JP3707895B2 - Oil changer - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an oil changer that is installed mainly in a gas station or a maintenance shop and changes oil used for power steering of an automobile.
[0002]
[Prior art]
Conventionally, for example, as a method of exchanging waste oil in the reserve tank for power steering oil, using an existing engine oil changer, etc. A method of injecting gradually with a pump or weighing out the drained waste oil with a weight meter such as a separate load cell and automatically injecting the same amount of new oil, or a dedicated function with only the extraction function After removing the waste oil in the reserve tank with a pump with a pump, gradually injecting new oil with an oil mug etc. while visually checking the liquid level position, and a pump with a relatively small capacity After removing the waste oil with a special machine equipped with a light sensor on the nozzle, the injection stops when the liquid level rises to the sensor part at the time of new oil injection. It had been taken.
[0003]
[Problems to be solved by the invention]
However, in the existing engine oil changer, since the amount of oil to be changed is considerably large, the pump capacity of the changer is relatively large. Therefore, with a small capacity such as a reserve tank for power steering oil, no matter how much the load cell is used to make the extraction amount and the injection amount the same, the injection amount will go too far and overflow when a new oil is injected There was a risk of waking up.
[0004]
In addition, power steering oil is not an oil that needs to be changed as often as engine oil because of its nature, so even if it reduces the pump capacity and improves the engine oil changer equipped with a load cell, it is a device that replaces power steering oil. Even if it does, since the cost will become expensive, when the depreciation of an apparatus is considered, it will become something which is not worthy.
[0005]
In addition, in dedicated machines that only perform extraction, not only is it cumbersome to visually check the liquid level during injection, but some reserve tanks are made of resin with the liquid level visible from the side of the tank. There are structures that cannot be seen inside, and even resin-made ones can check the liquid level, but it is very difficult to check the liquid level in a dark place where dirt is attached to the peripheral surface of the tank. Therefore, it is almost impossible to perform accurate injection. Sometimes, as in the case described above, overflow occurs and oil is applied to peripheral devices.
[0006]
Furthermore, if you use a pump with a relatively small capacity and a special machine equipped with a light sensor, it is possible to stop the injection when the new oil level rises to the light sensor. The positional relationship between the optical sensor that detects the liquid level and the nozzle is always constant, and the insertion level of the nozzle, that is, the position of the liquid level at the end of the new oil injection is also determined by the position of the optical sensor. Depending on the situation, the level of the new oil injection liquid may not be the normal height. In this case, when inserting the nozzle before draining the waste oil, the insertion position of the optical sensor should be visually adjusted in advance. Necessity arises.
[0007]
An object of the present invention is to provide an oil changer that can solve the above-mentioned problems.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention extracts and accommodates a capacitive liquid level sensor also serving as a nozzle, which is formed in a double cylindrical shape at an appropriate interval, and waste oil in a reserve tank. A waste oil tank for storage, a new oil tank for storing new oil to be injected into the reserve tank, a pump means and a pipe connected to one of the liquid level sensors and driven by a motor to the other Based on the extraction and injection pipelines connected to the waste oil tank and the new oil tank via the path switching means, and the detection value from the liquid level sensor, the start and stop of the pump means and the switching of the pipeline switching means are controlled. And a control means that detects the liquid level of waste oil contained in the reserve tank when the liquid level sensor is inserted into the reserve tank, and sets the initial liquid level. Recollecting, extracting the waste oil in the reserve tank into the waste oil tank, injecting the new oil in the new oil tank into the reserve tank, and the initial stage during the injection process The process of temporarily stopping injection when a liquid level that is lower than the liquid level by a predetermined amount is detected, and the liquid level when the liquid level of new oil that continues to be discharged for a while after the pause stops changing Is detected and stored as an excessive liquid level, and whether or not a value obtained by subtracting the temporary liquid level from the excessive liquid level is equal to or greater than a predetermined value, the inner diameter of the reserve tank is determined. The specified stroke, the inner diameter of the specified reserve tank, the liquid level difference between the initial liquid level and the overshoot liquid level, and the unit per unit time of the pump means Based on the rated discharge amount and the excess amount when the specified reserve tank has an inside diameter, a step of calculating an injection time required to inject new oil to the initial liquid level, and only the injection time The process of reinjecting new oil, the process of determining whether the liquid level after reinjection is substantially the initial liquid level, and based on the determination result, the reinjection is repeated or injected. It is an object of the present invention to provide an oil changer having an end process.
[0009]
[Action]
While repeatedly performing the process of suspending the injection process and estimating the inner diameter of the reserve tank based on the amount of overshoot at that time, and determining how much more pump means can be driven to the initial liquid level Since inching is injected, it can be injected accurately into any shape of reserve tank.
【Example】
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0010]
FIG. 1 is an overall configuration diagram of an oil changer according to an embodiment of the present invention. In a main body 1, a waste oil tank 2 for storing extracted waste oil and a new oil tank 3 for storing new oil to be injected are stored. Are respectively disposed, and the extraction pipe 4 and the injection pipe 5 are connected to the tanks 2 and 3, respectively.
[0011]
An operation unit 6 is provided on the outer surface of the upper portion of the main body 1, and a fully automatic selection switch 29 for performing oil change a plurality of times while the engine is idling to automatically change all oil in the power steering hydraulic system. And an automatic selection switch 7 for automatically changing the oil in the reserve tank 20 of the power steering only once in a state where the engine is stopped, and a sampling selection switch 8 and an injection for manually performing the sampling and the injection, respectively. A selection switch 9 and a start switch 10 and a stop switch 11 for executing and stopping each process after the selection switches of fully automatic, automatic, sampling, and injection are selected.
[0012]
The pipes 4 and 5 are provided with solenoid valves 13, 14, 15 and 16, which are pipe switching means, and a motor-driven reversible pump 17 capable of normal and reverse rotation. It is controlled by a control means 18 comprising a conventionally known microcomputer which receives a switch input, so that the pipes 4 and 5 can be switched and the rotation direction of the reversible pump 17 can be changed.
[0013]
Both pipes 4 and 5 outside the main body 1 are flexible flexible hoses, and their tips are electrostatically combined with a nozzle that is formed in a double cylindrical shape with a certain interval as appropriate. It is connected to a capacity type liquid level sensor 19 and is inserted into the reserve tank 20 for power steering oil as shown in FIG. A long hole is bored over the entire length so that even oil with viscosity can easily enter and exit the liquid level sensor 19.
[0014]
FIG. 2 is a cross-sectional view of the main part of the liquid level sensor 19, and the portion that also serves as the nozzle portion is a metal inner cylinder 21, and the tip of the flexible hose is connected to the root of the inner cylinder 21. Oil can be extracted and injected from the inner cylinder 21.
[0015]
In addition, metal outer cylinders 22 are also fixed to insulating guides 23 and 24, respectively, with appropriate intervals on the outer periphery thereof. These inner cylinders 21 and outer cylinders 22 form so-called capacitors. Thus, oil can quickly enter the inner cylinder 21 through the long hole drilled in the outer cylinder 22, and the capacitance by the capacitor can also change rapidly following the change in the liquid level. It has become.
[0016]
Further, the tip portions of the inner cylinder 21 and the outer cylinder 22 are supported by an insulating cylindrical support 25 so that the inner cylinder 21 and the outer cylinder 22 do not short-circuit by touching the metal reserve tank. At the same time, the support 25 is provided with a plurality of holes on the bottom surface and the bottom peripheral surface, and these holes serve as oil passages.
[0017]
An oscillation circuit 26 for repeatedly charging and discharging the inner cylinder 21 and the outer cylinder 22 is provided inside the guide 24 (the inner cylinder 21 and the outer cylinder 22 that change as the liquid level changes). This is a circuit that captures a change in capacitance as a change in charge / discharge time interval and outputs the change as a change in pulse signal. From 26, a signal line 28 for wiring the charge / discharge repetition into the number of pulses and sending it to the control means 18 is wired.
[0018]
Next, the usage and operation of the embodiment will be described with reference to the flowcharts of FIGS.
[0019]
By the way, the oil changer of the present invention performs a plurality of extractions and injections while idling the engine, fully automatic change that changes not only the power reserve tank but also the oil in the hydraulic mechanism, and the engine. It is possible to perform automatic replacement in which only the oil in the reserve tank is replaced and manual replacement in which the extraction and injection are performed manually. For the sake of clarity, the case of automatic exchange will be described here.
