JPS58214083A - Proportional pressure control valve - Google Patents

Abstract

PURPOSE:To enable dispersion in force balance to be adjusted, by providing a movable magnet to a member associated with a valve element, and by arranging a stationary magnet so that the same poles of the movable and stationary magnets are opposed together, thereby the relative position between the movable magnet and the stationary magnet may be adjusted. CONSTITUTION:A stationary magnet 14 is arranged so that one pole thereof is opposed to the same kind of the pole of a movable magnet 13 of a permanent type which is disposed in the upper part of a plunger 9 associated wth a valve 5, and is provided with a threaded part 15 which is screwed into an outer casing 16. The relative position between the movable magnet 13 and the stationary magnet 14 may be adjusted by screwing the threaded part 15 with the use of a tool such as, for example, driver.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention continuously proportionally controls the pressure (flow rate) of a fluid according to the amount of current applied, and when used in a gas water heater, for example, the amount of combustion remains constant even when the amount of hot water output changes. This invention relates to a pressure proportional control valve that makes it possible to obtain a constant water temperature by varying the water temperature.

A conventional example is shown in FIG. Reference numeral 1 denotes a valve body, which has a fluid intake 2, a fluid outlet 3, and a valve seat 4. A valve body 6 is provided facing the valve seat 4, and a diaphragm 6 and a diaphragm 6 are airtightly attached to the body 1 on the outer periphery. , the valve body 6 is interlocked. 7 is the valve body 6
This is a spring that acts in the direction of pushing the valve seat 4 toward the valve seat 4. A plunger 9 supported by two leaf springs 8 is in contact with the upper part of the valve body 6. The yoke 10 constitutes a magnetic circuit. When the coil 11 is energized, the electromagnetic force is applied to the valve body 6.
acts on the valve, overcomes the valve closing force of the spring 7, and opens the valve. Reference numeral 12 denotes an air hole that communicates the back pressure chamber 13 with the atmosphere. As is well known, the basic operation of the conventional example is that an electromagnetic force is generated by energizing the coil 11, and this force is applied to the 2F body 5,
The fluid pressure is controlled by the balance with the force of the fluid passing through the body 1, and at the same time, when the energization level to the coil 11 is constant, the pressure on the fluid population 2 side (hereinafter referred to as medical use) is controlled. ) changes, the pressure on the fluid outlet 3 side (hereinafter referred to as secondary pressure) is maintained.

The problems with the conventional example are the set position of the leaf spring 8 and the spring 7.
This is due to variations in the control characteristics. I will now explain this point in a little more detail. FIG. 2 shows the control characteristics of the conventional example, where the horizontal axis is the current 11 flowing through the coil 11, and the vertical axis is the secondary pressure P2. If the electromagnetic force is F8, then F
. -01・l2 (C1; proportionality constant) and P2=Fo/S
S-8v-8D (Sv: Valve body 5 effective pressure receiving area, SD;
diaphragm effective pressure receiving area). Therefore, it becomes P2-C1.I/S, and the secondary pressure P2 increases in proportion to the square of the electric current.

In FIG. 2, if the valve closing force by the spring 7 is F3, and the sum of the force due to the deflection of the leaf spring 8 and the weight of the valve body 5 and the plunger 9, that is, the force pushing down the valve body 6 downward, is Fs-FW. When , P2 increases in proportion to engineering, as is the characteristic of .

However, since there are variations in the setting position of the leaf spring 8 and the dimensions of the spring 7, the characteristics deviate as shown in the characteristic B when, for example, Fs>FW. That is, when obtaining the set secondary pressure Ps, a difference in current value of I-11 occurs. When actually used in gas appliances, by connecting a resistor (not shown) to the coil 11 and increasing or decreasing the resistance value, it is possible to adjust the current value Im to the set secondary pressure Ps, as shown in Figure 3. Minimum secondary pressure (determined from the burner side), current value I that becomes PT
It is possible to make t the same. In other words, in the case of the characteristic shown in Fig. 2B, by reducing the resistance, the characteristic shown in Fig. 3B is
It is possible to have phantom chronicity in '.

