JPH0134787Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electric flow rate proportional control valve, and more particularly, to an electric flow rate proportional control valve that is easy to assemble.

The electric flow rate proportional control valve is configured to open and close a slide valve using an electromagnetically operated linear motor, thereby making it possible to supply a flow rate approximately proportional to the applied current. Electric flow rate proportional control valves are often used in exhaust gas purification devices, and in this case, the input port is connected to the air cleaner and the output port is connected to the upstream side of the two-way catalyst in the exhaust system.
The current applied to the electric flow rate proportional control valve is changed using signals according to engine negative pressure, temperature, and rotation speed.
It functions to supply the air necessary to achieve the most preferable exhaust gas concentration for the three-way catalyst to the exhaust gas purification system.

This type of electric flow rate proportional control valve uses one end of the hollow iron core that constitutes the linear motor as an outlet port.
A set screw and a cover for holding the electric cord are arranged at the other end, and a blind plug is provided inside the hollow core to cut off communication at both ends. Further, a holder for a spring that biases the slide valve is fitted onto the outer periphery of the hollow core that constitutes the linear motor.

Such a configuration requires assembly work such as press-fitting the blind plug into the hollow core and further fitting the spring holder to the hollow core, increasing the number of parts and the number of assembly steps. In addition, conventional electrically operated proportional flow rate control valves have a structure between the exhaust system and the outlet port of the valve in order to prevent exhaust gas from flowing from the exhaust system into the valve, that is, to prevent the exhaust system from flowing back into the valve. Although a reed valve is used, this reed valve is assembled as an independent valve, which similarly increases the number of parts and the number of assembly steps.

This idea focuses on the points mentioned above, and in order to integrate the parts, the blind stopper and the cover are integrally molded, a spring holder is fitted into the hollow part of the cover, and a hollow iron core is used. This has the effect of making it shorter and lighter. Furthermore, since the reed valve is housed in the case, there is an advantage that the man-hours required to attach the reed valve to the vehicle can be omitted.

According to this invention, a linear motor in a case having an input port and an output port operates a slide valve that opens and closes a communication hole formed in a hollow iron core that constitutes the linear motor, and the input port and the output port are connected to each other. In the electric flow rate proportional control valve for controlling communication with the hollow iron core, a blind stopper that enters the hollow core is integrally molded with a cap-shaped cover, a spring holder is slidably attached to the cylindrical part of the cap-shaped cover, and , a reed valve is fixed to the output port side of the case, and when the exhaust system is under negative pressure, the output port and the exhaust system are communicated through the reed valve. provided.

An embodiment of this invention will be described with reference to the accompanying drawings.

The electric flow rate proportional control valve 1 houses a linear motor 3 in a case 2, and has a cover 4 fixed to a side opening of the case 2. A slide valve or bobbin 5 is actuated and displaced by a linear motor 3 to supply fluid from an input port 6 to an output port 7 while controlling its flow rate.

The case 2 has a chamber 11 extending laterally and outwardly on the output port 7 side, and a valve hole 20 is provided at the outlet of the chamber 11.
A reed valve 22 that normally closes the valve hole 20 is fixed to the plate 2. 23 is a stopper that restricts warping of the reed valve 22. The reed valve 22 is covered by a housing 25 having an outlet 24, forming a passage between the output port 7 through the reed valve 22 and the outlet 24 of the housing 25. The outlet 24 of the housing 25 is connected to the exhaust system.

The cover 4 has a cap-shaped cylindrical portion 26, the tip of which is inserted into a hollow portion of a hollow core 9, which will be described later, and functions as a blind plug. Outer part 27 of cover 4
is fixed to the case 2 using screws 28 and sealing material 29. The cylindrical portion 26 and the outer portion 27 are press-worked from a single metal plate and integrally formed.

The moving coil type linear motor 3 has a hollow core 9 having an output port 7 at one end thereof, and the input port 6 can communicate with the output port 7 via a passage 10 of the core 9 . A bobbin 5 made of a non-magnetic material and around which an electromagnetic coil 12 is wound is slidably disposed on a hollow iron core 9. A pair of permanent magnets 13 through which magnetic flux passes in a direction perpendicular to the winding of the electromagnetic coil 12 is provided, and a magnetic yoke 14 that forms a magnetic circuit of the permanent magnets 13 together with the iron core 9 is disposed within the case 2. A bobbin 5 that slides along the outer peripheral surface of the iron core 9 is connected to the passage 1.
Controls opening and closing of 0.

