Brake booster device with a multi-part fastening device for a brake booster

Abstract

The invention relates to a brake booster device, which has a brake booster (10) mounted on a vehicle component (30) via a fastening device (50). According to the invention, the fastening device (50) has at least two fasteners (51; 52), wherein the first fastener (51) is firmly connected to the brake booster (10) and the second fastener (52) is firmly connected to the vehicle component (30). The two fasteners (51; 52) are connected to each other via at least one connecting element (60; 60'), which is deformed by shear stress when the brake booster (10) moves along the vehicle component (30). The two fasteners (51; 52) are slidably moved in a guide in a nested manner in the direction of the vehicle component (30), and each fastener has a recess (53; 54), wherein the recesses (53; 54) are flush with each other and a push rod (80) of a brake pedal is guided through the recess (53; 54).

Description

Technical Field

[0001] The invention relates to a brake booster device having a brake booster which is mounted on a vehicle component via a fastening device. Background Art

[0002] Motor vehicles are equipped with a brake booster for increasing the pedal force. A low-pressure brake booster can be used here. However, motor vehicles can also be equipped with an electric brake booster, which is particularly advantageous in the case of electric vehicles and hybrid vehicles. In the case of an electric brake booster, pulses of the brake pedal are used to induce an alternating voltage in the coil via a combination of a coil and an iron core to release kinetic energy that supports the braking force of the pedal. For example, DE 20 2010 017 605 describes such an electric brake booster.

[0003] Transmissions for hybrid vehicles are usually of relatively large size, since they contain components and functions that are not required in transmissions specifically for vehicles with internal combustion engines. For example, it must be possible to switch between different drive types (e.g. electric and internal combustion engine). In addition, one or more electric motors may be located in the transmission housing.

[0004] If a large transmission with an associated housing and electric brake booster is used in a hybrid vehicle, a direct force connection between the transmission housing and the system of the electric brake booster can occur during a frontal collision in the X direction due to the mounting situation between the transmission housing and the system of the electric brake booster. However, this is problematic in terms of the safety of the vehicle occupants, since in the event of a frontal collision this can lead to deformation of the bulkhead, resulting in displacement of the brake pedal and deformation of the instrument panel bracket. The steering column may also move. This significantly impairs the integrity of the passenger compartment and is unacceptable in terms of occupant safety.

[0005] Therefore, in view of the proven prior art, there is still room for improvement in improving occupant safety for different combinations of transmission and brake booster. Summary of the invention

[0006] The invention is based on the object of providing a brake booster device, by which the occupant safety in the event of a frontal collision can be improved. In particular, the brake booster device is intended to improve passenger safety when an electric brake booster is used in combination with a large transmission.

[0007] According to the invention, this object is achieved by a brake booster device according to the invention. Other particularly advantageous embodiments of the invention are disclosed in the following.

[0008] It should be pointed out that in the following description, the features and measures presented individually can be combined with one another in any technically useful manner and present further embodiments of the invention. The description particularly in conjunction with the drawings additionally characterizes and specifies the invention.

[0009] The brake booster device according to the invention has a brake booster mounted on a vehicle component via a fastening device. In particular, the brake booster is an electric or electromechanical brake booster. However, such a fastening device can also be used for conventional vacuum brake boosters to separate them from a bulkhead. The vehicle component is in particular a bulkhead of a vehicle. The fastening device for the brake booster can be formed, for example, by a fastening plate and a plurality of threaded connections. However, the fastening device according to the invention has at least two fasteners, wherein a first fastener is firmly connected to the brake booster and a second fastener is firmly connected to the vehicle component. The two fasteners can be formed by a plate and / or a profile. The firm connection of the fastener to the brake booster or the vehicle component can be formed, for example, by a threaded connection. The at least two fasteners are then connected to each other via at least one connecting element, which is deformed due to shear stress loads when the brake booster moves along the vehicle component.

[0010] Such a movement of the brake booster along the bulkhead occurs, for example, in the event of a frontal collision, whereby the brake booster is displaced by other vehicle components that apply forces to the brake booster. In this case, the two fasteners of the fastening device are displaced in planes parallel to one another, whereby at least one connecting element is deformed. In addition to bending, such a deformation may also involve a breakage of the connecting element. In each case, the connection between the two fasteners is separated, so that the brake booster can be displaced along the vehicle component.

[0011] The two fastening elements of the fastening device are preferably connected to each other via a plurality of connecting elements. The connecting elements can be formed, for example, by bolts which are guided through mutually flush holes in the first fastening element and the second fastening element. Such bolts can also be referred to as shear pins which, due to their material and / or their dimensions, give way under certain shear stress loads. However, other forms of connecting elements, such as clips, can also be used.

[0012] The displacement of the brake booster takes place in particular upwards in the Z direction. However, the movement here can also have a component in the X direction, so that the brake booster moves upwards at a certain slope, as in the case of a bulkhead which extends at a certain slope in a conventional manner. The terms "up" and "down" here relate to the installation state of the brake booster device in the vehicle. The X direction here represents the longitudinal direction of the motor vehicle in the vehicle coordinate system, while the Z direction represents the vertical direction. The Y direction corresponds to the transverse direction of the vehicle. The movement of the brake booster in the Z direction is caused by the action of a force in the X direction by another component of the vehicle when it strikes the brake booster from below.

[0013] In the event of a frontal collision, the component that applies a force in the X direction to the lower side of the brake booster is, for example, the transmission housing. The transmission housing moves from bottom to top under the brake booster and pushes it upwards. However, in a preferred embodiment of the invention, the brake booster is arranged with an actuator, by means of which the brake booster can be displaced along the vehicle component, wherein in the event of a frontal collision the actuator can be activated by the force action of the transmission housing. The transmission housing applies a force in the X direction to the actuator, which therefore applies a force to the brake booster in the Z direction.

[0014] The actuator is mounted and designed accordingly for this purpose. For example, the actuator is pivotably mounted below the brake booster and exerts an upward force on the brake booster in the Z direction during the pivoting movement. If the housing of the transmission of the motor vehicle moves in the X direction towards the brake booster in the event of a head-on collision, the transmission housing hits the actuator before this, so that the actuator pivots upward and thus exerts a force on the brake booster in the Z direction. The actuator is thus pivoted out of the normal position, in which the actuator does not exert any force on the brake booster, into an activated position, in which the actuator pushes the brake booster away in the Z direction. The actuator here can already be in contact with the brake booster in the normal position, or the necessary contact can only be brought into place due to the pivoting movement. The brake booster is displaced in the Z direction due to the force of the actuator. The brake booster is thus pushed upward as a whole along a vehicle component, such as a bulkhead.

[0015] Such an actuator can be designed in various ways. For example, it can be a tilting arm pivotably mounted on a vehicle component at one end. The actuator can also be formed by a plurality of elements which change their position relative to each other during the pivoting movement of the actuator. In both cases, the actuator protrudes from the vehicle component in the direction of the transmission housing. The actuator can be formed by bars, tubes, profiles, plates or other rigid components. These elements are designed to be so rigid and stable as to withstand the forces occurring and not to deform. For this purpose, the elements are preferably designed to be high-strength, for example, consisting of steel, sheet metal, aluminum, forged components, etc. The joining connection of the actuator to another vehicle component, such as a bulkhead, can be realized in various ways. For example, the connection can be a joint with a certain degree of freedom, such as that seen in a hinge. The joining connection can thus be formed, for example, by a bolt guided through two bushings.

[0016] However, the connection of the actuator to the vehicle component can also be produced via a material section with a lower stiffness than the remaining material of the actuator. For example, in this area, the actuator can be formed from a sheet or profile made of metal, which is bent. The stiffness of the metal in this bent area is lower than the stiffness of the metal in the remaining area. In normal operation, the actuator retains its shape and the position of the actuator does not change. However, as soon as a force effect is introduced in the X direction via the transmission housing, the connection area with the lower stiffness gives way and the actuator pivots upward.

