Automatic retarder controller

• US 6,299,263 B1
• Filed: 09/24/1999
• Issued: 10/09/2001
• Est. Priority Date: 03/26/1997
• Status: Expired due to Term

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Uematsu, Kouji, Hasegawa, Nobuki
• Primary Examiner(s): Oberleitner, Robert J.
• Assistant Examiner(s): KRAMER, DEVON C
• Application Number:
  US09/381,804
• Time in Patent Office: 746 Days
• Field of Search: 303/192, 303/121, 303/123, 303/125, 303/129, 303/131, 188/DIG.4
• US Class Current: 303/192
• CPC Class Codes: B60K 31/00 Vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator fittings acting on two or more sub-units B60W30/14; speedometers G01P; systems or devices for controlling speed in general G05D13/00 ; in traffic anti-collision system for road vehicles G08G1/16
• CPC Class Codes: B60K 31/042 where at least one electrical quantity is set by the vehicle operator
• CPC Class Codes: B60T 10/00 Control or regulation for continuous braking making use of fluid or powdered medium, e.g. for use when descending a long slope
• CPC Class Codes: B60T 10/02 with hydrodynamic brake
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60W 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60Y 2200/14 Trucks; Load vehicles, Busses

Abstract

An automatic retarder controller for a vehicle, which can prevent overheating, and can more precisely control the vehicle speed to remain constant. For this purpose, in the automatic retarder controller which is mounted on a load-carrying vehicle together with a cooled retarder (31) for exerting a braking force in response to a driving signal, and which automatically controls the driving signal so that the slope descending speed of the vehicle remains nearly constant, a detector for detecting the loading weight of the vehicle is included, and the controller impresses the gain corresponding to the detected loading weight upon the driving signal while the controller controls the vehicle speed to remain constant.

Claims

1. An automatic retarder controller which is mounted on a load-carrying vehicle together with a cooled retarder, and which automatically controls a braking force of said retarder so that a slope descending vehicle speed remains nearly constant, comprising:

a means for detecting an accelerator pedal depressing signal;

means for detecting braking signals during the manipulation of said retarder and other brakes;

a means for outputting a set signal inputted from the outside; and

a means for detecting the vehicle speed,

wherein the controller previously stores the slope descending vehicle speed as a plurality of stepwise setting vehicle speeds, and allows the slope descending vehicle speed to be selected from said plurality of setting vehicle speeds,

while controlling the vehicle speed to remain constant, when said detected accelerator pedal depressing signal is inputted, said controller intermitting said control of the vehicle speed to remain constant to allow the vehicle speed to increase, and when said detected braking signals are inputted, intermitting said control of the vehicle speed to remain constant to allow the vehicle speed to decrease, and

when said set signal is inputted during said intermissions, extracting the vehicle speed closest to said detected vehicle speed from said plurality of setting vehicle speeds, and restarting said control of a vehicle speed to remain constant with said extracted vehicle speed being set as a new slope descending vehicle speed.

3. The automatic retarder controller in accordance with claim 1 or 2, wherein said controller stores a heat balance critical temperature therein, said controller further comprising:

a means for detecting a cooling oil temperature of said retarder; and

a means for detecting the present vehicle speed,

while controlling the vehicle speed to remain constant, said controller estimating an estimated oil temperature after a first reference period of time based on said detected cooling oil temperature, when said estimated oil temperature exceeds said heat balance critical temperature, extracting a vehicle speed in a lower speed side than the present slope descending vehicle speed detected by said means for detecting the present vehicle speed from said plurality of setting vehicle speeds to set the same as a new slope descending vehicle speed, and when said estimated oil temperature is not higher than the beat balance critical temperature, extracting a vehicle speed in a higher speed side than the present slope descending vehicle speed detected by said means for detecting the present vehicle speed from said plurality of setting vehicle speeds to set the same as a new slope descending vehicle speed.

4. The automatic retarder controller in accordance with claim 1 or 2, wherein said controller stores a heat balance critical temperature therein, said controller further comprising:

a means for detecting a cooling oil temperature of said retarder; and

a means for detecting the present vehicle speed,

while controlling the vehicle speed to remain constant, said controller estimating a period of time taken before said detected cooling oil temperature reaches or exceeds the heat balance critical temperature, when said estimated period of time is less than a second reference period of time, extracting a vehicle speed in a lower speed side than the present slope descending vehicle speed detected by said means for detecting the present vehicle speed from said plurality of setting vehicle speeds to set the same as a new slope descending vehicle speed, and when said estimated period of time is not less than the second reference period of time, extracting a vehicle speed in a higher speed side than the present slope descending vehicle speed detected by said means for detecting the present vehicle speed from said plurality of setting vehicle speeds to set the same as a new slope descending vehicle speed.

