JPH03248951A - Retarding control device - Google Patents

Abstract

PURPOSE:To eliminate a fear of a brake force being increased to an excessive value during manual down and to reduce a shift shock by controlling so that a brake force generated by a retarder connected to an automatic transmission is reduced during manual down. CONSTITUTION:When a retarder change-over switch 18 is turned ON, a solenoid 20 is charged with a current by means of an ECU 11 to actuate a control valve 19. Through introduction of pressure oil to a retarder 21, a specific brake force generated by the retarder 21 is exerted on an output shaft 18. In this case, during the above operation, a shift lever 12 is operated, and when manual down is decided based on outputs from a shift position sensor 13 and a throttle opening sensor 14, power feeding amount to the solenoid 20 is decreased so that a brake force generated by the retarder 21 is reduced by an amount equivalent to a brake force set in each position of the shift lever 12. This constitution prevents a brake force from being increased to an excessive value due to application of an engine brake.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a retarder operated by manual switching.

(Prior Art) In general, most heavy-duty vehicles are equipped with an auxiliary brake such as an exhaust brake or a fluid retarder in addition to a foot brake as a braking device.

FIG. 4 shows a conventional retarding control device equipped with a fluid retarder, and when the changeover switch 1 is turned on by manual operation.

E to which the switching signal from this changeover switch 1 is input
The CU 2 outputs current to the solenoid 3 to operate the control valve 4 and introduce hydraulic pressure to the fluid retarder 5, thereby causing the retarder 5 to generate braking force.

(Problem to be Solved by the Invention) In the conventional retarding control device as described above, the braking force by the retarder 5 is adjusted only by operating the changeover switch 1. When combined with this, if manual down is performed by operating the shift lever while the selector switch 1 is turned on and the retarder 5 is operating,
Since the braking force from the engine brake associated with manual down is added to the braking force from the retarder 5, the braking force becomes excessive. Due to these changes, the shift shock increased and the driving feeling deteriorated.

The present invention was made in order to solve the problems in the conventional retarding control device as described above. That is, the present invention provides a retarding control device that can obtain the optimum braking force corresponding to the driving condition even when a retarder operated by a manually operated changeover switch is used in combination with an automatic transmission. The purpose is to provide.

(Means for achieving the task) This invention aims to achieve the above object.

In a retarding control device that controls the operation of a retarder connected to an automatic transmission by operating a retarder actuating device by operating a retarder changeover switch, the retarding control device includes a shift lever shift position detecting means, a throttle opening detecting means, and these shift positions. The control means receives a shift position signal from the detection means, a throttle opening signal from the throttle opening detection means, and a switching signal from the retarder changeover switch and outputs an activation signal to the retarder actuation device. When a switching signal for operating the retarder is input from the selector switch and manual down is determined based on the shift position signal and throttle opening signal, an operating signal is sent to the retarder operating device to reduce the braking force by the retarder by a predetermined value. It is characterized by decreasing

In addition to the configuration of the first invention, a retarding control device according to a second invention is provided in which, in addition to the configuration of the first invention, the value of the reduction in the braking force of the retarder during manual down by the control device corresponds to the shift position after manual down. It is characterized by being set.

In addition to the configuration of the first invention, the retarding control device according to the third invention further includes vehicle speed detection means, and the control means controls the retarder actuating device based on the vehicle speed signal from the vehicle speed detection means. It is characterized by setting a time for reducing the actuation signal.

(Function) In the retarding control device according to the present invention, when the retarder switching switch is turned on and a retarder switching signal for operating the retarder is input to the control means, a 1 operating signal is output to the retarder operating device, and the retarder is activated. A certain amount of braking force is generated.

When the retarder changeover switch is turned on and braking is being performed by the retarder, the shift lever is operated and a shift position signal from the shift position detection means and a throttle opening signal from the throttle opening detection means are input. When the control means determines manual down based on.

The output of the actuation signal to the retarder actuator is decreased by a predetermined value. Therefore, during manual down, the braking force by the retarder is reduced by the amount that the actuation signal is reduced by one.

According to the second invention, the reduced braking force of the retarder during manual down is set for each shift position after manual down, and the braking force of the retarder is controlled in response to each manual down.

Further, according to the third invention, the time period for reducing the activation signal to the retarder activation device during manual down is set based on the vehicle speed signal from the vehicle speed detection means, and the braking force of the retarder is controlled in accordance with the vehicle speed at that time. will be held.

(Example) Hereinafter, the present invention will be described in further detail based on an example shown in two drawings.

