JP2003162788A - Multi-sensor system, sensor unit and bearing device - Google Patents

Abstract

(57) [Problem] To reduce the number of signal lines to be used to make a cable thinner and to reduce the number of pins of a connector, thereby reducing the configuration and cost. SOLUTION: A sensor unit 11 provided with various sensors 12a to 12e, and a control device 21 for taking in various sensor signals from the sensor unit, two signal lines 31, 32 between the sensor unit and the control device. And the sensor unit generates a synchronizing signal from the synchronizing signal generator 18 and transmits the synchronizing signal to the control device via one signal line 32. Switch circuit 1 for outputting signals from various sensors as channel signals to the other signal line 31
3 and a signal switch 19 for switching and controlling this switch circuit to time-division-transmit each channel signal to the other signal line.
The control device sequentially extracts each channel signal transmitted in a time-division manner by the counter 25 and the microcomputer 22 for inputting a synchronization signal and a clock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-sensor system using various sensors, a sensor unit and a bearing device.

[0002]

2. Description of the Related Art Conventionally, as a multi-sensor system,
As shown in FIG. 5, a rotation speed sensor 1a that detects a rotation speed, a temperature sensor 1b that detects a temperature, and a vibration (acceleration)
A sensor unit 1 provided with various sensors for outputting analog or digital measurement signals such as a vibration sensor 1c for detecting vibrations and a displacement sensor 1d for detecting displacements, and a control device 2 for receiving various sensor signals from the sensor unit 1 are arranged. However, the control device 2 is adapted to receive various sensor signals from the sensor unit 1 by using dedicated signal lines 3a to 3d. That is, the rotation speed detection signal from the rotation speed sensor 1a is received from the signal line 3a, the temperature detection signal from the temperature sensor 1b is received from the signal line 3b, and the vibration detection signal from the vibration sensor 1c is received from the signal line 3c. However, the displacement detection signal from the displacement sensor 1d is received from the signal line 3d.

[0003]

As described above, the prior art is as follows.
Since the signals of each sensor are transmitted using dedicated signal lines, as many signal lines as the number of sensors are required. Therefore, the cable that bundles the signal lines becomes thicker, and the connector for connection is also thicker. There are problems that the number of pins is increased, the system configuration is enlarged, and the cost is increased.

Therefore, according to the present invention, by reducing the number of signal lines to be used, the cable can be made thin and the number of pins of the connector can be reduced, whereby the size of the structure and the cost can be reduced. A multi-sensor system, a sensor unit, and a bearing device that can be used are provided.

[0005]

The invention according to claim 1 is
It is composed of a sensor unit provided with various sensors and a control device for fetching various sensor signals from the sensor unit. Two signal lines are connected between the sensor unit and the control device, and the sensor unit generates a synchronization signal. In addition, a synchronization signal generating means for transmitting a synchronization signal to the control device through one signal line, a switch circuit for outputting the signals of various sensors as channel signals to the other signal line, and a synchronization signal The control circuit is time-divisionally transmitted by the other signal line, which is provided with signal switching means for switching-controlling the switch circuit according to a time determined on the basis of the signal and for time-divisionally transmitting each channel signal to the other signal line. A multi-sensor that sequentially extracts each channel signal at a specified time based on the synchronization signal received from one signal line In the system.

According to a second aspect of the present invention, in the multi-sensor system according to the first aspect, the sensor unit is further provided with a clock generating means for generating a clock, and the synchronizing signal is generated based on the clock from the clock generating means. The generating means generates the synchronizing signal, and the signal switching means controls switching of the switch circuit.

According to a third aspect of the present invention, there is provided a sensor unit provided with various sensors and a control device for fetching various sensor signals from the sensor unit, and one signal line is provided between the sensor unit and the control device. After connecting, the sensor unit outputs the signals of various sensors to the signal lines as channel signals and outputs a synchronizing signal to the signal lines, and a switching circuit that controls the switching of the switching circuits. , And a signal switching means for causing the control device to perform time-division transmission via the signal line, and the control device sequentially transmits the channel signals time-divisionally transmitted by the signal line at a time determined based on a synchronization signal received. It is in a multi-sensor system that takes out.

