JPH0421199Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a capacitive proximity sensor for automobiles.

[Conventional technology and problems]

Conventionally, as such a capacitive proximity sensor for an automobile, one having a circuit configuration as shown in FIG. 5 is known. The sensor section 1 is installed, for example, near the outside of a bumper corner at the front or rear end of an automobile, and is oscillated at a predetermined frequency by an oscillation circuit 2 connected to the sensor section 1. Here, this sensor unit 1 has a capacitance between it and other objects such as obstacles, and the capacitance increases as the distance from the other object decreases. When another object such as an obstacle approaches, the current value of the output signal from the sensor section 1 decreases.
This output signal is amplified by a high frequency amplifier 4 and a low frequency amplifier 5 via a sensor cord 3, and then judged by a discrimination section 6. If the output signal becomes lower than a predetermined value, a signal is sent to a buzzer drive section 7. By outputting this and making a buzzer 8 sound, a warning of the approach of an object is issued.

Of the above configuration, the other components except the sensor section 1, the buzzer drive section 7, and the buzzer 8 are housed in one control box 9, and this control box 9 is located where the sensor section 1 is installed. It is installed inside the bumper corner.

However, in the automotive capacitive proximity sensor configured as described above, if a so-called remote control pole is provided, for example, at the left end corner of the front bumper of the vehicle, the sensor section 1 is partially attached to the remote control pole. It will have the capacity,
The partial capacitance of the sensor unit 1 differs between cars equipped with the remote control ball and cars without it, resulting in a large discrepancy between the initially set detection distance and the actual detection distance.Especially in the case of an electric remote control pole, the motor also Since they are integrated, the above-mentioned deviation in detection distance becomes significantly large.

[Purpose of invention]

In view of the above points, it is an object of the present invention to provide a capacitive proximity sensor for automobiles that prevents a large deviation in detection distance even in a vehicle equipped with a remote control pole.

[Means and actions for solving problems]

The above object, according to the present invention, includes a sensor section installed near the outside corner of a bumper at the front end or rear end of an automobile, an oscillation circuit connected to the sensor section, and an oscillation circuit connected to the sensor section. A capacitor for an automobile that includes a discrimination circuit that compares an output signal with a predetermined value and detects the proximity of an object if the output signal is less than the predetermined value, and a warning circuit that issues a warning when the discrimination circuit detects the proximity of an object. In the type proximity sensor, the bottom of the control box that houses the oscillation circuit and discrimination circuit extends downward at one edge to form a mounting part, and this mounting part has a plurality of holes arranged parallel to the bottom. The mounting means are provided symmetrically, and in the case of a car that is not equipped with a remote control pole, the sensor part is mounted near the outside of the bumper corner at the front or rear end of the car, and the control box is mounted on the top surface of the car. Attach the sensor part horizontally so that it faces outward near the inside of the bumper corner, and in the case of a car equipped with a remote control pole, install the sensor part near the outside of the bumper corner at the front or rear end of the car. The control box is installed horizontally near the inside of the bumper corner with the top surface facing inward.

According to this invention, when an object approaches the sensor section, the capacitance of the sensor section increases, so that when the output signal from the sensor section by the oscillation circuit becomes lower than a predetermined value. The discrimination circuit detects the proximity of an object and outputs a detection signal.Based on this detection signal, the warning circuit issues a warning.When installing the control box inside the bumper corner, in the case of a car that does not have a remote control pole installed. If the control box is installed with the top surface facing outward, the mounting part extends downward from one edge of the bottom surface, so the control box will not touch the sensor part installed on the outside of the bumper corner. Since the control box is installed relatively close to the sensor, the partial capacity of the sensor part is also relatively large.On the other hand, in the case of a car equipped with a remote control pole, if the control box is installed with its top facing inward, the same effect can be achieved. Since the control box is installed relatively far away from the sensor section on the outside of the bumper corner, the partial capacity of the sensor section relative to the control box is also relatively small. Because of the existence of partial capacitance, the partial capacitance of the sensor section is approximately equal to the partial capacitance of the sensor section when the control box is installed with its top facing outward in the case of a car without a remote control pole. Even when installed on a vehicle equipped with a remote control pole, the deviation in detection distance is extremely small.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on the embodiments shown in the drawings.

FIG. 1 shows an embodiment of a capacitive proximity sensor for an automobile according to the present invention, and the capacitive proximity sensor 10 for an automobile has a sensor portion 11 located outside the front bumper corner of the automobile. Furthermore, the control box 12 is attached to the inside of the bumper corner where the sensor section 11 is attached, as will be described later. The internal structure of the control box 12 is similar to the conventional one shown in FIG.

As shown in FIG. 2, the control box 12 has a bottom extending downward at one edge, and a mounting portion 1.
2a is formed. The mounting portion 12a has a plurality of (in the illustrated case,
The mounting means (4 pieces), for example, the mounting holes 12b, are provided symmetrically, and even when the control box 12 is turned upside down, one of the mounting holes 12b is always aligned with the boss of the mounting part 13 on the bumper side, so that the screws cannot be screwed. It is becoming fixed.

