JPH0984207A - Auxiliary brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the auxiliary brake device which is mounted on a vehicle having an exhaust brake device and a retarder device and with which the uncomfortable feeling to a driver by the sudden change of a braking force when both the exhaust brake device and the retarder device are released from operation in order to avoid an engine stall in the low speed drive can be eliminated. SOLUTION: If an acceleration pedal 17 is released in a high speed drive region, brake forces of both an exhaust brake device 23 and a retarder device 13 are started and the engine brake effect is generated. If the deceleration is progressed and the drive speed is lowered below 10km/hour, an auxiliary brake device 32 starts releasing the exhaust brake device 23 from operation first and then, after 500msec, starts releasing the retarder device 13 from operation. However, if the speed or the engine revolution declines suddenly, the retarder device 13 is immediately released from operation. With this constitution, the sudden decline of the brake force at the time of operation release can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary brake device for decelerating an automobile by controlling the operation / release of an exhaust brake device and a retarder device and the level of a braking force output.

[0002]

2. Description of the Related Art For vehicles such as buses and trucks, which have a large total weight of vehicles including the mounted vehicles and are frequently used on expressways, because of the fact that they cannot expect much braking force due to engine braking because they are equipped with exhaust turbines, An auxiliary braking device such as an exhaust braking device or a retarder device may be installed. The auxiliary brake device supplements the engine brake of the automobile and reduces the frequency and burden of using the service brake. Here, the service brake frictionally restrains the rotation of the wheels with a pressure corresponding to the amount of depression of the brake pedal by the 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 arranged by being inserted in a driving force transmission path from an engine of an automobile to wheels, and outputs a braking force to the driving force transmission path. Practical application of an eddy current retarder device that generates electromagnetic braking force using permanent magnets and electromagnets, and a fluid-type retarder device that circulates oil using an oil pump and generates braking force from oil flow resistance Has been done. These retarder devices do not change the operating condition of the engine as much as the exhaust brake,
Even if the braking force is output to an engine speed lower than that of the exhaust brake, no engine stall occurs. Further, it is possible to output the braking force with high reproducibility by finely setting the level and the temporal change of the braking force.

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 shutting off (narrowing down) the flow passage area of the exhaust path with the valve element, the engine braking effect of the engine is increased. The exhaust brake device can generate a large braking force with a small applied power. Japanese Unexamined Patent Publication No. 2-258462 discloses an exhaust brake device in which the opening of a valve element is adjusted to an intermediate value so that the level of braking force can be continuously changed. However, the normal exhaust brake device cannot adjust the level of the braking force like the retarder device or cannot maintain it at a constant level, and is used in two positions of operation / non-operation (ON / OFF).

A general auxiliary brake device starts operation when the driver releases the depression of the accelerator pedal while the auxiliary brake switch provided in the vehicle compartment is turned on, and outputs a predetermined level of braking force. Then, the operation is released when the driver restarts the depression of the accelerator pedal and shifts to the acceleration state.

[0006] Japanese Patent Laid-Open No. 63-114506 discloses an example in which both an exhaust brake device and a retarder device are installed in an automobile as an auxiliary brake device, and the operation / non-operation of the exhaust brake device and the retarder device is comprehensively controlled. And Japanese Patent Laid-Open No. 4-193656. JP-A-63-
In the control disclosed in Japanese Patent No. 114506, the braking force of the retarder device is raised to a predetermined level prior to the exhaust brake device, the braking force of the retarder device is eliminated, and the exhaust brake device is operated at the same time. As a result, the deceleration shock that accompanies the sudden rise of the braking force by the exhaust brake device is suppressed, and the degree of increase of the braking force as the auxiliary braking device is moderated. Japanese Patent Laid-Open No. 4-193
In the control disclosed in Japanese Patent No. 656, a driver operates a switch from among a plurality of levels of braking force obtained by individually or simultaneously operating an exhaust brake device and a retarder device, and the driver can respond to a driving condition or a required braking force condition. Select the optimal braking force.

