JP6315406B2 - Transmission control device - Google Patents

Description

  The present invention relates to a transmission control device, and more particularly to transmission control of a transmission at a cryogenic temperature.

  For example, in a mechanical automatic transmission (so-called AMT: Automated Manual Transmission), when the vehicle is in a very low temperature state in a cold region or the like, the hydraulic oil that intervenes on the friction surface of the synchro mechanism in the transmission gear until the warm-up is completed. Since the viscosity of (for example, ATF: Automatic Transmission Fluid) is high, the synchronizing action of the synchro mechanism is hindered and gearing becomes difficult. Further, if the viscosity of the hydraulic oil that lubricates the transmission gear is high, it becomes a resistance to the gear speed increasing action by the synchro mechanism.

  Furthermore, when the clutch is lubricated with hydraulic fluid, the increase in the viscosity of the hydraulic fluid causes power to be transmitted through the hydraulic fluid even when the clutch is disengaged, increasing the so-called drag torque. However, gearing in the transmission becomes difficult.

  Therefore, a heat exchanger for exchanging heat between the engine coolant and the transmission hydraulic fluid is provided, and the flow rate of the hydraulic fluid to be circulated through the heat exchanger is increased to increase the hydraulic fluid temperature of the transmission. Technology has been developed (see Patent Document 1).

JP 2010-53772 A

  However, in Patent Document 1, since a heat exchanger for warming up the hydraulic fluid of the transmission must be provided, there is a problem that the number of parts is increased and the layout is complicated.

  In addition, when the vehicle travels before the warm-up is completed, a shift failure or gear squealing due to the viscosity of the hydraulic oil occurs, or the vehicle safety device causes a failure due to inability to engage the transmission gear. It may be determined that the vehicle has fallen into a road fault.

  The present invention was made to solve such a problem, the purpose of which is to solve the problem caused by the viscosity of the hydraulic oil when the vehicle travels in a low temperature state before the completion of warm-up, An object of the present invention is to provide a transmission control device capable of improving the reliability of the transmission.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

  (1) In the transmission control device according to this application example, a transmission that is connected to the engine of the vehicle and that changes the rotational driving force of the engine by switching a transmission gear according to a plurality of shift stages; A hydraulic pressure supply means that is driven by the engine and supplies hydraulic oil to the transmission; a hydraulic pressure adjustment means that adjusts the hydraulic pressure of the hydraulic oil to the transmission and switches a gear position; and detects the temperature of the hydraulic oil. And an oil temperature detecting means for detecting the vehicle speed of the vehicle, and when the temperature of the hydraulic oil detected by the oil temperature detecting means is equal to or lower than a predetermined temperature, the transmission is geared. The hydraulic pressure adjustment is performed so that the transmission gear is set to neutral by prohibiting gearing when the transmission gear is in a position other than a predetermined predetermined speed and the vehicle speed detected by the vehicle speed detection means is equal to or higher than the predetermined vehicle speed. A transmission gear that is geared in the transmission is other than the predetermined gear and the vehicle speed detected by the vehicle speed detection means is less than a predetermined vehicle speed, or a gear that is geared is Shift control means for controlling the hydraulic pressure adjusting means so as to permit only gearing to the predetermined speed when the speed is the predetermined speed.

(2) In the transmission control apparatus according to this application example, the predetermined stage may be a first speed and a reverse stage.

  According to the present invention using the above means, it is possible to eliminate problems caused by the viscosity of the hydraulic oil when the vehicle travels in a low temperature state before completion of warming up, and to improve the reliability of the transmission.

It is a schematic block diagram which shows the drive system of a vehicle provided with the control apparatus of the transmission which concerns on one Embodiment of this invention. It is a flowchart which shows the shift control routine before the warming-up completion which TCU which concerns on one Embodiment of this invention performs.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a drive system of a vehicle provided with a transmission control device according to an embodiment of the present invention.

  A vehicle 1 shown in FIG. 1 includes a drive device having a configuration in which an engine 2 that is a driving source for traveling is connected to a transmission unit 4 via a clutch unit 3. The vehicle 1 travels by transmitting the driving force from the engine 2 to the left and right drive wheels 5 and 5 (for example, rear wheels) through the clutch unit 3 and the transmission unit 4.

