JPH0988653A - Gear shift shock reducer - Google Patents

Abstract

(57) An object of the present invention is to provide a gear shift shock reducing device capable of effectively reducing gear shift shock by temporarily reducing the input rotation of the automatic transmission 12 without changing the combustion state of the diesel engine 11. . SOLUTION: An exhaust brake 23, which is an auxiliary brake device attached to the diesel engine 11, is operated to reduce the torque of input rotation of the automatic transmission 12 during shifting. The gear ratio G is obtained from the outputs of the turbine sensor 28 and the vehicle speed sensor 20 to determine the gear shift start timing and gear shift completion timing. From the start of gear change to the end of gear change, 1st-2nd, 2nd
The exhaust brake 23 is set with an operation amount BD corresponding to the shift mode such as the third speed and the throttle opening TVO.
The torque obtained by subtracting the torque corresponding to the resistance of the exhaust brake 23 from the output of the diesel engine 11 is input to the automatic transmission 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear shift for reducing the shock of gear shift of a vehicle body accompanying a gear shift operation of the automatic transmission by temporarily reducing the torque input from the engine side to the automatic transmission during gear shifting. It relates to a shock reducing device.

[0002]

2. Description of the Related Art In a vehicle equipped with an exhaust turbine, a truck vehicle having a large total weight of the vehicle including the mounted vehicle, a large bus used frequently on a highway, etc., the effect of engine braking tends to be insufficient and the service brake is consumed. Because it is large, it is equipped with an exhaust brake device and a retarder device. The service brake frictionally restrains the rotation of the wheels with a pressure according to the amount of depression of the brake pedal. The engine brake cancels the driving force transmitted from the wheel side to the engine by utilizing the compression resistance of the engine when the depression amount of the accelerator pedal is reduced. On the other hand, in the exhaust brake device and the retarder device, the braking force can be changed according to the driving state of the vehicle by controlling the microcomputer circuit or the like to operate semi-automatically.

The retarder device is a device for absorbing energy by applying a load to the rotation of a driving force transmission system of an automobile, and uses an eddy current type for generating an electromagnetic braking force using a permanent magnet or an electromagnet, and an oil pump. A fluid type that generates a braking force by changing the flow path resistance of the oil circulated in is used.

The exhaust brake device is composed of a valve element provided in the exhaust path of the engine and a drive mechanism for the valve element.
By blocking (narrowing) the flow passage area of the exhaust path with the valve element, a large rotational resistance is formed and the engine braking effect is increased. Japanese Patent Laid-Open No. 2-258462 discloses that
An exhaust brake device is shown in which the level of the braking force can be continuously changed by adjusting the opening degree of the valve element to an intermediate value. However, in a normal exhaust brake device, the braking force is not finely adjusted or the constant braking force is not maintained, and it is exclusively used in two positions of operation / non-operation (ON / OFF).

By the way, there is a technique for reducing the shift shock of the vehicle body due to the shift operation of the automatic transmission by temporarily reducing the engine output input to the automatic transmission during the period from the start to the completion of the shift operation. JP-A-64-454
No. 4 and Japanese Patent Laid-Open No. 5-312059.

In Japanese Patent Laid-Open No. 64-4544, the rotational speed of the input shaft of the transmission mechanism of the automatic transmission (by the turbine shaft of the torque converter) and the rotational speed of the output shaft of the transmission mechanism (by the vehicle speed sensor) are detected. Therefore, the time when the engine output starts to decrease and the time when the engine output is restored to the original value are accurately obtained. Accurate estimation of the timing of occurrence and completion of transient gear shift shock caused by changing the clutch and brake of the gear shift mechanism by finding the point of change in the gear ratio calculated from the rotation speed of the input / output shaft of the gear shift mechanism However, unnecessary shocks due to an incorrect timing of reducing / restoring the engine output are avoided.

