JPH0719367A - Proportional solenoid valve for flow control and method for adjusting gap amount in the solenoid valve - Google Patents

Abstract

(57) [Summary] [Purpose] The air gap on the suction surface can be adjusted to a constant value by a gap adjuster, and it is possible to reduce the variation in flow rate characteristics due to the variation in the air gap. [Structure] Body 11 having input port 13, output ports 12 and 14, and drain port 15 and each port 1
A flow control valve 27 including a spool 17 slidably provided in a valve cylinder (spool hole) 18 that connects 2, 13, 14, 15 and controlling an output flow rate by the sliding amount, and a core 3 by an input current. In a proportional solenoid valve for flow control, which includes a solenoid 19 that drives the spool 17 by sliding the plunger 5 in balance with the generated suction force and spring force, a core 3 is provided between the valve body 17 and the plunger 5. A gap adjuster 25 for adjusting the amount of the gap with the plunger 5 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proportional solenoid valve for proportionally controlling an oil pressure or an oil flow rate of an automobile and an industrial machine and a method of adjusting a gap amount thereof. The present invention relates to a proportional solenoid valve for flow rate control and a gap adjusting method that can eliminate variations in an air gap by adjusting a gap amount adjusting member (adjuster).

[0002]

2. Description of the Related Art As a conventionally known technique, for example, there is one described in Japanese Utility Model Laid-Open No. 2-31970. This publication discloses an example in which the generated suction force with respect to the input flow rate is adjustable from the outside.

Further, Japanese Patent Laid-Open No. 59-47584 discloses an electromagnetic fluid pressure control valve constructed so that the gap between the right end of the movable core and the left end of the iron core can be adjusted to a desired value. .

Further, Japanese Patent Application Laid-Open No. 57-177477 discloses a gas flow control valve constructed so that the positions of the movable core and the valve body can be adjusted from the outside.

[0005]

By the way, in the technique disclosed in Japanese Utility Model Laid-Open No. 2-31970, the generated suction force with respect to the input flow rate is formed so as to be adjustable from the outside, but the air gap generated on the suction surface is generated. No particular consideration was given to the variation of Therefore, it is undeniable that the balance point between the attraction force and the spring force with respect to the input current varies, which causes a large variation in the flow rate characteristics.

Further, in the technique disclosed in Japanese Patent Application No. 59-47584, the position of the iron core can be adjusted from the outside to adjust the value of the gap. Since the electromagnetic characteristics change, the flow rate cannot be controlled accurately as a proportional solenoid valve.

Further, in the technique disclosed in Japanese Patent Application No. 57-177477, the positions of the movable iron core and the valve body can be adjusted from the outside. For low flow regulation,
No consideration is given to adjusting the air gap to suppress variations in flow rate characteristics.

The present invention has been made in view of the above technical background, and an object thereof is to suppress variations in the air gap to reduce variations in the balance point between the attraction force and the spring force with respect to the input current. However, it is another object of the present invention to provide a proportional solenoid valve for flow rate control that can obtain stable flow rate characteristics by making the sliding amount of the valve body of the flow rate control valve constant.

[0009]

In order to achieve the above object, the present invention provides a valve body of a flow control valve (hereinafter also referred to as a spool valve) using a spool for controlling the flow rate and a shaft of a solenoid plunger. A member (hereinafter, also referred to as a gap adjuster) that adjusts a gap amount between the solenoid core and the plunger is provided between the tip and the tip.
A structure in which the shaft that is integrated with the plunger that forms the suction surface contacts the gap adjuster to regulate the position, or the gap adjuster is attached to the shaft,
The structure is such that the gap adjuster contacts the valve body to regulate the position, and by adjusting the position of the gap adjuster, a constant air gap is always obtained between the core and the plunger.

[0010]

As described above, the gap adjuster that defines the contact position between the valve body and the shaft is provided, and the position of the shaft with respect to the valve body can be adjusted by changing the position of the gap adjuster. Is adjusted. Therefore, by adjusting the gap adjuster, it is possible to eliminate the variation in the air gap between the plunger and the suction surface of the core, which is caused by the variation in the dimensions of the spool valve including the valve body, the body, the shaft press fit dimension, the case, the core, and the plunger. You can This makes it possible to always obtain stable suction force characteristics,
There is no variation in the balance point with the spring force, the sliding amount of the valve element of the spool valve that is determined by the balance point between the attraction force and the spring force with respect to the input current is stable, and the valve accuracy is substantially reduced by reducing the variation in the flow rate characteristics. Can be improved.

[0011]

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

FIG. 1 is a longitudinal sectional view of a proportional solenoid valve for flow rate control according to an embodiment. In the figure, a proportional solenoid valve for flow control drives a spool valve 27 as a flow control valve having a spool 17 slidably set in a spool hole (valve cylinder) 18 in a body 11 and a spool 27. It is composed of a solenoid 19 as a driving means for operating. With this configuration, in the case of this example, the spool 17 constitutes a valve body.

The solenoid 19 is further provided with a terminal 1, a coil 2, a core 3, an adjusting screw 7, a plunger spring 6, a plunger 5 into which a shaft 4 for holding the plunger and transmitting suction force is press-fitted, and an O for airtight holding. It consists of rings 8 and 9 and a bracket 23. On the other hand, the spool valve 27 includes a spool spring 16 for balancing the attraction force of the solenoid 19 and the input port 1.
3, output A port 12, output B port 14, drain port 15, body 11 having spool hole 18
And the suction force of the solenoid 19 causes the spool hole 18
It is constituted by a spool 17 as a valve body that slides on and controls the flow rate.

A gap adjuster 25 as a member for adjusting the gap amount is provided at the tip of the spool 17, and the gap between the core 3 and the plunger 5 (air gap) is adjusted by adjusting the position of the gap adjuster 25. ) L can be constant. Also, the spool 17
Is formed by a cylindrical body, and as a result, the insertion hole 38 is formed along the axis. Spool hole 1
In the drawing of FIG. 8, the lower end is opened to the outer surface of the body 11, and the opened portion is the opening 30. A blind screw 26 for closing the spool hole 18 is screwed into a female screw 28 screwed on the inner surface of the opening 30 so that the blind screw 26 can be opened and closed. Therefore, by removing the blind screw 26, the driver can be inserted through the insertion hole 38 in the spool 17 to the gap adjuster 25. Therefore, the gap adjuster 25 is attached by screwing it into a female screw 29 screwed on the inner surface of the spool 17, and the driver is inserted through the opening 30 and the tip end thereof is engaged with the engaging groove 31 of the gap adjuster 25. By the gap adjuster 25
Can be easily rotated, whereby the position of the gap adjuster 25 can be easily adjusted with the solenoid 19 attached to the body 11.

When the gap adjuster 25 is thus rotated and the axial position of the gap adjuster 25 is moved, the shaft 4 integral with the plunger 5 which is in contact with the gap adjuster 25 is also axially moved. By moving, the distance L between the plunger 5 and the end of the core 3 is adjusted. The solenoid 19 is fixed to the body 11 by the bracket 23 and the set screws 22a and 22b.
The O-ring 10 maintains airtightness.

FIG. 2 is a diagram for explaining the operation of the proportional solenoid valve for flow control constructed as described above, and FIG. 3 is a characteristic diagram showing the characteristics of the proportional solenoid valve for flow control according to the embodiment and the conventional example. The operation of the flow control proportional solenoid valve configured as described above will be described with reference to these drawings.

In the proportional solenoid valve for flow control according to the embodiment, when the coil 2 is not energized, the solenoid 19 does not generate a suction force, and the plunger spring 6 sets the load stronger than the spool spring 16. Therefore, the spool 17 is connected to the body 11 through the shaft 4 of the plunger 5.
It is pressed against the end portion 18a of the spool hole 18. In this state, the maximum flow rate of the oil supplied from the input port 13 is output from the output A port 12 through the gap of the control unit 20 on the output A port 12 side (FIG. 2).
(A)). This maximum flow rate can be arbitrarily set depending on the size of the gap (FIGS. 3A and 3B).