The bobbin 5 is preferably made of an aluminum alloy material, and a bobbin holder 30 is press-fitted into one side of the electromagnetic coil 12. To prevent damage to the bobbin 5 when the holder 30 is press-fitted into the bobbin 5, the holder 3
The inner peripheral surface of 0 is bored to reduce the press-fitting allowance. Further, the outer peripheries of the electromagnetic coil 12 and the bobbin holder 30 are coated with a resin 31, and this is cured to integrate the electromagnetic coil 12, the bobbin holder 30, and the bobbin 5 with the resin. Hollow core 9 of bobbin 5
In order to reduce the sliding resistance against the bobbin 5, the inner peripheral surface of the bobbin 5 is bored as shown in the figure.

The bobbin 5 is positioned to the left in FIG. 1 under the biasing force of the coil spring 15, and the slide valve, that is, the left end of the bobbin 5 comes into contact with the stopper surface 16. Further, the electromagnetic coil 12 is connected to the power source via a spring 15 and a cord 17.

The spring holder 8 that receives one end of the spring 15 can change its position relative to the bobbin 5, that is, the dimension between them, by means of an adjustment screw screwed into the cover 4. This position adjustment of the spring holder 8 adjusts the biasing force of the spring 15. Also, the hollow protrusion 18 of the spring holder 8 fits into the cover 4, and the electric cord 17 is inserted into the protrusion 1.
It is electrically connected to the spring 15 through the hollow part of 8. 19 is a sealing body made of hardened resin. The sealing material 32 around the hollow protrusion 18 is applied to the spring holder 8 before the resin is cured.
This prevents air from flowing into the case 2 during position adjustment and improves adjustment accuracy. Cord protector 33,
The protector 33 is locked to the edge of the cup 34 and its tongue piece 35 is embedded in the seal body 19 to stop the movement of the protector 33 and firmly fix it.

As is clear from the figure, the spring holder 8 is fitted into the cylindrical portion 26 of the cover 4, and its tip is inserted into the hollow portion of the hollow iron core 9. The airtightness between the hollow core 9 and the cylindrical portion 26 of the cover is achieved by the O-ring 3.
Secure it at 6. The portion of the cylindrical portion 26 of the cover 4 inserted into the hollow core 9 functions as a blind plug that closes one end of the hollow core 9.

A part of the sealing material 37 placed between the hollow iron core 9 and the case 2 is extended inward to form the stopper surface 16 of the bobbin 5. Even when the stopper surface 16 made of an elastic material comes into contact with the bobbin 5, it does not generate a hitting sound or impart undesirable vibrations to the bobbin 5.

When the current is not energized as shown in FIG. When a current is applied, a force proportional to the current value is generated in the right direction as seen in FIG. 5 opens the passageway 10 by an amount proportional to the applied current, allowing fluid flow from the input port 6 to the first output port 7. The fluid supplied to the output port 7 causes the reed valve 22 to open when the exhaust system is under negative pressure and flows out into the exhaust system.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of an electric flow rate proportional control valve. In the diagram: 1...Electric flow rate proportional control valve, 3...Linear motor, 4...Cover, 5...Bobbin, 6...
...Input port, 7...Output port, 8...Spring holder, 18...Protrusion, 21...Seal member, 22...Reed valve, 26...Cylindrical part, 30...
...Bobbin holder, 33...Cord protector.

Claims (1)

[Scope of utility model registration request] A linear motor in a case having an input port and an output port operates a slide valve that opens and closes a communication hole drilled in a hollow iron core that constitutes the linear motor, and controls communication between the input port and the output port. In the electric flow rate proportional control valve, a blind stopper that enters the hollow core is integrally molded with the cover in a cap shape, a spring holder is slidably attached to the cylindrical portion of the cap-shaped cover, and the An electric flow rate proportional control valve, characterized in that a reed valve is fixed to an output port side, and the output port and the exhaust system are communicated through the reed valve when the exhaust system is under negative pressure.