[0007]

The auxiliary braking device is
Normally, the operation is released when the vehicle speed decreases and falls below a predetermined threshold value. This is to prevent the braking force of the auxiliary braking device from excessively reducing the rotation of the engine and reaching the engine stall state. Further, the deceleration process just before the stop is devoted solely to the braking force of the service brake to execute the stop as intended by the driver.

However, when both an exhaust brake device and a retarder device are installed in an automobile as an auxiliary brake device, if both operations are released at the same time when the vehicle speed decreases and the threshold value is exceeded, both brakes are controlled. The deceleration state due to the large braking force to which the power is added suddenly shifts to the inertial running, and the driver feels uncomfortable due to the shock as if the vehicle body started to accelerate.
At this time, when the driver excessively reacts to the change in the deceleration state and strongly depresses the service brake, the vehicle body suddenly stops at a position far before the driver desires, which further increases the driver's discomfort.

Here, referring to the control disclosed in Japanese Patent Laid-Open No. 63-114506, the braking force of the retarder device is increased in parallel with the progress of the release of the operation of the exhaust brake device to release the operation of the exhaust brake device. It is assumed that the braking force of the retarder device is gradually reduced after completion of the above. In this case, the braking force decreases gradually from the start of the deactivation of the exhaust brake device to the completion of the deactivation of the retarder device, but the braking force of the retarder device is reduced until the exhaust brake device is deactivated. Not available for deceleration. Therefore, although the exhaust brake device and the retarder device are both mounted, the maximum braking force of the auxiliary brake device does not exceed the braking force of the exhaust brake device.

According to the present invention, when the vehicle speed falls below a predetermined threshold value, the braking force is gently released, the transition to the deceleration process by the service brake is smoothly performed, and the driver does not feel uncomfortable. On the other hand, in the process of decelerating the vehicle body from a high vehicle speed, on the other hand, it is an object to provide an auxiliary braking device that can use a strong braking force obtained by adding the braking forces of both the exhaust braking device and the retarder device.

[0011]

According to a first aspect of the present invention, there is provided a retarder device which is disposed by being inserted in a driving force transmission path from an engine of an automobile to a wheel and which can output a braking force to the driving force transmission path. An exhaust brake device that is inserted into the exhaust path of the engine and increases the engine braking effect of the engine, and controls at least operation and deactivation of the exhaust brake device and the retarder device according to the operating state of the vehicle. An auxiliary brake device having a control device for controlling the exhaust brake device, wherein the control device first starts an exhaust brake releasing operation when the vehicle speed falls below a predetermined set value, and an exhaust brake releasing operation. And a retarder device releasing means for starting operation release of the retarder device after a predetermined time has elapsed after the start of Than it is.

According to a second aspect of the present invention, the retarder device according to the first aspect is arranged between the engine of the automobile and the automatic transmission.

In a third aspect of the present invention, the retarder device releasing means in the first or second aspect of the invention adjusts the predetermined time in accordance with at least one of a vehicle speed, an engine speed, a deceleration, and a deceleration rate of the engine speed. To do.

According to a fourth aspect of the present invention, a retarder device that is disposed by being inserted in a driving force transmission path from an engine of an automobile to a wheel and that can output a braking force to the driving force transmission path, and an exhaust path of the engine are provided. An exhaust brake device that is inserted and arranged to increase the engine braking effect of the engine, and at least the operation / operation of the exhaust brake device and the retarder device according to the running state and the operating state of the vehicle.
In the auxiliary braking device having a control device for controlling non-operation, the control device, when the vehicle speed falls below a predetermined set value, firstly, a retarder device releasing means for starting operation release of the retarder device, and the retarder device. After the release of the operation is started, the exhaust brake releasing means is provided for waiting the elapse of a predetermined time to start the release of the exhaust brake device.

[0015]

In the auxiliary braking device according to the first aspect, when the vehicle speed falls below a predetermined set value, first the deactivation of the exhaust braking device is started, and then the deactivation of the retarder device is started after a lapse of a predetermined time. .

