Electromechanically actuable brake pressure generator

Abstract

The present invention relates to an electromechanically drivable brake pressure generator for a vehicle hydraulic braking system. [Solution] In this case, the electromechanically drivable brake pressure generator has an electric motor (18) capable of generating a drive speed, and a planetary gear set (22) driven by the electric motor (18) on the input side to convert the transmission ratio of the drive speed of the electric motor (18) to a low speed, in which case the planetary gear set (22) has a ring gear (34) that is supported in a ring gear support portion (46) so as not to be able to rotate relative to the ring gear support portion (46), and further the brake pressure generator has a hydraulic module (30) that is connected to the output side of the planetary gear set (22) and brake pressure is generated by the hydraulic module (30). At least one torque support (50) is disposed between the ring gear (34) and the ring gear seat (46), and the torque support (50) extends axially relative to the planetary gear set (22) and cooperates with the notch (62) to hold the ring gear (34) and the ring gear seat (46) non-rotatable relative to each other.

Description

[Technical Field]

[0001] The present invention relates to an electromechanically actuable brake pressure generator for a hydraulic braking system of a vehicle, comprising an electric motor capable of generating a drive speed and a planetary gear driven on its input side by the electric motor for converting the drive speed transmission ratio to a lower speed, the planetary gear having a ring gear mounted in a ring gear holder so as not to rotate relative to the ring gear holder, and the brake pressure generator having a hydraulic module connected to the output side of the planetary gear and for generating brake pressure by means of the hydraulic module. The present invention also relates to a vehicle having such an electromechanically actuable brake pressure generator. [Background technology]

[0002] Since the driver's pedal force is often insufficient to brake a vehicle, automobiles are generally equipped with a brake booster. Conventional brake boosters usually operate using the vacuum generated by the internal combustion engine. In this case, the pressure difference between the engine pressure and the ambient pressure is used to add a boosting force to the driver's pedal force.

[0003] For future drive concepts of motor vehicles, selective brake pressure generators are required, since vacuum is no longer available to drive conventional vacuum brake boosters. For this reason, related electromechanical brake pressure generators are being developed.

[0004] In this case, the actuation force is generated by an electric motor, which controls the movement of a hydraulic piston via a transmission to generate brake pressure. This type of electromechanical brake pressure generator can be used not only to provide auxiliary force but also to generate the actuation force independently in a brake-by-wire system. Therefore, electromechanical brake pressure generators are particularly advantageous in connection with autonomous driving.

[0005] From Patent Document 1, an electromechanical brake pressure generator is known which amplifies the pedal force applied via a ball spindle, whereby a recirculating ball nut is arranged on the ball spindle, which is driven by an electric motor via a planetary gear set in order to amplify the pedal force. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2012 / 013314 Brochure Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION It is an object of the present invention to provide an electromechanically actuable brake pressure generator for a hydraulic brake system of a vehicle which has reduced construction space. [Means for solving the problem]

[0008] This problem is solved by an electromechanically actuable brake pressure generator in combination with the characteristic features of claim 1. The subsequent dependent claims describe preferred embodiments of the invention. Claim 9 describes a vehicle having a hydraulic braking system with an electromechanically actuable brake pressure generator according to the invention.

[0009] The present invention includes the technical theory that at least one torque support is arranged between the ring gear and the ring gear holder, and this torque support extends in the axial direction relative to the planetary gear device and cooperates with the notch to hold the ring gear and the ring gear holder against relative rotation with respect to each other.

[0010] Within the scope of the present invention, a hydraulic module is understood to mean a module via which the rotational movement of the planetary gear is converted into the movement of a hydraulic piston for generating brake pressure for an electromechanical brake pressure generator, which is preferably configured via a spindle nut arrangement, via which the rotational movement is converted into a translational movement of the hydraulic piston in a hydraulic cylinder.

[0011] According to the invention, the torque support is a structural element that can receive torque. For this purpose, the torque support cooperates with a correspondingly shaped recess, thereby preventing the two components from rotating relative to one another. Preferably, at least two torque supports are provided. Particularly preferably, multiple torque supports are provided, arranged equidistant from one another. In this invention, the torque supports are configured axially. This allows for a savings in structural space compared to radial torque supports, with the same transmission ratio.

[0012] Particularly preferably, this saved construction space is utilized to form a ring gear with a larger diameter, which allows for a larger transmission ratio. Correspondingly, the motor can be operated at, for example, a higher rotational speed, which allows for a shorter driving length of the motor. The motor can therefore be designed compactly, which can save construction space and costs for the motor.

[0013] According to a preferred embodiment of the invention, at least one torque support is rigidly connected to the ring gear and / or the ring gear carrier. In the context of the invention, rigid means that the torque support is formed integrally with the corresponding components or is at least rigidly connected to the components by means of a screw connection, welding, etc. This allows the torque support to be formed either by the ring gear, the ring gear carrier, or both. This allows for a high degree of flexibility in the torque support.

[0014] According to another embodiment of the present invention, at least one torque support engages in a recess in the ring gear holder and / or the ring gear to connect the ring gear and the ring gear holder non-rotatably. Again, the recess can be formed by the ring gear, the ring gear holder, or both. In this case, at least one material removal portion is considered as the recess, thus forming at least one cavity. Such a recess preferably has the same shape as the torque support. This results in a positive lock, which ensures a generally play-free anti-rotation mechanism.

[0015] In a preferred embodiment, at least one torque support is configured as a pin. Such a circular, pin-shaped torque support has the advantage that it can be easily installed in a hole formed by a drilling process. In particular, the pin-shaped member can be inserted into the hole of the ring gear or the ring gear carrier after manufacturing these components and firmly connected to them. During assembly, the pin can be inserted into the corresponding hole of the mating part.

[0016] In a preferred embodiment, the recess is configured as an opening. In this case, an opening is understood to mean a recess that penetrates completely through the thickness of the material in which the recess is formed. The recess therefore extends through the entire material thickness. Such an opening allows high torques to be transmitted, especially in thin-walled materials in which the recess is to be provided.

[0017] Preferably, at least one torque support is crimped on the axially outer side of the ring gear holder. The crimping process radially expands the torque support on the outside like a rivet. This secures the ring gear and the ring gear holder to one another in the axial direction. Additionally, the crimping in the area of ​​the opening eliminates play due to manufacturing tolerances.

[0018] In another preferred embodiment, at least one torque support is configured as a deep-drawn part of the ring gear holder, and the torque support engages in a recess in the ring gear. The deep-drawing step allows such a torque support to be configured simply and economically. The torque support can also be attached after assembly of the ring gear and the ring gear holder, so that the torque support can be provided where the corresponding recess is located.

[0019] According to a preferred embodiment, at least one torque support is made of a plastic material. Plastic materials have the advantage of being light in weight and easily manufactured by injection molding. Plastic materials also have lower material costs. Therefore, an electromechanically drivable brake pressure generator that can be manufactured economically can be provided using such materials. Plastic materials also have the advantage that the crimping process can be performed as a heat crimping process, which melts the plastic material. Such a heat crimping process can be easily manufactured. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic diagram of an embodiment of a power transmission mechanism for an electromechanical brake pressure generator according to the present invention; [Figure 2] FIG. 1 is a perspective view of a planetary gear unit according to the prior art. [Figure 3] 1 is a cross-sectional view of an embodiment of a planetary gear device according to the present invention. [Figure 4] FIG. 4 is a perspective view of the planetary gear unit shown in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0021] An embodiment of the invention is shown in the drawings and is explained in more detail below.

[0022] 1 shows a schematic diagram of an embodiment of a power transmission 14 of an electromechanical brake pressure generator according to the invention. The power transmission 14 has an electric motor 18, via which a drive speed can be generated. The electric motor 18 is mechanically connected to the input side of a planetary gear set 22. In this embodiment, the planetary gear set 22 is positioned coaxially with respect to an electric motor axis 26. The planetary gear set 22 is additionally arranged in a housing part 28 of the brake pressure generator, which may be, for example, a valve housing.

[0023] Via the planetary gear 22, the drive speed of the electric motor 18 is changed to a lower speed. The planetary gear 22 is mechanically connected on the output side to a hydraulic module 30. In this case, the hydraulic module 30 has a brake pressure piston that can be moved axially via a spindle / nut arrangement to generate brake pressure. The power transmission 14 shown in this embodiment is arranged biaxially, meaning that the hydraulic module 30 is arranged parallel to the electric motor axis 26.

[0024] 2 shows a perspective view of a planetary gear set 22 according to the prior art, from which the sun gear 32 (see FIG. 3) has been omitted for clarity. In this case, the planetary gear set 22 has a ring gear 34 with an internal toothing 38 configured in an inclined manner. Three planet gears 42 are arranged within the ring gear 34, and these planet gears 42 mesh with the internal toothing 38 of the ring gear 34.

[0025] The ring gear 34 is received in a ring gear holder 46, which is a deep-drawn sheet metal part. The ring gear 34 has torque supports 50 in its outer peripheral region, which protrude radially from the periphery. The torque supports 50 engage in form-locking manner with torque support grooves 54 formed by the ring gear holder 46, so that the ring gear 34 is held in the ring gear holder 46 and is non-rotatable relative to the ring gear holder 46. Accordingly, the torque supports 50 protrude from the radially outer side 58 of the thin-walled ring gear holder 46.

[0026] A cross-sectional view of one embodiment of the planetary gear set 22 according to the invention is shown in Figure 3. The sun gear 32 is additionally shown in this drawing. Unlike the prior art shown in Figure 2, the torque support 50 extends in the axial direction of the planetary gear set 22 from the axial ring gear outer side 60. In this embodiment, the torque support 50 is rigidly connected to the ring gear 34 or is configured integrally with the ring gear 34. In this case, the torque support 50 cooperates with a recess 62 in the ring gear seat 46.

