JPH09192540A - Liquid injection device with liquid level sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of the shortage of injected liquid due to a false detection of a liquid level and of a condition in which the detection of the level is impossible. SOLUTION: A protective cover is provided to cover at least the injection nozzle side of the detection part of a contact type optical level sensor to ensure the detection of a level by preventing the adhesion of liquid to the detection part during injection. The liquid ejection direction of an injection nozzle 42 is arranged not to cross the measuring route of a non-contact type level sensor 41 so that the generation of a condition in which the measurement of the distance between levels is made impossible by the shut-off of the measuring route caused by the scatter of liquid etc., during injection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid injection device for injecting a liquid such as oil into a container to a certain level.

[0002]

2. Description of the Related Art For example, an automatic transmission (hereinafter referred to as A / T) of a vehicle is filled with a predetermined amount of hydraulic oil (hereinafter referred to as A / T oil). This filling of A / T oil is finally carried out after the A / T is mounted on the vehicle body and the equipment of other devices of the drive system is completed, and then a dedicated oil injection machine is installed in parallel with the filling of engine oil and the like. Is done using. In the oil injecting machine dedicated to injecting A / T oil, since the inner diameter of the filler tube for injecting is as small as about 10 mm, the outer diameter of the injecting nozzle is also formed to be small so that it can be inserted into the filler tube. ing.

The conventional oil injecting machine measures the amount of oil by a weight sensor system and injects a fixed amount of A / T oil. After inserting the oil into the filler tube through the oil tube, setting the amount in the operating part, and then turning on the injection switch, the motor drives the pump
T oil is automatically injected. Then, the A / T oil passes through the injection nozzle at the set injection flow rate,
Sent inside. Therefore, a preset amount of A / T oil is injected into the A / T.

However, filling the A / T oil requires the A / T
The A / T oil injected at this time is extracted after the operation test is completed, but the A / T oil injected at this time is extracted after the operation test is completed. A / supplied to each part of T
The T oil is not completely recovered and remains inside the A / T. In this way, the amount of A / T oil remaining inside the A / T is not constant and may vary, and the difference between the maximum amount and the minimum amount may be large.

Therefore, since it is impossible to visually check the inside of the A / T, the amount of the remaining A / T oil cannot be confirmed for each A / T. Therefore, if the conventional oil injection machine described above is used, the A / T
A certain amount of A / T that is set on the assumption that there is oil remaining in the A / T when the final oil injection is performed.
The oil was injected uniformly. As a result, there is a problem that the amount of A / T oil filled varies depending on the amount of remaining oil in the A / T.

As a method of eliminating the difference in the filling amount and filling a fixed amount of A / T oil, for example, when the A / T oil is injected, the liquid level height of the A / T oil in the A / T is detected. A possible method is to stop the injection of oil by detecting that the liquid level has risen to a predetermined height and filled with a substantially constant amount of A / T oil.

To carry out this method, a liquid level sensor that can be inserted into the A / T from the filler tube together with the injection nozzle, for example, an optical liquid level sensor using an optical fiber cable can be used. FIG. 14 shows an example of a commercially available optical liquid level sensor. The liquid level sensor 1 includes a light emitting diode (LED) 2 as a light source and a sensor body having a phototransistor 3 for photoelectric conversion. 4, a light projecting optical fiber cable 5 that serves as a waveguide for the light emitted from the light emitting diode 2, and a light receiving optical fiber cable 6 that serves as a path for reflected light. The flexible extension part 7 and a detection part 8 made of a transparent conical tetrafluoroethylene resin provided at the tip of the flexible extension part 7 are provided.
The tip ends of both the optical fiber cables 5 and 6 inserted into the protective tube are made parallel by the fiber cable fixing jig 9 and the end faces of the optical fiber cables 5 and 6 are made parallel. It is configured to be in close contact with the bottom surface of the conical detection unit 8.

