JP2019145652A - External force detection device of solenoid - Google Patents

Abstract

To detect the external force applied to a solenoid before plunger malfunction due to the external force applied to the solenoid.SOLUTION: A microcomputer 51 detects the external force applied to a solenoid 31 on the basis of a change in inductance of a drive coil 32 accompanying the movement of a detection body 54. The urging force of an external force detection spring 55 is smaller than the external force at which a plunger 34 starts to move due to the external force applied to the solenoid 31. Therefore, when the external force applied to the solenoid 31 exceeds the urging force of the external force detection spring 55, a detection body 54 moves against the urging force of the external force detection spring 55, however, the self-maintained state of the plunger 34 is maintained. Therefore, before malfunction of the plunger 34 due to the external force applied to the solenoid 31, a microcomputer 51 detects the external force applied to the solenoid 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solenoid external force detection device that detects an external force applied to a solenoid.

  The solenoid has a drive coil and a plunger that moves by excitation of the drive coil. Further, for example, Patent Document 1 discloses a movement failure detection device that monitors an inductance generated by excitation of a driving coil and detects a movement failure of a plunger based on a change in the inductance.

JP 2008-304041 A

  By the way, for example, even if an external force such as vibration or impact is applied to the solenoid and the plunger malfunctions, Patent Document 1 detects the position of the plunger by monitoring the change in inductance of the drive coil accompanying the movement of the plunger. Therefore, it is possible to detect a malfunction of the plunger due to an external force applied to the solenoid. However, when an external force is applied to the solenoid, the change in inductance of the drive coil does not occur before the plunger moves, so the external force applied to the solenoid is detected by monitoring the change in the inductance of the drive coil. I can't do it. Therefore, the external force applied to the solenoid cannot be detected before the plunger malfunctions due to the external force applied to the solenoid.

  The present invention has been made in order to solve the above-described problem, and an object of the present invention is to provide a solenoid that can detect the external force applied to the solenoid before the plunger malfunctions due to the external force applied to the solenoid. The object is to provide an external force detection device.

  A solenoid external force detection device that solves the above problem is a solenoid external force detection device that includes a drive coil and a plunger that is moved by excitation of the drive coil, wherein the detection body and the detection body are arranged in a certain direction. An external force detection spring that is held in a biased state, a detection coil for detecting the movement of the detection body, and the detection change that changes due to a change in the magnetic path length of the magnetic circuit accompanying the movement of the detection body An external force detection unit that detects an external force applied to the solenoid based on a change in inductance of the coil or a change in electromotive force of the detection coil that changes due to a change in magnetic flux accompanying the movement of the detection body; The urging force of the external force detection spring is smaller than the external force at which the plunger starts to move due to the external force applied to the solenoid.

  In the external force detection device for a solenoid, the external force detection unit may detect an external force applied to the solenoid based on a change in the inductance of the detection coil accompanying the movement of the detection body.

  In the solenoid external force detection device, the solenoid includes a fixed iron core having a suction surface that sucks the plunger, a plunger spring that biases the plunger in a direction in which the plunger separates from the suction surface, and the plunger When the direction of the current supplied to the driving coil is a forward direction, the magnetomotive force of the driving coil and the attractive force of the magnet However, when the plunger moves toward the suction surface against the biasing force of the plunger spring, and the plunger is attracted to the suction surface, the energization to the drive coil is stopped, When the plunger is self-held while being attracted to the attracting surface by the attraction force of the magnet, and the direction of the current applied to the drive coil is in the reverse direction The attraction force of the magnet is reduced by the magnetomotive force of the driving coil, the plunger is moved away from the attracting surface by the biasing force of the plunger spring, and the energization to the driving coil is stopped. Then, the biasing force of the plunger spring overcomes the attractive force of the magnet, and the plunger is self-held in a state of being separated from the attracting surface, and the driving coil also functions as the detection coil, The urging force of the external force detection spring may be smaller than the urging force of the plunger spring.

  In the solenoid external force detection device, the detection body and the external force detection spring may be housed in a housing recess formed in the plunger, and the detection body may be a sphere.

  In the solenoid external force detection device, the housing recess has a large-diameter hole that accommodates the detection body, an inner diameter smaller than the large-diameter hole, and is opposite to the detection body in the external force detection spring. Preferably, the detector has a small-diameter hole that accommodates the end portion, and a step surface that connects the large-diameter hole and the small-diameter hole, and the detection body is capable of contacting the step surface.

  According to the present invention, the external force applied to the solenoid can be detected before the plunger malfunctions due to the external force applied to the solenoid.

Sectional drawing of the self-holding-type solenoid valve in embodiment. Sectional drawing which expanded a part of self-holding type solenoid valve. Sectional drawing which shows a magnetic circuit. Sectional drawing which shows a magnetic circuit. Sectional drawing of a self-holding solenoid valve. Sectional drawing which expanded a part of self-holding type solenoid valve. The expanded sectional view of the self-holding type | mold solenoid valve which expands and shows the detection body periphery. Sectional drawing which shows the state in which the external force was added to the solenoid, when the plunger self-holds in the state adsorb | sucked to the fixed iron core. Sectional drawing which shows the state in which the external force was added to the solenoid, when the plunger is self-holding in the state spaced apart from the fixed iron core.

  An embodiment embodying a solenoid external force detection device will be described below with reference to FIGS. The solenoid external force detection device of this embodiment detects an external force applied to a solenoid used in a self-holding solenoid valve.

  As shown in FIG. 1, the body 11 of the self-holding solenoid valve 10 includes a long rectangular block-shaped valve body 12, a connection block 13 connected to one end side in the longitudinal direction of the valve body 12, and a connection block 13. It has a bottomed rectangular tube-shaped magnetic cover 14 connected to the opposite side to the valve body 12. The valve body 12, the connection block 13, and the magnetic cover 14 are made of, for example, a synthetic resin material. Therefore, the valve body 12, the connection block 13, and the magnetic cover 14 are made of a nonmagnetic material.

  As shown in FIG. 2, the valve body 12 is formed with a circular valve hole 16 that accommodates the spool valve 15 so as to reciprocate. The valve body 12 is formed with a supply port 17, an output port 18, and a discharge port 19. The supply port 17, the output port 18, and the discharge port 19 communicate with the valve hole 16 and are formed in the valve body 12 side by side in this order in the axial direction of the spool valve 15. In the axial direction of the spool valve 15, the discharge port 19 is located closer to the connection block 13 than the output port 18, and the supply port 17 is located opposite to the connection block 13 relative to the output port 18. . The self-holding solenoid valve 10 of this embodiment is a three-port solenoid valve.

