JPS61189355A - Speed change controlling method of automatic speed changing gears - Google Patents

Abstract

PURPOSE:To enhance exhaust brake effect by resetting a car speed at which a gear position is to be shifted to a higher position, to a higher car speed so as to maintain the gear position of lower car speed. CONSTITUTION:Where a driver does not step on an accelerating pedal 37, a car speed at which a gear position is to be shifted to a higher gear position is set high. That is, when a car is running on a down slope or the like where an exhaust brake system is in operation and the driver does not step on the accelerating pedal 37, car speed will be increased, however, the car speed of the gear shifting point to higher gear position is kept high. The gear position of a lower speed range may be maintained so that the exhaust brake effect and the engine braking effect are enhanced.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention electronically controls a friction clutch interposed between an engine and a transmission via a first gear unit, and adjusts the meshing position of the transmission to one gear. The present invention relates to a speed change control method for an automatic transmission that is electronically controlled via a position switching means.

<Conventional technology> In recent years, automatic transmission devices that can automatically select the gear position according to the driving conditions of the vehicle have been developed in order to reduce the burden of driving operations on the driver of large freight vehicles, passenger cars, etc. It is considered.

Conventional automatic transmissions are aimed exclusively at small passenger cars, and are equipped with a fluid coupling such as a torque converter between the engine and the planetary gear transmission, using pressure oil as the control medium. A type of transmission equipped with gear position switching means is common.

<Problems to be solved by the invention> In developing automatic transmission devices for large freight vehicles, etc., it is important to avoid expensive torque converters, etc., since the number of vehicles produced is significantly smaller than that of passenger cars. Designing a new one is extremely disadvantageous in terms of cost, and it is desirable to use the existing drive system, including friction clutches and transmissions, as is, including existing production equipment.

Based on this knowledge, it is an object of the present invention to provide a speed change control method for an automatic transmission device that can automatically achieve smooth speed change operations through electronic control using a conventional drive system as is.

Means for Solving the Problems> A speed change control method for an automatic transmission according to the present invention includes a friction clutch connected to an output shaft of an engine, a clutch actuator for operating this friction clutch, and an input shaft connected to the friction clutch. a gear type transmission to which the gear type transmission is connected, a gear position switching means for changing the gear position of the gear type transmission, and an actuation of the clutch actuator and the gear position switching means based on the driver's intention and vehicle running conditions. In an automatic transmission device equipped with a control device that controls the vehicle speed, when the exhaust brake device is in operation and the driver is not pressing the accelerator pedal, the vehicle speed is changed to a higher gear position. The vehicle speed is set to .

Function> II The friction clutch control device is operated via the clutch actuator to cut off the transmission of driving force from the engine to the gear type transmission. In addition, the control device controls the operating characteristics of the clutch actuator to transmit driving force with less shift shock, but Wi! A gear position switching means is operated by the control device in conjunction with the movement of the friction clutch, and the optimum gear position is automatically selected. This speed change operation is performed based on the driver's will and preset vehicle driving conditions.

On the other hand, if the exhaust brake system is operating and the driver is not pressing the accelerator pedal, such as when driving downhill, the vehicle speed will be set to the high speed side even if the vehicle speed increases. Therefore, the gear position on the low gear side is maintained, further enhancing the exhaust braking effect and engine braking effect.

Embodiment As shown in FIG. 1, which shows the concept of an embodiment of an automatic transmission that implements the method of the present invention, this automatic transmission includes a diesel engine (hereinafter simply referred to as engine) 30 and its output shaft. The gear type transmission 32 receives a rotational force of 30 a through a friction clutch 31.

