JPH0662790U - Eddy current type speed reducer - Google Patents

Abstract

(57) [Summary] [Object] To provide an eddy current type speed reducer capable of controlling the position of a magnet support ring in multiple stages. [Structure] The rotor 1 is fitted to one end of the rotary shaft 7,
A support ring 4 around which a plurality of permanent magnets 3 are provided so that the polarities of adjacent magnets are opposite to each other, and the pole faces of the permanent magnets face the rotor in the axial direction of the rotary shaft with a required gap. In an eddy current type speed reducer that moves back and forth from the position to the position where all surfaces are disengaged, it is a multi-stage position that can be stopped at a plurality of predetermined positions between the position that entirely opposes the rotor and the position where all surfaces disengage. The position of the support ring 4 is controlled by the control cylinder 10. [Effect] By controlling the generated braking torque in multiple stages, it is possible to easily control the braking force and apply it to a wide range of deceleration.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of an eddy current type speed reducer used for large vehicles such as buses and trucks.

[0002]

[Prior art]

 As a speed reducer or braking device for large vehicles, in addition to the foot brake, which is the main brake, and the exhaust brake, which is the auxiliary brake, perform stable deceleration when descending a long slope and prevent burnout of the foot brake. An eddy current type speed reducer is used to prevent this. There are two types of eddy current type reduction gears that use electromagnets and ones that use permanent magnets. The applicant has previously made various types of lightweight, power-saving eddy current reduction gears that use permanent magnets. Invented (Japanese Patent Laid-Open No. 1-234043, etc.).

In the eddy current type speed reducer disclosed in the above-mentioned Japanese Patent Laid-Open No. 1-234043, a rotor is fitted to one end of a rotary shaft so that the polarities of adjacent magnets are opposite to each other. The support ring around each of the permanent magnets is moved back and forth in the axial direction of the rotating shaft from the position where the pole surface of the permanent magnet faces the rotor at the required gap to the position where it completely separates from the rotor. The speed reducer is characterized by controlling the braking force.

The advance / retreat position control of the support ring is performed by the following method, for example. A 2 position control (single acting) Control by air cylinder Normally, 2 position control is performed, that is, braking ON position (100% torque) ← → braking OFF (torque = 0). The stability at the stop position and the response speed are good, and the control circuit is simple and inexpensive, but it has the drawback of not being able to control the braking force in multiple stages.

Control by B Motor and Ball Screw Control at any position is possible. The required torque of the motor is large and the response speed is slow. The control circuit is rather complicated and there is a problem with the durability of the motor.

Control by C double-acting hydraulic cylinder Control at any position is possible. The stop position is inaccurate and the response speed is slow. The control circuit becomes complicated.

Each of these conventional position control methods has advantages and disadvantages, and the advent of a position control device having each characteristic is desired.

[0008]

[Problems to be solved by the device]

 The present invention solves the above-mentioned drawbacks of the prior art and enables multi-step position control, high response speed, good stability at the stop position, good stop position accuracy, etc. The present invention provides an eddy current type deceleration device having a support ring position control mechanism that also has features.

[0009]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the eddy current type speed reducer of the present invention has a rotor fitted on one end of a rotary shaft so that the polarities of adjacent magnets are opposite to each other. An eddy current type speed reducer that moves the circumference of the support ring in the axial direction of the rotating shaft from the position where the pole surface of the permanent magnet faces the rotor at the required gap to the position where it completely disengages from the rotor. In the above, the position of the support ring is controlled by a multi-stage position control cylinder that can be stopped at a plurality of predetermined positions between a position where the rotor faces the entire surface and a position where the rotor completely separates.

[0010]

[Action]

As shown in FIG. 2, when the permanent magnet 3 is held at a position (stroke of cylinder: S ₁ + S ₂ ) facing the cylindrical portion 2 of the rotor through the pole piece 8, the permanent magnet 3 is formed between the adjacent permanent magnets. An eddy current flows through the rotor due to the magnetic circuit that generates the maximum braking torque.

As shown in FIG. 3, when the permanent magnet 3 that is entirely opposed to the cylindrical portion 2 of the rotor is moved to and held at the position (stroke: S ₁ ) which is retracted by one step, the braking torque is as shown in FIG. It is smaller than the maximum torque when facing the entire surface. As shown in FIG. 4, when the vehicle is moved and held at the position (stroke: S ₂ ) further retracted by one step, the braking torque further decreases.

Then, as shown in FIG. 5, when the permanent magnet 3 is moved to and held at the most retracted position (stroke: 0), that is, the position where the permanent magnet 3 is completely separated from the cylindrical portion 2 of the rotor, no damping torque is generated. , Braking is released.

[0013]

【Example】

 An embodiment of this invention will be described with reference to the drawings. FIG. 1 shows an essential part of an eddy current type speed reducer according to the implementation of the present invention. The rotor 1 has a cylindrical portion 2 around which a large number of fins are provided, and the boss portion is fitted on the rotating shaft 7. Then, a support ring 4 having a plurality of permanent magnets 3 arranged so that the polarities of adjacent magnets are opposite to each other is housed in a magnetic shield casing formed by joining a casing 5 and a casing cover 6. The permanent magnet 3 in the state of generating the maximum braking torque is entirely opposed to the cylindrical portion 2 of the rotor via the pole piece 8 arranged on the casing cover 6.

The support ring 4 is provided on both end surfaces of the casing 5 and the casing cover 6 so that the permanent magnet 3 can be retracted from a position facing the inner peripheral surface of the rotor cylindrical portion 2 to a magnetically separated position. It is supported by a plurality of guide shafts 9 which pass through the space and are circumferentially arranged so as to be slidable in the axial direction of the rotary shaft 7.

Further, a plurality of air cylinders 10 are circumferentially arranged on the outer end surface of the casing 5, and rods 11 thereof are attached to the support ring 4, and the operation of the air cylinder 10 causes the support ring 4 to move. It is provided so that it can move forward and backward.

2 to 5 show the detailed structure and operating state of the air cylinder 10. The flow of compressed air is controlled by a directional control valve provided in the middle of the pipe connecting the ports a, b, and c of the air cylinder 10 to the compressed air source, but it is omitted here.

In FIG. 2, compressed air is sent to the port a of the air cylinder 10, and the ports b and c are exhausted (stroke S ₁ + S ₂ ). At this time, the support ring 4 around which the permanent magnet 3 is provided is held at a position where the permanent magnet 3 is entirely opposed to the cylindrical portion 2 of the rotor, and the maximum braking torque is generated.

When the permanent magnet 3 shown in FIG. 2 faces the cylindrical portion 2 of the rotor, compressed air is sent to the ports a and c, and the port b is exhausted so that it is supported as shown in FIG. The ring 4 is held at a position (stroke S ₁ ) where the permanent magnet 3 is retracted from the position where the permanent magnet 3 is entirely opposed to the cylindrical portion 2 of the rotor, and the braking torque is reduced as compared with the maximum torque when the entire surface is opposed in FIG. .

FIG. 4 shows a state in which compressed air is sent to port b, ports a and c are in an exhausted state, and the support ring 4 is further retracted (stroke S ₂ ) and the braking torque is further reduced. Becomes

In FIG. 5, compressed air is sent to ports b and c, and port a is in an exhausted state (stroke 0). At this time, the support ring 4 around which the permanent magnet 3 is provided is held at a position where the permanent magnet 3 is completely removed from the cylindrical portion 2 of the rotor, so that braking torque is not generated and the damping is released.

FIG. 6 shows a comparison of the braking torques generated in each of the above states. As a result, the braking torque can be easily adjusted by changing the stroke of the piston of the air cylinder and controlling the stop position of the support ring in multiple stages.

[Effect of device]

 According to the speed reducer of the present invention, the generated braking torque can be adjusted in multiple steps, so that the braking force can be easily controlled and applied to a wide range of speed reductions. Also, because compressed air is used as the drive source, the response speed is fast, and the control circuit is simple and inexpensive. Further, the air cylinder capable of multi-stage position control has good stability at the stop position and can always easily obtain a predetermined braking torque.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of an eddy current type speed reducer according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a cylinder position (stroke S ₁ + S ₂₎ in a state in which a maximum braking torque is generated when the eddy current type speed reducer shown in FIG. 1 is braking ON.

3 is an enlarged cross-sectional view showing a cylinder position (stroke S ₁ ) in a state where a reduced braking torque is generated when the eddy current type speed reducer shown in FIG. 1 is turned on.

FIG. 4 is an enlarged cross-sectional view showing a cylinder position (stroke S ₂ ) in a state where a further reduced braking torque is generated when the eddy current type speed reducer shown in FIG. 1 is turned on.

5 is an enlarged cross-sectional view showing a cylinder position (stroke 0) when the eddy current type speed reducer shown in FIG. 1 is in a braking OFF state.

[FIG. 6] FIG. 6 is a diagram illustrating a case where braking is ON and a case where braking is OFF illustrated in FIGS.
It is a graph which shows the relationship between vehicle speed and braking torque at the time.

[Explanation of symbols]

 1 Rotor 2 Cylindrical part 3 Permanent magnet 4 Support ring 5 Casing 6 Casing cover 7 Rotating shaft 8 Pole piece 9 Guide shaft 10 Air cylinder 11 Rod

Claims (1)

[Scope of utility model registration request] 1. A rotor is fitted to one end of a rotary shaft,
From the position where the pole surface of the permanent magnet faces the rotor with a required gap in the axial direction of the rotating shaft, the support ring is formed by surrounding a plurality of permanent magnets so that the polarities of the adjacent magnets are opposite to each other. In an eddy current type speed reducer that moves the length up and down to a position where it is completely separated, a support ring by a multi-stage position control cylinder that can be stopped at a plurality of predetermined positions between a position where it is entirely opposed to the rotor and a position where it is completely separated. Eddy current type speed reducer configured to perform position control of the.