JP2751668B2 - Transmission control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission, and more particularly, to an improvement in a shift control device including a shift control for simultaneously shifting gears of a plurality of stepped transmissions for shifting. .

[0002]

2. Description of the Related Art In an automatic transmission for a vehicle, as the number of gears increases, an extremely fine gear shift according to a running state becomes possible, and a shift shock is reduced and running performance is improved. There are various advantages. For this reason,
2. Description of the Related Art An automatic transmission that includes a plurality of stepped transmissions and that performs a multi-stage shift by a combination of the shift speeds of the plurality of stepped transmissions has been proposed. For example, FIG. 2 shows a first transmission that can shift three forward speeds and one reverse speed, and a second transmission that can shift two stages of H (high) and L (low). This is a case in which five forward speeds and one reverse speed can be obtained by a combination of shift speeds of the transmission.

[0003] In such an automatic transmission, when the gears of a plurality of stepped transmissions are simultaneously switched, for example, one of the gears is shifted between "2nd" and "3rd" in FIG. In some cases, the speed of the stepped transmission is shifted to the low gear side, and the speed of the other stepped transmission is shifted to the high gear side. In this case, if the shift timing of both the stepped transmissions is shifted, there is a problem that a shift shock occurs due to a torque change.
As described in Japanese Patent Application Publication No. 50 and Japanese Patent Application Laid-Open No. 62-83541, the operating oil supplied to clutches, brakes, and the like by detecting the rotational speed and oil temperature of each part, and starting the shift of both transmissions. It has been considered that the shift timing of both stepped transmissions is adjusted by controlling the hydraulic pressure of the transmission. In addition, since such a shift control is generally set based on a normal driving condition, for example, a shift as intended is not performed under special driving conditions such as a warm-up operation and a cold operation. Therefore, it has been considered to prohibit shifting by simultaneously switching the gear positions of a plurality of stepped transmissions under predetermined predetermined conditions. For example, JP-A-61
The device described in JP-A-228148 is an example of such a device, and when the hydraulic oil supplied to a clutch or a brake for switching a gear position is not sufficiently warm, differences in viscosity, leakage amount, and the like may occur. As a result, the rise of the hydraulic pressure changes, and the gear shift is not performed as intended. Therefore, when the oil temperature is equal to or lower than a predetermined fixed value, gear shift by simultaneous switching of the gears of both transmissions is prohibited.

Here, a specific description will be given, with reference to FIG. 2, of the prohibition of gear shifting by simultaneously switching the gear positions of a plurality of stepped transmissions. In FIG. 2, "2nd" and "3r
The shift between “d” and “d” corresponds to the shift by simultaneous switching. However, even if the shift to “3rd” is prohibited, “2nd” and “4”
th ”, it is necessary to switch simultaneously, so“ 2nd ”
To "1st", "3rd", "4t"
The speed is changed in four forward speeds of "h" and "5th". Note that shifting to “3rd” and “4th” is prohibited and “1st”, “2nd”, and “5t”
h), it is possible to have three forward steps, but “2nd”
The difference in gear ratio between "5th" and "5th" is not preferable.

[0005]

However, even in such a shift control device which controls the shift timing of a plurality of stepped transmissions or inhibits shifting by simultaneous switching under certain conditions, the simultaneous switching is also required. If the sensor system involved in the speed change control fails, the control of the speed change timing and the prohibition of the speed change by simultaneous switching cannot be performed normally, and a problem such as a speed change shock occurs.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a failure in a sensor system involved in shift control for simultaneously switching the gears of a plurality of stepped transmissions. Another object of the present invention is to prevent a problem such as a shift shock from occurring.

[0007]

In order to achieve the above object, it is only necessary to prohibit gear shifting by simultaneous switching when the sensor system has failed. Multi-stage shifting is performed by a combination of the gears of the plurality of stepped transmissions, and when the gears of the plurality of stepped transmissions are simultaneously switched, the gear is switched based on an output signal from a sensor. (A) abnormality detecting means for detecting an abnormality of a sensor involved in a shift control for simultaneously switching gears of the plurality of stepped transmissions, and (b) detecting the abnormality. A simultaneous switching restricting means is provided for prohibiting a shift by simultaneous switching of the gear positions of the plurality of stepped transmissions when an abnormality of the sensor is detected by the means.

