JP2541225B2 - Different fuel mixture ratio detector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a device for detecting a mixing ratio of different kinds of fuel supplied to an internal combustion engine capable of operating with a mixture of different kinds of fuel as a fuel, and particularly to, for example, gasoline. For optimally controlling the fuel injection amount, the fuel injection timing, the compression ratio, etc. according to the change in the mixing ratio of gasoline and alcohol supplied to an internal combustion engine for automobiles that can operate with a mixture of alcohol and alcohol as fuel. The present invention relates to a different fuel mixture ratio detection device suitable for use as a detection device.

[Prior Art] Generally, many automobile engines and the like operate using gasoline as a fuel, but in recent years, an engine (alcohol / gasoline mixed type engine) that operates using a mixture of gasoline and alcohol as fuel, Engines that use alcohol as fuel instead of gasoline (engines exclusively for alcohol) have also been developed.

By the way, although gasoline refueling facilities are widespread, the penetration rate of alcohol refueling facilities is very low at present. Therefore, in the case of such an engine exclusively for alcohol, the fuel cannot be reliably refueled, and there is a possibility that the fuel will often run out.

On the other hand, in the case of an alcohol / gasoline mixed type engine that uses a mixture of alcohol and gasoline as fuel, the various fuel characteristics of alcohol and gasoline differ, so if the mixing ratio of alcohol and gasoline changes, the engine will be appropriate. There is a risk that it may interfere with the operation in this state.

Therefore, it is considered to control the engine according to the mixing ratio so that the engine operates properly even if the mixing ratio of alcohol and gasoline changes.
For example, depending on the mixing ratio of alcohol and gasoline,
It is conceivable to control the fuel injection amount, fuel injection timing, compression ratio, etc. to be optimum.

For this purpose, first, it is necessary to detect the mixing ratio of alcohol as a fuel and gasoline. Conventionally, an alcohol as a different fuel mixing ratio detecting device for detecting such a mixing ratio of alcohol and gasoline is used. Various sensors are considered.

As such an alcohol sensor, for example, in a mixture of alcohol and gasoline, an optical sensor is used in a fuel flow path, a fuel tank, etc. by utilizing the correlation between the mixing ratio and the refractive index of light. It is considered to install it, measure the refractive index of light in the mixed fuel, and calculate the mixing ratio based on it.

As another alcohol sensor, which uses the correlation between the mixing ratio and the permittivity, a capacitance sensor is installed in the fuel flow passage, the fuel tank, or the like to determine the permittivity in the mixed fuel. It is also considered that the mixing ratio is calculated based on the measured value.

Further, as another alcohol sensor, a microwave attenuation rate detection method is also considered as one utilizing the correlation between the mixing ratio and the microwave attenuation rate.

The range of the mixing ratio of alcohol and gasoline (ratio of the amount of alcohol to the total amount) with which the engine can obtain the required output is required to be, for example, about 0 to 85%.

[Problems to be Solved by the Invention] By the way, in each of the alcohol sensors described above, the physical quantity detected, that is, the refractive index, the dielectric constant, and the microwave attenuation rate of light slightly change with the temperature change of the fuel. Therefore, a highly accurate fuel temperature sensor is required to be provided side by side, and a temperature correction means based on the detected value of this fuel temperature sensor is also required. However, the structure of the optical sensor, the capacitance sensor, the microwave attenuation factor sensor, and the highly accurate fuel temperature sensor described above is complicated and expensive, which causes a problem in putting the alcohol / gasoline mixed engine into practical use. Has become.

SUMMARY OF THE INVENTION The present invention is intended to solve such problems, and has a practical structure of an internal combustion engine which can be constructed with a simple structure and at low cost and can be operated by a mixture of different fuels such as an alcohol / gasoline mixed engine. It is an object of the present invention to provide a different fuel mixture ratio detection device that can contribute to realization.

[Means for Solving the Problems] Therefore, the heterogeneous fuel mixture ratio detection device of the present invention has the first position in the fuel tank or the fuel supply passage of the internal combustion engine which can be operated by the mixture of heterogeneous fuels. And a second position, a movable body that can move a constant stroke while receiving the viscous resistance of the fuel, a holding unit that holds the movable body in the first position, and a holding unit that resists the holding unit. Driving means for driving the moving body from the first position to the second position, and a response from the start of the operation of the driving means until the moving body reaches the second position from the first position. Response time detecting means for detecting time, a temperature sensor for detecting the temperature of the mixture of different types of fuel near the moving body, and a mixture of the different types of fuel based on the response time signal detected by the response time detecting means. Viscosity calculation to calculate viscosity Means and a mixing ratio calculating means for calculating the mixing ratio of the different kinds of fuel based on the viscosity signal calculated by the same viscosity calculating means and the temperature signal detected by the temperature sensor.