According to a fourth aspect of the present invention, in the multi-sensor system according to the third aspect, the sensor unit is further provided with clock generating means for generating a clock, and the signal switching means is based on the clock from the clock generating means. Is to control the switching of the switching circuit.

According to a fifth aspect of the present invention, various sensors, a synchronizing signal generating means for generating a synchronizing signal and transmitting the synchronizing signal to the control device through the first signal line, and a signal for each sensor are respectively provided in channels. A switch circuit for outputting as a signal to the second signal line, and switching control of the switch circuit according to a time determined based on a signal corresponding to the synchronization signal, and each channel signal is time-divisionally transmitted to the second signal line. And a signal switching means for switching the sensor unit.

According to a sixth aspect of the present invention, various sensors, a switch circuit for outputting signals of the various sensors as channel signals to the signal line and a synchronization signal to the signal line, and switching the switch circuits. The sensor unit is provided with a signal switching means for controlling and transmitting each channel signal and the synchronizing signal to the control device in a time division manner via a signal line.

The invention according to claim 7 is a bearing device in which the sensor unit according to claim 5 or 6 is incorporated in a rolling bearing or in the vicinity thereof.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) In FIG. 1, 11 is a sensor unit and 21 is a control device on the receiving side. The sensor unit 11 includes a temperature sensor 12a and a displacement sensor 12
b, a pressure sensor 12c, a rotation speed sensor 12d, and an acceleration sensor 12e.

[0013] The output terminal of the temperature sensor 12a is connected to the terminal _{T 11} of the unit through a switch 13a constituting the switching circuit 13, an output terminal of said displacement sensor 12b via the switch 13b constituting the switching circuit 13 connected to the terminal T _11, the output terminal of the pressure sensor 12c is connected to the terminal T ₁₁ via a switch 13c that constitute the switching circuit 13, the rotational speed sensor 1
An output terminal of 2d is connected to the terminal _{T 11} via a switch 13d constituting the switching circuit 13, an output terminal of the acceleration sensor 12e is via an RMS converter 14, furthermore, the switch 13e constituting the switching circuit 13 It is connected to the terminal T ₁₁ via.

The switches 13a to 13e constituting the switch circuit 13 are analog switches, semiconductor switches such as bipolar transistors and FETs, mechanical switches such as relays, and the like.

The sensor unit 11 is further provided with a clock generator 15 which is a clock generating means, generates a clock as shown in FIG. 2A from the clock generator 15, and divides the clock by a frequency divider. The frequency is divided by 16 and supplied to the counter 17. For example, the clock generator 15 generates a 4096 Hz clock, which is divided by the frequency divider 16 to be converted into a 1 Hz clock.
We are counting at 7. The counter 17 is, for example,
The 3-bit configuration counts up each time a 1 Hz clock is input from the frequency divider 16 and outputs each output D ₀ ,
When D ₁ and D ₂ are set, the output changes as shown in FIG. 2B, and the count value of 0 to 4 is repeatedly output.

The count value of the counter 17 is supplied to a synchronization signal generator 18 which is a synchronization signal generating means and a signal switching device 19 which is a signal switching means.
When the synchronization signal generator 18 is the count value of the counter 17 becomes "4", and generates a synchronizing signal, as shown in FIG. 2 (c), it outputs the synchronization signal to the terminal T ₁₂ There is.

The signal switch 19 is provided with the counter 17
Each of the switches 13a to 13e is selectively turned on in accordance with the count value of 1). When the count value is "0", only the switch 13b is turned on, and when the count value is "1", only the switch 13c is turned on. To turn on the
When the count value is "2", only the switch 13d is turned on, and when the count value is "3", the switch 13e is turned on.
Only the switch 13a is turned on when the count value is "4".

