CN2379783Y - Electronic odometer gauge for measuring vehicle's speed and mileage having both analog and digital parts - Google Patents

Abstract

The utility model relates to a digital-analog electronic speedometer gauge, which belongs to the vehicle speed instrument equipment. The utility model comprises a non flexible driven point gear of the speedometer, a photoelectric sensing device, a single-chip microcomputer, and a counting and display circuit, wherein, the photoelectric sensor device is altered to be arranged inside the magnetoelectric speedometer gauge; the vehicle speed digit indicated on the vehicle speed dial by the pointer is converted into vehicle speed pulse signals; the vehicle speed pulse signals are amplified, shaped and processed by an arithmetic circuit into digital signals comprising speed and mileage, and the digital signals are displayed on a digitron or a liquid crystal display. The utility model is novel digital-analog vehicle speed instrument equipment of which the digital display has a linear function.

Description

The electronic speedometer gauge outfit that a kind of analog/digital has both

The electronic speedometer gauge outfit that a kind of analog/digital of the utility model has both is mainly used in the motor vehicles such as automobile, locomotive of non-flexible axle transmission, also can be used for common meter speed meter device.

Since the early 1990s, a kind ofly drive the electronic speedometer of the pointer indication speed of a motor vehicle in the electro-induction mode, the existing trend that replaces traditional mechanical flexible axle speedometer, and promptly in the car of a new generation, come into operation.This electro-induction formula speedometer generally is made up of speed pickup and indicating instrument two parts.The speed of a motor vehicle is to obtain current signal or vehicle speed pulse signal from the speed pickup that is installed in vehicle transmission part (as wheel box).When automobile travels with the friction speed variation, speed of a motor vehicle speed-transmitter produces different closing of contact frequency signals, the often output of stable trigger circuit control constant current source, change the current value of hot-wire coil in the speedometer point gear, the acting force that hot-wire coil is subjected in the stationary magnetic field changes and changes the deflection angle of speedometer pointer on index dial, realizes that electro-induction drives the pointer indication speed of a motor vehicle.

If above-mentioned electronic vehicle speed list index simulation meter speed is converted to corresponding digital quantity electric signal, utilize speed and time function relation directly in circuit system software, to calculate mileage, save stepper motor and hardware components in having the records of distance by the log, the realization of the speed of a motor vehicle digital display linear function that the dilatation interface, particularly secondary digitizing that very helps this electron-like speedometer is brought.Far and away, this will be the much progress in the existing electronic speedometer meter speed technology.The electronic speedometer gauge outfit that a kind of analog/digital that the utility model proposes has both is for above-mentioned purpose designs.

Utility model is achieved in that it is parent form that the utility model adopts wide-angle magneto-electric reometer.On this basis, further on the flat weighing apparatus Block of magneto-electric electric current gauge outfit, change to add and load onto a photoelectric sensing and pop one's head in the pointer coaxial rotation; In addition, in gauge outfit, the leaded light ring corresponding with speed of a motor vehicle index dial speed of a motor vehicle number (scale numbering), that the surface is printed with regulations and parameters white calibration oblique line bar, also change be installed at the direct projection of photoelectric sensing probe emission luminous energy to the gauge outfit inner peripheral wall on.When vehicle ', the photoelectric sensing probe of equilibrium activity of having held concurrently rotates synchronously with needle pivot and pointer, utilize the photosensitive tube in the photoelectric sensing probe to receive the light pulse signal that leaded light ring reflected light produces, be converted to the identical digital signal of vehicle speed value corresponding amount of indicating with pointer through amplification, shaping, counting, and in charactron or liquid crystal, show the purpose of the electronic speedometer gauge outfit that a kind of analog/digital that realization the utility model proposes has both.

Below in conjunction with accompanying drawing, describe the utility model detail in detail.

Fig. 1 is the utility model structure principle chart; Wherein: Fig. 1 .1 is a hairspring, and 2 is shape of a hoof magnetic conductor, and 3 are the photoelectric sensing probe, and 4 is the leaded light ring, and 5 is balance stem, and 6 is permanent magnet, and 7 is pull spring, and 8 is pointer, and 9 is speed of a motor vehicle index dial, and 10 is needle pivot, and 11 is the light reflection bar, and 12 is moving-coil.

Fig. 2 is vehicle speed pulse input and diagram; Wherein, Fig. 2 .1 is the thin portion of Fig. 1 .3 photoelectric sensing probe intraware, and Fig. 2 .2 is Fig. 1 .4 leaded light ring stretch-out view, and Fig. 2 .3 is the array coding in Fig. 1 .11 light reflection bar.

