JP2010135469A - Solenoid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid suppressing an influence of a contamination. <P>SOLUTION: The solenoid 1 which drives a mother machine includes a base 2 penetrating a shaft 5, a bearing 7 supporting the shaft 5 slidably on the base 2, a bearing front chamber 73 defined by the bearing 7 on the mother machine side, and a base penetration path 62 penetrating the base 2 to communicate the mother machine side to the bearing front chamber 73. Hydraulic oil moves between the mother machine side and bearing front chamber 73 through the base penetration path 62 as the shaft 5 moves, and the shaft 5 is formed such that a shaft base penetration portion 51 penetrating the base penetration path 62 is thinner than a shaft support portion 53 supported by the bearing 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solenoid that moves a shaft in an axial direction by a magnetic field generated in a coil.

  Conventionally, for example, in the case of a solenoid attached to a mother machine such as a hydraulic device, hydraulic fluid guided from the mother machine to the solenoid includes contamination made of wear powder generated in the mother machine. If this contamination accumulates in the strong magnetic field part of the solenoid, the solenoid thrust may be weakened, the sliding resistance during shaft movement may increase, and the solenoid may malfunction.

  In each of the solenoids disclosed in Patent Documents 1 and 2, a plunger is slidably provided between a base constituting a magnetic circuit and a sleeve, and the plunger is driven by a magnetic field generated in the coil and coupled to the plunger. The shaft is moved in the axial direction to drive the valve body.

  The solenoid disclosed in Patent Document 1 is provided with an annular member (contamination block 71) for slidably fitting the shaft, and hydraulic oil flowing from the mother machine is blocked by the annular member (contamination block 71) to the outside. It escapes and it is comprised so that the hydraulic fluid containing a contamination may not flow into a plunger accommodating chamber.

The solenoid disclosed in Patent Document 2 is provided with an annular filter (ring filter 11) for slidably fitting a shaft, and a chamber (contamination reservoir 12) for collecting contaminants in the vicinity of the filter. Contamination of the flowing hydraulic oil is configured not to enter the plunger accommodating chamber.
JP 2006-64076 A Japanese Patent Laid-Open No. 11-31617

  However, in such a conventional solenoid, as the shaft reciprocates due to the solenoid thrust, the volume of hydraulic oil that the shaft moves moves between the mother machine side and the solenoid. There was a problem that it was difficult to sufficiently suppress intrusion contamination.

  The present invention has been made in view of the above problems, and an object thereof is to provide a solenoid that suppresses the influence of contamination.

  The present invention is a solenoid that drives a base by driving a plunger by a magnetic field generated in a coil and moving a shaft coupled to the plunger in an axial direction. A bearing that slidably supports the shaft, a bearing front chamber that is defined on the mother machine side from the bearing, and a base through passage that passes through the base and communicates the mother machine side and the bearing front chamber. With the movement, the hydraulic oil moves between the base machine side and the bearing front chamber through the base through passage, and the shaft has a shaft base through portion that penetrates the base through passage from the shaft support portion supported by the bearing. It was set as the structure formed thinly.

  According to the present invention, the movement volume of the shaft relative to the base is reduced, so that the flow rate of the hydraulic oil that moves between the base machine side and the bearing front chamber through the base through passage when the shaft reciprocates is reduced. . As a result, it is possible to prevent contamination of the hydraulic oil from entering the solenoid, prevent malfunction of the solenoid due to contamination, and extend the movable time during which the solenoid operates stably.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a front view of the solenoid 1, and FIG. 2 is a cross-sectional view taken along line A-O-A in FIG.

  The solenoid 1 is an electromagnetic actuator that drives the plunger 4 by a magnetic field generated in the coil 12 and moves the shaft 5 coupled to the plunger 4 in the axial direction.

  The solenoid 1 is attached to a mother machine of a hydraulic device (not shown). The front end portion 59 of the shaft 5 is linked to a hydraulic valve provided in the mother machine, and drives the hydraulic valve to open and close.

