SU1138674A2 - Device for measuring average indicated pressure in piston machine cylinders - Google Patents

Abstract

DEVICE FOR MEASURING MEDIUM INDICATOR PRESSURE IN CYLINDERS OF PISTON MACHINES on auth.St. No. 757891.0 tons of flow, in order to increase the accuracy of measurement and enhance the functionality by ensuring the measurement of the average indicator pressure is divided into the working cycles and pump strokes in several engine cylinders, additional pressure transducers by the number of cylinders, channel switch, dual mode switch, threshold amplifier, second integrator, measurement switch, electronic switch, with fixed contacts and The channel switch is connected to the pressure transducer outputs, and the moving contact is to the moving contact of the first direction of the operating mode switch, the first fixed contact of this switch is connected to the input of the amplifier amplifier signal, and the second to the threshold amplifier, the output of which is connected to the second fixed contact the second direction of the operating mode switch, the first contact of which is connected to the output of the signal amplifier of the pressure transducers, and fixed from the first the input of the computational unit, with the output of the scale of the amplifier through two series-connected closing contacts of the relay of the control unit and the electronic switch connected in parallel to the inputs of two integrating links, the outputs of which are connected to the fixed contacts of the measurement switch, the moving contact of which is connected to the recording device, CO 00 At this, the control input of the electronic switch is connected to the output of the pulse former.

Description

1 The invention relates to a measurement technique, in particular, to devices for determining the value of the average indicator pressure in the cylinders of piston machines. According to the main author. St. No. 75789, a device for measuring the average indicator pressure in cylinders of piston machines is known, which contains a computational bpock, one input of which is connected to a crankshaft angle transducer and another through an amplifier connected to a pressure transducer in the cylinder, an integrating element, the output of which is connected to a registering device the amplifier and the control unit, consisting of a pulse generator, an And element, a pulse counter, an indicator — a measurement window, a stop trigger, and a control separate inputs of the counting trigger, stop relay, control relay, switch and bus Reset, the input of the scale amplifier is connected to the output of the computing unit, and the output of the scale amplifier via two sequentially connected 1-1 contacts of the control relay and the stop relay are connected to the input of the integrating link; which is connected to the input through the disconnecting contacts of the control relay, while the angle-of-rotation converter of the knee shaft is made in the form of consecutively sinus-cosine rotary transformer and demodulator, and its output through the disconnecting contacts of the switch is connected to the input of the pulse former, the output of which is connected to one input of the element AND, and the output of the element AND connected to the input of the pulse counter, the installation input of which is connected to the installation single input of the counting trigger, with single inputs of triggers, stop and control, and through the closing contacts of the switch with the reset bus, and the output of the impulse counter is connected to the zero input of the stop trigger, zero in the stroke of which is connected to the indicator of the end of measurements, and a single output to the stop relay and to another input of the And element, while the zero output of the control trigger is connected to the third input of the And element and to the control relay, and the zero input is connected to the pulse output of the counting trigger, the counting input of which is connected to the output of the pulse former t. A disadvantage of the known device is that it is intended to indicate only one of the cylinders in one operation mode and measure the average indicator value This pressure produces | s without separating the working cycles and pumping strokes of the engine. In addition, the accuracy of measuring the average indicator pressure with this device depends on the accuracy of setting the top dead center of the piston in the engine cylinder, which is carried out using other, more coarse methods. The purpose of the invention is to improve the accuracy of measurement of the average indicator pressure in the cylinders of piston machines and expansion the functionality of the device by providing the ability to measure the average indicator pressure separately for duty cycles and pump strokes B a few cylinder The aim is achieved by adding additional pressure transducers for the number of cylinders, channel switch, dual mode switch, threshold amplifier, second integrator, measurement switch, electronic switch, and fixed contacts to a device for measuring the average indicator pressure in the cylinders of piston machines. the channel switches are connected to the outputs of the pressure transducers, and the moving contact to the moving contacts of the first direction the operating mode switch, the first fixed contact of this switch is connected to the input of the amplifier of the pressure transducer signals, and the second to the threshold amplifier, the output of which is connected to the second fixed contact of the second direction of the working mode switch, the first contact of which is connected to the output of the amplifier of the pressure transducer signals, and fixed - with the first input of the computing unit, while the output of the scale amplifier through

3

Two successively connected contactors of the control unit relay and an electronic switch are connected in parallel to the inputs of two integrating links, the outputs of which are connected to fixed contacts of the measurement switch, the moving contact of which is connected to the recording device, and the control input of the electronic switch is connected to the output of the electronic switch : pulse puller

The drawing shows the functional diagram of the device.