[0008]

In such a shift control device, as shown in the claim correspondence diagram of FIG.
Abnormality of a sensor involved in shift control for simultaneously switching the gear positions of a plurality of stepped transmissions, for example, control for controlling the shift timing of a plurality of stepped transmissions or prohibiting shifting by simultaneous switching, is detected by abnormality detection means. Detected,
When the abnormality is detected by the abnormality detecting means, the simultaneous switching restricting means inhibits the shift by simultaneously switching the gears of the plurality of stepped transmissions, and the gears of the plurality of stepped transmissions are respectively changed. The shift speed can be switched only by a simple shift control that can be switched alone.
This prevents the shift timing from being shifted due to a sensor abnormality or the shift from being performed when the shift by simultaneous switching should be prohibited, and is effective when the gears of a plurality of stepped transmissions are simultaneously switched. The occurrence of problems such as a shift shock due to a shift in shift timing is avoided.

Although two stepped transmissions are provided in FIG. 8, the number of stepped transmissions may be three or more. Also, a plurality of sensors are provided as necessary.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram of an automatic transmission for a vehicle according to an embodiment of the present invention.
A transmission 12 and a second transmission 14 are provided. The pump wheel of the torque converter 10 is connected to the crankshaft 18 of the engine 16, and the turbine wheel is connected to the input shaft 20.
Through the carrier 22 of the second transmission 14. The second transmission 14 includes a sun gear 24, a ring gear 2
6 and a planetary gear set comprising a planetary gear 28 rotatably disposed on the carrier 22 and engaged with the sun gear 24 and the ring gear 26. A clutch C is provided between the sun gear 24 and the carrier 22.
₀ and a one-way clutch F ₀ are provided in parallel, and a brake B ₀ is provided between the sun gear 24 and the housing 30. In the second transmission 14, the ring gear 26 is rotationally driven in two stages of L (low) and H (high) depending on whether the engagement of the clutch C _O is controlled or the engagement of the brake B ₀ is controlled. The rotation of the shaft 20 is changed in two stages and output from the ring gear 26. Since the one-way clutch F ₀ is provided between the sun gear 24 and the carrier 22, even when the clutch C ₀ is released in a state where power is transmitted from the engine 16, the one-way clutch F ₀ is used. The same operation as in the case where the engagement control is performed on C ₀ is obtained.

The first transmission 12 is rotatably disposed on the sun gear 32, the pair of ring gears 34, 36, and the carrier 38, and is rotatable on the sun gear 32, the planetary gear 40 meshed with the ring gear 34, and the carrier 42. The planetary gear unit includes a sun gear 32, a ring gear 36, and a planetary gear 44 meshed with the ring gear 36. The planetary gear unit includes a compound planetary gear unit. clutch C ₁ is provided, the sun gear 32 and the clutch C ₂ is provided between the ring gear 26, and the brake B ₁ represents between the sun gear 32 and the housing 30, the one-way clutch F ₁ which are disposed in series and a brake B ₂ is disposed in parallel, the brake B ₃ and unidirectional click between the carrier 38 and the housing 30 Pitch F ₂ are provided in parallel. The ring gear 34 and the carrier 42 are integrally connected to an output shaft 46. The first transmission 12
The clutch C _1, C _2, and the brake B _1, B _2,
By selectively controlling the engagement of B ₃ , the output of the second transmission 14 is shifted at three forward speeds and one reverse speed and output to the output shaft 46.

[0013] The clutch C ₀ -C ₂ and the brake B
_{0 to} B ₃ are engagement controlled by a hydraulic actuator such as a multi-plate clutch or a band brake,
The hydraulic actuator is supplied with hydraulic oil from a hydraulic control circuit 50. Hydraulic control circuit 50
Is provided with a number of switching valves and the like.
Excitation of the solenoids S1 and S2 according to the signal from
By switching the non-excitation, the first transmission 12 establishes any one of the three forward speeds, and the second transmission 14 is switched to either H or L by excitation and non-excitation of the solenoid S3. These gear stages are established.
By combining these shift speeds of the first transmission 12 and the second transmission 14, in this embodiment, five forward speeds and one reverse speed can be obtained as shown in FIG. That is, the first transmission 12 is in the first stage and the second transmission 14 is in the L position.
"1st", the first transmission 12 is in the first stage and the second transmission 1
4 is H “2nd”, the first transmission 12 is in the second stage and the second transmission 14 is L “3rd”, the first transmission 12 is in the third stage and the second transmission 14 is L “4th”. "5th" where the first transmission 12 is in the third gear and the second transmission 14 is H, and "Rev" in which the first transmission 12 is backward and the second transmission 14 is L. clutch C ₀ -C ₂ and the brake B ₀ .about.B
It can be alternatively established by the engagement control of ₃ . In the drawing, a mark “○” means engagement control, and a mark “△” means engagement control during engine braking. In the present embodiment, the first transmission 12 and the second transmission 14 correspond to a plurality of stepped transmissions. The hydraulic control circuit 50
In addition to the solenoids S1 to S3, a solenoid is provided in addition to the solenoids S1 to S3, and the hydraulic pressure is controlled by, for example, duty control of the on-off valve to change the time required for engagement or disengagement of the clutch or brake to change the gear position. The switching time can be adjusted.

