JPH0427708Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a braking force sensor employed in a vehicle.

(Prior art) When driving a car, the brake pedal is suddenly depressed to apply sudden braking in order to avoid unexpected obstacles such as a child or elderly person jumping out, or to avoid rear-ending a car in front that has suddenly stopped. Sometimes. At the time of such sudden braking, it is desirable to warn the driver of the following vehicle of the sudden braking in order to prevent a rear-end collision with the following vehicle.

In conventional cars, brake lights are installed on the rear of the car body.
When braking, a sensor detects changes in brake pressure or the depression of the brake pedal, and lights up the brake lights to warn drivers of cars behind.

However, in the above-mentioned warning method, the brake lights simply turn on when braking, so the driver of the following vehicle cannot tell whether the vehicle in front braked gently or suddenly from only the illumination of the brake lights. As a result, there is a concern that the braking of the following vehicle will be delayed, causing the following vehicle to rear-end the vehicle in front that brakes suddenly, and when braking suddenly, the driver of the vehicle is always exposed to the fear of being rear-ended by the vehicle following. That is the reality.

In addition, if a car collides with some kind of obstacle without pressing the brake pedal at all, the brake lights will not come on and the driver of the following car will not notice the collision with the car in front and may end up rear-ending the car in front. There are concerns.

In response, various sudden braking warning devices have been proposed that detect the braking force acting on the vehicle body using a braking force sensor and turn on or blink a brake light or a warning light separate from the brake light.

For example, as shown in Japanese Unexamined Patent Publication No. 62-295741, the braking force acting on the vehicle body is detected from changes in the level of conductive liquid, and the brake lights are made to blink; As shown in the publications, the braking force is detected from the displacement of the mass body due to the inertial force during braking, and a warning light is turned on.
As shown in Japanese Utility Model Publication No. 33736, a braking force sensor is constructed from a mass body and a spring member, and a warning light is turned on. As shown in
Some devices are known in which the braking force of the vehicle body is detected using an accelerometer.

(Problem to be solved by the invention) However, with the conventional sudden braking warning device,
The brake force sensor may malfunction due to the fluid level changing due to vehicle vibration or driving on a slope, or the moving part of the sensor may operate, causing the brake light or warning light to blink even though it is not during sudden braking. Or there was a problem that the lights would turn on.

In addition, in conventional sudden braking warning devices, the spring member absorbs the negative effects of running vibrations and running on slopes, and there is no risk of sensor malfunction, but due to the biasing force of the spring member, the response of the mass body to sudden braking is On the one hand, there is a problem that a delay occurs and the responsiveness of the braking force sensor is poor, and on the other hand, when the biasing force of the spring member is reduced to improve the responsiveness of the mass body, there is a problem that the braking force sensor is adversely affected by running vibration and running on a slope. Ta.

Furthermore, conventional sudden braking warning devices do not take into account the effects of running vibrations or running on slopes on the accelerometer.

In any case, with conventional sudden braking warning devices for vehicles, due to the structure of the braking force sensor, there is a problem in which the warning light suddenly lights up or flashes due to vibrations or driving on a slope, surprising the driver of the following vehicle. It was hot.

On the other hand, as shown in Japanese Unexamined Patent Publication No. 55-30693, a method has been known for preventing malfunction by immersing the mass body in a liquid in an accelerometer composed of a mass body and a spring member. ing.

Furthermore, as shown in Japanese Patent Application Laid-Open No. 62-19771, a roller is moved along an inclined surface according to the magnitude and direction of acceleration, and the acceleration is detected from the amount of movement. Accelerometers that allow accurate detection have been proposed.

Therefore, if the malfunction prevention method described in JP-A-55-30693 is applied to the accelerometer described in JP-A-62-19771, an accurate braking force sensor that eliminates the influence of running vibration can be obtained. We can expect that.

However, if the rollers are simply immersed in liquid, the liquid will act as resistance to the movement of the rollers.
The problem of delayed response remains. Moreover, it cannot respond to malfunctions when driving on slopes.

