JPS61189353A - Speed change controlling method of automatic speed changing gears - Google Patents

Abstract

PURPOSE:To efficiently effort speed changing operation by an automatic manner by having a controller determine whether or not speed can be changed to a higher speed used before speed is changed and then inhibiting the gear shift operation to a higher speed range if the controller determined that the higher speed cannot be maintained. CONSTITUTION:If shift-up operation is performed when an horsepower of an engine is not sufficient, the current car speed will then be reduced excessively so that the speed used before the shifting operation may not be maintained. Because of the reason, if a shift-up; is determined, surplus horsepower of a vehicle is found from the position of a control rack 35 of an injection pump 34 which is sensed by a rack position sensor 77. Only when it is found that there is any surplus horsepower, the shift up will be performed actually. Using an electronic control, speed changing operation can be attained efficiently.

Description

[Detailed Description of the Invention] <Industrial Application> The present invention electronically controls a friction clutch interposed between an engine and a transmission via an actuator, and also adjusts the meshing position of the transmission to the gear position. The present invention relates to a speed change control method for an automatic transmission that is electronically controlled via a 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 existing drive systems such as friction clutches and transmissions as they are, 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 equipped with a control device that controls the gear position, the stroke position of the control rack of the fuel injection device is detected when changing the gear position to the high gear side, and even if the control rack is in the full stroke state, the vehicle speed before the shift is changed. The present invention is characterized in that, if it is determined that the speed cannot be maintained, the gear shifting operation is not performed.

Function: The am clutch is operated by the control device via the clutch actuator, and the transmission of driving force from the engine to the gear type transmission is interrupted. Further, the control device controls the operating characteristics of the clutch actuator to transmit the driving force with less shift shock, and the control device operates the gear position switching means in conjunction with the operation of the friction clutch.
The optimal gear position is automatically selected. This speed change operation is performed based on the driver's will and preset driving conditions of the vehicle.

On the other hand, when the vehicle is traveling uphill etc. and the gear position is changed to the high speed side, the stroke position of the control rack of the fuel injection system at this time is detected, and if the control rack is brought to full stroke from this state, The control device determines whether the vehicle speed can be increased to or higher than the pre-shift speed, and if it is determined that the speed cannot be maintained, the gear position is not shifted to the high speed side.

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 30a via 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 that generates a rotational speed signal of the output shaft 30a of the engine 30 is attached, and a rack position sensor 77 that generates a rack position signal is attached to the control rack 35. The friction clutch 31 presses the clutch plate 41 against the flywheel 40 by a well-known clamping means (not shown), and when the air cylinder 42 as a clutch actuator shifts from the non-operating state to the operating state, the clamping means moves in the releasing direction. Activated, the clutch 31 changes from the connected state to the disconnected state (FIG. 1 shows the disconnected state). In addition, for this clutch 3 construction, the disconnected state or connected state of the clutch 31 is set to ON10FF.
Although a clutch air sensor 70 is attached to detect the actuation, 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 to generate 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 the air tank 4 as a high-pressure air source.
8 is connected. 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. Gear type transmission 3 that achieves each gear stage
To change the gear position No. 2, the driver operates the change lever 54 to a shift position corresponding to the shift pattern shown in FIG. Based on this, the gear shift unit 51 serving as gear position switching means is operated to switch the gear position 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,
DP and D indicate arbitrary automatic gears from 2nd to 7th gears, and when the hemorrhoid range is selected, 2nd to 7th gears are selected based on the vehicle driving conditions by the optimum gear determination process described later. Determined automatically. As shown in Fig. 3, which shows the shift range between DP, which is a powerful automatic gear, and A, which is an economy automatic gear, the shift timings of 2nd to 7th gears are shown in the DP range, which is indicated by a dotted line, and the DE range, which is indicated by a solid line. teeth,
The DP range is set to the lower speed side in order to deal with situations such as when the vehicle is under high load. The gear shift unit 51 includes a plurality of electromagnetic valves (only one is shown in FIG. 1) 53 that are actuated by an actuation signal from a control unit 52.
and a pair of power cylinders (not shown) to which high-pressure operating air is supplied from the air tank 48 via the electromagnetic valves 53 to operate the select fork and shift fork (not shown) of the gear type transmission 32, and the electromagnetic valves 53
The power cylinders are operated in accordance with the actuation signals given to the gear transmissions 32 and 32 to change the meshing mode of the gear transmission 32 in the order of select and shift. 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. Moreover, the output shaft 5 of the gear type transmission 32
7 is attached with a vehicle speed sensor 58 that generates a vehicle speed signal, and the accelerator pedal 37 generates a resistance change according to the amount of depression of the accelerator pedal 37 as a voltage value, which is sent to an A/D converter 59.
Accelerator load sensor 60 that converts into a digital signal and outputs it.
is installed. A brake sensor 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 that starts the engine 30 by meshing with a ring gear on the outer periphery of the flywheel 40 in a timely manner is attached, and a starter relay 64 thereof 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 in response to input signals from various sensors (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/decrease of the rotation speed of the output shaft 30a of the engine 30 (hereinafter referred to as engine rotation speed) by increasing/decreasing the fuel. unit 52
An output signal as an engine rotation increase/decrease signal from the engine 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 control unit 52 is a microcomputer dedicated to the automatic transmission, and is composed of a microprocessor (hereinafter referred to as CPU) 66, a memory 67, and an interface 68 as an input signal processing circuit.

