Electromagnetic Actuator

Abstract

To provide an electromagnetic actuator capable of preventing coaxial alignment of a shaft in a shaft press-fitting and a body fastening, and suppressing a suction force deterioration and a hysteresis deterioration caused by an increase in friction resistance.SOLUTION: A construction of an electromagnetic actuator comprises: a cylindrical bottomed body; a coil housed in the body; a core attached to an open of the body; a shaft press-fitted to the body and the core; a plunger that slides the shaft as an axis; and a pusher that is pressed by the plunger. The core includes: a cylinder part that plays a role of a fixed iron core; a concave part constructing a volume variation chamber in an open end of the cylinder part; a pusher guide that is arranged in an inner part of the cylinder part; a partition wall that separates the concave part and the pusher guide; a shaft press-fitting hole which is formed at a center of the partition wall and into which the shaft is press-fitted; and a pusher insertion hole which is formed in the circumference of the shaft press-fitting hole and into which a leg of the pusher is inserted. The pusher includes a projection for sliding the inner wall of the pusher guide.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electromagnetic actuator mounted on a vehicle or the like. [Background technology]

[0002] An example of an electromagnetic actuator mounted on a vehicle or the like is the solenoid valve described in Patent Document 1. The solenoid valve in Patent Document 1 has "a pressure adjusting section that forms a hydraulic pressure supply port by a spool slidably inserted into a sleeve, and an electromagnetic section that is attached integrally to the pressure adjusting section."

[0003] The electromagnetic section of Patent Document 1 comprises "an axial member positioned coaxially with the spool of the pressure adjustment section, a movable body slidably fitted into the axial member, a yoke section fixed to one end of the axial member by a press-fit section provided at one end of the axial member, a core member fixed to the other end of the axial member by a press-fit section provided at the other end of the movable body, a solenoid assembly fitted onto the outer periphery of the yoke member and the core member, a body member into which the outer periphery of the solenoid assembly is fitted and one end of which is crimped to the flange of the core member, and a pusher member adjacent to the axial member into which the other end of the axial member is press-fitted, which applies the suction force of the movable body to the pressure adjustment section." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6094059 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, the pusher member has at least two or more legs that are evenly spaced in the circumferential direction and are integrally formed with the base, and the legs are fitted into grooves provided in the core member. The pusher member is guided by an axial member (shaft) and applies the suction force of the plunger to the pressure adjustment unit via the pusher.

[0006] When the pusher member has a sliding structure guided by the shaft, as in Patent Document 1, the grooves into which the legs of the pusher member are inserted must be positioned so that they overlap with part of the press-fit hole of the core into which the shaft is press-fit. This requires the core's press-fit hole to have multiple inward protrusions arranged radially. This results in low rigidity, with some of the protrusions coming into contact with the shaft when the shaft is press-fitted, causing plastic deformation due to the press-fit load. This can lead to coaxial misalignment of the shaft after press-fitting and after the body is swaged. This can result in a decrease in suction force and worsening hysteresis due to increased frictional resistance caused by the radial load when the moving body (plunger) moves.

[0007] In view of these problems, the present invention aims to provide an electromagnetic actuator that can prevent coaxial misalignment after the shaft is pressed into place and the body is crimped, and that can suppress an increase in frictional resistance and the resulting decrease in attractive force and deterioration of hysteresis. [Means for solving the problem]

[0008] In order to solve the above problems, a typical configuration of an electromagnetic actuator according to the present invention includes a cylindrical body with a bottom, a coil housed in the body, a core attached to an opening of the body, a shaft press-fitted into the body and the core, a plunger that slides around the shaft as an axis, and a pusher pushed by the plunger, wherein the core has a cylindrical portion that serves as a fixed iron core, a recess at the open end of the cylindrical portion that forms a volume-varying chamber, a pusher guide disposed inside the cylindrical portion, a partition wall separating the recess from the pusher guide, a shaft press-fit hole formed in the center of the partition wall and into which the shaft is press-fit, and pusher insertion holes formed around the shaft press-fit hole and into which legs of the pusher are inserted, and the pusher has protrusions that slide on the inner wall of the pusher guide. The shaft press-fit hole may be circular with an entire circumference. [Effects of the Invention]

