WO2013110526A1 - Hydraulic arrangement - Google Patents

Description

 hydraulic arrangement

The invention relates to a hydraulic arrangement for hydraulically actuating a multiple clutch, which comprises at least one first / second clutch, which is actuated via a first / second operating pressure generated by a first / second hydraulic pump, which is driven by a first / second electric motor, and is transmitted to a first / second hydraulic actuator via a first / second actuating leak site.

The object of the invention is to simplify or improve the operation of multiple clutches.

The object is achieved by a hydraulic arrangement for hydraulically actuating a multiple clutch, which comprises at least one first / second clutch, which is actuated via a first / second actuating pressure, which is driven by a first / second hydraulic pump, which is driven by a first / second electric motor generated and is transmitted via a first / second actuating leakage point to a first / second hydraulic actuator, wherein the hydraulic pumps have reversible conveying directions. The term reversible conveying directions means that the hydraulic pumps each have a conveying direction to the respective actuating device and a further conveying direction away from the respective actuating device. The hydraulic pumps can thus promote in opposite directions. The hydraulic pumps are preferably designed as positive displacement pumps, in particular as gear pumps, for example gerotor pumps. The reversible conveying directions of the hydraulic pumps can be achieved in such a positive displacement in a simple manner, for example, by reversing the driving direction of rotation. When the hydraulic pumps deliver hydraulic fluid to the respective actuator, the pressure in a hydraulic actuator path that opens into the respective actuator increases. The actuators are designed, for example, as a clutch slave cylinder, in which a clutch slave piston is acted upon by the pressure provided by the respective hydraulic pump. If the pressure is sufficient to move the clutch slave piston in motion, then the pressure of the hydraulic fluid may be referred to as the actuation pressure. By the movement of the clutch slave piston, the clutch is actuated, that is open or closed. The current pressure is, for example, before the first / second actuation leakage point, preferably detected by a first / second pressure sensor. The recorded pressure values are used to control the electric motors, which in turn drive the hydraulic pumps. Due to the reversible conveying directions, deactivating the clutches is considerably simplified. When the hydraulic pumps deliver in the opposite flow directions, the actuation pressure can be actively released quickly. This allows the hydraulic pumps downstream additional leakage points are minimized. Such additional leakage points preferably comprise a hydraulic resistance, such as a throttle or orifice, via which or the hydraulic medium, for example, into a hydraulic medium tank, can be discharged. The actuating leaks are preferably designed as leaking rotary unions.

A preferred embodiment of the hydraulic system is characterized in that the hydraulic pumps are actively switchable from a conveying direction in an opposite conveying direction. The reversal or reversal of the conveying direction can be achieved in a simple manner by reversing the direction of rotation of the electric motors which drive the hydraulic pumps.

The above-stated object is alternatively or additionally achieved by a hydraulic arrangement for hydraulically actuating a multiple clutch comprising at least one first / second clutch actuated by a first / second operating pressure supplied by a first / second hydraulic pump driven by a first / second second electric motor is driven, generated and transmitted via a first / second actuating leakage point to a first / second hydraulic actuator, wherein the first / second hydraulic pump, a first / second additional leakage point is connected downstream of a leakage valve. The additional leakage point allows or simplifies the Einregeln a defined pressure. Through the leakage valve, the additional leakage point can be minimized. The additional leakage point includes, for example, a hydraulic resistance such as a shutter or a throttle.

A further preferred embodiment of the hydraulic system is characterized in that the leakage valve is designed as a 2/2-way valve with a leakage position and a closed position. In the leakage position, a minimum leakage is discharged via the 2/2-way valve. In the closed position of the leakage valve, no leakage is removed. As a result, unwanted losses, especially for constant trips, for example on the highway, can be minimized. A further preferred embodiment of the hydraulic system is characterized in that the leakage valve is designed as a 2/2-way valve with a leakage position and a deactivation position. In the leakage position, for example, a leakage required for the safe regulation of a defined pressure is discharged via the leakage valve. In the deactivation position, the leakage valve provides a significantly larger leakage cross section than in the leakage position. This allows a quick deactivation of the clutch via the leakage valve. Thus, the deactivation times of the clutches can be reduced, in particular without the hydraulic pumps having reversible conveying directions.

According to a further embodiment, the functions described in the two preceding sections can also be combined in the leakage valve. Such a combined leakage valve would thus have a leakage position, a closed position and a deactivation position and corresponding connections. This could reduce both losses and deactivation times.