[0020]
First, the operator inserts the nozzle level liquid level sensor 19 into the power steering oil reserve tank 20, presses the automatic selection switch 7 (step 1), and then presses the start switch 10 (step 2). A pulse signal corresponding to the level of the waste oil in the reserve tank 20 at that time is sent from the oscillation circuit 26 in the level sensor 19 to the control means 18 through the signal line 28 (the device is turned on). When the voltage is applied to the liquid level sensor 19 through the power line 27 and the pulse signal is sent from the oscillation circuit 26, the control means 18 does not stop until the start switch 10 is pressed. The control means 18 stores the number of pulses as the initial liquid level A (step 3). Control means 18 is rotated in the direction sampling a reversible pump 17 by opening the electromagnetic valve 13, 14 (Step 4).
[0021]
Then, the waste oil in the reserve tank 20 is extracted into the waste oil tank 2 through the inner cylinder 21 and the extraction pipe 4, and the extraction process is started.
[0022]
Eventually, when the waste oil in the reserve tank 20 decreases and the liquid level falls below the round hole formed in the peripheral surface of the support 25 at the tip of the liquid level sensor 19, air is sucked from the inner cylinder 21, and oscillation occurs. The number of pulses sent from the circuit 26 to the control means 18 does not change (step 5), and the control means 18 receives this and determines that the extraction is completed, closes the electromagnetic valves 13 and 14, and instead of the electromagnetic valve 15 , 16 are opened, and the reversible pump 17 is reversely driven in the injection direction (step 6).
[0023]
Then, the new oil in the new oil tank 3 is injected into the reserve tank 20 through the injection pipe 5 and the inner cylinder 21 to start the injection process.
[0024]
When the injection process is started, the liquid level in the reserve tank 20 gradually rises, but since the inner diameter of the reserve tank 20 is quite thin, the liquid level rise speed is considerably high, and the initial liquid level level is kept as it is. If it is injected up to A, there is a risk of overflow.
[0025]
Therefore, when the control means 18 detects a liquid level B lower than the initial liquid level A by a predetermined amount (step 7), the reversible pump 17 is stopped and the solenoid valves 15 and 16 are closed (step 8). ) The injection is temporarily stopped, but the rise in the liquid level does not stop immediately, but it goes too far due to the fluid inertia. Therefore, the timer which is kept in the control means 18 until a time t enough for the excess to pass is passed. Starts counting.
[0026]
After that, when time t has passed and the liquid level has settled (step 9), the control means 18 subtracts the temporary stop liquid level B from the excessive liquid level, and the value is stored in advance as a reference value. For example, the inner diameter of the reserve tank 20 that is being replaced this time is specified based on whether or not the inner diameter of the reserve tank 20 is larger than the liquid level difference when the inner diameter is 65 mm.
[0027]
Here, if the reserve tank 20 is larger than the reference value, the inner diameter of the reserve tank 20 is 65 mm, and if it is less than 45 mm (assuming that there is no reserve tank having an inner diameter smaller than this), the control means is temporarily specified. Based on the inching injection table when 18 is 65 mm or 45 mm, the subsequent inching injection is performed (step 10).
[0028]
In other words, when it is larger than the reference value, it is assumed that the inner diameter of the reserve tank 20 is 65 mm. Next, from the initial liquid level A, the current overshoot liquid level and the overshoot amount at the next inching injection (preliminary control means) 18 is used, the excess amount when the inner diameter of the reserve tank 20 is 65 mm is used) and the area of the circle with the inner diameter of 65 mm is multiplied by the value obtained by subtracting the area of the circle with the inner diameter of 65 mm. When the reversible pump 17 needs to be driven until the initial liquid level is reached, the reserve tank 20 has an inner diameter of 45 mm. Next, from the initial liquid level A, the current overshoot liquid level and the overshoot amount at the next inching injection (based on a table previously stored in the control means 18). Then, the excess amount when the inner diameter of the reserve tank 20 is 45 mm is used.) Is multiplied by the area of the circle with the inner diameter of 45 mm, and then divided by the discharge amount per unit time of the reversible pump 17. The time required to drive the reversible pump 17 until the liquid level is reached is calculated (steps 11 and 17).
[0029]
By the way, since the driving times Tx and Ty of the reversible pump 17 calculated as described above are both calculated as an inner diameter smaller than the actual inner diameter, the driving time Tx and Ty are both approached to the initial liquid level A and never initial. It is not time to exceed the liquid level A.
[0030]
After determining in this way, the control means 18 drives the reversible pump 17 in the injection direction, opens the electromagnetic valves 15 and 16 (steps 12 and 18), restarts the injection, and the drive time of the reversible pump 17 is increased. When Tx or Ty is reached (steps 13 and 19), the reversible pump 17 is stopped and the solenoid valves 15 and 16 are closed (steps 14 and 20), the injection is stopped, the overshoot is stopped, and the time t when the liquid level is settled is reached. After a lapse (steps 15 and 21), the liquid level sensor 19 detects the liquid level and confirms whether or not the initial liquid level A has been reached (actually with a slight negative error within the range). (Steps 16 and 22), if it has reached, the replacement operation is terminated, and if not, based on the specified inner diameter of the reserve tank 20 etc. Unishi injection driving time Tx or Ty calculated again Te, repeated inching injection operation.
[0031]
As described above, inching injection up to the initial liquid surface level is performed quickly and reliably. Needless to say, such inching injection can be performed even in the case of fully automatic replacement in which a plurality of replacements are performed continuously. Absent.
[0032]
By the way, the reversible pump 17 is used here, and the extraction pipe line 4 and the injection pipe line 5 are partly shared. However, in order to prevent the mixing of waste oil and new oil during oil exchange strictly, it is expensive. However, a structure may be adopted in which the extraction pipe line and the injection pipe line are separately provided and a dedicated pump is provided for each.
[0033]
【The invention's effect】
As described above, according to the present invention, when replacing oil such as power steering oil that has almost no change in oil amount as long as there is no leakage from the pipe, it is possible to accurately and quickly perform the operation with little trouble for the operator. The oil can be changed.
Also, when injecting new oil, the specified amount of inching can be accurately injected without overflow.
Further, since the nozzle and the liquid level sensor are used in combination, it can be manufactured at a lower cost compared to a conventional load cell or other weight meter.
Also, depending on the driving condition of the vehicle, the inching injection is performed by specifying the inner diameter of the reserve tank using the new oil that is relatively stable in temperature, rather than the waste oil having a large variation in oil temperature. There is little error, and stable oil exchange is possible.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an oil changer according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a main part of a liquid level sensor of the same apparatus.
FIG. 3 to FIG. 5 are flowcharts showing an operation state of the apparatus.
[Explanation of symbols]
2 Waste oil tank 3 New oil tank 4 Extraction pipe 5 Injection pipes 13, 14, 15, 16 Switching means 17 Reversible pump 18 Control means 19 Liquid level sensor 20 Reserve tank 21 Inner cylinder 22 Outer cylinder

Claims (1)

Capacitance-type liquid level sensor also serving as a nozzle, which is formed into a double cylinder with a constant interval as appropriate,
A waste oil tank for extracting and storing waste oil in the reserve tank; a new oil tank for storing new oil to be injected into the reserve tank;
One is connected to the liquid level sensor, and the other is connected to the waste oil tank and the new oil tank through a pump means and a pipe switching means driven by a motor, and an extraction and injection pipe line,
Based on the detection value from the liquid level sensor, it is composed of control means for controlling the start and stop of the pump means and the switching of the pipeline switching means,
Detecting the liquid level of waste oil contained in the reserve tank when the liquid level sensor is inserted into the reserve tank, and storing it as an initial liquid level;
An extraction step of extracting the waste oil in the reserve tank into the waste oil tank;
An injection step of injecting new oil in the new oil tank into the reserve tank;
During the injection process, the process of temporarily stopping the injection upon detecting a pause liquid level lower than the initial liquid level by a predetermined amount;
The process of detecting and storing the liquid level when the liquid level of the new oil that continues to be discharged for a while after the temporary stop does not change as the excessive liquid level,
Determining whether or not a value obtained by subtracting the suspension liquid level from the excess liquid level is a predetermined value or more, and a step of specifying an inner diameter of the reserve tank;
The identified reserve tank inner diameter, the liquid level difference between the initial liquid level and the excess liquid level, the rated discharge amount per unit time of the pump means, and the identified reserve tank inner diameter A process of calculating an injection time required to inject new oil up to the initial liquid level based on an overshoot amount at a certain time;
Re-injecting new oil for the injection time;
A step of determining whether or not the liquid level after reinjection is substantially the initial liquid level;
An oil changer comprising: a step of repeatedly performing the reinjection or ending the injection based on the determination result.

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