The engine 30 has a fuel injection pump (
An accelerator pedal 37 and an electromagnetic actuator 38 are connected to the control rack 35 of the pump 34 via a link 36, and an electromagnetic actuator 38 is connected to the input shaft 33. An engine rotation sensor 39 is attached that generates a rotation speed signal of the output shaft 30a of the engine 30. Friction clutch 31
The clutch plate 41 is brought into pressure contact with the flywheel 40 by a well-known clamping means (not shown), and when the air cylinder 42 as a clutch actuator shifts from a non-operating state to an operating state, the clamping means operates in the releasing direction,
The clutch 31 changes from a connected state to a disconnected state (first
(The figure shows the cut-off state). In addition, this clutch 3
1, the clutch 31 is in the disconnected state or connected state.
0FF Clutch air sensor 70 that detects constant operation
is attached, but a clutch touch sensor 43 may be attached instead. Further, a clutch rotation speed sensor 45 is attached to the input shaft 44 of the gear type transmission 32, which generates a signal of the rotation speed of the input shaft 44 (hereinafter referred to as clutch rotation speed). An air passage 47 is connected to the air chamber 46 of the air cylinder 42, and this is connected to an air tank 48 as a high-pressure air source.

An electromagnetic cut valve 49 is installed in the middle of the air passage 47 as an opening/closing means for controlling the supply of working air, and a duty-controlled normally closed electromagnetic valve 50 is also provided to open the air chamber 46 to the atmosphere. is installed. The air cylinder 42 is equipped with the aforementioned clutch air sensor 70 that outputs an ON signal when the internal air pressure exceeds a specified value that causes the clutch 31 to be disengaged, and the air tank 48 is further equipped with the clutch air sensor 70 that outputs an ON signal when the internal air pressure exceeds a specified value that causes the clutch 31 to be disengaged. An air sensor 72 is attached that outputs an ON signal when the condition is reached. To change the gear position of the gear type transmission 32 that achieves each gear, the driver operates the change lever 54 to a gear position corresponding to a shift pattern as shown in FIG. 2, for example. A gear shift unit 51 as gear position switching means is operated based on a gear shift signal obtained by switching the selection switch 55, and the gear position is switched to a target gear position corresponding to the shift pattern. Here, R indicates reverse gear, N is neutral, 1.2.3
indicates each designated gear, and D2゜ is from 2nd gear to 7th gear.
When the D, .

In addition, as shown in Fig. 3, which shows the shift range between the powerful automatic gear and D6, which is the economy automatic gear, the 2nd to 7th gear ranges are represented by the dotted line and solid line. The timing is set on the lower speed side in the D2 range in order to cope with times when the vehicle is under high load.

The gear shift unit 51 is a control unit 5
A plurality of solenoid valves (the first
) 53 (only one is shown in the figure) and these solenoid valves 53
It has a pair of power cylinders (not shown) to which high-pressure operating air is supplied from the air tank 48 through the air tank 48 to operate the select fork and shift fork (not shown) of the gear type transmission 32, and is applied to the electromagnetic valve 53. Operate the power cylinders according to the operation signal to select, select,
It operates to change the meshing mode of the gear type transmission 32 in the order of shifts. Further, the gear shift unit 51 is provided with gear position switches 56 as gear position sensors that detect the positions of each gear, and gear position signals from these gear position switches 56 are output to the control unit 52. Further, a vehicle speed sensor 58 is attached to the output shaft 57 of the gear type transmission 32 and outputs a vehicle speed signal.
An accelerator load sensor 60 is attached to the accelerator load sensor 7. The accelerator load sensor 60 generates a resistance change according to the amount of depression as a voltage value, converts this into a digital signal by an A/D converter 59, and outputs the digital signal. A brake pedal 62 is attached to the brake pedal 61 and outputs a high-level brake signal when the brake pedal 61 is depressed.
A starter 63 for starting the engine is installed, and its starter relay 64 is connected to the control unit 52. In addition, the reference numeral 65 in the figure indicates a microcomputer that is attached to the vehicle separately from the control unit 52 and performs various controls of the vehicle, and controls the drive of the engine 30 by receiving input signals from each sensor (not shown). etc. This microcomputer 65 gives an operating signal to the electromagnetic actuator 38 of the injection pump 34, and can control the increase or decrease of the rotation speed of the output shaft 30a of the engine 30 (hereinafter referred to as engine rotation speed) by increasing or decreasing fuel. An output signal as an engine rotation increase/decrease signal from the unit 52 can be received with priority over the amount of depression of the accelerator pedal 37 via the link 36, and the engine rotation speed is increased or decreased in accordance with this output signal.