In the liquid level sensor 1, when the detecting portion 8 at the lower end of the liquid level sensor 1 is in the air (see the left half portion of FIG. 14).
The light emitted from the light emitting diode 2 passes through the light projecting optical fiber cable 6 and is applied to the detection unit 8. At this time, the refractive index (1.
Since 3) is larger than the refractive index (1.0) of air, most of the irradiated light is reflected inside the detection unit 8 and its traveling direction is converted by 180 degrees and received by the light receiving optical fiber cable 6. Further, the light reaching the sensor body 4 through the light receiving optical fiber cable 6 is photoelectrically converted into a voltage having a height corresponding to the amount of light by the phototransistor 3 of the sensor body 4, and this is made a liquid level non-detection signal. .

Then, as shown in the right half of FIG.
When the A / T oil is further injected and the rising liquid level reaches a predetermined level, the detecting portion 8 of the liquid level sensor 1 is immersed in the A / T oil. At this time, since the refractive index (1.3) of the detection unit 8 made of tetrafluoroethylene resin is smaller than the refractive index (1.47) of the light of A / T oil, a part of the light irradiated on this detection unit 8 is Since the light is refracted at the boundary surface and transmitted through the liquid, the amount of reflected light is reduced. As a result, the amount of light reaching the phototransistor 3 via the light receiving optical fiber cable 6 is also reduced, and the voltage is photoelectrically converted into a voltage having a height corresponding to the amount of light. Therefore, the voltage or voltage change generated by photoelectric conversion in the phototransistor 3 is used as the liquid level detection signal.

Next, the above-mentioned commercially available liquid level sensor 1 is attached near the discharge port of the injection nozzle of the oil injection machine, and A /
Insert it into a filler tube for T oil injection, integrated with the injection nozzle, set it to a predetermined height inside the A / T, and
The control when the T oil is injected will be described based on the flowchart of FIG.

That is, when injecting A / T oil, first, when the program is started, the switch of the liquid level sensor 1 is turned on in step 1, and then the reflected light amount I is detected in step 2.

Next, in step 3, the detected reflected light amount I is compared with the reference reflected light amount I ₀ in the A / T oil, and if I> I ₀ , the detection unit 8 of the liquid level sensor 1 Since it is still in the air and the injection amount is insufficient, the process returns to step 2 and the reflected light amount I is detected again. And
As a result of the comparison in step 3, if I ≦ I ₀ , it is detected that the liquid surface has risen to a predetermined height. That is, since the liquid level rises and the detection unit 8 is immersed in the A / T oil, a part of the light is transmitted from the detection unit into the A / T oil, so that the phototransistor is passed through the light receiving fiber cable. This is the result of the decrease in the amount of reflected light reaching 3 Therefore, since the predetermined amount of A / T oil has been filled, the process proceeds to step 4 and the injection is stopped and the injection control ends.

[0013]

However, as shown in FIG. 16, the conventional liquid level sensor 1 described above is used as the injection nozzle 1.
When the liquid level sensor 1 and the injection nozzle 10 are inserted into the filler tube 11 and used in the vicinity of the discharge port 10a of No. 0, the A / T oil ejected from the discharge port 10a scatters and the liquid When the film adheres to the detection unit 8 of the surface sensor 1 and a film of A / T oil is formed on the surface of the surface sensor 1, a part of the light emitted from the light projecting optical fiber cable 5 into the detection unit 8 forms a boundary. A / T because it refracts at the surface and transmits to the outside
There is a possibility that the oil level may be erroneously detected and the oil injection machine may be stopped. In this case, the problem of insufficient A / T oil filling occurs.

As a non-contact type liquid surface sensor, for example, light is intermittently irradiated toward the liquid surface, and the distance from the arrival time of the reflected light to the light receiving portion to the liquid surface is measured to obtain the liquid surface. There is a system on the market that detects that the height has risen to a predetermined height.

As shown in FIG. 17, the non-contact type liquid level sensor 12 has substantially the same structure as that of the contact type liquid level sensor 1 from which the conical detecting portion 8 is removed. The intermittent light from the light emitting diode as the light source is projected from the lower end of the liquid level sensor 12 toward the liquid surface via the light projecting optical fiber cable. Then, the reflected light from the liquid surface is sent to the sensor main body via the light receiving optical fiber cable, and the distance from the projected time to the reception of the reflected light to the liquid surface is obtained.

Therefore, the non-contact type liquid level sensor 12 having the above structure has its lower end as shown in FIG.
When the liquid level sensor 12 is attached near the discharge port 13a of the injection nozzle 13 and is inserted into the filler tube 14 integrally with the injection nozzle 13 and is set at a predetermined height to detect the distance to the liquid surface. In addition, if there is a flow or splash of A / T oil ejected from the discharge port 13a in the irradiation range of the light projected from the lower end of the liquid level sensor 12, that is, in the measurement optical path, the irradiated light is blocked. However, there is a problem in that the distance to the liquid surface cannot be measured.

Further, when the liquid surface is wavy due to the momentum of the injected A / T oil, as shown in FIG. 19, the irradiated light is diffusely reflected even when it reaches the liquid surface. There is a problem that the reflected light cannot be received and the distance to the liquid surface cannot be measured.

The present invention has been made in view of the above circumstances, and a contact type liquid level sensor or a nozzle which prevents erroneous detection of the liquid level due to adhesion of liquid splashing during injection to the sensor or the like. An object of the present invention is to provide a liquid injecting device having a non-contact type liquid level sensor that prevents the liquid level from being undetectable due to the blocking of the measurement optical path by the liquid.

The purpose of this is to prevent the liquid from adhering to the detecting portion in the contact type liquid level sensor, and to prevent the measurement optical path from being blocked by the scattering of the liquid in the non-contact type liquid level sensor, Alternatively, it is achieved by preventing the liquid surface from undulating.

[0020]

Means for Solving the Problem and Its Action As a means for solving the above problems, a liquid injecting apparatus having a liquid level sensor according to the present invention has an injecting nozzle inserted from an injection port into a container. While injecting a liquid, the liquid level in the container that rises with the injection of the liquid is detected, and in the liquid injection device that performs the injection control of the liquid based on the detected liquid level, the liquid A contact type optical sensor in which a detection unit for detecting the liquid level height by contacting the surface is installed near the discharge port of the injection nozzle and integrally with the injection nozzle, and above and to the detection unit. A protective member for preventing contact and adhesion of liquid from one side is provided so as to cover at least the ejection port side of the detection unit.

According to a second aspect of the present invention, an injection nozzle is inserted into the container through the injection port to inject the liquid, and the liquid level height in the container that rises as the liquid is injected is detected. In a liquid injecting device that controls the injection of the liquid based on the height of the liquid surface, a detector having a function of receiving and transmitting electromagnetic waves such as light and radio waves or liquid level detection waves such as sound waves and ultrasonic waves is injected. A non-contact type optical sensor installed near the ejection port of the nozzle and integrally with the injection nozzle, wherein the ejection port is arranged so that the ejection direction of the liquid from the ejection port is between the detection unit and the liquid surface. It is characterized in that it is provided so as not to intersect the passage of the liquid level detection wave.

Therefore, according to the first aspect of the invention, the protective member is provided so as to cover at least the ejection port side of the injection nozzle of the detection portion of the liquid level sensor. It is possible to prevent the liquid ejected from the ejection port from adhering to the detection unit, and thus prevent the liquid surface from being erroneously detected due to the liquid adhering to the detection unit.

According to the second aspect of the present invention, the ejection port of the injection nozzle has a direction in which the ejection direction of the liquid from the ejection port does not intersect the passage of the detection wave between the detection unit and the liquid surface. Since the electromagnetic waves caused by the liquid to be injected do not block the passage of detection waves such as sound waves, the liquid level cannot be detected due to the passage blocking.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION A liquid injection device having a liquid level sensor of the present invention will be described below with reference to FIGS.

1 to 8 show an automatic transmission (hereinafter, referred to as A / T) of an automobile in a device of the present invention.
That. ) Shows a first embodiment applied to an oil injecting device for injecting A / T oil. The oil injecting device 21 has a liquid level of A / T oil inside the A / T as shown in FIG. Liquid level sensor 22 for detecting height, pressure sensor 23 for measuring internal pressure of A / T, and liquid level sensor 22
And a control device 24 for controlling A / T oil injection based on a signal from the pressure sensor 23, and the control device 24.
Hydraulic circuit 28 that adjusts the injection hydraulic pressure according to commands from
And an injecting machine 29 for injecting with the adjusted hydraulic pressure. The liquid level sensor 22 is a commercially available optical type that detects the liquid level by the detection part 22a at the tip contacting the liquid level. A liquid level sensor (see the diagram showing the liquid level detection principle in FIG. 14) is used.

Further, a flexible pressure-resistant hose 32a having a tip end serving as an injection nozzle 32 is connected to the injection machine 29. Further, a detecting portion 22a of the liquid level sensor 22 and a pressure detecting portion 23a of the pressure sensor 23 are arranged adjacent to the injection nozzle 32, and respective end portions of the detecting portion 22a and the pressure detecting portion 23a are respectively attached to the injection nozzle 32. Of the heat-shrinkable tube or the like, and are bundled together by a binding means 34 such as a heat-shrinkable tube, and are inserted into the filler tube 31 of the A / T 30 (see FIG. 2). The A / T oil is injected by arranging so as to face the bottom surface 30a of the T30 or the liquid surface of the residual oil substantially vertically.

The detection unit 22a of the liquid level sensor 22 and the pressure detection unit 23a of the pressure sensor 23, which are integrally bound to the tip end side of the injection nozzle 32, detect the liquid level sensor 22 as shown in FIG. The portion 22a is adjacent to the tip of the injection nozzle 32 and projects downward from the ejection port 32b. A semi-cylindrical protection cover 33 is attached to the ejection port 32b side of the projecting detection unit 22a. Thus, the A / T oil ejected from the ejection port 32b is covered so as not to fly from above and to the side and adhere to the detection portion 22a.

Further, in this embodiment, the injection nozzle 32, the sensor detecting portion 22a and the pressure detecting portion 23b are provided.
When the filler tube 31 is inserted into the filler tube 31, the opening area of the filler tube 31 is significantly reduced and the discharge efficiency of the internal air is reduced.
The internal pressure increases with the injection of oil. The increase in the internal pressure causes the discharge amount from the injection nozzle 32 of the injector 29 to gradually decrease. To prevent this, the pressure sensor 2
3 together with the liquid level sensor 22 measures the internal pressure that rises with the injection of A / T oil, increases the discharge pressure of the injection machine 29 by the amount of increase in the internal pressure, and the injection flow rate is always constant. In this way, it is possible to prevent the extension of the injection time due to the gradual decrease of the discharge amount, and to make it possible to inject to a certain level within a certain time, thereby preventing the variation and delay of the cycle time.

FIG. 4 shows an example of the construction of the hydraulic circuit in the apparatus of this embodiment, in which the liquid level detection signal from the liquid level sensor 22 and the pressure signal from the pressure sensor 23 are supplied to the motor 28b and the pressure control valve. The motor 28b, the pressure control valve 28c, and the sluice valve 28d are instantaneously operated together with the input of a signal by feeding back to the 28c and the sluice valve 28d.

Next, the operation of the oil injecting device 21 of this embodiment configured as described above will be described with reference to the flow sheet of FIG. 4, the flowchart of FIG. 5 and the diagrams of FIGS. 6 to 8. .

The injection nozzle 32 of the injection machine 29 is inserted into the filler tube 31, and the detection portion 22a of the liquid level sensor 22 and the pressure detection portion 23a of the pressure sensor 23, which are integrally bound with the injection nozzle 32, are combined. , A / T 30 is set to a predetermined height from the bottom surface 30a, and then the switch of the oil injection device 21 is turned on, the motor 28b (see FIG. 4) of the hydraulic circuit 28 is activated, and the pump 28a activates the oil tank 35. At the same time that the A / T oil therein is pumped up and the pressure control valve 28c is adjusted to a predetermined hydraulic pressure, the control program starts at the same time. Then, in step 1, the sluice valve 29a is first opened, and injection is started from the injection machine 29 at a predetermined discharge amount l ₁ .

At this time, the A / T oil ejected from the ejection port 32b of the injection nozzle 32 is scattered toward the detection unit 22a of the liquid level sensor 22 provided in the vicinity of the ejection port 32b, but the detection unit 22a. Since the side of the discharge port 32b is covered with the protective cover 33, the A / T oil is prevented from adhering to the detection portion 22a. Therefore, the erroneous detection of the liquid surface caused by the A / T oil adhering to the surface of the detection unit 22a is prevented.

Since the exhaust efficiency of the filler tube 31 is lowered by inserting the injection nozzle 32 or the like, the internal pressure of the A / T rises as the injection progresses, and if the discharge pressure is maintained constant, the discharge amount l ₁ gradually decreases.

Therefore, in step 2, the pressure sensor 23 measures the internal pressure P in the A / T 30, and in step 3, the measured internal pressure P is compared with the preset pressure P _1. If P ≦ P ₁ , the process proceeds to Step 4, the rotation speed of the motor 28b is increased to increase the pump driving force, and further to Step 5, the opening degree of the pressure control valve 28d is increased. after being adjusted to be the set pressure P ₁ until the predetermined time t _1, the flow returns to step 1.

As a result of the comparison in step 3, P
If> P ₁ , as can be seen from the diagram in FIG. 6 showing the change in A / T internal pressure with the passage of injection time, the injection of A / T oil proceeds and the liquid level rises to near the set level. , Judge that the injection is almost completed and proceed to step 7.

In step 7, the pressure control valve 28d
To reduce the degree of opening of the discharge amount l _1, as shown in the diagram of FIG. 7 reduces the discharge amount l ₂ by injection is carried out. As described above, by reducing the discharge amount immediately before the injection is stopped, the injection error amount caused by the influence of the time lag until the closing operation of the sluice valve 29a when the injection is stopped is reduced, and the A / T 30 inside the injection is completed. The variation in the oil level of is reduced.

Then, in step 8, whether or not the liquid level is detected is checked by checking whether or not the liquid level detection voltage is generated, as shown in the diagram of FIG. 8, and the liquid level is detected. If not, return to step 6.If the liquid level is detected and the liquid level detection voltage is generated, step 9
After stopping the motor 28b by proceeding to step S10, proceeding to step S10, the sluice valve 29a is closed and the control ends.

As described above, in this embodiment, the detecting portion 22a of the liquid level sensor 22 is covered with the half-cylindrical protection cover 33 only on the ejection port 32b side of the injection nozzle 32, and the detecting portion 22a is covered. Since the side opposite to the discharge port is opened, the air bleeding property and the liquid draining property between the protective cover 33 and the detection unit 22a are good, and therefore, the liquid level rises and the air bubbles when the detection unit 22a is immersed in the oil are eliminated. It is possible to prevent liquid level detection failure due to generation or the like, and erroneous detection of the liquid level due to oil remaining on the surface of the detection unit 22a when the liquid is separated from the liquid level after immersion. Further, the protective cover 33 may be formed in a non-annular shape such as a cylindrical shape with slits in addition to the half-cylindrical shape.

Further, in this embodiment, since the liquid level detection signal is fed back to the motor 28b and the sluice valve 28d in the hydraulic circuit 28, the oil fed by the inertia of the pump 28a after the liquid level sensor 22 detects the liquid level. The inflow of is instantaneously shut off by the sluice valve 28d, and
The A / T oil whose pressure is increased on the upstream side of the gate valve 28 d is discharged to the oil tank 36. Therefore, it is possible to reduce the influence of the time lag from the liquid level detection to the injection stop, which is caused by the inertia of the pump, and as a result, the factor that increases the variation in the oil level in the A / T after injection is removed,
High-precision injection control is possible.

Further, the pressure sensor 23 is used together with the liquid level sensor 22 so that the A / T internal pressure can be detected. Therefore, the filler tube 31 having a small diameter reduces the exhaust efficiency by inserting the injection nozzle 32 or the like. Since it is possible to detect an increase in the internal pressure during the injection process, it is possible to prevent the decrease in the injection flow rate due to the increase in the A / T internal pressure, and it is possible to prevent the cycle time of the A / T oil injection step from being extended.

Further, FIGS. 9 to 13 show a second embodiment in which the device of the present invention is applied to an oil injection device for an A / T of an automobile, like the first embodiment. A commercially available non-contact optical liquid level sensor 41 is used in place of the contact type optical liquid level sensor used in the embodiment, and the liquid level sensor 41 is provided near the tip of the injection nozzle 42 of this oil injection device. Of the A / T oil injected from the injection nozzle 42 with the injection nozzle 42 inserted into the filler tube 31 and installed at a predetermined height from the bottom of the A / T. The surface height is detected.

The liquid level sensor 42 detects the liquid level by detecting the reflected light from the liquid level of the light emitted from the liquid level sensor 42 (see FIG. 7 showing the principle of the liquid level detection). . Therefore, in this oil injection device, the injection nozzle 42 has the lower end 4 as shown in FIG.
2a is closed, and three slit-shaped discharge ports 42b (see FIG. 10) are formed in a portion of the side surface near the lower end that is opposite to the liquid level sensor 41 that is located adjacently. The A / T oil is ejected from these ejection ports 42b in a direction away from the liquid level sensor 42 so that the measurement optical path of the liquid level sensor 41 is not blocked by the A / T oil at the time of injection.

Next, the operation of this embodiment configured as described above will be described with reference to FIGS. 11 to 13.

FIG. 12 is a view showing the position of the liquid surface and the state of the liquid surface in the process of injecting the A / T oil. The liquid surface in the initial stage of the injection is the state in which the inside of the A / T is open to the atmospheric pressure. Therefore, the injected A / T oil causes a wavy and vibrating wavefront. However, since the injection nozzle 42 and the liquid level sensor 41 are inserted and the exhaust efficiency of the filler tube 31 is reduced, the internal pressure rises as A / T oil is injected. As a result, since the liquid surface is pressed by the internal pressure, the liquid surface becomes more stable and quasi-static than in the atmosphere open state, and the measurement accuracy of the distance to the liquid surface becomes high. Further, the liquid level in the A / T becomes quasi-static, and the injection level is reduced to further stabilize the liquid level, so that the measurement accuracy can be improved.

Therefore, when the distance y from the liquid level sensor 42 to the liquid level when the liquid level in the A / T becomes almost quasi-static is the injection flow rate switching level y ₁ and the liquid level stop level y ₀ The injection control will be described below.

FIG. 11 is a flow chart showing a program of injection control executed in the oil injection apparatus of this embodiment. Explaining with reference to this flow chart and FIGS. 12 and 13, the injection nozzle 42 is placed inside the filler tube 31. The liquid level sensor 42, which is inserted and bound integrally with the injection nozzle 42, is set at a predetermined height from the bottom surface of the A / T, and then the switch of the oil injection device is turned on. A / at constant injection flow rate
The injection of T oil is started and at the same time, the control program is started. Then, in step 1, the liquid level sensor 41 is first switched on, and the measurement light is emitted toward the liquid level.

Next, in step 2, the distance y from the reflected light from the liquid surface to the liquid surface is measured, and in step 3, the measured value y and the injection flow rate switching level y ₁ are compared, and y <y _{If 1} , return to step 2. Then, if y ≧ y ₁ in step 3, the process proceeds to step 4, the injection flow rate is switched so as to decrease, the distance y is measured again in step 5, and the measured value y and the liquid level stop level y _{0 in} step 6. When y ≠ y ₀ , step 5
If y = y ₀ , the process proceeds to step 7 to stop the injection and end the control.

Therefore, in this embodiment, since the ejection port 42a is formed so that the injection direction of the A / T oil from the injection nozzle 42 is opposite to the direction of the liquid level sensor 41, the ejection port 42a is injected from the ejection port 42a at the time of injection. The jetting oil does not block the measurement optical path between the liquid level sensor 41 and the liquid level, and the distance y to the liquid level can be measured reliably, and the injection control based on this measured distance y. Is possible. Further, since the injection flow rate is reduced near the completion of injection to stabilize the liquid surface, highly accurate injection can be performed in a short time.

[0049]

As described above, according to the first aspect of the present invention, the contact type optical liquid level sensor is provided with the protective cover, and the liquid splashed at the time of injection adheres to the sensor from above and from the side. Since this is prevented, erroneous detection of the liquid surface can be reliably prevented without impairing the detection accuracy. Also,
According to a second aspect of the present invention, the liquid ejection direction of the injection nozzle is
Since the direction is such that it does not intersect with the measurement path of the non-contact type liquid level sensor, it is possible to reliably prevent the measurement of the liquid surface distance from occurring due to the liquid jetting or splashing from the nozzle blocking the measurement path during injection. You can

[Brief description of the drawings]

FIG. 1 is a perspective view of an essential part of a liquid level sensor mounting portion of an oil injection device according to a first embodiment of the present invention with a part of which is cut away.

FIG. 2 is a cross-sectional plan view showing a state where an injection nozzle is inserted in a filler tube.

FIG. 3 is a block diagram showing the overall configuration of the apparatus.

FIG. 4 is a flow sheet showing a configuration example of a hydraulic circuit.

FIG. 5 is a flowchart showing the flow of injection control in order.

FIG. 6 is a diagram showing a change in internal pressure due to control based on a measurement value of a pressure sensor.

FIG. 7 is a diagram showing a discharge amount control corresponding to a change in internal pressure.

FIG. 8 is a diagram showing a change in liquid level detection voltage according to a change in internal pressure.

FIG. 9 is a perspective view of a main part of the oil injection device according to the second embodiment of the present invention with a part of the liquid level sensor mounting part cut away.

FIG. 10 is a perspective view of an injection nozzle having a discharge port formed on a side surface.

FIG. 11 is a flowchart showing a flow of injection control in order.

FIG. 12 is an explanatory diagram showing the relationship between the liquid level sensor and the liquid level in the injection process.

FIG. 13 is a diagram showing a change in distance between a sensor and a liquid surface due to injection.

FIG. 14 is an explanatory diagram showing a liquid level detection principle of a contact type optical liquid level sensor.

FIG. 15 is a flowchart showing injection control when a contact type optical liquid level sensor is used.

FIG. 16 is an explanatory diagram showing the cause of erroneous detection of the liquid level that occurs when a contact type optical liquid level sensor is arranged near the injection nozzle.

FIG. 17 is an explanatory diagram showing a liquid level detection principle of a non-contact type optical liquid level sensor.

FIG. 18 is an explanatory diagram showing a liquid level undetectable state that occurs when a non-contact type optical liquid level sensor is arranged near the injection nozzle.

FIG. 19 is an explanatory diagram showing another example of the same state in which the liquid surface cannot be detected.

[Explanation of Codes] 21 Oil Injection Device 22 Liquid Level Sensor 22a Detection Unit 23 Pressure Sensor 23a Pressure Detection Unit 30 Automatic Transmission (A / T) 31 Filler Tube 32 Injection Nozzle 32b Discharge Port 33 Protective Cover 41 Liquid Level Sensor 42 Injection Nozzle 42b outlet

Claims (2)

[Claims] 1. A liquid is injected by inserting an injection nozzle into the container from the injection port, and the liquid level in the container that rises as the liquid is injected is detected, and the detected liquid level is detected. In a liquid injecting device that controls injection of the liquid based on the above, a detection unit that detects the liquid level height by contacting with the liquid surface is installed near the discharge port of the injection nozzle and integrally with the injection nozzle. It is provided with a contact type optical sensor, and a protection member for preventing the liquid from coming into contact with and adhering to the detection unit from above and laterally is provided so as to cover at least the ejection port side of the detection unit. A liquid injection device having a characteristic liquid level sensor. 2. The liquid is injected by inserting an injection nozzle into the container from the injection port, and the liquid level in the container rising as the liquid is injected is detected, and the detected liquid level is detected. In a liquid injection device that controls injection of the liquid based on the above, a detection unit having a function of transmitting and receiving electromagnetic waves such as light and radio waves or sound waves such as ultrasonic waves and ultrasonic waves is provided near the ejection port of the injection nozzle. And a non-contact type optical sensor installed integrally with the injection nozzle, wherein the discharge port has a discharge direction of liquid from the discharge port and a passage of the liquid level detection wave between the detection unit and the liquid surface. A liquid injection device having a liquid level sensor, wherein the liquid injection device is provided so as not to intersect.