass filter 18 , 18 ′, 18 ″ of a converter unit 1 . 3 is shown. Preferably, converter unit 1 . 3 has three first resistors 13 . 5 , 13 . 5 ′, 13 . 5 ″. The three first resistors 13 . 5 , 13 . 5 ′, 13 . 5 ″ are designed identically.

[0168] exist Figure 1 and Figure 2In the embodiment shown, the first resistor 13.5, 13.5′, 13.5″ is a resistor coating made of a resistor material such as Al2O3, ceramic, Al2O3 ceramic, etc. The resistor coating is realized by chemical vapor deposition, physical vapor deposition, etc. The resistor coating is a resistor thin layer. In the sense of the present invention, the resistor coating is also a “thin layer”, which has a thickness of preferably less than 0.1 mm in a direction extending perpendicular to the plane. The resistor coating is applied directly on the first normal side surface 12.7 (according to Figure 1 and Figure 3 The first embodiment of the acceleration sensor 1), or on the bracket 13.7 (according to Figure 2 and Figure 4 The resistive coating may be structured by using a template, photolithography, laser ablation or the like.

[0169] In accordance with Figure 2 and Figure 4 In the embodiment of the present invention, the first resistors 13.5, 13.5', 13.5" are electrical components having a resistance material made of ceramic, metal oxide, etc. and connecting wires.

[0170] Each first base conductor 13.3, 13.3′, 13.3″ contacts a first resistor 13.5, 13.5′, 13.5″. The type and manner of contact are arbitrary. Each first resistor 13.5, 13.5′, 13.5″ is electrically connected in parallel with one of the three piezoelectric elements 10, 10′, 10″. The parallel connection forms a high-pass filter 18, 18′, 18″ because the first, second or third piezoelectric element 10, 10′, 10″ is a capacitor. The high-pass filter 18, 18′, 18″ filters out frequencies below the cut-off frequency. Preferably, the cut-off frequency is 10 Hz. When the acceleration sensor 1 starts to detect acceleration, the discharge of the first, second or third piezoelectric element 10, 10′, 10″ may cause low interference frequencies below the cut-off frequency. This low interference frequency is applied to the input of the transimpedance converter 13.10, 13.10′, 13.10″ and forms an undefined time constant. This low interference frequency may distort the detection of acceleration. By filtering the low interference frequency, the transimpedance converter 13.10, 13.10′, 13.10″ obtains a defined time constant. The cut-off frequency can be adjusted by the value of the first resistor 13.5, 13.5′, 13.5″.

[0171] Fig.13A schematic diagram of a low-pass filter 17, 17', 17" of a converter unit 1.3 is shown. Preferably, the converter unit 1.3 has three second resistors 13.6, 13.6', 13.6". The three second resistors 13.6, 13.6', 13.6" are constructed identically. The second resistors 13.6, 13.6', 13.6" are electrical components having a resistance material made of, for example, ceramic, metal oxide or the like and connecting wires. A first base conductor 13.3, 13.3', 13.3" contacts the second resistors 13.6, 13.6', 13.6". The type and manner of contact are arbitrary. Each second resistor 13.6, 13.6', 13.6" is electrically connected in series with one of the three piezoelectric elements 10, 10', 10". This series connection forms a low-pass filter 17, 17', 17" because the first, second or third piezoelectric element 10, 10', 10" is a capacitor. The low-pass filters 17, 17', 17" filter out high interference frequencies that are higher than the natural frequency of the acceleration sensor 1. The high interference frequencies are caused by the mechanical excitation of the acceleration sensor 1. The high interference frequencies are applied to the input ends of the transimpedance converters 13.10, 13.10', 13.10", and saturate the transimpedance converters 13.10, 13.10, 13.10, resulting in distortion of acceleration detection. Depending on the value of the second resistors 13.6, 13.6', 13.6", the low-pass filters 17, 17', 17" are adjusted to the natural frequency of the acceleration sensor 1.

