JP2022072833A - Vehicle speed information generator - Google Patents

Abstract

To provide a vehicle speed information generator that facilitates mounting the sensor element of a wheel speed sensor in a limited mounting space inside a wheel.SOLUTION: Disclosed is a vehicle speed information generator, comprising: a signal processing unit which is an entity separate from the sensor element of a wheel speed sensor attached to a wheel and is connected via external wiring to the sensor element, for processing a sensor signal received from the sensor element and generating a vehicle speed pulse signal; and a processing device which is an entity separate from the signal processing unit and is connected via external wiring to the signal processing unit, for outputting vehicle speed information on the basis of the vehicle speed pulse signal received from the signal processing unit. The signal processing unit can be connected via external wiring to other processing devices in parallel to the processing device in a mode where the vehicle speed pulse signal is suppliable to other processing devices different from the processing device.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a vehicle speed information generator.

A technique is known in which a sensor element (Hall element, magnetoresistive element (MR element), etc.) of a wheel speed sensor is formed by an integrated (modularized) unit with an amplifier circuit or a waveform shaping circuit.

Japanese Unexamined Patent Publication No. 2005-351913

However, in the above-mentioned conventional technique, since the sensor element and the amplifier circuit or the waveform shaping circuit are unitized (modularized), the unit tends to be large in size, and the unit is mounted in the limited mounting space in the wheel. Can be difficult.

Therefore, an object of the present disclosure is to provide a vehicle speed information generation device in which a sensor element of a wheel speed sensor can be easily mounted in a limited mounting space in a wheel.

On one side, it is separate from the sensor element of the wheel speed sensor attached to the wheel, is connected to the sensor element via external wiring, processes the sensor signal received from the sensor element, and outputs the vehicle speed pulse signal. The signal processing unit to generate and
A processing device that is separate from the signal processing unit, is connected to the signal processing unit via external wiring, and outputs vehicle speed information based on a vehicle speed pulse signal received from the signal processing unit.
The signal processing unit is such that the vehicle speed pulse signal can be supplied to another processing device different from the processing device, and the other processing device is connected to the other processing device in parallel with the processing device via external wiring. A vehicle speed information generator that can be connected is disclosed.

According to the present disclosure, it is possible to obtain a vehicle speed information generation device in which a sensor element of a wheel speed sensor can be easily mounted in a limited mounting space in a wheel.

It is a schematic diagram which shows the vehicle speed information generation apparatus by this Example. It is explanatory drawing of various waveforms in a vehicle speed information generator. It is explanatory drawing of the terminal structure of a signal processing part. It is explanatory drawing of the connector part of a signal processing part. It is a circuit diagram which shows the preferable embodiment of a filter circuit. It is explanatory drawing of 1st comparative example. It is explanatory drawing of the 2nd comparative example.

Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic view showing a vehicle speed information generation device 1 according to the present embodiment. FIG. 2 is an explanatory diagram of various waveforms. FIG. 1 also shows a wheel speed sensor 20 electrically connected to the vehicle speed information generator 1.

The vehicle speed information generation device 1 is electrically connected to a sensor element 21 of a wheel speed sensor 20 attached to a wheel (not shown). The wheel speed sensor 20 includes, for example, a sensor element 21 and a sensor ring (sensor rotor) 22. The sensor element 21 is, for example, a Hall element, a magnetoresistive element, or the like, and the sensor ring 22 rotates integrally with the wheel, and magnets or the like are regularly arranged on the outer peripheral portion in the circumferential direction.

The wheel to which the wheel speed sensor 20 is attached may be a wheel of any vehicle, and may be a wheel of a railway vehicle or the like as well as an automobile. However, in this embodiment, since the sensor element 21 can be mounted in the limited mounting space in the wheels, the vehicle speed information generation device 1 is suitable for the wheels of a motorcycle in which the mounting space is relatively limited.

Hereinafter, unless otherwise specified, the vehicle speed information generation device 1 according to one wheel speed sensor 20 will be described, but this embodiment can also be applied to a vehicle in which a wheel speed sensor 20 is provided for each of a plurality of wheels. be. In a vehicle in which a wheel speed sensor 20 is provided for each of a plurality of wheels, the vehicle speed information generation device 1 may be provided for each wheel, or a part of the vehicle speed information generation device 1 (for example, a signal processing unit 30) may be provided. It may be provided for each wheel.