[0009] According to the present invention, an electromagnetic actuator can be provided that can prevent the shaft from becoming misaligned after being pressed into place and the body is tightened, and can suppress an increase in frictional resistance and the resulting decrease in attractive force and deterioration of hysteresis. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B are diagrams illustrating an electromagnetic actuator according to an embodiment of the present invention. [Figure 2] 2 is a diagram showing a state in which the plunger of the electromagnetic actuator in FIG. 1 has moved to a volume varying chamber. [Figure 3] FIG. 2 is a perspective view of a core and a pusher according to the present embodiment. [Figure 4] FIG. [Figure 5] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0012] Fig. 1 is a diagram for explaining an electromagnetic actuator 100 of this embodiment, illustrating a vertical cross section near the center of the electromagnetic actuator 100. Fig. 2 is a diagram illustrating a state in which the plunger 140 of the electromagnetic actuator 100 of Fig. 1 has moved into the volume varying chamber 106. The electromagnetic actuator 100 is a component that is mounted on, for example, a vehicle, and in Figs. 1 and 2, the shaft 102 and rod 108 are arranged vertically so as to extend in the up-down direction.

[0013] 1 and 2, the electromagnetic actuator 100 includes a body 110, a coil 120, a core 130, a shaft 102, a plunger 140, and a pusher 150. The body 110 is a cylinder with a bottom, and houses the coil 120 therein. Electric power is supplied to the coil 120 from a power source (not shown) connected to a connector 104.

[0014] A core 130 (fixed iron core) that seals the opening is attached to the body 110. A shaft 102 is press-fitted into the body 110 and the core 130. A plunger 140 (movable iron core) that slides around the shaft 102 as an axis is disposed inside the body 110. A pusher 150 that is pushed and moved by the plunger 140 is disposed inside the core 130.

[0015] Fig. 3 is a perspective view of the core 130 and the pusher 150 of this embodiment. Fig. 3(a) is a perspective view showing the core 130 and the pusher 150 as viewed obliquely from above in Fig. 1, and Fig. 3(b) is a perspective view showing the core 130 and the pusher 150 as viewed obliquely from below in Fig. 1.

[0016] Fig. 4 is an overall view of the core 130. Fig. 4(a) is a bottom view of the core 130, and Fig. 4(b) is a cross-sectional view taken along line AA in Fig. 4(a). Fig. 5 is an overall view of the pusher 150. Fig. 5(a) is an overall perspective view of the pusher 150, Fig. 5(b) is a plan view of the pusher 150, and Fig. 5(c) is a cross-sectional view taken along line BB in Fig. 5(a).

[0017] As shown in Figures 3 and 4, the core 130 includes a cylindrical portion 130a and a flange 130b extending from the edge of the cylindrical portion 130a. The cylindrical portion 130a mainly functions as a fixed iron core. The flange 130b mainly functions as a lid for the body 110. An attachment notch 134 is formed in the flange 130b, and a partition wall 130c provided inside the cylindrical portion 130a.

[0018] In the internal space of the cylindrical portion 130a, a recessed portion 132 that constitutes the volume varying chamber 106 is disposed at the open end (the lower end in the figure). In addition, in the internal space of the cylindrical portion 130a, a pusher guide 131 that guides the pusher is disposed above the recessed portion 132. The pusher guide 131 can also be said to be a space in which the pusher 150 moves. A partition wall 130c separates the recessed portion 132 and the pusher guide 131.

[0019] The shaft press-fitting hole 136 is formed in the center of the partition wall 130c, and the shaft 102 is press-fitted therein. In particular, in this embodiment, the shaft press-fitting hole 136 is a circle having a full circumference (a circle without any notches). The pusher insertion hole 138 is formed around the shaft press-fitting hole 136, and a leg 154 of a pusher 150 (described later) is inserted therethrough.

