JPH0338542Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a solenoid valve that can detect opening/closing operation status.

(Prior Art) As an example of a solenoid valve for high-pressure fluid control, the applicant has developed one constructed as follows. That is, this electromagnetic valve includes a valve body having a valve seat and a fluid passage, a stator attached to the valve body, and a cover attached to the stator. A disc-shaped armature is housed in the housing space between the stator and the cover, and a needle-shaped valve element is connected to the armature for moving toward and away from the valve seat to open and close the fluid passage. Further, a mounting hole is formed in the center of the cover, and a stopper is inserted and supported in this mounting hole. A coil spring is housed in the stopper, and the coil spring biases the valve element in a direction away from the stator. A locking flange is formed on the stopper, and this locking flange locks the armature pulled up by the coil spring.

Furthermore, some electromagnetic valves configured as described above are capable of detecting their opening/closing operation status. That is, only when the valve seat formed in the valve body and the valve element come into contact, electrical continuity is established between the two and this is detected. To enable this detection, the valve element side structures, such as the valve element, coil spring, and stopper, are electrically insulated from the valve seat side structures, which are the valve body, stator, and cover. .

Specifically, an insulating bushing is interposed between the valve element and the valve body. Furthermore, as shown in FIG. 2, between the cover 32 and the stopper 40,
It has an insulated structure. That is, the insulating bush 41' is interposed between the inner peripheral surface of the mounting hole 32a of the cover 32 and the outer peripheral surface of the stopper 40.
Further, a flange 41a' formed at one end of this insulating bushing 41' is connected to the inner surface of the cover 32 and the stopper 4.
0 and the locking flange 40b. The stopper 40 is attached to the cover 32 in an insulated state by tightening a nut 45 screwed onto the stopper 40 via an insulating gasket 42'.

(Problem to be solved by the invention) In order to keep the biasing force of the coil spring 50 and the movement stroke of the armature constant, the stopper 40 is
must be positioned accurately, and for this purpose the insulating bushing 41' and the insulating gasket 42' must have a predetermined shape-maintaining function.

In addition, in the above-mentioned solenoid valve, because the pressure inside the fluid passage is high, the fluid passes through a small gap between the valve element and the structure such as the valve body that supports it, and is transferred between the stator and the cover. It invades the formed accommodation space and fills the accommodation space.
Therefore, the insulating bushing 41' and the insulating gasket 42' must also have a sealing function against fluid.

However, there are not many materials that are excellent in all of the above-mentioned shape retention properties, electrical insulation properties, and sealing properties, and if emphasis is placed on shape retention properties and electrical insulation properties, there is an inconvenience that fluid leaks from between the cover and the stopper. Furthermore, if emphasis was placed on sealing performance, the positioning of the stopper would be uncertain, resulting in variations in the characteristics of the solenoid valve, and the insulation would be incomplete, making it impossible to reliably detect the opening/closing operation status.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and the gist thereof is to provide a valve body having a valve seat and a fluid passage, a stator attached to the valve body, a cover attached to the stator and having a mounting hole in the center; a plate-shaped armature disposed in a housing space between the stator and the cover; and a valve element connected to the armature and brought into contact with and separated from the valve seat to open and close the fluid passage. a cylindrical stopper that is inserted and supported in the mounting hole of the cover and has a locking flange for regulating movement of the armature; and a coil spring that is housed in the stopper and biases the armature in a direction away from the stator. In the solenoid valve, there is a gap between the inner circumferential surface of the mounting hole of the cover and the outer circumferential surface of the stopper.
A pair of insulating bushes having a flange at one end are inserted, the flange of one insulating bushing is sandwiched between the locking flange of the stopper and the inner surface of the cover, and the flange of the other insulating bush is inserted into the stopper. It is sandwiched between the screwed nut and the outer surface of the cover, and further,
The electromagnetic valve is characterized in that a seal ring sandwiched between the other ends of the pair of insulating bushes is interposed between the inner peripheral surface of the mounting hole and the outer peripheral surface of the stopper.