As shown in FIG. 1, the vehicle speed information generation device 1 includes a signal processing unit 30 and a processing device 51.

The signal processing unit 30 is separate from the wheel speed sensor 20 (and the sensor element 21 accordingly). In the present specification, the term "separate body" refers to a state in which they are physically separated from each other (or a configuration capable of realizing the state), and typically, a state in which they are not housed in the same housing. Point to. Therefore, external wiring is required to electrically connect the two separate elements.
The signal processing unit 30 is electrically connected to the wheel speed sensor 20 by wiring 40. The wiring 40 is an external wiring different from the internal wiring that can be formed on the circuit board that forms the wheel speed sensor 20 and the circuit board that forms the signal processing unit 30. However, the wiring 40 may be realized by a flexible substrate or the like as long as it is the external wiring defined above. The connection between the signal processing unit 30 and the wheel speed sensor 20 by the wiring 40 may be, for example, a two-wire system or a three-wire system. As shown in FIG. 1, the signal processing unit 30 may be connected to the wheel speed sensor 20 without intervening other circuit units (that is, via only the wiring 40).

The signal processing unit 30 processes the sensor signal (see waveform A1) received from the wheel speed sensor 20 to generate a vehicle speed pulse signal (see waveform A3). Note that FIG. 1 shows the positions where the sensor signal (see waveform A1) and the vehicle speed pulse signal (see waveform A3) flow, respectively, with signs A1 and A3, and FIG. 2 shows an example of each waveform. It is shown.

The signal processing unit 30 functions as a vehicle speed pulse conversion device, and includes an amplifier circuit 31, a waveform shaping circuit 32, and a filter circuit 33.

The amplifier circuit 31 amplifies the sensor signal (see waveform A1) received from the wheel speed sensor 20. The waveform shaping circuit 32 waveform-shapes the signal amplified by the amplifier circuit 31 (see waveform A2) into a pulse shape. The signal whose waveform is shaped by the waveform shaping circuit 32 is output as a vehicle speed pulse signal (see waveform A3).

The filter circuit 33 removes noise components and the like included in the sensor signal (see waveform A1) received from the wheel speed sensor 20. The filter circuit 33 may be provided in the front stage of the amplifier circuit 31 and / or may be provided in the rear stage of the amplifier circuit 31.

The processing device 51 includes, for example, a microcomputer or the like. The processing device 51 is separate from the signal processing unit 30, and is electrically connected to the signal processing unit 30 by wiring 41. The processing device 51 calculates the vehicle speed based on the vehicle speed pulse signal (see waveform A3) received from the signal processing unit 30, and outputs the vehicle speed information representing the calculated vehicle speed. In a vehicle in which a wheel speed sensor 20 is provided for each of the plurality of wheels, the processing device 51 may output averaged vehicle speed information based on sensor signals from the plurality of wheel speed sensors 20.

The processing device 51 may be incorporated in, for example, an ECU (Electronic Control Unit) that controls a meter. In this case, the processing device 51 outputs vehicle speed information via the meter. For example, the processing device 51 may rotate the pointer to a position corresponding to the vehicle speed by a stepping motor (not shown).

In this embodiment, as schematically shown by the dotted line in FIG. 1, the vehicle speed pulse signal (see waveform A3) from the signal processing unit 30 is processed in addition to the processing device 51 by other processing different from the processing device 51. It can be supplied to an apparatus (hereinafter referred to as "second processing apparatus 52"). Specifically, as shown in FIG. 1, the second processing device 52 is connected to the wiring 41 at the branch point P41. In this way, in the present embodiment, the signal processing unit 30 can supply the vehicle speed pulse signal to the second processing device 52 different from the processing device 51, and the signal processing unit 30 can supply the processing device to the second processing device 52. It can be connected in parallel with the 51 via the wiring 41. The wiring 41 is an external wiring different from the internal wiring that can be formed on the circuit board that forms the signal processing unit 30 and the circuit board that forms the processing device 51. However, the wiring 41 may be realized by a flexible substrate or the like as long as it is the external wiring defined above. Further, the branch point P41 may be formed in the wiring 41, or may be realized by a connector or the like.

The second processing device 52 is a device that performs arbitrary predetermined control based on the vehicle speed pulse signal (see waveform A3). The second processing device 52 may be, for example, a device that outputs vehicle speed information in a mode different from that of the meter, or may be a device that controls an in-vehicle electronic device (not shown) based on the vehicle speed. .. For example, the second processing device 52 may be an ECU that controls an engine and / or an electric motor (not shown) according to the vehicle speed. Further, the second processing device 52 may be an electronic device that a user (driver or the like) can bring into the vehicle. Further, a plurality of second processing devices 52 may exist. That is, a plurality of second processing devices 52 may be connected to one signal processing unit 30 in parallel with the processing device 51.

Next, the terminal structure and the like of the signal processing unit 30 will be described with reference to FIGS. 3 and 4.

FIG. 3 is an explanatory diagram of the terminal structure of the signal processing unit 30, and FIG. 4 is an explanatory diagram of the connector unit 300 of the signal processing unit 30. FIG. 4 also shows a wiring structure related to the wiring 40 connected to the connector portion 300.

In the example shown in FIG. 3, the signal processing unit 30 is a two-wire system as an example, and has five connection terminals SP_OUTPUT, SP_Vcc, SP_PULSE, IGN, and GND as external connection terminals.

The connection terminal SP_OUTPUT is an output terminal for a vehicle speed pulse signal (see waveform A3), the connection terminal SP_Vcc is a terminal for supplying power to the wheel speed sensor 20, and the connection terminal SP_PULSE is a sensor from the wheel speed sensor 20. It is an input terminal of a signal (see waveform A1), a terminal IGN is a terminal for receiving power from a power supply voltage 50, and a terminal GND is a terminal for ground connection.

In the example shown in FIG. 3, the signal processing unit 30 has a power supply circuit 34 that generates a power supply voltage for operation of the wheel speed sensor 20 based on the power supply voltage from the power supply voltage 50. As a result, the signal processing unit 30 can supply electric power to the wheel speed sensor 20 via the connection terminal SP_Vcc. Therefore, since it is not necessary to provide the power supply circuit corresponding to the power supply circuit 34 in the wheel speed sensor 20, it is possible to improve the mountability of the wheel speed sensor 20 on the wheel which can be a limited mounting space.

As shown in FIG. 4, the five connection terminals SP_OUTPUT, SP_Vcc, SP_PULSE, IGN, and GND are integrated into one connector unit 300. The connector unit 300 is arranged in a housing (not shown) of the signal processing unit 30.

In the connector unit 300, the corresponding connection units 302 to 306 are preferably color-coded so that the five connection terminals SP_OUTPUT, SP_Vcc, SP_PULSE, IGN, and GND can be easily distinguished. In the example shown in FIGS. 3 and 4, the five connection terminals SP_OUTPUT, SP_Vcc, SP_PULSE, IGN, and GND are assigned different colors (W1 to W5), respectively. The method of assigning each color can be set arbitrarily. In this case, the wiring portion connected to the five connection terminals SP_OUTPUT, SP_Vcc, SP_PULSE, IGN, and GND may be similarly colored or attached with a colored tag or the like. As a result, even when a plurality of connection terminals are integrated in the connector portion 300, it is possible to easily realize assembly without causing an error.
In the example shown in FIG. 4, the connector portion 300 has six connecting portions 301 to 306, and one of the connecting portions 301 is not used. The connection portion 301 may be sealed so that it cannot be used, or may be omitted. Alternatively, the connection portion 301 may be used as the connection portion for the branch point P41 described above.

The connector portion 300 is preferably waterproof. As a result, even when the signal processing unit 30 (and the connector unit 300) is arranged at a relatively short distance to the wheels that are easily exposed to a relatively harsh environment such as a motorcycle, the signal processing unit 30 can be used. Can be properly protected. From the same viewpoint, it is desirable that the housing (not shown) of the signal processing unit 30 is also waterproof.

