JP2004135418A - Eddy current reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide am eddy current reduction gear capable of easily detecting an operation failure. <P>SOLUTION: The temperature of a rotor is measured directly by a thermometer, or is measured indirectly by the thermometer provided at a non-rotation portion near the rotor to obtain temperature measurements. The measurements are compared with preset temperatures, and by the comparative results, a failure in the eddy current reduction gear is diagnosed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to an eddy current type speed reducer, and more particularly, to an eddy current type speed reducer having a structure in which a permanent magnet is moved toward or away from a braking member made of a ferromagnetic material to apply or cancel braking to a rotating shaft. .
[0002]
[Prior art]
BACKGROUND ART An eddy current type speed reducer (hereinafter, referred to as a “retarder”), for example, arranges a magnet support ring provided with a plurality of permanent magnets on the outer periphery in a stator case, and moves the magnet support ring to generate a braking force. Is switched. Such retarders are often installed in large vehicles such as trucks. When the retarder is classified according to the moving direction of the magnet, a type in which the magnet support ring moves forward and backward in a direction parallel to the rotation axis of the rotor (hereinafter, referred to as an "axis slide method"), and a method in which the magnet support ring moves in the rotor rotation direction It is classified into a type of turning movement (hereinafter, referred to as “turning method”).
[0003]
In the stator case, the magnet support ring is driven using an air cylinder. That is, the cylinder rod connected to the piston in the air cylinder is connected to the magnet support ring, and the magnet support ring moves in parallel or turns in a predetermined direction by the reciprocating operation of the cylinder rod.
[0004]
[Problems to be solved by the invention]
The conventional eddy current type speed reducer causes a malfunction due to a foreign object getting stuck in the magnet movable part or a failure of the actuator operating fluid path, and the braking state is maintained even if the brake release command is output from the control device. In some cases. Further, even when the fixed portion and the rotor rub against each other due to abnormal eccentricity of the rotor, failure or abnormality of the device cannot be detected. In the case of such a failure, it is necessary to repair or replace the eddy current speed reducer immediately.
[0005]
An object of the present invention is to provide an eddy current type speed reducer capable of easily detecting a failure or abnormal operation.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a temperature measurement value is obtained by directly measuring the temperature of the rotor with a thermometer or indirectly measuring the temperature of the rotor with a thermometer provided in a non-rotating portion near the rotor. Then, the temperature measurement value is compared with a preset value, and a failure of the eddy current type speed reducer is determined based on the comparison result.
[0007]
That is, the eddy current type speed reducer according to the present invention includes at least a braking unit that applies and releases a braking force to a rotating shaft; a first temperature sensor that detects a temperature of the braking unit or a vicinity thereof; A determining unit that determines whether there is a failure in the device based on an output of the first temperature sensor.
[0008]
The present invention is based on the following principle and phenomenon.
[0009]
In an eddy current type reduction gear, when a magnetic force exerted by a magnet during braking acts on the rotor surface, an eddy current is generated in the rotor and Joule heat is generated. Due to this heat generation, the temperature of the rotor during braking rises and becomes higher than the ambient temperature. Conversely, during non-braking, the temperature of the rotor drops until there is no difference from the ambient temperature. Here, when the rotor and the fixed portion rub against each other due to abnormal eccentricity of the rotor, frictional heat is generated and the temperature of the rotor and the fixed portion increases even during the braking release instruction. Therefore, if the eddy current type speed reduction device is normal, the device is brought into a non-braking state by the braking release command, and the rotor temperature does not rise. If the rotor temperature rises during the braking release command, it can be determined that the eddy current type speed reducer has a malfunction such as malfunctioning while the brake state is being entered or a friction between the rotor and the fixed portion.
[0010]
On the other hand, if the eddy current type speed reduction device is normal, the device is brought into a braking state by the braking command, and the rotor temperature becomes higher than the ambient temperature. If the rotor temperature does not become higher than the ambient temperature during the braking command, it can be determined that the operation is defective in a non-braking state where the vehicle does not enter the braking state.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
[0012]
With respect to the eddy current type reduction gear transmission according to the present invention, a failure detection function during a braking release command (during vehicle running) (first to fourth embodiments) and a failure detection function during a braking command (during vehicle braking) (fifth embodiment) To the eighth embodiment).
[0013]
First Embodiment FIG. 1 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a first embodiment of the present invention. FIG. 2 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the first embodiment. FIG. 3 is a graph showing changes in the temperature of the rotor and the vicinity of the rotor of a general eddy current type reduction gear transmission.
[0014]
The failure detection unit according to the present embodiment includes a first temperature sensor 12 for detecting the temperature of the rotor or its vicinity of the braking unit 10 including the rotor; a controller 14; a temperature ΔT and a reference temperature ΔTc given by the controller. And a warning device 16 for giving a predetermined warning such as the flashing of a fluorescent lamp. The controller 14 supplies a braking command or a braking command release command to the braking unit 10. The braking unit 10 starts or stops the braking operation based on a command signal from the controller 14.
[0015]
The first temperature sensor 12 always or directly measures the rotor temperature T directly or indirectly. The controller 14 stores the temperature measurement value T ₀ at the time of switching from the braking command to the braking release command, and calculates the difference between the rotor temperature measurement value T during the braking release command and the temperature measurement value T ₀ at the time of switching as the temperature rise value. ΔT (ΔT = T−T ₀ ) is obtained. The comparator 18 compares the temperature rise value ΔT given from the controller 14 with a preset upper limit value ΔTc, and transmits the comparison result to the controller 14. In the controller 14, when it becomes a [Delta] T ≧ [Delta] T _c, it is determined that the failure of the eddy current type reduction gear, for transmitting a failure signal to the warning device 16. The warning device 16 outputs a warning of abnormality to a driver of the vehicle or a control device of the vehicle. Thus, it is possible to detect a failure of the speed reduction device during a braking release command of the speed reduction device (while the vehicle is running).
[0016]
The method of measuring the rotor temperature includes a method of directly measuring the temperature and a method of measuring the temperature indirectly. Direct temperature measurement methods include attaching a contact thermometer such as a thermocouple, resistance temperature detector or thermistor directly to the rotor, or measuring the rotor temperature with a non-contact thermometer such as a radiation thermometer. . In the method of indirectly measuring the temperature, a contact thermometer such as a thermocouple, a resistance thermometer, or a thermistor is attached to a fixed portion near the rotor, and the ambient temperature near the rotor is measured. Since there is a correlation between the actual rotor temperature and the nearby ambient temperature, the measured temperature value of the ambient temperature near the rotor can be used as the measured temperature value for failure detection instead of the actual rotor temperature.
[0017]
The value of ΔT _c is set to an optimum value in consideration of the method of measuring the rotor temperature and its position, and the operation response of the eddy current type speed reducer.
[0018]
In the measurement of the data (actual measurement results) shown in FIG. 3, the rotor temperature was measured by embedding a thermocouple directly in the heat generating portion of the rotor. The temperature of the fixed portion (near the rotor) was measured by attaching a thermocouple to the fixed portion side facing the rotor heat-generating portion so as not to contact the rotor. As shown, the braking command causes the device to be in a braking state, and the rotor temperature increases. If the eddy current type speed reducer has not failed, the rotor temperature will decrease by the braking release command, but if the actual braking cannot be released even during the braking release command due to the failure, the rotor temperature will decrease as shown by the broken line in the figure. To rise.
[0019]
When the rotor is measured directly, as in the results of this experiment, the rotor temperature drops immediately after the braking release command.However, when the rotor temperature is measured indirectly by a thermometer attached to the fixed part, the rotor release normal even when releasing the braking, because the temperature measuring values of the thermometer to temporarily increase, it is necessary to set the upper limit value [Delta] T _c in consideration of the temporary increase amount. According to the results of this experiment, the temporary increase amount when braking was normally released was 4.2 ° C., so it is necessary to set the upper limit of the temperature increase to 4.2 ° C. or more. Even if the same eddy current type reduction gear is used, the temporary temperature rise value after braking when the rotor temperature is indirectly measured is the rotor speed, the rotor temperature when braking is released, and the temperature when braking is released. It depends on the temperature of the thermometer, the ambient temperature, etc. Therefore, by changing the test conditions, the most temperature considering rise value at the time of rise, the value of [Delta] T _c is required to be higher.
[0020]
Second Embodiment FIG. 4 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a second embodiment of the present invention. FIG. 5 is a graph showing a change in the temperature of the rotor and the vicinity of the rotor of a general eddy current type reduction gear, showing a case where the vehicle is suddenly stopped. FIG. 6 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the second embodiment. In the description of the present embodiment, components that are the same as or correspond to those of the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.