Fig. 3 is a speed of a motor vehicle digital circuit schematic diagram; Wherein: 1 is photoelectricity vehicle speed pulse sensing circuit, and 2 is single-chip microcomputer speed of a motor vehicle computing circuit, and 3 is speed of a motor vehicle digital display circuit.

Fig. 4 is the second embodiment synoptic diagram; Wherein: 1 is needle pivot, and 2 is the photoelectric sensing probe, and 3 is the light reflection bar, and 4 is the leaded light ring, and 5 is pointer, and 6 is that (surplus parts and Fig. 1's speed of a motor vehicle index dial do not draw among the figure together, slightly).

Among Fig. 1, being wound with that moving-coil (12) that the current-carrying coil of coiling and framework constitute is arranged at needle pivot (10) be a side of turning axle, through the balance stem (5) and the photoelectric sensing of opposite side pop one's head in (3) obtain transient equilibrium.Again among Fig. 1, be enclosed within shape of a hoof magnetic conductor (2) uniform width of cloth under permanent magnet (6) magnetic conduction in the moving-coil (12) and penetrate magnetic field and just act on the moving-coil (12).When moving-coil oil silk (1) and pull spring (7) are made power supply or electric signal output entry loop and are fed electric current in a direction indicated by the arrow, two sides that moving-coil (12) is vertical with shape of a hoof magnetic conductor (2) magnetic field magnetic line produce acting force and make moving-coil (12) clockwise direction deflection, and forming photoelectric sensing probe (3) is that situation is rotated in the axle center synchronously with pointer (8) with needle pivot (10).Like this, when the utility model is worked, also at first accept from the electric current of vehicle speed sensor to the different speed of a motor vehicle variations of the reflection of moving-coil input, under oil silk (9) and pull spring (7) reaction force acts, changing moving-coil (12) deflection dynamics every now and then, thereby correspondingly changing the deflection angle of pointer on speed of a motor vehicle index dial (9), reflect the different vehicle simulation speed of a motor vehicle constantly with pointer (8) indication.This is in the existing technology, and speed of a motor vehicle part is indicated in the simulation of the utility model pointer.

Continuing to describe the utility model in detail with Fig. 1 below simulates the speed of a motor vehicle with pointer and is converted to corresponding digital quantity electric signal method and principle.

At first, should be noted that in Fig. 1 and design and installation of the present utility model, with the photoelectric sensing of needle pivot (10) coaxial rotation probe (3) when the Installation and Debugging, should and pointer (8) in the lump with speed of a motor vehicle index dial (9) demarcation of making zero, when guaranteeing which kind of motion state no matter automobile be in, it is to rotate synchronously on the same vertical plane in axle center that pointer (8) and photoelectric sensing probe (3) all are in needle pivot (10); In addition, first is reflected and demarcates this light reflection spot into " zero " by leaded light ring (4) light signal that sends at photoelectric sensing probe (3), also need and the speed of a motor vehicle index dial demarcation of making zero.Thereby, in Fig. 1, is the speed of a motor vehicle number of unit with the linear segmentation of whole ten scale numberings on the speed of a motor vehicle index dial to " 1 ", adopt the equidistant array of An * 3, Bn * 3+1, Cn * 3+2 isogonism corresponding be provided be coated with the regulations and parameters light reflection bar (white calibration oblique line bar) that is imprinted on the leaded light ring (4) with the relative motion of photoelectric sensing probe (3) in, the light generation conducting pick-off signal that will launch as " cutting " photoelectric sensing probe (3) as a lot of grating.So when automotive ignition also starts to walk to advance, photoelectric sensing probe (3) will constantly receive the light pulse signal that reflects from each row light reflection spot of light reflection bar (11), in the utility model circuit system and single-chip microcomputer, carry out plus-minus counting, resulting moment the numeral vehicle speed value, will be digital corresponding identical with the speed of a motor vehicle of pointer indication on speed of a motor vehicle index dial (9), specific design and method add detailed description again by following Fig. 2.