The controller 1 and roll unit 52 are microcomputers dedicated to automatic transmissions, and are composed of a microprocessor (hereinafter referred to as CPU) 66, a memory 67, and an interface 68 as an input signal processing circuit.

The input port 69 of the interface 68 has the above-mentioned gear selection switch 55, brake sensor 62, accelerator load sensor 60, engine rotation sensor 39, clutch number sensor 45, gear position switch 56, vehicle speed sensor 58, and clutch touch sensor. 43 (The disconnected state or connected state of the friction clutch 31 is detected by the clutch air sensor 7.
(used when detecting instead of 0), the clutch air sensor 70, and the air sensor 72.

On the other hand, the output port 74 is connected to the above-mentioned microcomputer 65, starter relay 64, solenoid valves 50, 53, and cut valve 49, respectively, and can send output signals to these. In addition, the code 75 in the figure is the air tank 48.
76 is an air warning lamp that lights up in response to an output from a drive circuit (not shown) when the air pressure does not reach a set value, and 76 lights up in response to an output when the amount of wear on the friction clutch 31 exceeds a specified value. This is a clutch warning lamp.

The memory 67 is a read-only ROM in which programs and data shown in flowcharts in FIGS. 5 to 8 are written.
It consists of a RAM that can be used for both reading and writing. That is,
In addition to the above program, the duty rate α of the solenoid valve 50 corresponding to the value of the accelerator load signal is previously stored in the ROM as a map as shown in FIG. read out. The gear selection switch 55 described above outputs a select signal and a shift signal as a gear change signal, but the gear position corresponding to a pair of combinations of these signals is stored in advance as a data map, and the select signal and shift signal are stored in advance. When receiving the map, the corresponding output signal is outputted to each solenoid valve 53 of the gear shift unit 51 with reference to this map, and the gear position is adjusted to the target gear position corresponding to the gear shift signal.

In this case, the gear position signal from the gear position switch 56 is output when the gear shift is completed, and it is determined whether all the gear position signals corresponding to the select signal and the shift signal have been output, and whether the meshing is normal or abnormal is determined. Used to send signals. Furthermore, the ROM also stores a map for determining the optimum gear position based on vehicle speed, accelerator load, and engine rotation signals when a target gear position exists in the DP range or the forward range.

Here, the speed change control procedure of this embodiment will be explained based on FIGS. 5 to 8.

As shown in FIGS. 5(al and bl), when the program starts, the control unit 52 enters the starting process, and after the starting process is completed, inputs a vehicle speed signal, and sets the value to a specified value (for example, Okm/h to 3 km). /h) or below, the start process is performed, and if it is above the specified value, the gear change process is performed.However, if the engine speed is below the specified value (for example, idle speed) before calculating the engine speed) and performing the start process, If the oil pump is stopped, it is determined whether or not the oil pump has stopped, and if the oil pump is stopped, it is assumed that the engine has stopped and the startup process is performed again.If the oil pump is not stopped or the engine rotation speed is
If it exceeds the specified value, it is determined whether or not the start process is in progress, and if the start process is not in progress, the amount of accelerator depression (hereinafter referred to as the accelerator load signal) is compared with the specified value. It is determined whether the driver has the intention to start. During the start processing and when the accelerator load signal is below the specified value, the engine rotation speed is compared with the first engine stop (hereinafter simply referred to as engine stall) prevention rotation speed NESTI, and the engine rotation speed is determined as the first engine rotation speed. Engine stall prevention rotation speed NE!
If it is less than iTl, the friction clutch 31 is disengaged and a start process is performed. On the other hand, if the accelerator load signal exceeds the specified value, the engine rotation speed N and the first engine stall prevention rotation speed N
The second engine stall prevention rotation speed NE5 is higher than 1-9TI, and the engine rotation speed NE is the second engine stall prevention rotation speed N! : If the engine speed is below ST2, the clutch is disengaged and the start process is performed, and if the engine speed NE exceeds the second engine stall prevention speed NEsT2 or the engine speed N6 exceeds the first engine stall prevention speed N. Move on to the start process.

In the starting process shown in FIG. 6, the engine rotation speed NE (7) signal is input, it is determined whether the value is within the stop range of the engine 30, and if the engine 30 is stopped, a clutch connection signal is output. At the same time, there is a time lag, and the friction clutch 31 is connected at the normal pressure and in the normal state.

