CN205620011U - Piezoelectric vehicle dynamic weighing sensor - Google Patents

Abstract

The utility model discloses a piezoelectric vehicle dynamic weighing sensor, include: the elastomer, transversal personally submitting " worker " word roof beam shape, including parallel arrangement's upper and lower end plate and connect and be provided with closed chamber along length direction in the connecting portion between the upper and lower end plate, connecting portion, the upper end passes the power piece and passes the power piece with the lower extreme, links from top to bottom to install vertically bottom the closed chamber inner wall and between the top after as an organic whole, FPC is fixed in the upper end passes the power piece and the lower extreme passes the junction between the power piece, piezoceramics, along length direction evenly distributed in FPC is last to pass through FPC circuit parallel connection. The utility model discloses a solving present piezoelectric vehicle dynamic weighing sensor, to weigh sensing element easy in uneven damaged, loaded down with trivial details, the high scheduling problem of cost of labor of preparation of atress, uses FPC to in the FPC that will weld the sensing element that weighs arranges the recess in, make that to weigh the sensing element atress more evenly more difficult damaged, the manufacture craft is very simplified.

Description

A kind of piezoelectric type dynamic weighing sensor for vehicle

Technical field

This utility model relates to a kind of piezoelectric type dynamic weighing sensor for vehicle, specifically a kind of piezoelectric type dynamic weighing sensor for vehicle being easily assembled to using flexible PCB (FPC) transmission piezoelectric signal.

Background technology

Along with the fast development with transport service that gradually forms of China's freeway net, vehicle overload overloading increasingly sharpens, and vehicle overload overloads and brings tremendous influence to highway in China construction, traffic safety and overall economic efficiency.And set up effective vehicle dynamic weighing system and in the case of not affecting wagon flow, possible overweight vehicle can be carried out early warning, then to being precisely weighed by early warning vehicle, thus vehicle overload overloading can be exercised supervision.In recent years, Vehicle weigh-in-motion technology is all studied by many countries, and has the application of some reality.

In existing piezoelectric type Vehicle weigh-in-motion technology, sensing element of weighing (piezoelectric ceramics or quartz) in sensor directly bears the cyclical impact loading transmitted by force-transmitting block, in long pressurized process, sensing element of weighing may be damaged due to unbalance stress.Additionally, weigh, sensing element transmits piezoelectric signal by welding lead, and wire is laid loaded down with trivial details, and cost of labor is higher.A kind of piezoelectric type dynamic weighing sensor for vehicle involved by this utility model patent, can preferably solve the problems referred to above, provides for highway overweight vehicle early warning and ensures reliably.

Utility model content

The purpose of this utility model is to overcome the deficiencies in the prior art, designs one and weighs sensing element reasonable stress thus durability degree is higher, and processing technology is simple, the dynamic weighing device for vehicle that cost of labor is little.

For achieving the above object, the technical solution of the utility model is as follows:

A kind of piezoelectric type dynamic weighing sensor for vehicle, including:

Elastomer, cross section, in " work " word beam shape, including the connecting portion between the upper and lower end plate be arrangeding in parallel and connection and described upper and lower end plate, is provided with airtight chamber along its length in described connecting portion；

Upper end force-transmitting block and lower end force-transmitting block, be vertically mounted to after being connected as a single entity up and down bottom described airtight chamber inwall and between top；

FPC, is fixed on the junction between described upper end force-transmitting block and lower end force-transmitting block；

Piezoelectric ceramics, is uniformly distributed on described FPC along its length, and realizes circuit in parallel connection by FPC.

Further, described lower end force-transmitting block is provided with groove for accommodating FPC and piezoelectric ceramics along its length.

Further, described depth of groove is more than FPC and piezoelectric ceramic thickness sum.

Further, it is provided with in described groove for upper end force-transmitting block and the epoxy resin of lower end force-transmitting block of boning, plays connection, seal and cushioning effect.

Further, described FPC is spaced 20～30mm and is provided with the solder joint for welding with piezoelectric ceramics circuit, after all of solder joint circuit in parallel, connect external circuit by terminals.

