JPH0527780B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Field of Application) The present invention relates to an electronically controlled transmission for a vehicle, and particularly to an electronically controlled transmission for a vehicle having a high-speed fixed range in which a gear is fixed to a high gear. (Prior Art) There are two types of transmissions included in automobiles: manual transmissions and automatic transmissions. Manual transmissions have the advantage of providing a comfortable driving feel because the gears are selected by the driver's operation, but on the other hand, they require cumbersome clutch operations when changing gears, making it difficult for the driver to operate. It has disadvantages such as increasing fatigue. On the other hand, automatic transmissions have the advantage that they do not require clutch operation, making driving operations easier and reducing driver fatigue. In automobiles whose driving conditions change significantly depending on the loaded state, it is difficult to always obtain the optimum gear position depending on each driving condition, and this has disadvantages such as deterioration of fuel efficiency. In view of these circumstances, in recent years, transmissions that combine the advantages of both manual transmissions and automatic transmissions have been equipped with a plurality of friction engagement means to obtain a plurality of gears, and have also been developed to provide transmissions that combine the advantages of both manual transmissions and automatic transmissions. It is equipped with a plurality of fixed ranges that can be switched by manual shift operation, and an automatic transmission range that is automatically switched, that is, a D range, and can change between the fixed ranges without requiring clutch operation. 2. Description of the Related Art Transmissions in which gears can be changed by manual operation are being put into practical use. By the way, this type of transmission switches the power transmission path of the transmission gear mechanism by selectively operating the plurality of frictional engagement means, and selects a gear position according to the shifted range or the driving state of the vehicle. However, among the above-mentioned frictional engagement means, those that are engaged at low gears such as 1st and 2nd gears must transmit the large torque necessary for starting the car, etc. While the torque capacity is set to be large, the torque capacity of gears that are engaged at high speeds such as 3rd and 4th gears is usually set to be small because the torque to be transmitted is relatively small. However, in an automobile equipped with a plurality of frictional engagement means as described above and a transmission having a plurality of fixed ranges for switching these engagement means by manual operation, when the vehicle is stationary or at an extremely low speed, If the driver depresses the accelerator pedal to start or suddenly accelerate from a low speed even though the shift lever has been shifted to a high-speed fixed range such as 3rd or 4th gear, , seizing may occur due to slippage of the friction fastening means. In other words, in the high-speed gear corresponding to the high-speed fixed range, a friction engagement means with a small torque capacity is engaged as described above, but when a large torque required for starting the car is input to this friction engagement means, This exceeds the torque capacity of the frictional fastening means, causing slippage between the friction plates constituting the frictional fastening means, and this slippage causes the friction plates to seize. By the way, there is an invention disclosed in, for example, Japanese Patent Publication No. 13928/1983, which allows an automobile equipped with an automatic transmission to start smoothly. In this invention, when the torque input to the frictional engagement means is large and the throttle opening is high, the vehicle is started in first gear, and when the torque is small and the throttle opening is low, the vehicle is started in second gear. However, this is related to starting when the gear is shifted to the D range, which automatically changes the gear, and it is not possible to set it to a high gear such as 3rd or 4th gear when starting or at an extremely low vehicle speed. This is not possible, and therefore, the present invention does not solve the above-mentioned problem at the time of starting when the vehicle is shifted to the high-speed fixed range. (Object of the Invention) The present invention is configured such that a plurality of gears can be obtained by selectively engaging a plurality of friction engagement means,
It also addresses the above-mentioned problem in transmissions that are equipped with multiple fixed ranges for manually changing gears, and it is possible to start or shift to a high-speed fixed range such as 3rd or 4th gear. The purpose of this invention is to prevent the frictional fastening means from slipping or seizing when attempting to suddenly accelerate the vehicle. (Structure of the Invention) In order to achieve the above object, the present invention is characterized by the following structure. That is, as shown in FIG. 1, a variable speed gear mechanism 2 connected to the output shaft of an engine 1, a plurality of frictional fastening means 3...3 for switching the power transmission path of the variable speed gear mechanism 2, and these friction fastening means. 3... has a hydraulic control circuit 4 for selectively engaging 3, and
