JPH0618281Y2 - Vehicle raindrop detection device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a raindrop detection device for a vehicle, which can advantageously wipe off raindrops or the like adhering to a window of a windshield of an automobile with a wiper blade, for example.

BACKGROUND ART FIG. 8 is a front view of an automobile 1 showing a prior art.
The figure is a side view of the automobile 1. A light emitting element 4 and a light receiving element 5 are respectively incorporated in a pair of back mirrors 2 and 3 provided in the front part of the vehicle body of the automobile 1. The light from the light emitting element 4 is received by the light receiving element 5. Since the raindrops pass through the optical path between the light emitting element 4 and the light receiving element 5, the amount of light received by the light receiving element 5 decreases, whereby the raindrops are detected. The windshield 6 is wiped by the wiper blade 7 according to such a change in the amount of light in the light receiving element 5.

In such a prior art, the distance between the light emitting element 4 and the light receiving element 5 is relatively long, and therefore the light receiving element 5 receives a sufficient amount of light unless the amount of light emitted from the light emitting element 4 is increased. I can't. Therefore, the efficiency of light energy is poor. It is conceivable that the light from the light emitting element 4 may be converged by using a lens to be guided to the light receiving element 5 to improve the efficiency of light energy. However, in such a case, the configuration becomes large and the back mirrors 2, 3 It becomes difficult to incorporate the light emitting element 4 into the optical disk, or a new problem arises in that the optical axes of the light emitting element 4 and the light receiving element 5 need to be set with high accuracy.

As another prior art for solving such a problem, Japanese Unexamined Patent Publication (Kokai) No.
There is one disclosed in Japanese Unexamined Patent Publication No. 8-112854. This will be described with reference to FIG. 10. A rectangular tubular main body 8 is mounted on the vehicle body of an automobile, for example, on a bonnet. An opening 9 extending vertically is formed in the main body 8.
The light emitting element 10 faces one end of the opening 9, and the light from the light emitting element 10 is received by the light receiving element 11 provided at the other end of the opening 9. As the raindrop passes through the opening 9 and further passes through the light path formed by the light emitting / receiving elements 11 and 10, the light amount by the light receiving element 11 changes, and accordingly the windshield wiper blade is driven. It

In such prior art, raindrops falling in a substantially vertical direction can pass through the opening 9 and be detected,
Even if the raindrops sprayed obliquely cannot pass through the opening 9 even if they pass through the opening 9, it is difficult to detect the raindrops. In this regard, in particular, there is a large tendency that raindrops are not detected while the vehicle is running, which is a big drawback. Another problem with this prior art is that it is difficult to clean the light emitting element 10 and the light receiving element 11 when they become dirty.

Problems to be Solved by the Invention The purpose of the present invention is to be able to detect raindrops reliably, have good light energy efficiency, do not require high precision for installation, and facilitate maintenance such as cleaning. An object is to provide an improved vehicular raindrop detection device.

Means for Solving the Problems The present invention is directed to a vehicle raindrop detection device mounted on a vehicle, wherein a pair of protrusions projecting upward at a predetermined interval in the horizontal direction has a height higher than that of the protrusions. Main bodies that are formed so that the intervals are sufficiently long and the space between the protrusions is open to the outside, a light-emitting element that is mounted in the one protrusion and emits modulated light, and the other protrusion is A light receiving element that is attached and receives the modulated light emitted from the light emitting element, a filter that passes only the component of the modulated light from the light received by the light receiving element, and the output of the filter is detected. A raindrop signal extraction means, and a light path formed by the light emitting element and the light receiving element is mounted on the vehicle so that the light path is horizontal and substantially vertical to the longitudinal direction of the vehicle. Rain for vehicles It is a drop detection device.

According to the present invention, in a raindrop detection device mounted on a vehicle and used for wiper control and the like, a pair of light emitting and receiving elements for optically detecting raindrops are formed on an upper portion of a main body attached to the vehicle. Are arranged in the pair of protrusions, respectively. The protrusions are formed so as to project upward at a predetermined interval in the horizontal direction, and are selected so that the intervals are sufficiently longer than the height of the protrusions. The main body is mounted on a vehicle such that a light path formed between the light emitting and receiving elements is horizontal and is substantially vertical to the front-rear direction of the vehicle.

