JPH09107698A - Retarder control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a retarder control apparatus by which a driver is not perplexed with a speed change shock when the driver manually select a deceleration so as to start a shifted-down speed change suddenly after a short time after a changeover. SOLUTION: A driver operates a selection lever 19 at a vehicle speed which is higher than a two-speed prevention line so as to manually reduce an automatic transmission 12 to a two-speed range. Then, a shifted-down speed change at the automatic transmission 12 is set to a standby state. A retarder control apparatus 26 raises the braking force of a retarder device 13, and a pseudo speed-change shock is generated. In addition, when a vehicle speed is lowered and immediately before the shifted-down speed change is started by the automatic transmission 12, the operation of the retarder device 13 is released so as to prevent an excessive deceleration shock from being generated due to the shifted-down speed change. Irrespective of whether the shifted-down speed change is started immediately after that, the driver ensures the response of a constant deceleration at every operation of a manually selected speed reduction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls a retarder device provided as an auxiliary brake system in an automobile equipped with an automatic transmission to output a braking force of a level corresponding to an operating state or a running state of the automobile. Regarding the control device.

[0002]

2. Description of the Related Art A service brake frictionally restrains the rotation of wheels with a pressure corresponding to the amount of depression of a brake pedal by a driver. The engine brake cancels the driving force transmitted from the wheel side to the engine by utilizing the compression resistance of the engine. The retarder device is an auxiliary brake device mounted on a vehicle in addition to these brakes. The retarder system is installed in vehicles equipped with exhaust turbines where the braking force of the engine brake cannot be expected to a great extent, and in large vehicles such as buses and trucks that have a large total vehicle weight including the equipment and are frequently used on the expressway. To reduce the frequency and burden of using the service brake.

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. The retarder device is capable of finely setting the level of braking force and temporal change and outputting with high reproducibility. Further, in Japanese Patent Laid-Open No. 2-258462, the opening of an exhaust brake attached to an exhaust path of an engine is automatically adjustable, and the exhaust brake is used as a retarder device.

The general control of the retarder device is to detect the release of the accelerator pedal when the permission switch in the vehicle compartment is turned on by the driver to detect the braking force of a predetermined level corresponding to the pseudo engine braking effect. Is output. Further, in a vehicle equipped with an automatic transmission, when the driver sets a shift mode of the first speed range or the second speed range in a situation where engine braking is required, the release of the accelerator pedal is detected and the retarder device controls a predetermined level. Power is output to reinforce the engine braking effect.

[Problems to be solved by the invention]

In an automobile equipped with an automatic transmission, the downshift of the automatic transmission may be started much later than the driver's operation of changing the shift mode. Japanese Unexamined Patent Publication (Kokai) No. 56-141446 discloses control of an automatic transmission related to downshifting. Here, even if the driver sets the shift mode of the first speed range or the second speed range, the downshift is not executed immediately, but the downshift is started after waiting for the vehicle speed to sufficiently decrease.
As a result, it is possible to avoid a situation in which the downshift is performed at the second or first speed at a high vehicle speed and the engine speed increases excessively. However, in this case, even if the driver wants to decelerate by downshifting and shifts the shifting mode, coasting continues and the downshifting starts forever unless the vehicle speed falls below a certain threshold (shift prevention line). Not done.

Specifically, when the driver turns off the overdrive switch while traveling at a vehicle speed higher than the third speed prevention line in the fourth speed of the overdrive speed, the downshift to the third speed is immediately executed. However, when the vehicle speed decreases due to a decrease in the amount of depression of the accelerator pedal by the driver, an uphill approach, etc. and the third speed prevention line is interrupted, the downshift to the third speed is started. At this time, if the overdrive switch is turned off and more than a few seconds have passed, the driver uncomfortably feels a sudden shift shock that acts on the vehicle body due to the downshift to the third speed. This is because it is difficult to understand that the shift shock is caused by the shift-down shift.

The same applies when the driver operates the select lever to manually select down to the second speed range while traveling at a vehicle speed higher than the second speed prevention line at the third speed with a gear ratio of 1. Immediately, the downshift to the 2nd speed is not executed, but the vehicle speed decreases due to the operation of the retarder device that produces a pseudo engine braking effect, the decrease in the amount of depression of the accelerator pedal by the driver, etc. The shift-down shift to the 2nd speed is started at the time when is interrupted.