In a transmission 5 equipped with a plurality of fixed ranges including a high-speed fixed range, a vehicle speed sensor 6 detects vehicle speed, a range switch 7 indicates that the shift lever is shifted to the high-speed fixed range,
A control means 8 is provided for receiving output signals from the range switch 7 and the vehicle speed sensor 6 to control the hydraulic control circuit 4. This control means 8 controls the plurality of frictions when the vehicle speed indicated by the output signal from the vehicle speed sensor 6 is less than or equal to the set vehicle speed and the output signal from the range switch 7 indicates that the output signal is shifted to the high-speed fixed range. A control signal is output to the hydraulic control circuit 4 so as to cut off or prevent engagement of the friction engagement means necessary for obtaining the gear stage corresponding to the high speed fixed range among the engagement means 3...3. According to such a configuration, even when the accelerator pedal is depressed with the shift lever shifted to a high-speed fixed range such as 3rd or 4th gear when the vehicle is stopped or at a low vehicle speed, the friction engagement to obtain the high-speed gear is not performed. Since the means is not connected, a large torque required for starting or sudden acceleration exceeding the torque capacity of the fastening means is prevented from being input to the fastening means. (Effects of the Invention) As described above, according to the present invention, a plurality of gear stages can be obtained by selectively engaging a plurality of friction engagement means,
In addition, in a transmission configured so that these gears can be manually switched between multiple fixed ranges, it is difficult to start while shifting to the high-speed fixed range or to suddenly accelerate from a low vehicle speed. blocked. As a result, when starting or suddenly accelerating in such a state, the friction engagement means for obtaining the gear corresponding to the high-speed fixed range may slip or seize, or the transmission may malfunction due to this. This also prevents deterioration of durability and the like. (Example) Hereinafter, an example of the present invention will be described based on the drawings. The present embodiment relates to an electronically controlled transmission having a shift pattern with a fixed range of 1st to 4th speeds. As shown in FIG. 2, the electronically controlled transmission 10 receives signals a to f from the shift device 11 provided in the cabin of the vehicle, signals a to f from the shift device 11, and a vehicle speed signal g from the vehicle speed sensor 12. A control circuit 13 that outputs a control signal h to an actuator 14 composed of a plurality of solenoid valves;
The hydraulic circuit 15 supplies and discharges hydraulic oil to the plurality of frictional fastening members in the gear shift device 16 by selectively operating the plurality of solenoid valves in the actuator 14 based on the above. The shift device 11 has fixed ranges 17 ₁ to 17 ₄ for 1st to 4th speeds, and a D range 17 ₅ for automatic shifting.
and R range ₁₇₆ for reverse speed, and a shift lever 18 for switching between these ranges ₁₇₁ to ₁₇₆ .
and has. And each of the above ranges 17 ₁ to 17 ₆
are provided with range switches 17a to 17f, respectively.
17f, only the range switch of the range to which the shift lever 18 is shifted is turned on, and each of these range switches 17a to 17a is turned on.
Range signals a to f indicating ON/OFF status of 17f
are respectively input to the control circuit 13. Here, the general configuration of the gear changeover device 16 used in this embodiment will be explained. This gear changeover device 16 includes an input shaft 20 into which power is input from the output shaft 19a of the engine 19;
It has an output shaft 30 disposed coaxially with the input shaft 20, and a counter shaft 40 parallel to these shafts 20, 30, and a plurality of gear trains 51 between each of the shafts 20, 30, 40. - 54 are provided, and first to fourth friction clutches 61 to 64 and first and second one-way clutches 71 and 72 are provided for selectively bringing these gear trains 51 to 54 into a power transmission state. There is. By selectively engaging these first to fourth friction clutches 61 to 64, the following four forward power transmission paths are obtained. That is, from the input shaft 20 to the first
One-way clutch 71, second gear train 52, second
Friction clutch 62, countershaft 40, third
A path (first speed) passing through the gear train 53, the second one-way clutch 72, and the fourth friction clutch 64 to the output shaft 30, and a path from the input shaft 20 to the first friction clutch 61, the first gear train 51, and the counter. shaft 40, third gear train 53,
A path (second speed) passing through the second one-way clutch 72 and the fourth friction clutch 64 to the output shaft 30, and a path from the input shaft 20 to the output shaft via the first one-way clutch 71 and the third friction clutch 63. 30, a path (3rd speed) through which power is directly transmitted to Friction clutch 6
A path (4th speed) that passes through 3 and reaches the output shaft 30 is obtained. In addition, the power transmission path for reverse speed is the input shaft 20.
from the first one-way clutch 71, the second gear train 5
2. Second friction clutch 62, countershaft 4
0 and the fourth gear train 54 to the output shaft 30. Incidentally, this gear stage switching device 16 includes first and second one-way clutches 7.
