JPH017898Y2 - - Google Patents

Description

[Detailed description of the invention] This invention supplies secondary air to the air control valve, particularly the intake system or exhaust system of the engine, to adjust the air-fuel ratio of the air-fuel mixture to the engine or to control the air-fuel ratio in the exhaust gas from the engine. This invention relates to improvements in air control valves used to control the combustion of residual fuel, etc. in exhaust gas by adjusting the amount of oxygen.

Conventionally, as shown in FIG. 4, this type of air control valve has an air intake port 1, an air discharge port 2, and a valve seat provided at a position between the air intake port 1 and the air discharge port 2. 3, a valve body 4 that comes into contact with and away from the valve seat 3 to measure circulating air, a shaft 5 that supports the valve body 4, a stator core 6 that is coaxially arranged outside of the shaft 5, and a stator core that There is a device that has a solenoid 7 disposed outside of the valve body 6 and a yoke 8 that encloses the solenoid 7, and controls the position of the valve body 4 according to the strength of the magnetic field excited by the solenoid 7. . In this case, the current to the solenoid 7 is controlled by a command signal from a control unit based on a signal from a sensor for detecting the state of engine exhaust gas, such as an O ₂ sensor.

In such an air control valve,
The terminal 9 of the solenoid 7 is connected to the lead wire 1
0 and a filler such as thermosetting epoxy resin 1
1 is generally molded. Further, inside the yoke 8, a gap 13 exists between the outside of the solenoid 7 made of a coil wound around a bobbin 12 and the inner peripheral surface of the yoke 8.

For this reason, in the conventional air control valve, the heat generated by energizing the solenoid 7 is trapped inside due to the heat insulating effect of the air in the gap 13, causing the disadvantage that the entire air control valve becomes high temperature. Therefore, in the worst case, the coil of the solenoid 7 may burn out. In addition, when controlling the position of the valve body 4 according to the voltage, the current flowing through the coil decreases significantly due to the increase in resistance due to heat generation in the coil, thereby controlling the amount of air in accordance with the current. There is an inconvenience that you will not be able to do so.

Furthermore, the air within the gap 13 expands and contracts by repeatedly heating and dissipating heat by turning on and off the power supply to the solenoid 7, so that moisture and the like are drawn in from the outside during the contraction, causing problems such as short circuits and rust.

The present invention has been developed to solve the above-mentioned problems, and by injecting and solidifying a filler into the gap between the solenoid and the yoke, it improves the heat dissipation of the coil and prevents moisture from entering. It is an object of the present invention to provide an air control valve which is molded together with the terminal part and a part of the lead wire when the filler is injected.

This invention consists of an air suction port, an air discharge port, a valve seat provided between the air suction port and the air discharge port, a valve body that is in contact with and separate from the valve seat to measure the circulating air, and It has a shaft that supports the valve body, a stator core that is coaxially arranged outside the shaft, a solenoid that is arranged outside the stator core, and a yoke that includes the solenoid, and is excited by the solenoid. In an air control valve that controls the position of the valve body according to the strength of a magnetic field, a small diameter yoke rear end portion protruding further rearward from a center portion of the rear end surface of the yoke, and the valve body of the stator core. a protrusion at the rear end of the stator core that protrudes on the opposite side and is fitted and fixed to the inner diameter of the rear end of the yoke; a filler injection port formed on the rear end surface of the yoke so as to communicate the inside and outside of the yoke; and a rear end of the yoke. a rubber cover that is fitted to a corner of the end face and surrounds the rear end of the yoke with a gap between the inner circumferential surface of the yoke and the solenoid through the filler injection port; Injecting and solidifying a filler into the void, and injecting and solidifying the filler continuously with the void on the outside of the rear end protrusion of the stator core and the rear end of the yoke, inside the rubber cover, and near the rear end surface of the yoke. This will achieve the above objectives.

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the same or corresponding parts as those of the air control valve shown in FIG. 4 are given the same reference numerals, and the explanation thereof will be omitted.

