E146 – Dual-Stroke Piston BBW
with HDS 2.2 & Reduced Valve Count
Complete brake-by-wire system with double-stroke piston pressure supply (DHK), bidirectional pressure control (MUX 2.0 / HDS 2.2), and model-based multi-wheel control. 11 independent inventions · 9 granted rights · EP · US · CN · JP · DE
| Applicant | IPGATE AG, Churerstraße 160a, 8808 Pfäffikon (CH) |
| Inventors | Heinz Leiber, Dr. Thomas Leiber |
| Priority / Filing Date | March 16, 2015 (DE202015107072.1, DE202015107075.6, DE202015107079.9) |
| PCT Application | PCT/EP2015/081402 |
| Technology | Double-stroke piston brake-by-wire (DHK-BBW) with HDS 2.2 (MUX 2.0) — bidirectional pressure control with reduced valve count |
| Innovations | 11 independent inventions (device + method) · 7 invention complexes |
Double-Stroke Piston BBW
with HDS 2.2 & Reduced Valve Count
Patent family E146 claims a complete electrohydraulic brake-by-wire system with a double-stroke piston (DHK) pressure supply unit and highly dynamic bidirectional pressure control (MUX 2.0 / HDS 2.2) — extending beyond E145 by exploiting both the forward and return strokes of the piston for pressure build-up and reduction.
While E141 protects the HDS 2 control method in isolation and E145 claims the complete brake system in the HDS 2.1 configuration (plunger), E146 advances to the HDS 2.2 configuration with a double-stroke piston (DHK) as the pressure supply unit. The DHK enables bidirectional pressure control — pressure build-up in the forward stroke and pressure reduction in the return stroke — creating new degrees of freedom compared to the single-stroke plunger.
E146 extends the scope of protection to cover reduced valve costs via novel bidirectional inlet valves, model-based multi-wheel pressure control using stored pressure-volume characteristics, THZ floating piston diagnostics, and high-pressure relief procedures for pressures ≥ 100 bar. The family spans 5 jurisdictions with 9 granted rights across 10 property rights (1 US divisional pending), covering 14 independent claims total.
HDS Generations & DHK Advancement
E146 is the second complete system patent in the HDS 2 generation (alongside E145), specifically realizing the HDS 2.2 variant with a double-acting piston. The three HDS 2 pump-type variants are defined as follows:
| Variant | Pump Type | Control Strategy |
|---|---|---|
| HDS 2.1 | Plunger (single-stroke) | Volume control — pressure build-up/reduction + outlet valve(s) · Claimed in E145 |
| HDS 2.2 | Double-acting piston (DHK) | Bidirectional volume control — pressure build-up in forward stroke, reduction in return stroke + outlet valve(s) · Claimed in E146 |
| HDS 2.3 | Rotary pump | Volume control only — pressure build-up + outlet valve(s) for reduction |
Seven Invention Complexes
The 11 independent inventions of E146 are organized into 7 invention complexes covering the DHK pressure control system, valve architecture, model-based control, diagnostics, and safety functions.
Invention Complexes, Descriptions & Keywords
14 independent claims organized into 11 inventions across 7 invention complexes. EP: 5 claims (3 patents) · CN: 9 claims (2 patents) · US: 3 claims (1 patent) · JP: 1 claim.
