EP1260997A2 - Electromagnetic actuator - Google Patents
Electromagnetic actuator Download PDFInfo
- Publication number
- EP1260997A2 EP1260997A2 EP02010452A EP02010452A EP1260997A2 EP 1260997 A2 EP1260997 A2 EP 1260997A2 EP 02010452 A EP02010452 A EP 02010452A EP 02010452 A EP02010452 A EP 02010452A EP 1260997 A2 EP1260997 A2 EP 1260997A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- armature
- electromagnetic actuator
- core
- electromagnets
- coil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
- F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/06—Electromagnets; Actuators including electromagnets
- H01F7/08—Electromagnets; Actuators including electromagnets with armatures
- H01F7/127—Assembling
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/06—Electromagnets; Actuators including electromagnets
- H01F7/08—Electromagnets; Actuators including electromagnets with armatures
- H01F7/16—Rectilinearly-movable armatures
- H01F7/1638—Armatures not entering the winding
Definitions
- the invention relates to an electromagnetic actuator.
- an electromagnetic actuator can be used to open and close intake and exhaust valves in an internal combustion engine.
- the electromagnetic actuator includes an armature, which moves integrally with a valve body, and a pair of core assemblies (electromagnets), between which the armature is provided. These core assemblies provide a coil and a core that retains the coil. These core assemblies exert an electromagnetic attraction on the armature as an electromagnet. When the pair of core assemblies alternatively exert the electromagnetic attraction on the armature, the armature reciprocates so that the electromagnetic actuator is driven and the intake and exhaust valves in an internal combustion engine are opened and closed.
- core assemblies electromagnets
- FIG. 4 is a side cross-sectional view showing the arrangement of the spacer and the core assemblies of the electromagnetic actuator according to JP-A-11-260638.
- the conventional structure shown in Fig. 4 illustrates the space required for the armature to move by the spacer.
- a pair of core assemblies 102 are provided on both sides of the moving directions of an armature 101 (e.g., as shown by the up and down direction in FIG. 4).
- a horizontal hole 103 is formed and extends along the width direction of each core assembly 102 (e.g., as shown by the right and left direction in FIG. 4).
- Spacers 104 are provided on both sides of the pair of core assemblies 102 along the width direction.
- a pin hole 105 is provided in the spacer 104.
- a constant distance between the pair of core assemblies 102 is maintained by the spacers 104.
- Pins 106 are inserted into the pin holes 105 aligned with the horizontal holes 103 to ensure the constant distance.
- the pin 106 in addition to requiring spacers 104, the pin 106 must be inserted into each core assembly 102 in order to secure the space for the armature 101 to move by inserting the pin 106 into the horizontal hole 103 and the pin holes 105. As a result, an increase in the number of components is necessary.
- a first aspect of the invention relates to an electromagnetic actuator.
- the electromagnetic actuator reciprocates an armature between a pair of electromagnets by an electromagnetic attraction.
- the pair of electromagnets is provided in both sides of the moving path direction of the armature with a coil being provided inside the pair of electromagnets.
- a spacer is formed by molding to be integral with a coil and is located between the pair of electromagnets. The spacer secures a space for the armature to reciprocate.
- the spacer which determines relative positions of a pair of the electromagnets to the neutral position of the armature, does not deviate in the reciprocating directions of the armature since the spacer is located between the electromagnets.
- the spacer is formed by molding to be integral with the coil, so that the number of components is not increased. Therefore, deviation of the relative position of the pair of core assemblies to the neutral position of the armature from the appropriate position and to change a maximum displacement of the armature can be prevented without increasing the number of components.
- the electromagnetic actuator may have more than one spacer.
- plural spacers are located between the pair of electromagnets. Therefore, the relative positions of the electromagnets to the neutral position of the armature can be determined by each spacer appropriately. Then the maximum displacement of the armature can be maintained within appropriate values with certainty.
- the spacers may be located on opposite sides of the armature as viewed in a direction perpendicular to the moving direction of the armature.
- the spacer are located on opposite sides of the armature as viewed in a direction perpendicular to the moving direction of the armature. Therefore, the relative positions of the electromagnets to the neutral position of the armature can be determined by each spacer appropriately. Then the maximum displacement of the armature can be maintained within the appropriate values with certainty.
- a noise absorbing material may be provided between a first surface defined by at least one of the spacer and the coil opposite to a side adjacent to the armature and a second surface defined matingly opposite to the first surface.
- the noise absorbing material may be provided on at least one of the spacer and the coil.
