PRIMARY PISTON, MASTER BRAKE CYLINDER INCLUDING THE PRIMARY PISTON, GEAR DEVICE, AND BRAKE PRESSURE GENERATOR

Abstract

The present invention relates to a primary piston (10) for a master brake cylinder (14) or a gear unit (26), having on a first side (10a) a first recess (20) into which at least a partial area facing towards the primary piston (10) of a primary spring (12) of a master brake cylinder (14) carrying or cooperating with the primary piston (10) can be inserted or mounted, and on a second side (10b) of the primary piston (10) facing away from the first side (10a) a second recess (28) is formed into which at least a partial area facing towards the primary piston (10) of a primary spring (12) of a master brake cylinder (14) carrying or cooperating with the primary piston (10) can be inserted or mounted, At least a partial area of ​​a spindle (22) of a gearing (26) equipped with or cooperating with the primary piston (10), facing towards the primary piston (10), and at the same time at least a partial area of ​​a nut (24) of the gearing (26), arranged on the spindle (22), facing towards the primary piston (10), are insertable and / or attached, such that a first recess (20) formed in a first side (10a) of the primary piston (10) surrounds at least a partial area of ​​the second recess (28), facing towards the first side (10a).

Description

[Technical field]

[0001] The present invention relates to a primary piston for a master brake cylinder or a gear arrangement, as well as to a master brake cylinder for a brake-by-wire braking system, a gear arrangement for a brake-by-wire braking system, and a brake pressure generator for a brake-by-wire braking system. [Background technology]

[0002] From the prior art, for example from DE 10 200 03 13 A1, a primary piston for a master brake cylinder is known which can cooperate with an electromechanical brake booster arranged upstream of the master brake cylinder. The primary piston is supported on its first side by a primary spring which projects into a recess of the primary piston, whereby a force can be transmitted by a spindle and a nut of the electromechanical brake booster to a second side of the primary piston facing away from the first side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] German Patent Application Publication No. 102017203559A1 Summary of the Invention

[0004] The present invention provides a primary piston for a master brake cylinder or a gear arrangement having the features of claim 1, a master brake cylinder for a brake-by-wire braking system having the features of claim 5, a gear arrangement for a brake-by-wire braking system having the features of claim 7, and a brake pressure generator for a brake-by-wire braking system having the features of claim 10.

[0005] The present invention provides a primary piston, the preferred configuration of which allows a reduction in the design length of a brake pressure generator with the combined functions of a master brake cylinder and a gearing, which is equipped with the primary piston. The compactness of the brake pressure generator equipped with the primary piston according to the invention can also be increased, since at least a partial area of ​​the spindle of the brake pressure generator facing the primary piston and at the same time at least a partial area of ​​the nut of the brake pressure generator facing the brake piston can be inserted and / or is inserted into the second recess of the primary piston. Due to the reduction in the design length of the brake pressure generator caused by the present invention or due to the increased compactness of its design configuration, the design space of the vehicle / automobile constructed therewith can be reduced.

[0006] In one preferred embodiment of the primary piston, at least a partial area of ​​the spindle facing the primary piston is mountable or mounted in the second recess, while at the same time at least a partial area of ​​the nut that rotates about the spindle facing the primary piston is insertable into the second recess. In this way, the design space created by the primary piston can be utilized for the spindle with the nut that cooperates with it.

[0007] In another preferred embodiment of the primary piston, at least a partial area of ​​the nut facing the primary piston is mountable or attached in the second recess, whereas at the same time at least a partial area of ​​the rotating spindle facing the primary piston is insertable into the second recess. As will become clear in the following, the embodiment of the primary piston described here allows the nut cooperating therewith to be (almost) completely "sunken" in the second recess, which causes a significant reduction in the design length of the brake pressure generator equipped therewith.

[0008] If at least the partial area of ​​the nut facing the primary piston is mounted in the second recess, the nut can be a recirculating ball nut or a threaded nut, in this way any type of nut can be applied for cooperation with the primary piston according to the invention.

[0009] The advantages explained above are also ensured in a master brake cylinder for a brake-by-wire brake system having a primary piston of this type and a primary spring cooperating with the primary piston, in which at least a partial area of ​​the primary spring facing towards the primary piston is mounted in a first recess of the primary piston.

