10. Storing specific load collectives decentrally in the brake unit or in the control device and/or in additional storage media A further version provides that the total wear sensor is located in the driver device with a spindle drive and a planetary gear mechanism coaxially with the threaded plunger. This provides an advantageously compact structure.
EP18815573.3 5
A compact structure can moreover be improved advantageously by providing that the total wear sensor and the pressure sensor, together with a spindle drive and a planetary gear mechanism, form a sensor unit, the sensor unit and the coupling member being located in the driver device.
Itis furthermore advantageous if the pressure sensor is integrated on a printed circuit board of the total wear sensor.
In this it is also possible that the pressure sensor is designed as a plug- in component or plug-in board, thus facilitating advantageous retrofitting.
In a further configuration the coupling member is arranged coaxially with the threaded plunger and in the manner of a sleeve over the threaded plunger of the driver device, wherein
— the coupling member is non-rotatably coupled to the threaded plunger at one end via a drive section, and wherein the other end of the coupling member is connected to the spindle drive via a driven section.
This provides not only a compact structure, but also an advantageously simple assembly.
In yet another version, in which the synchronising device of the disc brake has coupling
— wheels which are located at the bridge in a stationary and rotatable manner and of which one each is coupled to the respective threaded plunger, it is provided that the drive section of the coupling member is non-rotatably coupled to that coupling wheel of the synchronising device which belongs to the threaded plunger of the driver device.
In this case the advantage is that the coupling member, by being coupled to the coupling wheel, not only undergoes the rotary movement of the threaded plunger in a readjustment process, but is also subjected to the stroke of the bridge in each braking process and thus to the stroke of the brake rotary lever.
In yet another version it is provided that the coupling member has two oppositely arranged connecting sections connecting the drive section and the driven section, and wherein each connecting section consists of two triangular sections the apexes of which are connected, and wherein the base side of the one triangular section is connected to the drive section and the base side of the other triangular section is connected to the driven section.
As a result of this particularly elastic structure, the coupling member is capable of transmitting the relevant movements (rotation, translation) virtually without play while compensating for radial movements caused by disturbance variables such as vibrations etc.
In a further version the coupling member is coupled to the planetary gear mechanism in such a way that the coupling member transmits a rotary movement of the threaded spindle to a first
EP18815573.3 6 input of the planetary gear mechanism, and that the coupling member is coupled to the spindle drive in such a way that the coupling member transmits a linear stroking movement of the bridge to the spindle drive as a linear stroking movement coaxial with the threaded plunger in the direction of the brake disc axis.
Itis furthermore provided that the spindle drive is coupled to the planetary gear mechanism in such a way that the spindle drive transmits the rotary movement of the coupling member to a first input of the planetary gear mechanism and that the spindle drive converts the linear stroking movement of the coupling member into a rotary movement and transmits said rotary movement to a second input of the planetary gear mechanism.
In yet another version the coupling member, the spindle drive, the planetary gear mechanism and the total wear sensor are arranged one behind the other in the course of a driver axis of the driver device, starting from the bridge.
In this way an advantageously compact structure is obtained.
It is furthermore advantageous — not only for a compact structure, but also for simple assembly — if the spindle drive, the planetary gear mechanism, the total wear sensor and the pressure sensor are located as a sensor unit within a sensor housing or on a support, wherein the sensor housing extends through a through-opening — assigned to the driver device — of an outer wall of the application section of the brake calliper and projects outwards from the outer wall with a cap-like section.
— If the cap-like section of the sensor housing has a lateral extension having both a pluggable connection to a connecting section of the calliper sensor and a common connection of the sensors, the advantage of an integrated connection of the calliper sensor is obtained.
In this it is additionally advantageous if the lateral extension of the cap-like section of the sensor housing forms a holder for the calliper sensor.
In another version the calliper sensor comprises a housing with the connecting section, a rod and a spring, wherein a free end of the rod has a contact section, wherein the other end of the rod extends into the housing, is displaceably guided therein against a spring force of the spring and coupled to a linear sensor.
This is an advantageously simple and compact structure.
EP18815573.3 7 In a further version the calliper sensor is attached to the application section of the brake calliper outside the brake calliper in such a way that the contact section of the free end of the rod of the calliper sensor is in contact with a stationary component/part of the disc brake or a stationary part of a vehicle to which the disc brake is assigned and/or a section of the stationary component/part and is pressed against the stationary component by the spring force of the spring.