When a current is applied to the coil 2, a suction force is generated in the solenoid 19 in the F direction in FIG. 1, and the suction force increases as the current increases. When the suction force becomes large enough to overcome the elastic force of the plunger spring 6, the plunger 5 is sucked by the core 3, so that the spool 17 starts moving in the F direction, and the clearance of the control unit 20 gradually becomes smaller. The output flow rate from 12 decreases (FIGS. 3b-c). In this way, when the spool 7 is moved to a position where the gaps between the control units 20 and 21 are both 0 as shown in FIG. 2B, the oil output amount is equal to the outer diameter of the spool 17 and the spool hole 18. It is only the amount of leakage from the clearance with the inner diameter of. Almost no leakage at this time
It is liter / min. This state continues until a gap is generated in the control unit 21 on the output B port 14 side as shown in FIG. 2C (FIGS. 3c to 3d). The spacer 24 made of a non-magnetic material, which operates integrally with the plunger 5, is
The gap of the control unit 21 continues to increase until it comes into contact with the end surface 3a of Fig. 3 and the flow rate also gradually increases (Figs. 3d to e), and when the spacer 24 and the end surface 3a of the core 3 come into contact, the operation of the spool 17 also stops. The output amount from the output B port 14 becomes maximum until the input current becomes maximum (FIG. 3).
ef). When configured and operated in this manner, the adjusting screw 7 can adjust the pressing load of the spool 17 to shift the points b, c, d, and e of the flow rate characteristic.

FIG. 4 is a characteristic diagram showing variations in the balance point between the suction force and the spring force due to variations in the air gap L. As can be seen from this figure, in the structure of the conventional product that does not have the adjustment mechanism of the air gap L, the air gap L = 1 ± 0.15 [mm], and the variation of the point c in FIG.
0.03 [mm], variation of d point ± 0.03 [mm]
And thickness variation of spacer 24 ± 0.01 [mm]
Considering all of these, 0.45 when the air gap L is maximum and when the air gap L is minimum.
The equilibrium points for which the spring load is set in [A] are the one-dot chain line and the broken line in FIG. 4, respectively. The flow rate characteristics plotted from this balance point (input current value) are the characteristics shown by the one-dot chain line and the broken line in FIG.

According to the proportional solenoid valve for flow rate control of this embodiment, since the air gap L can be constantly set by the gap adjuster 25, the variation in the flow rate characteristic is ± 0. 03 [mm] and the deviation of the spacer 24 is ± 0.01 [mm] only, which is the balance point shown by the solid line in FIG. The flow rate characteristics plotted from this balance point are within the shaded area in Fig. 3,
It can be seen that the variation is much smaller than the conventional characteristics. In addition, if you look at this with the input power as a parameter, the variation in the flow rate characteristics of the conventional product is ±
In contrast to 0.115 [A], in the proportional solenoid valve of the embodiment,
It becomes 0.02 [A], and the variation can be reduced by about 83%. From this, it can be seen that the proportional solenoid valve according to this embodiment obtains stable characteristics without variation without increasing the component accuracy.

Therefore, in the conventional product, the required performance can be satisfied only by making the dimensional tolerance of each part related to the suction force characteristic and the flow rate characteristic as severe as possible, or by combining the spool valve, the cover and the like, and the cost is high. Nevertheless, according to the solenoid proportional valve according to the embodiment, the structure is simple and the dimensional tolerance of each part is large. In other words, it is not necessary to set it so severely, which is advantageous in cost.

The adjustment of the gap adjuster 25
As described above, the blind screw 26 can be removed, and the adjustment can be performed from the outside of the body 11 using an adjusting jig such as a driver with the solenoid 19 attached to the body 11. Before mounting, the amount of protrusion of the shaft 4 from the end surface of the solenoid 19 on the body 11 mounting side is measured, and the solenoid 19 of the body 11 of the spool 17 in the spool hole 18 is measured.
The air gap L can also be adjusted by adjusting the advance or retreat amount of the gap adjuster 25 from the end face of the spool 17 in consideration of the retreat amount from the end face on the mounting side. For this reason, as can be seen from FIG. 1, the gap adjuster 25 is provided with engagement grooves 31 and 32 on both end surfaces for fitting the tip of the driver.

In this embodiment, the spool valve 27
Although the gap adjuster 25 is provided at the end of the spool 17, the gap adjuster may be provided at the end of the shaft 4 of the solenoid 19. An example of this is shown in FIG.

In another embodiment shown in FIG. 5, a male screw 33 is screwed on the outer periphery of the lower end portion of the jaft 4, and a gap adjuster 34 is screwed onto the male screw 33 to make the spool 1
An abutting portion 35 with which the gap adjuster 34 abuts is formed at the upper end portion of 7. In addition, the contact portion 35
An insertion hole 36 is formed in the center of the body 11, and the tip of the driver inserted into the spool 17 from the outside of the body 11 is formed in the engagement groove 37 formed at the end of the gap adjuster 34.
It is possible to adjust by engaging with. Other than that, each part not particularly explained is constructed in the same manner as the embodiment shown in FIG.