On the other hand, the gear shift shock reducing apparatus disclosed in Japanese Patent Laid-Open No. 5-312059 is designed to change the torque level of rotation input to the automatic transmission in order to change the fuel injection time of the engine, the ignition timing of the engine and the engine. One of the intake air amount and the load amount of the compressor and turbocharger attached to the engine is changed, and the engine output is temporarily reduced depending on whether the fuel is regular gasoline or premium gasoline. By making the amount different, the shift shock is effectively reduced in the same manner even if the fuel is different.

[0008]

When the engine connected to the automatic transmission is a diesel engine, there is a problem that control for temporarily reducing the output of the engine is difficult as compared with a gasoline engine. With a diesel engine, when the fuel injection amount, the ignition timing, or the intake air amount is changed, a quick response and a reproducible large torque adjustment range, unlike those of a gasoline engine, cannot be obtained. Further, there is a possibility that the engine stalls easily occur, or the combustion state in the cylinder changes to increase the emission amount of nitrogen oxides and exhaust particulates.

Further, the shift shock changes depending on the running condition such as the weight of the vehicle body, the vehicle speed and the inclination of the road surface. Therefore, the torque reduction amount can be finely set according to the running condition, or within 1 second from the start to the end of the shift. It is possible to change the amount of torque reduction over time. In this case, the responsiveness and reproducibility of torque reduction will be insufficient even in the case of a gasoline engine. Because the combustion state in the engine cylinder is based on a delicate balance of various conditions, there is a limit to finely controlling the torque reduction amount in the engine, and thermal (temperature) stability is limited. There is a possibility that the torque reduction amount fluctuates greatly due to the loss of torque. Therefore, in some cases, a gear shift shock may appear significantly, or the torque reduction itself may be an unpleasant shock.

It is an object of the present invention to provide a gear shift shock reducing device capable of effectively reducing gear shift shock by temporarily reducing the input rotation of the automatic transmission without changing the operating condition of the engine. .

[0011]

According to a first aspect of the present invention, an input torque changing means for changing the input torque of an automatic transmission,
A shift detecting means for detecting the start of the shift in the automatic transmission, and a torque down control for operating the input torque changing means to reduce the input torque during the shift when the shift detecting means detects the start of the shift. In the gear shift shock reducing device having means, the input torque changing means is an exhaust brake or a retarder device that is provided alongside the engine and applies an auxiliary braking force to the vehicle body.

According to a second aspect of the invention, the input torque changing means in the structure of the first aspect is an exhaust brake, and the torque down control means determines the operating amount of the exhaust brake according to the throttle opening. It includes a quantity determining means.

[0013]

In the gear shift shock reducing device of the first aspect, the torque obtained by subtracting the torque of the braking force generated in the exhaust brake and the retarder device from the output torque of the engine is input to the automatic transmission. It is not necessary to change the operating state of the engine itself because the torque is reduced by using these auxiliary braking devices provided in the engine. Exhaust brakes and retarder devices have a wide range of torque reduction that is far more reproducible and responsive than when changing the engine operating state through the same operation as when outputting the original auxiliary braking force. Quantity can be realized.

In the shift shock reducing device of the second aspect, the exhaust brake is configured so that the operation amount in the intermediate stage can be set in addition to the normal ON / OFF2 position. The range of large braking force by the exhaust brake is used as the range of torque reduction. The exhaust brake as an auxiliary braking device operates only when the accelerator pedal is released and the throttle opening is reduced, but when executing torque reduction, the accelerator pedal is depressed and the throttle opening is reduced. It is operated even at a high price. When the throttle opening is high, the output torque of the engine is high, so the shift shock through the automatic transmission also becomes large. Therefore, the operation amount of the exhaust brake is set so that the torque reduction amount is larger than that when the throttle opening is low.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An auxiliary brake device according to an embodiment will be described with reference to FIGS. FIG. 1 is an explanatory diagram of a configuration of an auxiliary brake device, FIG. 2 is a time chart of torque reduction by an exhaust brake, and FIG. 3 is a flowchart of torque reduction control.

As shown in FIG. 1, the diesel engine 11 has an exhaust brake 23 as an auxiliary brake device.
And the retarder device 13 are installed side by side. The eddy current retarder device 13 applies a braking force according to the current level supplied from the auxiliary brake control device 32 to the diesel engine 1
Output to 1 output shaft. The torque obtained by subtracting the braking torque of the retarder device 13 from the output torque of the diesel engine 11 is input to the automatic transmission 12.