In this way it becomes advantageously possible for the calliper sensor not only to be easily accessible and replaceable for maintenance and replacement operations, but also to be capable of retrofitting at a later occasion.
A yet further version provides that the stationary component of the disc brake is the adapter,
so that advantageously there is no need for an additional component.
It is advantageous if the stationary component of the disc brake is an adapter beam of the adapter, since this provides a section which has already been machined during the production of the adapter for the mounting thereof and can thus be used as a reference for the calliper sensor without any additional machining.
In an alternative version the calliper sensor can be attached outside the brake calliper with its housing to a stationary axle part of a vehicle to which the disc brake is assigned or to the adapter in such a way that the contact section of the free end of the rod of the calliper sensor is in contact with the brake calliper and/or with a section of the brake calliper and is pressed against the brake calliper and/or the section of the brake calliper by the spring force of the
— spring.
This can be advantageous in special installation conditions.
In a further version it is provided that the assembly for monitoring the condition of the disc brake has at least one temperature sensor within and/or outside the brake calliper.
This offers the advantage of an expansion of the monitoring the conditions of the disc brake.
It is particularly advantageous if the assembly for monitoring the condition of the disc brake has at least one interface common to the sensors, because in this case there is no need for additional wiring.
In a further version of the method, by means of a pressure sensor, a monitoring of seals of an interior of an application section of a brake calliper of the disc brake, a monitoring of hot boxes by a temperature-eguivalent signal of the pressure sensor and a clearance plausibility check are performed.
This offers the advantage that the pressure sensor can be used for several detection tasks.
This results in the advantage of a further important condition
EP18815573.3 8 monitoring of the seals.
Damaged or faulty seals lead to ingress of moisture into the brake interior and thus eventually to the failure of electronic components or to the corrosion of mechanical components.
This can therefore advantageously be detected early enough and therefore prevented.
In yet another version by means of a calliper sensor a detection and monitoring of the position of the brake calliper, an individual pad wear of an outer or rear brake pad and a monitoring of a condition of guides and/or mounting of the brake calliper are performed.
This results in a reduction of additional sensors, since these functions can be taken over by the calliper sensor.
If temperatures of the disc brake can be detected and monitored by means of at least one temperature sensor, condition monitoring can be improved advantageously, because from the temperature curves and temperatures compared to previously determined limit values, predictions can be made for specific maintenance operations.
This can save costs, and a working time can be extended as well.
— It is furthermore advantageous if a data transmission of the signals of the sensors is carried out via a common analogue data line and/or via a digital data link, because in this way additional installation operations involving wiring or retrofitting can be omitted.
In one version an analogue data transmission of the signals of the sensors is carried out by means of a multiplexer by a seguential reading-in of the monitoring data of the individual sensors.
This facilitates an advantageous communication with a corresponding control device of the brake if said control device is designed for analogue data transmission only, for example.
In another version a digital data transmission of the signals of the sensors can be carried out using a digital bus protocol, a master being located in an external control device.
This facilitates an advantageous communication with a bus system of a control device.
In addition it is advantageously possible to monitor the response pressure, the application pressure, the release of the brake and the hysteresis.
As a further advantage, a plausibility check of the parking brake can be performed by the condition monitoring device.
This yields the following advantages:
EP18815573.3 9
1. Modular expandability of the cable interface between brake and braking system (cable is an OEM purchase). As a result fleet operators can for example fit individual vehicles in a targeted manner with suitable sensor systems.
2. Complete monitoring of the disc brake and thus monitoring of all relevant state variables
3. Expansion by tightness monitoring
4. The described solutions detect the clearance of the disc brake and thereby prevent a so-called hot box of the brake if the clearance is significantly too low. A hot box is safety-relevant, because it can damage or destroy the tyre. Pure position measuring here does not provide a 100% reliable indication for a hot box, because brake pads can compensate for continuous drag by hot wear, thus preventing a hot box. An erroneous warning signal and a resulting workshop visit can be avoided by evaluating the temperature of the braking system or a further temperature-eguivalent signal This is also ensured by the evaluation of the internal pressure of the brakes. If the pressure level rises disproportionately compared to the pressure level of the other brake, conclusions can be drawn about a heat development, because temperature and pressure are physically connected as described by the thermal state eguation.