[0027] In this case, the recess 62 is configured as a circular opening, while the torque support 50 engaging in this opening has the form of a pin. The length of the torque support 50 is dimensioned in this embodiment so that the torque support 50 extends beyond the axial outside 66 of the ring gear seat 46. In an embodiment not shown, the portion of the torque support 50 extending beyond the axial outside 66 can be further crimped, whereby the ring gear 34 is additionally held axially on the ring gear seat 46.

[0028] Unlike the prior art shown in Figure 2, torque support groove 54 is not required, which reduces the radial construction space required for this purpose. Likewise, the radial construction space required in Figure 2 can be provided for a ring gear 34 with a larger diameter, resulting in a higher transmission ratio.

[0029] Figure 4 shows a perspective view of the planetary gear unit 22 of Figure 3. It clearly shows that a number of equidistantly spaced axial torque supports 50 are provided to allow sufficient torque transmission between the ring gear 34 and the ring gear seat 46. It can also be seen that the ring gear seat 46 does not have a torque support groove 54 on its radially outer side 58.

[0030] In an embodiment not shown here, the torque support 50 can also be formed by an axially deep-drawn part of the ring gear seat 46, which then engages in a corresponding recess 62 in the ring gear 34. [Explanation of symbols]

[0031] 14 Power transmission mechanism 18 Electric motor 22 Planetary gear unit 26 Motor axis 28 Housing part 30 Hydraulic Module 32 Sun Gear 34 Ring gear 38 Inner dentition 42 Planetary gear 46 Annular gear holder 50 Torque support part 54 Torque support groove 58 radially outward 60 Annular gear outer 62 Notch 66 Axial Outer

Claims

1. 1. An electromechanically actuable brake pressure generator for a hydraulic braking system of a vehicle, comprising: It has an electric motor (18) capable of generating a driving speed, The drive train includes a planetary gear set (22) driven by the electric motor (18) on the input side to convert the transmission ratio of the drive rotational speed to a low speed, wherein the planetary gear set (22) includes a planetary gear (42) that meshes with a sun gear (32) attached to the output shaft of the electric motor (18) and a ring gear (34) that meshes with the planetary gear (42), and the ring gear (34) is supported in a ring gear support (46) so as not to rotate relative to the ring gear support (46); A hydraulic module (30) is connected to the output side of the planetary gear set (22) and brake pressure is generated by the hydraulic module (30), at least one torque support (50) provided on the outer peripheral area of ​​the ring gear (34) and extending in the axial direction relative to the planetary gear set (22) cooperates with a recess (62) configured as an opening so that the ring gear (34) and the ring gear seat (46) are held non-rotatable relative to one another; at least one of said torque support portions (50) is rigidly connected to said ring gear (34) and / or said ring gear seat (46); Electromechanically drivable brake pressure generator, characterized in that at least one of said torque support parts (50) is crimped to the axially outer side (66) of said ring gear receiving part (46).

2. An electromechanically drivable brake pressure generator for a vehicle hydraulic braking system, comprising: It has an electric motor (18) capable of generating a driving speed, The drive train includes a planetary gear set (22) driven by the electric motor (18) on the input side to convert the transmission ratio of the drive rotational speed to a low speed, wherein the planetary gear set (22) includes a planetary gear (42) that meshes with a sun gear (32) attached to the output shaft of the electric motor (18) and a ring gear (34) that meshes with the planetary gear (42), and the ring gear (34) is supported in a ring gear support (46) so as not to rotate relative to the ring gear support (46); A hydraulic module (30) is connected to the output side of the planetary gear set (22) and brake pressure is generated by the hydraulic module (30), at least one torque support (50) provided on the outer peripheral area of ​​the ring gear (34) and extending in the axial direction relative to the planetary gear set (22) cooperates with a recess (62) configured as an opening so that the ring gear (34) and the ring gear seat (46) are held non-rotatable relative to one another; at least one of said torque support portions (50) is rigidly connected to said ring gear (34) and / or said ring gear seat (46); 1. An electromechanically drivable brake pressure generator, characterized in that at least one of the torque bearing parts (50) is configured in the form of a deep-drawn part of the ring gear seat (46), the torque bearing part (50) engaging in a recess (62) of the ring gear (34).

3. 3. An electromechanically actuable brake pressure generator according to claim 1, wherein at least one of the torque supports (50) is designed in the form of a pin.

4. An electromechanically drivable brake pressure generator as described in any one of claims 1 to 3, characterized in that at least one of the torque support parts (50) is made of a plastic material.

5. A vehicle having an electromechanically drivable brake pressure generator as described in any one of claims 1 to 4.

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