RU199330U1 - DEVICE FOR DETERMINING ELECTROMAGNET DYNAMIC CHARACTERISTICS - Google Patents

Abstract

The utility model relates to electrical engineering. The technical result consists in the possibility of accurate determination of the traction force at various distances between the electromagnet and the armature, as well as the time of the traction force creation. A device for determining the dynamic characteristics of an electromagnet includes a force sensor, a measuring rod, and a part for securing the electromagnet. The force sensor is made in the form of a package of pre-compressed piezoelectric rings, between which current-conducting contacts are located. The armature of the electromagnet is rigidly connected to the measuring rod and the force sensor. The specified distance between the armature and the electromagnet is provided by moving the electromagnet relative to the armature, controlled by an indicator and fixed with a locknut. 2 ill.

Description

The utility model relates to instrumentation and can be used to determine the dynamic characteristics of the electromagnet for controlling the fuel injector of an internal combustion engine.

Certain dynamic characteristics are required from the electromagnets for controlling the fuel injectors of internal combustion engines, including the magnitude of the traction force at different distances of the electromagnet armature from the yoke (magnetic circuit) and the length of time that this force is generated after a corresponding voltage pulse is applied to the electromagnet contacts.

Known device for monitoring the operation of an electromagnet, including a piezoelectric element and installed with an axial clearance on the body of the controlled electromagnet [A.S. USSR No. 408097, publ. 10.12.1973. Bul. No. 47]. According to the known solution, the piezoelectric element is connected to the magnetically conducting core so that when the controlled electromagnet is triggered, the core tends to be attracted to the electromagnet body, deforming the piezoelectric element. Due to the piezoelectric effect, a voltage of a certain polarity appears on the contacts of the device, indicating the operation of the controlled electromagnet.

The disadvantages of the known solution include the limited information obtained during the control: only the very fact of actuation is recorded without taking into account the dynamic characteristics of the electromagnet - the tractive effort and the length of time required for the development of this effort.

There is a known device for taking the power characteristics of electromagnets, in which, before taking measurements, the electromagnet under test is fixed motionless, the electromagnet armature is manually moved to a predetermined position, and to determine the force, a dynamometer is used connected to the electric motor through a gearbox, a lead screw and a pusher with a nut (US Pat. No. SU No. 1356013, publ. 30.11.1987. Bull; No. 44). The anchor of the electromagnet under test is connected to a dynamometer and a system of weights. The system of weights is required for the case when the traction force of the electromagnet exceeds the limit of the dynamometer measurement scale, and is connected to the armature of the electromagnet by a thread thrown over the block. In this case, the controlled tractive effort is proposed to be determined as the sum of the readings of the dynamometer and the system of weights. The traction force is recorded when the dynamometer is stretched, and if, for some reason, the armature of the electromagnet has not touched the stop, that is, it has not reached the position specified by the presetting, the electric motor is turned on, which, through the gearbox and the lead screw, weakens the tension of the dynamometer until the armature is rests against the pusher.

The disadvantages of the known solution include the complexity of the device due to the presence of an electric motor with a gearbox, a lead screw, a system of weights with a block and a thread. The accuracy of measurements is influenced by the positioning accuracy of not only the armature, but also the dynamometer.

The closest in terms of the set of essential features - the prototype of the claimed utility model - is a device for determining the dynamic characteristics of electromagnets, including a force sensor, a measuring rod, a part for securing an electromagnet (AS No. 822153, publ. 15.04.1981. Bull. No. 14) ... The force sensor is fixed outside the electromagnet, and the armature of the electromagnet can move freely and, when voltage is applied to the contacts of the electromagnet, acts on the force sensor through the measuring rod. The output signals are sent to the oscilloscope. The disadvantages of the known solution include the fact that the design of the device does not provide for measures to ensure accurate positioning of the armature of the electromagnet relative to the electromagnet at the time of registration of the tractive effort. Also, it is not possible to initially place the armature of the electromagnet at different distances from the electromagnet.

The technical problem to be solved by the proposed utility model is to eliminate the shortcomings of the prototype: to ensure accurate positioning of the armature at the moment of registration of the tractive effort and to ensure the possibility of measuring the traction force at different distances of the electromagnet armature from the electromagnet.

The task is solved by:

- rigid connection of the armature of the electromagnet with the measuring rod and the force sensor;

- execution of the pressure transducer in the form of a package of pre-compressed piezoelectric rings, between which current conducting contacts are placed so that the output signal is fed to the oscilloscope;

- the fact that the distance between the armature and the electromagnet is provided by the movement of the electromagnet relative to the armature, is controlled by an indicator and is fixed with a locknut.

A novelty in the proposed device for determining the dynamic characteristics of an electromagnet is the combined use of the above design solutions.

The indicated features are new, significant and industrially feasible and are aimed at solving the technical problem posed by the utility model.

The device proposed as a useful model for determining the dynamic characteristics of an electromagnet is illustrated by drawings (Fig. 1, 2). where the positions indicate: plate 1, body 2, measuring rod 3, nut 4, washer 5, conductive contacts 6, piezoelectric rings 7, electromagnet armature 8, nut 9.clock nut 10, screwdriver 11, tip 12, indicator 13, spring 14, the tested electromagnet 15, including the magnetic circuit 151 and the edge of the inductance 152.

The body 2 is fixed on the plate 1. The measuring rod 3 has a stepped shape so that when the nuts 4 are tightened, the piezoelectric rings 7, the conductive contacts 6 on one side and the electromagnet armature 8 on the other side are pressed through the washer 5 to the ends of the body 2. Thus, by the time the tests start, the piezoelectric rings 7 are pre-compressed. The nut 4, in contact with the washer 5, is locked against loosening by the same nut 4. The measuring rod 3 with its large diameter goes inside the tested electromagnet 15, and the material of the measuring rod 3, in its magnetic properties, and its volume inside the electromagnet 15 correspond to the material and the volume of the part installed in the electromagnet when assembling the nozzle for which it is intended. The locknut 10 is screwed onto the threaded part of the body 2. The screwdriver 11 is installed in a regular hole in the upper part of the electromagnet 15.

A device for determining the dynamic characteristics of an electromagnet operates as follows.

A spring 14 is installed on the upper end of the measuring rod 3. The electromagnet 15 is installed in the housing 2, while the spring 14 enters the central hole of the electromagnet 15 and rests on its inner end.

Nut 9 is put on electromagnet 15 like this. that it is installed with the inner ring shoulder on the shoulders of the electromagnet 15. Bring the electromagnet 15 until the armature of the electromagnet 8 touches. The nut 9 is tightened in this way. that the electromagnet 15 can not spontaneously rise from the armature of the electromagnet 8. Bring the tip 12 of the indicator 13 to the upper end of the screw-in 11. Set the indicator reading to zero.

Rotate the nut 9 in the direction of its unscrewing. Under the action of the force of the spring 14, the electromagnet 15 moves from the armature of the electromagnet 8. The magnitude of the movement is recorded by the indicator 13. Retracting the electromagnet 15 to the desired distance from the armature of the electromagnet 8. Lock the nut 9 with the locknut 10. The screwdriver 11 constantly touches the nut 9.

An electric voltage is applied to the contacts of the electromagnet 15. The voltage supply law - the control signal - corresponds to the operating conditions of the electromagnet in the fuel injector.

After applying voltage to the contacts of the electromagnet 15 in the magnetic system, including the magnetic circuit 151, the inductor 152ts and the armature of the electromagnet 8, a magnetic field is created. A traction force develops, tending to attract the armature of the electromagnet 8 to the electromagnet 15. Traction force is transmitted to the piezoelectric rings 7. Due to the direct piezoelectric effect, an electric voltage arises between the surfaces of the piezoelectric rings 7, which is directed through the conductive contacts 6 to the input of the oscilloscope (not shown in the explanatory drawings conventionally ).

The technical result of the proposed utility model is the ability to accurately determine the traction force at various distances between the electromagnet and the armature, as well as the time of creating the traction force, which is of great importance when developing the design of the electromagnets for controlling the fuel injectors.

The device proposed as a useful model for determining the dynamic characteristics of an electromagnet is used to create new electromagnets at the Altai Precision Products Plant.

Claims (1)

A device for determining the dynamic characteristics of an electromagnet, including a force sensor, a measuring rod, a part for fixing an electromagnet, characterized in that the force sensor is made in the form of a package of pre-compressed piezoelectric rings, between which current-conducting contacts are located, the armature of the electromagnet is rigidly connected to the measuring rod and the force sensor , and the specified distance between the armature and the electromagnet is provided by the movement of the electromagnet relative to the armature, controlled by an indicator and fixed with a locknut.

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