# US 7,611,434 B2 · Hydraulic controlling apparatus for automatic transmission for vehicle

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- Number: US 7,611,434 B2
- Document ID: US7611434B2
- Status: Granted
- Kind: B2
- Application number: 11/553,717
- Filed: 2006-10-27
- Published: 2007-05-24
- Granted: 2009-11-03
- Earliest claimed: 2005-11-24
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Inventors: Hiroshi Fukushima; Naoki Kato; Kenichi Tsuchida
- Web page: https://patentgrep.com/patent/US7611434B2

## CPC

- F16H 61/12: Detecting malfunction or potential malfunction, e.g. fail safe (in control of hydrostatic gearing F16H61/4192) {; Circumventing or fixing failures}
- F16H 3/663: {with conveying rotary motion between axially spaced orbital gears, e.g. a stepped orbital gear or Ravigneaux}
- F16H 61/686: with orbital gears
- F16H 2061/1232: {Bringing the control into a predefined state, e.g. giving priority to particular actuators or gear ratios}
- F16H 2061/1236: {using fail priority valves}
- F16H 2061/1264: {Hydraulic parts of the controller, e.g. a sticking valve or clogged channel}
- F16H 2200/0052: the gear ratios comprising six forward speeds
- F16H 2200/2007: with two sets of orbital gears
- F16H 2200/2023: using a Ravigneaux set with 4 connections
- F16H 2200/2043: with five engaging means
- Y10S 477/906: Means detecting or ameliorating the effects of malfunction or potential malfunction
- F16H: GEARING
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

The fail-safe gear step switching valve (120) can be switched to the first position to establish the low-speed side fail-safe gear step (third speed-change gear step) or the second position to establish the high-speed side fail-safe gear step (fifth speed-change gear step). Upon the failure state of the solenoid valve device (SLC1, SLC2), the fail-safe gear step switching valve is held at the second position by the line hydraulic pressure (PL1). Two kinds of the fail-safe gear steps i.e., the third speed-change gear step and the fifth speed-change gear step can be established depending on the vehicle state just before the failure occurrence of the fail-safe gear step switching valve. Even if the D→N operation of the shift lever (72) is performed during the vehicle running in the fifth speed-change gear step, the fail-safe gear step switching valve remains at the second position to establish the fifth speed-change gear step even upon the shifting operation of the shift lever to the “D” position again.

## Claims

### Claim 1

A hydraulic controlling apparatus for an automatic transmission for vehicle, comprising:
a hydraulic pump that outputs an operation oil pressure;
a manual valve that generates a hydraulic pressure for forward running based on the operation oil pressure, when a valve position of the manual valve is switched in accordance with a shifting operation to a forward running position;
a first solenoid valve device, that, when the first solenoid valve is in a normal state selectively supplies an output hydraulic pressure to plural hydraulic type frictionally engaging devices to establish plural speed-change steps of the automatic transmission; and
a fail-safe gear step switching valve that (i) upon a failure state of the first solenoid valve, switches to a first position to establish a low-speed side fail-safe gear step or to a second position to establish a high-speed side fail-fail gear step, of plural speed-change steps of the automatic transmission, both the first position and the second position being set in advance based on the output hydraulic pressure from the solenoid valve device just before failure thereof occurs, so that the low-speed side fail-safe gear step or the high-speed side fail-safe gear step is selected in an alternative way, and (ii) is held at the second position based on a base pressure which is based on the operation oil pressure from the hydraulic pump, wherein the base pressure is supplied independent of the valve position of the manual valve.

### Claim 2 (depends on 1)

A hydraulic controlling apparatus according to claim 1, wherein the fail-safe gear step switching valve is held at the first position based on a decreased base pressure and biasing force of a bias member.