  The valve hole 16 has a first hole 16a, a second hole 16b, a third hole 16c, and a fourth hole 16d having different hole diameters. The first hole 16a, the second hole 16b, the third hole 16c, and the fourth hole 16d are arranged in this order from the end surface of the valve body 12 opposite to the connection block 13 toward the connection block 13 and are spooled. Each extends in the axial direction of the valve 15. The second hole 16b has a smaller hole diameter than the first hole 16a. The third hole 16c has a smaller hole diameter than the second hole 16b. The fourth hole 16d has a larger hole diameter than the second hole 16b and the third hole 16c, and a smaller hole diameter than the first hole 16a.

  The first hole 16 a and the second hole 16 b are connected by an annular first step surface 16 e that extends in a direction orthogonal to the axial direction of the spool valve 15. The second hole 16b and the third hole 16c are connected by an annular second step surface 16f extending in a direction orthogonal to the axial direction of the spool valve 15. The third hole 16c and the fourth hole 16d are connected by an annular third step surface 16g extending in a direction orthogonal to the axial direction of the spool valve 15. The first hole 16 a communicates with the supply port 17 and the output port 18. The second hole 16 b communicates with the discharge port 19. The end of the first hole 16a opposite to the second hole 16b is a female screw hole 16h.

  The valve body 12 is provided with a bottomed cylindrical plug 20 that closes the end of the valve hole 16 opposite to the connection block 13. The plug 20 includes a disk-shaped bottom portion 20a and a cylindrical extending portion 20b extending along the inner peripheral surface of the valve hole 16 from the peripheral portion of the bottom portion 20a. A male screw 20c that is screwed into the female screw hole 16h is formed on the outer peripheral surface of the bottom portion 20a. The plug 20 is attached to the valve hole 16 of the valve body 12 by screwing the male screw 20c of the bottom portion 20a into the female screw hole 16h, and the bottom portion 20a is an end portion of the valve hole 16 opposite to the connecting block 13. Is blocked.

  A mounting hole 20d is formed in the bottom portion 20a. The mounting hole 20 d passes through the bottom 20 a in the axial direction of the spool valve 15. A manual suction shaft 21 is attached to the mounting hole 20d. The manual suction shaft 21 is mounted in the mounting hole 20d by being inserted into the mounting hole 20d from the inside of the extending portion 20b. The manual suction shaft 21 has an annular flange portion 21a that contacts the periphery of the mounting hole 20d on the inner surface of the bottom portion 20a. The flange portion 21a abuts against the inner surface of the bottom portion 20a, thereby preventing the flange portion 21a from falling out of the valve body 12 through the mounting hole 20d.

  The extending portion 20 b passes through the periphery of the opening to the first hole 16 a in the supply port 17 and extends to the periphery of the opening to the first hole 16 a in the output port 18. The inside of the extension part 20b communicates with the first hole 16a. A communication hole 20e is formed in a portion of the extending portion 20b that faces the supply port 17.

  On the outer peripheral surface of the extending portion 20b, an annular first seal that seals between the portion between the supply port 17 and the output port 18 on the inner peripheral surface of the first hole 16a and the outer peripheral surface of the extending portion 20b. A seal member 22a is attached. Then, the supply port 17 and the output port are interposed between the portion between the supply port 17 and the output port 18 on the inner peripheral surface of the first hole 16a and the outer peripheral surface of the extending portion 20b by the first seal member 22a. Fluid leakage between the two is regulated.

  Further, the outer peripheral surface of the extending portion 20b is a circle that seals between the portion of the inner peripheral surface of the first hole 16a opposite to the output port 18 from the supply port 17 and the outer peripheral surface of the extending portion 20b. An annular second seal member 22b is attached. Then, by the second seal member 22b, from the supply port 17 between the portion on the inner peripheral surface of the first hole 16a opposite to the output port 18 from the supply port 17 and the outer peripheral surface of the extending portion 20b. The leakage of fluid is regulated.

  The distal end surface of the extending portion 20 b faces the first step surface 16 e in the axial direction of the spool valve 15. An annular first valve seat 23 projects from the distal end surface of the extending portion 20b. An annular second valve seat 24 protrudes from the first step surface 16e. The second valve seat 24 extends toward the first valve seat 23, and the first valve seat 23 and the second valve seat 24 face each other in the axial direction of the spool valve 15. Between the 1st valve seat 23 and the 2nd valve seat 24 in the 1st hole 16a, it is the valve chamber 25 in which the valve body 15v with which the outer peripheral surface of the spool valve 15 was mounted | worn is accommodated.

  The spool valve 15 has a cylindrical shaft portion 15a and an annular large-diameter portion 15b protruding from the outer peripheral surface of the shaft portion 15a. The shaft portion 15a passes from the fourth hole 16d through the third hole 16c and the second hole 16b, protrudes into the first hole 16a, and enters the extension portion 20b of the plug 20. The outer diameter of the shaft portion 15a is the same as the hole diameter of the third hole 16c. When the spool valve 15 moves in the axial direction, the inner peripheral surface of the third hole 16c is in sliding contact with the outer peripheral surface of the shaft portion 15a and functions as a guide surface that guides the movement of the spool valve 15 in the axial direction.

  The valve body 15v is made of rubber and has an annular shape, and is attached to the large diameter portion 15b so as to cover the outer peripheral surface of the large diameter portion 15b. The valve body 15 v is disposed between the first valve seat 23 and the second valve seat 24 in the axial direction of the spool valve 15. The valve body 15v can be brought into contact with and separated from the first valve seat 23 and the second valve seat 24.

  A shaft member 26 is attached to the end surface of the shaft portion 15a on the plug 20 side. The shaft member 26 is disposed in the extending portion 20 b of the plug 20. The shaft member 26 includes a press-fit portion 26a, a large-diameter portion 26b having a larger diameter than the outer diameter of the press-fit portion 26a, and a shaft portion 26c continuous on the opposite side of the large-diameter portion 26b from the press-fit portion 26a. doing. The shaft member 26 is attached to the shaft portion 15a by the press-fit portion 26a being press-fitted into a press-fit hole 15c formed in the end surface of the shaft portion 15a on the plug 20 side, and moves together with the spool valve 15. Is possible. The outer diameter of the large diameter portion 26b is substantially the same as the inner diameter of the extending portion 20b. An end surface of the shaft portion 26c opposite to the large diameter portion 26b faces the suction manual shaft 21.

