JPH0646367U - Gasoline characterization device - Google Patents

Abstract

(57) [Summary] [Purpose] To quickly determine the temperature gradient of the electrostatic quantity of gasoline and determine the properties of gasoline in a short time. [Structure] One side oil supply passage 101B of oil supply tube 101
In addition, a first capacitance sensor 110 and a first temperature sensor 11 which detect the capacitance and temperature of low-temperature gasoline, respectively.
1 is provided, and the other side oil supply passage 101C has a second capacitance sensor 113 and a second temperature sensor 1 for detecting the capacitance and temperature of the gasoline heated by the heater 112, respectively.
14 is provided, and the start of refueling is started by the refueling port switch 11
5 and the fuel meter 109 are used for detection. As a result, when refueling of the fuel tank 100 is started,
The heater 112 causes a temperature difference between the oil supply passages 101B and 101C, and the control unit 117 determines the property of gasoline based on the detection signals from the sensors 110, 111 and 113, 114.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gasoline property determination device suitable for use in determining whether the properties of gasoline used in an automobile engine are heavy, light, or medium, and particularly to a fuel tank The present invention relates to a gasoline property determination device that determines the properties during refueling.

[0002]

[Prior art]

 In general, gasoline used for automobile engines includes heavy gasoline that contains heptane, pentane, etc. as its main components and has a property that is difficult to vaporize, and light gasoline that contains benzene, etc. as a main component that has the property of being easily vaporized. There are three types, mid-range gasoline, which is located almost in the middle of the two, and for a normal gasoline engine, the ignition timing and fuel injection amount are set according to the light gasoline. However, in recent years, gasoline has become heavier due to environmental protection, and while heavy gasoline and light and medium gasoline are mixed in the market, it was originally heavy gasoline due to the injection of various additives. However, there is a problem in that the engine, which is fixedly adjusted to light gasoline, may cause problems such as startability.

Therefore, based on the capacitance sensor for detecting the capacitance of gasoline interposed between the electrodes facing each other, the temperature sensor for detecting the temperature of gasoline, and the detection signal from each sensor, the gasoline is A gasoline property determination device has been proposed, which includes a determination means for determining whether the quality is light, light, or medium.

Then, the gasoline property determination device of this type determines whether or not the point specified by the detection signal from each of the sensors is in a determination region for determining whether it is pseudo heavy or not. If it is judged to be pseudo-heavy after performing one-step property determination, wait for the temperature of the gasoline to rise naturally due to the heat of the engine, etc., and then read the detection signal of each sensor again. Therefore, the temperature change of the capacitance of gasoline, that is, the temperature gradient is calculated, and whether the gasoline judged to be pseudo-heavy based on this temperature gradient is truly heavy (true heavy), Alternatively, it is determined whether various additives have been mixed in heavy gasoline and subsequently lightened or neutralized.

[0005]

[Problems to be solved by the device]

 By the way, in the gasoline property determination device according to the above-described conventional technique, whether the gasoline determined to be the pseudo heavy is the true heavy by determining the temperature gradient of the detection signal output from the capacitance sensor. It is determined whether the temperature is light or medium, but in order to obtain this temperature gradient, it is necessary to wait until the temperature of gasoline naturally rises due to heat generation of the engine.

