JP2010074013A - Electromagnet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnet apparatus which is capable of reducing power consumption without increasing a current value of power supply to a coil more than necessary by approximating fixing a resultant resistance value for flow of a current of power supply to the coil against the temperature rise. <P>SOLUTION: A resistor 25 having a resistance value fixed against the temperature rise is connected in parallel to an NTC thermistor 24 having a negative temperature coefficient having such a characteristic that the resistance value curvilinearly decreases in accordance with the temperature rise due to power supply to a coil 16 or the like, to generate a parallel resultant resistance value approximately linearly decreasing in accordance with the temperature rise, and a resistance value of the coil 16 linearly increasing in accordance with the temperature rise and the parallel resultant resistance value approximately linearly decreasing in accordance with the temperature rise are added. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electromagnet device that attracts a movable iron core to a fixed iron core by energizing a coil, and more particularly to an electromagnet device that is applied to an electromagnetic valve that controls fluid.

In this type of electromagnet device, as disclosed in Patent Document 1, a thermistor having a characteristic in which a resistance value decreases as a temperature rises is connected in series with a coil, and the resistance value of the thermistor increases as the solenoid temperature rises due to energization. The decreasing resistance value is added to obtain a series combined resistance value, and a stable suction force is obtained regardless of the temperature rise.
Japanese Utility Model Publication No. 63-80813

  However, in such a conventional solenoid, the coil has a characteristic that the resistance value increases linearly as the temperature of the solenoid increases, whereas the thermistor has a characteristic that the resistance value decreases in a curve as the temperature increases. Therefore, the resistance value of the thermistor that decreases linearly is added to the resistance value of the coil that linearly increases with respect to the temperature rise, and the series combined resistance value of the coil and the thermistor is kept substantially constant with respect to the temperature rise. It is difficult to obtain the necessary attraction force where the current value flowing through the coil is minimized, and in the region where the combined resistance value is small, the current value flowing through the coil becomes larger than necessary, reducing the power consumption. There was a problem of wasting.

  An object of the present invention is to provide an electromagnet device capable of reducing power consumption without making the combined resistance value through which a current flowing through a coil flows substantially constant with respect to a temperature rise and increasing the current value flowing through the coil more than necessary. It is to provide.

In order to achieve this problem, the present invention has taken the following measures. That is,
A resistor with a constant resistance against temperature rise is connected in parallel to a thermistor that draws the movable iron core into the fixed core by energizing the coil and curbs the resistance value against temperature rise. Creates a parallel combined resistance value that decreases the resistance value almost linearly with respect to temperature rise, and connects the thermistor and resistor connected in parallel to the coil in series to increase linearly with temperature rise. This is an electromagnet device characterized by adding the resistance value of the above and the parallel combined resistance value decreasing substantially linearly with respect to the temperature rise. In this case, the coil may be wound around a coil bobbin, the thermistor may be disposed on the outer periphery of the coil wound around the coil bobbin, and the thermistor and the resistor may be integrally formed with the coil by a resin mold.

  As described in detail above, the invention according to claim 1 is connected in parallel to a thermistor having a characteristic that the resistance value decreases in a curve with a rise in temperature. Then, a parallel combined resistance value that decreases the resistance value substantially linearly with respect to the temperature rise is created, and the resistance value of the coil that increases linearly with respect to the temperature rise and decreases approximately linearly with respect to the temperature rise. Therefore, the added combined resistance value can be made substantially constant with respect to the temperature rise, and power consumption can be reduced without increasing the current value to be supplied to the coil more than necessary. Can be reduced.

  In addition to the effect of the invention described in claim 1, the invention described in claim 2 has a thermistor disposed on the outer periphery of the coil wound around the coil bobbin. The temperature at which the coil rises can be accurately detected, and the accuracy of the characteristic that decreases approximately linearly with respect to the temperature rise in the parallel combined resistance value of the resistance value of the thermistor and the resistance value of the resistor is achieved. It can be further enhanced. Furthermore, since the thermistor and the resistor are integrally formed with the coil by the resin mold, the thermistor and the resistor can be arranged together and the enlargement of the entire electromagnet device can be suppressed.