  In the extended portion 20 b, a space between the large diameter portion 26 b and the bottom portion 20 a of the plug 20 is a spring accommodating chamber 27. A valve spring 28 is accommodated in the spring accommodating chamber 27. The valve spring 28 is interposed between the large-diameter portion 26b and the manual suction shaft 21. The valve body spring 28 urges the shaft member 26 and the spool valve 15 in a direction in which the valve body 15 v is separated from the first valve seat 23.

  A packing 29 is attached to the outer peripheral surface of the large diameter portion 26b. The packing 29 is located on the bottom 20a side of the plug 20 with respect to the communication hole 20e of the plug 20. The packing 29 restricts fluid leakage from the supply port 17 to the spring accommodating chamber 27 between the outer peripheral surface of the large diameter portion 26b and the inner peripheral surface of the extending portion 20b.

  As shown in FIG. 1, the connecting block 13 is formed with a through hole 13 a that communicates with the valve hole 16. The axial center of the through hole 13 a coincides with the axial center of the valve hole 16. The magnetic cover 14 includes a bottom wall 14a and a peripheral wall 14b extending from the peripheral edge of the bottom wall 14a. The axis of the peripheral wall 14 b coincides with the axis of the through hole 13 a and the axis of the valve hole 16. An insertion hole 14c is formed in the bottom wall 14a. The axis of the insertion hole 14c coincides with the axis of the peripheral wall 14b.

  A magnetic frame 30 made of a magnetic material is embedded in the magnetic cover 14. The magnetic frame 30 includes a plate-like bottom portion 30a extending along the inner surface of the bottom wall 14a of the magnetic cover 14, a cylindrical extending portion 30b extending from the peripheral portion of the bottom portion 30a along the peripheral wall 14b of the magnetic cover 14, have. The magnetic frame 30 is integrated with the magnetic cover 14 by the extension portion 30 b being embedded in the peripheral wall 14 b of the magnetic cover 14. A portion on the tip side on the inner peripheral surface of the extending portion 30 b is exposed from the inner peripheral surface of the peripheral wall 14 b of the magnetic cover 14. A female screw hole 30c is formed in the bottom 30a. The female screw hole 30c is located inside the insertion hole 14c. The axis of the female screw hole 30c coincides with the axis of the insertion hole 14c.

  The self-holding solenoid valve 10 includes a solenoid 31. The solenoid 31 has a drive coil 32, a fixed iron core 33, a plunger 34, and a plunger spring 35. The fixed iron core 33 and the plunger 34 are made of a magnetic material. A cylindrical bobbin 36 around which the drive coil 32 is wound is accommodated in the magnetic cover 14. The axis of the bobbin 36 coincides with the axis of the peripheral wall 14 b of the magnetic cover 14.

  The fixed iron core 33 is accommodated in the magnetic cover 14. The fixed iron core 33 includes a shaft portion 33a and an annular flange portion 33b protruding from the end portion of the shaft portion 33a in a direction orthogonal to the axial direction of the shaft portion 33a. The shaft portion 33 a is inserted into the bobbin 36 from the bottom wall 14 a side of the magnetic cover 14. The axial length of the shaft portion 33 a is shorter than the axial length of the bobbin 36. An end surface 33e opposite to the flange portion 33b in the shaft portion 33a has a flat surface shape. The flange portion 33b is in contact with the surface of the bobbin 36 on the bottom wall 14a side of the magnetic cover 14.

  The plunger 34 has a columnar shape protruding from the inside of the bobbin 36 into the through hole 13 a of the connection block 13. The plunger 34 is located closer to the valve body 12 than the fixed iron core 33. The axis of the plunger 34 coincides with the axis of the shaft portion 33 a of the fixed iron core 33. The end surface 34a of the plunger 34 on the fixed iron core 33 side is a flat surface. The end surface 34 a of the plunger 34 can come into surface contact with the end surface 33 e of the shaft portion 33 a of the fixed iron core 33.

  An annular flange 34 c protrudes from the outer peripheral surface of the plunger 34. The flange 34 c protrudes from the end of the plunger 34 on the end surface 34 b side opposite to the fixed iron core 33 on the outer peripheral surface of the plunger 34. The flange portion 34 c is located inside the through hole 13 a of the connection block 13.

  An accommodation recess 60 is formed on the end surface 34 b of the plunger 34. The housing recess 60 extends in the axial direction of the plunger 34. A portion on the end surface 34 b side of the plunger 34 in the housing recess 60 is a female screw hole 61. A columnar plunger plug 62 is attached to the female screw hole 61. The opening of the housing recess 60 is closed by a plunger plug 62.

  The plunger plug 62 is made of a synthetic resin material. Therefore, the plunger plug 62 is made of a nonmagnetic material. The plunger plug 62 includes a screw portion 63 that is screwed into the female screw hole 61, and a columnar protrusion portion 64 that is continuous with the screw portion 63 and protrudes from the housing recess 60.

  As shown in FIG. 2, the protruding portion 64 is continuous with the screw portion 63 and has an outer diameter that is larger than that of the screw portion 63, and an end portion of the intermediate diameter portion 64 a opposite to the screw portion 63. A large-diameter portion 64b that is continuous and has an outer diameter larger than the outer diameter of the medium-diameter portion 64a. The large diameter portion 64 b of the protruding portion 64 protrudes from the through hole 13 a of the connecting block 13 into the fourth hole 16 d of the valve body 12. An end face 64e on the opposite side of the medium diameter part 64a in the large diameter part 64b of the protruding part 64 can contact and separate from the shaft part 15a of the spool valve 15.

  The manual shaft recess 34d is formed by the end surface 34b of the plunger 34, the outer peripheral surface of the medium diameter portion 64a of the protrusion 64, and the annular step surface 64c that connects the medium diameter portion 64a and the large diameter portion 64b. The manual shaft recess 34d is continuous with the flange 34c.