The controller 52 includes a CPU, a RAM, an R
The microcomputer is configured by a microcomputer having an OM, and executes signal processing in accordance with a program stored in the ROM while utilizing a temporary storage function of the RAM to excite or deactivate the solenoids S1, S2, and S3. The excitation is switched. The controller 52, the rotational speed signal from the rotational speed sensor 56 for detecting throttle opening signal Sθ from a throttle opening sensor 54 for detecting the throttle opening θ corresponding to the engine load, the rotational speed N _T of the input shaft 20 SN _T , a rotation speed sensor 5 for detecting the rotation speed N _O of the output shaft 46
8, the rotation speed signal SN _O , the shift position of the shift lever 60 “D (drive)”, “L (low)”, “2”
(Second), “P (parking)”, “N (neutral)”, “R (reverse)”, etc., a shift position signal SS, and an oil temperature sensor for detecting the oil temperature T of the hydraulic oil of the hydraulic control circuit 50 An oil temperature signal ST is supplied from 62. The throttle opening θ represented by the throttle opening signal Sθ and the rotation speed signal SN
_O based on the rotational speed N _O i.e. the vehicle speed V represented, the excitation of the solenoid S1, S2, and S3, by switching the non-energized, changes the gear position according to a pre-stored shift map shown in FIG. 3 I do. It should be noted that one of a plurality of shift maps can be selected according to the driver's preference, and that the brake operation state, road surface gradient,
It is also possible to detect various other running states such as engine cooling water temperature, vehicle acceleration, and throttle opening change rate, and to control the gear shift very finely.

Here, when the gears of the first transmission 12 and the second transmission 14 are simultaneously switched to change the gear, that is, when the gear is changed between "2nd" and "3rd",
Since both transmission 12, 14 shift shock and shift timing gear is shifted in occurs, detects the shifting state based on the rotational speed N _T of the input shaft 20 to the rotational speed signal SN _T represents, solenoid S1~S3 By controlling the switching start time, oil pressure, and the like, the shift timing of both transmissions 12 and 14 is adjusted. For example, as described in FIG. 4 of the Japanese 62-4950 JP, hydraulic pressure duty control drain hydraulic That transitional oil pressure at the time of opening of the brake B ₀ for switching the gear position of the second transmission 14 When a circuit is provided, the shift timing of the second transmission 14 can be adjusted by the start time and end time of the duty control or the drain oil pressure by the duty control. Also, when the oil temperature T of the hydraulic oil of the hydraulic control circuit 50 is low, the rise of the oil pressure changes due to the difference in the viscosity and the amount of leakage, and the gear shift is not performed as intended. When the indicated oil temperature T is equal to or less than a predetermined fixed value, shifting by simultaneous switching of the gears of both transmissions 12 and 14 is prohibited. That is, the shift map includes a 2nd permitted shift mode in which “2nd” exists as shown in FIG.
From the shift map of FIG. 3, “1 →
2 ”and“ 2 ← 3 ”shift lines indicated by two-dot chain lines are removed, and“ 1st ”,“ 3rd ”,“ 4th ”,
And a second 5th prohibited speed change mode including four forward speeds. When the oil temperature T is low, the transmissions 12 and 14 are set as the 2nd prohibited speed change mode.
The shift by the simultaneous switching of the gears is prohibited. In this case, the shift lines of “2 → 3” and “1 ← 2” are “1 → 3” and “1 ← 3”, respectively. Further, in order to avoid a sudden shift from “1st” or “3rd” to “2nd” due to an increase in the oil temperature T, 2nd
Switching from the prohibited shift mode to the 2nd permitted shift mode is performed when the shift speed is set to “4th” or “5th”. In this embodiment, the rotational speed for detecting the rotational speed N _T and the oil temperature T sensor 56 and oil temperature sensor 62
Are sensors involved in shift control for simultaneously switching the shift speeds of a plurality of stepped transmissions.