- level of contact noise caused by contacting the armature with the electromagnets as the armature reciprocates can be lowered by the noise absorbing material.
- the noise absorbing material may contain foam metal.
- the level of contact noise caused by contacting the armature with the electromagnets as the armature reciprocates can be lowered by the noise absorbing material containing foam metal.
- the surface of the armature may be hardened, for example, by colliding high-speed metal particles with the surface of the armature. Therefore, anti abrasion of the armature can be improved by surface-hardening treatment described above.
- the electromagnetic actuator may be provided in an internal combustion engine to drive a valve body of an intake valve or an exhaust valve.
- FIG. 1 shows an electromagnetically driven valve 1 having a valve body 4 which opens and closes a port 3 connected to a combustion chamber 2, a valve shaft 6 which projects from the valve body 4 and is reciprocatingly supported by a cylinder head 5 .
- An electromagnetic actuator 7 reciprocates the valve shaft 6.
- the port 3 is opened and closed when the valve body 4 seats to and moves away from a valve seat 3a as the valve shaft 6 reciprocates.
- a lower retainer 8 is provided at an opposite end to the valve body 4 side end of the valve shaft 6.
- a lower spring 9 is compressed and provided between the lower retainer 8 and the cylinder head 5.
- the valve body 4 and the valve shaft 6 are biased in the direction of closing the valve (e.g., upwardly as shown in FIG. 1) by the lower spring 9.
- the electromagnetic actuator 7 includes an armature shaft 10 which is provided along the same axis as the valve shaft 6, an armature 11 which is plate-shaped and contains a material with high magnetic permeability, and a pair of core assemblies 12a and 12b which are provided on both sides of a thickness direction of the armature 11.
- the armature 11 is fixed at approximately the center of the armature shaft 10.
- An upper cap 14 is provided on top of the core assembly 12a.
- An adjustment bolt 29 is screwed into and out of the upper cap 14 to adjust a neutral position of the armature 11.
- the upper cap 14 and the pair of core assemblies 12a and 12b are fixed by pins 15, which extends parallel to the armature shaft 10, and a bolt 16.
- the upper cap 14 and the pair of core assemblies 12a and 12b are located at orthogonal angles to the armature shaft 10.
- the armature shaft 10 penetrates through the pair of core assemblies 12a and 12b. One end (e.g., the lower end as shown in FIG. 1) of the armature shaft 10 is contacted with the lower retainer 8 side end of the valve shaft 6. An upper retainer 13 is fixed on the other end of the armature shaft 10. An upper spring 17 is compressed and provided between the upper retainer 13 and the upper cap 14. The armature shaft 10 is biased on the side of the valve shaft 6 by the upper spring 17. The valve shaft 6 and the valve body 4 are biased in the direction of opening the valve (e.g., downwardly as shown in FIG. 1) by the biased armature 10.
- a core 18 which contains a material with high magnetic permeability and a coil unit 19 retained by the core 18 are provided in the pair of core assemblies 12a and 12b.
- a coil 20 is embedded in the coil unit 19.
- the core assemblies 12a and 12b work as an electromagnet by conducting electricity to the coil 20 and exert electromagnetic attraction on the armature 11.
- the core 18, a core block 22, and a coil part 23 (mentioned later) as an electromagnet according to the exemplary embodiment. Therefore, the core 18, a core block 22, and the coil part 23 are called electromagnets 30a and 30b according to the exemplary embodiment.
- the electromagnet 30a is side of the core assembly 12a and the electromagnet 30b is side of the core assembly 12b.
- valve body 4 opens and closes by controlling electricity conduction to the two coils 20 located on both sides of the core assemblies 12a and 12b and by alternately exerting electromagnetic attraction from the core assemblies 12a and 12b on the armature 11.
- the surface of the armature 11 is treated to improve anti-abrasion.
- anti-abrasion improvement of the surface of the armature 11 is carried out by colliding metal particles with the surface of the armature 11 at a high speed by air to increase the hardness of the surface. Therefore, when the armature 11 comes into contact with the core assemblies 12a and 12b, and as the armature 11 reciprocates, abrasion of the armature 11 can be restrained.
- FIG. 2 is an exploded perspective view which shows an interior structure of an electromagnetic actuator 7.
- the core assemblies 12a and 12b are arranged symmetrically from the armature 11.
- the two core assemblies 12a and 12b are identical except for their arrangement and working timing such that only the core assembly 12b is referred to hereafter.
- the core assembly 12b includes a core plate 21 with which the core 18 contacts, and a pair of core blocks 22.