By configuring the signal processing unit 30 with high waterproofness in this way, the signal processing unit 30 can be placed at a position close to the wheel, that is, the wheel speed, even for wheels that are easily exposed to a relatively harsh environment such as a motorcycle. It can be arranged at a position close to the sensor 20. By arranging the connector portion 300 at a position close to the wheel speed sensor 20, the wiring length L1 (see FIG. 4) related to the wiring 40 between the connector portion 300 and the wheel speed sensor 20 can be reduced. For example, the wiring length L1 is between 50 mm and 200 mm, and may be, for example, about 100 mm. As a result, the noise that may be superimposed on the wiring 40 between the connector portion 300 and the wheel speed sensor 20 can be reduced, and the noise of the signal before being amplified by the amplifier circuit 31 can be effectively reduced.

The wiring 40 is preferably protected by a tube 400 or the like. The tube 400 may have flexibility. For example, the wiring 40 is in the form of a harness and is passed through, for example, a hollow tube 400 having a circular cross section. In this case, the end portion (opening portion) of the tube 400 is preferably sealed by being filled with a resin or the like. Thereby, the waterproof property in the tube 400 can be enhanced, and the wiring structure related to the wiring 40 can be effectively protected.

Next, a preferred embodiment of the filter circuit 33 will be described with reference to FIG.

FIG. 5 is a circuit diagram showing a preferred embodiment of the filter circuit 33.

The filter circuit 33 is preferably a specification in which the characteristics can be switched as shown in FIG. Specifically, the filter circuit 33 includes a first filter circuit unit 331, a second filter circuit unit 332, and switching units SW1 and SW2.

The first filter circuit unit 331 forms an RC low-pass filter having a resistance R1 and a capacitor C1, and has a filter characteristic determined by the resistance value of the resistance R1 and the capacitance value of the capacitor C1.

The second filter circuit unit 332 forms an RC low-pass filter having a resistance R2 and a capacitor C2, and has a filter characteristic determined by the resistance value of the resistance R2 and the capacitance value of the capacitor C2. The resistance value of the resistor R2 and / or the capacitance value of the capacitor C2 is different from the resistance value of the resistor R1 and / or the capacitance value of the capacitor C1. As a result, the first filter circuit unit 331 and the second filter circuit unit 332 can have different filter characteristics from each other.

The switching units SW1 and SW2 are switches for switching the functioning filter circuit unit in the filter circuit 33 between the first filter circuit unit 331 and the second filter circuit unit 332. That is, when the switching units SW1 and SW2 form the first conduction state, the first filter circuit unit 331 functions, and when the switching units SW1 and SW2 form the second conduction state, the second filter circuit unit 332 functions. Switching between the first conduction state and the second conduction state of the switching units SW1 and SW2 may be realized by a small switch such as a DIP switch.

In this embodiment, as an example, the first filter circuit unit 331 is suitable for a vehicle having a relatively low vehicle speed range (for example, a vehicle having a relatively small displacement), and is suitable for a low frequency sensor signal. It has the filter characteristics. On the other hand, the second filter circuit unit 332 is suitable for a vehicle having a relatively high vehicle speed range (for example, a vehicle having a relatively large displacement), and has filter characteristics suitable for a high frequency sensor signal. ..

In this way, when the filter circuit 33 as shown in FIG. 5 is provided, the signal processing unit 30 can be used for various vehicles having different vehicle speed regions to be used. That is, the versatility of the signal processing unit 30 can be enhanced. For example, even for a range of a plurality of input frequencies according to the frequency of the vehicle speed, such as 1 to 1000 Hz and 1 to 4000 Hz, the switching units SW1 and SW2 can be used to switch to an appropriate frequency for various vehicles. It can also handle input pulses.

In the example shown in FIG. 5, the filter circuit 33 is configured to selectively realize two types of filter characteristics, but may be configured to selectively realize the three types of filter characteristics. good.

Next, the effect of the vehicle speed information generation device 1 according to this embodiment will be further described with reference to the comparative examples shown in FIGS. 6 and 7.

FIG. 6 is a diagram showing a vehicle speed information generation device 1A according to the first comparative example.

The vehicle speed information generation device 1A is different from the vehicle speed information generation device 1 according to the present embodiment in that the signal processing unit 30A having an amplifier circuit, a waveform shaping circuit, etc. and the processing device 51A for generating vehicle speed information are not separate bodies. , Realized by the same unit (module).