[0017] If this pivot axis between the actuator and the vehicle component is formed by a material portion with lower rigidity, a reinforcing element is preferably provided for this purpose, which is firmly fixed to the vehicle component. The reinforcing element and the actuator are then formed by a common component, which is however bent in the area where the axis of rotation is to be produced. In this bent portion, the rigidity of the material of the component is lower than in the material portion forming the actuator and the reinforcing element. If a force is applied to the actuator in the X direction via the transmission housing, the material portion with low rigidity is deformed. This creates a pivot axis about which the actuator can pivot. The reinforcing element on the vehicle component can also be formed by bars, tubes, profiles, plates or other components. In this case, the fasteners of the reinforcing element on the vehicle component are very close to the pivot axis to be produced in order to cause a defined fold in this area.

[0018] However, the description of such an actuator should only be regarded as an example, and the actuator can also be designed in other advantageous ways. Furthermore, it is not necessary to provide an actuator that is specially designed for displacing the brake booster; instead, the displacement can also be caused by other components present in the vehicle. In any case, the displacement of the brake booster in the Z direction takes place along a vehicle component such as a bulkhead. The two fasteners of the fastening device are displaced relative to each other here. The first fastener on the brake booster moves together with the brake booster, while the second fastener remains fixed to the vehicle component.

[0019] According to the present invention, a guide is provided so that two fasteners can be displaced relative to each other in a controlled manner. The guide can be designed using various types of guide elements (including grooves, tracks, slideways, etc.). According to the present invention, two fasteners are provided, which slide and move in a nested manner in the guide along the direction of the vehicle component. For example, for this purpose, the fastener has at least two slide grooves extending in the Z direction, in which the corresponding sliding elements of another fastener are respectively accommodated. The two slide grooves can extend parallel to each other, although their mutual spacing can also vary. In particular, it can be provided that the spacing between the slide grooves increases along the Z direction. The two slide grooves are therefore tapered upward or form a V shape together. The sliding groove can also be formed in a V shape in the X direction. If the brake booster moves upward along the Z direction together with the fastener, it is convenient to perform a simple and reliable displacement of the brake booster.

[0020] According to the invention, the two fasteners also each have a recess, wherein the two recesses are flush with each other and through which the push rod of the brake pedal is guided. Thus, the two halves of the fastening device can be displaced relative to each other in an unhindered manner without being hindered by the coupling rod. The recess here is selected to be large enough in the Z direction so that the push rod of the brake pedal can also be freely guided through the recess after the brake booster has been displaced. For this purpose, the recess is formed in particular by an elongated hole of the longitudinal structure extending in the Z direction.

[0021] In normal operation, the fastener of the brake booster is held on the fastener of the vehicle component by means of the connecting element. In order to bear the weight of the brake booster, a support element that supports the brake booster can also be provided. In one embodiment of the invention, the second fastener has, for example, a support element that projects from it in the direction of the brake booster. The second fastener on the vehicle component is then formed in an L-shape, and the first fastener, together with the weight of the brake booster, rests on the support element formed in this way. This improves the noise behavior and the durability of the brake booster device.

[0022] The brake booster, together with the multi-part fastening device on the vehicle component, thus forms an inventive brake booster device that can be advantageously used in a motor vehicle. In the event of a frontal collision, the brake booster is displaced in a controlled manner along the vehicle component in the Z direction. The load path from the transmission housing to the brake booster in the X direction is thus advantageously interrupted. Due to the deformation of the connecting element between the two fastening elements, the displacement takes place in a controlled manner without the brake booster tilting. As a result, the deformation of the bulkhead of the vehicle is small, and the fastening bolts on the brake booster and on the vehicle component are not damaged. In addition, the brake pedal and the steering column are not displaced in the direction of the vehicle compartment, or are only displaced slightly. This increases the safety of the occupants in the event of a frontal collision.

[0023] Furthermore, it is possible to produce a fastening arrangement again after a frontal collision, since the two fastening parts are connected to one another via a new connecting element.

[0024] The invention is particularly suitable for large transmissions with large transmission housings, such as are often used in hybrid vehicles. It is also particularly suitable for electric brake boosters, which are also used in hybrid vehicles. Due to the size and arrangement of these vehicle components, the invention can be used particularly advantageously here, although it can also be used advantageously with other combinations of transmissions and modules (brake boosters, electronic stability program (ESP) modules, etc.) assembled on the bulkhead.