[0010] The master brake cylinder housing is preferably a gravity die casting, which allows the master brake cylinder housing to be manufactured at relatively low cost.

[0011] The advantages described above are also realized in a gear arrangement for a brake-by-wire brake system having a corresponding primary piston and a spindle and a nut arranged on the spindle cooperating with the primary piston, wherein at least a partial area of ​​the spindle facing towards the primary piston or at least a partial area of ​​the nut facing towards the primary piston is mounted in a second recess of the primary piston.

[0012] In a preferred development, if at least a partial area of ​​the spindle facing the primary piston is mounted in the second recess of the primary piston, at least one torque-supporting component can be attached or configured on the primary piston, so that the primary piston is supported on an inner wall of the gear housing of the gear device. Alternatively, if at least a partial area of ​​the nut facing the primary piston is mounted in the second recess of the primary piston, at least one torque-supporting component can be attached or configured on the nut, so that the nut is supported on an inner wall of the gear housing of the gear device. In both cases, the at least one torque-supporting component can prevent undesired co-rotational movements of the primary piston.

[0013] Furthermore, a brake pressure generation for a brake-by-wire brake system equipped with a primary piston of this type, a master brake cylinder and its primary spring cooperating with the primary piston, in which at least a partial area of ​​the primary spring facing towards the primary piston is attached in a first recess of the primary piston, and a gear device cooperating with the primary piston and having a spindle and a nut arranged on the spindle, in which at least a partial area of ​​the spindle facing towards the primary piston or at least a partial area of ​​the nut facing towards the primary piston is attached in a second recess of the primary piston, also has the advantages explained above.

[0014] In one preferred embodiment of the brake pressure generator, the master brake cylinder housing is a gravity die casting, in which case the master brake cylinder housing can be manufactured at relatively low cost.

[0015] Alternatively or additionally, the housing of the master brake cylinder may be screwed to the gear housing of the gear unit, which simplifies repair or replacement of the master brake cylinder.

[0016] Further features and advantages of the invention will be described below with reference to the drawings, in which: [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a schematic diagram showing a first embodiment of a primary piston or of a brake pressure generator equipped with the primary piston; [Diagram 2] FIG. 2 is a schematic diagram showing a second embodiment of a primary piston or of a brake pressure generator equipped with the primary piston; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] FIG. 1 shows a schematic diagram of a first embodiment of a primary piston or of a brake pressure generator equipped with it.

[0019] A primary piston 10, which is shown diagrammatically in Fig. 1, is shaped on a first side 10a in such a way that a primary spring 12 of a master brake cylinder 14, which is equipped with or cooperates with the primary piston 10, can / is in mechanical contact with the primary piston 10 on the first side 10a. By way of example, the primary piston 10 can / is supported by a secondary piston 16 of the master brake cylinder 14 by the primary spring 12 in the embodiment of Fig. 1, which can / is supported by an inner wall of the master brake cylinder 14 by a secondary spring 18. Alternatively, however, the primary piston 10 can / is supported by the inner wall of the master brake cylinder 14 by the primary spring 12. A first recess 20 is formed on the first side 10a of the primary piston 10, into which at least a partial area of ​​the primary spring 12 facing the primary piston 10 can / is attached. The first side 10a of the primary piston 10 can thus be referred to as the stepped side or stepped inner contour side. The first recess 20 on the first side 10a of the primary piston 10 is preferably configured annularly. The inner diameter of the annularly configured first recess 20 can be equal to or smaller than the inner diameter of the primary spring 12, whereas the outer diameter of the annularly configured first recess 20 is preferably equal to or larger than the outer diameter of the primary spring.

[0020] Furthermore, the primary piston 10 is shaped on a second side 10b facing away from the first side 10a such that it can transmit / is capable of transmitting a force to the primary piston 10 via a spindle 22 and a nut 24 arranged on the spindle 22 of a gearing 26 equipped with or cooperating with the primary piston 10. This force can be transmitted to the spindle 22 and the nut 24 cooperating therewith by a motor (not shown) for example and then further transmitted to the primary piston 10 via the spindle 22 and the nut 24. This motor can be the motor of the gearing 26 or can be a motor connected externally to the gearing 26. The spindle 22 and the nut 24 jointly constitute a rotational-translational gear stage of the gearing 26. The rotational-translational gear stage constituted by the spindle 22 and the nut 24 can in particular be the final gear stage of the force transmission chain of the gearing 26. The gearing 26 may be at least a part of an electromechanical brake booster.