・Input hole of interface 68) 69・ku”
(Hi is the above-mentioned gear selection switch 55, brake sensor 62, accelerator load sensor 60, engine rotation sensor 39, clutch rotation speed sensor 45, and gear position switch 5.
Output signals are input from 6, vehicle speed sensor 58, clutch touch sensor 43 (used to detect the disconnected state or connected state of friction clutch 31 in place of clutch air sensor 70), clutch air sensor 70, and air sensor 72. . On the other hand, the output port 74 is connected to the above-mentioned micro convenience store 5, starter relay 64, and solenoid valve 5.
0, 53 and the cut valve 49, respectively, and output signals can be sent to these. In addition, the reference numeral 75 in the figure is an air warning lamp that lights up upon receiving an output from a drive circuit (not shown) when the air pressure in the air tank 48 does not reach a set value, and 76 is an air warning lamp that lights up when the amount of wear of the friction clutch 31 is specified. This is a clutch warning lamp that lights up in response to the output when the value is exceeded.

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, gear position 1'N from gear position switch 56
The signal is output when the gear shift is completed, and is used to determine whether all gear position signals corresponding to the select signal and shift signal have been output, and to issue a signal as to whether the meshing is normal or abnormal. 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 D2 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(a) and 5(bl), when the program starts, the control unit 52 enters the starting process, and after the starting process is completed, inputs the vehicle speed signal, and sets the value to a specified value (for example, Okm/h to 3 k+5h) or less, 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 N and performing the start process, Determine whether or not the oil pump has stopped, and if it has stopped, consider the engine to have stopped and start the engine again.If the oil pump has not stopped or the engine speed NE exceeds the specified value, Determine whether the start process is in progress,
If the start process is not in progress, the amount of accelerator depression (hereinafter referred to as an accelerator load signal) is compared with a specified value to determine whether the driver has an intention to start. During the start process and when the accelerator load signal is below the specified value, the engine rotation speed N6 and the first engine stop (hereinafter referred to as
Compared to the prevention rotation speed NEl□, which is simply written as engine stall,
Engine speed NE is the first engine stall prevention speed NE9
□□ In the following cases, the friction clutch 31 is disengaged and the start process is performed. On the other hand, if the accelerator load signal exceeds the specified value, the engine rotation speed N1 and the first engine stall prevention rotation speed N
If the engine speed NE is less than the second engine stall prevention speed N, the clutch is disengaged and the start processing is performed, and the engine speed NE is lower than the second engine stall prevention speed N. If the second engine stall prevention rotation speed NEli72 is exceeded or the engine rotation speed N - the first engine stall prevention rotation speed Nl"lTI
If it exceeds the limit, the process moves to start processing.

In the starting process shown in FIG. 6, a signal of engine rotation speed N6 is input, and it is determined whether the value is within the stop range of the engine 30. If the engine 30 is stopped, a clutch connection signal is output and a time lag is detected. , and the friction clutch 31 is connected at the normal pressure and in the normal state.

When the friction clutch 31 is connected at 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). LE point) is corrected depending on the wear condition of the facing of the friction clutch 31, 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.E.
When the point 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 (A) designated by the gear switch 55 is reached.

When the Dp range is selected, it is determined whether the gear positions of the gear type transmission 329 are aligned (for example, set in advance to ζZ 2nd speed).・If the position of the change lever 54 and the gear position are different, it is determined whether the air in the main tank 48 has reached the specified pressure, and if the pressure has been reached, the friction clutch is activated. 31
is turned off, the air in the air tank 48 is used to operate an actuator (not shown), the gear position is automatically matched to the position of the change lever 54, the friction clutch 31 is connected, and the air tank 48 (main tank) and a sub tank (not shown) are connected. 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 friction 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. Informs that the air in the 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 scooter enable relay is turned off, it is checked whether the air in the air tank 48 and the sub-tank has reached the specified pressure, and if the air has not reached the specified pressure, the air warning lamp 75 is lit and the air is turned off. The determination is repeated until the pressure reaches the specified pressure, and when the pressure reaches the specified pressure, the air warning lamp 75 is turned off and the starting 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 FIG. 7(a) and (bl), first the CPU 66
outputs an ON signal to the cut valve 49 to disengage the friction clutch 31, thereby disengaging the friction clutch 31. Next, it is determined whether the position of the change lever 54 and the gear position are the same, and 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. Also, if the gear position is other than neutral
In this case, the friction clutch 31 is connected to the LE point. Next, it is determined whether the accelerator load signal value exceeds a specified value (voltage low enough to indicate the driver's intention to start), and if NO, which indicates that the driver has no intention to start, each of the steps described above is performed. Repeat. On the other hand, Y is judged to have the intention of starting.
In the case of ES, the process proceeds to the next step, where the accelerator load signal value is detected, and the optimum duty rate α corresponding to this value is read 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 outputs a selection signal to the input port 69 to continue inputting the engine speed signal, and changes the engine speed N6 over time based on the engine speed N6 signal.
are sequentially stored in the RAM in the memory 67, and the engine rotational speed N and clutch rotational speed N are stored in RAM in the memory 67. 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 this time T1. Note that the peak point M is at engine 30.
This occurs because the output shaft 30a of the output shaft 30a decreases as power begins to be transmitted to the driving wheels as the rotation of the input shaft 44 of the gear type transmission 32 via the friction clutch 31.

Next, the LEOFF routine is executed.

This LEOFF routine is used to deal with cases where the vehicle is slightly moved with the clutch in a partially engaged state rather than a normal start.In the LEOFF routine, it is first determined whether the vehicle speed is greater than a specified value; If YES, it is determined that it is a normal start, and the LEOFF routine ends and returns to the start flow. 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,
W! 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 friction clutch 31 is connected from the half-clutch state at the LE point to the clutch engagement, but at this time, the engine rotation speed N6 after passing the peak point M is equal to the gear The clutch rotation speed N corresponds to the rotation of the input shaft 44 of the type transmission 32. Considering that the engine speed NE gradually decreases as L increases, the engine speed NE is controlled 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 rate of decrease in engine speed ΔN6 for each predetermined period of time is equal to or less than the first set value 1x11 shown in FIG. 10. In the case of YES, 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 engaged based on this duty rate α. After this, the engine speed reduction rate Δ
The town has the second setting value 1x21 (1x11< 1x21
) or less, and if NO, use the LEOFF mentioned above.
Returning to the point before the routine, the loop of keeping the engine speed reduction rate ΔN constant is repeated.

On the other hand, if the engine speed reduction rate ΔNE is greater than lx, I, it is determined whether the engine speed reduction rate ΔNE is greater than or equal to a third set value 1y21 (1x21 < 1y21). If YES here, after executing the LEOFF routine, the friction clutch 3 is
Gradually cut 1. Thereafter, it is determined whether or not the engine speed reduction rate ΔNE is equal to or less than the fourth set value 1y11 (ly, l < 1y21), and in the case of 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 ΔN5 is 1y21 or less, in the case of YES in the step of determining whether the engine speed decrease rate ΔN5 is 1X21 or more.
In the case of ES, 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 the engaged state without causing a shift shock in the half-clutch state, and without prolonging the shift time excessively. Hold. this&,
CPU66 is the engine rotation speed and clutch rotation speed N. L
The difference from the specified value (for example, INENoJ = 10 rpm
If the answer is NO, the above-mentioned loop is repeated, and after a predetermined time lag at T2, which is the time of YES, the solenoid valve 50 is fully opened and clutch engagement is performed. Thereafter, after a predetermined time lag on the condition that the engine rotational speed is equal to or higher than the idle rotational speed, the CPU 66 determines the slip rate of the friction clutch 31 (the difference between the engine rotational speed N6 and the clutch rotational speed N.L/ Calculate the engine rotation speed N- and compare this value with the specified value,
If the value is below the specified value, the process returns to the main flow. On the other hand, when the slip rate exceeds the specified value, the clutch warning lamp 76
outputs an ON signal as a clutch wear signal to the clutch via the output boat 74 and a drive circuit (not shown),
The clutch warning lamp 76 is turned on.

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 (
al , (bl , (As shown in C1, first, a selection signal is given to the input port 69 to check whether there is a brake failure or not. If YES, there is a failure in the brake, 1 is applied to stop the vehicle as described later. Shift down step by step. On the other hand, brake failure is N.

In this case, use an acceleration sensor, for example, to check whether the vehicle is applying sudden braking with deceleration exceeding a certain value, and if YES, the braking distance will become longer if the gear change operation described below is performed. Therefore, the main flow is returned to and the gear shifting operation is temporarily blocked. However, if the friction clutch 31 is disengaged even when the brakes are applied suddenly, it is determined that the gear shift is in progress, so the gear shift operation is completed and the friction clutch 31 is 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 the specified gear stage 1, 2.3 other than DE is set. Division or DP,
It is determined whether the automatic gear position is D, R, or N.

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 positioned at one of the target gears 1, 2. 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. As shown in FIG. 11, which shows the operational concept of this downshift operation, the control signal of the control rack 35 is outputted to the electromagnetic actuator 38 via the output port 74 and the microcomputer 65, and the engine speed remains unchanged. Hold on. Then, the cut valve 49 is turned on for a predetermined period of time via the output port 74.
A signal is output to turn off the friction latch 31, and a control signal is output to each electromagnetic valve 53 of the gear shift unit 51 to perform a downshift to a gear position one step lower than the gear position before shifting. Next, the clutch rotation speed N is caused to increase the engine rotation speed N to the electromagnetic actuator 38 via the output port 74 and the microcomputer 65. 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 matches the engine rotation speed N, air is removed from the air cylinder 42, and the friction clutch 31 is moved to the LE point. Move it to a half-clutch position. 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 rotational speed N and the clutch rotational speed N is compared with a specified value set in advance for each gear stage. Then, the operation of connecting the friction clutch 31 at the duty rate α is repeated until INE-NCL' becomes equal to or less than the specified value.

Then, after INE-NCL' becomes below the specified value,
A clutch connection signal is output, the connection of the jiI friction clutch 31 is completed with a time lag of a predetermined time, the accelerator pseudo signal is released, and the process returns to the main flow. Note that 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, and the friction clutch 31 is not connected and the operation shown in FIG. 5(a) is performed.
Proceed to the middle connector and perform LE point correction.

On the other hand, if the result of the determination as to whether this corresponds to a downshift from the Dp or DE range 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 set to 1 as the designated gear.・2,3
The output is outputted to each electromagnetic valve 53 via the output port 74 so as to match the target gear position, which is one of the following. Thereafter, the operation after outputting the accelerator pseudo signal of the downshift operation is performed to obtain the clutch rotation speed N after the gear shift. Engine speed N for L,! They match, complete the connection of the friction clutch 31, and return to the main flow. If the result of the above judgment on whether or not to shift up is NO, it is judged whether or not the overrun is within the range, and when it is YES, the engine speed is held at the same state, and the friction clutch is 31 and set the gear position to 1, which is the specified gear position.
In accordance with one of the target gears 2 and 3, the operation after outputting the accelerator pseudo signal of the downshift operation is performed, and the process returns to the main flow. Also, the result of the determination as to whether or not the above-mentioned overrun is within the range is N.