With this structure, the air gap L can be adjusted also in this embodiment as in the embodiment shown in FIG.

[0026]

As is apparent from the above description, according to the present invention, a member for adjusting the gap amount between the core and the plunger is provided between the valve body of the flow control valve and the plunger of the solenoid. So, by adjusting the member,
It is possible to suppress the variation in the air gap, which suppresses the variation in the balance point between the suction force and the spring force with respect to the input current, and to obtain a stable flow rate characteristic.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a proportional solenoid valve for flow rate control according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a control unit of a proportional solenoid valve for flow rate control according to an embodiment.

FIG. 3 is a characteristic diagram showing an outline of flow rate characteristics of a proportional solenoid valve for flow rate control according to an embodiment and showing variation width.

FIG. 4 is a characteristic diagram showing a balance between an input current, a suction force characteristic, and a spring force of the proportional solenoid valve for flow rate control according to the embodiment.

FIG. 5 is a sectional view showing details of a gap adjuster portion according to another embodiment.

[Explanation of symbols]

 1 Terminal 2 Coil 3 Core 4 Shaft 5 Plunger 6 Plunger Spring 7 Adjusting Screw 8, 9, 10 O-ring 11 Body 12 Output A Port 13 Input Port 14 Output B Port 15 Drain Port 16 Spool Spring 17 Spool 18 Spool Hole 19 Solenoid 20 A port side control part 21 B port side control part 22a, 22b Set screw 23 Bracket 24 Spacer 25, 34 Gap adjuster 26 Blind screw 27 Flow control valve (spool valve) 28, 29 Female screw 30 Opening part 31, 32, 37 Groove 33 Male thread 35 Abutment 38 Insertion hole

Claims (8)

[Claims] 1. A body having an oil supply port, a plurality of output ports and a drain port, and a valve body slidably provided on a valve cylinder connecting the ports and controlling an output flow rate by the sliding amount. In a proportional solenoid valve for flow control, comprising: a flow control valve, and a solenoid that drives the valve element by sliding a plunger in balance with a suction force and a spring force generated in a core by an input current,
A proportional solenoid valve for flow control, wherein a member for adjusting a gap amount between the core and the plunger is provided between the valve body and the plunger. 2. The proportional solenoid valve for flow rate control according to claim 1, wherein the member for adjusting the gap amount is provided at an end of the valve body facing the plunger. 3. The proportional solenoid valve for flow rate control according to claim 1, wherein a member for adjusting the gap amount is provided at an end of the shaft of the plunger facing the valve body. 4. A member for adjusting the gap amount and a member to which the member for adjusting the gap amount is attached,
The proportional solenoid valve for flow control according to claim 2 or 3, wherein each screw is screwed, and the gap amount is adjustable via the screw. 5. The member for adjusting the gap amount is provided with a groove with which a tip of a driver for rotating the member can be engaged. Proportional solenoid valve for flow control described. 6. An insertion hole is formed along an axial center of the valve body, and a driver is inserted through the insertion hole to a member for adjusting the gap amount on an end surface of the body on the side opposite to the plunger of the valve cylinder. The proportional solenoid valve for flow control according to claim 1, wherein a possible opening is formed. 7. A valve body slidably provided on a body having an oil supply port, a plurality of output ports and a drain port, and a valve cylinder connecting the respective ports, and controlling an output flow rate by the sliding amount. And a core of a proportional solenoid valve for flow control including a solenoid for driving the valve element by sliding a plunger in balance with a suction force and a spring force generated in the core by an input current. In a method for adjusting a gap amount for adjusting a gap between the plunger and the plunger, a member for adjusting a gap amount between the core and the plunger is provided between the valve body and the plunger via a screw mechanism, A method for adjusting a gap amount, characterized in that the gap amount is adjusted by rotating a member for adjusting the gap amount to adjust an axial position. Law. 8. The gap amount according to claim 7, wherein the gap amount is adjusted by rotating a member for adjusting the gap amount from the outside of the body while the solenoid is attached to the body. Adjustment method.