Therefore, the light path, which is the detection area, is largely opened to the outside, and raindrops sprayed obliquely as well as in the vertical direction can be accurately detected.

Further, modulated light of, for example, 100 kHz is emitted from the light emitting element, and the light received by the light receiving element is detected by the detecting means after only the component of the modulated light is extracted by the filter, A raindrop signal used for wiper control or the like is derived. Therefore. Raindrops can be accurately detected without being affected by outside light.

Embodiment FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention.
A pair of protrusions 14 and 15 are formed at an upper portion of the main body 13 made of a material such as synthetic resin and spaced apart in the horizontal direction. These protrusions 14 and 15 project upward. A light emitting element 16 such as a light emitting diode that emits infrared rays is provided on one of the protrusions 14. The light from the light emitting element 16 is received by the light receiving element 17 provided on the other protrusion 15.
The light is received by. In this way, the raindrop detection device 18
Is configured.

As shown in FIG. 2, the raindrop detecting device 18 is used for the automobile 1
The upper part 2 of the back mirror 20 attached to the door of 9, etc.
0a, which is used to automatically drive the wiper blade 22 that wipes the windshield 21 when it is raining by reciprocating angular displacement as indicated by the arrow 23.
The number of times the wiper blade 22 is driven in the direction of the arrow 23 corresponds to the degree of rain detected by the raindrop detection device 18.

3 is a perspective view of the vicinity of the back mirror 20, FIG. 4 is a sectional view taken along section line IV-IV in FIG. 3, and FIG. 5 is section line V-V in FIG. It is a partial cross section seen from FIG. Mounting holes 24 and 25 are formed in the casing 20b of the back mirror 20, and projections 14 and 15 project upward in the mounting holes 24 and 25.
The main body 13 is inside the casing 20b.

FIG. 6 is a block diagram of an electric circuit related to the light emitting element 16 and the light receiving element 17. The oscillation circuit 27 has, for example, 1
Oscillation operation of 00kHz is performed and its output is the drive circuit 28.
And the light emitting element 16 is driven. Light emitting element 16
The axes of the light receiving element 17 and the light receiving element 17 are aligned with each other.
The light from the light emitting element 16 received by the light source 7 is converted into an electric signal and given to the band pass filter 29. The band pass filter 29 passes and waves a frequency signal of 100 kHz ± 10 kHz, and noise due to sunlight or the like is removed.
The output from the bandpass filter 29 is amplified by the amplifier circuit 30 and given to the detection circuit 31. As a result, only the component of the output fluctuation of the light receiving element 17 caused by the raindrops passing through the optical path between the light emitting element 16 and the light receiving element 17 is extracted and given to the band pass filter 32. The bandpass filter 32 is, for example, 500
It is a wave that passes through a frequency component of not less than Hz and not more than 20 kHz, and only an electric signal due to the raindrop passing through the optical path is integrated by the integrating circuit 33. This integrated output is given to the comparison circuit 35 from the line 34. The integrating circuit 33 integrates the signal generated by the raindrop passing through the optical path. When the integrated output exceeds a predetermined level in the comparison circuit 35, the comparison circuit 35 derives a high level signal on the line 36, whereby the common contact 65 of the switch SW1 switches to the individual contact 37. It conducts. When the output from the integrating circuit 33 input to the comparing circuit 35 is less than the predetermined value, a low level signal is derived on the line 36, whereby the common contact 65 of the switch SW1 is connected to the individual contact 38. There is continuity. Individual contact 38 is line 39
Is applied to the integration circuit 33, and thereby the integration circuit 33 is reset, and the integrated output of the line 34 becomes zero. This individual contact 38 also has another switch SW.
It is connected to two common contacts 40. The common contact 40 of the switch SW2 can be led out by switching to the individual contacts 41 and 42. The individual contact 37 of the switch SW1 and the individual contact 41 of the switching switch SW2 are connected to a power supply 44 via a line 43. Another individual contact 42 is connected to the vehicle body via a line 45, to which a power supply 44 is also connected.

The motor M has three terminals 46, 47 and 48. When electric power is supplied between the terminals 46 and 47, the motor M is rotationally driven at a low speed. When electric power is supplied between the terminals 46 and 48, the motor M is rotationally driven at a high speed. Switch SW
1, the common contact 65, the line 43, the terminals 47 and 48, the line 49, and the vehicle body include the terminals S and S of the switch circuit 50.
B, P1, Q1, C and E are connected respectively.

The switch circuit 50 can be manually switched to any of the switching modes (1) to (4) shown in Table 1 below.

In this switch circuit 50, terminals S, B, P1, Q1, C and E indicated by reference numeral "1" in Table 1 are mutually connected. When the switch circuit 50 is in the switching mode (1), the terminals S and P1 are conductive, and when the switching circuit 50 is in the switching mode (2) for intermittent driving, the terminals S and P1 are conductive. , Terminals C and E indicated by reference numeral "2" in Table 1 are conductive. Similarly, when the switching mode (3) for rotating the motor M at a low speed is set, the terminals B and P1 are conductive. In the switching mode (4) in which the motor M is rotationally driven at a high speed, the terminals B and Q1 are conductive. Such switching modes (1) to (4) can be appropriately selected manually.

The line 49 is connected to the oscillator circuit 27, and when the oscillator circuit 27 is supplied with power via the line 49, the oscillator circuit 27 is activated.

FIG. 7 is a perspective view showing the motor 7 and the structure in the vicinity thereof. A disk 53 made of an electrically insulating material is rotationally driven by the output shaft 52 of the motor 7. This disc 53 has
Conductors 54, 55 extending in the circumferential direction at different positions in the radial direction
Is formed. The common contact 40 of the switch SW2 extending in the radial direction is mounted in a fixed position so as to be able to make common contact with the conductors 54, 55. Individual contacts 42 can contact the conductors 54. The individual contact 41 can contact the conductor 55. The blade 22 is angularly displaced and driven by the output shaft 52 of the motor 7, the blade 22 is in the rest position at the reference position 56, and the blade 22 is reciprocally driven by one rotation of the disk 53, and thus the original position is restored. You can return to the rest position.

Since the wiper blade 22 is automatically driven when it is raining, the switch circuit 50 is set to the switching mode (2) in Table 1. As a result, the terminals C and E are conducted, and the oscillation circuit 27 is activated. Light emitting element 16
When the raindrop passes through the optical path between the light receiving element 17 and the light receiving element 17, the level of the integrated output derived to the line 34 of the integrating circuit 33 increases. When the integrated output is less than a preset value in the comparison circuit 35, the line 36 is at a low level and the common contact 65 of the switch SW1 is electrically connected to the individual contact 38. The wiper blade 22 is in the rest position, and the common contact 40 of the switch SW2 is electrically connected to the individual contact 42 via the conductor 54. Therefore, the terminal 46 of the motor M includes the line 45, the individual contact 42, the common contact 40, the line 39, and the individual contact 3
8, common contact 65, terminals S and P of switch circuit 50
1 is connected to the terminal 47, and the motor M is stopped.

As the raindrop passes through the optical path between the light emitting element 16 and the light receiving element 17, the integrated output rises. When the integrated output exceeds a predetermined value in the comparison circuit 35, the line 36 becomes high level and the switch S
The common contact 65 of W1 is switched to the individual contact 37 to conduct. Therefore, the power from the power source 44 is supplied to the line 43, the individual contact 37, the common contact 65, the terminal S of the switch circuit 50,
It is given to the terminal 47 via P1 and thereby the motor M
Is energized to drive the blade 22 in angular displacement. At the same time, the disk 53 is driven to rotate and the common contact 40
Switches from the conduction state of the individual contact 42 via the conductor 54 to the conduction state of the individual contact 41 via the conductor 55.
As a result, the line 43 is connected to the individual contact 41 and the common contact 40.
And the reset signal is sent via the line 39 to the integrating circuit 3
3 and the integrated output becomes zero. Therefore, the comparison circuit 35 derives a low level signal on the line 36, and the common contact 65 of the switch SW1 becomes conductive with the individual contact 38. Therefore, the power of the power source 44 is supplied from the line 43 to the individual contact 41, the common contact 40, the line 39, and the individual contact 3
Electric power is supplied to the terminal 47 via the common contact 65, the terminals S and P1, and the motor M continues to rotate.