  As shown in FIG. 1, a bottomed cylindrical accommodating member 37 is accommodated in the magnetic cover 14. The housing member 37 is disposed between the bobbin 36 and the bottom 30 a of the magnetic frame 30 in the axial direction of the plunger 34. The housing member 37 includes a plate-shaped bottom portion 37a and a cylindrical extending portion 37b extending from the peripheral edge portion of the bottom portion 37a along the inner peripheral surface of the peripheral wall 14b of the magnetic cover 14. An insertion hole 37c is formed in the bottom portion 37a. The axial center of the insertion hole 37 c coincides with the axial center of the female screw hole 30 c of the magnetic frame 30.

  The flange portion 33 b of the fixed iron core 33 is located inside the housing member 37. The outer peripheral surface of the flange portion 33 b is in contact with the inner peripheral surface of the extending portion 37 b of the housing member 37. A plate-like magnet 38 is housed inside the housing member 37. The magnet 38 is disposed between the fixed iron core 33 and the bottom portion 37 a of the housing member 37 in the axial direction of the plunger 34. The outer peripheral surface of the magnet 38 is in contact with the inner peripheral surface of the extending portion 37 b of the housing member 37.

  A first magnetic core 39 is screwed into the female screw hole 30 c of the magnetic frame 30. The first magnetic core 39 includes a screw portion 39b having a male screw 39a formed on the outer peripheral surface, and a columnar insertion portion 39c that protrudes from the screw portion 39b and is inserted into the insertion hole 37c of the housing member 37. ing. An end surface of the insertion portion 39c opposite to the screw portion 39b is in contact with the magnet 38. The outer peripheral surface of the insertion part 39c is in contact with the inner peripheral surface of the insertion hole 37c.

  As shown in FIGS. 3 and 4, in the self-holding solenoid valve 10, the magnetic flux of the magnet 38 is generated as shown by the solid line arrow. The magnetic flux of the magnet 38 passes through the magnet 38 → the flange 34 c of the fixed iron core 33 → the housing member 37 → the insertion part 39 c of the first magnetic core 39 → the magnet 38.

  As shown in FIG. 1, a cylindrical second magnetic core 40 is disposed inside the tip side of the magnetic frame 30. The second magnetic core 40 is located closer to the connecting block 13 than the bobbin 36 in the axial direction of the plunger 34. The outer peripheral surface of the second magnetic core 40 is in contact with the tip side portion of the inner peripheral surface of the extending portion 30 b of the magnetic frame 30. The plunger 34 passes through the inside of the second magnetic core 40.

  The plunger spring 35 is interposed between the second magnetic core 40 and the flange portion 34 c of the plunger 34. One end of the plunger spring 35 is supported by the end surface of the second magnetic core 40, and the other end of the plunger spring 35 is supported by the flange portion 34 c of the plunger 34. The plunger spring 35 urges the plunger 34 in a direction in which the end surface 34 a of the plunger 34 is separated from the end surface 33 e of the shaft portion 33 a of the fixed iron core 33. The urging force of the plunger spring 35 is larger than the urging force of the valve body spring 28.

  As shown in FIG. 2, a manual shaft accommodation hole 42 is formed in the connection block 13. The manual shaft accommodation hole 42 extends in a direction orthogonal to the axial direction of the plunger 34 and communicates with the through hole 13a. A columnar detachable manual shaft 43 is accommodated in the manual shaft accommodation hole 42. The detachable manual shaft 43 can reciprocate in the manual shaft accommodation hole 42. The distal end portion of the detachable manual shaft 43 can be projected and retracted with respect to the manual shaft accommodation hole 42. An inclined surface 43 a is formed at the distal end of the detachment manual shaft 43. The inclined surface 43 a is formed on the valve body 12 side at the distal end portion of the manual shaft 43 for detachment. The inclined surface 43a can be slidably brought into contact with the corner 34e on the valve body 12 side of the manual shaft recess 34d when the distal end portion of the manual shaft 43 for detachment protrudes from the manual shaft receiving hole 42. The corner 34e is tapered.

  A return spring 44 is housed in the manual shaft housing hole 42. The return spring 44 urges the detachment manual shaft 43 in a direction in which the distal end portion of the detachment manual shaft 43 is inserted into the manual shaft accommodation hole 42. Further, an insertion hole 43 h that penetrates in a direction orthogonal to the moving direction of the detachment manual shaft 43 is formed in the detachment manual shaft 43. A columnar insertion member 45 supported by the connection block 13 is inserted into the insertion hole 43h. There is a relatively large gap between the insertion member 45 and the inner peripheral surface of the insertion hole 43h in the moving direction of the manual shaft 43 for detachment. The detachable manual shaft 43 is movable in the manual shaft accommodation hole 42 by the gap between the insertion member 45 and the inner peripheral surface of the insertion hole 43h. The movement of the detachment manual shaft 43 due to the urging force of the return spring 44 is regulated by the inner peripheral surface of the insertion hole 43 h coming into contact with the insertion member 45, and the detachment manual shaft 43 jumps out of the manual shaft accommodation hole 42. There is no such thing.

  As shown in FIG. 1, the self-holding solenoid valve 10 includes a control board 50 that controls energization of the drive coil 32. A microcomputer 51 is mounted on the control board 50. The drive coil 32 is electrically connected to the control board 50 via the drive coil terminal 32a. The self-holding solenoid valve 10 includes a power feeding unit 52. A power source (not shown) is connected to the power supply unit 52.

  Then, when an input voltage is applied from the power source to the control board 50 via the power supply unit 52, energization from the control board 50 to the driving coil 32 is started. The microcomputer 51 controls the drive of the control board 50 so that the direction of the current supplied to the drive coil 32 is forward or reverse.

  As shown in FIG. 3, for example, when the direction of the current supplied to the drive coil 32 is the forward direction, as indicated by the two-dot chain line arrow, the fixed iron core 33 → the plunger 34 → the second magnetic core 40 → A magnetic circuit through which magnetic flux passes is formed in the order of the magnetic frame 30 → the first magnetic core 39 → the magnet 38 → the fixed iron core 33. The direction in which the magnetic flux of this magnetic circuit passes is the same as the direction in which the magnetic flux of the magnet 38 passes. The magnetic circuit is formed by exciting the drive coil 32.

  The magnetomotive force of the drive coil 32 acts in the direction in which the plunger 34 is attracted toward the fixed iron core 33, and the magnetomotive force of the drive coil 32 and the attractive force of the magnet 38 resist the urging force of the plunger spring 35. Thus, the plunger 34 moves together with the plunger plug 62 in a direction in which the end surface 34 a of the plunger 34 approaches the end surface 33 e of the shaft portion 33 a of the fixed iron core 33. Therefore, the plunger 34 is moved by the excitation of the driving coil 32.

