SU684319A1 - Electronic conveyer-tyre weighing apparatus - Google Patents

Description

one

The invention relates to the field of weighing technology.

Conveyor scales are known that contain two or more roller supports associated with weight sensors connected to a signal processing unit and a recording device Ll, L2.

Also known are conveyor scales, which contain a weight sensor and a speed sensor, connected to an enabling unit, the output of which is connected to a 3J counter.

The closest in technical dryness to the invention are belt scales, containing two load-receiving roller supports with frequency weight sensors connected to an adder, a speed sensor, a digital integrator, a total counter, and a pulse generator t4J.

The known device does not have the required reliability due to the complexity of the adder and its exposure to interference.

The purpose of the invention is to improve the reliability and simplify the electronic belt scales.

In the proposed conveyor scales, this is achieved by the fact that the adder

made in the form of two pairs of D-flip-flops and an NAND circuit, the frequency sensors of the weight connected to the D-inputs of the first pair of D-flip-flops, the C-inputs of which are connected respectively to the direct and inverse outputs of the push-pull pulse generator, and the single outputs of this pairs of D-flip-flops are connected to the input of a push-pull pulse generator, while the single outputs of the second pair of) -triggers are connected to the inputs of NAND.

The drawing shows the block diagram of the described scales.

five

The balance contains two single-roller supports 1.2, each of which transmits the load to one of the frequency sensors of weight 3.4, a pulse sensor

0 speed 5, adder 6, two pairs of D-flip-flops 7.8 and 9.10, AND 11 scheme, digital integrator 12, push-pull pulse generator 13 and total counter 14.

five

The two-stroke pulse generator includes a trigger 15 and a pulse source 16.

Work electronic belt scales as follows.

0 When there is no load on the conveyor belt, the weight sensors 3.4 generate voltages with initial frequencies. These frequencies are summed by an adder and the recording signal is fed to a digital integrator 12, where the initial frequency is compensated in such a way that the final counter 14 1 MPs are not received. When the load moves through the weight-measuring section, the frequency of the weight sensors .3.4 increases, and the frequency signal proportional to the linear mass, gr, is supplied to the sum of the torb b. Af, / t) .Kp .., ftn () - Xp ,, - K pj-Vjt-v), where Af-,, Af., Is the frequency increment of the first and second weight sensors; (rf are the coefficients of conversion of force to the frequency of the first and second weight sensors; H are the coefficients of conversion of the linear load mass due to the weight sensors; cjjj is the linear weight of the load; K is the distance between the rollers of the weighing platforms, V is the speed t - time. After summing up the frequency components lf / Afv2 multiplied by a signal proportional to the velocity (K, V), integration is performed and the total counter is received in the number, where KU is the proportionality factor of the digital integrator 12; T is the weighting time, or taking into account the values of Af (t) and Affti (t) N-K, Kp, (- t) vWdt.VpfДpXrf | Wv The integral in the first term is equal to the mass of the load M, which passed through the first roller bearing 1l for the time T and the integral in the second component - the mass of the cargo M, passed through the roller bearing 2. During the beginning and at the end of the weighing period, there was a load, then, and the number of pulses is equal to: NX, K, f (K, p, Kpf; K p / pf,) M XMM From the last expression it can be seen that in the described weights a platform with different conversion factors K can be used and weight sensors with different conversion factors Kp,, and this does not introduce a methodical load. shnosti. The summation of the frequency signal with the adder b is as follows. The rectangular pulses from the weight sensors 3.4 are fed to the O inputs of the flip-flops 7 and 8. The C-inputs of these triggers are fed by the rectangular pulses from the output of the flip-flop 15. At the instants of the arrival of the pulses, the triggers 7 and 8 switch to from the potential level at the D input. Since C input 7 is connected to the direct one, and trigger 8 to the inverse output of trigger 15, the pulse fronts at these inputs do not coincide in time (they are shifted in phase by half a period). For this reason, the information from the T-inputs cannot be recorded in triggers 7 and 8 at the same time. The smallest time shift is a half-cycle clock frequency. When a trigger 7 (or 8) is set to i, the trigger 9 (or 10) is written O, since the D inputs of the trigger 9 and 10 have a zero potential. The installation of flip-flops 9, 10V is not hampered by the potential at the S-inputs, since at the moments corresponding to the fronts of the pulses at the C-inputs, the potential at the S-inputs has already taken the value corresponding to. a half-period, the voltage at the output of the push-pull generator 13 will take the value corresponding to O. At the same time, one of the flip-flops 9 or 10, which was set to O, will again go into one state. Thus, negative (fixed below level 1} rectangular pulses at the outputs of the flip-flops 9 and 10 are formed. The duration of these pulses is the half-cycle of the pulse of the generator 13. The AND-NE circuit 11 performs the function of the disjunctor for the received pulses, since the number of pulses at the output of this circuit equal to the sum of the number of pulses of the NCT inputs of the trigger 7 and 8, and, therefore, the circuit IS-NOT 11 performs the function of the adder frequency signals. The adder b has a high noise immunity, since the signal of the weight sensors is fed to aticheskie informatsionnyeD -Log triggers 7,8fa not dynamic inputs, as is known in summing schemes. Thus any interference amplitude, e nakladyvayuschies on the pulse,