[0021]
This embodiment is obtained by adding control based on the vehicle speed to the apparatus of the first embodiment. As a specific configuration, a vehicle speed sensor 22 and a comparator 24 are added. A vehicle speed V of a vehicle equipped with the eddy current type reduction gear according to the present embodiment is detected by a vehicle speed sensor 22. When the detected vehicle speed V is equal to or higher than the preset value Vc in the comparator 24, it functions similarly to the first embodiment. If the vehicle speed is lower than the value Vc, the failure is not considered even if the temperature rise value ΔT is equal to or higher than ΔTc. That is, the controller 14 does not output an alarm signal to the alarm device.
[0022]
FIG. 5 shows an actual measurement result when the rotation of the rotor is suddenly stopped in a state where the rotor temperature is high (corresponding to a state where the vehicle is suddenly stopped), and the state is switched from the braking state to the non-braking state. If the rotor suddenly stops rotating at a high temperature, the temperature of the rotor itself gradually decreases, but the thermometer attached to the fixed part (near the rotor) measures the heat from the rotor even during non-braking. The temperature rises. Therefore, when the vehicle speed is low (especially when the vehicle is stopped), the temperature measurement value (in the vicinity of the rotor) may increase significantly during the braking release command even though there is no failure. Therefore, if the vehicle speed is lower than a certain value Vc, a failure alarm is not issued even if the temperature rise value ΔT is equal to or higher than ΔTc.
[0023]
Third Embodiment FIG. 7 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a third embodiment of the present invention. FIG. 8 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the third embodiment. In the description of the present embodiment, the same reference numerals are given to the same or corresponding components as those of the above-described embodiments, and duplicate description will be omitted.
[0024]
The device according to the present embodiment is different from the first embodiment in that control based on the vehicle speed is added so that the upper limit value ΔTc varies according to the vehicle speed. As a specific configuration, a vehicle speed sensor 22 is added. The relationship between the vehicle speed V and the upper limit value ΔTc is stored in the controller 29 in advance, and the upper limit value ΔTc according to the vehicle speed V at that time is selected. Then, the comparator 18 compares the selected ΔTc and ΔT to determine a failure. This makes it possible to detect a failure more accurately than in the first embodiment or the second embodiment.
[0025]
Fourth Embodiment FIG. 9 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a fourth embodiment of the present invention. FIG. 10 is a flowchart showing a procedure for detecting a failure of the eddy current type reduction gear transmission according to the fourth embodiment. In the description of the present embodiment, the same reference numerals are given to the same or corresponding components as those of the above-described embodiments, and duplicate description will be omitted.
[0026]
The fourth embodiment is configured by combining the second embodiment and the third embodiment. That is, controller 34 adopts a different value as upper limit value ΔTc according to vehicle speed V. Further, if the vehicle speed V is lower than a certain value Vc, no failure alarm is issued.
[0027]
Fifth embodiment FIG. 11 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a fifth embodiment of the present invention. FIG. 12 is a flowchart showing a procedure for detecting a failure of the eddy current type reduction gear according to the fifth embodiment. In the description of the present embodiment, the same reference numerals are given to the same or corresponding components as those of the above-described embodiments, and duplicate description will be omitted.
[0028]
In the present embodiment, the first temperature sensor 12a constantly or directly measures the rotor temperature, and the second temperature sensor 12b measures the ambient temperature of a portion that is not affected by the heat generated by the rotor. The output of the first temperature sensor 12a is input to the comparator 48 via the controller 44 or directly. The output of the second temperature sensor 12b is input to the controller 44. The controller 44 calculates a reference value Tc (= Ta + α) based on the ambient temperature Ta detected by the second temperature sensor 12b.
[0029]
Generally, depending on the measurement position of the ambient temperature and the method and position of the rotor temperature, the ambient temperature and the rotor temperature do not always have the same value even in the non-braking state, so the correction amount α is employed. The optimum value is selected in consideration of these.
[0030]
The comparator 48 compares the rotor temperature T with the reference value Tc, and returns the result to the controller 44. When T ≦ Tc, the controller 44 determines that it is a failure of the eddy current type speed reducer, and transmits a warning signal to the warning device 16. The warning device 16 outputs a warning of an abnormality to a driver's seat or a control device of a vehicle. This makes it possible to detect a failure when an operation failure occurs in a non-braking state despite a braking command.
