JPH0320581Y2 - - Google Patents

Description

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

(Background 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, for example, the present applicant applied for
The one proposed in No. 163228 is a mechanical clutch type without a torque converter.
It is configured as shown in Figures 1 and 2.

FIG. 1 is an overall schematic diagram, in which a transmission 30 equipped with a known countershaft is attached to a diesel engine 10 equipped with a fuel injection pump 11 via a mechanical disc clutch 20, and the main The shaft 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 a governor 11a and controls the fuel injection amount.

The clutch 20 is provided with a clutch position sensor 21 for detecting the position of the clutch and a clutch disconnection device 22 for controlling engagement and disconnection of 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 34 that detects the number of rotations of the countershaft, and a gear shift device 35 that controls the gear shift position 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 includes a shift change determination circuit 41 that determines whether or not to change gears, that is, change a shift, based on detection signals from the engine rotation sensor 12, vehicle speed sensor 32, and load sensor 15; 41 and a detection signal from the shift position sensor 34, a shift change control circuit 42 outputs a signal to perform a shift change, an engine control circuit 43, a clutch engagement control circuit 44, and a transmission control circuit 45, which will be described later. , and a start control circuit 50.

The engine control circuit 43 receives the output signal of the shift change control circuit 42 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 engagement control circuit 44 receives the output signal of the shift change control circuit 42 or the start control circuit 5.
Based on the output signal of 0 and the detection signal of the clutch position sensor 21, the clutch disengagement device 22 is operated to engage and disengage the clutch 20 so as to optimally perform gear shifting or starting.

The transmission control circuit 45 receives the output signal of the shift change control circuit 42, 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.

The start control circuit 50 determines the start state based on the detected positions of the load sensor 15, vehicle speed sensor 32, engine rotation sensor 12, and shift position sensor 34, and when a predetermined accelerator opening is exceeded at the time of start, the clutch disengagement control circuit is activated. Based on a preset pattern at 44, an actuation signal is outputted to engage the clutch 20 while keeping it in a half-clutch state.

During driving in the D (drive) range, if the shift change determination circuit 41 determines that a shift should be made, for example, a shift up command is output from the shift change control circuit 42 to the main control circuits 43 to 45 based on the determination signal. . Then, the clutch disengagement control circuit 44 outputs a control signal to the clutch disengagement device 22 to disengage the clutch 20, thereby disengaging the clutch 20 and setting 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. From the gear shift control circuit 45,
A control signal to put the transmission 30 into neutral is output to the gear shift device 35, and the transmission is put into 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 engaged.

On the other hand, when the start control circuit 50 outputs a start signal, the clutch disengagement control circuit 44 operates the clutch disengagement device 22 as described above, whereby the clutch 20 is connected while maintaining the half-clutch state for a predetermined period of time. You can get a smooth start on par with a torque converter.

Incidentally, with such automatic transmissions, it is now possible to freely select the gear position between, for example, 1st to 4th gear by manual operation, but for this reason, when transitioning from driving to stopping, it is possible to select the gear position freely. Even if you decelerate while the engine is selected, the engine speed will be set to idle speed (varies depending on coolant temperature) + α to prevent engine stalling.
(usually α=100 to 150 rpm), the clutch on/off control circuit 44 outputs a signal to disconnect the clutch 20.

Therefore, for example, even if you try to drive at an extremely low speed by putting the gear in 1st gear on a congested road, the clutch 20 will be disengaged when the engine 10 reaches idling speed +α, so the engine 10 will be kept at idling speed as in the case of a manual clutch. There was no way I could maintain it and drive slowly.

(Purpose of the invention) This invention did not focus on such problems, and only when the gear shift position of the transmission is in a low gear,
The purpose of the present invention is to provide an automatic transmission device for a vehicle capable of running at an extremely low speed by keeping an engine at idle speed.

(Structure and operation of the invention) Therefore, as shown in FIG.
In a vehicle automatic transmission device equipped with a control circuit A that drives the engine, the control circuit A controls the engine speed,
Means B, C, and E for detecting the accelerator opening and the shift position of the transmission, means D for determining the deceleration state from the accelerator opening and engine rotational speed, and means D for determining the deceleration state from the accelerator opening and engine rotational speed, and when the shift position is at a low gear during deceleration, the actual Means F is provided for disengaging the clutch at a rotation speed lower than the idle rotation, but at a rotation speed higher than the actual idle rotation at other shift positions.

