JPS6229985B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a retarder, which is a deceleration brake for a vehicle. In particular, it relates to improvements in electromagnetic retarders.

[Conventional technology]

Generally, in large vehicles such as trucks and buses,
If you descend a long slope using only the engine brake and the service brake, there is a risk that the braking force of the service brake will decrease, so an exhaust brake, hydraulic retarder, or electromagnetic retarder is used as an auxiliary deceleration brake.

However, in recent years, due to the need to improve the fuel efficiency of vehicle engines, it has become possible to obtain engines that produce the same level of horsepower as conventional engines at low rotational speeds, and these types of engines are smaller, lighter, and have a smaller total displacement. Therefore, the braking force of conventional engine brakes and exhaust brakes as deceleration brakes is relatively reduced, and it becomes necessary to provide a new deceleration brake.

Another type of deceleration brake, the fluid-type retarder, uses liquid as a braking medium to convert the vehicle's kinetic energy into thermal energy, but the disadvantage is that it is not easy to control the amount of fluid and the overall structure is complicated. It was hot.

In addition, conventional electromagnetic retarders create a magnetic field using a coil, and utilize the deceleration force generated by the eddy current when a disk is rotated within the magnetic field. The brake torque changes depending on the rotation speed, and installation is easy as it is done between the transmission and the rear wheel via a universal joint.
Moreover, it has the advantage that only an excitation current is required as an energy source, and control is easy and the structure is simple.

[Problem that the invention seeks to solve]

However, conventional electromagnetic retarders are heavy because they include the iron parts and rotors that make up the magnetic circuit, and because they are installed between the transmission and the rear wheels, they require a special propeller shaft. Braking force is generated regardless of the gear ratio of the transmission, and since the kinetic energy is converted into thermal energy by the rotor in the magnetic circuit, cooling of the rotor is limited to air cooling, and forced cooling methods using water, oil, etc. can be used. As a result, the cooling effect was not sufficient, and the brake torque decreased due to a decrease in current due to a rise in rotor temperature.

For this reason, a magnetic pole is provided on the outer periphery of the flywheel, and a magnetic body and excitation wire are placed on the outer frame of the flywheel. When the flywheel rotates, an eddy current is generated in the magnetic body, and this eddy current generates an eddy current in the magnetic body. A cooling device for an eddy current retarder has been proposed in which the heat generated by the magnetic material is removed by providing grooves on the outer periphery of the magnetic material as cooling water passages and circulating cooling water from the outside. - Publication No. 16887).

However, with the eddy current method in which eddy currents are generated in a magnetic material and the resulting heat is removed, the device overheats and the braking force cannot be very large. Therefore, it has not been possible to realize a lightweight and compact retarder with a large brake torque.

The present invention solves the above-mentioned drawbacks, and even if the engine is made smaller and lighter and the total displacement is reduced, a braking force corresponding to the gear ratio of the transmission can be obtained like a conventional engine brake, and a special brake force can be obtained. The purpose of the present invention is to provide a retarder that does not require a propeller shaft, is lightweight, has a large braking force, and is easy to control.

[Means for solving problems]

In the present invention, a magnetic flywheel having teeth formed on its surface is rotor-mounted to a crankshaft between an engine and a transmission, a base end is fixed to a housing of the flywheel, and a tip end is attached to the teeth. a power source means comprising a magnetic body provided close to the body and having a first coil wound around the body as a field, and including a control means for applying a variable excitation current to the first coil; It is characterized by comprising a second coil wound as a short-circuit ring near the tip.

Further, it is preferable that the cooling medium be configured to circulate within the short-circuit ring.

Furthermore, it is preferable that the magnitude of the excitation current of the power source means is configured to change depending on the amount of depression of the brake pedal.

[Effect]

When an excitation current is passed through a first coil wound around a magnetic body fixed to the housing of the flywheel, this magnetic body is excited and becomes a field.

Teeth made of magnetic material are formed on the outer periphery of the flywheel, and as the flywheel rotates, the magnetic path changes alternately between the teeth and the above-mentioned magnetic material.

Due to this change in the magnetic path, a current is generated in the second coil wound around the tip of the magnetic body in a direction that prevents the magnetic field lines from decreasing. Take out this current,
Or convert it into heat and cool this heat. As a result, a force acts on the teeth of the flywheel that prevents them from moving toward or away from the magnetic material, which acts as a braking force for the retarder.

In this device, the electrical energy generated by braking appears as a current in the second coil, and does not immediately become an iron loss. Since this electrical energy can be converted into heat and cooled, a large amount of energy can be generated. In principle, the device itself does not generate heat.

〔Example〕

Examples will be described in detail below based on the drawings.