  Further, the plunger 34 moves in a direction in which the end surface 34 a of the plunger 34 approaches the end surface 33 e of the shaft portion 33 a of the fixed iron core 33, and the end surface 34 a of the plunger 34 is attracted to the end surface 33 e of the shaft portion 33 a of the fixed iron core 33. The Therefore, the end surface 33 e of the shaft portion 33 a of the fixed iron core 33 is an adsorption surface that adsorbs the plunger 34.

  As the plunger 34 moves, the shaft member 26 and the spool valve 15 are moved in a direction in which the valve body 15v is separated from the first valve seat 23 by the biasing force of the valve body spring 28, and the valve body 15v is moved to the second valve. Sit on the seat 24. Thereby, as shown in FIGS. 1 and 2, the supply port 17 and the output port 18 communicate with each other through the communication hole 20 e, the extension portion 20 b, and the valve chamber 25, and are supplied from the supply port 17. The fluid is supplied to the fluid pressure device through the communication hole 20e, the inside of the extending portion 20b, and the valve chamber 25.

  When the energization of the drive coil 32 is stopped, the magnetomotive force of the drive coil 32 is not generated, but the attractive force of the magnet 38 overcomes the urging force of the plunger spring 35 and the end surface 34a of the plunger 34 is fixed to the fixed iron core 33. Is held by the end surface 33e of the shaft portion 33a. Therefore, in the state where the end surface 34 a of the plunger 34 is attracted to the end surface 33 e of the shaft portion 33 a of the fixed iron core 33, when the energization to the driving coil 32 is stopped, the attractive force of the magnet 38 is applied to the plunger spring 35. The urging force of the plunger spring 35 is set so as to overcome the urging force. Therefore, the magnet 38 holds the plunger 34 in a state in which the plunger 34 is attracted to the end surface 33 e of the shaft portion 33 a of the fixed iron core 33.

  As shown in FIG. 4, for example, when the direction of the current supplied to the drive coil 32 is opposite, the fixed iron core 33 → the magnet 38 → the first magnetic core 39 → A magnetic circuit through which the magnetic flux passes is formed in the order of the magnetic frame 30 → the second magnetic core 40 → the plunger 34 → the fixed iron core 33. The direction in which the magnetic flux of the magnetic circuit passes is opposite to the direction in which the magnetic flux of the magnet 38 passes. Then, the attractive force of the magnet 38 is reduced by the magnetomotive force of the driving coil 32.

  As shown in FIGS. 5 and 6, when the attractive force of the magnet 38 is reduced by the magnetomotive force of the driving coil 32, the urging force of the plunger spring 35 overcomes the attractive force of the magnet 38 and the end surface 34 a of the plunger 34. The plunger 34 moves together with the plunger plug 62 in a direction away from the end surface 33 e of the shaft portion 33 a of the fixed iron core 33. Then, the urging force of the plunger spring 35 overcomes the urging force of the valve spring 28, so that the end surface 64 e of the projecting portion 64 of the plunger plug 62 abuts against the shaft portion 15 a of the spool valve 15, and the spool valve 15 and the shaft member. 26 is pressed, the valve body 15v moves away from the second valve seat 24, and the valve body 15v is seated on the first valve seat 23. As a result, the output port 18 and the discharge port 19 communicate with each other via the valve chamber 25 and the second hole 16b, and fluid flows from the output port 18 to the outside via the valve chamber 25, the second hole 16b, and the discharge port 19. Is discharged.

  Further, when the energization to the driving coil 32 is stopped, the magnetomotive force of the driving coil 32 is not generated. At this time, since the end surface 34a of the plunger 34 is separated from the end surface 33e of the shaft portion 33a of the fixed iron core 33, the urging force of the plunger spring 35 overcomes the attractive force of the magnet 38, and the end surface 34a of the plunger 34 is fixed. The iron core 33 is self-held in a state of being separated from the end surface 33e of the shaft portion 33a. Therefore, when energization of the drive coil 32 is stopped in a state where the end surface 34 a of the plunger 34 is separated from the end surface 33 e of the shaft portion 33 a of the fixed iron core 33, the biasing force of the plunger spring 35 is attracted by the magnet 38. The biasing force of the plunger spring 35 is set so as to overcome the force.

  Thus, in the self-holding solenoid valve 10, the drive coil 32 is energized when switching between the state in which the supply port 17 and the output port 18 communicate with each other and the state in which the output port 18 and the discharge port 19 communicate with each other. State. In the self-holding solenoid valve 10, when the supply port 17 and the output port 18 are kept in communication with each other, or when the output port 18 and the discharge port 19 are kept in communication with each other, the driving coil is used. There is no need to energize 32.

  In addition, when the power to the drive coil 32 is stopped while the end surface 34a of the plunger 34 is attracted to the end surface 33e of the shaft portion 33a of the fixed iron core 33, if the release manual shaft 43 is pressed, The distal end portion of the manual shaft 43 for projection protrudes from the manual shaft receiving hole 42, and the inclined surface 43a of the distal end portion of the manual shaft 43 for separation comes into sliding contact with the corner portion 34e of the manual shaft concave portion 34d. In a direction in which the end surface 34a of the plunger 34 is separated from the end surface 33e of the shaft portion 33a of the fixed iron core 33 by the sliding contact between the inclined surface 43a of the tip portion of the manual shaft 43 for detachment and the corner portion 34e of the manual shaft recess 34d. The plunger 34 moves with the plunger plug 62. Then, the plunger plug 62 presses the spool valve 15 and the shaft member 26, the valve body 15 v moves in a direction away from the second valve seat 24, and the valve body 15 v is seated on the first valve seat 23. As a result, the output port 18 and the discharge port 19 communicate with each other via the valve chamber 25 and the second hole 16b. Thus, in the self-holding solenoid valve 10 of the present embodiment, the supply port 17 and the output port 18 communicate with each other without energizing the drive coil 32 by pressing the manual release shaft 43. The output port 18 and the discharge port 19 can be switched to the state in which the output port 18 and the discharge port 19 communicate with each other, and the operation of the self-holding electromagnetic valve 10 can be confirmed.