[0172] Preferably, the converter unit 1.3 has three first base output conductors 13.8, 13.8', 13.8". The respective output ends of the transimpedance converters 13.10, 13.10', 13.10" contact the first base output contacts 13.08, 13.08', 13.08" via the first base conductors 13.3, 13.3', 13.3". Preferably, the converter unit 1.3 has a second base output conductor 13.9. The second base conductors 13.4, 13.4', 13.4" contact the second base output conductor 13.9 via the second base output contact 13.09. The first and second base output contacts 13.08, 13.08', 13.08", 13.09 are fastened to the first normal side 12.7 (according to Figure 1 and Figure 3 The first embodiment of the acceleration sensor 1) or fastened to the bracket 13.7 (according to Figure 2 and Figure 4 The first and second substrate output contacts 13.08, 13.08', 13.08", 13.09 are material combinations such as wire bonding, soldering, etc. For wire bonding, methods such as thermocompression bonding, thermosonic ball wedge bonding, ultrasonic wedge-wedge bonding, etc. are applicable. Fig.11 The circular first and second base output contacts 13.08, 13.08', 13.08", 13.09 are molded leads.

[0173] The first substrate output conductors 13.8, 13.8', 13.8" transmit the converted first acceleration signal S1 to the signal output terminal 1.4. The second substrate output conductor 13.9 transmits the sum of the second acceleration signal S2 to the signal output terminal 1.4.

[0174] The signal output terminal 1.4 is partially fastened to the housing 1.2. Figure 1 and Figure 2 The signal output 1.4 of the embodiment of the acceleration sensor 1 is a cable. The signal output 1.4 has signal conductors 14.1, 14.1', 14.1", 14.2, a protective cover 14.3, a cover flange 14.4, an electrical insulation 14.5 and a potting material 14.6.

[0175] Viewed in cross section, the signal output terminal 1.4 has a multi-layer structure.

[0176] The signal conductors 14.1, 14.1', 14.1", 14.2 form an inner layer. Preferably, the signal output end 1.4 has three first signal conductors 14.1, 14.1', 14.1" and one second signal conductor 14.2. The signal conductors 14.1, 14.1', 14.1", 14.2 are made of a conductive material such as copper, a copper alloy, gold, a gold alloy, aluminum, an aluminum alloy, etc. Preferably, each signal conductor 14.1, 14.1', 14.1", 14.2 has an electrically insulating shield. The first and second base output conductors 13.8, 13.8', 13.8", 13.9 contact the first and second signal conductors 14.1, 14.1', 14.1", 14.2. Each first base output conductor 13.8, 13.8', 13.8" contacts a first signal conductor 14.1, 14.1', 14.1". The second base output conductor 13 . 9 contacts the second signal conductor 14 . 2 .

[0177] The electrical insulation 14.5 forms an intermediate layer and is arranged around the signal conductors 14.1, 14.1', 14.1", 14.2. The electrical insulation 14.5 electrically insulates the signal conductors 14.1, 14.1', 14.1", 14.2 from the protective cover 14.3. The electrical insulation 14.5 is made of an electrically insulating material such as Al2O3, ceramic, Al2O3 ceramic, fiber reinforced plastic, etc.

[0178] The protective cover 14.3 forms an outer layer. The protective cover 14.3 protects the electrical insulation 14.5 and the signal conductors 14.1, 14.1', 14.1", 14.2 from harmful environmental influences such as pollutants (dust, moisture, etc.) and from electromagnetic waves, which may cause undesirable interference effects in the first and second acceleration signals S1, S2. The protective cover 14.3 is made of a mechanically resistant material, such as metal, plastic, etc.

[0179] Figures 14 to 18 Shown according to Figure 2 The acceleration sensor 1 of the embodiment shown is assembled in steps.

[0180] Fig.14 A first assembly step is shown, in which signal conductors 14.1, 14.1′, 14.1″, 14.2 are introduced into the housing 1.2. The housing 1.2 has a signal output opening 1.22. The signal output opening 1.22 preferably has the shape and size of the outer diameter of the protective cover 14.3. The ends of the signal conductors 14.1, 14.1′, 14.1″, 14.2 are stripped, and the electrically insulating shield has been partially removed here. The ends of the signal conductors 14.1, 14.1′, 14.1″, 14.2 extend through the signal output opening 1.22 into the interior of the housing 1.2. The interior of the housing 1.2 is the area around the housing bottom 1.23.

[0181] The signal output opening 1.22 is closed to the outside by the protective cover 14.3 and the protective cover flange 14.3. Preferably, the end of the protective cover 14.3 is fastened to the protective cover flange 14.4. The protective cover flange 14.4 is made of a mechanically resistant material, such as metal, plastic, etc. The fastening of the protective cover 14.3 and the protective cover flange 14.4 is achieved by force fitting, such as crimping.