- the pair of core blocks 22 contact the core plate 21 and is provided in a way such that the core 18 is located between the core blocks 22.
- the coil unit 19 having an annular shape includes a coil part 23 into which the coil 20 (e.g., shown in FIG. 1) is embedded, and a pair of spacers 24 which is formed integrally with the coil part 23 at the outer margins of and on top of the coil part 23 (e.g., as shown in FIG. 2).
- the coil part 23 is molded out of a thermoplastic resin to be integral with the coil 20.
- the spacers 24 are also molded out of thermoplastic to be integral with the coil 20.
- the coil unit 19 On a side opposite to the armature 11 (the under-side of the coil part 23 and the spacers 24, e.g., as shown in FIG. 2), the coil unit 19 has a noise absorbing material 25 attached, which is a sheet-shape and contains a foam metal such as a foam cast iron.
- a retaining groove 26 with an annular shape, which houses the coil part 23, is formed in the core 18 and the core blocks 22.
- the coil unit 19 is matingly fixed on the core 18 and the core blocks 22 by inserting the coil part 23 into the retaining groove 26.
- the spacers 24 are located above the core blocks 22 as shown in FIG. 2.
- the noise absorbing material 25 attached on the coil unit 19 is located between two groups. One group comprises the coil part 23 and the spacers 24. The other group comprises the core 18 and the core blocks 22.
- Pin holes 27, through which pins 15 penetrate, and bolt holes 28 into which bolts 16 are screwed, are formed in the spacers 24, core blocks 22, and the core plate 21.
- the pins 15 and the bolts 16 are shown in FIG. 1.
- the core assemblies 12a and 12b are fixed to meet at least the following two requirements. The first requirement is that the armature 11 is arranged between the core assemblies 12a and 12b. The second requirement is that the spacers 24 on both sides of the core assembly 12a and 12b are contacted together. This arrangement is fixed by tightening the bolts 16 screwed into the bolt holes 28 after inserting the pins 15 into the pin holes 27.
- the spacers 24 are located on both sides of the armature 11 (along the moving path of the armature shaft 10) and between the electromagnet 30a of the core assembly 12a and the electromagnet 30b of the core assembly 12b.
- the relative position of the electromagnets 30a and 30b to the neutral position of the armature 11 is determined by the spacers 24.
- a space 11a for the armature 11 to reciprocate between the core assemblies 12a and 12b is secured.
- Maximum displacement of the armature 11 is determined in proportion to the length of moving direction of the armature 11 in the space 11a.
- the spacers 24, for determining the relative positions of the electromagnets 30a and 30b to the neutral position of the armature 11, are located between the electromagnets 30a and 30b. Therefore, the spacers 24 do not deviate in the reciprocating direction of the armature 11 (e.g., in the direction of the axis of the armature shaft 10).
- the spacers 24 are formed by molding to be integral with the coils 20 as the coil unit 19. Therefore, the number of components of the electromagnetic actuator 7 are few and is not increased. Furthermore, deviation of the relative position of the electromagnets 30a and 30b from the neutral position of the armature 11 from an appropriate position can be prevented. Change in the maximum displacement of the armature 11 accompanied by the above-mentioned deviation can also be prevented.
- the spacers 24 are located on opposite sides of the armature 11 as viewed in a direction perpendicular to the moving direction of the armature 11. Because of the above-described relation of the positions among the spacers 24 and the armature 11, the spacers 24 are located between the electromagnets 30a and 30b. Both electromagnets 30a and 30b are located along the axis of the armature shaft 10. Therefore, the position of the electromagnets 30a and 30b relative to the neutral position of the armature 11 can be determined by the spacers 24 appropriately and the maximum displacement of the armature 11 can be maintained within an appropriate value with greater certainty.
- the level of contact noise caused by contacting the armature 11 with the core assemblies 12a and 12b, as the armature 11 reciprocates, can be lowered by the noise absorbing materials 25 located between the two groups of components.
- one group comprises the coil part 23 and the spacers 24.
- the other group comprises the core 18 and the core blocks 22.
- the exemplary embodiment may be modified as follows.
- each spacer 24 may be provided at each coil unit 19.
- the two coil units 19 may be installed in the electromagnetic actuator in the way that spacers 24 of coil units 19 are located on opposite sides of the armature 11 as viewed in a direction perpendicular to the moving direction of the armature 11.
- the noise absorbing material 25 is attached to the coil part 23 and the spacers 24 on the side opposite to the armature 11 (e.g., the under-side of the coil part 23 and the spacers 24 as shown in FIG. 2).