[0021] As shown pictorially in FIG. 1, a second recess 28 is formed in the second side 10b of the primary piston 10, into which at least a partial area of ​​the spindle 22 facing the primary piston 10 and at the same time at least a partial area of ​​the nut 24 facing the primary piston 10 can be inserted and / or attached. The second side 10b of the primary piston 10 can therefore also be described as a stepped side or stepped inner contour side of the primary piston 10. The second recess 28 is configured with a large volume, such that the first recess 20 formed in the first side 10a of the primary piston 10 surrounds at least a partial area of ​​the second recess 28 facing the first side 10a. In other words, it can also be said that the second recess 28 of the primary piston 10 extends from the second side 10b to the piston partial volume 10c of the primary piston 10 surrounded by the first recess 20. A covered area / piston bottom 10d of the piston partial volume 10c formed on the first side 10a of the primary piston 10 may prevent the ingress of brake fluid from the master brake cylinder 14 into the second recess 28 of the primary piston 10. The second recess 28 of the primary piston 10 preferably extends from the second side 10b into the primary piston 10 to such an extent that the partial area of ​​the second recess 28 facing towards the first side 10a of the primary piston 10 is separated from the first side 10a of the primary piston 10 only by the covered area 10d. The thickness of the covered area 10d along the maximum extension of the primary piston 10 may be, for example, less than one tenth of the maximum extension of the primary piston 10, in particular less than one fifteenth of the maximum extension of the primary piston 10.

[0022] The shape of the primary piston 10 creates the possibility of intrusion of at least a partial area of ​​the spindle 22 facing towards the primary piston 10 and of at least a partial area of ​​the nut 24 facing towards the primary piston, so that the design space of the primary piston 10 can be shared at least for partial areas of the spindle 22 and the nut 24. As can be seen in figure 1, the preferred shape of the primary piston 10 described above therefore makes it possible to clearly reduce the design length of the brake pressure generator with the function of the brake booster 14 and the gearing 26.

[0023] Optionally, the first side 10a of the primary piston 10 may further comprise an edge region 10e surrounding the first recess 20 of the primary piston 10. The second recess 28 on the second side 10b of the primary piston 10 may comprise an outer region 28a adjacent to the second side 10b and an inner region 28b located on the outer region 28a facing away from the second side 10b. The inner region 28b of the second recess 28 may extend into the piston partial volume 10c surrounded by the first recess 20. The maximum diameter of the inner region 28b is preferably smaller than the minimum diameter of the outer region 28a of the second recess 28. This simplifies the configuration of the inner region 28b of the second recess 28 also inside the piston partial volume 10c of the primary piston 10 surrounded by the first recess 20.

[0024] In the embodiment of FIG. 1, at least a partial area of ​​the spindle 22 facing towards the primary piston 10 can be attached / mounted in the second recess 28. To that end, the maximum diameter of the inner area 28b of the second recess 28 can be (approximately) equal to the maximum diameter of the partial area of ​​the spindle 22 attached to the inner area 28b. The nut 24 can be excited to a rotational movement about the spindle 22 by the action of the motor, while the spindle 22 is fixed to the primary piston 10. In particular, in the embodiment of FIG. 1, the nut 24 is supported via a bearing 30. The rotational movement of the nut 24 causes a linear adjustment of the spindle 22 and the primary piston attached thereto, whereby the second recess 28 / its outer area 28a of the adjusted primary piston 10 receives or releases the rotating partial area of ​​the nut 24 facing towards the primary piston 10. Therefore, the minimum diameter of the outer region 28a of the second recess 28 is preferably greater than the maximum diameter of a partial region of the nut 24 that can be inserted into the outer region 28a.

[0025] As a preferred development, in the embodiment of Fig. 1 at least one torque-bearing component 32 is furthermore attached or arranged on the primary piston 10. By means of the at least one torque-bearing component 32 the primary piston 10 can be supported on an inner wall of a gear housing 34 of the gear device 26 in such a way that an undesired co-rotational movement of the primary piston 10 together with the nut 24 which is in a rotating movement does not occur.