A further preferred embodiment of the hydraulic arrangement is characterized in that the leakage valve is designed as a rheological valve and is operated with a rheological fluid. If the rheological fluid is activated, then the additional leakage location is minimized or absent. If the rheological fluid is not activated, the fluid can flow off quickly via the additional leakage point, without the conveying direction of the respective hydraulic pump having to be reversed or reversed. It may be advantageous to separate the hydraulic actuating sections of the hydraulic cooling section, since rheological fluids are only partially used as a coolant. Furthermore, it may be advantageous to dispense with the actuating leaks and to use so-called Zentralein- or Zentralausrücker to simplify the separation of the rheological fluid of the cooling medium. Particularly advantageous the Theological valves are used in hydraulic arrangements with dry clutches, since they do not need a cooling medium for cooling.

The above-stated object is alternatively or additionally achieved by a hydraulic arrangement for hydraulically actuating a multiple clutch comprising at least one first / second clutch actuated by a first / second operating pressure supplied by a first / second hydraulic pump driven by a first / second second electric motor is driven, generated and a first / second actuating leakage point to a first / second hydraulic actuator is transmitted, wherein the first / second clutch normally closed and the second / first clutch is normally open. The normally closed clutch can be used particularly advantageous for constant driving, that is for driving at a constant speed, for example on the highway. The normally closed clutch is biased by a cup spring device into its closed position, for example. This provides the advantage that no clutch operation is required to close the clutch. As a result, the losses during operation of the hydraulic system can be further reduced.

The above-stated object is alternatively or additionally achieved by a hydraulic arrangement for hydraulically actuating a multiple clutch comprising at least one first / second clutch actuated by a first / second operating pressure supplied by a first / second hydraulic pump driven by a first / second second electric motor is driven, generated and transmitted via a first / second actuating leakage point to a first / second hydraulic actuator, wherein for cooling the clutches a hydraulic cooling path is provided with a suction-side limitation of the maximum amount of cooling medium. This provides the advantage that at high speeds of the internal combustion engine, which is used to drive the cooling medium pump, not unnecessarily much cooling medium is fed into the clutches.

A further preferred embodiment of the hydraulic system is characterized in that a hydraulic medium mechanically driven by an internal combustion engine, a hydraulic resistance is connected upstream, which limits the amount of cooling medium on a suction side of the cooling medium pump. The cooling medium pump is designed, for example, as a displacement pump, in particular a gear pump. The hydraulic resistor includes, for example, a throttle or orifice, which limits the maximum possible cooling medium flow on the suction side of the cooling medium pump. As a result, the losses during operation of the hydraulic system can be further reduced.

Another preferred embodiment of the hydraulic system is characterized in that the multiple clutch is designed as a wet-running double clutch. In the execution of the hydraulic arrangement with rheological valves, however, the clutches are advantageously designed as dry clutches, since no cooling oil function is necessary in these. Accordingly, in the embodiment with the rheological valves preferably also no hydraulic cooling path is provided. Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawing, various embodiments are described in detail. Show it:

1 shows a hydraulic circuit diagram of a hydraulic arrangement according to a first embodiment with reversible hydraulic pumps and a suction-side limitation of a maximum amount of cooling medium;

Figure 2 shows a similar embodiment as in Figure 1 with leakage valves to illustrate an additional leakage point;

Figure 3 shows a similar embodiment as in Figure 2 with a normally open and a normally closed coupling;

Figure 4 shows a similar embodiment as in Figure 2, wherein the leakage valves are designed as rheological valves and

Figure 5 shows a similar embodiment as in Figure 4 without cooling function.

FIGS. 1 to 5 show different exemplary embodiments of hydraulic arrangements for the hydraulic actuation of double clutches in the form of hydraulic circuit diagrams. To designate the same parts, the same reference numerals are used.

All hydraulic systems shown each comprise a first hydraulic actuating section 1 and a second hydraulic actuating section 2. The hydraulic arrangements illustrated in FIGS. 1 to 4 additionally comprise a hydraulic cooling section 4. The hydraulic arrangement illustrated in FIG. 5 does not comprise a hydraulic cooling section.

A hydraulic medium required for operating the hydraulic system is provided in a hydraulic medium reservoir 6. In the hydraulic medium is in the hydraulic arrangements shown in Figures 1 to 3 to today usual hydraulic oil / gear oil. In the hydraulic arrangements illustrated in FIGS. 4 and 5, the hydraulic actuating sections 1 and 2 are operated with a rheological fluid. The hydraulic medium passes through a suction filter 8 in the hydraulic operating sections 1, 2 and the hydraulic cooling section 4. The first hydraulic actuating path 1 comprises a first clutch 1 1, which is actuated via a first actuating pressure 12. The first actuating pressure 12 is generated by means of a first hydraulic pump 13, which is driven by a first electric motor 14.

The hydraulic medium delivered by the first hydraulic pump 13 is supplied to a first hydraulic actuating device 16 via a first actuating leakage point 15. The first hydraulic pump 13 is followed by a first additional leakage point 17. The first additional leakage point 17 is connected between the first hydraulic pump 13 and a first pressure sensor 18. The first pressure sensor 18 is connected upstream of the first actuating leak point 15 and serves to detect the current pressure which is provided by means of the first hydraulic pump 13.