[0018] Then, the when the switch 13a is turned on in the temperature detection signal from the temperature sensor 12a is output to the terminal _{T 11} as the channel signal CH1, the displacement sensor 12b when said switch 13b is turned on
Displacement detection signal from the output to the terminal T ₁₁ as the channel signal CH2, the pressure detection signal from the pressure sensor 12c when said switch 13c is turned on is output to the output terminal T ₁₁ as the channel signal CH3, the switch 13d is When turned on, the rotation speed detection signal from the rotation speed sensor 12b is the channel signal CH4.
Is output to the output terminal T ₁₁ as
There has so acceleration detection signal from the acceleration sensor 12e is output to the output terminal T ₁₁ via the RMS converter 14 as a channel signal CH5 is when turned on.

The sensor unit 11 has a terminal T
₁₃ and T ₁₄ , the terminal T ₁₃ is a power supply terminal for taking in the power supply Vs from the outside, supplies the taken-in power supply Vs to each part in the unit, and the terminal T ₁₄ is connected to the ground in the unit.

The control device 21 is provided with a microcomputer 22, an A / D converter 23, a clock generator 24, a counter 25, etc., and also has terminals T ₂₁ , T ₂₂ , T ₂₂ .
₂₃ and T ₂₄ are provided. The control device 21 is installed at a position apart from the sensor unit 11, and the terminals T ₁₁ and T _{21 of the} sensor unit 11 are connected to the signal line 31.
, The terminal T ₁₂ and the terminal T ₂₂ of the sensor unit 11 are connected by a synchronization signal line 32, the terminal T ₁₃ and the terminal T ₂₃ of the sensor unit 11 are connected by a power supply line 33, and Terminal T ₁₄ and terminal T
₂₄ are connected by a ground line 34. The terminal T
₂₃ is connected to the power source Vs, and the terminal T ₂₄ is connected to the ground in the device. The power source Vs is supplied to each unit in the device.

The A / D converter 23 has the terminal T _21.
The signals of the respective sensors input from the are converted into digital signals and then supplied to the microcomputer 22. The synchronization signal input from the terminal T22 is input to the counter 25. A clock as shown in (e) of FIG. 2 is also input to the counter 25 from the clock generator 24. This clock has the same frequency as the clock from the clock generator 15 of the sensor unit 11, and is 4096 Hz in this case.

The counter 25 measures the input timing of each channel signal in response to the rising edge of the synchronizing signal and the clock, and the microcomputer 22 outputs the count value from the A / D converter 23 at a predetermined timing based on the count value of the counter 25. The channel signals CH1 to CH5 are taken in.

In such a structure, in the sensor unit 11, the counter 17 has the counter 1 from the frequency divider 16.
The clock of Hz is counted and the count value is "0",
The synchronization signal generator 18 generates a synchronization signal at the timing of the count value "4", and the signal switch 19 causes the synchronization signal generator 18 to change to "1", "2", "3", "4", "0", .... The switch 13b is turned on at the timing of the count value "0",
The switch 13c is turned on at the timing of the count value "1", and the switch 1 is turned on at the timing of the count value "2".
3d is turned on, the switch 13e is turned on at the timing of the count value "3", and the switch 13a is turned on at the timing of the count value "4".

Therefore, the temperature detection signal from the temperature sensor 12a, the displacement detection signal from the displacement sensor 12b, the pressure detection signal from the pressure sensor 12c, the rotation speed detection signal from the rotation speed sensor 12d, and the acceleration detection from the acceleration sensor 12e. The signal is transmitted from the terminal T ₁₁ via the signal line 31 to the terminal T ₂₁ of the control device 21 in a time division manner. An example of the output signal at this time is a signal as shown in FIG. Further, the synchronization signal from the synchronization signal generator 18 is transmitted from the terminal T ₁₂ to the terminal T ₂₂ of the control device 21 via the synchronization signal line 32.

[0025] In the control unit 21 receives a synchronizing signal from the terminal T ₂₂ in the counter 25, the clock from rising and the clock generator 24 of the synchronizing signal, measuring the input timing of each channel signal. Further, after the detection signal of each sensor from the terminal ₂₁ is converted into a digital signal by the A / D converter 23, it is taken in by the microcomputer 22.

The microcomputer 22 has a counter 2
Based on the count value of 5, it is determined which channel the digital signal from the A / D converter 23 is, that is, which sensor signal, and the digital signal is fetched. That is, as shown in (f) of FIG. 2, the temperature detection signal of the channel CH1, the displacement detection signal of the channel CH2, the pressure detection signal of the channel CH3, the rotation speed detection signal of the channel CH4, and the acceleration detection signal of the channel CH5 are predetermined. Take in sequentially at the timing of.

In this case, since the clock from the clock generator 15 of the sensor unit 11 and the clock from the clock generator 24 of the control device 21 are not in phase, both clocks are sufficiently higher than the frequency for switching channels. Requires high frequencies. Here, a 4096 Hz clock is used as the clock. Further, if there is a difference between the clock frequencies of the both, a deviation occurs in the signal acquisition timing, so that high accuracy of the frequency is required.

However, even if the accuracy is improved in this way, in reality, a slight difference occurs in the channel switching timing between the sensor unit 11 and the control device 21, so that the signal acquisition is performed immediately before and immediately after the channel switching. Instead, the signal is captured at the timing within the range indicated by the diagonal lines in FIG.

In this way, the microcomputer 2
2 can accurately capture the detection signal of each sensor that is time-divisionally transmitted from the sensor unit 11. In this system, the sensor unit 11 and the control device 2
The number of signal lines connecting 1 with the signal line 31 and the number of synchronizing signal lines 3
It is good to use 2 of 2 and can be reduced. Therefore, even if the power supply line 33 and the ground line 34 are added to this, the number of lines is four, and when these are bundled into a cable, the cable can be made thin. Further, when this cable is connected to the sensor unit 11 and the control device 21 by a connector, the number of terminals is small, so that a small connector with a small number of pins can be used as the connector. Therefore, it is possible to reduce the size, the weight, and the cost as a whole.

Since the size and weight can be reduced as a whole as described above, it is possible to construct a bearing device in which the sensor unit 11 is incorporated in the rolling bearing or in the vicinity thereof. In this case, the operating state of the bearing device is monitored by various sensors, the detection signals of the various sensors are time-divisionally transmitted to the control device 21 via the cable, and the control device 21 operates the operation of the bearing device from the detection signals of the various sensors. You can control to grasp the status. In particular, it is suitable for measuring the temperature, vibration (acceleration), displacement, rotational speed, etc. at regular time intervals in order to monitor the operating states of large steel bearings and axle bearings for railway vehicles.

In this embodiment, in the sensor unit 11, the clock from the frequency divider 16 is counted by the counter 17, and the synchronizing signal generator 18 generates the synchronizing signal using the count value of this counter. Also, the signal switch 19 is configured to generate the timing for selectively turning on the switches 13a to 13e, but the timing may be changed by other methods such as using a timer IC or a microcomputer without using a counter. May be generated.

Further, in this embodiment, the control device 21
In the above, the counter 25 measures the input timing of each channel signal by the rising edge of the synchronization signal from the sensor unit and the clock from the clock generator 24, but the invention is not necessarily limited to this. Since the microcomputer 22 normally operates in synchronization with an accurate clock, the input timing of each channel signal may be measured by software using this clock, for example.

Further, in this embodiment, in the sensor unit 11, the switches 13a to 13e of the signal switch 19 are arranged so that the transmission times of the channel signals become equal.
However, the present invention is not limited to this. For example, the ON time of the switch 13a is made longer than the ON time of the switch 13b.
The switches 13a to 13e may be turned on so that the transmission time of each channel signal is different.

