JPH08113134A - Braking force control device of eddy current type reduction gear - Google Patents

Abstract

PURPOSE: To prevent the locking of rear wheels by increasing and decreasing the operating amount of a magnet holding circle to the inside of a braking drum according to the empty-loading condition. CONSTITUTION: A guide tube 29 is provided inside a braking drum 27 which rotates together with the output shaft 5 of a transmission 10. To the peripheral wall of the guide tube 29 opposing to the braking drum 27, numerous ferromagnetic plates 28 are combined at the same intervals in the peripheral direction. A magnet holding circle 24 furnishing magnets 25 opposing to the ferromagnetic plates 28 on the peripheral wall is held to the guide tube 29 movable in the axial direction step by step. The loading amount of a vehicle is found from the signal of an empty-loading sensor 9 to detect the empty-loading condition of the vehicle, an optimum braking force is found from the loading amount of the vehicle, an object operating amount of magnet holding circle 24 corresponding to the optimum braking force is found from the control map of an electron control device 12 corresponding to the running condition such as the car speed, and a servomotor 23 to drive the magnet holding circle 24 is controlled by the electron control device 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current type speed reducer for a vehicle, and more particularly to a braking force control device for an eddy current type speed reducer capable of adjusting a braking force according to running conditions.

[0002]

2. Description of the Related Art In an eddy current type speed reducer using a permanent magnet (hereinafter, simply referred to as a magnet), a magnet support ring provided with a large number of magnets at equal intervals in a circumferential direction is connected to, for example, an output shaft of a transmission. It is configured so that it can project and retract inside the braking drum. If the driver closes the retarder switch and releases the accelerator pedal even when the clutch pedal is released, the pneumatic actuator will cause the magnet support ring to project into the braking drum, and a braking force based on eddy current will be generated in the braking drum. It is about to do. However, the braking force of the eddy current type speed reducer is significantly different depending on the loaded state and the empty state of the vehicle, and the eddy current type speed reducer is used while traveling downhill in the empty state where the rear wheel load of the vehicle is small. Braking may cause rear wheels to lock, causing the vehicle to spin.

[0003]

SUMMARY OF THE INVENTION In view of the above problems, the object of the present invention is to prevent the locking of the rear wheels by adjusting the amount of movement of the magnet support ring inside the braking drum depending on the empty / loaded state. An object of the present invention is to provide a braking force control device for such an eddy current type speed reducer.

[0004]

In order to achieve the above object, the structure of the present invention has a guide cylinder disposed inside a braking drum that rotates together with a drive shaft, and a peripheral wall of the guide cylinder facing the braking drum. A large number of ferromagnetic plates are connected at equal intervals in the circumferential direction, and a magnet support ring with magnets facing each ferromagnetic plate on the peripheral wall is supported by a guide tube so that the magnet support ring can move axially in stages.・ Determine the loading capacity of the vehicle from the signal of the empty / loading sensor that detects the loading status, find the optimum braking force from the loading capacity of the vehicle, and set the target operation amount of the magnet support ring that corresponds to the optimum braking force. It is obtained from a control map of an electronic control unit corresponding to traveling conditions such as vehicle speed, and the actuator for driving the magnet support ring is controlled by the electronic control unit.

[0005]

In order to determine the empty / loaded state of the vehicle, the loading amount of the vehicle is obtained from the signal of the empty / loaded sensor for detecting the rear wheel load, and the optimum braking force is obtained from the loading amount of the vehicle. The target operation amount of the magnet support ring corresponding to the optimum braking force is obtained from the control map of the electronic control unit corresponding to the traveling condition such as the vehicle speed.

An actuator for driving the magnet support ring is drive-controlled by an electronic control unit to drive the magnet support ring to a target position and prevent locking of the rear wheels. The stroke sensor detects the amount of movement of the magnet support ring to control the actuator feedback feedback.

