JPS5924874Y2 - Pressure regulating device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a pressure regulating device for controlling the fluid pressure sent out from a compressor within a certain pressure range. The purpose is to provide a device with a simple structure.

The fluid pressure delivered from the compressor is usually detected by a pressure switch and communicated to the compressor drive device, which turns off the switch when it reaches a certain upper limit pressure and turns it on when the pressure drops to the lower limit pressure. controlled by a pressure regulator.

The pressure detection mechanism in conventional pressure switches includes a structure in which the displacement of the membrane plate in the detection cylinder due to fluid pressure is transmitted to a snap actuation mechanism via a lever to switch the contact of the switch, or a structure in which the displacement of the membrane plate is transmitted to the snap actuation mechanism via a lever, or a structure in which the displacement of the membrane plate is transmitted to the snap actuation mechanism by a piston rod. and a structure that switches the contact by stroking a cam that operates the switch via an interlocking arm connected to the tip of the piston rod.
Alternatively, there is a structure that combines a bellows and a microswitch.

However, since all of them use a direct drive contact switch switching method, it is necessary to polish the switch contacts as the period of use increases, and it is also necessary to correct error indications due to contact wear, which requires maintenance and inspection. is complicated.

In particular, in the case of the first conventional example, there is a risk that the contact part may fall off or break due to the snap action, or the lead wire may break. The wiring needs to be changed and cannot be done easily.

Second. In the case of the third conventional example, when changing the contact configuration, it is necessary to replace the cam, wiring, etc.

There is also a method that starts and stops the compressor by detecting the displacement of the pressure cylinder using a high-frequency oscillation type proximity switch and electronic circuit, but it depends on environmental conditions such as temperature, vibration, and electrical noise. It is easily influenced by
It also has many parts, is expensive, and requires complicated maintenance.

The present invention is a pressure regulating device designed to solve the above-mentioned inconveniences, and uses two proximity switches to operate the two proximity switches at different positions to move the membrane plate inside the valve body. Accordingly, the switch is moved through the interlocking arm to open and close the switch, and the proximal piece can be attached to the interlocking arm so that its position can be changed, making it easy and reliable to change the pressure setting range.
In addition, switching between the a contact and the b contact of the switch can be easily performed by changing the initial position of the proximity piece, and a self-holding circuit is built into the proximity switch to simplify the start/stop circuit for the compressor.

The configuration of the present invention will be explained in detail with reference to examples.

FIG. 1 is a front view of a pressure detection unit using an example of implementation;
FIG. 2 is a sectional view taken along line AA, and FIG. 3 is a sectional view taken along line BB in FIG.

The valve bodies 1 and 1a have a cylindrical shape, and are configured so that the fluid whose pressure is to be detected flows into the membrane plate chamber 3 through the hole 2 and pushes up the membrane plate 4.

Reference numeral 5 denotes a piston rod attached to the membrane plate 4, and a thrust bearing 7 and a spring receiver 8 are attached to the intermediate stage of the rod to prevent the torsion of the spring 9 from being transmitted to the membrane plate 4, and the piston rod has a predetermined tension. A spring 9 is provided between the valve base and the spring receiver 8, the force of which is balanced by the aforementioned force pushing up the membrane plate 4.

An interlocking arm 11 is fixed to the part of the piston rod 5 that protrudes out of the valve body 1a through the sliding hole 10, and its tip is bent to align with the piston rod axis of the valve body 1a (the central axis of the piston rod 5). ), and is configured to move up and down in conjunction with the up and down movement of the membrane plate 4.

A guide rod 13 is fixed to the interlocking arm 11, and is fitted into a guide hole 14 provided in the valve body 1a to guide the vertical movement of the interlocking arm 11. This prevents it from rotating.

Further, a pair of adjustment screws 15, 15a are rotatably attached to the interlocking arm 11, and a proximity piece block 16, 163 of a proximity switch is screwed into the intermediate portion of the screw.

The front surface of the proximal block 16, 161 is connected to the parallel member 12.
A pair of elongated holes 1 provided in this parallel member 12 are in contact with
It is fixed to this parallel member 12 via 7 and 17a and set screws 18 and 18a.

Loosen the set screws 18, 181 and adjust the screws 15,
When 15a is rotated, the proximal block 1
6.16a moves along the long holes 17, 17a, and its position can be freely selected by tightening the set screws 18, 18a at any position.

As shown in FIG.
are provided with plate-shaped proximal pieces 20, 203, which are inserted into engagement grooves 22, 22a of the proximity switches 19, 19a.

Proximity switches 19, 193 are attached to valve body 1a by set screws 21.21a.

As shown in FIGS. 4 and 5, the magnetic proximity switch (commonly known as a reed switch) used in this embodiment has a pair of switch pieces 23, 23 with a matching groove 22 provided in the longitudinal direction of the proximity switch 19. A and magnets 24 are installed in the switch bodies on both sides at regular intervals, and the proximal piece 20 made of a magnetic baffle plate is inserted into the loose groove 22 so as to be movable without contact.

Reference numerals 25 and 25a denote external terminal outlets connected to the respective switch pieces 23 and 23a, to which lead wires are connected.

Proximity piece 2 is placed between switch pieces 23, 23a and magnet 24.
When 0 is inserted, the switch pieces 23, 23a open, and when the proximal piece 20 is removed, the switch pieces 23, 23a are closed by magnetic force.

Normally, the main body of this proximity switch 19 is made of synthetic resin.
The switch pieces 23, 23a and the magnet 24 are built in at regular intervals and are integrally molded.

Figure 6 shows both proximity switches 19 and 19 for pressure detection.
FIG. 2 is an electrical circuit diagram between a and a compressor drive circuit C,
0 and 20a are the proximal pieces, and 1a is a schematic diagram of the valve bodies 1 and 1a for pressure detection.

Auxiliary relay 26 and power relay 27 are connected in series,
It is connected to the power supply E via the circuit 29.

A proximity switch circuit 28 that connects the contact 26a of the auxiliary relay 26 and the proximity switch 19 in series is a proximity switch circuit 28a in which the proximity switch 19a is arranged.
is connected in parallel with the power supply E and the relay 26.

27a is a contact point of the power relay 27, which is connected to the compressor drive circuit C.

Next, the operation of this embodiment will be explained.

Now, if you want to control the fluid pressure between the lower limit pressure P1 and the upper limit pressure 22, in the process of increasing and decreasing the fluid pressure, (1)
This is the effect when the compressor is driven when the contact 27a of the power relay 27 is on.

First, the action when the fluid pressure gradually increases and passes through Pl and P2 will be described.

When the pressure of the fluid flowing into the membrane plate chamber 3 from 712 increases, the fluid pushes up the membrane plate 4 against the spring 9, and the piston rod 5
．． Interlocking arm 11. Parallel member 12. Proximity piece block 16,1
6. Move a together upward.

Proximal piece block 1 with attached proximal piece 20.20H
6, 16a are the elongated holes 17, 17a shifted by the amount of displacement of the spring 9 corresponding to the pressure difference of <P2P1 as shown in FIG.
It is fixed to the parallel member 12 by set screws 18, 183 via
2, 22a is set at a position that does not interrupt the connection between the switch piece 23 and the magnet 24.

When the pressure is below P1, both proximity switches 19, 19a are on, and the auxiliary relay 26 and power relay 27
is excited, contacts 26a and 27a are turned on, and the compressor is driven.

Further, the proximity switch circuit 28 forms a self-holding circuit when the contact 26a is turned on.

As the fluid pressure increases, both proximal pieces 20, 20 a
When the pressure also rises and the pressure reaches Pl, the proximity piece 20a enters the cutoff position and turns off the proximity switch 19a.

However, because of the self-holding circuit, the power relay 27 is not demagnetized and the contact 27a remains on.

When the fluid pressure further increases and reaches P2 pressure, the adjacent piece 2
0 also enters the switch cutoff position, the proximity switch 19 is turned off, the self-holding circuit is opened, and the compressor is stopped.

This state is shown in the switch opening/closing diagram indicated by the rightward arrow in FIG.

Conversely, the fluid pressure is lower than the high pressure and P2. When passing through the P1 pressure, the proximity switch 19 is first turned on at the P2 pressure, as shown by the left arrow diagram in Figure 7, but since the contact 26a remains open, each relay is not energized and compressed. The aircraft remains stopped.

When the pressure further decreases and the proximity switch 19a is turned on at P1 pressure, both relays are energized, the compressor is driven, and a self-holding circuit is formed.

Therefore, when the pressure increases, the compressor stops at the upper limit pressure P2, and when the pressure decreases, the compressor is driven at the lower limit pressure P1, and the compressor stops at the lower limit pressure P2.
I. Fluid pressure can be controlled within the pressure range of upper limit P2.

(2) Operation when the compressor is driven when the contact 27a of the power relay 27 is on.