  Not limited to this, the solenoid 1 may be provided in a pneumatic device, other machine, or facility, and may drive a pneumatic valve or other movable part.

  The solenoid 1 includes a case 9, a base 2, a sleeve 3, a plunger 4, a shaft 5, a gap embedded body 6, first and second bearings 7 and 8, a pair of O-rings 19, a coil assembly 10, and the like as components. .

  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 includes a cylindrical enclosure 16 in which the bobbin 11 and the coil 12 are accommodated, and a connector 15 that protrudes from one end of the enclosure 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 constituting member for guiding the magnetic flux of the coil 12, a case 9, a base 2, a plunger 4, and a sleeve 3 are provided, which are each formed of a magnetic material.

  The case 9 is formed in a bottomed cylindrical shape and has a pair of flange portions 91 protruding from the opening end portion thereof. Bolt holes 98 are opened in each flange portion 91 and are fastened to the mounting seat of the mother machine by two bolts (not shown) that pass through the respective bolt holes 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, and the connector 15 projects from the notch 97.

  1 and 2, O is the center line of the shaft 5. In FIG. 1, each flange portion 91 protrudes in the left-right direction so as to be orthogonal to the center line O, and the connector portion 15 protrudes upward so as to be orthogonal to the center line O.

  Not only this but the direction which the flange part 91 and the connector part 15 protrude is arbitrarily arrange | positioned corresponding to the shape of the other party to which the solenoid 1 is attached. For example, the connector part 15 may be protruded in the center line O direction, and the mating connector may be inserted / removed in the center line O direction.

  The cylindrical base 2 and the sleeve 3 are arranged on the inner side of the case 9 and coaxially with the center line O, and the shaft 5 and the plunger 4 are inserted into the inner sides thereof. The base 2 is disposed on the opening end side of the case 9, and the sleeve 3 is disposed on the back side of the case 9.

  The sleeve 3 has an outer peripheral surface 31 fitted into the inner peripheral surface of the bobbin 11, an end surface 32 abutting against the bottom surface 93 of the case 9, and is arranged coaxially with the center line O of the shaft 5.

  The outer peripheral surface 30 of the base 2 is fitted to the inner peripheral surface of the bobbin 11 and is arranged coaxially with the center line O of the shaft 5.

  A disc-shaped base collar 21 is formed at one end of the base 2, and the base collar 21 is coupled to the open end of the case 9. Also by this, the case 9 is arranged coaxially with the center line O of the shaft 5.

  An annular step 92 is formed at the open end of the case 9. The annular step portion 92 is formed in a planar shape orthogonal to the center line O, and constitutes a seating surface for the base 2. The end surface 22 of the base flange 21 abuts on the annular step 92 of the case 9, and the outer peripheral surface 23 of the base flange 21 is fitted to the inner peripheral surface 94 of the case 9.

  An annular step 24 is formed on the outer peripheral surface of the base flange 21. A caulking portion 95 is formed at the opening end of the case 9, and the caulking portion 95 is engaged with the annular step portion 24, thereby preventing the base 2 from coming off.

  When the case 9 is fastened to the mounting seat of the mother machine with bolts, the end surface 96 of the case 9 comes into contact with the mounting seat of the other mother machine (not shown).

  The shaft 5 is made of a nonmagnetic material and penetrates the sleeve 3 and the base 2.

  The columnar shaft 5 includes a shaft base penetrating portion 51 on the small diameter front end side and a shaft support portion 53 on the large diameter rear end side.

  The shaft support portion 53 is slidably supported in the direction of the center line O via the first and second bearings 7 and 8. The cylindrical plunger 4 is disposed between the first and second bearings 7 and 8. The plunger 4 is fitted to the outer peripheral surface 54 of the shaft support portion 53 and coupled by welding or caulking. The sleeve 3 has a small-diameter sleeve inner peripheral surface 33 and a large-diameter sleeve inner peripheral surface 34 on its inner periphery.

  The outer peripheral surface 81 of the bearing 8 is fitted and attached to the inner peripheral surface 33 of the small diameter sleeve.

