Control unit for an automated manual transmission and at least one clutch

Abstract

Control unit (1) for an automated manual transmission and at least one clutch (2, 3) connecting the manual transmission to a drive train of a motor vehicle, wherein a fluid for cooling the clutch (2, 3) can be supplied to the clutch (2, 3) via at least one clutch cooling valve (4) connected to the clutch (2, 3) of the control unit (1), wherein the control unit (1) has at least one control valve (5) which is connected to at least one electric machine (6) that can be connected to the drive train of the motor vehicle for supplying the fluid, characterized in that a storage charging valve (10) is connected upstream of the control valve (5), by means of which fluid at the storage charging valve (10) under a boost pressure is supplied to the control valve (5) and / or a high-pressure storage tank (11).

Description

[0001] The invention relates to a control unit for an automated manual transmission and at least one clutch that operatively connects the manual transmission to the drivetrain of a motor vehicle. A fluid for cooling the clutch can be supplied to the clutch via at least one clutch cooling valve connected to the control unit.

[0002] A generic control unit for an automated manual transmission is known from DE 10 2014 018 128 A1. Further manual transmissions are known from US 2015 / 0 367 793 A1 and DE 10 2012 010 322 A1.

[0003] Control units are widely used in transmission technology. For example, EP 1 635 092 A1 describes a hydraulic control device for a shift fork in a manual transmission. The shift fork engages or disengages a gear in the transmission, and is connected to the piston unit of a shift cylinder, which moves the shift fork. The control device is designed to ensure that the movement of the piston unit is as smooth as possible.

[0004] In the field of automatic transmissions, such as dual-clutch transmissions, automated control units primarily serve to manage the complex interaction between the components of such an automatic transmission. This is largely due to the fact that automatic transmissions have a sophisticated mechanical structure, and the shifting and clutch processes associated with gear changes require an equally complex interplay of electrical, electromagnetic, mechanical, and hydraulic components.

[0005] A hydraulic control system for a dual-clutch transmission that performs this function is described in DE 10 2014 216 648 A1. In this system, the hydraulic energy source of the control device, which is designed as a pump, is driven by the internal combustion engine of a commercial vehicle and / or an electric motor located in the commercial vehicle. In addition to actuating the dual clutch, the hydraulic control system also enables its cooling. For this purpose, the cooling branch of the dual clutch connected to the control system is supplied with hydraulic oil via a clutch cooling valve piloted by a pilot valve. The clutch cooling valve is designed, in particular, as a pressure regulator which can maintain a minimum flow rate through the clutch cooling valve to ensure continuous cooling of the dual clutch.

[0006] In addition to vehicles with combustion engines, so-called hybrid vehicles have become established in recent years. These vehicles have at least one additional electric motor that works alongside the combustion engine to propel the vehicle. Especially when combined with an automatic transmission, and particularly a dual-clutch transmission, hybrid vehicles offer an optimal combination of comfort and low fuel consumption.

[0007] Due to the high power consumption of the electric motor required to propel a motor vehicle, it is generally necessary to cool the motor during operation. This cooling is achieved through a separate cooling circuit, which, disadvantageously, results in increased design complexity and space requirements for components such as additional pumps, as well as higher manufacturing costs.

[0008] Against this background, the invention is based on the objective of designing a control unit of the type mentioned above in such a way that an additional cooling circuit for cooling the electric motor can be dispensed with.

[0009] This problem is solved with a control unit according to the features of claim 1. The dependent claims relate to particularly advantageous further developments of the invention.

[0010] According to the invention, a control unit for an automated manual transmission and at least one clutch connecting the transmission to the drivetrain of a motor vehicle are provided. A fluid for cooling the clutch(es) can be supplied to the clutch(es) via at least one clutch cooling valve connected to the control unit, preferably hydraulically. Furthermore, the control unit, according to the invention, has at least one control valve connected to at least one electric motor, preferably hydraulically, for supplying the fluid to the drivetrain of the motor vehicle. Supplying the fluid to the electric motor via the connection of the electric motor to the control unit would advantageously allow for its cooling and / or lubrication without the need for an additional fluid circuit.Due to the connection with the existing fluid circuit of the control unit for cooling the clutch(es) of the automated transmission, a structurally elegant and economically advantageous solution for cooling and / or lubricating the electric motor can be provided. The fluid circuit and the control unit should also serve to actuate the clutches and perform shifting operations of the transmission. The fluid itself can be a hydraulic fluid, in particular hydraulic oil.