In view of this, the object of this invention is to provide a braking force sensor that can accurately and responsively detect braking force without being affected by running vibrations or running on a slope.

(Means for Solving the Problems) Therefore, the braking force sensor according to the present invention is a braking force sensor that detects the braking force acting on the vehicle body, which includes a first case attached to the vehicle body, a first case, a second case rotatably supported within the case around an axis in the vehicle width direction and filled with liquid between the second case and the first case; a weight for holding the second case in a horizontal state; an inclined surface extending in the longitudinal direction of the vehicle; a roller movably provided on the inclined surface; and when the vehicle is braking, the roller moves to a predetermined position on the inclined surface by inertia caused by the braking. The main point is that the device is equipped with a switch that detects when the vehicle has moved to a certain point.

Here, the braking force sensor according to the present invention is highly effective when applied to a sudden braking warning device, but of course it can also be applied to other devices that operate based on braking force.

In addition, when applying the braking force sensor to a sudden braking warning device, a warning light is installed on the vehicle body separately from the brake light.
It is preferable to configure the warning light to turn on or blink based on a signal from a switch when the braking force exceeds a predetermined value.

In this case, the warning light may be installed anywhere on the vehicle body as long as it can be recognized from the rear; for example, it may be installed alongside a conventional brake light. Additionally, this warning light may turn on or flash during sudden braking.
Alternatively, the light may be turned on during sudden braking, and may be made to blink during further sudden braking.

In addition, for controlling the warning light, a conventionally known circuit may be used whether the warning light is turned on or blinked.

(Function) In this invention, the sensor case is
Since this is a double case and the space between both cases is filled with liquid, steering vibrations are attenuated by the liquid between both cases, and almost no running vibrations are transmitted into the inner second case.

Furthermore, since the second case is rotatable relative to the first case and is held horizontally by the weight, the sensor portion is held horizontally even when the vehicle is running on a slope.

Furthermore, since the area around the rollers is not filled with liquid that would cause movement resistance, the rollers move along the slope with good responsiveness during sudden braking.

(Example) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 show a braking force sensor according to an embodiment of the present invention, which is an example applied to a sudden braking warning device for a vehicle. In FIG. 1, a braking force sensor 3 is mounted on a vehicle body 2 of an automobile (vehicle) 1, and detects the magnitude of a braking force B based on the magnitude of an inertial force A acting on a mass body within the vehicle body 2. Above car body 2
A warning light 5 is attached to the rear side of the vehicle in parallel with the brake light 4, and the vehicle body 2 is further provided with a control circuit 6 for turning on or blinking the warning light 5 based on the output of the braking force sensor 3.

In the above-mentioned braking force sensor 3, as shown in FIG. Both cases 7 and 8 are stored in an open state and are supported by a rotating shaft 8b in the vehicle width direction.
Concentric arcuate walls 7a and 8a are formed around the rotating shaft 8b, and the space between the outer case 7 and the inner case 8 is filled with a liquid 10 such as water or oil having a predetermined viscosity. There is.

A weight 11 is fixed to the bottom of the inner case 8, and an arcuate guide rail (slope) 12 having a predetermined curvature is provided inside the inner case 8, and a mass body is mounted on the guide rail 12. roller 13
A switch 1 is placed on the front side of the vehicle body 2 of the guide rail 12 and is turned on by a roller 13.
4 and 15 are provided.

Further, in the control circuit 6, as shown in FIG. 4, one contact of the switch 14 and the switch 15 is connected in parallel to the power supply 16,
The other contact point of the switches 14 and 15 is the warning light 5.
A relay switch 17 is connected between the switch 15 and the warning light 5 and is connected to the switch 15 and the warning light 5, and is connected to the switch 15 and the warning light 5. Here, as the relay switch 17, a configuration similar to that of a turn signal relay used for controlling turn signals is adopted, for example.

Further, the vehicle body 2 is provided with a circuit that detects depression of the brake pedal and turns on the brake light 4, but since this is the same as a conventionally known circuit, a detailed explanation thereof will be omitted.

Next, the operation will be explained.

When the brake pedal is depressed and braking is performed while the car 1 is running, a rearward braking force B acts on the car body 2, and the running speed of the car body 2 decreases.
An inertial force A acts on the mass body within the vehicle body 2. Then, in the braking force sensor 3, the roller 13 rolls forward on the guide rail 12 (see arrow C in FIG. 3) with good responsiveness, and if the brake pedal is depressed slowly at this time, the inertia force A is small, the roller 13 does not reach the switches 14 and 15,
Only the depression of the brake pedal is detected, and the second
As shown in Figure a, only the brake light 4 lights up, allowing the driver of the following vehicle to determine that the preceding vehicle has applied gentle braking.

On the other hand, when the brake pedal is suddenly depressed, the inertia force A increases, and the roller 13 now reaches the switch 14, which turns on.
Then, a current flows through the path between the power source 16, the switch 14, and the warning light 5, and the brake light 4 and warning light 5 light up as shown in FIG. It can be determined that the Furthermore, when the brake pedal is further depressed, the inertial force A becomes even larger, and the roller 13 turns on the switch 15. Then,
A current flows through the path of the power source 16, the switch 15, the relay switch 17, and the warning light 5, and at this time, the relay switch 17 is repeatedly connected and disconnected at predetermined time intervals, so the warning light 5 blinks, and thus, as shown in FIG.
As shown in , the brake light 4 lights up and the warning light 5 flashes, allowing the driver of the following vehicle to determine that the preceding vehicle has applied extremely sudden braking.

Furthermore, if the car 1 collides with some obstacle without depressing the brake pedal, the inertia force A corresponding to the impact will act on the mass body within the car body 2 in the same way as above, and the impact will depend on the magnitude of the impact. Since the warning light 5 lights up or flashes, the driver of the following vehicle can detect an unexpected collision with the preceding vehicle.

In addition, the roller type braking force sensor 3 as described above is also used.
When using a braking force sensor 3, there is a concern that the sensor 3 may malfunction due to running vibrations or running on a slope. 10 absorbs the vibration, the sensor 3 will not malfunction, and when driving on a slope, the liquid 10 will be absorbed into the cases 7 and 8.
During this time, the case 8 slowly rotates around the rotating shaft 8b and is held horizontally by the action of the weight 11, and the sensor 3 will not malfunction in this case as well. .

(Effects of the Invention) As described above, the braking force sensor according to the present invention has the effect of being able to accurately and responsively detect the braking force of the vehicle body without being affected by running vibrations or running on a slope.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing a sudden braking warning device for a vehicle equipped with a braking force sensor according to an embodiment of the present invention, and FIGS. Diagrams showing the lighting and flashing states of the brake light 4 and warning light 5 of the above device, Figures 3a, b,
4c is a side sectional view, a front sectional view, and a plan sectional view showing the braking force sensor 3 in the above device, respectively, and FIG. 4 is a configuration diagram showing the control circuit 6 in the above device. 1... Car (vehicle, 2... Vehicle body, 3... Braking force sensor, 4... Brake light, 5... Warning light, 6...
Control circuit, 7...outer case (first case),
8... Inner case (second case), 10... Liquid, 11... Weight, 12... Guide rail (slope), 13... Roller, 14, 15... Switch,
A... Inertia force, B... Braking force.

Claims (1)

[Scope of Claim for Utility Model Registration] A braking force sensor that detects braking force acting on a vehicle body, comprising a first case attached to the vehicle body, and a sensor that rotates around an axis in the vehicle width direction within the first case. a second case that is freely supported and filled with liquid between it and the first case; a weight that holds the second case in a horizontal state; and a weight that extends in the longitudinal direction of the vehicle body within the second case. an inclined surface formed to extend; a roller movably provided on the inclined surface; and when the vehicle is braked, the roller is moved to a predetermined position on the inclined surface by an inertial force caused by the braking. A braking force sensor comprising a detection switch.