[0025] The invention also includes a motor vehicle having an embodiment of the brake booster device according to the invention. This relates in particular to hybrid vehicles having a transmission which is designed to switch between electric drive and another type of drive. Within the scope of the invention, a frontal collision is any collision (ie an accident) in which a corresponding force component is generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further advantageous embodiments of the invention are disclosed in the following description of the attached drawings, which show:

[0027] Figure 1 is a schematic side view of a transmission housing and a brake booster with an actuator;

[0028] Figure 2 is a schematic section in the ZX plane through an embodiment of a fastening device for a brake booster in normal operation;

[0029] Figure 3 is through according to Figure 2 Schematic cross section AA of the fastening device;

[0030] Figure 4 is through according to Figure 2 Schematic cross section BB of the fastening device;

[0031] Figure 5 is through according to Figure 2 A schematic cross section of the fastening device in the ZX plane after the brake booster is displaced;

[0032] Figure 6 is a front view of a first embodiment of a fixed fastener;

[0033] Figure 7 is a front view of a second embodiment of a fixed fastener;

[0034] Figure 8is a front view of a second embodiment of a movable fastener; and

[0035] Fig. 9 is through according to Figure 8 Schematic cross section CC of the fastening device;

[0036] In the various figures, identical parts are always provided with the same reference symbols and are therefore generally also described only once. DETAILED DESCRIPTION

[0037] Figure 1 The schematic side view of shows an embodiment of a brake booster as part of a brake booster device according to the invention. In particular, the brake booster is an electric brake booster. Here, Figure 1 The view of the figure shows a view of the brake booster 10 in the Y direction of the motor vehicle. The brake booster 10 is fastened to a bulkhead 30 of the motor vehicle and is connected in a known manner to a brake pedal and a brake system of the motor vehicle (not shown). The brake booster 10 is mounted on the bulkhead 30 via a multi-part fastening device 50. To the right of the bulkhead 30 there is the vehicle interior with the driver's footwell. The bulkhead 30 is shown here only schematically and can be designed in a known manner.

[0038] The actuator 20 is mounted below the brake booster 10 on the bulkhead 30. The actuator is essentially formed by an inclined arm which is pivotably mounted on the bulkhead 30 via a pivot axis 21. The pivot axis 21 of the actuator 20 here extends in the Y direction. The actuator 20 is mounted below the brake booster 10 in such a way that its free end faces in the direction of the underside of the brake booster 10. In normal operation of the motor vehicle, this tip of the actuator 20 is in contact with the underside of the brake booster 10 or is located at a small distance from the underside of the brake booster 10. The actuator 20 protrudes from the bulkhead 30 and is held in this position by a retaining clip (not shown) or a corresponding clamping force on the pivot axis 21.

[0039] Figure 1 The actuator 20 is shown at a moment when the transmission housing has moved from its normal position 40 into the position 40' due to a frontal collision and has contacted the actuator 20 on its convex side. The actuator 20 is thus pivoted upward about its pivot axis 21, contacts the underside of the brake booster 10 and pushes the brake booster 10 upward in the direction of the arrow. As a result, the brake booster 10 moves along the bulkhead 30.

[0040] The force of the transmission housing 40' in the X direction is thus advantageously converted by the actuator 20 into a force on the brake booster 10 in the Z direction. The load path between the transmission housing 40' and the brake booster 10 in the X direction is thus increased. The transmission housing 40' can be moved under the brake booster 10, or the brake booster 10 can slide with its lower side along the upper side of the transmission housing 40'. However, such an actuator 20 does not necessarily have to be present; on the contrary, in the event of a frontal collision, the brake booster 10 can also be displaced in the Z direction by other components of the vehicle. For example, direct contact can occur between the lower sides of the transmission housing 40 and the brake booster 10.

