JP2010025135A - Solenoid valve - Google Patents

Abstract

An electromagnetic valve having a structure that does not corrode even when a fluid containing a component that induces corrosion of a metal such as water vapor flows through a fluid passage.
A fixing portion 14a that is press-fitted and fixed to a fitting hole 13b of a case 13 on an end side of a boss 14, and a protruding portion that protrudes into a fluid passage 1a with a diameter smaller than that of the fitting hole 13b on the distal end side of the fixing portion 14a. 14b. Further, the surfaces of the case 13 and the boss 14 are covered with plating layers 13c and 14c of a corrosion-resistant member. When assembling the electromagnetic valve, the protruding portion 14b penetrates without contacting the inner peripheral surface of the fitting hole 13b and protrudes into the fluid passage 1a, and the fixing portion 14a is press-fitted and fixed to the fitting hole 13b.
[Selection] Figure 1

Description

  The present invention relates to a solenoid valve for fluid control.

As shown in Patent Document 1, a conventional solenoid valve has a case in which a solenoid driving unit including a plunger as a mover, a boss that slidably accommodates the plunger, a coil that is provided around the outer periphery of the boss, and the like. It was stored and a fluid passage was provided outside the case. The boss and the case are made of a magnetic member such as iron, and constitute a magnetic circuit of the solenoid driving unit.
The boss is press-fitted and fixed in a hole drilled in the case so that one end of the boss penetrates the case and protrudes into the fluid passage. The shaft coupled to the plunger extends through the inside of the one end of the boss to the fluid passage, and a valve body is attached to the tip of the shaft.
When the coil of the solenoid drive unit is energized, the plunger is moved by the electromagnetic force generated by the coil, and the valve provided at the tip of the shaft coupled to the plunger is opened and closed, so that the flow rate of the fluid flowing through the fluid passage is increased. Be controlled.
Electromagnetic valves used in automobiles and the like control the amount of air flow, but due to recent system diversification, components that induce metal corrosion such as water vapor may be included in the flow fluid. For this reason, the boss and case made of magnetic material facing the fluid passage are plated for rust prevention to prevent corrosion when assembling the solenoid valve, and then the boss is press-fitted and fixed to the case. It had been.

JP-A-6-213359

  Since the conventional solenoid valve is configured as described above, even if the outer surface of the boss is plated for rust prevention, the boss is press-fitted while being in contact with the peripheral surface of the hole formed in the case. As a result, the plating layer of the protrusion to the fluid passage of the boss requiring the most plating layer has been peeled off. Therefore, when a fluid containing a component that induces corrosion of a metal such as water vapor flows through the fluid passage, there is a problem in that the protruding portion of the boss in contact with the fluid is corroded.

  The present invention has been made to solve the above-described problems, and provides an electromagnetic valve having a structure that does not corrode even when a fluid containing a component that induces corrosion of a metal such as water vapor flows through a fluid passage. With the goal.

  A solenoid valve according to the present invention includes a plunger as a mover of a magnetic circuit, a boss as a stator of a magnetic circuit that houses the plunger, a case that houses the plunger and the boss, and one end fixed to the plunger together with the plunger A housing provided with a fluid passage communicating with a driven shaft, an input port through which fluid flows in and an output port through which the fluid flows, a valve body for opening and closing the fluid passage, and a biasing force for the valve body in one direction The boss has a fixed portion that is press-fitted and fixed in the fitting hole in the bottom portion of the case, and a protruding portion that protrudes from the fixed portion to the fluid passage on the tip side of the boss. The diameter was smaller than the diameter of the fitting hole.

  According to this invention, the surface of the boss is covered with the coating of the corrosion-resistant member, and the protrusion that protrudes into the fluid passage of the boss is made smaller than the diameter of the fitting hole of the case. When penetrating through the fitting hole, the plating layer is not peeled off by contact with the hole peripheral surface. As a result, even when a fluid containing a component that induces corrosion of a metal such as water vapor circulates in the fluid passage, corrosion of the protruding portion in contact with the fluid can be prevented.