[0011] The number of clutches cooled and actuated by the control unit, as described, should be at least one, preferably more than one clutch, and in particular more than two clutches, which can be cooled and actuated by the control unit. Two of the clutches could be configured as a dual clutch of a dual-clutch transmission.

[0012] The electric machine should be designed as an electric motor, which could be mechanically connected to the vehicle's drivetrain via a coupling. It is conceivable that, in addition to the electric machine (designed as an electric motor), the fluid could also be supplied via the control unit to a coupling that connects the electric machine or electric motor to the vehicle's drivetrain.

[0013] The control unit, also known as the mechatronics module, which operates mechanically, hydraulically and electronically, thus represents the control center of the automated transmission, with the control unit in particular controlling and / or regulating shifting and clutch operations.

[0014] In a particularly advantageous further development of the invention, the control valve is the clutch cooling valve, thus eliminating the need for a separate control valve and allowing the use of the clutch cooling valve already used to supply fluid for cooling the clutches of the automated transmission. Besides economic advantages, this offers a structurally simpler solution with better space utilization, reduced manufacturing costs, and lower susceptibility to errors. It is also possible for the clutch cooling valve itself to be designed as a pilot-operated valve; however, it is preferably directly actuated.

[0015] Another particularly promising embodiment of the invention is characterized in that the control valve has at least three switching positions, whereby the fluid can advantageously be supplied to the electric machine via a single valve, as well as to other components of the control unit and components arranged outside the control unit. Furthermore, if the fluid can be supplied to the electric machine in a first switching position of the control valve, to a first clutch in a second switching position, and to a second clutch in a third switching position, then the fluid can be supplied to the two clutches, particularly for the purpose of cooling them, with the first and second clutches being designed, for example, as a dual clutch of an automated manual transmission.The first switching position of the control valve should be designed as a neutral position, in which, for example, a valve piston, which is slidably arranged within the control valve against a return element, is deflected from its home position over its entire travel distance, thereby allowing the fluid to be supplied to the electric machine. In contrast, the second switching position can be configured so that the aforementioned valve piston of the control valve is in its home position under the influence of the return element and thus remains undejected, or, in the third switching position, it is positioned in a maximum position with virtually the greatest possible deflection from its home position.

[0016] According to the invention, a storage charging valve is connected upstream of the control valve, by means of which fluid at the storage charging valve, operating at a charging pressure, is supplied to the control valve and / or a high-pressure accumulator. This is very advantageous because, during a necessary charging process of the high-pressure accumulator, an excessive supply of fluid for cooling and / or lubricating the electric motor and, if applicable, for cooling the clutches, can be prevented, which could lead to an insufficient supply of fluid to the high-pressure accumulator. The storage charging valve can thus function as a bypass when required, bypassing the supply of fluid to the control valve.If, however, charging the high-pressure accumulator is not necessary, for example, due to a sufficiently high storage pressure in the accumulator, the excess fluid not required for charging can be used for cooling and / or lubricating the electric motor, as well as for cooling the first and second clutches, by means of the accumulator charging valve located upstream of the control valve. The accumulator charging valve and the control valve could be directly controlled, for example, by an actuator, or pilot-operated, particularly hydraulically. In a practical design, the actuator would be, for example, an electromagnet that is an integral part of the control valve or the accumulator charging valve.It would be advantageous if the valve piston exhibited a dependence of the displacement over its total displacement path on the current strength of the electric current flowing through the electromagnet that was as linear as possible.

