JPS61126452A - Optical detecting device - Google Patents

Abstract

PURPOSE:To detect the concentration of fluid to be detected precisely without any influence of foreign matter by providing a hollow member which spreads outward to an intake, and guiding the fluid to a cylinder body and inhibiting the entry of foreign matter. CONSTITUTION:A fluid admitting member 70 consisting of a rod 72 and cylinder bodies 73 and 74 is provided to the front end part of the cylinder part 80 of a transmitted light type detector S having a light emitting element 32, a photodetecting element 42, etc., across a ring 71 so that it projects from the intake P in a spread shape. Consequently, forward fluid to be detected, e.g. a dust flow is inhibited from entering the cylinder body 80 by the relation between the mutual intervals of the rod 72 and cylinder parts 73 and 74 and their surface shapes, and a lateral powdery dust flow due to a parallel running vehicle, etc., on the other hand, is inhibited by the relation between intervals of the cylinder part 74 and intake P, and cylinder part 74 and ring 71, and the outer surface shape of the cylinder part 74, so that only a dust flow after waste is removed is admitted into the cylinder body 80.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical detection device such as a transmitted light type or a scattered light type.

[Prior art]

Conventionally, this type of optical detection device has a cylindrical introduction part that introduces the fluid to be detected into the interior through an inlet, and a peripheral wall of the cylindrical introduction part that is provided on both sides of the cylindrical introduction part. first and second cylindrical accommodating parts each having an opening that opens into the first cylindrical accommodating part; a light emitting body that is housed in the first cylindrical accommodating part and emits light toward the opening of the first cylindrical accommodating part; a photoreceptor that is housed in the second cylindrical housing part so as to receive light from the light emitter through its opening and detects a change in the amount of received light that occurs when the detected fluid is introduced into the cylindrical introduction part; There is a structure composed of

[Problem that the invention seeks to solve]

By the way, when the optical detection device configured as described above is placed at an appropriate location on the vehicle body, for example, as a dust sensor for a vehicle interior/exterior air switching control system, dust may be introduced into the cylindrical introduction portion through the introduction port. If dirt attached to the dust is introduced together with the dust, or if mud, water, etc. enter the cylindrical introduction part depending on the placement position of the dust sensor, the amount of light received by the photoreceptor from the light emitter may decrease. filth,
It will also fluctuate due to foreign substances other than dust such as mud and water. In other words, the dust sensor detects not only dust but also foreign matter other than this dust, so the detection result of this dust sensor is incorrect and the control to switch and introduce outside and outside air into the vehicle interior becomes inappropriate. occurs. Furthermore, there is a risk that the optical mechanism provided in the light emitter, the photoreceptor, or the dust sensor may be contaminated by the above-mentioned foreign matter, leading to a decrease in the optical function of the dust sensor.

The present invention aims to solve these problems by 1. In the optical detection device described above, foreign matter other than the fluid to be detected is prevented from entering the cylindrical introduction portion.

[Means for solving problems]

In solving this problem, the structural features of the present invention are as follows:
In the above-mentioned optical detection device, the cylindrical introduction part is provided with a hollow member that protrudes outward from the central part of the introduction port of the cylindrical introduction part, and the hollow member protrudes outward from the center of the introduction port of the cylindrical introduction part. A forward fluid portion from the front is guided into the inlet through the hollow part of the hollow member, and a lateral fluid portion from the lateral direction of the inlet of the detected fluid is guided along the outer peripheral surface of the hollow member. The present invention is arranged so that it is guided into the introduction port.

[Function and effect of the invention]

By configuring the present invention in this way, even if various foreign substances such as dirt, water, and dirt attached to each particle of the detected fluid try to enter the cylindrical introduction part together with the detected fluid, The hollow member prevents the foreign matter from entering the cylindrical introduction section on its inner circumferential surface side and outer circumferential surface side, and a portion of the fluid to be detected from which the foreign matter has been removed flows from the front of the hollow member. The fluid to be detected is smoothly guided and introduced into the cylindrical introduction part through the hollow part, and the remaining part of the fluid to be detected enters the cylindrical introduction part from the lateral direction along the outer peripheral surface of the protruding part from the introduction port of the hollow member. Since it is smoothly guided into the introduction port, the various foreign objects mentioned above do not affect the decrease in the amount of light received by the photoreceptor (as a result, the detection results of this photoreceptor are transmitted in all directions into the introduction port). It can be obtained with high accuracy that correctly corresponds to the concentration of only the fluid to be detected flowing in from the fluid.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
The figure shows a transmitted light type detector S according to the present invention applied to the vehicle internal/external air switching control system shown in FIG. 2, and as shown in FIG. A cooling fan 10a of the radiator 10 located on the front side of the
It is attached to a part of the front surface 11a of the front grill 11 in front of the front grill 11. The detector S is equipped with a casing 20, as shown in FIG. 1 and FIGS. It is attached to a part of the front 11a of.

