JPH0796376B2 - Vehicle speed limiter - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle speed limiting device for limiting a vehicle speed to a certain value or more.

(Prior Art) Conventionally, for example, as disclosed in Japanese Utility Model Laid-Open No. 60-192935, by detecting the vehicle speed and interrupting the ignition circuit when the speed exceeds a certain value, A vehicle speed limiting device is known in which an engine is stopped so that the vehicle speed does not become abnormally high.

(Problems to be Solved by the Invention) However, in this conventional technique, the engine output is suppressed when the modification is performed, and the operation performance during the modification is deteriorated.

Therefore, an object of the present invention is to solve the problems of the prior art and to provide a vehicle speed limiting device that does not deteriorate driving performance.

(Means and Actions for Solving Problems) In order to achieve this object, according to the present invention, a vehicle speed detecting means (1) that detects a traveling speed of a vehicle and outputs a signal when the traveling speed is equal to or lower than a predetermined traveling speed. ), An engine output limiting means (2) for detecting the engine speed and limiting the engine rotation when the engine speed is equal to or higher than a predetermined engine speed, and a signal from the vehicle speed detecting means (1). And a prohibiting means (3) for disabling the engine output limiting means (2) during generation. With such a configuration, the rotation speed detection circuit can be operated in response to a signal abnormality from the speedometer system that may occur in various situations, and the speed limiting function can be secured.

Embodiments of the Invention Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, in each figure, the same reference numerals denote the same objects.

FIG. 1 shows a system diagram of a vehicle speed limiting device according to an embodiment of the present invention. In the figure, (1) is a proper speed signal generation circuit that outputs a voltage signal by detecting that the speed index built into the meter unit of the speedometer is within the proper speed range, (2)
Is a rotation speed detection circuit which is incorporated in the ignition circuit unit (4) and detects that the engine rotation speed has become a certain value or more to make the engine ignition circuit inoperative, and (3) is an appropriate speed signal generation circuit (1 ) Monitoring the output signal, and a voltage monitoring circuit so that the rotation speed detection circuit can operate with respect to a voltage other than this signal voltage, (5) is a switching transistor that deactivates the ignition circuit, (6) Is a bias resistor,
(8) is the main circuit of the ignition circuit. These will be described below.

The proper speed signal generation circuit (1) is
0), rotating light shield (11) (Fig. 2), bias resistor (1
2), (13), a constant voltage diode (14), and a diode (15). The photocoupler (10) is fixed at a predetermined position in the meter unit, and the light from the light emitting diode passes or is blocked by the light shielding plate (11) as shown in FIG. Here, the light shielding plate (11) is of a shape that rotates together with the pointer of the speedometer. That is, the light shielding plate (11) is a disk shape having a radius (r1) having a rotation center (11a) coaxial with the pointer of the speedometer, but a radius (r2) that allows a constant angle θ from the rotation center (11a). It has a notch (11b) of (<r1). This angle θ sets an appropriate speed range, one end (11c) of the cutout portion (11b) corresponds to speed 0, and the other end (11d) of the cutout portion (11b) corresponds to the speed limit. I am allowed. Therefore, when the speed is 0, the light of the photocoupler (10) is at one end (11c) of the light shielding plate (11).
Notched part (11b) in case of proper speed range
Is located in the photocoupler (10), the photocoupler (1
The light of 0) is not blocked. When the speed limit is reached, the light from the photocoupler (10) is blocked by the light shield plate (11).
It is also blocked by the other end (11d). Therefore, in the proper speed range, the phototransistor of the photocoupler (10) is turned on, and the constant voltage diode (14) is reverse-biased to the breakdown state by the power supply voltage V 1 to obtain the constant voltage VD1.
Can be obtained. Outside the proper speed range (speed 0 and above the speed limit), the light of the photocoupler (10) is blocked by the light shield (11), so the photocoupler (10) is in the off state and the constant voltage diode (14). There is no voltage drop across. Thus, the voltage VD1 obtained through the diode (15) is used as a signal indicating that the speed is within the proper range. In the above description, the voltage as the proper speed signal is generated when the vehicle speed is in the proper range, but the polarity of the photocoupler (10) is changed or the light shield plate (1
By reversing the concave-convex relationship of 1), it is possible to set the voltage to 0 in the proper speed range and to generate the alarm voltage at an abnormal speed (speed 0 and above the speed limit).