[Operation] In the above-described heterogeneous fuel mixture ratio detection device of the present invention, when the moving body is driven in the fuel tank or the fuel supply path by the activation of the driving means, the moving body mixes the different fuels. While being subjected to the viscous resistance of, the response time corresponding to the viscosity reaches from the first position to the second position, and the time required for this movement (response time) is detected by the response time detecting means. On the other hand, the temperature sensor detects the temperature of the mixture of different types of fuel near the moving body. Then, the viscosity calculating means receives the response time signal detected by the response time detecting means and calculates the viscosity of the mixture of the different kinds of fuel based on the response time signal. Further, the mixing ratio calculating means receives the viscosity signal calculated by the viscosity calculating means and the temperature signal detected by the temperature sensor, and determines the mixing ratio of the different fuels based on the viscosity signal and the temperature signal. It is calculated, and as a result, the mixing ratio of different types of fuel is detected.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a heterogeneous fuel mixture ratio detecting device as a first embodiment thereof, and FIG. 1 shows its entire configuration. FIG. 2 is a schematic vertical sectional view of a fuel tank showing an installation example of the present device, and FIG. 3 is a schematic diagram showing an overall configuration of a heterogeneous fuel mixture ratio detection device as a second embodiment thereof. Is. In FIG. 3, the same reference numerals as those shown in FIG. 1 denote the same members.

Now, the different fuel mixture ratio detecting device according to each embodiment is
The present invention is applied to an internal combustion engine (alcohol / gasoline mixed type engine) for an automobile that uses a mixture of alcohol and gasoline as fuel. First, a first embodiment of the present invention will be described.

The heterogeneous fuel mixture ratio detecting apparatus of this embodiment partially uses a solenoid valve, and as shown in FIGS. 1 and 2, the solenoid valve 1 is installed at the bottom of the fuel tank 5.

The solenoid valve 1 includes a casing 2 that is liquid-tightly fixed to a fuel tank 5, a plunger 8 that is vertically movable with respect to the casing 2, and an upper end of the plunger 8 that is orthogonal to the plunger 8. Disk-shaped moving body 4 provided as a normal valve and acting as a valve, a spring 7 as a holding means for holding the moving body 4 together with the plunger 8 in the first position (uppermost position), and the moving body 4 as the plunger. Second position with 8 (lowermost position)
It is composed of a solenoid 6 as a driving means for driving to.

A plunger guide for guiding the plunger 8 in the vertical direction is provided between the plunger 8 and the casing 2 with a sealing device for liquid-tightening the bottom of the fuel tank 5.
2a is interposed, and the spring 7 is interposed by engaging the guide 2a and the collar-shaped portion 8a formed on the plunger 8 at the upper and lower ends thereof. Further, the solenoid 6 is turned on and off at an appropriate time interval when the engine is operating.

Further, in the fuel tank 5, a disk-shaped fixed plate 3 is horizontally provided so as to face the disk-shaped moving body 4. In particular, the fixed plate 3 is provided so that the gap between the fixed plate 3 and the moving body 4 becomes small when the moving body 4 is in the first position.
Is fixed so that the influence of the viscous resistance from the fuel during the response movement of the moving body 4 can be detected more clearly.

Further, the switch SW that can come into contact with the moving body 4 and the casing 2 only when the moving body 4 takes the second position.
Is provided. The switch SW is composed of an upper terminal attached to the lower portion of the moving body 4 and a lower terminal attached to the upper portion of the casing 2.

One end of each electric wire is connected to the plunger 8 and the casing 2, and the other end of each electric wire has a response time (time required for movement) from the first position to the second position of the moving body 4. It is connected to a switch interlocking type time counter 10 as a response time detecting means for detecting. Therefore, the upper terminals of the switch SW are the moving body 4 and the plunger 8.
And the electric wire to the time counter 10, and the lower terminal of the switch SW is connected to the time counter 10 via the casing 8 and the electric wire. And time counter
In 10, when the input to the solenoid 6 is started, the input start signal is received to start the time counting, and the closing of the switch SW ends the time counting to detect the response time of the moving body 4.

Further, there is provided a viscosity calculating means 11 which receives the response time information of the moving body 4 detected by the time counter 10 and calculates the viscosity of the mixture of different kinds of fuel based on this response time information.

Further, a temperature sensor 9 for measuring the temperature of the mixture of different types of fuel is installed near the moving body 4.

Then, a mixing ratio calculating means 12 for calculating a mixing ratio of the mixture of different fuels based on the viscosity information of the mixture calculated by the viscosity calculating means 11 and the temperature information of the mixture detected by the temperature sensor 9 is provided. Has been.