[0016] The controller 52 also has a function shown in Figure 4, when the oil temperature sensor 62 for detecting the rotational speed sensor 56 or the oil temperature T for detecting the rotational speed N _T is abnormal Is adapted to switch the shift map to a 2nd prohibited shift mode. The rotational speed sensor abnormality detection block 64 is a block for detecting an abnormality of the rotational speed sensor 56, and is specifically executed according to the flowchart of FIG. That is, first, in step S1, it is determined whether or not the current gear is "4th" or "5th". If it is "4th" or "5th", the rotational speed sensors 56 and 58 are determined in steps S2 and S3. rotational speed signal supplied from the SN _T, the rotational speed N _T which represents the SN _O, reads N _O.
In a succeeding step S4, it is determined whether or not a difference | N _T −N _O × i | between a product N _O × i of the rotation speed N _O and the gear ratio i and the rotation speed _NT is smaller than a predetermined judgment value ΔN. Is determined,
If YES, the flag F _N = 0 in step S6.
If NO, the flag F is set in step S5.
_N = 1. The gear ratio i is the first transmission 12
The gear ratio “4t”
h "or" 5th ".
Basically, N _T ON _O × i, and the difference | N _T −N _O
× i | ≒ 0. The judgment value ΔN is set in consideration of the accuracy and rotation error of the sensor, and the difference | N _T −N
_{When O} × i | is equal to or greater than ΔN, that is, the flag F _N = 1
This means that the rotation speed sensor 56 has an abnormality. The determination of the abnormality of the rotation speed sensor 56 is based on the assumption that the rotation speed sensor 58 for detecting the vehicle speed V has no abnormality.

An oil temperature sensor abnormality detection block 66 shown in FIG.
Is a block for detecting an abnormality of the oil temperature sensor 62, and is specifically executed according to the flowchart of FIG. That is, first, in step S11, the sensor resistance value, specifically, the signal value of the oil temperature signal ST is read,
In step S12, it is determined whether or not the magnitude of the signal value is within a predetermined range. The oil temperature sensor 62 is formed of a thermistor or the like whose resistance value changes according to the temperature. If the resistance value is Δ or 0, it means that there is an abnormality such as disconnection or short circuit. . Therefore, when the signal value of oil temperature signal ST is not within the predetermined range, it is determined that oil temperature sensor 62 is abnormal, and flag F _T = 1 in step S13.
If it is within the predetermined range, the flag F _T = 0 is set in step S14.

The shift mode switching block 68 shown in FIG.
Is the flag F _N, which is for switching the shift mode of the shift map according to the value of F _T, is specifically executed according to the flowchart of FIG. That is, the read flag F _N in step S21, F _N = 1 whether, it is determined whether the rotational speed sensor 56 in other words abnormal in step S22, F _N
If = 1, the shift map is set to 2 in step S26.
The second shift mode is set. Further, the read flag F _T in step S23, F _T = 1 whether in step S24, it is determined whether the oil temperature sensor 62 is abnormal in other words, F _T = 1 in the case step S2
In step 6, the shift map is set to the 2nd prohibited shift mode.
If both the flags F _N and F _T are not 1, the shift map is set to the second permission mode in step S25. Switching between these shift modes is performed, for example, when the shift speed is “4th” or “5th”. Further, the step S is executed to set the shift map to the 2nd prohibited shift mode.
In 26, the driver may be notified of the abnormality by a warning lamp or the like in the driver's seat. The shift mode switching block 68 corresponds to simultaneous switching limiting means, and the rotational speed sensor abnormality detection block 64 and the oil temperature sensor abnormality detection block 66 correspond to abnormality detection means.

As described above, in the shift control apparatus for an automatic transmission according to the present embodiment, the shift control when the shift speeds of the first transmission 12 and the second transmission 14 are simultaneously switched to shift, that is, "2nd" The abnormality is detected in the rotational speed sensor 56 and the oil temperature sensor 62 involved in the shift control between the transmission and the "3rd". "1st", "3rd", "4t" consisting only of simple shift control for independently switching the 12th and 14th gears.
h ”and“ 5th ”in four forward speeds.
Therefore, during the shift control between “2nd” and “3rd”, both transmissions 12
When the shift timings of the transmissions 12 and 14 are shifted and the shift speed of the transmissions 12 and 14 cannot be changed at an appropriate shift timing due to the low oil temperature T, the oil temperature sensor 62 malfunctions. Thus, the shift speed is switched in the 2nd permitted shift mode, and the occurrence of a shift shock during shifting between “2nd” and “3rd” is favorably avoided.

