DE102017112088A1 - Pump assembly for an ABS system and driver assistance system with the pump assembly - Google Patents

Abstract

Motor vehicles often have driver assistance systems for driver assistance. A basic component of the driver assistance systems form anti-lock braking devices, which cause the wheels of the motor vehicle to not lock during a braking operation. The antilock devices have in many designs a pump to stabilize a brake pressure. The invention has for its object to propose a pump assembly for an ABS system, which is particularly failures sicher.Hierzu a pump assembly 1 is proposed for an ABS system, with a housing 4, with a pump shaft 3 for driving at least one piston, wherein the pump shaft 3 is mounted in the housing 4, and with a vibration sensor 17 for detecting vibrations of the pump assembly 1 and with an evaluation unit 18 for analyzing the detected vibrations.

Description

The invention relates to a pump assembly for an ABS system in a vehicle having the features of the preamble of claim 1. The invention also relates to a driver assistance system with the pump assembly.

Motor vehicles often have driver assistance systems for driver assistance. A basic component of the driver assistance systems form anti-lock braking devices, which cause the wheels of the motor vehicle to not lock during a braking operation. The anti-lock devices have a pump in many designs to stabilize a brake pressure.

The publication WO 2007/118722 A1 describes such a pump, which can be used in a hydraulic unit of an ABS system, in particular an ESP system. The pump has a pump housing with a drive shaft and a drive motor, wherein the drive shaft is mounted in the pump housing and converts via an eccentric bearing rotational movement of the drive shaft in a linear movement for a piston.

The invention has for its object to propose a pump assembly for an ABS system, which is particularly fail-safe. This object is achieved by a pump arrangement having the features of claim 1 and by a driving assistance system having the features of claim 10. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and / or the accompanying figures.

The subject matter of the invention is a pump arrangement which is suitable and / or designed for an ABS system of a vehicle. The vehicle may be designed as a passenger car, truck, bus, etc. In particular, the pump arrangement is arranged and / or integrated in a hydraulic unit of the ABS system. The ABS system can also be referred to as anti-lock braking system. The pump arrangement is preferably used for generating and / or stabilizing a brake pressure in the brake system of the vehicle.

The pump assembly has a housing in which components of the pump assembly are arranged. Preferably, the housing is integrally formed.

The pump assembly has a pump shaft, wherein the pump shaft is mounted in the housing. The pump shaft serves to drive at least one piston of the pump assembly. Preferably, the at least one piston forms a component of the pump arrangement. For example, the pump arrangement may comprise two pistons, three pistons, four pistons or more pistons. In particular, a rotational movement of the pump shaft via the pump arrangement is converted into a linear movement of the at least one piston.

In the context of the invention, it is proposed that the pump arrangement has a vibration sensor, wherein the vibration sensor serves to detect vibrations of the pump arrangement. In particular, the vibration sensor is used to detect the vibrations during operation of the pump assembly. The vibration sensor is preferably positioned undamped in the pump arrangement in order to provide as accurate as possible measured values. The vibration sensor may be formed as a piezoelectric sensor, electrodynamic sensor, capacitive sensor or inductive sensor. Alternatively, the vibration sensor may be realized as an optical sensor.

The pump assembly also has an evaluation unit, which is signal-technically coupled to the vibration sensor. In particular, sensor data can be transmitted from the vibration sensor to the evaluation unit. It is possible that the data transfer is implemented by cable. Alternatively, the sensor data is transmitted wirelessly from the vibration sensor to the evaluation unit. The evaluation unit is preferably designed as a digital data processing device, such as a microprocessor or the like.

The evaluation unit is designed programmatically and / or software technically to perform an analysis of the vibrations detected by the vibration sensor. The vibration sensor measures the vibrations of the pump assembly, in particular the components of the pump assembly. In the event that irregularities or incipient defects in the pump assembly occur, these change the vibrations of the pump assembly and are thus detected by the vibration sensor. The vibrations of the pump assembly are transmitted as sensor signals to the evaluation and analyzed by this. This can in the analysis on irregularities, defects or incipient defects in the pump assembly close. In this way, it is preferably possible to detect defects before the performance of the pump assembly deteriorates or even complete failure of the pump assembly occurs. As a result, it can be avoided that the pump arrangement and thus the ABS system based thereon surprisingly fail, so that this can no longer support the driver in a critical situation.