[0182] The metal flange 14.4 is in turn fastened to the housing 1.2 by material bonding. Preferably, the metal flange 14.4 is fastened to the outer edge of the housing opening 1.22 facing away from the interior of the housing 1.2. The material bonding is achieved by welding, brazing, bonding, etc. Fastening the protective cover flange 14.4 to the housing 1.2 will result in stress relief (Zugentlastung) of the protective cover 14.3. Due to the stress relief of the protective cover 14.3, the mechanical load from the protective cover 14.3 cannot be transmitted to the interior of the housing 1.2 and reach the converter unit 1.3 and cause damage there, such as the base output conductors 13.8, 13.8′, 13.8″, 13.9 being torn (Abreissen) or scratched (Anreissen). This mechanical load originates from the rotation, twisting (Verzwirbelung), etc. of the protective cover 14.3 around its long extension axis.

[0183] Fig.15The second assembly step is shown, in which the signal conductors 14.1, 14.1′, 14.1″, 14.2 in the housing 1.2 are potted with a potting material 14.6. The potting material 14.6 is applied to the signal conductors 14.1, 14.1′, 14.1″, 14.2 in the signal output opening 1.21 through the housing opening 1.20. The potting material 14.6 is a chemically hardening adhesive or a physically curable adhesive, or a combination of a chemically hardening adhesive and a physically curable adhesive. Preferably, the potting material 14.6 is made of an adhesive, such as epoxy, polyurethane, cyanoacrylate, methyl methacrylate, etc. The potting material 14.6 is a material having a viscosity greater than 10 12 Ωmm 2 Preferably, enough potting material 14.6 is applied to the signal conductors 14.1, 14.1', 14.1", 14.2 in the signal output opening 1.21 so that the signal output opening 1.21 is completely closed.

[0184] Fig.16The third assembly step is shown, in which the signal conductors 14.1, 14.1′, 14.1″, 14.2 potted with potting material 14.6 are partially exposed in the housing 1.2. The exposed parts 14.7 of the signal conductors 14.1, 14.1′, 14.1″, 14.2 are realized by a suitable cutting tool (e.g. a cutting wedge, a milling cutter, etc.). The cutting tool enters the interior of the housing 1.2 through the housing opening 1.20 and cuts off the ends of 14.1, 14.1′, 14.1″, 14.2 and the area of ​​the hardened potting material 14.6. The exposed parts 14.7 are realized in a plane spanned by the transverse axis x and the longitudinal axis y. In the area of ​​the exposed parts 14.7, the end faces of the cut-off ends of the signal conductors 14.1, 14.1′, 14.1″, 14.2 are exposed in a plane. Preferably, the plane extends parallel to the housing opening 1.20. In the area of ​​the exposed portion 14.7, the sides of the signal conductors 14.1, 14.1′, 14.1″, 14.2 are completely surrounded by the potting material 14.6. The potting material 14.6 secures the signal conductors 14.1, 14.1′, 14.1″, 14.2 in a stress-relieved manner. Due to the stress relief of the signal conductors 14.1, 14.1′, 14.1″, 14.2, mechanical loads from the signal conductors 14.1, 14.1′, 14.1″, 14.2 cannot be transmitted into the interior of the housing 1.2 and reach the converter unit 1.3, and cause damage there, such as the base output conductors 13.8, 13.8′, 13.8″, 13.9 being torn or scratched. Such mechanical loads originate from rotation, twisting (Verzwirbelung), etc. of the signal conductors 14.1, 14.1′, 14.1″, 14.2 around their long extension axis. And the potting material 14.6 hermetically closes the signal output opening 1.21. The hermetic sealing of the signal output opening 1.21 prevents moisture from penetrating through the signal conductors 14.1, 14.1', 14.1", 14.2 into the interior of the housing 1.2 and reaching the sensor unit 1.1, where moisture could impair the function of the piezoelectric element 10, 10', 10", because piezoelectric materials such as quartz are very hygroscopic.

[0185] Fig.17 A fourth assembly step is shown, in which the sensor unit 1.1 is placed in the housing 1.2. The sensor unit 1.1 with the converter unit 1.3 is introduced into the interior of the housing 1.2 through the housing opening 1.20. The second normal side surface 12.6 is materially fastened to the housing bottom 1.23, for example by gluing, soldering, etc. Preferably, the sensor unit 1.1 is oriented so that the fourth tangential side surface 12.4 is spatially close to the exposed portion 14.7.

[0186] Fig.18A fifth assembly step is shown, in which the sensor unit 1.1 contacts the converter unit 1.3. The contacting of the converter unit 1.3 is effected by suitable contacting means, such as wire bonding etc. The contacting means are guided into the interior of the housing 1.2 through the housing opening 1.20. The contacting tool connects the first and second base conductors 13.3, 13.3′, 13.3″, 13.4, 13.4′, 13.4″ of the converter unit 1.3 via the first and second piezoelectric element conductors 13.1, 13.1′, 13.1″, 13.2, 13.2′, 13.2″ to the first side 130 of the first, second or third piezoelectric element 10, 10′, 10″. And the contacting tool connects the first and second base conductors 13.3, 13.3′, 13.3″, 13.4, 13.4′, 13.4″ of the converter unit 1.3 via the first and second base output conductors 13.8, 13.8′, 13.8″, 13.9 to the signal conductors 14.1, 14.1′, 14.1″, 14.2 of the signal output end 1.4.

[0187] Preferably, the first and second substrate output conductors 13.8, 13.8', 13.8", 13.9 are in direct contact with the end faces of the cut-off ends of the signal conductors 14.1, 14.1', 14.1", 14.2. The advantage of such direct contact between the first and second substrate output conductors 13.8, 13.8', 13.8", 13.9 and the signal conductors 14.1, 14.1', 14.1", 14.2 is that no other supporting devices, such as circuit boards, are required, which keeps the size and weight of the acceleration sensor small and makes the assembly of the acceleration sensor simple and cost-effective. Another advantage of the direct contact of the first and second base output conductors 13.8, 13.8', 13.8", 13.9 with the signal conductors 14.1, 14.1', 14.1", 14.2 is that the converter unit 1.3 is in stress-relieved contact with the signal conductors 14.1, 14.1', 14.1", 14.2 via the mechanically flexible base output conductors 13.8, 13.8', 13.8", 13.9, because the mechanically flexible base output conductors 13.8, 13.8', 13.8", 13.9 reduce the mechanical loads reaching the signal conductors 14.1, 14.1', 14.1", 14.2.

[0188] After the electrical contact converter unit 1.3 has been closed, the housing opening 1.20 is sealed in a gas-tight manner by means of the housing cover 1.21. The sealing is carried out by means of a material connection, for example welding, soldering, adhesive bonding or the like.

Claims

1. An acceleration sensor (1), comprising: - a base body (12) having tangential side surfaces (12.1, 12.2, 12.3, 12.4) and normal side surfaces (12.6, 12.7), the tangential side surfaces (12.1, 12.2, 12.3, 12.4) being arranged tangentially with respect to a vertical axis (z), and the normal side surfaces (12.6, 12.7) being arranged normally with respect to the vertical axis (z); - at least one piezoelectric element (10, 10', 10") fastened to a tangential side (12.1, 12.2, 12.3); - at least one test mass (11, 11', 11") fastened to said piezoelectric element (10, 10', 10"); and - a housing (1.2) and a signal output terminal (1.4), the signal output terminal (1.4) being fastened to the housing (1.2) and having a signal conductor (14.1, 14.1', 14.1", 14.2); It is characterized in that A tangential side surface (12.4) to which no piezoelectric element (10, 10', 10") is fastened is arranged spaced apart from the signal conductor (14.1, 14.1', 14.1", 14.2) by an assembly gap (1.24) extending perpendicularly to the vertical axis (z); The first normal side surface (12.7) has a converter unit (1.3) and a substrate output conductor (13.8, 13.8', 13.8", 13.9), the converter unit (1.3) being arranged only and directly on the first normal side surface (12.7); or A support (13.7) fastened to a first normal side surface (12.7) comprises a converter unit (1.3) and a base output conductor (13.8, 13.8', 13.8", 13.9), wherein the converter unit (1.3) is arranged only and directly on the support (13.7); and the base output conductor (13.8, 13.8', 13.8", 13.9) is in direct contact with the signal conductor (14.1, 14.1', 14.1", 14.2) across an assembly gap (1.24) perpendicular to the vertical axis (z).

