SU514218A1

SU514218A1 - Device for measuring average indicator pressure in piston machines

Info

Publication number: SU514218A1
Application number: SU1987181A
Authority: SU
Inventors: Борис Дмитриевич Ефремов; Борис Львович Ермилов
Original assignee: Предприятие П/Я Р-6794
Priority date: 1974-01-21
Filing date: 1974-01-21
Publication date: 1976-05-15

Description

Изобретение относитс к области коитрольно-измерительной техники и может быть применено дл работы двигателей внутреннего сгорани , поршневых компрессоров и др.The invention relates to the field of co-measuring technology and can be applied to the operation of internal combustion engines, piston compressors, etc.

Известно устройство дл измерени среднего индикаторного давлени в поршневых машинах, построенное на принципе вычислепи по заданному алгоритму по сигналам датчиков давлени и угла поворота коленчатого вала, содержащее дискретные делители, коммутатор, масштабные узлы и усилитель с фильтром.A device is known for measuring the average indicator pressure in piston machines, built on the principle of calculating according to a predetermined algorithm using signals from pressure sensors and crankshaft angles containing discrete dividers, a switch, large-scale components and an amplifier with a filter.

Но известное устройство имеет низкую точность , котора обусловлена применением дискретных делителей.But the known device has low accuracy, which is due to the use of discrete dividers.

Целью предложенного устройства вл етс повышение точности измерени .The purpose of the proposed device is to improve the measurement accuracy.

Это достигаетс тем, что предложенное устройство содержит функциональный преобразователь , интегратор, операционный усилиталь , бесконтактный ключ, истоковый повторитель , блок задержки и схему разделени , при этом входы функционального преобразовател соединены с датчиком давлени и через коммутатор с датчиком тла поворота, а выход подключен к интегратору, который через бескоптактный ключ и истоковый повторитель соединен с операционным усилителем, резистор обратной св зи которого подключен к входу бесконтактного ключа, а конденсатор This is achieved in that the proposed device comprises a functional converter, an integrator, an operational amplifier, a contactless key, a source follower, a delay unit and a separation circuit, the inputs of the functional converter are connected to the pressure sensor and through a switch with a turn signal sensor, and the output is connected to the integrator which is connected to an operational amplifier via a contactless key and a source follower, the feedback resistor of which is connected to the input of a contactless key, and the condensate op

ооратной св зи - к входу истокового повторител , при этом датчик }тла поворота непосредственно и через блок задержки соединен со схемой разделени , выход которой подключен к управл юшему входу бесконтактного ключа.Our communication is connected to the input of the source follower, while the rotation sensor is directly and via a delay unit connected to a separation circuit, the output of which is connected to the control input of the contactless key.

Блок-схема предложенного устройства представлена на чертеже. Устройство состоит из датчика давлени 1, функционального преобразовател 2, датчика 3 угла поворота, коммутатора 4. блока задержкн 5, иптегратора 6, резистора 7, беског1тактного ключа 8, истокового повторител 9, резистора 10 обратной св зи, конденсатора 11 обратной св зи, операционного усилител 12, схемы разделени 13 и измерительного прибора 4.The block diagram of the proposed device is shown in the drawing. The device consists of a pressure sensor 1, a functional converter 2, a rotation angle sensor 3, a switch 4. a block of delay 5, an integrator 6, a resistor 7, a contactless switch 8, a source follower 9, a feedback resistor 10, a feedback capacitor 11, an operational amplifier 12, separation circuits 13 and measuring device 4.

Устройство работает следуюшим образом.The device works as follows.

Claims

Pressure sensor 1 outputs a signal proportional to the current value of pressure in the cylinder, to the input of the functional converter

2. Sensor 3 generates an upper dead center signal and a "P" equal to the distance angular marks per revolution. According to these signals, the commutator 4 generates the right 1, and the pulses on the functional transducer 2, which generates the attenuation coefficient as the sum of the harmonic components of the main and double frequency in the n sections. At the same time, within each region, the current pressure value is multiplied by this coefficient. The received signal, passed through the integrator 6, is supplied to the non-concatenated AND key 8, in order to realize the separation of the signal in cycles. The signal then flows through the source follower 9 and the operational amplifier 12. The contactless switch 8 is opened through the separation circuit 13 at the beginning of the cycle with a pulse corresponding to the upper dead center. The integrating capacitor 11 is charged to a voltage proportional to the indicator pressure per cycle, and after the switch 8 is closed, the capacitor stores the charge, and a constant voltage is maintained at the output of the operational amplifier 12 for a period from the time the switch 8 is closed until the end of the next cycle. proportional to the indicator pressure for the previous cycle. The closure of the switch 8 is determined by the delay time of the circuit 13. Thus, at the output of the op amp, the difference in indicator pressure is formed for the previous and next cycles. The proposed scheme differs from that known for its simplicity. The introduction of an analog memory allows to extend the functionality of the device. 4 The invention The device for measuring the average indicator pressure in piston machines, containing sensors of pressure, angle of rotation and switch, characterized in that, in order to improve accuracy, it contains a functional converter, integrator, operational amplifier, contactless switch, source follower, delay unit and a separation circuit, wherein the inputs of the functional converter are connected to a pressure sensor and through a switch with a rotation angle sensor, and the output is connected to an integrator, which The contactless switch and the source follower are connected to an operational amplifier, the feedback resistor of which is connected to the input of the contactless switch, and the feedback capacitor is connected to the input of the source follower, and the angle sensor is connected directly and through the delay unit to the separation circuit whose output is connected to the control input of the contactless key.