JPH0660837B2 - Liquid level measuring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid level display device, and more specifically, it uses a photoconductive portion, a light source and a light receiving portion, and the photoconductive portion is a liquid to be measured. The present invention relates to a device in which the refraction characteristic of the surface of the photoconductive portion changes as it is immersed in the light.

[Conventional technology]

U.S. Pat. No. 3,448,616 discloses a representative device of the type described above using a tapered photoconductive portion for measuring the liquid level. The photoconductive rod is mounted vertically in the tank, and a light source and a photodetector are provided at the upper end of the photoconductive rod. As the liquid surface rises and the water immersion portion of the photoconductive rod increases, less light is refracted from the interface between the photoconductive rod and the liquid, and the amount of light received by the photodetector decreases. In this way, the photodetector will be sensitive to the degree of immersion of the photoconductive rod in the liquid.

U.S. Pat. No. 3,299,770 discloses a device for measuring the liquid level in a conduit, which device comprises a uniform transparent rod with a light reflecting surface at its lower end. The measurement is carried out by directing a light beam downwards into this rod and detecting with a photocell the light reflected upwards from the interface between the rod and the liquid.

A similar device is described in US Pat. No. 3,766,395.
No. 3,834,235, No. 4134022, No. 4242590, No. 4354180, and No. 4
It is also disclosed in the specification of 458567.

Also, US Pat. Nos. 3,917,411 and 3
No. 932038 and No. 3977790,
Various types of transparent rods that refract light to measure liquids have been disclosed. Unlike the US patents listed in the preceding paragraph, these three US patents disclose a measuring device for measuring the density or specific gravity of a liquid. In these devices, a photodetector in combination with a transparent rod receives an amount of light that varies with density or specific gravity.

[Problems to be solved by the invention]

Most of the devices disclosed in the above-mentioned patents have a transparent rod that is elongated and exposed over most of its length, making it susceptible to damage.

Further, most of the liquid level sensors disclosed in the above-mentioned U.S. patents are designed to be mounted in a substantially vertical position on the container, i.e., the transparent portion is positioned vertically downward. It is normally attached to the top cover of the container while stretched. Therefore, it is unsuitable for use in automobiles.

For years, there has been a need for a rugged, reliable, convenient automotive level indicator that could be mounted on the vertical wall of an oil pan. Eliminating the various moving parts was also important. This is because mechanical floats and switches that combine moving parts are considered unreliable. Furthermore, not only the temperature range in the oil pan is wide, but it is also necessary to withstand harsh environments such as mechanical shock and engine vibration during operation. The indicator was not suitable.

An example of a measuring device dedicated to measuring the liquid level in an oil pan is disclosed in US Pat. No. 3,939,470. In the device disclosed in this patent specification, two sensors each composed of a resistance element whose resistance value changes according to temperature are used, and one resistance element is positioned on one longitudinal wall of the oil pan and the other is positioned. The resistance element is mounted on an adjacent wall in a direction perpendicular to the former resistance element. This is to compensate for errors that may occur when taking a reading when the vehicle is not in a horizontal plane.

The invention disclosed in this patent specification aims to solve the problem of reading error that occurs when the vehicle is tilted, but a technical solution using two detection elements is provided. Is deficient, and it is believed that reading errors will occur if the vehicle attempts to lean to one side or from front to back.

Further, an optical sensor having a conical tip that is to be immersed in the liquid to be measured has been required until now to operate with the axis of the conical tip vertically arranged. Was there. According to the invention of the present application, a sensor with a conical tip may be mounted with its axis substantially horizontal, i.e. as if mounted on the longitudinal wall of the oil pan, which is significantly and unexpectedly good. Can be obtained. Furthermore, since extremely high sensitivity is obtained, fluctuations of the order of 3 mm in length in the area of the sensor unit can be detected with excellent repeatability and reliability.

The above-mentioned drawbacks of conventional liquid display devices are overcome by the present invention. The invention of the present application is a remarkably simple structure, resistant to damage, and reliable in operation on the upper side even when used for a long time. An improved display device that prevents inaccuracies and errors in detection and reading, and liquid level in response to certain movements including the driver of the car such as opening the door and removing the gas tank cap To provide an apparatus for automatically starting reading, in which a transparent prism having a conical tip has annular grooves for increasing efficiency, and an apparatus for preventing undesired leakage of a liquid to be measured. With the goal.

