The torque converter characteristics to be determined for the simulation tool input consist of Tpum 1000 (the reference torque at 1 000 rpm input speed) and μ (the torque ratio of the torque converter). Both are depending on the speed ratio v (= output (turbine) speed / input (pump) speed for the torque converter) of the torque converter.
For determination of the characteristics of the TC, the applicant for a certificate shall apply the following method, irrespective of the chosen option for the assessment of the transmission torque losses.
To take the two possible arrangements of the TC and the mechanical transmission parts into account, the following differentiation between case S and P shall apply:
:
TC and mechanical transmission parts in serial arrangement
:
TC and mechanical transmission parts in parallel arrangement (power split installation)
For case S arrangements the TC characteristics may be evaluated either separate from the mechanical transmission or in combination with the mechanical transmission. For case P arrangements the evaluation of TC characteristic is only possible in combination with the mechanical transmission. However, in this case and for the hydromechanical gears subject to measurement the whole arrangement, torque converter and mechanical transmission, is considered as a TC with similar characteristic curves as a sole torque converter.
For the determination of the torque converter characteristics two measurement options may be applied:
Option A: measurement at constant input speed
Option B: measurement at constant input torque according to SAE J643
The manufacturer may choose option A or B for case S and case P arrangements.
For the input to the simulation tool, the torque ratio μ and reference torque Tpum of the torque converter shall be measured for a range of v ≤ 0,95 (= vehicle propulsion mode). The range of v ≥ 1,00 (= vehicle coasting mode) may either be measured or covered by using the standard values of Table 1.
In case of measurements together with a mechanical transmission the overrun point may be different from v = 1,00 and therefor the range of measured speed ratios shall be adjusted accordingly.
In case of use of standard values the data on torque converter characteristics provided to the simulation tool shall only cover the range of v ≤ 0,95 (or the adjusted speed ratio). The simulation tool automatically adds the standard values for overrun conditions.
Default values for v ≥ 1,00
v | μ | Tpum 1000 |
---|---|---|
1,000 | 1,0000 | 0,00 |
1,100 | 0,9999 | – 40,34 |
1,222 | 0,9998 | – 80,34 |
1,375 | 0,9997 | – 136,11 |
1,571 | 0,9996 | – 216,52 |
1,833 | 0,9995 | – 335,19 |
2,200 | 0,9994 | – 528,77 |
2,500 | 0,9993 | – 721,00 |
3,000 | 0,9992 | – 1 122,0 |
3,500 | 0,9991 | – 1 648,0 |
4,000 | 0,9990 | – 2 326,0 |
4,500 | 0,9989 | – 3 182,0 |
5,000 | 0,9988 | – 4 242,0 |
The torque converter used for the measurements shall be in accordance with the drawing specifications for series production torque converters.
Modifications to the TC to meet the testing requirements of this Annex, e.g. for the inclusion of measurement sensors are permitted.
Upon request of the approval authority the applicant for a certificate shall specify and prove the conformity with the requirements defined in this Annex.
The input oil temperature to the TC shall meet the following requirements:
The oil temperature for measurements of the TC separate from the transmission shall be 90 °C + 7/– 3 K.
The oil temperature for measurements of the TC together with the transmission (case S and case P) shall be 90 °C + 20/– 3 K.
The oil temperature shall be measured at the drain plug or in the oil sump.
In case the TC characteristics are measured separately form the transmission, the oil temperature shall be measured prior to entering the converter test drum/bench.
The input TC oil flow rate and output oil pressure of the TC shall be kept within the specified operational limits for the torque converter, depending on the related transmission type and the tested maximum input speed.
As specified for transmission testing in 3.1.2.5.3 and 3.1.2.5.4.
The torque converter shall be installed on a testbed with a torque sensor, speed sensor and an electric machine installed at the input and output shaft of the TC.
The calibration laboratory facilities shall comply with the requirements of either ISO/TS 16949, ISO 9000 series or ISO/IEC 17025. All laboratory reference measurement equipment, used for calibration and/or verification, shall be traceable to national (international) standards.
The torque sensor measurement uncertainty shall be below 1 % of the measured torque value.
The use of torque sensors with higher measurement uncertainties is allowed if the part of the uncertainty exceeding 1 % of the measured torque can be calculated and is added to the measured torque loss as described in 4.1.7.
The uncertainty of the speed sensors shall not exceed ± 1 rpm.
The uncertainty of the temperature sensors for the measurement of the ambient temperature shall not exceed ± 1,5 K.
The uncertainty of the temperature sensors for the measurement of the oil temperature shall not exceed ± 1,5 K.
As specified in 3.1.6.1.
1 000 rpm ≤ npum ≤ 2 000 rpm
At least the following signals shall be recorded during the measurement:
Input (pump) torque Tc,pum [Nm]
Output (turbine) torque Tc,tur [Nm]
Input rotational (pump) speed npum [rpm]
Output rotational (turbine) speed ntur [rpm]
TC input oil temperature KTCin [°C]
The sampling and recording rate shall be 100 Hz or higher.
A low pass filter shall be applied to avoid measurement errors.
for the calculation of ΔUT,pum/tur: smallest averaged torque value for Tc,pum/tur
for the calculation of torque ratio μ: largest averaged torque value for Tc,pum
for the calculation of torque ratio μ: smallest averaged torque value for Tc,tur
for the calculation of reference torque Tpum1000: smallest averaged torque value for Tc,pum
The part of the calculated measurement uncertainty UT,pum/tur exceeding 1 % of the measured torque Tc,pum/tur shall be used to correct the characteristic value of the TC as defined below.
ΔUT,pum/tur = MAX (0, (UT,pum/tur – 0,01 * Tc,pum/tur))
The uncertainty UT,pum/tur of the torque measurement shall be calculated based on the following parameter:
Calibration error (incl. sensitivity tolerance, linearity, hysteresis and repeatability)
The uncertainty UT,pum/tur of the torque measurement is based on the uncertainties of the sensors at 95 % confidence level.
UT,pum/tur = 2 * ucal
where:
=
Current / measured torque value at input/output torque sensor (uncorrected) [Nm]
=
Input (pump) torque (after uncertainty correction) [Nm]
=
Uncertainty of input / output torque measurement at 95 % confidence level separately for input and output torque sensor[Nm]
=
Nominal torque value of torque sensor [Nm]
=
Uncertainty by torque sensor calibration [Nm]
=
Relative calibration uncertainty (related to nominal torque) [%]
=
Calibration advancement factor (if declared by sensor manufacturer, otherwise = 1)
For each measurement point, the following calculations shall be applied to the measurement data:
The torque ratio of the TC shall be calculated by
The speed ratio of the TC shall be calculated by
The reference torque at 1 000 rpm shall be calculated by
where:
=
Torque ratio of the TC [-]
=
Speed ratio of the TC [-]
=
Input (pump) torque (corrected) [Nm]
=
Input rotational (pump) speed [rpm]
=
Output rotational (turbine) speed [rpm]
=
Reference torque at 1 000 rpm [Nm]
As specified in 4.1.1.
As specified in 4.1.2.
As specified in 4.1.3.
As specified in 4.1.4.
As specified in 4.1.5.
As specified in 4.1.6.
As specified in 3.1.6.1.
As specified in 4.1.8.
As specified in 4.1.9.
As specified in 4.1.9.
As specified in 4.1.11.