  Specifically, the rotational driving force output from the engine 2 (hereinafter simply referred to as driving force) is input to the clutch unit 3 via the input shaft 10 and branched into two systems within the clutch unit 3. The clutch unit 3 has two clutches, a first clutch 11a and a second clutch 11b, and one of the driving forces of the engine 2 branched into two systems in the clutch unit 3 is on the input side of the first clutch 11a. The other is transmitted to the input side of the second clutch 11b. Although the first clutch 11a and the second clutch 11b are shown in parallel in the drawing, the first clutch 11a is actually arranged on the inner side, and the second clutch 11b is arranged on the outer side. Has been.

  The transmission unit 4 includes two transmission mechanisms, a first transmission mechanism 12a (G1 in FIG. 1) and a second transmission mechanism 12b (G2 in FIG. 1), corresponding to the first clutch 11a and the second clutch 11b. ing. The output side of the first clutch 11a is connected to the input shaft of the first transmission mechanism 12a, and the output side of the second clutch 11b is connected to the input shaft of the second transmission mechanism 12b.

  The first speed change mechanism 12a has first-speed, third-speed, and fifth-speed transmission gears as forward speeds. On the other hand, the second speed change mechanism 12b has even-numbered speed change gears of second speed, fourth speed, and sixth speed as forward shift speeds. Although the reverse gear stage is not shown, it is assumed that it is included in the first transmission mechanism 12a.

  Although not shown, a synchro mechanism is provided for each gear position. The synchro mechanism performs gear engagement by synchronizing the rotation of the input side and the output side of the transmission gear corresponding to the time of shifting of the gear position (during gear shifting).

  Although a simplified block diagram is shown in FIG. 1, the transmission unit 4 has a hydraulic circuit for operating the synchro mechanism. The hydraulic circuit is connected to a hydraulic pressure adjusting mechanism 15 (hydraulic pressure adjusting means) from a hydraulic pump 13 (hydraulic pressure supplying means) that is driven in accordance with the rotation of the engine 2 via a connecting oil passage 14. 12a and 12b are connected to the synchro mechanism. The hydraulic adjustment mechanism 15 has an electromagnetic valve corresponding to the synchronization mechanism of each transmission gear, and the hydraulic oil (ATF) pumped from the hydraulic pump 13 is adjusted by the electromagnetic valve and supplied to the synchronization mechanism. . The synchro mechanism performs gearing of the corresponding transmission gear according to the hydraulic pressure of the supplied hydraulic oil.

  An oil temperature sensor 17 (oil temperature detecting means) for detecting the temperature of the hydraulic oil (oil temperature) is provided in the introduction oil passage 16 for introducing the hydraulic oil from the oil pan to the hydraulic pump 13. Although not shown, the clutch unit 3 also has a hydraulic circuit different from that of the transmission unit 4, and each of the clutches 11 a and 11 b is a wet multi-plate clutch that is connected / disconnected by hydraulic pressure of hydraulic oil.

  The driving force output from the first transmission mechanism 12a and the driving force output from the second transmission mechanism 12b are both transmitted to the differential device 19 via the common output shaft 18, and the left and right drive wheels 5 are driven. 5 is assigned. As described above, in the present embodiment, the clutch unit 3 and the transmission unit 4 constitute a so-called dual clutch transmission 20 (transmission).

  When the first clutch 11a and the second clutch 11b are in the disengaged state, or when the gears of the first transmission mechanism 12a and the second transmission mechanism 12b are not geared, the vehicle 1 having the above configuration is neutral. It becomes a state. On the other hand, when one of the first clutch 11a and the second clutch 11b is in the connected state, the engine 2 is mechanically connected to the drive wheels 5 and the like via the speed change mechanism corresponding to the clutch in the connected state in the speed change unit 4. Will be connected.

  As described above, the vehicle 1 includes the first power transmission system in which the power of the engine 2 is transmitted to the drive wheels 5 through the first clutch 11a and the first transmission mechanism 12a, and the power of the engine 2 in the second clutch 11b and There are two power transmission systems of a second power transmission system that is transmitted to the drive wheels 5 via the second speed change mechanism 12b.

  The vehicle 1 is equipped with a TCU (transmission control unit) 30 (transmission control means) for controlling such a dual clutch transmission 20. The TCU 30 is connected to the oil temperature sensor 17 and various sensors such as a vehicle speed sensor 31 (vehicle speed detection means) for detecting the speed (vehicle speed) of the vehicle 1 by, for example, a conductive wire, and the oil detected by the oil temperature sensor 17. Temperature information and vehicle speed information detected by the vehicle speed sensor 31 can be acquired.