(Second Embodiment) Incidentally, the above-mentioned first embodiment
The same parts as those of the embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 3, 111 is a sensor unit and 211 is a control device on the receiving side. The sensor unit 111 includes a temperature sensor 12a and a displacement sensor 12
b, various sensors such as the acceleration sensor 12e are provided.

The output terminal of the temperature sensor 12a is a switch.
Unit terminal T via switch 13b ₁₁Connect to the above
The output terminal of the displacement sensor 12b is via a switch 13c.
The terminal T₁₁To the output of the acceleration sensor 12e.
The input terminal is via the RMS converter 14, and the switch 1
The terminal T through 3d₁₁Connected to. In addition,
Switch 13a to the terminal T₁₁And power supply terminal T_ThirteenBetween
The switch 13e to the terminal T₁₁And ground
It is connected between and.

The sensor unit 111 generates a clock as shown in FIG. 4A from the clock generator 15 and divides the clock by the frequency divider 16 to generate a counter 17
Is being supplied to. For example, clock generators 15-40
A 96 Hz clock is generated, this is divided by a frequency divider 16 to be converted into a 1 Hz clock, and this is counted by a counter 17. The counter 17 counts the 1 Hz clock from the frequency divider 16 and outputs D ₀ , D ₁ ,
D ₂ is changed as shown in FIG. 4B, and the count values of 0 to 4 are repeatedly output.

Then, the count value of the counter 17 is supplied to the signal switcher 19. The signal switch 19
Is for selectively turning on the switches 13a to 13e according to the count value of the counter 17,
When the count value is "0", only the switch 13b is turned on, and when the count value is "1", the switch 13c is turned on.
Only the switch 13d is turned on when the count value is "2", only the switch 13e is turned on when the count value is "3", and the switch 13e is turned on when the count value is "4". Only 13a is turned on.

[0038] Then, the when the switch 13b is turned on the temperature detection signal from the temperature sensor 12a is output to the terminal _{T 11} as the channel signal CH1, the displacement sensor 12b when said switch 13c is turned on
As channel signal CH2 displacement detection signal is output to the terminal T _11, to the output terminal T ₁₁ acceleration detection signal via the RMS converter 14 as a channel signal CH3 from the acceleration sensor 12e when said switch 13d is turned on from It is supposed to be output.

Further, the when the switch 13e is turned on to output the ground potential to the terminal _{T 11,} the power supply V to the terminal _{T 11} when the switch 13a is turned on
The voltage of s is output, the synchronizing signal is created by the ground potential and the power supply voltage at this time, and the signal from the terminal T ₁₁ to the signal line 3 is generated.
1 to the terminal T ₂₁ of the control device 211.

That is, from the terminal T ₁₁ of the sensor unit 211, the counter 17 has “0”, “1”,
When counting as "2", change the channel signal to CH1 →
CH2 → CH3 is output sequentially, and the counter 17 is "3",
A synchronization signal is output when counting "4".

If the output voltage level of the sync signal and the output voltage range from each sensor are made different, the sync signal can be easily separated by using a comparator or the like on the control device side. For example, the voltage of the power supply Vs is 15V
At this time, if the input range of the detection signal is adjusted by an amplifier or the like so as to be in the range of 3V to 10V, when a synchronization signal is put in the detection signal, the comparator with the threshold value of 13V is set on the control device side. It is easy to separate the sync signal by the (comparator).

The control device 211 includes a clock generator 2
4, a counter 25, a synchronization signal separation circuit 26, a separation signal generator 27, a switch circuit 28 including switches 28a, 28b, 28c, and the like, and terminals T ₂₁ , T ₂₃ , and T ₂₄ .

The synchronizing signal separation circuit 26 has the terminal T
_The synchronizing signal is separated from the signal input from the reference numeral ₂₁ by using, for example, a comparator, and the separated synchronizing signal is supplied to the counter 25. That is, the sync signal separation circuit 26 has count values of "3" and "4".
The sync signal is separated based on the portion of the signal output at the time of changing from the low level to the high level, and this is supplied to the counter 25 as the sync signal.