Before explaining the rotation speed detection circuit (2) and the voltage monitoring circuit (3), the main circuit (8) of the ignition circuit (4) will be described. Ignition circuit is a generator that rotates in synchronization with the engine (not shown)
Spark plugs for engine combustion chambers based on the output of (45)
Is to ignite. That is, the output of the generator (not shown) is rectified by the diode (40) and charges the capacitor (41). The electric energy stored in the capacitor (41) is discharged by triggering the gate of the thyristor (42) by the timing circuit (43) at a predetermined timing. Since this discharge current flows back through the primary coil of the ignition coil (44), LC
A large oscillating current is generated by the circuit and a high voltage is generated on the secondary side of the ignition coil (44) to ignite the ignition plug (45). The timing circuit (43) for triggering the gate of the thyristor (42) forms a gate trigger signal at a predetermined timing based on the output signal of the timing signal forming coil (pulsar coil) provided in the generator. .

The engine speed detection circuit (2) detects that the engine speed has exceeded a certain limit value and detects the engine ignition circuit (8).
Is made inoperative. The rotation speed detection circuit (2) rectifies the output signal from the pulsar coil by the diode (20) and the smoothing circuit (21) to obtain a DC voltage proportional to the engine rotation speed. The diode (22) is selected so that the constant voltage diode (22) breaks down when the DC voltage corresponds to the limited rotation speed.
When the constant voltage diode (22) breaks down, a voltage is applied to the base of the switching transistor (5) by the action of the bias resistor (6), and the transistor (5) in the off state is turned on. As a result, the gate of the thyristor (42) becomes substantially ground potential, and the main circuit (8) of the ignition circuit does not operate.

The voltage monitoring circuit (3) monitors the output signal of the proper speed signal generation circuit (1) and enables the rotation speed detection circuit (2) to operate on a voltage other than this signal voltage. This voltage monitoring circuit (3) includes two switching transistors (30), (32), a current limiting resistor (31),
(33) and a constant voltage diode (34). The base of the switching transistor (5) is connected to the cathode of the output diode (15) of the proper speed signal generation circuit (1) via the resistor (31) and the connection cord (9). The collector of the switching transistor (5) is connected to the base of the transistor (5) and the emitter is grounded. The collector of the transistor (32) is connected to the base of the transistor (30), and the emitter of the transistor (32) is grounded. A resistor (33) and a constant voltage diode (34) are connected in series to the base of the transistor (32), and these elements (33),
Similarly to the transistor (30), the base of the transistor (32) is also connected to the cathode of the diode (15) of the proper speed signal generation circuit (1) via the connection cord (9) via the (34). . The breakdown voltage VD2 of the constant voltage diode (34) is higher than the breakdown voltage VD1 of the constant voltage diode (14) of the proper speed signal generation circuit (1) (VD2> VD1). According to such a voltage monitoring circuit (3), when the vehicle speed is in the proper range, the constant voltage diode (14) of the proper speed signal generating circuit (1) is broken down, and this voltage signal (the proper speed signal ) Is applied to the base of the switching transistor (30) via the diode (15) and the resistor (31).
Therefore, at this time, the transistor (30) is turned on to guide the base potential of the switching transistor (5) to the ground potential. Such a transistor (30) is used for the constant voltage diode (3
It turns off only when a voltage that exceeds the breakdown voltage VD2 in 4) is input.

Next, the operation of this embodiment will be described.

First, when the speed index is within the proper speed range, the proper speed signal generation circuit (1) generates the proper speed signal because the constant voltage diode (14) breaks down, and the transistor (30) of the voltage monitoring circuit (3). ) Is turned on by this. Therefore, the base potential of the transistor (5) is substantially at the ground potential, and the transistor (5) maintains the off state. Therefore, the ignition circuit (4) can operate normally, and the gate of the thyristor (42) is triggered by the timing circuit (43) at a predetermined timing. At this time, even if the rotation speed detection circuit (2) detects the voltage corresponding to the limited rotation speed and generates a voltage at the output end, the voltage monitoring circuit (3) already turns off the transistor (5). The transistor (5) is not driven by the output of the rotation speed detection circuit (2).