[0007]

1 is a side view showing a schematic structure of an eddy current type speed reducer having a braking force control device according to the present invention. The eddy current type speed reducer A includes a braking drum 27 that is connected to the output shaft 5 of the transmission 10, and a magnet support ring 24 that projects and retracts inside the braking drum 27 along a guide tube 29. The braking drum 27 has a large number of cooling fins 26 connected to its outer peripheral wall, and one end of the braking drum 27 is connected to a large number of spokes 30 extending radially from the boss portion 31 of the output shaft 5.
The stationary guide tube 29 made of a non-magnetic material is used for the braking drum 27.
A large number of openings are provided in the circumferential wall facing each other at equal intervals in the circumferential direction, and a ferromagnetic plate 28 is coupled to each opening. Magnet support ring 2
Reference numeral 4 designates a magnet 25 that is supported by a guide tube 29 so as to be movable in the axial direction and that has magnets 25 facing the ferromagnetic plates 28 on the outer peripheral wall.
The polarities with respect to 8 are coupled so as to be alternately different in the circumferential direction.

In order to drive the magnet support ring 24, a plurality of drive rods 22 extending in the axial direction of the braking drum 27 are connected to the magnet support ring 24 at equal intervals in the circumferential direction. The pinion 26 that meshes with the rack of each drive rod 22 meshes with the gear that is coupled to the main shaft of the servomotor 23 as an actuator. The electronic control unit 12 that drives and controls the magnet support ring 24 is provided in the steering cylinder 3 and a stroke sensor 21 that detects an operation amount of the magnet support ring 24, a rotation speed sensor 4 that detects the rotation speed of the output shaft 5. Manual retarder switch 2 and accelerator sensor 6 mounted on the accelerator pedal
Then, the braking condition of the eddy current type speed reducer A is judged based on the signals of the clutch sensor 7 provided on the clutch pedal and the empty / vehicle sensor 9, and a drive signal is sent to the servo motor 23.

That is, even if the driver closes the retarder switch 2 and the clutch pedal is released, when the accelerator pedal is released, the vehicle loading amount W is obtained from the signal of the empty / load sensor 9 and the loading amount of the vehicle is determined. The optimum braking force T is obtained from W. The target operation amount of the magnet support ring 24 (the operation amount of the magnet support ring 24 from the non-braking position to the braking position shown in FIG. 1) so corresponding to the optimum braking force T is defined as the vehicle speed (the rotation speed N of the output shaft 5).
It is obtained from the control map of the electronic control unit 12 corresponding to the traveling conditions such as, and the relay switch 13 is excited, and the servo motor 23 is passed from the power source battery 14 through the relay switch 13.
Energize to. The magnet support ring 2 by the stroke sensor 21.
The operation amount sa of 4 is detected, and the servo motor 23 is feedback-controlled.

The stroke sensor 21 is arranged opposite to the drive rod 22. The rotation speed sensor 4 is arranged to face the output shaft 5 of the transmission 10. The empty / loaded vehicle sensor 9 detects the displacement amount of the rear wheel suspension spring or the supporting load of the rear axle.
In the case of a vehicle equipped with an automatic transmission, the clutch sensor 7 is not necessary because there is no clutch pedal.

Generally, the braking force T of an eddy current type speed reducer is
Even if the amount of movement of the magnet support ring 24 is the same, it varies depending on running conditions such as vehicle speed, weather, and road surface conditions. Therefore, the optimum braking force T according to the loading amount W or the loading rate (the ratio of the actual loading amount to the maximum loading amount) is obtained, and the target operation amount so of the magnet support ring 24 corresponding to the braking force T is electronically controlled. It is determined from a control map suitable for running conditions such as vehicle speed, weather, and road surface condition stored in advance in the device 12. Operation amount of the magnet support ring 24 sa
And the braking force T of the eddy current type speed reducer have the characteristics shown in FIG. 2, and the braking force T required for the loading capacity W of the vehicle has the performance shown in FIG. 3 under a predetermined traveling condition. Required.
Therefore, if the loading amount W is known, the required braking force T is obtained, and if the braking force T is known, the target operation amount so of the magnet support ring 24 corresponding to the rotation speed N of the braking drum 27 is obtained.

FIG. 4 is a flow chart of a control program for controlling the above-mentioned control by an electronic control unit composed of a microcomputer. In FIG. 4, p11 to p17 represent steps of the control program. This control program starts at p11, initializes the calculation unit, and at p12, the empty / load sensor 9 empty /
Read the loading signal. In p13, find the loading rate from the empty / loading signal. At p14, the target operation amount so of the magnet support ring 24 corresponding to the loading ratio is obtained from the control map corresponding to the running condition. The servo motor 23 is driven at p15. At p16, it is determined whether the operation amount sa of the magnet support ring 24 is larger than the target operation amount so (including the case where the operation amount sa is equal to the target operation amount so). When the operation amount sa of the magnet support ring 24 is smaller than the target operation amount so, the process returns to p15, and when the operation amount sa of the magnet support ring 24 is larger than the target operation amount so (the operation amount sa is the target operation amount so.
(including the case equal to so) ends at p17.

In the second embodiment shown in FIG. 5, servomotors 34 and 4 as actuators are used for empty vehicles and loaded vehicles.
4, the magnet support ring 24 is driven in two steps. That is, the magnet support ring 24 is supported by the long and short drive rods 32 and 42. When the servo motor 34 is driven, the magnet support ring 24 operates to the half braking position, and when the servo motor 44 is driven, the magnet support ring 24 is supported. The annulus 24 operates to the full braking position.

A plurality (preferably three) of short drive rods 32 and a plurality of long drive rods 42 are supported by the guide wall 33 so as to be slidable at equal intervals in the circumferential direction. The drive rod 32 is formed with a flange 32a capable of contacting the guide wall 33 at the base end, and the tip small diameter shaft portion is fitted into a through hole 37 provided in the magnet support ring 24. The rack formed on the drive rod 32 is meshed with the pinion 36, and the pinion 36 is connected to the servo motor 34.
Is meshed with a gear 35 connected to the main shaft of the. The drive rod 42 is formed with a flange 42a capable of contacting the guide wall 33 at the base end, and the tip small diameter shaft portion is fitted into the through hole 47 provided in the magnet support ring 24, and the tip small diameter shaft portion is prevented from coming off. Or it is fastened by nut 42b. The rack formed on the drive rod 42 is meshed with the pinion 46, and the pinion 46 is connected to the main shaft of the servomotor 44 by the gear 4
5 is meshed.

In the second embodiment, although not shown, the stroke sensor 21 includes the flanges 32a and 42 of the guide wall 33.
It is arranged at the portion where a contacts. As the empty / load sensor 9, it is easy to use a manual empty / load switch. Also, instead of the servo motors 34, 44 for driving the drive rods 32, 42, ordinary motors or fluid pressure actuators may be used.

When the driver closes the retarder switch 2 and releases the clutch pedal and the accelerator pedal, the servo motor 34 rotates during half braking in an empty state, and the drive rod 32 moves to the right from the non-braking position shown in FIG. And the servo motor 44 idles. The flange 32a is the guide wall 33
When it comes into contact with the servo motor 34, the servo motor 34 stops. The magnet support ring 24 moves to the right by the operation amount s1, approximately half of the magnet support ring 24 projects into the braking drum 27, and exerts an intermediate braking force based on the eddy current on the braking drum 27.

At the time of full braking in the loaded state, the servo motor 44 rotates, the drive rod 42 moves to the right from the non-braking position shown in FIG. 5, and the servo motor 44 is brought into contact with the guide wall 33 at the flange 42a. 44 stops. The magnet support ring 24 moves to the right by the movement amount s2, and the magnet support ring 24 projects entirely into the braking drum 27, and exerts a total braking force based on the eddy current on the braking drum 27.

When the servomotor 44 is rotated in the reverse direction when the brake is released, the magnet support ring 24 is pulled to the left by the drive rod 42 and returns to the non-braking position shown in the figure. The tip small diameter shaft portion of the drive rod 32 is made long so as not to come off from the magnet support 24 at all braking positions.