2. The acceleration sensor (1) according to claim 1, characterized in that The housing (1.2) has a housing opening (1.20) and a housing bottom (1.23); The base body (12) can be placed into the interior of the housing (1.2) through the housing opening (1.20); and the base body (12) is fastened to the housing bottom (1.23) by material fit via a second normal side surface (12.6).

3. The acceleration sensor (1) according to claim 1, characterized in that The housing (1.2) has a signal output opening (1.21); the signal conductors (14.1, 14.1', 14.1", 14.2) are guided into the interior of the housing (1.2) through the signal output opening (1.21).

4. The acceleration sensor (1) according to claim 3, characterized in that The signal output end (1.4) is fastened to the outer edge of the signal output opening (1.21) by means of a metal flange (14.4) in a material-fitting manner.

5. The acceleration sensor (1) according to claim 3, characterized in that: The signal conductors (14.1, 14.1', 14.1", 14.2) are potted with a potting material (14.6) in the housing (1.2); the potting material (14.6) secures the signal conductors (14.1, 14.1', 14.1", 14.2) in a stress-relieving manner; and the potting material (14.6) hermetically seals the signal output opening (1.21).

6. The acceleration sensor (1) according to any one of claims 1 to 5, characterized in that: The piezoelectric element (10, 10', 10") has an end surface (110, 120); and the piezoelectric element (10, 10', 10") has high sensitivity to the shear force applied by the test block (11, 11', 11"), and generates piezoelectric charge on the end surface (110, 120) under the action of the shear force.

7. The acceleration sensor (1) according to claim 6, characterized in that The piezoelectric element (10, 10', 10") has side surfaces (130, 140, 150, 160); the first end surface (110) has a first conductive end surface coating (111); the second end surface (120) has a second conductive end surface coating (121); the first side surface (130) has a first conductive side surface coating (131) and another first conductive side surface coating (133); the first conductive end surface coating (111) and the first conductive side surface coating (131) form a first continuous conductive coating (101); the second conductive end surface coating (121) and the another first conductive side surface coating (133) form a second continuous conductive coating (102).

8. The acceleration sensor (1) according to claim 7, characterized in that The converter unit comprises a first piezoelectric element conductor (13.1, 13.1′, 13.1″) and a second piezoelectric element conductor (13.2, 13.2′, 13.2″); the first conductive side coating (131) is connected to the first piezoelectric element conductor (13.1, 13.1′, 13.1″) by material fit; the other first conductive side coating (133) is connected to the second piezoelectric element conductor (13.2, 13.2′, 13.2″) by material fit; the first piezoelectric element conductor (13.1, 13.1′, 13.1″) intercepts piezoelectric charge from the first conductive side coating (131) and derives it as a first acceleration signal (S1); and the second piezoelectric element conductor (13.2, 13.2′, 13.2″) intercepts piezoelectric charge from the other first conductive side coating (133) and derives it as a second acceleration signal (S2).

9. The acceleration sensor (1) according to claim 8, characterized in that The converter unit (1.3) comprises a first base conductor (13.3, 13.3', 13.3", a second base conductor (13.4, 13.4', 13.4") and a transimpedance converter (13.10, 13.10', 13.10"); the first piezoelectric element conductor (13.1, 13.1', 13.1") is in contact with the first base conductor (13.3, 13.3', 13.3"); the first base conductor (13.3, 13.3', 13.3") converts the first acceleration signal The signal (S1) is transmitted to the transimpedance converter (13.10, 13.10′, 13.10″), and the transimpedance converter (13.10, 13.10′, 13.10″) converts the first acceleration signal (S1); the second piezoelectric element conductor (13.2, 13.2′, 13.2″) is in contact with the second base conductor (13.4, 13.4′, 13.4″); and the second base conductor (13.4, 13.4′, 13.4″) transmits the second acceleration signal (S2).

10. The acceleration sensor (1) according to claim 9, characterized in that The first substrate conductor (13.3, 13.3', 13.3") is in contact with a first substrate output conductor (13.8, 13.8', 13.8"), wherein the first substrate output conductor (13.8, 13.8', 13.8") conducts the converted first acceleration signal (S1) to the signal output terminal (1.4); and the second substrate conductor (13.4, 13.4', 13.4") is in contact with a second substrate output conductor (13.9), wherein the second substrate output conductor (13.9) conducts the second acceleration signal (S2) to the signal output terminal (1.4).

11. The acceleration sensor (1) according to any one of claims 1 to 5, characterized in that: The acceleration sensor (1) has exactly three piezoelectric elements (10, 10', 10") and exactly three test blocks (11, 11', 11"); and exactly one of the three piezoelectric elements (10, 10', 10") is fastened to each of the three tangential sides (12.1, 12.2, 12.3); and exactly one of the three test blocks (11, 11', 11") is fastened to each of the piezoelectric elements (10, 10', 10") 12. The acceleration sensor (1) according to claim 11, characterized in that Each of the three test blocks (11, 11', 11") applies a shear force proportional to the acceleration to a piezoelectric element (10, 10', 10") fastened thereto when accelerated; the first piezoelectric element (10) is highly sensitive to the shear force along the longitudinal axis (y) applied by the first test block (11), and generates a piezoelectric charge under the action of the shear force along the longitudinal axis (y); the second piezoelectric element (10') is highly sensitive to the shear force along the transverse axis (x) applied by the second test block (11'), and generates a piezoelectric charge under the action of the shear force along the transverse axis (x); and the third piezoelectric element (10") is highly sensitive to the shear force along the vertical axis (z) applied by the third test block (11"), and generates a piezoelectric charge under the action of the shear force along the vertical axis (z).

13. A method for assembling an acceleration sensor (1) according to any one of claims 1 to 12, characterized in that: A housing (1.2) is provided, the housing having a housing opening (1.20), a signal output opening (1.21) and a housing bottom (1.23); a signal output end (1.4) is provided, the signal output end having a signal conductor (14.1, 14.1', 14.1", 14.2); the signal conductor (14.1, 14.1', 14.1", 14.2) is guided into the interior of the housing (1.2) through the signal output opening (1.21); Providing a potting material (14.6); potting the signal conductor (14.1, 14.1′, 14.1″, 14.2) in the housing (1.2) with the potting material (14.6); fastening the signal conductor (14.1, 14.1′, 14.1″, 14.2) by the potting material (14.6) in a stress-relieving manner; and hermetically sealing the signal output opening (1.21) by the potting material (14.6).

14. The method according to claim 13, characterized in that A base body (12), at least one piezoelectric element (10, 10', 10"), at least one test block (11, 11', 11") and a converter unit (1.3) are provided, the base body (12) having tangential side surfaces (12.1, 12.2, 12.3, 12.4) and normal side surfaces (12.6, 12.7), the tangential side surfaces (12.1, 12.2, 12.3, 12.4) being arranged tangentially with respect to a vertical axis (z), and the normal side surfaces (12.6, 12.7). 6, 12.7) are arranged normally with respect to the vertical axis (z); the converter unit (1.3) has a piezoelectric element conductor (13.1, 13.1', 13.1", 13.2, 13.2', 13.2") and a substrate output conductor (13.8, 13.8', 13.8", 13.9), wherein a piezoelectric element (10, 10', 10") is fastened to a tangential side (12.1, 12.2, 12.3), wherein the piezoelectric element (10, 10', 10") is fastened to a tangential side (12.1, 12.2, 12.3) and ... A test block (11, 11', 11") is fastened to a piezoelectric element (10, 10', 10"), wherein the piezoelectric element (10, 10', 10") has a side surface (130) with a first conductive side surface coating (131) and a further first conductive side surface coating (133); and wherein the first normal side surface (12.7) has the transducer unit (1.3) or a transducer unit fastened to the first normal side surface (12.7) (1.3) of the support (13.7); the base (12) is placed inside the housing (1.2) through the housing opening (1.20); the tangential side (12.4) on which the piezoelectric element (10, 10', 10") is not fastened is arranged on the signal output end (1.4) at intervals through an assembly gap (1.24); and the base (12) is fastened to the housing bottom (1.23) by material fit through a second normal side (12.6).

15. The method according to claim 14, characterized in that Each first conductive side coating (131) is materially connected to a first piezoelectric element conductor (13.1, 13.1′, 13.1″); each other first conductive side coating (133) is materially connected to a second piezoelectric element conductor (13.2, 13.2′, 13.2″); the substrate output conductor (13.8, 13.8′, 13.8″, 13.9) is materially connected to the signal conductor (14.1, 14.1′, 14.1″, 14.2); a housing cover (1.21) is provided; and the housing opening (1.20) is hermetically sealed using the housing cover (1.21).

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