[0041] In order to enable the brake booster 10 to slide along the bulkhead 30 in a controlled manner, the fastening device 50 is constructed in at least two parts. Figure 2 Two fasteners 51 and 52 of the fastening device 50 are shown. The first fastener 51 is mounted on the brake booster 10, which is shown by dashed lines. This is achieved via a plurality of fastening points, for example in the form of screw connections, of which two screw connections 61 and 62 are shown. Since the first fastener 51 can be moved together with the brake booster 10, it is also referred to below as a movable fastener. The second fastener 52 is mounted on a bulkhead (not shown). This is also done via a plurality of fastening points, of which two fastening points 63 and 64 are shown. The second fastener 52 is also referred to below as a fixed fastener.

[0042] The fasteners 51, 52 are formed by profiled plates placed parallel to each other. The fasteners 51, 52 are connected to each other via at least one connecting element. Figure 2 In the embodiment of the embodiment of the invention, a connecting element 60 in the form of a bolt or a shear pin is shown. This bolt 60 is guided through holes in the first and second fasteners which are flush with each other. Both fasteners 51, 52 also have recesses 53 and 54 which are also flush with each other. The push rod of the brake pedal is guided to the brake booster 10 through these recesses 53, 54 which are not shown.

[0043] Furthermore, the fixed fastening element 52 is configured in an L-shape in its lower region to form a region protruding from the fastening element 52 serving as a supporting element 55. The lower end of the movable fastening element 51 is located on the supporting element 55 so that the weight of the brake booster 10 is supported on the supporting element 55.

[0044] Figure 3 Shown by Figure 2Schematic section AA of a fastening device 50. From this section it can be seen that the fixed fastener 52 is mounted in a movable fastener 51 in a guide. For this purpose, two sliding grooves 70 and 70' are formed in the movable fastener 51. The fixed fastener 52 has corresponding sliding elements 71 and 71', which are guided in these sliding grooves 70, 70'. The two fastening elements 51, 52 can therefore be displaced relative to each other in the Z direction. Figure 3 Also shown are mutually flush recesses 53 , 54 for the push rod and further fastening points 61 ′ and 63 ′ of the brake pedal. Figure 4 Shown through the Figure 2 Schematic section BB of a fastening device 50. The section extends through two connecting elements 60, 60'.

[0045] If the brake booster 10 is pushed upward in the Z direction, shear stress is generated in the connecting elements 60, 60'. The material and dimensions of the connecting elements are selected so that they deform under a certain shear stress and enable the movable fastening device 51 to move relative to the fixed fastening device 52. Figure 5 As can be seen in the figure, the shear pin is broken. Figure 5 The broken connecting element 60 is shown. The movable fastener 51 can thus be moved upwards in the direction of the arrow with the brake booster 10. Here too the two recesses 53 and 54 are displaced relative to one another, but as before, the dimensions of the recesses are chosen such that the push rod 80 (schematically indicated by dashed lines) can still be guided freely through the fastening device 50 to the brake booster 10.

[0046] Figure 6 A front view of the fixing fastener 52 (i.e. the fastener on the bulkhead) is shown. From this view, two upper fastening points 63, 63' and two lower fastening points 64, 64' can be seen. In addition, the two connecting elements 60 and 60' and the form of the recess 54 can be seen. The recess 54 is formed as an elongated hole whose longitudinal structure extends in the Z direction.

[0047] Figure 6 Also shown are two sliding elements 71 and 71' extending on opposite sides of the fastener 52 in the Z direction. The sliding elements 71, 71' do not extend in parallel here; rather, the spacing between the two sliding elements increases upwards in the Z direction. The spacing B between the two sliding elements 71, 71' is greater at the upper end of the fastener 52 than the spacing b at the lower end. The two sliding elements 71, 71' thus extend to form a V-shape together. The same therefore applies to the associated sliding groove in the movable fastener.

[0048] Here, the sliding elements 71, 71' can be configured to be continuous in the Z direction. However, they can also be configured so that they are as shown in FIG. Figure 7In the embodiment of FIG. 5 , the sliding element is interrupted or shortened so that the sliding element does not extend over the entire height of the fastener. Figure 8 The front view of shows a second embodiment of the movable fastener, i.e. the fastener 51 on the brake booster. Similar to the interrupted sliding elements 71 and 71' on the fixed fastener 52, it is demonstrated that there are interrupted sliding grooves 70 and 70' on this component. Due to the interruption of the sliding grooves and sliding elements, these can be easily separated from each other in the case of movement of the brake booster in the Z-axis direction (which corresponds to a movement of several millimeters).