FIG. 1 is a diagram of the mounting structure of a retarder according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view along AA' shown in FIG. 1. In FIGS. 1 and 2, a flywheel 5 made of a magnetic material is attached to a crankshaft 3 between an engine 1 and a transmission 2. As shown in FIGS. The housing 6 of this flywheel 5 is made of magnetic material,
Retarder units 7 and 7' are fixed to the upper part of the housing 6. This flywheel 5 acts as a rotor, and the retarder units 7, 7' act as a field.

A large number of teeth 9 are provided at equal intervals on the outer peripheral edge of the flywheel 5. The retardant nuts 7 and 7' are attached to the housing 6 with a unit cover 10 at intervals corresponding to the teeth 9.
and 10', respectively.
Both sides of this housing 6 are fixed to a chassis frame 12 integrally with the engine 1 via a stand 11, respectively.

FIG. 3 is an enlarged perspective view of the retarder unit 7. In Fig. 3, the retarder unit 7
is a prismatic core 13 made of magnetic material, and this core 1
The coil winding frame 15 is fitted onto the body of the iron core 13 and around which the excitation coil 14 is wound, and the short-circuit ring 16 is fitted onto the tip of the iron core 13. The tip of this iron core 13 is provided close to the teeth 9, and when a current is applied to the excitation coil 14 when the iron core 13 faces the teeth 9 as shown in FIG. 2, the opposing teeth 9 are excited and magnetized. do.

Four bolt holes are drilled at the base end of this iron core 13, and the iron core 13 has four bolts 17 made of magnetic material.
It is fixed to the unit cover 10 by. The shorting ring 16 also includes a hollow conductive pipe 18 and an inflow pipe 21 and an outflow pipe 22 that communicate with the conductive pipe 18 and circulate a cooling medium within the conductive pipe 18. Cooling water from a radiator (not shown) is introduced as this cooling medium. Further, a current is generated in the conductive pipe 18 of the short circuit ring 16 due to a change in the magnetic lines of force generated in the iron core 13 due to the movement of the teeth 9 as the flywheel 5 rotates as shown in FIG. circulates and converts mechanical energy into thermal energy. Also, on the surface of the unit cover 10, an excitation coil 1 is provided.
Four electrical terminals 23, 24 are provided.

The structure of the retarder unit 7' is the same as that of the retarder unit 7, so a repeated explanation will be omitted.

FIG. 4 is a circuit diagram including the retarder units 7 and 7'. In FIG. 4, one end of the vehicle's power supply 25 is connected to the key switch 26 of the engine 1.
connected to one end of the The other end of the key switch 26 is connected to a load 27 and one end of a retarder switch 29, respectively. This retarder switch 2
9 is disposed at the same position as other switches in the driver's seat so that the driver can easily operate the switch while driving.

The other end of the retarder switch 29 is connected via a control circuit 30 to the electric terminals 23, 24' of the retarder units 7, 7', respectively.
The amount of depression of a brake pedal (not shown) is converted into an electrical signal and given to a control input terminal 31 of this control circuit 30. Sometimes retarder units 7, 7'
The brake pedal is configured to apply a large amount of current to the brake pedal, and to apply a small amount of current when the amount of depression of the brake pedal is small. Further, the other ends of the power source 25 and the load 27, as well as the electrical terminals 24 and 23', are grounded.

With such a configuration, the operation of the retarder of this embodiment will be explained.

First, the retarder switch 29 is turned on when the vehicle is going down a long slope, or when the vehicle is going down a slope with a large amount of cargo or passengers on board. When the driver stops depressing the accelerator pedal (not shown) and starts depressing the brake pedal, an excitation current is applied from the power source 1 to the retarder units 7, 7' via the control circuit 30.

At this time, the retarder units 7, 7' and the flywheel 5 are arranged as shown in FIG. 5a: iron core 13 → teeth 9a → teeth 9b → iron core 13'.
→ Unit cover 10' → Housing 6a → Unit cover 10 → Iron core 13. A magnetic circuit M is constructed.

Next, as shown in FIG. 5b, when the flywheel 5 rotates in the direction of the arrow and the teeth 9 move, the magnetic circuit M is no longer formed and the iron core 1
3 and 13' are reduced and the short-circuit ring 16,
A current is generated in the conductive pipes 18, 18' of 16' in a direction that prevents the reduction of the magnetic lines of force. The heat generated in the conductive pipes 18, 18' by this current is forcibly cooled down by the cooling medium flowing in from the inflow pipes 21, 21'.

At this time, since the teeth 9a and 9b retain the magnetic force that tends to continue forming the magnetic circuit M, the teeth 9a and 9b have the iron cores 13 and 1.
A force acts that prevents each from moving away from 3'. This becomes a braking force for the flywheel 5.

