JPH03239200A - Electromagnetic damping device - Google Patents

Abstract

PURPOSE:To control a current of a solenoid by inputting a rotor temperature as an object to be controlled and to suppress heat detriment to a periphery, deformation of a rotor by inputting presumed using limit temperature data of a drum corresponding to variation in traveling conditions such as a descent road, etc., to control means, and automatically controlling a conducting period of the solenoid. CONSTITUTION:When speed data D1 and temperature data D2 corresponding to traveling condition of a descent road, etc., loading conditions of a vehicle are input to control means 18, switching data D4 is output from the means 18. Conducting periods of currents flowing to a plurality of solenoids 12 are controlled by switching means 14 based on the data D4. Thus, electric circuits regarding the plurality of solenoids 12 are not individually opened, but all the circuits are held closed, and a damping torque can be controlled within a range that the presumed using temperature of a rotor 13 formed of a rotating conductor does not reach its using limit temperature.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Prior art (Figure 7) Means for solving the problems to be solved by the invention (Figure 1) Working examples (Figure 2) ~Figure 6) Effects of the invention [Summary] An electromagnetic braking device rotates a rotor made of a conductor in a magnetic field, converts rotational energy into heat by eddy current flowing through the rotor, and generates braking torque. Regarding the control function of the braking device designed to dissipate this heat, the current control of the electromagnetic coil is controlled by incorporating the temperature of the Rogue into the control target without increasing or decreasing the number of electromagnetic coils that drive the electromagnetic coil. The purpose is to suppress heat damage and deformation of the rollers as much as possible by rotating a rotor made of a conductor in a magnetic field and converting rotational energy into heat using eddy currents flowing through the rotor to generate braking torque. In an electromagnetic braking device, a rotor comprising a plurality of electromagnetic coils provided on a fixed part side of a power supply means, a conductor provided on a rotating shaft side of the power supply means, and a switching device connected to the electromagnetic coils. a speed detector that detects the rotational speed of the rotating shaft of the power supply means and outputs speed data; and a first temperature detector that detects the temperature of the electromagnetic coil and outputs first temperature data. a second temperature detector mounted close to the rotor to detect the ambient temperature of the rotor and output second temperature data; and a storage means for storing a service limit temperature data table of the rotor. ,
The switching means, the speed detector, the first. a second temperature detector and a control means for controlling input/output of the storage means, and the control means includes at least the first speed data. The method includes estimating a service limit temperature of the rotor based on the ambient temperature based on the second temperature data, and outputting switching data to the switching means.

Field of Industrial Application) The present invention relates to an NFdl braking device, and more specifically, it rotates a rotor made of a conductor in a magnetic field, and converts rotational energy into heat using eddy currents flowing through the rotor. The present invention relates to a control function of a braking device that generates braking torque and dissipates this heat.

In recent years, due to improvements in engine performance and the expansion of expressway networks, large and medium-sized freight vehicles are increasingly being driven over long distances at high speeds. Along with this, auxiliary brakes such as electromagnetic braking devices are being used to reduce the burden on a main braking device (hereinafter referred to as main brake) that obtains braking torque through hydraulic pressure control.

According to this, usage conditions (road slope, usage time).

The rotor may reach a high temperature of 600'C or higher depending on the type of engine (e.g., engine load), which may cause heat damage to the surrounding area or deformation of the rotational roughness.

Therefore, there is a need for a braking device that takes the rotor temperature as a control target and controls the current of the electromagnetic coil to obtain smooth braking characteristics and prevent the rotor temperature from becoming high.

[Conventional technology]

FIG. 7 shows a configuration diagram of a conventional i-magnetic braking device.

In the figure, an electromagnetic braking system for large and medium-sized freight vehicles etc. is equipped with a magnetic coil (Ll-L8) installed on the fixed part side of the transmission of the engine L.
2, and a propeller shaft 3a that transmits power to the tires 6.
a rotating drum 3 provided in the coil 2; a relay circuit 4 including a plurality of relays RL l -RL 8 connected to correspond to each of the coils 2; a mode selection switch 5 selected by the driver; It consists of a main relay SW9 that changes the supply current to 0N10FF, and a foot switch 9 provided on the fund brake 7.