In FIG. 1, the ECU 11 includes a shift lever 1.
Shift position signal α from the shift position sensor (shift position detection means) 13 attached to 2
, the throttle opening signal β from the throttle opening sensor (throttle opening detection means) 14 attached to the accelerator pedal, is sent to the output shaft 16 of the automatic transmission 15 (=I
A vehicle speed signal γ from a vehicle speed sensor (vehicle speed detection means) 17 and a retarder switching signal δ from a retarder switching switch 18 are input, and a retarder is output from the ECLI 11 to a solenoid 20 connected to a control valve 19 for controlling the retarder. A fluid type retarder 21 which outputs a solenoid signal (current) ■ to control the operation of the control valve 19 and is attached to the output shaft 16 of the automatic transmission 15.
Increase or decrease the hydraulic pressure supplied to the

HCU II is.

i) Throttle opening is zero.

ll) The shift position of the shift lever 12 is D → 3,
D→2. D-4L, 3→2, 3→L, or 2→L.

It is set to determine manual down when the two-line property is satisfied.

When the retarder changeover switch 18 is turned on and the retarder changeover signal δ is input to the ECU 11.

When the current I is output to the solenoid 20 and hydraulic pressure is introduced into the retarder 2I by actuation of the control valve 19, a constant braking force F by the retarder 21 acts on the output shaft 16.

As described above, when the retarder changeover switch 18 is turned on and braking is being performed by the retarder 21, the shift lever 12 is operated, and the shift position signal α from the shift position sensor 13 and the throttle signal α from the throttle opening sensor 14 are ECU based on input of opening signal β
When 11 determines manual down, EC[I
11 is the braking force ΔF set for each position of the shift lever 12 when downshifting, as shown in FIG.
In order to reduce the braking force by the retarder 21, the output of the electric current to the solenoid is reduced by the amount of current 61 corresponding to this reduced braking force ΔF. As can be seen from FIG. 2, this reduced braking force ΔF is set to be greater at the lower speed shift position.

For example, in FIG. 3, the retarder changeover switch 18 is on and the throttle opening is zero.

When the shift position signal α indicates D→3 (a).

Reduced braking force ΔF3 corresponding to the 3rd position of the shift lever 12 (see Figure 2) Current Δ corresponding to (C)
Decrease the current ■ to solenoid 20 by I3 (b)
.

Therefore, the braking force F acting on the vehicle at this time is the braking force by the foot brake F2. Let F3 be the braking force due to engine braking associated with manual down.

F-F, +F2+F3-ΔF3 becomes.

The time T for decreasing this current ΔI is set in proportion to the vehicle speed at that time. That is, the ECU 11 calculates a time T based on the vehicle speed signal δ from the vehicle speed sensor I7, and calculates a time T based on the following formula: Ta - Na: constant N: rotational speed of the output shaft (-vehicle speed), and operates the solenoid 2 for this time T.
The current ■ to 0 is decreased by ΔI, and after one hour T has elapsed, the decrease in current flow is stopped.

Due to the retarding control device as described above, the degree of change in vehicle speed and deceleration becomes gentler as shown by the solid lines in FIG. 3 (d) and (e) compared to the conventional case shown by the dotted line. Shift shock is significantly reduced.

(Effects of the Invention) As described above, according to the present invention, the braking force by the retarder connected to the automatic transmission is reduced when the manual gear is down. There is no risk that the applied braking force will be excessive, reducing shift shock and improving driving feeling.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention, and FIG. 2 is a graph showing reduced braking force in the same embodiment. FIG. 3 is an explanatory diagram for explaining control of retarder braking force in the same embodiment, and FIG. 4 is a circuit diagram showing a conventional example. 11... ECII (control means) 12... Shift lever 13... Shift position sensor (shift position detection means) 14... Throttle opening sensor (throttle opening detection means) 17... Vehicle speed sensor ( Vehicle speed detection means) 18... Retarder changeover switch 19... Control valve 1 (Retarder operating device) 20... Solenoid (Retarder operating device) 21...
retarder

Claims (1)

[Scope of Claims] 1. In a retarding control device that operates a retarder actuating device by operating a retarder changeover switch to control the actuation of a retarder connected to an automatic transmission, a shift position detecting means of a shift lever, a throttle opening control means which receives a shift position signal from the shift position detection means, a throttle opening signal from the throttle opening detection means, and a switching signal from the retarder changeover switch and outputs an operating signal to the retarder operating device. The control means is configured to reduce the braking force by the retarder by a predetermined value when a switching signal for activating the retarder is input from the retarder selector switch and the control means determines manual down based on the shift position signal and the throttle opening signal. A retarding control device that reduces an actuation signal to a retarder actuation device. 2. The retarding control device according to claim 1, wherein the value of reduction in the braking force of the retarder when the control device performs manual down is set corresponding to the shift position after manual down. 3. The retarding control device according to claim 1, further comprising vehicle speed detection means, wherein the control means sets a time period during which the actuation signal to the retarder actuation device is reduced based on a vehicle speed signal from the vehicle speed detection means.