The exhaust brake 23 arranged in the exhaust path of the diesel engine 11 is driven by the air cylinder 24, and the flow passage area of the exhaust path is narrowed to increase the exhaust pressure of the diesel engine 11 to increase the exhaust pressure of the diesel engine 11. 11 increases the rotational resistance. The torque obtained by subtracting the torque corresponding to this rotational resistance from the output torque of the diesel engine 11 is input to the automatic transmission 12.

When the auxiliary brake control device 32 turns on the solenoid valve 25, compressed air is supplied from the air tank 26 to the air cylinder 24 and the exhaust brake 23 operates. The air cylinder 24 is provided with a stroke adjusting mechanism (not shown) capable of setting the pushing amount of the piston in a plurality of steps. The auxiliary brake control device 32 can control the stroke adjusting mechanism to adjust the flow passage area of the exhaust path when the exhaust brake 23 is operated in a plurality of steps. When the auxiliary brake control device 32 turns off the solenoid valve 25, the compressed air in the air cylinder 24 is discharged, and the flow passage area of the exhaust path is opened.

The output rotation of the diesel engine 11 is speed-changed by the automatic transmission 12 and transmitted from the propeller shaft 16 to the rear wheels 15 via the differential mechanism 14.
The output of the diesel engine 11 changes according to the throttle opening TVO of the throttle valve 18, which is adjusted by the driver depressing the accelerator pedal 17. The throttle sensor 22 provided in the throttle valve 18 outputs an analog voltage signal according to the throttle opening TVO.

A vehicle speed sensor 20 provided in the automatic transmission 12
Outputs a voltage signal having a frequency corresponding to the vehicle speed. The turbine sensor 28 outputs a voltage signal having a frequency corresponding to the rotation speed of the output shaft of the torque converter of the automatic transmission 12. The inhibitor switch 21 outputs a code signal corresponding to the shift mode set by the driver operating the select lever 19. The shift modes are the D range selected in normal driving, the 2nd speed range and the 1st speed range selected when engine braking or rapid acceleration is required, and the neutral N range and P range.
Range, R range selected when moving backward.

The automatic transmission control unit 31 includes
The throttle opening TVO is calculated based on the output of the throttle sensor 22, the vehicle speed VSP and the output speed NS based on the output of the vehicle speed sensor 20, and the turbine speed NT is calculated based on the output of the turbine sensor 28. The automatic transmission control unit 31 identifies the shift mode set through the inhibitor switch 21, selects a shift map, and checks the throttle opening TVO and the vehicle speed VSP with the shift map every moment to determine the shift timing. The solenoid valve SV of the transmission 12 is operated to set the necessary shift speed in the automatic transmission 12. The automatic transmission control unit 31
The gear ratio G is calculated every moment from the turbine speed NT and the output speed NS, and the shift start timing and shift end timing are identified based on the change in the gear ratio G. Then, the hydraulic pressure level of the automatic transmission 12 is adjusted stepwise within a time period of about 1 second from the start of the gear shift to the end of the gear shift so that the clutch and the brake can be changed over smoothly during the gear shift.

The auxiliary brake control device 32 obtains various information including the throttle opening TVO, the vehicle speed VSP, the gear ratio G, and the output state for the automatic transmission 12 through the automatic transmission control unit 31. The auxiliary brake control device 32 operates the exhaust brake device 23 and the retarder device 13 to operate the exhaust brake device 23 and the retarder device 13 when the driver releases the depression of the accelerator pedal 17 while the auxiliary brake switch 27 provided in the vehicle compartment is turned on. A braking force added to the engine braking effect of 11 itself is generated to exert a large deceleration force on the vehicle body.