The function of the device is as follows: First, when the driver judges that the main brake will be overloaded due to the driving conditions, such as the road leading to the exit, or that braking using only the electromagnetic braking device is sufficient, the mode selection switch 5 is activated. Each switch 5WI-3W8 is selected.Next, by stepping on the foot brake 7, the controller 9 and the main relay Si are turned on. At this time, each relay RLI~l? of the relay circuit 4 corresponding to the mode selection 3 inches 5? L8 is ON
L, the battery power source is connected to the selected electromagnetic coil 2 to magnetize it.

As a result, the rotating drum 3 is placed in the magnetic field created by the electromagnetic coil 2.
As a result of the rotation, eddy currents flow through the rotating drum 3, generating Joule heat, generating braking torque, and applying braking force to the vehicle.

[Problem to be solved by the invention]

By the way, according to the conventional example, when handling an electromagnetic braking device in conjunction with the main brake, the driver selects each switch SWI to SGA8 of the mode selection switch 5 every time the driving conditions such as the exit road change. There is.

Depending on the driving conditions, all switches SWI to S-8 are turned on for a long period of time, resulting in the temperature of the rotor 3 reaching 600℃ (depending on the road gradient, usage conditions, load capacity, etc.). High temperatures of C1 or higher may be reached.

As shown in the temperature characteristics of Fig. 8, the braking torque Dτ
is constant, the number of selected coils n1n2. As n3 decreases, the temperature T of the rotating drum 3 tends to increase. That is, as the number of selected solenoids decreases, the magnetic field they create increases, causing eddy currents to concentrate on the rotating drum 3. As a result, the Joule heat of the drum 3 increases and the temperature rises.

This caused the first problem that the surrounding area was heated and the rotating drum 3 was deformed.

Also, from the state where all TL electromagnetic coils are ON, depending on the change in driving conditions, operate the mode selection 3 inch 5 to select a specific electromagnetic coil, reduce the braking torque, and then turn on all the electromagnetic coils again and start braking. Increase torque. By repeating such a state, a certain 1! A second problem was that the magnetic coil overheated.

The present invention was created in view of the problems of the conventional example, and incorporates the rotor temperature into the control target without increasing or decreasing the number of electromagnetic coils to be driven.
The object of the present invention is to provide an electromagnetic braking device that makes it possible to control the `wL flow of the coil and to suppress heat damage to the surrounding area and deformation of the rotor as much as possible.

[Means to solve the problem]

FIG. 1 shows a principle diagram of an electromagnetic braking device according to the present invention.

The device consists of a rotor 1 consisting of conductors in a magnetic field.
In a magnetic braking device, a plurality of magnets 1 are provided on the fixed part side 11A of the power supply means 11. A rotor 13 composed of a coil 12, a conductor provided on the rotating shaft side 11B of the power supply means 11, a switching means 14 connected to the magnetic coil 12, and a rotor 13 that is connected to the rotor 13 on the rotating shaft side 11B of the power supply means 11. a speed detection "Jits" that detects the rotational speed of the side 11B and outputs speed data Di; a first temperature detector 16 that detects the temperature of the electromagnetic coil 12 and outputs first temperature data D2; a second temperature detector 20 that is installed close to the rotor 13 and detects the ambient temperature of the rotor 13 and outputs second temperature data D5;
ViI rotor 13 service limit temperature data table D
3, and the switching means 1
4 speed detector 15. 1st. a second temperature detector 1620 and a control means 18 for controlling input and output of the storage means 17;
, 1st. Second temperature data D2. According to the present invention, at least the speed data Based on the Di temperature data D2, the use limit temperature data table D
3, by estimating the operating limit temperature D6 of the rotor 13 based on the ambient temperature and comparing the operating limit temperature D6 with the second temperature data D5, the true operating temperature of the rotor 13 described in I; A switching circuit D is connected to the switching means 14 so that the voltage does not rise to a limit value.
Control means 18 for outputting 4 is provided.

For example, when speed data D1 and temperature data]]2 corresponding to running conditions such as the exit road, loading conditions of the vehicle, etc. are input to the control means 18, the switching circuit data D4 is input from the control means 18 to the switching means 14. is output. Based on this data O4, the switching means 14
The energization period of the current flowing through the plurality of electric 6n coils 12 is controlled.

For this reason, the electric circuits related to the plurality of electromagnetic coils 12 are not individually opened in the open circuit state as in the conventional example, but all the circuits are kept in the closed circuit state, and the rotor 1 composed of rotating conductors
The braking torque can be controlled steplessly within a range in which the estimated operating temperature of No. 3 does not reach its operating limit temperature.

From this point on, the individual energization loads of the electromagnetic coils 12 are equalized, and the influence of temperature on peripheral devices is suppressed as much as possible.
And it becomes possible to maintain the predetermined shape of the rotor 13.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

2 to 4 are diagrams for explaining an electromagnetic braking device according to an embodiment of the present invention, and FIG. 2 shows a configuration diagram thereof.

In the figure, 2I is an engine which is an example of a power supply means, and supplies power to drive tires 29 of a wide-swath truck or the like.

A solenoid 22 is an example of the electromagnetic coil 12, and is provided on the fixed part side 21A of the engine 21, for example, in the rear stage of the transmission. In the embodiment of the present invention, the electromagnetic coil 22 has eight solenoids (ILI to L8) arranged at 45 degrees.
It is placed in place.

23 is a rotating drum which is an embodiment of the rotor 13 made of a conductor, and the power of the engine 21 is transferred to the driving tires 2.
9 is attached to the propeller shaft 21B. In addition, the rotating drum 23 has a propeller shaft 21B.
It has a cylindrical shape with the central axis as the electromagnetic coil 22.
It is in a state of being covered. As a result, both 22
．． 23 constitutes a magnetic circuit through a gap.

Reference numeral 24 denotes a switching circuit which is an embodiment of the switching means 14, and is composed of switching transistors T1 to T8 connected to each of the solenoids Ll to L8. Field effect transistors are used as the transistors T1 to T8.

A speed sensor 25 is an embodiment of the speed detector 15, and detects the number of revolutions of the propeller shaft 21B to output speed data Dn of the vehicle.

Reference numeral 26 denotes a thermistor which is an example of the 10th) temperature detector I6, and is used to measure the operating temperature of the coil portion 22B of the electromagnetic coil 22, as shown in the broken line circle in the figure.

A thermistor 30 is an embodiment of the second temperature detector 2o, and is used to measure the temperature of the rotating drum 23. The thermistor 3o is a core part 22A of the electromagnetic coil 22.
It is thermally insulated and is provided closest to the drum 23.

Reference numerals 27a and 27b are memory circuits which are an embodiment of the storage means 17, and include a ROM (memory for continuous processing) that stores a program for a processing unit (hereinafter referred to as CPU) and an RAu (memory for continuous processing) that temporarily stores other control data. FfJ write/readable memory), etc. are shown respectively. In the embodiment of the present invention, the ROM 27a stores the operating limit temperature Tc based on the ambient temperature of the rfiI control means 28 and the TL Yuko coil 22, which is an example of the operating limit temperature data table D3.
The relationship characteristics with the operating temperature of the coil portion 22B are stored. The characteristics will be explained in detail in FIG.

2 is a CPU serving as an embodiment of the control means, and the temperature data Dt5, the temperature data Dt2, the speed data Dn, the service limit temperature data table D3. Other data destinations, such as brake data Db, tarasochi data Dc, and accelerator data Da, are input to the switching circuit 24G to output a driving nozzle P. As an example of the control content, if the vehicle speed of the i5 vehicle becomes low, it will be activated. IJI gi b! ? Cancel 3m. Also,
These conditional solutions Vr forcefully restart the process.

Reference numeral 29 indicates a drive tire of the vehicle, which is an example of the drive shaft 19, and is %11 of the electromagnetic braking device. It is targeted for X1. Depending on the driving conditions of the vehicle, the hydraulic pressure 111n
When the force, force, or force exerted on the main brake by the magnetic braking device is insufficient, or when braking by only the 1i magnetic braking device is sufficient, the braking force is applied to the drive tire 29 in combination or alone. Given.

