WO2018077330A1

WO2018077330A1 - Hydraulic system having pressure sensor and valve

Info

Publication number: WO2018077330A1
Application number: PCT/DE2017/100830
Authority: WO
Inventors: André PALMEN; Roshan Willeke
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2016-10-27
Filing date: 2017-09-28
Publication date: 2018-05-03

Abstract

The invention relates to a hydraulic system (1) for clutch and/or transmission actuation, comprising a reversible pump (2) and two main lines (3, 4), wherein the pump (2) can be connected to a first consumer (7) at a first pump connection (5) by means of a first main line (3) and can be connected to a second consumer (8) at a second pump connection (6) by means of a second main line (4), as well as comprising a pressure sensor (9) which can be connected optionally with one of the main lines (3, 4) or which is permanently connected to both main lines (3, 4) in order to determine a working pressure in the respective main line (3, 4), wherein a first valve (13) is provided, having two control connections (10, 11) and an outlet (12), which is designed in such a way that the outlet (12) that is/can be coupled to a storage means (14) is connected to one of the control connections (10, 11), each connected to one of the main lines (3, 4), depending on a position of the first valve (13). The invention also relates to a clutch and a transmission having a hydraulic system (1).

Description

Hvdrauliksvstem with pressure sensor and valve

The invention relates to a hydraulic system for a clutch and / or Getriebebetä- tion, with a reversible pump, i. a reversing pump, and two main lines, the pump being connected or connectable at its first pump connection by means of a first main line to a first consumer and at a second pump connection by means of a second main line to a second consumer, and to a pressure sensor, the to determine a working pressure in the respective main line alternately connected to one of the main lines or permanently connected to the two main lines. The hydraulic system can be used, for example, to actuate a clutch or to adjust the gear in a transmission, so that furthermore a coupling and a transmission with this hydraulic system are affected by the invention.

Generic prior art is already well known. The

DE 1 1 2005 000 814 B4 discloses a hydraulic system for the control of two clutches of a transmission, wherein each of the two clutches has a slave cylinder and the hydraulic fluid from a controllable pump unit from a reservoir via a first pressure line to the first slave cylinder and via a second pressure line the second slave cylinder is provided.

Further prior art is known from DE 103 44 648 A1, the

DE 10 2006 061 516 A1 and DE 10 201 1 102 277 A1.

However, it has proved to be disadvantageous in the known hydraulic systems that they are often relatively complex and cost-intensive. This is due, in particular, to the fact that a plurality of pressure sensors are integrated in the hydraulic systems and, at the same time or alternatively, a multiplicity of different valves, which are relatively expensive per se. The structure of the individual hydraulic systems is thereby relatively complex. It is therefore the object of the present invention to remedy these known from the prior art disadvantages and in particular to provide a hydraulic system available, by which the manufacturing cost to be further reduced. This is inventively achieved in that a two control terminals and an output exhibiting first valve is provided, which is designed so that the memory with a memory (such as a tank) coupled or coupled output in response to a position of the first valve with one of the control terminals, each connected to one of the main lines is connected.

Through this combined use of the first valve together with the pressure sensor, a significantly simplified hydraulic system is implemented. The pressure sensor can be used both for measuring the working pressure in the first main line and in the second main line. The structure of the system is thereby significantly simplified.

Further advantageous embodiments are claimed in the subclaims and explained in more detail below. If the pressure sensor for alternating hydraulic pressure detection is coupled to the two main lines by means of a second valve, the working pressure in one of the main lines can be detected independently of the pressure in the other main line. As a result, a particularly precise detection of the working pressure is performed. In this regard, it is also advantageous if the second valve is designed as a change-over valve / or valve. As a result, the valve is constructed particularly effectively, wherein it ensures the connection of the pressure sensor to the first main line in a first position and the connection of the pressure sensor to the second main line in a second position.

As an alternative to the formation of the alternating hydraulic pressure sensing, it is also advantageous if the pressure sensor is designed as a differential pressure sensor having two measuring ports, a first measuring port being connected to the first Main line (permanent) and a second measuring connection with the second main line (permanently) connected / connected to this. As a result, in particular the shuttle valve can in turn be saved and the structure of the hydraulic system can be further simplified.