- the noise absorbing material 25 may be attached either on the coil part 23 or the spacers 24.
- the noise absorbing material 25 is optional and can be omitted to reduce the number of components.
- the electromagnetic actuator 7 may be applied to structures other than an engine valve.
- An electromagnetic actuator (7) includes a pair of core assemblies (12a, 12b) and a spacer (24).
- the armature (11) is provided between the pair of core assemblies (12a, 12b).
- the spacer (24) is formed by molding to be integral with a coil (20) provided in electromagnets (30a, 30b) of the core assemblies (12a, 12b) and is located between the electromagnets (30a, 30b). And relative positions of the pair of electromagnets (30a and 30b) to each other are determined by the spacer (24).
- a space to allow the armature to reciprocate is secured between the core assemblies (12a, 12b) by the spacer (24).
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- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Valve Device For Special Equipments (AREA)
- Magnetically Actuated Valves (AREA)
- Electromagnets (AREA)
Abstract
Description
- The invention relates to an electromagnetic actuator.
- It has been suggested that an electromagnetic actuator can be used to open and close intake and exhaust valves in an internal combustion engine.
- Conventionally, the electromagnetic actuator includes an armature, which moves integrally with a valve body, and a pair of core assemblies (electromagnets), between which the armature is provided. These core assemblies provide a coil and a core that retains the coil. These core assemblies exert an electromagnetic attraction on the armature as an electromagnet. When the pair of core assemblies alternatively exert the electromagnetic attraction on the armature, the armature reciprocates so that the electromagnetic actuator is driven and the intake and exhaust valves in an internal combustion engine are opened and closed.
- In the above-described electromagnetic actuator, it is necessary that a space be secured for the armature to reciprocate between the pair of core assemblies. Therefore, it is conceivable that a spacer is used to secure the space for the armature to reciprocate like an electromagnetic actuator according to a Laid-Open Japanese patent Publication No. JP 11-260638.
- FIG. 4 is a side cross-sectional view showing the arrangement of the spacer and the core assemblies of the electromagnetic actuator according to JP-A-11-260638. The conventional structure shown in Fig. 4 illustrates the space required for the armature to move by the spacer.
- As shown in FIG. 4, a pair of
core assemblies 102 are provided on both sides of the moving directions of an armature 101 (e.g., as shown by the up and down direction in FIG. 4). Ahorizontal hole 103 is formed and extends along the width direction of each core assembly 102 (e.g., as shown by the right and left direction in FIG. 4).Spacers 104 are provided on both sides of the pair ofcore assemblies 102 along the width direction. At each location corresponding to one of thehorizontal holes 103, apin hole 105 is provided in thespacer 104. A constant distance between the pair ofcore assemblies 102 is maintained by thespacers 104.Pins 106 are inserted into thepin holes 105 aligned with thehorizontal holes 103 to ensure the constant distance. - If the
pins 106 are inserted into thepin holes 105 and thehorizontal holes 103 inaccurately, relative positions between the pair ofcore assemblies 102 deviate from appropriate positions. For example, the relative positions deviate in the reciprocating directions of thearmature 101. As a result, an appropriate size of space for thearmature 101 to move between thecore assemblies 102 cannot be maintained and maximum displacement of thearmature 101 will deviate from appropriate values. If thearmature 101 contacts one of the core assemblies 102 as thearmature 101 reciprocates, an impact generated from the contact is translated among thehorizontal hole 103, thepin holes 105, and thepin 106. Therefore, if thepin 106 is inserted into thepin holes 105 and thehorizontal hole 103 inaccurately, a contact force between thearmature 101 and one of thecore assemblies 102 deviates in the reciprocating direction of thearmature 101 due to the impact. As a result, there is a great chance that the relative position of the core assemblies 102, with respect to a neutral position of thearmature 101, will deviate from the appropriate values by many degrees. - Furthermore, in addition to requiring
spacers 104, thepin 106 must be inserted into eachcore assembly 102 in order to secure the space for thearmature 101 to move by inserting thepin 106 into thehorizontal hole 103 and thepin holes 105. As a result, an increase in the number of components is necessary. - It is an object of the invention to provide an electromagnetic actuator to prevent a deviation of the relative positions of a pair of electromagnets with respect to a neutral position of an armature from an appropriate position and to change a maximum displacement of the armature without increasing the number of components parts.
- A first aspect of the invention relates to an electromagnetic actuator. The electromagnetic actuator reciprocates an armature between a pair of electromagnets by an electromagnetic attraction. The pair of electromagnets is provided in both sides of the moving path direction of the armature with a coil being provided inside the pair of electromagnets. In the electromagnetic actuator described above, a spacer is formed by molding to be integral with a coil and is located between the pair of electromagnets. The spacer secures a space for the armature to reciprocate.