5. Additional free interfaces can moreover be provided for retrofitting potential sensors.
6. The modular structure in particular results in several combinations, starting with a starting variant which can be described as minimal variant: Total wear sensor and pressure sensor Total wear sensor and stroke monitoring by means of spindle drive Total wear sensor and calliper position sensor Total wear sensor, stroke monitoring by means of spindle drive and pressure sensor Total wear sensor, pressure sensor and calliper position sensor Total wear sensor, stroke monitoring by means of spindle drive and calliper position sensor
EP18815573.3 10 Total wear sensor, stroke monitoring by means of spindle drive, calliper position sensor and pressure sensor
7. Thanks to the modular structure there is no need for different housing variants either, so that additional outlay for additional variants can be avoided preventively. The invention is now explained in greater detail with reference to the attached drawings, of which:
Fig. 1 is a diagrammatic sectional view of a disc brake according to prior art; Figs.2to4 are perspective diagrammatic part-sectional views of an embodiment of a disc brake according to the invention;
Fig. 5 is a diagrammatic side view of a calliper sensor;
Fig. 6 is a diagrammatic side view of a coupling member and a part-sectional view of a sensor unit; and
Fig. 7 is a diagrammatic perspective view of the coupling member.
Fig. 1 is a diagrammatic sectional view of a disc brake 1” according to prior art. The term “top” or “upper side” should be understood to be that side of the component in question which points to the application side in the installed state of the disc brake 1, 1°, The “lower side” or “bottom” then points toward the brake disc 2. The disc brake 1” according to prior art is described only briefly below in outline. Structure and function are explained in detail in DE 10 2012 108 672 B3. The disc brake 1? is here a twin-plunger brake and comprises a brake disc 2 with a brake disc axis 2a, brake pads 3, 3°, an adapter 4, a brake calliper 5, an application device with two threaded plungers 6, 6°, a bridge 7 and a brake rotary lever 9, a wear readjustment apparatus 10 with a readjustment device 10a and a driver device 10b with a wear sensor 11 as well as a synchronising device 16. A control device 26 is also assigned to the disc brake 1°. On both sides of the brake disc 2, a brake pad 3, 3” with a backing plate 3a, 3’a, to each of which a friction lining 3b, 3°b is attached, is located. The brake pad 3 located between the application section 5a and the brake disc 2 is described as application-side brake pad 3, while
EP18815573.3 11 the brake pad 3? on the other side of the brake disc 2 between the rear section 5b and the brake disc 2 is called rear or reaction-side brake pad 3°. The brake disc 2 is overlapped by the brake calliper 5, which is here designed as a floating calliper.
The brake calliper 5 has an application section 5a and a rear section 5b and is mounted at the stationary adapter 4 by way of calliper guides 4a 4'a with the application section 5a while being displaceably guided in the direction of the brake disc axis 2a.
In the application section Sa of the brake calliper 5, the application device is located in an interior Sc of the application section Sa.
The application side backing plate 3a is in contact with the threaded plungers 6, 6” via — pressure pads 6b, 6’b located at the ends of the threaded plungers 6, 6°. The other, reaction- side, backing plate 3’a is fixed on the other side of the brake disc in the rear section 5b of the brake calliper 5. The threaded plungers 6, 6? are in each case located in the bridge 7, which is also called traverse, being rotatable in threads.
On a side averted from the brake disc 2, the bridge 7 is in contact with the brake rotary lever 9, and on the opposite side facing the brake disc 2, it is provided with a return spring 7a supported on a base plate 8. The base plate 8 closes the interior 5c of the application section 5a of the brake calliper 5, the threaded plungers 6, 6° with the pressure pads 6b, 6’b extending through an opening each through the base plate 8. In this each of the pressure pads 6b, 6’b is sealed against the base plate 8 by a seal 8a, 8’a, here a bellows.
The interior 5c of the application section 5a is moreover defined by an outer wall 5d in the region of the other ends of the threaded plungers 6, 6’. The outer wall 5d is provided with through-openings coaxial with the threaded plungers 6, 6°. The through-opening belonging to the threaded plunger 6? with the readjustment device 10a in the interior is tightly closed by a — cover 12. The other through-opening, which is assigned to the other threaded plunger 6 with the driver device 10b, it tightly closed by a sensor housing 13 with the wear sensor 11. The synchronising device 16 is located on the bridge 7 with its synchronising gears 16a, 16'a and a synchronising means 16b, which here is a chain.