Friction clutches 65 and 66 for engine braking are provided in parallel with 1 and 72. Then, the first to fourth routes when configuring each of the above routes are
The operating states of the friction clutches 61 to 64 and the first and second one-way clutches 71 and 72 are shown in Table 1. Here, in Table 1, the circle mark indicates a clutch that transmits power.

[Table] By the way, when the shift lever 18 in the shift device 11 is shifted to the D range ₁₇₅ (when the D range switch 17e is ON), such switching of the power transmission path or the gear stage is performed as follows.
The corresponding friction clutch is selected via the actuator 14 and the hydraulic circuit 15 in accordance with the control signal h output from the control circuit 13 in response to the vehicle speed indicated by the signal g from the vehicle speed sensor 12 and the signal from the accelerator opening sensor (not shown). However, when the shift lever 18 is shifted to any of the fixed ranges 17 ₁ to 17 ₄ of the 1st to 4th speeds, based on the signal from the range switch, Control circuit 13, actuator 1
4. A friction clutch is engaged via the hydraulic circuit 15 to obtain a gear position corresponding to the range. That is, the shift lever 18 in the shift device 11 is in the 1st speed range 17, for example.
When shifted to ₁ , only the 1st speed range switch 17a is turned on, and a range signal a indicating this is input to the control circuit 13, and a plurality of range switches An actuator 14 comprising solenoid valves selectively operates these solenoid valves,
In response to this operation, hydraulic oil is supplied and discharged from the hydraulic circuit 15 to the first to fourth friction clutches 61 to 64. As a result, each of the clutches 61 to 64 is in the state shown in Table 1 when the gear stage is 1st gear, and as long as the shift lever 18 is shifted to the 1st gear range ₁₇₁ , each clutch 61 to 64 is in the state shown in Table 1. It is designed to remain in that state. In addition, the shift lever 18 is set to each fixed range 17 ₂ to 1 of 2nd to 4th speeds.
Even when shifted to ₇₄ , each of the clutches 61 to 64 is similarly maintained at the 2nd to 4th speeds shown in the table. When the shift lever 18 is operated to shift between the fixed ranges ₁₇₁ to ₁₇₄ , the engaged state of each of the clutches 61 to 64 is switched, thereby performing manual gear shifting in accordance with the shift operation. become. However, when starting a car, the shift lever 18 is usually shifted to the first or second fixed range 17 ₁ , 17 ₂ or the D range 17 ₅ , but if the driver accidentally When an attempt is made to start with the vehicle shifted to the third or fourth high speed fixed ranges 17 ₃ , 17 ₄ , the operation of the control circuit 13 prevents the vehicle from starting in such a state. Next, the above operation of the control circuit 13 will be explained based on the flowchart shown in FIG. Prior to starting the automobile, the control circuit 13 first receives the range signal a from each range switch 17a to 17f disposed in the shift device ₁₁ in step X1.
~f detects which range the shift lever 18 is shifted to, and then steps
At _X2 , it is determined whether the shifted range is the 3rd or 4th high speed fixed range ₁₇₃ , ₁₇₄ . In that case, at the time of normal start, the low speed fixed range 17 1 or 2 speed 17 ₁ , 17 ₂ ,
The control circuit 13 is shifted to either the D range ₁₇₅ or the R range ₁₇₆ .
Executing X ₂ to X ₃ , the first to fourth friction clutches 61 to 64 in the gear changeover device 16 are set to any of the first, second, or reverse speeds shown in Table 1 via the actuator 14 and hydraulic circuit 15. Set to the fastened state. Then, when the driver depresses the accelerator pedal, a normal start is performed. Therefore, the shift positions indicated by the range signals a to f are in the high-speed fixed range 17 ₃ , such as 3rd or 4th gear.
17 ₄ , the control circuit 13 executes steps X ₂ to X ₄ described above to control the vehicle speed sensor 12.