[0031]
Immediately after switching from the non-braking state (during running) to the braking state, the temperature measurement value T does not exceed Ta + α, so that the failure determination is performed after a lapse of the set time ts after the switching of the braking. As a specific configuration, a braking command signal output from the controller 44 is transmitted to the timer 46 in addition to the braking unit 10. The timer 46 measures the time from when the braking command signal is input, and outputs a predetermined signal to the controller 44 after a predetermined time ts has elapsed. If the set time ts has not been reached after the output of the braking command signal, no failure is determined even if T ≦ Tc.
[0032]
Sixth Embodiment FIG. 13 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a sixth embodiment of the present invention. FIG. 14 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the sixth embodiment. In the description of the present embodiment, the same reference numerals are given to the same or corresponding components as those of the above-described embodiments, and duplicate description will be omitted.
[0033]
In the present embodiment, control based on the vehicle speed V is performed in the failure detection during braking, as in the second embodiment. As a specific configuration, a vehicle speed sensor 22 and a comparator 24 are added. A vehicle speed V of a vehicle equipped with the eddy current type reduction gear according to the present embodiment is detected by a vehicle speed sensor 22. When the detected vehicle speed V is equal to or higher than the preset value Vc in the comparator 24, the comparator 24 functions in the same manner as in the fifth embodiment. If the vehicle speed is lower than the value Vc, the failure is not considered even if the temperature rise value ΔT is equal to or higher than ΔTc. That is, the controller 54 does not output an alarm signal to the alarm device.
[0034]
Generally, when the vehicle speed V is low, the temperature of the rotor itself hardly rises even if the device is normally braked by a braking command. Taking the case where the rotation of the rotor is stopped as an example, the rotor does not rotate, so that no eddy current is generated in the rotor and the rotor does not generate heat. For this reason, the value of the thermometer also takes the same value as the ambient temperature. Therefore, when the vehicle speed is low, the temperature measurement value does not greatly differ from the ambient temperature even during the braking command even though there is no failure. Therefore, if the vehicle speed is lower than a certain value Vc, no failure alarm is issued even if the temperature measurement value satisfies T ≦ Tc.
[0035]
Seventh Embodiment FIG. 15 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a seventh embodiment of the present invention. FIG. 16 is a flowchart showing a procedure for detecting a failure of the eddy current type reduction gear according to the seventh embodiment. In the description of the present embodiment, the same reference numerals are given to the same or corresponding components as those of the above-described embodiments, and duplicate description will be omitted.
[0036]
In the present embodiment, control is performed based on the vehicle speed V in detecting a failure during braking, as in the third embodiment. That is, the correction amount α takes a different value according to the vehicle speed V. As a specific configuration, a vehicle speed sensor 22 is added. The relationship between the vehicle speed V and the correction amount α is stored in the controller 64 in advance, and the correction amount α according to the vehicle speed V at that time is selected. This makes it possible to detect a failure more accurately than in the fifth and sixth embodiments.
[0037]
Eighth Embodiment FIG. 17 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to an eighth embodiment of the present invention. FIG. 18 is a flowchart showing a procedure for detecting a failure of the eddy current type reduction gear according to the eighth embodiment. In the description of the present embodiment, the same reference numerals are given to the same or corresponding components as those of the above-described embodiments, and duplicate description will be omitted.
[0038]
The eighth embodiment is configured by combining the sixth embodiment and the seventh embodiment. That is, the controller 74 adopts a different value as the correction amount α according to the vehicle speed V. Further, if the vehicle speed V is lower than a certain value Vc, no failure alarm is issued.
[0039]
The embodiments (embodiments, embodiments) of the present invention have been described above. However, the present invention is not limited to these embodiments, and changes may be made within the scope of the technical idea described in the appended claims. It is possible.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a first embodiment of the present invention.
FIG. 2 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the first embodiment.
FIG. 3 is a graph showing a change in the temperature of the rotor and the vicinity of the rotor in a general eddy current type speed reducer.
FIG. 4 is a block diagram illustrating a configuration of a failure detection unit of an eddy current type reduction gear according to a second embodiment of the present invention.
FIG. 5 is a graph showing a change in the temperature of the rotor and the vicinity of the rotor of a general eddy current type speed reducer, showing a case where the vehicle is suddenly stopped.