  Then, by releasing the pressing of the detaching manual shaft 43, the detaching manual shaft 43 is returned to the original position before the detaching manual shaft 43 is pressed by the urging force of the return spring 44. At this time, since the end surface 34a of the plunger 34 is separated from the end surface 33e of the shaft portion 33a of the fixed iron core 33, the urging force of the plunger spring 35 overcomes the attractive force of the magnet 38, and the end surface 34a of the plunger 34 is fixed. The iron core 33 is self-held in a state of being separated from the end surface 33e of the shaft portion 33a.

  Further, in the state where the end face 34a of the plunger 34 is separated from the end face 33e of the shaft portion 33a of the fixed iron core 33, when the energization to the driving coil 32 is stopped, the suction manual shaft 21 is moved to the shaft portion 26c. Is pressed against the shaft portion 26c, the shaft portion 26c and the spool valve 15 are pressed by the suction manual shaft 21. Then, the shaft portion 26c and the spool valve 15 move in a direction in which the valve body 15v moves away from the first valve seat 23, and in a direction in which the end surface 34a of the plunger 34 approaches the end surface 33e of the shaft portion 33a of the fixed iron core 33. The plunger 34 moves together with the plunger plug 62, and the valve body 15 v is seated on the second valve seat 24. As a result, the supply port 17 and the output port 18 communicate with each other through the communication hole 20 e, the inside of the extending portion 20 b, and the valve chamber 25. As described above, in the self-holding solenoid valve 10 according to the present embodiment, the output port 18 and the discharge port 19 communicate with each other without energizing the drive coil 32 by pressing the manual suction shaft 21. It is possible to switch from the above state to the state where the supply port 17 and the output port 18 communicate with each other, and the operation of the self-holding solenoid valve 10 can be confirmed.

  Then, by releasing the pressing of the suction manual shaft 21, the suction manual shaft 21 is returned to the original position before the suction manual shaft 21 is pressed by the urging force of the valve spring 28. At this time, the attracting force of the magnet 38 overcomes the urging force of the plunger spring 35, whereby the end surface 34 a of the plunger 34 is self-held in a state of being attracted to the end surface 33 e of the shaft portion 33 a of the fixed iron core 33.

  As shown in FIG. 7, the accommodating recess 60 formed in the plunger 34 includes a large diameter hole 60a, a small diameter hole 60b whose inner diameter is smaller than the large diameter hole 60a, a large diameter hole 60a, and a small diameter hole 60b. And an annular stepped surface 60c to be connected. The end of the large diameter hole 60 a opposite to the small diameter hole 60 b is continuous with the female screw hole 61.

  The self-holding solenoid valve 10 includes an external force detection device 53 that detects an external force such as vibration or impact applied to the solenoid 31. The external force detection device 53 includes three detection bodies 54 made of a magnetic material that is a sphere, and an external force detection spring 55 that holds the detection body 54 in a state of being biased in a certain direction. The three detection bodies 54 and the external force detection spring 55 are housed in the housing recess 60. The three detectors 54 are accommodated in the large-diameter hole 60a along a straight line in the axial direction of the plunger 34. Therefore, the large diameter hole 60 a accommodates the three detection bodies 54. The three detection bodies 54 can roll in the large-diameter hole 60a while their outer peripheral surfaces are in contact with the inner peripheral surface of the large-diameter hole 60a.

  One end of the external force detection spring 55 is supported by the bottom surface of the housing recess 60, and the other end of the external force detection spring 55 is supported by the detection body 54 closest to the bottom surface of the housing recess 60 among the three detection bodies 54. Has been. Therefore, the small-diameter hole 60b accommodates the end of the external force detection spring 55 opposite to the detection body 54. The urging force Fs1 of the external force detection spring 55 is smaller than the urging force Fs2 of the plunger spring 35. The detection body 54 is disposed at a position where the attractive force of the magnet 38 is smaller than the biasing force Fs1 of the external force detection spring 55.

  The three detection bodies 54 are biased toward the plunger plug 62 by the biasing force Fs1 of the external force detection spring 55. The three detection bodies 54 are held by the external force detection spring 55 in a state where the detection body 54 closest to the plunger plug 62 among the three detection bodies 54 is pressed against the plunger plug 62. Of the three detectors 54, the detector 54 closest to the plunger plug 62 can be brought into and out of contact with the plunger plug 62. When the external force Fe1 applied to the solenoid 31 exceeds the biasing force Fs1 of the external force detection spring 55, the three detection bodies 54 are accommodated in a direction away from the plunger plug 62 against the biasing force of the external force detection spring 55. It moves in the recess 60.

  Of the three detectors 54, the detector 54 closest to the bottom surface of the housing recess 60, that is, the detector 54 closest to the small-diameter hole 60b among the three detectors 54 can contact the step surface 60c. Of the three detectors 54, the detector 54 closest to the small diameter hole 60 b is located inside the drive coil 32.

  When the external force Fe1 applied to the solenoid 31 exceeds the urging force Fs1 of the external force detection spring 55, the plunger 34 is maintained in a self-held state. Therefore, the urging force Fs1 of the external force detection spring 55 is smaller than the external force Fe2 at which the plunger 34 starts to move due to the external force applied to the solenoid 31.

  The microcomputer 51 detects an external force applied to the solenoid 31 based on a change in magnetic path length acting on the driving coil 32 accompanying the movement of the detection body 54, that is, a change in inductance due to a change in plunger stroke. The inductance of the driving coil 32 changes due to a change in the magnetic path length of the magnetic circuit accompanying the movement of the detection body 54. The microcomputer 51 functions as an external force detection unit that detects an external force applied to the solenoid 31. Therefore, in the present embodiment, the external force detection unit included in the external force detection device 53 is the microcomputer 51 mounted on the control board 50 that controls the energization of the drive coil 32. Therefore, the drive coil 32 also functions as a detection coil for detecting the movement of the detection body 54.

Next, the operation of this embodiment will be described.
As shown in FIG. 8, it is assumed that an external force is applied to the solenoid 31 when the end surface 34 a of the plunger 34 is held by itself while being attracted to the end surface 33 e of the shaft portion 33 a of the fixed iron core 33. At this time, when the external force Fe1 applied to the solenoid 31 exceeds the biasing force Fs1 of the external force detection spring 55, the three detection bodies 54 are separated from the plunger plug 62 against the biasing force of the external force detection spring 55. It moves in the accommodating recess 60 in the direction. At this time, the plunger 34 is self-held in a state in which the end surface 34 a of the plunger 34 is attracted to the end surface 33 e of the shaft portion 33 a of the fixed iron core 33 by the attractive force of the magnet 38. Therefore, the urging force Fs1 of the external force detection spring 55 is caused by the external force applied to the solenoid 31 when the end surface 34a of the plunger 34 is held by the end surface 33e of the shaft portion 33a of the fixed iron core 33. It is smaller than the external force Fe2 at which the plunger 34 starts to move.