The vehicle speed V indicated by the signal g from the vehicle is detected, and in step _X5 it is determined whether this vehicle speed V is faster than the set vehicle speed _V0 . Here, the above-mentioned set vehicle speed V ₀ is set to a vehicle speed corresponding to an engine rotation speed of 800 to 1000 RPM, in other words, a very low vehicle speed that is stopped or close to a stopped state, so when starting or at a very low vehicle speed, Since V<V ₀ , the control circuit 13
executes step X ₅ to step X ₆ . Therefore, the friction clutch for 3rd speed or 4th speed shown in Table 1, that is, the third friction clutch 63 when shifted to the 3rd speed fixed range, and the first friction clutch 63 when shifted to the 4th speed fixed range. ~At least one of the third friction clutches 61-63 is disconnected. Then, in step _X7 , a warning is issued by a buzzer, lamp, etc. As a result, the transmission of power from the input shaft 20 to the output shaft 30 is cut off, and when the shift lever 18 is shifted to the 3rd or 4th high-speed fixed range 17 ₃ , 17 ₄ , the vehicle starts or starts. Rapid acceleration from a low vehicle speed is no longer possible, and the above-mentioned warning allows the driver to recognize that the vehicle has been erroneously shifted to the high-speed fixed range. By the way, when a car starts or suddenly accelerates from a low speed, the large torque increased by the reduction gear must be transmitted to the output shaft 30 via the friction clutch. A friction clutch that is engaged when in 2nd gear,
That is, the first, second, and fourth friction clutches 61, 6
2 and 64 have a larger torque capacity, but 3
A friction clutch that is only engaged in 3rd and 4th gears because there is no need to transmit the large torque mentioned above when driving in high gears such as 3rd or 4th gears.
In other words, the third friction clutch 63 has a reduced torque capacity. Therefore, the gear stage is 3rd or 4th gear.
When the car is started at a high speed, a large torque is input to the third friction clutch 63, which has a small torque capacity, and as a result, the clutch 63
Slippage occurs between the plurality of friction plates making up the friction plate, and the friction plates seize. However, in this transmission 10, as described above, the operation of the control circuit 13 prevents starting in the high gears of 3rd and 4th gears and sudden acceleration from low vehicle speeds, so the above-mentioned friction is prevented. Seizing of the board will no longer occur. This prevents the transmission from malfunctioning or from deteriorating its durability due to starting or the like with the transmission shifted to the high-speed fixed range. Furthermore, if the vehicle speed V is higher than the set vehicle speed _V0 , the control circuit 13 performs the above step _X5 when the shift lever is shifted to a high-speed fixed range such as 3rd or 4th speed.
Then, _step It becomes possible. Here, in this embodiment, the present invention is applied to a transmission having a parallel two-shaft type gear change device as shown in FIG. It can be similarly applied to a transmission having the following. In addition, although this embodiment shows an example in which the friction clutch corresponding to each gear stage is controlled intermittently, in the case of an engine equipped with a main friction clutch between the output shaft of the engine and the transmission gear mechanism, this main friction clutch is Of course, it is also possible to control.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of the present invention, FIG. 2 is a schematic configuration diagram of an electronically controlled transmission in an embodiment of the present invention,
FIG. 3 is a flowchart showing the operation of the embodiment of the present invention. 2, 20, 30, 40, 51-54... Speed change gear mechanism, 3, 61-64... Friction fastening means (first
~4th friction clutch), 5, 10... Electronically controlled transmission, 6, 12... Vehicle speed sensor, 7, 17a-1
7f... Range switch, 8, 13... Control means (control circuit), 17 ₃ , 17 ₄ ... High speed fixed range (3rd and 4th speed range), 18... Shift lever.

Claims (1)

[Claims] 1. A high-speed fixed range configured so that a plurality of gears can be obtained by switching the power transmission path of the gear mechanism by selectively operating a plurality of frictional fastening members, and in which the gear is fixed to a high-speed gear. The electronically controlled transmission for a vehicle is equipped with a vehicle speed sensor that detects the traveling speed of the vehicle, and a range switch that indicates that the shift lever is shifted to the fixed range, and the vehicle speed sensor and a control means that receives a signal from the range switch and disconnects the frictional fastening member necessary to obtain a gear position corresponding to the high-speed fixed range when the vehicle speed is less than the set vehicle speed and the high-speed fixed range is shifted. An electronically controlled transmission for a vehicle, characterized in that it is equipped with the following.