### Claim 3

A hydraulic controlling apparatus for an automatic transmission for vehicle, comprising:
a hydraulic pump that outputs an operation oil pressure;
a manual valve that generates a hydraulic pressure for forward running based on the operation oil pressure, when a valve position of the manual valve is switched in accordance with a shifting operation to a forward running position;
a solenoid valve device, that, when the first solenoid valve is in a normal state, selectively supplies an output hydraulic pressure to plural hydraulic type frictionally engaging devices to establish plural speed-change steps of the automatic transmission; and
a fail-safe gear step switching valve that (i) upon a failure state of the solenoid valve, switches to a first position to establish a low-speed side fail-safe gear step or to a second position to establish a high-speed side fail-fail gear step, of plural speed-change steps of the automatic transmission, both the first position and the second position being set in advance based on the output hydraulic pressure from the solenoid valve device just before failure thereof occurs, so that the low-speed side fail-safe gear step or the high-speed side fail-safe gear step is selected in an alternative way, and (ii) is held at the second position based on a base pressure which is based on the operation oil pressure from the hydraulic pump and which does not fluctuate regardless of the valve position of the manual valve,
wherein the fail-safe gear step switching valve is held at the first position based on a decreased base pressure and biasing force of a bias member,
the solenoid valve device includes a first solenoid pressure regulation valve that supplies the output hydraulic pressure to a first hydraulic type frictionally engaging device for establishing the low-speed side gear step including a lowest-speed gear step and the fail-safe gear step switching valve, and a second solenoid pressure regulation valve that supplies the output hydraulic pressure to a second hydraulic type frictionally engaging device for establishing the high-speed side gear step including a highest-speed gear step and the fail-safe gear step switching valve, and
the fail-safe gear step switching valve is switched to the first position based on the output hydraulic pressure from the first solenoid pressure regulation valve, and switched to the second position based on the output hydraulic pressure from the second solenoid pressure regulation valve.

### Claim 4 (depends on 3)

A hydraulic controlling apparatus according to claim 3, wherein the fail-safe gear step switching valve in the first position thereof outputs the hydraulic pressure for forward running to the first hydraulic type frictionally engaging device, and in the second position thereof outputs the hydraulic pressure for forward running to the second hydraulic type frictionally engaging device.

### Claim 5 (depends on 4)

A hydraulic controlling apparatus according to claim 4, wherein the solenoid valve device further includes a third solenoid pressure regulation valve that supplies the output hydraulic pressure to a third hydraulic type frictionally engaging device establishing the low-speed side fail-safe gear step and the high-speed side fail-safe gear step together with the first hydraulic type frictionally engaging device and the second hydraulic type frictionally engaging device.

### Claim 6 (depends on 5)

A hydraulic controlling apparatus according to claim 5, further including a normal/failure switching valve to be switched to a normal side position upon normal state of the solenoid valve device for allowing the output hydraulic pressure from the solenoid valve device to be supplied to the hydraulic type frictionally engaging device, or a failure side position upon failure state of the solenoid valve device for allowing the hydraulic pressure for forward running or the base pressure to be supplied to the hydraulic type frictionally engaging device.

### Claim 7 (depends on 6)

A hydraulic controlling apparatus according to claim 6, wherein the normal failure switching valve in the normal side position thereof allows the output hydraulic pressure from the first solenoid pressure regulation valve to be supplied to the first hydraulic type frictionally engaging device, from the second solenoid pressure regulation valve to be supplied to the second hydraulic type frictionally engaging device, and from the third solenoid pressure regulation valve to be supplied to the third hydraulic type frictionally engaging device, and in the failure side position thereof allows the hydraulic pressure for forward running from the fail-safe gear step switching valve to be supplied to the first hydraulic type frictionally engaging device or second hydraulic type frictionally engaging device, and the base pressure or the hydraulic pressure for forward running to be supplied to the third hydraulic type frictionally engaging device.

### Claim 8 (depends on 7)

A hydraulic controlling apparatus according to claim 7, wherein the first solenoid pressure regulation valve, second solenoid pressure regulation valve and third solenoid pressure regulation valve are normally-closed type pressure regulation solenoid valves.

### Claim 9 (depends on 8)

A hydraulic controlling apparatus according to claim 8, wherein the base pressure is a pressure-regulated value regulated by the pressure regulated valve.

### Claim 10 (depends on 1)

A hydraulic controlling apparatus according to claim 1, further comprising a second solenoid valve device, that, when the second solenoid valve is in a normal state, supplies a predetermined control pressure to a normal/failure switching valve.

### Claim 11 (depends on 10)

A hydraulic controlling apparatus according to claim 10, wherein the second solenoid valve device is independently controlled by an electronic controlling apparatus.

### Claim 12 (depends on 10)

A hydraulic controlling apparatus according to claim 10, wherein the predetermined control pressure is less than a modulate hydraulic pressure.

### Claim 13 (depends on 12)

A hydraulic controlling apparatus according to claim 12, wherein the predetermined control pressure is in a range from 0 to 80% of the modulate hydraulic pressure upon the normal state.