At this time, if a certain time has passed after executing the manual select down, the driver uncomfortably feels a sudden shock that acts on the vehicle body in association with the shift down to the second speed. If you mistakenly think that the downshift is already completed from the feeling of deceleration immediately after the manual selectdown (due to engine braking, etc.), the driver has a sudden shock that is a shift shock resulting from his manual selectdown. I can't imagine that, and I think about the cause of the shock and hinder my concentration on driving.

SUMMARY OF THE INVENTION An object of the present invention is to provide a retarder control device which produces a feeling of deceleration in response to a shift mode switching operation by a driver and which does not cause the driver to feel a shift shock unpleasantly.

[0010]

According to a first aspect of the present invention, a retarder device mounted on an automobile equipped with an automatic transmission is controlled to output a braking force of a level corresponding to an operating state or a running state of the automobile. In the retarder control device, a shift mode identifying means for identifying whether or not the driver has set a shift mode involving a downshift in the automatic transmission, and a vehicle speed after the shift mode involving a downshift is set. A standby state identifying means for identifying whether or not the automatic transmission is in a state of waiting for a downshift in the automatic transmission until it cuts in the shift prevention line, and a braking force of a predetermined level in the state of waiting for the downshift. Is output from the retarder device.

According to a second aspect of the present invention, the output control means in the first aspect executes the shift-down shift when the vehicle speed reaches the shift-prevention line and the shift-down shift is possible, and the retarder device is provided. It includes a brake releasing means for releasing the braking force of.

According to a third aspect of the present invention, a shift command for starting a downshift in the automatic transmission after a predetermined time has elapsed after the braking release means in the configuration of the second aspect releases the braking force of the retarder device. It includes means.

[0013]

In the retarder control device according to the first aspect of the present invention, even if the driver sets a shift mode involving a downshift such as manual downshift to the 1st or 2nd speed range or overdrive release, the vehicle speed is prevented from shifting. Therefore, when the actual downshift in the automatic transmission is in a standby state, the retarder device outputs the braking force to generate a pseudo downshift shift shock. As a result, the vehicle speed decreases promptly after setting the shift mode. The deceleration shock that the braking force of the retarder device exerts on the vehicle body gives the driver a virtual reality as if the downshift was executed immediately after switching the shift mode.

In the retarder control device of the second aspect, when the vehicle speed reaches the shift prevention line, the actual downshift is started, and in response to this, the braking force of the retarder device is released. Therefore, it is possible to prevent the braking force accompanying the downshift from being added to the braking force of the retarder device to cause excessive deceleration of the vehicle body.

According to another aspect of the retarder control device of the present invention, the start timing of the downshift in the automatic transmission is delayed by a predetermined time. After the vehicle speed reaches the gear shift prevention line and the braking force of the retarder device is released, a predetermined time elapses and then an instruction to start the shift down gear shift in the automatic transmission is issued.
By starting the shift-down shift with the braking force of the retarder device completely disappeared, the shift shock accompanying the shift-down shift is set to a level that does not attract the driver's attention.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described with reference to FIGS. FIG. 1 is an explanatory diagram of a configuration of a control system of a retarder device, FIG. 2 is an explanatory diagram of control of the first embodiment, and FIG. 3 is a flowchart of control of the first embodiment. In FIG.
(A) is a shift map of the D range in the OD permission state,
(B) is a shift map of the D range in the overdrive prohibited state.

As shown in FIG. 1, the eddy current type retarder device 13 is disposed on the output side of the automatic transmission 12 and applies a braking force to the propeller shaft 16 according to the current level supplied from the retarder control device 26. Output. The output of the engine 11 is changed by the automatic transmission 12 and then the propeller shaft 16
Is transmitted to the rear wheel 15 via the differential mechanism 14. The output of the engine 11 changes according to the depression of the accelerator pedal 17 by the driver. The accelerator pedal 17 changes the throttle opening TVO of the throttle valve 18. As for the shift mode of the automatic transmission 12, the driver turns on / off the OD cancel switch 27.
Then, the selection lever 19 is slid and set. The shift modes that can be set include a D range in which the OD cancel switch 27 is turned off and the OD of the overdrive speed of up to the 4th speed, and a OD cancel switch 27 that is turned on in the 3rd speed of the direct connection.
There are seven types of range, the second speed range and the first speed range where engine braking is actively used, the neutral N range and P range, and the reverse R range. In the D range, 1st speed, 2nd
The engine braking does not work even at high speeds.