  Further, a change lever 32 for switching the travel range is provided in the driver's seat of the vehicle 1. A shift position sensor 33 that detects a shift position (shift range) selected by a change lever operation by the driver is also provided. The shift position includes a P (parking) range selected during parking, an N (neutral) range in which the gear of the speed change unit 4 is neutral, a D (drive) range selected during forward travel, and an R (reverse) range selected during reverse travel. Etc. That is, the P range and N range are non-traveling ranges, and the D range and R range are traveling ranges. The TCU 30 is connected to the shift position sensor 33 by, for example, CAN, and can acquire shift position information detected by the shift position sensor 33.

  Further, the TCU 30 is also connected to an engine ECU 34 that controls the engine 2 and another control unit (not shown), and can acquire information such as the engine speed and engine torque from the engine ECU 34.

  The TCU 30 is also connected to a hydraulic pressure adjusting mechanism (not shown) of the clutch unit 3 and a hydraulic pressure adjusting mechanism 15 of the transmission unit 4, and performs shift control by controlling these hydraulic pressure adjusting mechanisms.

  The TCU 30 in the present embodiment is based on the case where the vehicle travels before the warm-up is completed in a low-temperature environment such as a cold region based on the temperature of the hydraulic oil, the shift position, the gear position being geared, and the vehicle speed. Shift control is performed to eliminate the problem.

  FIG. 2 shows a flowchart showing a shift control routine executed by the TCU 30 before completion of warm-up in the present embodiment, and will be described below with reference to the flowchart of FIG.

  First, in step S1 shown in FIG. 2, the TCU 30 determines whether or not the temperature of the hydraulic oil of the transmission unit 4 detected by the oil temperature sensor 17 is lower than a predetermined temperature. The predetermined temperature is set to a temperature at which the viscosity of the hydraulic oil is high and gearing is difficult or gear noise is generated, and is set to, for example, −10 ° C. in the present embodiment. When the determination result is false (No), that is, when the temperature of the hydraulic oil is −10 ° C. or higher, the process proceeds to step S2.

  In step S2, the TCU 30 exits from the routine as performing normal shift control (normal shift).

  On the other hand, if the determination result in step S1 is true (Yes), that is, if the temperature of the hydraulic oil is in an extremely low temperature state lower than −10 ° C., the process proceeds to step S3.

  In step S3, the TCU 30 detects the current shift position by the shift position sensor 33, and determines whether or not the selected shift position is the travel range, that is, the D range or the R range. When the determination result is false (No), that is, when the shift position is the non-traveling range of the P range or the N range, the process proceeds to the above-described step S2 and the normal shift is performed.

  On the other hand, if the determination result in step S3 is true (Yes), that is, if the shift position is the driving range of the D range or the R range, the process proceeds to step S4.

  In step S4, the TCU 30 determines whether or not the gear stage currently geared in the transmission unit 4 is a predetermined stage. The predetermined stage here is preferably a relatively low speed stage where the running torque becomes large, and in this embodiment, the first speed and the reverse speed are the lowest speed stages.

  If the determination result in step S4 is false (No), that is, if the transmission unit 4 is geared to a speed change gear other than the first speed or reverse speed, or is in a neutral state, the process proceeds to step S5.

  In step S5, the TCU 30 determines whether or not the vehicle speed detected by the vehicle speed sensor 31 is lower than a predetermined vehicle speed. The predetermined vehicle speed here is a vehicle speed equivalent to a stop at which it can be determined that the vehicle is stopped, and is 3 km / h in this embodiment.

  If the determination result in step S5 is false (No), that is, if it can be determined that the vehicle speed is equal to or higher than the predetermined vehicle speed and the vehicle 1 is in the traveling state, the process proceeds to step S6.

  In step S6, the TCU 30 inhibits the hydraulic adjustment mechanism 15 from engaging the transmission unit 4 and returns to the routine in a neutral state.

  On the other hand, if the determination result in step S5 is true (Yes), that is, if the vehicle speed is in a stopped state below a predetermined vehicle speed, the process proceeds to step S7.

  Further, also when the determination result of the above step S4 is true (Yes), that is, when the shift stage of the transmission unit 4 is geared to a predetermined stage, the process proceeds to step S7.