In other words, when the transmission is in a low gear position, the clutch is not disengaged until the engine speed drops to a set value below idle speed, making it possible to keep the engine at idle speed and drive at extremely low speeds. becomes.

(Example) This invention will be explained below according to the example shown in FIGS. 4 to 7.

The clutch engagement control circuit 44A operates the clutch engagement device 22 to optimize gear shifting or starting based on the output signal of the shift change control circuit 42 or the output signal of the start control circuit 50 and the detection signal of the clutch position sensor 21. The clutch 20 is controlled intermittently to enable the operation.

When the clutch intermittent control circuit 44A determines deceleration based on the outputs from the accelerator opening sensor 15 and the engine rotation speed sensor 12, the clutch disengagement control circuit 44A determines whether the deceleration has occurred based on the output from the accelerator opening sensor 15 and the engine rotation speed sensor 12, and then controls the transmission 3 based on the input signal from the shift position sensor 34.
0 shift position is low gear (e.g. reverse, 1
When in high gear (3rd gear or higher), the clutch 20 is not disengaged until the engine speed reaches idle rotation - β (for example, β = 50 rpm), and when in high gear (3rd gear or higher), the clutch 20 is not disengaged until the engine speed reaches idle rotation + α (for example, α = 150 rpm). A signal for disengaging the clutch 20 is output.

Note that the control of this embodiment is performed by a microcomputer, and the input/output interface,
Display of CPU, memory, etc. is omitted.

The apparatus is constructed as described above, and other parts that are the same as those in FIG. 2 are designated by the same reference numerals.Next, the operation thereof will be explained according to the flowchart in FIG. 5.

The engine speed N, access opening θ, and shift position S are read, and it is first determined whether or not deceleration is occurring. When shifting to deceleration, check whether the shift position S is a high speed gear or a low gear gear, and when the shift position S is a high speed gear or higher, the engine rotation speed N is set to idle rotation +
The clutch disconnects when the speed drops below 150 rpm.

On the other hand, when the shift position S is in reverse and in a low gear such as 1st or 2nd gear, the clutch is disengaged when the engine speed N becomes less than idling rotation -50 rpm.

Note that when the clutch is disengaged, unless the engine speed N rises again above the set value, other controls, such as setting the transmission to neutral, are performed to bring the vehicle to a stop.

In this way, when the shift position of the transmission 30 is in a low gear, as shown in FIG. As shown by the dashed line in the figure, it is possible to maintain the engine speed at an idling speed and run at an extremely low speed.

On the other hand, when the shift position of the transmission 30 is in the high gear position, as shown in FIG.
Since the clutch 20 is disengaged at this point, the engine will not stall even if the vehicle is decelerated while the vehicle is in a high gear and transitions from extremely low speed to a stop.

(Effects of the invention) In summary, according to this invention, when the clutch is in a low gear, the clutch is disengaged at a rotation speed lower than the actual idle rotation, so it is possible to maintain the idle rotation and drive at an extremely low speed on a congested road. This makes it possible to improve drivability at low speeds.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional device, FIG. 2 is a block diagram of a control device, and FIG. 3 is a diagram corresponding to claims of this invention. FIG. 4 is a block diagram of a control device showing an embodiment of this invention, FIG. 5 is a flowchart showing an example of its control operation, and FIGS. 6 and 7 are engine rotation characteristic diagrams. 12... Engine rotation sensor, 32... Main shaft rotation sensor, 34... Shift position sensor, 35... Gear shift device, 41... Shift change determination circuit, 42... Shift change control circuit, 43... Engine control circuit , 44A...Clutch engagement control circuit, 45...Transmission control circuit, 50...Start control circuit.

Claims (1)

[Scope of utility model registration request] In an automatic transmission system for a vehicle, which is equipped with a control circuit that automatically performs gear shifting and clutch engagement based on a preset pattern depending on the driving condition of the vehicle, the control circuit controls engine rotation speed, accelerator opening, and gear change. A means for detecting the shift position of the machine, a means for determining the deceleration state from the accelerator opening degree and engine rotation, and a means for determining the deceleration state from the accelerator opening degree and engine rotation; An automatic transmission device for a vehicle, characterized in that it is provided with means for disengaging a clutch at a rotational speed higher than the actual idle rotational speed.