Loosen the set screws 18, 183 in advance and turn the adjustment screws 15, 153 to set the proximal piece block 16.1.
6a along the elongated holes 17, 17a, move the proximal pieces 20, 20a to a position that cuts off between the switch piece of the proximity switch and the magnet, and change the relative position of the proximal pieces 20, 20a as described above. Set the proximal piece 20 upward in the opposite way to the case described above.

Therefore, when the pressure is below P1, both proximity switches are off, contact 27a of power relay 27 is also off, and the compressor is being driven.

When the fluid pressure gradually rises and reaches P1 pressure, the proximal piece 20 of both proximal pieces that has risen is removed from the magnetic force cutoff position of the proximity switch 19 and turns on, but the contact 26a of the proximity switch circuit 28 is turned off. Therefore, the power relay 27 is not excited.

Then, when the pressure reaches P2, the left proximity switch 19 a
is also turned on, power relay 27 is energized and contact 27 is turned on.
a turns on and the compressor stops.

Conversely, in the case of pressure drop, first turn on proximity switch 1 at P2 pressure.
9a enters the magnetic force cutoff position and turns off, but since the self-holding circuit 28 of the proximity switch 19 is still on, the contact 27a remains on and the compressor remains stopped.

Then, when the pressure reaches P1, the proximity switch 19 is turned off, the contact 27a is also turned off, and the compressor starts to drive.

If the above is plotted as a diagram, it will look like Figure 8.

Since the guide rod 13 slides within the guide hole 14, the proximal pieces 20, 20a move up and down accurately, and horizontal movement of the proximal pieces due to twisting of the piston rod 5 is completely prevented.

Further, due to the thrust bearing 7, the deflection of the spring 9 is not transmitted to the piston rod 5.

Further, in this embodiment, the auxiliary relay 26 and the power relay 27 may be connected in parallel as shown in FIG. 9.

Note that if the contact capacity of the power relay is small, one of the double contacts of the auxiliary relay 26 may be used for power, and in this case, the power relay 27 can be omitted.

The present invention having the structure and operation described in the above embodiments has the following effects.

(a) A highly accurate set pressure value can be easily obtained by finely adjusting the adjustment screw 15, and errors can be minimized.

(b) Since a proximity switch is used to open and close the contacts in a non-contact manner, there are fewer failures in the contact parts, and there are no cross sections, which simplifies maintenance and inspection.

(c) Regardless of whether the compressor drive circuit is driven when it is on or off, the proximity piece block in the proximity switch can be adjusted and easily moved using the elongated hole mechanism. I can do it.

(d) A small and simple electric circuit with a self-holding circuit can reliably start and stop the compressor and accurately control the fluid pressure within a certain range, resulting in great economical effects.

[Brief explanation of drawings]

Fig. 1 is a front view of the pressure detection part of the present invention-embodiment, Fig. 2 is a sectional view taken along the line AA in Fig. 1, Fig. 3 is a sectional view taken along BB in Fig. 2, and Fig. 4 is a magnetic proximity view. 5 is a plan view of the switch 19, FIG. 6 is an electrical circuit diagram of the embodiment, FIGS. 7 and 8 are diagrams explaining the operation of the present invention, and FIG. 9 is an electrical diagram of another embodiment. It is a circuit diagram. 1.1a... Valve body, 2... Hole, 3...
...Membrane plate chamber, 4...Membrane plate, 5...
Piston rod, 9... Spring, 11... Interlocking arm, 12... Parallel member, 15, 15 a...
...Adjustment screw, 16, 16 a... Proximity piece block, 17, 17 a... Long hole, 19.1
9 a... Proximity switch, 20, 20a...
... Proximity piece, 26 ... Auxiliary relay, 27 ...
...Power relay, 26 a, 27 a...
... Contact, 28, 28 a ... Proximity switch circuit.

Claims (1)

[Scope of utility model registration request] A valve body containing a piston rod that receives detected fluid pressure and strokes against a spring with a predetermined load, and two proximity switches attached to the valve body parallel to the moving direction of the piston rod;
two proximity pieces connected to the piston rod and repositionably attached to members parallel to the piston rod, facing the proximity switch, and operating in a non-contact manner by vertical movement of the piston rod to open and close proximity switch contacts; The two proximity switches are connected in parallel, a contact that opens and closes when one of the proximity switches is activated is connected to the other proximity switch circuit, and a compressor drive circuit is connected to the parallel circuit of both the proximity switches. . A pressure regulating device configured to drive a compressor when both switches in the parallel circuit are activated.