JPS6020631B2 - Solenoid proportional control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electromagnetic proportional control valve for steplessly proportionally controlling the flow rate of gas or the like using electric current, and particularly to improving sealing performance with the outside and preventing vibration.

Configuration of the related example and its problems In conventional solenoid valves, in order to seal the fluid coil and the outside air, the drive shaft of the valve is sealed, or the entire movable member such as the plunger is placed inside the sealing pipe. All of them have sliding parts between the movable member and the fixed member, and while this configuration poses no problem for on-off type solenoid valves, it does not cause problems with proportional control type solenoid valves due to sliding resistance. Smooth proportional movement is not restricted, making it difficult to adopt.

Therefore, a proportional control valve that uses a leaf spring to hold the plunger without sliding relative to a fixed member isolates the coil from the fluid passage only by the fixed part without using a sliding member, and isolates it from the outside air. It was considered difficult to seal, and a movable member such as a diaphragm was used to create a seal, as shown in Utility Model No. 442 from 1973. An example of this substructure is shown in FIG.

A yoke 5 and an electromagnetic coil 6, which constitute a magnetic circuit, are fixed to the upper part of the valve body 1, which serves as a fluid passage, via a diaphragm 4 and its supporting members 2 and 3, and a plunger 7 is attached to a plate spring 8 in the center thereof. , 9, and a valve rubber 10 is provided at the lower end of the plunger 7 via a diaphragm 4. The two leaf springs 8 and 9 are attached to the leaf spring mounting bracket 11.
is riveted to the yoke 5, and screws 12 and 13 are attached to the yoke 5.
It has been concluded by

The leaf spring mounting bracket 11 has an elongated hole 15 that mates with the protrusion 14 of the yoke 5, and has a structure that allows it to be moved slightly up and down before the screws are installed vertically, allowing the force of the leaf spring to be adjusted. I can do it. In this configuration, when a current is passed through the coil 6, a magnetic force corresponding to the current value acts in a direction that raises the plunger 7, and the valve rubber 10 provided at the lower end of the plunger 7 floats up from the valve seat provided in the valve body 11. do.

The distance that the valve rubber 10 floats above the valve seat (hereinafter referred to as valve lift) is determined by the magnitude of the current, and therefore the flow rate of the fluid flowing inside the valve body 1 can be arbitrarily controlled by the current.

The first issue in this conventional example was the fear that the diaphragm 4 would be damaged and fluid would leak to the outside.

In other words, in the conventional example, the sealing of the fluid from the outside air depends on the diaphragm 4, and if it were to break during long-term use, the fluid would leak into the coil part or into the atmosphere. There has been a desire for an electromagnetic proportional control valve that can be used for a long period of time with care. The second topic is that the plunger 7 sends two leaf springs 8 and 9 to the fixed part village.
Since the valve rubber 101 is supported without sliding, the fluid flow acts on the valve rubber 101, causing valve vibration, and the leaf springs 8, 9
There was a problem in that the plunger 7 supported by the bracket vibrates, causing valve vibration, and once the vibration becomes serious, the vibration is difficult to stop, and the vibration of the bracket impairs the function of the proportional control valve.

Technical Problems of the Invention The present invention has been made in view of the above-mentioned problems, and it is a proportional control valve with a leaf spring support structure that "seals the fluid, outside air, and coil without using any moving parts, and maintains the seal for a long period of time." In order to improve reliability and prevent valve vibration, a plate spring that supports the plunger or a vibration isolator is placed in contact with the plunger to prevent valve vibration with moderately low sliding friction without impairing the smooth operation of the plunger. The purpose is to prevent this from occurring and improve the stability of proportional control characteristics.

Technical Main Stage of the Invention In order to achieve this object, the present invention has a pipe penetrated through the center of the coil and the yoke, a plunger supported by a support plate spring inside the pipe, and an upper part to which the support plate spring is attached. and the lower leaf spring mounting base is airtightly attached to the valve body.
The upper leaf spring mounting base is covered with a sealing structure, and a vibration isolator is brought into contact with the support leaf spring or plunger to prevent vibration.

Effect of the Invention With this configuration, the fluid in the valve body is sealed from the coil and the outside air without using any moving parts, and the vibration isolator prevents vibration of the plunger, making it possible to maintain stable proportional control characteristics. .

Embodiment Structure Below, regarding one embodiment of the present invention, the second to fourth embodiments will be described.
This will be explained using figures.

A lower leaf spring mounting base 18 is attached to the upper part of the valve body 16 having a fluid inlet 16a, a fluid outlet 16b, and a valve seat 16c via a packing 17, and a box-shaped yoke 19 and an auxiliary yoke 20 are attached to the upper part of the lower leaf spring mounting base 18. and upper leaf spring mounting base 2
1 and a lid 23 is further attached via a packing 22.