The throttle sensor 23 provided on the throttle valve 18 outputs an analog voltage signal corresponding to the throttle opening TVO which is adjusted by the driver depressing the accelerator pedal 17. Vehicle speed sensor 2 provided in the automatic transmission 12
2 outputs a voltage signal having a frequency corresponding to the vehicle speed (rotational speed of the propeller shaft 16). The inhibitor switch 21 provided in the automatic transmission 12 outputs a code signal corresponding to the shift mode set in the automatic transmission 12.

The automatic transmission control unit 25 is
From the multiple shift maps shown in FIG. 2, the OD is selected.
Cancel switch 27 and inhibitor switch 21
Select one according to the setting state of. Then, the momentary throttle opening T calculated from the output of the throttle sensor 23
Instantaneous vehicle speed VS obtained from the output of VO and the vehicle speed sensor 22
Based on P, the shift timing is determined according to the shift map corresponding to the set shift mode, and the solenoid valve 24 for hydraulically controlling the automatic transmission 12 is operated to shift up and down in the automatic transmission 12. Let it run.
When the vehicle speed VSP is too high to execute the shift down shift to the third speed when the driver turns on the OD cancel switch 27 to switch to the OD prohibition state, the shift down shift is put on standby and described later. Wait for the vehicle speed VSP to decrease to the third speed prevention line, and start the downshift.

The retarder control device 26 determines whether the automatic transmission control unit 25 has instructed the automatic transmission 12 to set the OD cancel switch 27 and the select lever 19 and to start the shift-down shift. To read. In the above-described case where the shift down shift to the third speed is on standby, the retarder device 13 is actuated from immediately after the OD cancel switch 27 is turned on until the shift down shift is actually started. It will cause a shift shock.

D in the OD permission state shown in FIG.
In the range, four-stage gear shifting is executed up to the OD4 speed of the overdrive gear stage based on the throttle opening TVO and the vehicle speed VSP. This shift mode is set by the driver in a situation where the vehicle can perform inertial high-speed traveling for a long time, such as on a highway, and reduces the rotational speed of the engine 11 to realize fuel-efficient traveling. In the D range in the OD prohibited state shown in FIG. 2B, the throttle opening TVO and the vehicle speed V
Based on SP, three-step shifting up to the third speed with a gear ratio of 1 is executed. The broken line TI in the figure indicates the throttle opening TV.
O threshold value. Throttle opening TVO is broken line TI
When the engine is interrupted, the automatic transmission control unit 25 determines that the engine 11 is in the idle state.

Here, in a state A in which the driver depresses the accelerator pedal 17 by recognizing a preceding vehicle at a low speed while traveling at the OD4 speed, the driver turns on the OD cancel switch 27 to automatically It is assumed that the shift mode of the transmission 12 is switched from the overdrive permitted state to the overridden state. However, as shown in FIG. 2B, in this shift mode, a third speed prevention line is provided on the shift map in order to avoid excessive rotation of the engine 11, and
The downshift from the third speed to the third speed is executed after the vehicle speed VSP has dropped to the third speed prevention line. Therefore, even if the driver turns on the OD cancel switch 27 at time A, the downshift from 4th speed to 3rd speed is not executed until the state B in which the vehicle speed VSP has dropped to the 3rd speed prevention line.

Therefore, in the first embodiment, the braking force of the retarder device 13 is started immediately after the driver turns on the OD cancel switch 27 in the state A, and shifts immediately after turning on the OD cancel switch 27. A deceleration shock is generated as if a downshift was performed. The braking force of the retarder device 13 quickly reduces the vehicle speed VSP to the state B, and the OD cancel switch 27
The time from the ON operation to the actual downshift is shortened. Then, when the actual downshift is started with the braking force of the retarder device 13 kept rising, a shift shock is added to the braking force of the retarder device 13 to cause excessive deceleration of the vehicle body. The operation of the retarder device 13 is released in the state B in which the VSP has dropped to the third speed prevention line.

The retarder control device 26 in the first embodiment
Executes the control procedure of the flowchart shown in FIG. In step 111, the shift mode in the previous flow is compared with the shift mode in this flow, and O
Whether or not the D cancel switch 27 has been switched ON / OFF is identified. Step 11 if switched
2, the O corresponding to the ON of the OD cancel switch 27
The D prohibition state or the OD permission state corresponding to OFF is identified. If the overdrive is prohibited, it is determined in step 114 whether or not the automatic transmission 12 is instructed to start shifting. 3
When the driver switches the shift mode from the overdrive permitted state to the overridden state at the vehicle speed VSP that exceeds the speed prevention line, the downshift is waited.
From 2 to step 114, the process proceeds to steps 118 and 119. At step 118, a retarding force of a predetermined level is output from the retarder device 13, and at step 119, the flag F is output.
Is set to 1.

If the shift mode does not change in the subsequent flow, the flow returning to step 114 via step 113 is repeated, and the retarder device 13 continues to operate until the shift start is detected in step 114. When the shift start is detected in step 114, it is determined in step 115 whether or not the retarder device 13 is operating. If the retarder device 13 is operating, the process proceeds to steps 116 and 117. At step 116, the level of the braking force output by the retarder device 13 is returned to 0, and at step 117, the flag F is reset to 0. When the change of the shift mode is detected in step 111 and the select-up is identified in step 112, the operation of the retarder device 13 is similarly released. When the flag F is identified as 0 in step 113, or when the retarder device 13 is identified as inactive in step 115, the flow of the subsequent parts is bypassed.

According to the control of the first embodiment, since the retarder device outputs a braking force of a predetermined level immediately after switching the shift mode from the overdrive permitted state to the overdrive inhibited state,
Even if the driver does not depress the brake pedal, the vehicle speed VSP is quickly reduced to the third speed prevention line, and the downshift to the third speed is executed without much time. Further, since the operation of the retarder device 13 is released in response to the start of the downshift, the retarder device 1
The braking force of No. 3 and the shift shock accompanying the shift-down shift are continuous, and the driver does not feel uncomfortable as in the case where the shift shock suddenly rises. Even when the select-up is switched, the braking force of the retarder device 13 is released and the acceleration state can be immediately entered.

Note that steps 111 and 112 correspond to the shift mode identifying means of the invention, step 114 corresponds to the standby state identifying means of the invention, step 118 corresponds to the output control means of the invention, and steps 115 and 116 correspond to the braking release means of the invention. .

The second embodiment will be described with reference to FIGS. FIG. 4 is an explanatory diagram of the control of the second embodiment, and FIG. 5 is a flow chart of the control of the second embodiment. In FIG. 4, (a) is O
The shift map for the D range in the D permitted state, the shift map for the D range in the overdrive prohibited state, and the shift map for the second speed range in (c). The second embodiment is one in which the control content of the retarder control device 26 shown in FIG. 1 is slightly different from that of the first embodiment. The retarder control device 26 in the second embodiment not only unilaterally receives information from the automatic transmission control unit 25 as in the first embodiment, but also the setting state of the select lever 19 and the vehicle speed V every moment.
The SP is read to determine the start timing of the downshift, and the automatic transmission control unit 25 is instructed to start the downshift.

The retarder control device 26 switches the range even when the driver switches the select lever 19 from the D range to the second speed range and the vehicle speed VSP is too high and the downshift to the second speed is waited. The retarder device 13 outputs a braking force of a predetermined level during the waiting period from immediately after that until the actual downshift is started.
Then, when the vehicle speed VSP is reduced to the second speed prevention line and the downshift can be performed, the operation of the retarder device 13 is released, but the set time T is set after the operation of the retarder device 13 is released.
automatic transmission control unit 2 until s has elapsed
The downshift in the automatic transmission 12 is made to stand by through 5.

D in the OD permission state shown in FIG.
In the range, four stages of shifting are executed up to the fourth speed of the overdrive gear stage. In the D range of the overdrive inhibition state shown in FIG. 4B, three-stage gear shifting up to the third gear with a gear ratio of 1 is executed. However, in the deceleration process, the downshift to the third speed is executed after waiting for the vehicle speed VSP to decrease until the third speed prevention line is interrupted. In the second speed range shown in (c) of FIG. 4, a two-stage gear shift using the first speed and the second speed is executed. However, in the deceleration process, the downshift to the second speed is executed after waiting for the vehicle speed VSP to decrease until the second speed prevention line is interrupted.

As shown in FIGS. 4A and 4B, OD
State A in which the accelerator pedal 17 is released at the 4th speed
When the driver turns on the OD cancel switch 27 to switch the shift mode of the automatic transmission 12 from the D range in the OD allowed state to the D range in the OD prohibited state, the retarder control device 26 immediately after the switching, Device 13
Is actuated to generate a pseudo gear shift shock, and the retarder device 1 is operated in a state B in which the vehicle speed VSP has decreased to the third speed prevention line.
Release the operation of 3. Then, in the state C where the set time Ts has elapsed after the release, the automatic transmission control unit 2
5 is instructed to start the shift down shift of the automatic transmission 12 to the third speed.