Further, described piezoelectric ceramics is diameter 5～10mm, the cylinder of thickness 0.4～0.6mm, and its positive and negative electrode is arranged on the same face, and draws positive and negative polarities with the copper sheet being pasted onto on electrode, it is ensured that piezoelectric ceramics uniform force.

Further, being provided with the elastomer lower recess for installing lower end force-transmitting block bottom described airtight chamber inwall along its length, top is provided with the elastomer upper grooves for installing upper end force-transmitting block 3 along its length.

Further, the upper surface of described elastomer is evenly distributed with the screw hole that spacing is 40～50mm along its length, is provided with the screw unit for compressing upper end force-transmitting block in described screw hole.

Further, a length of the 800～1000mm of described elastomer.

Further, the shape of cross section of described airtight chamber is circular or oval.

Compared to existing technology, the advantage of this utility model device is:

1. the load of force-transmitting block does not act directly on and weighs on sensing element, sensing element uniform force of weighing under Impact Load, can be well protected, survivable, improves the service life of sensing element of weighing.

2. replace traditional wire, to simplify the processing technology of sensor with FPC.

Accompanying drawing explanation

Fig. 1 is the cross sectional representation of this utility model embodiment.

Fig. 2 is enlarged diagram at A in Fig. 1.

Fig. 3 is the schematic top plan view of this utility model embodiment.

Fig. 4 is FPC and the piezoelectric ceramics position schematic diagram in the force-transmitting block groove of lower end of this utility model embodiment.

Fig. 5 is the piezoceramic structures schematic diagram of this utility model embodiment.

Fig. 6 is that this utility model embodiment is in bicycle road installation site schematic top plan view.

Fig. 7 is that this utility model embodiment is in bicycle road installation site cross-sectional schematic.

Fig. 8 is the signals collecting schematic diagram of this utility model embodiment.

In figure: 1 elastomer；1-1 elastomer lower recess；1-2 elastomer upper grooves；2 lower end force-transmitting blocks；3 upper end force-transmitting blocks；4 screw unit；5——FPC；5-1 solder joint；5-2 circuit；5-3 terminals；6 piezoelectric ceramics；7 epoxy resin；8 dynamic weighing sensors；9 driving tire footprint；10 direction of traffics；11 tires；12 charge amplifiers；13 data collecting systems.

Detailed description of the invention

Being described in further detail the purpose of this utility model below by specific embodiment, embodiment can not repeat one by one at this, but the most therefore embodiment of the present utility model is defined in following example.

As it is shown in figure 1, a kind of piezoelectric type dynamic weighing sensor for vehicle, including elastomer 1, lower end force-transmitting block 2, upper end force-transmitting block 3, screw unit 4, FPC5, piezoelectric ceramics 6, epoxy resin 7.

A length of 800～1000mm (ensureing that its length is more than any vehicle tyre width) of described elastomer 1, cross section is in " work " word beam shape, including the connecting portion between the upper and lower end plate be arrangeding in parallel and connection and described upper and lower end plate, being provided with shape of cross section in described connecting portion along its length is circular or oval airtight chamber, and the present embodiment is circular.Being provided with the elastomer lower recess 1-1 for installing lower end force-transmitting block 2 bottom described airtight chamber inwall along its length, top is provided with elastomer upper grooves 1-2 for installing upper end force-transmitting block 3 along its length.

As shown in Figure 2, described lower end force-transmitting block 2 is isometric with upper end force-transmitting block 3 and elastomer 1, simultaneously, it is provided with for accommodating FPC5 and the groove of piezoelectric ceramics 6 on lower end force-transmitting block 2 along its length, described depth of groove is 0.8～1mm, more than FPC5 and piezoelectric ceramics 6 thickness sum, described upper end force-transmitting block 3 and lower end force-transmitting block about 2 are vertically mounted to after being connected as a single entity between elastomer lower recess 1-1 and elastomer upper grooves 1-2 of described airtight chamber inwall.

The epoxy resin 7 for bond upper end force-transmitting block 3 and lower end force-transmitting block 2 it is provided with in described groove.

