RU168466U1 - Object position sensor made of magnetic material - Google Patents

Abstract

The invention relates to the field of operation of an internal combustion engine, and more particularly, to the design of a sensor for determining the position of an object made of magnetic material. The technical result of the proposed technical solution is to reduce the cost of manufacturing the device due to the formation of a constant magnetic field from several small permanent magnets, properly located on a magnetic circuit made of less valuable magnetic material. When the receiving part of the camshaft rotates in the area of the sensing module 12, a special protrusion or a special cavity periodically appears. The sensitive module 12 responds to a change in the magnitude of the magnetic field created by the magnets 3 of the sensitive module 12 caused by the appearance of a protrusion or depression near it. In this case, for example, when a special protrusion enters the area under the sensitive module 12, the voltage at the output of the sensor becomes equal to the input voltage. Further, such an electrical signal is supplied to the relay or to the ADC (analog-to-digital converter) of the microcontroller located in the engine control unit for further regulation of the ignition timing. 3 s.p. f-ly, 4 ill.

Description

Technical field

The technical solution relates to internal combustion engines, and more particularly to the design of the sensor for determining the position of an object made of magnetic material.

State of the art

An analogue is the camshaft position sensor, which can serve as a sensor of the position of an object made of magnetic material. This analogue is described in the application for the invention of the Russian Federation No.20001014 62, publication date 10.11.2001.

The known device contains: a housing, a Hall microcircuit, a permanent magnet. The housing is made cylindrical of a non-magnetic material, for example, plastic. The Hall microcircuit is magnetically sensitive. In other words, the Hall microcircuit is composed of electronic components connected in the required manner, providing a change in the output voltage in accordance with a change in the magnetic field in which the camshaft position sensor is located. The Hall microcircuit is located on the inner surface of the housing. The permanent magnet has the shape of a ring with a rectangular cross-sectional profile and is located in the housing.

The closest technical solution (prototype) is the position sensor of the gear tooth, which can serve as a camshaft position sensor. The specified prototype is described in RF patent 2207575, publication date 06/27/2003.

The known device comprises: a housing made non-magnetic in the form of a sleeve with an internal thread, a magnetically sensitive transducer, an annular permanent magnet, a magnetic circuit made magnetically soft in the form of a cylinder with a thread. The permanent magnet is magnetized axially. The magnetic core is located inside an annular permanent magnet. The magnetosensitive transducer is installed on the side of the end of the magnetic circuit. The magnetic core can move inside a permanent magnet along its axis.

The whole device is located on the side of the gear rim in such a way that there is a gap between the pole of the permanent magnet and the transducer, into which the gear tooth is made of soft magnetic material.

A disadvantage of the known technical solutions is the use of a permanent ring-shaped magnet made of rare-earth metals (Gd, Tb, Dy, Ho, Er) or other ferromagnets (Fe, Co, Ni) and occupying a significant part of the body cavity, as a result, having significant weight.

The technical result of the proposed technical solution is to reduce the weight of the device, as well as the cost of manufacturing the device due to the formation of a constant magnetic field from several small permanent magnets located properly on the magnetic circuit made of less valuable magnetic material.

The specified technical result is achieved due to the fact that in the position sensor of an object made of magnetic material containing a housing with an internal cavity, which is made of non-magnetic material, and a sensitive module, the sensitive module comprising a first part and a second part, a holder that are made of non-magnetic material , the first magnetic circuit and the second magnetic circuit made of soft magnetic material, at least one magnet, a Hall sensor, while the first magnetic circuit is placed for at least an hour typically, in the holder with the possibility of moving in it, the holder is attached to the first part, the second magnetic circuit is placed on the opposite side of the first part from the holder, the second magnetic circuit is located on the opposite side of the second magnetic circuit from the first magnetic circuit, and the Hall sensor is located on the opposite side of the second magnetic circuit and the corresponding magnet is placed in the first part to ensure that it touches the second magnetic circuit, the sensing module is placed in the internal cavity by the Hall sensor towards its bottom, in In this case, the second part is provided on one side with a groove in which the Hall sensor is located, and on the other hand, with a fourth hole in which the second magnetic circuit is located, in another particular case, the poles of the corresponding magnet are located one on the side of the second magnetic circuit, and the other on the side of the magnet opposite to the second magnetic circuit, in the third particular case, the poles of the respective magnets are located similarly.

Brief Description of the Drawings

The position sensor of an object made of magnetic material is illustrated by drawings (FIGS. 1, 2, 3, 4), where in FIG. 1 shows an assembly drawing of a device with a visual representation of the arrangement of elements in it; FIG. 2 shows an isometric view with a cut-out of a quarter of the body and cap of the device, in FIG. 3 shows an isometric view of the assembly of the sensor module and the electric board; FIG. 4 is an isometric view of the assembly of the sensor module and the electrical board with a simple cut.