Secondly, consider a case where the speed index is outside the proper speed range, that is, the speed is 0 or the speed is equal to or higher than the speed limit. At this time, the transistor of the photocoupler (10) does not turn on, and therefore the constant voltage diode (14) does not break down. That is, the proper speed signal generation circuit (1) does not generate the proper speed signal. Therefore, the transistor (30) of the voltage monitoring circuit (3) is in the off state, and the rotation speed detection circuit (2) can operate. Therefore, when the engine speed exceeds the predetermined limit value, the constant voltage diode (22) of the speed detection circuit (2) breaks down and turns on the transistor (5). As a result, the thyristor (4
The gate potential of 2) becomes the ground potential, the thyristor (42) is not triggered regardless of the output signal of the timing circuit (43), and therefore the main circuit (8) of the ignition circuit does not operate. Such a situation may occur due to a failure such as a speedometer cable drop, but the speed limiting function is not impaired by the operation of the rotation speed detection circuit (2). Also, even if the connection cable (9) is broken, the same situation will occur and the proper speed signal will not be generated.
Similarly, the speed limit function can be secured by the rotation speed detection circuit (2).

Thirdly, consider the case where an abnormal voltage is applied to the input terminal of the voltage monitoring circuit (3). For example, when the power supply voltage is directly applied to the voltage monitoring circuit (3) through the connection cord (9), the power supply voltage V _B is generally equal to or higher than the breakdown voltage VD2 of the constant voltage diode (34), so The diode (34) breaks down and the transistor (32) is turned on, so that the transistor (30) is turned off. Therefore, when the rotation speed detection circuit (2) is in an operable state and the engine rotation speed rises abnormally, the constant voltage diode (22) breaks down and the transistor (5) is turned on, and the ignition circuit The thyristor (42) is prevented from turning on, and the speed limiting function works. Such a voltage monitoring circuit (3) is effective in protecting the transistor (30) and preventing malfunction, and has a voltage slightly higher than the voltage (a voltage slightly lower than VD1) that can turn on the transistor (30). By selecting the breakdown voltage VD2 of the constant voltage diode (34),
The operating range of the transistor (30) can be limited and reliable. In order to further limit the operating range of the transistor (30), as shown in FIG. 3, a constant voltage diode (3) is connected in series with the resistor (31) of the voltage monitoring circuit (3).
4) A constant voltage diode (35) is connected in parallel with this, and the breakdown voltage VD3 of this constant voltage diode (35) is VD3 <VD1 <VD2.
It may be selected so as to satisfy the condition of.

In the above embodiment, the proper speed signal generation circuit (1)
Is designed to generate an appropriate speed signal based on a mechanical index such as a light-shielding plate that rotates together with the pointer of the speedometer, but the appropriate speed range is electronically determined by the presence or absence of a signal at the output end of a digital counter or the like. It can also be detected.

(Effect of the Invention) According to the present invention, in addition to the means for detecting the speed limit based on the speed index as described above, a rotation speed detection circuit capable of speed limitation according to the engine speed is provided in the ignition circuit unit. By incorporating it, it is possible to obtain a vehicle speed limiting device that does not deteriorate the driving performance even if it is modified.

[Brief description of drawings]

FIG. 1 is a system diagram of a vehicle speed limiting device according to an embodiment of the present invention, FIG. 2 is an explanatory view of main parts of a vehicle speed limiting device according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. It is a modification explanatory view of the vehicle speed limiting device which concerns. In the drawing, (1) is an appropriate speed signal generation circuit, (2)
Is a rotation speed detection circuit, (3) is a voltage monitoring circuit, (4) is an ignition circuit, (5) is a transistor, (8) is a main circuit of an ignition circuit, (9) is a connection cord, and (10) is a photocoupler. ,
(11) is a shading plate, (14), (22) and (34) are constant voltage diodes, (30) and (32) are transistors, (44) is an ignition coil, and (45) is an ignition plug.

Claims (1)

[Claims] 1. A vehicle speed detecting means for detecting a traveling speed of a vehicle and outputting a signal when the traveling speed is equal to or lower than a predetermined traveling speed, and an engine speed is detected. When the engine speed is equal to or higher than a predetermined engine speed, the engine speed is limited. A vehicle speed limiting device comprising: an engine output limiting means for controlling the engine output limiting means; and a prohibiting means for deactivating the engine output limiting means while receiving the signal from the vehicle speed detecting means.