The counter 25 measures the input timing of each channel signal CH1, CH2, CH3 by the rising edge of the synchronizing signal and the clock from the clock generator 24, and uses the measured timing as a count value for the separation signal generator 27.
Is being supplied to.

The separation signal generator 27 generates a separation signal for separating each channel signal based on the count value, and only the switch 28a is turned on at the timing when the channel signal CH1 is input to the terminal T21 by this separation signal. Only the switch 28b is turned on when the channel signal CH2 is input to the terminal T21, and only the switch 28c is turned on when the channel signal CH3 is input to the terminal T21.

In such a configuration, in the sensor unit 111, the counter 17 counts the 1 Hz clock from the frequency divider 16 and sets the count value to "0",
The value is changed to "1", "2", "3", "4", "0", ..., and the signal switch 19 turns on the switch 13b at the timing of the count value "0", and the count value "1". The switch 13c is turned on at the timing of, and the switch 13d is turned on at the timing of the count value "2".
The switch 13e is turned on at the timing of the count value "3", and the switch 1 is turned on at the timing of the count value "4".
3a is turned on.

Therefore, the temperature detection signal from the temperature sensor 12a, the displacement detection signal from the displacement sensor 12b, the acceleration detection signal from the acceleration sensor 12e, and the synchronizing signal are sent to the terminal T.
₁₁ through the signal line 31 to the terminal T of the control device 211
₂₁ is transmitted in a time division manner. An example of the output signal at this time is a signal as shown in FIG.

In the control device 211, the signal from the terminal T21 is taken into the sync signal separation circuit 26 to separate the sync signal, and the sync signal as shown in FIG. The counter 25 measures the input timing of each channel signal by the rising edge of the synchronizing signal and the clock from the clock generator 24.

The separation signal generator 27 determines the input timing of each channel signal based on the count value of the counter 25, and turns on the switch 28a at the timing when the channel signal CH1 is input. As a result, in FIG.
As shown in (e), the temperature detection signal from the temperature sensor 12a is taken out via the switch 28a. In addition, the switch 28 is set at the timing when the channel signal CH2 is input.
Turn on b. As a result, the displacement detection signal from the displacement sensor 12b is taken out via the switch 28b as shown in FIG. 4 (f). Also, the channel signal CH
The switch 28c is turned on at the timing when 3 is input. As a result, as shown in (g) of FIG.
An acceleration detection signal from the acceleration sensor 12e is taken out via c.

In this way, the control device 211 can accurately take in the detection signals of the respective sensors, which are time-divisionally transmitted from the sensor unit 111. In this embodiment, it is premised that the channel switching timings of the sensor unit side and the control device side are the same, but in reality there is some deviation, so in that case, immediately before switching. , It suffices to control so as not to capture the input signal immediately after.

In this system, the number of signal lines connecting the sensor unit 111 and the control device 211 may be one signal line 31, which can be reduced. Therefore, even if the power supply line 33 and the ground line 34 are added to this, the number of lines is three, and when these are bundled into a cable, the cable can be made thin. Further, when the cable is connected to the sensor unit 111 and the control device 211 by a connector, the number of terminals is small, so that a small connector with a small number of pins can be used as the connector. Therefore, also in this embodiment, it is possible to reduce the size and weight as a whole and to reduce the cost.

Since the size and weight can be reduced as a whole as described above, it is possible to construct the bearing unit in which the sensor unit 111 is incorporated in the rolling bearing or in the vicinity thereof also in this embodiment. In this case, the operating state of the bearing device is monitored by various sensors, the detection signals of the various sensors are time-divisionally transmitted to the control device 211 via the cable, and the control device 211 operates the operation of the bearing device from the detection signals of the various sensors. You can control to grasp the status.

In this embodiment, the sync signal transmitted from the sensor unit 111 in a time-division manner is separated in the control device 211 using the sync signal separation circuit 26 and supplied to the counter 25. 27, switches 28a, 28 based on the count value of the counter 25.
Although b and 28c are selectively turned on to take out the detection signal of each sensor, the present invention is not limited to this.

