JPS6126690Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetically responsive valve for regulating fluid pressure.

BACKGROUND ART Fluid pressure or negative pressure is often used for control operations, such as in controlling the traveling speed of automobiles or controlling exhaust gas purification devices. For this purpose, a fluid pressure regulating valve (abbreviated as a pressure regulating valve) is required to control the fluid pressure as desired.

The first requirement of the above-mentioned pressure regulating valve is excellent responsiveness to control signal input.

Conventionally, in electromagnetic force-responsive pressure regulating valves,
Because sufficient consideration was not given to the effects of the distance between the electromagnetic coil and the armature, the coil inductance, etc. on the response, pressure regulating valves that repeat minute operating cycles had particularly high response. is a reality that cannot be hoped for.

The present invention is intended to avoid the above-mentioned drawbacks of the conventional technology, and by securing a predetermined gap between the electromagnetic coil and the armature that responds to the magnetic force of this electromagnetic coil during operation, it is possible to prevent the armature from returning when the armature is activated. The difference between the coil current values is set small to prevent the armature's responsiveness from slowing down due to the time constant. That is, by attaching a plate of non-magnetic material or weakly magnetic material having a predetermined thickness to the surface of the armature facing the electromagnetic coil, a predetermined distance is stably maintained between the armature and the magnetic coil during operation. .

The main idea will be explained below with reference to the figures. The case where the present invention is applied to an actuator for a constant speed running device of an automobile will be explained below, but the control operation in which the transmission ratio of the operating current changes during one cycle of operation, that is,
Of course, the present invention can be widely applied when controlling a pressure regulating valve by so-called duty control.

In FIG. 1, 1 on the left is an accelerator pedal of an automobile, and 2 is a throttle valve. 3 is an intake manifold of an automobile engine, and 4 is an actuator. A rod 5 of the actuator 4 is linked to the throttle valve 2 by a link 6. The throttle valve 2 can be operated by the operator operating the accelerator pedal 1, or can be operated automatically by operating the actuator 4.

First, a description will be given of how the automatic constant speed traveling system for an automobile is operated by the operation of the actuator 4.

In FIG. 1, the actuator 4 of the present invention is electrically connected to various parts below as shown by dotted lines. However, the control valve and release valve on the right side are parts installed inside the actuator 4, but for convenience of illustration and explanation, they are shown taken out to the outside.
The left vehicle speed detector detects the vehicle speed at which the vehicle is actually traveling and outputs this as an output of an actual vehicle speed signal. On the other hand, the vehicle speed desired at that time, that is, the target value is set in the speed setting device. The comparator that receives the target value and the actual vehicle speed signal detects the difference between the two input signals, and sends an output in response to the difference to the second comparator. The second comparator receives the speed error signal from the first comparator and the throttle opening signal from the throttle opening detector, and adjusts the throttle opening necessary to eliminate the error according to the speed error signal. Issue a correction signal to do so. This output signal is received and amplified by a next-order amplifier to provide an output for controlling the next-order control valve. The control valve controls the operating fluid pressure sent to the actuator 4 in response to an input signal from the amplifier. Since the actuator 4 operates the throttle valve 2 of the carburetor via the rod 5 and the link 6, the throttle valve is controlled in response to the signal from the amplifier, so that the vehicle runs at a constant speed. The slot valve can also be depressed separately from the above-mentioned crop of actuators by means of the accelerator pedal 1.

When the release signal enters the release valve, the working fluid pressure to the actuator 4 is canceled and the actuator is deactivated, and in the event of an emergency, the actuator is deactivated and automatic constant speed driving is stopped.

The actuator 4 (see FIG. 2) is constructed by connecting two housings 7 and 8. The periphery of the diaphragm 9 is sandwiched and fixed to the connection point,
The inside of the housing is divided into two chambers. The diaphragm 9 is sandwiched between the guide 10 and the root of the rod 5, and these three are tied together with a rivet 11.
A compressed return spring 12 is installed in the inner bottom surface of the guide 10 and the inner bottom surface of the housing 7.