  Of the three detectors 54, the detector 54 closest to the small-diameter hole 60b moves inside the drive coil 32 in the axial direction of the plunger 34, whereby an electromotive force is generated in the drive coil 32, and the drive The inductance of the coil 32 for use changes. The microcomputer 51 detects an external force applied to the solenoid 31 based on a change in inductance of the driving coil 32 accompanying the movement of the detection body 54. Thus, the external force applied to the solenoid 31 is detected before the plunger 34 malfunctions due to the external force applied to the solenoid 31. The microcomputer 51 controls the drive of the control board 50 so that the direction of the current supplied to the drive coil 32 is the forward direction, and supplies the drive coil 32 with current. Thus, in addition to the attractive force of the magnet 38, the magnetomotive force of the driving coil 32 assists the solenoid 31 in order to assist the end surface 34a of the plunger 34 being attracted to the end surface 33e of the shaft portion 33a of the fixed iron core 33. It is avoided that the plunger 34 malfunctions when an external force is applied.

  As shown in FIG. 9, it is assumed that an external force is applied to the solenoid 31 when the plunger 34 is self-held in a state of being separated from the end surface 33 e of the shaft portion 33 a of the fixed iron core 33. At this time, when the external force Fe1 applied to the solenoid 31 exceeds the biasing force Fs1 of the external force detection spring 55, the three detection bodies 54 are separated from the plunger plug 62 against the biasing force of the external force detection spring 55. It moves in the accommodating recess 60 in the direction. At this time, the plunger 34 is held by the biasing force Fs2 of the plunger spring 35 in a state of being separated from the end surface 33e of the shaft portion 33a of the fixed iron core 33. Accordingly, the urging force Fs1 of the external force detection spring 55 is moved by the external force applied to the solenoid 31 when the plunger 34 is self-held with the plunger 34 being separated from the end surface 33e of the shaft portion 33a of the fixed iron core 33. It is smaller than the external force Fe2 that starts.

  Of the three detectors 54, the detector 54 closest to the small-diameter hole 60b moves inside the drive coil 32 in the axial direction of the plunger 34, whereby an electromotive force is generated in the drive coil 32, and the drive The inductance of the coil 32 for use changes. The microcomputer 51 detects an external force applied to the solenoid 31 based on a change in inductance of the driving coil 32 accompanying the movement of the detection body 54. Thus, the external force applied to the solenoid 31 is detected before the plunger 34 malfunctions due to the external force applied to the solenoid 31. Then, the microcomputer 51 controls the drive of the control board 50 so that the direction of the current supplied to the drive coil 32 is opposite, and supplies the drive coil 32 with current. As a result, the attractive force of the magnet 38 is reduced by the magnetomotive force of the driving coil 32, so that it is avoided that the plunger 34 malfunctions when an external force is applied to the solenoid 31.

In the above embodiment, the following effects can be obtained.
(1) The microcomputer 51 detects an external force applied to the solenoid 31 based on a change in inductance of the driving coil 32 accompanying the movement of the detection body 54. The urging force Fs1 of the external force detection spring 55 is smaller than the external force Fe2 at which the plunger 34 starts to move due to the external force applied to the solenoid 31. According to this, when the external force Fe1 applied to the solenoid 31 exceeds the biasing force Fs1 of the external force detection spring 55, the detection body 54 moves against the biasing force of the external force detection spring 55, but the plunger 34 The self-maintained state is maintained. Therefore, the external force applied to the solenoid 31 can be detected by the microcomputer 51 before the plunger 34 malfunctions due to the external force applied to the solenoid 31.

  (2) The microcomputer 51 detects an external force applied to the solenoid 31 based on a change in inductance of the drive coil 32. For this reason, for example, the detection of the external force applied to the solenoid 31 is more accurate than the case where the external force applied to the solenoid 31 is detected based on the change in the electromotive force of the driving coil 32 caused by the movement of the detection body 54. Can be done well.

  (3) In the solenoid 31 used in the self-holding solenoid valve 10, since the energization to the driving coil 32 is stopped in the state where the plunger 34 is held by itself, the driving coil 32 is detected by the detection body. It can also function as a detection coil for detecting the movement of 54. Therefore, since it is not necessary to provide a detection coil for detecting the movement of the detection body 54 separately from the drive coil 32, it is possible to avoid the configuration of the self-holding solenoid valve 10 from becoming complicated. . Further, for example, when the plunger 34 is self-held while being separated from the end surface 33 e of the shaft portion 33 a of the fixed iron core 33, the external force Fe 1 applied to the solenoid 31 exceeds the urging force Fs 1 of the external force detection spring 55. Then, the detection body 54 moves against the urging force of the external force detection spring 55. At this time, since the urging force Fs1 of the external force detection spring 55 is smaller than the urging force Fs2 of the plunger spring 35, the plunger 34 is maintained in a state where it is held by the urging force Fs2 of the plunger spring 35. Therefore, the external force applied to the solenoid 31 can be detected by the microcomputer 51 before the plunger 34 malfunctions due to the external force applied to the solenoid 31.

  (4) The detection body 54 is a sphere. According to this, for example, the large-diameter hole 60a in the detection body 54 is compared with a case where the detection body 54 is columnar and the outer peripheral surface of the detection body 54 and the inner peripheral surface of the large-diameter hole 60a are in surface contact. The contact area with respect to the inner peripheral surface can be reduced. Therefore, since the sliding resistance generated between the outer peripheral surface of the detection body 54 and the inner peripheral surface of the large-diameter hole 60a can be reduced, the movement of the detection body 54 becomes smooth and the external force applied to the solenoid 31 is reduced. Detection can be performed with high accuracy.

  (5) The detection body 54 can contact the step surface 60c. According to this, the movement of the detection body 54 in the housing recess 60 against the urging force Fs1 of the external force detection spring 55 is restricted when the detection body 54 contacts the step surface 60c. Therefore, the external force detection spring 55 can be prevented from being excessively compressed, and the durability of the external force detection spring 55 can be improved.

