JPH0341181Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a flow rate proportional control valve, and in particular to a flow rate proportional control valve that reduces spool sliding resistance during operation and improves hysteresis.

[Prior art and its problems]

Generally, in the case of a conventional flow rate proportional control valve, as shown in FIGS. 5 and 6, a main body 31 has a vertical hole 32 and a horizontal hole 33 perpendicular to each other. A cylindrical spool guide 34 is disposed inside the vertical hole 32, and a spool 35 is slidably disposed inside the spool guide 34. 33 has an inflow hole 33a on one side, and
Outflow holes 33b are formed on the other side.

A long hole 36 facing in the vertical direction is bored in the circumferential surface of the spool guide 34 located in the horizontal hole 33, and the inflow hole 33a and the outflow hole 33b are connected through this long hole 36. It is designed to communicate with the spool guide 3.
Inside the spool 4, there is a spool 35 whose upper and lower parts 35a and 35b have a size that almost matches the inner surface of the spool guide 34, and whose central part 35c that connects the upper and lower parts 35a and 35b has a small diameter. This spool 35 is slidably arranged.
Although not shown, is provided on the upper part of the main body 31 and is moved up and down by a plunger that is activated when the coil is energized.

In the conventional flow rate proportional control valve configured as described above, first, the spool 35 slides vertically inside the spool guide 34 by energizing the coil, and the small diameter central portion 35c When aligned with the elongated hole 36 of the spool guide 34, the inflow hole 33
The fluid flowing from a enters the inside of the spool guide 34 through the long hole 36 of the spool guide 34, passes through the circumferential surface of the central portion 35c of the spool 35, and then flows through the long hole 36 of the spool guide 34. The fluid flows out from the outflow hole 33b, and the distance between the elongated hole 36 and the center portion 35c is displaced depending on the position where the central portion 35c faces the elongated hole 36, thereby controlling the flow rate. ing.

However, in the conventional flow rate proportional control valve configured as described above, when the center portion 35c of the spool 35 is operated to coincide with the elongated hole 36 of the spool guide 34, the fluid acting on the center portion 35c is A long hole 3 drilled on one side of the spool guide 34
6 only, the spool 35 is pressed toward the outflow hole 33b, and as a result, the flow rate is not proportional to the amount of current flowing through the coil, and the due date, which is the time during which current is applied to the coil, is forced. The flow rate curve representing the relationship between the ratio and the flow rate becomes as shown in FIG. 7, resulting in large hysteresis, which poses a problem in that accurate flow rate control cannot be performed.

This invention solves the problems of the conventional ones as described above, and improves hysteresis by reducing the sliding resistance of the spool against the spool guide, thereby making it possible to accurately control the flow rate. The purpose of the present invention is to provide a flow rate proportional control valve that can be used.

[Means for solving problems]

In order to solve the above problems, this invention disposes a spool guide inside the main body, and also drills an inflow side hole and an outflow side hole that communicate with the hole provided in the spool guide. A spool is slidably disposed inside the spool guide, and in order to slide the spool, a plunger is provided that operates according to the amount of current applied to the coil, and the spool is slid inside the spool guide. The flow control valve is configured to cause fluid flowing in from the inflow side hole to flow out through the hole in the spool guide after passing around a small diameter portion of the spool, the flow control valve being provided in the spool guide. A means is adopted in which holes communicating with the inflow side holes are provided at two locations facing each other with respect to the small diameter portion of the spool, and the flow flows into the inside of the spool guide from both holes. be.

[Effect]

By adopting the above-mentioned means, this idea
Since the inflowing fluid flows into the inside of the spool guide through the holes drilled at two opposing locations in the spool guide, the fluid at this time is pushed in opposite directions at two opposing locations relative to the small diameter portion of the spool. Therefore, the spool, which is located inside the spool guide and can slide, is not subjected to any pressing force due to the action of the fluid, so the spool guide moves in response to the operation of the plunger. This means that good flow characteristics can be obtained.

〔Example〕

Embodiments of this invention shown in the drawings will be described below.

1 and 2 show a flow rate proportional control valve according to this invention, which has a vertical hole 2 in the center, communicates with the vertical hole 2 in the center, and , the main body 1 has two horizontal holes 3 and 4 perpendicular to each other,
A spool guide 5 is inserted into the vertical hole 2 from above, and a third
Two sets of vertical long holes 6 facing each other as shown in the figure
is drilled.

A spool 9 is disposed inside the spool guide 5 so as to be slidable in the vertical direction via a spring 8 disposed between it and a plug member 7 that closes the lower end of the vertical hole 2. .

Further, the upper part of the main body 1 has a cylindrical shape via a receiving plate 10, and a coil 1 on the outer peripheral surface.
A bobbin 12, on which the bobbin 1 is wound, is disposed so that its cylindrical interior is aligned with the vertical hole 2 of the main body 1, and inside the bobbin 12 there is a cylinder whose upper surface is tapered. A holding member 13 having a shape of
A plunger 15 having a rod 14 inserted through the hollow interior of the bobbin 12 is disposed, and the upper end of the plunger 15 is connected to a lid member 16 that closes the upper end of the bobbin 12.
The lower end of the rod 14, which forms a part of the plunger 15, is arranged so as to be slidable in the vertical direction inside the spool guide 5. The upper end of the spool 9 is in contact with the upper end of the spool 9.

