JPH0443386Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to improvement of an automatic transmission for a vehicle.

(Prior Art) In recent years, in order to reduce driver fatigue, an increasing number of vehicles are equipped with automatic transmissions that automatically change gears by interposing a torque converter between the engine and the transmission. Since the torque converter is a fluid coupling, the output transmission efficiency is inevitably lower than that of a mechanical clutch, which is disadvantageous in terms of improving fuel efficiency.

Therefore, in order to improve not only ease of operation but also fuel efficiency, we used a conventional transmission and mechanical clutch, and instead of having the driver operate the clutch or transmission, they were automatically controlled by electronic control. The applicant of the present invention has proposed an automatic transmission device in which a gear change operation is performed automatically (see, for example, Japanese Utility Model Application No. 60-44579).

FIG. 6 is a flowchart showing the control operation, and the basic operation is the same as the operation of an automatic transmission using a torque converter.

In addition, the transmission employs a synchronized mesh mechanism that quickly matches the rotational speeds of the gears that engage, but basically the gears that engage are aligned within a predetermined relative rotational speed difference range (synchronizable range). If they can be accommodated, they can be meshed without causing gear noise, etc., even without a synchronized mesh mechanism.

Therefore, in order to reduce costs, this device omit the synchronized mesh mechanism, which has a complicated structure, and detects the rotational speed of the gears to be meshed, and sets the gears when the two reach the synchronized range (synchronized range). I'm letting it happen. In addition, Figure 7 is the 6th
This shows the shift-up control operation performed at step 8 in the figure.

Furthermore, according to another prior application, a region (shift region) is set on a map in which shifting up and down can be performed optimally according to driving conditions (for example, vehicle speed and engine load).
Based on this map, the hysteresis area is set with the aim of improving driving fuel efficiency and reducing the so-called dry running feeling that occurs due to the discrepancy between the driver's intention and the actual control, which is unique to automatic gear shifting. A downshift is performed only when a downshift is truly necessary, such as when the vehicle speed decreases beyond the hysteresis area.
-Refer to No. 193360).

In other words, in this prior application, the downshift operation is
As shown in Figure 8, when two conditions are simultaneously satisfied: (1) the vehicle speed V is V < Vo (predetermined value), and (2) the accelerator pedal is depressed from the fully closed position. We plan to do so only on a limited basis. Note that FIG. 8 is a flowchart showing the operation of downshift control.

Here, Vo is the vehicle speed corresponding to the boundary (broken line) of the hysteresis area (shaded area) shown in FIGS. 9 and 10. For example, in Figure 10, 4
If the accelerator opening is constant, the vehicle speed V will decrease from point A and will cross the vehicle speed Vo ₃ , which is the boundary of the hysteresis region, to the next step below. B in the shift stage (3rd gear) area
Move to a point. At point B, the accelerator pedal is depressed and V<Vo ₃ , so the conditions for performing a downshift operation are satisfied and the downshift operation is performed.

Furthermore, Fig. 9 and Fig. 10 are characteristic diagrams explaining the downshift region with respect to vehicle speed. Fig. 9 shows the case where the accelerator opening is used as an element, and Fig. 10 shows the case where the accelerator opening is not used as an element. .

(Problem to be solved by the invention) The signal when the accelerator pedal is depressed from the fully closed position is used as a condition for performing an upshift operation when the D range is specified or as a starting condition for the aforementioned downshift operation. and is also used as a condition to release the exhaust brake.

For this reason, a fully closed accelerator detection means is provided on the accelerator pedal, but in a diesel engine, this fully closed accelerator detection means is normally attached to the control lever of the fuel injection pump, which is closely related to the engine load condition. Direct attachment is preferable from the viewpoint of detection accuracy and responsiveness than attachment to an accelerator pedal or the like that is far away from the engine.

However, in these earlier applications, in the shift-up control shown in FIG. 7, in order to synchronously connect the meshing gears, it is necessary to reduce the engine rotation to a range where synchronous connection is possible, and the accelerator fully closed signal is once output at 20. Then, the control lever of the fuel injection pump is returned to the no-load position, and after the gear setting is completed, an accelerator return signal is output at 27 to return the control lever to its original position.