The bridge 7 and thus the screwed-in threaded plungers 6, 6” can be adjusted by the brake rotary lever 9 towards the brake disc axis 2a.
A movement towards the brake disc 2 is
EP18815573.3 12 described as application movement and a movement in the opposite direction is called release movement. By means of the return spring 7a, the bridge 7 is returned into the released position of the disc brake 1 in the release movement as shown in Fig. 1. A distance between the brake pads 3, 3” and the brake disc 2 in the released position is described as clearance. The wear readjustment apparatus 10 is designed to readjust a previously determined clearance described as nominal clearance. The term “readjustment” is here to be understood to mean a clearance reduction. The wear readjustment apparatus 10 here comprises the readjustment device 10a and the — driver device 10b. The readjustment device 10a is located at the one threaded plunger 6’ coaxially with this and a readjuster axis 6’a forming the central axis of the threaded plunger
6’. A detailed description of the readjustment device 10a can be found in DE 10 2012 108 672 B3. The driver device 10b is located coaxially with the other threaded plunger 6 and with a driver — axis 6a forming the central axis of the threaded plunger 6. In contrast to the threaded plunger 6’ of the readjustment device 10a, an attachment sleeve 15 is non-rotatably fitted to the threaded plunger 6. The application-side end of the attachment sleeve 15 is designed as a coupling 15a. By means of said coupling 15a, the attachment sleeve 15 is coupled to the wear sensor 11. A pick-up element of the wear sensor 11 is an angle sensor, e.g. a potentiometer, and detects the angular position of the threaded plunger 6 about the driver axis 6a. The evaluation of said angular position permits a conclusion to be drawn about the wear condition of the brake pads 3, 3’ and the brake disc 2, because the threaded plunger 6 is coupled to the other threaded plunger 6 by way of the synchronising device 16. The wear sensor 11 is thus used to detect — the wear condition of the brake pads 3, 3” and the brake disc 2. Via a connection 14 having an interface, e.g. a cable interface, the wear sensor 11 is connected by cables (not shown) (electrically or optically conductive) to the control device 100, which can perform the evaluation. The driver axis 6a, the readjuster axis 6’a and the brake disc axis 2a are arranged to be parallel to one another.
EP18815573.3 13 The readjustment device 10a of the wear readjustment apparatus 10 interacts with the brake rotary lever 9 via a drive not shown in the drawing. The readjustment device 10a and the driver device 10b are coupled by the synchronising device 16 in such a way that a twisting movement of the threaded plunger 6” about the — readjuster axis 6’a causes a corresponding twisting movement of the other threaded plunger 6 about the readjuster axis 6’a and vice versa. A twisting movement for readjusting the threaded plungers 6, 6° in the case of pad wear is generated by the readjustment device 10a, driven by the brake rotary lever 9. For a further description we refer to DE 10 2012 108 672
B3. The synchronising device 16 is here located on a top side of the bridge 7 between the bridge 7 and the brake rotary lever 9 and comprises a coupling wheel 16?a coupled to the threaded plunger 6 with the readjustment device 10a, a further coupling wheel 16a coupled to the other threaded plunger 6 and to the driver device 10b and a synchronising means 16b, by which the coupling wheels 16a and 16’a are coupled. The synchronising means 16b is here a — chain. The coupling wheels 16a, 16’a are therefore designed as sprockets. This ensures a synchronised rotary movement of the threaded plungers 6, 6’ in wear readjustment operations (drive by the readjustment device 10a) and adjustments during maintenance operations, e.g. pad change (manual drive via an actuating end of the driver device 10b not shown here). At the same time the wear sensor 11, which is coupled to the driver device 10b, is adjusted as a function of the wear readjustment of the readjustment device 10a. In Figures 2 to 4 perspective diagrammatic part-sectional views of an embodiment of a disc brake 1 according to the invention are shown.
Fig. 2 shows the disc brake 1 according to the invention with a condition monitoring assembly 200. The disc brake 1 is shown with a view of the outer wall 5d of the application — section Sa of the brake calliper 5 with a brake cylinder flange BZ, to which a brake drive, e.g. a pneumatic cylinder, is attached. A part-section extends in the direction of the brake disc axis 2a in a vertical plane through the brake disc 2, the brake pads 3, 3’, the adapter 4, the application section Sa and the rear section 5b of the brake calliper 5. In addition a vertical sectional plane and a horizontal sectional plane extend in the driver axis 6a through the driver device 10b with the threaded plunger 5. Fig. 3 and Fig. 4 show enlarged representations.