The spool 9 has upper and lower parts 9a and 9b.
has a size that matches the inner circumferential surface of the spool guide 5, and the central portion 9c has a small diameter.

Furthermore, inside the main body 1, the two horizontal holes 3 and 4 that are perpendicular to each other are divided into two parts at the center with a distance between them by the vertical hole 2. , which is divided into two parts as shown in FIG.
The plug member 20 is fitted into the other of the divided and orthogonal holes, and therefore, one of the horizontal holes is divided into two, with one being the inflow side.
Due to the presence of the communication hole 19, the holes are opened into the spool guide in a state where they face each other, and the other hole which is divided into two in the horizontal direction merges due to the presence of the communication hole 19.
One of the divided parts is the outflow side, and holes are opened at four locations on the circumferential surface of the spool guide, and the opposing parts are in communication with each other.

Next, the operation of the above will be explained.

First, in the initial state shown in FIG. 1, the coil is not energized, so the spool 9 is raised by the biasing force of the spring 8, and the plunger is moved by the spool via the rod 14. 15 rises against the biasing force of spring 17, and therefore,
Since the lower part 9b of the spool 9 is located above the elongated hole 6 of the spool guide 5, the fluid that flows in from the hole 3 in one horizontal direction, which is the inflow side,
The flow is blocked by the spool guide 5.

Next, when the coil 11 is energized and the plunger 15 is attracted, the plunger 15 is lowered, and the spool 9 is lowered via the rod 14 against the biasing force of the spring 8.
When the lower part 9b of the spool guide 5 is located below the upper end of the long hole 6 of the spool guide 5, a gap is formed between the long hole 6 of the spool guide 5 and the lower part 9b of the spool 9. Fluid flows in from two opposing locations via the .

The inflowing fluid then passes through the periphery of the central portion 9c of the spool 9, flows into the other horizontal hole 4 from the other two opposing locations, merges in the middle, and flows out from the horizontal hole 4. becomes.

During the above operation, conventionally, the water flows in from one of the opposing long holes of the spool guide and flows out from the other long hole.
The spool was pressed against the inner surface of the spool guide by the fluid flowing in, but in the case of this invention, the fluid flowing in from two opposing locations cancels the pressure of the spool against the spool guide. Therefore, long hole 6
Even when a gap is formed between the coil 1 and the lower part 9b of the spool 9 and the fluid is flowing, the spool is not pressed against the spool guide.
When changing the amount of energization to 1, plunger 15
The spool 9 slides smoothly through the coil 11. Therefore, regarding the relationship between the duty ratio, which is the amount of current applied to the coil 11, and the flow rate, a flow rate characteristic with small hysteresis can be obtained as shown in Fig. 4. It is something that can be done.

[Effect of idea]

By configuring this idea as described above,
When the fluid flows in, the fluid flows in from two opposing locations so that the forces acting on the spool from the fluid cancel each other out, so the spool is not pressed against the spool guide by the fluid. When the plunger, which operates according to the amount of current applied to the coil, presses the spool, no load is applied to the plunger, so it has excellent effects such as being able to control the flow rate according to the amount of current applied to the coil. It is something.

[Brief explanation of the drawing]

1 and 2 show the entire flow proportional control valve according to this invention, with FIG. 1 being a schematic longitudinal sectional view of the whole in an inoperative state, FIG. 2 being a schematic longitudinal sectional view of the whole in an operating state, and FIG. Figure 3 is a schematic diagram showing the main parts, Figure 4
5 and 6 are schematic diagrams showing the main parts of a conventional flow rate proportional control valve, and FIG. 7 is a diagram showing the flow characteristics. 1, 31... Main body, 2, 32... Vertical hole, 3, 4, 33... Horizontal hole, 5, 34...
...Spool guide, 6,36...Long hole, 7,20
... Plug member, 8, 17 ... Spring, 9, 35 ... Spool, 9a, 35a ... Upper part, 9b, 35b ...
...lower part, 9c, 35c...center part, 10...receiving plate, 11...coil, 12...bobbin, 13...
Holding member, 14... Rod, 15... Plunger, 16... Lid member, 18, 19... Communication hole.

Claims (1)

[Scope of utility model registration request] A spool guide 5 is disposed inside the main body 1, and an inflow side hole 3 and an outflow side hole 4 communicating with the hole 6 provided in the spool guide 5 are bored inside the spool guide 5. The spool 9 is slidably disposed, and in order to slide the spool 9, a plunger 15 is provided which operates according to the amount of current applied to the coil 11, and the spool 9 is slid inside the spool guide 5. The flow rate proportional control valve is configured such that the fluid flowing in from the inflow side hole 3 passes around the small diameter portion 9c of the spool 9 and then flows out through the hole 6 of the spool guide 5. , holes 6 provided in the spool guide 5 and communicating with the holes 3 on the inflow side are provided at two locations opposite to the small diameter portion 9c of the spool 9, and the holes 6 are provided in the spool guide 5 at two locations opposite to each other with respect to the small diameter portion 9c of the spool 9, 5. A flow proportional control valve characterized in that the flow is caused to flow into the interior of the valve.