JP2011233664A - Solenoid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid in which, at the same time, the winding number of coils of an auxiliary spring can be sufficiently secured, and miniaturization of a device can be achieved.SOLUTION: In the solenoid 1, a plunger 4 is driven by magnetic field generated in a coil 12, and a shaft 5 coupled to this plunger 4 moves in a shaft direction. This solenoid includes: a coil-shaped auxiliary spring 66 by which the shaft 5 is energized in the shaft direction; and an adjuster 80 by which a spring force of this auxiliary spring 66 is adjusted. An auxiliary spring tip housing recess 57 is formed to a shaft 5 which houses the tip of the auxiliary spring 66 in the shaft.

Description

  The present invention relates to a solenoid that moves a shaft in an axial direction in accordance with an exciting current.

  Generally, a solenoid valve (electromagnetic valve) is widely used to control the operation of a hydraulic and pneumatic control mechanism provided in a vehicle (see Patent Document 1).

  Conventionally, a solenoid constituting this type of solenoid valve has a plunger driven by a magnetic field generated in a coil, a shaft coupled to the plunger, an auxiliary spring for urging the shaft in an axial direction, and the auxiliary spring. And an adjuster for adjusting the spring force.

By changing the screwing position of the adjuster, the contraction amount (spring length) of the coiled auxiliary spring is changed, and the spring force of the auxiliary spring is adjusted.
JP 2002-195439 A

  However, in such a conventional solenoid, since the shaft, the auxiliary spring, and the adjuster are arranged side by side in the axial direction, when the number of windings of the wire forming the auxiliary spring increases, the adjuster for the solenoid case is increased. There is a problem in that the amount of protrusion increases and the size of the apparatus increases.

  Further, when the number of windings of the wire rod increases, the auxiliary spring may be twisted and buckled by the frictional force applied from the end face of the adjuster when the screwing position of the adjuster is changed. For this reason, even if the torsion and buckling of the auxiliary spring is eliminated during operation of the solenoid, there is a problem that the accuracy of the spring load of the auxiliary spring adjusted by the adjuster is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a solenoid that can achieve both a sufficient number of coil turns of an auxiliary spring and a reduction in the size of the device. .

  The present invention relates to a solenoid that drives a plunger by a magnetic field generated in a coil and moves a shaft coupled to the plunger in the axial direction, and a coil-shaped auxiliary spring that urges the shaft in the axial direction, and the auxiliary And an adjuster for adjusting the spring force of the spring, and an auxiliary spring tip receiving recess for receiving the tip of the auxiliary spring is formed on the shaft.

  According to the present invention, in the solenoid, the tip of the auxiliary spring is housed in the auxiliary spring tip housing recess of the shaft, so that most of the auxiliary spring can be disposed inside the coil, and the amount of protrusion of the adjuster relative to the case can be suppressed. . As a result, it is possible to achieve both a sufficient number of coil turns of the auxiliary spring and a reduction in the size of the apparatus.

The sectional view of the solenoid which shows the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  A solenoid 1 shown in FIG. 1 drives a spool (valve element) (not shown) by electromagnetic force to switch the flow of hydraulic oil (working fluid).

  The solenoid 1 is attached to a mother machine mounted on a vehicle (not shown). The spool driven by the solenoid 1 is interposed in the hydraulic passage of the mother machine. In the mother machine, the hydraulic oil discharged from the hydraulic pump is guided to the hydraulic actuator in accordance with the position of the spool, and the hydraulic actuator is operated.

  Note that a working fluid such as a water-soluble alternative liquid may be used instead of the oil as the working oil.

  The solenoid 1 includes a case 9, a base 2, a plunger 4, a shaft 5, first and second bearings 7 and 8, a coil assembly 10, and the like as components. As will be described later, the plunger 4 and the shaft 5 are moved in the axial direction by the electromagnetic force of the coil assembly 10, and a spool (not shown) connected to the tip of the shaft 5 opens and closes the hydraulic passage of the mother machine. Yes.

  The coil assembly 10 includes an electromagnetic coil 12 disposed around the plunger 4, and constitutes an electromagnetic actuator that drives the plunger (movable iron core) 4 by a magnetic field generated in the coil 12.

  The coil assembly 10 includes a cylindrical bobbin 11 having flanges at both ends, a coil 12 formed by winding a magnet wire around the bobbin 11, and a pair of terminals coupled to both ends of the magnet wire of the coil 12. 13 and a mold resin 14 surrounding the coil 12.