EP18815573.3 14 The condition monitoring assembly 200 in the illustrated embodiment preferably comprises one, several or all of the following condition monitoring facilities: Calliper position monitoring (position of the brake calliper 5 in the direction of the brake disc axis (2a) Seal condition monitoring of the interior Sc of the application section 5a of the brake calliper 5 Hot box monitoring of the friction partners brake pads 3, 3” and brake disc 2 Clearance monitoring of the friction partners brake pads 3, 3? and brake disc 2 Lever or application stroke monitoring (brake rotary lever 9, bridge 7) Monitoring of the parking brake Monitoring of the mechanical condition of the calliper guides 4a, 4'a Monitoring of the mechanical condition of the internal mechanics Hysteresis monitoring Total wear monitoring of the friction partners brake pads 3, 3” and brake disc 2 Disc wear monitoring of the brake disc 2 Individual wear monitoring of the friction partners brake pads 3, 3” and brake disc 2 Temperature monitoring The condition monitoring assembly 200 comprises a calliper sensor 17, a total wear sensor 18, a pressure sensor 19, a coupling member 21 and a switching unit 25. In addition the — condition monitoring assembly 200 can have a temperature sensor which is not shown here but is conceivable.
With this one or all of the following condition data of the disc brake 1 to be measured can be detected: Measuring the pad thickness or the individual wear of the friction partners brake pads 3, 3" and brake disc 2 Measuring the total wear of the friction partners brake pads 3, 3? and brake disc 2 Measuring the calliper position, i.e. the position of the brake calliper 5 in the direction of the brake disc axis 2a, for drawing conclusions about the condition of the calliper guide(s) 4a, 4’a Measuring the calliper interior pressure, i.e. the pressure in the interior Sc of the application section Sa of the brake calliper 5, to monitor the condition of the seals of
EP18815573.3 15 the base plate 8, the seals 8a, 8'a of the pressure pads 6b, 6’b, the seals of cover 12 and sensor housing 13 and the like Measuring the lever stroke or the stroke of the application unit (brake rotary lever 9 or bridge 7)
Measuring the temperature of the braking system or a temperature equivalent (pressure) for condition monitoring (hot boxes) Monitoring the parking brake or plausibility check Monitoring the condition of the internal mechanics Monitoring hysteresis Storage of specific load collectives decentrally in the brake unit or in the control device 26 and/or in additional storage media
The sensors 17, 18, 19 (and temperature sensor(s)) are here connected to an electronic switching unit 25 in a wired or wireless manner.
The electronic switching unit 25 exchanges information with the external control device 26 in a wired or wireless manner (connection
25a). The switching unit 25 also collects, via the sensor system in or at the disc brake 1, specific information and transmits it to the external control device 26 for transfer into specific load collectives.
The sensor system here has a modular structure, while the interfaces in the sensor system and from the switching unit 25 to the external control device 26 are maintained irrespective of the amount of sensors used.
In this way a simple modular upgrade of the monitoring facilities is possible, because the existing connection between the switching unit 25 and the external control device 26 remains unchanged.
The necessary evaluation is carried out with the aid of a microcontroller in the switching unit 25 and/or by the external control unit/the external control device 26.
The calliper sensor 17 is not located in the brake calliper 5, but outside the application section Sa of the brake calliper 5 below the driver device 10b parallel thereto and senses on an adapter beam 4b of the adapter 4, whereby the adapter 4 is here mounted in a stationary position at a vehicle.
The calliper sensor 17 will be explained in greater detail below.
The total wear sensor 18 and the pressure sensor 19, together with a spindle drive 22 and a planetary gear mechanism 23, form a sensor unit 100. The sensor unit 100 and the coupling member 21 are located in the driver device 10b, the pressure sensor 19 being integrated on a printed circuit board of the total wear sensor 18.