When the friction clutch 31 is connected with the normal pressure and in the normal state, the friction clutch 31 is disengaged to some extent from this position and the drive wheels of the vehicle shift from the rotating state to the stopped state (hereinafter referred to as the half-clutch state position). (denoted as a point) is jI
The correction is made depending on the wear condition of the I-friction clutch 31 casing, the presence or absence of a loaded object, etc. In other words, the stroke of the clutch plate 41 from the LE point until the friction clutch 31 is completely engaged is always approximately constant, and the friction clutch 31 is smoothly engaged regardless of the state of the vehicle. L
When point E is corrected, it is determined whether the position of the change lever 54 and the gear position are the same, that is, the shift signal and the gear position signal are the same and the target gear position (hemorrhoids) specified by the gear switch 55 is determined.

When the DP range is selected, it is determined whether or not the gear positions of the gear type transmission 32 are aligned (preset to 2nd speed, for example). If the position of the change lever 54 and the gear position are different, it is determined whether the air in the air tank 48 which is the main tank has reached a specified pressure, and if the pressure has been reached, the ws friction clutch 31 is Then, the air in the air tank 48 is used to operate an actuator (not shown) to automatically align the gear position with the position of the λ change lever 54, connect the friction clutch 31, and connect the air tank 48 (main tank) to the sub tank (not shown). After turning off the switching solenoid valve, it is again determined whether the position of the change lever 54 and the gear position are the same.

If the air in the air tank 48 has not reached the specified pressure, it is determined whether the air in the sub-tank has reached the specified pressure, and if the air has reached the specified pressure, the switching solenoid valve is turned on. Then, the 1ltl clutch 31 is disengaged, and the power cylinder is actuated with the air in the sub-tank to automatically select the gear position corresponding to the position of the change lever 54. If the air in the sub-tank has not reached the specified pressure, the air warning lamp 75 is turned on to notify the driver that the air in the air tank 48 and sub-tank is below the specified pressure. On the other hand, if the position of the change lever 54 and the gear position are the same, a relay for enabling starter is output.

When the starter enable relay is output, the starter 63 can be started to start the engine 30, so it is determined whether the engine 30 has started, and if the engine 30 has started, the starter enable relay is turned off. If the engine 30 does not start, it is again determined whether the change lever 54 position and the gear position are the same. When the starter enable relay is turned off, air tank 4
8 and check whether the air in the sub-tank has reached the specified pressure. If it has not reached the specified pressure, turn on the air warning lamp 75 and repeat the judgment until the air reaches the specified pressure. If the threshold is reached, the air warning lamp 75 is turned off and the startup process is completed.

After the start process is completed, the vehicle speed signal is read, and if it is below a specified value, the start process begins.

As shown in FIGS. 7(al) and (b), the CPU 66 first outputs an ON signal to the cut valve 49 to disengage the friction clutch 31, thereby disengaging the friction clutch 31. Next, the position of the change lever 54 and the gear position and determine whether they are the same or not.
If No, the gear position is adjusted to the target gear position. When the position of the change lever 54 and the gear position become the same, it is determined again whether the vehicle speed is smaller than the specified value, and if the vehicle speed is higher than the specified value (No), the process proceeds to the step of detecting the accelerator load signal described later. move on. On the other hand, if this is not the case, it is read from the shift signal whether the next gear position that has reached the target gear position is neutral or not, and if YES, the LE point correction is performed again. If the gear position is other than neutral (No), the friction clutch 31 is connected to the LE point. Next, it is determined whether or not the accelerator load signal value exceeds a specified value (voltage low enough to indicate the driver's intention to start), and if No, indicating that the driver has no intention to start, each of the steps described above is performed. Repeat. On the other hand, YE is judged to have the intention of starting.
In the case of S, the process proceeds to the next step, detects the accelerator load signal value, and further reads the optimum duty rate α corresponding to the value B from the map shown in FIG. Then, a pulse signal with the obtained optimum duty rate α is outputted to the electromagnetic valve 50, and the friction clutch 31 is gradually connected. At this point, the CPU 66 has output a selection signal to the input port 69 to continue inputting the signal of the engine rotation speed N6, and the engine rotation speed over time based on the engine rotation speed N (7) signal is stored in the memory 67. The engine rotation speed Nl: and the clutch rotation speed N are sequentially stored in the RAM. As shown in FIG. 9, which shows an example of the change in L, arithmetic processing is performed to find the peak point M, and until the peak point M is detected, the process goes to NO and repeats from the accelerator load signal detection step. on the other hand,
When the peak point M is detected, the solenoid valve 50 is held ON from time T8. Note that the peak point M is at the output shaft 30a of the engine 30! This occurs because power begins to be transmitted to the driving wheels as rotation of the input shaft 44 of the gear type transmission 32 via the friction clutch 31, resulting in a decrease in the torque.

