JP4254402B2 - Vehicle remote control system - Google Patents

Description

  The present invention relates to a remote control system such as a vehicle keyless entry system or a tire pressure monitoring system.

Conventionally, as a remote control system adopted for a vehicle, it is one of vehicle safety measures, and a tire pressure monitoring system that warns a driver's seat when an excess or insufficient air pressure or temperature abnormality occurs in a running tire. Is known (see, for example, Patent Document 1). In this system, basically, a transmitter incorporating a sensor for detecting tire air pressure and temperature is attached to each tire, and a receiving unit for receiving a radio signal from the transmitter in a passenger compartment. The information signal indicating the tire pressure and temperature detected by the sensor is transmitted by radio waves from the transmitter and received by the receiving unit, so that the driver's seat is notified of the pressure and temperature.
Also known as a remote control system is a so-called keyless entry system that locks and unlocks the door of a vehicle by transmitting radio waves from a transmitter carried by the passenger and receiving it by a receiving unit in the passenger compartment.

JP 2000-182164 A

  In the tire pressure monitoring system described above, the metal underbody (mainly the floor panel) interposed between the transmitter attached to each tire and the receiving unit mounted on the vehicle body is a radio wave shielding object. There is a possibility that radio waves sent from the aircraft will be disturbed. In order to avoid this, conventionally, a method of providing holes or slits for allowing radio waves to pass through the floor panel, or using holes or slits formed in the floor panel for other purposes is adopted. . However, with such a method, it is still difficult to stably secure the required reception strength, and the rigidity of the floor panel of the vehicle may be reduced depending on how the holes and slits are formed. It was.

  The present invention has been made in view of the above technical problem, and avoids the influence of a radio wave shielding object and uses a relatively inexpensive structure to receive a transmitter signal from outside the passenger compartment on the receiving unit side. An object of the present invention is to provide a vehicle remote control system capable of improving performance.

  By the way, as a characteristic of radio waves, radio waves that hit a metal body are once converted into current on the surface of the metal body, and as the current moves in the metal body, radio waves are generated and radiated in all directions. The phenomenon is known. In this re-radiation, when the metal body is considerably large with respect to the strength of the radio wave, the current is diffused throughout the metal body, so that the radio wave becomes weak. Therefore, it is usually adopted, for example, in a tire pressure monitoring system. With the strength of the radio waves from the transmitter, there is little possibility of useful re-radiation on the vehicle floor panel. The present invention employs a structure that causes re-radiation in the floor panel with radio waves from the transmitter, and improves the reception performance of radio waves from the transmitter using the radio waves re-radiated from the floor panel. it can.

The invention according to claim 1 of the present application provides a remote control system for a vehicle including a transmitter that transmits radio waves from outside the vehicle interior and a receiving unit that receives a signal from the transmitter in the vehicle interior. The floor panel is provided with a re-radiation structure part that is formed in a concave shape or a hole shape that is recessed downward from the upper surface side of the floor panel and re-radiates the radio waves received from the transmitter toward the vehicle interior. machine is to detect the air pressure of the tire is obtained by said der Rukoto which transmits the detection signal in radio waves.

Still, the invention according to claim 2 of the present application, Oite the inventions according to claim 1, said re-radiating structure is, along the direction of the radio wave transmitted from each transmitter, radio wave It is characterized by having a length that is half of one wavelength.

Still, the invention according to claim 3 of the present application is characterized in that Oite the inventions according to claim 1, the receiving unit is disposed in the vicinity of the re-emission structure in the passenger compartment It is what.

Furthermore, the invention according to claim 4 of the present application is characterized in that, in the invention according to claim 1 , the floor panel is provided substantially at the center in the vehicle front-rear direction and the vehicle width direction. .

According to the invention according to claim 1 of the present application, by providing a re-radiating structure portion on the floor panel as a radio wave shielding object, the transmitter from the outside of the passenger compartment is provided on the receiving unit side while avoiding the influence of the floor panel. Signal reception performance can be improved.
Furthermore, the re-radiation structure has a simple configuration, and the reception performance on the receiving unit side can be improved without incurring an increase in cost.

Furthermore, according to the invention of claim 2 of the present application, the radio wave transmitted from the transmitter is likely to resonate at the re-radiating structure, and re-radiation occurs effectively.

Furthermore, according to the invention according to claim 3 of the present application, the radio wave re-radiated by the re-radiation structure portion is easily received on the receiving unit side without being obstructed elsewhere, and more stable reception performance is obtained. .

Furthermore, according to the invention according to claim 4 of the present application, the re-radiating structure is positioned at almost equal intervals from each tire, and is stabilized almost uniformly from the transmitter provided in each tire. Can receive radio waves.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIGS. 1 and 2 schematically show a manner in which a detection signal from each tire is received by a receiving unit inside the vehicle in the vehicle tire pressure monitoring system according to the embodiment of the present invention. It is the figure seen from the figure and the vehicle body bottom side. 1 and 2, the left side in the figure corresponds to the front side of the vehicle, and the right side corresponds to the rear side of the vehicle.

  In this vehicle 1, as a tire pressure monitoring system, a transmitter 3 incorporating a sensor (not shown) that detects the state of the tire 2 such as air pressure, temperature, and rotational speed is attached to each tire 2. On the vehicle body side, a receiving unit 6 for receiving a signal from the transmitter 3 is mounted. Each transmitter 3 wirelessly transmits an information signal representing the state of the tire 2 such as air pressure, temperature, and rotational speed detected by the sensor. Although not particularly illustrated, the receiving unit 6 includes a predetermined signal processing circuit, performs calculation and control based on the received signal, and generates a signal for notifying the driver's seat.

  In this vehicle 1, a concave re-radiation structure 10 is formed on a floor panel 5 that forms an underbody of the vehicle in the vicinity of the receiving unit 6, so that a concave re-radiating structure 10 is formed. It protrudes at. As can be clearly understood from FIG. 2, the re-radiating structure portion 10 is disposed substantially at the center in the vehicle front-rear direction and the vehicle width direction, and is positioned at substantially equal intervals from the four tires 2. As a result, on the lower surface side of the floor panel 5, a substantially uniform and stable radio wave is supplied from the transmitter 3 provided in each tire 4 to the re-radiating structure 10.

  Moreover, the re-radiation structure part 10 is formed so that it may extend along the front-back direction of a vehicle. The direction of the re-radiating structure 10 is set based on the directivity of the radio wave emitted from the transmitter 3 attached to each tire 4. In this embodiment, the combined component of the radio wave from each transmitter 3 is set. Is along the front-rear direction of the vehicle, the re-radiating structure 10 is formed along the front-rear direction of the vehicle. Depending on the direction of the synthesized radio wave, the re-radiating structure 10 may be provided with a predetermined inclination angle with respect to the front-rear direction of the vehicle.

By providing such a re-radiating structure 10, the transmission wave W ₁ transmitted from the transmitter 3 attached to each tire 4 is re-radiated on the lower surface side of the floor panel 5 as can be seen from FIG. The part 10 is irradiated. The transmission wave W ₁ is converted into a current at the re-radiation structure 10 and its vicinity, and the re-radiation wave W ₂ is radiated with the generation of this current. Then, the re-radiated wave W ₂ radiated into the passenger compartment is received by the receiving unit 6, so that the air pressure, temperature, rotational speed, etc. of the tire 2 detected by each transmitter 3 on the receiving unit 6 side. Is obtained.

  FIG. 3 is a perspective view schematically showing the receiving unit 6 and the re-radiating structure 10 formed in the vicinity thereof. The left side in the figure corresponds to the front side of the vehicle, while the right side corresponds to the rear side of the vehicle. In this embodiment, the length L along the vehicle front-rear direction in the re-radiating structure 10 is set to one half (λ / 2) of one wavelength λ of the radio wave transmitted by the transmitter 2. According to the experiment conducted by the inventors of the present application, it has been found that, under such setting conditions, the radio wave resonates more easily in the re-radiation structure 10 and re-radiation is likely to occur. In general, as a radio wave of the transmitter 2, a UHF band having a frequency of about 300 MHz is used, and a radio wave wavelength λ is about 90 cm. That is, when L is set to λ / 2 = 40 to 50 cm, the radio wave is likely to resonate and re-radiation occurs effectively.

  By the way, in order to obtain better reception performance, it is desirable to arrange the receiving unit 6 and the re-radiating structure part close to each other, such as arranging the re-radiating structure part almost directly below the receiving unit 6. FIG. 4 shows a form in which the receiving unit 6 and the re-radiating structure are arranged so as to be close to each other. In this embodiment, the receiving unit 6 is disposed inside a concave re-radiating structure 20 formed on the floor panel 5. The receiving unit 6 is held in the re-radiation structure 20 by a support member (not shown) made of an insulator so as not to contact the inner wall surface of the re-radiation structure 20. According to this form, since the receiving unit 6 is disposed in the re-radiating structure unit 20, it is apparent that the radio waves re-radiated by the re-radiating structure unit 20 are easily received by the receiving unit 6. Moreover, according to this form, it is not necessary to prepare the arrangement place of the receiving unit 6 separately, and the arrangement space for the receiving unit 6 can be secured simultaneously with the formation of the re-radiating structure 20.

  In the embodiment described above, the re-radiating structure 20 is formed by recessing a part of the floor panel 5 downward from the upper surface side. However, the present invention is not limited to this, and FIGS. The form shown in (c) may be adopted. In the form shown in FIG. 5 (a), a hole 35 is formed in the floor panel 5, and the resin container 30 opened upward from the hole 35 has a peripheral flange 30 a at the edge of the hole 35. The re-radiating structure is configured by joining and attaching. A receiving unit 6 is disposed inside the container 30.

  In this embodiment, since the receiving unit 6 is held at a position lower than the floor panel 5 and the resin container 30 is a radio wave transmitting material, the radio wave from the transmitter 3 is directly transmitted to the receiving unit 6 (strictly speaking, Easy to receive) (via container 30 only). In addition, in this case, since re-radiation may occur at the edge of the hole 35, the reception performance of the receiving unit 6 is determined by the combination of the radio wave directly transmitted from the transmitter 3 and the re-radiated radio wave. Can be further improved.

  Next, in the form shown in FIG. 5B, a slit 45 is formed in the floor panel 5, and a resin lid is formed so as to cover the slit 45 from the upper surface side (that is, the vehicle interior side) of the floor panel 5. A member 40 is attached. The receiving unit 6 is disposed on the upper surface of the lid member 40.

  In this embodiment, the receiving unit 6 has the resin lid member 40 made of a radio wave transmitting material, so that the radio wave passing through the slit 45 and passing through the lid member 40 is received by the receiving unit 6. In addition, in this case, since re-radiation may occur at the edge of the hole 45, the re-radiated radio wave is transmitted directly from the transmitter 3 (strictly, only through the lid member 40). The reception performance of the reception unit 6 can be further improved by the combination with the radio wave.

  Further, in the form shown in FIG. 5C, a small hole 55 is formed in the floor panel 5, and the receiving unit 6 is disposed on the floor panel 5 in the vicinity of the small hole 55. The antenna element 50 connected to the receiving unit 6 passes through the small hole 55 and protrudes to the lower surface side of the floor panel 5.

  In this embodiment, since the antenna element 50 is held at a position lower than the floor panel 5, the radio wave from the transmitter 3 is easily received by the receiving unit 6. In addition, in this case, since re-radiation may occur at the edge of the hole 55, the reception performance of the receiving unit 6 is determined by the combination of the radio wave directly transmitted from the transmitter 3 and the re-radiated radio wave. Can be further improved.

  Although not particularly illustrated, as the re-radiation structure, a convex re-radiation structure that protrudes upward from the upper surface side of the floor panel of the vehicle may be formed. Furthermore, as the re-radiating structure, it is possible to use existing unevenness, slits and holes formed for other purposes such as reinforcement of the floor panel, absorption of sound and vibration. Conversely, it is also possible to give the re-radiating structure part actions such as reinforcement of the floor panel and absorption of sound and vibration.

FIG. 6 is a schematic configuration diagram of a keyless entry system according to another embodiment of the present invention. This embodiment is different from the above-described embodiment only in that the door of the vehicle 1 (for example, the left and right doors 70A and 70B) is locked and unlocked using a signal from the transmitter 60 carried by the passenger. The other points are the same.
It should be noted that the present invention is not limited to the illustrated embodiments, and it goes without saying that various improvements and design changes can be made without departing from the scope of the present invention.

In the tire pressure monitoring system for a vehicle according to the embodiment of the present invention, it is a view from the side of the vehicle body schematically showing how signals are transmitted from a transmitter provided in each tire to a receiving unit inside the vehicle. In the said tire pressure monitoring system, it is a figure from the vehicle body bottom side which shows a mode that a signal transmits from the transmitter provided in each tire to the receiving unit inside a vehicle. It is a perspective view which shows the re-radiation structure part arrange | positioned in the receiving unit and its vicinity. It is a perspective view which shows the re-radiation structure part by which the receiving unit is arrange | positioned inside. (A) It is longitudinal cross-sectional explanatory drawing which shows the 1st modification of a re-radiation structure part. (B) It is longitudinal cross-sectional explanatory drawing which shows the 2nd modification of a re-radiation structure part. (C) It is longitudinal cross-sectional explanatory drawing which shows the 3rd modification of a re-radiation structure part. It is a schematic block diagram of the keyless entry system of the vehicle which concerns on other embodiment of this invention.

Explanation of symbols

1 ... vehicle 2 ... tire 3 ... Tire pressure monitoring system for transmitter 5 ... floor panel 6 ... receiving unit 10 ... re-emission structures 60 ... keyless entry system transmitter 70A, 70B ... door W 1 _... transmission wave W ₂ ... Re-radiated wave

Claims (4)

In a vehicle remote control system comprising a transmitter for transmitting radio waves from outside the vehicle compartment and a receiving unit for receiving signals from the transmitter in the vehicle compartment,
The vehicle floor panel is provided with a re-radiation structure portion that is formed in a concave shape or a hole shape that is recessed downward from the upper surface side of the floor panel and re-radiates the radio waves received from the transmitter toward the vehicle interior. ,
The transmitter detects the air pressure of the tires, the vehicle remote control system according to claim der Rukoto which transmits the detection signal in radio waves. 2. The vehicle according to claim 1, wherein the re-radiating structure has a length that is ½ of one wavelength of the radio wave along a direction of the radio wave transmitted from each transmitter. Remote control system. 2. The vehicle remote control system according to claim 1, wherein the receiving unit is disposed in the vicinity of the re-radiating structure in the vehicle interior. The vehicle remote control system according to claim 1, wherein the re-radiating structure is provided at a substantially center of the floor panel in the vehicle front-rear direction and the vehicle width direction.

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