[0017] A further advantageous embodiment of the invention can also be described by the fact that the fluid applied to the storage charging valve is a partial volume flow of the total volume flow generated by a pressure generator. This allows the partial volume flow applied to the storage charging valve to have a pressure level that differs from at least one other partial volume flow, such as the charging pressure for the high-pressure storage tank. This advantageously enables partial fluid circuits of the control unit's fluid circuit, as well as the components connected to these partial fluid circuits, particularly hydraulically, to be supplied with partial volume flows of differing pressure levels. Accordingly, partial fluid circuits can be designed that, for example, have a low-pressure level or a high-pressure level.A high-pressure partial fluid circuit could be used to actuate the clutches and perform the shifting operations of the automated transmission, while a low-pressure partial fluid circuit could be used to cool the clutches. Furthermore, it is conceivable that the total volume flow is generated entirely by the pressure generator and then divided into partial volume flows via the fluid circuit. Alternatively, the total volume flow could already be divided into partial volume flows when it is generated by the pressure generator. This could be the case, for example, if the pressure generator consists of at least two pumps that produce separate partial volume flows.However, the pumps that provide the effect could have a single drive, for example a torque-generating motor, whereby the pump and motor could also be designed as one component, for example as a motor-pump unit.

[0018] Another advantageous embodiment of the invention is present when the storage charging valve has a switching hysteresis, or when the storage charging valve has a switching hysteresis formed by a hydraulically generated detent function. In principle, a mechanically generated detent function of the storage charging valve is also conceivable instead of a hydraulically generated detent function. However, compared to a mechanically generated detent function, a hydraulically generated detent function offers the advantage that the storage charging valve is subject to significantly reduced wear and can therefore have a longer service life. The switching hysteresis manifests itself in the fact that the two valve positions of the storage charging valve are established at control pressures acting on the storage charging valve that differ in magnitude. This would, for example, prevent the storage charging valve from...Only when a first control pressure threshold is exceeded is the valve switched from its first position to its second position, and consequently, only when a second switching pressure threshold is undershot (which, for example, is at a lower control pressure level than the first switching pressure threshold), is it switched back from its second position to its first. The switching pressure applied to the accumulator charging valve could be the charging pressure generated by the pressure generator or the accumulator pressure present in the high-pressure accumulator.Due to the design of the storage charging valve with such a switching hysteresis, it is advantageously possible to direct the fluid applied to the storage charging valve under charging pressure, in particular the partial volume flow of the fluid supplied via the pressure generator, to different control pressure levels or control pressure points of the switching pressure applied to the storage charging valve, either to the high-pressure storage tank or to the control valve. Particularly advantageous is the significant reduction in the power consumption of the pressure generator due to the alternating supply of the fluid to the high-pressure storage tank or the control valve.

[0019] If the accumulator charging valve is pilot-operated, particularly depending on the boost pressure or the accumulator pressure, and / or if the switching hysteresis, and especially the switching hysteresis via the hydraulically generated detent function of the accumulator charging valve, is controlled by the pilot valve, then, on the one hand, the fluid can be kept at high boost pressures that would not be achievable with a directly controlled accumulator charging valve, and on the other hand, unwanted intermediate positions of the accumulator charging valve, and thus potentially inconsistent switching behavior of the accumulator charging valve, can be avoided. It is conceivable that the accumulator charging valve and the pilot valve are integrated as a single unit, i.e., for example, in one housing, and thus can be in the form of a cartridge valve.

[0020] Furthermore, a highly promising embodiment of the invention can be assumed if a pressure port of the control unit, associated with the electric machine and connected to the control valve, is connected to the pressure generator, particularly hydraulically, and / or if a throttle, preferably reducing the flow rate to or from the pressure port, is interposed between the connection between the pressure port (here associated with the electric machine) and the pressure generator. This would advantageously enable continuous, independent, and permanent cooling and / or lubrication of the electric machine. The connection between the pressure port of the control unit and the pressure generator can be made via a hydraulic line integrated into the control unit.By inserting a restrictor into the connection between the pressure port and the pressure generator, the volume flow supplied or discharged via the hydraulic line, which may be a partial flow not under boost pressure, can be limited. This can be achieved by installing an orifice plate in the hydraulic line to reduce its cross-section, or by having such a small cross-section that the hydraulic line itself acts as the restrictor.

[0021] An embodiment of the invention is also highly advantageous if the pressure port of the control unit associated with the electric machine is connected to the accumulator charging valve, particularly hydraulically, and / or if a throttle, preferably reducing the volume flow from the pressure port, is interposed between the pressure port (here associated with the electric machine) and the accumulator charging valve. This is particularly advantageous insofar as it limits the volume of an additional partial volume flow of fluid supplied to the control valve, which is not the partial volume flow supplied via the accumulator charging valve and is under charging pressure, so that this partial volume flow is not entirely supplied to the electric machine and / or the couplings.

[0022] The connection between the pressure port of the control unit and the accumulator charging valve can also be made via a hydraulic line integrated into the control unit. By inserting a restrictor into the connection between the pressure port and the accumulator charging valve, the flow rate discharged from the pressure port via the hydraulic line could be limited. This can be achieved either by installing an orifice plate in the hydraulic line to reduce its cross-section, or by having such a small cross-section that the hydraulic line itself acts as the restrictor.

[0023] Furthermore, if the pressure port associated with the electric motor is connected to a tank, particularly hydraulically, via the accumulator charging valve in a charging position of the accumulator charging valve, then it can be assumed that, advantageously, excess fluid from the electric motor and / or the couplings can be returned to the tank, i.e., a low-pressure accumulator for the fluid, also called a sump, and / or an insufficient fluid level in the tank can be avoided by supplying excessive amounts of fluid to the electric motor and / or the couplings during the necessary supply of fluid to the high-pressure accumulator. In the accumulator charging position, which is one of the valve positions of the accumulator valve already described, the supply of fluid to the control valve would be blocked, and the accumulator charging valve can function as a bypass, so that the high-pressure accumulator is charged with the fluid.

[0024] The invention allows for numerous embodiments. To further illustrate its basic principle, one of these is shown in the drawing and described below. This shows in Fig. 1 a hydraulic circuit diagram of a further development of the control unit according to the invention; Fig. 2a, Fig. 2b Representations of volume flow curves; Fig. 3a, Fig. 3b Representations of volume flow curves.

