JPS58676A - Fluid pressure control unit - Google Patents

Abstract

PURPOSE:To remove variations in a control characteristic by disposing a detecting element for detecting flux density in a magnetic circuit and compensating for quantity applied to an electromagnetic coil in such a manner that a force working on a pressure control member is kept constant corresponding to the detecting signal. CONSTITUTION:As a used temperature changes, flux density B of a magnetic gap formed by yokes 9, 10 changes. Such change is detected by a hole element 20, and the output signal is sent to a converter 21 and input to an electric control circuit 13. That is, corresponding to a change in flux density of the magnetic gap, the quantity of electricity applied to an electromagnetic coil 12 is controlled in such a manner as to keep constant a value of F in the equation: F=B.i.l (wherein F is a force which an electric driver generates, i is the quantity of electricity applied to the coil 12, and l is the length of the coil 12). Accordingly, even if the used temperature changes, a predetermined pressure can be always obtained with high accuracy at a fluid outlet 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid pressure control device that has an electric drive section and a pressure control section and controls gas in proportion to the amount of current supplied, and particularly relates to a fluid pressure control device that has an electric drive section and a pressure control section and controls gas in proportion to the amount of current supplied. The purpose is to eliminate variations in control characteristics due to temperature characteristics.

Fig. 1 shows a conventional example, in which 1 is a fluid inlet, 2 is a fluid outlet, 3 is a valve seat provided between the fluid port 1 and the fluid outlet, and 4 is a valve body provided opposite the valve seat 3. A diaphragm 5 is provided on top of the diaphragm 5.

Reference numeral 6 denotes an air hole that communicates the back pressure chamber 7 of the diaphragm 5 with the atmosphere, and the above-mentioned components constitute a pressure control section. Note that the pressure control section also has a so-called governor function that keeps the pressure on the fluid outlet 2 side constant even if the pressure of the fluid population 1 (+111) fluctuates.

A permanent magnet 8, a center yoke 9, and a tonnage yoke 10 constitute an outer magnet type magnetic circuit which is a magnetic loop forming means. Reference numeral 11 designates a coil bobbin provided in a magnetic gear block formed by the center yoke 9 and the top yoke 10, on which an electromagnetic coil 12 is attached. J.O.J.
, , h constitute an electric drive unit. Reference numeral 13 denotes an electric control circuit that controls the amount of current applied to the electromagnetic coil 12 based on changes in the temperature of hot water, for example. Here, the electromagnetic coil 12
When energized, the force F-B1・e causes pressure control □□1
It is transmitted to the valve body 4 of the section. Here, F: Force generated by the electric drive unit B; Magnetic flux density of the magnetic gap 1; Amount of current flowing to the electromagnetic coil 12 l; Length of the electromagnetic coil 12 Considering the balance of forces in the above configuration, F + PI
-3V-P+ -8D + B2 Sv --i
llF; Force Pl generated by the electric drive unit; Pressure B2 of fluid population 1; Pressure S of fluid outlet 2; Forced pressure receiving area SD of valve body 4; Effective pressure receiving area of diaphragm 5. Here, in general, 5v=sD. Don't do it, formula 11 is F:
πB2・Sv, and the pressure P2 at the fluid outlet 2 is proportional to F, that is, the energization to the electromagnetic coil 12 (tl゛,
obtained in proportion to

The problem with the conventional example described above is that since the members constituting the electric drive section have a temperature coefficient, the magnetic flux density B changes depending on the operating temperature, and the above relational expression F''-B・1・e Therefore, the force F generated by the electric drive unit changes,
This causes variations in the pressure at the fluid outlet 2.

In the case of (commonly used) = light-based permanent magnets, the temperature coefficient is as large as -0.18'%/'C, and especially when used in combustion appliances, it is radiant heat and thermal conduction.

Due to changes in outside temperature, etc., the amount of combustion will vary. FIG. 2 is a characteristic diagram of the fluid pressure control device when the operating temperature t is used as a parameter, and shows the relationship between the current value i and the pressure P at the fluid outlet 2. The current is 1a at tl, and the pressure Pa1
If the operating temperature is set to be higher than t5, the pressure obtained will be pa3, and conversely, if the operating temperature is lower than tl, the pressure will be pa2. That is, if the same current is used, i4 is multiplied by χ*1, the pressure of fluid [12] obtained depending on the operating temperature will vary within the range of P2L3 to P2L2.