FIG. 6 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the second embodiment.
FIG. 7 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a third embodiment of the present invention.
FIG. 8 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the third embodiment.
FIG. 9 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a fourth embodiment of the present invention.
FIG. 10 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the fourth embodiment.
FIG. 11 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear according to a fifth embodiment of the present invention.
FIG. 12 is a flowchart illustrating a fault detection procedure of the eddy current type reduction gear according to the fifth embodiment.
FIG. 13 is a block diagram illustrating a configuration of a failure detection unit of an eddy current type reduction gear according to a sixth embodiment of the present invention.
FIG. 14 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the sixth embodiment.
FIG. 15 is a block diagram showing a configuration of a failure detection unit of the eddy current type reduction gear transmission according to Embodiment 7 of the present invention.
FIG. 16 is a flowchart illustrating a fault detection procedure of the eddy current type reduction gear according to the seventh embodiment.
FIG. 17 is a block diagram showing a configuration of a failure detection unit of an eddy current type reduction gear transmission according to an eighth embodiment of the present invention.
FIG. 18 is a flowchart illustrating a failure detection procedure of the eddy current type reduction gear according to the eighth embodiment.
[Explanation of symbols]
10 Braking unit (rotor)
12 First temperature sensor 14 Controller 16 Warning device 18 Comparator

Claims (11)

In the eddy current type reduction gear,
A braking unit that applies and releases a braking force to the rotating shaft;
A first temperature sensor for detecting the temperature of the braking unit or the vicinity thereof;
An eddy current type speed reducer, comprising: a determination unit configured to determine the presence or absence of a device failure based on an output of the first temperature sensor. The eddy current type reduction gear according to claim 1, further comprising a warning unit that issues a predetermined warning when a failure of the device is found as a result of the determination by the determination unit. 3. The device according to claim 1, wherein the determination unit determines whether the device has a failure using a predetermined reference value and a temperature detected by the first temperature sensor. 4. Eddy current type reduction gear. The eddy current type reduction gear according to claim 1, 2, or 3, wherein the reference value is determined based on a detection condition of the first temperature sensor and a braking condition of the braking unit. The determination unit determines a difference ΔT (T−T0) between a temperature T0 at the time of a brake release command and a detection value T of the first temperature sensor during a brake release command (during a non-braking operation) in advance. 5. The eddy current type reduction gear according to claim 1, wherein a failure is determined when the temperature difference becomes equal to or larger than ΔTc. A vehicle speed sensor for detecting a speed V of a vehicle on which the eddy current type reduction gear is mounted;
The first temperature sensor is configured to detect a temperature near the braking unit,
The eddy current type reduction gear device according to claim 5, wherein the determination unit determines that the vehicle has failed only when the vehicle speed V detected by the vehicle speed sensor is equal to or higher than a predetermined vehicle speed Vc. A vehicle speed sensor for detecting a speed V of a vehicle on which the eddy current type reduction gear is mounted;
7. The eddy current type reduction gear according to claim 5, wherein the specified temperature difference ΔTc is set according to a vehicle speed V detected by the vehicle speed sensor. A second temperature sensor that detects a temperature Ta of a portion that is not substantially affected by heat generated by the braking unit;
The determination unit may determine whether a difference (T−Ta) between the detection value T of the first temperature sensor and the detection value Ta of the second temperature sensor during braking is equal to or less than a predetermined reference value α. 5. The eddy current type speed reducer according to claim 1, wherein a failure is determined. It further comprises a timer that detects the time since the braking command was input,
The eddy current type reduction gear transmission according to claim 8, wherein the determination unit performs a failure determination after a predetermined time has elapsed from the braking command based on an output of the timer. A vehicle speed sensor for detecting a speed V of a vehicle on which the eddy current type reduction gear is mounted;
The first temperature sensor is configured to detect a temperature near the braking unit,
10. The eddy current type deceleration according to claim 8, wherein the determination unit determines that a failure has occurred only when the vehicle speed V detected by the vehicle speed sensor is equal to or higher than a predetermined vehicle speed Vc. apparatus. A vehicle speed sensor for detecting a speed V of a vehicle on which the eddy current type reduction gear is mounted;
The eddy current type reduction gear according to claim 8, 9 or 10, wherein the reference value α is set according to a vehicle speed V detected by the vehicle speed sensor.

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