The device contains pressure transducers 1 in the cylinders of the Gcanal engines into an electrical signal, an amplifier 2, a crankshaft rotation angle converter 3. made in the form of serially connected sine-cosine rotary transformer 4 and demodulator 5, a computing unit 6, a large-scale amplifier 7, two integrating link 8, the recording device 9, the control unit, which includes the driver 10 pulses, the element And And, the counter 12 pulses, trigger 13.antova with separate inputs, the indicator 14 is completed and measurement, a stop relay 15 with closing contacts 6, a control relay 17 with a closing 18 and 1 with 19 contacts, a control trigger 20 with separate inputs, a counting trigger 21, a switch 22, a reset bus 23, a switch 24 of information from channel cylinders ), a bi-directional operation mode switch 25A, 25B, and a threshold amplifier 26 for providing the top dead center setting of the piston; an electronic switch 27 made according to a key scheme and intended for connecting one or the other; its link according to the clock cycle engine operation, the switch 28 measurements.

The device works as follows.

In the position § of the operation mode switch 25A, 25B, one of the inputs of the computing unit 6 receives an electrical signal proportional to the pressure in that engine cylinder, to the pressure transducer of which, the switch 24 channels connect amplifier 2, and the other

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The input of the computing unit 6 receives an electrical signal proportional to the angle of rotation of the engine crankshaft.

, Computing unit 6 calculates a non-linear relationship between the volume of the engine cylinder and the angle of rotation of the crankshaft.

Itc fi

Jjr / t /

 ((-cosuiV --- (l-cosflbV-, 44 with j

where Y is the effective volume of the engine cylinder J

About the diameter of the engine cylinder,

R - crank radius}

oi - crank angle

Banaj

o is the length of the connecting rod; 1 is the angle of deviation of the axis of the connecting rod 0 from the axis of the cylinder;

Vj is the volume of the compression chamber, and calculates the function.

t n

rPtir

5 where P is the effective pressure in

the cylinder of the engine. I

With an increase in the accuracy of measuring the average indicator pressure, it averages the tl cycles of the engine, for which the output of the computing unit 6 is connected to a May-head amplifier 7 with a transfer ratio of 1 / L.

The output signal of the integrating 5 links 8 is equal to the average indicator pressure for the n cycles of the engine

Pr-rrlMv,

40 where Vf, is the working volume of the cylinder.

The signal corresponding to the value of P is fed through the measurement switch 28 to the register 9 of the device 9.

5 For the synchronous start of the integrating links and the beginning of the calculation of engine cycles, to stop the flow of an electrical signal to the input of the integrating iO link through the steps of the engine j to separate the operating cycles and pumping strokes, the device is equipped with a control unit,

 The control unit works as follows.