Hereinafter, an embodiment of the present invention in which an electromagnet device is applied to an electromagnetic valve will be described with reference to the drawings.
1 and 2, reference numeral 1 denotes a valve body of an electromagnetic valve, which is formed by penetrating an insertion hole 2 in the axial direction, and an electromagnet device 3 is detachably mounted on one side surface of the valve body 1. 2 is closed, and the lid member 4 is detachably attached to the other side of the valve body 1 to close the opening of the fitting hole 2 to the other side. In the insertion hole 2, a supply flow path P for supplying pressure fluid to the substantially central portion in the axial direction is opened, and two load flow paths are connected to fluid actuators (not shown) on both sides in the axial direction of the openings of the supply flow path P. A and B are opened, and discharge channels R connected to the low-pressure side are opened on the axially outer sides of the opening portions of the two load channels A and B, respectively. Reference numeral 5 denotes a spool-like valve element that is slidably inserted in the insertion hole 2 in the axial direction. When the electromagnet apparatus 3 shown in FIG. The supply channel P and one load channel A are switched and urged by force, and the other load channel B and the discharge channel R are switched and communicated. Further, the valve element 5 moves to the right end of FIG. 2 against the elastic force of the spring 6 by the attractive force generated by energizing the electromagnet device 3, and the supply flow path P and the other load flow path B Is switched and communicated with one load channel A and the discharge channel R. 7 is a terminal box for electrically connecting the electromagnet device 3 to the external power source E, and is detachably mounted on the upper surface of the valve body 1.

  The electromagnet device 3 is configured by assembling a cylindrical portion 8 and a coil portion 9 with a nut 10. The cylindrical portion 8 has a fixed iron core 11 screwed into an opening to one side of the fitting hole 2 of the valve body 1, and one end of a cylindrical member 12 formed of a nonmagnetic material is welded and fixed to the fixed iron core 11. A lid member 14 made of a magnetic material is welded and fixed to the other end opposite to one end of the member 12, and the movable iron core 13 sucked by the fixed iron core 11 is slid in the axial direction inside the cylinder member 12 and the lid member 14. It is inserted so as to be movable, and is provided to face the fixed iron core 11. Reference numeral 15 denotes a push rod provided through the fixed iron core 11 so as to be movable in the axial direction. One end of the push rod is in contact with the movable iron core 13 and the other end is in contact with the valve body 5. The valve body 5 is movably provided at the right end of FIG.

  In the coil portion 9, a disc-shaped end plate 18 is disposed at one end in the axial direction of a coil bobbin 17 around which the coil 16 is wound, and a cylindrical tube body 19 is disposed on the outer periphery of the coil bobbin 17. The cylindrical body 19 is provided with an opening along the axial direction on the upper side in FIG. 2, and a protruding piece 17 </ b> A is provided protruding from the opening so as to be provided at the axial end of the coil bobbin 17 and extending radially outward. The projecting piece 17A is provided with two conductive pin members 20A and 20B with a gap in the direction perpendicular to the plane of FIG. 2 (only the front conductive pin member 20A is shown in FIG. 2). 20A and 20B are provided so as to protrude in the axial direction, and the protruding end portions thereof are inserted into female terminal fittings 21A and 21B provided with a gap in the direction perpendicular to the plane of FIG. As with the conductive pin member 20A, only the front female terminal 21A is shown), and is electrically connected to the electrical wirings 22A and 22B from the external power source E. One conductive pin member 20A is electrically connected to the winding start end of the coil 16 by a lead wire 23A, and a thermistor 24 and a resistor 25 are connected in parallel to the lead wire 23A, and the coil 16 is connected in series. The thermistor 24 and the resistor 25 connected in parallel are arranged on the outer periphery of the coil 16 on the opening side of the cylindrical body 19. The other conductive pin member 20B is electrically connected to the winding end of the coil 16 through a lead wire 23B. The coil portion 9 is formed by integrally forming a coil bobbin 17 around which a coil 16 is wound, an end plate 18, a cylindrical body 19, conductive pin members 20A and 20B, lead wires 23A and 23B, a thermistor 24, and a resistor 25 using a resin mold. 26 is formed. In the electromagnet device 3, a fixed iron core 11 is screwed into an opening portion of the insertion hole 2 to one side of the valve body 1 to fix the tubular portion 8 to the valve body 1, and the coil portion 9 is attached to the tubular portion 8. The nut 10 that is fitted and screwed to the lid member 14 that is the projecting end of the cylindrical portion 8 is rotated to sandwich the coil portion 9 between one side surface of the valve body 1 and the nut 10. Then, the electromagnet device 3 attracts and moves the movable iron core 13 to the fixed iron core 11 by the attractive force generated by energizing the coil 16, and moves the valve body 5 to the right end of FIG. When the coil 16 is not energized, the attraction force disappears, and the elastic force of the spring 6 causes the movable core 13 to move back together with the valve body 5 to the state shown in FIG.

  As shown by line C in FIG. 3, the thermistor 24 has a characteristic that the resistance value is reduced in a curve with respect to a temperature rise caused by energization of the coil 16 or heat transfer from the pressure fluid flowing through the valve body 1. This is an NTC thermistor with a negative temperature coefficient. The parallel resistance composite value obtained by connecting the thermistor 24 and the resistor 25 having a constant resistance against temperature rise in parallel is a product of the resistance value of the thermistor 24 and the resistance value of the resistor 25, and the resistance of the thermistor 24. It is obtained by dividing by the sum of the value and the resistance value of the resistor 25, and as shown by the line D in FIG. As shown by line F in FIG. 3, the coil 16 linearly increases the resistance value with respect to the temperature rise. The combined resistance value obtained by adding the resistance value of the coil 16 indicated by the line F and the parallel combined resistance value indicated by the line D becomes substantially constant as the temperature rises as indicated by the line G in FIG.

Next, the operation of this configuration will be described.
The state of FIG. 2 shows a non-energized state of the coil 16 of the electromagnet device 3, and the valve body 5 is urged by the elastic force of the spring 6 and located at the left end, and the supply flow path P and one load flow The channel A is switched and communicated, and the other load channel B and the discharge channel R are switched and communicated. In the electromagnet device 3, the elastic force of the spring 6 is applied to the movable iron core 13 via the push rod 15, and the movable iron core 13 is separated from the fixed iron core 11.

  In this state, when the coil 16 of the electromagnet device 3 is energized, an attractive force is generated and the movable iron core 13 is attracted and moved to the fixed iron core 11. The valve body 5 is given a suction movement of the movable iron core 13 via the push rod 15 and moves to the right end in FIG. 2 against the elastic force of the spring 6, and the supply flow path P and the other load flow path B Are switched and communicated with one load channel A and the discharge channel R. When the coil 16 of the electromagnet device 3 is deenergized, the attractive force is eliminated, and the valve body 5 returns to the state shown in FIG. 2 by the elastic force of the spring 6. In the electromagnet device 3, the elastic force of the spring 6 is applied to the movable iron core 13 via the push rod 15, and the movable iron core 13 returns to the state shown in FIG. 2 and is separated from the fixed iron core 11.

  With such an operation, the NTC thermistor 24 having a negative temperature coefficient having a characteristic (curve C in FIG. 3) that reduces the resistance value in a curved manner with respect to the temperature rise has a resistance that is constant with respect to the temperature rise. A parallel combined resistance value (line D in FIG. 3) that decreases the resistance value substantially linearly with respect to the temperature rise is created by connecting the devices 25 in parallel, and the coil 16 that increases linearly with respect to the temperature rise. Since the resistance value (line F in FIG. 3) and the parallel combined resistance value (line D in FIG. 3) that decrease substantially linearly with respect to the temperature rise are added, the added combined resistance value is As shown by the line G in FIG. 3, it can be made substantially constant with respect to the temperature rise, and the power consumption can be reduced without increasing the current value supplied to the coil 16 more than necessary.

  Further, since the thermistor 24 is arranged on the outer periphery of the coil 16 wound around the coil bobbin 17, the thermistor 24 is positioned in the vicinity of the coil 16 that is a heat generation source, and the rising temperature of the coil 16 is accurately detected. Can do. Furthermore, since the thermistor 24 and the resistor 25 are integrally formed with the coil 16 by a resin mold, the thermistor 24 and the resistor 25 can be arranged together and the enlargement of the entire electromagnet device can be suppressed. it can.

  In one embodiment, the electromagnetic valve device 3 is mounted on one side of the valve body 1 and the valve body 5 is movable to two positions, the right end and the left end in FIG. Needless to say, the device 3 may be mounted on both side surfaces of the valve body 1 and the valve body 5 may be movably provided at three positions, ie, a substantially central position in the axial direction, a right end, and a left end. .

It is an electric circuit diagram of an electromagnet device showing an embodiment of the present invention. It is a longitudinal cross-sectional view of the solenoid valve to which the electromagnet apparatus of one Embodiment is applied. It is a graph which shows the characteristic of resistance value and temperature of one Embodiment.

Explanation of symbols

3: Electromagnet device 11: Fixed iron core 13: Movable iron core 16: Coil 24: Thermistor 25: Resistor

Claims (2)

  A resistor with a constant resistance against temperature rise is connected in parallel to a thermistor that draws the movable core into the fixed core by energizing the coil and reduces the resistance value in a curve with temperature rise. Then, a parallel composite resistance value that decreases the resistance value almost linearly with respect to the temperature rise is created, and a parallel-connected thermistor and resistor are connected in series with the coil to increase linearly with respect to the temperature rise. 2. An electromagnet device comprising: a resistance value of a coil and a parallel combined resistance value that decreases substantially linearly with respect to a temperature rise.   2. The coil according to claim 1, wherein the coil is wound around a coil bobbin, the thermistor is disposed on an outer periphery of the coil wound around the coil bobbin, and the thermistor and the resistor are integrally formed with the coil by a resin mold. The composite electromagnetic switching valve as described.

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