The second hydraulic actuating path 2 comprises a second clutch 21, which is actuated via a second actuating pressure 22. The second actuating pressure 22 is generated by means of a second hydraulic pump 23, which is driven by a second electric motor 24.

The hydraulic medium delivered by the second hydraulic pump 23 is supplied via a second actuating leakage point 25 to a second hydraulic actuating device 26. The second hydraulic pump 23 is followed by a second additional leakage point 27. The second additional leakage point 27 is connected between the second hydraulic pump 23 and a second pressure sensor 28. The second pressure sensor 28 is connected upstream of the second actuating leak point 25 and serves to detect the current pressure which is provided by means of the second hydraulic pump 23.

Depending on the pressure sensor 18; 28 of the respective hydraulic actuating path 1; 2 detected actual pressure values is set for the desired clutch state required target pressure, in particular controlled or regulated. The operation leakage point 15; 25 is designed as a leaking rotary feedthrough. The additional leakage point 17; For example, Fig. 27 includes an orifice in the direction of tank pressure.

The hydraulic cooling section 4 comprises a mechanically driven by an internal combustion engine 30 cooling medium pump 32. The cooling medium pump 32 is a cooling medium valve 34th downstream. The cooling medium valve 34, in turn, a cooling medium leakage point 35 is connected downstream, which is represented for example by the same rotary feedthrough as the actuating leakage point 15; 25. Arrows 38 and 39 indicate that the cooling medium supplied via the hydraulic cooling section 4, the clutches 1 1; 21 is supplied. The cooling medium is, for example, cooling oil.

According to one aspect of the invention, the maximum amount of cooling medium that can be supplied via the hydraulic cooling section 4 is limited on the suction side of the cooling medium pump 32. For this purpose, a hydraulic resistor 40 in the form of a throttle or a diaphragm between the suction filter 8 and the input of the cooling medium pump 32 is connected. By the hydraulic resistance 40, the maximum cooling medium volume flow is limited by the hydraulic cooling section 4.

In the embodiment shown in Figure 1, the hydraulic pumps 13; 23 in the hydraulic actuating sections 1; 2 actively reversible executed. This means that the hydraulic pumps 13; 23 have two flow directions or flow directions. The two conveying directions are in the pump symbols of the hydraulic pumps 13; 23 indicated by two arrowheads.

The reversible hydraulic pumps 13; 23 in Figure 1 provide the advantage that the clutches 1 1; 21 via the hydraulic pumps 13; 23 can be disabled. Disabling the clutches 1 1; 21 then does not need the additional leaks 17; 27 to take place. As a result, the additional leaks 17; 27, which include, for example, a by-pass aperture, can be minimized. The additional leaks 17; 27 serve in the embodiment shown in Figure 1 only to safe Einregelung a defined pressure in the hydraulic actuating sections 1; Second

In the embodiment shown in Figure 2, the hydraulic pumps 13; 23 only one direction of flow or conveying direction. When or to disable the clutches 1 1; 21 becomes hydraulic medium from the hydraulic operating sections 1; 2 via additional leaks 57; 67 discharged into the hydraulic medium reservoir 6.

According to another aspect of the invention, the additional leaks 57; 67 with a leakage valve 58; 68 equipped. The leakage valves 58; 68 are designed as 2/2-way valves with a closed position and an open position. Springs are the return valves 58; 68 biased in its illustrated closed position. If necessary, the leakage valves 58; 68 switched to its open position to hydraulic medium from the hydraulic actuating links 1; 2 to dissipate into the hydraulic medium reservoir 6.

The leakage valve 58; 68 may also have an aperture function instead of its closed position. Thus, instead of a closed position and an open position, such a leakage valve has two different open positions, in which differently sized cross-sections are made available to the hydraulic medium reservoir 6. A smaller or smaller average cross-section is used for safe regulation of a defined pressure in the hydraulic actuating path 1; 2. A larger or larger passage cross-section to the hydraulic medium reservoir 6 is used to deactivate the respective clutch 1 1; 21st

In the embodiments shown in Figures 1, 2 and 4, 5, the clutches are 1 1; Both are normally open. An open clutch does not transmit torque. This means that the normally open clutch must also be permanently activated for constant travel, ie driving at constant speed, for example on the motorway. For intentionally or accidentally leaking systems, this means that a permanent supply of energy is needed to keep the normally open clutch closed.

In the embodiment shown in Figure 3, the first clutch 1 1 is normally closed and the second clutch 21 normally open. Constant travel described above can be advantageously covered in a partial transmission with the normally closed first clutch 1 1, without energy for the clutch operation is required. The normally closed clutch 1 1 is biased by a spring means in its closed position.

