Actuating arrangement for the controlled actuation of a transmission and / or a clutch and drive train with such an actuating arrangement

Abstract

Actuating arrangement for the controlled actuation of a transmission and / or a clutch, comprising at least two piston-cylinder units (26, 28), at least one switching logic (16), at least one first actuator (12), at least one second actuator (14) and a pressure medium supply (18), wherein the piston-cylinder units (26, 28) are hydraulically or hydrostatically connected to each other via the switching logic (16) with the first actuator (12) and the second actuator (14) such that the first actuator (12) and the second actuator (14) actuate at least one of the two piston-cylinder units (26, 28), wherein the first actuator (12) and / or the second actuator (14) is a double-acting actuator.

Description

[0001] The invention relates to an actuating arrangement for the controlled actuation of a transmission and / or a clutch.

[0002] In motor vehicles with automatic transmissions, actuators are required for the transmission function. One actuator is used for clutch actuation. These known solutions always represent a compromise between the individual sub-functions of "engaging the clutch" and "modulating torque." This results in compromises in system costs, dynamics, and energy consumption.

[0003] For example, it is known from DE 10 2010 052 693 A1 to control 4 receivers with exactly one pump actuator.

[0004] The task, therefore, is to provide an actuation arrangement with good properties and good dynamics.

[0005] The problem is solved according to the invention by an actuating arrangement having the features of claim 1. Preferred embodiments of the invention are specified in dependent claims 2 to 9, each of which can individually or in combination represent an aspect of the invention.

[0006] The invention relates to an actuating arrangement for the controlled actuation of a transmission and / or a clutch, in particular in the drive train of a motor vehicle, comprising at least two piston-cylinder units, at least one switching logic, at least one first actuator, at least one second actuator and a pressure medium supply, wherein the piston-cylinder units are hydraulically or hydrostatically connected to each other via the switching logic with the first actuator and the second actuator in such a way that the first actuator and the second actuator actuate at least one of the two piston-cylinder units, wherein the first actuator and / or the second actuator is a double-acting actuator.

[0007] By using a double-acting actuator, double utilization of the actuator's power is possible. For example, the coupling is a double coupling, and the double-acting actuator can be mounted in such a way that it comes into direct contact with the piston-cylinder units and, in particular, connects the two piston-cylinder units to each other.

[0008] The term "dual clutch" describes a load-shifting clutch unit consisting of two sub-clutches, usually arranged coaxially. These sub-clutches can be located on two drive shafts. For example, one sub-clutch can control the engagement and disengagement of the odd-numbered gears of a transmission, while the second sub-clutch can control the engagement and disengagement of the odd-numbered gears. While the vehicle is driving, one sub-clutch can be engaged, while the transmission actuator can simultaneously pre-select the next gear for the other, open sub-clutch. A gear change can be achieved by simultaneously opening the engaged sub-clutch and engaging the open sub-clutch. The gear change can be initiated, for example, via a hydraulic connection between the first and second actuators.

[0009] The term piston-cylinder unit describes a slave cylinder of a partial clutch or transmission. The piston-cylinder unit transmits pressure to the partial clutch or transmission to actuate it. The first and / or second actuator for each piston-cylinder unit can have its own connection.

[0010] The term "connection logic" describes a valve arrangement with at least one valve. The connection logic can control the connection of the first and second actuators to the piston-cylinder units of the partial couplings and to the respective actuators. In this way, the connection logic allows the first and / or the second actuator to be coupled to the partial coupling(s) or to each other, depending on the function.

[0011] With the aid of a double-acting actuator, different switching positions can be achieved. In particular, overlaps with boost can be enabled and utilized, which would otherwise be impossible. The term "boost" here means that both actuators can be connected to one of the two cylinder-piston units. This allows, for example, a larger total flow rate to be provided, making it easier to adjust the pressure in the actuators to the pressure of the piston-cylinder unit being connected, thus enabling smoother switching of the actuators. Furthermore, especially in a switching / overlap without boost, depending on the switching type, either the open or the closed partial clutch can slip. Therefore, a change in the hydraulic connection of the closed clutch under load may be provided.In this way, an actuation arrangement with good properties and good dynamics is provided.

[0012] Furthermore, the first and second actuators can be designed differently. This allows, for example, a dual-coupling system to eliminate the fixed coupling of each actuator to a sub-coupling with varying requirements. By using different first and second actuators, the power flow of the first and second actuators can be coupled to the sub-coupling(s) independently of their function. This coupling can be achieved through several technical implementations, such as hydraulic or hydrostatic coupling.

[0013] The following describes actuators and consumers with hydraulic or hydrostatic coupling and switching logic, for example, valves of a dual clutch. However, it would be conceivable to use the actuation arrangement for an all-wheel drive disconnect clutch or other clutches.

[0014] The first actuator can be selected based on the main criteria of cost reduction and dynamics. For example, the first actuator can be designed for the rapid engagement of the partial coupling and torque build-up. The second actuator, on the other hand, can be selected based on the criteria of tightness and low holding currents, and, for example, in the case of an active partial coupling, is responsible for torque modulation and holding. In this way, the fixed coupling to the partial coupling can be eliminated, allowing for variable actuator requirements. Instead, the power flow of the actuators can be coupled to the partial coupling(s) depending on the function.

[0015] In a preferred embodiment, the first actuator is a pump actuator and the second actuator is a hydraulic coupling actuator. The first actuator actuates a pump. The pump can be connected to a hydraulic fluid supply. The pump can, for example, be a positive displacement pump or a variable displacement pump. Furthermore, the hydraulic fluid supply can be a reservoir that stores the fluid for the hydraulic or hydrostatic coupling of the first actuator, the second actuator, the switching logic, and the partial couplings. The second actuator is a hydrostatic coupling actuator, abbreviated as HCA in the following. By using a first actuator in the form of a pump actuator and a second actuator in the form of an HCA, the power flow of the actuators can be coupled to the partial coupling(s) in a function-dependent manner.For example, in a coupling, the first actuator can use the pump to quickly engage a partial coupling and enable rapid torque build-up. The HCA (High-Performance Control) can then be used to maintain and finely modulate the coupling torque, whereby the pump can be disconnected from the active partial coupling via the wiring logic. Furthermore, in switching operations, especially at overlaps, the slipping partial coupling can be controlled by the more precisely modulated HCA.

[0016] Preferably, the first actuator and / or the second actuator are arranged between the two piston-cylinder units. This allows for boost overlap with a larger total fluid volume. For example, the first actuator, with its pump, can pump fluid from one piston-cylinder unit to the other with the maximum possible fluid dynamics at any given time. The second actuator, acting as a high-speed actuator (HSA), then controls the partial coupling that needs to move faster due to the non-linear torque characteristic over the engagement stroke of the dual coupling. This enables the second actuator to supply the corresponding partial coupling with the appropriate flow rate. As a result, a slightly larger total flow rate can be provided than with a single actuator.The second actuator can always support the less closed partial coupling, so that before the overlap, the transfer of the closed partial coupling from the second actuator to the first actuator and subsequently a transfer of the now closed partial coupling from the first actuator to the second actuator may be necessary. Furthermore, during the overlap, the second actuator can be switched from one partial coupling to the other.

[0017] In a preferred embodiment, the actuating arrangement includes a gear actuator. This allows the actuating arrangement to drive a gear actuator even while a partial clutch is active. For example, while the active partial clutch is being controlled by the second actuator, the first actuator can be used to supply energy to the gear actuator. To ensure that the first actuator is always connected to the reservoir on the correct side in both operating modes—clutch actuation and gear actuation—a dual-pressure valve can be used. Furthermore, it may be necessary to shut off the first actuator from both the clutch and the second actuator to reliably isolate the flow of fluids to and from the gear from the clutch actuation. Additionally, the position of the dual-pressure valve can be defined before the first actuator is connected to either clutch.

