JP3323926B2 - Manufacturing method of solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solenoid valve for controlling opening and closing of a fluid passage.

[0002]

2. Description of the Related Art In a solenoid valve, a ball valve element is generally fixed to a tip of a plunger for controlling opening and closing of the valve. Various methods have been proposed for this fixing. For example, a method of forming a hemispherical recess slightly smaller than the ball valve body at the tip of the plunger and press-fitting the ball valve body into the recess, forming a hemispherical recess at the tip of the plunger, and bonding to the inner surface of the recess A method of applying an agent, fitting a ball valve body, and bonding. However, in the former method, there is a fear that cracks or breakage may occur due to excessive stress acting on the tip of the plunger, particularly at the surface of the plunger at the time of press-fitting. It is necessary to make contact, and if the processing accuracy is low, fixing is insufficient, and it is a win. Further, in the latter method, there is a fear that the adhesive layer is broken due to an impact acting on the valve body due to opening and closing of the valve or a rise in the temperature of the plunger due to the passage of hot fluid, and the ball valve body is detached.

[0003]

SUMMARY OF THE INVENTION The present invention solves these problems of the prior art and provides an electromagnetic valve structure capable of securely fixing a ball valve body at the tip of a plunger so that no gap is formed. Aim.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to provide an armature core fixed to the inner periphery of an armature coil, and the armature core being energized by the electric coil to excite the armature core. A method of manufacturing a solenoid valve comprising: a plunger that moves in an axial direction to control opening and closing of a fluid flow path; and a ball valve body fixed to a tip of the plunger, wherein a plunger having a through hole on an axis is provided. respect of the through hole, respectively slightly larger ball valve element and press-fit pins than the diameter of the through hole, and press fitting the plunger back to the valve seat side by the ball valve body to the head, the press-fitting said ball valve element Boost with pin
The ball valve body is held in a state where the ball valve body partially protrudes from the through hole .
Is achieved.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view showing one embodiment of a solenoid valve. The solenoid valve 10 includes a housing 12 that covers the whole, and the housing 12 is provided with openings 12a and 12b for opening a passage of a valve seat member described below on the side wall and the upper wall of the housing, respectively. Have been.

The solenoid valve 10 includes a valve body 14 made of a cylindrical magnetic metal, an electromagnetic coil 15 housed in the valve body, an armature core 16 held inside the electromagnetic coil, and a housing. A valve seat member 17 is disposed and held on the upper part of the armature 12, and a plunger 18 is slidably inserted between the armature core 16 and the valve seat member 17.

[0007] The electromagnetic coil 15 is held by a holding member 19, and radially extends from the lower end of the holding member.
0 protrudes outside. The armature core 16 has a large-diameter lower portion 16a press-fit into the housing 12 and is fixed.
The upper part 16b is reduced in diameter and extends into the electromagnetic coil. An axial passage 21 is formed in the valve seat member 17 along the central axis, the upper end thereof communicates with the outside through the opening 12b, and the lower end surface has a concave valve seat 2 along the sphere of the ball valve body 24.
It is 2. A groove extending in the radial direction is provided on the lower surface of the valve seat member 17 to form a radial passage 25 communicating the opening 12a and the passage 21.

The plunger 18 has an axial through hole 27.
It is formed in a substantially columnar shape having In the through hole 27, the ball valve element 24 is supported in a state that it protrudes partially toward the tip of the plunger, and a press-fit pin 28 is inserted into the back side thereof. A compression coil spring 29 is inserted between the press-fit pin 28 and the armature core 16 in the through hole 27 to urge the ball valve body 24 toward the valve seat 22.

When the coil 15 is energized by power supply from an unillustrated power source based on such a structure, the plunger 18 moves downward against the elastic force of the compression coil spring to open the passage 21. Thus, the fluid entering from the opening 12a flows to the passage 21 via the radial passage 25.

Hereinafter, the plunger 1 which is a feature of the present invention will be described.
A method of fixing the ball valve body 24 to the ball 8 will be described.
The plunger 18 has a cylindrical shape in which a through hole 27 is formed on the axis. The plunger can be obtained, for example, by sintering or cutting. From the back side of the plunger (a side away from the valve seat), a ball valve body 24 slightly larger than the diameter of the through hole and a cylindrical press-fit pin slightly larger than the diameter of the ball valve body are pushed into the through hole. (FIG. 2A), the pushing is stopped when the ball valve element 24 is pushed out about two-fifths from the tip side (FIG. 2B). Here, the reason why the diameter of the press-fit pin is made larger than the diameter of the ball valve body is that the press-fitting of the ball valve body slightly increases the inner diameter of the plunger, so that the press-fit allowance for holding the ball valve body is secured. To do that. Thereafter, the corner of the plunger is cut into a tapered shape (FIG. 2c). Although it is possible to form the taper in advance, it is more advantageous after the ball valve element and the press-fit pin have been pushed in that cracking is less likely to occur.

The dimensions of each member used in this embodiment are as follows.

Plunger length: 14 mm Diameter of through hole: 2.08 mm Diameter of ball valve element: 3.0 mm Diameter of press-fit pin: 3.02 mm Plunger and press-fit pin can be any of general metal and sintered metal However, since the ball valve element 24 tends to be pushed into the through hole due to the impact of the opening and closing of the valve, it is preferable that both are made of sintered metal from the viewpoint of imparting frictional properties. Also, by using a sintered metal for the plunger, the weight reduction is further promoted and the inertial force due to the valve operation is reduced, so that the response of opening and closing the radial passage can be improved.

[0013]

According to the solenoid valve of the present invention, a through hole is formed in a plunger for controlling the opening and closing of the solenoid valve, and a ball valve body slightly larger than the diameter of the through hole is press-fitted while being in contact with the press-fit pin. Therefore, the plunger can be securely fixed without cracking, breakage and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a solenoid valve structure according to the present invention.

FIG. 2 is an explanatory view sequentially showing a process of mounting a ball valve body on a plunger in one example of the method of the present invention.

[Explanation of symbols]

 Reference Signs List 10 solenoid valve 12 housing 15 solenoid coil 16 armature iron core 18 plunger 24 ball valve body 27 through hole

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-300478 (JP, A) JP-A-63-178677 (JP, U) JP2-6308 (JP, Y2) (58) Survey Field (Int.Cl. ⁷ , DB name) F16K 31/06-31/11

Claims (1)

(57) [Claims] 1. An armature core fixed to the inner periphery of an armature coil, and the armature core is excited by the armature coil to move in the axial direction of the armature core to open and close a fluid flow path. In a method of manufacturing a solenoid valve having a plunger to be controlled and a ball valve body fixed to a tip of the plunger, the through-holes of the plunger having a through-hole on an axis are respectively formed by the through-holes. The ball valve body and the press-fit pin slightly larger than the diameter of the ball valve body are pressed into the valve seat side from the back of the plunger with the ball valve body at the head, and the ball valve body is press-fitted.
A method of manufacturing a solenoid valve, wherein the ball valve body is held in a state where the ball valve body partially protrudes from the through hole by being pushed back with a pin .