IPGATE AG – Patent Family E147 · Next-Generation Safety & Control Architecture for BBW Systems
4
Granted Rights
4
Jurisdictions
3
Invention Complexes
2015
First Priority
HDS
Compatible Architecture

Inverted Inlet Valve Wiring &
Check-Valve-Free Fault-Tolerant BBW

Patent family E147 introduces a novel safety and control architecture for brake-by-wire systems in which brake pressure is regulated not directly, but via a combination of volume control (ΔV) and time control (Δt) of the inlet valves — with an inverted valve connection that eliminates the need for check valves while ensuring fail-safe pressure relief.

The central innovation of E147 is the special wiring of the inlet valves: the armature chamber (Ei) is hydraulically connected to the brake circuit (BK), while the valve seat outlet (Ea) leads to the wheel brake (RB). This "reverse" connection enables purely volume- and time-controlled pressure regulation during pressure build-up, extending degrees of freedom that are unavailable in conventional check-valve architectures.

Critically, this wiring means that a wheel brake pressure higher than the inlet pressure acts on the ball seat in the opening direction — so in the event of a power failure, the valve opens automatically and releases any enclosed pressure. For the first time, this delivers a check-valve-free, fault-tolerant architecture that ensures safe valve opening even at high differential pressures. The family is compatible with MUX, HDS, HDS 2.1, and other pressure control strategies (E87, E102, E141, E145, E146).

EP US CN

ABS History & the Check-Valve Problem

Since the introduction of ABS series production in 1978, brake pressure has been finely regulated during ABS control via PWM-controlled inlet valves (pulse width modulation). Check valves in parallel with the inlet valves ensure that no unintended excess pressure remains trapped in the wheel brake if supply pressure falls below wheel brake pressure and the power supply fails.

Prior Art Limitation: With conventional wiring — valve seat outlet connected to the supply line, armature chamber to the wheel brake — a high wheel brake pressure acts on the armature surface when the valve is closed and energized, pressing it into the seat. If power fails, the valve cannot open because the differential pressure exceeds the spring force. The pressure in the wheel brake remains trapped: a potentially safety-critical condition requiring check valves as a safeguard.

Furthermore, conventional check-valve architectures constrain pressure control to one direction: if the supply pressure is higher than any wheel brake pressure, each wheel can be individually maintained or raised via PWM. However, if the supply pressure drops — e.g., to service one wheel at low pressure — the check valve will automatically equalize all other wheel brakes downward. Maintaining asymmetric pressures during a supply-pressure decrease is impossible with check valves.

E147 Advance: By inverting the valve connection (Ei → BK, Ea → RB), the wheel brake pressure acts on the ball seat in the opening direction. Power failure causes automatic valve opening and safe pressure relief — without check valves. Simultaneously, the architecture allows wheel brake pressure to be maintained even when supply pressure drops below it, enabling wheel-selective asymmetric pressure control during regenerative braking, torque vectoring, and brake-steer functions.

This solution ideally requires pressure-balanced valves that are resistant to closing under flow forces. Standard inlet valves can also be used, provided that pressure build-up dynamics are limited — either via passive throttling elements or by software-based volume flow limitation (e.g., limiting the drive motor speed of the pressure supply). The trade-off is that PWM pressure control during pressure build-up is eliminated; instead, pressure is regulated purely via volume control through the plunger, while PWM remains available during pressure reduction.

Three Invention Complexes

The 3 invention complexes of E147 cover the inverted-valve device architecture, a dual-circuit bypass-valve variant, and the fault-tolerant check-valve-free control method.