The embodiment of the proximity sensor according to the present invention is configured as described above, and in the case of a car not equipped with a remote control pole, as shown in FIG. 1A,
The sensor unit 11 is attached to the outside of the corner of the front bumper (not shown) of the automobile with screws, and the control box 12 is installed horizontally inside the corner with the top surface facing outside. The mounting hole 12b provided in the mounting portion 12a of the control box 12 is aligned with the mounting portion 13, and the control box 12 is fixed with a screw.

As shown in FIG. 3, the automotive capacitive proximity sensor 10 attached to the corner of the bumper in this manner has the control box 12 attached to the attachment hole 12b provided in the attachment portion 12a.
Since it is located outside the center of , it is located relatively close to the sensor section 11 (distance l ₁ ). Therefore, the partial capacitance _C1 of the sensor section 11 with respect to the control box 12 is relatively large.

In addition, if the vehicle is equipped with a remote control pole, the first
As shown in FIG. The mounting hole 12b of the mounting part 12a of the control box 12 is aligned with the side mounting part 13 and fixed with screws, and the remote control pole 14 is mounted on the outside of the bumper corner via the bracket 14a.

As shown in FIG. 4, the automotive capacitive proximity sensor 10 attached to the corner of the bumper in this manner has the control box 12 located inside the center of the attachment hole 12b provided in the attachment portion 12a. Therefore, it is located relatively far from the sensor section 11 (distance l ₂ ). Therefore, the partial capacitance _C2 of the sensor section 11 to the control box 12 becomes relatively small.
In this case, since the sensor section 11 also has a partial capacitance C ₃ with respect to the remote control pole 14, the sensor section 11 is
It has a partial capacity of (C ₂ + C ₃ ).

Here, if the mounting hole 12b provided in the mounting part of the control box 12 is selected so that the distance l ₀ from the bottom surface thereof becomes the above partial capacitance C ₁ = C ₂ + C ₃ , the remote control pole can be attached. Regardless of whether the vehicle is equipped with a remote control pole or not, the simple operation of simply reversing the installation direction of the control box 12 allows
The partial capacitance of the sensor section 11 can be made substantially constant, and therefore, in any case, the approach of an object can be detected at substantially the initially set detection distance.

[Effect of idea]

As described above, according to the present invention, there is provided a sensor section installed near the outside corner of a bumper at the front end or rear end of an automobile, an oscillation circuit connected to the sensor section, and a sensor using the oscillation circuit. for automobiles, including a discrimination circuit that compares an output signal from a predetermined value with a predetermined value and detects the proximity of an object if the output signal is less than the predetermined value; and a warning circuit that issues a warning when the discrimination circuit detects the proximity of an object. For capacitive proximity sensors, when installing the control box inside the bumper corner, if the car is not equipped with a remote control pole, install the control box with the top facing outward.
Since the mounting portion extends downward from one edge of the bottom surface, the control box is installed relatively close to the sensor portion installed on the outside of the bumper corner. Therefore, the partial capacitance of the sensor section is also relatively large.On the other hand, in the case of a car equipped with a remote control pole, if the control box is installed with its top facing inward,
Similarly, since the control box is installed relatively far from the sensor section on the outside of the bumper corner, the partial capacity of the sensor section relative to the control box is also relatively small.
At this time, since there is a partial capacitance of the sensor part with respect to the remote control pole, the partial capacitance of the sensor part is the same as the partial capacitance of the sensor part when the control box is installed with the top surface facing outward in the case of a car without a remote control pole. Since it is almost equal to the partial capacitance of , the deviation in detection distance is extremely small even when installed on a vehicle equipped with a remote control pole.

Thus, according to the present invention, objects that become obstacles can be detected favorably.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an installed state of an embodiment of an automotive capacitive proximity sensor according to the present invention, FIG. 2 is a perspective view showing a control box of the embodiment of FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing how the remote control pole is attached to a car without the remote control pole installed, and FIG. 4 is a cross-sectional view showing how the remote control pole is installed to a car equipped with the remote control pole. FIG. 5 is a block diagram showing the circuit configuration of an example of a conventional capacitive proximity sensor for automobiles. 10... Capacitive proximity sensor for automobiles, 11
...Sensor part, 12...Control box,
12a...Mounting part, 12b...Mounting hole, 13
...Mounting part on the bumper side, 14...Remote control pole, 14a...Bracket.

Claims (1)

[Scope of utility model registration request] A sensor section installed near the outside of the bumper corner at the front end or rear end of the automobile, an oscillation circuit connected to the sensor section, and an output signal from the sensor section by the oscillation circuit is compared with a predetermined value to determine a predetermined value. In an automotive capacitive proximity sensor, the oscillation circuit and the discrimination circuit include a discrimination circuit that detects the proximity of an object in the following cases, and a warning circuit that issues a warning when the discrimination circuit detects the proximity of an object. The bottom surface of the control box housing the control box extends downward at one edge to form a mounting section, and the mounting section is provided with a plurality of mounting means symmetrically arranged parallel to the bottom surface. In the case of a car that is not equipped with a remote control pole, attach the sensor section near the outside of the bumper corner at the front or rear end of the car, and place the control box sideways at the bumper corner with the top surface facing outward. In the case of a car equipped with a remote control pole, the sensor part should be installed near the outside of the bumper corner at the front or rear end of the car, and the control box should be mounted so that its top surface faces inward. A capacitive proximity sensor for an automobile, characterized in that it is installed horizontally near the inside of the bumper corner.