The means for calculating the mixing ratio in the above-mentioned mixing ratio calculating means 12 is based on the following idea.

In other words, since the viscosity (viscosity or viscosity coefficient) of alcohol and the viscosity of gasoline are different, the viscosity of the mixture of alcohol and gasoline differs depending on the mixing ratio, and the viscosity of the mixture and the mixing ratio thereof. There is a certain correlation between and. Moreover, since the viscosity also depends on the temperature of the fluid, the correlation between the viscosity in the mixture and the mixing ratio thereof differs depending on the temperature of the mixture of alcohol and gasoline. Therefore, for example, by using the correlation for each temperature of the mixture (correlation between viscosity and mixing ratio), the mixing ratio can be calculated from the viscosity degree of the mixture in each temperature state.

The mixing ratio calculation means 12 is connected to an electronic control unit (ECU) 13 of the engine. The electronic control unit 13 is designed to perform optimum engine control at each mixing ratio based on the mixing ratio information from the mixing ratio calculating means 12. Such control includes, for example, control of the fuel injection rate and fuel injection timing in a fuel injection valve (not shown) that injects fuel from the fuel tank 5 into the intake passage through a fuel passage (not shown), and the compression ratio in the combustion chamber. There is control.

It should be noted that an on / off signal to the solenoid 6 is issued from a computer or the like so that the above-mentioned mixture ratio is automatically detected at a predetermined time interval, and the solenoid valve 1
Is controlled in its operation.

Since the different fuel mixture ratio detecting device as the first embodiment of the present invention is configured as described above, for example, when alcohol and gasoline are mixed and supplied to the engine,
The viscosity of the mixed fuel is measured in the fuel tank 5 at appropriate time intervals, and the mixing ratio is calculated based on the viscosity.

That is, when the solenoid 6 is input at appropriate time intervals, the moving body 4 held at the first position by the spring 7 is driven and moves from the first position to the second position. At this time, the moving body 4 moves from the first position to the second position at a speed corresponding to the degree of viscosity (viscosity) while receiving viscous resistance by the mixture of different kinds of fuel. And
The time required for this movement, that is, the response time is detected by the time counter 10 as the response time detecting means.

Then, in the viscosity calculating means 11, the response time detecting means
Based on the response time information detected in 10, the viscosity of the mixture of different types of fuel, that is, the mixture of alcohol and gasoline is calculated.

On the other hand, the temperature sensor 9 detects the temperature of the mixture of different kinds of fuel near the moving body.

Then, the mixing ratio calculating means 12 receives the viscosity information of the mixture calculated by the viscosity calculating means 11 and the temperature information of the mixture detected by the temperature sensor 9, and outputs the viscosity information and the temperature information of the mixture. Based on this, the mixing ratio of different types of fuel (alcohol and gasoline) is calculated, and the mixing ratio of different types of fuel is detected.

After the mixing ratio of the alcohol and the gasoline is calculated in this way, the mixing ratio information of the alcohol and the gasoline is taken into the electronic control unit 13 from the mixing ratio calculating means 12 and the mixing ratio is calculated in the electronic control unit 13. Based on the ratio information, optimum engine control is performed at each mixing ratio, for example, control such that the fuel injection rate, the combustion injection timing, the compression ratio, etc. are optimized.

The detection of the mixing ratio of different types of fuel by calculating the viscosity can be configured relatively easily by using an existing solenoid valve, and has an advantage that it can be installed at a low cost as compared with conventional sensors and the like. Therefore, the present heterogeneous fuel mixture ratio detection device can be manufactured with a simple structure and at low cost, and is put into practical use for an internal combustion engine that can be operated by a heterogeneous fuel mixture such as an alcohol / gasoline mixed engine. There is an advantage that it can contribute.

In the present embodiment, a mixture of alcohol and gasoline is described as an example of the different fuel mixture, but the present different fuel mixture ratio detection device is not limited to these mixtures, but a mixture of various other fuels. Can also be applied to.

Further, although the present embodiment has been described with reference to an internal combustion engine (engine) for an automobile in particular, the present invention is not limited to the internal combustion engine for an automobile and can be applied to various other engines that use a mixture of different kinds of fuel as a fuel. It is a thing.

The fixed plate 3 is intended to more clearly detect the degree of viscous resistance of the moving body 4 received from the fuel, but the fixed plate 3 does not necessarily have to be installed. It may be possible to set the size so that the degree of viscous resistance that the moving body 4 receives from the fuel can be detected to some extent clearly even if the fixed plate 3 is removed.