  In step S <b> 7, the TCU 30 fixes the gear position to the predetermined speed by permitting only the gear adjustment to the predetermined speed to the hydraulic pressure adjusting mechanism 15, and returns the routine. Specifically, if the gear is already in the predetermined gear (when Step S4 is Yes), the gear in the predetermined gear is maintained as it is. On the other hand, when the gear is engaged at a position other than the predetermined stage and the vehicle is stopped (when Step S5 is Yes), when the shift position is in the D range, it is in the 1st speed, and in the R range. Put gears in reverse.

  By repeating the control routine as described above, the TCU 30 can travel only at a predetermined stage set to a low speed stage in a state before the warm-up is completed when the hydraulic oil is lower than a predetermined temperature. Even if the vehicle can travel at a speed other than the specified level (2nd speed or more) before the warm-up is complete, or when the temperature of the hydraulic oil becomes lower than the specified temperature while the vehicle is running, the gear change is prohibited and the neutral state is entered. When the vehicle 1 stops, a shift to a predetermined speed is performed.

  As a result, gear shifting is not performed when the hydraulic oil is in a low temperature state, so that a gear shift failure or gear ringing due to the viscosity of the hydraulic fluid does not occur, and a state where it is difficult to engage the gear is not recognized as a vehicle failure.

  And the predetermined stage which can be shifted at the time of a stop is set to low speed stages, such as the 1st speed and the reverse stage, and the driving | running | working which ensured sufficient torque is attained. Further, when the gear is engaged at a low speed, the number of rotations of the gear in the transmission unit 4 is increased and the stirring action is increased, so that warm-up can be promoted. In addition to the first speed and the reverse speed, the predetermined speed may be set to a predetermined speed, for example, when the start speed for forward movement of the vehicle 1 is 2 or more, and there are a plurality of reverse speeds. May set the starting stage for reverse driving to a predetermined stage.

  Although the description of the embodiment of the transmission control device according to the present invention has been completed above, the embodiment is not limited to the above embodiment.

  Moreover, although the automatic transmission of the said embodiment is the dual clutch transmission 20 by the clutch unit 3 and the transmission unit 4, the automatic transmission which can apply this invention is not restricted to this. The present invention can also be applied to other automatic transmissions that switch transmission gears by hydraulic pressure. Furthermore, the present invention is also applicable to other automatic transmissions that switch gears by other power such as electric power or compressed air pressure.

  In the above embodiment, the temperature of the hydraulic oil is directly detected by the oil temperature sensor 17, but the temperature of the hydraulic oil in the transmission unit 4 is estimated based on, for example, the engine water temperature, and the warm-up state is determined. You may judge.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 3 Clutch unit 4 Transmission unit 10 Input shaft 11a 1st clutch 11b 2nd clutch 12a 1st transmission mechanism 12b 2nd transmission mechanism 13 Hydraulic pump (hydraulic supply means)
15 Hydraulic adjustment mechanism (hydraulic adjustment means)
17 Oil temperature sensor (oil temperature detection means)
18 Output shaft 19 Differential device 20 Dual clutch transmission (transmission)
30 TCU (shift control means)
31 Vehicle speed sensor (vehicle speed detection means)
32 Change lever 33 Shift position sensor 34 Engine ECU

Claims (2)

A transmission that is connected to an engine of the vehicle and that changes a rotational driving force of the engine by switching a transmission gear according to a plurality of shift stages;
A hydraulic pressure supply means that is driven by the engine and supplies hydraulic oil to the transmission;
Hydraulic pressure adjusting means for adjusting the hydraulic pressure of hydraulic oil to the transmission and switching the gear position;
Oil temperature detecting means for detecting the temperature of the hydraulic oil;
Vehicle speed detecting means for detecting the vehicle speed of the vehicle;
When the temperature of the hydraulic oil detected by the oil temperature detection means is equal to or lower than a predetermined temperature,
If the transmission gear that is geared in the transmission is in a position other than a predetermined level and the vehicle speed detected by the vehicle speed detection means is equal to or higher than the predetermined vehicle speed, the gearing of the transmission is prohibited and neutral. Controlling the hydraulic pressure adjusting means to
The transmission gear that is geared in the transmission is other than the predetermined speed and the vehicle speed detected by the vehicle speed detection means is less than the predetermined vehicle speed, or the speed change gear that is geared is the predetermined speed. In this case, a shift control means for controlling the hydraulic pressure adjustment means so as to allow only gearing to the predetermined stage;
A transmission control apparatus comprising:   The transmission control apparatus according to claim 1, wherein the predetermined stages are a first speed and a reverse stage.

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