FIG. 2 shows a cross-section of the regulating valve, which in FIG. 3 is designated at 13 on the left in the housing 7. A release valve 14 is integrally provided on the right side thereof.
Both valves are integrally constructed by their yoke 15 as will be explained below. Returning to FIG. 2, the upper right yoke 15 is fixed to the bottom of the housing 7 by screws 24 (FIG. 3) and racks 15a as shown, and forms a magnetic circuit together with the fixed core 16 inside. 17 is a coil surrounding the fixed core, and 18 is a lever-shaped armature. The armature 18 is made of magnetic metal, but the flapper 19 attached to its tip is made of non-magnetic material such as phosphor bronze or beryllium copper plate. The free end of the flapper 19 has valve seats 20 on both sides. Both sheets are interposed between the lower nozzle 21 and the upper nozzle 22. The root of the armature 18 is a thin hole 23 in the yoke.
The lever is operated using this as a fulcrum. 25 is a return spring. Nozzle 21 communicates with the engine intake manifold, and nozzle 22 communicates with the atmosphere via an air cleaner 26. Reference numeral 27 at the lower left of FIG. 2 is a variable resistor for detecting the throttle opening. The pin 29 of the rod 5 is engaged with the elongated hole 30 of the arm 28 at the shaft end, and as the rod moves in and out, the arm rotates and the variable resistor 27 is operated.

FIG. 4 shows a sectional view taken along the - line in FIG. 3. 31 is a bobbin made of the same non-magnetic material as the housing 7. The bobbin 31 is a yoke 1 made of magnetic metal.
The coil 32 is tightly fitted and fixed in the hollow interior of the coil 5 and has a coil 32 surrounding it. A movable core 33 is fitted into the bobbin 31 so as to be able to reciprocate, and its right end faces the hole 34 of the yoke. 36 is a return spring. The hole 34 communicates with the atmosphere through the hole 35 in the housing and through the ecleaner 26.

Next, the operation will be explained. Control valve 13
When an input signal is applied from the amplifier and the coil 17 is excited, the armature 18 is pulled upward in FIG. 2, and the seat 20 of the flapper 19 closes the upper nozzle 22, and conversely opens the lower nozzle 21. . Therefore, the chamber 36, which was previously communicating with the atmosphere via the nozzle 22, communicates with the intake manifold 3 via the nozzle 21. As a result, the diaphragm 9 moves to the right in FIG. 2 and is subsequently moved in the direction of opening the throttle valve 2. When the diaphragm is at the leftmost position, the slot valve 2 is fully closed.

Contrary to the above, if the input signal from the amplifier stops,
The sheet 20 closes the nozzle 21 as shown in FIG.
Open nozzle 22. Chamber 36 is isolated from the negative pressure of the intake manifold and is open to atmospheric pressure.

The diaphragm 9 therefore returns to the state shown in FIG.
The above operation is performed when the actual vehicle speed is more or less than the set speed. As a result, the actuator 4 automatically operates the throttle valve 2 to achieve constant speed running. Although not shown in the figure, a configuration is required so that the pedal operation does not interfere with the above-mentioned actuator, but since this configuration uses a conventionally well-known configuration and does not constitute the main point of this proposal, no further explanation is required. omitted.

Next, the coil 32 of the release valve 14 (Fig. 4)
Since the movable core 33 is normally energized and excited, the movable core 33 moves to the right in the figure against the return spring 36 and closes the hole 34. In case of emergency, the coil 32 is de-energized by the release signal. The movable core 33 is returned to the illustrated position by a return spring 36. As a result, the atmospheric pressure is
Enter the room 36 through the . Since the diameter of each of these holes is set to be sufficiently larger than the diameter of the nozzle 21, the interior of the chamber 36 becomes atmospheric pressure due to the above operation of the release valve 14, regardless of whether the control valve 13 is in operation or not. Therefore, actuator 4 becomes inactive. 38 in FIG. 4 is a magnetic ring.

As shown in FIG. 5, the armature 18 must be fairly thick and have sufficient capacity for the required magnetic flux.

The feature of the present invention is that, as shown in FIG. 5, a flapper 19 having a predetermined thickness and made of a non-magnetic material or a weakly magnetic material is attached to the surface of the armature 18 facing the core 16. As mentioned above, suitable materials for the flapper 19 include phosphor bronze, beryllium copper plate, and the like. This is because these materials are non-magnetic, have elasticity necessary for the flapper, and have the characteristics described below. The operation when the flapper made of non-magnetic material is set to a predetermined thickness will be described in detail below.

When the armature 18 is at the rest position as shown in FIG. 5, the distance between the armature 18 and the core 16 is _D1 . Also, assume that the thickness of the flapper 19 is D ₃ and that the minute gap created between the armature 18 and the core 16 is D ₂ when the armature 18 directly contacts and is attracted to the core 16 without the flapper 19. do.

As shown in the graph of Fig. 6, the armature 18
The distance D between the cores 16 and 16 is plotted on the horizontal axis, and the force F required to start the armature from the rest state in FIG. 5 is plotted on the vertical axis. Force F, distance D and coil 1
The relationship F=kI/D ² (1) holds between the currents I of 7.

The force F is applied to the armature 18 in FIG. 5 by the return spring 25.
Therefore, if the value of the force F decreases even slightly, the armature 18, which is attracted to the core 16, returns to the rest position shown in FIG. 5 by the force of the return spring 25. Since the armature 18 is separated from the core 16 by a distance of D ₃ due to the thickness of the flapper 19 even when it is in operation (the position indicated by the chain line in Fig. 5), if the current flowing through the coil 17 is reduced to a value smaller than 3I, , the active armature 18 can be returned to the rest position (solid line position in FIG. 5).

Therefore, if the armature 18 is a conventional pressure regulating valve that is directly attracted to the core 16 without using the flapper 19 made of non-magnetic material, the distance between the core 16 and the armature 18 is , since D ₂ during armature operation, coil 1
It can be seen that the armature 18 cannot be returned to its rest position unless the current flowing through it is reduced to a value smaller than the value of I.

In short, the armature 1 operated with a current of 3I
8 indicates that in the present pressure regulating valve equipped with a flapper 19, it is possible to return to the rest position by reducing this current to less than 2I, whereas if the flapper 19 made of non-magnetic material is not used, the current in the coil 17 is further reduced. Unless it is reduced to a value below the small I, it cannot be returned to the rest position. This greatly affects the responsiveness of pressure regulating valves that repeat minute operation cycles in small increments.
In particular, in electromagnetic devices that utilize electromagnetic coils, inductance degrades responsiveness as will be explained below.

The pressure regulating valve of the present invention is controlled so that a small operation cycle is repeated frequently and the energization time ratio during one cycle is changed without changing the frequency, so the power-off time of the coil 17 is shortened. If it is too high, the next cycle of voltage will be applied to the coil 18 before the current value of the coil has attenuated until the armature 18 is released and returned to its original state, and the armature 18 may not be able to return to its original state and may continue to operate. It becomes possible. This will be explained below with reference to FIGS. 6 and 7.

The voltage for controlling the pressure regulating valve of the present invention is applied to the coil 17 with a rectangular waveform as shown by the solid line in FIG. 7A. Coil 17 due to inductance
The current flowing through the circuit draws the waveform shown by the dotted line in FIG. The line D ₁ in the figure is the distance D ₁ from the core 16 (solid line position in Figure 5)
indicates the required current value to generate the force F in the coil 17 required to cause the armature 18 to actuate.
D ₃ indicates that the armature 18 is operating and the core 16
Indicates the limit of the current value that must be attenuated in order to return to the rest position (solid line position in Figure 5) when the motor is at a distance of D ₃ (dotted line position in Figure 5).
When the coil current attenuates to a current value below this limit, the armature 18 leaves the core 16 and returns to the position shown by the solid line in FIG.

Next, D ₂ in Fig. 7 A is assumed to be armature 18.
without passing through the flapper 19 of non-magnetic material,
If the armature 18 is directly attracted to the core 16, the return spring 25
Indicates the limit value of the current value that must be attenuated when returning to the rest position by .

According to A in FIG. 7, when the current flowing through the coil 17 reaches point a, the armature 18 operates, and b
When it decays to a point, it returns to its rest position. If the operation of the armature 18 is illustrated in a diagram, it will be shaped like a wave as shown in B of FIG. The waveform in Figure 7B is affected by the inductance, and the input voltage in Figure 7A is _V1.
This results in a shaped wave that is slightly delayed in time compared to the shaped wave created by V ₂ , etc. Point a' of the waveform in Figure 7B is A' in the same figure.
The timing coincides with point a in Figure A, and the timing of point b' coincides with point b in Figure A.

Returning to Figure 7A, if armature 18 is core 1
If the coil 17 is operated at a distance of D ₂ from point C, it can be seen that the current in the coil 17 must be attenuated below the current value at point C in order for the armature to return. However, this point C coincides with the input voltage v ₂ of the next control cycle, and the current value in the coil 17 also begins to rise. Therefore, when the armature 18 is in operation, the current in the coil 17 is at a predetermined value.
D Since the damping does not occur below ₂ , it is not possible to return to the rest position at point C. As a result, as shown in Fig. 7C, the armature 18 continues to operate at point a'' without returning to the rest position.The timing of point a'' is the same as that of point a in Fig. 7A. matches.

To summarize the above, as shown by equation (1), the magnetic force F is inversely proportional to the square of the distance between the core 16 and the armature 18 attracted to it, so the current value required to excite the coil 17 when the armature is activated The armature 18 cannot be reset unless the coil current is attenuated to a much smaller current value. The difference between the current value required when the armature operates and the current value when the armature returns, that is, the larger the required attenuation current value, the longer the time required for the attenuation, and as described above, the armature cannot return. The more this occurs, the more the response of the pressure regulating valve deteriorates.

In order to improve the responsiveness of the pressure regulating valve by reducing the width of the above-mentioned required damping value as much as possible, the distance between the operating position of the armature 18 and the core 16, and the distance between the armature's resting position and the core must be adjusted. of distance,
It is desirable that the difference between both distances be as small as possible. Moreover, it is desirable that the ratio of this difference to the distance between the armature rest position and the core be small. The reason for this is that the smaller the rate of change of D in equation (1), the smaller the rate of change of current I can be made. The smaller the rate of change of the core current, that is, the above-mentioned attenuation rate, in other words, the larger the required current value when the armature 18 returns, the more responsiveness of the pressure regulating valve can be improved. In the present invention, as the most stable and reliable means for achieving this purpose, a plate made of a non-magnetic or weakly magnetic material is attached to the surface of the armature facing the coil. The pressure regulating valve of the present invention can sufficiently follow the pressure regulating valve input voltage which repeats the operation cycle particularly at a high frequency, and can improve responsiveness.

In addition, since the flapper 19 of the present invention is curved as shown in FIG. 5 and comes into close contact with the mouth of each nozzle, a sufficient sealing effect can be obtained. The present invention has a sheet 20 attached to the tip of the flapper 19 to further improve the sealing effect, but even if this sheet 20 is not provided, the same effect can be obtained from the elastic flapper as described above. .

[Brief explanation of the drawing]

Fig. 1 is an overall layout diagram showing the operation of the actuator of the present invention, Fig. 2 is a longitudinal cross-sectional view along the axis of the actuator, Fig. 3 is a cross-sectional view taken along the - line in Fig. 2, and Fig. 4 is Fig. 3. 5 is a partially enlarged view of FIG. 2, and A, B, and C of FIGS. FIG. 1... Accelerator pedal, 4... Actuator, 7, 8... Housing, 13... Adjustment valve, 14... Release valve.

Claims (1)

[Scope of utility model registration request] It has a fixed core, a coil surrounding the core, a yoke that forms a magnetic circuit together with the fixed core, and an armature made of magnetic metal that faces the fixed core, and when the coil is energized, the armature is attracted to the fixed core and a fluid is drawn. In the magnetic force response valve for fluid pressure regulation that opens and closes a passage, a flapper has one end fixed to the armature so as to be interposed between the armature and the fixed core when the armature is attracted to the fixed core. 1. A magnetic force-responsive valve for adjusting fluid pressure, characterized in that the flapper is provided with a valve seat for opening and closing a fluid passage at the other end of the flapper, and the flapper is made of a plate made of a non-magnetic material or a weakly magnetic material.