(Function) The pair of insulating bushes mainly has the function of maintaining the shape for positioning the stopper and the function of electrically insulating between the cover and the stopper, and materials with excellent properties are selected and used for these functions. In addition, the seal ring sandwiched between the insulating bushes is mainly responsible for the sealing function.
Select and use materials with excellent sealing properties.

As a result, the stopper can be positioned well and the characteristics of the solenoid valve are stabilized. Further, the insulation between the cover and the stopper can be improved, and the opening/closing operation status of the solenoid valve can be reliably detected. Furthermore, leakage of fluid from between the cover and the stopper can be reliably prevented.

(Example) Hereinafter, an example of the present invention will be described based on FIG. 1. The illustrated electromagnetic valve 1 is connected in parallel with a delivery valve to a high pressure chamber of a diesel engine fuel injection pump 100, for example, and by releasing high pressure fuel oil (high pressure fluid), the amount of injection from the delivery valve to the injection nozzle is reduced. It controls the

The electromagnetic valve 1 has a valve body 10. Valve body 1
0 consists of a cylindrical portion 11 and a flange portion 12 formed at its upper end. A storage hole 13 is formed on the central axis of the cylindrical portion 11, and a sleeve 15 is stored in the storage hole 13 via an insulating bushing 14. The insulating bushing 14 has a flange 14a at its lower end, and the flange 14a is interposed between the bottom surface of the storage hole 13 and the lower end surface of the sleeve 15. Therefore, the sleeve 15 and the valve body 10 are electrically insulated.

A fluid passage 16 through which fuel oil flows is formed below the storage hole 13. This fluid passage 16 includes two inlet ports 16a, one outlet port 16b, and these ports 16a, 16.
It has a chamber 16c that communicates with b. One ends of these ports 16a and 16b open to the lower end surface of the valve body 10. Chamber 16c and outflow port 16
b is formed coaxially with the storage hole 13, and a tapered valve seat 17 is formed at the boundary thereof.

Note that the valve body 10 is a fuel injection pump 10.
Retainer 18 screwed into fixing hole 101 of 0
This retainer 18 is fixed to the fuel injection pump 100 by a nut 19 that locks it.

A needle-shaped valve element 20 is slidably supported by the sleeve 15 supported by the valve body 10 . The valve element 20 has a tapered tip 21 that comes into contact with and separates from the valve seat 17 of the valve body 10 to open and close the fluid passage 16.

A stator 30 made of a magnetic material is fixed to the flange 12 of the valve body 10, and a plurality of coils 31 are concentrically embedded in the upper surface of the stator so that the direction of current flow is opposite to each other. ing. Further, a cover 32 is screwed onto the periphery of the stator 30. A disk-shaped armature 33 made of a magnetic material is housed in a flat housing space formed by the cover 32 and the stator 30.

The valve element 20 is connected to the center of the armature 33. That is, a midway portion of the valve element 20 passes through a through hole 33a formed in the center of the armature 33 via the insulating bush 34. A projecting portion 22 is formed in the valve element 20 below a portion corresponding to the through hole 33a.
The armature 33 is mounted on the armature 2 via a seat plate 35 and a flange 34a formed at the lower end of the insulating bush 34. In addition, valve element 2
0, a male thread 23 is formed above the portion corresponding to the through hole 33a, and this male thread 2
The valve element 20 is connected to the armature 33 by tightening the armature 33 through a seat plate 37 and an insulating seat plate 38 with a nut 36 that is screwed into the valve element 3 .

The armature 33 and the valve element 20 are electrically insulated by the insulating bushing 34 and the insulating seat plate 38.

A mounting hole 32a is formed in the center of the cover 32, and a cylindrical stopper 40 is inserted and supported in this mounting hole 32a. This stopper 40
is a male thread with 40 screws on the middle part and upper end of the outer circumferential surface.
a, 40b, a locking collar portion 40c at the lower end, and an annular spring receiving portion 40d inside. Note that the male threads 40a and 40b are opposite threads to each other.

A pair of insulating bushes 41 and 42 and a seal ring 43 are interposed between the inner circumferential surface of the mounting hole 32a of the cover 32 and the outer circumferential surface of the stopper 40, which are the characteristics of the present invention.