| Complex · References | Cat. | Description | Keyword |
|---|---|---|---|
| EK 1 – DHK Core System EP3271221B1 · US11760329B2 · JP6827946B · DE202015008976 |
Device | Electrohydraulic BBW system with double-stroke piston (DHK) pressure supply. The DHK limits two working chambers and is operated in both directions: pressure build-up in the forward stroke, pressure reduction in the return stroke by enlarging volume. | DHK · Two working chambers · Bidirectional pressure control |
| EK 2 – DHK Pressure Reduction EP4292893B1 · CN113696868B |
Method | Targeted DHK pressure reduction via pressure-volume control. The DHK reduces brake pressure by controlled volume change: in the return stroke by enlarging the first working chamber, in the forward stroke by enlarging the second working chamber. | Pressure reduction · Volume control · Return/forward stroke |
| EK 3 – Simultaneous Control EP24194897.5 (A1, A2, A5) |
Device | Three independent inventions: (A1) simultaneous pressure reduction via piston and outlet valve time control; (A2) simultaneous pressure build-up AND reduction; (A5) simultaneous build-up/reduction via DHK with two working chambers — enabling independent per-wheel pressure targets. | Simultaneous control · Three DOF · Time-controlled outlet valves |
| EK 4 – Valve-Reduced Architecture CN107531216B · CN113696868B |
Device | Max. one outlet valve per brake circuit (50% valve reduction vs. conventional ABS). Bidirectional inlet valves: hydraulic medium flows from the brake circuit via the armature chamber to the valve seat and on to the wheel cylinder — eliminating the need for separate return-path valves. | 1 AV per circuit · Bidirectional inlet valve · Armature chamber |
| EK 5 – Model-Based Control CN107531216B (A25, A30) · US11760329B2 (A18, A23) |
Method | Two inventions: model-based multi-wheel pressure control for (A25/A18) pressure reduction and (A30/A23) pressure build-up. Control device uses stored pressure-volume characteristics per wheel brake, calculates required piston stroke for each pressure change, and applies individually timed valve openings for simultaneous multi-wheel target pressures. | P-V characteristic · Piston stroke · Simultaneous multi-wheel |
| EK 6 – THZ Diagnosis CN107531216B (A34) · CN113696868B (A39, A41) |
Method | Two inventions: floating piston tightness and mobility monitoring during (A34) driving — via radial channel pressure difference and pressure-volume curve comparison with floating piston engaged; and (A39/A41) parking — via pressure storage in second circuit, reduction in first, valve opening, and equalization analysis. | Floating piston · Radial channel · Pressure equalization |
| EK 7 – High-Pressure Relief CN107531216B (A36) · CN113696868B (A42) |
Method | Active bidirectional pressure reduction at pressures ≥ 100 bar. Multi-stage procedure via pressure relief valve, forward and return stroke combinations of the DHK with closed-loop pressure measurement and volume control, followed by DHK repositioning. | Pressure relief · ≥ 100 bar · Multi-stage DHK strokes |
Jurisdictions & Status
All members of the E146 patent family as of February 2026. 9 granted or registered rights across 5 jurisdictions; 1 US divisional application pending.
| File No. | Country | Status | Type | Registration No. | Filed | Grant No. | Granted |
|---|---|---|---|---|---|---|---|
| E146WOEP | EP | Granted | Patent | 15823175.3 | Dec. 30, 2015 | EP 3271221 B1 | Nov. 1, 2023 |
| E146WOEP1 | EP | Granted | Divisional | 23207002.9 | Dec. 30, 2015 | EP 4292893 B1 | Jun. 18, 2025 |
| E146WOEP2 | EP | Granted | Divisional | 24194897.5 | Dec. 30, 2015 | EP 4446182 B1 | Feb. 4, 2026 |
| E146WOCN | CN | Granted | Patent | 201580077962.X | Dec. 30, 2015 | CN 107531216 B | Aug. 3, 2021 |
| E146WOCN1 | CN | Granted | Divisional | 202110785648.4 | Dec. 30, 2015 | CN 113696868 B | Mar. 19, 2024 |
| E146WOUS | US | Granted | Patent | 15/558,419 | Dec. 30, 2015 | US 11,760,329 B2 | Nov. 19, 2023 |
| E146WOUS1 | US | Granted | Divisional | 18/235,567 | Dec. 30, 2015 | US 12,384,348 B2 | Aug. 12, 2025 |
| E146WOUS2 | US | Pending | Divisional | 18/411,652 | Dec. 30, 2015 | — | — |
| E146WOJP | JP | Granted | Patent | 2017-548870 | Dec. 30, 2015 | JP 6827946 B2 | Jan. 22, 2021 |
| E146GDE | DE | Registered | Utility Model | 202015008976.3 | Dec. 30, 2015 | DE 202015008976 | — |