Inside the casing 20, an insertion hole 21 is formed in the vertical direction as shown in FIG. is formed.

A light emitter 30 is installed in the small hole 22a of the stepped hole 22, and a light receiver 40 is installed in the small hole 23a of the stepped hole 23.
is assembled. The light emitter 30 has an annular member 31 made of a synthetic resin material, and this annular member 31 is
The annular protrusion 31a formed on the outer periphery of the stepped hole 22 is coaxially fitted into an annular groove formed along the inner circumferential surface of the small hole 22a of the stepped hole 22 against elasticity. . A light emitting element 32 is fitted into the hollow part of the annular member 31 with its light emitting surface facing the opening of the stepped hole 22.
The light emitting axis of 2 coincides with the axis of the stepped hole 22. In such a case, the light emitting element 32 has a built-in light emitting diode 32a (see FIG. 2), and the light emitting diode 32a emits light generated by intermittent conduction in a pulsed manner along the light emitting axis.

The light receiver 40 has an annular member 41 made of a synthetic resin material, and this annular member 41 has an annular protrusion 4.1a formed on its outer periphery inside the small hole 23a of the stepped hole 23. It is assembled by fitting coaxially into an annular groove formed along the circumferential surface against elasticity. A light receiving element 42 is fitted into the hollow part of the annular member 41 with its light receiving surface facing the opening of the stepped hole 23, and the light receiving axis of the light receiving element 42 is aligned with the axis of the stepped hole 23, that is, the light emitting element. It coincides with the emission axis of No. 32. In such a case, the light receiving element 42 is a phototransistor 42a.
(see FIG. 2), and this phototransistor 42a intermittently generates light reception pulses caused by intermittent conduction associated with intermittent light reception.

The inner peripheral surface of the large hole portion 22b of the stepped hole 22 has four (hard annular grooves 22c, 22d, 22e, and 22f in steps).
They are arranged in parallel at a predetermined interval perpendicular to the axis of the hole 22,
In each of these annular grooves 22c, 22d, 22e, 22f,
Four rectangular shielding plates 50, 51, 52, and 53 are assembled by fitting their respective outer peripheral edges. In addition, a small hole 5 is provided in the center of each shielding plate 50, 51, 52, 53.
0a, 51a, 52a, 53a are drilled, respectively, and the both-hand holes 50a, 51a have the same opening area (for example, have a straight t'M 4, 5 mm), and the both-hand holes 52a, 53a, Together, each small hole 50a,
Same opening area wider than 51a (for example, 6.5 mm in diameter
).

On the other hand, on the inner peripheral surface of the large hole portion 23b of the stepped hole 23, four annular grooves 23C123d, 23e, and 23f are arranged in parallel at predetermined intervals at right angles to the axis of the stepped hole 23,
In each of these annular grooves 23c, 23d, 23e, 23f,
Four rectangular shielding plates 60, 61, 62, and 63 are assembled by fitting their respective outer peripheral edges. In addition, a small hole 6 is provided in the center of each shielding plate 60, 61, 62, 63.
0a, 61a, 62a, and 63a are drilled, respectively, and the opening area of each of the two-hand holes 60a and 61a is equal to that of each small hole 50a.
, 51a, and both hand holes 62a.
, 63a correspond to the opening area of each small hole 52a, 53a.

At the front end of the insertion hole 21 of the casing 20, that is, within the introduction port P, there is a fluid introduction member 7 integrally molded from a synthetic resin material.
0 is assembled as shown in FIG. The fluid introducing member 70 is shown in FIGS. 1, 5, 6, 7, and 8.
As shown in the figure, it has a ring 71 that is engaged with the stepped part 21a of the insertion hole 21, and the hollow part of this ring 71 has a
Two auxiliary arms 71a and 71b are formed integrally with the inner peripheral surface of the ring 71 in a cross shape. The rod 72 has a predetermined thickness and protrudes forward by a predetermined length from the front end Pa of the introduction port P coaxially with the insertion hole 21 from the center of both auxiliary arms 71a and 71b. It is formed into a spherical shape so that a forward fluid portion of dust fluid and other detected fluids from the front of the inlet P can be smoothly introduced into a cylinder 80 to be described later.

Further, the fluid introduction member 70 has a pair of cylindrical portions 73 and 74, and these cylindrical portions 73 and 74 both extend concentrically from both auxiliary arms 71a and 71b to the rod 72 and are identical to the rod 72. The length extends forward of the front end Pa of the introduction port P in a widening shape. In such a case, each of these cylindrical portions 13
．． The curvature of the tip of 14, the radial spacing between each cylindrical portion 73 and 74, and the radial spacing between cylindrical portion 73 and rod 72 are determined to prevent dirt, water, dust deposits, and other various foreign substances from forming on the cylindrical body. 80
The forward fluid portion is connected to the cylindrical body 80 while preventing the fluid from entering the inside.
It is designed so that it can be smoothly introduced into the interior. Further, the predetermined length of each cylindrical portion 73, 74, the radial distance between the cylindrical portion 74 and the inlet P, and the radial distance between the cylindrical portion 74 and the ring 71 are determined by the fluid to be detected. The lateral fluid portion flowing laterally along the front end Pa of the inlet P is smoothly introduced into the cylindrical body 80 while preventing mud, water, dust deposits, and various other foreign substances from entering the cylindrical body 80. It is set up so that it can be introduced. The curvature of the tip of the cylindrical portion 74 is set in consideration of smooth introduction of the transverse fluid portion into the cylindrical body 80 along the outer peripheral surface of the cylindrical portion 74.

The cylinder 80 is fitted into the insertion hole 21 so as to be engaged with the ring 71 of the fluid introduction member 70, and the flange portion 81
At step 21b of the insertion hole 21, tighten the screws 81a to 81a.
(See Figures 1, 4, and 5). As shown in FIG. 4, openings 82.83 are provided in the circumferential wall portions of the cylindrical body 80 facing each other on the axis of the stepped holes 22.23 of the casing 20. Each of these openings 82.
The small holes 53a of each shielding plate 53.63 have the same opening area and are much narrower than the inner diameter area of the cylinder 80.
It is wider than the opening area of 63a.

In this embodiment configured as described above, if the detector S according to the present invention is connected to the internal/external air switching control system of the vehicle as shown in FIG. The light emitted from the light emitting diode 32a, that is, the light emitting element 32 cooperates with each shielding plate 5 along its light emitting axis.
The small holes 50a to 53a numbered 0 to 53 are sequentially passed through to the inside of the cylindrical body 80 and straight from the opening 82. Thus, the light that has gone straight into the cylinder 80 passes through the opening 83 of the cylinder 80 and the small holes 632 to 60a of each of the shielding plates 63 to 60, and passes through the light receiving element 4.
2, the light is received on its light receiving axis. Then, in response to intermittent light reception from the light emitting element 32, the phototransistor 42a of the light receiving element 42 is turned on intermittently to sequentially generate light reception pulses, and in response to each of these light reception pulses, the signal processing circuit 1
00 generates detection pulses sequentially.

At such a stage, the dust flow may reach the front grill 11.
When the dust flow tries to flow into the cylinder from the front, the dust flow passes through the fluid introduction member 70 and is introduced into the cylinder 8o, and the light receiving element 4
2. That is, the amount of light received by the phototransistor 42a decreases in accordance with the concentration of the dust flow, and the vibration value of each light reception pulse from the phototransistor 42a, that is, each detection pulse from the signal processing circuit 100, decreases accordingly. . In such a case, even if various foreign substances such as mud, water, and dirt attached to each part of the dust in the dust flow try to enter the cylinder 80 together with the dust flow, these foreign substances will be blocked by the rod 72 of the fluid introduction member 70 and each cylinder. Due to the mutual spacing between the sections 73 and 74 and the respective surface shapes of these rods and the tube sections, intrusion into the tube body 80 is prevented, and only the dust flow from which dirt has been removed flows through the rod 72 of the fluid introduction member 70 and the respective surface shapes of the rods and tube sections. Since the foreign matter is smoothly introduced into the cylindrical body 80 along the inner and outer surfaces of the cylindrical portions 73 and 74, the above-mentioned foreign matter does not affect the reduction in the amount of light received by the phototransistor 42a, and as a result, the foreign matter is introduced from the phototransistor 42a into the cylindrical body 80. The amplitude value of each of the received light pulses (that is, each detection pulse from the signal processing circuit 100) is accurately reduced in accordance with only the dust concentration.

In addition, the front surface 11 of the front grille 11 of the vehicle may be damaged due to other vehicles running on the side of the vehicle or other causes.
When the dust flow flows laterally along the direction a, the dust flow collides with the outer peripheral surface portion of the inlet P of the cylindrical portion 74 of the fluid introduction member 70 protruding from the front wheel portion Pa, and the rear cylindrical portion The dust particles are guided into the introduction port P along the outer peripheral surface of the dust flow and introduced into the cylindrical body 80, and the amplitude value of each detection pulse from the signal processing circuit 100 decreases in accordance with the concentration of the dust flow, as described above.

In such a case, even if the various foreign substances mentioned above try to enter the cylindrical body 80 together with the lateral dust flow, these foreign substances may interfere with the distance between the cylindrical part 74 and the inlet P, and the rings 7 and 1 between the cylindrical part 74 and the cylindrical part 74.
Due to the distance between the cylindrical part 74 and the shape of the outer surface of the cylindrical part 74, intrusion into the cylindrical body 80 is prevented, and only the dust flow from which dirt has been removed flows smoothly into the cylindrical body 80 along the outer surface of the cylindrical part 74. As described above, a decrease in the amplitude value of each detection pulse from the signal processing circuit 100 results in an increase in accuracy corresponding only to the dust concentration.

In addition, the detector S is configured as described above (radiator
Since the radiator 10 is located in front of the radiator 10, the outside air flow (including the dust flow) immediately before entering the radiator 10
is introduced into the detector S, and as a result, the detector S can always detect changes in actual dirt (i.e., dust concentration) in the outside air with high precision, sensitivity, and responsiveness. obtain. Moreover, as mentioned above, the detector S is connected to the radiator 1
Since it is located in front of the cooling fan IQa of 0, each dust flow in the forward direction and/or the lateral direction is caused to flow inside the detector S based on the negative pressure generated behind the front grill 11 due to the operation of the cooling fan 10a. Since the vehicle is actually introduced from the front and/or side, even if the vehicle is stopped,
The same effects as described above can be achieved reliably.

In addition, each opening 82.83 of the cylinder 80, the shielding plate 52.53
．． 62, 63, and shielding plates 50, 51, 60.
Since the opening area of each small hole 61 is determined as described above, the small hole 53a of the dust flow shielding plate 53 and the shielding plate 6
The inflow direction component into the small hole 63a of No. 3 almost never occurs. Further, if a part of the dust flow is caused by each small hole 53a,
2a (or each small hole 63a, 62a) through stepped hole 2
2 (or 23), both hand holes 51a
, 52a (or 61a, 62a) is larger than the difference in opening area between the two-hand holes 53a, 52a (or 63a, 62a), so a part of the dust flow flows through each small hole 51a, 50a ( or 61a, 60a) without reaching the light emitting element 32 (or light receiving element 42), and both shielding plates 5]a, 52a (or 51a, 62a)
between and both shielding plates 50a, 5Ia (or 60a, 61
a) The part of the dust flow that has entered the gap becomes a diffusion flow, efficiently flows backward toward the larger small hole, and returns into the cylinder 80. Therefore, the light-emitting surface of the light-emitting element 32 and the light-receiving surface of the light-receiving element 42 are reliably protected from dirt caused by dust flow, and their optical functions can always be maintained normally.

As described above, when each detection pulse is sequentially generated from the signal processing circuit 100, each detection pulse from the signal processing circuit 100 is digitally converted by the AD converter 110. Then, the microcomputer 120
Based on the digital conversion value from the D converter 110, the inside air inlet 15 of the air duct 15 (see Fig. 2) of the vehicle concerned is
performs calculation processing necessary for controlling the switching damper 16 that selectively opens and closes the outside air inlet 15a and the outside air inlet 15b, generates this as an output signal, and cooperates with a drive circuit 130 in which the servo mechanism 17 responds to the output signal. The switching damper 16 is actuated. In such a case, the detector S, that is, the signal processing circuit 10
As mentioned above, the actual concentration state of only the dust flow contained in the outside air flow immediately before entering the radiator 10 is detected from all directions of the front grille 11 based on the normal optical function of the detector S. Since each detection pulse is generated based on the inflowing dust flow, the switching control of the switching damper 16 is always performed in a responsive and appropriate manner according to the actual change in dirt in the outside airflow. The introduction of dirty outside air, that is, the introduction of dirty outside air from the front and/or side directions of the vehicle, can be reliably prevented regardless of whether the vehicle is running or stopped.

In the above embodiment, the detector S was attached to a part of the front face of the front grill 11, but instead of this, the detector S was attached to a part of the back face of the front grill 11 as shown in FIG. (corresponds to the front of the cooling fan 10a)
Alternatively, even if it is attached to the front side of the radiator 10 at the rear thereof, the same effects as in the above embodiment can be achieved.

In addition, in carrying out the present invention, the detector S is
As shown in the figure, the detector S may be installed at the center of the lower edge of the front bumper 12 of the vehicle.
If an appropriate fan is integrally provided behind the vehicle, the same effects as in the above embodiment can be achieved by operating the fan while the vehicle is stopped.

In addition, in the embodiment described above, the dust flow is smoothly introduced into the cylinder 80, and various foreign substances such as mud and water are removed from the cylinder 80.
The fluid introduction member 70 serves as a means for preventing intrusion into the interior of the
Although an example employing this fluid introduction member 70 has been described, the present invention is not limited to this, and a member having the same function as this fluid introduction member 70 may be employed in place of the fluid introduction member 70. In such a case, one example is one in which the cylindrical portion 73 (or 74) of the fluid introduction member 70 is omitted.

Further, in the above embodiment, an example was described in which four square shielding plates were arranged in parallel in each stepped hole 22 and 23 of the casing 20, but the number of shielding plates is not limited to this. It may be implemented with modification, and in such a case, for example, a circular shielding plate may be adopted instead of each of these shielding plates.

Furthermore, in the above embodiments, an example in which the present invention is applied to a transmitted light type detector S has been described, but instead of this, the present invention may be applied to a scattered light type detector.

Further, in the above embodiment, an example in which the present invention is applied to an internal/external air switching control system for a vehicle has been described, but instead of this, the present invention may be adopted and implemented as a fire detector, for example.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a transmitted light type detector according to the present invention, Fig. 2 is a block diagram of a vehicle internal/external air switching control system to which the detector in Fig. 1 is applied, and Fig. 3 is the arrangement of the detector. figure,
Figure 4 is a side view with the main parts broken away, Figure 5 is the rear view, Figure 6 is the front view, Figure 7 is a partially cutaway side view of the fluid introduction member in Figure 1, and Figure 8 is the front view. This figure, as well as FIGS. 9 and 10, are diagrams showing modified examples of the arrangement locations of the detectors. Explanation of symbols P...Inlet, S...Transmitted light type detector, 20...
Casing, 22.23...Stepped hole, 32...Light emitting element, 42...Light receiving element, 70...Fluid introduction member,
74...Cylinder part, 80...Cylinder body.

Claims (1)

[Claims] A first tube having a cylindrical introduction section for introducing the fluid to be detected into the interior through the introduction port, and openings provided on both sides of the cylindrical introduction section and opening into the inside of the cylindrical introduction section through the peripheral wall of the cylindrical introduction section.
a second cylindrical accommodating part; a light emitting body housed in the first cylindrical accommodating part and emitting light toward an opening of the first cylindrical accommodating part; and a photoreceptor that is housed so as to receive light from the light emitter through the tube and detects a change in the amount of received light that occurs when the fluid to be detected is introduced into the cylindrical introduction section. A hollow member protruding outward from a central portion of the introduction port of the cylindrical introduction portion is provided in the cylindrical introduction portion, and a forward fluid portion from the front of the introduction port of the fluid to be detected is directed into the hollow member. The fluid is guided into the introduction port through the hollow part of the member, and a lateral fluid portion of the detected fluid from the lateral direction of the introduction port is guided into the introduction port along the outer peripheral surface of the hollow member. An optical detection device featuring: