JPH0939773A - Retarder controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retarder controller which ensures natural decelerating feeling and thus does not give unpleasant feeling to a driver even if a shiftdown operation is suddenly started in some time after a manual-shift-down mode is set. SOLUTION: A control unit 30 for an automatic transmission keeps the level of braking force output by a retarder 13 constant until the automatic transmission 12 starts a shifting-down operation even after a driver sets a manual- selectdown mode by a selector lever 19. When it starts the shifting-down operation, the level of braking force is reduced by an amount Q to prevent decelerating force from increasing excessively. The decrease amount Q is made the larger as the time from the setting of the manual-select-down mode to the start of the shift-down operation is longer, thereby reducing shock caused by the gear shift.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retarder control device for controlling a level and an output timing of a braking force output from a retarder device mounted as an auxiliary brake system on a vehicle equipped with an automatic transmission.

[0002]

2. Description of the Related Art A retarder device uses a service brake that frictionally restrains the rotation of a wheel with a pressure corresponding to the amount of depression of a brake pedal by a driver, and a drive transmitted from the wheel side to an engine by using compression resistance of the engine. It is an auxiliary braking system added to the engine braking that offsets the force. The retarder device is equipped with a turbocharger with an exhaust turbine, and cannot be expected to have much braking force due to engine braking.For vehicles and buses that have a large total gross vehicle weight and are frequently used on the highway, including the mounted components. Mainly installed in large vehicles, it supplements the engine braking effect and reduces the frequency and burden of service braking.

As the retarder device, an eddy current type in which a permanent magnet or an electromagnet is used to generate an electromagnetic braking force, and a fluid in which an oil pump is used to circulate oil to generate a braking force from a flow resistance of the oil The mold is already in practical use. There is also an example in which an exhaust brake that increases the exhaust pressure of the engine by closing a valve provided in the exhaust path of the engine is used as a retarder device. The retarder device can output the braking force with high reproducibility by finely setting the level of the braking force to be output and the output timing.
A general retarder device in a vehicle equipped with an automatic transmission operates when the driver releases the accelerator pedal while the permission switch in the vehicle compartment is turned on. The retarder device outputs a braking force to a power transmission path from the engine to the wheels to generate a pseudo engine braking effect on the vehicle body.

By the way, Japanese Patent Laid-Open No. 3-248951 discloses a technique for adjusting the level and the output timing of the braking force output from the retarder device to reduce the shift shock when the automatic transmission shifts downshifts. . Here, the driver operates the select lever to select the 1st speed range or 2
When the engine braking request position such as the speed range is set, the level of the braking force output from the retarder device in operation is temporarily reduced until the shift down shift of the automatic transmission is completed. This avoids a situation in which the deceleration associated with the downshift of the automatic transmission is added to the braking force of the retarder to cause excessive deceleration (shift shock).

Since the shift shock at the time of downshifting to the first speed is larger than the shift shock at the time of downshifting to the second speed, the retarder device outputs the smaller shift speed at the downshift destination. By significantly reducing the braking force applied, it is possible to prevent the gearshift shock due to the downshift from appearing significantly in addition to the deceleration effect of the retarder device until the downshift starts.

[0006]

The timing of shift-up and shift-down of the automatic transmission is ascertained with reference to a shift map in which throttle opening and vehicle speed regions are assigned to each shift speed, and the throttle opening and vehicle speed are changed every moment. Is detected and judged. On the shift map, allocation areas of the first, second, third, and fourth speeds are arranged in the directions of high vehicle speed and low throttle opening. For example, as the vehicle speed increases, the combination of throttle opening and vehicle speed becomes the third speed. And 3 when the boundary of 4th gear is reached
A shift operation from the fourth speed to the fourth speed is commanded.