In a preferred embodiment of the invention, the evaluation unit is designed to determine an operating state of the pump assembly based on the analysis. For example, a state of wear or a defect state can be determined as the operating state of the pump arrangement, in particular of the components of the pump arrangement. Optionally, the pump arrangement, the ABS system or the driver assistance system has an output interface for outputting a warning signal. For example, the interface may be signal-technically coupled to a warning light or indicator light. In the event that the evaluation unit determines a wear state or a defect state via the analysis as the operating state, the warning light or indicator light can be activated via the output interface so that it is activated and the driver is warned. It can also be provided that the evaluation unit holds a threshold value, wherein the warning light or the indicator light only comes on when the threshold value is exceeded. In this way, false warnings can be avoided. As a result, a defect or imminent defect is detected by the pump assembly with the vibration sensor and the evaluation unit through the analysis and thus recognized in time, optionally displayed, so that appropriate measures, such. Repair of the pump assembly, can be initiated.

In a possible development of the invention, the pump arrangement has a speed interface for taking over a speed datum of the pump shaft. Under the speed data is preferably understood the speed of the pump shaft or a date which can be converted into the speed of the pump shaft. For example, the speed data may be a relative value of the speed of the pump shaft. However, it is also possible that the speed data is a speed of an electric motor that drives the pump shaft. In known gear ratios, it is possible in a simple manner to convert the speed of the electric motor into a rotational speed of the pump shaft. The evaluation unit is designed to carry out the analysis on the basis of the speed data. It is a consideration of this development that, when damaged by the rotating and / or oscillating components of the pump assembly irregularities occur, which are in relation to the speed of the pump shaft. Thus, it may assist the analysis if the speed of the pump shaft is taken into account in the analysis of the vibrations.

In an advantageous development of the invention, the evaluation unit is designed to determine a rollover frequency of components of the pump arrangement and to check whether irregularities in the vibrations occur at the same frequency as the rollover frequency. The rollover frequency is the rotational frequency of components of the pump assembly. In the event that the components pass an impurity in circulation, the vibrations have irregularities with the rollover frequency, ie with the frequency of the respective component. With the additional information of the speed data, the reliability of the analysis, in particular the determination of the operating state can be improved.

For example, the analysis includes a frequency analysis step and / or an order analysis step. These steps clearly show the regular disturbances in the vibrations. The frequency analysis step comprises a method for determining how often certain events occur in a certain time unit, or which frequency components are represented as strongly in a signal. An order analysis is the analysis of the vibrations with regard to the order of the vibrations.

In a preferred development of the invention, the pump arrangement has at least one first shaft support bearing for mounting the pump shaft in the housing. The first shaft support bearing is preferably formed as a roller bearing, such as a ball bearing. In preferred embodiments, the shaft support bearing has an outer ring, which is accommodated in the housing, and an inner ring, which sits on the pump shaft. The pump shaft may also have a plurality of such shaft support bearings.

Furthermore, it is preferred that the pump arrangement has an eccentric bearing device which is arranged on the pump shaft and which drives the piston. Preferably, the eccentric bearing device comprises an inner ring, wherein the inner ring is connected to the pump shaft, and an outer ring, wherein the outer ring has a raceway for a piston or an intermediate element to the piston. Preferably, the outer ring is formed as an outer sleeve. It can be provided that the inner ring is arranged on a shaft section arranged eccentrically to a rotation axis of the pump shaft. In this way, the inner ring is rotated eccentrically. Alternatively, the inner ring may be formed as an eccentric ring and placed on a coaxial portion of the pump shaft. In this alternative, an eccentric movement results through the outer surface of the inner ring. Preferably, the eccentric bearing device is designed as a needle bearing.

While the inner ring of the first shaft support bearing and / or the eccentric bearing rotates at the same rotational speed as the pump shaft and thus has the rotational frequency of the pump shaft as a rollover frequency, the rolling elements, ie in particular the balls in the shaft support bearing and / or the needles in the eccentric bearing, with rotate at a different rotational speed, so that they have a different rollover frequency. The outer ring in the eccentric bearing device can in turn assume a different rollover frequency.

In a first possible embodiment of the invention, the vibration sensor is arranged such that it directly contacts one or the first shaft support bearing. In this case, the vibration sensor may be arranged on the inner ring or on the outer ring. In this way, particularly irregular irregularities are absorbed by the shaft support bearing.