FIG. 6 is a flow chart of a control program for the eddy current type speed reducer according to the second embodiment. This control program starts at p21 and reads the empty / vehicle signal of the empty / vehicle sensor 9 at p22. In p23, it is determined whether or not the vehicle is empty based on the empty / load signal. When the vehicle is in a loaded state, the servomotor 44 is driven at p24, and the process goes to p26. If the vehicle is empty at p23, the servomotor 34 is driven at p25, and the process ends at p26.

[0020]

As described above, according to the present invention, the guide cylinder is arranged inside the braking drum that rotates together with the drive shaft, and a large number of strong cylinders are provided at equal intervals in the circumferential direction on the peripheral wall of the guide cylinder facing the braking drum. A magnet support ring, which is connected to a magnetic plate and has magnets facing each ferromagnetic plate on its peripheral wall, is supported by a guide cylinder so that the magnet can be moved axially in stages. The load capacity of the vehicle is calculated from the signal of the load sensor, the optimum braking force is calculated from the load capacity of the vehicle, and the target operation amount of the magnet support ring corresponding to the optimum braking force is determined by the electronic value corresponding to the running conditions such as vehicle speed. Obtained from the control map of the control device, the actuator that drives the magnet support ring is controlled by the electronic control device, so the amount of movement of the magnet support ring inside the braking drum is adjusted according to the empty / loaded state, Rear wheels can be prevented from locking and vehicle spin can be prevented.

[Brief description of drawings]

FIG. 1 is a side sectional view of a braking force control device for an eddy current type speed reducer according to a first embodiment of the present invention.

FIG. 2 is a diagram showing characteristics of an operation amount of a magnet support ring and a braking force of an eddy current type speed reducer.

FIG. 3 is a diagram showing a braking force required with respect to a loading amount of a vehicle.

FIG. 4 is a flow chart of a control program of an electronic control device including a microcomputer for controlling the eddy current type speed reducer.

FIG. 5 is a side sectional view of a braking force control device for an eddy current type speed reducer according to a second embodiment of the present invention.

FIG. 6 is a flow chart of a control program of an electronic control device including a microcomputer for controlling the eddy current type speed reducer.

[Explanation of symbols]

A: eddy current type speed reducer 2: retarder switch 3: steering cylinder 4: rotational speed sensor 5: output shaft 6: accelerator sensor 7: clutch sensor 9: empty / load sensor 10: transmission 12: electronic control device 13: Relay switch 14: Power supply battery 21: Stroke sensor
22: Drive rod 23: Servo motor 24: Magnet support ring 25: Magnet 26: Cooling fin 27: Braking drum 28: Ferromagnetic plate 29: Guide tube 30: Spoke
31: Boss part 32, 42: Drive rod 32a, 42a: Flange 33: Guide wall 34, 4
4: Servo motor 35, 45: Gear 36, 46: Pinion 37, 47: Through hole

Claims (2)

[Claims] 1. A guide cylinder is disposed inside a braking drum that rotates together with a drive shaft, and a large number of ferromagnetic plates are connected to a peripheral wall of the guide cylinder facing the braking drum at equal intervals in the circumferential direction. A magnet support ring, which has a magnet facing the magnetic plate on its peripheral wall, is supported on a guide tube so that it can move axially in stages, and the vehicle's empty / vehicle sensor signal is used to detect the vehicle's empty / loaded state. The load capacity is determined, the optimum braking force is determined from the load capacity of the vehicle, and the target operation amount of the magnet support ring corresponding to the optimum braking force is determined from the control map of the electronic control unit corresponding to the traveling conditions such as the vehicle speed.
A braking force control device for an eddy current type speed reducer, characterized in that an actuator for driving a magnet support ring is controlled by an electronic control device. 2. A long and short drive rod that slidably supports a long and short drive rod having a flange at its base end on a guide wall, and a small diameter shaft portion of the short drive rod is inserted into a through hole of a magnet support ring. 2. The eddy current deceleration according to claim 1, wherein the rod is connected to the magnet support ring, and the short drive rod drives the magnet support ring to the semi-braking position and the long drive rod drives the magnet support ring to the full braking position. Device braking force control device.