Apparatus for the measurement and/or regulation of a braking force and/or of a braking torque

• US 4,790,606 A
• Filed: 08/25/1987
• Issued: 12/13/1988
• Est. Priority Date: 01/23/1985
• Status: Expired due to Term

• Current Assignee: Wabco Westinghouse Fahrzeugbremsen GmbH
• Original Assignee: Wabco Westinghouse Fahrzeugbremsen GmbH
• Inventors: Reinecke, Erich
• Primary Examiner(s): Butler, Douglas C.
• Application Number:
  US07/089,186
• Time in Patent Office: 476 Days
• Field of Search: 303/100, 303/103, 303/104, 303/112, 303/96, 303/91, 303/92, 303/20, 340/52 B, 340/52 C, 340/52 A, 340/52 R, 73/862.12, 73/862.13, 374/46, 374/48, 374/153, 188/181 T, 188/1.11, 188/195
• US Class Current: 303/191
• CPC Class Codes: B60T 13/10 with fluid assistance, drive, or release
• CPC Class Codes: B60T 13/74 with electrical assistance or drive
• CPC Class Codes: B60T 17/22 Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B60T 8/00 Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force by changing number of effective brake cylinders in power brake systems B60T17/10
• CPC Class Codes: B60T 8/1708 for lorries or tractor-trailer combinations
• CPC Class Codes: F16D 2066/001 Temperature
• CPC Class Codes: F16D 2066/005 Force, torque, stress or strain
• CPC Class Codes: F16D 2066/006 without direct measurement of the quantity monitored, e.g. wear or temperature calculated form force and duration of braking
• CPC Class Codes: F16D 66/00 Arrangements for monitoring working conditions, e.g. wear, temperature
• CPC Class Codes: F16D 66/021 using electrical detection or indication means

Abstract

An apparatus which measures and regulates the braking torque of a brake unit in long-term operational use. The brake unit includes both a brakable element and the braking device. An output signal from at least one temperature-dependent measuring element, located on or in one of the brakable elements and the braking device, is supplied to an evaluation apparatus. The evaluation apparatus determines, from the current value of the output signal of the temperature-measuring element, a present braking torque, and adjusts such torque when desirable.

Claims

1. An apparatus for performing at least one of measuring and regulating a braking force produced by at least one of at least two brake units, which braking force of each of said at least two brake units is transmitted to a brakable element for decelerating such brakable element, said apparatus comprising:

(a) a deceleration sensor mounted on said brakable element to provide an output signal value that is representative of a measured deceleration value of said brakable element;

(b) at least one mass sensor mounted on said brakable element to provide an output signal value that is representative of a measured mass value of said brakable element;

(c) at least one temperature-dependent measuring element mounted on each brake unit to provide an output signal value that is representative of a measured temperature value of a brake unit on which said at least one temperature-dependent measuring element is mounted;

(d) an evaluation means connected to receive said output signal values of said deceleration sensor and said at least one mass sensor and said at least one temperature-dependent element;

(e) said evaluation means having parameters stored therein of each brake unit for determining a temperature-development of each brake unit during activation of each such brake unit;

(f) said evaluation means having a capability of determining changes of temperature signal values of said brake units having occurred in a time interval at least during an activation of said brake units;

(g) said evaluation means being capable of determining a medium deceleration value in said time interval; and

(h) said evaluation means from said changes of said temperature signal values of said brake units and from said output signal value of said mass sensor and from said medium deceleration value generates and transmits an output signal value representative of a medium braking force produced by said at least one brake unit during said time interval.

2. An apparatus, according to claim 1, wherein said time interval is a cyclus time of said evaluation means.

3. An apparatus, according to claim 1, wherein said evaluation means further includes means for varying said time interval.

4. An apparatus, according to claim 3, wherein said means for varying said time interval is capable of determining a length of said time interval dependent on an absolute temperature level signalled by an output signal value of at least one of said temperature-dependent measuring elements.

5. An apparatus, according to claim 4, wherein said time interval is essentially inversely proportional to said absolute temperature level.

6. An apparatus, according to claim 1, wherein said apparatus further includes a comparison means for comparing said output signal value from said evaluation means with at least one preselected command value and for generating an output signal based upon said comparison.

7. An apparatus, according to claim 6, wherein said command value is representative of a maximum allowable temperature and wherein said output signal of said comparison means is transmitted to a warning system.

8. An apparatus, according to claim 6, wherein said command value is an output signal of said evaluation means for another one of said brake units and wherein said comparison means generates its output signal when said output signals of said evaluation means for said two brake units differ by more than a predetermined value.