In a second possible embodiment of the invention, the vibration sensor is arranged so that it contacts the eccentric bearing device directly. It is preferred that the vibration sensor directly contacts the outer ring. In this way, particularly irregular irregularities are absorbed by the eccentric bearing device.

In a third possible embodiment of the invention, the vibration sensor is arranged so that it contacts the housing directly. In this way, vibrations of all the moving parts stored in the housing are absorbed by the vibration sensor.

The position of the vibration sensor thus makes it possible to vary the sensitivity of the vibration sensor with respect to different components of the pump arrangement. For example, it is also possible for the vibration sensor to be arranged between the outer ring of the shaft support bearing and the housing. It is also possible for the housing to have bores or receiving openings for the pistons, wherein the oscillation sensor is arranged in the region of the bores or the receiving opening.

Another object of the invention relates to a driver assistance system for the vehicle, wherein the driver assistance system has an ABS system with the pump assembly, as described above or according to one of the preceding claims. Particularly preferably, the driver assistance system is designed exclusively as the ABS system or designed as a traction control system (ASR), Adaptive Cruise Control or Brake Assist (BAS).

• 1 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein erstes Ausführungsbeispiel der Erfindung,
• 2 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein zweites Ausführungsbeispiel der Erfindung,
• 3 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein drittes Ausführungsbeispiel der Erfindung,
• 4 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein viertes Ausführungsbeispiel der Erfindung,
• 5 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein fünftes Ausführungsbeispiel der Erfindung,
• 6 in einer schematischen Längsschnittdarstellung eine Pumpenanordnung als ein sechstes Ausführungsbeispiel der Erfindung.

Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention and the accompanying figures. These show:

• 1 in a schematic longitudinal sectional view of a pump arrangement as a first embodiment of the invention,
• 2 in a schematic longitudinal sectional view of a pump arrangement as a second embodiment of the invention,
• 3 in a schematic longitudinal sectional view of a pump arrangement as a third embodiment of the invention,
• 4 in a schematic longitudinal sectional view of a pump arrangement as a fourth embodiment of the invention,
• 5 in a schematic longitudinal sectional view of a pump arrangement as a fifth embodiment of the invention,
• 6 in a schematic longitudinal sectional view of a pump assembly as a sixth embodiment of the invention.

Corresponding or equal sizes or components are identified by corresponding reference numerals.

The 1 shows a schematic longitudinal sectional view of a pump assembly 1 as a first embodiment of the invention. The pump arrangement 1 forms part of a driver assistance system 2 , where the driver assistance system 2 can be designed as an ABS system or as a driver assistance system 2 which accesses the ABS system. The pump arrangement 1 has the function of pumping and / or pressurizing a brake fluid. In the figures, the pump assembly 1 only partially shown. The pump arrangement 1 has a pump shaft 3 and a housing 4 on, with the pump shaft 3 in the case 4 around a rotation axis R is rotatably mounted. The pump shaft 3 is with a motor 5 operatively connected, so that the pump shaft 3 can be rotated. For example, the pump shaft 3 with a rotor shaft of the motor 5 rotatably connected.

The pump shaft 3 is about a first shaft support bearing 6 in the case 4 rotatably mounted. The first shaft support bearing 6 has an inner ring 7 and an outer ring 8th on, between which rolling elements 9 are arranged rolling. The inner ring 7 sits on the pump shaft 3 , the outer ring 8th is on the other hand in the housing 4 arranged, for example, pressed. On the pump shaft 3 is an eccentric bearing device 10 arranged. The eccentric bearing device 10 has an eccentric pin 11 on, which is an end portion of the pump shaft 3 forms and eccentric to the pump shaft 3 is arranged. On the eccentric pin 11 is a needle bearing 12 arranged, which is eccentrically rotated in operation. The eccentric bearing device 10 , in particular the needle bearing 12 has a series of rolling elements, in this case needles, and an outer ring 14 which is formed as a sleeve. The outer ring 14 forms on the inner circumference of a raceway for the rolling elements and on the outer circumference of a raceway for piston or intermediate elements to the piston. The pistons are graphically suppressed in the figures, but they are shots 15 for the pistons in the housing 4 brought in. The pictures 15 are perpendicular to the axis of rotation R the pump shaft 3 , The pump shaft 3 as well as the eccentric bearing device 10 are in a bearing bore 16 arranged, which is coaxial with the axis of rotation of the pump shaft 3 extends.