FIG. 3 shows a temperature characteristic diagram illustrating the δ8 memory contents of the ROM according to the embodiment of the present invention.

In the figure, the vertical axis is the atmospheric temperature (acceptable limit temperature TC), and the horizontal axis is the coil portion 22B of the electromagnetic coil 22.
is the temperature TL. Nl, N2. N3... is the number of drum rotations, and there is a relationship of Nl<N2<N3.... The characteristic is a model temperature characteristic stored in advance as a control target for the braking device. For example, CPU
2B is the operating temperature limit data table D of the rotating drum 23
3, when referring to the electromagnetic coil 2 from the ROM 27a.
2, the speed data Dn is obtained from the operating temperature Dt2, and by interpolating this interval by Dn, Dn and Dt2
The operating limit temperature D6 corresponding to the above is determined.

FIG. 4 shows a control characteristic diagram illustrating the operation of the CPU according to the embodiment of the present invention.

In the figure, the vertical axis is drum temperature T and duty ratio t1/
(l+t2)×100, and the horizontal axis indicates time t. Further, MT is the true limit temperature for use.

DT is the true drum temperature characteristic.

The CPU 28 controls the duty ratio of the drive pulse P within the range of the use limit temperature MT, following the analogized use limit temperature D6 of the drum. Note that the duty ratio control will be explained in detail in FIG. 5.

These constitute the NN braking device according to the embodiment of the present invention.

Next, the operation of the device will be explained.

FIG. 5 shows an operation time chart of the electromagnetic braking device according to the embodiment of the present invention.

In the figure, the CPU 28 first recognizes the driving conditions of the vehicle from the rotational speed of the propeller shaft, the state of the brake, the engagement state of the clutch, and the state of the accelerator, and outputs a drive pulse P to the switching circuit 24. At this time, for example, assuming that one cycle of the drive pulse P is approximately 100100, the duty ratio tl/(tl+t2) between the ON period t1 and the OFF period t2 is controlled B.

In addition, the duty ratio t 1/(t l + t2) is the number of rotations of the drum Nl, N2 . N3..., drum atmosphere temperature data Dt5, and tMi coil operating temperature data Dt
2 and the drum's use limit temperature D6, which is analogized. That is, when DL5 is lower than D6, the CPU increases the duty ratio L1/(LI+t2) of the drive pulse P so as to enhance the effect of the electromagnetic braking device, and turns the pulse P ON! 11Lengthen the interval. When the drum temperature becomes high, the duty ratio L1/(t1+L2) of the drive pulse P is conversely reduced and the OFF period of the pulse P is lengthened so as to weaken the effect.

Next, a drive pulse P with a duty ratio t 1 /(t 1 +t2) is applied to the gates of the switching transistors Tl to T8. As a result, each solenoid 1 to L8
The coil current 11-18 flowing in the duty ratio tl/(
The energization period is controlled based on tl+t2). At this time, as a result of the drum 23 being rotated in the magnetic field created by the electromagnetic coil 22, an eddy current flows through the drum 23, generating Joule heat therein, generating braking torque, and applying braking force to the vehicle. act.

FIG. 6 shows a characteristic diagram of the 'g1 magnetic braking device according to the embodiment of the present invention.

In the figure, the vertical axis represents the braking torque Dτ, and the horizontal axis represents the duty ratio. According to this, the conventional TLN
Compared to the control method of increasing or decreasing the number of coils, the method of controlling the duty ratio of the present invention allows the braking torque Dτ to change steplessly in a linear function.

In this way, according to the embodiment of the present invention, the operating limit temperature D6 of the rotary drum 23 is estimated based on at least the speed data Dn, the temperature data Dt2 and Dt5, and the operating limit temperature data D3, and the operating limit temperature D6 of the rotating drum 23 is A CPU 28 that outputs a drive pulse P is provided.