[Means for solving problems]

The purpose of these is to provide a novel liquid level indicator attached to the wall of the oil pan, which is composed of a mounting portion having a bowl-shaped container having a through hole and formed with a male screw for screwing, and a detection component arranged in the through hole. Achieved by the device. Inside the bowl-shaped container, a wall made of a prism having a conical end portion that is immersed in the liquid to be measured is formed. A light source, a light sensitive mechanism, and a mounting mechanism for these are provided in the container. The prism is formed so as to enclose a conical concave portion that has the same axis as the conical end exposed to the outside, and the light from the light source passes through the surface of this concave portion and is exposed to the outside. Is bent toward the prism end by refraction, and the light ray reflected from the conical exposed end passes through the surface of the conical recess, and is bent toward the light-sensitive mechanism by refraction.

The novel display device according to the present invention is a molded body in which a bowl-shaped liquid having a bottom wall integrally formed in a translucent plastic material and provided with a prism forming portion in the transverse direction does not enter, In order to ensure accurate and practical reading regardless of whether the molded body is mounted vertically or horizontally on the wall of the liquid container or on its surface, it is necessary to have a molded body in which the prism forming part is arranged. Characterize. A small light emitting diode and a small photosensitive element are provided in the molded body along with the prism forming portion, and by arranging them side by side, each can supply light and receive light from the prism forming portion. I am doing it. These elements arranged side by side are arranged at an angle with respect to each other, and face the conical concave portion formed in the prism forming portion to reduce the size, thereby achieving a size reduction of the device. The reduced size allows the entire device to fit within the relatively small holes formed in the wall of the liquid container. For ease of installation, the hole in the wall of the liquid container can be threaded and the detection device can be retained in a threaded bush that is screwed into the hole by biting a liquid tight seal.

Other features and unique effects will be described later.

〔Example〕

Referring to FIGS. 1 and 9 to 11, the metal fitting 10 is provided with a body 12 having a screw 14 and a hexagonal head 16. This body 12
The inner projecting edge 17 of is circular. The fixture 10 is
The sealing washer 20 can be bitten and screwed onto the side wall of the vehicle oil pan 18. The insulating connector block 22 of the fixture 10 is provided with guide holes 24 for three conducting projections 26, 28 and 30 for connection with a wiring harness of an automobile as shown in FIG. The connector block 22 includes these energizing protrusions 26, 28 and 30.
To form a concave portion 32. The connector block 22 has
As shown in FIG. 4, FIG. 7 and FIG. 8, a slope 33 that is interrupted is formed and a skirt 34 is formed to protect the protrusions 26, 28 and 30. Ribs 35 are connected to the skirt 34.

The connector block 22 is formed with an annular step portion 36 to be tightened by the flange of the fixture 10.

The skirt 34 is provided with a fixing projection 37. The step 40 (see FIG. 9) formed in the fixture 10 mates with the step 42 (see FIG. 5) of the connector block 22. A ridge 44 is formed on the step portion 42, and sealing is performed by the concave ring 46.

In the inner hole of the fitting 10, an improved sealed sensor device 50 for measuring the liquid level in the oil pan 18 is provided. The sensor device 50 comprises an annular body 52 having a prism 54 on the bottom wall. In the annular body 52, the condenser lens 5
In addition to the light source 56 including the light source 7, the lead wires 58 and 60 connected to the conducting protrusions 28 and 30, the optical sensor 62 including the condenser lens 63, and the three lead wires 64, 66 and 6 are provided.
And 8 are accommodated. The lead wire 64 has a protruding portion 28 for energization.
The lead wire 66 is connected to the conducting projection 28 via the resistor 70, and the lead wire 68 is connected to the conducting projection 2.
Connect with 6. The prism 54 is made of a transparent or semitransparent heat-resistant material such as yellow polyether sulfone. A holding block 72 is provided in the annulus 52 and constitutes the correct receiving part 74, 76 for the light source 56 and the optical sensor 62.

The light source 56 can be an infrared light emitting diode,
The sensor 62 may also be a phototransistor.

The holding block 72 has a step portion 7 having five holes 80.
8 and the lead wires 64, 66 and 68 are provided in these holes.
Pass through. Light emitting diode 56 and phototransistor 62
Each bottom portion of the abuts a step 78.

The conductive protrusions 26, 28 and 30 are all the same. As shown in FIGS. 15 to 17, the current-carrying protrusion 26 includes leg portions 81 and 82 and a mounting hole 86.
And a U-shaped portion including a coupling portion 84 having
The three conducting projections are the finger-shaped pieces 8 of the holding block 72.
Fits in each of 8, 90 and 92. These finger mold pieces include
Mounting holes 94, 96 and 98 having the same axis are formed.

After soldering the lead wires 58 and 60 from the light emitting diode 56, the lead wires 64 and 68 from the phototransistor 63, and the lead wires from the resistor 70 to the conducting projections 30, 28 and 26, These are connector blocks 2
It is inserted into the guide hole 24 of No. 2 and assembled into the annular body 52. The surface 99 (see FIG. 12) of the annular body 52 meshes with the step portion 101 (see FIGS. 5 and 8) provided on the connector block 22.

The prism 54 has a conical surface 102 that is immersed in the liquid to be measured.
This conical surface forms a fitting 1 for protection.
It is located in a recessed area within 0.

According to the present invention, the conical concave portion 104 having the same axis as the conical surface 102 is formed inside, and the light emitting diode 5
6 and the phototransistor 62 are mounted at an angle to the axis of this conical surface. Furthermore, the annular groove 1
06 surrounds the conical recess 14 and forms a well-defined area through which the light rays pass.

1 and 34 show details and compactness of the device. The prism 54 has cylindrical walls 54a and 54b and a thin portion 54c formed between these cylindrical walls. With these, the bottom wall is configured together with the prism 54. The light rays shown by the arrows in FIG.
It reflects through 4 and is used with an electronic circuit described later to exert its detection ability.

The optical angle between the axis of the inner conical surface 102 and the axes of the light emitting diode 56 and the phototransistor 62 is about 9 °. The angle between the surface of the conical recess 104 and the cross section is 9
It is optional between 0 ° and 13 °, and is typically 11 °. The rays emitted by the light emitting diode 56 are bent by refraction as they enter the transparent portion of the annulus 52.
In addition, the light beam is directed toward the conical surface 102 toward the prism 5
As it passes through 4, the rays are substantially parallel to the prism axis. As the ray exits the conical recess 104, the reflected ray bends and strikes the phototransistor 62. At this time, the light rays are substantially parallel to the axis of the phototransistor 62. The annular groove 106 blocks a part of the light from the light emitting diode 56, and most of the blocked light is scattered and does not reach the conical surface 102. The distance between the conical surface 103 and the conical recess 104 is approximately the same as the maximum diameter of the conical surface 102. Conical recess 1
04 is relatively flat compared to the conical surface 102.

In accordance with the present invention, the conical surface 102 is relatively small, which includes a shallow conical recess 104 and an annular groove 106.
And, with the angled arrangement of the light emitting diode 56 and the phototransistor 62, provides a very accurate and significantly higher sensitivity. In the transverse direction of the conical surface 102, the measurement can be accurately performed even in the range of only about 3 millimeters.

An annular groove 108 is formed so as to surround the conical surface 102 to prevent the occurrence of capillarity.

The present invention also provides an improved vehicle tilt detector 110 that can be used with the sensor device 50 described above, and a control circuit shown in FIG. 32 that eliminates reading errors.

The inclination detector 110 shown in FIGS. 18 to 27 is
It is composed of two divided cases 112 and 114 made of a transparent material. One case 112 shown in FIGS. 21 to 23.
Is in the shape of a bowl and has an annular step portion 116 formed inside, and the other case 114 can be fitted into this step portion. The other case 114, as shown in FIGS. 24 to 27, includes a flat plate-shaped body having a conical recess 118 formed on the inner surface thereof. One case and the other case are sealed with a gasket 119. Both cases 112 and 114 have an annular protrusion 12 with the same axis.
0 and 122 are provided. A light emitting element 124 is provided on the annular protruding portion 122, and a light receiving element 126 is provided on the other annular protruding portion 120. The opaque sphere 128 can move within the combined case. Lead wires 129 and 1
Bend 30 and 132, 134 and 136 at right angles,
It is attached to the printed circuit board 138. Printed circuit board 138
A notch 140 for attachment is formed in the.