Next, the LEOFF routine is executed.

The LEOFF routine in Part B deals with cases where the clutch is left in a partially engaged state and the clutch is slightly moved, rather than a normal start.The LEOFF routine first determines whether the vehicle speed is greater than a specified value, and then In the case of a large YES, it is determined that it is a normal start, and the LEOFF routine ends and returns to the flow of this start. On the other hand, in the case of NO, it is next determined whether or not the accelerator pedal 37 is depressed, and in the case of YES, the LEOFF routine ends in the same way, and in the case of No, the LEOFF routine continues until the LE point is reached. The friction clutch 31 is disengaged. Meanwhile, it is also determined whether or not the accelerator pedal 37 is depressed, and when the accelerator pedal 37 is depressed, the process returns to the aforementioned accelerator load signal detection step. or,
After the friction clutch 31 has retreated to the LE point, the process returns to the step of determining the position of the change lever 54 and the gear position described above.

When the LEOFF routine is completed and it is determined that a normal start has occurred, the IJ friction clutch 31 is connected from the half-clutch state at the LE point to clutch engagement, but at this time the peak point M
Considering that the engine rotation speed N after passing the engine rotation speed gradually decreases as the clutch rotation speed N, which corresponds to the rotation of the input shaft 44 of the gear type transmission 32, increases, this engine rotation speed N, 17) Control is performed so that the rate of decrease falls within a predetermined range and the shift shock becomes small. That is, first, it is determined whether the engine speed reduction rate ΔN6 for each predetermined time is less than or equal to the first set value 1x1 (YES) shown in FIG.
In the case of , after executing the above-mentioned LEOFF routine, the accelerator load signal is detected again, the optimum duty rate α corresponding to this value is determined, and the friction clutch 31 is gradually connected according to the duty rate α. After this, the engine speed reduction rate ΔN becomes the second set value 1x21 (lx, l <
1x21) or less, and if NO, the process returns to before the LEOFF routine described above and repeats the loop of keeping the engine speed reduction rate ΔN constant.

On the other hand, if the engine speed reduction rate ΔN5 is greater than 1x11, it is determined whether the engine speed reduction rate ΔN is greater than or equal to a third set value 1y21 (1x21 < 1y21). If YES here, the LEOFF routine is executed, and then the friction clutch 31 is gradually disengaged by off-duty. Thereafter, it is determined whether the engine speed reduction rate ΔNl: is equal to or less than the fourth set value 1y11 (ly, l < 1y21), and if NO, the loop of disconnecting the friction clutch 31 is repeated. In the case of YES, or in the case of No in the step of determining whether the engine speed decrease rate ΔNE is 1y21 or less, the engine speed decrease rate ΔN
, YES in the step of determining whether or not is 1x21 or more
In the case of , at this point, the engine speed reduction rate ΔN- falls approximately within the area shown by diagonal lines in FIG. Therefore, conditions have been established for switching the friction clutch 31 to a half-engaged state without causing a shift shock and without prolonging the shift time excessively, so that v! The air pressure of the X friction clutch 31 is held at the current state. After this,
The CPU 66 receives the engine rotation speed N6 and the clutch rotation speed N.

The difference from L is the specified value (for example, IN, NcJ = 1 Or
pm) or less, and if No, the above loop is repeated, and after a predetermined time lag at T, which is the time of YES, the solenoid valve 5° is fully opened and clutch engagement is performed. . Thereafter, after a predetermined time lag on the condition that the engine speed NE is equal to or higher than the idle speed, the CPU 56 determines the slip rate of the friction clutch 31 (difference between engine speed and clutch speed NcL&/engine speed). N- is calculated and this value is compared with a specified value, and if the slip rate is less than the specified value, the process returns to the main flow.On the other hand, if the slip ratio is greater than the specified value, it is determined that the amount of wear on the friction clutch 31 is large. Due to clutch warning lamp 7
6, output an ON signal as a clutch wear signal through the output port 74 and a drive circuit (not shown), and turn on the clutch warning lamp 76.

After the starting process is completed, the CPU 66 reads the vehicle speed signal and, if the signal exceeds a specified value, starts the speed change process. Figure 8 (
a), (b), ((As shown in (), first give a selection signal to the input port 69 to check whether the brake has failed or not. If YES indicates that the brake is malfunctioning, stop the vehicle as described later. On the other hand, if the brake fail is NO, use an acceleration sensor, for example, to check whether the brake is being applied suddenly with a deceleration greater than a certain value, and if YES is selected. If there is, the braking distance will become longer if the gear shift operation described below is performed, so the main flow is returned to and the gear shift operation is temporarily blocked.However, even if the brake is applied suddenly, the friction clutch 31 is disengaged. If so, it is determined that the gear shift is in progress, so the gear shift operation is completed and the friction clutch 31 is closed.
will be connected.

On the other hand, when there is no sudden braking operation or when the friction clutch 31 is disengaged as described above even during sudden braking, the position of the change lever 54 is read and this is set to D.
p, 1.2.3 designated gear stage classification other than DE or Dp,
DI: Determine whether it is an automatic gear, an R gear, or an N gear.

1.2.3 In the case of the specified gear stage, the change lever 54
It is determined whether or not the position of and the gear position are the same, and if YES, return to the main flow, and if NO, proceed to the next step. In this step, the change lever 54 is located at - of target gears 1, 2, and 3, and the current gear position before shifting is Dp, D, and range, which corresponds to a downshift from here. Decide whether or not to do so. If YES, it is determined whether the downshift can be performed without overrunning the rotation of the engine 30, and if NO, proceeding to the next step and warning the driver of the overrun with a reverse warning buzzer. Return to the main flow without changing gears.

If the determination as to whether or not there is an overrun is YES, a downshift operation is performed by one gear from the current gear position as follows. No. 11 representing the operational concept of this downshift operation.
As shown in the figure, a control signal for the control rack 35 is outputted to the electromagnetic actuator 38 via the output port 74 and the microcomputer 65, and the engine rotational speed Nl:J& is held at the same state. Then, an ON signal is output to the cut valve 49 for a predetermined period of time via the output port 74 to disengage the friction clutch 31, and a control f&U signal is output to each electromagnetic valve 53 of the gear shift unit 51 to change the gear position from the pre-shift gear position. Downshift to the next lower gear position. Next, the electromagnetic actuator 3 is connected via the output port 74 and the microcomputer 65.
Clutch rotation speed N to increase engine rotation speed N to 8.

A voltage signal that causes the same rotation as L is output as an accelerator pseudo signal, and the clutch rotation speed N after shifting. L and the number of engine revolutions are matched, air is removed from the air cylinder 42, and the friction clutch 31 is moved to a half-clutch state at the LE point. Next, the friction clutch 31 is connected at the optimum duty rate α corresponding to the accelerator load signal, and the difference between the engine rotation speed and the clutch rotation speed NcL is compared with a specified value preset for each gear, 1NE-
The above duty rate α is maintained until NCL' becomes below the specified value.
The operation of connecting the w1 friction clutch 31 is repeated.

After lN-N1 becomes equal to or less than the specified value, a clutch engagement signal is output, the engagement of the friction clutch 31 is completed after a predetermined time lag, the accelerator pseudo signal is released, and the process returns to the main flow. In addition, if the clutch rotation speed N exceeds the specified value in the above operation, it is assumed that the friction clutch 31 is worn out.
Without connecting the m-clutch 31, proceed to the glue connector in Figure 5 (al) and perform the LE point correction.

On the other hand, if the result of the determination as to whether or not this corresponds to a downshift from the H DP and DE ranges is No, a determination is made as to whether or not it is a shift up. If the answer is YES, a shift-up operation is performed as follows, and the process returns to the main flow. As shown in FIG. 12, which shows the operational concept of this shift-up operation, a control signal for the control rack 35 is output to the electromagnetic actuator 38 via the output port 74 and the microcomputer 65, and the engine speed N is set to idle speed. return. After disengaging the friction clutch 31, the gear position is outputted to each electromagnetic valve 53 via the output port 74 so as to match the target gear position, which is one of 1.2.3 as the designated gear position. do. Thereafter, the operation after outputting the accelerator pseudo signal of the downshift operation is performed, and the engine rotational speed N, ! for the clutch rotational speed NcL after shifting! They match, complete the connection of the friction clutch 31, and return to the main flow. Furthermore, as a result of the above judgment as to whether or not to shift up, if the result is No, it is judged whether or not it is within the overrun, and if this is YES, the engine speed is held at the same state as N and Q, and II
Disengage the three friction clutches and set the gear position to the specified gear 1.
, 2 and 3, perform the operations after outputting the accelerator pseudo signal of the downshift operation, and return to the main flow. Further, if the result of the determination as to whether or not the overrun is within the range is NO, a warning is issued by a warning buzzer.

The above operation is performed when the result of the determination of the position of the change lever 54 is the designated gear stage of 1, 2.3, but the result of the determination of the position of the change lever 54 is Dp, DE. If the vehicle is in the automatic gear position, the following operations are performed. That is, the vehicle speed and the amount of depression of the accelerator pedal 37 are detected, and it is determined whether or not the exhaust brake device (extreme brake) is being used.If NO, map A shown in FIG. 13 is selected. It is determined whether the change lever 54 is in the Dp range or the hemorrhoid range, and as shown in FIG. 13, the optimum gear position that is regarded as the target gear position in each range of 1 or GA is determined from the preset map A. do. After this, it is determined whether the gear position matches the optimum gear position, and Y
In the case of ES, the process returns to the main flow, and in the case of NO, the process moves to the step of determining whether to upshift or not, and the same speed change operation as described above is performed.

In addition, in map A shown in Fig. 13, in order to make it easier to see when upshifting and downshifting, the DP and HO ranges are represented by the same line (a solid line when upshifting and a dotted line when downshifting). However, as shown in FIG. 3, D2 is actually set to a lower speed than DI:.

If an exhaust brake device is used, see Section 14.15.
Select the pine 70B shown in the figure.

In this map B, when the driver does not press down on the accelerator pedal 37 as shown in the figure, the vehicle speed is set to a higher speed when the vehicle is shifted to a higher gear position. In other words, when driving downhill, etc., when the exhaust brake device is in operation and the driver does not press the accelerator pedal 37,
Even when the vehicle speed increases, since the vehicle speed is set to the high speed side, the gear position on the low speed side is maintained, further enhancing the exhaust braking effect and the engine braking effect. When map B is selected, it is determined whether the change lever 54 is in the D2 range or the D5 range, and from map B, the optimum gear position that is regarded as the target gear position in each range of D2 or Boar is determined. , determine whether the gear position matches the optimum gear position or not.
In the case of ES, the process returns to the main flow, and in the case of NO, the process moves to the step of determining whether to shift up or not, and the same speed change operation as described above is performed.

Further, if the result of the determination of the position of the change lever 54 is R gear, the CPU 66 determines whether or not the gear position matches R gear as the target gear, and selects YES if reverse operation is currently in progress. If the answer is NO, which is an incorrect operation, do the same as above and change the engine speed N,
is set to idle rotation and the lI friction clutch 31 is disengaged. Then, in order to return the gear position to neutral, an output is sent to each electromagnetic valve 53 via the output port 74, and after lighting a reverse warning lamp that indicates a gear shift error, the friction clutch 31 is connected and the main flow returns. .