  The mold resin 14 has a cylindrical surrounding portion 16 in which the bobbin 11 and the coil 12 are accommodated, and a connector portion 15 that protrudes from one end of the surrounding portion 16 and faces the terminal 13. A mating connector (not shown) is inserted into the connector portion 15. When the coil 12 is energized through the mating connector, a magnetic field is generated around the coil 12. Not limited to this, the coil 12 may be energized via a lead wire.

  As a magnetic path constituent member for guiding the magnetic flux of the coil 12, a case 9, a base 2, and a plunger 4 are provided, which are each formed of a magnetic material.

  The case 9 is formed in a bottomed cylindrical shape, and has a plurality of flange portions 91 protruding from the opening end portions thereof, and bolt holes 98 are opened in the flange portions 91. The case 9 is fastened to the mounting seat of the mother machine by a bolt (not shown) that passes through each bolt hole 98.

  A coil assembly 10 is accommodated inside the case 9. A notch 97 opening on the side surface of the case 9 is formed. The connector portion 15 protrudes from the cutout portion 97 to the outside of the case 9.

  A cylindrical sleeve 3 is provided on the back side of the case 9. In the figure, O is the center line of the shaft 5. The cylindrical base 2 and the sleeve 3 are arranged inside the case 9 so as to be coaxial with the center line O, and the shaft 5 and the plunger 4 are arranged inside each of them.

  Although the sleeve 3 is formed separately from the case 9, the sleeve 3 may be formed integrally with the case 9.

  The sleeve 3 is assembled by fitting its outer peripheral surface 31 to the inner peripheral surface of the bobbin 11. The outer peripheral surface 25 of the base 2 is fitted to the inner peripheral surface of the bobbin 11.

  The shaft 5 is made of a nonmagnetic material and is formed in a hollow cylindrical shape. The shaft 5 passes through the sleeve 3 and the base 2 and is supported so as to be slidable in the direction of the center line O via the first and second bearings 7 and 8. The first and second bearings 7 and 8 are made of a nonmagnetic material.

  The plunger 4 is made of a magnetic material and is formed in a hollow cylindrical shape. The inner peripheral surface of the plunger 4 is fitted to the outer peripheral surface of the shaft 5 and is coupled to the shaft 5 by welding or caulking. The plunger 4 is disposed between the first and second bearings 7 and 8.

  The sleeve 3 has a small-diameter sleeve inner peripheral surface 34 and a large-diameter sleeve inner peripheral surface 33 on the inner periphery thereof.

  The outer peripheral surface 81 of the second bearing 8 is fitted and attached to the inner peripheral surface 34 of the small diameter sleeve.

  An annular gap 55 is formed between the large-diameter sleeve inner peripheral surface 33 and the plunger outer peripheral surface 41.

  The base 2 has base inner peripheral surfaces 26 to 28 having different diameters on the inner periphery thereof.

  The base inner peripheral surface 26 having the smallest diameter defines a gap 56 between the base outer peripheral surface 51 and the outer peripheral surface 51 of the shaft 5.

  The outer peripheral surface 71 of the first bearing 7 is fitted and attached to the base inner peripheral surface 27 having the second smallest diameter.

  The base inner peripheral surface 28 having the largest diameter defines an annular gap 59 between the plunger outer peripheral surface 41.

  In the solenoid 1, a plunger front chamber 74, a plunger back chamber 75, and a second bearing back chamber 76 are provided around the shaft 5 and the plunger 4, and hydraulic oil from the mother machine is guided to these.

  The plunger front chamber 74 is defined between the first bearing 7 and the plunger front end surface 47.

  The 1st bearing 7 does not have a flow path which penetrates this, and fulfill | performs the function which interrupts | blocks the shortest path | route which the plunger front chamber 74 connects with respect to a main | base machine.

  The plunger back chamber 75 is defined between the rear end surface 48 of the plunger 4 and the second bearing 8.

  The plunger 4 is interposed between the plunger front chamber 74 and the plunger back chamber 75. An annular gap 55 is defined around the plunger outer peripheral surface 41 to prevent magnetic adsorption between the sleeve 3 and the plunger 4. The gap 55 constitutes a plunger outer circumferential path 63 that allows the plunger front chamber 74 and the plunger back chamber 75 to communicate with each other.

  A plurality of grooves 42 are formed in the plunger outer peripheral surface 41 as the plunger outer peripheral path 63. The hydraulic oil is configured to flow between the plunger front chamber 74 and the plunger back chamber 75 through the grooves 42.

  By defining the plunger outer circumferential path 63 by the plurality of grooves 42, the clearance of the gap 55 can be reduced, and the magnetic efficiency for driving the plunger 4 is enhanced.

  The second bearing back chamber 76 is provided behind the second bearing 8 and is defined between the second bearing 8 and an adjuster 80 described later on the inside of the sleeve inner peripheral surface 34.

  The second bearing 8 is interposed between the plunger back chamber 75 and the second bearing back chamber 76. A plurality of grooves 82 are formed on the outer peripheral surface 81 of the second bearing 8. These grooves 82 constitute a second bearing through passage 64 that allows the plunger back chamber 75 and the second bearing back chamber 76 to communicate with each other.

  A vertical through hole 53 that penetrates the shaft 5 in the direction of the center line O and a horizontal through hole 54 that penetrates the shaft 5 in the radial direction orthogonal to the center line O are formed. The vertical through hole 53 and the horizontal through hole 54 constitute a shaft through path 65 that communicates a valve chamber (not shown) and the second bearing rear chamber 76.

  A disc-shaped base collar portion 21 and a base fitting portion 22 are formed at one end of the base 2. In the base 2, the base flange portion 21 is coupled to the opening end portion of the case 9 and is disposed coaxially with the center line O.

  The end surface 96 of the case 9 abuts on a mounting seat of a mother machine (not shown).

  When the solenoid 1 is assembled to the mother machine, the cylindrical base fitting part 22 is fitted into the spigot part of the mother machine (not shown).

  After the solenoid 1 is assembled to the mother machine, the hydraulic oil from the mother machine is filled into the solenoid 1 through the following path.

  The hydraulic oil from the mother machine is filled into the second bearing rear chamber 76 through the valve chamber and the shaft through passage 65 (the horizontal through hole 54 and the vertical through hole 53).

  The hydraulic oil in the second bearing back chamber 76 is filled into the plunger back chamber 75 through the second bearing through passage 64 (groove 82).

  The hydraulic oil in the plunger back chamber 75 is filled into the plunger front chamber 74 through the plunger outer peripheral path 63 (gap 55, groove 42).

  A filler ring 6 that fits over the outer periphery of the sleeve 3 and the case 9 is provided. The filler ring 6 is formed in a thin cylindrical shape made of a nonmagnetic material. The filler ring 6 covers the magnetic gap 18 between the base 2 and the sleeve 3, and constitutes a pressure vessel that accommodates the plunger 4 and the shaft 5 by the sleeve 3 and the case 9. The solenoid 1 prevents hydraulic oil from leaking out of the solenoid 1 by a pressure vessel constituted by the sleeve 3, filler ring 6, case 9, and the like.

  The solenoid 1 drives the plunger 4 by the magnetic force of the coil 12, slides the shaft 5 coupled to the plunger 4 in the axial direction, and moves the spool.

  The base 2 is formed with a base adsorption surface 46 that adsorbs the plunger 4 by magnetic force. The base suction surface 46 is formed as an annular step between the base inner peripheral surface 27 and the base inner peripheral surface 28. The base suction surface 46 is formed in a planar shape orthogonal to the center line O and faces the plunger front end surface 47 in parallel.

  The base 2 has an annular tapered end surface 45 that is inclined with respect to the center line O. The position and shape (inclination angle with respect to the center line O) of the annular tapered end face 45 are arbitrarily set, and the magnetic flux density from the base 2 toward the plunger 4 is adjusted.

  On the other hand, the sleeve 3 has an annular end surface 35 orthogonal to the center line O. The annular end face 35 may be inclined without being orthogonal to the center line O.

  The magnetic flux generated inside the coil 12 is guided by the case 9, the base 2, the plunger 4, and the sleeve 3. Since the magnetic flux passing between the base 2 and the sleeve 3 is blocked by the magnetic gap 18, the magnetic flux is guided through the plunger 4 and travels from the base 2 to the plunger 4. The shape and position of the magnetic gap 18 are arbitrarily set so that a solenoid thrust corresponding to the stroke of the plunger 4 moving in the direction of the center line O can be obtained.

  The cylindrical plunger 4 is provided as a movable iron core that is driven by the magnetic force of the coil 12. As the exciting current flowing through the coil 12 increases, the plunger 4 is displaced in the left direction in the figure against the spring force of the counter spring (not shown).

  An adjuster (adjuster bolt) 80 that is screwed into the sleeve 3 is provided, and a coil-shaped auxiliary spring 66 is compressed and interposed between the base end portion of the shaft 5 and the adjuster 80. The shaft 5 and the spool are urged leftward in the drawing by the spring force of the auxiliary spring 66, and the tip of the shaft 5 is pushed out from the base 2.

  When the coil 12 is energized, the magnetic field generated inside the coil 12 drives the plunger 4 toward the base 2 to move the shaft 5 and the spool in the distal direction (left direction in the figure).

  When the shaft 5 slides in the front end direction, the volume of hydraulic oil from which the shaft 5 retreats from the second bearing back chamber 76 passes from the valve chamber in which the spool is accommodated through the shaft through passage 65 to the second bearing back chamber. 76.

  At this time, as the plunger 4 moves in the distal direction, the hydraulic oil corresponding to the moving volume of the plunger 4 flows from the plunger front chamber 74 that contracts into the plunger back chamber 75 that extends through the plunger outer circumferential path 63.

  When the energization of the coil 12 is stopped from this state, the shaft 5 slides in the proximal direction (rightward in the drawing) by the biasing force of the counter spring and the auxiliary spring 66, and the spool moves to the neutral position and is held. The

  Thus, when the shaft 5 slides in the proximal direction, the volume of hydraulic oil that the shaft 5 enters the second bearing back chamber 76 passes from the second bearing back chamber 76 to the mother machine through the shaft through passage 65 and the valve chamber. leak.

  At this time, when the plunger 4 moves rearward, the hydraulic oil corresponding to the moving volume of the plunger 4 flows from the plunger back chamber 75 that contracts into the plunger front chamber 74 that extends through the plunger outer peripheral path 63.

  By the way, the hydraulic fluid led from the mother machine to the solenoid 1 includes contaminations such as wear powder generated in the mother machine. Among these contaminants, magnetic iron powder or the like enters the strong magnetic field B where the magnetic flux concentrates between the base 2 and the end of the plunger 4 when entering the plunger front chamber 74 and the plunger back chamber 75 of the solenoid 1. get together. When many contaminants adhere to the surface of the magnetic material (base 2 and plunger 4) constituting the strong magnetic field part B, the following problems occur.

  The solenoid thrust that attracts the plunger 4 to the base attracting surface 46 of the base 2 is changed by the magnetic field generated around the coil 12.

  The sliding resistance of the plunger 4 increases, the hysteresis characteristic of the solenoid 1 increases, and the stroke range in which the plunger 4 slides is narrowed.

  In response to this, the solenoid 1 blocks communication between the valve chamber and the plunger front chamber 74 by the first bearing 7, and hydraulic fluid of the mother machine passes through the shaft passage 65, the second bearing rear chamber 76, and the second bearing. The plunger 64 is guided to the plunger back chamber 75 through the passage 64. As a result, the path for the contamination of the hydraulic oil to reach the strong magnetic field portion B around the plunger 4 is lengthened, and the contamination adheres to the surface of the magnetic material (base 2, plunger 4) constituting the strong magnetic field portion B, and accumulates. Can be suppressed. Thereby, the malfunction of the solenoid 1 resulting from the contamination of hydraulic oil can be prevented, and the movable time during which the solenoid 1 operates stably can be extended.

  Further, since the second bearing back chamber 76 expanded and contracted by sliding of the shaft 5 communicates with the plunger back chamber 75 via the second bearing through passage 64, pressure fluctuation from the mother machine is caused by the second bearing back chamber. Even when the pressure is transmitted to 76, the pressure fluctuation in the second bearing back chamber 76 is transmitted to the plunger back chamber 75 through the second bearing through passage 64, and the second bearing 8 is pressured in the second bearing back chamber 76 and the plunger back chamber 75. It is possible to prevent movement (dropout) due to the difference.

  The plunger outer circumferential path 63 includes an annular gap 55 defined around the plunger outer circumferential surface 41 to prevent magnetic adsorption between the sleeve 3 and the plunger 4, and a plurality of grooves 42 opened in the plunger outer circumferential surface 41. Therefore, when the plunger 4 moves, the flow rate of the hydraulic oil around the plunger 4 is suppressed, the viscous resistance of the hydraulic oil applied to the plunger 4 is reduced, and the operation responsiveness of the solenoid 1 is improved. Thus, when the plunger 4 moves at a high speed, the contamination accumulated on the plunger 4 is removed. Thereby, the malfunctioning of the solenoid 1 resulting from the contamination of hydraulic fluid can be prevented.

  Since the plunger outer circumferential path 63 includes a plurality of grooves 42 formed on the plunger outer circumferential surface 41, the flow path cross-sectional area of the plunger outer circumferential path 63 is expanded by these grooves 42. Thereby, when the plunger 4 moves, the flow of the hydraulic oil around the plunger 4 is suppressed, the viscosity resistance of the hydraulic oil applied to the plunger 4 is reduced, and the operation responsiveness of the solenoid 1 is improved.

  As described above, when the energization of the coil 12 is stopped, the solenoid thrust of the coil 12 is not generated, and the spool is held at the neutral position where the spring force of the counter spring and the auxiliary spring 66 is balanced.

  By changing the screwing position of the adjuster 80 to the sleeve 3, the contraction amount of the counter spring and the auxiliary spring 66 applied to the shaft 5 is increased and decreased, and the neutral position of the spool is adjusted.

  The adjuster 80 has a male screw portion 83 on its outer periphery, and this male screw portion 83 is screwed into a screw hole 39 formed on the inner periphery of the sleeve 3.

  A nut 50 is provided outside the solenoid 1 so as to be screwed into the male screw portion 83 of the adjuster 80. After the screwing position of the adjuster 80 is changed and the contraction amount of the counter spring and the auxiliary spring 66 is adjusted, the nut 50 is brought into contact with the end face of the sleeve 3 and fastened, whereby the adjuster 80 is prevented from loosening.

  An O-ring 52 is interposed between the adjuster 80 and the sleeve inner peripheral surface 34. The solenoid 1 is sealed through the O-ring 52 to prevent hydraulic oil from leaking out of the solenoid 1 by the pressure vessel formed by the sleeve 3, filler ring 6, case 9 and adjuster 80. .

  The adjuster 80 has an annular step 84 formed on the outer periphery thereof by expanding the diameter of the left end of the male screw 83 in the drawing. The adjuster 80 is inserted into the sleeve 3 from the base 2 side (left side in the figure) with respect to the sleeve 3, the male screw portion 83 is screwed into the screw hole 39 of the sleeve 3, and the step portion 84 is the end portion of the screw hole 39. , It is locked that the screwing position of the adjuster 80 further moves to the right in the drawing. This prevents the adjuster 80 from falling off the sleeve 3.

  At the end of the adjuster 80 facing the sleeve 3, an annular auxiliary spring base end receiving recess 85 for receiving the base end of the auxiliary spring 66 is formed.

  The auxiliary spring base end accommodating recess 85 is formed in a hole shape centered on the center line O, and a conical seat surface 86 is formed on the bottom thereof.

  A ball 90 is interposed between the base end of the auxiliary spring 66 and the bottom seat surface 86 of the auxiliary spring base end accommodating recess 85.

  The auxiliary spring 66 is formed by winding a linear spring material in a coil shape (spiral shape). Ring-shaped winding portions 67 and 68 each formed by winding a spring material in an annular shape are formed at the front end and the base end of the auxiliary spring 66, respectively. In the free state, the auxiliary spring 66 is formed such that the winding portions 67 and 68 at the distal end and the proximal end are along a plane substantially orthogonal to the center line O.

  The spherical ball 90 has an outer diameter larger than the inner diameter of the winding portion 68 of the auxiliary spring 66, and holds the auxiliary spring 66 seated on the outer peripheral surface on the center line O. In this state, the ball 90 is pressed against the conical seat surface 86 by the spring force of the auxiliary spring 66 and held on the center line O.

  The ball 90 is made of a metal such as steel, and the surface thereof is mirror-finished so that the friction coefficient with respect to the auxiliary spring 66 seated on the ball 90 is suppressed to a predetermined value or less.

  An annular auxiliary spring distal end accommodating recess 57 for accommodating the distal end portion of the auxiliary spring 66 is formed at the base end portion of the cylindrical shaft 5.

  The auxiliary spring tip accommodating recess 57 is formed by expanding the diameter of the base end portion of the vertical through hole 53 that passes through the shaft 5 in the direction of the center line O.

  The auxiliary spring tip accommodating recess 57 has an annular step 58 at the bottom thereof, and the annular step 58 is formed in a planar shape substantially perpendicular to the center line O. The auxiliary spring 66 abuts the winding portion 67 at the tip thereof on the annular step portion 58 and urges the shaft 5 to the left in the drawing so as to push out the shaft 5 from the base 2.

  As described above, in the present embodiment, the plunger 4 is driven by the magnetic field generated in the coil 12, and the shaft 5 coupled to the plunger 4 is moved in the axial direction to adjust the valve opening degree. A coil-shaped auxiliary spring 66 for urging the shaft 5 in the axial direction, and an adjuster 80 for adjusting the spring force (shrinkage amount) of the auxiliary spring 66. The auxiliary spring tip accommodating recess 57 for accommodating is formed.

  Based on the above configuration, in the solenoid 1, the tip of the auxiliary spring 66 is accommodated in the auxiliary spring tip accommodating recess 57 of the shaft 5, and most of the auxiliary spring 66 can be disposed inside the coil 12. The amount of protrusion of the adjuster 80 with respect to can be suppressed. As a result, it is possible to achieve both a sufficient number of coil turns of the auxiliary spring 66 and a reduction in the size of the apparatus.

  In the present embodiment, the adjuster 80 is configured to be formed with the auxiliary spring base end accommodating recess 85 for accommodating the base end of the auxiliary spring 66.

  Based on the above configuration, since the base end portion of the auxiliary spring 66 is housed in the auxiliary spring base end housing recess 85, the amount of protrusion of the adjuster 80 relative to the case 9 is suppressed. As a result, it is possible to achieve both a sufficient number of coil turns of the auxiliary spring 66 and a reduction in the size of the apparatus.

  In this embodiment, a spherical ball 90 is interposed between the adjuster 80 and the base end of the auxiliary spring 66, and the base end of the auxiliary spring 66 is slidably seated on the outer peripheral surface of the ball 90.

  Based on the above configuration, when adjusting the spring load for rotating the adjuster 80, when the base end of the auxiliary spring 66 slides with respect to the outer peripheral surface of the ball 90, the friction in the rotational direction applied to the base end of the auxiliary spring 66. Force is reduced. As a result, the auxiliary spring 66 can be prevented from being twisted, the auxiliary spring 66 can be prevented from buckling, and the spring load of the auxiliary spring 66 can be adjusted with high accuracy.

  In the present embodiment, a cylindrical base 2 and a sleeve 3 constituting a magnetic path are provided, and an adjuster 80 includes a male screw portion 83 screwed into a screw hole 39 of the sleeve 3 and a base end of the male screw portion 83. And a step portion 84 formed by expanding the diameter of the sleeve 3, and is inserted into the sleeve 3 from the base 2 side and screwed into the screw hole 39 of the sleeve 3.

  Based on the above configuration, the adjuster 80 is prevented from falling out of the sleeve 3 when the stepped portion 84 contacts the end of the screw hole 39.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The solenoid of the present invention is useful for hydraulic equipment, other machines and equipment.

DESCRIPTION OF SYMBOLS 1 Solenoid 2 Base 3 Sleeve 4 Plunger 5 Shaft 12 Electromagnetic coil 39 Screw hole 57 Auxiliary spring tip accommodation recessed part 66 Auxiliary spring 80 Adjuster 83 Male thread part 84 Step part 85 Auxiliary spring base end accommodation recessed part 90 Ball

Claims (3)

The plunger is driven by the magnetic field generated in the coil,
A solenoid that moves the shaft coupled to the plunger in an axial direction,
A coiled auxiliary spring for urging the shaft in the axial direction;
An adjuster for adjusting the spring force of the auxiliary spring;
The solenoid is characterized in that an auxiliary spring tip receiving recess for receiving the tip of the auxiliary spring is formed in the shaft. A spherical ball is interposed between the adjuster and the base end of the auxiliary spring,
The solenoid according to claim 1, wherein a base end of the auxiliary spring is slidably seated on an outer peripheral surface of the ball. A cylindrical base and a sleeve constituting a magnetic path are provided,
The adjuster is
A male screw portion screwed into the screw hole of the sleeve;
And a stepped portion formed by expanding the diameter at the base end of the male screw portion,
The solenoid according to claim 1, wherein the solenoid is inserted into the sleeve from the base side and is screwed into a screw hole of the sleeve.

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