EP18815573.3 16 The coupling member 21 is arranged coaxially with the threaded plunger 6 and in the manner of a sleeve over the threaded plunger 6 of the driver device 10b and coupled non-rotatably to the threaded plunger 6 at one end. The other end of the coupling member 21 is connected both to the spindle drive 22 and to the planetary gear mechanism 23 via a drive section 21c. The spindle drive 22 is also coupled to the planetary gear mechanism 23, which interacts with the total wear sensor 18. The coupling member 21 transmits both a rotary movement of the threaded spindle 6 and a linear stroking movement of the bridge 7. The rotary movement of the coupling member 21 is transmitted to a first input 23a of the planetary gear mechanism 23, wherein the linear stroking movement of the coupling member 21 is transmitted to the spindle drive 22. By means of the spindle drive 22, said stroking movement is converted into a rotary movement in a way not described further and introduced into a second input 23b of the planetary gear mechanism 23. The coupling member 21 is described further below. The coupling member 21, the spindle drive 22, the planetary gear mechanism 23 and the total — wear sensor 18 are arranged one behind the other along the driver axis 6a, starting from the bridge 7. The spindle drive 22, the planetary gear mechanism 23 and the total wear sensor 18 as well as the pressure sensor 19 are located within the sensor housing 13 on or in a support 27 (see Fig. 6). The sensor housing 13 extends through a through-opening — assigned to the driver device 10b — of the outer wall 5d and projects outwards from the outer wall 5d. The projecting cap-like section of the sensor housing 13 has a lateral extension 20, which extends vertically downwards and has both a connection to a connecting section 17f of the calliper sensor 17 and the connection 14. The connection 14 is connected to a connection 14a connected to the switching unit 25. The connection 14a forms a common connecting line of the calliper sensor 17, the total wear — sensor 18 and the pressure sensor 19 to the switching unit 25. The switching unit 25 has moreover one or more interface(s) to the sensors. The switching unit 25 is in turn connected to a further connection 25a to the control device 100. The connections 14a and 25a can be wired or wireless.
Fig. 5 is a diagrammatic side view of the calliper sensor 17. The calliper sensor 17 comprises a housing 17b with the connecting section 17f, a rod 17c and a spring 17e. The housing 17b, the rod 17c and the spring 17e are arranged coaxially with
EP18815573.3 17 a calliper sensor axis 17a.
The rod 17c extends towards the calliper sensor axis 17a and is provided with a contact section 17d at a free end.
The other end of the rod 17c extends into the housing 17b, is guided therein for longitudinal displacement in the direction of the calliper sensor axis 17a and coupled to a linear sensor, e.g. potentiometer, Hall sensor or the — like, which is not shown but can be imagined easily.
The spring 17e is pushed onto the rod 17c and supported there and at a collar 17g, which is attached in the region of the free end of the rod 17c and permanently joined to the rod 17c.
By way of its connecting section 17f, the calliper sensor 17 is connected to the sensor housing 13 via the connection 20. The connecting section 17f and the connection 20 are designed as pluggable and releasable
— connections.
The connection 20 forms both a mechanical holder for the calliper sensor 17 and an electrically conductive connection for its linear sensor with the connection 14. The connection 20 can have other forms as well, which form a suitable and vibration-proof holder for the calliper sensor 17. In addition further holders — which are not shown but can be imagined — can be provided for the calliper sensor 17 at the brake calliper 5.
—Thecalliper sensor 17 is mounted below the application section Sa of the brake calliper 5 in such a way that the calliper sensor axis 14a extends parallel to the driver axis 6a and parallel to the brake disc axis 2a.
In this the contact section 17d of the free end of the rod 17c of the calliper sensor 17 is in contact with the adapter beam 4b of the adapter 4. For this purpose the contact section 17d is pressed against the adapter 4 by the spring force of the spring 17e.
In this way a displacement of the brake calliper 5 towards the brake disc axis 2a is transmitted to the calliper sensor 17, since this is permanently connected with its housing 7b to the application section Sa of the brake calliper 5 via the sensor housing 13 and has the displacement thereof with respect to the stationary adapter 4 as a reference.
Independently thereof, further reference points are possible for sensing the position of the
— brake calliper 5; the invention is not restricted to the adapter beam as reference point, which is only used in the embodiment described here.
All stationary parts are suitable reference points.
These comprise both the adapter 4 and stationary axle parts of the vehicle to which the disc brake 1 is assigned.
An inverse approach is also possible, wherein the calliper sensor 17 is mounted on a stationary axle part or the adapter 4 with its housing 17b or its connecting section 17f.
In this the reference point is defined by the brake calliper 5.
