Solenoid assembly with single coil equipped with two-way assisted permanent magnet, solenoid with single coil equipped with two-way assisted permanent magnet, electromagnetic switching unit, method for manufacture of solenoid with single coil and two-way

Description of the invention

The subject of the invention is an electromagnetic switching device, consisting of a body with a single coil of wire wound around it, a movable armature inside a single coil, and a permanent magnet.

Electromagnetic switching devices such as solenoids have common applications, for example in fuel shut-off devices or in various types of liquid pumps. Solenoids are often used on throttle, choke, valves, clutches, and engine components for overspeeding protection. Solenoids are used in a variety of motorized equipment such as boats, lawn care equipment, vehicles, generators, and the like.

Solenoids are designed to convert electrical energy into mechanical work. Typically, a movable magnetic armature or spindle moves linearly from one position to another as a current flows in the coil (s) in which the armature / pin is placed. The current flowing through the coil / i creates a magnetic field around the armature which causes the actuator to move in one direction. Accordingly, the armature may be connected to a device or piece of equipment that the armature may turn on, off, open or close when energized in a current coil.

Solenoids usually contain a single coil or a pair of copper wire coils. In a single coil solenoid, when a current is applied to the solenoid, a magnetic field is created that causes the spindle or armature to move. The magnetic field usually moves the spindle to the retracted or active position. In a single coil solenoid, the current flowing through the coil to create a magnetic field causing the armature or magnetic pin to move must not only be sufficient to push or pull the pin, but must also be sufficient to hold the pin in the active position. A disadvantage of a single coil solenoid is that after the coil is energized for an extended period of time, it can overheat, causing the solenoid to fail. To overcome this drawback, in applications where there may be a need to keep a plunger or a magnetic armature in an active position for long periods of time, two solenoids are typically used.

A typical two-coil solenoid is shown in Fig. 1. Solenoid 10 includes a first or pulling coil 12 and a second or holding coil 14. The first coil 12 turns are energized with high current to provide maximum pulling or pushing force on wand 16. The second coil 14 is used to hold the spindle 16 in the position that the spindle reaches after it has made a full stroke, for which less energy is required. The coils 12 and 14 are usually made of copper wire and the spindle is made of a magnetic material overlaid with a wear, friction and corrosion resistant coating. The amperage needed to hold plunger 16 in the holding position is typically less than that needed to push or pull plunger 16, so the dual solenoid can be energized continuously without overheating. The coils 12 and 14, as well as the pin 16, are typically housed in a steel housing 18, which may be provided with mounting brackets 20 to allow the solenoid to be attached to the frame or other piece of equipment. Some solenoids may furthermore be equipped with a return spring 22 which is used to bring the spindle 16 to the rest position. The magnetic force on the spindle 16, created by the high current flowing through the first coil 12, must be sufficient to overcome the setting force of spring 22. In solenoids employing a return spring 22, a flexible shroud 24 is typically used to enclose the return spring 22 and protect it against the spring 22. dust. Shield 24 is typically mounted on or connected to housing 18. Typically, at the opposite end of housing 18 is a double chopper switch 26 which controls the power to the coils. The chopper switch 26 can be energized to dynamically control the current through the pull / push coil 12 and the holding coil 14. The double interrupt switch 26 is normally sealed against dust by a cover 28 that is attached to the housing 18. . Terminal blocks 30 are led out through the sheath 28 for connection of electrical conductors to the solenoid.

As shown in Fig. 1, a typical solenoid is made of copper wire wound on a non-conductive, non-magnetic body that together form a coil assembly. The coil assembly embedded in the magnetically conductive sheath forms with it an electromagnet which, when energized, can generate a force on a moving magnetic object such as a pin or an armature. The force acting on the mandrel is directly proportional to the current strength and the number of turns of the wire on the body. Thus, the greater the number of ampere turns, the greater the force produced. From this proportional relationship

It follows that by increasing the number of turns of the coil or increasing the current, it is possible to increase the magnitude of the generated force. Some solenoids for specific applications use two separate coils wound on one body. As described above, these coils are typically referred to as a "pull" coil and a "hold" coil.