For example, a signal transmitted from the sensor unit 111 in a time division manner is converted into a digital signal by an A / D converter and then taken into a microcomputer, and the microcomputer detects a synchronizing signal by software,
The detection signal from each sensor can be separated and taken out using the synchronization signal.

[0055]

As described in detail above, according to the present invention,
By reducing the number of signal lines to be used, the cable can be made thinner and the number of pins of the connector can be reduced, whereby the configuration can be downsized and the cost can be reduced. A device can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of an entire system showing a first embodiment of the present invention.

FIG. 2 is a diagram showing operation timings and output waveforms of each unit in the same embodiment.

FIG. 3 is a block diagram of an entire system showing a second embodiment of the present invention.

FIG. 4 is a diagram showing operation timings and output waveforms of each unit in the same embodiment.

FIG. 5 is a block diagram showing a conventional example.

[Explanation of symbols]

11 ... Sensor unit 21 ... Control device 12a ... Temperature sensor 12b ... Displacement sensor 12c ... Pressure sensor 12d ... Rotation speed sensor 12e ... Acceleration sensor 13 ... Switch circuit 17 ... Counter 18 ... Synchronous signal generator 19 ... Signal changer 22 ... Microcomputer 25 ... Counter

Claims (7)

[Claims] 1. A sensor unit provided with various sensors,
And a control device for fetching various sensor signals from the sensor unit, wherein two signal lines are connected between the sensor unit and the control device, and the sensor unit generates a synchronization signal and connects one signal line to the other. A synchronization signal generating means for transmitting a synchronization signal to the control device via the switch, a switch circuit for outputting the signals of the various sensors as channel signals to the other signal line, and a signal corresponding to the synchronization signal as a reference. Signal switching means for switching control of the switch circuit according to a predetermined time and transmitting the respective channel signals to the other signal line in a time division manner, and the control device is time division transmitted by the other signal line. Sequentially extracting each channel signal at a time determined based on the synchronization signal received from the one signal line. Multi-sensor system comprising. 2. The sensor unit is further provided with clock generating means for generating a clock, and based on the clock from this clock generating means, the synchronizing signal generating means generates a synchronizing signal and the signal switching means comprises a switch circuit. The multi-sensor system according to claim 1, wherein switching control is performed. 3. A sensor unit provided with various sensors,
And a control device for fetching various sensor signals from the sensor unit, wherein one signal line is connected between the sensor unit and the control device, and the sensor unit uses the signals of the various sensors as channel signals. A switch circuit for outputting to the signal line and a sync signal to the signal line, and switching control of the switch circuit to time-division the channel signals and the sync signal to the control device via the signal line. A multi-sensor system, comprising: a signal switching unit for transmitting the signal, wherein the control device sequentially extracts each channel signal time-divisionally transmitted by the signal line at a time determined based on a synchronization signal received. 4. The sensor unit is further provided with a clock generating means for generating a clock, and the signal switching means controls switching of the switch circuit based on the clock from the clock generating means. Multi-sensor system. 5. A variety of sensors, a synchronization signal generating means for generating a synchronization signal and transmitting the synchronization signal to a control device through a first signal line, and a signal of each of the various sensors as a channel signal for a second signal. A switch circuit for outputting to the signal line, and a signal for controlling switching of the switch circuit according to a time determined with reference to a signal corresponding to the synchronization signal, and transmitting each channel signal to the second signal line in a time division manner. A sensor unit comprising switching means. 6. Various sensors, a switch circuit for outputting signals of the various sensors as channel signals to a signal line and a synchronous signal to the signal line, and switching control of the switch circuits to control each of the switches. A sensor unit, comprising: a signal switching unit for time-divisionally transmitting a channel signal and a synchronization signal to the control device via the signal line. 7. A bearing device, wherein the sensor unit according to claim 5 or 6 is incorporated in a rolling bearing or in the vicinity thereof.