In the auxiliary braking device according to the second aspect, the retarder device directly suppresses the rotation of the engine, like the exhaust braking device. Since the rotation cannot be shut off by releasing the torque converter or clutch of the automatic transmission, be sure to complete the deactivation of the retarder device before the engine stalls.

In the auxiliary braking device according to the third aspect of the invention, the waiting time from the start of deactivating the exhaust braking device to the start of deactivating the retarder device depends on the vehicle speed, the engine speed, the deceleration, and the decreasing speed of the engine speed. It is adjusted according to at least one.

In the auxiliary braking device according to the fourth aspect, when the vehicle speed falls below a predetermined set value, first, the deactivation of the retarder device is started, and thereafter, the deactivation of the exhaust braking device is started.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An auxiliary brake device according to a first embodiment will be described with reference to FIGS. FIG. 1 is an explanatory diagram of the configuration of the auxiliary braking device, FIG. 2 is an explanatory diagram of an operating region and a deactivating region of the auxiliary braking device, FIG. 3 is a time chart of the operating state of the auxiliary braking device, and FIG. 4 is control of the auxiliary braking device. It is a flowchart of. In FIG. 3, (a) shows the control of the first embodiment, and (b) shows a comparative example in which the exhaust brake and the operation release of the retarder device are simultaneously executed.

As shown in FIG. 1, an eddy current type retarder device 13 directly connected to the output shaft of the engine 11 and arranged between the engine 11 and the automatic transmission 12 is supplied from an auxiliary brake control device 32. The braking force according to the current level is directly applied to the output shaft of the engine 11. Unlike the case where the retarder device is arranged on the output side of the automatic transmission 12, the braking force of the retarder device 13 directly lowers the rotation of the engine 11, so that the auxiliary brake control device 32
When the rotation speed of the engine 11 decreases, the deactivation of the retarder device 13 is completed before the engine stalls. The exhaust brake 23 arranged in the exhaust path of the engine 11 is driven by the air cylinder 24 and narrows the flow passage area of the exhaust path to increase the exhaust pressure of the engine 11, thereby increasing the engine braking effect.

When the electric power supplied from 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 flow passage area of the exhaust path is narrowed. When the solenoid valve 25 is turned off,
The compressed air of the air cylinder 24 is discharged, and the flow passage area of the exhaust path is opened. The exhaust brake 23 operates in two positions corresponding to ON / OFF of the electric power supplied from the auxiliary brake control device 32 to the solenoid valve 25. The output rotation of the engine 11 is shifted by the automatic transmission 12 and transmitted from the propeller shaft 16 to the rear wheel 15 via the differential mechanism 14.

The output state of the 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. The vehicle speed sensor 20 provided in the automatic transmission 12 outputs an analog voltage signal having a frequency corresponding to the vehicle speed. The inhibitor switch 21 outputs a code signal corresponding to the shift mode set by the driver operating the select lever 19. As the gear change mode, D selected during normal driving
There are a range, a second speed range and a first speed range that are selected when engine braking or rapid acceleration in a low speed range is required, a neutral N range and a P range, and an R range that is selected when moving backward.

The automatic transmission control unit 31 includes
The throttle opening TVO and the vehicle speed VSP are calculated based on the outputs of the throttle sensor 22 and the vehicle speed sensor 20. The speed change timing is determined by collating with the speed change map as shown in FIG. 2 selected corresponding to the set speed change mode, and the electromagnetic valve 28 of the automatic transmission 12 is operated to change the speed required for the automatic transmission 12. To set.

The auxiliary brake control device 32 controls ON / OFF of the exhaust brake device 23 and the retarder device 13 and the level of the braking force output by the retarder device 13 in accordance with the running condition and the driving condition of the automobile. 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, the auxiliary brake control device 32 turns on the exhaust brake device 23 and at the same time applies the braking force of the retarder device 13. Start the startup. Further, the exhaust brake device 23 and the retarder device 1
When the vehicle speed VSP falls below 10 km / hour while 3 is operating, the exhaust brake device 23 is turned off first. After that, the braking force of the retarder device 13 is reduced by delaying it for 500 msec, and the operation of the retarder device 13 is also released over 1 to 2 seconds.