The printed circuit board 138 is suitably mounted in the vehicle so that the conical recess 118 faces vertically upwards when the vehicle is in a substantially horizontal position. The sphere 128 occupies the center of the conical recess 118 by the action of gravity, and when in the center, the sphere blocks the light rays from the light emitting element 124 and prevents most of the light rays from reaching the light receiving element 126. Can be prevented. If the car is tilted at 5 ° or 10 °, a sphere of 128
Moves out of the optical path and moves outward in the radial direction as shown by the dotted line in FIG. In this way, the light receiving element 12
The 6 can be used to prevent reading errors by providing information about the tilt of the vehicle.

A plurality of ribs 142 may be provided so as to extend in the radial direction so as to weaken the movement of the sphere 128. Support legs 144 and 146 are provided on one case 112,
The other case 114 also has similar support legs 148 and 15
It is good to set 0.

FIG. 32 shows a vehicle battery 152, an ignition switch 154, a door side pillar switch 156, a light emitting diode 56, and a phototransistor 6.
2, the resistor 70, the light emitting element 124, and the light receiving element 12
6 and 6 are shown. The outline shown by the dotted line shows the printed circuit board.

7 electric terminals 158, 160, 162, 164, 16
6, 168 and 170 connect to the printed circuit board 138. The electrical terminal 164 connects with the battery 162 of the automobile. The passive current that is constantly drawn through the electrical terminals 164 is negligible.

The diode 172 provided at the terminal 164 is for protecting the circuit. The voltage adjustment is performed by the Zener diode 174 and the resistor 176. Filtering
The filtering is done by the capacitor 178. The connecting lead wire 180 of the Zener diode 174 and the capacitor 178 constitutes a regulated positive power supply. B ⁺ terminal in the connection lead 180 is connected to the portion of the six B ⁺ terminal of drawing absolute.

The light emitting diode 56 is energized for a predetermined time through the switching transistor 182 and the resistor 184 after the driver opens the door. At the same time, the light emitting element 124 is also energized via the resistor 189. The base of the switching transistor 182 has a resistor 188 following the terminal 160.
Connected to. This terminal 160 is connected to the positive power line 18
Normally at zero potential, when the driver opens the door, the door side post switch 156 closes and is installed through this switch.

The resistor 70 is connected between the base of the phototransistor 62 and the emitter. The collector of the phototransistor 62 is connected to the terminal 162 through the conducting projection 26. The terminal 162 extends to a load resistor 190 connected to the positive power supply line 180, and further, via first and second resistors 192 and 194 connected in series, respectively.
Connect to one input 196 of flip-flop 198. The flip-flop consists of NAND gates 200 and 202 connected together. The connection point of these two resistors 192 and 194 connected in series and the terminal 16
Connect the diode 204 between 0 and
6 is connected to the power supply line 180. NAND gate 2
The output 207 from 02 is supplied to the gate of the transistor 210 forming a switch through the resistor 208. The drain of transistor 210 is connected to terminal 168 to drive an on-board module called a "driver information center" (not shown) that activates the indicator light on the automotive dashboard. Alternatively, as shown in FIG. 32, the indicator lamp 212 is arranged so that it can be directly driven through the terminal 168.
The source of the transistor 210 is grounded via the terminal 170. The other input of flip-flop 198 is at 214. The output 216 of NAND gate 200 is connected to the input 218 of NAND gate 202, and the output 207 of NAND gate 202 is similarly
Connected to input 222 of NAND gate 200.

Connected to terminal 158 is a diode 224 which, when the ignition switch 154 is closed, applies a positive (battery) voltage from the switch and prevents the polarity of the circuit from being reversed. Resistors 226 and 228 are connected to the diode 224,
The latter resistor is the input 2 of the separate NAND gate 232.
Connected to 30. Between this input 230 and ground,
The capacitor 234 and the resistor 236 are connected. Input 240 connects to power line 180.