On the other hand, when deceleration is started from high speed running and the driver operates the select lever to manually select down to the second speed range or the first speed range, the second speed or the first speed is immediately selected.
If the gear ratio is suddenly increased by shifting down to the high speed, the engine speed may be abnormally increased, and the engine may be damaged. So, in the 2nd speed range and the 1st speed range,
A shift prevention line corresponding to the upper limit of the engine speed is set on the shift map, and the shift down shift is executed after the vehicle speed decreases to the level of the shift prevention line after the manual select down operation is executed.

However, if the manual select down is executed at a vehicle speed higher than the gear shift prevention line, the driver operates the select lever in anticipation of the immediate engine braking effect, but at that time, the speed is reduced by the shift down. The effect does not appear, and the big deceleration effect due to the downshift suddenly appears only after the vehicle speed decreases to the level of the gear shift prevention line after a while. A large deceleration effect at a driver's unexpected timing makes the driver feel uncomfortable.

Here, as disclosed in Japanese Unexamined Patent Publication No. 3-248915, the level of the braking force output from the retarder device is lowered at the timing of manual select down, and the braking force is completed when the downshift is completed. You may restore the level of. By temporarily reducing the deceleration effect by the retarder device, the total deceleration effect obtained by adding the downshift effect to the deceleration effect by the retarder device becomes small in the period from the start to the end of the downshift. However, the waiting time from the manual select down to the start of the shift down shift is low because the braking force of the retarder device is low, so the feeling of deceleration of the vehicle body after the manual select down is insufficient, and the driver depresses the brake pedal. It is necessary to brake. Then, when the downshift is suddenly started in the state where the brake pedal is depressed to give the additional braking force, the braking force becomes excessive and makes the driver feel uncomfortable.

According to the present invention, when the driver performs a manual select down operation at a vehicle speed higher than the shift prevention line, the deceleration state of the vehicle body changes smoothly from the timing of manual select down to the completion of the shift down shift. It is an object of the present invention to provide a retarder control device that provides a natural deceleration feeling.

[0011]

According to the invention of claim 1, the retarder device arranged in the drive force transmission path of the vehicle equipped with the automatic transmission can be controlled to adjust the level of the braking force to be output and the output timing. In the retarder control device, a braking continuation unit that continues to output a braking force of a predetermined level from the retarder device during the period from the driver setting the manual select down to the start of the downshift, and the driver manually Measuring means for measuring the select elapsed time from the setting of the select down until the shift down is started, and the level of the braking force output from the retarder device at the start of the shift down is determined according to the select elapsed time. However, as the select elapsed time is longer, there is an output adjusting means for making the shift shock at the start of downshifting less noticeable. It is intended.

According to a second aspect of the present invention, the output adjusting means in the configuration of the first aspect uses the braking force at the predetermined level as a reference value, and the braking force through the downshift period increases as the select elapsed time increases. The amount of decrease from the standard value is increased.

[0013]

In the retarder control device according to the first aspect of the present invention, the level of the braking force is not lowered immediately when the driver sets the manual select down, but the braking force of a predetermined level is maintained until the shift down is started. Then, the level of the braking force is lowered corresponding to the start of the shift down. Then, instead of uniformly lowering the level of the braking force, the degree of decrease is changed according to the length of the select elapsed time, and at least the shift shock at the start of downshift becomes less noticeable as the select elapsed time becomes longer. There is. That is, when the select elapsed time is short, the driver is strongly impressed with the execution of the shift down shift, and priority is given to the response to the manual select down setting operation. Since it becomes difficult to understand the relationship of the shock, the shift shock associated with the downshift is made not to stand out so much from the level of the braking force output from the retarder device until the downshift starts.