Therefore, the above-mentioned conventional technique has a problem that it takes a long time to obtain the final result of property determination and the responsiveness is low. Especially when starting in cold regions, it takes a long time for the gasoline temperature to rise by the minimum temperature difference required to obtain the temperature gradient, so the response is significantly reduced and the reliability is greatly reduced. To do. Also, when the engine is at high temperature, ignition is performed even if the gasoline is heavy, light, or medium in quality, so there is little operational problem, but when the engine is cold at the time of starting, etc. Since the gasoline vaporization is small, whether the gasoline is heavy, light or medium has a great effect on startability.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a gasoline property determination device capable of quickly determining the property of gasoline.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the configuration adopted by the present invention has a fuel supply tube having a base end side connected to a fuel tank and a tip end side serving as a fuel supply port, and a fuel supply tube provided in the middle of the fuel supply tube. A first capacitance sensor for detecting capacitance, a first temperature sensor provided in the refueling tube near the first capacitance sensor for detecting the temperature of gasoline, and No. 1 capacitance sensor is provided in the middle of the refueling tube to heat gasoline at the time of refueling, and a heating means provided near the heating means and in the middle of the refueling tube to heat the gasoline. A second capacitance sensor for detecting the capacitance of the gasoline heated by the means, and a second capacitance sensor located in the vicinity of the second capacitance sensor and provided in the middle of the refueling tube. Heated A second temperature sensor for detecting the temperature of the sorin, a refueling start detecting means for detecting the start of refueling by the refueling tube, and the first, first when the refueling start detecting means detects the start of refueling. The temperature gradient of the capacitance of gasoline is calculated from the detection signals from the second capacitance sensor and the temperatures detected from the first and second temperature sensors described above. It consists of a judging means for judging whether there is light, light or medium quality.

[0009]

[Action]

 When the refueling start detection means detects the start of refueling via the refueling tube, the determination means determines the electrostatic capacity and temperature of gasoline in a low temperature state from the first capacitance sensor and the first temperature sensor. On the other hand, by detecting the capacitance and the temperature of the gasoline in the high temperature state heated by the heating means from the second capacitance sensor and the second temperature sensor, the temperature of the capacitance of the gasoline is detected. The gradient is calculated, and it is determined whether the gasoline is heavy, light, or medium based on this temperature gradient.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

First, FIGS. 1 to 5 relate to a first embodiment of the present invention. In the drawings, 100 is a fuel tank in the form of a closed container in which gasoline is stored, 101 is the fuel tank 100 at the base end side. Each of the oil supply tubes is connected to the oil supply tube 101, and the tip end side of the oil supply tube 101 serves as an oil supply port 101A that opens to the rear side of the vehicle body (not shown). The middle portion of the oil supply tube 101 is bifurcated into one side oil supply passage 101B and the other side oil supply passage 101C, and the oil supply passages 101B and 101C are connected to each other on the inflow side and the outflow side. ing. At the time of refueling, the refueling cap 102 is removed and the refueling nozzle (not shown) of the refueling device is inserted into the refueling port 101A of the refueling tube 101, so that the return tube 103 bleeds air from the fuel tank 100. The fuel tank 100 is constantly refueled.

Reference numeral 104 denotes a fuel pump that is provided in the fuel tank 100 and is configured as, for example, a turbine fuel pump, and the fuel pump 104 transfers the gasoline sucked from the suction port 104A through the discharge port 104B to a fuel pipe described later. The liquid is discharged into 106.

Reference numeral 105 denotes an injection valve provided in an intake manifold (neither is shown) located near the cylinder head of the engine. The injection valve 105 is a needle in response to a control signal from a control unit 117 described later. By opening and closing the valve, the gasoline supplied from the fuel pump 104 through the fuel pipe 106 is injected toward the combustion chamber (not shown) of the engine.

Reference numeral 106 denotes a fuel pipe provided between the fuel pump 104 and the injection valve 105, and the inflow side of the fuel pipe 106 is connected to a discharge port 104B of the fuel pump 104 via a filter (not shown). It is connected, and its outflow side is connected to a pressure regulator 107 described later. Reference numeral 107 denotes a pressure regulator connected to the outflow side of the fuel pipe 106. The pressure regulator 107 returns the gasoline in the fuel pipe 106 to the fuel tank 100 via the return pipe 108, thereby The fuel pressure in 106 is maintained at a predetermined value.

Reference numeral 109 denotes a float type fuel gauge provided in the fuel tank 100, and the fuel gauge 109 causes the float 109B provided at the tip side of the arm 109A to follow in accordance with the liquid level of gasoline, The remaining amount of gasoline is detected according to the rotation angle of the arm 109A, and this is output to the control unit 117 as a remaining amount detection signal C.

