SU1511452A2 - Dwell angle monitoring device for ic-engine ignition system - Google Patents

Abstract

The invention relates to control and adjustment equipment for testing interrupters of distributors of ignition systems of internal combustion engines and is intended to diagnose and monitor distributors under production conditions. The purpose of the invention is to expand the scope of use, increase productivity and control accuracy. The goal is achieved by inserting a gate switch 25 with two switching sections, rigidly fixed relative to the rotating disk 4, tachometer and phase measuring blocks 29, 37 into the device. In addition, the device contains a drive 1 with a device 2 for installing and fastening a controlled distributor 3 The rotating disk 4, on the surface of which LEDs 5-17 are mounted, forming the indicator light 18. 3 Il.

Description

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To fix relative to the rotating disk 4, tachometric and phase-measuring blocks 37, 29. In addition, the device contains a drive 1 with a device 2 for mounting and fixing a controlled distributor distributor 3, a rotating disk 4, on the surface of which LEDs 5-17 are installed, forming a light indicator 18. 3 silt,

The invention relates to control and adjusting equipment for testing breakers of the distributor of ignition systems of the internal combustion engine and is intended for the production and diagnostic control of their parameters. The aim of the invention is to expand the field of application, increasing the accuracy and performance of control. FIG. 1 shows a device with an LED switching circuit and a phase-measuring circuit for monitoring three types of interrupters; Fig. 2 shows the layout of the LED and the switching sections of the gate switch with respect to the rotating disk and the block diagram of the device; in fig. 3 - device operation diagrams; Device for monitoring the angle of the closed contacts of the ignition system interrupter of an internal combustion engine consists of a drive 1 with a device 2 / for mounting and fixing a controlled distributor distributor 3, a rotating disk 4, to the surface of which LEDs are attached 5-17, forming the indicator light 18 and connected to the power supply 19 in parallel with the contacts 20 of the controlled breaker 3, collector plugs 21 and 22, the switch 23, the transparent measuring scale s 24, the gate switch 25 to change-over switches yuschimi portions 26, 27 and feed:; input 28, phase-measuring unit 29, which includes differential inputs 30 and 31, made on diodes and 1 resistive-capacitive filters, first and second transistors 32 and 33, load resistor 34 and instrument indicator 35, connected between collectors of transistors 32 and 33 , the collector of the second transistor 33 is connected to the first power supply bus of the device for controlling the angle of the closed state of the contacts of the chopper through the resistor 36. The device also contains a tachometer block 37, a device 38 of the tachometer block and a cam 39 of the chopper distributor. The input of the tachometer unit 37 can be connected, for example, to the contacts of the predator 20. The number of LEDs on the light indicator 18 and their location on the surface of the rotating disk 4 are determined by the type of controlled chopper 3. Switching groups of LEDs is performed by switch 23, which actually serves as the power input of the light indicator 18. The number of LEDs in the group is equal to the number of cam projections 39 breaker 3, and the shift angle of the melod is equal to the angle between the projections of this cam. Therefore, the switching sections 26 and 27 of the gate switch 25 (FIG. 2) must be designed so that the angular extent of one of them is at least not much less than the smallest shear angle between the LEDs of the same group. For example, for an 8-cylinder ICE, the shear angle of them is equal to 45 °. Therefore, the angular extent of the switching portion 26 must be less than 45. Only in this case is the corresponding 1Y signal at the output of the gating gene-. A rator can be compared with a signal from any indicator LED. FIG. 3 are designated: 40 - a sequence of pulse signals arriving at the input 31 of phase measurement. The target unit 29, coinciding 1x in frequency, phase and duration with the luminescence of that group of LEDs, which is activated by the corresponding position of the switch 23, in the mode of the ignition advance zero setting; 41 - the same, in the mode of some advanced ignition; 42the same, in the mode of maximum advance ignition; 43 - sequential strobe; their pulses at the input of 30 phase-measuring

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block 29, coinciding in frequency with the frequency of the drive rotation, in duration with the angular length of the switching section 27.

The device works as follows.

A checked, for example, eight-circuit breaker-distributor 3 (there may be any distributor of a contact-transistor or contact-free ignition system) is installed in the device 2 and its shaft is connected to the drive shaft 1 (Fig. 1). The actuator 1 is turned on, with the cam 39, the disk 4 and the gates 26 and 27 of the gate switch 25 begin to rotate synchronously. The switch 23 is set to a position corresponding to the inclusion of a group of eight LEDs. At the same time, a group of LEDs 5-12, parallel to it contacts 20 of the chopper 3, a gate switch 25 with a phase-measuring unit 29 and a tachometer block 37 are included in the power supply circuit. When the contacts 20 (or the corresponding valve) are open, the current from the power source 19 flows through the circuit: plus source 19, additional resistance, collector sleeve 21, switch 23, group of parallel-connected LEDs 5-12, collector sleeve 22, minus source 19. At the same time With this, however, regardless of the state of the contacts 20, the voltage of the source 19 goes to the gate switch 25 and generates a signal that goes to the differential switch. The social input 30 of the phase-measuring unit 29, if at the considered moment the power input 28 is switched to section 27. The arising base current, transistor 33 unlocks it, thereby reliably blocking the unlocking of transistor 32, since the resistor 36 is almost closed to the common wire. In other words, if at any moment when the transistor 33 is in the saturation state, an unlocking positive signal arrives at the input 31, and this happens every time the contacts 20 are opened, the transistor 32 still opens, since there is no zmitter voltage on it.