  An annular gap 55 is formed between the inner peripheral surface 34 of the large diameter sleeve and the outer peripheral surface 41 of the plunger.

  The base 2 has an annular tapered end surface 45 that is inclined with respect to the center line O of the shaft 5. On the other hand, the sleeve 3 has an annular end surface 35 orthogonal to the center line O of the shaft 5. An annular magnetic gap is formed between the annular tapered end surface 45 of the base 2 and the annular end surface 35 of the shaft 5. The annular end face 35 may be inclined without being orthogonal to the center line O.

  A gap buried body 6 made of a nonmagnetic material is interposed in the magnetic gap. The gap embedded body 6 may not be interposed between the annular tapered end surface 45 of the base 2 and the annular end surface 35 of the sleeve 3, and a gap may be formed.

  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, the magnetic flux is guided through the plunger 4 to ensure the magnetic flux from the base 2 toward the plunger 4.

  The shape and position of the magnetic gap are arbitrarily set, and a solenoid thrust force corresponding to a stroke in which the plunger 4 moves in the direction of the center line O is obtained.

  In the coil assembly 10, O-rings 19 are interposed at both ends of the bobbin 11. One O-ring 19 is in contact with the base flange 21, and the other O-ring 19 is in contact with the bottom surface 93 of the case 9. The base 2, the coil assembly 10 (bobbin 11), and the case 9 constitute a pressure vessel that houses the plunger 4 and the shaft 5. This also prevents the hydraulic oil flowing into the solenoid 1 from the mother machine from leaking out of the solenoid 1.

  The solenoid 1 is provided with a bearing front chamber 73, a plunger front chamber 74, a plunger back chamber 75, and a bearing back chamber 76 around the shaft 5 and the plunger 4, and hydraulic oil from the mother machine is guided to these.

  The plunger 4 is interposed between the plunger front chamber 74 and the plunger back chamber 75. In order to prevent the magnetic adsorption between the sleeve 3 and the plunger 4, an annular gap 55 is defined around the plunger outer peripheral surface 41. The annular gap 55 constitutes a plunger outer circumferential path 63 that communicates the plunger front chamber 74 and the plunger back chamber 75.

  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. By reducing the clearance of the gap 55, the magnetic efficiency for driving the plunger 4 can be increased.

  When the flow path cross-sectional area of the plunger outer circumferential path 63 is sufficiently secured, the flow of the hydraulic oil around the plunger 4 is promoted when the plunger 4 moves, and the viscous resistance of the hydraulic oil applied to the plunger 4 is reduced. Thus, the operation response of the solenoid 1 can be enhanced. As the plunger 4 moves at a high speed, the contamination accumulated on the plunger outer peripheral surface 41 is removed.

  The bearing back chamber 76 is provided behind the bearing 8 and is defined between the bearing 8 and the bottom surface 93 of the case 9.

  The plunger back chamber 75 is defined between the end surface 48 of the plunger 4 and the bearing 8. The bearing 8 is interposed between the plunger back chamber 75 and the bearing back chamber 76. A plurality of grooves 82 are formed in the outer peripheral surface 81 of the bearing 8. These grooves 82 constitute a bearing through passage 64 that allows the plunger back chamber 75 and the bearing back chamber 76 to communicate with each other.

  The plunger front chamber 74 is defined between the bearing 7 and the plunger front end surface 47. The bearing 7 is interposed between the bearing front chamber 73 and the plunger front chamber 74. A plurality of grooves 72 are formed in the outer peripheral surface 71 of the bearing 7. These grooves 72 constitute a bearing through passage 68 that communicates the bearing front chamber 73 and the plunger front chamber 74.

  The front bearing chamber 73 is provided in front of the bearing 7 and is defined between the base 2 and the bearing 7. The bearing front chamber 73 communicates with the mother machine side through a gap 56 defined between the shaft 5 and the base 2 and the annular recess 35, and hydraulic oil from the mother machine is guided. This gap 56 constitutes a base through passage 62 that communicates the mother machine side and the bearing front chamber 73.