However, it is impossible to eliminate the variation in inclination, and o=c, ,/”ip, (C2; constant of proportionality)
Due to the relationship, the flow rate control characteristics have the characteristics shown as A" and B", respectively, as shown in FIG.

In other words, a flow rate difference of ΔQ occurs, and this difference becomes larger on the low flow rate side, and when highly accurate flow rate control such as air-fuel ratio control is required, the air-fuel ratio deteriorates and incomplete combustion occurs.

In view of the above problems, the present invention eliminates variations in control characteristics caused by variations in leaf springs and springs, and provides a pressure proportional control valve suitable even in cases where highly accurate control characteristics are required such as air-fuel ratio control. The purpose is to provide.

In order to achieve this object, the present invention includes a valve seat, a valve body that faces the valve seat and changes a fluid flow path area, a diaphragm that interlocks with the valve body, a coil that applies an electromagnetic force to the valve body,
A yoke and a plunger are provided, the plunger is supported by a leaf spring, and a movable magnet is provided in a member that interlocks with the valve body, a fixed magnet is provided with the same pole facing the movable magnet, and the movable magnet and the fixed magnet are provided. The structure is such that the relative positions of the two can be adjusted.

With this configuration, if you adjust the relative position of the movable magnet and the fixed magnet, the repulsive force will change in proportion to the square of the cap. Variations can be adjusted and therefore variations in control characteristics can be eliminated.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 6 shows an embodiment of the pressure proportional control valve according to the present invention, in which a movable magnet 13 made of a permanent magnetic material is provided on the upper part of the plunger 9 that interlocks with the valve body 5, and the movable magnet 13 has the same poles facing each other. , a fixed magnet 14 is provided, and a fixed magnet 14 is provided.
is provided with a threaded portion 15 and screwed into the outer casing 16, and the movable magnet 1
3 and the fixed magnet 14 (gap X) can be adjusted by rotating the threaded portion 15 with a tool such as a screwdriver. Other members are the same as those in the conventional example, are given the same numbers, and will not be described further.

Next, the operation will be explained. FIG. 6 shows the relationship between the gap X between the movable magnet 13 and the fixed magnet 14 and the magnetic repulsion force Fm, and it can be seen that Fm changes in proportion to the square of X. As explained in the conventional example, the valve closing force by the spring 7 is F3,
The force due to the deflection of the leaf spring 8 and the valve body 6. Plunger 9
Letting the sum of the weights of FW be FW, considering the dispersion, FB <
If it becomes FW, use a tool such as a screwdriver to tighten the screw part 1.
Turn 5 to reduce the gap X from xa to xb.
Therefore, by increasing the magnetic repulsion force F by ΔFm, Fs
=FW+ΔFm.

Figure 7 shows the relationship between the coil current value I, secondary pressure P2 and flow rate Q according to the present invention, and it is possible to change the current-secondary characteristic of C to the characteristic of D, and the current-flow rate characteristic is also a straight line. It can be made to have characteristics that change over time.

As described above, in one embodiment of the present invention, variations in the force caused by the mounting position of the leaf spring 8 and variations in the spring 7 can be avoided. It is possible to eliminate variations in control characteristics caused by changes in force due to force, and it is also possible to improve the linearity of current-flow characteristics.

Although not shown, the movable magnet 13 is attached to the lower part 1 of the valve body 5.
7, with the same pole facing the movable magnet 13, and the fixed magnet 1
4 may be provided, and the threaded portion 16 may be screwed into the lower surface 18 of the valve body 1. In this case, it is necessary to provide the threaded portion 16 with a sealing member to prevent gas leakage. With this configuration, the outer casing 16 is not required, and if the gap .

As detailed above, the present invention provides a movable magnet in a member that interlocks with the valve body, a fixed magnet with the same pole facing the movable magnet, and a configuration in which the relative positions of the movable magnet and the fixed magnet can be adjusted. This makes it possible to eliminate variations in control characteristics caused by variations in the operating force of leaf springs and valve-closing springs, making it a suitable pressure control valve even in cases where highly accurate control characteristics are required, such as air-fuel ratio control. Can be provided. Since the linearity of current-flow characteristics can still be improved, the drive electric control circuit can be simplified.

