JPS59187268A - Display information measuring apparatus for vehicle - Google Patents

Abstract

PURPOSE:To enable a measurement processing with a circuit having a number of common parts by sampling at least original information on revolutions of the engine and original information for display of acceleration from a single information signal or a sensor as the same original information. CONSTITUTION:A ignition timing signal Si of the internal combustion engine for a vehicle is inputted into an input terminal In from an ignition timing signal detecting section 2. When this signal Si is inputted into an frequency-voltage conversion circuit 3, the output Svo thereof varies in the voltage in proportion to the revolutions of the internal combustion engine. When this output Svo is inputted into an acceleration computation circuit 4 to compute the variation rate thereof, the output Sa thereof appears at an output terminal O1 as bearing acceleration information transformed in voltage. On the other hand, the output Svo of the circuit 3 can be sent as output signal Sr having the revolutions of the engine transformed in voltage by introducing to an output terminal O2. Signals Sa and Sr developed at the terminals O1 and O2 are processed with displays Da and Dr to be indicated on a operating vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display information measuring device for a vehicle, and in particular,
The present invention relates to a vehicle display information measuring device that extracts and measures rotation speed information for displaying engine rotation speed and extracts and measures information for displaying vehicle or engine acceleration using a rational configuration.

In recent years, automobiles, which are considered to be relatively high-end products, have begun to incorporate engine speed information into the information to be displayed to the driver. The so-called tachometer is the display means for this. In the future, the diversification of such display information will be further promoted, and in particular,
It is said that the display of vehicle acceleration will attract more attention. It is also expected that these display means will change from mechanical and analog to digital ones.

However, looking at the current situation, despite the diversification of information to be displayed, the extraction and measurement of information for each display has been carried out using extremely irrational measures. Currently, normal display information is the vehicle speed display and the engine speed display mentioned above, but even if we limit ourselves to these two types of display information, in the past, each type of display information was sent to the engine from a dedicated sensor. Rotational speed information and vehicle speed information are separately extracted, and respective display means or displays are driven through their own measurement circuits. It is not necessarily a disadvantage that the display means are individual, and it may be easier for the driver to see the display than by switching to one display, but it does make it easier to extract information. 17)
1/) is a big problem. Considering that the amount of information that needs to be displayed will increase from now on, such as the above-mentioned counter and acceleration display, each piece of information will require a dedicated sensor and measurement circuit. Not only is this extremely uneconomical and unreasonable, but it also significantly impedes the space factor.

The present invention has been made in view of these points, and therefore, at least the original information of the engine rotation speed and the original information for displaying acceleration are extracted as the same original information from a single information signal source or sensor, We attempted to measure and process this using a circuit configuration with as many common parts as possible.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the basic configuration and basic embodiments of the vehicle display information measuring device of the present invention.

The vehicle display information measuring device 1 of the present invention is constructed as one unit, and has a frequency-to-voltage conversion (F-V conversion) circuit 3 and an acceleration calculation circuit 4 as main components. The ignition timing signal Si of the internal combustion engine of the vehicle is input from the ignition timing signal detection section 2 to the input of the frequency-to-voltage conversion circuit 3 or the input terminal In of this circuit 1 . One feature of the present invention is that the information signal source or original signal Si is obtained from a single detection section, and the ignition timing signal Si is generally connected to the negative terminal (minus terminal) of the internal combustion engine ignition coil. It can be easily extracted from here as an ignition timing signal detection section.

This ignition timing signal Si has a frequency that changes in proportion to the rotational speed of the internal combustion engine, in other words, it converts frequency information into the internal combustion engine rotational speed information. This is what I am responsible for.

Therefore, when this signal Si is input to the frequency-to-voltage conversion circuit 3, the output Svo changes in voltage in proportion to the rotational speed of the internal combustion engine.

If this output Svo is inputted to an appropriate acceleration calculation circuit 4 (to be described later) and its rate of change is calculated, the output signal Sa of the Karo speed calculation circuit will carry acceleration information embodied in voltage, and this circuit 1 The output 01 & appears.

On the other hand, by directing the output 5VOC of the frequency-to-voltage conversion circuit 3 as it is to the second output terminal 02, it can be output as an output signal Sr having engine speed information embodied in voltage. The signal Sa appearing at each output terminal Q1.024,
Sr can be easily processed and displayed to the driver by appropriate display devices Oa and Dr, respectively.

The configuration of the display device itself can be arbitrary using known techniques, and can be easily assembled by those skilled in the art, whether it is an analog type or a digital type.

The acceleration calculation circuit 4 can have several configurations depending on the calculation principle. If you want to obtain the vehicle acceleration as an accurate number, you can apply a differentiation circuit,
If a relative representation is sufficient, a difference calculation circuit or a subtraction circuit devised as shown in the embodiment described later may be applied.

FIG. 2 shows the main configuration of an embodiment in which a subtraction circuit devised by the applicant is used in the acceleration calculation circuit 4 in the basic embodiment of the present invention described above, and FIG. The figure shows a circuit configuration using specific circuit elements in its main parts.

In the vehicle display information measuring device 1 of this embodiment, when the internal combustion engine ignition timing signal detection circuit 2 extracts the ignition timing detection signal S1, the primary side negative terminal Ti- This signal Si is extracted from. In other words, the ignition coil portion itself including the -next-side negative terminal Ti- is used as the internal combustion engine ignition timing signal detection circuit, and the -next-side negative terminal Ti- essentially becomes the detection section 2.

As is well known, each time the primary current path of the ignition coil is interrupted in accordance with the ignition timing, the negative terminal Ti of the primary side coil
In general, impulses of several hundreds of volts are generated at an analog level, and the pulse repetition period or signal frequency is proportional to the engine speed. Therefore, this impulse signal Si includes engine rotational speed information embodied in frequency information.

Figure 4 shows this impulse signal Si, and when the engine is rotating at a constant speed, each impulse that rises in the negative direction from a reference potential (generally ground potential) also has a constant pulse interval, that is, a constant frequency. However, when the engine is in the process of increasing its rotational speed, the frequency is also in the process of increasing. Furthermore, in FIG. 4, if the time axis is viewed from the right end toward the left in a folded manner, as the engine's rotational speed decreases, the pulse intervals gradually widen (that is, the frequency also decreases).

In this way, the impulse signal Si, whose frequency changes in accordance with the engine speed, is not desirable because its analog level is too high to be handled directly, and there are too many noise components. Since this is not the case, it is recommended that the waveform be shaped by the waveform shaping circuit 5 first.

In the case shown in Fig. 3, the signal Si applied to the input In is clipped by the Zener diode 51 to prevent excessive input, and then inputted to the base of the npn) transistor 52, whose collector is used as a waveform shaping output. An engine ignition timing signal Si' with a clean waveform is extracted from.

In order to make this signal SI' into a pulse train signal that is easier to handle, a monostable multi-seven divider 31 with a constant pulse width Pw is used to obtain a pulse generator +1sb whose frequency is proportional to the engine speed. figure).

This pulse train signal sb is then processed so that the output voltage changes according to the change in frequency. In the embodiment shown in FIG. 3, this converter has the simplest configuration, which is a normal ripple filter or integration circuit including capacitors 32, 34 and resistor 33.

In this way, the average voltage value of the converted voltage signal Svo appearing at the output of the frequency-to-voltage conversion circuit 3 comprising the monostable multivibrator 31 and ripple filters (32, 33, 34) is schematically shown in FIG. As shown simply and linearly by the two-dot chain line, when the engine speed increases from a constant engine speed Vi, the level increases, and when it falls, the level decreases accordingly.

This converted voltage output Sv(+) is input to the acceleration calculation circuit 4, but in this embodiment, as mentioned earlier, the subtraction method is adopted, and the circuit configuration is a simple one developed by the applicant. It has a reliable configuration.

As shown in block form in FIG. 2 and slightly more concretely in FIG. 6.7, and the outputs of both integrating circuits Sv1. and a subtracter 8 that takes the difference in the voltage dimension of Sv2.

'The first and second integrating circuits 6.7 are simple CF
i circuit, and the time constant formed by the resistor 61 and capacitor 62 in the first integrating circuit 6 is 1, and the time constant formed by the resistor 71 and capacitor 72 in the second integrating circuit 7 is smaller than 2. (τ1×τ
2).

Below, if we follow the operation according to the schematic diagram of engine rotational speed change shown in Figure 4, when the engine is rotating at a constant rotational speed, the output terminal of the frequency-to-voltage conversion circuit 3 is an analog level signal S corresponding to the rotation speed at that time.
vo appears. If this state continues for a relatively long time, the capacitors 82 and 72 re-input to the comparator will be fully charged, and the potentials at both ends will be stable, and both will be approximately y (the output signal Sv+ of the frequency-to-voltage conversion circuit 3 at that time). The potential is the same as that of

Thereafter, the average voltage of the potentials across the capacitor is expressed as a signal St1. When understood as Sl, during such constant speed rotation, the subtraction circuit 8 that calculates the difference between both signals Sv1.3w2
output, that is, the acceleration signal S appearing at the output terminal 01 of this circuit
The value of a is zero in principle, indicating that the acceleration is zero.

Next, in FIG. 4, during the process where the engine speed is rising or increasing, the number of revolutions of one ignition timing signal Si to Si' is
As a result, the frequency of the vibrator output signal sb increases, so that the potential of the output Svo of the frequency-to-voltage conversion circuit 3 increases by two steps from the point described above, as shown in FIG. Therefore, the capacitors 62.7 at both inputs of the subtraction circuit 8
2 are both charged toward a higher voltage value, but as mentioned above, the first integrating circuit 6 including the capacitor C2
Since the time constant of 1 is shorter than that of the other 7 and 2, in such a transient state or acceleration state, the first integrating circuit output signal Sv+ shown by the solid line in FIG. exceeds the potential of the distribution path output signal Sv+, and therefore,
At the output of the subtraction circuit 8, a voltage signal Sa corresponding to the difference appears.

However, the difference is the magnitude of the acceleration of the engine, that is, the signal Sv1. Since the magnitude differs depending on the degree of inclination of Si2 and the difference in degree thereof, this signal Sa ultimately includes information on the acceleration when the engine speed increases. Of course, negative acceleration is also possible, and information thereof can be obtained from the output signal Sa as the rotation speed decreases from constant speed rotation.

The acceleration signal Sa obtained in this way can be displayed on a suitable display using existing technology. however,
- As an example, FIG. 3 shows a specific example of this acceleration display device Da.

When the subtraction circuit 8 is used for acceleration calculation as in this embodiment, the idea is that it is sufficient to intuitively inform the driver of the degree of acceleration, rather than outputting the acceleration accurately as an absolute value. In many cases, it is immediate. Therefore, in order to comply with this purpose, it is possible to use an analog guideline deflection, but
It is desirable to display the information digitally/in the form of a graph because visibility is good and the added value of the product is high.

Therefore, in the embodiment shown in the third figure, this circuit output terminal 0! The acceleration signal Sa appearing in the image is input to an analog-digital (A/D) converter 10, converted into a digital signal with an appropriate number of bits n, and then sent through an appropriate decoder driver 11 with n bits to emit light of 2] or less. The diode array 12 is driven. If necessary, this light emitting diode can be installed on the driver's dashboard.
Appropriate graduations may be provided along the array 12. however,
The acceleration display 12 may be a digital one, such as a liquid crystal display, an electrochromic display, or a flat panel, which will be described later.
display can be used. Regarding this point, the same can be said about displays for displaying information other than those described below.

Next, considering the engine speed display, as mentioned above,
Frequency-to-voltage conversion circuit 3 of this vehicle display information measurement device l
The output signal Svo is transformed into a voltage and carries engine speed information, so if it is sent as is to the second output O2 of the vehicle display information measuring device l, it can be output to an appropriate display in the same way. The engine speed information can be displayed in an analog or digital manner.

However, as can be seen from the drawings, in this embodiment, the output signal Svo of the frequency-to-voltage conversion circuit 3 is not directly sent to the output terminal, but the output signal Sv1 of the first integration circuit 6 is output as the engine speed signal Sr. It was withdrawn on 02. This is the fifth
As is clear from the figure, the output signals of the frequency-to-voltage conversion circuit 3, the first integration circuit 6, and the second integration circuit 7 all carry engine speed information, and therefore, as a general rule, , as shown by the imaginary line 13 in FIG. 02. Signal Svx
, Si2, isometrically the same as extracting the signal Svo in terms of engine speed information.

Conversely, from this, the ripple filter in the frequency-to-voltage conversion circuit 3 has its function as the first integration circuit 6,
The second integrating circuit 7 can also serve as the filter, and in such a case, this filter can be omitted.

In the embodiment shown in FIGS. 2 and 3, the engine speed signal Sr is
This is processed digitally. Regarding the display unit Dr, an n-bit analog-digital (A/D) converter 14 whose input is connected to the second output terminal 02 of this circuit 1 converts a voltage signal into a quantum signal, and converts the voltage signal into a quantum signal. A decoder/driver 15 generates 2n continuous staircase signals, and a bar graph is displayed on the liquid crystal display 16. In the configuration of the vehicle display information measuring device 1, the potential of the engine rotation speed signal Sr and the engine rotation speeds r, p, and m are substantially completely linear. Therefore, the liquid crystal display 1
Even if a scale is attached to 6, the number of rotations can be displayed with considerable accuracy. Of course, in terms of response speed, this type of display is currently available with a sufficiently high response speed. In terms of design, even though it is an 8-graph, attempts have already been made to design the display shape so that it draws an arc across the whole, and incorporate some of the previous analog tastes, so this shape May be adopted.

Furthermore, as shown by a virtual line in FIG. 2 and a solid line in FIG. Similarly, if the engine speed signal Sr is extracted and stored, the traveling speed of the vehicle can also be displayed by subjecting it to appropriate electronic arithmetic processing.

The engine speed and the vehicle running speed do not always have a one-to-one correspondence, and usually a gear ratio or reduction ratio intervenes as a coefficient between the two. Therefore, if we obtain information on whether the vehicle is running in the gear at the current speed, or in other words, what the current reduction ratio is, then by using this as a coefficient in the following equation, we can calculate the The running speed of the vehicle can be determined from the rotational speed. On the other hand, this calculation can be easily performed using an operational amplifier.

FIG. 3 also shows such an example, where for the engine speed signal Sr obtained at the third output terminal 03 of this circuit l,
The calculation circuit 17 calculates the current reduction ratio obtained from the reduction ratio information output circuit 18 sent to the appropriate transmission part.
For example, although not shown in the figure, the external resistance of the operational amplifier can be varied using an appropriate analog switch circuit depending on the reduction ratio at the time. Once the number vs. vehicle speed output signal is obtained, an analog or digital display 20 can be activated via a suitable driver circuit 18. Of course, the vehicle running speed display section Dv as a whole can also take other forms.

As mentioned above, when it comes to displaying acceleration, it seems unnecessary to display the specific number of meters/5ec2. Even if such a display is displayed, it would be difficult to actually feel it. However, it cannot be said that display using such accurate absolute values may not be required in special cases. In order to meet this requirement, as shown in FIG. 6, the acceleration calculation circuit 4 in the vehicle display information measuring device 1 may be configured with a differentiator 9 using a suitable electronic circuit. According to this, the output signal Svo of the frequency-to-voltage conversion circuit 3
On the other hand, the output signal Sa of the acceleration calculation circuit 4 to the differentiator 9 almost linearly corresponds to the acceleration in terms of voltage.

As mentioned above, FIG. 7 shows a desirable configuration example in the case where one display for each information is shared as a special request.