While the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be embodied in other forms.

For example, in the above-described embodiment, when the first transmission 12 is in the first speed, the speed of the second transmission 14 is switched to "2".
nd ", the first transmission 12
Is also in the second gear, the gear of the second transmission 14 is switched so that the second transmission 14 adds "3rd '" of H between "3rd" and "4th" to make the gear 6 forward. It is also possible. In this case, by eliminating "2nd" and "3rd '" or eliminating "3rd" and "4th", it is possible to prohibit shifting by simultaneous switching of the gears of both transmissions 12 and 14. .

Further, in the above-described embodiment, in the speed change control for simultaneously switching the speed stages of the two transmissions 12 and 14, that is, in the speed change control between "2nd" and "3rd", the transmissions are controlled based on the rotational speed _NT. Although the shift timings of the shifts 12 and 14 are controlled and the shift mode is switched based on the oil temperature T, the present invention is also applied to a shift control device that performs shift control at the time of simultaneous switching with only one of the shift modes. The same can be applied. The control of the shift timing may be performed by detecting the rotation speed of another member such as the sun gear 24 or other physical quantities such as torque and hydraulic pressure as described in Japanese Patent Application Laid-Open No. 62-4950. It is possible to switch the shift mode.
It is also possible to use an engine cooling water temperature or the like as described in Japanese Patent Publication No. 228148 or the like.

In the above embodiment, the shift mode is switched by removing a predetermined shift line in the shift map. However, in the 2nd prohibited shift mode, "2 (1)" is used.
→ 3 ”Shift the shift line to the lower vehicle speed side and“ 1 ← 2 ”
(3) "The shift line may be shifted to the high vehicle speed side to optimize the shift, and two types of shift maps for permitting 2nd and prohibiting 2nd may be used.

The abnormality detection method of the sensor in the above embodiment is merely an example, and various abnormality detection methods can be adopted according to the type, function, characteristics, etc. of the sensor for which abnormality is to be detected.

In the above embodiment, the rotation speed sensor 56 and the oil temperature sensor 6 are controlled by the signal processing in the controller 52.
Although the second abnormality is detected, an abnormality detector may be separately provided.

Although not specifically exemplified, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an automatic transmission including a shift control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a shift speed of the automatic transmission of FIG. 1 and engagement states of a clutch and a brake for establishing the shift speed.

FIG. 3 is a diagram showing a relationship between a shift speed of the automatic transmission of FIG. 1, a vehicle speed, and a throttle opening.

FIG. 4 is a block diagram illustrating functions provided in a controller of the automatic transmission in FIG. 1;

FIG. 5 is a flowchart illustrating a rotation speed sensor abnormality detection block in FIG. 4;

FIG. 6 is a flowchart illustrating an oil temperature sensor abnormality detection block in FIG. 4;

FIG. 7 is a flowchart illustrating a shift mode switching block of FIG. 4;

FIG. 8 is a diagram corresponding to claims of the present invention.

[Explanation of symbols]

12: first transmission (stepped transmission) 14: second transmission (stepped transmission) 52: controller 56: rotation speed sensor 62: oil temperature sensor 64: rotation speed sensor abnormality detection block (abnormality detection means) 66: Oil temperature sensor abnormality detection block (abnormality detection means) 68: Shift mode switching block (simultaneous switching restriction means)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noriaki Asahara 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Yasuo Hojo 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) reference Patent Sho 61-228148 (JP, a) JP Akira 62-4948 (JP, a) JP Akira 62-20938 (JP, a) (58 ) investigated the field (Int.Cl. ⁶ , DB name) F16H 59/00-63/30

Claims (1)

(57) [Claims] A plurality of stepped transmissions, wherein a plurality of stepped transmissions are combined to perform a multi-stage shift, and a sensor is provided for simultaneously switching the plurality of stepped transmissions. Abnormality detection for detecting an abnormality of a sensor involved in a shift control for simultaneously switching the shift speeds of the plurality of stepped transmissions, in the shift control device for an automatic transmission, which controls the shift speed shift based on an output signal from the control unit. Means and a simultaneous switching restricting means for prohibiting a shift by simultaneous switching of the gears of the plurality of stepped transmissions when the abnormality of the sensor is detected by the abnormality detecting means. Transmission control device for automatic transmission.