Furthermore, as a unique effect, it is also possible to improve the governor characteristics. I will now explain this point in a little more detail. Figure 8 shows the valve body displacement amount S and the electromagnetic force Fa generated by the coil.
It can be seen that even when the magnetomotive force is constant, Fa changes as the plunger is displaced. Figure 9 shows the well-known governor characteristics, namely - medical P1 and secondary pressure P.
This shows the relationship between the two. As shown in Figures 8 and 9, standard pressure P1
Assuming that the coil current is set so that the rated secondary pressure PS is obtained at n, in the conventional example, the electromagnetic force Fa is Fan,
The valve body displacement amount S is balanced at the point where it becomes Sn.

When the coil current is kept constant 2 and the primary pressure is increased to the maximum pressure P1m', the valve body is displaced in the valve closing direction and the relationship between S and Fa reaches the point al. After that, when P1 is decreased by 01, the valve body changes in the valve closing direction, and the maximum displacement amount is 5rfl.
becomes. The relationship between S and Fa at that time is point a2. In other words, the electromagnetic force is Fam.

After that, when P1 is increased again, the overshoot of secondary pressure P2 as shown in Y will occur, as it cannot be balanced with secondary pressure P2 at F, which is larger than the electromagnetic force Fan at the time of setting, and the set value will be increased by ΔP2. is on the top row.

According to the present invention, due to the repulsive force between the movable magnet and the fixed magnet,
Correct the change in electromagnetic force Fa. In other words, the amount of change ΔFa can be reduced as shown in FIG. 8 γ. Therefore, it also has the effect of eliminating the amount of overshoot in the governor characteristics.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional configuration diagram of a conventional pressure proportional control valve.
Figures 2 and 3 are characteristic diagrams showing the relationship between the coil current and secondary pressure, Figure 4 is a characteristic diagram showing the relationship between the coil current and flow rate, and Figure 5 shows an embodiment of the present invention. Figure 6 is a characteristic diagram showing the relationship between the gap and repulsive force, Figure 7 is a characteristic diagram showing the relationship between the coil current, secondary pressure, and flow rate, and Figure 8 is a cross-sectional diagram of the pressure proportional control valve. FIG. 9 is a characteristic diagram showing the relationship between the displacement amount of the valve body and electromagnetic force, and FIG. 9 is a governor characteristic diagram showing the relationship between medical use and secondary pressure. 1... Valve body, 4... Valve seat, 6...
...Valve body, 6...Diaphragm, 8...
...Plate spring, 9...Plunger, 1o...
... Yoke, 11 ... Coil, 13 ...
...Movable magnet, 14...Fixed magnet, 16...
...Screw part, 16...Outer casing, 17...
Lower part of the valve body, 18... Lower surface of the valve body. , name of agent Patent attorney Toshio Nakao and 1 other person --d Stomach! Kakori ε: of
□Seaweed
Maiku 00 Lolid Law

Claims (3)

[Claims] (1) A valve body provided with a valve seat, a valve body provided opposite to the valve seat to change a fluid passage area, a diaphragm that operates in conjunction with the valve body in response to fluid pressure, and an electromagnetic force applied to the valve body. A coil, a yoke, and a plunger are provided, the plunger is supported by a leaf spring, and a movable magnet that interlocks with the valve body and a fixed magnet are provided with the same poles facing the movable magnet, and the movable magnet and the fixed magnet are fixed. A pressure proportional control valve that allows the relative position of magnets to be adjusted. (2) The pressure proportional control valve according to claim 1, wherein a movable magnet is provided above the plunger, a threaded portion is provided on the fixed magnet, and the threaded portion is screwed into the outer casing. (3) A movable magnet is provided at the bottom of the valve body, and a threaded portion is provided on the fixed magnet, and the threaded portion is placed on the bottom surface of the valve body. The pressure proportional control valve according to claim 1, which is screwed together.