Embodiment 1 FIG.
1 and 2 are sectional views of a solenoid valve according to Embodiment 1 of the present invention. FIG. 1 shows a solenoid valve in a valve-closed state when not energized, and FIG. 2 shows a solenoid valve in a valve-open state when energized. The electromagnetic valve includes a housing portion having a fluid passage and a solenoid driving portion that drives a valve body for opening and closing the fluid passage.

The housing 1 constituting the housing portion has an input port 2 and an output port 3, and a fluid passage 1 a that connects the input port 2 and the output port 3 is formed in the housing 1. A valve seat 4 is fixed by press-fitting between the input port 2 and the output port 3, and a flow path 4 a that connects the fluid passage 1 a and the output port 3 is formed inside the valve seat 4.
The valve (valve element) 5 is installed so as to contact the surface of the valve seat 4 on the side of the solenoid driving unit. A spring 6 that urges the valve 5 in a direction to press the valve 5 against the valve seat 4 is installed on the surface of the valve 5 on the side of the solenoid driving portion, and a guide portion 5 b that guides the spring 6 is formed. Rubber 5a is baked and bonded to the surface of the valve 5 facing the valve seat 4. The rubber 5 a functions as a seal when the valve 5 comes into contact with the valve seat 4.

  When the solenoid valve is energized, the solenoid drive unit moves the valve 5 upward against the urging force of the spring 6 to cause the input port 2 and the output port 3 to communicate with each other. When no power is supplied, the valve 5 is moved downward by the biasing force of the spring 6, and the valve 5 closes the flow path 4 a of the valve seat 4 that communicates the input port 2 and the output port 3.

  Next, the solenoid driving unit will be described. A coil 8 is wound around the outer periphery of the resin-formed bobbin 7, and one end of the coil 8 is fixed so as to be electrically connected to the terminal 9 by fusing. This terminal 9 is fixed to the bobbin 7 by press fitting or the like. The bobbin 7, the coil 8, and the terminal 9 are fixed integrally with the exterior resin portion 10 when the exterior resin portion 10 is formed by insert molding. In addition, when insert molding the exterior resin part 10, the connector part 11 is also formed simultaneously.

A coil molded body 12 including an exterior resin portion 10 and a connector portion 11 that are insert-molded including the bobbin 7, the coil 8, and the terminal 9 is housed in a case 13 that forms a magnetic circuit. Further, a boss 14 and a core 15 which are stators constituting a magnetic circuit are arranged inside the coil molded body 12, and the boss 14 is fixed to the case 13 by press-fitting, and the core 15 is fixed to the case 13 by caulking. ing.
The case 13, the boss 14 and the core 15 are formed of a magnetic member such as iron, and each surface is subjected to a rust-proof plating process.

A plunger 18 made of a magnetic SUS (stainless steel) material is slidably accommodated inside the cylindrical boss 14. The plunger 18 forms a mover of the magnetic circuit and moves toward the core 15 when energized. A nonmagnetic shaft 21 is fixed by press-fitting to the end of the plunger 18 opposite to the core 15.
A rod 19 is press-fitted and fixed to the other end of the plunger 18, and a rubber stopper 20 is installed at a position facing the rod 19 inside the core 15. The rod 19 has a function of restricting the movement distance of the plunger 18 and preventing a contact sound during operation by contacting the stopper 20 fixed inside the core 15 when energized.

  A Ni-Cu sintered bush 16 is press-fitted between the plunger 18 and the boss 14, and the plunger 18 is supported by the sintered bush 16. Below that, between the shaft 21 and the boss 14, a Ni—Cu sintered bush 17 having a diameter different from that of the sintered bush 16 is press-fitted and fixed, and the shaft 21 is supported by the sintered bush 17.

The shaft 21 has one end coupled to the plunger 18 and the other end coupled to the valve 5. The other end of the shaft 21 is fixed to the valve 5 by high spin caulking at a portion protruding from the lower end surface of the valve 5 on the valve seat 4 side.
The case 13 is coaxially inserted into the housing 1, and both are fastened by a bracket portion 22 and a bolt 23.