As shown in the figure, this embodiment includes an air intake port 1, an air discharge port 2, a valve seat 3 provided at a position between the air intake port 1 and the air discharge port 2, and this valve. A valve body 4 that comes into contact with and separates from the seat 3 to measure circulating air, a shaft 5 that supports this valve body 4, and this shaft 5
a stator core 6 coaxially arranged on the outside of the stator core 6;
It has a solenoid 7 disposed outside of the stator core 6 and a yoke 8 that encloses the solenoid 7, and the air is used to control the position of the valve body 4 according to the strength of the magnetic field excited by the solenoid 7. In the control valve, a small-diameter yoke rear end 8B protrudes further rearward from the center of the rear end surface 8A of the yoke 8, and a yoke rear end 8B on the opposite side of the valve body 4 of the stator core 6. A stator core rear end protrusion 6A that is fitted and fixed to the inner diameter and further protrudes rearward from here, a filler injection port 14 formed on the rear end surface 8A of the yoke 8 so as to communicate between the inside and outside of the yoke 8, and the yoke 8. a rubber cover 15 that is fitted into the rear end face corner 8C of the yoke 8B and surrounds the yoke rear end 8B with a gap therebetween; A gap 1 between the inner circumferential surface of 8 and the solenoid 7
3 and solidify the filler 11, and fill the space 13 continuously with the outside of the rear end protrusion 6A of the stator core 6 and the rear end 8B of the yoke, inside the rubber cover 15, and near the rear end surface 8A of the yoke. It is made by injecting and solidifying the agent.

The filler inlet 14 is inserted into the rear end surface 8 of the yoke 8 at equal angular intervals so that the filler flows uniformly around the solenoid 7, as shown in FIG.
It is formed in A.

When injecting and solidifying the filler 11, as shown in FIGS. 1 and 2, the rubber cover 15 is fitted to the rear end face corner 8C of the yoke 8, and the rear end protrusion 6A of the stator core 6 is Place the entire valve so that it faces upward, and in this state, remove the rubber cover 15.
A fluid filler is injected from above into the space formed by the rear end protrusion 6A of the stator core 6, the yoke rear end 8B, and the rear end surface 8A of the yoke 8. At this time, the rubber cover 1
If the rubber cover 15 is dimensioned so that the tip of the rear end protrusion 6A of the stator core 6 is above the upper end of the stator core 5, the filler in a fluid state is prevented from flowing into the stator core.

The fluidized filler injected into the space is
The filler enters the yoke 8 through the filler injection port 14, fills the void 13, and is solidified integrally with the filler injection port 14 and the inside of the rubber cover 15 embedded therein.

Reference numeral 16 in the figure is an O-ring disposed between the rear end inner circumference side of the bobbin 17 of the solenoid 7 and the inner circumference of the yoke 8, and 18 is an O-ring disposed between the front end outer circumference side of the bobbin 17 and the rear end surface of the magnetic plate 19. Each shows an O-ring placed between them. These O-rings prevent water from entering into the stator core 6, and also prevent the filler in a fluid state from entering the stator core 6 side when the filler 11 is injected.

The magnetic plate 19 is integrally attached to the housing 20 with the yoke 8 by bolts 21 with its flange 19A being inserted between the flange 8B of the yoke 8 and the housing 20.

Reference numeral 22 in the figure indicates an O-ring disposed between the flange 8B of the yoke 8 and the flange 19A of the magnetic plate 19.

The magnetic plate 19 has a moving core 24 integrally attached to the shaft 5 through a bearing bush 23 at its center.
is supported slidably in the axial direction. A ventilation hole 25 is formed in this magnetic plate 19, which communicates the space before and after the magnetic plate 19.
When the moving core 24 reciprocates together with the shaft 5, these spaces are prevented from being compressed or expanded and acting as a damper.

Further, the magnetic plate 19 supports the thick rear end portion 27A of the bellows 27 by inserting the gasket 26 between the magnetic plate 19 and the stepped portion 20A of the housing 20.

The bellows 27 is formed integrally with the valve body 4 from the same material, for example, a fluororesin such as Teflon (trade name), and forms a sealed space 28 at the rear of the valve body 4 .

A vent hole 30 is formed in the valve body 4 to communicate the sealed space 28 with the front side space 29 of the valve body 4, thereby eliminating the influence of the pressure difference between the rear side and the front side of the valve body 4. By removing this, the control characteristics of the circulating air can be made more precise.