Three output terminals 01 of the wood 11i dual-use display information measuring device l
．． 02.03 are three-input analog switch circuit 2, respectively.
However, as mentioned earlier, in the line from the third output 03 to the input of this analog switch, the calculation coefficient of the linear equation is calculated by the reduction ratio signal from the reduction ratio information output circuit 18. An arithmetic circuit 17 is involved which determines and performs calculations. Also, for example, when displaying on the same display, it is necessary to match the units to each piece of information, resulting in differences in digits or voltage levels. To match the unit,
It may also be necessary to insert an appropriate voltage level matching circuit or arithmetic circuit into the line of the acceleration signal Sa. Furthermore, when displaying the acceleration of the vehicle at any given time instead of the acceleration of the rotational angular velocity of the engine (which is generally more common when displaying accurate numerical values), the reduction ratio information from the reduction ratio information output circuit 18 In some cases, an arithmetic circuit 21 that also has the function of calculating based on .

The three-input analog switch circuit 22 is a known and commercially available IC.
Only the information signal corresponding to the display mode selected by the display mode selection unit 23 operated by the driver is allowed to pass through. The passed signal (S
a. be done. In the illustrated case, the display 26 is shown as a seven segment display, and therefore requires display of units corresponding to each piece of selected information. You can just write each unit on the side of the display, but the display mode selection section 23
It is convenient to obtain selection information from the system, and to selectively display units corresponding to each piece of information, for example, via the transparent display section 27, based on the signals, and additionally, the commercial value is increased. Of course, the display section 26 may be based on other display principles mentioned above.

In any case, according to the present invention, at least the retrieval of original information for displaying acceleration and engine speed, and the measurement processing thereof, can be carried out in an extremely rational manner, with many circuit elements that can be used without using dedicated sensors. It is possible to provide a vehicle display information measuring device, and it will make a tremendous contribution to this type of technical field in the future.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a principle or basic embodiment of a vehicle display information measuring device 1 according to the present invention, and FIG. 2 is a schematic configuration diagram of an embodiment of the present invention in which a subtraction method is adopted for calculation of acceleration. , Fig. 3 is a circuit configuration diagram showing the circuit shown in Fig. 2 in a slightly more concrete manner, and Fig. 4 is an explanatory diagram of changes in engine speed and the signals that carry this engine speed information in the form of frequency. , FIG. 5 is an explanatory diagram of a signal when the engine speed information embodied in frequency is converted into voltage, and FIG. 6 is an illustration of an embodiment of the present invention when a differential method is adopted for calculating acceleration. FIG. 7 is a schematic configuration diagram of an example of a desirable circuit configuration when a display for displaying each information is shared. In the figure, 1 is a vehicle display information measuring device, 2 is an ignition timing signal detection section, 3 is a frequency-to-voltage conversion circuit, 4 is an acceleration calculation circuit, 5 is a waveform shaping circuit, 6 is a first integration circuit, and 7 is a first integration circuit. 2 integral circuits, 8 is a subtraction circuit, 9 is a differential circuit, Da is an acceleration display circuit, Or is an engine speed display circuit, 01 is an acceleration signal output terminal, 02 is an engine speed signal output terminal, Si is an ignition timing signal, Svo is a frequency-to-voltage conversion voltage signal, Sa is an acceleration signal, and Sr is an engine rotation speed signal.

Claims (1)

[Claims] A vehicle display information measuring device for displaying the rotation speed of an internal combustion engine and the acceleration of a vehicle or engine, which detects the ignition timing of the engine and converts the engine rotation speed into a frequency. an ignition timing signal detection unit that obtains an ignition timing signal carried by the ignition timing signal; a frequency-to-voltage conversion circuit that converts the ignition timing signal into a voltage signal; and an acceleration calculation circuit that performs calculations on the voltage signal to obtain an acceleration signal. and an output terminal for the acceleration signal and an output terminal for the voltage signal whose voltage value changes in response to the engine speed. A vehicle display information measuring device comprising: