JP2000310264A - Brake mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake mechanism, capable of reducing the size of a mechanism inside a tire. SOLUTION: A converter 15 installed on a body is connected to a master cylinder interlocked with a brake pedal via a hydraulic pipe 25, and also connected to a brake unit 12 inside a brake drum 5 via a cable 30. The converter 15 comprises a sub cylinder 13 and a cam mechanism 16 converts a hydraulic pressure received by the sub cylinder 13 by the cam mechanism 16, and remotely control a brake shoe from the outside of the brake drum 5 to perform braking operation. Because there is no need for a wheel cylinder to be assembled into the brake drum 5, the volume of the brake drum 5 can be reduced, and as a result, an electric motor 1 can be moved nearer to a drive wheel 2 side and reduce the size of the mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake mechanism.

[0002]

2. Description of the Related Art FIG. 8 shows the structure of an electric motor 100 and tires 101 in an electric vehicle. Electric motor 1
From the center of 00, a rotating shaft 1 for rotating the tire 101
02 is extended. On the other hand, the tire 101 is provided with a brake drum 103 so as to surround the rotating shaft 102. A brake shoe 104 is provided inside the brake drum 103.
04 is connected to a wheel cylinder 105.

As shown in FIG. 9, when a driver of an electric vehicle operates a brake pedal 108, a wheel cylinder 105 receiving hydraulic pressure from a master cylinder 109 is operated.
However, when the brake shoe 104 is driven and the brake shoe 104 is pressed against the inner wall of the brake drum 103, the rotational movement of the tire 101 is braked.

[0004]

By the way, in the above-mentioned brake mechanism, the wheel cylinder 105 is
4 is directly driven, and its installation location is limited to the internal space of the brake drum 103. Therefore, inside the brake drum 103, in addition to the space for accommodating the brake shoes 104, the wheel cylinder 1
It is necessary to provide a space for accommodating the tire 101
This was an obstacle to downsizing the internal mechanism.

In the conventional brake mechanism, as shown in FIG. 9, the master cylinder 109 and the wheel cylinder 105 are used to change the braking ratio of the front and rear wheels.
In between, it was necessary to provide an expensive proportioning valve 110.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a brake mechanism that can make a mechanism inside a tire compact, and another object is to use a proportioning valve. It is to provide a brake mechanism that does not need to be performed.

[0007]

According to a first aspect of the present invention, there is provided a brake mechanism, comprising: a brake mechanism provided inside a brake drum; a release state separated from a sliding contact surface of the brake drum; A brake mechanism displaceable between a brake state in which the brake shoe is pressed against the sliding contact surface of the brake drum, and a hydraulic mechanism interlocked with a brake operating member is disposed outside the brake drum, while the brake shoe A shoe drive unit that brings the brake shoe into the released state and the brake state by moving the end of the brake shoe closer or further away is interposed, and the shoe drive unit and the hydraulic mechanism are mechanically operated. It is characterized in that it is connected so as to be interlockable by the connecting means. The “mechanical connecting means” includes a connecting mechanism using a cable and a connecting mechanism using a cam. The "brake operation member" includes a manual operation type as well as a stepping type.

According to a second aspect of the present invention, there is provided the brake mechanism according to the first aspect, wherein the hydraulic mechanism receives a hydraulic pressure from the master cylinder and a master cylinder interlocked with the brake operating member. And a sub-cylinder that reciprocates the pistons in synchronism with each other, and both pistons of the sub-cylinder are connected to the shoe driving units disposed on the left and right wheels, respectively.

According to a third aspect of the present invention, there is provided the brake mechanism according to the first or second aspect, wherein a wheel mechanism is provided between the hydraulic mechanism and the mechanical connecting means in the brake mechanism disposed on each of the front and rear wheels. An adjustment lever for variably adjusting the braking force before and after is rotatably arranged, and the end of one arm of the adjustment lever is connected to the hydraulic mechanism, and the end of the other arm is connected to the mechanical connection means. It is characterized by being connected.

[0010]

According to the first aspect of the present invention, the input by the operation of the brake operating unit is transmitted from the hydraulic mechanism via the mechanical connecting means. Then, the brake is operated by the mechanical connection means operating the shoe drive unit. For this reason, since it is not necessary to provide a wheel cylinder in the brake drum, the capacity of the brake drum can be reduced, and the mechanism inside the tire can be made compact.

According to the second aspect of the present invention, it is possible to operate the shoe drive unit disposed on each wheel via the sub-cylinder, and it is not necessary to provide a wheel cylinder for each tire as in the prior art, so that the brake mechanism can be simplified. Can be

According to the third aspect of the present invention, the braking force can be adjusted before and after the wheel by the adjusting lever without using a proportioning valve as in the prior art.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In this embodiment, a brake mechanism is used in an electric vehicle of a wheel-in-motor type (a type in which tires are directly connected to a rotating shaft of an electric motor). This will be described below with reference to FIGS.

FIG. 1 shows an outline of a brake mechanism according to this embodiment. The brake pedal 31 (brake operating member) is connected to a master cylinder 32 that is linked to the movement of the brake pedal 31. The master cylinder 32 is connected to the converter 15. The converter 15 includes a sub-cylinder 13 (which forms a hydraulic mechanism together with the master cylinder 32) and a cam mechanism 16, and is connected to the brake shoe 9. The brake mechanism connected in this way transmits the brake operation performed by the driver to the brake shoe 9 to perform the brake operation.

FIG. 2 shows the vicinity of the drive wheels 2 of a wheel-in-motor type electric vehicle. From the car body 3,
The support member 17 and the leaf spring 17S are paired up and down and extend outward, one end of the support member 17 is rotatably connected to the vehicle body 3, and the leaf spring 17S is They are connected so as to be able to bend in the vertical direction. The electric motor 1 is supported on the other end side of the support member 17 and the leaf spring 17S, and these connection portions are rotatable. The electric motor 1 is rotatable in the forward and reverse directions.
The rotation shaft 6 protrudes toward. Also, the electric motor 1
An assembly part 8 for assembling the brake unit 12 is formed on a surface of the motor casing 7 facing the drive wheel 2. The assembling portion 8 has a peripheral wall along substantially the entire circumference, and is formed in a short cylindrical shape concentric with the rotating shaft 6.

The brake according to the present embodiment includes:
A drum brake type is adopted, and a bottomed cylindrical brake drum 5 opening toward the electric motor 1 side.
have. This brake drum 5 is driven by an electric motor 1 by a lock bolt 18 fastened to the shaft end of the rotating shaft 6.
In this state, the opening surface of the brake drum 5 is almost covered by the mounting portion 8 of the motor casing 7. The brake drum 5 can be fitted to the tire 19 and the wheel 4 via a mounting hole 4A opened at the center of the wheel 4. Brake drum 5
The ribs 20 protrude from the outer peripheral surface at intervals of 90 °, and hub bolts 21 are attached to the respective ribs 20 by press-fitting, inserted into the wheel 4 side, and tightened with the nuts 22 so that the driving wheel 2 is attached. It is possible (see FIG. 3).

A brake unit 12 for applying a braking force to the driving wheels 2 is provided inside the brake drum 5. The brake unit 12 includes a pair of brake shoes 9, 9 and a shoe driving unit 14. As shown in FIGS. 4 and 5, each of the brake shoes 9, 9 has a substantially crescent shape, is rotatably supported by an anchor pin 10 at a position where its upper ends abut each other, and has a lower end 9A.
The brake cam 11 is interposed therebetween so as to form a ring as a whole. The brake cam 11 has a substantially rectangular cross-sectional shape and is rotatably mounted. By the rotation of the brake cam 11, the lower end 9A of the brake shoes 9, 9 is displaced from the close state to the separated state. The shoe drive unit 14 rotatably supports the brake cam 11, and transmits an input from a cable 30 (mechanical coupling unit) described later to the brake shoe 9. The two brake shoes 9, 9 are provided with springs 2 above and below.
At normal times, the brake shoes are urged toward each other by the springs 23,23.

When the lower ends 9A of the brake shoes 9, 9 are separated by the rotation of the brake cam 11,
Due to the rotation about the anchor pin 10, both brake shoes 9 rotate in the expanding direction, the outer surface of the brake shoes 9 is pressed against the brake drum 5, and the driving of the drive wheels 2 is controlled (FIGS. 4 and 4). 5).

In the present embodiment, a well-known brake pedal 31 is provided at the foot of the driver's seat, and is connected to a piston (not shown) of a master cylinder 32. The master cylinder 32 includes a piston and a cylinder, and is filled with brake oil. Brake pedal 31
When the master cylinder 32 is actuated in accordance with the operation, the hydraulic pressure of the brake oil is changed, and the change in the hydraulic pressure generated in the
Transmit to 5.

In this embodiment, the converter 15 is provided at an intermediate portion of the cross member 3S of the vehicle body 3 in the vehicle width direction.
The bottom surface is fixed together with the leaf spring 17S. The converter 15 includes a sub-cylinder 13 and a cam mechanism 1 in a housing having a hexagonal cross section in the front-rear direction as shown in FIG.
6 is provided.

The sub-cylinder 13 is formed in a cylindrical shape,
A pair of pistons 24, 24 are provided on both left and right side surfaces. As shown in FIG. 6, a hydraulic pipe 25 is connected to an intermediate portion in the width direction of the sub-cylinder 13. When hydraulic pressure is transmitted from the hydraulic pipe 25 to brake oil filled in the sub-cylinder 13, the hydraulic pressure is The piston 24 is displaced in proportion to. Then, the displacement of the piston 24 is transmitted to the cam mechanism 16.

As shown in FIG. 6, the cam mechanism 16 has a cam rod 26 (adjustment lever) attached so as to be rotatable about a cam shaft 27. One end of the cam rod 26 is provided with a cam portion 28 having a curved edge. The cam portion 28 is in contact with the piston 24 of the sub cylinder 13 and rotates the cam rod 26 following the displacement of the piston 24. A wire 30W of the cable 30 is connected to the other end of the cam rod 26 by a wire fixing portion 29, and the load is transmitted by pushing and pulling the wire 30W by the rotation of the cam rod 26. The cam mechanism 16 is a cam rod 2
The load transmitted to the wire 30W can be adjusted by the shape of No. 6. Specifically, the distance between the cam shaft 27 and the wire fixing portion 29 is changed, or the piston 24
It can be adjusted by changing the shape such as the curvature of the cam portion 28 that comes into contact with the cam portion.

The cable 30 is configured by housing a slidable wire 30W inside a coating 30S. Cable 30
At one end, the tip of the coating 30S is fixed to the converter 15, and the tip of the wire 30W is connected to the cam rod 26 as described above.
Is connected to the wire fixing portion 29. The other end of the cable 30 is connected to the above-described brake unit 12, the tip of the sheath 30S is fixed to the sheath mounting portion 14A of the shoe driving unit 14, and the tip of the wire 30W is connected to the above-described brake cam 11. (See FIG. 4). For this reason, when a load acts on the wire 30W of the cable 30, the brake cam 11 rotates, so that the brake unit 12 is operated.

Next, the operation and effect of the present embodiment configured as described above will be described. First, when the brake is not operated, the converter 15 is in the state shown in FIG. 6, and the brake drum 5 and the brake shoe 9 are separated from each other at a predetermined interval as shown in FIG. The brake unit 12 does not brake the rotational movement of the motor 1.

When the driver steps on the brake pedal 31, the master cylinder 3
The piston 2 is displaced, and the hydraulic pressure in the master cylinder 32 increases. The change in the hydraulic pressure generated in master cylinder 32 is transmitted to sub-cylinder 13 of converter 15 via hydraulic piping 25. Then, the left and right pistons 24 of the sub-cylinder 13 are displaced in the protruding directions as shown in FIG. 7 by the transmitted hydraulic pressure, and press the cam portion 28 of the cam mechanism 16. When the cam rod 26 rotates about the cam shaft 27 by the pressing of the cam portion 28, the cable 3 connected to the wire fixing portion 29
The zero wire 30W receives a tensile load. Then, as shown in FIG. 5, an input from the wire 30 </ b> W that has received the tensile load causes the brake cam 11 to rotate via the shoe drive unit 14. Then, the brake cam 11 spreads both ends of the brake shoe 9 (see FIG. 5). The brake shoe 9 is pressed against the brake drum 5 by the push-spread operation, and the rotation of the drive wheel 2 is controlled. Thus, a series of braking operations are performed.

As described above, according to the present embodiment, the vehicle body 3
Is connected via a hydraulic pipe 25 to a master cylinder 32 interlocking with a brake pedal 31 and is connected via a cable 30 to the brake unit 12 in the brake drum 5. Converter 15 converts the hydraulic pressure received by sub-cylinder 13 to cam mechanism 1.
The driving force is converted into the driving force of the wire 30W by the brake 6, and the brake operation is performed by remotely controlling the brake shoe 9 from outside the brake drum 5. Therefore, it is not necessary to incorporate the wheel cylinder 105 in the brake drum 5, so that the capacity of the brake drum 5 can be reduced, whereby the electric motor 1 can be made closer to the drive wheel 2 side, and the size can be reduced.

Furthermore, according to the present embodiment, the wheel cylinders 105 which had to be provided in the respective brake drums 103 of the respective drive wheels 101 can be combined into one converter 15 in the related art. And can be directly installed on the vehicle body 3. Therefore, the number of parts can be reduced, the weight can be reduced, and the unsprung weight can be reduced, so that the running performance can be improved.

In addition, since the input to the brake unit 12 can be adjusted by the cam mechanism 16 of the converter 15, the proportioning valve 11 conventionally required to change the braking ratio of the front and rear wheel brakes is changed.
Adjustment is possible without using 0.

<Other Embodiments> The present invention is not limited to the above embodiments, and can be implemented in various modifications without changing the gist thereof. For example, those described below are also included in the technical scope of the present invention. (1) In the above embodiment, a system using a drum brake is used, but a brake using another system such as a disk brake may be used. (2) In the above embodiment, the present invention is applied to an electric vehicle.
The invention is not limited to electric vehicles, and may be applied to gasoline vehicles. (3) In the above embodiment, the present invention is applied to driving wheels, but may be applied to other than driving wheels. (4) In the above embodiment, the master cylinder 32 and the sub-cylinder 13 are formed separately, but may be formed by an integral hydraulic mechanism.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a brake mechanism according to an embodiment.

FIG. 2 is a sectional view of a drive wheel including a brake mechanism for a wheel-in motor and a peripheral portion thereof.

FIG. 3 is a sectional view of a drive wheel.

FIG. 4 is a partially enlarged view of the brake unit when the brake is not driven.

FIG. 5 is a partially enlarged view of a brake unit when a brake is driven.

FIG. 6 is a sectional view of the converter when the brake is not driven.

FIG. 7 is a cross-sectional view of the converter when a brake is driven.

FIG. 8 is a sectional view showing a brake mechanism in a conventional example.

FIG. 9 is a diagram showing an outline of a brake mechanism in a conventional example.

[Explanation of symbols]

 5 Brake drum 9 Brake shoe 13 Subcylinder 14 Shoe drive unit 24 Piston 26 Cam rod (adjustment lever) 30 Cable (mechanical coupling means) 31 Brake pedal (brake operating member) 32 Master cylinder

Claims (3)

[Claims] 1. A brake mechanism having a brake shoe disposed inside a brake drum, the brake shoe being displaceable between a released state separated from a sliding contact surface of the brake drum and a brake state pressed against the sliding contact surface of the brake drum. A hydraulic mechanism interlocked with a brake operating member is disposed outside the brake drum, and the brake shoe is moved toward or away from the brake shoe by moving an end of the brake shoe toward or away from the brake shoe. And a shoe drive unit for setting the brake state is interposed, and the shoe drive unit and the hydraulic mechanism are operatively connected to each other by mechanical connection means. 2. The hydraulic mechanism comprises a master cylinder interlocked with the brake operating member, and a sub-cylinder that receives a hydraulic pressure from the master cylinder and synchronously reciprocates a pair of pistons built therein, and 2. The brake mechanism according to claim 1, wherein both pistons of the sub-cylinder are connected to the shoe driving units disposed on left and right wheels, respectively. 3. A brake mechanism disposed on each of the front and rear wheels, wherein an adjusting lever for variably adjusting a braking force before and after the wheel is rotatably disposed between the hydraulic mechanism and the mechanical connection means. 3. The brake mechanism according to claim 1, wherein an end of one arm of the adjusting lever is connected to the hydraulic mechanism, and an end of the other arm is connected to the mechanical coupling means. .