Among Fig. 2, photoelectric sensing probe (1) is VA-VA ', VB-VB ', and three reflection type optical sensors of VC-VC ' are formed; A ₀, B ₁, C ₂A ₃, B ₄, C ₅A ₁₁₇, B ₁₁₈, C ₁₁₉A ₁₂₀Deng the coding on the light reflection bar (3), (n is 0,1,2,3,4,5 according to aforementioned lights array An * 3, Bn * 3+1, Cn * 3+2 ... 120 ... the subscript number) is provided with, in fact also all be on the leaded light ring (2) one by one with the digital corresponding smooth reflection spot of the speed of a motor vehicle index dial speed of a motor vehicle, wherein, the A on the first thick stick light reflection bar (3) ₀The light reflection spot, corresponding to 0 on the speed of a motor vehicle index dial (kilometer/hour) speed of a motor vehicle number, B ₁Corresponding to the dish on 1 (kilometer/hour) speed of a motor vehicle number, C ₂Corresponding to 2 on the dish (kilometer/hour) speed of a motor vehicle number, the rest may be inferred by analogy to 120 (kilometer/hour) or higher speed of a motor vehicle number, will be that the method mode of row (thick stick) is implemented all according to above-mentioned optical arrays three smooth reflection spots.

Explanation according to Fig. 1, Fig. 2, pulse output that the different speed of a motor vehicle constantly change in the reflection vehicle traveling process and counting are performed such: among Fig. 2, when the automotive ignition starting is travelled, power supply will be switched on, and the light signal that Fig. 2 photoelectric sensing probe (1) sends just in time is radiated at first thick stick light reflection bar (3) A in the leaded light ring (2) ₀(the A place among Fig. 2 on the light reflection spot of coding, also promptly be on the white calibration oblique line bar end of position, clear zone), make the VA-VA ' optical sensor in the photoelectric sensing probe (1) be in conducting state, from VA-VA ' output represent 0 (kilometer/hour) the vehicle speed pulse signal, VB-VB ' and VC-VC ' two optical sensors of this moment do not enter coding B as yet ₁, C ₂Light reflection spot and be in the position, dark space of cut-off state; When vehicle starting travelled, Fig. 2 photoelectric sensing probe (1) was with the deflection of pointer clockwise direction, and the photoelectric sensing probe optical signal is radiated at coding B ₁The light reflection spot on (the B place among Fig. 2), at this moment, VA-VA ' departs from A ₀The clear zone transfers cut-off state to from conducting, and VC-VC ' still is in the position, dark space, also is in cut-off state.Formerly enter B from the dark space ₁VB-VB ' the optical sensor in clear zone receives B ₁After the illumination on the light reflection spot, transfer conducting state immediately to from former cut-off state, from VB-VB ' optical sensor output represent 1 (kilometer/hour) the vehicle speed pulse signal.When instantaneous vehicle speedup to 2 kilometer/hour, the light signal that VC-VC ' sends is radiated at coding C ₂On the light reflection spot (the C place among Fig. 2), at this moment, VA-VA ' keeps the dark space partly, VB-VB ' then just enters the dark space from the clear zone, VA-VA ', VB-VB ' optical sensor all is in cut-off state, the VC-VC ' optical sensor that is in the clear zone conducting state satisfy output represent 2 (kilometer/hour) the vehicle speed pulse signal.So far, the A on the first thick stick light reflection bar ₀, B ₁, C ₂The light reflection spot has been finished the purpose that the speed of a motor vehicle number on the speed of a motor vehicle index dial is converted to corresponding vehicle speed pulse signal, continues to enter the A in Fig. 2 second thick stick light reflection bar ₃, B ₄, C ₅On the light reflection spot coding position, till vehicle stops to quicken, photoelectric sensing probe (1) all with the identical photoelectric conversion mode of the first thick stick light reflection bar (3), again and again from optical sensor VA-VA ' → VB-VB ' → VC-VC ' output one by one with speed of a motor vehicle index dial on the identical vehicle speed pulse signal of the digital corresponding amount of the speed of a motor vehicle, be treated to speed of a motor vehicle digital signal through Fig. 3 circuit accumulated counts again, and on charactron or liquid crystal, show.

But automobile is not to do uniformly accelerated motion in the process of moving always, and single pulse accumulation counting algorithm is to reflect increase and decrease speed motion rapid in the vehicle traveling process.For this reason, the utility model is again by Fig. 2 car deceleration diagrammatic sketch, illustrating that photoelectric sensing probe (1) reverses with pointer exports the vehicle speed pulse signal method from VC-VC ' → VB-VB ' → VA-VA ' opposite direction, for the plus-minus step-by-step counting of Fig. 3 circuit provides the foundation that can differentiate.

Below, be example with Fig. 2 vehicle deceleration, automobile is described in moderating process, the generation of deceleration pulse signal and method.