Therefore, if the control lever is equipped with an accelerator fully closed switch (turned ON in no-load condition), each time the shift-up is operated, the same signal as when a load is applied from a no-load condition will be output.
This signal satisfies condition (2) for starting the downshift operation.

Therefore, in a driving range where the vehicle speed V decreases significantly after the end of the upshift operation, the start condition (1) for the downshift operation is satisfied, and as a result, all the start conditions for the downshift operation are satisfied, and the upshift operation ends. Immediately thereafter, a downshift operation is performed.

For example, if the accelerator pedal is at a predetermined opening on a steep climb, the vehicle speed V increases by 1
A shift-up operation is performed to the next higher gear, but since the gear ratio after the shift-up operation is smaller than before the shift-up operation, the engine output cannot be obtained with the accelerator opening at that time. , the vehicle speed V decreases beyond the hysteresis region to a region where a downshift operation is performed one step lower, and a downshift is performed. Through this downshift operation, an output is obtained, the vehicle speed V increases again, and an upshift operation is performed, but unless the accelerator opening is changed, the same process will be repeated as the vehicle speed V decreases. The reason why such control hunting occurs is that a downshift operation is performed due to the output of a signal that changes from ON to OFF accompanying an upshift operation.

Therefore, an accelerator full-close switch is provided on the accelerator pedal, although it is far from the engine, to avoid the problem of a downshift operation being performed following an upshift operation using such a signal accompanying an upshift operation.

However, if the signal from the accelerator fully closed switch attached directly to the control lever can be used, the engine condition can be directly detected, thereby improving control responsiveness and detection accuracy.

Therefore, an object of this invention is to provide an automatic transmission device that enables direct detection of the no-load state of the engine without causing hunting between upshifting and downshifting operations.

(Means for solving the problem) FIG. 1 is an overall configuration diagram showing clearly the configuration of this invention.

In the figure, 33 is an engine rotation control means for controlling the rotation of the engine 37, 34 is a clutch disconnection means for connecting and disconnecting the mechanical clutch 38, and 35 is a gear shift means for shifting the gear of the transmission 39.

32A is a shift area setting means that is set according to the driving state of the area in which upshifting and downshifting is to be performed, and 32A is a means for starting a downshifting operation when the vehicle speed becomes less than a predetermined value and the engine changes from a no-load state to a loaded state. This is a downshift activation determining means that determines that the downshift is activated. Note that the vehicle speed is detected by the vehicle speed detection means 30.

Reference numeral 31 denotes a speed change operation control means, which increases the rotation of the engine 37 via the engine rotation control means 33, the clutch disconnection means 34, and the gear shift means 35, and disengages the clutch 38 to a predetermined level based on the start determination signal for the downshift operation. Shift the gear to the gear position.

This invention provides an automatic transmission configured in this manner with a no-load detection means 40A that detects a no-load state from a control member of the fuel supply means, and a signal that ignores this no-load signal within a predetermined time after the completion of a shift-up operation. A processing means 40B is provided.

(Function) With this configuration, the no-load detection means 40A provided directly on the control member of the fuel supply means outputs a signal that changes the engine from the no-load state to the loaded state every time the shift-up operation is performed. This signal is ignored by the signal processing means 40B within a predetermined period of time after the completion of the shift-up operation, and is treated as if the signal was not output.
A downshift operation is not performed subsequent to an upshift operation on a steep climb or the like, and control hunting can be avoided.

As a result, the no-load state of the engine can be detected directly from the control member of the fuel supply means, which improves responsiveness compared to the case where the no-load state is detected using an accelerator pedal or the like that is far away from the engine. can be improved to improve detection accuracy.

(Embodiment) FIG. 2 is a schematic diagram showing the mechanical configuration of an embodiment of this invention applied to a diesel engine, and FIG. 3 is a block diagram of the same. In this example, the fuel injection pump 41, mechanical clutch 42, and transmission 43 are provided with various detection means for detecting their operating states and actuators for driving them, and a microcomputer transmits information based on signals from these detection means. A control unit 60 configured therein controls the actuator to realize automatic gear shifting.

First, a means for detecting the operating state is required as a detection means, and this operating state is determined by the engine load,
This can be determined from the position of the select lever, the engagement/disengagement state of the clutch, the actual shift position of the transmission, and the vehicle speed. For this reason,
The accelerator pedal 45 has an accelerator opening sensor 50 that detects the depression angle (accelerator opening) of the accelerator pedal 45 as an engine load, and the shift tower 48 has a selector position sensor 50 that detects the position of a select lever (selector) 49. The mechanical clutch 42 includes a clutch stroke sensor 54 that detects the stroke amount of the clutch, the transmission 43 includes a shift position sensor 58 that detects the actual shift position, and the rear axle via the propeller shaft 44. A main shaft rotation sensor 56 is provided for detecting the rotation speed of a main shaft connected to each of the main shafts. Note that since the main shaft rotation speed is proportional to the vehicle speed, the main shaft rotation speed sensor 56 functions as a vehicle speed sensor.

In addition, synchronization of the gears to be meshed is achieved by driving the gear shift mechanism when the rotational speed Ng of the main gear idly rotating on the main shaft enters the synchronization range established with respect to the rotational speed Nsyc of the main shaft, so the main gear rotational speed It is necessary to detect Ng. In this case, since the main gear is in synchronous meshing with the countershaft that transmits the engine output, the rotational speed of the countershaft is equal to the rotational speed Ng of the main gear, and therefore the countershaft rotation sensor 57 is provided.

Next, 52 is an accelerator fully closed switch provided as a no-load detection means, which is the essential part of this invention.
It is attached directly to the control lever of the fuel injection pump 41 as a control member of the fuel supply means, and when the control lever is in the no-load position.
Outputs a signal that turns ON, and outputs a signal that turns OFF when the control lever is in the load position.

For these detection means, as an actuator to be controlled by the control unit 60,
The fuel injection pump 41 includes a governor control device 53 that drives a control lever according to demand and controls the engine rotation to match the engine rotation with the requested rotation. The actuator 55 is provided in the transmission 43, and the gear shift actuator 59 is provided in the transmission 43 to drive the gear shift mechanism and set a gear shift.

The control unit 60 that controls these actuators includes a synchro determination circuit 62, a shift area storage circuit 66B, and a downshift activation determination circuit 6.
6A, and a transmission control circuit 64 and an engine control circuit 6 that constitute a gear shift operation control means.
3, a clutch engagement control circuit 65 and a shift change control circuit 61.

Here, the synchronization determination circuit 62 determines, based on the rotation speed signals from the main shaft rotation sensor 56 and the countershaft rotation sensor 57, a rotation speed range that is higher or lower than the main shaft rotation speed Nsyc by a predetermined value as a synchronizable region.

The shift area storage circuit 66B stores shift up,
A shift-up map and a shift-down map are stored in which the region for downshift operation is set according to the driving state, and the shift-down activation determination circuit 66A determines the rotation from the main shaft rotation sensor 56 based on the shift-down map. When the vehicle speed V converted from the speed signal becomes less than a predetermined value Vo and the signal from the accelerator fully closed switch 52 changes from ON to OFF, it is determined that the downshift operation is to be started.

Further, the shift change control circuit 61 outputs a shift down control signal to the control circuits 63 to 65 when it is determined whether to start a downshift operation based on the signal of the downshift start determination circuit 66A. In addition, the shift change control circuit 6
1, an accelerator opening sensor 50, an accelerator fully closed switch 52, etc. as a driving state detecting means, and a main shaft rotation sensor 56 as a vehicle speed detecting means.
When it is determined whether to perform a shift-up operation based on the signal from the shift-up control signal, a shift-up control signal is output.

This shift-up control signal drives the governor control device 53 and clutch actuator 55 to increase the engine rotation, disengage the clutch, and shift the gear to a predetermined gear position.

Next, the shift change control circuit 61 functions as a signal processing means, which is the essential part of this invention. That is, the shift change control circuit 61 functions to ignore the signal from the accelerator fully closed switch 52 that changes from ON to OFF within a predetermined time after the shift up operation is completed.

In this example, so that only the clutch operation at the time of starting can be performed manually, a clutch pedal switch 67 that turns on when the clutch pedal 46 is depressed, and a fuel injection pump that directly controls the accelerator opening of the accelerator pedal 45 are used. A switching device 68 is provided which communicates with the control lever 41.

4 and 5 are flowcharts for explaining the operations of shift-up control and shift-down start control performed by the control unit 60, and the shift-up control and shift-down start control will be explained based on these flow charts, respectively. The numbers in the figure indicate processing numbers.

First, the shift-up operations performed in steps 20 to 27 will be explained. This is the same as in the previous application.

For example, when the accelerator pedal 45 is depressed and it is determined that a shift up operation is necessary,
At steps 20-22, the control lever of the fuel injection pump 41 is returned to the no-load position, the mechanical clutch 42 is simultaneously disengaged, and the transmission 43 is set to the neutral position.

Thereafter, at 23, the clutch 42 is immediately connected.
In manual transmission, it is normal to connect the clutch 42 after completing the gear shift, but during this time the engine speed decreases toward idle speed, and if this decrease is large, the engine speed decreases when the clutch is connected. The force required to raise the gear acts as a large load, causing gear shift shock. Therefore, in order to reduce this shift shock and further shorten the time required for shifting, the clutch 42 is connected to the engine output shaft except when the transmission 43 is set in the neutral position.

At 24, the gear rotation speed Ng of the main gear idling on the main shaft is detected, and at 25, Ng decreases.
When Ng≦Nsyc+ΔN, it is determined that Ng is in the synchro region, and gear setting to mesh the main gear and main shaft is started, and after the gear setting is completed, the control lever is returned to its original position at 27.

Here, Nsyc is the rotational speed of the main shaft connected to the rear axle, ΔN is the tolerance range set as the range in which synchronous meshing can be achieved without causing gear noise etc. for this Nsyc, and Nsyc +
ΔN gives the upper limit of the synchronization area.

Next, the main part of this invention is to ignore the signal that changes from ON to OFF from the accelerator fully closed switch 52 within a predetermined period of time after the shift-up operation is completed, and this function is shown in Fig. 4 during the shift-up operation. 80 to 82 following , and 90 located at the beginning of the downshift starting operation in FIG.

In other words, after the accelerator return signal is output, the signal ignore flag is set at 80 for a predetermined period of time (for example, about 1.5 seconds).
ON, and while this signal ignore flag is ON,
This is to prevent downshift operations after 91.

The earlier application did not have these functions, so 20, 27
Accelerator fully closed switch 5 output by the operation of
The signal goes from 92 to 94 due to the signal turning OFF from ON in 2, and the vehicle speed V is V on a steep climb road etc.
If it were lower than that, a downshift operation would be performed at 95 and 96, resulting in control hunting in which upshifting and downshifting operations are repeated alternately, as described above.

By the way, in this example, the signal ignore flag output after the upshift operation is turned ON, so it is not possible to proceed from 90 to the downshift operation after 91.

However, after a predetermined period of time, the signal disregard flag is displayed.
After being turned off, it is possible to proceed to a downshift operation. For example, when accelerating again by releasing the accelerator pedal 45 and then depressing it again, the shift down operation proceeds from 90 to 91. Therefore, a downshift operation is not performed outside the driving range where downshifting is truly required, and it is therefore possible to match the driver's intention with the actual control. It can eliminate the feeling of empty running.

If you make a mistake in setting the gear at step 26, the control lever will be rotated from the no-load position to the predetermined load position in order to increase the engine speed again and set the gear. outputs a signal that changes from ON to OFF, but in this case as well, measures are taken to ignore this signal, just as after the shift-up operation is completed.

Also, the signal from the accelerator fully closed switch 52 that changes from ON to OFF is ignored only when the signal is generated by the shift up operation. It is possible to know whether or not the is in a no-load state. In this case, since the accelerator fully closed switch 52 is turned off by turning the control lever 41 of the fuel injection pump, the engine state can be directly detected.

From turning on this accelerator fully closed switch 52
The OFF signal is used as a release signal for the exhaust brake, and is also used as a condition for upshifting when the D range is specified, and as a starting condition for downshifting. When signals that directly detect engine conditions are used for engine brake control and gear shift control, responsiveness improves, and signals are quickly issued in response to ever-changing driving conditions, resulting in smoother driving. That is to say.