  (6) The plunger plug 62 is made of a synthetic resin material. According to this, for example, the combined weight of the plunger 34 and the plunger plug 62 can be reduced as compared with the case where the plunger plug 62 is made of metal. Therefore, when an external force is applied to the solenoid 31, it is difficult for the plunger 34 to move together with the plunger plug 62, and it is possible to easily avoid the malfunction of the plunger 34.

  (7) When the microcomputer 51 detects the external force applied to the solenoid 31 when the end surface 34a of the plunger 34 is held by the end surface 33e of the shaft portion 33a of the fixed iron core 33, the microcomputer 51 The drive of the control board 50 is controlled so that the direction of the current supplied to the current 32 is the forward direction, and the current is supplied to the drive coil 32. According to this, in addition to the attractive force of the magnet 38, the magnetomotive force of the driving coil 32 assists the state in which the end surface 34 a of the plunger 34 is attracted to the end surface 33 e of the shaft portion 33 a of the fixed iron core 33. When an external force is applied to 31, it can be avoided that the plunger 34 malfunctions.

  (8) When the microcomputer 51 detects the external force applied to the solenoid 31 when the plunger 34 is held by the plunger 34 in a state of being separated from the end surface 33e of the shaft portion 33a of the fixed iron core 33, the microcomputer 51 is energized. The drive of the control board 50 is controlled so that the direction of the current to be reversed is applied, and the drive coil 32 is energized. According to this, since the attractive force of the magnet 38 is reduced by the magnetomotive force of the driving coil 32, it is possible to avoid the malfunction of the plunger 34 when an external force is applied to the solenoid 31.

In addition, you may change the said embodiment as follows.
In the embodiment, the external force applied to the solenoid 31 may be detected based on the change in the electromotive force of the drive coil 32 that changes due to the change in the magnetic flux accompanying the movement of the detection body 54. When the detector 54 starts to move, an electromotive force is generated in the driving coil 32 due to an electromagnetic induction effect in which the magnetic flux in the driving coil 32 changes.

-In embodiment, the number of the detection bodies 54 is not specifically limited.
-In embodiment, the detection body 54 may be columnar, for example, and the shape of the detection body 54 is not specifically limited.

In the embodiment, the housing recess 60 may not have the step surface 60c, and the detection body 54 may not be in contact with the step surface 60c.
In the embodiment, an external force detection unit may be provided separately from the microcomputer 51.

In the embodiment, the self-holding solenoid valve 10 may be a 5-port solenoid valve.
In the embodiment, the external force detection device 53 does not have to detect the external force applied to the solenoid 31 used in the self-holding solenoid valve 10, for example, the external force applied to the solenoid used in the pilot type solenoid valve May be detected. In this case, it is necessary to provide a detection coil for detecting the movement of the detection body 54 separately from the drive coil 32. In this case, the detection body 54 and the external force detection spring 55 may not be accommodated in the accommodation recess 60 of the plunger 34. In short, as long as the detection body 54 is located inside the detection coil, the arrangement positions of the detection body 54 and the external force detection spring 55 are not particularly limited.

  DESCRIPTION OF SYMBOLS 31 ... Solenoid, 32 ... Drive coil which functions also as a detection coil, 33 ... Fixed iron core, 33e ... End surface which is an adsorption surface, 34 ... Plunger, 35 ... Plunger spring, 38 ... Magnet, 50 ... Control board, 51 ... A microcomputer functioning as an external force detection unit, 53 ... an external force detection device, 54 ... a detection body, 55 ... an external force detection spring, 60 ... an accommodation recess, 60a ... a large diameter hole, 60b ... a small diameter hole, 60c ... a step surface.

Claims (5)

A drive coil;
A solenoid that moves by excitation of the driving coil, and a solenoid external force detection device,
A detection object;
An external force detection spring for holding the detection body in a state of being biased in a certain direction;
A detection coil for detecting movement of the detection body;
Change in inductance of the detection coil that changes due to change in magnetic path length of the magnetic circuit accompanying movement of the detection body, or change in electromotive force of the detection coil that changes due to change in magnetic flux due to movement of the detection body And an external force detector for detecting an external force applied to the solenoid,
An external force detection device for a solenoid, wherein an urging force of the external force detection spring is smaller than an external force at which the plunger starts to move due to an external force applied to the solenoid.   2. The external force detection of the solenoid according to claim 1, wherein the external force detection unit detects an external force applied to the solenoid based on a change in the inductance of the detection coil accompanying the movement of the detection body. apparatus. The solenoid is
A fixed iron core having an adsorption surface for adsorbing the plunger;
A plunger spring that biases the plunger in a direction in which the plunger separates from the adsorption surface;
A magnet that holds the plunger in a state of being attracted to the attracting surface;
When the direction of the current supplied to the drive coil is a forward direction, the magnetomotive force of the drive coil and the attractive force of the magnet resist the biasing force of the plunger spring, and the plunger When the plunger is attracted to the attracting surface, the energization to the driving coil is stopped, and the plunger is self-held in the state where the plunger is attracted to the attracting surface by the attraction force of the magnet. And
When the direction of the current supplied to the driving coil is reverse, the attractive force of the magnet is reduced by the magnetomotive force of the driving coil, and the plunger is moved away from the attracting surface by the biasing force of the plunger spring. When the energization to the drive coil is stopped after moving in the separating direction, the biasing force of the plunger spring overcomes the attractive force of the magnet, and the plunger is self-held in a state of being separated from the attracting surface. ,
The drive coil also functions as the detection coil,
3. The solenoid external force detection device according to claim 1, wherein an urging force of the external force detection spring is smaller than an urging force of the plunger spring. 4. The detection body and the external force detection spring are housed in a housing recess formed in the plunger,
The said detection body is a spherical body, The external force detection apparatus of the solenoid of Claim 3 characterized by the above-mentioned. The receiving recess is
A large-diameter hole for accommodating the detection body;
A small-diameter hole that has an inner diameter smaller than the large-diameter hole and accommodates an end of the external force detection spring opposite to the detection body;
A step surface connecting the large-diameter hole and the small-diameter hole,
The said detection body can contact | abut to the said level | step difference surface, The external force detection apparatus of the solenoid of Claim 4 characterized by the above-mentioned.