If car speed is when 120 kilometers/hour drop to 119 kilometers/hour, speed indicator will from speed of a motor vehicle index dial indicate 120 (kilometer/hour) speed of a motor vehicle number reduce to 119 (kilometer/hour) speed of a motor vehicle number on.Because the photoelectric sensing probe under any circumstance all is to rotate synchronously with pointer, at this moment, among Fig. 2, with the corresponding coding A of VA-VA ' optical sensor in the photoelectric sensing probe ₁₂₀The light reflection spot along with the probe leaving away and by C ₁₁₉The light reflection spot enters on the position corresponding with VC-VC ' optical sensor (A to C that arrow indicates among Fig. 2 locates) VA-VA ' and is in cut-off state, thereupon in the other direction by VC-VC ' output one at the mid-vehicle speed pulse signal that is decided to be deceleration of Fig. 3 circuit, do to subtract a computing by counter, calculate with speed of a motor vehicle index dial on pointer indicated 119 (kilometer/hour) vehicle speed pulse number that the speed of a motor vehicle is digital identical; When car speed when 119 kilometers/hour are reduced to 118 kilometers/hour again, the signal of VC-VC ' output ends, by coding B ₁₁₈The light that reflects of light reflection spot make VB-VB ' conducting in the photoelectric sensing probe (1), satisfy and continue output one deceleration pulse signal (C to B that arrow indicates among Fig. 2 locates); When the speed of a motor vehicle drops to 117 kilometers/hour again, also be that VA-VA ' optical sensor is in corresponding with it coding A in the photoelectric sensing probe (1) ₁₁₇The light reflection spot on (B to A that arrow indicates among Fig. 2 locates), VB-VB ' ends, VA-VA ' conducting, the pulse signal of its output continues to do to subtract a computing in Fig. 3 circuit.The above-mentioned vehicle speed pulse signal detection method of successively decreasing is carried under the continuous decline situation in the speed of a motor vehicle, with coding A in Fig. 2 light reflection bar (3) ₁₂₀, C ₁₁₉, B ₁₁₈, A ₁₁₇A ₀The corresponding scanning of light reflection spot and the photoelectric sensing probe crossed, will be always by VA-VA ' ← VB-VB ' ← VC-VC ' opposite direction export (deceleration) pulse signal when automobile is changed into speedup till.Thereby, when automobile in constantly speedup or moderating process, no matter automobile is in any speed or state, according to the above-mentioned design of the utility model, the pulse number by Fig. 2 photoelectric sensing probe (1) output can pass through optical sensor VA-VA ', VB-VB ', plus-minus counting is carried out in the positive designature output of VC-VC ' in Fig. 3 circuit, and the linear speed of a motor vehicle that shows of real-time digital.Detail is described in detail by Fig. 3 .1 photoelectricity vehicle speed pulse sensing circuit, Fig. 3 .2 single-chip microcomputer speed of a motor vehicle computing circuit, Fig. 3 .3 speed of a motor vehicle digital display circuit.

In Fig. 3 .1, VA ', VB ', VC ' are the optical sensor in the photoelectricity vehicle speed pulse sensing circuit, also are the inner photo detector of photoelectric sensing probe (1) among Fig. 2.

When automotive ignition started, the VCC power supply among Fig. 3 .1 provided electric current by the metering function of resistance R 4 to probe internal illumination element VA, VB, VC, makes VA, VB, VC send the light of certain intensity; And photo detector VA ' VB ' VC ' and separately build-out resistor R ₁, R ₂, R ₃Formed the voltage-type photoswitch.When light that certain light-emitting component VA or VB or VC among Fig. 3 .1 send by the light reflection bar in corresponding smooth reflection spot when reflexing to separately photo detector, wherein receive catoptrical photo detector and be in conducting state, do not receive catoptrical photo detector and then be in cut-off state, the photo detector that is switched on makes power supply VCC be applied to resistance R with its coupling ₁, R ₂, R ₃The e that joins ₁, e ₂, e ₃On the point, formation meets the voltage signal of TTL logical one level, and is in the photo detector of cut-off state, with power supply VCC and e ₁, e ₂, e ₃End separates, and is passed through resistance R by power ground ₁, R ₂, R ₃Drag down into the voltage signal of TTL logical zero level, " 0 " or " 1 " logic level signal that the reflection vehicle speed pulse of above-mentioned VA ', VB ', VC ' output is changed passes through P respectively ₁₀, P ₁₁, P ₁₂Three signal input line input Fig. 3 .2 single-chip microcomputer 8748P ₁On the mouth, and with input P ₁The varying level logical value of mouth is carried out plus and minus calculation, can calculate vehicle place speed constantly at any time.

Because during vehicle starting, the speed of a motor vehicle is all from 0 kilometer indicated beginning of speed indicator, so when the automotive ignition speed of a motor vehicle was 0 kilometer/hour, according to the utility model design and Fig. 2, the light signal that optical sensor VA-VA ' sends was by light reflection bar A ₀Coding light reflection spot reflexes on its photo detector VA ', and the VA ' among Fig. 2 .1 is in conducting state, and this moment other two optical sensor VB-VB ', VC-VC ' and B ₁, C ₂Relative position still is in and departs from state, and the light signal that VB, VC send is not by B ₁, C ₂Reflect, photo detector VB ', VC ' are in the cut-off state of no rayed.The VA ' that is in the rayed conducting state is treated to " 1 " logic level in Fig. 3 .1 photoelectricity vehicle speed pulse sensing circuit; And the VB ', the VC ' that are in cut-off state all are treated to " 0 " logic level input Fig. 3 .2 single-chip microcomputer 8748P in Fig. 3 .1 photoelectricity vehicle speed pulse sensing circuit ₁Mouthful, form Fig. 3 .2 single-chip microcomputer 8748P ₁P on the mouth _1.0, P _1.1, P _1.2Three signal wire logical values are P _1.0=" 1 ", P _1.1=" 0 ", P _1.2=" 0 ", thus single-chip microcomputer to draw a speed of a motor vehicle be 0 numerical value, and numerical value is deposited in the inner vehicle speed value storage unit of single-chip microcomputer.

Work as vehicle starting, when the speed of a motor vehicle is increased to 1 kilometer/hour, photoelectric sensing probe upward deflects with the clockwise direction of speed indicator and departs from A0 light reflection spot, B1 light reflection spot in the leaded light ring enters VB-VB ' optical sensor rayed position thereupon, and this moment, C2 did not enter VC-VC ' rayed position as yet, thereby, the cut-off state of photo detector VB ' among the VB-VB ' during from 0 kilometer/hour changed into conducting state, the conducting state of VA-VA ' during by automotive ignition changed into cut-off state, and VC-VC ' does not receive reflected light signal as yet, still be in cut-off state, 8748P among Fig. 3 .2 ₁The logical value of mouth input is P _1.0=" 0 ", P _1.1=" 1 ", P _1.2=" 0 ", single-chip microcomputer then adds 1 with the numerical value in the vehicle speed value memory block 0, and the numerical value 1 that must make new advances is in the vehicle speed value memory block of restoring.

When car speed was increased to 2 kilometers/hour, the photoelectric sensing probe continued clockwise aspect with speed indicator and upward deflects, and forms A ₀, B ₁The light reflection spot departs from VA-VA ', VB-VB ' optical sensor rayed position, and C ₂Enter VC-VC ' rayed position.So the VA ' among Fig. 3 .1 keeps cut-off state, VB ' also is in cut-off state, and VC ' then is a conducting state.Fig. 3 .2 single-chip microcomputer 8748P ₁The logical value of mouth input is P ₁₀=" 0 ", P ₁₁=" 0 ", P ₁₂It is 2 that=" 1 ", single-chip microcomputer continue to add 1 with the numerical value in the vehicle speed value memory block thereupon, in the former vehicle speed value memory block of restoring.So far, optical sensor VA-VA ', VB-VB ', VC-VC ' have finished A in the first thick stick light reflection bar ₀, B ₁, C ₂The detection scanning process of coding.

When car speed was increased to 3 kilometers/hour again, the photoelectric sensing probe had increased the speed unit of " 1 " again with speed indicator, was in the A of this speed unit ₃Coding light reflection spot enters VA-VA ' optical sensor rayed position, at this moment the B in the second thick stick light reflection bar ₄, C ₅Coding light reflection spot still is in and does not enter VB-VB ', VC-VC ' optical sensor rayed position.Fig. 3 .2 single-chip microcomputer is from P ₁Signal input on the mouth has repeated P again _1.0=" 1 ", P _1.1=" 0 ", P _1.2=" 0 " logical value.Single-chip microcomputer continues numerical value with the former storage in vehicle speed value memory block and adds 1 and become and the vehicle speed value identical speed of a motor vehicle numerical value 3 of speed indicator indication on speed of a motor vehicle index dial.In the case, if vehicle continues to advance with the speedup state, optical sensor VA-VA ', VB-VB ', VC-VC ' also will continue from A ₃Coding begins with VA ' → VB ' → VC ' direction, and is continuous repeatedly, again and again from single-chip microcomputer 8748P ₁Mouthful input " 100 ", " 010 ", " 001 " logical value, and in single-chip microcomputer vehicle speed value memory block is till continuous add-one operation is when automobile stops to quicken.

Opposite, when automobile stops to quicken to enter deceleration or lasting deceleration regime, the variation of the light reflection spot relative position in VA-VA ', VB-VB ', VC-VC ' optical sensor and the leaded light ring in the photoelectric sensing probe reverses, first vehicle speed pulse signal of photoelectric sensing probe output during from reverse, the opposite signal of direction makes three signal wire P of Fig. 3 .2 single-chip microcomputer P1 mouth during from Fig. 3 .1VA ', VB ', VC ' output and acceleration ₁₀, P ₁₁, P ₁₂The logical value of input is changed into " 001 ", " 010 ", " 100 " state; Meanwhile, automobile is in moderating process, and the numerical value of single-chip microcomputer vehicle speed value memory block stored will successively do to subtract 1 computing, when automobile stops to slow down till, its result is identical with the vehicle deceleration indicated vehicle speed value that descends with pointer.

According to above-mentioned increase and decrease speed logical value Changing Pattern, same reason is when automobile remains a constant speed when travelling by a certain speed, because the photoelectric sensing probe remains unchanged single-chip microcomputer 8748P with leaded light ring relative position ₁The logical value of input is also constant on the mouth, keeps the numerical value of former vehicle speed value memory block stored.Even change less than 1 in particular cases in the speed of a motor vehicle, because the light reflection bar has at interval between arranging, VA ', the VB ', the VC ' photo detector that occur in the light sensing probe all can not get reflected light and are in cut-off state simultaneously, from single-chip microcomputer 8748P ₁The logical value of input is P on the mouth _1.0=" 0 ", P _1.1=" 0 ", P _1.2=" 0 ", single-chip microcomputer keep the speed of a motor vehicle numerical value of former storage.In other words, when vehicle ', no matter how the speed of a motor vehicle changes, and Fig. 3 .2 single-chip microcomputer need only will be somebody's turn to do constantly from P ₁The logical value memory of mouthful input keeps, and increases, slows down or not speed change state and P according to vehicle ₁Mouthful corresponding Changing Pattern of logical value and software program add 1 or subtract 1 or add 0 continuous computing with former numerical value in the vehicle speed value memory block, can draw all the time and pointer indication identical speed of a motor vehicle numerical value on speed of a motor vehicle index dial.The speed of a motor vehicle numerical value that the drawn Fig. 3 .3 speed of a motor vehicle digital display circuit by Fig. 3 .2 single-chip microcomputer 8748 external units is shown.

Fig. 3 .3 is a speed of a motor vehicle digital display circuit.

Wherein, comprise D ₂In three identical 74LS77 data latches, D ₃In three identical 74LS248 charactron drivers, and three LC5011 charactrons that show usefulness as speed of a motor vehicle numeral.

In Fig. 3 .2 single-chip microcomputer speed of a motor vehicle computing circuit, single-chip microcomputer 8748 passes through P ₁The Different Logic value level signal of mouthful input changes carries out plus and minus calculation, with the speed of a motor vehicle numerical value that calculates at every turn by hundred, ten, individual the D that respectively be transported in Fig. 3 .3 speed of a motor vehicle digital display circuit of data bus (DATA) by speed of a motor vehicle numerical value ₂Three latch 74LS77 latch, and stablize so that numeral shows.Three latch 74LS77 are with the corresponding respectively again D that outputs in Fig. 3 .3 speed of a motor vehicle digital display circuit of video data that locks ₃On three charactron driver 74LS248, every 74LS248 driver drives each only coupled LS5011 light-emitting nixie tube more respectively, and hundred, ten, individual the speed of a motor vehicle numerical value that latch 74LS77 is latched shows.Above-mentioned speed of a motor vehicle numeral show also can be by single-chip microcomputer 8748 data port with speed of a motor vehicle numerical string line output to LCD driver MC145453, speed of a motor vehicle numerical value is shown.In this process, single-chip microcomputer 8748 constantly repeats above-mentioned action, till automobile flameout.

With regard to mileage number word problem, describe the concrete grammar and the principle that realize in detail below.

S=V * T is the Vehicle-Miles of Travel computing formula.In the formula, S is the vehicle ' distance, and V is a Vehicle Speed, and T is the vehicle ' time.According to S=V * T formula, the utility model Fig. 3 .2 single-chip microcomputer 8748 can be easy to calculate the distance travelled of vehicle according to the funtcional relationship of speed and time.