In the embodiment shown in Figure 4, the additional leakage point 57 comprises; 67, a leakage valve 59; 69, which is designed as a rheological valve. The rheological valves 59; 69 serve to bypass the leakage over the additional leaks 57; 67 to adjust as needed. For this purpose, the hydraulic medium reservoir 6 contains a rheological fluid. If the rheological fluid is activated, then the bypass leak is at the additional leaks 57; 67 small or not available. If the rheological fluid is not activated, the fluid from the hydraulic actuating sections 1; 2 via the additional leakage point 57; 67 with the leakage valve 59; 69 drain quickly without the respective hydraulic pump 13; 23 has to reverse.

The hydraulic cooling section 4 can be operated with the theological fluid. However, it may be advantageous for the hydraulic cooling section 4 of the hydraulic actuating sections 1; 2, since rheological fluids are only partially usable as a cooling medium.

FIG. 5 shows an exemplary embodiment with rheological leakage valves 59; 69 shown without hydraulic cooling line. In this embodiment, the clutches are 1 1; 21 advantageously designed as dry clutches, since they do not require fluid cooling.

Reference numeral list first hydraulic actuation range

second hydraulic actuating section hydraulic cooling section

Hydraulic fluid reservoir

Suction

first clutch

first actuation pressure

first hydraulic pump

first electric motor

first job leakage point

first hydraulic actuator first additional leakage point

first pressure sensor

second clutch

second actuation pressure

second hydraulic pump

second electric motor

second actuation leak site

second hydraulic actuator second additional leakage point

second pressure sensor

Internal combustion engine

Coolant pump

Coolant valve

Coolant leakage point

arrow

arrow

hydraulic resistance

first additional leakage point

leakage valve

leakage valve

second additional leakage point

leakage valve

leakage valve

Claims

claims 1 . Hydraulic arrangement for hydraulically actuating a multiple clutch comprising at least one first / second clutch (1 1/21) actuated by a first / second actuating pressure (12/22) supplied by a first / second hydraulic pump (13/23), which is driven by a first / second electric motor (14/24) is generated and transmitted via a first / second actuating leakage point (15/25) to a first / second hydraulic actuator (16/26), wherein the hydraulic pumps (13/23 ) have reversible conveying directions. 2. Hydraulic arrangement according to claim 1, characterized in that the hydraulic pumps (13/23) are actively switchable from a conveying direction in an opposite conveying direction. A hydraulic arrangement for hydraulically actuating a multiple clutch comprising at least one first / second clutch (1 1/21) actuated by a first / second actuating pressure (12/22) provided by a first / second hydraulic pump (13/23) ), which is driven by a first / second electric motor (14/24) is generated and transmitted via a first / second actuating leakage point (15/25) to a first / second hydraulic actuator (16/26), in particular according to claim 1 or 2, wherein the first / second hydraulic pump (13/23), a first / second additional leakage point (57/67) with a leakage valve (58/68), 59/69) is connected downstream. 4. Hydraulic arrangement according to claim 3, characterized in that the leakage valve (58/68) is designed as a 2/2-way valve with a leakage position and a closed position. 5. Hydraulic arrangement according to claim 3, characterized in that the leakage valve (58/68) is designed as a 2/2-way valve with a leakage position and a deactivation position. 6. Hydraulic arrangement according to claim 3, characterized in that the leakage valve (59/69) is designed as a rheological valve and is operated with a rheological fluid. A hydraulic arrangement for hydraulically actuating a multiple clutch comprising at least one first / second clutch (1 1/21) actuated by a first / second actuating pressure (12/22) supplied by a first / second hydraulic pump (13/23) ) which is driven by a first / second electric motor (14/24) is generated and transmitted via a first / second actuating leakage point (15/25) to a first / second hydraulic actuator (16/26), in particular according to one of the claims 1 to 6, wherein the first / second clutch (1 1/21) normally closed and the second / first clutch (21/1 1) is normally open. A hydraulic arrangement for hydraulically actuating a multiple clutch comprising at least one first / second clutch (1 1/21) actuated by a first / second actuating pressure (12/22) provided by a first / second hydraulic pump (13/23) ) which is driven by a first / second electric motor (14/24) is generated and transmitted via a first / second actuating leakage point (15/25) to a first / second hydraulic actuator (16/26), in particular according to one of the claims 1 to 7, wherein for cooling the clutches (1 1/21) a hydraulic cooling section (4) is provided with a suction-side limitation of the maximum amount of cooling medium. 9. Hydraulic arrangement according to claim 8, characterized in that a mechanically driven by an internal combustion engine cooling medium pump (32) is preceded by a hydraulic resistance (40) which limits the amount of cooling medium on a suction side of the cooling medium pump (32). 10. Hydraulic arrangement according to one of the preceding claims, characterized in that the multiple clutch is designed as a wet-running double clutch.