9. An apparatus, according to claim 6, wherein said apparatus further includes at least one of a signal-processing means and a memory storage means for receiving said output signal from said comparison means.

10. An apparatus, according to claim 9, wherein said signal-processing means is a braking force control apparatus for controlling said braking force in response to said output signal from said comparison means.

11. An apparatus, according to claim 9, wherein said output signal from said comparison means is buffered in said memory storage means and wherein said comparison means extracts said buffered output signal from said memory storage means and transmits it to said signal-processing means when said brake units are activated.

12. An apparatus, according to claim 11, wherein said signal-processing means is a braking force control apparatus for controlling said braking force in response to said output signal from said comparison means.

13. An apparatus, according to claim 10, wherein:

(a) said brakable element is a vehicle wherein each of said brake units is represented by a wheel brake on one side of an axle or on one side of a group of axles respectively of said vehicle; and

(b) a braking force control apparatus is provided for each wheel brake.

14. An apparatus, according to claim 12, wherein:

(a) said brakable element is a vehicle wherein each of said brake units is represented by a wheel brake on one side of an axle or on one side of a group of axles respectively of said vehicle; and

(b) a braking force control apparatus is provided for each wheel brake.

16. An apparatus, according to claim 14, wherein said evaluation means further has stored therein a dynamic wheel radius and wherein said evaluation means by means of said dynamic wheel radius transforms said output signal value representative of a medium braking force into an output signal representative of a medium braking torque.

18. An apparatus, according to claim 16, wherein said vehicle further includes at least one brake activation means for arbitrarily setting said braking torque of said wheel brakes.

20. An apparatus, according to claim 18, wherein said at least one mass sensor is composed of at least one axle load sensor for each vehicle axle and wherein said brake activation means automatically adjusts a distribution of said braking torques between said vehicle axles to an axle load distribution.

21. An apparatus, according to claim 10, wherein said output signal value that is representative of a measured temperature value is an average output signal value from said temperature-dependent measuring elements on each wheel brake on one side of a group of axles.

22. An apparatus, according to claim 12, wherein said output signal value that is representative of a measured temperature value is an average output signal value from said temperature-dependent measuring elements on each wheel brake on one side of a group of axles.

15. An apparatus, according to clam 13, wherein said evaluation means further has stored therein a dynamic wheel radius and wherein said evaluation means by means of said dynamic wheel radius transforms said output signal value representative of a medium braking force into an output signal value representative of a medium braking torque.

17. An apparatus, according to claim 15, wherein said vehicle further includes at least one brake activation means for arbitrarily setting said braking torque of said wheel brakes.

19. An apparatus, according to claim 17, wherein said at least one mass sensor is composed of at least one axle load sensor for each vehicle axle and wherein said brake activation means automatically adjusts a distribution of said braking torque between said vehicle axles to an axle load distribution.

23. A method of at least one of measuring and regulating a braking force produced by at least one of at least two brake units, which braking force of each of said at least two brake units is transmitted to a brakable element for decelerating such brakable element, said method comprising the steps of:

(a) generating an output signal value that is representative of a measured deceleration value of said brakable element;

(b) generating an output signal value that is representative of a measured mass value of said brakable element;

(c) generating an output signal value that is representative of a measured temperature value of a brake unit;

(d) transmitting said output signal values generated in steps (a) and (b) and (c) to an evaluation means having stored therein parameters for determining a temperature development of each brake unit during activation of such brake unit;

(e) determining changes of said measured temperature value of said brake unit as they occur in a time interval at least during an activation of said brake unit;

(f) determining a medium deceleration value in said time interval; and

(g) generating and transmitting an output signal value from said evaluation means that is representative of a medium braking force produced by said at least one brake unit during said time interval as determined in said evaluation means from said changes of said temperature signal values of said brake units and from said output signal value of said mass sensor and from said medium deceleration value.

24. A method, according to claim 23, wherein said time interval is a cyclus time of said evaluation means.

25. A method, according to claim 23, wherein said method includes the additional step of varying said time interval.

26. A method, according to claim 25, wherein said step of varying said time interval includes the step of determining a length of said time interval dependent on an absolute temperature level signalled by an output signal value of at least one of said temperature-dependent measuring elements.

27. A method, according to claim 26, wherein said time interval is essentially inversely proportional to said absolute temperature level.

28. A method, according to claim 23, wherein said method includes the additional step of comparing said output signal from said evaluation means with at least one preselected command value and generating an output signal based on said comparison.

29. A method, according to claim 28, wherein said command value is representative of a maximum allowable temperature and said method includes the additional step of transmitting said output signal from said comparison means to a warning system.