Next, a description will be given of a heterogeneous fuel mixture ratio detecting device as a second embodiment of the present invention. As shown in FIG. 3, the moving body 4'and the fixed plate 3'are both cylindrical, and the moving body 4 '. The fixed plate 3'is fixed substantially concentrically with the moving body 4 ', with a small gap around the moving body 4', so that the influence of the viscous resistance from the fuel can be detected more clearly when the moving body moves. . The other parts are constructed in the same manner as in the first embodiment.

With this configuration, this embodiment can also obtain substantially the same operation and effect as the first embodiment.

The moving body and the fixed plate are not limited to the moving bodies 4 and 4'and the fixed plates 3 and 3'in the first and second embodiments, and various other shapes and structures that are susceptible to the viscous resistance of the mixed fuel. Can also be considered.

Further, in each embodiment, the different fuel mixture ratio detecting device is provided in the fuel tank 5, but it may be provided in the fuel supply passage.
In particular, a means for detecting the viscosity of the fuel by using the fuel injection valve itself instead of the solenoid 5 is also conceivable. For example, a means is conceivable in which the moving body is moved by fuel injection, the movement (response) of the moving body is detected, and this is used for detecting the different fuel mixture ratio.

Further, in each of the embodiments, when the moving body 4 is in the first position, the solenoid 6 is off, and the solenoid 6 is turned on upon receiving the fail signal to drive the moving body 4. On the contrary, when the moving body 4 is in the second position, the solenoid 6 is turned on to fix the moving body 4 in the first position against the spring 7, and when the fail signal is received, the solenoid 6 is turned off. The moving body 4 may be configured to be driven to the second position. In this case, the spring 7 serves as a driving means for the moving body 4 and the solenoid 6 serves as a holding means for the moving body 4.

[Effects of the Invention] As described in detail above, according to the heterogeneous fuel mixture ratio detection device of the present invention, the first device is provided in the fuel tank or the fuel supply passage of the fuel engine that can operate with the mixture of different fuels. A movable body that can move a constant stroke between the position and the second position while receiving the viscous resistance of the fuel, a holding means that holds the movable body in the first position, and a holding means that resists the holding means. Driving means for driving the moving body from the first position to the second position, and starting the operation of the driving means until the moving body reaches the second position from the first position. Response time detecting means for detecting a response time, a temperature sensor for detecting the temperature of a mixture of different types of fuel near the moving body, and a mixture of the different types of fuel based on a response time signal detected by the response time detecting means Viscosity calculation to calculate the viscosity of And a mixing ratio calculating unit for calculating the mixing ratio of the different types of fuel based on the viscosity signal calculated by the viscosity calculating unit and the temperature signal detected by the temperature sensor. Since the device can be manufactured at low cost, there is an advantage that it can greatly contribute to the practical application of a mixed fuel type engine (engine) such as an alcohol / gasoline mixed type engine.

[Brief description of drawings]

FIGS. 1 and 2 show a heterogeneous fuel mixture ratio detecting device as a first embodiment of the present invention. FIG. 1 is a schematic diagram showing the entire structure thereof, and FIG. 2 is a fuel showing an installation example of the device. FIG. 3 is a schematic vertical cross-sectional view of a tank, and FIG. 3 is a schematic diagram showing an overall configuration of a heterogeneous fuel mixture ratio detection device as a second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Solenoid valve, 2 ... Casing, 2a ... Plunger guide, 3,3 '... Fixing plate, 4,4' ... Moving body, 5 ... Fuel tank, 6 ... Moving body driving means , A spring as a means for holding a moving body, 8 ... a plunger, 8a ... a collar portion, 9 ... a temperature sensor, 10 ... a switch interlocking type time counter as a response time detecting means, 11 ...... Viscosity calculation means, 12 …… Mixing ratio calculation means, 13 …… Engine electronic control unit (EC
U), SW ... switch.

Claims (1)

(57) [Claims] 1. In a fuel tank or a fuel supply passage of an internal combustion engine capable of operating with a mixture of different types of fuel, the first
Of the movable body that can move for a constant stroke between the position and the second position while receiving the viscous resistance of the fuel, a holding unit that holds the movable body in the first position, and a holding unit that holds the moving unit. Drive means for driving the moving body from the first position to the second position, and until the moving body reaches the second position from the first position by starting the operation of the driving means. Response time detecting means for detecting the response time, a temperature sensor for detecting the temperature of the mixture of different fuels in the vicinity of the moving body, and a mixture of the different fuels based on the response time signal detected by the response time detecting means. Provided are a viscosity calculating means for calculating the viscosity of the body, and a mixing ratio calculating means for calculating the mixing ratio of the different fuels based on the viscosity signal calculated by the viscosity calculating means and the temperature signal detected by the temperature sensor. Is characterized by , Improper fuel mixing ratio detecting device.