As shown in FIGS. 4B and 4C, the driver operates the select lever 19 to release the accelerator pedal 17 at the third speed in the D range, and the automatic transmission 12 is operated. When the shift mode of (1) is switched from the D range to the second speed range, the retarder device 13 is activated immediately after the switching to generate a pseudo shift shock that is clearly sensed by the driver. And the vehicle speed V to the second speed prevention line
The operation of the retarder device 13 is released in the state E in which SP is lowered, and the automatic transmission control unit 25 is instructed to the automatic transmission 12 in the state F in which a set time Ts has elapsed after release.
Instructing the start of downshifting to the 2nd speed.

Retarder control device 26 in the second embodiment
Is a broken line frame 11 in the flowchart shown in FIG.
The control procedure in which the flow inside 0 is replaced with the flow shown in FIG. 5 is executed. Regarding the flow of the portion outside the broken line frame 110, in step 111 shown in FIG. 3, it is determined whether or not the select lever 19 is operated in addition to whether or not the OD cancel switch 27 is operated.
In addition to the prohibition state, a change is made so as to determine whether or not the selection is down. However, other than that, the description is omitted because it is similar to the first embodiment. In the flow shown in FIG. 5, the timing for releasing the operation of the retarder device 13 is determined based on the vehicle speed VSP every moment, and a command (permit) to start the downshift is made at the stage when the set time Ts has elapsed since the operation was released. .

In step 131, it is discriminated whether the flag G is 0 in the case of OD prohibited state, select down or F = 1. The flag G = 1 corresponds to step 1 described later.
This corresponds to a state in which the shift-down gear shifting is on standby after the deactivation of the retarder device 13 at 37. Step 132
Then, whether it is the fourth speed or not is discriminated. If the fourth speed, the step 13
At 3, it is identified whether or not the vehicle speed VSP has crossed the third speed prevention line. In step 134, it is discriminated whether or not the third speed is selected,
If the vehicle speed is high, it is determined in step 135 whether the vehicle speed VSP has crossed the second speed prevention line.

When the vehicle speed VSP is below the third speed prevention line at the fourth speed and when the vehicle speed VSP is below the second speed prevention line at the third speed, it is determined in step 136 whether the retarder device 13 is operating. Is identified. In step 136, it is also determined whether or not the retarder device 13 is in operation for the route SU identified as select-up in step 112 shown in FIG. If the retarder device 13 is operating, the process proceeds to steps 137 and 138 to cancel the operation of the retarder device 13, reset the timer T, and set the flag G.
To 1. When the flag G becomes 1, step 132 is performed until it is determined in step 139 that the set time Ts has elapsed.
~ 138 is bypassed, and the flow of the timer function of incrementing the count of the timer T in step 142 is repeated. When it is determined in step 139 that the set time Ts has elapsed, the process proceeds to steps 140 and 141 to start the corresponding downshift, and resets the flag G. If the retarder device 13 is inactive in step 136, the process directly proceeds to step 140 to immediately start the corresponding downshift.

If it is determined in steps 132 and 134 that the speed is neither the fourth speed nor the third speed, steps 136 to 1
The processing of 42 is bypassed. Vehicle speed V in step 133
When it is determined that SP exceeds the third speed prevention line and when it is determined in step 135 that the vehicle speed VSP exceeds the second speed prevention line, steps 118 and 119 shown in FIG. Then, the operation of the retarder device 13 is continued.

According to the control of the second embodiment, the retarder device outputs a predetermined level of braking force when the OD permitted state is set to the OD prohibited state or when the D range is switched to the second speed range. Even if the brake pedal is not depressed, the vehicle speed VSP rapidly decreases to the third speed prevention line or the second speed prevention line, and the downshift to the third speed or the second speed is executed without much time. Also, the set time Ts
Since the shift down shift is started after the braking force of the retarder device 13 is completely released after the passage of, the shift shock accompanying the shift down shift partially overlaps with the braking force of the retarder device 13 and is large. There is no need to worry about deceleration shocks on the car body. In the automatic transmission 12, it is only necessary to carry out the shift-down shift in the same manner as in the normal case, which is unrelated to the braking force of the retarder device 13. Therefore, it is not necessary to apply special transient hydraulic pressure control or timing adjustment that is different from usual.

In the second embodiment, step 111 is the shift mode identifying means of the invention, steps 132 and 133 and steps 134 and 135 are standby state identifying means of the invention, step 118 is output control means of the invention, and steps 136 and 1 are.
Reference numeral 37 corresponds to the braking release means of the invention, and steps 139 and 140 correspond to the shift command means of the invention.