[0020] 3 and 5, in the electromagnetic actuator 100 of this embodiment, the pusher 150 has a base 152, a foot 154, and a protrusion 156. The foot 154 extends from the base 152 toward the plunger 140 and is inserted into a pusher insertion hole 138 formed in the core 130. The protrusion 156 protrudes from the base 152 toward the inner wall of the pusher guide 131 and slides against the inner wall when the pusher 150 moves within the pusher guide 131. That is, the circumscribing circle of the protrusion 156 (the distance from the center of the base 152 to the tip of the protrusion 156) is larger than the circumscribing circle of the foot 154 (the distance from the center of the base 152 to the outer edge of the foot 154).

[0021] 5, the three feet 154 and the three protrusions 156 are alternately arranged around the periphery of the base 152, with the spacing groove 158 sandwiched therebetween. Note that in this embodiment, three pusher insertion holes 138 and three feet 154 of the pusher 150 are provided, but this is not limited to this. The numbers of pusher insertion holes 138 and three feet 154 of the pusher 150 can be changed as needed.

[0022] When the above-described pusher 150 is inserted into the pusher guide 131 of the core 130, the base 152 is disposed between the shaft 102 and the rod 108, and the three legs 154 of the pusher 150 are inserted into and protrude from the pusher insertion hole 138 of the core 130, as shown in Fig. 1. When the legs 154 of the pusher 150 are pressed by the plunger 140, the pusher 150 slides within the pusher guide 131, moving the rod 108, as shown in Fig. 2.

[0023] As described above, in the electromagnetic actuator 100 of this embodiment, the pusher insertion hole 138 is formed around the shaft press-fit hole 136. In other words, the pusher insertion hole 138 does not overlap with the shaft press-fit hole 136 in a plan view, and the shaft press-fit hole 136 is a circle with no notches and has an entire circumference. As a result, when the shaft 102 is press-fitted, the entire circumference of the shaft press-fit hole 136 comes into contact with the shaft 102, preventing the shaft 102 from shifting out of alignment with its axis when the shaft is press-fitted and when the body 110 is crimped. This makes it possible to prevent an increase in frictional resistance and the resulting decrease in attractive force and deterioration of hysteresis.

[0024] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention. [Industrial Applicability]

[0025] The present invention can be used as an electromagnetic actuator mounted on a vehicle or the like. [Explanation of symbols]

[0026] 100...electromagnetic actuator, 102...shaft, 104...connector, 106...volume varying chamber, 108...rod, 110...body, 120...coil, 130...core, 130a...cylindrical portion, 130b...flange, 130c...partition wall, 131...pusher guide, 132...recess, 134...mounting notch, 136...shaft press-fit hole, 138...pusher insertion hole, 140...plunger, 150...pusher, 152...base, 154...foot, 156...protrusion, 158...spacer groove

Claims

1. A cylindrical body with a bottom, a coil housed within the body; a core attached to an opening in the body; a shaft press-fitted into the body and the core; a plunger that slides around the shaft; a pusher pushed by the plunger; Equipped with The pusher A base and a plurality of feet extending from the base toward the plunger and being pushed by the plunger; The core is A cylindrical part that acts as a fixed iron core, a recessed portion that forms a volume variable chamber at an open end of the cylindrical portion; a pusher guide disposed inside the cylindrical portion; a partition wall that separates the recess and the pusher guide; a shaft press-fitting hole formed in the center of the partition wall and into which the shaft is press-fitted; a pusher insertion hole formed around the shaft press-fitting hole and into which a leg of the pusher is inserted; and The pusher further has a plurality of protrusions protruding from the base toward an inner wall of the pusher guide, The plurality of feet and protrusions are alternately arranged around the periphery of the base with the spacing grooves therebetween, The distance from the center of the base to the tip of the protrusion is greater than the distance from the center of the base to the outer edge of the foot, The electromagnetic actuator is characterized in that the protrusion slides on the inner wall of the pusher guide when the foot of the pusher is pressed by the plunger.

2. 2. The electromagnetic actuator according to claim 1, wherein the shaft press-fit hole is circular with a full circumference.

Images