In such a first comparative example, the second processing apparatus 52'needs to similarly include a signal processing unit 30A having an amplifier circuit, a waveform shaping circuit, and the like.

In this regard, according to the vehicle speed information generation device 1 according to the present embodiment, since the second processing device 52 does not need to include an amplifier circuit, a waveform shaping circuit, or the like, the configuration of the second processing device 52 can be simplified. can. That is, an efficient configuration can be realized for the entire system that requires vehicle speed information.

Further, in the vehicle speed information generation device 1A according to the first comparative example, the vehicle speed pulse signal generated by the signal processing unit 30A of the vehicle speed information generation device 1A and the vehicle speed pulse generated by the signal processing unit 30A of the second processing device 52' The signal may not match. This is because the signal processing unit 30A of the vehicle speed information generation device 1A and the signal processing unit 30A of the second processing device 52'may have different circuit characteristics, etc., and even if the circuit characteristics, etc. are the same, there are individual differences. This is because there may be cases.

In this regard, according to the vehicle speed information generation device 1 according to the present embodiment, since the processing device 51 and the second processing device 52 can use the vehicle speed pulse signal from the same signal processing unit 30, the first comparative example described above can be used. It is possible to prevent the inconvenience that may occur in the case of.

FIG. 7 is a diagram showing a vehicle speed information generation device 1B according to a second comparative example.
Unlike the vehicle speed information generation device 1 according to the present embodiment, the vehicle speed information generation device 1B does not have a separate sensor element 21 and a signal processing unit 30B having an amplifier circuit, a waveform shaping circuit, or the like, but is the same unit ( It is realized by the module).

In such a second comparative example, the processing device 51B can be simplified by eliminating the signal processing unit 30B from the processing device 51B, but the unit including the signal processing unit 30B and the sensor element 21 tends to be large, and the wheels are limited. It may be difficult to mount the unit in the mounting space inside.

In this regard, according to the vehicle speed information generation device 1 according to the present embodiment, since the sensor element 21 is a separate body from the signal processing unit 30, it is possible to prevent inconveniences that may occur in the case of the second comparative example described above. That is, it is possible to provide the vehicle speed information generation device 1 capable of mounting the sensor element 21 in the limited mounting space in the wheel.

Although each embodiment has been described in detail above, the present invention is not limited to a specific embodiment, and various modifications and changes can be made within the scope of the claims. It is also possible to combine all or a plurality of the components of the above-described embodiment.

1 Vehicle speed information generator 20 Wheel speed sensor 21 Sensor element 22 Sensor ring 30 Signal processing unit 31 Amplifier circuit 32 Waveform shaping circuit 33 Filter circuit 34 Power supply circuit 40 Wiring 41 Wiring 50 Power supply voltage 51 Processing device 52 Second processing device 300 Connector unit 331 1st filter circuit part 332 2nd filter circuit part 400 tube

Claims (6)

A signal processing unit that is separate from the sensor element of the wheel speed sensor attached to the wheel, is connected to the sensor element via an external wiring, processes the sensor signal received from the sensor element, and generates a vehicle speed pulse signal. When,
A processing device that is separate from the signal processing unit, is connected to the signal processing unit via external wiring, and outputs vehicle speed information based on a vehicle speed pulse signal received from the signal processing unit.
The signal processing unit is such that the vehicle speed pulse signal can be supplied to another processing device different from the processing device, and the other processing device is connected to the other processing device in parallel with the processing device via external wiring. A vehicle speed information generator that can be connected. The vehicle speed information generation device according to claim 1, wherein the signal processing unit amplifies the sensor signal received from the sensor element and shapes the waveform. The vehicle speed information generation device according to claim 1 or 2, wherein the signal processing unit has a filter circuit whose characteristics can be switched. The vehicle speed information generation device according to any one of claims 1 to 3, wherein the signal processing unit has a power supply circuit that generates electric power to be supplied to the wheel speed sensor. The vehicle speed according to any one of claims 1 to 4, wherein the signal processing unit has a waterproof connector unit, and all external connection terminals in the signal processing unit are integrated in the connector unit. Information generator. The vehicle speed information generator according to any one of claims 1 to 5, wherein the wiring between the signal processing unit and the wheel speed sensor is protected by a tube whose end is sealed.

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