[0018] It is preferred that a fluid volume can be transferred directly from one piston-cylinder unit to the other via the first or second actuator. This reduces the response time of the dual clutch, as the fluid volume can be transferred from one piston-cylinder unit to the other without having to pass through the pressure lines. Preferably, the circuit logic includes a setting that connects all enclosed fluid volumes in the operating arrangement to the hydraulic fluid supply. In particular, this setting can be activated by switching off the vehicle. This avoids problematic pressure situations caused by the thermal expansion of the fluid. This setting may be unnecessary if there is sufficient leakage in the hydraulic circuit.Furthermore, connecting all fluid chambers to the pressure medium supply can cause the two partial couplings of the double coupling to open faster, thus advantageously influencing the functional safety function of the actuating arrangement.

[0019] In a preferred embodiment, the switching logic includes a setting that, when the second actuator switches from one piston-cylinder unit to the other, provides an intermediate position to adjust the pressure between the two piston-cylinder units. This can be achieved, for example, by a sealed valve center position. In this way, pressure surges can be avoided. Otherwise, due to the volume elasticity of the encoder piston, uncontrolled flow rates and thus pressure surges could occur in the corresponding piston-cylinder unit. The pressure changes may not be noticeable in the first actuator because, due to the significantly higher stiffness of the pump, the flow rates generated by switching can be small. If the pressure changes should become noticeable in the first actuator, a sealed valve center position can also be incorporated into the switching logic.

[0020] It is preferred that the wiring logic includes a setting that allows the second actuator to "sniff" (or "sniff"). In particular, during prolonged operation of a partial clutch with the second actuator, for example due to fluid leakage or thermal expansion, the travel of the second actuator may reach its limits, making "sniffing" necessary. The term "sniffing" here describes a pressure equalization process. Sniffing can occur under pressure or without pressure. In pressureless sniffing, the connection to the piston-cylinder unit of the partial clutch can be blocked, allowing the piston-cylinder unit to maintain pressure and position. Simultaneously, the wiring logic can establish a connection between the hydraulic fluid supply and the HCA (High Pressure Assist). This type of pressureless sniffing is particularly feasible if the wiring logic has its own dedicated hydraulic fluid supply line.Furthermore, in the case of highly leaky actuation arrangements, it may be necessary to keep the active partial clutch closed via the first actuator while the second actuator is being sniffed. For such sniffing, however, the circuit logic may require a separate circuit between the first actuator and the active partial clutch. When sniffing under pressure, the first actuator, the second actuator, and the piston-cylinder unit of the active partial clutch can be connected together, and the second actuator can be moved under constant pressure while both actuators are simultaneously actuated.

[0021] Preferably, the second actuator, when arranged between the two piston-cylinder units, comprises a double piston. The double piston can have a piston arranged to be longitudinally displaceable within a cylinder, which divides the cylinder volume into a first and a second space. These spaces can be located on opposite sides of the piston. The first and second spaces can each be connected to the respective piston-cylinder units of the partial couplings via the connection logic. By arranging the two spaces on opposite sides of the piston, pressure can be built up during both the forward and reverse movements, thus significantly increasing the response time, as the piston's retraction process is not wasted.

[0022] The invention is explained below by way of example with reference to the accompanying drawings and preferred embodiments, wherein the features shown below can represent an aspect of the invention, either individually or in combination. The drawings show: Fig. 1. A schematic diagram of an actuation arrangement for a double clutch; Fig. 2. A switching diagram and a legend for the switching diagram for the actuation arrangement according to Fig. 1; Fig. 3 a schematic diagram of the actuation arrangement Fig. 1 in a different representation; Fig. 4 a schematic diagram of a further embodiment of an actuating arrangement; Fig. 5 a schematic representation of a concrete implementation of the operating order Fig. 1 and Fig. 3; Fig. 6 a switching diagram and a legend for the actuation arrangement according to Fig. 5; Fig. 7 a schematic diagram of a further embodiment of an actuating arrangement; Fig. 8 a switching scheme for the operation and the safe state of the actuating arrangement according to the Fig. 7; and Fig. 9 a schematic diagram of a further embodiment of an actuating arrangement with a geared actuator.