FIG. 2 shows the operating area Asa and the releasing area Aka of the exhaust brake device 23 and the retarder device 13 in an overlapping manner on the shift map of the second speed range. Auxiliary brake control device 32
When the vehicle speed VSP exceeds 15 km / hour and the throttle opening TVO falls below the threshold value TI, it is determined that the driver has released the depression of the accelerator pedal 17, so that the exhaust brake device 23 and the retarder device 13 are released. Is activated to exert a great engine braking effect on the vehicle body. In the second speed range, the automatic transmission control unit 31 has one
The automatic transmission 12 is set to the first gear and the second gear. The shift line indicated by the solid line executes the shift-up shift from the first speed to the second gear, and the shift line indicated by the broken line executes the shift-down shift from the second speed to the first gear.

The auxiliary brake control device 32 controls the vehicle speed VSP.
Is less than 10 km / hour, in order to avoid engine stall due to excessive decrease in engine speed NE,
The operation of the exhaust brake device 23 and the retarder device 13 is released. In a state where the vehicle continues to travel at 10 km / hour or less, or in a deceleration process in which the vehicle speed is further reduced to stop, the driver does not output the braking force from the exhaust brake device 23 and the retarder device 13, and the driver depresses the brake pedal. The braking force of the service brake controls the deceleration of the vehicle body.

FIG. 3A is a timing chart showing the control of the operation and release of the exhaust brake device 23 and the retarder device 13 in the first embodiment. When the driver releases the depression of the accelerator pedal 17 at time A, the exhaust brake device 23 is turned on and, at the same time, the braking force output by the retarder device 13 starts to rise. At time B, the total braking force acting on the vehicle body reaches the maximum level. here,
The rising of the braking force of the retarder device 13 is moderated,
Avoids a sudden rise in total braking force.

When the vehicle speed VSP falls below 10 km / hour at time E, the exhaust brake device 23 is immediately deactivated. The speed at which the exhaust brake device 23 is deactivated is
The passage resistance of the compressed air flowing into the air cylinder is adjusted so that the reduction of the braking force does not give the driver a feeling of strangeness. When the timer is started at time E and the braking force of the retarder device 13 is started to be reduced at time F when 500 msec has elapsed, the deactivation of the retarder device 13 is completed at time G. During the period from the start to the completion of the deactivation of the retarder device 13, the auxiliary braking device 32 adjusts the current value supplied to the retarder device 13 to adjust the current to the retarder device 13.
The reduction speed of the braking force due to the release of the operation is set to be smaller than the reduction speed of the braking force due to the release of the operation of the exhaust brake device 23. Therefore, the braking force gradually disappears and the braking by the service brake is smoothly performed. Migration is secured.

FIG. 3B shows the exhaust brake device 23.
7 shows a comparative example in which the retarder device 13 and the retarder device 13 are simultaneously deactivated. When the vehicle speed VSP falls below 10 km / hour at time Ea, the exhaust brake device 23 and the retarder device 13 are immediately deactivated. The total braking force becomes 0 at time Ga at which the deactivation of the retarder device 13 is completed. In this case, the total braking force sharply decreases immediately after time Ea, and even if the driver who has become accustomed to the deceleration state of the vehicle until time Ea has not stepped on the accelerator pedal 17, the time Ea is set. There is a feeling of strangeness as if the car body suddenly started accelerating at the boundary.