[0026] For further features and advantages of the brake pressure generator of FIG. 1, see the following description.

[0027] FIG. 2 shows a schematic diagram of a second embodiment of a primary piston and a brake pressure generator equipped with it.

[0028] Different from the embodiment described above, in the primary piston 10 of Fig. 2 at least a partial area of ​​the nut 24 facing the primary piston 10 can be mounted / is mounted in the second recess 28 / its outer area 28a. To that end, the maximum diameter of the outer area 28a of the second recess 28 is preferably (substantially) equal to the maximum diameter of the partial area of ​​the nut 24 mounted in the second recess 28 / its outer area 28a. While the nut 24 is fixed to the primary piston 10, the spindle 22 can be excited by the action of the motor to a rotational movement about the longitudinal axis of the spindle 22 relative to the primary piston 10. At least a partial area of ​​the rotating spindle 22 facing the primary piston 10 rotates during the rotational movement into or out of the second recess 28 / its inner area 28b. The minimum diameter of the inner section 28b of the second recess 28 is therefore preferably greater than the maximum diameter of a partial section of the spindle 22 that can be inserted into the inner section 28b. To support the axial forces, the spindle 22 can be supported via a bearing 36.

[0029] 1 and 2, it becomes clear that in the embodiment of FIG. 1, the spindle 22 extends into the second recess 28 up to the covered area 10d. The maximum stroke of the spindle 22 and the nut 24 can therefore be accommodated completely within the design space of the primary piston 10. The brake pressure generator of FIG. 2 therefore has a shorter design length than the embodiment of FIG. 1. The compactness of the design of the brake pressure generator of FIG. 2 is thus further optimized.

[0030] In a preferred development, at least one torque-bearing component 38 is furthermore attached / configured to the nut 24 of the brake pressure generator of Fig. 2, by means of which the nut 24, and thus also the primary piston 10, is supported on an inner wall of a gear housing 34 of the gear device 26. In this way, undesirable co-rotational movements of the primary piston 10 together with the rotating spindle 22 are also prevented in the brake pressure generator of Fig. 2.

[0031] For other configuration requirements and characteristics of the brake pressure generator of FIG. 2, please refer to the description of the embodiment of FIG. 1 and the following description.

[0032] All the brake pressure generators described above can be applied for brake-by-wire brake systems, servo brakes, or power brakes, however the applicability of the brake pressure generators described above is not limited to the applications listed here.

[0033] In any of the brake pressure generators described above, the nut 24 can also be called a spindle nut. The nut 24 can be, for example, a recirculating ball nut or a threaded nut. The spindle 22 can be understood to be a threaded spindle, a recirculating ball spindle, or a rack.

[0034] The housing 40 of the master brake cylinder 14 can be / is screwed to the gear housing 34 of the gear arrangement 26 by means of at least one screw 42. This simplifies the assembly of the master brake cylinder 14 to the gear arrangement 26 and allows for a quick and easy replacement of the master brake cylinder 14 during service operations. Furthermore, in this case the master brake cylinder 14 can be manufactured separately from the gear arrangement 26 as a separate module. The housing 40 of the master brake cylinder 14 is preferably a gravity die casting, in particular a gravity die casting made of aluminum. In this case the master brake cylinder 14 can be manufactured at relatively low cost.

[0035] All of the brake pressure generators described above can be utilized to implement a dual circuit brake system. However, it should be noted that the master brake cylinder 14 of the brake pressure generators described above is configured as a tandem master brake cylinder by way of example only. Alternatively, the master brake cylinder 14 may be configured for hydraulic connection of only a single brake circuit.