The present invention has been made in order to solve the problems of the prior art as described above, and will be explained below with reference to the drawings. Fig. 3 shows an embodiment of the present invention, and 2o is a permanent magnet 8. Center yoke9.
This is a Hall element provided in the magnetic gap of the magnetic circuit formed from the top yoke 10, and detects the magnetic flux density B of the magnetic gap. 21 is a converter that converts the signal of Hall element-f-20 into a control signal; 22 is a setting device that sets the value of magnetic flux density B at the design stage; and 23 is a converter that converts the signals of the converter 21 and setting device 23. A comparator compares the value and sends the difference from the set value of the setter 23 to the amplifier 24.

Converter 21 below. Setting device 22. Comparator 23. amplifier 2
4 constitutes a compensation circuit 25. 1. The rest of the structure is the same as that of the conventional example shown in FIG. 1, and the same members and elements are given the same symbols Id and detailed explanations will be omitted. In the configuration described in 1- above, when the operating temperature changes, the magnetic flux density B of the magnetic gap formed by the center yoke 9 and the top yoke 1o also changes accordingly. The Hall element 20 detects the change in the magnetic flux density B and sends a signal to the converter 21. The signal from the converter 21 and the signal set in advance by the setting device 21 are compared, and the difference is calculated by the device 23. The signal is passed through the amplifier 24 and sent to the electrical control circuit 13.

In other words, in accordance with changes in the magnetic flux density B of the magnetic gap, the amount of current applied to the electromagnetic coil 12 is controlled so that the value of F in the relational expression F=B1[ is kept constant. therefore,
Even if the operating temperature changes, a predetermined pressure at the fluid outlet 2 can always be obtained with high precision, and when used in a combustion appliance, a predetermined combustion amount can be obtained even when the temperature difference is large, such as in summer and winter.

FIG. 4 shows another embodiment of the present invention, in which a search coil 20& is wound around the electromagnetic coil 12 as an element for detecting the magnetic flux density B of the magnetic gear, and when the search coil 20fL moves in the magnetic field. The value of magnetic flux density B is detected by the generated current or voltage. This embodiment has the same effect as the embodiment shown in FIG. 3, and is even easier to install. In addition, in the embodiment of the present invention, the outer magnets ++ and +j were explained as the magnetic circuit of the drive part, but 1)
It is not limited to.

1-Explained: Sea urchin The present invention is based on 1. Magnetic circuit #'r
In order to reduce the variation in the suppressing characteristics due to the roof IW characteristics of the TiE member, a detection wheel is installed in the magnetic circuit to detect the magnetic flux density, and a force acting on the force control section is adjusted according to the detection signal. Electric coil 1 so that F is constant
A compensation circuit is provided to control the energization of the liquid to m1. It provides equipment.

A structural diagram, Fig. 2 is a characteristic diagram showing the relationship between the energizing fluid to the electromagnetic coil and the pressure on the fluid output side in a conventional example, and Fig. 3 is a structural diagram of a fluid pressure control device showing an embodiment of the present invention. , 4th
The figure is a circuit diagram of a main part of a fluid pressure control device showing another embodiment of the present invention.

8... Electromagnetic coil, 12... Electromagnetic coil, 13
・・Electric control circuit, 20...Pole element, 20
& Zarch Coil, 25... Compensation [1J1 Road.

Name of agent: Patent attorney Toshi Nakao and 1 other person No. 1
W7 leather 2 figure 3 figure 4) 2

Claims (3)

[Claims] (1) Generating electromagnetic force by energizing the electromagnetic coil from the magnetic loop forming means and the electromagnetic coil;
An electric drive unit, an electric control circuit that controls the amount of current supplied to the drive unit,
A pressure control section for controlling fluid pressure in response to the electromagnetic force is provided, a detection element for detecting the magnetic flux density of the magnetic loop forming means, and a signal from the detection element for controlling the amount of current to be applied to the electromagnetic coil. A fluid pressure control device comprising a compensation circuit for compensating and supplying a signal to the electrical control circuit. (2) The fluid pressure control device according to claim 1, wherein a Hall element is provided in the magnetic loop forming means as a detecting element for magnetic flux density. (3) The fluid pressure control device according to claim 1, wherein a Zarch coil is provided in the magnetic loop forming means as a magnetic flux density detection element.