When the flywheel 5 further rotates, the teeth 9c and 9d shown in FIG.
13' and the above operations are repeated continuously.

FIG. 6 is a developed view showing the relationship between the field and the rotor of the retarder according to the second embodiment of the present invention.

A characteristic feature of this embodiment is that the tip of the iron core 13 of the retarder unit 7 is branched so as to face a plurality of (four in this example) teeth 9.

As a result, one iron core 13 has a large number of teeth 9.
Since the frequency of the current generated in the short circuit ring 16 becomes high, the magnetic portion of the retarder unit 7 can be downsized and the structure can be simplified.

FIG. 7 is a developed view showing the relationship between the field and the rotor of a retarder according to a third embodiment of the present invention.

The characteristic configuration of this embodiment is that a plurality of (n in this example) retarder units 7 _-1 , _{7 -2} . is to be erected.

This increases the magnetic efficiency of the retarder unit 7, increases the amount of energy consumed by the short-circuit ring 16, and provides a retarder with high braking force.

In addition, in the above example, the coil for extracting current and the energy conversion means are used as a short-circuit ring, but this coil and energy conversion means are not limited to the short-circuit ring, and can also be used as a power source. It may also be a means of dissipating heat. For example, a load resistor can be connected outside the retarder by using the short-circuit ring as a coil, and the load resistor can convert current into heat. Alternatively, a battery can be connected in place of the load resistor and used for charging.

Further, although an example has been shown in which the excitation current is controlled in accordance with the amount of depression of the brake pedal, the excitation current may be controlled manually by the driver using a manual switch instead of the brake pedal.

〔Effect of the invention〕

As described above, according to the present invention, a large number of teeth are provided on the outer peripheral edge of an existing flywheel,
By fixing a pair or a number of retarder units to the flywheel housing in accordance with the spacing between teeth, and using the flywheel as a rotor to provide a field to the retarder units, the engine becomes smaller and lighter, reducing total displacement. Even in vehicles where the transmission is high-speed and has a small gear ratio, it provides the same braking force as conventional engine braking, does not require a special propeller shaft, is lightweight, and has braking force. It is possible to realize a retarder with excellent performance and easy control.

In this retarder device, the electrical energy generated by braking is extracted as a current in a coil and converted into heat. Therefore, mechanical energy is not immediately consumed as iron loss, so there is an advantage that the device does not generate heat in principle.

Further, since a cooling means can be provided on the fixed field side, forced cooling is possible, and there is an excellent effect that brake torque does not decrease.

This ensures the performance of the main brake, extends the life of the lining, prevents tire damage, reduces driver fatigue, and enables safe driving.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing the mounting structure of a retarder according to a first embodiment of the present invention. Figure 2 is shown in Figure 1.
AA′ cross-sectional view. FIG. 3 is a perspective view of the retarder unit. FIG. 4 is a circuit diagram of the retarder as well. FIG. 5 is an enlarged side view of the main parts of the retarder.
FIG. 6 is a developed view showing the relationship between the field and the rotor of the retarder according to the second embodiment of the present invention. FIG. 7 is a developed view showing the relationship between the field and the rotor of a retarder according to a third embodiment of the present invention. 1...Engine, 2...Transmission, 3...Crankshaft,
5... Flywheel, 6... Housing, 7, 7'
...Retarder unit, 9...Teeth, 10,1
0'... Unit cover, 11... Stand, 12... Chassis frame, 13, 13'... Iron core, 14, 14'... Excitation coil, 15, 15'... Coil winding frame, 16, 1
6'...Short ring, 17,17'...Bolt, 18,1
8'... Conductive pipe, 21, 21'... Inflow pipe, 2
2, 22'...Outflow pipe, 23, 23', 24, 2
4'...Electrical terminal, 25...Power supply, 26...Key switch, 27...Load, 29...Retarder switch, 3
0...Control circuit, 31...Control input terminal.

Claims (1)

[Scope of Claims] 1. A magnetic flywheel with teeth formed on its surface is rotor-mounted to the crankshaft between the engine and the transmission, and the base end is fixed to the housing of the flywheel and the tip end is fixed to the housing of the flywheel. is provided close to the teeth and has a magnetic body around which a first coil is wound around the body as a field, and includes a control means for applying a variable excitation current to the first coil; A retarder comprising: a second coil wound as a short ring near the tip of the magnetic material; 2. The retarder according to claim 1, wherein at least a portion of the second coil is a hollow pipe through which a cooling medium circulates. 3. The retarder according to claim 1 or 2, wherein the power source means includes means for controlling the magnitude of the excitation current according to the amount of depression of the brake pedal.