When the blade 22 returns to the rest position, the switch S
The common contact 40 of W1 is switched to the individual contact 42 through the conductor 54 to conduct. Thus, electric power is not supplied to the motor M, and the motor M is deenergized.

The integrating circuit 33 is provided with the light emitting element 1 after being reset.
The integrated output that rises again due to the signal caused by the raindrops passing through the optical path between 6 and the light receiving element 17 is derived and given to the comparison circuit 35. In this way, as the number of passing raindrops increases, the wiper blade 22 is frequently driven to perform reciprocal angular displacement.

Thus, in the raindrop detection device 18 according to the present invention, the main body 1
3 is provided with a pair of protrusions 14 and 15 protruding upward, and the light emitting element 16 and the light receiving element 17 are arranged to face each other in the protrusions 14 and 15, so that these light receiving and emitting elements 17 and 16 are provided. Since the light path between them is not covered with a peripheral wall or the like and is opened particularly in the traveling direction of the automobile 19, raindrops falling obliquely due to the traveling of the automobile 19 can be accurately detected, and the water can be removed. Of course, this can improve the detection accuracy.

Further, since only a minimum of obstacles are projected from the main body 13, there is little possibility that dust or the like will be accumulated between the light paths, and when the light emitting / receiving elements 17 and 16 are dirty, they can be easily cleaned. It can be performed. As a result, maintenance work can be simplified.

The present invention is not only implemented in connection with automobile wiper blades, but can be widely implemented in other applications.

As described above, according to the present invention, in a raindrop detection device mounted on a vehicle and used for wiper control or the like, a pair of light emitting and receiving elements for optically detecting raindrops are mounted on a vehicle body. Of the optical path formed between the light emitting / receiving elements, the upper part of the optical path extending upward at a predetermined interval in the horizontal direction and arranged in a pair of protrusions formed sufficiently lower than the interval. Is mounted on the vehicle so that it is horizontal and is substantially vertical to the front-back direction of the vehicle, so the light path that is the detection area is largely open to the outside, and is sprayed not only vertically but also diagonally. Raindrops can also be detected accurately.

Further, since modulated light of 100 kHz is used between the light receiving elements, raindrops can be accurately detected without being affected by outside light.

[Brief description of drawings]

1 is a perspective view of an embodiment of the present invention, FIG. 2 is a perspective view showing a state in which a raindrop detection device 18 according to the present invention is mounted on an automobile 19, FIG. 3 is a perspective view near a back mirror 20, and FIG. FIG. 5 is a sectional view taken along section line IV-IV in FIG. 3, FIG. 5 is a partial sectional view taken along section line VV in FIG. 3, and FIG.
FIG. 7 is a block diagram showing an electric circuit related to the light emitting element 16 and the light receiving element 17, FIG. 7 is a perspective view showing a configuration related to the motor 7, FIG. 8 is a front view of a prior art, and FIG. FIG. 10 is a side view of the prior art shown in the drawing, and FIG. 10 is a perspective view in which a part of another prior art is cut away. 13 ... Main body, 14, 15 ... Protrusion, 16 ... Light emitting element, 17 ... Light receiving element, 18 ... Raindrop detecting device,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kibun Iyuda No. 1 Toyota-cho, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Seiji Ishikawa No. 1 Toyota-cho, Aichi Prefecture, Toyota Motor Co., Ltd. ( 56) References Japanese Unexamined Patent Publication No. 58-112854 (JP, A) Actually published Sho-49-129584 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A vehicle raindrop detection device mounted on a vehicle, wherein a pair of protrusions projecting upward at a predetermined interval in the horizontal direction are sufficiently longer than the height of the protrusions. Main bodies that are respectively formed and have a space between the protrusions largely open to the outside, a light emitting element that is mounted in the one protrusion and emits modulated light, and a main body that is mounted in the other protrusion and is formed from the light emitting element. A light receiving element that receives the emitted modulated light, a filter that passes only the modulated light component from the light received by the light receiving element, and a detection means that detects the raindrop signal by detecting the output of the filter. A raindrop detection device for a vehicle, comprising: a light emitting element and a light receiving element, the light path being formed in the vehicle such that a light path formed by the light emitting element and the light receiving element is horizontal and substantially vertical to a front-rear direction of the vehicle.