[0023] Fig. Figure 1 shows a schematic diagram of an actuating arrangement 10 with a first actuator 12, a second actuator 14, a switching logic unit 16, a hydraulic fluid supply 18, and a double clutch 20. The double clutch 20 has two sub-couplings 22 and 24, each of which is connected to the first actuator 12 and the second actuator 14 via a piston-cylinder unit 26 and 28, respectively, through the switching logic unit 16. The first actuator 12 is a pump actuator with a pump 30, which is depicted as a double-acting pump. This is indicated by the two arrows in the pump 30. The second actuator 14 is depicted as a hydraulic clutch actuator. The first actuator 12, the second actuator 14, the hydraulic fluid supply 18, the switching logic unit 16, and the piston-cylinder units 26 and 28 are connected to each other via a hydraulic connection. This is indicated by the black lines.

[0024] Fig. Figure 2 shows the switching diagram and a legend for the switching diagram for the actuation arrangement according to Fig. 1. The dashed arrows represent the relationships between the switching options.

[0025] For example, the partial clutch 22 is active and is controlled by the more precisely modulated second actuator 14. The inactive or open partial clutch 24 is controlled by the more dynamic, but less precisely controllable, pump 30. This is represented by the switching option drive CI1. If the second partial clutch 24 is active and the first partial clutch is inactive or open, this is represented by the switching option drive CI2. Switching the actuator on the active partial clutch is achieved via the switching option block all. This switching option adapts the pressures in the actuators to the pressures of the piston-cylinder units 26, 28 to be connected, thus enabling a more convenient switching of the actuators for the driver of the vehicle.

[0026] In the illustrated actuation arrangement 10, the second actuator 14 always supports the less closed partial coupling 22, 24. Therefore, before the overlap, the closed partial coupling must be transferred from the first actuator 14 to the pump 30, and subsequently, the now closed partial coupling must be transferred from the pump 30 to the second actuator 14. This is represented by the switching option boost / refill CI1 or boost / refill CI2. During the overlap, the first actuator switches from one partial coupling to the other. This is represented by the switching option boost-intermediate.

[0027] During extended operation of a partial clutch with the second actuator 14 (represented by the switching options drive CI1 and drive CI2), leakage or thermal expansion of the fluid can cause the travel of the second actuator 14 to reach its limits. In this case, the second actuator is designed to "sniff" fluid. This is represented by the switching options refill, boost / refill CI1, and boost / refill CI2. Sniffing can be performed under pressure or without pressure. During pressureless sniffing, the connection to the piston-cylinder unit of the partial clutch is closed, allowing the piston-cylinder unit to maintain its pressure and partial clutch position. Simultaneously, the circuit logic 16 opens a connection between the hydraulic fluid supply 18 and the second actuator 14. This is represented by the switching option refill.In systems with very high leakage, it may be necessary to keep the active partial coupling closed via pump 30 while sniffing at the second actuator 14. This requires separate hydraulic connections, which are not shown.

[0028] During pressure sniffing, the second actuator 14, the pump 30, and the corresponding piston-cylinder unit 26, 28 of the active partial coupling 22, 24 are connected together, and with simultaneous actuation of both actuators 12, 14, the second actuator 14 is moved under constant pressure 14. This is represented by boost / refill CI1 and boost / refill CI2.