Specifically, each insulating bushing 41, 42 is made of a material with excellent shape retention and insulation properties, and has flanges 41a, 42a at one end. The flange 41a of the lower insulating bush 41 is interposed between the locking flange 40c of the stopper 40 and the inner surface of the cover 32. In addition, the collar portion 42 of the upper insulating bushing 42
a is interposed between the lower surface of a nut 45 screwed into the male thread 40a of the stopper 40 and the upper surface of the cover 32.

The seal ring 43 is made of a material with excellent sealing properties, and is interposed between the inner peripheral surface of the mounting hole 32a of the cover 32 and the outer peripheral surface of the stopper 40 while being sandwiched between the insulating bushes 41 and 42. There is.

Then, by tightening the nut 45, the stopper 40 is firmly attached to the cover 32, and the seal ring 43 is deformed by the insulating bushes 41 and 42, so that the attachment hole 32a of the cover 32 is deformed.
The inner peripheral surface of the stopper 40 is brought into pressure contact with the outer peripheral surface of the stopper 40.

When the stopper 40 is installed, the stopper 40
The aforementioned nut 36 is inserted at the bottom of the
The seat plate 37 on the armature 33 side comes into contact with the lower surface of the locking flange 40c of the stopper 40, thereby restricting the upward movement of the armature 33 and the valve element 20.

A compression coil spring 50 is disposed around the upper end of the valve element 20. The lower end of this coil spring 50 is connected to the spring receiving portion 40d of the stopper 40.
The upper end of the seat plate 51 is in contact with a spring receiving member 53 supported by the valve element 20 via a snap spring 52 . This coil spring 50 urges the armature 33 and the valve element 20 upward.

A cap 55 having a thread opposite to that of the nut 45 is screwed into the male thread 40b at the upper end of the stopper 40. Note that a gasket 54 is interposed between the upper end surface of the stopper 40 and the cap 55.

The cap 55 and cover 32 are provided with detection terminals 58 and 59 made of solder to which one ends of lead wires 56 and 57 are connected. This detection terminal 5
8 and 59 are connected to a control unit 60.

Next, the operation of the electromagnetic valve 1 having the above configuration will be explained. The pressure of fuel oil sent from a discharge port (not shown) of the fuel injection pump 100 is applied to the inflow side port 16a of the solenoid valve 1. When the coil 31 is energized, its magnetic force causes the coil spring 5 to
0, the armature 33 is drawn toward the stator 30, that is, downward, and the valve element 2
Since the tip 21 of the valve 0 hits the valve seat 17, the fluid passage 16 is blocked. As a result, the fuel oil is sent to the injection nozzle via the delivery valve without escaping from the solenoid valve 1.

When the coil 31 is no longer energized, the armature 33 is pulled up by the elastic force of the coil spring 50 until it hits the stopper 40, and the tip 21 of the valve element 20 separates from the valve seat 17. As a result, the fuel oil flows through the inlet port 16a and the chamber 16c.
From the outflow side port 16b through the injection pump 10
0 escape port (not shown), and the supply of fuel oil from the delivery valve to the injection nozzle is stopped.

The valve seat 17 includes the valve body 10, the stator 30,
It is electrically connected to the detection terminal 59 via the cover 32. Further, the valve element 20 is electrically connected to a detection terminal 58 via a coil spring 50, a stopper 40, and a cap 55. Therefore, when the valve element 20 is on the valve seat 17, the detection terminals 58 and 59 are in a conductive state, and the control unit 60 detects this conductive state and determines that the solenoid valve 1 is in the closed state. do.

Further, an insulating bushing 14 is interposed between the valve body 10 and the sleeve 15, and an insulating bushing 4 is also interposed between the cover 32 and the stopper 40.
1 and 42 are interposed, the valve element 2
0 leaves the valve seat 17, both detection terminals 58,
59 becomes non-conductive. The control unit 60 detects this non-conducting state and determines that the solenoid valve 1 is in the open state.

By the way, since the pressure in the fluid passage 16 is high, the fuel oil flows onto the outer circumferential surface of the valve element 20 and the sleeve 15.
The stator 30 penetrates into a minute space between the
and the cover 32, and is filled therewith. This fuel oil can be prevented from leaking between the cover 32 and the stopper 40 by the seal ring 43 made of a material with excellent sealing properties.

Furthermore, since the insulating bushes 41 and 42 have excellent shape retention, the stopper 40 can be positioned reliably, the biasing force of the coil spring 50 and the movement stroke of the armature 33 can be kept constant, and the characteristics of the solenoid valve 1 can be maintained. It can be stabilized.

Further, since the insulating bushes 41 and 42 have excellent insulation properties, insulation between the cover 32 and the stopper 40 can be reliably achieved, and the opening/closing operation status of the solenoid valve 1 can be reliably detected.

Furthermore, the armature 33 has a very small movement amount during the opening/closing operation of the solenoid valve 1, and the stator 30
is always separated by a slight distance from the top surface of
Insulation between these is maintained, but if iron powder or the like gets into this small gap, the insulation will be impaired. In the conventional device, the valve element 20 is fixed to the armature 33 only through a metal seat plate, so if the insulation between the armature 33 and the stator 30 is impaired as described above, the valve element 20 Even if the valve is away from the valve seat 17, the detection terminals 58 and 59 will be in a conductive state, causing erroneous detection and erroneous control in the control unit 60. However, in this embodiment, since the valve element 20 and the armature 33 are insulated by the insulating bushing 34 and the insulating seat plate 38,
The above-mentioned false detection and false control will not occur.

Further, since the cap 55 and the nut 45 are threaded in the opposite direction, the nut 45 does not loosen when the cap 55 is tightened, and the fixed state of the stopper 40 can be ensured.

The present invention is not limited to the above embodiments and can be modified in various ways. For example, in the above embodiments, the stator and the valve body may be integrated.

Furthermore, the position of the detection terminal can be selected from various positions. For example, the detection terminal on the valve seat side may be provided on the fuel injection pump, or may be grounded on the vehicle body or the like.

Furthermore, a cap nut may be used in place of the nut 45, and may also serve as a cap for covering the upper opening of the stopper 40.

(Effects of the Invention) As explained above, in the present invention, the pair of insulating bushes take on the functions of maintaining the shape and insulating, and the seal ring takes on the function of sealing. Therefore, the stopper can be positioned reliably and stable characteristics of the solenoid valve can be obtained.
Further, the insulation between the cover and the stopper can be improved, and the opening/closing operation status of the solenoid valve can be reliably detected. Furthermore, leakage of fluid from between the cover and the stopper can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a solenoid valve that is an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of a part of a conventional solenoid valve. DESCRIPTION OF SYMBOLS 1... Solenoid valve, 10... Valve body, 16... Fluid passage, 17... Valve seat, 20... Valve element, 3
0... Stator, 32... Cover, 32a... Mounting hole, 33... Armature, 40... Stopper, 40c... Locking flange, 41, 42... Insulating bushing, 41a, 42a... Flange, 43... Seal ring, 45... Nut, 50... Coil spring.

Claims (1)

[Scope of utility model registration request] A valve body having a valve seat and a fluid passage, a stator attached to the valve body, a cover attached to the stator and having a mounting hole in the center, and a plate-shaped armature arranged in a housing space between the stator and the cover. a valve element that is connected to the armature and opens and closes the fluid passage by approaching and separating from the valve seat; a cylindrical stopper that is inserted and supported in the mounting hole of the cover and has a locking flange for regulating movement of the armature; In a solenoid valve comprising a coil spring housed in a stopper and biasing the armature in a direction away from the stator, the inner circumferential surface of the mounting hole of the cover;
A pair of insulating bushes each having a flange at one end are inserted between the stopper and the outer peripheral surface of the stopper, and the flange of one of the insulating bushes is sandwiched between the locking flange of the stopper and the inner surface of the cover. The flange of the other insulating bushing is sandwiched between the nut screwed onto the stopper and the outer surface of the cover, and the pair of flange portions are sandwiched between the inner circumferential surface of the mounting hole and the outer circumferential surface of the stopper. A solenoid valve characterized by having a seal ring sandwiched between the other end of an insulating bushing.