- According to the above-described structure of the electromagnetic actuator, the spacer, which determines relative positions of a pair of the electromagnets to the neutral position of the armature, does not deviate in the reciprocating directions of the armature since the spacer is located between the electromagnets. The spacer is formed by molding to be integral with the coil, so that the number of components is not increased. Therefore, deviation of the relative position of the pair of core assemblies to the neutral position of the armature from the appropriate position and to change a maximum displacement of the armature can be prevented without increasing the number of components.
- Furthermore, the electromagnetic actuator may have more than one spacer.
- According to the above-described structure, plural spacers are located between the pair of electromagnets. Therefore, the relative positions of the electromagnets to the neutral position of the armature can be determined by each spacer appropriately. Then the maximum displacement of the armature can be maintained within appropriate values with certainty.
- Furthermore, the spacers may be located on opposite sides of the armature as viewed in a direction perpendicular to the moving direction of the armature.
- According to the above-described structure, the spacer are located on opposite sides of the armature as viewed in a direction perpendicular to the moving direction of the armature. Therefore, the relative positions of the electromagnets to the neutral position of the armature can be determined by each spacer appropriately. Then the maximum displacement of the armature can be maintained within the appropriate values with certainty.
- Furthermore, a noise absorbing material may be provided between a first surface defined by at least one of the spacer and the coil opposite to a side adjacent to the armature and a second surface defined matingly opposite to the first surface.
- The noise absorbing material may be provided on at least one of the spacer and the coil.
- According to the above-described structure, level of contact noise caused by contacting the armature with the electromagnets as the armature reciprocates can be lowered by the noise absorbing material.
- The noise absorbing material may contain foam metal.
- According to the above-described structure, the level of contact noise caused by contacting the armature with the electromagnets as the armature reciprocates can be lowered by the noise absorbing material containing foam metal.
- The surface of the armature may be hardened, for example, by colliding high-speed metal particles with the surface of the armature. Therefore, anti abrasion of the armature can be improved by surface-hardening treatment described above.
- The electromagnetic actuator may be provided in an internal combustion engine to drive a valve body of an intake valve or an exhaust valve.
- The foregoing and further objects, features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:
- FIG. 1 is a cross-sectional view of an electromagnetically driven valve applied by an electromagnetic actuator according to an exemplary embodiment of the invention;
- FIG. 2 is an exploded perspective view which shows an interior structure of the electromagnetic actuator;
- FIG. 3 is a schematic view of a modified embodiment of a shape of a coil unit according to the exemplary embodiment; and
- FIG. 4 is a side cross-sectional view illustrating a structure for securing a space for an electromagnetic actuator to move with a spacer.
-
- The following is an explanation of an exemplary embodiment of the invention applying an electromagnetic actuator to an electromagnetically driven valve as an intake valve or an exhaust valve in an internal combustion engine.
- FIG. 1 shows an electromagnetically driven
valve 1 having avalve body 4 which opens and closes aport 3 connected to acombustion chamber 2, avalve shaft 6 which projects from thevalve body 4 and is reciprocatingly supported by a cylinder head 5 . Anelectromagnetic actuator 7 reciprocates thevalve shaft 6. Theport 3 is opened and closed when thevalve body 4 seats to and moves away from avalve seat 3a as thevalve shaft 6 reciprocates. - A lower retainer 8 is provided at an opposite end to the
valve body 4 side end of thevalve shaft 6. A lower spring 9 is compressed and provided between the lower retainer 8 and the cylinder head 5. Thevalve body 4 and thevalve shaft 6 are biased in the direction of closing the valve (e.g., upwardly as shown in FIG. 1) by the lower spring 9. - The
electromagnetic actuator 7 includes anarmature shaft 10 which is provided along the same axis as thevalve shaft 6, anarmature 11 which is plate-shaped and contains a material with high magnetic permeability, and a pair ofcore assemblies armature 11. Thearmature 11 is fixed at approximately the center of thearmature shaft 10. Anupper cap 14 is provided on top of thecore assembly 12a. Anadjustment bolt 29 is screwed into and out of theupper cap 14 to adjust a neutral position of thearmature 11. Furthermore, theupper cap 14 and the pair ofcore assemblies pins 15, which extends parallel to thearmature shaft 10, and abolt 16. Theupper cap 14 and the pair ofcore assemblies armature shaft 10. - The
armature shaft 10 penetrates through the pair ofcore assemblies armature shaft 10 is contacted with the lower retainer 8 side end of thevalve shaft 6. Anupper retainer 13 is fixed on the other end of thearmature shaft 10. Anupper spring 17 is compressed and provided between theupper retainer 13 and theupper cap 14. Thearmature shaft 10 is biased on the side of thevalve shaft 6 by theupper spring 17. Thevalve shaft 6 and thevalve body 4 are biased in the direction of opening the valve (e.g., downwardly as shown in FIG. 1) by thebiased armature 10. - A core 18 which contains a material with high magnetic permeability and a
coil unit 19 retained by thecore 18 are provided in the pair ofcore assemblies coil 20 is embedded in thecoil unit 19. Thecore assemblies coil 20 and exert electromagnetic attraction on thearmature 11. In this connection, thecore 18, acore block 22, and a coil part 23 (mentioned later) as an electromagnet according to the exemplary embodiment. Therefore, thecore 18, acore block 22, and thecoil part 23 are calledelectromagnets electromagnet 30a is side of thecore assembly 12a and theelectromagnet 30b is side of thecore assembly 12b. As thearmature shaft 10 and thearmature 11 reciprocate in the direction along the axis of thevalve shaft 6, thevalve body 4 opens and closes by controlling electricity conduction to the twocoils 20 located on both sides of thecore assemblies core assemblies armature 11. - The surface of the
armature 11 is treated to improve anti-abrasion. In other words, anti-abrasion improvement of the surface of thearmature 11 is carried out by colliding metal particles with the surface of thearmature 11 at a high speed by air to increase the hardness of the surface. Therefore, when thearmature 11 comes into contact with thecore assemblies armature 11 reciprocates, abrasion of thearmature 11 can be restrained. - FIG. 2 is an exploded perspective view which shows an interior structure of an
electromagnetic actuator 7. Thecore assemblies armature 11. The twocore assemblies core assembly 12b is referred to hereafter. - As shown in FIG. 2, in addition to the
core 18 and thecoil unit 19, thecore assembly 12b includes acore plate 21 with which the core 18 contacts, and a pair of core blocks 22. The pair of core blocks 22 contact thecore plate 21 and is provided in a way such that thecore 18 is located between the core blocks 22. - The
coil unit 19 having an annular shape includes acoil part 23 into which the coil 20 (e.g., shown in FIG. 1) is embedded, and a pair ofspacers 24 which is formed integrally with thecoil part 23 at the outer margins of and on top of the coil part 23 (e.g., as shown in FIG. 2). Thecoil part 23 is molded out of a thermoplastic resin to be integral with thecoil 20. Thespacers 24 are also molded out of thermoplastic to be integral with thecoil 20. On a side opposite to the armature 11 (the under-side of thecoil part 23 and thespacers 24, e.g., as shown in FIG. 2), thecoil unit 19 has anoise absorbing material 25 attached, which is a sheet-shape and contains a foam metal such as a foam cast iron. - A retaining
groove 26 with an annular shape, which houses thecoil part 23, is formed in thecore 18 and the core blocks 22. Thecoil unit 19 is matingly fixed on thecore 18 and the core blocks 22 by inserting thecoil part 23 into the retaininggroove 26. Thespacers 24 are located above the core blocks 22 as shown in FIG. 2. Thenoise absorbing material 25 attached on thecoil unit 19 is located between two groups. One group comprises thecoil part 23 and thespacers 24. The other group comprises thecore 18 and the core blocks 22. - Pin holes 27, through which pins 15 penetrate, and bolt
holes 28 into whichbolts 16 are screwed, are formed in thespacers 24, core blocks 22, and thecore plate 21. Thepins 15 and thebolts 16 are shown in FIG. 1. Thecore assemblies armature 11 is arranged between thecore assemblies spacers 24 on both sides of thecore assembly bolts 16 screwed into the bolt holes 28 after inserting thepins 15 into the pin holes 27. - As described above, when the
core assemblies spacers 24 are located on both sides of the armature 11 (along the moving path of the armature shaft 10) and between theelectromagnet 30a of thecore assembly 12a and theelectromagnet 30b of thecore assembly 12b. The relative position of theelectromagnets armature 11 is determined by thespacers 24. Aspace 11a for thearmature 11 to reciprocate between thecore assemblies armature 11 is determined in proportion to the length of moving direction of thearmature 11 in thespace 11a. - According to the exemplary embodiment described above, the following characteristics can be obtained. The
spacers 24, for determining the relative positions of theelectromagnets armature 11, are located between theelectromagnets spacers 24 do not deviate in the reciprocating direction of the armature 11 (e.g., in the direction of the axis of the armature shaft 10). Thespacers 24 are formed by molding to be integral with thecoils 20 as thecoil unit 19. Therefore, the number of components of theelectromagnetic actuator 7 are few and is not increased. Furthermore, deviation of the relative position of theelectromagnets armature 11 from an appropriate position can be prevented. Change in the maximum displacement of thearmature 11 accompanied by the above-mentioned deviation can also be prevented. - The
spacers 24 are located on opposite sides of thearmature 11 as viewed in a direction perpendicular to the moving direction of thearmature 11. Because of the above-described relation of the positions among thespacers 24 and thearmature 11, thespacers 24 are located between theelectromagnets electromagnets armature shaft 10. Therefore, the position of theelectromagnets armature 11 can be determined by thespacers 24 appropriately and the maximum displacement of thearmature 11 can be maintained within an appropriate value with greater certainty. - The level of contact noise caused by contacting the
armature 11 with thecore assemblies armature 11 reciprocates, can be lowered by thenoise absorbing materials 25 located between the two groups of components. As mentioned before, one group comprises thecoil part 23 and thespacers 24. The other group comprises thecore 18 and the core blocks 22. - The exemplary embodiment may be modified as follows.
- According to the exemplary embodiment, two of the
spacers 24 are provided at eachcoil unit 19. On the other hand, as shown in FIG. 3, for example, eachspacer 24 may be provided at eachcoil unit 19. And the twocoil units 19 may be installed in the electromagnetic actuator in the way that spacers 24 ofcoil units 19 are located on opposite sides of thearmature 11 as viewed in a direction perpendicular to the moving direction of thearmature 11. - According to the exemplary embodiment, the
noise absorbing material 25 is attached to thecoil part 23 and thespacers 24 on the side opposite to the armature 11 (e.g., the under-side of thecoil part 23 and thespacers 24 as shown in FIG. 2). In the alternative, thenoise absorbing material 25 may be attached either on thecoil part 23 or thespacers 24. - The
noise absorbing material 25 is optional and can be omitted to reduce the number of components. Theelectromagnetic actuator 7 may be applied to structures other than an engine valve. - While the invention has been described with reference to the exemplary embodiments thereof, it is to be understood that the invention is not limited to the exemplary embodiments or constructions. To the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the exemplary embodiments are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or only a single element, are also within the spirit and scope of the invention.
- An electromagnetic actuator (7) includes a pair of core assemblies (12a, 12b) and a spacer (24). The armature (11) is provided between the pair of core assemblies (12a, 12b). The spacer (24) is formed by molding to be integral with a coil (20) provided in electromagnets (30a, 30b) of the core assemblies (12a, 12b) and is located between the electromagnets (30a, 30b). And relative positions of the pair of electromagnets (30a and 30b) to each other are determined by the spacer (24). A space to allow the armature to reciprocate is secured between the core assemblies (12a, 12b) by the spacer (24).
Selected Figure: FIG. 2
Claims (9)
- An electromagnetic actuator including a pair of electromagnets (30a, 30b) being provided on opposite sides of the armature (11) reciprocating between the pair of electromagnets (30a, 30b) by electromagnetic attraction with a coil (20) being provided inside each the electromagnet (30a, 30b), characterized in that a spacer (24), that secures a space for the armature (11) to reciprocate, is formed by molding to be integral with the coil (20) and is located between the pair of electromagnets (30a, 30b).
- The electromagnetic actuator according to claim 1, wherein the electromagnetic actuator has at least two of the spacers (24).
- The electromagnetic actuator according to claim 2, wherein the spacers (24) are located on opposite sides of the armature (11) as viewed in a direction perpendicular to the moving direction of the armature (11).
- The electromagnetic actuator according any one of claims 1 to 3, wherein a noise absorbing material (25) is provided between a first surface defined by at least one of the spacer (24) and the coil (20) opposite to a side adjacent to the armature (34) and a second surface defined matingly opposite to the first surface.
- The electromagnetic actuator according claim 4, wherein the noise absorbing material (25) is provided on at least one of the spacer (24) and the coil (20).
- The electromagnetic actuator according to claim 4 or claim 5, wherein the noise absorbing material (25) comprises a foam metal.
- The electromagnetic actuator according to any one of claims 1 to 6, wherein a surface of the armature (11) is hardened by a surface-hardening treatment.