Reference numeral 110 denotes a first capacitance sensor provided in the one side oil supply passage 101B located in the middle of the oil supply tube 101, and the first capacitance sensor 110 is as shown in FIG. For example, a pair of electrodes are formed in a parallel plate type or a coaxial cylindrical type, and a capacitance detection unit 110A for detecting a capacitance according to the dielectric constant of gasoline in the one side oil supply passage 101B and the static electricity detection unit 110A. An LC-type oscillation circuit 110B that oscillates an oscillation frequency based on the electrostatic capacitance detected by the capacitance detection unit 110A, and a frequency-voltage conversion circuit 110C (hereinafter, referred to as a voltage-voltage conversion circuit 110C that converts the oscillation frequency from the oscillation circuit 110B into a voltage signal). "F / V conversion circuit 110C") and an inverting amplifier circuit 110D which inverts and amplifies the voltage signal converted by the f / V conversion circuit 110C to form a detection signal V1. The first electrostatic capacitance sensor 110 detects the electrostatic capacitance of gasoline flowing in the one side oil supply passage 101B of the oil supply tube 101 and outputs it to the control unit 117 as a detection signal V1.

Reference numeral 111 denotes a first temperature sensor provided near the first capacitance sensor 110 and provided in the one side oil supply passage 101 B of the oil supply tube 101, and the first temperature sensor 111 is For example, it is composed of a temperature sensitive element such as a thermistor, and detects the temperature t1 of gasoline whose electrostatic capacity is detected by the electrostatic capacity detection unit 110A and outputs the detected temperature t1 to the control unit 117.

Reference numeral 112 denotes a heater that is provided in the other oil supply passage 101C on the other side of the oil supply tube 101 and is configured as, for example, a ceramic heater and serves as a heating means. A capacitance sensor 113 is attached. Then, as will be described later, the heater 112 generates heat in response to a control signal from the control unit 117 at the start of refueling, thereby raising the temperature of the gasoline flowing toward the second capacitance sensor 113. .

Reference numeral 113 denotes a second capacitance sensor which is located on the downstream side of the heater 112 and is provided in the other side oil supply passage 101C of the oil supply tube 101, and the second capacitance sensor 1 13 is As in the case of the first capacitance sensor 110, as shown in FIG. 2, the capacitance detection unit 113A, the oscillation circuit 113B, the frequency-voltage conversion circuit 113C (hereinafter referred to as "f / V conversion circuit 113C"). ) And an inverting amplifier circuit 113D. The second capacitance sensor 113 detects the capacitance of gasoline flowing in the other side oil supply passage 101C of the oil supply tube 101, and outputs it as the detection signal V2 to the control unit 117. is there.

Reference numeral 114 denotes a second temperature sensor provided in the other side oil supply passage 101C of the oil supply tube 101, which is located in the vicinity of the second capacitance sensor 113, and the second temperature sensor 114 is Almost the same as the first temperature sensor 111, the first temperature sensor 111 includes a temperature sensitive element such as a thermistor. Then, the second temperature sensor 114 detects the temperature t2 of the gas whose capacitance is detected by the capacitance detection unit 113A of the second electrostatic capacitance sensor 113, and the detected temperature t2 is used as the control unit. It is output to 117.

Reference numeral 115 denotes a fuel filler switch provided in the vicinity of the fuel filler port 101A of the fuel filler tube 101, and is composed of, for example, a reed switch, a proximity switch, etc. The fuel filler switch 115 is used together with the fuel meter 109 described above, or It independently constitutes the refueling start detecting means which is a constituent feature of the present invention, and detects when the refueling cap 102 is removed and outputs it to the control unit 117.

Reference numeral 116 denotes a third temperature sensor located upstream of the injection valve 105 and provided in the middle of the fuel pipe 106. The third temperature sensor 116 is the above-mentioned first temperature sensor 111, Almost the same as the second temperature sensor 114, the second temperature sensor 114 includes a temperature-sensitive element such as a thermistor. The third temperature sensor 116 detects the temperature t3 of gasoline supplied to the injection valve 105 and outputs the detected temperature t3 to the control unit 117.