A pipe 25 passes through the center of the yoke 19 and the coil 24, and both ends of the pipe 25 are inserted into the upper leaf spring mounting base 21 and the lower plate spring mounting base 18, and are sealed with an O-ring 25. . Support leaf springs 26 are attached to the upper and lower leaf spring mounts, respectively, and their free ends are made of a non-magnetic material and are press-fitted into the lower part of the plunger 27 and the other into the upper part of the plunger 27. Supporter 2
8 to support the plunger 27 so as not to contact the center of the pipe 25. A valve body 29 is swingably attached to the lower part of the plunger 27 and faces the valve seat 16c. A coil spring 30 and an adjusting screw 31 are provided on the upper part of the plunger 27, and the adjusting screw 31 is screwed into a female screw provided in the center of the lid 23 to adjust the force of the coil spring 30. A blind cap 32 is applied with a sealant and press-fitted into the opening of the female thread part of the lid 23 for sealing. The vibration isolator 3 is connected to the lower support plate spring 26 via a base plate 33.
4 will be provided. The main part is shown in Figure 3. In FIG. 3, the hole in the center of the support plate spring 26 is the plunger attachment hole 35. Effects of the Example The effects of this configuration will be explained below.

Figure 2 shows a state in which no current is flowing through the coil 24, and the valve body 29 is pressed against the valve seat 16c by the force of the three coil springs (hereinafter, this force is referred to as valve closing pressure), and the valve is in the closed state. . The spring force acting on the plunger 27 is the sum of the forces of the two holding leaf springs 26 and the coil spring 30, but the purpose of the support leaf spring 26 is to support the plunger 27 at the center of the pipe 25 without contact. , is sufficiently weak compared to the force of the coil spring 30. Next, when a current is applied to the coil 24 from zero and increased to , a magnetic force is generated and acts to raise the plunger 27 upwards, and when the current generates a magnetic force stronger than the valve closing pressure, the valve body 29 floats up from the valve seat 16c. Further, the valve lift that increases the current increases in proportion to the current, and when the current reaches a predetermined value, the valve lift reaches its maximum and becomes fully open. Therefore, an arbitrary valve lift can be obtained depending on the magnitude of the current, and the flow rate of the fluid can be controlled steplessly.
The vibration isolator 34 prevents the valve body 29 from vibrating up and down together with the plunger 27.

Now considering the situation where this anti-vibration plate spring 34 is not present, the coil 2
When a predetermined current flows through the valve seat 4 and the rubber 29 rises slightly from the valve seat 16c, the plunger 27 is supported by the two support plate springs 26 and is not subjected to any sliding resistance. If fluid acts on the valve body 29 in this state, vibrations may occur depending on the conditions. This vibration is permanent and impairs the function of the proportional control valve. FIG. 4 shows the mutual relationship between the support plate spring 26 and the vibration isolator 34, and the action of the vibration isolator 34 will be explained.

FIG. 4a shows a state in which the support plate spring 26 is straight and the plunger 27 in FIG. 2 is raised upward.

In this case, the point on the support plate spring 26 that the vibration isolator 34 contacts is P. FIG. 4b shows a state in which the support plate spring 26 is bent downward, and the plunger 27 in FIG. 2 has come down.

In this case, the point on the support plate spring 26 with which the vibration isolator 34 comes into contact is P', which is clearly different from the above-mentioned P. This P point and P'
A vibration isolator 34 slides on the support plate spring 26 between the two points. This results in sliding resistance. This sliding resistance occurs in a direction that inhibits the movement of both leaf springs, and therefore acts to inhibit vibrations of the valve body 29 and plunger 27. Furthermore, the purpose of vibration isolation can be achieved without impairing the function of the electromagnetic proportional control valve. Further, in the above embodiment, the support leaf spring 2
6 has been described with a configuration in which the vibration isolator 34 is brought into contact with the vibration isolator 34 to suppress vibration, but as another example, a similar effect can be obtained by a configuration in which the vibration isolator is brought into contact with a movable part such as the plunger 27. .

Effects of the Invention As described above, the electromagnetic proportional control valve of the present invention provides the following effects.

1 Proportional control valves in which the plunger is supported by a leaf spring conventionally use a diaphragm as a movable part to seal the fluid, coil, and outside air; can be completely sealed, improving long-term seal reliability.

Particularly when the fluid is gas, this is highly effective in preventing gas leak accidents. 2. In proportional control valves in which the plunger is non-slidingly supported by a plate spring, conventional valve vibrations occur due to the influence of fluid flow, and the vibrations do not stop permanently. The structure is such that it contacts the branch plate spring or the plunger, so it acts to suppress the vibration of the plunger, ensuring smooth operation of the plunger and valve, preventing the occurrence of valve vibration, and improving the proportional control characteristics. Stability can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional proportional control valve, FIG. 2 is a sectional view of an electromagnetic proportional control valve according to an embodiment of the present invention, FIG. Figures a and b are cross-sectional views for explaining the operation of the vibration isolator. 24...Coil, 19...Yoke, 27...Plunger, 26...Support leaf spring, 6c...Valve seat, 2
9... Valve body, 34... Vibration isolator. Figure 3 Figure 4 Figure 1 Figure 2

Claims (1)

[Claims] 1. a coil, a yoke, a plunger, and a leaf spring that supports the plunger at a central portion of the coil and yoke;
An electromagnetic proportional control valve comprising a valve body provided at one end of the plunger, a valve seat facing the valve body, and a vibration isolator brought into contact with the support plate spring or the plunger.