JPH078675U - Solenoid valve structure - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce cost while preventing malfunction due to overvoltage applied to the solenoid. [Structure] A pair of first and second electromagnetic coils 28, 29 provided inside the solenoid casing 23 are provided at both ends.
Second cores 31 and 32 are provided. Both cores 31,
A plunger 34, which slides in the axial direction by relative energization of both electromagnetic coils 28 and 29, is provided between the two. A stopper member 37 that regulates the maximum leftward sliding position of the plunger 34 is provided integrally with the cap 25. Then, the protruding portion 37b formed on the end surface of the base portion 37a of the stopper member 37 is provided from the through hole 31c of the first core 31 to the plunger 34 side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an auxiliary air amount control device which is provided in an intake system of an internal combustion engine and stabilizes idling speed.

[0002]

[Prior art]

 2. Description of the Related Art Conventionally, as an auxiliary air amount control device for an automobile gasoline engine, a device as shown in FIG. In brief, a valve housing 5 of a solenoid valve 4 and a side portion of the valve housing 5 are provided in a bypass passage 3 that connects an upstream side and a downstream side of a throttle valve 2 provided in the middle of an intake passage 1. The solenoid casing 6 fixed to the is interposed. The solenoid casing 6 has an outer end opening closed by a cap 6a, two electromagnetic coils 7 and 8 axially arranged inside each other, and first electromagnetic coils 7 and 8 provided at both ends of the electromagnetic coils 7 and 8, respectively. 1, a plunger 11 slidably housed between the second cores 9a and 9b and having a drive rod 10 at its tip.

On the other hand, in the valve housing 5, an air introducing chamber 3a that constitutes a part of the bypass passage 3, an annular valve seat 12 that defines the air introducing chamber 3a, and one end of the guide portion 18 are provided. A valve body 13 connected to the tip of the drive rod 10 via a sliding shaft 13a that slides inside is housed.

The valve body 13 is seated on the valve seat 12 to control the opening amount of the orifice 12 a at the center of the valve seat 12, and the valve spring 15 mounted on the adjusting end wall 14 side at the other end side. By the relative spring force of the plunger spring 16 mounted between the first core 9a and the plunger 10, it is elastically held at a substantially intermediate position of all the strokes in the front-rear direction.

Further, a stopper member 17 for restricting the leftmost sliding position of the plunger 11 in the drawing is press-fitted inside the first core 9a. The stopper member 17 is composed of a cylindrical base portion 17a held on the inner peripheral surface of the first core 9a and a protruding portion 17b protruding from the base portion 17a toward the plunger 11, and the outer peripheral portion of the base portion 17a. In addition, it has a function as a spring retainer by elastically holding one end of the plunger spring 11 from the axial direction.

When a duty control current having a relative opposite phase is applied to each of the electromagnetic coils 7 and 8, the plunger 11 is slid to the right in the figure by the attraction force of the second core 9b. On the other hand, the valve element 13 is moved to operate in the opening direction, while on the contrary, the valve element 13 is operated in the closing direction by sliding to the left in the figure by the suction force of the first core 9a. Therefore, even if the amount of electricity supplied to the electromagnetic coils 7 and 8 is reduced due to the increase in electric resistance due to the increase in temperature of the engine, the sufficient stroke amount of the plunger 11 optimizes the air flow rate through the orifice. It can be controlled.

Further, the stopper member 17 prevents excessive sliding of the plunger 11 to the left when excessive voltage is applied to the one-side electromagnetic coil 8 to prevent defective opening / closing operation of the valve body 13. It is like this. That is, when the stopper member 17 is not present, the tapered left outer peripheral surface of the plunger 11 is fitted and fixed to the tapered inner peripheral surface of the core 9a by the application of the overvoltage, and then the voltage is reduced. Even if it is done, the plunger 11 may not be separated from the core 9a, which may cause malfunction. Therefore, the stopper member 17 prevents such malfunction.