Utility Model Disclosure

The figures indicate: housing 1, first magnetic circuit 2, magnet 3, first part 4, slice 5, second magnetic circuit 6, second part 7, groove 8, cap 9, first hole 10, first chamfer 11, sensitive module 12, slot 13, mounting hole 14, connector 15, second hole 16, recess 17, ledge 18, internal cavity 19, bottom 20, circuit board 21, third hole 22, second bevel 23, holder 24, second end 25, first end 26, Hall sensor 27 fourth hole 28.

The device consists of a housing 1 with a cap 9, a sensing module 12, an electric board 21. The sensing module 12 is an assembly of the first part 4, magnets 3, the first magnetic circuit 2, the second magnetic circuit 6, the second part 7 and the Hall sensor 27.

The housing 1 of the position sensor of the object of magnetic material is made in one with the connector 15 or otherwise. The housing 1 is made of plastic or other non-magnetic material and has a shape formed by the intersection of surfaces of the first or second order. The housing is provided with a second hole 16 and a mounting hole 14 made through. The housing 1 can be provided with walls on its surface to protect the conductors supplied to the connector 15, as well as stiffeners, ensuring reliable fastening of such walls to the housing 1 (to the end side of the plate). Case 1 and the entire device as a whole has a plane of symmetry - a plane that divides the object into two equal mirror-symmetric halves. The housing 1 has a recess 17 concentric with the second hole 16.

The cap 9 is made, for example, in the form of a cylinder of the same material as the housing 1 (by a cylinder we mean a geometric body of circular cross section bounded by a cylindrical surface and two parallel planes intersecting it perpendicularly). On the outer cylindrical surface of the cap 9, near the open edge, a step 18 is made. Assembled, the open edge of the cap 9 is located in the recess 17 of the housing 1, the ledge 18 abuts against the edge of the recess 17. In this case, the second hole 16 of the housing 1 and the cap 9 form an internal cavity 19, limited on one side by the bottom 20 of the cap 9. The cap 9 is fastened based on the friction force of the contacting surfaces during assembly or otherwise (latches, additional threads, fasteners, glue).

The connector 15 is made to ensure compatibility with the receiving part located in the vehicle. Connector 15 has, for example, three pin contacts (input of an electrical signal to an object’s position sensor from magnetic material, output of an electric signal from an object’s position sensor from magnetic material when it is triggered by a relay and a logical ground or negative common potential).

A sensing module 12 is located in the inner cavity 19. The sensing module 12 is an assembly of a Hall sensor 27, a second part 7, which is rigidly connected to the first part 4, the second magnetic circuit 6, magnets 3 and the holder 24, in which the first magnetic circuit 2 is located.

The second part 7 is made in the form of a disk of non-magnetic material, such as plastic. On one side of such a disk, in its center, a fourth hole 28 is made. The fourth hole 28 can be blind. The diameter of the fourth hole 28 is, for example, twelve millimeters. On the other hand of the second part 7, a groove 8 is made for fixing a Hall sensor of arbitrary shape. The thickness of the second part 7 can be three millimeters, the depth of the fourth hole 28 is one millimeter and the depth of the groove 8 is one millimeter. On the side of the second part 7, a slice 5 is made in the shape of a segment, including a protrusion. The plane of cut 5 is perpendicular to the plane of symmetry of the position sensor of an object made of magnetic material. The groove 8 of one of its smaller sides faces the slice 5 or goes into it. The size and shape of the cut 5 correspond to the size of the electric board 21 (if available in the device). The diameter of the second part 7 may be fifteen millimeters.

A second magnetic circuit 6. is placed in the fourth hole 28. The second magnetic circuit 6 is made of magnetic material, in particular a soft magnetic material, and may be in the form of a washer with an external diameter of twelve millimeters and a thickness of one millimeter. Magnetic material is a ferromagnetic material with a magnetic permeability significantly greater than unity, strongly attracted by the magnetic field and significantly changing the magnetic field around it (definition of magnetic material - Big Polytechnic Encyclopedia, see http://polytechnic_dictionary.academic.ru/1220/MAGNETIC, date circulation 04/18/2016) Soft magnetic material - a material with a coercive force by induction of not more than 4 kA / m (the definition is given from GOST 19693-74). Soft magnetic materials include permalloy — an alloy of nickel and iron (Ni + Fe), silicon electrical steel, and others. In particular, for the manufacture of the first magnetic circuit 2 and the second magnetic circuit 6, material St3 (steel 3) is applicable.

On the surface of the second part 7, from the placement side of the second magnetic circuit 6, the first part 4 is placed. The first part 4 is made of arbitrary shape from non-magnetic material. In this case, the first part 4 is placed coaxially with the second part 7 and can be inscribed in a circle of the same diameter as the second part 7 or otherwise. In the first part 4, through the first holes are made 10. The first holes 10 can be arranged in a circular array in the amount of several, for example, three. In other words, the centers of such first holes 10 lie on a circle, the concentric edge of the disk (first part 4), and are, for example, one hundred and twenty degrees between themselves relative to the center of the first part 4. The first holes 10 can be offset to the side surface of the first part 4 in this way so that their inner surfaces intersect with the lateral surface of the first part 4. On the surface of the first part 4, from the side opposite the second part 7, between the first holes 10, the holder 24 is rigidly attached to the first end 26. The thickness of the first hour and 4 may be three millimeter, and its fifteen millimeters in diameter. On the side surface of the first part 4, a slice 5 is made, the position, shape and size of which corresponds to a slice 5 of the second part 7.

In the first holes 10 are placed magnets 3. Magnets 3 are made of ferromagnets or rare earth metals. The magnets 3 are made in the form of a disk or cylinder and are magnetized axially. The size of the magnets 3 corresponds to the size of the first holes 10. The magnets 3 in the first holes 10 touch the second magnetic circuit 6.

The holder 24 has a cylindrical or other shape. The holder 24 is made, for example, in the form of a sleeve and is attached to the first part 4 in the above manner generally coaxial with the first part 4. In the center of the holder 24, from the side of its second end 25, a blind or through axial third threaded hole 22 is made, for example , M 4.0 × 0.6. The third hole 22 is provided with a second chamfer 23. The third hole 22 can be made through (through through the holder 24 and the first part 4).

The first magnetic circuit 2 is a cylindrical element of magnetic material, in the particular case of soft magnetic material. A thread is made on the side surface, for example, M 4.0 × 0.6. The first magnetic circuit 2 is provided with a slot at one end and the first bevel 11 at the other end.

The Hall sensor 27 is a transistor made with the possibility of changing the control current of the base depending on the change in the magnetic field and thereby the implementation of collector-emitter communication. The Hall sensor 27 is located in the groove 8 of the second part 7. The Hall sensor 27 is electrically connected to the connector 15 (its pin contacts).

The electrical connection of the Hall sensor 27 can be carried out by means of flat conductors located on the electric board 21. The electric board 21 can be made of fiberglass and contain electronic components for the correct operation of the Hall sensor 27, for example, a resistor to normalize the control current of the base. The electric board 21 at one end can be rigidly attached to the housing 1, and the other end can be placed in the slice 5 of the first part 4 and the second part 7.

Utility Model Implementation

In the case of using the above elements and means, the utility model is implemented as follows. A housing 1 is formed with a connector 15, a mounting hole 14 and a second hole 16. An example of this is the production of two parts of the housing 1 made of plastic by injection molding and their connection in a heated state together with metal pin contacts located in the required location of the connector 15. The pin contacts with their ends are placed not only in the connector 15, but also in the second hole 16 for the possibility of wiring.

The first part 4 with the first holes 10, cut 5 and the holder 24, and the second part 7 with the groove 8, cut 5 and the fourth hole 28 are formed from plastic. We apply the casting method using plastic with subsequent grinding of the surfaces of the parts obtained. The required holes, chamfers and cuts can be made by drilling and milling. The thread of the holder 24 can be made using a tap - a tool for cutting internal threads.

The cap 9 together with the step 18 can be made of plastic similarly by casting. Suppose the manufacturing option of the housing 1 and the cap 9 as a whole with the preliminary placement of the sensing module 12 in the internal cavity 19.

The first magnetic circuit 2 with the first chamfer 11 and the second magnetic circuit 6 are made of a suitable magnetic material (St3), for example, by casting followed by grinding. From one end of the first magnetic circuit 2, a shallow slot 13 is made for a screwdriver, for example, with a metal circular saw. On the lateral surface of the first magnetic circuit 2, an external thread is formed by a die - a tool for cutting external threads.

An electric board 21 is made from foil-coated fiberglass (or other suitable material). In this case, the shape of the electric board 21 is chosen so that it can be positioned in the second hole 16, in the cap 9 and in the cut 5 of the sensing module 12. Flat conductors are formed on the surface an electric board 21 for subsequent connection of the electronic components with the connector 15. We apply the method of etching with chlorine iron excess conductive material (copper foil) from the surface of the electric board 21, having previously protected the board pattern (future flat conductors) with varnish. The electronic components, including the Hall sensor 27, are placed on the electric board 21, they are fastened and electrically connected in the required manner with the pin contacts of the connector 15 by soldering.

Acceptable method (stamping or other) make magnets 3 from a suitable material (St3). In this case, the magnets 3 magnetize axially - forming two poles from the two end faces of each magnet 3.

Assemble the manufactured elements in a strictly established manner (see Fig. 1). The sensitive module 12 is assembled by placing the second magnetic circuit 6 in the fourth hole 28, the magnets 3 in the first holes 10 and then coaxially connecting the first part 4 and the second part 7. The resulting intermediate assembly of the sensitive module 12 with a cut 5 is placed on the electric board 21 in such a way so that the Hall sensor 27 is in the groove 8 and this groove 8 is turned in the opposite direction from the second hole 16.

Perform the axial alignment of the first magnetic circuit 2 and the holder 24 with the first chamfer 11 and the second chamfer 23, respectively, and screw the first magnetic circuit 2 into the holder 24 with the slot 13 upward. Close the sensing module 12 with a cap 9.

The position sensor of an object made of magnetic material can be used to determine the position of the camshaft in order to adjust the ignition timing. In this case, during operation of the position sensor of an object made of magnetic material, the Hall sensor 27 is located in close proximity to the receiving part of the camshaft. The receiving part can be made in the form of a gear wheel with a missing tooth in the row of teeth or another feature affecting the value of the magnetic field strength at the location of the Hall sensor 27. In general, the receiving part is made with a special cavity or with a special protrusion, and determines the position ( rotation angle relative to the axis) of this camshaft. The position sensor of an object made of magnetic material can be mounted on a car engine using a mounting hole 14 in its housing 1 and connecting elements (bolts or other type). The camshaft position sensor connector 15 is connected to the engine control unit located in the car in order to control its characteristics, for example, the moment of fuel injection, the moments of opening or closing of valves, etc.

Due to the presence of a thread on the first magnetic circuit 2 and the possibility of its movement in the holder 24, it is possible to adjust the camshaft position sensor to various gaps (distance to the receiving part of the camshaft) and the geometry of the receiving part. Adjustment is possible without dismantling the camshaft position sensor - using a suitable screwdriver through the second hole 16 in the housing 1.

When the receiving part of the camshaft rotates in the area of the sensing module 12, a special protrusion or a special cavity periodically appears. The sensitive module 12 responds to a change in the magnitude of the magnetic field created by the magnets 3 of the sensitive module 12 caused by the appearance of a protrusion or depression near it. In this case, for example, when a special protrusion enters the area under the sensitive module 12, the voltage at the output of the sensor becomes equal to the input voltage. Further, such an electrical signal is supplied to the relay or to the ADC (analog-to-digital converter) of the microcontroller located in the engine control unit for further regulation of the ignition timing.

Thus, the implementation of the device in the manner described above allows the manufacture of an object position sensor from magnetic material using fewer expensive rare-earth metals (Gd, Tb, Dy, Ho, Er) or other ferromagnets (Fe, Co, Ni) through the use of magnets 3 a cylindrical shape and small size (as a result, having a reduced mass) located in a circular array with a touch of the second magnetic circuit 6. In other words, the implementation of the device as described above provides the cost of manufacturing the position sensor of an object from magnetic material without losing its functionality.

Claims (4)

1. The position sensor of an object made of magnetic material, comprising a housing with an internal cavity that is made of non-magnetic material, and a sensing module, the sensing module comprising a first part and a second part, a holder that are made of non-magnetic material, a first magnetic circuit and a second magnetic circuit, made of soft magnetic material, at least one magnet, a Hall sensor, while the first magnetic circuit is placed, at least partially, in the holder with the possibility of movement in it, the holder it is attached to the first part, the second magnetic circuit is located on the opposite side of the side of the first part, the second part is located on the opposite side of the second side of the second magnetic circuit, the Hall sensor is located on the opposite side of the second magnetic circuit and the corresponding magnet is placed in the first part them of the second magnetic circuit, the sensitive module is placed in the internal cavity by the Hall sensor in the direction of its bottom. 2. The device according to claim 1, characterized in that the second part is provided on one side with a groove in which the Hall sensor is located, and on the other hand, with a fourth hole in which the second magnetic circuit is located. 3. The device according to claim 1, characterized in that the poles of the corresponding magnet are located one on the side of the second magnetic circuit and the other on the side of the magnet opposite to the second magnetic circuit. 4. The device according to p. 3, characterized in that the poles of the respective magnets are located similarly.

Images