Oil supply device for automatic transmission mechanism

Abstract

The invention relates to an oil supply device for an automatic transmission or an automatic shifting transmission in a drive train, the oil supply device comprising an oil sump and a heat exchanger, wherein the oil supply device is provided for at least the following operating states of the automatic transmission: torque converter operation; driving operation using one of the mechanical gears; retarder operation. In order to optimize the cooling of the oil volume flow in different operating states, according to the invention, two heat exchangers (11, 12) are provided, through which the oil volume flow can be conveyed, respectively, depending on the operating state of the automatic transmission.

Description

Technical Field

[0001] The invention relates to an oil supply device for an automatic transmission mechanism or an automatic shift transmission mechanism in a drive transmission system. Background Art

[0002] The oil supply device of an automatic transmission or an automatic gearshift transmission usually has an oil pump driven by a combustion engine. The oil pump conveys oil from the oil sump into the oil supply network in order to supply oil to the transmission components.

[0003] The various elements present in an automatic transmission or automatic gearshift transmission include the clutch, brake, torque converter, hydraulic brake (retarder) and lubrication points of the transmission.

[0004] During operation of the vehicle, different components require very different oil volume flows with very different oil pressures at different times.

[0005] For reliable and trouble-free operation of an automatic transmission or an automatic shift transmission, it is also important that the oil temperature remains within a certain range.

[0006] Patent document DE 10 2015 218 358 A1 discloses an oil supply system in which, for monitoring the oil temperature, a temperature sensor is arranged downstream of a pump device in the flow direction in order to detect the oil temperature in the pressure line. This positioning of the temperature sensor makes it possible in particular to detect critical temperatures in the pressure line. In order to further improve operational reliability, the temperature sensor can be arranged downstream of the torque converter, as viewed in the flow direction.

[0007] Oil sump temperature measurement is also known. Monitoring the oil temperature in the transmission therefore requires two temperature sensors. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide an oil supply device for an automatic transmission or an automatic shift transmission, which allows optimal cooling of the oil volume flow in different operating states.

[0009] An oil supply device for an automatic transmission or an automatic shift transmission in a drive train is proposed, the oil supply device comprising an oil sump and a heat exchanger, wherein the oil supply device is provided for at least the following operating states of the automatic transmission:

[0010] Torque converter operation;

[0011] Driving operation using one of the mechanical gears;

[0012] Retarder operation.

[0013] In order to optimize the cooling of the oil volume flow in different operating states, the invention proposes to provide two heat exchangers through which the oil volume flow can be conveyed, respectively, depending on the operating state of the automatic transmission. When two heat exchangers are used, the two heat exchangers can be adapted to the conditions of the operating state, thereby improving the cooling of the corresponding oil volume flow.

[0014] In a preferred embodiment, a measuring device for measuring the temperature of the oil circuit can be provided, by means of which the temperature of the oil volume flow can be measured in all operating states. Thus, for each operating state, the critical temperature can always be monitored and the function of the transmission can be ensured without the risk of overheating of the oil.

[0015] In the event of a potential oil overheating, a control strategy can be provided in order to keep or regulate the temperature of the oil volume flow at a desired level for this operating state. Thus, in torque converter operation, the temperature of the oil volume flow through the torque converter can be measured, in retarder operation, the temperature of the oil volume flow through the retarder can be measured, and in driving operation using one of the mechanical gears, the oil sump temperature can be measured.

[0016] In a preferred specific embodiment, two heat exchangers are provided for the torque converter operation and the driving operation, and only the second heat exchanger is used for the retarder operation.

[0017] Furthermore, the measuring device can include a sensor by means of which the temperature of the oil volume flow flowing into the second heat exchanger can be measured. In particular when using a double-tube heat exchanger in which the supply connections to the two heat exchanger channels for the oil volume flow are arranged close to one another, in the event of a strong increase in the temperature of the oil flow flowing into the first heat exchanger, a certain heat transfer occurs to the supply connection of the second heat exchanger, so that such a temperature increase can also be detected due to this heat transfer.

[0018] By positioning the temperature sensor in front of the heat exchanger inlet of the second heat exchanger, different temperatures can be measured depending on the operating state of the transmission, since the oil volume flow is conveyed through the second heat exchanger in all operating states. Therefore, the second temperature sensor can be omitted.

[0019] In other embodiments, the heat exchanger can be designed for different oil volume flows. For example, in the case of a double-tube heat exchanger, the passages through the heat exchanger can be designed differently.

[0020] Thus, the flow ratio or the ratio of the oil volume flow through the first heat exchanger and the second heat exchanger is preferably designed to be 1: 2. However, other different ratios in the range of 1:1.25 to 1:3 are also conceivable.

[0021] Valves can also be provided in the oil cooling circuit, by means of which the oil volume flow can be adjusted. These can be valves for adjusting the torque converter and the retarder in particular.

[0022] Thus, a pressure regulating valve can be provided for regulating the oil volume flow through the torque converter, wherein the pressure regulating valve is arranged between the torque converter and the first and second heat exchangers.

[0023] Furthermore, a first switching valve and a second switching valve may be provided so that, in braking operation of the retarder, an oil volume flow can be conveyed through the second heat exchanger in order to dissipate braking energy.

[0024] The first switching valve can be switched such that, during driving operation using one of the mechanical gears of the automatic transmission, an oil volume flow from the oil sump can be conveyed via the bypass line through the second heat exchanger and / or the first heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further advantageous features of the invention are explained with reference to the accompanying drawings by means of exemplary embodiments. The features can be advantageously implemented not only in the combination shown, but also individually in combination with one another. In the accompanying drawings:

[0026] Figure 1 A functional diagram showing an oil circulation circuit for oil supply;

[0027] Figure 2 A view showing a heat exchanger bracket. DETAILED DESCRIPTION

[0028] exist Figure 1 1 shows a functional diagram of an oil circuit for supplying oil to an automatic transmission mechanism according to the present invention. Here, the diagram is simplified to the details important to the present invention, which are necessary for oil cooling.

[0029] A pump (not shown) delivers oil from the oil pan 19 via the oil supply line 3 to all relevant components in the transmission mechanism, thereby ensuring oil supply for at least the following operating conditions of the automatic transmission mechanism:

[0030] Torque converter operation;

[0031] Driving operation using one of the mechanical gears;

[0032] Retarder operation.

[0033] These three operating states result in an input of energy into the oil, which results in an increase in the temperature of the oil. When the motor vehicle is started, the transmission is switched to torque converter operation by means of valve 26. For torque converter operation, the regulating valve 5 is adjusted so that at least a portion of the oil volume flow 21d delivered by the pump is delivered through the torque converter 2.

[0034] The function of the control valve 5 is to regulate the power regulation of the torque converter 4 , which is not discussed in detail here. The heated oil, ie the oil volume flow, is supplied to the heat exchangers 11 and 12 via the line 6 and the WT (heat exchanger) supply line 7 .

[0035] During driving operation using one of the mechanical gears of the automatic transmission, an oil volume flow 21 d is supplied from the oil sump 19 via the bypass line 4 , the line 6 and the WT supply line 7 to the heat exchangers 11 and 12 .

[0036] Different types of connection can be used here. In the illustrated switched position of the first switching valve 13, the oil volume flow 21d from the torque converter 2 is conveyed through the second heat exchanger 12 and the first heat exchanger 11. The oil volume flow 21d is divided into oil volume flows 21a and 21b.

[0037] However, it is also conceivable to switch only the first switching valve 13 to the second switching position so that the oil volume flow 21d from the torque converter 2 or the bypass 4 is conveyed via the connecting channel 25a only through the first heat exchanger 11. The oil volume flow 21d corresponds to the oil volume flow 21a.

[0038] In retarder operation, the two switching valves 13 and 14 are switched simultaneously, so that in retarder operation, only the second heat exchanger 12 is used to cool the oil in order to discharge braking energy. In relation to the present invention, the retarder control is not discussed further.

[0039] Alternatively, however, provision can also be made to switch the switching valve 14 in a first step so that the retarder is filled and, at the latest when the filling is complete, also switch the switching valve 13 so that the entire oil volume flow 21c is pumped through the retarder 9 and conveyed via the connecting channel 25b through the heat exchanger 12.

[0040] Furthermore, the measuring device 20 is essential to the invention, the position of which in the region of the connecting channel 25b is Figure 2 Detailed description is given in FIG. The measuring device is provided for measuring the temperature of the oil volume flow 21 b. A sensor of the measuring device 20 is arranged on the connecting channel 25 b. The temperature of the oil volume flow 21 b in the second heat exchanger 12 can thus be measured for all operating states.

[0041] Since the oil volume flow is conveyed via the connecting channel 25b in all operating states, the temperature of the oil volume flow 21b can be measured for all operating states. Thus, critical temperature limits can be monitored in each operating state. This ensures the function of the transmission and prevents overheating of the oil.

[0042] In the event of potential oil overheating, a control strategy should be implemented to adjust the oil temperature to a determinable limit temperature, for example by reducing the braking power of the retarder.

[0043] The other shown lines and elements of the oil circuit will not be discussed in detail in the present invention, because they are not important for explaining the present invention. However, these lines and elements are necessary to realize the overall function of the transmission mechanism.

[0044] Reference numerals list

[0045] 1 Oil circulation circuit

[0046] 2 Torque converter

[0047] 3 Oil supply line

[0048] 4 Bypass line

[0049] 5-valve-torque converter adjustment device

[0050] 6 Pipeline

[0051] 7 WT supply line

[0052] 8 Leakage flow line

[0053] 9 Retarder

[0054] 10 Supply line

[0055] 11. Heat exchanger

[0056] 12 Heat exchanger

[0057] 13. Switching valve

[0058] 14 Switching valve

[0059] 15 Return line

[0060] 16 Core wheel filling line (Kernringbefüllleitung)

[0061] 17 Gap filling pipeline

[0062] 18 Return line

[0063] 19 Oil sump

[0064] 20. Measuring device with sensor

[0065] 21a, b, c, d Oil volume flow

[0066] 22 Heat exchanger bracket

[0067] 23 Heat exchanger

[0068] 24a, b Bracket

[0069] 25 Connection Channels

[0070] 26, 27 valves

Claims

1. An oil supply device for an automatic transmission mechanism or an automatic shift transmission mechanism in a drive train, the oil supply device comprising an oil pan (19) and a heat exchanger, wherein: The oil supply device is provided for at least the following operating states of the automatic transmission mechanism: Torque converter operation; Driving operation using one of the mechanical gears; Retarder operation, It is characterized in that A first heat exchanger (11) and a second heat exchanger (12) are provided, through which oil volume flows (21a, b, c) can be conveyed, respectively, depending on the operating state of the automatic transmission mechanism. A measuring device (20) for measuring the temperature of the oil circuit is provided, by means of which the temperature of the oil volume flow (21a, b, c) can be measured in all operating states. The measuring device (20) comprises a sensor, and the second heat exchanger (12) is connected to the oil supply device in such a way that in each operating state at least a portion of the oil volume flow (21a, b, c) is conveyed through the second heat exchanger (12), wherein the sensor is arranged at the heat exchanger inlet of the second heat exchanger (12), by means of which the temperature of the oil volume flow (21b) fed into the second heat exchanger (12) can be measured.

2. The oil supply device according to claim 1, characterized in that: The heat exchanger is designed for different oil volume flows (21a, b).

3. The oil supply device according to claim 1, characterized in that: The ratio of the oil volume flows (21a, b) flowing through the first heat exchanger (11) and the second heat exchanger is designed to be 1:

2.

4. The oil supply device according to claim 1, characterized in that: Valves (5, 13, 14) are provided, by means of which the oil volume flows (21a, b) can be adjusted.

5. The oil supply device according to claim 1, characterized in that: A pressure regulating valve (5) is provided for regulating an oil volume flow (21d) through the torque converter (2), wherein the pressure regulating valve (5) is arranged between the torque converter (2) and the first and second heat exchangers.

6. The oil supply device according to claim 1, characterized in that: A first switching valve (13) and a second switching valve (14) are provided so that, during braking operation of the retarder, an oil volume flow (21c) can be conveyed through the second heat exchanger (12) in order to dissipate braking energy.

7. The oil supply device according to claim 1, characterized in that: The first switching valve (13) can be switched in such a way that, during driving operation using one of the mechanical gears of the automatic transmission, an oil volume flow (21d) from the oil pan (19) can be conveyed via the bypass line (4) through the second heat exchanger (12) and / or the first heat exchanger (11).

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