In operation, the pump shaft 3 through the engine 5 rotates. This will cause the eccentric pin 11 set in an eccentric motion, focusing on the outer ring 14 the eccentric bearing device 10 transfers. Due to the eccentric movement of the outer ring 14 can the rotational movement of the pump shaft 3 be converted into a linear motion for the pistons.

The pump arrangement 1 forms a basis for the ABS system and driver assistance systems based on it 2 , A failure of the pump assembly 1 inevitably leads to failure of the ABS system and the driver assistance systems based on it 2 , To improve the reliability, the pump assembly 1 a vibration sensor 17 and an evaluation unit 18 on which signaling technology with the vibration sensor 17 connected is. These components make it possible to damage or malfunction the pump assembly 1 , in particular at one of the bearings 6 . 10 to be able to detect and remedy this in good time before the pump arrangement 1 completely fails.

The vibration sensor 17 Measures vibrations (acceleration or speed) of the pump assembly 1 , in particular of the shaft support bearing 6 or the eccentric bearing device 10 , About the evaluation unit 18 The recorded vibrations can be analyzed and searched for specific irregularities. These irregularities can be caused by slight damage to one of the raceways, the rolling elements or a cage of the bearings 6 . 10 arise. In this way, irregularities can be detected before the performance of the pump assembly 1 , in particular of the shaft support bearing 6 and / or the eccentric bearing device 10 , wears off or a failure threatens.

The recorded vibrations are from the vibration sensor 17 to the evaluation unit 18 either wired or wirelessly transmitted. In the evaluation unit 18 An analysis of the detected vibrations is performed, based on the analysis of an operating state of the pump assembly 1 is determined. Depending on the embodiment may be used as the operating state of the pump assembly 1 also an operating state of the shaft support bearing 6 and / or the eccentric bearing device 10 be determined. The operating state is, in particular, a state of wear of the pump arrangement 1 or the warehouse 6 . 10 ,

Optionally, the evaluation unit 18 an interface 19 to apply a speed datum to the speed of the pump shaft 3 on. The speed data is the speed of the pump shaft 3 derivable. In particular, the speed data can be directly the speed of the pump shaft 3 Alternatively, a relative value, such as, for example, a speed of the motor, may also be described 5 be adopted via the interface. Based on the speed datum, a rollover frequency may be provided for the various components of the pump assembly 1 be determined. For components that are non-rotatable with the pump shaft 3 are connected, the rollover frequency corresponds to the rotational frequency of the pump shaft 3 , The rolling elements in the bearings and the outer ring 14 have different rollover frequencies. However, these are derivable from the speed data.

The evaluation unit 18 examines the detected vibrations for irregularities, in particular with the same frequency as the rollover frequency. This analysis is based on the consideration that in case of damage to components of the pump assembly 1 periodic vibration changes occur, with the changes having the same frequency as the causative component. Thus, with damage of the inner ring 7 or the eccentric pin 11 Irregularities with the rotation frequency of the pump shaft 3 to be expected as a rollover frequency. At the rolling elements or the outer ring 14 On the other hand, the irregularities in the corresponding rollover frequencies are to be expected. In order to be able to work out the irregularities particularly clearly, it is possible that the evaluation unit 18 performs a frequency analysis step and / or an order analysis step in the analysis.

With this analysis, patterns in the detected vibrations can be detected by characteristic deflections in the rollover frequencies or the associated orders.

In the 1 is an embodiment of the pump assembly 1 shown, wherein in the housing 4 two shots 15 in the case 4 are introduced. The vibration sensor 17 is on the outer ring 8th the eccentric bearing device 10 arranged on an axial end face and takes vibrations from the eccentric bearing device 10 or its outer ring 14 on. In this measuring position can irregularities of the eccentric bearing device 10 be particularly sensitive.

The 2 shows in the same representation as the 1 A second embodiment of the pump assembly 1 , wherein the vibration sensor 17 at the edge of one of the pictures 15 is arranged. When used piston is the vibration sensor 17 thus between the case 4 and the piston arranged. In this measuring position can be irregularities from the piston or from both camps 6 . 10 About structure-borne noise through the housing 4 be received sensitive.

In the 3 is the pump arrangement 1 in the same representation as shown in the preceding figures. The vibration sensor 17 is between the outer ring 8th of the first shaft support bearing 6 and the housing 4 arranged. In this measuring position, on the one hand, irregularities of the first shaft support bearing 6 be particularly sensitive recorded and on the other irregularities from the other components on structure-borne noise through the housing 4 also be included.