The calliper sensor 17 here takes over the following monitoring functions as a linear sensor:
EP18815573.3 18 Position monitoring of the brake calliper 5 Individual wear monitoring Monitoring of the mechanical condition of the calliper guides 4a, 4'a (no sluggishness) — By evaluating the calliper position, i.e. the position of the brake calliper 5 in the direction of the brake disc axis 2a, the condition of the calliper guide system or the calliper mounting (calliper guides 4a, 4’a) can be monitored when actuating the disc brake 1, and the individual pad wear of the rear-side brake pad 3’ can be monitored as well. The total wear sensor 18 (with a conventional planetary gear mechanism with two inpits as illustrated in DE 10 2013 112 813 Al, for example) with integrated stroke monitoring has the following monitoring functions: Total wear monitoring Disc wear monitoring (after pad replacement) Hysteresis monitoring Monitoring of the mechanical condition of the internal mechanics Monitoring of the parking brake Lever or application stroke monitoring Clearance monitoring
Fig. 6 shows a diagrammatic side view of the coupling member 21 and a part-sectional view of a sensor unit 100. A diagrammatic perspective view of the coupling member 21 is shown in Fig. 7. The coupling member 21 comprises a drive section 21a, two connecting sections 21b, a driven section 21c, tongues 21d, internal projections 21e and external projections 21f. The coupling member 21 is arranged coaxially with the driver axis 6a. The drive section 21a of the coupling member 21 is non-rotatably coupled to that coupling wheel 16a of the synchronising device 16 which belongs to the threaded plunger 6 of the driver device 10b via the tongues 21d and the external projections 21f. In addition the internal projections 21e are in engagement with grooves of the threaded plunger 6 for the axial guidance of the coupling member 21 and for non-rotatable coupling.
EP18815573.3 19 Two connecting sections 21b located opposite each other connect the drive section 21a and the driven section 21c.
Each connecting section 21b consists of two triangular sections with joined tips, wherein the base side of the one triangular section is joined to the drive section 21a and the base side of the other triangular section is joined to the is joined to the driven
— section 21c.
In this way the drive section 21a and the driven section 21c are coupled rotationally and translationally.
The driven section 21c of the coupling member 21 is coupled to the first input 23a of the planetary gear mechanism 23 on the one hand and to the spindle drive 22 on the other hand in a way not described in detail.
The spindle drive 22, the planetary gear mechanism 23, the total wear sensor 18 and the pressure sensor 19 form the sensor unit 100 and are mounted on the support 27 of the sensor unit 100. The sensor unit 100 is located with the support 27 in the sensor housing 13 (see Fig. 4) and partially in that through-hole of the outer wall 5d of the application section 5a of the brake calliper 5 which is assigned to the driver device 10a.
— For stroke sensing and for implementing the condition monitoring applications described above, the linear stroking movement of the application unit (brake lever 9, bridge 7) is transmitted to the spindle drive 22 via the coupling member 21. This converts the linear movement of the coupling member 21 into a rotation and introduces this into the planetary gear mechanism 23 in use via the second input 23b of the planetary gear mechanism 23. By
— the drive of the second input 23b superimposed on the first input 23a, the angular change corresponding to the stroking movement of the rotation converted in this way can be detected and evaluated in the total wear sensor 18. By intelligent evaluation of the angle signal, the parking brake, if operated wrongly, and the hysteresis and condition of the internal mechanics can be monitored as well.
In this way the coupling member 21 between the total wear sensor 18 and the bridge/spindle assembly (i.e. bridge 7 with the screwed-in threaded plungers 6, 6°) does not only introduce the rotary movement of the threaded plungers 6, 6? caused by readjustment processes into the planetary gear mechanism 23 of the total wear sensor 18, but also transmits the linear stroking movement of the bridge/spindle assembly to the downstream spindle drive 22 when the brake is actuated.
Owing to the transmission ratios of the drive inputs, i.e. first input 23a and second input 23b, of the planetary gear mechanism 23, the measurement of the stroking movement can be differentiated from the wear measurement.
In this the first input 23a of the
EP18815573.3 20 planetary gear mechanism 23 is here represented in a way not described in detail by a sun gear (not identified) of the planetary gear mechanism 23. A planet carrier (not identified) of the planetary gear mechanism 23 here forms the second input 23b of the planetary gear mechanism 23.
Owing to its special elastic structure, the coupling piece 21 is capable of transmitting the relevant movements (rotation, translation) virtually without play while compensating for radial movements caused by disturbance variables such as vibrations etc.
