Inner plunger of solenoid assembly for differential clutch of vehicle and manufacturing method thereof

Abstract

An inner plunger of a solenoid coil assembly for a differential clutch of a vehicle contributes to weight lightening and price reduction of a solenoid assembly, provide various shapes, reduce friction against an inner housing, and improve the function of the solenoid assembly. The inner plunger includes an outer wheel combined with a coil bobbin of a solenoid assembly and an inner wheel combined with an inner housing. The inner wheel is molded of insulator synthetic resin with excellent moldability, magnetic metal as the outer wheel is inserted into the outer circumferential surface of the inner wheel made of the synthetic resin, and an undercut groove is formed on the whole inner surface of the inner wheel made of synthetic resin in order to reduce friction against an inner housing.

Claims

1. A manufacturing method of an inner plunger of a solenoid assembly for a differential clutch of a vehicle comprising the steps of: preparing a mold, which has a space for inserting an outer ring of the inner plunger and a space for forming an inner ring, and a core, which has an undercut molding part for forming an undercut groove on a whole inner surface of the inner ring in order to reduce friction against an inner housing; and putting an outer wheel made of magnetic metal in the space of the mold for inserting the outer ring of the inner plunger, combining the core having the undercut molding part with a middle of the mold, forming the inner ring with nonmagnetic synthetic resin by injection of synthetic resin, and removing the mold.

2. The manufacturing method of claim 1, wherein the inner ring is formed with nonmagnetic synthetic resin that is moldable in order to vary the shape of the inner plunger and to reduce weight.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:

(2) FIG. 1 is a perspective view showing an inner plunger according to the present invention;

(3) FIG. 2 is a sectional view showing the inner plunger according to the present invention;

(4) FIG. 3 is a partially sectional view showing a state where the inner plunger according to the present invention is installed;

(5) FIG. 4 is a partially sectional view of a mold for manufacturing the inner plunger according to the present invention; and

(6) FIG. 5 is a partially sectional view showing a state where the inner plunger according to the present invention is molded.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(7) Hereinafter, example embodiments of an inner plunger and a manufacturing method thereof according to the present invention will be described in detail, and the example embodiments of the present invention are to realize the present invention. It should be understood, however, that the example embodiments of the present invention do not limit the technical idea of the present invention, but are to cover all modifications, equivalents, and alternatives falling within the technical idea and scope of the present invention.

(8) Furthermore, even though actions and effects obtained by the components of the present invention are not explicitly described, it is natural that predictable effects obtained by the components of the present invention belong to the technical scope of the present invention.

(9) With reference to the attached drawings, an inner plunger of a solenoid coil assembly for a differential clutch of a vehicle according to the present invention will be described in detail.

(10) Referring to FIGS. 1 to 3, an inner plunger 1 of a solenoid assembly for a clutch according to the present invention includes: an outer wheel 3 constituting the solenoid assembly and combined with a coil bobbin 10 to form an electromagnetic force; and an inner wheel 2 united with the outer wheel and combined with an inner housing 20. The inner plunger reciprocates inside the inner housing 20 by the electromagnetic force formed by the coil bobbin 10.

(11) The inner wheel 2 of the inner plunger 1 is molded with insulator synthetic resin with excellent moldability, and the outer wheel 3 made of magnetic metal is inserted into the outer circumferential surface of the inner wheel 2 made of synthetic resin as described above.

(12) An undercut groove 2-1 is formed in the whole inner surface of the inner wheel 2 in order to reduce friction against the inner housing when the inner wheel 2 made of synthetic resin performs a reciprocating action along the inner housing 20.

(13) The unexplained reference numeral 10-1 designates a coil.

(14) A manufacturing method of the inner plunger of the solenoid assembly for the clutch according to the present invention is achieved by a mold and an insert molding.

(15) Referring to FIGS. 4 and 5, the mold for insert molding of the inner plunger will be described.

(16) The mold includes: a mold 30 having a space 30-1 for inserting the outer wheel 3 of the inner plunger and a space 30-2 for forming the inner wheel 2; and a core 40 having an undercut molding part 40-1 through which an undercut groove 2-1 is formed on the whole inner surface of the inner wheel 2 in order to reduce friction against the inner housing.

(17) After that, the inner plunger is insert-molded in the mold 30.

(18) First, in the mold 30, an outer wheel made of magnetic metal is put in the space 30-1 for inserting an outer wheel 3 of the inner plunger. The core 40 having the undercut molding part 40-1 is combined with the middle of the mold 30, and injection molding of nonmagnetic synthetic resin is performed to form an inner wheel 2. After that, the mold is removed. Then, the inner plunger 1 is manufactured.

(19) Now, actions of the inner plunger of the solenoid assembly for the differential clutch of the vehicle according to the present invention will be described in detail as follows.

(20) First, basic actions of the solenoid assembly for the differential clutch of the vehicle will be described.

(21) The solenoid assembly is combined with the inner housing 20 of the differential of the vehicle. If it is necessary to actuate the differential, electricity is provided to the coil bobbin 10 to form an electromagnetic force.

(22) Then, the inner plunger 1 moves along the inner housing 20 by the electromagnetic force by a magnetic field generate from the coil bobbin 10.

(23) The above action is a general action of the solenoid assembly for the differential clutch of the vehicle. So, detailed description on the action of the solenoid assembly will be omitted, but only the actions of the components of the inner plunger will be described.

(24) First, when the inner plunger 1 moves along the inner housing 20 by the electromagnetic force by the magnetic field generate from the coil bobbin 10, since the inner wheel 2 of the inner plunger 1 is less influenced by the electromagnetic force since being made of synthetic resin, responsibility is improved, and it helps the action that the inner plunger 1 moves along the inner housing 20.

(25) Especially, since the undercut groove 2-1 is formed on the whole inner surface of the inner wheel 2 more simply while the inner wheel 2 is formed with the nonmagnetic synthetic resin, the inner plunger can reduce friction against the inner housing 20 when reciprocating along the inner housing 20, so that the inner plunger is free from frictional resistance and facilitates the reciprocating action along the inner housing 20.

(26) Moreover, the inner plunger can provide various shapes due to its excellent moldability since the inner wheel 2 is made of nonmagnetic synthetic resin. Therefore, the inner plunger can improve its function and productivity according to shapes of the inner plunger.

(27) Because the magnetic metal as the outer wheel is inserted into the outer circumferential surface of the inner wheel 2 of the inner plunger, the inner wheel 2 and the outer wheel 3 can keep their shapes for a long time without separation from each other.

(28) Additionally, because the magnetic metal inserted into the outer circumferential surface of the inner wheel 2 of the inner plunger forms the outer wheel 3, it prevents a loss of the electromagnetic force generated from the coil bobbin 10, so that the inner plunger can act smoothly.