In the 4 is the pump arrangement 1 in the same representation as shown in the preceding figures. The vibration sensor 17 is in an imaginary extension of the pump shaft 3 at the edge in the housing 4 integrated, so no direct contact with the camps 6 . 10 consists. In this measuring position, irregularities of all components through structure-borne noise through the housing 4 be recorded.

The 5 shows a pump assembly 1 , which a total of four shots 15 for pistons, which are each in pairs opposite. The pump shaft 3 is about another shaft support bearing 20 , which end to the pump shaft 3 is arranged and attached to the housing 4 supports, stored. The pump arrangement. 1 has two eccentric bearing devices 10 a . b which, however, compared to the previous figures on a coaxial portion of the pump shaft 3 are set up. Each of the eccentric bearing devices 10 a . b has an inner ring 21 a . b on, with the inner rings 21 a . b with the pump shaft 3 are rotatably connected and formed as eccentric rings. With a rotation of the pump shaft 3 becomes an eccentric movement of the inner rings 21 a . b generated.

The vibration sensor 17 is in the area of the bearing bore 16 arranged on the input side, so that irregularities of the components by structure-borne noise over the housing 4 be transmitted.

In the 6 is the same pump arrangement 1 like in the 5 shown. The vibration sensor 17 is on the outer ring 8th of the first shaft support bearing 6 arranged so that these irregularities from the first shaft support bearing 6 particularly sensitive.

While in the embodiments of each pump assembly 1 exactly one vibration sensor 17 it was also possible that in one of the pump arrangements 1 more than a vibration sensor 17 is arranged.

LIST OF REFERENCE NUMBERS

1

pump assembly

2

Driver assistance system

3

pump shaft

4

casing

5

engine

6

first shaft support bearing

7

inner ring

8th

outer ring

9

rolling elements

10, 10a, b

Exzenterlagereinrichtung

11

eccentric

12

needle roller bearings

13

needles

14

outer ring

15

Recordings

16

bearing bore

17

vibration sensor

18

evaluation

19

interface

20

another shaft support bearing

21 a, b

inner ring

R

axis of rotation

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2007/118722 A1 [0003]

Claims (10)

Pump arrangement (1) for an ABS system, comprising a housing (4), with a pump shaft (3) for driving at least one piston, the pump shaft (3) being mounted in the housing (4), characterized by a vibration sensor ( 17) for detecting vibrations of the pump assembly (1) and by an evaluation unit (18) for analyzing the detected vibrations. Pump arrangement (1) after Claim 1 , characterized in that the evaluation unit (18) is designed to determine an operating state of the pump arrangement (1) on the basis of the analysis. Pump arrangement (1) after Claim 1 or 2 , characterized in that the pump arrangement (1) has an interface (19) for taking over a speed datum of the pump shaft (3), wherein the evaluation unit (18) is designed to carry out the analysis on the basis of the speed datum. Pump arrangement (1) after Claim 3 , characterized in that the evaluation unit (18) is adapted to determine a rollover frequency in dependence on the speed data and to perform the analysis based on the rollover frequency. Pump arrangement (1) according to one of the preceding claims, characterized in that the analysis comprises a frequency analysis step and / or an order analysis step. Pump arrangement (1) according to one of the preceding claims, characterized in that the vibration sensor (17) contacts the housing (4). Pump arrangement (1) according to one of the preceding claims, characterized in that the pump arrangement (1) has at least one first shaft support bearing (6) for mounting the pump shaft (3) in the housing (4), wherein the vibration sensor (17) the shaft support bearing ( 6) contacted. Pump arrangement (1) according to one of the preceding claims, characterized in that the pump arrangement (1) has an eccentric bearing device (10, 10a, b), wherein the eccentric bearing device (10, 10a, b) for driving the piston on the pump shaft (3 ), wherein the vibration sensor (17) contacts the eccentric bearing device (10, 10a, b). Pump arrangement (1) according to one of Claims 7 or 8th , characterized in that the vibration sensor (17) contacts on the one hand the housing (4) and on the other hand the eccentric bearing device (10, 10a, b) or the first shaft support bearing (6). Driver assistance system (2) for a vehicle with a pump arrangement (1) according to one of the preceding claims.

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