2. An automatic retarder controller which is mounted on a load-carrying vehicle together with a cooled retarder, and which automatically controls a braking force of said retarder so that a slope descending vehicle speed remains nearly constant, comprising:

a means for detecting the present vehicle speed; and

a means for outputting an up-down signal inputted from the outside,

wherein the controller previously stores the slope descending vehicle speed as a plurality of stepwise setting vehicle speeds, and allows the slope descending vehicle speed to be selected from said plurality of setting vehicle speeds, and

while controlling the vehicle speed to remain constant, said controller extracting a vehicle speed in a higher speed side than the present slope descending vehicle speed detected by said means for detecting the present vehicle speed by one level from said plurality of setting vehicle speeds to set the same as a new slope descending vehicle speed every time an up signal is inputted from said means for outputting an up-down signal inputted from the outside, and extracting a vehicle speed in a lower speed side than the present slope descending vehicle speed detected by said means for detecting the present vehicle speed by one level from said plurality of setting vehicle speeds to set the same as a new slope descending vehicle speed every time a down signal is inputted from said means for outputting an up-down signal inputted from the outside.

5. An automatic retarder controller which is mounted on a load-carrying vehicle together with a cooled retarder for exerting a braking force in response to a driving signal, and which automatically controls said driving signal so that a slope descending vehicle speed remains nearly constant, comprising:

a first means for detecting a loading weight of said vehicle; and

a second means for detecting a cooling oil temperature of said retarder,

while controlling the vehicle speed to remain constant, the controller impressing a gain corresponding to said detected loading weight on said driving signal; and

estimating an estimated oil temperature after a first reference period of time based on said detected cooling oil temperature, when said estimated oil temperature exceeds a heat balance critical temperature, increasing the driving signal on which said gain is impressed, and when said estimated oil temperature is not higher than the heat balance critical temperature, decreasing the driving signal on which said gain is impressed.

6. An automatic retarder controller which is mounted on a load-carrying vehicle together with a cooled retarder for exerting a braking force in response to a driving signal, and which automatically controls said driving signal so that a slope descending vehicle speed remains nearly constant, comprising:

a first means for detecting a loading weight of said vehicle; and

a second means for detecting a cooling oil temperature of said retarder, the controller previously storing gains corresponding to a laden state and an unladen state of said vehicle, and a heat balance critical temperature,

while controlling the vehicle speed to remain constant, determining whether the vehicle is in the laden state or the unladen state based on said detected loading weight, and impressing the gain corresponding to said determined state on said driving signal; and

estimating a period of time taken before said detected cooling oil temperature reaches or exceeds the heat balance critical temperature, when said estimated period of time is less than a second reference period of time, increasing the driving signal on which said gain is impressed, and when said estimated period of time is not less than the second reference period of time, decreasing the driving signal on which said gain is impressed.

7. An automatic retarder controller which is mounted on a load-carrying vehicle together with a cooled retarder for exerting a braking force in response to a driving signal, and which automatically controls said driving signal so that a slope descending vehicle speed remains nearly constant, comprising:

a first means for detecting a loading weight of said vehicle; and

a second means for detecting a cooling oil temperature of said retarder,

the controller previously storing gains corresponding to a laden state and an unladen state of said vehicle, while controlling the vehicle speed to remain constant, determining whether the vehicle is in the laden state or the unladen state based on said detected loading weight, and impressing the gain corresponding to said determined state on said driving signal; and

estimating an estimated oil temperature after a first reference period of time based on said detected cooling oil temperature, when said estimated oil temperature exceeds a heat balance critical temperature, increasing the driving signal on which said gain is impressed, and when said estimated oil temperature is not higher than the heat balance critical temperature, decreasing the driving signal on which said gain is impressed.

8. An automatic retarder controller which is mounted on a load-carrying vehicle together with a cooled retarder for exerting a braking force in response to a driving signal, and which automatically controls said driving signal so that a slope descending vehicle speed remains nearly constant, comprising:

a first means for detecting a loading weight of said vehicle; and

a second means for detecting a cooling oil temperature of said retarder, while controlling the vehicle speed to remain constant, the controller impressing a gain corresponding to said detected loading weight on said driving signal; and

estimating a period of time taken before said detected cooling oil temperature reaches or exceeds the heat balance critical temperature, when said estimated period of time is less than a second reference period of time, increasing the driving signal on which said gain is impressed, and when said estimated period of time is not less than the second reference period of time, decreasing the driving signal on which said gain is impressed.