Before starting the measurements, set the switch 22 to. Reset, the operator sends a signal from the bus Reset 23 to the corresponding inputs of the flip-flops 13, 20, 21 and the bits of the counter 12, driving them to their initial state. After that, the trigger 13 triggers a signal to the stop relay 15 and it is activated, closing the closing contacts 16 and thereby preparing an electrical signal to the inputs of the integrating links 8. At the same time, the signal from the 1.3 trigger arrives at the input of the element 11, preparing it to the passage of pulses from the imaging unit 10, the integrating links 8 at this time are in a blocked state, since the feedback is short-circuited by contacts 19, resulting in a signal coming to the recording device 9, equal to en zero. When the Reset signal is given, the device is in the initial state. Starting measurement is P-, the operator sets the switch 22 to the position. Start and signals convert the bodies of the angle of rotation of the crankshaft 3, converted by the shaper 10 into pulses, corresponding to the rotation of the crankshaft from O to 180, arrive at the input of the circuit 11, to the counting input of the trigger 21 and to the control input of the switch 27. After the next pulse arrives from the driver 10, the counting trigger 21 issues a Transfer signal, which overturns the control trigger 20 and a signal arrives at the control relay 17. Relay 17 is activated, closing contacts 18 and opening contacts 19, after which the electrical signal from computing unit 6 through scale amplifier 7 and commutator 27 is fed to the input of unlocked integrating links 8. At the same time, the signal from trigger 2 arrives at H 11, allowing the pulses to pass from the generator 10 to the input of the counter 12. The input to the control input of the switch 27, the signals of the generator of 10 pulses, corresponding to the working cycles and pumping strokes, connect the input of the switch 27 to one or the other The link 8, This pattern on one of the integrating links 8 in the process of measurement accumulates information corresponding to the operating cycles of the engine, and on the other - information corresponding to its pumping strokes. The number of bits of the counter 12 pulses is determined by the number of clock cycles P of the engine, for which P is measured. After a 12C-TH pulse arrives at the counter, it generates an Overflow signal and overturns the flush trigger 13. The stop relay 15 is de-energized and the contacts 16 are opened, stopping the further flow of an electrical signal to the inputs of the integrating links 8. At the same time, one of the signals at the input of the And 11 element disappears, stopping the flow of pulses to the input of the counter 12. In addition, the indicator 14 of the end of measurement triggers, signaling readability. Connecting the recording device 9 through the measurement switch 28 to the outputs of the integrating links 8, the operator reads the indications corresponding to the average indicator pressure of the operating cycles and pump strokes of the engine. After the end of the reading, the operator sets the switch 22 to the Reset position, giving the Reset signal to the corresponding elements and brings it back to its original state. If it is necessary to make an accurate setting of the top dead center of the engine, the mode switch 25A, 25B is set to position a and a signal proportional to the pressure in the engine cylinder into which the fuel supply is stopped enters the input of the threshold amplifier 26, the output of which in this case is connected to the input of the computing unit 6. The device is operated in the same way as described above. By changing the position of the stator of the sine-cosine transformer 4 relative to its rotor during engine operation, the operator achieves a zero value of P duty cycles. In this case, the upper dead point is considered to be set correctly. The threshold amplifier 26 provides a signal at its output symmetrically with respect to a correctly set top dead center of the engine.

The use of a threshold amplifier and an electronic switch in the device in conjunction with the operation mode and measurement switches allows using the same device to produce a fairly accurate setting of the upper dead

points of the piston in the cylinder of a running engine and measurement of the average indicator pressure.

The proposed device provides a reduction in the measurement error of the average indicator pressure by about half.

Claims (1)

DEVICE FOR MEASURING THE AVERAGE INDICATOR PRESSURE IN CYLINDERS OF PISTON MACHINES by ed. St. No. 757891, I distinguish it even more with the fact that, in order to increase the accuracy of measurement and expand the functionality by providing the ability to measure the average indicator pressure, it is divided by duty cycles and pump strokes in several engine cylinders, additional pressure transducers by number are introduced into it cylinders, channel selector, dual mode selector switch, threshold amplifier, second integrating link, measurement switch, electronic switch, and fixed switch contacts The channels are connected to the outputs of the pressure transducers, and the movable contact is connected to the movable contact of the first direction of the operating mode switch, the first fixed contact of this switch is connected to the input of the pressure transducer signal amplifier, and the second to the threshold amplifier, the output of which is connected to the second fixed contact the second direction of the operating mode switch, the first contact of which is connected to the output of the signal amplifier of the pressure transducers, and stationary with the first input of the subtractor of the casting unit, the amplifier scaled output through two series-connected make-up contacts of the control relay 6πογ and the electronic switch connected in parallel to the inputs of two integrating links, the outputs of which are connected to the fixed contacts of the measurement switch, the movable contact of which is connected to the recording device, while the control input electronic switch connected to the output of the pulse shaper. SU „„ 1138674