Described FPC5 is fixed on the junction between described upper end force-transmitting block and lower end force-transmitting block, width 20mm, and length is more slightly longer than lower end force-transmitting block 2.Described piezoelectric ceramics 6 is uniformly distributed on described FPC5 along its length, described FPC5 is spaced 20～30mm and is provided with the solder joint 5-1 for welding with piezoelectric ceramics 6 circuit, connect external circuit by terminals 5-3 after all of solder joint 5-1 circuit 5-2 parallel connection.

As it is shown in figure 5, described piezoelectric ceramics 6 is diameter 5～10mm, the cylinder of thickness 0.4～0.6mm, its positive and negative electrode is arranged on the same face, and draws positive and negative polarities with the copper sheet being pasted onto on electrode.

As shown in figures 1 and 3, the upper surface of described elastomer 1 is evenly distributed with the screw hole that spacing is 50mm along its length, is provided with the screw unit 4 for compressing upper end force-transmitting block (3) in described screw hole.

As shown in Figure 4, the assembling process of the present embodiment includes as follows:

FPC5 AB glue and is reserved terminals 5-3 in lower end force-transmitting block 2 groove；After AB glue produces some strength, piezoelectric ceramics 6 is pasted onto position suitable near the solder joint 5-1 of FPC5, enables the positive and negative copper plate electrode on piezoelectric ceramics 6 to weld with solder joint 5-1；In full for epoxy resin 4 groove being coated in lower end force-transmitting block 2, passing through epoxy resin 7 bonding by upper end force-transmitting block 3 and lower end force-transmitting block 2 is an entirety；After epoxy resin 7 hardens, the lower end force-transmitting block 2 bonded together and upper end force-transmitting block 3 are placed in elastomer lower recess 1-1 and elastomer upper grooves 1-2 of inwall in the cavity of elastomer 1；Again the screw unit 4 being stained with screw glue it is screwed in the screw hole of elastomer 1 and compresses upper end force-transmitting block 3, making piezoelectric ceramics 6 produce certain pretightning force；Finally, the terminals 5-3 of FPC5 is connected with data collecting system wire.

As shown in Figure 6 to 8, in use, the vertical direction of traffic of dynamic weighing sensor 8 that the present embodiment provides is embedded under driving tire footprint 9 road surface of one side, when the tire 11 of driving vehicle is by dynamic weighing sensor 8, wheel load is delivered on dynamic weighing sensor 8 by top course, i.e. pressure on vehicle tyre acts on dynamic weighing sensor 8 and transfers force to lower end force-transmitting block 2 and upper end force-transmitting block 3 by screw unit 4, and force-transmitting block produces strain；When the piezoelectric ceramics 6 in dynamic weighing sensor 8 is by external impetus load action, according to direct piezoelectric effect, piezoelectric ceramics 6 upper and lower surface of thickness deformation pattern can produce equivalent and the most contrary electric charge, the quantity of electric charge is directly proportional to external force, by the circuit 5-2 on FPC5, this electric charge is converted into voltage signal by charge amplifier 12 by terminals 5-3, finally by data collecting system 13, load signals collecting is stored, the relation that dynamic weighing sensor 8 exports between wheel load is set up by scene test, determine the sensitivity coefficient of dynamic weighing sensor 8 load, so that it is determined that all wheel loads in the one side of vehicle in Hang Shiing, it is believed that vehicle both sides all wheels weight sum is equal, unilateral all wheel loads are multiplied by 2 and are each wheel load sum, and then obtain complete vehicle weight, realize dynamic weighing.Concrete car weight computational methods are as follows:

$W_{gross}=2\∫\∫{\mathrm{\σ}}_{ij}dxdy=2\underset{j=1}{\overset{n}{\Σ}}\underset{i=1}{\overset{m}{\Σ}}\∫{\mathrm{\σ}}_{ij}dx=\frac{2V}{S}\underset{j=1}{\overset{n}{\Σ}}\underset{i=1}{\overset{m}{\Σ}}\∫Q_{ij}dt---\left(1\right)$

Wherein, W_grossRepresenting car weight, V represents speed；σ_ijRepresenting when jth tire passes through, the stress that i-th piezoelectric ceramics records, the quantity of electric charge of corresponding piezoelectric ceramics output is Q_ij；M represents the quantity of all dynamic weighing sensors of pressurized under wheel, and n represents all wheel count of vehicle side；S represents the sensitivity coefficient of dynamic weighing sensor, i.e. the output charge amount of piezoelectric ceramics during unitstress effect, can be obtained by scene test.IfU represents the nominal output voltage value of dynamic weighing sensor after charge amplifier, and k is electric charge amplification coefficient, then car weight can be expressed as

$W_{gross}=\frac{2V}{S}U---\left(2\right)$

Wherein, speed can be easy to be obtained by traditional measurement means, and the sensitivity coefficient of dynamic weighing sensor does not changes with the change of speed, if the sensitivity coefficient of dynamic weighing sensor isFormula (2) can be write as

W_gross=kU (3)

By formula (3), can directly calculate car weight.

Above example is only in order to illustrate that the technical solution of the utility model is not intended to limit.For a person skilled in the art, this utility model can have various change.All within spirit of the present utility model and principle, any amendment of being made utility model, equivalent etc., within should be included in protection domain of the present utility model.

Claims (10)

1. a piezoelectric type dynamic weighing sensor for vehicle, it is characterised in that including:

Elastomer (1), cross section is in " work " word beam shape, including the upper and lower end be arrangeding in parallel Connecting portion between plate and connection and described upper and lower end plate, in described connecting portion along its length It is provided with airtight chamber；

Upper end force-transmitting block (3) and lower end force-transmitting block (2), pacify after being connected as a single entity up and down vertically It is contained in bottom described airtight chamber inwall and between top；

FPC (5), is fixed on the junction between described upper end force-transmitting block and lower end force-transmitting block；

Piezoelectric ceramics (6), is uniformly distributed in along its length on described FPC (5), and leads to Cross FPC (5) and realize circuit in parallel connection.

Piezoelectric type dynamic weighing sensor for vehicle the most according to claim 1, its feature It is: be provided with along its length for accommodating FPC (5) on described lower end force-transmitting block (2) Groove with piezoelectric ceramics (6).

Piezoelectric type dynamic weighing sensor for vehicle the most according to claim 2, its feature It is: described depth of groove is more than FPC (5) and piezoelectric ceramics (6) thickness sum.

4., according to the piezoelectric type dynamic weighing sensor for vehicle described in claim 2, its feature exists In: it is provided with in described groove for upper end force-transmitting block (3) and the lower end force-transmitting block (2) of boning Epoxy resin (7).

5., according to the piezoelectric type dynamic weighing sensor for vehicle described in claim 1, its feature exists Be provided with in the upper interval 20～30mm of: described FPC (5) for piezoelectric ceramics (6) circuit Welding solder joint (5-1), all of solder joint (5-1) with after circuit (5-2) parallel connection pass through connect Line end (5-3) connects external circuit.

6., according to the piezoelectric type dynamic weighing sensor for vehicle described in claim 1, its feature exists In: described piezoelectric ceramics (6) is diameter 5～10mm, the cylinder of thickness 0.4～0.6mm, Its positive and negative electrode is arranged on the same face, and draws positive and negative two with the copper sheet being pasted onto on electrode Pole.

7., according to the piezoelectric type dynamic weighing sensor for vehicle described in claim 1, its feature exists In: it is provided with along its length bottom described airtight chamber inwall for installing lower end force-transmitting block (2) Elastomer lower recess (1-1), top is provided with along its length for installing upper end power transmission The elastomer upper grooves (1-2) of block (3).

8., according to the piezoelectric type dynamic weighing sensor for vehicle described in claim 1 or 7, it is special Levy and be: the upper surface of described elastomer (1) is evenly distributed with spacing along its length and is The screw hole of 40～50mm, is provided with in described screw hole for compressing upper end force-transmitting block (3) Screw unit (4).

9., according to the piezoelectric type dynamic weighing sensor for vehicle described in claim 1, its feature exists In: a length of the 800～1000mm of described elastomer (1).

10., according to the piezoelectric type dynamic weighing sensor for vehicle described in claim 1, its feature exists In: the shape of cross section of described airtight chamber is circular or oval.