The auxiliary brake control device 32 turns on / off the auxiliary brake switch 27 during the shifting operation of the automatic transmission 12.
The exhaust brake 23 is actuated regardless of the OFF state to reduce the shift shock of the vehicle body due to the shift operation. When the automatic transmission 12 determines the shift, the auxiliary brake control device 32 corresponds to the distinction between the shift modes such as 1st speed-2nd speed and 2nd speed-3rd speed and the level of the throttle opening TVO. Torque down amount QD is determined, and torque down amount Q
An operation amount BD of the exhaust brake 23 corresponding to D is obtained.
The auxiliary brake control device 32 activates the exhaust brake 23 up to the operation amount BD at the same time when the automatic transmission control unit 31 detects the shift start timing, and at the same time when the automatic transmission control unit 31 detects the shift end timing. Release the operation.

The automatic transmission control unit 31 has two
Even after the solenoid valve SV of the automatic transmission 12 is operated in the high speed state, as shown in FIG. 2, until the clutch and brake replacement is actually started inside the automatic transmission 12,
The gear ratio G of the automatic transmission 12 remains in the first speed state.
When the clutch and brake are actually replaced, the gear ratio G gradually decreases through the slipping process of the clutch and brake.
A high gear ratio G is obtained. At this time, since the shift shock F is the acceleration acting on the vehicle body with the change of the gear ratio G,
If torque reduction is not executed, it appears as shown by a broken line FN in the process of changing the gear ratio G. Therefore, in the embodiment, the exhaust brake 23 is operated by the operation amount BD from the start of the shift detected by the automatic transmission control unit 31 based on the change of the gear ratio G to the end of the shift, and the engine 1 is operated.
By reducing the torque Q input to the automatic transmission 12 from 1 by the torque reduction amount QD, the shift shock F is reduced to the level of the solid line FB.

Referring to FIG. 3, the auxiliary brake control device 32
The torque down control at the time of gear shift will be described. In step 112, it is identified whether or not a torque down request is issued from the automatic transmission control unit 31. When the automatic transmission control unit 31 determines that it is necessary to shift, it determines the necessity of torque reduction based on the shift mode, the level and variation of the vehicle speed VSP, the cargo loading amount, etc. Is output. When there is a torque down request, the routine proceeds to step 113, and when there is no torque down request, the following processing is bypassed.

In step 113, the automatic transmission control unit 31 controls the shift mode and throttle opening TVO.
In step 114, the torque reduction amount QD according to the shift mode and the throttle opening TVO is determined. Since the gear shift is performed on a shift line in which the throttle opening TVO and the vehicle speed VSP have a one-to-one correspondence, the torque down amount QD is also set according to the vehicle speed VSP.

In step 115, it is determined whether or not the automatic transmission control unit 31 is in a gear shift. As indicated by the broken line in FIG. 2, it is determined whether or not the period from the start of gear shift to the end of gear shift as seen from the gear ratio G is determined. If yes, the routine proceeds to step 117, where the exhaust brake 23 is operated. If not, the process proceeds to step 116. In step 116, it is determined whether or not the shift is completed, and if the shift is completed, the operation of the exhaust brake 23 is released.

According to the auxiliary brake device of the embodiment, the exhaust brake 23 is actuated to execute the torque down at the time of gear shifting, so that the vehicle body can be shortened even if the gear shifting time is set shorter than when the torque down is not performed. The gear shift shock is effectively reduced. If the shift time is completed in a short time, a smooth and crisp driving sensation is secured, and the life of the clutch and brake of the automatic transmission 12 is extended. In addition, since the operating condition of the diesel engine 11 can be maintained at the best condition by keeping the temperature conditions of the cylinder and the supply air constant without changing the fuel supply amount or the injection timing, the engine stall or disturbance of the diesel engine 11 can be maintained. There is no need to worry about causing fuel consumption or deteriorating the state of exhaust gas. Further, since the shift start / shift completion is accurately determined from the change in the gear ratio G of the automatic transmission 12, the unnecessary shock due to the deviation of the operation / release of the exhaust brake 23 from the actual shift period does not occur.

Further, since it is not necessary to control the diesel engine 11 in association with the torque reduction at the time of gear shift, and the torque reduction is realized by utilizing the structure of the existing auxiliary brake device as it is, there are the following advantages. (1) It is not necessary to mount a new device for torque reduction on the diesel engine 11. (2) It is not necessary to provide wiring for torque down control between the controller of the diesel engine 11 and the automatic shift control unit 31. (3) Since the exhaust brake 23 can generate a large resistance force to the output rotation of the diesel engine 11, it is possible to cancel even a large throttle shock TVO, a large shift shock corresponding to an empty load or a short shift time.

Although the auxiliary brake control device 32 independent of the automatic transmission control unit 31 is used in the embodiment, the function of the auxiliary brake control device 32 may be included in the automatic transmission control unit 31 to be executed. In this case, the automatic transmission control unit 31
No wiring or communication is required between the auxiliary brake control device 32 and the auxiliary brake control device 32, and information processing is not required, and the processing program is simplified. Further, instead of the exhaust brake 23, the retarder device 13 may output the braking force to realize the torque reduction at the time of shifting. Since the retarder device 13 can set the braking force with higher responsiveness and reproducibility than the exhaust brake 23, the torque reduction amount can be finely changed at each step during the shift, or the past torque reduction amount and the measured shift amount can be changed. It is also possible to execute learning control for correcting the next torque down pattern with the shock data. Further, the timing of the shift start / shift completion may be identified from the change of the engine speed NE or the like regardless of the gear ratio G.
As shown in Japanese Patent No. 12059, the operation amount BD of the exhaust brake 23 may be changed according to the type of fuel.

In the embodiment, the exhaust brake 23 is the input torque changing means of the invention, steps 113 and 114 are the torque down amount determining means of the invention, step 115 is the shift detecting means of the invention, and step 117 is the torque down control means. Equivalent to each.

[0032]

According to the gear shift shock reducing device of the first aspect, the input rotation of the automatic transmission is torqued down by the braking force of the auxiliary braking device, so that the operating state of the engine is not changed and a new one is provided. Torque down can be realized and gear shift shock can be effectively reduced without providing a device dedicated to torque down. Since the operating state of the engine does not have to be changed, engine stalling or disturbance is not caused, and the exhaust gas state or fuel consumption is not adversely affected. Exhaust brakes and retarders are superior in reproducibility of torque reduction, controllability, and responsiveness compared to control that changes the combustion state of the engine, which is based on a balance in which delicate variables are complicatedly mixed. Reduction of shift shock by down control becomes practical, and can be realized practically and effectively.

According to the gear shift shock reducing device of the second aspect, the torque reduction can be executed within the range of large resistance force due to the exhaust brake, so that even a large gear shift shock when the gear shift time is set short can be offset. Further, as compared with the retarder device, a large torque reduction can be obtained with a light and small device and little power consumption, and a control device for controlling the torque reduction amount can be simple.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of an auxiliary brake device.

FIG. 2 is a time chart of torque reduction due to an exhaust brake.

FIG. 3 is a flowchart of torque down control by an exhaust brake.

[Explanation of symbols]

 11 Diesel engine 12 Automatic transmission 13 Retarder device 14 Differential mechanism 15 Rear wheel 16 Propeller shaft 17 Accelerator pedal 18 Throttle valve 19 Select lever 20 Vehicle speed sensor 21 Inhibitor switch 22 Throttle sensor 23 Exhaust brake 24 Cylinder 25, SV solenoid valve 26 Air tank 27 Auxiliary brake switch 28 Turbine sensor 31 Automatic transmission control unit 32 Auxiliary brake control device

Claims (2)

[Claims] 1. An input torque changing means for changing an input torque of an automatic transmission, a shift detecting means for detecting a start of a shift in an automatic transmission, and a shift detecting means for detecting a start of a shift, In a gear shift shock reducing device having a torque down control means for operating the input torque changing means to reduce the input torque during gear shifting, the input torque changing means is provided alongside the engine to apply an auxiliary braking force to the vehicle body. A shift shock reducing device characterized by being an exhaust brake or a retarder device to be actuated. 2. The input torque changing means is an exhaust brake, and the torque down control means includes exhaust brake operation amount determining means for determining an operation amount of the exhaust brake according to a throttle opening. The shift shock reducing device according to claim 1.