Braking device for a hydraulic motor vehicle braking system having a ball screw drive

Patent metadata

Field	Value
Publication number	US-11072316-B2
Application number	US-201716082802-A
Country	US
Kind code	B2
Filing date	May 11, 2017
Priority date	May 13, 2016
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

A braking device for a hydraulic motor vehicle braking system having an electromechanically driven booster stage and a ball screw drive. In order to provide a braking device which is of particularly compact, cost-effective and weight-saving construction and has short pedal strokes, and an easily adjustable pedal characteristic curve, at the same time enabling effective direct action in case of failure of the booster stage and comfortable haptic feedback at the pedal during normal operation, the actuating force from a piston rod is introduced into the spindle, wherein the piston rod can be moved axially to a limited extent relative to the spindle and a spring element is inserted in the flow of force of the actuating force between the piston rod and the spindle, which spring is compressed axially when the actuating force is introduced.

First claim

The invention claimed is:

1. A braking device for a hydraulic motor vehicle braking system, comprising:
an electromechanical booster stage, which is driven by an electric-motor drive unit and has a booster housing, in which a ball screw drive having a rotatable ball screw nut and a spindle that can be moved in a linear manner is arranged for converting a rotary driving force of the drive unit into a translational boosting force,
a brake master cylinder having a cylinder piston which can be moved in a linear manner therein and acted upon both with an unboosted actuating force by the driver and with the boosting force by the booster stage, wherein the actuating force from a piston rod is introduced into the spindle, and wherein the piston rod can be moved axially to a limited extent relative to the spindle and a spring element is inserted in the flow of force of the actuating force between the piston rod and the spindle, which spring is compressed axially when the actuating force is introduced, the spring element being housed in a spring element housing formed separately from and coupled to the spindle, the spring element housing being directly joined to the spindle by a joint which transmits force, at least in the axial direction.

2. The braking device as claimed in claim 1 , wherein the ball screw drive has an outer pot with external toothing, to which rotation is imparted by the drive unit via the external toothing, and the ball screw drive is secured against rotation and guided in a manner which allows linear movement in the outer pot by virtue of the fact that the ball screw nut has a noncircular outer contour which cooperates with an inner contour of the outer pot, said inner contour corresponding thereto at least in some region or regions.

3. The braking device as claimed in claim 1 , wherein the spring element housing is mounted in a manner which allows linear movement in the booster housing.

4. The braking device as claimed in claim 3 , wherein the piston rod is mounted in a manner which allows axial movement relative to the spring element housing.

5. The braking device as claimed in claim 1 , wherein the booster housing is made of plastic.

6. The braking device as claimed in claim 1 , wherein the spring element has at least one diaphragm spring.

7. The braking device as claimed in claim 1 , wherein the spring element comprises elastomeric material.

8. The braking device as claimed in claim 1 , wherein a bearing housing made of metal is arranged in the booster housing in order to hold bearing elements for the rotatable mounting of the outer pot.

9. The braking device as claimed in claim 1 , wherein a sensor device having a fixed sensing part and a transmitter part that can be moved in a linear manner for detecting the position and/or the movement of the piston rod is provided, wherein the transmitter part is coupled to the piston rod.

10. The braking device as claimed in claim 8 wherein a return spring for returning the spindle to the unbraked initial position thereof is clamped between the bearing housing and the spring element housing, wherein the return spring is axially preloaded both by the action of the actuating force and that of the boosting force.

11. The braking device as claimed in claim 1 , wherein a sensor device having a fixed sensing part and a transmitter part that can be moved in a linear manner for detecting the position and/or the movement of the piston rod is provided, wherein the transmitter part is coupled to the piston rod via a connecting element which extends through an aperture in the spring element housing.

Assignees

• Continental Teves Ag & Co Ohg

Inventors

• Bach Uwe
• Hoffmann Jens
• Gädke Martin
• Von Hayn Holger
• Sefo Ahmed
• Messner Adrian
• Ritter Wolfgang

Classifications

• B60T13/74

  with electrical assistance or drive · CPC title

• B60T11/18 Primary

  Connection thereof to initiating means · CPC title

• B60T7/04

  foot actuated · CPC title

• B60T7/12

  for automatic initiation; for initiation not subject to will of driver or passenger {(limiting speed of vehicles other than rail vehicles B60K31/00)} · CPC title

• B60T11/20

  Tandem, side-by-side, or other multiple master cylinder units · CPC title