Yet in the vehicle ' process, the speed of a motor vehicle is constantly to change at random, is impossible go to calculate distance travelled in the mode that keeps the same speed of a motor vehicle.But in a very short time period △ t, the speed of vehicle ' then can be a fixed value, thereby in this time period, the mileage section △ S of vehicle ' then is a fixed value.With t in the time the free △ t mileage section △ S addition of being travelled, i.e. S=V1 △ t1+V2 △ t2+V3 △ t3+ ... just can totally draw the mileage value in the T time.△ t1, △ t2, △ t3 in the formula ..., all the △ t time periods are identical and add up to overall travel time T; V1, V2, V3 ... speed of a motor vehicle numerical value when being correspondence each time period △ tn.In the utility model, select time section △ t is set at 10ms, (also can be less than 10ms) greater than 10ms, so, all vehicle speed values 0,1,2,120 kilometers/hour mileage sections of travelling in the time at every 10ms just can precompute, and form one by the ascending tactic vehicle speed mileage section related table of the speed of a motor vehicle, computing formula is △ S=Vn ÷ 3600 ÷ 1000 * 10, and Vn is that the interior vehicle of form is from 0,1,2 ... 120 kilometers/hour pre-set speed of a motor vehicle numerical value (pre-set speed of a motor vehicle numerical value, decide on the speed car demand), Vn ÷ 3600 ÷ 1000 have then become the mileage value that every ms speed of a motor vehicle is travelled, and take advantage of 10ms can draw each mileage segment value △ S in the relation table again.With this vehicle speed mileage section relation table, reinstating special-purpose programming tool such as ALL-07 etc. with the executive routine one of single-chip microcomputer 8748 writes in the eprom memory in 8748 of the single-chip microcomputers in the lump, single-chip microcomputer 8748 just can go to search corresponding mileage segment value according to existing speed of a motor vehicle numerical value at any time, adds up work again and just can draw total distance travelled numerical value.The accumulative total work of total kilometrage can be with above-mentioned mileage formula, that is: S=V1 △ t1+V2 △ t2+V3 △ t3+ ... become Sn=Sn-1+Vn * △ tn, Sn-1 is the summation of the interior distance travelled of all minor time slice △ t before this time period in the formula, and Vn is the speed of a motor vehicle numerical value of vehicle ' in this time period △ t.The every 10ms of single-chip microcomputer 8748 one-period is ceaselessly calculated mileage value Sn; and after each mileage value Sn calculating finishes; it is deposited in the memory block RAM that has power down protection (single-chip microcomputer 8748 in have), so as to calculate next time use and prevent to stop after lose mileage numerical value.Available then and Fig. 3 .3 speed of a motor vehicle numeral shows identical method, respectively one (hundred meters values) behind ten myriabits in the mileage, myriabit, kilobit, hundred, ten, individual position and the radix point latched according to latch with seven numbers of elements, drive seven charactron LC5011 by seven driver 74LS248 again, the mileage that can obtain vehicle ' is handled and Presentation Function, realizes the purpose of the electronic speedometer gauge outfit that a kind of analog/digital of the utility model has both.

Fig. 4 is another embodiment synoptic diagram of the utility model

Among Fig. 4, photoelectric sensing probe (2) is identical with Fig. 1 .3 photoelectric sensing sonde configuration and function, all comprises the reflection type optical sensor of being made up of VA-VA ', VB-VB ', VC-VC ' luminotron and photosensitive tube.Difference is Fig. 4 photoelectric sensing probe (2) with fixed form installing (on table wall position), but not Fig. 1 .3 photoelectric sensing probe is installed on the Ping Heng Block with manner.Also have, in Fig. 4, the regulations and parameters light reflection bar (3) that a lot of white calibration oblique line bar in the leaded light ring (4) constitutes is the same with Fig. 1 .4 leaded light ring, also all be to adopt the not equidistant array An of isogonism * 3, Bn * 3+1, Cn * 3+2 pattern with the speed of a motor vehicle number on the speed of a motor vehicle index dial, indicates and every row one thick stick is coated with and is imprinted on the ring with the contraposition of coding mode.Difference is that leaded light ring (4) is installed on the needle pivot (1) that is rotating among Fig. 4, rather than tool is adorned surely and is attached on the gauge outfit inner peripheral wall.Moreover two embodiment are aspect adjustment makes zero, and its method is also identical.Among Fig. 4 embodiment, the VA-VA ' in the photoelectric sensing probe (2), the A in the leaded light ring (4) ₀Coding, all need with speed of a motor vehicle index dial on the pointer demarcation of making zero.Like this, when automotive ignition starts, the VA-VA ' emission light in Fig. 4 photoelectric sensing probe (2) will be radiated at the A of the first thick stick light reflection bar in the leaded light ring (4) ₀On the coding, and with one of the VA-VA ' output of conducting state from photoelectric sensing probe and pointer indicate on speed of a motor vehicle index dial 0 (kilometer/hour) pulse signal that speed of a motor vehicle number is corresponding.Connect down, along with different velocity variations constantly in the startup of automobile and the driving process, with the synchronous leaded light ring (4) that rotates of pointer (5), with the relative motion of the photoelectric sensing fixedly installed probe (2) in, also will be by the described speed of a motor vehicle state of Fig. 1 Fig. 2 first embodiment, end mode from VA-VA ' with conducting, VB-VB ', in VC-VC ' optical sensor, output is gone up digital corresponding identical acceleration of the indicated speed of a motor vehicle of pointer (5) or deceleration pulse signal with speed of a motor vehicle index dial (6) one by one, in the identical circuit system of Fig. 3, carry out plus-minus counting, and show (detail and first embodiment with, slightly) with digital form

At last, the described reflection-type photoelectric sensing probe of the utility model two embodiment also can adopt transmission-type photoelectric sensing probe to implement.Specific practice is with VA, VB, VC luminotron and VA ', VB ' in the probe, VC ' photosensitive tube separates from the leaded light ring with the gate-type unitized construction outer inboard.If this is coated with the white calibration oblique line bar of seal in leaded light ring, i.e. the light reflection bar printing opacity of then should slotting.

Illustrate: 1, the signal of the utility model first embodiment photoelectric sensing probe is exported into wiring, and it is complete to adopt the insulating sleeve mode to weave, and is enclosed within on the pull spring.(drawing does not draw, slightly)

2, the utility model single-chip microcomputer and TTL integrated circuit chip are not limited by Fig. 3 .3 sign model, can select identical function single-chip microcomputer and integrated circuit chip for use yet.

3, Fig. 2 diagram and coding are mainly the principle design explanation and conveniently show.When concrete calibration is made, because of 0-15 (kilometer/hour) the low regime deflection angle is narrow and small, can consider that non-linear simplification coding distributes, and do not influence vehicle meter speed precision and overall situation.

Claims (8)

1, a kind of electronic speedometer gauge outfit of not having the flexible axle transmission has magneto-electric reometer structure, also has photoelectric sensing probe, leaded light ring, single-chip microcomputer and circuit, it is characterized in that:

-have the photoelectric sensing assembly of exporting positive and negative pulse signal with the car speed increase and decrease, be satisfied with in the electronic speedometer gauge outfit;

-comprise the counting display circuit of speed and mileage, with the output line interface of a photoelectric sensing probe that constitutes by a plurality of luminotrons and photosensitive tube.

2, according to the described electronic speedometer gauge outfit of claim 1, it is characterized in that described photoelectric sensing probe is made up of three luminotrons and three photosensitive tubes respectively, be satisfied with on the counterbalance weight position of gauge outfit inside.

3, according to the described electronic speedometer gauge outfit of claim 1, it is characterized in that described one has the leaded light ring of multiple spot reflected light signal, dress is affixed on the gauge outfit inner peripheral wall.

4, according to the described electronic speedometer gauge outfit of claim 3, it is characterized in that the regulations and parameters light reflection bar on the described leaded light ring, be to paste or print by chequered with black and white oblique line bar dress.

5, a kind of electronic speedometer gauge outfit of not having the flexible axle transmission has magneto-electric reometer structure, also has photoelectric sensing probe, leaded light ring, single-chip microcomputer and circuit, it is characterized in that:

-have the photoelectric sensing assembly of exporting positive and negative pulse signal with the car speed increase and decrease, be satisfied with in the electronic vehicle speed table gauge outfit.

-comprise the output line interface of the photoelectric sensing probe that the counting display circuit of speed and mileage and are made of a plurality of luminotrons and photosensitive tube.

6, according to the described electronic speedometer gauge outfit of claim 5, it is characterized in that described one has the leaded light ring of multiple spot reflected light signal, also can be positioned on the needle pivot of indicator structure.

7,, it is characterized in that described photoelectric sensing probe also can be positioned on the gauge outfit inwall, and fixedly be positioned on the corresponding position of making zero with pointer according to the described electronic speedometer gauge outfit of claim 5.

8, according to the described electronic speedometer gauge outfit of claim 6, it is characterized in that the regulations and parameters light reflection bar on the described leaded light ring, be on pasting or print by chequered with black and white oblique line bar dress.

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