[0025] Fig. Figure 1 shows a hydraulic circuit diagram of a further development of the control unit 1 according to the invention. For the purpose of cooling the clutches 2, 3 and for cooling and lubricating the electric machine 6 (designed as an electric motor), a fluid in the form of hydraulic oil can be supplied to the clutches 2, 3 and the electric machine 6 via the control valve 5, which is designed as the clutch cooling valve 4. For this purpose, the control valve 5 has three switching positions 7, 8, 9. In the first switching position 7 of the control valve 5, the control valve 5 is hydraulically connected to the pressure port 14 associated with the electric machine 6 via the hydraulic line 19. In the second switching position 8 of the control valve 5, it is hydraulically connected to the first clutch 2 via the hydraulic line 20, and in the third switching position 9, it is hydraulically connected to the second clutch 3 via the hydraulic line 21.Thus, the cooling and lubrication of the electric machine takes place in the first switching position 7 of the control valve 5, the cooling of the first clutch 2 in the second switching position 8 of the control valve 5, and the cooling of the second clutch 3 in the third switching position 9 of the control valve 5, with the first switching position 7 corresponding to the center position of the control valve 5. The accumulator charging valve 10, which is pilot-operated by the pilot valve 13, is also connected upstream of the control valve 5. The fluid present at the accumulator charging valve 10 under a charging pressure, and in particular a partial volume flow of the total volume flow generated by the pressure generator 12, is supplied to the control valve 5 or the high-pressure accumulator 11, depending on the valve position of the accumulator charging valve 10.For this purpose, the control valve 5 is hydraulically connected via hydraulic line 22, and the high-pressure accumulator 11 via hydraulic line 23. The check valve 38 and hydraulic line 24 are hydraulically connected to the accumulator charging valve 10. In the accumulator charging position 17 of the accumulator charging valve 10, the flow of fluid from hydraulic line 23 to hydraulic line 22 is blocked, so that the fluid under charge pressure opens the check valve 38 and is supplied to the high-pressure accumulator 11 via hydraulic line 24. In addition to the accumulator charging position 17, a second valve position of the accumulator charging valve 10, the cooling position 43, can be achieved, in which hydraulic line 22 is hydraulically connected to hydraulic line 23 via the accumulator charging valve 10.The fluid under boost pressure, specifically the partial flow of fluid at the accumulator charging valve 10, is generated by the pressure generator 12 and reaches the accumulator charging valve 10 via hydraulic lines 23, 25 and the intermediate filter 40. This partial flow at the accumulator charging valve 10 is generated by the first pump 35 of the pressure generator 12, which also includes the second pump 36 and the motor 37 that drives pumps 35 and 36 at a variable speed. Furthermore, an additional fluid flow generated by pump 37, which is under cooling pressure, can be supplied to the control valve 5 via the cooler 42, the filter 41, and the connecting hydraulic lines 22, 26, and 27.Furthermore, the pressure port 14 of the control unit 1, which is assigned to the electric machine 6 and connected to the control valve 5, is hydraulically connected to the pressure generator 12 via the hydraulic lines 28 and 29, with the throttle 15 being interposed between the hydraulic lines 28 and 29 in the connection between the pressure port 14 and the pressure generator 12. The pressure port 14 is also hydraulically connected to the accumulator charging valve 10 via the hydraulic lines 30 and 31 and the interposed throttle 16, whereby, in the accumulator charging position 17 of the accumulator charging valve 10, the pressure port 14 is hydraulically connected to the tank 18 via the accumulator charging valve 10.

[0026] Fig. 2a and Fig. 2b each represent a qualitatively dependent aspect, also in Fig. 1 shown switch positions 7, 8, 9 of the in Fig. The control valve described in section 1 shows 5 adjustable fluid flow rates. This shows Fig. 2a Volume flows of the fluid, which are located in the Fig. 1. Set the storage charging position 17 of the storage charging valve 10 as shown, Fig. 2b Volume flows of the fluid, which are also in Fig. Set the cooling position 43 of the storage charging valve 10 as described in Figure 1. In both figures, these resulting volume flows are also shown as a function of different rotational speeds n1, n2, n3 of the valve. Fig. Figure 1 shows the motor 37 of the pressure generator 12. Switching positions 7, 8, and 9 correspond to the electric current IVKU flowing through the actuator of the control valve 5, which is designed as an electromagnet. It can be seen that with increasing current IVKU, switching position 8 transitions to switching position 7 and then to switching position 9. Fig. 2a includes the first clutch volume flow QK1 for cooling the first clutch 2, the second clutch volume flow QK2 for cooling the second clutch 3, the tank volume flow QT to tank 18, and the machine volume flow QE for cooling and lubricating the electric machine 6 at the corresponding speeds n1, n2, n3. However, Fig. 2b Only the coupling flow rates QK1, QK2 and the machine flow rate QE are measured, since in the cooling position 43 of the accumulator charging valve 10 no fluid is supplied to the tank 18 via the accumulator charging valve 10. As can be seen, with increasing rotational speeds n1, n2, n3, the coupling flow rates QK1, QK2, the machine flow rate QE and the tank flow rate QT also increase.