[0029] When the vehicle is switched off, all fluid volumes in the actuating assembly 10 are connected to the hydraulic supply to prevent problematic pressure situations caused by the thermal expansion of the fluid. This is represented by the off / safe state switch. This switch may not be necessary if there is sufficient leakage in the hydraulic system. Furthermore, connecting all fluid chambers of the actuating assembly 10 to the hydraulic supply 18 ensures that both partial couplings open quickly. This increases the functional safety of the actuating assembly 10.

[0030] Fig. 3 is a modified representation of operating order 10 from Fig. 1. In Fig. Figure 3 shows the arrangement of the first actuator 12 between the piston-cylinder units 26, 28 more clearly. Fig. 3 have the ones with the actuating device 10 of the Fig. 1. Comparable components have the same reference numerals.

[0031] Fig. Figure 4 shows a further embodiment of an actuating arrangement 32. Fig. 4 have the ones with the actuating device 10 of the Fig. 1. Comparable components have the same reference numerals. In this embodiment, the second actuator 14 has a double piston 34. In this embodiment, the second actuator 14 is arranged between the piston-cylinder units 26, 28 of the partial couplings 22, 24, instead of the first actuator 12. The pump 36 of the first actuator 12 is installed in a longitudinal arrangement. The more dynamic first actuator 14 can be used here for boosting overlaps. The double piston 34 has a piston 40 arranged to be longitudinally displaceable in a cylinder 38, which divides the cylinder volume into a first chamber 42 and a second chamber 44. The chambers 42, 44 are arranged on opposite sides of the piston 40. The first room area 42 and the second room area 44 are each connected via the connection logic 16 to the respective piston-cylinder units 26, 28 of the partial couplings 22, 24.By arranging the two space areas 42, 44 on opposite sides of the piston 40, pressure is built up both by the forward movement and by the backward movement, which significantly increases the reaction time, since the process of retracting the piston 40 is not wasted.

[0032] Fig. Figure 5 shows an embodiment of the actuating arrangement 10 of the Fig. 1 and Fig. 3 in which the circuit logic 16 has three 3 / 2-way valves 46,48, where two 3 / 2-way valves 46 are identical.

[0033] Fig. Figure 6 shows a switching diagram for the actuation arrangement of the Fig. 5. The meaning of the switching options can be found in the legend of the Fig. 2 can be taken from it. In Fig. Figure 6 shows that there is no safe-state switching option. Furthermore, the second actuator 14 cannot be completely disconnected, so a smooth transfer of the closed partial coupling from the second actuator 14 to the pump 36 and subsequently a transfer of the now closed partial coupling from the pump 36 to the second actuator 14 has not been implemented. The dashed arrows here indicate switching state changes that are possible through the movement of only one valve. The horizontal arrows refer to the first 3 / 2-way valve 46 of the first actuator 12, the vertical arrows to the second 3 / 2-way valve 46 of the first actuator 12, and the diagonal arrows to the 3 / 2-way valve 48 of the second actuator 14.

[0034] Fig. Figure 7 shows an embodiment of an actuating arrangement 50 in which the circuit logic additionally includes a 5 / 2-way valve 52 as a safety valve. Fig. 7 have the ones with the actuating device 10 of the Fig. 1. Comparable components have the same reference numerals.

[0035] Fig. Figure 8 shows the switching states of the actuating arrangement 50 of the Fig. 7. The legend for the switching options is from Fig. 2 removable. The 5 / 2-way valve 52 switches between the operating mode and the safe state independently of the position of the other valves. Only when the vehicle is switched off is the second actuator 14 moved to one of its two end positions so that the fluid volume in the second actuator 14 is connected to the pressure medium supply 18. The dashed arrows indicate switching state changes that are possible by moving only one valve. The horizontal arrows refer to the valve 54 of the second actuator 14, the vertical arrows to the first 3 / 2-way valve 46 of the first actuator 12, and the diagonal arrows to the second 3 / 2-way valve 46 of the first actuator 12. The absence of the "block all" switching option is not problematic, as switching between the two switching options "drive CI1" and "drive CI2" always requires switching the three valves 46, 52, which involves passing through several intermediate states that at least allow for pressure equalization in the second actuator 14.