EK 1 · Device
Bidirectional Volume/PWM Pressure Control via Inlet Valves
EP · US · CN · CN (Div.)
Actuating device with piston-cylinder unit and controllable pressure source. Control device regulates pressure build-up via volume control (ΔV) and/or time control (Δt) through inlet valves. Inverted wiring: armature chamber (Ei) → brake circuit (BK), valve seat outlet (Ea) → wheel brake (RB). Enables diagnosable wheel circuits, MUX/HDS compatibility, and pre-pressures set individually per wheel based on road friction coefficients.
EK 2 · Device
Dual-Circuit Bypass Valve Architecture
US
Actuating device with dual-circuit pressure supply. Two working chambers of the controllable pressure source are connected to the brake circuits via shut-off valves. The pressure source outputs are interconnected via a bypass valve (positioned before the shut-off valves). Volume control and/or time-controlled inlet valve opening; pre-pressures adjusted based on road friction coefficients per wheel.
EK 3 · Method
Check-Valve-Free, Fault-Tolerant Volume Pressure Control
EP · CN · CN (Div.)
Method for operating the actuating device: control pre-pressure (pvor) ≤ 150 bar (in particular ≤ 130 bar) relative to actual wheel brake pressure. In the MUX case, valves release enclosed pressure in the event of a fault without additional check valves. Eliminates the safety problem of unintentional inlet valve closure under power failure; enables wheel-selective pressure reduction via inlet valves alone.
Section 1 · Invention Overview

Invention Complexes, Descriptions & Keywords

3 invention complexes across 4 property rights (EP, US, JP, CN). Each complex covers one or more independent claims in the respective jurisdictions.

Complex · References Cat. Description Keyword
EK 1 – Inverted Valve Device
EP 3271220 B1 (A1) · US 11,584,348 B2 (A1) · CN 107428317 A (A1) · CN 118560434 A (A1)
Device Actuating device for vehicle brake system with control device, piston-cylinder unit, and controllable pressure source. Control device regulates pressure build-up via volume control (ΔV) and/or time control (Δt) through inlet valves. Inverted circuitry: armature chamber (Ei) connected to brake circuit (BK) via hydraulic line; valve seat outlet (Ea) connected to wheel brake (RB). Pre-pressures set individually per wheel based on road friction coefficients; time-window control for EV opening/closing. Inverted EV · Volume/Time Control · Wheel-selective pressure
EK 2 – Dual-Circuit Bypass
US 11,584,348 B2 (A20)
Device Actuating device with dual-circuit pressure supply. Two working chambers of the controllable pressure source connected to brake circuits via shut-off valves. Pressure source outputs interconnected via bypass valve (before shut-off valves). Volume control and/or time-controlled inlet valve opening with pre-pressures adjusted per wheel friction coefficient. Dual-circuit · Bypass valve · Shut-off valves
EK 3 – Fault-Tolerant Method
EP 3271220 B1 (A15) · CN 107428317 A (A22) · CN 118560434 A (A20)
Method Method for operating the actuating device: control pre-pressure (pvor) ≤ 150 bar (in particular ≤ 130 bar) relative to actual wheel brake pressure. In MUX operation, valves release enclosed pressure in the event of a power failure without additional check valves. Eliminates safety-critical pressure trapping and enables wheel-selective pressure reduction solely via inlet valves. pvor ≤ 150 bar · No check valves · Fail-safe relief
Section 2a · Family Overview

Jurisdictions & Status

All members of the E147 patent family as of February 2026. 4 granted rights across 4 jurisdictions; 2 CN applications pending.

File No. Country Status Type Registration No. Filed Grant No. Granted
E147WOEP EP Granted Patent 15817915.0 Dec. 30, 2015 EP 3271220 B1 Oct. 20, 2021
E147WOUS US Granted Patent 15/558,438 Dec. 30, 2015 US 11,584,348 B2 Feb. 21, 2023
E147WOJP Granted Patent 2017-548871 Dec. 30, 2015 JP 6941056 B2 Sep. 7, 2021
E147WOCN CN Pending Patent 201580077959.8 Dec. 30, 2015
E147WOJP1 Granted Divisional 2021-144039 Dec. 30, 2015 JP 7239657 B2 Mar. 6, 2023
E147WOCN1 CN Pending Divisional 202410767729.5 Dec. 30, 2015