On the other hand, if the accelerator fully closed switch is attached to the accelerator pedal 45 located far from the engine, the accelerator pedal is depressed from the fully closed position, and upon receiving this signal, the control lever rotates from the no-load position. Until then, there is inevitably a mechanical response delay, which results in poor responsiveness.
Therefore, no improvement in control accuracy can be expected.

Furthermore, the signal from the accelerator fully closed switch 52 is
Since a change from ON to OFF is the activation condition for downshifting, that state is held at 93 and 97 so that it can be compared with the previous state at the next time timing.

Although the case where the present invention is applied to a diesel engine has been described here, the present invention can be similarly applied to a gasoline engine.

(Effects of the invention) This invention provides a no-load detection means for detecting a no-load state from the control member of the fuel supply means, and a signal processing means for ignoring this no-load signal within a predetermined period of time after the completion of the shift-up operation. Therefore, the signal that changes from ON to OFF during an upshift operation is ignored, and the downshift operation will only be performed when a downshift is required, such as by releasing the accelerator pedal and then pressing it again.
It is possible to avoid hunting caused by repeated upshift and downshift operations, to match the driver's intention with the actual control, and to eliminate the driver's feeling of empty running.

In addition, since the no-load detection means can be directly attached to the control member of the fuel supply means, the engine condition can be detected directly, and the use of this detection signal increases responsiveness to respond to constantly changing operating conditions. It is possible to realize quick and agile gear shifting operations.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram to clearly show the configuration of this invention, FIG. 2 is a schematic diagram explaining the mechanical configuration of an embodiment of this invention, and FIG. 3 is a block diagram of this embodiment. 4 and 5 are flowcharts illustrating the shift-up control and shift-down activation operations performed within the control unit. FIG. 6 is a flowchart explaining the operation of the speed change control of the earlier application;
This figure is a flowchart explaining the operation of the shift-up control carried out in step 8 of FIG. 6, and FIG. 8 is a flowchart explaining the operation of the shift-down control carried out in step 9 of FIG. 6. Figures 9 and 10 are characteristic diagrams explaining the downshift region with respect to vehicle speed in the prior application. Figure 9 shows the case where the accelerator opening is an element, and Figure 10 shows the case where the accelerator opening is not an element. show. 30...Vehicle speed detection means, 31...Shift operation control means, 32A...Shift down activation determination means, 3
2B...Shift area setting means, 33...Engine rotation control means, 34...Clutch connection/disconnection means, 35...
...Gear shift means, 37...Engine, 38...
Mechanical clutch, 39...transmission,
40A... No-load detection means, 40B... Signal processing means, 41... Fuel injection pump, 42... Clutch, 43... Transmission, 49... Selector, 50... Accelerator opening sensor, 51... Selector position sensor, 52... Accelerator fully closed switch, 53... Governor control device, 54... Clutch stroke sensor, 55... Clutch actuator, 56... Main shaft rotation sensor, 57
... Counter shaft rotation sensor, 58 ... Shift position sensor, 59 ... Gear shift actuator, 60 ... Control unit, 61 ... Shift change control circuit, 62 ... Synchro determination circuit, 63 ... Engine control circuit, 64...Transmission control circuit, 65...Clutch intermittent control circuit, 66A...Shift down activation determination circuit,
66B...speed change area storage circuit.

Claims (1)

[Scope of utility model registration request] A clutch disconnection means for connecting and disconnecting a mechanical clutch, a gear shift means for shifting gears of a transmission, an engine rotation control means for controlling engine rotation, and a shift area in which an area for upshifting and downshifting is set according to driving conditions. a setting means; a shift-down start determining means for determining that a downshift operation is to be started when the vehicle speed becomes less than a predetermined value and the engine changes from a no-load state to a loaded state; In an automatic transmission system for a vehicle, the automatic transmission device includes a shift operation control means for increasing the engine speed based on a discrimination signal, disengaging the clutch, and shifting the gear to a predetermined gear position. An automatic transmission device for a vehicle, comprising a load detection means and a signal processing means for ignoring this no-load signal within a predetermined period of time after completion of a shift-up operation.