In the retarder control device according to the second aspect, the level of the braking force output from the retarder device is reduced from the start of the downshift to the end of the downshift. The decrease width is set to be larger as the select elapsed time becomes longer, with the level of the braking force output from the retarder device during the select elapsed time as a reference value.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A retarder control device according to an embodiment will be described with reference to FIGS. 1 is an explanatory view of the configuration of the control system of the retarder device, FIG. 2 is a shift map for each select position, FIG. 3 is a diagram for obtaining the retarder braking force decrease amount, FIG. 4 is a control timing chart, FIG.
FIG. 6 is a control flowchart. 2, (a) is the D range, (b) is the third speed range, (c) is the second speed range,
(D) is the first speed range. In FIG. 4, (a) shows a case where the select elapsed time is short, (b) shows a case where the select elapsed time is long, and (c) shows a comparative example by the conventional control for reducing the braking force of the retarder device simultaneously with the manual downshift. is there.

The fluid type retarder device 13 is arranged on the output shaft side of the automatic transmission 12 as shown in FIG.
The braking force corresponding to the hydraulic pressure level supplied from the retarder operating device 28 is output to the propeller shaft 18. The driver operates the retarder switch 16 provided in the vehicle compartment to set whether to use the retarder device 13 as an auxiliary brake. When the retarder switch 16 is turned on, the automatic transmission control unit 30 determines the necessity of braking and determines the level of braking force and the output timing.
3 is activated to output the braking force. The automatic transmission control unit 30 controls ON / OFF of the solenoid valve 26 mounted on the automatic transmission 12 to perform various gear shifting operations of the automatic transmission 12 and various adjustments in the gear shifting process.

The automatic transmission 12 is connected to the engine 11, and the output rotation of the engine 11 is changed by the automatic transmission 12 and transmitted from the propeller shaft 18 to the rear wheel 15 via the differential mechanism 14. The driver adjusts the throttle opening of the throttle valve 22 by adjusting the amount of depression of the accelerator pedal 17 to change the output and the rotational speed of the engine 11. The output of the throttle sensor 23 attached to the throttle valve 22 is input to the automatic transmission control unit 30 together with the output of the vehicle speed sensor 25 attached to the automatic transmission 12. When the driver operates the select lever 19 to select one of the travel ranges, the shift pattern of the automatic transmission 12 is set. The selected driving range is read by the rotary switch 21 and the automatic transmission control unit 30 is read.
Is input to

The automatic transmission control unit 30 is
A microcomputer circuit provided with a storage circuit, an arithmetic circuit, and an input / output circuit (not shown), and as described later with reference to the flowcharts of FIGS. , Throttle opening detection processing 32, travel range detection processing 33, select elapsed time measurement processing 34, retarder braking force control processing 35, traveling gear determination processing 36, retarder braking force reduction amount determination processing 3
7. In addition, various processes of the shift operation and shift process in the automatic transmission 12 are executed.

In the vehicle speed detection processing 31, the momentary vehicle speed VSP is calculated based on the output of the vehicle speed sensor 25. In the throttle opening detection process 32, the throttle opening TVO is calculated every moment based on the output of the throttle sensor 23. In the traveling range detection processing 33, the setting state of the traveling range is identified on the basis of the output of the rotary switch 21. In the traveling gear determination process 36, one of a plurality of prepared shift maps corresponding to the set travel range is selected, and the shift map is referred to to determine the vehicle speed VSP and the throttle opening TVO. Determine the shift timings for downshift and upshift.

The retarder braking force control processing 35 is performed by setting the retarder switch 16, the select lever 19 (rotary switch 21), and the throttle opening TV.
O, the retarder braking force reduction amount Q determined in the retarder braking force reduction amount determination process 37 is detected to determine whether the retarder device 13 is activated or not, and when it is activated, the level of the braking force is determined every moment. . In the select elapsed time measuring process 34,
After the select lever 19 is selected down, the elapsed time until the downshift is commanded by the traveling gear determination process 36 is measured. In the retarder braking force decrease amount determination process 37, as shown in FIG. 3, the select elapsed time T measured in the select elapsed time measuring process 34 is shown.
The retarder braking force reduction amount Q is determined according to As a result, the retarder braking force control processing 35 performs the retarder device 13 for the period from the start to the end of the downshift.
The level of the braking force output from is reduced by the retarder braking force reduction amount Q.