If the first valve is designed as a two-pressure valve, its construction is particularly effective.

In addition, it is advantageous if the pump is driven by a reversible / reversible drive device (preferably designed as an electric motor) in its direction of rotation. This makes a particularly powerful pump drive available.

Furthermore, it is expedient with respect to the pump, if it is equipped with a speed and / or direction of rotation detection device. This makes it possible to deduce the speed and the direction of rotation of the pump in a direct way.

In this regard, it is also advantageous if a control unit is present, which is so coupled to the speed and / or direction of rotation detection device and the pressure sensor that the working pressure in the respective main line by referencing the measurement signal of the pressure sensor on the detected speed and / or Direction of rotation of the speed and / or Drehrichtungserfassungseinrich- tion is done. This further simplifies the measurement setup.

Furthermore, the invention relates to a clutch and a transmission for a drive train of a motor vehicle, such as a car, truck, bus, other commercial vehicle or motorcycle, with a hydraulic system according to at least one of the previously described embodiments having actuator.

In other words, according to the invention, a hydraulic system with two pressure valves and a pressure sensor, such as differential pressure sensor, can be implemented. So far, a pressure signal is used to control and regulate a working pressure to return the actual value in the control loop, wherein the pressure is usually detected by a pressure sensor. To reduce manufacturing costs is the Number of used pressure sensors reduced. The hydraulic system according to the invention in this case has a reversing pump and a two-pressure valve (first valve) for controlling at least two consumers, in which pressure signals are detected and processed for the control or regulation of the working pressure. On the one hand, it is therefore proposed to use a sensor (pressure sensor) which is connected via an OR valve to the two connections of the reversing pump. The two connections (pump connections) in combination with the two-pressure valve serve both as pressure-carrying working connections to the consumer. On the other hand, a solution variant is presented, which consists in the use of a differential pressure sensor, wherein the differential pressure sensor is connected to the two terminals of the reversing pump. In both embodiments, a working pressure for both consumers is determined by the evaluation of a pressure signal and the speed signal of the pump preferably. The invention will now be explained in more detail with reference to figures, in which context also different embodiments are shown.

1 shows a schematic circuit diagram of a hydraulic system according to the invention according to a first exemplary embodiment, wherein two main lines connecting a reversing pump to a load are coupled to a pressure sensor by means of a shuttle valve (first valve), and FIG. 2 is a schematic circuit diagram of a hydraulic system according to the invention according to a second embodiment, wherein a differential pressure sensor is used for the pressure sensor and the shuttle valve.

The figures are merely schematic in nature and serve only to understand the invention. The same elements are provided with the same reference numerals. Also, the different features of the various embodiments can be combined freely with each other. 1 shows a first embodiment of the hydraulic system 1 according to the invention. The hydraulic system 1 is coupled to two consumers 7 and 8 shown here only schematically. The consumers 7 and 8 are also alternative, according to further embodiments, an integral part of the hydraulic system. 1 Consumers 7 and 8 form here together with hydraulic system 1 an actuating device 20. The consumer 7 and 8 are each designed as an actuator, preferably as a clutch actuator and / or gear actuator. As a clutch actuators serve the consumers 7 and 8 / is the actuator 20 for actuating a clutch, as a transmission actuators for actuating a transmission in a drive train of a motor vehicle.

The hydraulic system 1 has a pump 2. The pump 2 is called a reversing pump, i. as a reversible pump 2, executed. The pump 2 is coupled to an electric drive device / an electric motor which is reversible / reversible in its direction of rotation. The pump 2 has two connections, which are identified as pump connections 5 and 6. A first pump connection 5 is coupled to a first main line 3, which in turn is hydraulically connected to the first consumer 7. A second pump connection 6 is in turn hydraulically connected to the second consumer 8 by means of a second main line 4. Depending on the driving direction of rotation of the drive device 18 / the pump 2, hydraulic fluid is accordingly pumped from the first main line 3 into the second main line 4 or from the second main line 4 into the first main line 3 in order to move in the main line 3, 4 into which the Hydraulic fluid is pumped to produce a working pressure and the respective consumer 7, 8 supply / actuate. To nachzuliefern any replenished hydraulic fluid or due to excess hydraulic fluid, the two main lines 3 and 4 are further connected by a first valve 13 via a secondary line 19 to a memory 14.

The first valve 13 is configured as a two-pressure valve, wherein each one control terminal 10 or 1 1 of the first valve 13 with the first main line 3 and the second

Main line 4 is coupled. The first control connection 10 is connected to the first main line 3 and the second control connection 1 1 is connected to the second main line 3. device 4 connected. An input / output 12 of the first valve 13 is connected to the secondary line 19 and thereby leads to the memory 14th

The first valve 13 is further designed such that the input / output 12 coupled to the memory 14 is connected to one of the control terminals 10, 11 as a function of a position of the first valve 13. In particular, in turn, in a first position of the first valve 13, the first main line 3 is hydraulically connected to the memory 14 via the first control port 10, at the same time the second main line 4 is separated from the memory 14. In a second position of the first valve 13, the first main line 3 is separated from the memory 14 and the first valve 13 connects the second main line 4 by means of the second control terminal 1 1 with the memory 14th

For detecting a pressure / working pressure in the first main line 3 or in the second main line 4, a pressure sensor 9 is coupled by means of a second valve 15. This second valve 15 is designed as a shuttle valve. In the illustration of FIG. 1, the second valve 15 is connected in a first position such that the pressure sensor 9 is connected to the first main line 3 and at the same time separated from the second main line 4. As a result, the pressure sensor 9 detects a working pressure in the first main line 3 in this first position

For clarity, not shown second position of the second valve 15 is then in turn the first main line 3 separated from the pressure sensor 9 and the pressure sensor 9 to the second main line 9 hydraulically connected to detect a working pressure in the second main line 4.

Furthermore, it should be pointed out that there is typically a rotational speed and / or rotational direction detecting device, not shown here for clarity, which is, for example, a direct component of the pump 2 and detects the rotational speed or direction of rotation of the pump 2.

Also, a control unit is present, which is again not shown here for clarity, but also electrically connected to the pressure sensor 9 and the speed and / or direction of rotation detection device. In conjunction with FIG. 2, a second preferred embodiment can be seen, which second embodiment is constructed in principle according to the first embodiment and is functioning. For the sake of brevity, therefore, only the differences between the two exemplary embodiments will be discussed.

As can be seen in FIG. 2, the pressure sensor 9 in the second embodiment for hydraulic pressure detection in the main lines 3, 4 is no longer coupled to the two main lines 3 and 4 by means of a second valve 15, but directly to the two main lines 3 and 4 4 coupled. The pressure sensor 9 is designed as a differential pressure sensor. A first measuring connection 16 of the pressure sensor 9 is connected to the first main line 3, whereas a second measuring connection 17 of the pressure sensor 9 is connected to the second main line 4. The pressure sensor 9 is thus designed for the simultaneous detection of a working pressure in the first main line 3 and a working pressure in the second main line 4, which he forwards metrologically in the form of a differential pressure.

In particular, the differential pressure detected by the pressure sensor 9 is forwarded to a control unit and compared during operation with a speed or rotation value detected by the speed and / or rotation detection means such that the working pressure in the respective main line 3 and 4 is clearly detected / assigned. Taking into account the speed and / or direction of rotation of the pump 2 is therefore clearly detected, which working pressure in which main line 3, 4 is present.

In other words, according to the invention on the one hand the use of a sensor (pressure sensor 9), which is connected via an OR valve (second valve 15 / shuttle valve) to the two ports 5, 6 of the reversing 2, in combination with a two-pressure valve (first valve 13) both can be used as pressure-carrying working connections (main lines 3, 4) to the consumer 7, 8. The connection of the reversing pump 2, which does not serve as a working line but as a suction connection, is connected to the tank 14 via the first valve 13, such as a two-pressure valve. The detection of a pressure signal as working pressure follows the evaluation of the speed signal with consideration of the sign of the speed and the pressure signal with consideration of the sign of the pressure gradient. On the other hand, there is a further solution variant in the use of a differential pressure sensor (pressure sensor 9), which is connected to the two terminals 5, 6 of the Rever- sierpumpe 2. Again, the combination with a two-pressure valve 13 or a comparatively working valve circuit, both ports 5, 6 of the pump 2 to operate as a pressurized working connections. In both embodiments, by evaluating the one pressure signal and the speed signal of the pump 2, a working pressure for both consumers 7, 8 can be determined. In the second variant according to FIG. 2, the OR valve 15 is thus eliminated. The detection of the pressure signal as working pressure also takes place here through the evaluation and processing of the rotational speed signal and the change of the pressure signal. In this variant, it must be ensured by the valves 13 that a known pressure, such as, for example, the tank pressure (pressure in the reservoir 14) or the ambient pressure, is set at the suction connection of the pump 2 within the scope of the determination accuracy.

The presented detection of the working pressure of two consumers 7, 8 with a single sensor 9 is preferably used in hydraulic systems for clutch and gear actuator actuation.

List of Reference Numerals Hydraulic system

pump

first main line

second main line

first pump connection

second pump connection

first consumer

second consumer

pressure sensor

first control connection

second control connection

An exit

first valve

Storage

second valve

first measuring connection

second measuring connection

driving means

secondary line

actuator

Claims

claims

1 . Hydraulic system (1) for a clutch and / or transmission operation, comprising a reversible pump (2) and two main lines (3, 4), the pump (2) being connected to a first pump connection (5) by means of a first main line (3) a first consumer (7) and at a second pump connection (6) by means of a second main line (4) with a second consumer (8) is connectable, and with a pressure sensor (9) for determining a working pressure in the respective main line (3 4) is connectable to one of the main lines (3, 4) connectable or permanently connected to two main lines (3, 4), characterized in that a two control terminals (10, 1 1) and an outlet (12) exhibiting first valve ( 13) is provided, which is formed so that with a memory (14) coupled or coupled output (12) in response to a position of the first valve (13) with one of the control terminals (10, 1 1), each to a the main guide are connected (3, 4) connected.

2. Hydraulic system (1) according to claim 1, characterized in that the

Pressure sensor (9) for alternate hydraulic pressure detection by means of a second valve (15) is coupled to the two main lines.

3. Hydraulic system (1) according to claim 2, characterized in that the second valve (15) is designed as a shuttle valve.

4. Hydraulic system (1) according to claim 1, characterized in that the

Pressure sensor (9) as a two measuring connections (16, 17) exhibiting differential pressure sensor is formed, wherein a first measuring port (16) to the first main line (3) and a second measuring port (17) to the second main line (4) is connected.

5. Hydraulic system (1) according to one of claims 1 to 4, characterized in that the first valve (13) is designed as a two-pressure valve.

6. Hydraulic system (1) according to one of claims 1 to 5, characterized in that the pump (2) is driven by a reversible in its direction of rotation drive means (18).

7. Hydraulic system (1) according to one of claims 1 to 6, characterized in that the pump (2) is equipped with a speed and / or Drehrichtungser- detection device.

8. Hydraulic system (1) according to claim 7, characterized in that a control unit is present, which is coupled in such a way with the rotational speed and / or rotational direction detection device and the pressure sensor (9) that the working pressure in the respective main line (3, 4) by referencing the measurement signal of the pressure sensor (9) to the detected speed and / or rotational direction value of the rotational speed and / or Drehrichtungserfassungseinrich- device.

9. Coupling for a drive train of a motor vehicle, comprising a hydraulic system (1) according to one of claims 1 to 8 having actuating means (20).

10. Transmission for a drive train of a motor vehicle, comprising a hydraulic system (1) according to one of claims 1 to 8 having actuating means (20).