[0036] It should be pointed out again that all the brake pressure generators described above have a compact structure and can be manufactured at low cost, due to the favorable utilization of the design space of the primary piston 10, without having to pay the price of undesired intrusion of the spindle 22 into the interior space of the vehicle equipped with it. [Explanation of symbols]

[0037] 10 Primary piston 10a First Side 10b Second Side 12 Primary spring 14 Master brake cylinder 20 First recess 22 Spindle 24 Nut 26 Gear unit 28 Second recess 32 Torque Support Components 34 Gear housing 38 Torque Support Components 40 Housing

Claims

1. A primary piston (10) for a master brake cylinder (14) or a gear arrangement (26), comprising: A primary piston having a first recess (20) on a first side (10a) into which at least a partial area facing said primary piston (10) of a primary spring (12) of a master brake cylinder (14) carrying or cooperating with said primary piston (10) can be inserted or is attached, a second recess (28) is formed on a second side (10b) of the primary piston (10) facing away from the first side (10a), into which at least a partial area of ​​a spindle (22) of a gearing (26) carrying or cooperating with the primary piston (10) facing towards the primary piston (10) and at the same time at least a partial area of ​​a nut (24) of the gearing (26) arranged on the spindle (22) facing towards the primary piston (10) can be inserted and / or attached, 1. A primary piston, comprising: a first recess (20) formed in the first side (10a) of the primary piston (10) surrounding at least a partial area of ​​the second recess (28) facing towards the first side (10a).

2. 2. The primary piston (10) according to claim 1, wherein at least a partial area of ​​the spindle (22) facing towards the primary piston (10) is attachable or attached to the second recess (28), while at the same time at least a partial area of ​​the nut (24) rotating about the spindle (22) facing towards the primary piston (10) is insertable into the second recess (28).

3. 2. The primary piston (10) according to claim 1, wherein at least a partial area of ​​the nut (24) facing towards the primary piston (10) is attachable or attached to the second recess (28), while at the same time at least a partial area of ​​the rotationally moving spindle (22) facing towards the primary piston (10) is insertable into the second recess (28).

4. 4. The primary piston (10) of claim 3, wherein at least a partial area of ​​the nut (24) facing the primary piston (10) is attached to the second recess (28), and the nut (24) is a recirculating ball nut or a threaded nut.

5. A master brake cylinder (14) for a brake-by-wire brake system, A primary piston (10) according to any one of claims 1 to 4, and a primary spring (12) cooperating with the primary piston (10), A master brake cylinder, wherein at least a partial area of ​​said primary spring (12) facing said primary piston (10) is mounted in said first recess (20) of said primary piston (10).

6. 6. The master brake cylinder (14) of claim 5, wherein the housing (40) of the master brake cylinder (14) is a gravity die casting.

7. A gear arrangement (26) for a brake-by-wire brake system, comprising: A primary piston (10) according to any one of claims 1 to 4, said spindle (22) and said nut (24) disposed on said spindle (22) cooperating with said primary piston (10); at least a partial area of ​​the spindle (22) facing towards the primary piston (10) or at least a partial area of ​​the nut (24) facing towards the primary piston (10) is attached to the second recess (28) of the primary piston (10).

8. 8. The gear arrangement (26) according to claim 7, wherein at least a partial area of ​​the spindle (22) facing the primary piston (10) is attached to the second recess (28) of the primary piston (10) and at least one torque supporting component (32) is attached or configured to the primary piston (10) by means of which the primary piston (10) is supported on an inner wall of a gear housing (34) of the gear arrangement (26).

9. 8. The gear arrangement (26) of claim 7, wherein at least a partial area of ​​the nut (24) facing the primary piston (10) is attached to the second recess (28) of the primary piston (10) and wherein at least one torque supporting component (38) is attached to or configured on the nut (24) such that the nut (24) is supported on an inner wall of the gear housing (34) of the gear arrangement (26).

10. In a brake pressure generator for a brake-by-wire brake system, A primary piston (10) according to any one of claims 1 to 4, said master brake cylinder (14) and its primary spring (12) cooperating with said primary piston (10), at least a partial area of ​​said primary spring (12) facing said primary piston (10) being mounted in said first recess (20) of said primary piston (10); 1. A brake pressure generator comprising: a gear arrangement (26) having a spindle (22) and a nut (24) arranged on the spindle (22) cooperating with the primary piston (10), wherein at least a partial area of ​​the spindle (22) facing towards the primary piston (10) or at least a partial area of ​​the nut (24) facing towards the primary piston (10) is mounted in the second recess (28) of the primary piston (10).

11. 11. The brake pressure generator of claim 10, wherein the housing (40) of the master brake cylinder (14) is a gravity die casting.

12. 12. The brake pressure generator according to claim 10 or 11, wherein the housing (40) of the master brake cylinder (14) is screwed to the gear housing (34) of the gear device (26).

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