The control executed by the auxiliary brake control device 32 will be described with reference to the flowchart of FIG. In step 111, it is identified whether or not the vehicle speed VSP is below 10 km / hour. If the vehicle speed is below 10 km / hour, the routine proceeds to step 112, where the exhaust brake device 23 is deactivated. In step 113, it is identified whether or not the changing speed (dVSP / dt) of the vehicle speed VSP is equal to or lower than the threshold value -K. If the deceleration is greater than K and the vehicle speed VSP is rapidly decreasing, the process proceeds to step 119 to immediately deactivate the retarder device 13. In step 114, it is identified whether or not the vehicle speed VSP is below 5 km / hour. When the vehicle speed VSP is less than 5 km / hour and immediately before the stop, the process proceeds to step 119 to immediately deactivate the retarder device 13. In step 115, it is identified whether the engine speed NE is below 400 rpm. When the engine speed NE falls below 400 rpm, the possibility of engine stall increases, so the routine proceeds to step 119, where the retarder device 13 is immediately deactivated.

At step 116, it is identified whether the flag F is 1 or 0. F = 1 means that the timer is counting and bypasses step 117. If F = O, the process proceeds to step 117 to reset the timer T and set the flag F to 1. In step 118, it is identified whether or not the timer T exceeds the set time Ts (the number of counts corresponding to 500 msec). If the timer T is equal to or less than the set value Ts, the process proceeds to step 120 and the count of the timer T is incremented by 1. If the timer T exceeds the set value Ts, the routine proceeds to step 119, where the retarder device 13 is deactivated and the flag F is reset.

In step 111, the vehicle speed VSP is 10 km /
If it is equal to or greater than the hour, the routine proceeds to step 121, where it is judged if the throttle opening TVO is below the threshold value TI. If the throttle opening TVO is greater than or equal to the threshold value TI, the following flow is bypassed. When the throttle opening TVO is below the threshold value TI, the routine proceeds to step 122, where it is discriminated whether or not the auxiliary brake switch 27 is turned on. Auxiliary brake switch 27
If is OFF, the following flow is bypassed. When the auxiliary brake switch 27 is ON, the routine proceeds to step 123, where it is discriminated whether or not the vehicle speed VSP exceeds 15 km / hour. If the vehicle speed VSP is 15 km / hour or less, the following flow is bypassed. Vehicle speed VSP is 15km /
If the time is over, the routine proceeds to steps 124 and 125, and the retarder device 13 and the exhaust brake device 23 are actuated at substantially the same time.

The deactivation of the retarder device in step 119 is controlled in a transient state by an interrupt program (not shown). The deactivation is started in the first flow in step 119, and the deactivation is advanced each time the flow is repeated until the completion of the deactivation is detected by the interrupt program. When the operation state of the vehicle is changed before the completion of the operation release and the retarder device is activated in step 124, the braking force starts to be started from the middle stage of the operation release.

According to the auxiliary brake device of the first embodiment,
In the deceleration process from the high vehicle speed range, a large braking force that simultaneously operates the exhaust brake device 23 and the retarder device 13 can be used. In addition, when deactivating both the exhaust brake device 23 and the retarder device 13 due to the decrease in the vehicle speed VSP, it is 50
Since the deactivation of the retarder device is started with a delay of 0 msec, it is possible to avoid a situation in which the exhaust brake device 23 and the retarder device are deactivated so that the braking force is suddenly reduced and the driver is uncomfortable.

If the vehicle speed VSP and the engine speed NE are suddenly decreased by identifying the changing speed of the vehicle speed VSP, the deactivation of the retarder device is immediately started without waiting for 500 msec. It is possible to avoid a situation in which the braking force of the auxiliary brake device is involved in the delicate deceleration process of (1) and the driver's deceleration operation is erroneously performed, or the engine speed NE is excessively reduced to cause engine stall.

Further, since the operation of the exhaust brake device 23, which has a large influence on the operating condition of the engine 11, is executed first, and the operation of the retarder device 13, which has a small effect on the operating condition of the engine 11, is executed later, While avoiding the engine stall of 11, the braking force of the auxiliary braking device can be used in a considerably low speed range, and the frequency and load of using the service brake are reduced. Further, the retarder capable of setting the level of the braking force during the deactivating process by executing the deactivating operation of the exhaust brake device 23, in which the braking force immediately decreases immediately after the deactivating operation and the braking force is difficult to control. Since the deactivation of the device 13 is executed later, the transition to deceleration by the service brake becomes smooth.