If so, a warning will be 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, D. , 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 the change lever 54 is in the Dp range or the DE range, and as shown in FIG. Determine the optimum gear position to be considered as the target gear position in the range. Thereafter, it is determined whether the gear position matches the optimum gear position, and if YES, the process returns to the main flow. On the other hand, if No, that is, if the gear position does not match the optimal gear position, it is then determined whether or not to shift up, and if it is not to shift up, perform the same operation as described above and return to the main flow. . On the other hand, in the case of upshifting, for example when the engine does not have much spare horsepower, such as when climbing a hill, the vehicle speed will decrease even if the control rack 35 of the injection pump 34 of the fuel injection device is in the full stroke state. If this happens, you may not be able to maintain the vehicle speed before shifting. In that case, a wasteful operation of immediately downshifting and returning to the original gear position after the upshifting operation is performed. Therefore, in order to prevent this, when it is determined that an upshift is required, the surplus horsepower of the vehicle is determined from the position of the control rack 35 of the injection pump 34 detected by the rack position sensor 77, and only when there is sufficient surplus horsepower is determined. I'm trying to get it to shift up.

In other words, after reading the rack position, it is determined whether (current control rack position) / (rack full stroke) is greater than l x (gear ratio one step higher) / (current gear ratio), and the answer is YES. Shift operation is performed only when this is the case; otherwise, the process returns to the main flow. Here, η is the efficiency for each gear stage, and is determined from a preset map taking into account the weight of the loaded object (total vehicle weight), the slope of the slope, the time required for shifting, etc.

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 erroneous operation, the engine rotation speed is set to idle rotation and the friction clutch 31 is disengaged in the same manner as described above. 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 process returns to the main flow.

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, in the case of NO with N stage selected, the engine speed N5 is lowered to idling speed,
After disengaging the friction clutch 31 and setting the gear position to neutral, the friction latch 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 Kurasochi pedal may be installed for drivers who are switching from a manual transmission; in this case, the R gear, 1st, 2.3
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 actuator and the power cylinder of the gear position switching means are actuated to perform the gear shift operation, a low-cost automatic transmission device can be obtained without significantly improving conventional vehicle production equipment.

Also, during upshifting, the stroke position of the control rack of the fuel injection pump is detected, and if it is determined that the vehicle speed before shifting cannot be maintained even if the control rack is brought to full stroke from this state, the upshifting operation is performed. Since this is not done, there is an advantage that there is no need to perform unnecessary gear shifting operations.

[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 DP range and hemorrhoid range. 4 is a graph showing an example of a map for determining the duty rate, and FIG. 5 (a), (bl~
Figure 8(a). (bl, (C1 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 speed and clutch speed during the shift, and FIG. 10 is the engine speed during the shift. 11 is a conceptual diagram of the operation during a downshift operation, and FIG. 12 is a conceptual diagram of the operation during an upshift operation. In the drawings, 30 is the engine, and 30a is the engine Output shaft, 31 is l!j friction clutch, 32 is gear type transmission, 34 is fuel injection pump, 35 is control rack, 37 is accelerator pedal, 38 is electromagnetic actuator, 42 is air cylinder, 44 is gear type transmission 48 is an air tank, 50 is a solenoid valve, 51 is a gear shift unit, 52 is a control unit, 54 is a change lever, 65 is a microcomputer, and 77 is a rack position sensor.Patent applicant: Mitsubishi Motors Corporation Company agent

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 the vehicle running conditions,
When changing the gear position to the high gear side, the stroke position of the control rack of the fuel injection device is detected, and if it is determined that the vehicle speed before the shift cannot be maintained even if the control rack is set to the full stroke state, the shift operation is performed. A speed change control method characterized in that the transmission is not performed.