JPH0212351Y2 - - 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) Automatic transmissions that automatically shift up and down based on a preset pattern depending on driving conditions have already been widely used as transmissions for automobiles.

Among these, the applicant has proposed a mechanical clutch type without a torque converter as shown in Figs.
70610).

7 and 8, a transmission 30 equipped with a known cowl shaft is attached to a diesel engine 10 equipped with a fuel injection pump 11 via a mechanical disc clutch 20, and a main shaft of the transmission 30 is attached to the diesel engine 10 equipped with a fuel injection pump 11. 31 is linked to a rear axle (not shown).

The engine 10 is provided with an engine rotation sensor 12 that detects the engine rotation speed, and the fuel injection pump 11 is provided with a governor control device 13 that drives the governor 11a and controls the engine rotation speed.

The clutch 20 is provided with a clutch position sensor 21 that detects the engagement/disengagement position of the clutch, and a clutch disconnection device 22 that engages/disconnects the clutch.

The transmission 30 includes a vehicle speed sensor 32 that detects the rotation speed of the main shaft 31 and detects the vehicle speed.
A countershaft rotation sensor 33 that detects the rotational speed of the countershaft, a shift position sensor 34 that detects the gear shift position, and a gear shift device 35 that controls the gear shift are provided.

For example, the accelerator pedal 14 has a load sensor 1 that detects the pedal opening degree, that is, the engine load.
5 is provided.

On the other hand, the control device 40 controls the shift position sensor 3.
4. A shift change determination circuit 41 that determines whether or not to change gears, that is, to change a shift, based on a shift down and shift up map preset in the circuit in response to detection signals from the vehicle speed sensor 12 and load sensor 15; The engine control circuit 43 includes an engine control circuit 43, a clutch engagement control circuit 44, and a transmission control circuit 45.

The engine control circuit 43 receives the output signal of the shift change determination circuit 41 and the engine rotation sensor 12.
Based on the detection signal, the governor control device 13 is operated to optimally control the engine speed with respect to the gear shift.

The clutch disengagement control circuit 44 operates the clutch disengagement device 22 based on the output signal of the shift change determination circuit 41 and the detection signal of the clutch position sensor 21 to control the clutch 20 so as to perform the gear shift optimally. Intermittent control.

The transmission control circuit 45 receives the output signal of the shift change determination circuit 41, the countershaft rotation sensor 33, and the shift position sensor 34.
Based on the detection signal, the gear shift device 35 is operated to control the gear shift based on a preset pattern.

When performing a shift change, the shift operation is easiest when the rotational speeds of the countershaft and the main shaft 31 are substantially the same.
In the control device 40, a shift change determination circuit 41
If it is determined that the shift-up should be performed, the determination signal is output to each of the control circuits 43-45. Then, the clutch disengagement control circuit 44 outputs a control signal to the clutch disengagement device 22 to turn off the clutch 20, thereby turning off the clutch 20 and bringing the accelerator opening to 0%, that is, to the idling state. At the same time, a control signal is output from the engine control circuit 43 to the governor control device 13 in order to control the engine. A control signal for setting the transmission 30 to neutral is output from the gear shift control device 45 to the gear shift device 35,
The transmission is set to neutral.

The rotation speed of the countershaft decreases rapidly, but when the rotation speed of the countershaft and the main shaft, which should be synchronized in the next gear shift stage, become almost the same, the transmission is shifted up.
The clutch is then turned on.

By shifting up in this manner, the shifting operation is smooth and there is no impact when turning on the clutch.

A similar control is used for downshifting to ensure smooth downshifting.

(Problem to be solved by the invention) By the way, in such an automatic transmission device, the shift up and shift down maps set in the shift change judgment circuit 41 are as shown in FIG. Downshift control is performed frequently even when downshifting is not really necessary, such as when accelerating, resulting in problems such as worsening fuel efficiency and increasing the feeling of empty running that is characteristic of mechanical automatic vehicles.

For example, when decelerating relatively slowly, as the vehicle speed decreases, the downshifts are performed one after another according to the downshift map, but in reality, there is almost no need to downshift in such cases. For example, there is no problem even if the gear continues to decelerate while the gear is in 3rd gear.In fact, when downshifting, the clutch is temporarily disengaged, and unlike upshifting, downshifting suddenly increases the engine speed. Since it is necessary to raise the clutch, it takes time to switch, and during this time, the feeling of running with the clutch off increases the driver's anxiety.

It is an object of the present invention to solve these problems and provide an automatic transmission for a vehicle that downshifts only when absolutely necessary.

(Means for Solving the Problems) The present invention, as shown in FIG. , at least a downshift map that sets a gear shift stage to be selected corresponding to the vehicle speed, a means for detecting the vehicle speed, a means for detecting the accelerator opening, and a shift down map that sets the gear shift stage to be selected in accordance with the vehicle speed, a means for detecting the accelerator opening, and a shift down map that sets the gear shift stage to be selected in accordance with the vehicle speed, a means for detecting the accelerator opening, and a shift down map that sets the gear shift stage to be selected in accordance with the vehicle speed, a means for detecting the accelerator opening, and a shift down map that sets the gear shift stage to be selected in accordance with the vehicle speed, a means for detecting the accelerator opening, and a shift down map that sets the gear shift stage to be selected in accordance with the vehicle speed, a means for detecting the accelerator opening, and a shift down map that sets the gear shift stage to be selected in accordance with the vehicle speed, a means for detecting the accelerator opening, and a shift down map that sets the gear shift stage to be selected in accordance with the vehicle speed, a means for detecting the accelerator opening. and a control device that performs a downshift to a gear shift determined from the shift down map based on the vehicle speed when determining the downshift condition.