[0036] Fig. Figure 9 shows an actuation arrangement 60, which is an exemplary extension of the actuation arrangement 32. Fig. 4 is for the control of a gear actuator 56. In Fig. 9 have the one with the actuating device 10 of the Fig.The same reference numerals are used for the two comparable components. Since the active partial coupling is operated by the second actuator 14, the pump 36 of the first actuator 12 can be used to supply energy to the gearbox actuator 28 during these times. To ensure that the pump 36 is always connected to the pressure medium supply 18 on the correct side in both operating modes (clutch actuation or gearbox actuation), a dual-pressure AND valve 58 is used. In this case, it is necessary to shut off the first actuator 12 from the partial couplings 22, 24 and the second actuator 14 so that flow rates to and from the gearbox can be reliably decoupled from the clutch actuation. Furthermore, the position of the dual-pressure AND valve 58 must be defined before connecting the first actuator 12 to either partial coupling 22 or 24. Reference symbol list 10 Actuation arrangement 12 first actuator 14 second actor 16 Wiring logic 18 Pressure medium supply 20 dual clutch 22 first partial coupling 24 second partial coupling 26 piston-cylinder unit 28 piston-cylinder unit 30 pump 32 Actuation arrangement 34 twin pistons 36 Pump 38 cylinders 40 pistons 42 first room area 44 second room area 46 3 / 2-way valve 48 3 / 2-way valve 50 Actuation arrangement 52 5 / 2-way valve 54 valve 56 Gearbox actuator 58 Dual-pressure (AND) valve 60 Actuation arrangement

Claims

[1] Actuating arrangement for the controlled actuation of a transmission and / or a clutch, comprising at least two piston-cylinder units (26, 28), at least one switching logic (16), at least one first actuator (12), at least one second actuator (14) and a pressure medium supply (18), wherein the piston-cylinder units (26, 28) are hydraulically or hydrostatically connected to each other via the switching logic (16) with the first actuator (12) and the second actuator (14) such that the first actuator (12) and the second actuator (14) actuate at least one of the two piston-cylinder units (26, 28), wherein the first actuator (12) and / or the second actuator (14) is a double-acting actuator. [2] Actuating arrangement according to claim 1, characterized by , that the first actuator (12) is a pump actuator and the second actuator (14) is a hydraulic coupling actuator. [3] Actuating arrangement according to claim 1 or 2, characterized by, that the first actuator (12) and / or the second actuator (14) are arranged between the two piston-cylinder units (26, 28). [4] Actuating arrangement according to one of the preceding claims, characterized by , that the actuation arrangement comprises a geared actuator (56). [5] Actuation arrangement according to one of the preceding claims, characterized by , that a fluid volume can be transferred directly from one piston-cylinder unit to the other piston-cylinder unit by means of the first actuator (12) or the second actuator (14). [6] Actuating arrangement according to one of the preceding claims, characterized by , that the interconnection logic (16) includes a setting that connects all enclosed fluid volumes in the operating arrangement to the pressure medium supply (18). [7] Actuating arrangement according to one of the preceding claims, characterized by, that the circuit logic (16) includes a setting which, when the second actuator (12) changes from one piston-cylinder unit to the other piston-cylinder unit, has an intermediate position in order to make a pressure adjustment between the two piston-cylinder units (26, 28). [8] Actuating arrangement according to one of the preceding claims, characterized by , that the interconnection logic (16) includes a setting that allows snooping of the second actuator (14). [9] Actuation arrangement according to one of the preceding claims, characterized by , that the second actuator (14) has a double piston (34) when arranged between the two piston-cylinder units (26, 28). [10] Drive train of a motor vehicle with an actuating arrangement according to one of the preceding claims.

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