  The base 2 has first to fifth base inner peripheral surfaces 25 to 29 having different diameters on the inner periphery thereof.

  An annular gap 55 is formed between the fifth base inner peripheral surface 29 having the largest diameter and the plunger outer peripheral surface 41.

  The fourth base inner peripheral surface 28 is located on the front end side of the fifth base inner peripheral surface 29. An annular step 46 is formed between the fourth base inner peripheral surface 28 and the fifth base inner peripheral surface 29 in the base 2. The annular step 46 is formed in a planar shape orthogonal to the center line O of the shaft 5 and faces the plunger front end surface 47 in parallel.

  The third base inner peripheral surface 27 is located on the front end side of the fourth base inner peripheral surface 28. The outer peripheral surface 71 of the bearing 7 is fitted and attached to the third base inner peripheral surface 27.

  The second base inner peripheral surface 26 is located on the front end side of the third base inner peripheral surface 27. The second base inner peripheral surface 26 having the smallest diameter defines a gap 56 with the outer peripheral surface 52 of the shaft 5.

  The first base inner peripheral surface 25 is located on the front end side of the second base inner peripheral surface 26. The first base inner peripheral surface 25 defines an annular annular recess 35 between the first base inner peripheral surface 25 and the outer peripheral surface 52 of the shaft 5, and the annular recess 35 opens in the front end surface 49 of the base 2. The annular recess 35 communicates with the mother machine side and guides hydraulic oil from the mother machine.

  A filter 36 made of a filtering material is interposed in the annular recess 35. The filter 36 is formed in a cylindrical shape having an inner peripheral hole 37 at the center thereof, and the shaft base through portion 51 of the shaft 5 is slidably inserted into the inner peripheral hole 37.

  In this way, the filter 36 interposed in the bearing through-passage 68 filters the hydraulic oil introduced from the mother machine, and prevents contamination contained in the hydraulic oil from entering the solenoid 1.

  A dust seal 38 is interposed in the inner peripheral hole 37 of the filter 36. The shaft base through portion 51 is slidably inserted into the dust seal 38. The dust seal 38 is coupled to the opening end of the inner peripheral hole 37 with respect to the front end surface 49 of the base 2.

  The dust seal 38 has a lip portion (not shown) that slidably contacts the outer peripheral surface 52 of the shaft base penetrating portion 51, and the lip portion scrapes off the contaminants attached to the outer peripheral surface 52 of the shaft base penetrating portion 51. Do not enter the solenoid 1.

  The columnar shaft 5 has a stepped portion 58 between a small-diameter shaft base through portion 51 and a large-diameter shaft support portion 53. The step portion 58 is formed so as to be positioned in front of the bearing 7, and the shaft support portion 53 is slidably supported by the bearing 7 and the bearing 8.

  The diameter D53 of the shaft support portion 53 is set so that sufficient rigidity to support the plunger 4 is secured.

  On the other hand, the shaft base penetrating portion 51 penetrates the base penetrating passage 62, and the front end portion 59 projects from the front end surface 49 of the base 2. The front end portion 59 of the shaft base penetrating portion 51 is linked to a hydraulic valve provided in the mother machine, and the shaft 5 is reciprocated by a solenoid thrust to open and close the hydraulic valve of the mother machine.

  The diameter D51 of the shaft base penetrating portion 51 is set to a minimum within a range in which rigidity for opening and closing the hydraulic valve of the mother machine is sufficiently secured. As a result, when the shaft 5 reciprocates due to the solenoid thrust, the flow rate of the hydraulic oil that moves between the mother machine side and the bearing front chamber 73 in the solenoid 1 is minimized.

  Next, the operation of the embodiment of the present invention configured as described above will be described.

  When the solenoid 1 is assembled to the mother machine and the hydraulic oil (not shown) of the mother machine is filled with hydraulic oil, 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 filtered by the filter 36 and filled into the bearing front chamber 73 through the base through passage 62 (gap 56).