[0049] Fig. 9 It is shown that by having Figure 7 The fixing fastener 52 and according to Figure 8 Schematic section CC of a fastening device with a movable fastening element 51. However, here the two fastening elements are shown in a spaced manner from each other.

[0050] Reference numerals list

[0051] 10 Brake booster

[0052] 20 Actuator

[0053] 21 Pivot Axis

[0054] 30 Vehicle parts, bulkheads

[0055] 40 Position of the transmission housing in normal position

[0056] 40' Transmission housing position at first contact

[0057] 50 Fastening device

[0058] 51 First Fastener

[0059] 52 Second fastener

[0060] 53, 54 concave part

[0061] 55 Support element

[0062] 60, 60' connection element

[0063] 61, 61', 62, 62' Fastening points on brake booster, threaded connection

[0064] 63, 63', 64, 64' Fastening points on vehicle components, threaded connections

[0065] 70, 70' chute

[0066] 71, 71' sliding element

[0067] 80 Putter

Claims

1. A brake booster device comprising a brake booster (10) mounted on a vehicle component (30) via a fastening device (50), It is characterized in that The fastening device (50) has at least two fasteners (51; 52), wherein a first fastener (51) is firmly connected to the brake booster (10) and a second fastener (52) is firmly connected to the vehicle component (30), and wherein the two fasteners (51; 52) are connected to each other via at least one connecting element (60; 60'), and when the brake booster (10) moves along the vehicle component (30), the connecting element (60; 60') is deformed due to shear stress loads, wherein the two fasteners (51; 52) are slidably moved nested in one another in the direction along the vehicle component (30) and each have a recess (53; 54), wherein the recesses (53; 54) are flush with one another and a push rod (80) of a brake pedal is guided through the recess (53; 54), The brake booster device comprises an actuator (20) which is pivotally mounted on a vehicle component (30) below the brake booster (10) and by means of which the brake booster (10) can be displaced along the vehicle component (30).

2. The brake booster device according to claim 1, It is characterized in that The connecting element (60; 60') is formed by a bolt which is guided through mutually flush holes in the first fastening element (51) and the second fastening element (52).

3. The brake booster device according to claim 1 or 2, It is characterized in that A fastener has at least two sliding grooves (70; 70') extending in the Z direction, in which corresponding sliding elements (71; 71') of another fastener are respectively accommodated.

4. The brake booster device according to claim 3, It is characterized in that The spacing (B; b) between the sliding grooves (70; 70') increases along the Z direction.

5. The brake booster device according to claim 1, It is characterized in that The second fastening member (52) has a supporting element (55) protruding from the second fastening member (52) in the direction of the brake booster (10), wherein the first fastening member (51) is located on the supporting element (55) so that the weight of the brake booster is supported on the supporting element (55).

6. The brake booster device according to claim 1, It is characterized in that The recess (53; 54) is formed by a longitudinal hole, the longitudinal structure of which extends along the Z direction.

7. The brake booster device according to claim 1, It is characterized in that In the event of a frontal collision, the actuator (20) can be actuated under the force of the transmission housing (40), and the actuator (20) applies an upward force to the brake booster (10) in the Z direction during the pivoting movement.

8. Use of a fastening device (50) for mounting a module of a brake booster device on a vehicle component (30), the fastening device having at least two fastening elements (51; 52), characterized in that: A first fastener (51) is firmly connected to the module on the bulkhead side, while a second fastener (52) is firmly connected to the vehicle component (30), and wherein the two fasteners (51; 52) are connected to each other via at least one connecting element (60; 60'), which is deformed due to shear stress loads when the module moves along the vehicle component (30) on the bulkhead side, wherein the two fasteners (51; 52) slide and move nested in one another in the direction along the vehicle component (30) and each have a recess (53; 54), wherein the recesses (53; 54) are flush with each other and a push rod (80) of a brake pedal is guided through the recess (53; 54), The brake booster device has an actuator (20) which is pivotably mounted on the vehicle component (30) below the module and by means of which the module can be displaced along the vehicle component (30).

Images