[0027] Fig. 3a and Fig. Figure 3b also shows qualitative volume flow curves. These are in Fig. 3a and Fig. 3b as a function of the rotational speed n of the in Fig. 1 described motor 37 of the printing unit 12 is shown. Fig. 3a shows the flow rate profiles in the first switching position 7 of the in Fig. 1 of the control valve shown 5. Fig. Figure 3b, however, shows volume flows that are present in the second switching position 8 or the third switching position 9 of the control valve 5. Fig. 3a is to be taken from the tank volume flow QT and the machine volume flow QE in the storage charging position 17 of the storage charging valve 10 and from the machine volume flow QE in cooling position 43 of the storage charging valve 10. Fig. 3b represents the machine cooling flow QE, which is distributed across the Fig.Figure 1 illustrates the connection between pressure port 14 and pressure generator 12 via the throttle 15 and the hydraulic lines 28, 29. The diagram also shows the first coupling flow rate QK1 or the second coupling flow rate QK2, which do not occur simultaneously. Furthermore, a total flow rate is shown, which corresponds to the sum of the first coupling flow rate QK1 or the second coupling flow rate QK2 and the machine flow rate QE. Reference symbol list 1 control unit 2, 3 clutch 4 Clutch cooling valve 5 Control valve 6 Electric Machine 7, 8, 9 Switch position 10 Storage charging valve 11 high-pressure storage tanks 12 Printing unit 13 Pilot valve 14 Pressure connection 15, 16 Throttle 17 Storage charging position 18 Tank 19, 20, 21 Hydraulic line 22, 23, 24 Hydraulic line 25, 26, 27 Hydraulic line 28, 29, 30 Hydraulic line 31 Hydraulic line 35, 36 pump 37 Engine 38 Check valve 40, 41 filters 42 coolers 43 Cooling position n rotational speed n1, n2, n3 Rotational speed IVKU electricity QE Machine flow rate QK1 Coupling volume flow QK2 coupling volume flow QT Tank volume flow

Claims

[1] Control unit (1) for an automated manual transmission and at least one clutch (2, 3) connecting the manual transmission to a drive train of a motor vehicle, wherein a fluid for cooling the clutch (2, 3) can be supplied to the clutch (2, 3) via at least one clutch cooling valve (4) of the control unit (1) connected to the clutch (2, 3), wherein the control unit (1) has at least one control valve (5) which is connected to at least one electric machine (6) that can be connected to the drive train of the motor vehicle for supplying the fluid, characterized by , that a storage charging valve (10) is connected upstream of the control valve (5), by means of which fluid at the storage charging valve (10) under a charging pressure is supplied to the control valve (5) and / or a high-pressure storage tank (11). [2] Control unit (1) according to claim 1, characterized by , that the control valve (6) is the clutch cooling valve (5). [3] Control unit (1) according to claim 1 or 2, characterized by , that the control valve (5) has at least three switching positions (7, 8, 9) and / or that the fluid can be supplied to the electric machine (6) in a first switching position (8) of the control valve (5), to a first coupling (2) in a second switching position (7) of the control valve (5) and to a second coupling (3) in a third switching position (9) of the control valve (5). [4] Control unit (1) according to at least one of the preceding claims, characterized by , that the fluid applied to the storage charging valve (10) is a partial volume flow of the total volume flow caused by a pressure generator device (12). [5] Control unit (1) according to at least one of the preceding claims, characterized by , that the storage charging valve (10) has a switching hysteresis or the storage charging valve (10) has a switching hysteresis which is formed by a hydraulically generated detent function. [6] Control unit (1) according to at least one of the preceding claims, characterized by , that the storage charging valve (10) is pre-controlled via a pilot valve (13) and / or the switching hysteresis of the storage charging valve (10) is caused by the pilot valve (13) that pre-controls the storage charging valve (10). [7] Control unit (1) according to at least one of the preceding claims, characterized by , that a pressure port (14) of the control unit (1) associated with the electric machine (6) and connected to the control valve (5) is connected to the pressure generating device (12) and / or a throttle (15) is interposed between the connection of the pressure port (14) and the pressure generating device (12). [8] Control unit (1) according to claim 7, characterized by, that the pressure port (14) of the control unit (1) associated with the electric machine (6) is connected to the storage charging valve (10) and / or a throttle (16) is interposed between the connection of the pressure port (14) and the storage charging valve (10). [9] Control unit (1) according to claim 7, characterized by , that the pressure port (14) associated with the electric machine (6) is connected to a tank (18) via the storage charging valve (10) in a storage charging position (17) of the storage charging valve (10).

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