Since the LEDs 5-17 are connected in parallel, they light up simultaneously at the moment when the opening of the contacts 20 occurs, and go out,.

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as soon as the contacts 20 is closed. The time of their glow is equal to the open-contact time. Since during this time each LED describes an arc along the radius of its location on the rotating disk 4, the length of the arc between the faces of two luminous adjacent stripes shows

The angle of the closed state of the contacts on the corresponding face. In the direction of rotation of the disk 4, the beginning of the light arc coincides with the instant of opening of the contacts and means its own about the moment of ignition. The end of the light arc means the closure of the contacts. Since the LEDs are arranged so that they consistently come closer to the center of rotation, then with some increase in the frequency of rotation, at which a strobe effect is already observed, eight groups of light n (their arcs appear on the perimeter of the rotating disk, each with

Group 5 shows eight arcs arranged one above the other. Kx length, as well as the length of the arc gaps between them, is determined in angular radii using a transparent measuring scale 24. Since the light arcs are located above each other, it is easy to compare them and determine the difference in the angles of the closed state of the contacts on the face x those. measure asynchronism in the alternation of moments

5 ignition (at the beginning of the light arcs).

Simultaneously with each opening of the contacts 20, a front of the pulse signal is formed (Fig. 3, 40 - the voltage drop across the lit LEDs 5-12), which is applied to the differential input 31. However, if at this moment the transistor 33 is open, i.e. . from the gate switch 25 to the differential input 30 a positive voltage is applied, the transistor 32 does not open, and this position can be maintained for several more switching of the contacts 20. Undoubtedly, within one switching cycle there is a contact. Commodity 20 (in this case 8) will happen the one that precedes, the switching of the transistor 33 in the locked 5

Claims (3)

This state is due to the onset of cyclic pulse 43 dropping into the output of the gate switch 25. Then the next opening of the contacts 715 20 causes the transistor 33 to open and the current through the device frame 35. This ITOK can continue either until the Impulse 40 that supports the transistor 32 opens, the front end of the pulse A3 capable of opening the transistor 33 and, therefore, locking the transistor 32. However, due to the design features of the gating switch, the first one can never happen. Indeed, the angular extent of the switching section 26, from which a positive signal 43 arrives at the input 30, is certainly less than the smallest shift angle between the LEDs of the same group. Moreover, it is known that the operability of the ignition systems is ensured at certain values of the angle of the closed contact. For example, for 8- / spark distributors, the angle of the closed state should not be less than the DZ, so the angular extent of section 26 can correspond, for example, to 25 °. This means that the range of measurement of the angle of advance is 50. A random combination of the drop of pulse 43 and the front or fall of pulses 40 can either cause some current through the device 35 or not cause a current through it due to the fact that 26 fits into the gap-between the decay and the pulse front 40 in cyclic mode. In any case, turning the distributor distributor 3 in one direction or another causes the current through the device 35 to increase to the highest value, after which the distributor is turned up to the moment when the current drops sharply to zero. This is the zero setting position, which is done at low revs of the drive, when the centrifugal distributor has not yet started working. With an increase in the rotational speed (centrifugal advance characteristic) or with a change in pressure in the evacuated cavity of the device under test (advance load characteristic), the pulse sequence 40 begins to shift (Fig. 3, pulse 4.1), Since the decrease in pulse 41 corresponds to the ignition moment 2. If their mutual displacement with a further change in the frequency and load modes is so much greater that the decay of pulses 42 coincides with the front of pulse 43, then the device 35 shows the value of the maximum advance that it can measure. Since the devices 35 and 38 are directly in the field of view of the rotating disk 4, the observation of these devices makes it possible to simultaneously record the values of the angle of the closed state of the contacts, asynchronism. angle of advance and frequency of rotation, i.e. of all checked parameters of the chopper, excluding the errors of calculating the mean values of the advance and the errors caused by non-simultaneous observation of the rotation frequency and the angle of advance. Claim 1. Device for monitoring the angle of the closed state of the contacts of the interrupter of the ignition system of the internal combustion engine according to the author. No. 926347, characterized in that; In order to expand the field of application, increase accuracy and performance, the drive is additionally equipped with a gating switch with at least two bridging sections rigidly fixed relative to the rotating disk, a tachometric and phase measuring unit with two inputs, the nerve of which is connected to the LED power bus, the second is connected to the output of the gate switch, the input of which is connected to the first power supply bus of the device for monitoring the angle of the closed state of the breaker contacts, One of the switching sections of the gating switch has an angular extent smaller than the smallest shear angle between the LEDs, and the input of the tachometer unit is connected to the contacts of the chopper. 2. The device according to claim 1, characterized in that the phase-measuring unit is made on the first and second transistors, between which the collectors are connected to the load 91511452 J the chopper, and the emitters of the transistors — is made in the form of a brush, to the second power supply bus. Which node has one conducting and the other 3. A device according to claim 1, with non-conductive lamellas on the collector, which are strobe-connected to the drive shaft.