Next, the structure of the boss 14 will be described. FIG. 3 is an enlarged cross-sectional view of the portion surrounded by a round frame A in FIG.
In the case 13, a fitting hole 13 b for press-fitting and fixing the boss 14 is formed in a bottom portion 13 a that is in contact with the fluid passage 1 a formed in the housing portion. One end of the boss 14 on the shaft 21 side is reduced in diameter to a fixed portion 14a that is press-fitted into the fitting hole 13b of the case 13 and a protruding portion 14b that has a smaller diameter than the fitting hole 13b and protrudes through the fluid passage 1a. . The outer diameter of the fixing portion 14a is substantially the same as the diameter of the fitting hole 13b of the case 13, and the outer diameter of the protruding portion 14b is smaller than the diameter of the fitting hole 13b. Further, the surface of the bottom 13a of the case 13 where the fluid passage is exposed and the surface of the boss 14 are covered with plating layers 13c and 14c plated with a corrosion resistant member.
The boss 14 is fitted and held in the case 13 when the fixing portion 14 a is press-fitted into a fitting hole 13 b formed in the bottom portion 13 a of the case 13. One end side of the spring 6 is installed on the outer periphery of the protruding portion 14 b, and the protruding portion 14 b guides the spring 6.

  Next, a method for assembling the electromagnetic valve will be described. First, the sintered bushes 16 and 17 are press-fitted inside the boss 14. The boss 14 is inserted into the fitting hole 13b of the case 13 from the protruding portion 14b side, and the fixing portion 14a is press-fitted into the fitting hole 13b and is fitted.

By making the protrusion 14b smaller in diameter than the fitting hole 13b, the outer peripheral surface of the protrusion 14b can penetrate into the fluid passage 1a without coming into contact with the inner peripheral surface of the fitting hole 13b. It is possible to maintain the state in which the plating layer 14c of the protrusion 14b protruding to the left remains without peeling.
Since the plating layer 14c is held on the protrusion 14b even after the solenoid valve is assembled, the protrusion 14b of the boss 14 facing the fluid passage 1a inside the housing 1 and the exposed surface of the fluid passage of the case 13 are made of, for example, water vapor. Even in contact with a fluid that induces corrosion, corrosion (rust) that affects the function of each part can be prevented.

In assembling the electromagnetic valve, the shaft 21 is first temporarily fixed by light press-fitting or the like into a hole provided at one end of the shaft 21 at the center. Thereafter, the shaft 21 and the valve 5 are fixed by caulking the portion protruding from the valve 5 with high spin.
A rod 19 is fixed to the plunger 18, and a stopper 20 is press-fitted and fixed to the bottom of the rod insertion hole 15 a of the core 15. Subsequently, the plunger 18 is supported by a jig so that the rod 19 faces downward, and is inserted into the boss 14 fixed to the case 13. Further, the spring 6 is disposed on the bottom 13a of the case 13, the shaft 21 is inserted into the boss 14 from the sintered bush 17 side, and the shaft 21 and the plunger 18 are press-fitted and fixed.
The coil molded body 12 and the core 15 that are insert-molded including the bobbin 7, the coil 8, and the terminal 9 are installed in the case 13, and the upper portion 13d of the case 13 is caulked and fixed to complete the assembly of the solenoid drive unit. .

On the other hand, as for the housing portion, the valve seat 4 is press-fitted and fixed to the housing 1 in which the input port 2, the output port 3 and the fluid passage 1a are formed.
Finally, the case 13 of the solenoid drive unit is inserted into the housing 1 from the bottom 13a side, and is fastened by the bolt 23 screwed into the bracket portion of the case 13 and the screw hole of the bracket portion 24 of the housing 1 that are in contact with each other. This completes the solenoid valve.

  As described above, according to the first embodiment, the fixed portion 14a that is press-fitted and fixed to the fitting hole 13b of the case 13 on the end side of the boss 14, and the front end side of the fixing portion 14a is smaller in diameter than the fitting hole 13b. The projecting portion 14b projecting into the fluid passage 1a is formed. Therefore, when the fixing portion 14a of the boss 14 is press-fitted and fixed into the fitting hole 13b of the case 13, the plating layer 14c of the protruding portion 14b that penetrates the fitting hole 13b and protrudes into the fluid passage 1a does not peel off. Therefore, even when a fluid containing a component that induces corrosion of metal such as water vapor flows through the fluid passage 1a, it is possible to prevent the protrusion 14b in contact with the fluid from being corroded.

Embodiment 2. FIG.
The electromagnetic valve according to the first embodiment has a fitting hole located on the tip side of the fixing portion 14a when the fixing portion 14a of the boss 14 is press-fitted and fixed into the fitting hole 13b formed in the bottom portion 13a of the case 13. The protruding portion 14b of the boss 14 that passes through 13b and protrudes into the fluid passage 1a has a smaller diameter than the fitting hole 13b. In the second embodiment, the outer peripheral surface of the protrusion 14 b is tapered toward the tip of the boss 14.
4 is an enlarged cross-sectional view of the vicinity of a boss of a solenoid valve according to Embodiment 2 of the present invention, and FIG. 1 shows a cross-sectional shape at the same position as a portion surrounded by a round frame A. In FIG. 4, the same or corresponding parts as in FIG. The boss 14 shown in FIG. 4 has a projecting portion 14b projecting from the fitting hole 13b of the case 13 into the fluid passage 1a in a tapered shape, and a plated layer 14c is formed on the surface thereof. The inclination angle of the outer peripheral surface of the projecting portion 14b toward the shaft is set such that the spring 6 can be guided.

  By tapering the protruding portion 14b of the boss 14, the outer peripheral surface of the protruding portion 14b can penetrate into the fluid passage 1a without contacting the inner peripheral surface of the fitting hole 13b when assembling the solenoid valve. It is possible to maintain the state in which the plating layer 14c of the protruding portion 14b protruding to the passage 1a remains without being peeled off. Therefore, corrosion of the protrusion 14b can be prevented.

  As described above, according to the second embodiment, the protruding portion 14b of the boss 14 is tapered toward the front end in the penetration direction with respect to the fitting hole 13b of the case 13. Therefore, the protrusion 14b can be easily inserted into the fitting hole 13b, and the plating layer 14c of the protrusion 14b is not peeled off as in the first embodiment. As a result, even when a fluid containing a component that induces corrosion of a metal such as water vapor flows through the fluid passage 1a, it is possible to prevent the protrusion 14b in contact with the fluid from being corroded.

It is sectional drawing at the time of valve closing of the solenoid valve which concerns on Embodiment 1 of this invention. It is sectional drawing at the time of valve opening of the solenoid valve which concerns on Embodiment 1 of this invention. It is sectional drawing to which the principal part of the solenoid valve which concerns on Embodiment 1 of this invention was expanded. It is sectional drawing to which the principal part of the solenoid valve which concerns on Embodiment 2 of this invention was expanded.

Explanation of symbols

  1 Housing, 1a Fluid passage, 2 Input port, 3 Output port, 4 Valve seat, 4a Flow path, 5 Valve, 5a Rubber, 5b Guide part, 6 Spring, 7 Bobbin, 8 Coil, 9 Terminal, 10 Exterior resin part, DESCRIPTION OF SYMBOLS 11 Connector part, 12 Coil molding, 13 Case, 13a Bottom part, 13b Fitting hole, 13c, 14c Plating layer, 13d Upper part, 14 Boss, 14a Fixing part, 14b Protruding part, 15 Core, 15a Rod insertion hole, 16, 17 Sintered bush, 18 Plunger, 19 Rod, 20 Stopper, 21 Shaft, 22, 24 Bracket part, 23 bolt.

Claims (2)

A plunger as a mover of a magnetic circuit;
A boss as a stator of the magnetic circuit that houses the plunger;
A case for accommodating the plunger and the boss;
A shaft having one end fixed to the plunger and driven with the plunger;
A housing provided therein with a fluid passage communicating the input port through which the fluid flows in and the output port through which the fluid flows out;
A valve body for opening and closing the fluid passage;
In a solenoid valve comprising a spring that biases the valve body in one direction,
The boss has, on its end side, a fixing portion that is press-fitted and fixed into the fitting hole in the case bottom portion, and a protruding portion that protrudes into the fluid passage on the tip side from the fixing portion. A solenoid valve characterized in that the diameter is smaller than the diameter of the joint hole.   2. The solenoid valve according to claim 1, wherein the protruding portion of the boss tapers toward the front end in the penetrating direction with respect to the fitting hole at the bottom of the case.

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