- The electromagnetic actuator according any one of claims 1 to 7, wherein the electromagnetic actuator is provided in an internal combustion engine to drive a valve body of an intake valve.
- The electromagnetic actuator according any one of claims 1 to 7, wherein the electromagnetic actuator is provided in an internal combustion engine to drive a valve body (4) of an exhaust valve.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001150651A JP2002343631A (en) | 2001-05-21 | 2001-05-21 | Electromagnetic actuator |
JP2001150651 | 2001-05-21 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1260997A2 true EP1260997A2 (en) | 2002-11-27 |
EP1260997A3 EP1260997A3 (en) | 2003-01-29 |
Family
ID=18995635
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP02010452A Withdrawn EP1260997A3 (en) | 2001-05-21 | 2002-05-08 | Electromagnetic actuator |
Country Status (3)
Country | Link |
---|---|
US (1) | US20020170512A1 (en) |
EP (1) | EP1260997A3 (en) |
JP (1) | JP2002343631A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2870630A1 (en) * | 2004-05-24 | 2005-11-25 | Johnson Contr Automotive Elect | ELECTROMAGNETIC ACTUATOR COMPRISING AN ELECTROAIMANT WITH A COIL FREE FROM THE CORE |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004360626A (en) * | 2003-06-06 | 2004-12-24 | Hitachi Unisia Automotive Ltd | Fuel injection valve |
JP4840145B2 (en) * | 2006-01-17 | 2011-12-21 | 株式会社デンソー | Solenoid valve device |
KR102469922B1 (en) * | 2015-02-11 | 2022-11-22 | 도트. 아이엔지. 마리오 코자니 에스.알.엘. | Flow control actuator for reciprocating compressors |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE29700096U1 (en) * | 1997-01-04 | 1998-04-30 | FEV Motorentechnik GmbH & Co. KG, 52078 Aachen | Electromagnetic actuator for actuating a gas exchange valve with damping means to reduce the transmission of structure-borne noise |
JPH11260638A (en) * | 1997-12-09 | 1999-09-24 | Siemens Automot Corp | Electromagnetic actuator |
DE19914591A1 (en) * | 1999-03-31 | 2000-10-12 | Daimler Chrysler Ag | Electromagnet, especially of an actuator for IC engine electromagnetic valve control, is produced by alternating voltage application to an excitation coil during embedding in molding compound in a yoke coil window |
DE19924812A1 (en) * | 1999-05-29 | 2000-12-07 | Daimler Chrysler Ag | Process for the production of actuators for electromagnetic valve control |
-
2001
- 2001-05-21 JP JP2001150651A patent/JP2002343631A/en active Pending
-
2002
- 2002-04-26 US US10/132,146 patent/US20020170512A1/en not_active Abandoned
- 2002-05-08 EP EP02010452A patent/EP1260997A3/en not_active Withdrawn
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE29700096U1 (en) * | 1997-01-04 | 1998-04-30 | FEV Motorentechnik GmbH & Co. KG, 52078 Aachen | Electromagnetic actuator for actuating a gas exchange valve with damping means to reduce the transmission of structure-borne noise |
JPH11260638A (en) * | 1997-12-09 | 1999-09-24 | Siemens Automot Corp | Electromagnetic actuator |
DE19914591A1 (en) * | 1999-03-31 | 2000-10-12 | Daimler Chrysler Ag | Electromagnet, especially of an actuator for IC engine electromagnetic valve control, is produced by alternating voltage application to an excitation coil during embedding in molding compound in a yoke coil window |
DE19924812A1 (en) * | 1999-05-29 | 2000-12-07 | Daimler Chrysler Ag | Process for the production of actuators for electromagnetic valve control |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2870630A1 (en) * | 2004-05-24 | 2005-11-25 | Johnson Contr Automotive Elect | ELECTROMAGNETIC ACTUATOR COMPRISING AN ELECTROAIMANT WITH A COIL FREE FROM THE CORE |
WO2005119708A2 (en) * | 2004-05-24 | 2005-12-15 | Valeo Systemes De Controle Moteur | Electromagnetic actuator comprising two electromagnets provided with coils which are free in relation to the cores |
WO2005119708A3 (en) * | 2004-05-24 | 2007-04-26 | Valeo Sys Controle Moteur Sas | Electromagnetic actuator comprising two electromagnets provided with coils which are free in relation to the cores |
Also Published As
Publication number | Publication date |
---|---|
US20020170512A1 (en) | 2002-11-21 |
EP1260997A3 (en) | 2003-01-29 |
JP2002343631A (en) | 2002-11-29 |
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