The output 238 of NAND gate 232 comprises bypass capacitor 24 and is arranged to allow the gate of transistor 210 to be selectively clamped through diode 244. This output 238 is also connected to the input 214 of the NAND gate 200 through another diode 246. A resistor 248 is connected between the input 214 of the NAND gate 200 and the power supply line 180.
A coupling capacitor 250 is connected between the terminal 160 and the input 214 of the NAND gate 200. If the driver keeps the door closed, the terminal 160 will pull the resistor 2
Due to the action of 52, it is usually at a voltage equal to that of the power line 180.

The phototransistor 126 of the tilt detector 110 comprises a resistor 254 between the base and ground. The emitter of this phototransistor is the NAND gate 2 of Dion.
Connect to both inputs of 56. Phototransistor 12
The load of No. 6 is constituted by the resistor 258. Fourth NA
The output 260 of the ND gate 256 is connected to the gate of the transistor 210 via the diode 262.

Here, it is assumed that the axis of the prism 54 is in a substantially horizontal state. When the driver's vehicle door is opened in this state, the control circuit reads the liquid level in a very short time. Then, if the liquid level is low, the indicator lamp 212 is turned on (however, the ignition switch 1
(After closing 54), and then ignition switch 5
After turning on 4, the state is typically held for 30 seconds.

The drain of the transistor 210 connected to the indicator lamp 212 energizes the indicator lamp. When the side switch 156 of the door is opened and the ignition switch 154 is opened while the vehicle is idling, the NAND gate 2
The input terminal 214 of 00 becomes a high digital level due to the connection with the power supply line 180 through the resistor 248. At this time, the diode 246 is not conducting. This is because the output of NAND gate 232 is high, as will be described later. The input terminal 196 of the NAND gate 202 also has a diode 204 and a resistor 252.
High as a result of the bias given through. NA
The output terminal 207 of the ND gate 202 is either high or low. The level of the output 216 of the other NAND gate 200 is the inverted state of the output terminal 207.
That is, if the output of gate 202 is high, the output of gate 200 will be low, and if the output of gate 202 is low, the output of gate 200 will be high. If the ignition switch 154 has never been closed, the indicator light 212 will never light.

If the car is at ground potential, NAND gate 25
The output 260 of 6 goes high and therefore the diode 262 does not conduct. The NAND gate 256 and the diode 262 form a part of an inclination detection circuit of an automobile, the operation of which will be described in detail later.

When the driver of the automobile first opens the driver side door, the side pillar switch 156 of the door is closed and the liquid level is read. Reading is done by actuation of several components of the circuit. That is, a negative pulse is applied to input terminal 214 of NAND gate 200 via coupling capacitor 250, resulting in reset of flip-flop 198. Further, by closing the side pillar switch 156, one end of the resistor 188 is grounded, and the switching transistor 182 becomes conductive. The conduction of the switching transistor causes the light emitting diode 56
Both 24 and 24 are energized. The light emitting diode 56 is
It is assembled to the sensor device 50. When a light ray from the light emitting diode 56 hits the surface of the conical recess 104 shown in FIG. 1 and passes through this surface and enters the prism 54, it is bent by refraction and becomes substantially parallel to the axis of the conical surface 102. If the liquid level is above a certain point on the conical surface 102, there will be insufficient light to drive the photosensor, or phototransistor 62.
At the interface between 2 and oil, it is not reflected in the prism,
Therefore, the phototransistor will not conduct. Therefore, the terminal 162 is connected to the phototransistor 6
NA does not drop to a low digital voltage level due to 2.
The input 196 of the ND gate 202 remains high,
Therefore, the output 207 of the NAND gate drops to a low digital level. On the other hand, a low liquid level increases the amount of light rays striking the phototransistor 62, causing the potential at terminal 162 to drop, dropping the input terminal 196 of NAND gate 202 to a low digital level. As a result, NA
The output 207 of ND gate 202 is at a high digital level, sufficient to apply a gate voltage to transistor 210 (through resistor 208) unless diode 244 or 262 is conducting. However, until some other conditions are met, the indicator light 212
Does not indicate that the liquid level is low.

When the driver enters the vehicle and closes the door, the reading is held or stored by flip-flop 198, which consists of NAND gates 200 and 202, in place. For resetting the flip-flop has not happened yet.

If you close the ignition switch 154,
The operation of several parts of the circuit occurs. That is, by closing the ignition switch, one terminal of the display 212 is connected to the battery 152 of the automobile. At this time, if the gate voltage is applied to the transistor 210, the display lamp 212 is turned on at the moment when the ignition switch 154 is closed to warn the driver of the vehicle that the liquid level is below the normal state. It will be.

Further, by closing the ignition switch 154, a positive voltage is applied to the input 230 of the NAND gate 232 through the diode 224 and the resistor 228. Prior to the ignition switch 154 being closed, the output 238 of the NAND gate 232 was low. When the ignition switch is closed, NAND
Since the gate input 240 is high, the NAND gate output 238 is also high. Thus, when the NAND gate output is high, the diode 244 does not conduct, ie, does not interfere with the gate voltage to the transistor 210, and thus does not interfere with the lighting of the indicator light 212. Also, after the ignition switch is closed, the capacitor 234 has its own value and the resistor 228.
Charging starts at a speed determined by the value of and. The time constant of this circuit results in a delay of approximately 30 seconds. This 3
Output 238 of NAND gate 232 after a delay of 0 seconds
Becomes a low digital level, so that the diode 244 is made conductive. As a result, the gate voltage of transistor 210 is held at a low digital level and transistor 210 ceases to conduct. Thus, the indicator lamp 212 is turned off after this delay, for example, 30 seconds.

The above description assumes that the output 260 of NAND gate 256 is high and diode 262 is not conducting. This presupposes that the vehicle is in a substantially horizontal state, as opposed to trying to park the vehicle on a hill.

If the vehicle is on a slope, the sensor device 50 mounted in the vertical wall of the oil pan will be completely submerged, even if the liquid level is low, or the liquid level will be normal or higher than normal. Will be exposed,
Accurate reading will not be done.

In order to cope with such a situation, in the present invention, when the vehicle inclination sensor 110 detects that the vehicle is inclined, the NAND gate 260 is detected through the diode 262.
Output clamps the gate voltage of transistor 210. If the sphere 128 shown in FIG. 18 is inclined enough to move out of its light-blocking path, the switch ON of the light-emitting element 124 generated via the transistor 182 when the door of the automobile is opened will cause light-sensitivity. Illuminate this photosensitive element to an extent sufficient to cause element 126 to conduct, providing a high digital level on both inputs of NAND gate 256. Therefore, the output 260 of this NAND gate goes to a low digital level and clamps the gate voltage of the transistor through diode 262 so that transistor 210 does not conduct,
Do not turn on the indicator light 212. In this way, regardless of the liquid level in the oil pan, the indicator lamp 212 will not be energized if the vehicle is on an inclined surface.

Another embodiment of the present invention is shown in FIG. 33, which illustrates an automobile 266 and a filler tube 268 of a fuel tank 270. Furthermore, a screw cap 272 for energizing and a lid 27 attached to the vehicle body by a hinge.
4 is shown. In the present invention, the movement of the lid 74,
The present invention provides a mechanism for detecting any one of the screw cap 272 being unscrewed or unscrewed and issuing a trigger signal for starting the reading of the liquid level of the automobile. Reed switch 27
6 is combined with both a screw cap 272 and a lid 274, the lead switch is a filler tube 26.
It is good to attach to 8. Reed switch 276 may be a single pole, single throw contact 278, 280, leaving both contacts open near the surface of the screw cap or one or more magnets mounted inside. When the screw cap is rotated and removed, the reed switch contacts 276,
278 will close. This structure may be replaced by the structure shown in FIG. 32, in which case lead switch 276 is connected between ground and terminal 160, and the illustrated connection to side post switch 156 of the door is made. Stop.

Thus, every time the vehicle fuel is supplied, the reading of the liquid level is automatically started.

A further embodiment of the present invention is shown in FIG. 35, in which a bowl-shaped body 52c, a prism 54G provided on the bottom wall of the bowl-shaped body 52c, a conical recess 104c, and the recess 10 are provided.
A tapered inner hole or blind hole 28 formed in the bottom of 4c
2 is shown. By forming the blind hole 282, the bowl-shaped body 52c can be easily molded.

The indicator according to the invention has a simple structure and is reliable. The liquid level is read every time the driver's door is opened or the vehicle is refueled.

[Brief description of drawings]

FIG. 1 is an axial sectional view of a sensor device of the present invention. FIG. 2 shows a part of a left end view of the sensor device shown in FIG. FIG. 3 shows a side view of the holding block for the light source and the sensor. FIG. 4 shows a right end view of the sensor device. FIG. 5 shows an axial sectional view taken along the line 5-5 in FIG. FIG. 6 shows a left end view of FIG.
FIG. 7 shows a right end view of FIG. 8th
The figure shows an axial cross-section taken along line 8-8 in FIG. FIG. 9 shows an axial cross-section of the threaded mounting of the sensor device. FIG. 10 shows a part of the left end view of the fixture of FIG. FIG. 11 shows a part of the right end view of the fitting of FIG. FIG. 12 shows a sectional view in the axial direction of the bowl-shaped sensor portion and the prism-shaped end wall. FIG. 13 shows a left end view of FIG. FIG. 14 shows a part of the right end view of FIG. FIG. 15 shows a front view of the connector conducting projection. FIG. 16 shows a plan view of FIG. FIG. 17 shows a right end view of FIG. FIG. 18 shows a sectional view in the axial direction of a tilt detector for a sensor device. Figure 19 shows
FIG. 19 is a left end view of FIG. 18. Figure 20 shows
It is a right end view of FIG. Figure 21 shows
It is an axial direction sectional view of one case of an inclination detector. FIG. 22 is a left end view of FIG. FIG. 23 shows a right end view of FIG. FIG. 24 is a sectional view of the other side of the other case of the inclination detector in the axial direction. Figure 25 shows
FIG. 25 is a left end view of FIG. 24. FIG. 26 shows
FIG. 25 is a side view showing the opposite side of the case shown in FIG. 24. FIG. 27 shows a right end view of FIG. 24. FIG. 28 is a side view of the light source and the sensor holding block. FIG. 29 is a left end view of FIG. 28. FIG. 30 is a right side end view of FIG. 28. FIG. 31 is a plan view of FIG. 28. FIG. 32 is a circuit diagram of the liquid level indicator of the present invention. FIG. 33 is a schematic view of a fuel tank of an automobile showing a switch sensitive to opening the lid. FIG. 34 is a schematic explanatory view of the sensor device. FIG. 35 shows a modification of the sensor device. 10 ... Metal fitting, 12 ... Main body (protruding part),
14 ... Male screw, 18 ... Oil pan, 54 ... Prism, 56 ... Light source, 62 ... Optical sensor, 72 ... Holding block, 74 and 76 ... Cradle, 102 ... Conical surface,
104 ... Conical recess, 110 ... Inclination detector (gravity sensitive mechanism), 124 ... Light emitting element, 126 ... Light receiving element, 270 ... Gas tank, 274 ... Lid, 276
...... Lead switch (mechanism sensitive to opening of lid)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Donald J.A. Matteis, Connecticut, USA 06850, Nowalk, Douglas Drive 15 (56) Reference JP 54-58053 (JP, A) JP 57-122320 (JP, A) JP 54-95270 (JP, U) Actual Open Sho 56-44323 (JP, U) Actual Open Sho 56-166538 (JP, U) Actual Open Sho 53-20963 (JP, U) Actual Open Sho 58-177814 (JP, U) Actual Open Sho 58-146723 (JP, U)

Claims (18)

[Claims] 1. A metal fitting comprising a male threaded substantially cylindrical portion which can be secured to a hole in a wall of a liquid container by the male thread; and b) C) a through hole formed in a cylindrical portion, and c) a bowl-shaped container provided in the through hole, the bottom wall being a prism placed close to the inner end of the through hole. A bowl-shaped container having a substantially conical tip portion, which is dipped in the liquid to be measured, d) a sidewall of the bowl-shaped container juxtaposed with a sidewall of the cylindrical portion, and e) a light source mechanism, A light-sensitive mechanism, and a mechanism for attaching the light source and the light-sensitive mechanism to the bowl-shaped container; and f) a substantially conical recess formed in the prism for introducing light and transmitting light, The rays from the light source that enter the surface of the concave shape are refracted. A light ray reflected from the conical tip that is bent toward the conical tip and passes outwardly through the surface of the conical concave portion due to refraction. A liquid in a container, which is composed of a conical concave portion that introduces light and transmits light, which is formed in the prism with the same axis as the conical tip so that it can be bent toward the mechanism. Liquid level indicator for measuring. 2. The liquid level indicator according to claim 1, wherein the light source impinges a light beam on the surface of the conical recess. 3. The liquid level indicator according to claim 2, wherein a light beam passing outwardly through the surface of the conical recess is bent toward the light-sensitive mechanism by refraction. 4. The liquid level indicator according to claim 1, wherein a groove surrounding the conical concave portion is formed in an annular shape on the inner surface of the prism. 5. The liquid level indicator according to claim 4, wherein a groove surrounding the conical tip portion is formed in an annular shape on the outer surface of the prism. 6. An electrical connection mechanism held by the fixture, the electrical connection being connected to energize the light source and also to monitor the state of the light sensitive mechanism. The liquid level indicator according to claim 1, comprising a mechanism. 7. A) a mechanism for attaching the light source and the light-sensitive mechanism comprises a holding block which is accommodated in the bowl-shaped container from its open end, and b) the holding block is for the light source and the light-sensitive mechanism. The liquid level indicator according to claim 1, comprising a cradle. 8. A) a light source, b) a light-sensing mechanism, c) a prism having a conical end that dips into the liquid to be measured, and d) a conical prism formed at the other end of this prism. A recess, and e) a mechanism for attaching the light source and a light sensitive mechanism located at the other end of the prism in proximity to the conical recess, the light from the light source being part of the conical recess. Through the prism, hitting the conical end, refracting from it, exiting the prism at the other part of the conical recess, and then hitting the light-sensing mechanism. A liquid level indicator that measures the liquid in the container, which consists of a mounting mechanism. 9. The liquid level indicator according to claim 8, wherein the prism is an inner hole, the inner hole of which the opening intersects the surface of the conical recess. 10. The liquid level indicator according to claim 9, wherein the diameter of the inner hole is gradually reduced. 11. The prism is a blind hole, the opening of which is formed so as to intersect the surface of the conical recess.
The liquid level indicator according to claim 8. 12. A bowl-shaped liquid-tight structure having: a) a bottom wall provided with a prism forming portion in a transverse direction; and b) a light-emitting element and a light-sensing element arranged side by side in the bowl-shaped liquid-tight structure. An element, which is arranged side by side with respect to the prism forming portion of the bottom wall of the bowl-shaped liquid-tight structure, supplies light rays to the prism forming portion and receives light rays from the prism forming portion, respectively. A liquid level indicator for measuring a liquid in a container, which comprises a light emitting element and a light sensitive element, and the prism forming portion has a recess formed in the bottom wall facing the light emitting element and the light sensitive element. 13. The prism forming portion has, between its both ends,
The liquid level indicator according to claim 12, wherein the mounting mechanism is provided. 14. The liquid level indicator according to claim 13, wherein the prism forming portion has a cylindrical outer surface on one side of an attachment mechanism thereof. 15. The prism forming portion is provided with another cylindrical surface on the other side of the attachment mechanism thereof.
Liquid level indicator according to the item. 16. The method according to claim 12, wherein a) the light emitting element and the photosensitive element are arranged at an angle to each other, and b) the concave portion provided in the prism forming portion has a conical surface. Liquid level indicator. 17. The liquid level indicator according to claim 15, wherein the prism forming portion is formed with an annular groove on both sides of the mounting mechanism. 18. The liquid level indicator according to claim 17, wherein a conical outer wall is formed in the annular groove on the outer surface of the prism forming portion.