Incidentally, steps 113 to 120 shown in FIG.
In the flow of No. 2, the waiting time from the start of the deactivation of the exhaust brake device 23 to the start of the deactivation of the retarder device 13 is 0 seconds and 500 milliseconds depending on the changing speed of the vehicle speed VSP, the vehicle speed VSP and the engine speed NE. The waiting time may be adjusted more finely, although it is properly used depending on the stage. For example, as shown in FIG. 5, the set time Ts is finely set according to the deceleration Ga of the vehicle speed VSP and the deceleration Gn of the engine speed. As a result, the completion of the operation release of the exhaust brake device 23 and the start of the operation release of the retarder device 13 can be connected more smoothly.

Although the auxiliary brake device 32 independent of the automatic transmission control unit 31 is used in the first embodiment, the automatic transmission control unit 31 may be configured to perform the function of the auxiliary brake device 32. Also, in a vehicle with a manual transmission that does not use the automatic transmission 12, the exhaust brake device 23, the retarder device 13, the auxiliary brake control device 32, and the like can be mounted to perform similar control. Further, in the first embodiment, the retarder device 13 is arranged between the engine 11 and the automatic transmission 12, but the retarder device 13 may be arranged on the output side of the automatic transmission 12 to perform similar control. Good. In this case, the rotational drive is blocked by the torque converter and the clutch of the automatic transmission 12, so the engine 11 does not stall even if the retarder device 13 is continuously operated until the vehicle speed VSP becomes zero. However, in order to control the delicate deceleration process before the stop only by the braking force of the service brake, it is necessary to complete the deactivation of the service brake while the vehicle speed VSP is high to some extent. In the first embodiment,
Steps 111 and 112 correspond to the exhaust brake device releasing means of the invention, and steps 113 to 120 correspond to the retarder device releasing means of the invention.

FIG. 6 is an explanatory diagram of control in the second embodiment. In the second embodiment, the configuration of the auxiliary braking device shown in FIG. 1 is used as it is, and step 11 shown in FIG. 4 is used.
The control in which step 2 and step 119 are replaced is executed. Figure 6
In the second embodiment, the deactivation of the retarder device 13 is first started at time Eb when the vehicle speed VSP drops and falls below 10 km / hour, as shown in FIG. At time Fb when the set time Ts has passed from time Eb, the operation release of the exhaust brake device 23 is started. At time Gb when the braking force of the exhaust brake device 23 disappears, the total braking force becomes zero.

According to the auxiliary brake device of the second embodiment,
It is possible to use a large braking force by operating the exhaust brake device 23 and the retarder device 13 at the same time. Further, due to the decrease in vehicle speed VSP, the exhaust brake device 23 and the retarder device 13
When releasing both of the above, the exhaust brake device 2 is delayed by 500 msec from the start of the release of the retarder device 13.
Since the release of the operation of No. 3 is started, the exhaust brake device 23
It is possible to avoid a situation in which the deactivation of the retarder device and the deactivation of the retarder device cause a sudden decrease in the braking force and cause the driver to feel uncomfortable.

[0041]

According to the first aspect of the invention, a large braking force can be utilized by simultaneously operating the exhaust brake device and the retarder device during the deceleration process from a high vehicle speed. On the other hand, when the vehicle speed falls below a predetermined threshold to deactivate both the exhaust brake device and the retarder device, the deactivation of the retarder device is delayed to reduce the braking force immediately after the deactivation of the exhaust brake device. The driver does not feel uncomfortable due to excessive reduction in deceleration force. Further, since the retarder device, which has a smaller influence on the operating state of the engine than the exhaust brake, is deactivated later, the braking force of the auxiliary brake device can be used even in a considerably low vehicle speed range. In addition, since the retarder device, whose braking force level can be easily adjusted, is released later, the speed at which the braking force is reduced during the releasing process is adjusted to a smoother speed reduction operation in the low vehicle speed range due to the braking force of the service brake. Can be migrated. Further, at least during the deceleration process under the same conditions, the vehicle speed change from the start of the deactivation of the exhaust brake device to the completion of the deactivation of the retarder device is kept constant. The change in the braking force of the device can be repeatedly learned and easily predicted, and the transition to the deceleration operation in the low vehicle speed region by the braking force of the service brake becomes smoother.

According to the second aspect of the present invention, since the retarder device is arranged on the input side of the automatic transmission, the braking force of the retarder device is changed as compared with the case where it is arranged on the output side. Less likely to interfere with operation. Therefore, even if the timing of the gear shifting operation, the setting of the transient hydraulic pressure, and the like are not significantly changed in accordance with the presence or absence of the braking force of the retarder device, it is possible to perform the gear shifting smoothly, promptly, and with little gear shifting shock.

According to the third aspect of the present invention, in a situation where there is a high possibility that the vehicle speed or engine speed will suddenly drop and the engine will stall after the vehicle speed exceeds the threshold value, the retarder will be activated after the deactivation of the exhaust brake device is started. Since the time until the start of the deactivation of the device is set to be short, the engine speed is prevented from being excessively lowered, and the engine stall is prevented.

According to the fourth aspect of the invention, a large braking force can be utilized by simultaneously operating the exhaust brake device and the retarder device during the deceleration process from a high vehicle speed. On the other hand, when the vehicle speed falls below a predetermined threshold to deactivate the exhaust brake device and the retarder device, the deactivation of the retarder device is delayed to reduce the braking force immediately after the deactivation of the exhaust brake device and reduce the braking force. The driver does not feel uncomfortable due to excessive reduction of the deceleration force.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram of an operation area and an operation release area of the auxiliary brake device.

FIG. 3 is an explanatory diagram of an operating state of the auxiliary brake device according to the first embodiment.

FIG. 4 is a flowchart of control of an auxiliary brake device.

FIG. 5 is an explanatory diagram of another example of setting a set time.

FIG. 6 is an explanatory diagram of an operating state of the auxiliary brake device in the second embodiment.

[Explanation of symbols]

 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 20 vehicle speed sensor 21 inhibitor switch 22 throttle sensor 23 exhaust brake device 24 air cylinder 25, 28 solenoid valve 27 auxiliary Brake device 31 Automatic transmission control unit 32 Auxiliary brake control device

Claims (4)

[Claims] 1. A retarder device that is inserted and arranged in a driving force transmission path from an engine of an automobile to a wheel and is capable of outputting a braking force to the driving force transmission path, and is inserted and arranged in an exhaust path of the engine. An exhaust brake device that increases the engine braking effect of the engine, and an auxiliary brake device that includes a control device that controls at least operation and deactivation of the exhaust brake device and the retarder device according to an operating state of the vehicle, The control device, when the vehicle speed falls below a predetermined set value, first, an exhaust brake releasing means for starting the operation release of the exhaust brake device, and after the start of the operation release of the exhaust brake device, wait for a predetermined time. And a retarder device releasing means for starting the release of the operation of the retarder device. . 2. The auxiliary braking device according to claim 1, wherein the retarder device is arranged between an engine of an automobile and an automatic transmission. 3. The retarder device releasing means adjusts the predetermined time in accordance with at least one of a vehicle speed, an engine speed, a deceleration, and a deceleration speed of the engine speed. Auxiliary braking device described. 4. A retarder device that is inserted and arranged in a driving force transmission path from an engine of an automobile to a wheel, and is capable of outputting a braking force to the driving force transmission path, and is inserted and arranged in an exhaust path of the engine. An auxiliary brake having an exhaust brake device for increasing an engine braking effect of the engine, and a control device for controlling at least activation / deactivation of the exhaust brake device and the retarder device in accordance with a running state and a driving state of the vehicle. In the device, when the vehicle speed falls below a predetermined set value, the control device first starts retarder device releasing means for starting operation release of the retarder device, and after starting operation release of the retarder device, waits for elapse of a predetermined time. Exhaust brake releasing means for starting the release of the operation of the exhaust brake device. Apparatus.