Abstract:
A magnetic force transmission type tire pressure sensor device and related setting tool and setting method is disclosed. The invention uses a magnetic force sensor unit in the tire pressure sensor device, to receive lines of magnetic flux being transmitted by a magnetic force transmitter unit in the setting tool, and then the received waveform is converted into a communication protocol and stored in the tire pressure sensor device. Therefore, the invention not only can achieve the purpose of wireless transmission but also can enhance the stability of signal transmission, eliminate wireless regulatory constraints and improve product quality.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to tire pressure monitoring technology and more particularly, to a magnetic force transmission type tire pressure sensor device and the related setting tool and setting method for setting the magnetic force transmission type tire pressure sensor device. 2. Description of the Related Art 
         [0003]    Setting of commercial tire pressure sensor devices during installation is done in a wireless manner, i.e., using a setting tool to transmit a predetermined communication protocol or ID data to the tire pressure sensor device to finish the setting. Sending a signal by radio needs to modulate the dominant frequency to a predetermined level more than ten times over the frequency of the data. In consequence, the dominant frequency drive circuit and the mating demodulator circuit are complicated and consume much electrical power during operation. Further, extending the transmission distance of a radio signal requires a larger transmission power, however, long transmission distance is susceptible to interference or can cause signal distortion due to Doppler effect. Further, in various countries, it needs to apply for permission to sell wireless signal transmission equipment. All these issues still have room for improvement 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a magnetic force transmission type tire pressure sensor device and the related setting tool and setting method, which utilizes a magnetic force to transmit a wireless signal without any carrier, simplifying the circuit design, saving electrical power consumption and being free from the restrictions of telecommunication regulations. 
         [0005]    To achieve this and other objects of the present invention, a magnetic force transmission type tire pressure sensor device and related setting tool and setting method in accordance with the present invention includes: a tire pressure sensor device having installed therein a magnetic force sensor unit for sensing lines of magnetic flux being transmitted by a magnetic force transmitter unit in a setting tool. The magnetic force sensor unit outputs the waveform of the sensed magnetic force to a microcontroller unit of the tire pressure sensor device where the microcontroller unit converts the received data into the original control program. 
         [0006]    Other advantages and features of the present invention will be fully understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference signs denote like components of structure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a functional block diagram of a magnetic force transmission type tire pressure sensor device in accordance with a first embodiment of the present invention. 
           [0008]      FIG. 2  is a functional block diagram of a magnetic force transmission type tire pressure sensor device setting tool in accordance with the present invention. 
           [0009]      FIG. 3  is a circuit diagram of a part of the tire pressure sensor device setting tool and the tire pressure sensor device. 
           [0010]      FIG. 4  is a tire pressure sensor device setting tool operating flow chart in accordance with the present invention. 
           [0011]      FIG. 5  is a tire pressure sensor device operating flow chart in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    Referring to  FIGS. 1-3 , a magnetic force transmission type tire pressure sensor device and setting tool system in accordance with the present invention comprises a tire pressure sensor device  10  and a setting tool  20  mating the tire pressure sensor device  10 . 
         [0013]    The tire pressure sensor device  10 , as shown in  FIG. 1 , comprises a microcontroller unit  11 , a memory unit  12  electrically connected to the microcontroller unit  11 , a power supply device  13 , for example, a battery cell electrically connected to the microcontroller unit  11  and adapted to provide the tire pressure sensor device  10  with the necessary working electricity, a pressure sensor unit  14  electrically connected to the microcontroller unit  11  and adapted to measure the internal air pressure of the tire, a temperature sensor unit  15  electrically connected to the microcontroller unit  11  and adapted to measure the internal temperature of the tire, an acceleration sensor unit  16  electrically connected to the microcontroller unit  11  and adapted to measure the acceleration of the tire, a low-frequency transmission interface  17  electrically connected to the microcontroller unit  11  and adapted to transmit a low-frequency signal at 315 MHz or 433 MHz to an on-vehicle main unit or setting tool, a radio-frequency transmission interface  18  electrically connected to the microcontroller unit  11  and adapted to transmit a radio signal to the on-vehicle main unit or setting tool, and a magnetic force sensor unit  19 , for example, hall sensor electrically connected to the microcontroller unit  11  and adapted to sense the variation of a magnetic field and to convert the sensed waveform of the magnetic field into a corresponding signal and to output the signal to the microcontroller unit  11 . Further, the tire pressure sensor device  10  can be configured including only one of the low-frequency transmission interface  17  and the radio transmission interface  18 , or having both of them installed therein. Or alternatively, one of the low-frequency transmission interface  17  and the radio transmission interface  18  can be made in the form of a wire connection terminal for wired application. 
         [0014]    The setting tool  20  is configured to match the tire pressure sensor device  10 . As shown in  FIG. 2 , the setting tool  20  comprises a microcontroller unit  21 , a memory unit  22  electrically connected to the microcontroller unit  21  and adapted to store the ID of the tire pressure sensor device and related communication protocol data, a display unit  23  electrically connected to the microcontroller unit  21  and adapted to display the operating data of the setting tool  20 , a warning unit  24  electrically connected to the microcontroller unit  21  and controllable by the microcontroller unit  21  to provide a visual or audio warning signal, a magnetic force transmitter unit  25  electrically connected to the microcontroller unit  21  and controllable by the microcontroller unit  21  to transmit lines of magnetic flux, a low-frequency transmission interface  26  electrically connected to the microcontroller unit  21  and adapted to receive a low-frequency feedback signal transmitted by the tire pressure sensor device  10 , a radio-frequency transmission interface  27  electrically connected to the microcontroller unit  21  and adapted to receive a radio feedback signal transmitted by the tire pressure sensor device  10 , and a power supply device  29  adapted to provide the setting tool  20  with the necessary working electricity. Further, the setting tool  20  can be configured including only one of the low-frequency transmission interface  26  and the radio transmission interface  27 , or having both of them installed therein. Or alternatively, one of the low-frequency transmission interface  26  and the radio transmission interface  27  can be made in the form of a wire connection terminal for wired application. 
         [0015]      FIG. 3  is a circuit diagram of a part of the setting tool  20  and the tire pressure sensor device  10 . The microcontroller unit  21  of the setting tool  20  is electrically connected to four switches  28  for controlling four transistors, namely, the first transistor Q 1 , the second transistor Q 2 , the third transistor Q 3  and the fourth transistor Q 4 . The microcontroller unit  21  is also electrically connected to a bridge circuit formed of the aforesaid magnetic force transmitter unit  25 . Further, the third transistor Q 3  and the fourth transistor Q 4  are grounded. In this embodiment, the magnetic force transmitter unit  25  is an electromagnet. 
         [0016]    Referring to  FIG. 4  and FIG,  5 , based on the aforesaid tire pressure sensor device and setting tool, the operation of the present invention is outlined hereinafter. At first, select from the setting tool  20  the desired control program to be downloaded onto the tire pressure sensor device  10 . The control program varies with different car manufacturers and different car models. Thereafter, the microcontroller unit  21  of the setting tool  20  encodes the selected control program and then provides the encoded control program to the magnetic force transmitter unit  25  for transmission. The control can be done by, for example, enabling the microcontroller unit  21  to control the first transistor Q 1  and the fourth transistor Q 4  to be electrically conducted, and the second transistor Q 2  and the third transistor Q 3  to be electrically disconducted, thereby electrically conducting the electromagnet. At this time, the magnetic force sensor unit  19  of the tire pressure sensor device  10  will get to the N pole, and will then output Hi to the microcontroller unit  11  of the tire pressure sensor device  10 . If the microcontroller unit  21  controls the first transistor Q 1  and the fourth transistor Q 4  to be electrically disconducted, and the second transistor Q 2  and the third transistor Q 3  to be electrically conducted, the electromagnet will be conducted. At this time, the magnetic force sensor unit  19  of the tire pressure sensor device  10  will get to the S pole, and will then output Lo to the microcontroller unit  11  of the tire pressure sensor device  10 . 
         [0017]    Subject to the above-stated structural al features and control manner of the present invention, the magnetic force transmitter unit  25  of the setting tool  20  can be controlled to transmit the predetermined control program to the tire pressure sensor device  10 . After received the waveform outputted by the magnetic force sensor unit  19 , the microcontroller unit  11  of the tire pressure sensor device  10  restores the original. control program by calculation, and then stores the control program in the memory unit  12 . The tire pressure sensor device setting tool  20  will repeatedly transmit the control program and wait for a feedback signal from the tire pressure sensor device  10 . Upon receipt of data, the microcontroller unit  11  of the tire pressure sensor device  10  makes calculations for error detection. If the received data is correct, the tire pressure sensor device  10  will provide a feedback signal to the tire pressure sensor device. setting tool  20  via the radio transmission interface, low-frequency transmission interface, or wired transmission interface. The tire pressure sensor device setting tool stops the transmission of the control program immediately upon receipt of the feedback signal. In this embodiment, the control program can be a predetermined communication protocol, the ID of the tire pressure sensor device, or the combination of the predetermined communication protocol and the ID of the tire pressure sensor device. 
         [0018]    As shown in  FIG. 5 , if the data received by the tire pressure sensor device  10  is incorrect, the tire pressure sensor device  10  will not provide any feedback signal to the tire pressure sensor device setting tool  20 . Before receiving a feedback signal, the tire pressure sensor device setting tool  20  will transmit the control program to the tire pressure sensor device again, and this operation will be repeatedly performed till that the tire pressure sensor device setting tool  20  receives a feedback signal. 
         [0019]    Further, in order to eliminate the problem of counter-electromotive force (back electromotive force), the first transistor Q 1  and the second transistor Q 2 , enabling the third transistor Q 3  and the fourth transistor Q 4  to be electrically conducted, or all the first through fourth transistors Q 1 -Q 4  can be electrically disconducted, allowing bidirectional quick conversion of the magnetic force drive circuit, However, it is to be noted that the magnetic force drive circuit of the tire pressure sensor device setting tool is not limited to the design illustrated, instead of the illustrated four-switch double-loop design, the magnetic force drive circuit can be made in the form of a single loop using one single switch to control one single transistor and the magnetic force transmitter unit, achieving the same magnetic force output effect. Using magnetic force to transmit signal not only can achieve a wireless signal transmission effect but also simplify the circuit design and save power consumption. Further, this method eliminates wireless regulatory constraints and significantly improves the drawbacks of the prior art design, achieving the objects of the present invention. 
         [0020]    Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.