In the above embodiment, the automatic transmission 12
Although the retarder device is operated only in the standby state for the shift-down gear shift in (1), it may be combined with the conventional control that exerts a pseudo engine braking effect. For example, if the permission switch in the passenger compartment is turned on,
When the driver releases the depression of the accelerator pedal 17 with the select lever 19 set to the speed range, the retarder device 13 is operated to output a braking force equivalent to a pseudo engine braking effect. In this state, when the driver switches the shift mode involving the shift-down shift, the retarder control device 26 causes the retarder device 1 to
The level of the braking force output from 3 is further raised to generate a pseudo gear shift shock that can be distinguished from a normal pseudo engine braking effect.

Further, in the above embodiment, the retarder device 13 is operated in the standby state of the downshift, and the retarder device 13 is released before the start of the downshift. However, the retarder device 13 is operated. The shift down gear may be changed as it is, and thereafter, the retarder device 13 may be controlled to be released at the time when the driver performs a return operation of the shift mode. In this case, it is not necessary to finely control the release timing and the braking force of the retarder device 13 so as not to give the driver a feeling that the braking force is temporarily reduced when the retarder device 13 is released before the downshift. Will be easier.

In any of the above-mentioned controls, the vehicle speed for downshifting is moved to a lower vehicle speed side than normal, and is held until the vehicle speed becomes low only by the braking force of the retarder device 13. The downshift may be performed on the low vehicle speed side where the shift shock is small. Further, the control may be such that the shift down shift is prohibited until the driver performs the shift mode returning operation, and the shift down shift is permitted only when the shift mode is switched on the vehicle speed side lower than the shift prevention line. Further, although the eddy current type retarder device 13 is used in the above embodiments, a braking force may be exerted in the same situation by using a fluid type retarder or an exhaust brake.

[0042]

According to the first aspect of the present invention, in a state where the vehicle speed is above the shift prevention line and waiting for a downshift, the retarder device is made to output the braking force immediately after switching the shift mode. Since the vehicle body is decelerated by this, the vehicle speed decreases rapidly. The pseudo shift shock that starts immediately after switching the shift mode gives the driver the same feeling of deceleration as when the shift mode is switched while the vehicle speed is below the shift prevention line. A constant response can be secured for each setting of the accompanying shift mode, and stable and natural deceleration can be executed.

According to the second aspect of the present invention, the shift shock associated with the downshift is generated after the deceleration due to the braking force of the retarder device. Therefore, as compared with the case where an unexpected shift shock suddenly occurs during coasting. The driver's embarrassment and discomfort are low. Further, since the operation of the retarder device is released in response to the start of the shift down shift, there is no fear that the braking force of the retarder device is overlapped with the shift shock associated with the shift down shift and excessive deceleration shock occurs in the vehicle body.

According to the third aspect of the invention, the downshift is started in the state where the braking force of the retarder device is completely cut off. Therefore, the automatic transmission is similar to the normal case where the braking force of the retarder device does not act. Downshifts can be performed under various conditions. Therefore, special tuning for automatic transmission,
For example, a normal gear shift can be reproduced without setting transient hydraulic pressure control or the like.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of control of the first embodiment.

FIG. 3 is a flowchart of control according to the first embodiment.

FIG. 4 is an explanatory diagram of control of the second embodiment.

FIG. 5 is a flowchart of control according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 11 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 21 inhibitor switch 22 vehicle speed sensor 23 throttle sensor 24 solenoid valve 25 automatic transmission control unit 26 retarder control device 27 OD cancel switch

Claims (3)

[Claims] 1. A retarder control device for controlling a retarder device mounted on an automobile equipped with an automatic transmission to output a braking force at a level according to an operating state and a running state of the automobile, wherein the automatic shift is performed by a driver. A shift mode identifying means for identifying whether or not a shift mode involving a shift down shift is set in the machine, and the automatic transmission until the vehicle speed falls below a shift prevention line after the shift mode involving the shift down shift is set. A standby state identifying means for identifying whether or not the shift down shift is in a standby state, and an output control means for outputting a braking force of a predetermined level from the retarder device in the standby state for the down down shift. A retarder control device having. 2. The output control means executes a shift-down shift when the vehicle speed reaches a shift-prevention line and the shift-down shift is enabled, and a brake releasing means for releasing the braking force of the retarder device. The retarder control device according to claim 1, further comprising: 3. The braking release means includes shift command means for starting a downshift in the automatic transmission after a lapse of a predetermined time after releasing the braking force of the retarder device. The described retarder control device.