FIG. 2 shows four types of shift maps corresponding to the four forward drive ranges set by the select lever 19. In this embodiment, the throttle opening TV is set when the driver releases the depression of the accelerator pedal 17.
When the throttle opening TVO interrupts the reference value T1 shown in the drawing, the engine 11 is determined to be in the idle state in which the depression of the accelerator pedal 17 is released. In the D range of FIG. 2A, four shift speeds are used, in which an overdrive shift speed having a gear ratio of 1 or less is provided on a direct connection gear ratio of 1. In the third speed range of FIG. 2 (b), three speed stages that maximize the direct connection speed of gear ratio 1 are used. A 3rd speed prevention line is provided to prevent the engine 11 from causing excessive rotation, and when a manual select down from the D range to the 3rd speed range is performed during high-speed traveling beyond the 3rd speed prevention line, 3 The downshift is executed after waiting for the vehicle speed VSP to decrease to the speed prevention line.

In the second speed range of FIG. 2 (c), two speed stages are used with the second speed being the highest. The 2nd speed prevention line is provided along with the 3rd speed prevention line, and when a manual select down is made from the D range to the 2nd speed range during high-speed traveling beyond the 3rd speed prevention line, the vehicle speed VSP decreases to the 3rd speed prevention line. The shift down to the third gear is executed after waiting for the shift, and the shift down to the second gear is executed after waiting for the vehicle speed VSP to decrease to the second speed prevention line. In the first speed range of FIG. 2D, only the first speed stage is used. 3
The first speed prevention line is provided in addition to the second speed prevention line,
When the vehicle speed VSP exceeds the first speed prevention line and the manual select down is performed in the first speed range, the shift down to the first speed stage is executed after the vehicle speed VSP is reduced to the first speed prevention line.

The automatic transmission control unit 30 includes
In the retarder braking force reduction amount determination process 37, in the range E1 where the select elapsed time T from the execution of the manual select down by the driver to the actual start of the downshift is short, the shift shock of the downshift feels uncomfortable. Since it does not exist, the reduction amount Q is made small and the shift shock remains large. In the range E2, since there is some discomfort due to the shift shock, the decrease amount Q is gradually increased as the select elapsed time T is increased. On the other hand, in the range E3, the relationship between the shift shock and the manual select down cannot be understood, so the reduction amount Q is maximized, and the shift shock during the period from the start to the end of the shift down is delayed until the shift down is started. Do not let it protrude from the level of the braking force that was output from. The shift shock accompanying downshifting is suppressed to a level that is hardly noticeable to the driver.

For example, when the driver performs a manual select down from the D range to the third speed range at the point A shown in FIG. 2 (a), the vehicle speed reaches the third speed prevention line as shown in FIG. 2 (b). After VSP decreases, shift down to the third speed is executed. At this time, the decrease amount Q is increased as the select elapsed time T from the manual select down to the shift down is longer. Similarly, when the driver performs a manual select down to the second speed range at point B shown in FIG. 2C, or when the driver manually selects to the first speed range at point C shown in FIG. 2D. Even when down is executed, the decrease amount Q is increased as the select elapsed time T until the vehicle speed VSP decreases to the second speed prevention line and the first speed prevention line and downshift is executed, respectively.

A specific example of the control of the retarder device will be described with reference to FIGS. 4 (a) and 4 (b). At time t0, the driver releases the depression of the accelerator pedal 17. If the retarder switch 16 is turned on, the automatic transmission control unit 30 immediately causes the retarder device 13 to output a braking force of a predetermined level. Even if the driver who feels insufficient deceleration executes the manual select down at time t1, the automatic transmission control unit 30 maintains the braking force of the retarder device 13 at a predetermined level until the shift down is started. However, when the downshift is started at time t2, until the downshift is completed at time t3,
The automatic transmission control unit 30 reduces the braking force of the retarder device 13 at a predetermined level by the reduction amount Q.

In FIG. 4 (a), since the select elapsed time T is short, the decrease amount Q is set to a small value to cause a large shift shock as a response to the deceleration operation when the downshift is executed. In (b) of FIG. 4, since the select elapsed time T is long and the shift shock has a large discomfort, the reduction amount Q is set to a large value to make the shift down shift shock inconspicuous.

On the other hand, in the conventional control shown in FIG. 4C, the level of the braking force output from the retarder device 13 is reduced by the decrease amount Q at the same time when the manual select down is executed at time t1. After the reduction, the braking force is returned to the initial level at time t3 when the downshift is completed. In this case, while the braking force is insufficient from time t1 to time t2, the deceleration force rises sharply at time t2 and the vehicle body is in a strong deceleration state. Therefore, unless the shift down is started at the same time as the execution of the manual select down, the driver feels uncomfortable.

The control in the automatic transmission control unit 30 will be described with reference to FIGS. FIG. 5 is a flow of the traveling gear determination process 36 and the retarder braking force control process 35, and FIG. 6 is a flow of the select elapsed time measurement process 34 and the retarder braking force decrease amount determination process.

In step 101 shown in FIG. 5, the throttle opening TVO and the vehicle speed VSP are read. Step 1
In 02, ON / OFF of the retarder switch 16 is identified, and in step 103, it is identified whether or not the throttle opening TVO is less than a reference value TI for identifying an idle state. When the retarder switch 16 is ON and the throttle opening TVO is less than the reference value TI, the retarder device 13 is operated to output a braking force of a predetermined level. The level of the braking force is obtained by subtracting the reduction amount Q obtained by the flow of FIG. 6 from the reference deceleration force corrected according to the vehicle body weight and the inclination of the downhill. If the retarder switch 16 is OFF or if the stoll opening TVO is greater than or equal to the reference value TI, the retarder device 13 is not operated.

In step 105, the throttle opening TV
The start time of downshift is determined based on O and the vehicle speed VSP. In addition, other gear shifting operations of the automatic transmission 12, control of auxiliary mechanisms, and various adjustments in the gear shifting process are executed.

In step 121 of FIG. 6, the range signal R
Read new. Rn in each range of R, P, N, D
ew = 4. In the third speed, second speed, and first speed ranges, Rnew = 3, 2, and 1, respectively. Steps 122, 1
23 and 124, it is identified whether or not the manual select down is executed. Rnew> in step 122
In the case of Rold, it corresponds to manual select-up, so the process proceeds to steps 126 and 127 to reset the flag F and the timer T. Flag F = 1 in step 123
In case of, it means after manual select down,
The process proceeds to step 128 and thereafter to measure the elapsed selection time and the like. If Rnew = Rold is not satisfied at step 124, it means immediately after the manual select down is set, and therefore the routine proceeds to step 125, where the flag F is set to 1. If Rnew = Rold, it means that the select lever 19 is not operated.
6, the flag F and the timer T are reset.

At step 128, it is discriminated whether or not it is a downshift timing. The select elapsed time T is counted up in step 130 until the downshift is started. If it is the timing of the downshift, the reduction amount Q based on the select elapsed time T is calculated in step 129. In step 131, the flag F is reset, and in step 132, Rold is prepared for the next process.
Rewrite the value of. The value of Rnew in this processing becomes the value of Rold in the next processing.