  The hydraulic fluid in the bearing front chamber 73 is filled in the plunger front chamber 74 through the bearing through passage 68 (groove 72).

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

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

  When the coil 5 is energized and the shaft 5 moves forward (leftward in FIG. 2), the shaft base penetration 51 moves forward, so that the shaft base penetration 51 retracts from the bearing front chamber 73. The hydraulic oil flows into the mother machine → the filter 36 → the base through passage 62 → the bearing front chamber 73.

  At this time, when the shaft support portion 53 moves forward, the volume of hydraulic oil in which the shaft support portion 53 retreats from the bearing back chamber 76 becomes the bearing front chamber 73 → the bearing through passage 68 → plunger front chamber 74 → plunger. It flows into the bearing back chamber 76 through the outer peripheral path 63 → the plunger back chamber 75 → the bearing through path 64.

  Further, when the plunger 4 moves forward, 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, the shaft 5 moves rearward (to the right in FIG. 2) by the reaction force received from the hydraulic valve of the mother machine, and opens and closes the hydraulic valve of the mother machine.

  When the shaft 5 moves rearward, the shaft base penetrating part 51 moves rearward, so that the volume of hydraulic oil into which the shaft base penetrating part 51 enters the bearing front chamber 73 becomes the bearing front chamber 73 → the base through path. 62 → filter 36 → outflow to mother machine.

  At this time, when the shaft support portion 53 moves rearward, the volume of hydraulic oil into which the shaft support portion 53 enters the bearing back chamber 76 becomes the bearing back chamber 76 → the bearing through passage 64 → the plunger back chamber 75 → plunger. It flows into the bearing front chamber 73 through the outer circumferential path 63 → the plunger front chamber 74 → the bearing through path 68.

  Furthermore, as 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 magnetic flux density of the strong magnetic field portion B where the magnetic flux concentrates changes, and the characteristics of the solenoid 1 change.

  -The sliding resistance of the plunger 4 increases or the stroke range in which the plunger 4 slides is narrowed.

  In response to this, the shaft base penetrating portion 51 through which the shaft 5 penetrates the base through passage 62 is formed to be narrower than the shaft support portion 53 supported by the bearing 7, so that the moving volume of the shaft 5 is reduced and the base The flow rate of the hydraulic oil that moves between the mother machine side and the bearing front chamber 73 through the through passage 62 is reduced. Thereby, it is possible to prevent the contamination of the hydraulic oil from entering the solenoid 1, prevent the malfunction of the solenoid 1 due to the contamination of the hydraulic oil, and extend the movable time during which the solenoid 1 operates stably.

  On the other hand, the shaft base penetrating portion 51 penetrates the base penetrating passage 62, and the front end portion 59 projects from the front end surface 49 of the base 2. The front end portion 59 of the shaft base penetrating portion 51 is linked to a hydraulic valve provided in the mother machine, and the shaft 5 is reciprocated by a solenoid thrust to open and close the hydraulic valve of the mother machine.

  The diameter D51 of the shaft base penetrating portion 51 is set to a minimum within a range in which rigidity for opening and closing the hydraulic valve of the mother machine is sufficiently secured. As a result, when the shaft 5 reciprocates due to the solenoid thrust, the flow rate of the hydraulic oil that moves between the mother machine side and the bearing front chamber 73 in the solenoid 1 is minimized.

  The filter 36 interposed in the bearing through-passage 68 filters the hydraulic oil introduced from the mother machine, and prevents contamination contained in the hydraulic oil from entering the solenoid 1.

  The dust seal 38 interposed in the inner peripheral hole 37 of the filter 36 is in sliding contact with the outer peripheral surface 52 of the shaft base penetrating portion 51, scrapes off the contaminant attached to the outer peripheral surface 52 of the shaft base penetrating portion 51, and removes the contaminant. Do not let inside.

  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 drive the mother machine. 5, a base 7 that slidably supports the shaft 5 with respect to the base 2, a bearing front chamber 73 defined on the mother machine side from the bearing 7, and the base 2. A base through-passage 62 that communicates between the mother machine side and the bearing front chamber 73 is provided, and hydraulic oil moves between the mother machine side and the bearing front chamber 73 through the base through-passage 62 as the shaft 5 moves. The shaft 5 has a structure in which a shaft base through portion 51 penetrating the base through passage 62 is formed narrower than the shaft support portion 53 supported by the bearing 7.

  Based on the above configuration, the movement volume of the shaft 5 with respect to the base 2 is reduced, so that the hydraulic oil that moves between the base machine side and the bearing front chamber 73 through the base through passage 62 when the shaft 5 reciprocates is obtained. The flow rate is reduced. As a result, it is possible to prevent contamination of the hydraulic oil from entering the solenoid 1, prevent malfunction of the solenoid 1 due to contamination, and extend the movable time during which the solenoid 1 operates stably.

  In the present embodiment, the bearing through passage 68 is provided with a filter 36 for filtering hydraulic oil.

  Based on the above configuration, the hydraulic oil flowing into the solenoid 1 from the mother machine is filtered by the filter 36, so that contamination of the hydraulic oil can be prevented from entering the solenoid 1, and the malfunction of the solenoid 1 due to the contamination is prevented. The movable time during which the solenoid 1 operates stably can be extended.

  In the present embodiment, the dust seal 38 that is in sliding contact with the shaft 5 is interposed inside the filter 36.

  Based on the above configuration, contamination that adheres to the outer peripheral surface 52 of the shaft 5 inside the filter 36 is scraped off by the dust seal 38, so that contamination can be prevented from entering the solenoid 1 through the inside of the filter 36. Therefore, it is possible to prevent malfunction of the solenoid 1 due to contamination and extend the movable time during which the solenoid 1 operates stably.

  Next, another embodiment shown in FIG. 3 will be described. This has basically the same configuration as the embodiment of FIGS. 1 to 3, and only the differences will be described. In addition, the same code | symbol is attached | subjected to the same structure part as the said embodiment.

  The shaft 5 is configured to be coupled after the shaft base penetration portion 51 and the shaft support portion 53 are formed separately.

  The shaft base penetrating part 51 and the shaft support part 53 are coupled by fastening with screws. However, the present invention is not limited to this, and both may be combined by press-fitting or the like.

  In this case, by changing the size and shape of the shaft base through portion 51 coupled to the shaft support portion 53, it corresponds to the specifications of a hydraulic valve or the like provided on the mother machine side without changing the basic structure of the solenoid 1. be able to.

  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, pneumatic equipment, other machines and equipment.

The front view of the solenoid which shows embodiment of this invention. Sectional drawing of the solenoid which similarly follows the AOA line of FIG. Sectional drawing of the solenoid which shows other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solenoid 2 Base 3 Sleeve 4 Plunger 5 Shaft 7 Bearing 8 Bearing 9 Case 12 Coil 36 Filter 38 Dust seal 51 Shaft base penetration part 52 Outer peripheral surface 53 Shaft support part 62 Base penetration path 73 Bearing front chamber

Claims (4)

The plunger is driven by the magnetic field generated in the coil,
Move the shaft coupled to this plunger in the axial direction,
A solenoid that drives the mother machine,
A base that penetrates the shaft;
A bearing that slidably supports the shaft with respect to the base;
A bearing front chamber defined on the mother machine side from the bearing;
A base through passage that penetrates the base and communicates the base machine side and the bearing front chamber;
With the movement of the shaft, the hydraulic oil moves between the base machine side and the bearing front chamber through the base through passage,
The solenoid is characterized in that a shaft base penetration part that penetrates the base penetration path is formed narrower than a shaft support part supported by the bearing.   The solenoid according to claim 1, wherein a filter that filters hydraulic oil is interposed in the bearing through passage.   The solenoid according to claim 2, wherein a dust seal that is in sliding contact with the shaft is interposed inside the filter.   The solenoid according to any one of claims 1 to 3, wherein the shaft base penetrating part and the shaft support part are formed separately from each other.

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