Therefore, when the speed data Dn, temperature data Dt, and operating temperature limit data table D3 corresponding to the driving conditions of the drop-off road, etc., the loading conditions of the vehicle, etc. are manually input to the CPU 2B, tlcP (switching from J28 to the switching time IPI24) is performed. A drive pulse P serving as data D4 is output.Based on this drive pulse P, the switching circuit 24 controls the energization period of the current flowing through the eight solenoids 1 to L8.

Therefore, the electric circuits related to the eight solenoids 1 to L8 are not individually opened as in the conventional example, but all circuits are kept in a closed circuit state. The braking torque can be controlled steplessly within a range that does not reach the temperature MT.

This equalizes the energization load on each of the electromagnetic coils 22, and prevents the temperature of a particular coil from rising abnormally. Therefore, since the temperature distribution becomes uniform, it is possible to suppress the influence of temperature on peripheral equipment as much as possible, and to
It becomes possible to maintain the predetermined shape of No. 3.

[Efficacy of invention]

As explained above, according to the present invention, the energization period of the electromagnetic coil can be automatically controlled by inputting the estimated operating limit temperature data of the drum corresponding to changes in the running conditions such as the exit road to the control means. can.

For this reason, within the operating temperature limit of the drum, braking torque is continuously applied by switching transistors while keeping all circuits closed, instead of individually opening the electrical circuits associated with multiple solenoids as in conventional systems. can be controlled.

Furthermore, according to the present invention, the energization burden on each solenoid is equalized, making it possible to maintain the operating temperature of the solenoid at a low state.

Further, since the drum temperature does not become excessive, there is no need to redundantly increase the heat capacity (heavy IT) in order to withstand severe usage conditions. Furthermore, it is possible to extract maximum braking torque within the drum operating temperature limits. Additionally, an inexpensive method for measuring drum temperature can be provided.

[Brief explanation of drawings]

FIG. 1 is a principle diagram of an electromagnetic braking device according to the present invention, FIG. 2 is a configuration diagram of an electromagnetic braking device according to an embodiment of the present invention, and FIG. 3 is a ROM storage according to an embodiment of the present invention. 4 is a control characteristic diagram illustrating the operation of the CPU according to the embodiment of the present invention; FIG. 5 is an operation time chart of the electromagnetic braking device according to the embodiment of the present invention; FIG. 6 is a braking torque characteristic diagram of an electromagnetic braking device according to an embodiment of the present invention, and FIG. 7 is a configuration diagram of a conventional t-magnetic braking device. (Explanation of symbols) 11...Power supply means, 12...Rotor 13 composed of a conductor...? 14...Switching means, I5...Speed detector, 16...First temperature detector, 17...Storage means, 18...Control means, DI...Speed data , D2...First temperature data, D3...Usable temperature limit data table, D4...Switching data, D5...Second temperature data, D6...Usable limit temperature, 11A... Fixed part side, 11B...Rotating shaft side.

Claims (1)

[Claims] In an electromagnetic braking device that rotates a rotor (13) made of a conductor in a magnetic field and converts rotational energy into heat using eddy currents flowing through the rotor (13) to generate braking torque. , a plurality of electromagnetic coils (12) provided on the fixed part side (11A) of the power supply means (11), and the power supply means (11).
1), a rotor (13) composed of a conductor provided on the rotating shaft side (11B), a switching means (14) connected to the electromagnetic coil (12), and a rotation of the power supply means (11). a speed detector (15) that detects the rotational speed of the shaft side (11B) and outputs speed data (D1);
a first temperature detector (16) that detects the temperature of the electromagnetic coil (12) and outputs first temperature data (D2);
a second temperature detector (20) installed close to the rotor (13) to detect the ambient temperature of the rotor (13) and output second temperature data (D5); and the rotor (13). Usage limit temperature data table (D3
), and controls the input/output of the switching means (14), the speed detector (15), the first and second temperature detectors (16, 20), and the storage means (17). a control means (18) for controlling the control means (18);
8) at least the speed data (D1), the first,
Based on the second temperature data (D2, D5), the operating limit temperature (D6) of the rotor (13) according to the ambient temperature is determined.
An electromagnetic braking device characterized in that it estimates and outputs switching data (D4) to the switching means (14).