Procedure for commissioning an automated coupling system

Abstract

A method for commissioning an automated clutch system, in which a hydraulic system (6, 8, 10) of the clutch system is filled with a pressure medium (7) and, after filling the hydraulic system (6, 8, 10), a test is performed to determine the filling status of the hydraulic system (6, 8, 10), characterized in that, when a touch point determination is requested for a clutch (11) of the clutch system actuated by the hydraulic system (6, 8, 10), a period between the test of the filling status of the hydraulic system (6, 8, 10) and the request for touch point determination is evaluated, and a decision is made on whether to perform touch point determination depending on this period, wherein a timer is started at the beginning of the test, the timer value of which is evaluated at the time of the request for touch point determination, wherein, if a certain value is exceeded,The touch point determination is rejected by the timer value, which represents a time threshold reference value.

Description

[0001] The invention relates to a method for commissioning an automated clutch system, in which a hydraulic system of the drive train is filled with a pressure medium and, after filling the hydraulic system, a test is carried out to determine the filling status of the hydraulic system.

[0002] Automated clutch systems often actuate a clutch via a hydraulic system. Due to the expansion of the hydraulic fluid (e.g., oil or brake fluid), particularly due to heating of the hydraulic system, this system must be regularly depressurized to prevent undesirable shifts in the clutch characteristic curve. This is achieved by positioning an actuating piston within the hydraulic system to a position that allows the hydraulic system to connect to a low-pressure line or reservoir for fluid exchange.

[0003] There are hydraulic systems where, if a sniffing port connecting the hydraulic system to the low-pressure line or reservoir remains open for an extended period, the hydraulic path changes, a phenomenon known as the "soaking effect." During this soaking effect, the seal of the sniffing port loses elasticity. This change affects any subsequent touch point determination, during which the clutch characteristic curve is adapted. However, since the hydraulic path is depressurized before touch point determination, this soaking effect always occurs.

[0004] It is known that before commissioning the automated coupling system, the hydraulic system is filled and subsequently a test is carried out to determine the filling status of the hydraulic system.

[0005] Typically, the filling of a hydraulic clutch system in the production plant (transmission or vehicle factory) is carried out using a vacuum pressure filling process. This filling can be successful, partially successful, unsuccessful, or faulty. As an alternative, there is a so-called repair filling method, which takes considerably longer compared to vacuum pressure filling.

[0006] The invention is based on the objective of providing a method for commissioning an automated clutch system in which a faulty touch point determination due to a sniffing bore being open for too long is avoided.

[0007] According to the invention, the problem is solved by evaluating the time interval between checking the hydraulic system's fill status and requesting the touch point determination when a touch point determination is requested for a clutch actuated by the hydraulic system. Based on this time interval, a decision is made whether to perform the touch point determination. This has the advantage that if the time interval between checking the hydraulic system's fill status and requesting the touch point determination is too long, the touch point determination can be suppressed, thus preventing an incorrect adaptation of the clutch characteristic curve.

[0008] Advantageously, a timer is started when the fill status check begins, and its value is evaluated at the time the touchpoint determination is requested. This timer value thus represents the period that has elapsed between the start of the check and the request for touchpoint determination.

[0009] In one embodiment, if the timer value exceeds a reference value representing a time threshold, the probe point determination is rejected. This time threshold is used to infer whether the sniffer bore of the hydraulic system was open for too long, and thus a "soaking effect" most likely occurred.

[0010] Alternatively, the touch point determination is rejected if the timer has not started. The timer's failure to start suggests that the hydraulic system's fill level was not checked, implying that the hydraulic system was not filled.

[0011] In one variant, the touch point is requested by a higher-level control unit, which determines the time period between the start of the hydraulic system's fill status check and the request for touch point determination. Since the higher-level control unit, preferably a tester or diagnostic device, monitors the processes at the clutch system, it can advantageously decide whether to activate touch point adaptation.

[0012] In a further training exercise, an internal timer of the higher-level control unit is used as the timer. This eliminates the need for additional components, thus reducing the cost of the process.

[0013] In one embodiment, the time threshold is determined as a function of a calibratable maximum time period. Such a maximum time period can be adapted to the current operating conditions of the clutch system as well as to different clutch actuation systems, which is why the proposed method can be used for all possible clutches.

[0014] In one configuration, the higher-level control unit issues an error message if the touch point determination is suppressed. This error message, which is stored in memory, allows for tracking at any time that touch point adaptation was not possible.

[0015] In another embodiment, the error message is specified by indicating its cause. This specification provides maintenance personnel with information about the type of error when diagnosing the higher-level control unit.

[0016] The invention allows for numerous embodiments. One of these will be explained in more detail with reference to the figure shown in the drawing.

[0017] It shows:

[0018] Fig. 1 A schematic representation of a hydrostatic clutch actuation system with a hydrostatic transmission path.

[0019] Fig. Figure 1 shows a diagram of the hydrostatic clutch actuator. 1For use, for example, in a dual-clutch system (dry or wet) where a hydraulic clutch actuator is used, which requires the hydraulic system to be filled with brake fluid or mineral oil during initial commissioning. The hydrostatic clutch actuator 1 includes on the donor side 2 a clutch control unit 3 , which is the hydrostatic clutch actuator 1 controls.

[0020] The clutch actuator 1 is via a gearbox 4 with a piston 5 of the master cylinder 6 Kinematically connected. In the event of a change in the position of the coupling actuator. 1 and thus of the piston 5 in the master cylinder 6 Along the actuator path to the right, a volume of the encoder cylinder is measured. 6 This changes the pressure p in the master cylinder. 6 is built up, which uses a pressure medium 7 via a hydraulic line8 to the recipient side 9 is transferred. On the recipient side 9 The pressure p of the pressure medium causes 7 in a slave cylinder 10 a change of path that results in a clutch 11 is transmitted in order to activate them.

[0021] The master cylinder 6 is equipped with an expansion tank 12 connected, with a connecting opening 13 of the master cylinder 6 through the piston 5 of the master cylinder 6 is released when the piston 5 The piston is in a predetermined position. 5 This position is reached by moving further to the left from the position shown. The pressure medium is in this position. 7 normally unactuated and the pressure p in the master cylinder 6 minimal. Releasing the pressure causes an equalization of pressure, volume, and / or temperature of the pressure medium. 7This process is also called sniffing, and the position of the piston is determined. 5 , in which a connecting opening is referred to as a sniffing bore 13 Once a position is released, it is referred to as a snooping position.

[0022] During the commissioning of the coupling 11 The clutch control unit 3 connected to a test bench computer (not shown). Prior to this connection, the hydraulic system 6 , 8 , 10 with the pressure medium 7 filled. After filling with this pressure medium 7 The test bench computer performs a test to determine the filling status of the hydraulic system. 6 , 8 , 10 a test known as a "filling check". During this test, high pressure is applied within the hydraulic system. 6 , 8 , 10for example 30 bar is generated and then the hydraulic line 6 , 8 , 10 briefly relaxed again, whereby the piston 5 of the master cylinder 6 the sniffing bore 13 releases.

[0023] To reliably determine the filling status, this procedure is performed at least three times consecutively. The test bench computer evaluates the pressure gradient within the hydraulic system. 6 , 8 , 10 This occurs. There is absolutely no air left in the hydraulic system. 6 , 8 , 10 present, which means that the hydraulic system 6 , 8 , 10 If the system is sufficiently filled with hydraulic fluid, the pressure gradient does not change but remains stable. If there is still air in the hydraulic system... 6 , 8 , 10 , a change in the pressure gradient occurs.

[0024] To estimate a through the coupling 11 The transmitted clutch torque must, on the one hand, determine the position of the clutch actuator. 1 The coupling characteristic (coupling torque) must be known relative to the possible travel distance; on the other hand, the coupling characteristic curve must be referenced to the actuator travel as a function of the actuator position. This referencing is achieved via touch point determination. The touch point is a support point of the coupling characteristic curve and represents the position of the coupling. 11 This indicates the point at which it begins to transmit a clutch torque.

[0025] To determine whether the touch point determination can be carried out without errors, the filling status of the hydraulic system is checked at the beginning of the test. 6 , 8 , 10Simultaneously, a timer integrated into the test bench computer is started. If the test program requests a touch point determination, the test bench computer checks the timer's value. If the timer value exceeds a predefined time threshold, the touch point determination is suppressed because it is assumed that the probe bore is closed. 13 was open for too long, resulting in an incorrect touchpoint determination.

[0026] The timer value is a reference value representing a calibratable maximum value, which can be, for example, 6 seconds. If the touch point detection is rejected, an error message is generated in the test bench computer and displayed to the service personnel. The error message can advantageously be specified, such as "Timeout Filling Check," so that the reason for the rejection of the touch point detection is clearly identified.

[0027] The touchpoint detection is also rejected if the timer has not been started. This indicates that the fill status has not yet been checked, and therefore no reliable touchpoint detection can be determined.

[0028] This method prevents incorrect probe point determination due to the "soaking effect". Reference symbol list 1 hydrostatic clutch actuator 2 Sender side 3 Clutch control unit 4 gearboxes 5 pistons 6 master cylinders 7 Pressure instruments 8 Hydraulic lines 9 Recipient side 10 slave cylinders 11 Clutch 12 expansion tanks 13 Connecting opening

Claims

[1] Method for commissioning an automated coupling system in which a hydraulic system ( 6 , 8 , 10 ) of the coupling system with a pressure medium ( 7 ) is filled and after the hydraulic system is filled ( 6 , 8 , 10 ) a test to determine the filling status of the hydraulic system ( 6 , 8 , 10 ) is carried out, characterized by that when a touch point determination is requested for a hydraulic system ( 6 , 8 , 10 ) actuated clutch ( 11 ) of the coupling system, a period between checking the filling status of the hydraulic system ( 6 , 8 , 10 ) and the requirement for touch point determination is assessed, and a decision is made on whether to carry out touch point determination depending on this period. [2] Method according to claim 1, characterized by that a timer is started at the beginning of the test, the timer value of which is evaluated at the time the touch point determination is requested. [3] Method according to claim 2, characterized by that if the timer value exceeds a reference value representing a time threshold, the touch point determination is rejected. [4] Method according to claim 2, characterized by that the touch point averaging will be rejected if the timer is not started. [5] Method according to at least one of the preceding claims, characterized by that the request for touch point determination is made by a higher-level control unit, which determines the period between the check of the filling status of the hydraulic system and the request for touch point determination. [6] Method according to at least one of the preceding claims, characterized bythat an internal timer of the higher-level control device is used as the timer. [7] Method according to at least one of the preceding claims, characterized by that the time threshold is determined as a function of a calibratable maximum time period. [8] Method according to at least one of the preceding claims, characterized by that the higher-level control unit issues an error message when the touch point detection is suppressed. [9] Method according to claim 8, characterized by that the error message is specified, including the cause.

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