The pressure sensor 19 is integrated on a printed circuit board of the total wear sensor 18, which is not shown in detail but can be imagined easily.
With the pressure sensor 19, the
— following monitoring functions are possible:
Condition monitoring of the calliper seals Hot box monitoring Clearance plausibility check Since pressure has a physical association with temperature (thermal state eguation), a
— monitoring of the internal pressure of the interior 5c of the application section 5a of the brake calliper 5 provides hot box monitoring by a temperature-eguivalent signal.
By continuously monitoring the pressure of the interior 5c, the condition of the calliper seals can be monitored as well.
A sudden pressure drop or no increase of the calliper internal pressure at a brake actuation can indicate faulty seals.
— The assembly 200 for monitoring the condition of the disc brake 1 is expanded in a modular manner to a comprehensive condition monitoring facility by the modular expansion capabilities of the sensors 17, 18, 19. This makes a combination of several embodiments possible.
Starting with the starting variant with the total wear sensor 18, the following further variants
— are available:
Total wear sensor 18 and pressure sensor 19
Total wear sensor 18 and stroke monitoring by means of spindle drive 22
Total wear sensor 18 and calliper position sensor 17
Total wear sensor 18, stroke monitoring by means of spindle drive 22 and pressure sensor 19
EP18815573.3 21 Total wear sensor 18, pressure sensor 19 and calliper position sensor 17 Total wear sensor 18, stroke monitoring by means of spindle drive 22 and calliper position sensor 17 Total wear sensor 18, stroke monitoring by means of spindle drive 22, calliper position sensor 17 and pressure sensor 19 Owing to the modular structure there is also no need for different housing variants, thus preventively avoiding additional expenditure for additional variants. For data transmission the existing data link, e.g. 14a, to the switching unit 25 is used. Data can be transmitted via a common analogue data line or a digital data link, e.g. with bus — protocol. If an analogue data line is used, a sequential reading-in of the monitoring data of the individual sensors is ensured by means of so-called multiplexers. These are components of the so-called ASIC (application-specific integrated circuit) located on the available printed circuit board of the total wear sensor 18. The digital data link uses a digital bus protocol and a master in the external control device 26
(e.g. EPM). In an analogue data link multiplexers are used to sequentially read in the sensor data. A time- coordinated read-in is performed, so that the signals are simply and correctly separated (e.g. in the switching unit 25) before a transmission into the external control device 26 e.g. EPM). For temperature monitoring the modular structure can — irrespective of the combination of sensors in use — be expanded by a temperature measurement and the interface thereof. A temperature measurement both inside and outside the brake calliper 5 is conceivable. The assembly 200 for monitoring the condition of the disc brake 1 can furthermore have additional free interfaces for retrofitting further sensors. — The assembly 200 for monitoring the condition of the disc brake 1 with the modular structure of the sensors can be used both for pneumatically applied disc brakes in the commercial vehicle sector and in all other drive types of disc brakes. The invention can be modified in the context of the attached claims.
EP18815573.3 22 LIST OF REFERENCE SYMBOLS 1,1 Disc brake 2 Brake disc 2a Brake disc axis 33 Brake pad
3a,3’a Backing plate 3b, 3'b Friction lining 4 Adapter 4a,4’a Calliper guide
4b Adapter beam 5 Brake calliper Sa Application section 5b Rear section Sc Interior
5d Outer wall 6, 6 Threaded plunger 6a Driver axis a Readjuster axis 6b, 6'b Pressure pad
7 Bridge Ta Return spring 8 Base plate 8a, 8’a Seal 9 Brake rotaty lever
10 Wear readjustment apparatus 10a Readjustment device 10b Driver device 11 Wear sensor 12 Cover
EP18815573.3 23 13 Sensor housing 14 Connection 14a Connection 15 Attachment sleeve 15a Coupling
16 Synchronising device 16a, 16’a Coupling wheel 16b Synchronising means 17 Calliper sensor
17a Calliper sensor axis 17b Housing 17c Rod 17d Contact section 17e Spring
17f Connecting section 17g Collar 18 Total wear sensor 19 Pressure sensor Connection
20 21 Coupling member 21a Drive section 21b Connecting section 21c Driven section 21d Tongue
21e,21f Projection 22 Spindle drive 23 Planetary gear mechanism 23a,23b — Input 24 Interface