Furthermore, the result of determining the position of the change lever 54 is N.
In the case of gear shift, it is determined whether the change lever 54 has moved within a predetermined period of time, that is, whether or not the driver has simply passed through N gear during the gear change operation. If the result of this judgment is YES during the gear shifting operation, the position of the change lever 54 and the gear position are judged as described above, and the operation returns to the main flow or shifts up or down. An operation is performed to return to the main flow. However, if the N gear is selected (No), the engine speed is reduced to N idling speed, the friction clutch 31 is disengaged, the gear position is set to neutral, and then the friction clutch 31 is connected again to return to the main flow. .

In this embodiment, air pressure from an air tank 48 installed in the vehicle is used to drive the air cylinder 42 for operating the friction clutch 31, but it is of course possible to use hydraulic pressure as the control medium. However, in this case, a new hydraulic pressure generation source such as an oil pump must be added, which may increase costs.

Furthermore, it goes without saying that the speed change control procedure, shift pattern, etc. shown in this embodiment can be modified in detail as necessary, and the present invention is also applicable to vehicles equipped with a gasoline engine. be able to. Furthermore, a dummy clutch pedal may be installed for drivers who are switching from a manual transmission;
It is also possible to set the clutch pedal to function preferentially to the air cylinder 42 at the designated gear position.

<Effects of the Invention> According to the speed change control method for an automatic transmission of the present invention, a drive system such as a general friction clutch or gear type transmission is used as is, and air from an air tank installed in the vehicle is used as a control medium to control the friction clutch. Since the gear shift operation is performed by operating the 7 actuator and the power cylinder of the gear position switching means, a low-cost automatic transmission can be obtained without significantly improving conventional vehicle production equipment.

In addition, when the exhaust brake system is in operation and the driver is not pressing the accelerator pedal, the vehicle speed that causes the gear to shift to the high gear position is set to a higher vehicle speed.
When the exhaust brake system is in operation and the driver is not pressing the accelerator pedal, such as in the lower 9 hypothetical mode, the gear position on the low speed side is maintained even if the vehicle speed increases, further enhancing the exhaust brake effect and engine brake effect. becomes possible.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an automatic transmission according to an embodiment of the present invention, Fig. 2 is a conceptual diagram showing an example of its shift pattern, and Fig. 3 is an example of shift characteristics of the automatic transmission range and the hemorrhoid range. FIG. 4 is a graph showing an example of a map for determining the duty rate, and FIGS. 5(a) and 8(b) to FIG. 8(a). (bl, (Q) is a flowchart showing an example of the control program, Fig. 9 is a graph showing an example of changes over time in the engine rotation speed and clutch rotation speed during the shift, and Fig. 10 is the engine rotation during the shift. Figure 11 is a conceptual diagram of operation during downshift operation, Figure 12 is a conceptual diagram of operation during upshift operation, and Figure 13 is map A in Dp range and q range. FIG. 14 is a graph showing the speed change characteristics during upshifting of map B in the range and D6 range.
FIG. 15 is a graph showing the shift characteristics at the time of upshifting of map B in the DP range and the hemorrhoid range. In the drawing, 30 is an engine, 30a is an output shaft of the engine, 31 is a friction clutch, 32 is a gear type transmission, 34 is a fuel injection pump, 35 is a control rack, 37 is an accelerator pedal, 38 is an electromagnetic actuator, and 42 is an air 44 is an input shaft of a gear type transmission, 48 is an air tank, 50 is a solenoid valve, 51 is a gear shift unit, 52 is a control rack 1, 54 is a change lever, and 65 is a microcomputer. Figure 2 Figure 4 Low - Vehicle speed - High Figure 5 (CI) Figure 5 (b) Figure 8 (()) Figure 9 Time Figure 10 twJ Figure 11 Figure 12L1 Procedural amendment 1985 5 month day

Claims (1)

[Claims] A friction clutch that connects to the output shaft of the engine, a clutch actuator that operates the friction clutch, a gear type transmission that connects the input shaft to the friction clutch, and a gear position switch that changes the gear position of the gear type transmission. and a control device for controlling the operation of the clutch actuator and the gear position switching means based on the driver's intention and vehicle running conditions, when the exhaust brake device is in operation and the accelerator pedal is pressed. 1. A shift control method characterized in that, when a driver is not pressing the gear, the vehicle speed at which the gear is shifted to the higher gear position is set to a higher vehicle speed.