The draw coil is designed to conduct a very high current in order to create relatively high forces initially acting on the mandrel or the magnetic armature. This high force is usually applied for a short period of time, after which the current is disconnected to prevent the coil from overheating. Typically, the holding coil operates at a much lower current due to the fact that much less energy is required to hold an armature or a magnetic mandrel in position than to produce a "pull" force. The pull coils are disconnected in different ways, but the two most common are mechanical and electronic. In the mechanical pull-coil disconnection method, a pin is typically used to break the electrical circuit at the stroke turning point by opening a set of switch contacts that is part of the solenoid. The position of these contacts is critical as well as their ability to conduct high currents. The switch design has its own unique requirements that must be considered in the overall solenoid design, which creates a further complication to the solenoid as well as increasing manufacturing costs and potential reliability concerns. On the other hand, to implement the switching functionality, electronically controlled solenoids may use relays or semiconductor switching devices. However, the electronic components add to the cost of the solenoid. In another electronic switching method, a single wire wound coil is used, similar to a pull coil, in which a high current is applied to produce a high starting force. The electronics used therefore initially provide full power. When the wand has traveled fully, usually after a certain amount of time, the electronics begin turning the power on and off at a relatively high frequency, which reduces the effective amperage. This process is referred to as pulse width modulation and enables a single high current draw coil to be used as a low current holding coil. However, electronics not only increase the manufacturing cost but also the structural complexity of the solenoid.

US Patent No. US 6,218,921 discloses an electromagnetic switching device equipped with a solenoid. The solenoid consists of a single coil, a moving pin outside the coil bore, a permanent magnet outside the coil around the spindle, a fixed pin inside the coil bore, and a compression spring mounted around a fixed pin. The solenoid coil, when energized, generates a magnetic field sufficient for the spring to overcome the attraction force between the pin and the stationary pin, so the element that moves the pin after induction of current in the coil is a spring, not a permanent magnet. On the other hand, after the coil is energetically discharged, the actuator can be reset by physically pushing the spindle back into the retracted position. In this solution, the magnetic attraction force between the spindle and the permanent magnet always exists, regardless of whether the coil is energized or not.

United States Patent AP No. 4,419,643 shows a solenoid composed of a cylindrical member, with a single coil wrapped around it, a movable iron core embedded inside a cylindrical member, i.e. inside the coil, an annular permanent magnet placed near the end of a movable iron core, a non-magnetic spacer, located between the cylindrical member and the annular permanent magnet circumferentially around the movement path of the core, and the permanent receiver, at the opposite end of the cylindrical member to the position of the permanent magnet. With no current flowing through the coil, the core is attracted to the permanent magnet. Also, while the current flows through the coil, the core is attracted by the permanent magnet to the contact with the permanent receiver. Thus, the iron core of the solenoid only moves as a result of the magnetic attraction of the permanent magnet.

The object of the invention is to construct an electromagnetic switching device that includes a single wire coil with both push / pull and hold functions without increasing manufacturing costs as well as structural complexity with regard to mechanical and electronic switching assemblies.

The essence of the invention is an electromagnetic switching device consisting of a body with a single coil of wire wound around it, a movable armature located inside the single coil, and a permanent magnet.

PL 207 196 B1

The electromagnetic switching device is characterized in that the permanent magnet is separated from the armature by a non-magnetic spacer, the permanent magnet magnetically attracting the armature after an energy discharge of a single coil, and magnetically repels the armature after energizing the single coil. In addition, the device is equipped with a return spring that presses the armature against the non-magnetic spacer in the same direction as the direction of magnetic attraction of the permanent magnet.

When the coil of the electromagnetic device is energized, the magnetic object, preferably an armature or a pin, moves linearly through the bore of the coil. In the event of power failure to the coil, the armature is in the position where it contacts the non-magnetic spacer. In such electromagnetic conditions, a permanent magnet attracts the armature, pressing it against the non-magnetic spacer. When, on the other hand, the coil is energized, electromagnetic conditions are created in which the armature obtains the same magnetic polarity as that of the permanent magnet. As a result of such polarization, a repulsive force is created between the armature and the permanent magnet, which moves the armature linearly away from the non-magnetic spacer.

After inducing the current in the coil, its intensity should be sufficient not only to reverse the polarity of the armature, but also to create a force acting on the armature that will overcome the pressing force of the return spring.

The device is preferably provided with an end plate with an attracting pin connected to one end of the body, whereby an attraction force is induced between the attracting pin and the armature after energetically charging a single coil. The attractive force between the attracting pin and the armature is a result of the opposite polarity of the pin and armature after induction in the current coil.

The end plate with the pull pin is preferably mounted at the end opposite to the return spring.

In a preferred solution of the device, the return spring presses the armature against the non-magnetic spacer after an energy discharge of a single coil.

Preferably, the armature has a first polarity after single coil energy discharge, and a second polarity after single coil energy discharge. The second polarity of the armature is most preferably compatible with the polarity of the permanent magnet and opposite to that of the end plate.

Preferably, in its return position, the return spring biases the movable armature towards the non-magnetic spacer in the absence of current flow in a single coil.

The device preferably has a plurality of bypass elements arranged radially around the actuator between a single coil and a permanent magnet.

The device preferably comprises a housing in which there is a single coil, a movable armature, a non-magnetic spacer, and a body. In this solution, a plurality of bypass elements are advantageously connected to the body, most preferably arranged so that as the distance between these elements and the permanent magnet increases, the holding force between the movable armature and the permanent magnet decreases.

In yet another preferred embodiment of the device, an air gap is formed between the plurality of bypass elements and the housing.

In a further preferred embodiment, the device comprises a first magnetic circuit formed between the movable pin armature and a permanent magnet separated from the plunger by a non-magnetic spacer when the single coil wire is not energetically charged; and a second magnetic circuit formed between the plunger and the attracting member when the single coil wire is energetically charged.

Preferably, one end of the non-magnetic spacer rests against a permanent magnet, and its other end rests against a moving magnetic object in the absence of current induction in a single coil.

The return spring of the device is preferably located, at least partially, outside the solenoid.

The invention in the embodiment shown in the drawing, in which Fig. 1 shows the construction of a known solenoid in a side view with a partial longitudinal section, Fig. 2 - a solenoid according to the invention with coil off, in a longitudinal section, and Fig. 3 - the same power-on solenoid in longitudinal section.

2, the bi-directional, permanent magnet solenoid 32 of the present invention has a body 34 wrapped around which a single wire coil 36 is wrapped in a predetermined position at one end of solenoid 32. The body 34 has bypass elements 40 integral with the body 34. which are described in detail below. The body 34 is also provided with a non-magnetic spacer 42 adjacent the permanent magnet 38 and creating a fixed space or distance between the moving magnetic object 44 and the permanent magnet 38 in the event of a power failure to solenoid 32.

Figure 2 illustrates the solenoid 32 in a power-off position in which a movable magnetic target 44, such as a magnetic armature or a spindle, is separated from the permanent magnet 38 by a non-magnetic spacer 42. In the power-off solenoid position, that is, through the coil 36 zero or very little current flows, the moving magnetic object 44 has no polarity and is therefore attracted to the permanent magnet 38 with its characteristics. The attraction force created between the magnetic target 44 and the permanent magnet 38 keeps the magnetic target 44 pressed against the non-magnetic spacer 42. It should be obvious to those skilled in the art that the thickness of the non-magnetic spacer 42 is sufficient to obtain the desired holding force, so that the amount of energy / force needed for the latency of the magnetic target 44 when powered on could be adjusted for a particular application, and could vary. In order to obtain an additional biasing force, the actuator against the non-magnetic spacer 42 may optionally be used and connected to a magnetic object 44, such as an armature, a return spring 46. Thus, the force exerted on the magnetic target 44 consists of the forces generated by the permanent magnet 38 and the return spring 46. This allows for greater solenoid force to be obtained in its rest position or with power disconnected. When the coil 36 is energized, the magnetic target 44, like the armature, is magnetically polarized through the shunts 40, similar to the permanent magnet 38. The result is a repulsive force between the permanent magnet 38 and the magnetic target 44 which adds to the attraction force between the pin. attracting force 56 and magnetic object 44. This combined force must be sufficient to overcome the positioning force of the return spring 46.

The internal components of the solenoid 32 are enclosed in a relatively rigid and durable housing 50. An end plate 54 is attached to the end 52 of the housing opposite the end where the permanent magnet 38 is located, to which in turn the attracting pin 56 is attached. no current flows, then the attracting pin 56 and the magnetic object 44, such as the armature, have no real magnetic polarization. That is, there is no attraction force between the attracting pin 56 and the end of the magnetic object 44 in the vicinity of the attracting pin 56. In this case, the attraction forces of the permanent magnet 38 and the return spring 46 formed between them and the magnetic target 44 push this magnetic target 44 away from the attracting pin 56. Thus, the permanent magnet 38, the magnetic target 44 such as the armature, the shunting elements 40, and the solenoid housing 50 form a complete and efficient magnetic circuit that generates a relatively high attractive force on the magnetic target 44 due to the permanent magnet 38. The effect of the permanent magnet 38 on the magnetic target 44 is added to the force of the return spring 46, which generates a relatively high return force urging the magnetic target 44 into position against the non-magnetic spacer 42 in the event of a power failure to the coil 36.

The solenoid 32 includes bypass elements 40 which help to create a relatively large holding force to the magnetic target 44, such as an armature, in the event of a single coil 36 not being powered. The absence of these elements makes the magnetic path less efficient since the major part of the magnetic flux must flow through the magnetic target 44 and "jump" the relatively large air gap between the magnetic target 44 and the attracting pin 56. Moreover, the magnetic path length would be much longer, so a much greater force of the permanent magnet 38 would therefore be required. As a result, the operating point of the permanent magnet 38 would be much lower, which would reduce the holding force exerted by the permanent magnet 38 on the magnetic object 44. Effectiveness of bypass elements 40 it can be varied by varying the size of the air gap between the bypass members 40 and the housing 50. This pause not only affects the holding force acting on the magnetic target 44 in the event of a power failure, but also affects the amount of energy required to release the magnetic target 44 when energizing a single coil 36. Moreover, the axial location of the bypass elements 40 relative to the permanent magnet 38 also affects the holding force acting on the magnetic target 44 in the event of no power to the coil 36, and also the amount of energy required to release the magnetic target 44 in the event of a single coil 36 being energized. between the shunts 40 and the permanent magnet 38 increases, the holding force between the magnetic target 44 and the permanent magnet 38 then decreases. Therefore, the positioning of the bypass elements 40 with respect to the permanent magnet 38, the housing 50, the solenoid 32 and the magnetic target6

44 increases the efficiency of the magnetic circuit, resulting in an increase in the holding force in the de-energized position and a reduction in the energy required to release the magnetic target 44 while energizing a single coil 36.

With no or very little current flowing through a single coil 36 of wire wound around the body 34, the solenoid 32 is assumed to be in a de-energized state or position. In this position, the polarity of the magnetic target 44, such as the armature, depends on the polarity of the permanent magnet 38. The permanent magnet 38 generates a force attracting the magnetic target 44. The force of the permanent magnet 38 in combination with the positioning force of the return spring 46 creates a relatively high holding force on the magnetic target 44 which, as illustrated in Fig. 2, ensures the positioning of the magnetic target 44, such as armature, relative to the device or equipment with which the target is located. the magnetic 44 is engaged. Thus, in order to hold the magnetic target 44 in a rest position, no current is required to flow through a single coil 36.

Figure 3 shows the solenoid 32 in a position where current flows through a single coil 36. The polarity of the coil must be such that the bypass elements 40 have the same polarity as the face of the permanent magnet 38 which is adjacent to or contacts the magnetic target 44, such as the armature. The flow of current through the coil 36 causes the magnetic target 44 to be polarized the same as that of the permanent magnet 38. Accordingly, a repulsive force is created between the magnetic target 44 and the permanent magnet 38. Moreover, as the current flows through the coil 36, the polarization of the pole of the magnetic target 44 adjacent to the attracting pin 56 is opposite to that of the attracting pin 56, therefore, an attractive force is generated between the attracting pin 56 and the magnetic target 44. If the current through a single coil 36 is of sufficient amplitude, then the attraction force produced between the attracting pin 56 and the magnetic target 44 in conjunction with the repulsive force produced between the magnetic target 44 and the permanent magnet 36 will be sufficient to overcome the positioning force of the spring 46, which will in effect result in linear movement of the magnetic target 44 in the bore of the body 34 towards the end plate 54. Moreover, the recoil spring 46 is positioned and compressed such that, in the absence of current flow through the coil 36, the magnetic target 44 is withdrawn from the device or equipment with which it has been engaged.

The second magnetic circuit is formed by the housing 50, the end plate 54, the attracting pin 56, the magnetic target 44, and bypass elements 40 as the current passes through the single coil 36. The resulting electromagnetic conditions cause the magnetic target 44, such as the armature, to become a magnetic target. poles opposite to the poles of the permanent magnet 38, whereby a repulsive force is generated between them. This repulsive force, combined with the attractive force created between the attracting pin 56 and the magnetic target 44, minus the mechanical or positioning force of the return spring 46, effectively produces a greater tractive force on the magnetic target 44 than that achievable only from an electromagnetic coil. After the coil 36 is powered off, the return spring 46 retracts the magnetic target 44 until it contacts the non-magnetic spacer 42. Thus, the electromagnetic field decays as the magnetic target 44 approaches the permanent magnet 38 which attracts the magnetic target 44, adding this attraction force to the force of the return spring 46 applied to the magnetic object 44. Thus, the energy stored in the permanent magnet 38 is used to increase force acting on the magnetic object 44 in both directions of its displacement.

In an alternative embodiment of the invention, a second permanent magnet with a suitable magnetic orientation may be positioned between the attracting pin 56 and the end plate 54. The placement of the second permanent magnet aids the magnetic fine-tuning of the resultant force acting on the magnetic target 44. This means that the second permanent magnet may be oriented to increase the force exerted on the magnetic target 44 by the attracting pin 56. Additionally, a second set of bypass elements may be positioned within the coils of the magnetic alignment aid coil to obtain the desired resultant force on the magnetic target 44.

In general, according to an embodiment of the invention, the solenoid of an electromagnetic switching device comprises a magnetically conductive housing with a single coil of a wound wire disposed therein. The solenoid also contains a moving magnetic object located in a single coil bore that is susceptible to magnetic force when current flows through a single coil. The solenoid also includes a constant polarity permanent magnet that repels a moving magnetic target when current passes through a single coil, and attracts the end of a moving magnetic target when no current flows through the coil.

PL 207 196 B1

An embodiment of the invention relates to an electromagnetic switching device which comprises a body with a single coil wire wound thereon. In a single coil, just like a permanent magnet, there is a movable armature. The permanent magnet is separated from the armature by a non-magnetic spacer so that it attracts the armature when no current flows through the coil and pushes the armature away when current flows through the coil.

Another embodiment of the invention relates to a single coil electromagnetic switching device which comprises a first magnetic circuit formed between the movable pin armature and a spacer separated therefrom in the absence of current flow through the single coil winding, and a second magnetic circuit formed between the pin and the attracting elements at no current flowing through the single coil winding.

The embodiments of the invention presented in the description are exemplary, therefore modifications and alternative solutions defined by the scope of protection of the patent claims are possible.

List of designations known solenoid pulling coil spindle holding spindle housing mounting clamps return spring

24, 28 cover interrupting switch electrical connectors solenoid according to the invention body coil permanent magnet shunting elements non-magnetic spacer moving magnetic object (magnetic armature / pin) return spring housing housing end end plate pull pin