Reference numeral 117 denotes a control unit as a determination means, and the control unit 117 has an arithmetic processing circuit including a CPU, a storage circuit including a ROM and a RAM, an input / output circuit (none of which is shown), etc. And a capacitance sensor 110, 113, a temperature sensor 111, 114, 116, a fuel gauge 109, a fuel filler switch 115, an engine switch, a crank angle sensor, and an air flow. A meter (neither is shown) or the like is connected, and a fuel pump 104, an injection valve 105, a heater 112, an ignition plug (not shown), etc. are connected to the output side thereof. Further, a storage area 117A is formed in the storage circuit of the control unit 117, and in the storage area 117A, a temperature characteristic map 118, which will be described later with reference to FIG. 3, a property determination program shown in FIGS. The rate Cα0, the reference temperature difference Δt0 and the like are stored.

Here, the reference rate of increase Cα0 is for determining whether or not gasoline is refueled in the fuel tank 100 to perform regular refueling, and the reference temperature difference Δt0 is This is for determining whether or not the minimum temperature difference required to calculate the temperature gradient α of the capacitance of gasoline has occurred.

Reference numeral 118 shows a temperature characteristic map stored in the storage area 117 A of the control unit 117. As shown in FIG. 3, the temperature characteristic map 118 shows that, in each of heavy, medium and light gasoline, The relationship between the temperature t and the detection signal V from each of the electrostatic capacity sensors 110 and 113 is mapped, and it is determined whether the gasoline is light or medium quality gasoline, that is, the range indicating the existence range of the pseudo heavy fuel. A region 118A is provided. Further, the temperature characteristic map 118 stores a reference temperature gradient α 0 indicating the rate of change of the detection signal V 1 with respect to temperature in the genuine heavy gasoline, and the temperature is the true heavy based on the reference temperature gradient α 0. It is designed to judge whether or not it has been neutralized or lightened by additives.

The gasoline property discriminating apparatus according to the present embodiment has the above-described configuration. Next, the property discriminating process by the control unit 117 will be described with reference to FIGS. 4 and 5.

First, in step 1, the state of the fuel filler switch 115 is read, and in step 2, it is determined whether the fuel filler cap 102 is removed from the on / off state of the fuel filler switch 115. If “NO” is determined in this step 2, if the refueling cap 102 is not removed from the refueling port 101A of the refueling tube 101, that is, if refueling is not performed, the process proceeds to step 3, and in this step 3, The previous property determination result is set in the storage area 117A as it is, and the process returns to step 1. As a result, when the engine is started, the ignition timing and the like are controlled based on the result of the previous property determination.

On the other hand, if “YES” is determined in step 2, the refueling cap 102 has been removed from the refueling port 101A, so in the next step 4, the remaining amount detection signal C from the fuel gauge 109 is read, In step 5, the change rate Cα of the remaining amount detection signal C is calculated, and it is determined whether or not the change rate Cα exceeds the reference increase rate Cα0 in the storage area 117A. If "NO" is determined in this step 5, the amount of gasoline newly refueled in the fuel tank 100 via the refueling tube 101 is small, so it is not necessary to determine the property, or the additive etc. Since it is the case that only a relatively small amount of liquid has been injected, the process proceeds to step 3.

On the other hand, if “YES” is determined in step 5, it means that the liquid is injected into the fuel tank 100 at a momentum higher than the reference increase rate Cα0, that is, the regular refueling is started. Then, in step 6, the heater 112 is caused to generate heat to heat the gasoline flowing in the other side oil supply passage 101C of the oil supply tube 101. As a result, new gasoline flowing into the refueling tube 101 from the refueling device is split into the one side oil supply passage 101B and the other side oil supply passage 101C, and only the gasoline flowing in the other side oil supply passage 101C is heated.

Next, in step 7, the gasoline temperature t1 in the one side oil supply passage 101B of the oil supply tube 101 is read from the first temperature sensor 111, and in step 8, the detection signal from the first capacitance sensor 110 is read. Read V1.

Then, in step 9, it is determined whether or not the points defined by the temperature t 1 and the detection signal V 1 read in steps 7 and 8 exist in the determination region 118 A of the temperature characteristic map 118, that is, the pseudo heavy If it is determined to be "NO" in this step 9, the point specified by the temperature t1 and the detection signal V1 is out of the determination region 118A, and the gasoline in the refueling tube 101 is If it is not pseudo-heavy, the process moves to step 10 and is judged to be light or medium quality, and the process moves to step 18 described later.

On the other hand, if “YES” is determined in the step 9, it means that the point determined by the temperature t1 and the detection signal V1 exists in the determination area 118A, and the gasoline is determined to be the pseudo heavy fuel. , The temperature gradient α is calculated, and the process shown in FIG.

That is, in step 11, the gasoline temperature t2 (t2> t1) in the other side oil supply passage 101C heated by the heater 112 is read from the second temperature sensor 114, and in step 12, this other side oil supply passage 101C is read. The temperature difference Δt (Δt = t2-t1) between the gasoline temperature t2 inside the one side oil supply passage 101B and the gasoline temperature t1 inside the one side oil supply passage 101B is obtained, and whether or not this temperature difference Δt exceeds the reference temperature difference Δt0 inside the memory area 117A. Determine whether. If "NO" is determined in this step 12, the heat generation of the heater 112 is insufficient, the temperature difference Δt is still small, and it is not suitable for calculation of the temperature gradient α, so the process returns to the above step 11.

On the other hand, when the determination in step 12 is “YES”, the heating of the heater 112 causes the gasoline temperature t2 in the other side oil supply passage 101C to rise, resulting in a temperature difference Δt exceeding the reference temperature difference Δt0. Therefore, in step 13, the detection signal V2 is read from the second electrostatic capacitance sensor 113, and in the next step 14, the detection signal V2, the temperature t2 read in step 11 and the steps 7 and 7, From the temperature t1 read in 8 and the detection signal V1, the temperature gradient α of gasoline is

[0035]

[Equation 1] Calculate as

Then, in step 15, it is determined whether or not this temperature gradient α exceeds the reference temperature gradient α 0 stored in the storage area 117A, and when “NO” is determined in this step 15, the temperature gradient α is determined. Since α is smaller than the reference temperature gradient α 0, the routine proceeds to the next step 16, and it is determined that the gasoline in the refueling tube 101 is light and medium.

On the other hand, when the determination in step 15 is “YES”, since the temperature gradient α is larger than the reference temperature gradient α 0, the process moves to step 17, and the gasoline in the refueling tube 10 1 is an authentic heavy fuel. Then, in step 18, the power supply to the heater 112 is cut off and the heating is terminated.

Then, even after the heating of the heater 112 is stopped, refueling is performed through the refueling tube 101, and new gasoline is replenished in the fuel tank 100. Here, for example, when refueling the fuel tank 100 of an ordinary passenger car at a gas station until it is almost empty, it usually takes about several minutes depending on the capacity of the fuel tank 100. And

Therefore, assuming that the time required from the start of refueling to the end of refueling and restart of the engine is, for example, about 10 to 30 minutes, the temperature t3 of the gasoline remaining in the fuel pipe 106 during that time gradually decreases. However, the temperature of the gasoline in the fuel tank 100, which is filled with a large amount of new low-temperature gasoline, exceeds the temperature of the gasoline.

Therefore, when the engine is restarted and new gasoline flows through the fuel pipe 106, the gasoline temperature t3 detected by the third temperature sensor 116 drops sharply. By monitoring the change, it is possible to know whether new gasoline has been supplied to the injection valve 105.

That is, in step 19, the gasoline temperature t3 in the fuel pipe 106 is read from the third temperature sensor 116, and in step 20, the temperature t3 is differentiated to obtain the temperature decrease rate, and the change in the temperature decrease rate. Based on the above, it is determined whether or not the temperature decrease of the gasoline temperature t3 in the fuel pipe 106 has started. If "NO" is determined in this step 20, it means that new gasoline in the fuel tank 100 is not yet supplied in the fuel pipe 106, and therefore the process returns to step 19.

On the other hand, if “YES” is determined in the above step 20, it means that new gasoline from the fuel tank 100 is supplied into the fuel pipe 106 and the gasoline temperature t3 is lowered, so that the process proceeds to step 21. In this step 21, the property determination result in the storage area 117A is updated and stored in order to change the injection timing and the like according to the property of the new gasoline, and thereafter, the property of the refueled new gasoline is stored. The ignition timing, injection amount, etc. are controlled accordingly.

Thus, according to the present embodiment, the first capacitance sensor 110 and the first temperature for detecting the capacitance and temperature of low-temperature gasoline are respectively provided in the oil supply passage 101B on one side of the oil supply tube 101. A sensor 111 is provided, and a second capacitance sensor 113 and a second temperature sensor 114, which respectively detect the capacitance and temperature of gasoline heated by the heater 112, are provided on the other side oil supply passage 101C of the oil supply tube 101. At the same time, the start of refueling is detected by the refueling port switch 115 and the fuel gauge 109. Therefore, when refueling the fuel tank 100, the temperature gradient α is quickly increased without waiting for the temperature of gasoline to rise naturally. It is possible to determine the properties of gasoline in a short period of time by seeking, and it is possible to greatly improve the startability of the engine.

Further, by providing a third temperature sensor 116 located upstream of the injection valve 105 in the middle of the fuel pipe 106 and monitoring the temperature t3 detected by the third temperature sensor 116, the property can be improved. Since the determination result is updated and registered, the property of the old gasoline remaining in the fuel pipe 106 until the new gasoline in the fuel tank 100 is supplied to the injection valve 105 by the engine restart. The engine can be optimally controlled in accordance with the above, while on the other hand, when new gasoline reaches the injection valve 105, the engine can be optimally controlled based on the latest discrimination result.

Next, FIG. 6 shows a second embodiment of the present invention. The feature of this embodiment is that a throttle portion is provided in the middle of the oil supply passage on the other side where the second electrostatic capacity sensor is provided. It is in. In this embodiment, the same components as those in the first embodiment shown in FIGS. 1 to 5 described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 200 indicates an oil supply tube applied to this embodiment in place of the oil supply tube 101 described in the first embodiment, and the oil supply tube 200 is the oil supply tube described in the first embodiment. Similar to the tube 101, the base end side is connected to the fuel tank 100, and the tip end side is covered with the oil supply cap 200A by the oil supply cap 102, and the intermediate part is bifurcated into the one side oil supply passage 200B, the other. It is a side oil supply passage 200C. However, the refueling tube 200 according to the present embodiment is provided with the throttle portion 201 on the downstream side (outflow side) of the other side oil supply passage 200C, and the throttle portion 201 adjusts the flow rate of gasoline flowing in the other side oil supply passage 200C. This is different from the oil supply tube 101 according to the first embodiment.

Thus, in this embodiment having such a configuration, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. However, in particular, in the present embodiment, the throttle portion 201 is provided on the outflow side of the other side oil supply passage 200C of the oil supply tube 200, and the throttle portion 201 adjusts the gasoline flow rate in the other side oil supply passage 200C. , The staying time of gasoline in the other side oil supply passage 200C can be lengthened, the gasoline is effectively heated by the heater 112, and a large temperature difference Δt is generated between the gasoline in the one side oil supply passage 200B. It can be generated and the property can be easily discriminated.

Further, FIG. 7 shows a third embodiment of the present invention. The feature of this embodiment is that the refueling tube is formed as a single pipe line, and the first electrostatic tube is provided in the refueling tube. The capacitance sensor, the first temperature sensor, the second capacitance sensor, the second temperature sensor, and the like are arranged separately in the direction of gas flow. In this embodiment, the same components as those of the first embodiment shown in FIGS. 1 to 5 described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 300 denotes an oil supply tube applied to this embodiment, and the oil supply tube 300 has a fuel tank whose base end side is substantially the same as the oil supply tube 101 described in the first embodiment. The fuel supply port 300 </ b> A on the tip side is connected with a fuel supply cap 102. However, the refueling tube 300 according to the present embodiment is formed as a single conduit, and a first capacitance sensor 301, a second capacitance sensor 303, etc., which will be described later, are provided separately in the gasoline flow direction. This is different from the oil supply tubes 101 and 200 according to each of the above embodiments.

Reference numeral 301 denotes a first capacitance sensor which is provided on the inflow side and is located in the middle of the oil supply tube 300, and the first capacitance sensor 301 is the same as the first capacitance sensor described in the first embodiment. A first temperature sensor 302 is provided in the vicinity of the first capacitance sensor 110, which has almost the same configuration.

Reference numeral 303 denotes a heater as a heating means provided on the downstream side of the first capacitance sensor 301 so as to be separated from the first capacitance sensor 301, and the heater 303 is the heater described in the first embodiment. Like the heater 112, it is configured as a ceramics heater, for example.

Reference numeral 304 denotes a second capacitance sensor located downstream of the heater 303 and provided in the middle of the oil supply tube 300. The second capacitance sensor 304 is the same as in the first embodiment. The second capacitance sensor 113 has substantially the same structure as that of the second capacitance sensor 113 described above, and a second temperature sensor 305 is provided in the vicinity thereof.

Thus, in this embodiment having such a configuration, it is possible to obtain substantially the same operational effects as those of the first and second embodiments described above. However, in the present embodiment, the first capacitance sensor 301 and the like and the second capacitance sensor 304 and the like are separated in the refueling tube 300 formed as a single conduit in the gasoline flow direction. Since the heater 303 is provided, the property of the gasoline can be determined with a simple configuration while preventing the temperature of the gasoline on the first capacitance sensor 301 side from rising due to the heater 303.

Next, FIG. 8 shows a specific example of the second electrostatic capacity sensors 113 and 304 in each of the above-mentioned embodiments. In the figure, 1 is a rubber hose (not shown) in the middle of the oil supply tube. And the like, a coaxial cylindrical second capacitance sensor 2 is an external electrode constituting a casing of the second capacitance sensor 1, and the external electrode 2 is made of, for example, stainless steel or the like. It is made of a conductive material in a cylindrical shape, one end of which is covered with a lid 3 having an inlet 3A, and the other end is provided with an outlet 2A.

Reference numeral 4 denotes an internal electrode which is coaxially provided in the external electrode 2 and is formed in the shape of a cylinder with a bottom from a conductive material such as stainless steel. A cylindrical heater mounting portion 4B is formed so as to surround it, and a stepped cylindrical connecting portion 4C protruding toward the outside of the external electrode 2 is provided on one end side thereof. Further, a tubular flow path 5 is formed between the inner electrode 4 and the outer electrode 2, and the gasoline flowing into the flow path 5 from the inflow port 3A of the lid 3 has an outflow port 2A of the outer electrode 2. It is designed to be leaked through.

Reference numeral 6 denotes an external electrode terminal fitted to the outer peripheral side of the external electrode 2, and 7 denotes an internal electrode terminal fitted to the shaft portion 4 A of the internal electrode 4, respectively. Reference numeral 7 is connected to a control unit (neither is shown) via a lead wire.

Reference numeral 8 denotes a heater which is fitted into the heater mounting portion 4 B of the internal electrode 4 and is formed in a cylindrical shape from, for example, a ceramics heater or the like. It is connected to the control unit via a wire (not shown). Reference numeral 9 denotes a temperature sensor which is provided near the outlet 2A and is provided on the peripheral wall of the external electrode 2 and is composed of, for example, a temperature sensitive element such as a thermistor. It is connected to the control unit.

Reference numeral 10 is a cylindrical seal member provided between the lid 3 and the internal electrode 4, and 11 is provided outside the external electrode 2 so as to surround the outer peripheral side of the connection portion 4C of the internal electrode 4. The respective sealing members 10 and 11 are made of an insulating resin material.

Thus, the second capacitance sensors 113 and 304 in each embodiment are embodied as described above, for example, and are similar to the second capacitance sensors 113 and 304 according to each embodiment. Is obtained. However, in particular, in this example, since the heater mounting portion 4B is formed on the inner peripheral side of the inner electrode 4 and the cylindrical heater 8 is mounted in the heater mounting portion 4B, the heater 8 is used to The gasoline flowing in the flow path 5 can be uniformly and quickly heated through the thin outer peripheral side wall portion of the electrode 4, and the property can be accurately determined.

In each of the above-described embodiments, the fuel filler switch 115 or the fuel gauge 109 and steps 1 and 2 or 4 and 5 of the program shown in FIG. Here is an example:

Further, in each of the above embodiments, the gasoline temperature t3 in the fuel pipe 106 is monitored by steps 19 and 20 in FIG. 5, and when the temperature t3 is lowered, the latest property determination result is updated. However, the present invention is not limited to this, and, for example, after the power supply to the heater 112 (303) is cut off in step 18, the process immediately moves to step 21 to update the property determination result. May be

Alternatively, after the power supply to the heater 112 (303) is cut off in step 18, the remaining amount C1 after refueling is read from the fuel gauge 109, and the latest remaining amount C1 and the refueling start read in step 4 are started. The amount of newly refueled gasoline ΔC (= C1 −C) is calculated by comparing it with the immediately remaining amount C, and the gasoline in the fuel tank 100 is substantially renewed based on this amount of refueling ΔC. When it is determined that the gasoline has been replaced with a different gasoline, the latest property determination result may be registered. In this case, it is also possible to finely adjust the property determination result according to the ratio of the new gasoline supply amount ΔC and the old gasoline remaining amount C.

Further, in the above embodiment, the case where the inverting amplifier circuits 110D and 113D are used has been described as an example, but instead of this, an amplifier circuit may be used and amplification may be performed without being inverted.

[0064]

[Effect of device]

 As described in detail above, according to the present invention, the capacitance and the temperature of low-temperature gasoline refueled through the refueling tube are detected by the first capacitance sensor and the first temperature sensor. The capacitance and temperature of the high temperature gasoline heated by the heating means are detected by the second capacitance sensor and the second temperature sensor, and the property of gasoline is determined based on the detection signal from each sensor. With this configuration, the temperature difference of the electrostatic capacity of the gasoline can be quickly obtained by forcibly generating a temperature difference in the gasoline. Based on this temperature gradient, the gasoline property is either heavy or light, Whether it is medium quality or not can be determined in a short time, and engine startability, responsiveness, reliability, etc. can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an entire gasoline property determining apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a gasoline property determination device.

FIG. 3 is a characteristic diagram showing a temperature characteristic map.

FIG. 4 is a flowchart showing a property determination process.

FIG. 5 is a flowchart following FIG. 4;

FIG. 6 is an overall configuration diagram showing an entire gasoline property discriminating apparatus according to a second embodiment of the present invention.

FIG. 7 is an overall configuration diagram showing an entire gasoline property discriminating apparatus according to a third embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a specific example of a second capacitance sensor.

[Explanation of symbols]

 100 Fuel tank 101, 200, 300 Refueling tube 101A, 200A, 300A Refueling port 110, 301 First capacitance sensor 111, 302 First temperature sensor 112, 303 Heater (heating means) 113, 304 Second static Capacitance sensor 114,305 Second temperature sensor 117 Control unit (determination means)

Claims (1)

[Scope of utility model registration request] 1. A refueling tube having a base end side connected to a fuel tank and a front end side serving as a refueling port, and a first capacitance sensor provided in the middle of the refueling tube for detecting a capacitance of gasoline. A first temperature sensor provided in the refueling tube located near the first capacitance sensor to detect the temperature of gasoline; and the refueling tube spaced apart from the first capacitance sensor. A heating means for heating the gasoline at the time of refueling and a midway of the refueling tube located near the heating means for detecting the electrostatic capacity of the gasoline heated by the heating means. Two
And a second temperature sensor that is provided in the vicinity of the second capacitance sensor and that is provided in the middle of the refueling tube and that detects the temperature of the gasoline heated by the heating means. Refueling start detection means for detecting the start of refueling by the refueling tube, and detection signals from the first and second capacitance sensors and the first when the refueling start detection means detects the start of refueling. A determination means for calculating the temperature gradient of the electrostatic capacity of the gasoline based on the temperature detected by the second temperature sensor, and determining whether the gasoline is heavy, light or medium based on this temperature gradient. A gasoline property determination device consisting of: