Photo Suzuki Bergman 200
Suzuki Bergman 200, speedometer may stop working — recall
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As a remedy, replace all vehicles and speedometers with countermeasures.
Suzuki told the Ministry of Land, Infrastructure, Transport and Tourism that there was a problem with the speedometer of the light motorcycle scooter "Bergman 200" ... → Continue reading
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The type of speedometer is a speedometer that calculates the speed from the angular velocity of the wheel (how much it turns per unit time).空 気,WedMeasure the objective speed with a fluid such asPitot tube, In orbitArtificial satelliteUsing the signal sent fromGPSThe phase difference between the speedometer and the reflected wave of light or sound, that is,Doppler effectThere is a Doppler speedometer that uses.
- Motorcycles over 125cc are treated in the same way as automobiles under the Road Transport Vehicle Law, which is the basis for installing speedometers, so they will be referred to in this section.For Type XNUMX motorized bicycles that are treated in the same way as automobiles under the Road Traffic Act,#MopedSee item.
Domestically produced in JapanSmall carandOrdinary carSpeedometers are usually 160-180 km / h(NissanIn some models, the scale is engraved up to 190 km / h).Light car,Track-busIn the case of, most of them are engraved up to 120-140 km / h. Domestic motorcycle over 125cc (オ ー ト バ イ) Is usually graduated up to 180km / h.
However,Nissan GT-R,Mitsubishi Lancer EvolutionEtc. in the commercial statecircuitRunningCompetitionThere is a display of 180 km / h or more for the vehicle type corresponding to, and other than theseTuning carIn such cases, a speedometer with a display of 200 km / h or higher may be installed according to the user's needs.It should be noted thatImported car TheManufacturerSince it varies depending on the type, it cannot be said unconditionally regarding the display.
Internationally, roads with unlimited speed sections and over 130 km / hTop speedExists, but JapanPublic roadThe upper limit of the maximum speed of a car that can be specified in is 80 km / h on general roads (Legal speedBy signs above 60 km / h),Highway national roadandMotorwayThen,largeandSpecific medium sizeLorryAlso, three-wheeled vehicles are 80 km / h, and other vehicles are 120 km / h.Shin-Tomei ExpresswayThe maximum speed of 140 km / h is required in Japan, but it is not possible to increase the speed beyond this.Road Traffic LawForbidden in.Therefore, there are some negative opinions about equipping the vehicle with a speedometer that is engraved to a speed range that is not legally necessary.
There are various theories as to why the scale is engraved up to a speed that exceeds the upper limit of the maximum speed, but if it is a large freight car with an upper limit of the maximum speed of 80 km / h, the scale of the speedometer is only up to 80 km / h. If it is not engraved, the meter will run out when traveling at 80 km / h and visibility will be significantly reduced, and if it exceeds 80 km / h even a little, the current speed will not be displayed, the highest in the future There is a problem that it can not cope with speed increase, and in the case of ordinary cars, there is a similar problem if it is only carved up to 120 km / h, and it will be a hindrance when driving on a circuit.Also, to imported carsNon-tariff barriersCan actually beSpeed warning soundAnd large carsSpeed indicatorHas been removed from security standards as a non-tariff barrier.
Sold for the domestic market in JapanDomestic carThen on the displayunit TheKilometers per hour (km / h), butMilesIn countries where the unit is mainstreamMiles per hour Often expressed in (MPH), both kilometers per hour and miles per hour are listed (Digital displayIn the case of, there is also a speedometer (the unit can be switched).
The mounting position is for most car modelsDashboardDriver's side upper part or center upper part (Center meter), In the case of motorcycles, is it the center of the steering wheel?CowlIt is installed inside.In recent yearsTachometerMany models are equipped with a combination meter integrated with other instruments such as fuel gauges, fuel gauges, and water temperature gauges.In addition, in luxury cars and high-end passenger cars that have been handled in recent years, the speedometer is from the machine.LEDIt was usedDigital meterAnd some are displayed on the LCD monitor (Glass cockpitreference).
In general,ト ラ ン ス ミ ッ シ ョ ンDriven on the output sidegearThere is a method of detecting the vehicle speed and reflecting the numerical value on the speedometer.This can be roughly divided into mechanical type (the driven gear and speedometer are connected by a wire and the rotation signal is reflected in the instrument) and electronic type (the rotation signal obtained from the driven gear is converted into a pulse signal). There are two types (those that are reflected as numerical values on the instrument).
Laws and regulations
The speedometerRoad Transport Vehicle ActArticle 41 No. 17 (automobile equipment) and road transport vehiclesSecurity guardAs stipulated by Article 46, Paragraph 1 of the Standard (speedometer, etc.), it is legally essential equipment in Japan (however, automobiles and vehicles with a maximum speed of less than 20 km / h).Tow vehicleExcludes).It does not just have to be equipped, it must be installed in a position that the driver can easily check while driving, and the actual speed is remarkable when driving on a flat paved road surface.errorShould not be.
However, the maximum speed is less than 35km / hlargeSpecial carAnd for agricultural workSmallSpecial automobiles (eg for agriculture)ト ラ ク タ ー)about,Prime moverTachometerThe speedometer itself may not be required, as it is accepted as an alternative to the speedometer.
First classMotorized bicycleSpeedometers (less than 50 cc) are usually engraved up to 60 km / h.However, the legal speed of a first-class motorized bicycle is 30 km / h, and even if a higher maximum speed is specified, the legal speed will be applied, so this is the upper limit.Type XNUMX motorized bicycle (Small motorcycleIn the case of), it is carved up to around 100 km / h, depending on the model.The legal speed of a Type 60 motorized bicycle is 80 km / h, and it may be increased to a maximum speed of XNUMX km / h on general roads, but both Type XNUMX and Type XNUMX are the same as for automobiles. When driving on public roads, the scale is engraved to a speed range that is virtually unnecessary.
Since motorized bicycles are defined separately from automobiles by law, speedometers are also defined in Article 44-11 of the Road Transport Vehicle Law (structure and equipment of motorized bicycles) and Road Transport Vehicle Safety Standards No. 65. Although it is stipulated separately from the case of automobiles by Article 2 (speedometer), the legal regulations themselves are almost the same as those of automobiles.
The speedometer of a railroad vehicle is an important instrument for safety such as checking the speed limit at signals, points, and curves, and for the timeliness that accurately protects train schedules, and is installed in the most visible position in front of the driver's cab. Will be done.Most of the shapes are round, but horizontal ones are also available.Further, speed detection includes a method of mounting a small speed generator on the axle to measure the voltage and frequency generated, and a method of counting the gears of the drive device by magnetic induction.For speed display notches,Conventional line OfElectric train,RailcarInordinary-Rapid trainMost for 120-140km / h,Limited express trainMost of them are engraved up to 160-180km / h.
ShinkansenBecause it runs at high speed, it is difficult to check the signal on the ground, so everythingATCIt has become (Yamagata Shinkansen-Akita ShinkansenAll cars are equipped with cab signaling (except for direct conventional lines such as), and are usually engraved up to 300-400km / h.
Analog typeElectric meterIn many cases, a 110 mm square wide-angle indicator is used.
Meitetsu 7000 series(Digital)
Keikyu type 1500(analog)
JR West 207 series(Digital)
From ancient times to the presentAirspeed meter Called (ASI, airspeed indicator)Flight instrumentIs widely used.this isPitot tubeBy measuring the dynamic pressure obtained by subtracting the static pressure from the total pressure, the total pressure and static pressure measured usingAirspeedThe instruction of the instrument at this time included the error of the total pressure / static pressure system and the error of the speedometer itself, which changed depending on the turbulence of the airflow near the aircraft, the speed, attitude, the position of the flap, etc. Indicated airspeed (IAS: indicated air speed), and corrected the error from IAS CAS(Calibrated air speed), corrected to the value excluding the influence of air compressibility from CASEAS(Equivalent air speed, equivalent airspeed), and corrected the error that the speedometer reading changes due to changes in air density due to changes in altitude and temperature.TASThere is (true air speed), and what is displayed by a general airspeed meter isIAS.WingsOccurs inLiftAirspeed is a problem in maneuvering the aircraft, such as when thinking aboutstallThe speed and excess prohibition speed are indicated by airspeed, and the speedometer is different between single-engine and multi-engine aircraft.There is also a true airspeed meter.
In addition, the airspeed meter has a color mark around the scale plate, and by displaying the various speed limits of the aircraft with a common color sign, it is easy to check the safety in flight. I am trying to understand.
There are four meanings of color signs:
- Red radiation: Operation prohibition limit
- Green arc line: Normal operation range (normal operation range in flight state with flap raised and stored)
- Yellow arch: Warning range
- White arch line: Flap operation range (speed range in which the flap can be operated)
In an aircraft that flies at high altitudes, near or above the speed of sound, the speed of sound drops due to a drop in temperature at high altitudes, and when the airspeed approaches the speed of sound, part of the aircraft becomes above the speed of sound and shock waves. Know how fast the speed of sound is during flight because of the danger ofMachmeter (w: machmeter) Is equipped and held separately from the airspeed meter, or it is integrated in an integrated instrument such as PFD (primary flight display), or the airspeed meter is equipped with the airspeed depending on the speed of sound that changes with altitude. Equipped with red and white diagonal stripes (Barber Pole) to change and indicate the maximum operating speed of the aircraft.Maximum operational limit speedometerEquipped with.In addition, since the measurement of air data (barometric altitude, airspeed, outside air temperature, etc.) during flight becomes complicated, the electrical signal from the sensor that corrects the error between the measured total pressure and static pressure or static pressure is used.Air data computerAn electric signal is sent to the airspeed meter to indicate the airspeed and the maximum operating limit speed calculated by inputting to.
Airspeed meter for small machines.The green arc is the normal operating range in flight with the flaps raised and stowed.The lower limit is stall speed (VS1), The upper limit (boundary with the yellow band) is the maximum (structure) cruising speed (VDO NOT).The white belt isflapIn the operating range, the lower limit is the stall speed (VSO), The upper limit is the maximum flap lowering speed (VFE).The yellow arc is the alert range.The red line at the end of the upper limit of the yellow band is the operation prohibition limit speed (VNE).
Airspeed meter for multiple engines.The red line at the bottom of the green band is (w: critical engine) Minimum maneuvering speed when inactive (Vmc).The blue line pointed by the needle is the speed at which the best climb rate is achieved when the critical engine is inactive (VANN).
The operating principle of the airspeed meter.From the Pitot tube into the airspeed meterDiaphragmFull pressure is introduced up to.The differential pressure obtained by subtracting the static pressure of the surrounding atmosphere from the total pressure is the dynamic pressure, and the airspeed is calculated from the dynamic pressure.In large jet aircraft and the like, air is not directly guided to the instrument in this way, but is indicated by an electric signal via an air data computer.
On the other hand, when navigating, it is the speed of movement with respect to the ground.Ground speed (GS, ground speed) becomes a problem.Airspeed and ground speed are different when the surrounding air itself is moving, that is, when flying in the wind.Especially,Turbulence,Jet streamWhen flying in a strong air flow such as, the difference becomes large.Generally, when flying for a long time, the error between the distance calculated by airspeed and the actual flight distance becomes large.To correct this error, from ancient timesDirectional gyroIndependent flight technology using (DG, fixed needle) has been used, but in recent yearsInertial navigation systemWas used or even nowGlobal Positioning System Due to the generalization and price reduction of (GPS), more aircraft are equipped with GPS speedometers than gyroscopes.
Many current aircraft are equipped with both an airspeedometer and a ground speedometer using a Pitot tube, or have an integrated instrument that combines the functions of both.
ShipIn the case of, like an aircraft, if there is a speed difference with the water (fluid) in contact, a Pitot tube or Doppler speedometer is used, but since there is a difference in speed display between fluid and ground, in the old days星And observe -ChartMade full use ofNavigationI figured out the position of my ship and got the speed.Nowadays, the position and speed are calculated by GPS like an aircraft.
Especially in the case of large vessels, it is called a berthing speedometer.HarborSome have a speedometer dedicated to berthing at.this islaserThose that use the Doppler effect when reflecting, that is, the Doppler speedometer is the mainstream.
There used to be a mechanical speedometer, but nowadays, electronic ones that use magnets and sensors are the mainstream, and are called cycle computers.Not just speedodometerIt also functions as such.
Shin Aoki, 1938ji Tomoda "Latest Electricity Equipment Electric Meter" Shukyosha Shoin, 403. (pXNUMX Chapter XNUMX Speed Measuring Instrument)
- ^ speed meterIs sometimes written, but the correct alphabetical notation isspeedometer.
- ^ Under the Road Transport Vehicle Law, vehicles other than motorized bicycles of 125cc or less are included in automobiles.Therefore, this regulation applies not only to automobiles in general, but also to motorcycles over 125cc.