According to the control system of the embodiment, since the retarder device 13 is controlled by the automatic transmission control unit 30, the control according to the operation of the select lever 19 and the shift-down timing is performed without adding wiring or an electric circuit.
This can be realized simply by changing the program in the automatic transmission control unit 30. Therefore, the entire system is configured to be small and lightweight, and a highly reliable system can be provided at low cost. Further, since the level of the braking force output from the retarder device 13 is kept constant until the actual downshift starts even after the manual select down setting is performed, the deceleration state that does not make the driver feel uncomfortable can be obtained. It will be continued and the burden of service brake will be reduced. Further, since the level of the braking force output from the retarder device 13 is lowered when the shift down is started, there is no concern that the vehicle body is excessively decelerated due to the shift down. Also, if the time from manual select down to the start of downshift becomes long, the shift shock becomes less noticeable,
While the driver is satisfied with the fact that the operating condition of the automatic transmission can be accurately grasped through the shift shock, the shift shock that is out of the timing intended by the driver does not rise to an unpleasant level.

Although the fluid type retarder is used in the embodiment, an eddy current type retarder or an exhaust brake may be used to output the adjusted braking force in the same manner. In addition, the accelerator pedal 17 is released and the retarder switch 1 is released.
Although the retarder device 13 is actuated by turning ON 6 in FIG. 6, the retarder device 13 may be actuated for the first time by manual downshifting to the engine brake required range (first speed range, second speed range). In this case, the level of the braking force of the retarder device 13 is raised immediately after the manual downshift and is decreased by the decrease amount Q when the downshift is started. In this embodiment, the process of step 104 corresponds to the retarder braking force control process 35, the processes of steps 128 and 130 correspond to the selected elapsed time measuring process 34, and the process of step 129 corresponds to the retarder braking force decrease amount determination process 37. And step 1
Reference numeral 04 corresponds to the braking continuation means of the invention, steps 128 and 130 correspond to the measurement means of the invention, and step 129 corresponds to the output adjustment means of the invention.

[0035]

According to the invention of claim 1, since the level of the braking force output from the retarder device is kept large even after the manual select down is set, a smooth deceleration state is maintained even after the manual select down is set. continue. Further, since the shift shock is made inconspicuous when the select elapsed time is long, there is no fear that a large shift shock will suddenly occur at a time after the setting of the manual select down and the driver is uncomfortable.

According to the second aspect of the present invention, the shift shock from the start to the end of the downshift is uniformly reduced. Therefore, when the select elapsed time is long, the shift shock is hardly felt.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of a control system of a retarder device.

FIG. 2 is a shift map for each select position.

FIG. 3 is a diagram for obtaining a retarder braking force decrease amount.

FIG. 4 is a timing chart of control.

FIG. 5 is a flowchart of control.

FIG. 6 is a flowchart of control.

[Explanation of symbols]

 11 engine 12 automatic transmission 13 retarder device 14 differential mechanism 15 rear wheel 16 retarder switch 17 accelerator pedal 18 propeller shaft 19 select lever 21 rotary switch 22 throttle valve 23 throttle sensor 25 vehicle speed sensor 26 solenoid valve 28 retarder controller 30 automatic transmission control Unit 31 Vehicle speed detection processing 32 Throttle opening detection processing 33 Travel range detection processing 34 Select elapsed time measurement processing 35 Retarder braking force control processing 36 Travel gear determination processing 37 Retarder braking force reduction amount determination processing

Claims (2)

[Claims] 1. A retarder control device capable of controlling a retarder device arranged in a driving force transmission path of a vehicle equipped with an automatic transmission to adjust a level and an output timing of an output braking force, wherein a driver manually selects the retarder control device. During the period from the setting of down to the start of downshift, the braking continuation means for continuing to output a predetermined level of braking force from the retarder device and the downshift after the driver sets manual select down. Measuring means for measuring the select elapsed time until the start, and the level of the braking force output from the retarder device at the start of downshift is determined according to the select elapsed time. Retarder control, comprising: output adjusting means for making the shift shock at the start less noticeable. apparatus. 2. The output adjusting means uses the braking force of the predetermined level as a reference value, and increases the amount of decrease of the braking force from the reference value through the downshift period as the select elapsed time becomes longer. The retarder control device according to claim 1, which is characterized in that.