(Function) Therefore, only when the accelerator opening is depressed from the fully closed position to a predetermined opening or more during deceleration, a downshift is performed to the gear shift stage selected based on the downshift map.

Therefore, even if the vehicle speed simply decreases and shifts to a different gear range, such as during deceleration, unnecessary downshifts are not performed, and deterioration of fuel efficiency and increase in the feeling of empty running can be avoided.

(Example) In FIG. 2, 12 is an engine rotation sensor;
21 is a clutch position sensor, 32 is a main shaft rotation sensor (vehicle speed sensor), 33 is a counter shaft rotation sensor, 34 is a shift position sensor of the transmission 30, 15 is a load sensor (accelerator opening sensor), and these detection signals are detected. is input to the control device (microcomputer) 40A.

The microcomputer 40A is mainly composed of a microprocessor (central processing unit) 50, a memory (storage device) 51, and an interface (input/output signal processing device) 52. Shift-up and shift-down maps such as B and shift-down condition vehicle speed values set as shown in FIG. 4, for example, are stored for each shift stage that is lower than the boundary line of each shift stage in the shift-down map. .

Note that the downshift condition vehicle speed value can also be read from the value when the accelerator opening is zero in the downshift map.

Then, when the microcomputer 40A shifts to deceleration driving, the vehicle speed decreases below the downshift condition vehicle speed value at that time, and the accelerator is depressed from the fully closed position to a predetermined opening degree, that is, when a re-acceleration operation is performed. The governor control device 13 performs downshift control (that is, reads the shift gear from the shift down map according to the vehicle speed and accelerator opening degree, compares this shift gear with the current shift gear, and performs a shift change when the shift gear should be changed). The clutch disconnection device 22 outputs a control signal to the gear shift device 35).

FIG. 5 shows a flowchart for executing the above control. In step 100, the vehicle speed V at that time is detected, and in step 101, when the vehicle speed V is less than the current shift-down condition vehicle speed value Vo, the process proceeds to step 102.

When the accelerator opening degree θ is 0% in step 102, the downshift flag is turned on in step 103.

On the other hand, if the accelerator opening degree θ is not 0% in step 102, the process advances to step 104, and only when the downshift flag is on, downshift control is started in step 105, and the downshift flag is cleared.

In this way, only when the vehicle speed drops below the downshift condition vehicle speed value when transitioning to deceleration driving and the accelerator is pressed from fully closed, it is assumed that a re-acceleration operation has been performed and the downshift control is activated. This prevents the downshift control from being activated frequently during driving.

Therefore, when the accelerator is not pressed even when the vehicle speed drops below a predetermined value, such as during deceleration, downshifting will not be performed, and if the vehicle comes to a stop, unnecessary downshifting will be avoided and fuel efficiency will be reduced. It is possible to prevent the deterioration of the vehicle and the feeling of running idle.

Regarding the shift up, the same control as before is used to read the shift gear from the shift up map based on the vehicle speed and the accelerator opening, and if the shift gear is different from the current shift gear, the shift up is performed. Incidentally, the shift-up and shift-down maps may be such that the shift stage can be read out only based on the vehicle speed, as shown in FIG.

(Effects of the invention) In summary, according to this invention, downshifting is possible only when downshifting is really necessary, such as during re-acceleration, when the accelerator opening is stepped from the fully closed position to a predetermined opening, such as during deceleration. Since the down control is activated, it is possible to improve driving fuel efficiency and reduce the feeling of empty running characteristic of mechanical automatic vehicles.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of this invention, Fig. 2 is a schematic block diagram showing an embodiment of this invention, Figs. 3 A and B are shift up and shift down maps, and Fig. 4 is a shift down condition vehicle speed value table. 5 is a flowchart showing an example of the control operation for downshifting, and FIG. 6 is a flowchart showing an example of the control operation for downshifting, and FIG.
Shift down map, Fig. 7 is a schematic configuration diagram of the conventional device, Fig. 8 is a block diagram of its control device, Fig. 9
The figure also shows the shift up and shift down maps. 12... Engine rotation sensor, 13... Governor control device, 15... Load sensor, 21... Clutch position sensor, 22... Clutch disconnection device, 32
...Main shaft rotation sensor (vehicle speed sensor),
34...Shift position sensor, 35...Gear shift device, 40A...Microcomputer.

Claims (1)

[Scope of utility model registration request] In an automatic transmission system for a vehicle equipped with a control device that performs upshifts according to driving conditions based on a preset shift-up map, at least a shift-down map that sets a gear shift stage to be selected in accordance with the vehicle speed and a vehicle speed are detected. means for detecting an accelerator opening; a downshift condition determining means for determining that the accelerator opening has been depressed from fully closed to a predetermined opening; An automatic transmission device for a vehicle, comprising: a control device that downshifts to a gear shift stage determined from a down map.