The tip side of the bellows 27, that is, the valve body 4,
A bellows holder 3 is fitted with the tip of the shaft 5 passing through the bellows 27 and is press-fitted into the tip.
1 between the shaft 5 and the collar 5A.

Reference numeral 32 in the figure indicates a valve lip attached to the corner of the valve body side of the valve seat 3, and this valve lip 32 is made of an elastic material such as rubber.
It is designed to measure the circulating air by coming into contact with and separating from the tip of the pipe.

The rear end of the shaft 5 is axially movably supported by a bearing bush 33 disposed inside the stator core, and is biased by a return spring 34 in the direction in which the valve body 4 protrudes. There is.

The return spring 34 is interposed between the tip projection 35A of the adjusting screw 35 and the rear end projection 5B of the shaft 5. Further, the adjusting screw 35 is connected to the stator core 6.
A screw hole 36 formed at the rear of the rear end protrusion 6A
The return spring 34 is screwed from the rear end to adjust the set length of the return spring 34.

In this embodiment, a bellows 27 is provided at the rear of the valve body 4, and a sealed space 28 within the bellows 27 is communicated with a space 29 on the front side of the valve body 4 through a vent hole 30. The differential pressure between the front side and the rear side of the valve body 4 is eliminated, and therefore the valve body 4
The position is controlled only by the strength of the magnetic field excited by the solenoid 7 and the return spring 34, so that the amount of air flowing can be accurately controlled.

In addition, since the gap 13 between the solenoid 7 and the yoke 8 is filled with the filler 11, the heat dissipation of the solenoid coil is increased, preventing deterioration of control characteristics and burnout of the coil due to heat generation of the coil. This has the advantage that it is possible to prevent the intrusion of moisture due to the contraction and expansion of air within the void, and to prevent rust or shoots from occurring due to moisture.

Also, a rubber cover 15 that becomes a dam for the filler 11
Since it becomes a part of the air control valve V as it is, the filling operation is easy.

Furthermore, since the stator core 6 and the yoke 8 are connected by fitting the rear end protrusion 6A and the yoke rear end 8B, there is an advantage that the assembly strength is high.

In the above embodiment, a bellows 27 is provided at the rear of the valve body 4 to eliminate the differential pressure between the rear and front of the valve body, but the present invention is also applicable to cases where no bellows are used. It is something.

Since the present invention is constructed as described above, the heat dissipation of the coil is improved and moisture, etc., can be prevented from entering the inside, thereby greatly improving durability and reliability, and making it easy to inject filler. This has the excellent effect of reliably improving workability and increasing the assembly rigidity of the stator core and yoke.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the air control valve according to the present invention, Fig. 2 is an enlarged sectional view showing the main parts of the same embodiment, and Fig. 3 is a -
FIG. 4 is a partially sectional front view showing a conventional air control valve. V...Air control valve, 1...Air intake port, 2...Air discharge port, 3...Valve seat,
4... Valve body, 5... Shaft, 6... Stator core, 6
A... Rear end protrusion, 7... Solenoid, 8... Yoke,
8A... Rear end face, 8B... Rear end part, 8C... Rear end face corner part, 9... Terminal part, 10... Lead wire, 1
1... filler, 13... void, 14... filler injection port,
15...Rubber cover.

Claims (1)

[Scope of utility model registration request] An air intake port, an air discharge port, a valve seat provided between the air intake port and the air discharge port, a valve body that is in contact with and separate from this valve seat to measure circulating air, and supports this valve body. A stator core disposed coaxially outside the shaft, a solenoid disposed outside the stator core, and a yoke containing the solenoid, and the strength of the magnetic field excited by the solenoid An air control valve that controls the position of the valve body according to a protrusion at the rear end of the stator core fitted and fixed to the inner diameter of the rear end of the yoke; a filler injection port formed on the rear end surface of the yoke so as to communicate the inside and outside of the yoke; and a corner portion of the rear end surface of the yoke. a rubber cover that is fitted and surrounds the rear end of the yoke with a gap, and a filler is injected into the gap between the inner circumferential surface of the yoke and the solenoid through the filler injection port. is injected and solidified, and a filler is injected and solidified continuously into the void on the outside of the protrusion at the rear end of the stator core and the rear end of the yoke, inside the rubber cover, and near the rear end surface of the yoke. Air control valve.