[0008]

[Problems to be solved by the device]

 However, in such a conventional solenoid valve structure, since the stopper member 17 is formed separately from each of the other components, the number of components is inevitably increased, resulting in poor work efficiency during manufacturing and cost reduction. Inviting high. In addition, the management of parts becomes complicated, and since it is necessary to press-fit and fix the core 9a each time, it becomes a factor that deteriorates the workability of assembling the solenoid valve.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a solenoid valve structure capable of reducing the cost of the solenoid valve while preventing malfunctions caused by application of an overvoltage. And

[0010]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in the present invention, a solenoid casing whose one end opening is closed by an end plate, and a pair of electromagnetic coils arranged inside the solenoid casing along the axial direction are provided. , A pair of cores provided on the inner circumferences of both ends of the electromagnetic coils, a plunger that is relatively attracted by the cores and slides in the axial direction as the electromagnetic coils are energized, and one end of the plunger Drive rod having a valve body at the tip end thereof and a core provided on the opposite side of the drive rod from the inner end side of the one side core, so that the plunger has a maximum length in one direction. In a solenoid valve structure including a shaft-like stopper member that regulates a sliding position, the stopper member is integrally provided on the inner surface of the end plate, and is formed so as to penetrate in the inner axial direction of the one-side core. Through the through hole, It was 臨設 the tip of the member to the other end of the plunger. Also, the stopper member is integrally extended to the fixed end portion of the drive rod, and the tip end portion of the stopper member is provided on one core side from a through hole formed through the plunger in the central axis direction. Is preferred.

[0011]

[Action]

 In the above structure, since the stopper member is integrally provided on the end plate of the solenoid casing, the number of parts can be reduced. Further, when the stopper member is provided as it is on the fixed end portion of the drive rod as it is, the number of parts can be reduced and the manufacturing work efficiency can be further improved.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an auxiliary air amount control device for an internal combustion engine having an electromagnetic valve structure according to the present invention, in which 20 is a bypass passage bypassing a throttle valve of an intake passage of the internal combustion engine, and 21 is the valve. A solenoid valve provided in the middle of the bypass passage 20. The solenoid valve 21 is of a proportional solenoid type and is provided on a valve housing 22 and a seal ring 24 at one end of the valve housing 22. And a cylindrical solenoid casing 23 with a lid.

One end opening of the solenoid casing 23 is closed by a cap 25 which is an end plate made of synthetic resin, and a pair of bobbins 26 and 27, which are provided at axially front and rear positions inside, are provided with a pair of valve opening and closing. Two electromagnetic coils 28 and 29 for the valve are wound. A cylindrical plunger guide 30 is provided between the thin-walled tubular portions of both bobbins 26, 27, and a pair of first core 31 and second core 32 are provided on the inner peripheral side of the tubular portions. Is provided. An annular yoke 33 is interposed between the electromagnetic coils 28 and 29. Further, on the inner circumference of the plunger guide 30, a plunger 34 having a drive rod 35 connected to a tip end portion thereof is provided slidably in the axial direction. The drive rod 35 is slidably guided by a rod guide 36 held on the inner circumference of the second core 32 on the front side.

In the first core 31 and the second core 32, the inner peripheral surfaces 31 a and 32 a of the inner ends facing each other are formed into a conical tapered surface, while the plunger 34 is provided with the pair of the first core 31 and the second core 32. Outer peripheral surfaces 34a, 34b at the front and rear end portions facing the inner end portions of the core 31 and the second core 32 are formed as conical tapered surfaces having the same taper angles as the inner peripheral surfaces 31a, 32a. A plunger spring 38 for biasing the plunger 34 in the right direction in the drawing is contracted between a stopper member 37, which will be described later, disposed inside the first core 31 and a plunger 34.

The stopper member 37 is integrally formed with the cap 25 by a synthetic resin material, and has a substantially cylindrical base portion 37 a and a small-diameter shaft-shaped protruding portion protruding toward the plunger 34 on the front end surface of the base portion 37 a. 37b. In addition, the base portion 37a and the protruding portion 37b are disposed so as to penetrate through a through hole 31b that is formed through the center of the first core 31 in the axial direction, and the tip portion 37c of the protruding portion 37b is formed in the through hole 31b. The maximum protruding position of the plunger 34 to the left in the figure is regulated by projecting a predetermined amount from b.

In the figure, 39 is an O-ring that seals between the front end wall 23 a of the solenoid casing 23 and the bobbin 27, and 40 is an O-ring that seals between the rear end of the solenoid casing 23 and the cap 25. .

On the other hand, in the valve housing 22, the outer end opening is closed by an adjusting end wall 41, and an air inlet chamber 42 having a substantially inverted U-shaped cross section which forms a part of the bypass passage 20 is formed inside. There is. Further, the air introduction chamber 42 is provided with an annular valve sheet 43, and a valve element 45 which is seated on and off the valve seat 43 to open and close an orifice 44 at the center of the valve sheet 43. There is.

The valve body 45 includes a columnar portion 45 a and a large-diameter seating portion 45 b which is provided at one end of the columnar portion 45 a and which is seated on and detached from the valve seat 43. The cylindrical portion 45b is formed to have an outer diameter slightly smaller than the inner diameter of the orifice 44, and the outer diameter of the conical portion 45c at one end of the cylindrical portion 45b is gradually reduced toward the plunger 34 side. ing. That is, the opening area of the orifice 44 in the cylindrical portion 45a is substantially close to the fully closed state, and the opening area of the orifice 44 is gradually increased from the one end edge of the conical portion 45c on the cylindrical portion 45a side to the other end edge. It is formed so that it will be fully opened in the vicinity. The valve body 45 is provided with a guide shaft 46 slidably guided in the central guide hole 41a of the adjusting end wall 41 on the seating portion 45b side, and is slidably guided in the valve guide 36 at the front end portion. A sliding shaft 47 is provided and is connected to the drive rod 35 via this sliding shaft 47.

The valve element 45 is biased in a direction of closing the orifice 44 by a valve spring 48 elastically mounted between the valve element 45 and the adjusting end wall 41, and the orifice 44 is closed by the plunger spring 38. Is being urged in the direction of opening. That is, the valve element 45 is moved by the relative pressure between the spring force of the plunger spring 38 and the spring force of the valve spring 48 opposed to the spring force, that is, the intermediate position of all the strokes in the opening / closing direction, that is, the cylindrical portion 45a as shown in the figure. The vicinity of the boundary between the conical portion 45c and the conical portion 45c is located at the inner peripheral edge of the orifice 44, and is held at the opening position where the orifice 44 is slightly opened. Therefore, the valve seat 43 and the valve body 45 are not in contact with each other, and are held at a substantially intermediate position of the entire opening / closing stroke of the valve body 45.

A control current (duty signal) of opposite phase is applied to the two electromagnetic coils 28 and 29 in the solenoid casing 23 from a control circuit (not shown). When the control circuit increases the ON (H level) duty signal to the valve opening electromagnetic coil 29, the control circuit decreases the ON duty signal to the valve closing electromagnetic coil 28, and conversely the valve closing electromagnetic coil. When the ON duty signal for 28 is increased, the ON duty signal for the valve closing electromagnetic coil 29 is decreased.

Therefore, in the present embodiment, when the internal combustion engine is cold started, the ON duty signal applied to the valve opening electromagnetic coil 29 from the control circuit is increased, and the valve closing electromagnetic coil 28 is opened. The ON duty signal, which is sufficiently smaller than the electromagnetic coil 29 for application, is applied. Therefore, the plunger 34 is sucked in the right direction in the figure and pushes out the drive rod 35 in the same direction. As a result, the valve body 45 moves in the same direction from the intermediate position shown in the figure against the spring force of the valve spring 48, and the opening area of the orifice 44 increases due to the conical portion 45c. Is the maximum. As a result, the warm-up operation is promptly performed.

When the engine temperature rises due to warming up, the ON-duty signal to the valve-opening electromagnetic coil 29 applied from the control circuit is gradually decreased, while the valve-closing electromagnetic coil 29 is gradually decreased. The ON duty signal to 28 relatively gradually increases. Therefore, the plunger 34 moves leftward in the drawing against the spring force of the plunger spring 38, and the valve body 45 further moves leftward from the intermediate position shown in the drawing. Therefore, as the warm-up progresses, the seating portion 45b approaches the seat surface 43a to gradually reduce the opening area of the orifice 44, and when the warm-up is completed, the opening area is minimized to compensate for the passage of a predetermined air flow rate. become.

As described above, in this embodiment, the two electromagnetic coils 28 and 29 are used to attract the valve element 45 at the intermediate position of the stroke in the opening direction or the closing direction. As described above, even if the supply voltage is generated due to the increase of the coil resistance value at the low temperature start or the high temperature start and the suction force to the plunger 34 is reduced, the opening / closing stroke amount of the valve body 45 can be sufficiently secured. As a result, the air flow rate can be controlled with high accuracy, and a sufficient air flow rate can be secured especially at low temperature starting.

Moreover, as described above, since the stopper member 37 is integrally provided with the cap 25 by the synthetic resin material, the number of parts can be reduced, and the stopper member 37 can be molded together with the cap 25 by injection molding or the like. Therefore, the manufacturing work efficiency can be improved and the cost can be reduced.

Further, not only the parts management is improved by being integrated with the cap 25, but also the base portion 37a and the protruding portion 37b are simply inserted from the outside into the through hole 31b, so that the assembling workability is also good. become. Furthermore, since it is molded with a synthetic resin material, weight reduction can be promoted.

FIG. 2 is a view showing another embodiment of the present invention in which the above-mentioned stopper member 37 is integrally provided not on the first core 31 side but on the drive rod 35. That is, the stopper member 37 is continuously and integrally provided on the fixed end portion 35a of the metallic drive rod 35 located inside the plunger 34, and is formed in a small-diameter shaft shape as a whole, and is connected to the drive rod 35. It is coaxially extended rearward to a predetermined length. Further, the stopper member 37 has a distal end portion 37c penetrating through a through hole 34c formed in the inner axial direction of the plunger 34 to face the first core 31 side, so that the plunger 34 can slide to the left. Accordingly, the maximum sliding position is regulated by hitting the inner end surface 31c of the first core 31 at the predetermined sliding position.

Further, a convex portion 48 is integrally provided on the outer end surface of the guide shaft 46, and when the plunger 34 slides in the right direction, the convex component 48 abuts the bottom surface of the guide hole 41a to move the maximum sliding position. It is regulated.

Therefore, according to this embodiment, since the stopper member 37 is integrated with the drive rod 35, the number of parts can be reduced, the manufacturing work efficiency can be improved, and the structure can be simplified. Further, since it is simply inserted into the through hole 34c of the plunger 34, the workability of assembling is also improved.

Further, since the convex portion 48 restricts the excessive rightward movement of the plunger 34, the taper-shaped outer peripheral surface 34 b and the inner peripheral surface 32 a of the second core 32 are prevented from being fixed to each other.

[0030]

[Effect of device]

 As apparent from the above description, according to the present invention, not only the stopper member can prevent the plunger and the core from being fixed due to the application of the overvoltage to the electromagnetic coil, but the stopper member can be provided integrally with the cap or the drive rod. Therefore, the number of parts can be reduced. Therefore, it is possible to improve the manufacturing efficiency and reduce the cost while preventing the malfunction due to the application of the overvoltage. In addition, parts management becomes easier and assembly work becomes easier.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing another embodiment.

FIG. 3 is a vertical cross-sectional view showing a conventional solenoid valve structure.

[Explanation of symbols]

 21 Solenoid Valve 22 Valve Casing 23 Solenoid Casing 25 Cap (End Plate) 28, 29 Electromagnetic Coil 31 First Core 31b Through Hole 32 Second Core 34 Plunger 34c Through Hole 35 Drive Rod 35a Fixed End 37 Stopper Member 37a Base 37b Projection Part 37c Tip

Claims (2)

[Scope of utility model registration request] 1. A solenoid casing whose one end opening is closed by an end plate, a pair of electromagnetic coils arranged in parallel inside the solenoid casing along the axial direction, and provided on inner circumferences of both ends of both electromagnetic coils. A pair of cores, a plunger that is relatively attracted to both cores as the electromagnetic coils are energized, and slides in the axial direction, and a valve element that is connected to one end of the plunger and has a tip end. A drive rod provided and a shaft-shaped stopper member provided on the inner end side of the core on the one side located on the opposite side of the drive rod to restrict the maximum sliding position of the plunger in one direction. In the provided electromagnetic valve structure, the stopper member is integrally provided on the inner surface of the end plate, and the tip end portion of the stopper member is connected to the other end of the plunger through a through hole penetratingly formed in the inner axial direction of the one side core. On the edge Solenoid valve structure characterized by being installed. 2. The stopper member is integrally extended to a fixed end portion of a drive rod, and a tip end portion of the stopper member is provided on one core side from a through hole formed through the plunger in a central axial direction. The solenoid valve structure according to claim 1, wherein: