JPH02173478A - Fluid control valve - Google Patents

Abstract

PURPOSE:To enable a pressure of fluid and its flow quantity to be linearly controlled by a conduction current by arranging a land part overlapping with an opening part in accordance with sliding a spool and supplying fluid to and discharging it from a cylinder through a flow path formed by the opening part and the land part. CONSTITUTION:Fluid is supplied to and discharged from a cylinder 2 through a flow path formed by an opening part 21c communicating with a port 3 formed in the cylinder 2 and a land part 7 opposed facing to the opening part. Here an area of the flow path, formed between the opening part 21c and the land part 7, that is, an opening area into the cylinder 2 is changed in accordance with a shape of the opening part 21c of the cylinder 2 following sliding a spool 6. In this way, a relation of the spool 6 in its sliding stroke to the opening area into the cylinder 2 is controlled to the predetermined relation. Accordingly, the relation of the sliding stroke to the opening area is set in accordance with a relation between a conduction current to a drive source of the spool 6 and its sliding stroke, when the opening part 21c is formed in a shape satisfying this relation, a flow quantity of the fluid or its pressure can be linearly controlled in accordance with the conduction current.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a fluid control valve, and particularly to a pressure proportional control valve used for hydraulic control of automatic transmissions of automobiles, or cooling water control of internal combustion engines. The present invention relates to a fluid control valve suitable as a flow rate proportional control valve.

[Prior Art] Fluid control valves used in automobiles and the like are broadly classified into those for fluid pressure control and fluid flow control based on their functions and uses, and an electromagnetic solenoid is usually used as a driving source. In either case, with recent advances in electronic technology, it is desired to linearly control the pressure or flow rate of the fluid in accordance with the current supplied to the drive source.

As a conventional fluid control valve for automobiles, for example,
Japanese Patent No. 73206 discloses a hydraulic control solenoid valve for controlling power steering operation. This uses an electromagnetic solenoid to drive the spool and switch the hydraulic flow path, and an example is described in which one of the three flow paths alternately communicates with the other flow path in response to the sliding of the spool. However, there is no detailed explanation of fluid control.

Japanese Utility Model Application No. 62-177952 discloses an electromagnetic proportional solenoid valve used for hydraulic pressure control of an automatic transmission. This valve body houses a plunger and a spool driven by a solenoid, and the spool is driven against the biasing force of a spring against the spool to switch between three ports. There is. Regarding removal, it is explained that the spool is driven from the neutral position to the left and right by the plunger drive, and the let port is alternately switched to an inlet port and a drain port. That is, the outlet port is configured to be blocked at the neutral position of the spool, and to selectively communicate with either the inlet port or the trend port. Then, the solenoid is driven by a dithered pulsating drive current, and the amount of restriction between the three ports is changed, resulting in the characteristics shown in Figure 4 of the same publication, that is, the output hydraulic pressure characteristics of a nearly quadratic curve with respect to the solenoid current. It is explained that it can be obtained. In the device described in the publication, the solenoid valve is controlled by another control device, so it is not necessarily necessary for the solenoid valve itself to have linear output hydraulic pressure characteristics with respect to the energizing current. ,
If linear output hydraulic characteristics can be obtained from the valve itself, control becomes easier and there are various advantages.

Furthermore, a proportional electromagnetic pressure reducing valve that adjusts the set pressure according to an electric signal is disclosed in Japanese Patent Application Laid-Open No. 160680/1983, and as a conventional technology, a proportional electromagnetic solenoid that exerts a suction force according to an electric signal is used. A spool valve is disclosed. That is, the solenoid suction force is made constant with respect to the applied current regardless of the stroke of the spool, and a predetermined pressure reducing function is achieved from the balance between the liquid pressure and the suction force against the spool.

Further, in Japanese Utility Model Application Publication No. 61-75563, a flow rate control valve is used to control the flow rate characteristics of two fluid systems, such as the slow system and the main system of a carburetor, so that a predetermined difference in characteristics occurs between the two systems. A control valve is disclosed. In this method, the two edges of the spool, that is, one end face of the land part, are constructed with two inclined planes, and the opening area of one output port is adjusted according to a predetermined deviation in characteristics from the output characteristics of the other output port. It is designed so that it can be adjusted. In addition, in the graph described in the same publication, the current -
Although it is described that the flow rate characteristics are linear, the reason for this is not clear.

[Problems to be Solved by the Invention] As mentioned above, in automatic transmissions, power steering, etc., it is required to linearly control hydraulic pressure with respect to energizing current, and in speed-sensitive power steering, etc. It is required to linearly control the flow rate with respect to the current. However, none of the above-mentioned conventional techniques can meet this requirement. Japanese Patent Application Publication No. 5
In Japanese Patent No. 8-160680, linear control is difficult because the balance between hydraulic pressure and solenoid suction force is utilized. Although a graph showing linear characteristics is described in Japanese Utility Model Application Publication No. 61-75563, it is recognized that it simply shows a characteristic deviation between two output ports, and the proof that it is linear is unknown. Even if a linear flow rate characteristic could be obtained with the configuration described in the same publication, it would not be possible to prevent rotation by drilling a hole in the spool, inserting a pin into it, adjusting it with an adjuster, and then fixing it as described in the same publication. A mechanism is needed. Therefore, not only is the structure complicated, but vibration countermeasures become an important issue, especially when installed in an automobile.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fluid control valve that can linearly control the pressure and flow rate of fluid with respect to the current applied to a drive source with a simple configuration.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a cylinder and a spool having at least one land portion that slides inside the cylinder, and a spool that is bored in the radial direction of the cylinder. A fluid control valve that controls supply and discharge of fluid into and out of the cylinder by opening and closing a port provided in the cylinder according to the sliding of the land portion,
an opening having a predetermined shape formed in the cylinder and communicating with the port and opening into the cylinder, the land portion being arranged so as to overlap with the opening in response to sliding of the spool; The fluid is supplied and discharged into the cylinder through a flow path formed by at least the opening and the land.

Further, the present invention includes a cylinder and a spool having at least one land that slides inside the cylinder, and the land opens and closes a port bored in the radial direction of the cylinder in accordance with the sliding. In the fluid control valve that controls the supply and discharge of fluid into and out of the cylinder, an annular groove that communicates with the port and opens into the cylinder is formed on the inner surface of the cylinder, and the opening area into the cylinder is at least as large as the shaft. A cylindrical body having an opening whose shape changes non-linearly along the direction, the cylinder being fitted into the cylinder so that the opening faces the annular groove, and the spool can be freely slid into the cylindrical body. and arranged so that the land portion overlaps with the opening portion in response to sliding of the spool,
It is preferable that the fluid is supplied and discharged into the cylinder through a flow path formed by at least the opening and the runt part.

In this fluid control valve, in the axial direction of the cylinder,
It is preferable that a drive source for driving the spool is installed and a discharge port communicating with the inside of the cylinder is bored in the radial direction of the cylinder.

[Operation] According to the above fluid control valve, when the spool slides inside the cylinder, the land portion opens and closes the port bored in the cylinder. When fluid is supplied or discharged from the cylinder through this port, that is, when it is supplied or discharged, the flow rate and pressure of the fluid within the cylinder fluctuate. Specifically, fluid is supplied into or discharged from the cylinder through a flow path formed by an opening communicating with a port formed on the inner surface of the cylinder and a land portion facing the opening. In this case, the area of the flow path formed between the land portion and the land portion according to the shape of the opening of the cylinder as the spool slides;
That is, the opening area into the cylinder changes. This results in
A predetermined relationship is controlled between the sliding stroke of the spool and the opening area into the cylinder. The spool is connected to a desired drive source, and the relationship between the sliding stroke and the opening area is set according to the relationship between the current applied to the driving source and the sliding stroke of the spool. By forming the cylinder into a shape that satisfies this relationship, the flow rate or pressure of the fluid within the cylinder can be linearly controlled according to the applied current. In addition, an annular structure is formed on the inner surface of the cylinder,
A fluid control valve in which a cylindrical body is fitted so that the opening faces the cylindrical body operates in the same manner as described above.

[Embodiments] Hereinafter, preferred embodiments of the fluid control valve of the present invention will be described with reference to the drawings.

FIG. 1 shows a fluid control valve according to an embodiment of the present invention, which consists of a valve section 1 and a solenoid section 10 that is its driving source. The cylinder 2 of the valve part 1 is a substantially cylindrical body with a flange formed at one end, and the flange is caulked and fixed to the end of the cylindrical case 10a of the solenoid part 10.

A supply port 3, a control port 4, and a discharge port 5 are bored in the cylinder 2 in the radial direction, and these ports open into the stepped cylinder hole 2a. An annular groove 2b communicating with the supply port 3 is formed in the inner wall of the large diameter portion of the cylinder hole 2a. As shown in FIG. 2 as a cross-sectional view and as shown in FIG. 3 as a perspective view, a cylindrical body 21 is fitted into the large diameter portion of the cylinder hole 2a, and a cylindrical body 21 is fitted in the side wall of the cylinder 21, facing the annular groove 2b. An opening 21c is formed, and the opening 21c opens into the cylinder hole 2a. Axial end of cylinder 21 and annular groove 2
A gap is formed between the cylinder and the axial end of the cylinder 21, and the supply port 3 communicates with the cylinder hole 2a through this gap and the opening 21C of the cylinder 21. The shape of the opening 21c on the outer circumferential surface is such that the opening area changes nonlinearly in the axial direction from the axial end (hereinafter simply referred to as the end), for example, as shown in FIGS. 2 and 3, It consists of a part that decreases rapidly and a part that decreases slowly. Note that the opening 21c is formed directly on the side wall of the cylinder 2 by cold forging or the like without providing the cylindrical body 21.
, and a not-shown annular member having a supply port 3 may be fitted to cover this.

Further, a second cylindrical body 22 is fitted into the large diameter portion of the cylinder hole 2a, so that the inner surfaces of these cylindrical bodies 21 and the second cylindrical body 22 are continuous with the inner surface of the small diameter portion of the cylinder hole 2a. It is composed of The spool 6 is slidably housed in the cylinder hole 2a, the cylinder 21, and the second cylinder 22,
A plug body 2c is fitted to the end of the cylinder hole 2a via an annular seal ring 2d.

The spool 6 has land portions 7 and 8 formed at both ends, and the center portion is formed to have a smaller diameter than these land portions. Therefore,
A fluid chamber 9 is defined between the small diameter portion between the lands 7 and 8 and the cylinder hole 2a, and is constantly communicated with the control port 4 and the discharge port 5. Although the spool 6 is made of metal, it may also be made of resin.

The land portion 7 has a concave portion in the axial direction, and an end surface 7a faces the plug body 2c with a gap therebetween. A communication hole is bored approximately in the center of the plug body 2c, and the concave portion and end surface of the land portion 7 communicate with the atmosphere.

Note that the end surface 7a of the land portion 7 contacts the seal ring 2d at the initial position of the spool 6, but the contact area is very small, and the end surface 7a of the land portion 7 substantially has a cylinder hole 2a. The structure is such that an atmospheric pressure determined by the cross-sectional area of is applied.

In the initial position of the spool 6, the end surface 7b of the land portion 7 is located at the end of the annular groove 2b, and a gap is formed between the end of the cylinder 21 and the end surface 7b of the land portion 7.

As shown in FIG. 1, when the spool 6 is in its initial position and the land portion 7 is on the plug body 2c side, the annular groove 2b is formed between the end of the cylinder body 21 and the end surface 7b of the land portion 7. It communicates with the fluid chamber 9 through a gap between the two and a communication path of the entire opening area of the opening 21c, and connects the supply port 3 to the annular groove 2b.
As soon as the fluid is supplied to the gap and the opening 21c,
The control pressure is supplied into the fluid chamber 9 through the control port 4, and the control pressure is output from the control port 4. Then, the land portion 7 is connected to the cylinder hole 2a.
The opening area of the gap to the fluid chamber 9 decreases as it slides inside and moves toward the opposite side of the plug body 2C, that is, toward the solenoid section 10. When the land portion 7 further slides, the gap is closed, the opening area of the flow path formed by the land portion 7 and the opening 21c to the fluid chamber 9 decreases, and the annular groove 2b
The communication path that communicates the fluid chamber 9 with the fluid chamber 9 is constricted.

The land portion 7 further moves toward the solenoid portion 10 and the end face 7
When b exceeds the end of the opening 21c on the solenoid section 10 side, communication between the annular groove 2b and the fluid chamber 9 is cut off.

The flange of the cylinder 2 is joined to one open end of a cylindrical magnetic case 10a of the solenoid section 10. A magnetic base plate 10b is caulked to the other open end of the case 10a.
A hollow cylindrical magnetic core 10 is placed in the cylindrical part formed in the center of the
One end of c is fitted. A resin pobbin 11 having a hollow portion into which the core 10c is fitted and around which the solenoid coil 12 is wound is housed in the case 10a. The other end of the core 10c is formed in a tapered shape, and the plunger 13, which is a bottomed cylindrical magnetic material and has one end formed in a reverse tapered shape, is slidably fitted into the cylinder hole 2a. There is. The plunger 13 is coupled to the spool 6 and slides integrally with the spool 6 within the cylinder hole 2a.

A compression spring 16 is housed in the hollow part of the core 10c, and a cylindrical stopper 15 has one end in contact with the bottom surface of the inverted tapered end of the plunger 13 and the other end screwed onto the open end of the core 10c. The plunger 13 is urged toward the stopper 2c by coming into contact with the end face. The hollow part of the stopper 15 is opened to the atmosphere, so that the land part 8 of the spool 6
Atmospheric pressure corresponding to the cross-sectional area of the cylinder hole 2a is applied to the side.

In the above fluid control valve, the supply port 3 of the valve portion 1 is connected to a fluid pressure source (not shown), and a predetermined supply pressure P
s (kg/cm2) of fluid flows into the land portion 7.
and the gap between the annular groove 2b and the land portion 7 and the opening 21
The fluid is supplied into the fluid chamber 9 of the cylinder 2 through a flow path (hereinafter referred to as a flow path) formed by c. The control port 4 is connected to a control device (not shown), and the fluid pressure in the fluid chamber 9 is set to a control pressure P c (kg/cm 2 ).
is supplied to the control device as follows. The discharge port 5 is opened to the atmosphere and has approximately atmospheric pressure P o (kg/cm2)
It becomes.

FIG. 4 shows the operating principle of the valve part 1 of this embodiment, and shows the opening area of the gap and flow path to the fluid chamber 9 (the fourth
In the figure, As (0 m
2), the opening area of the discharge port 5 is expressed as Ao (0 m2). That is, in this embodiment, As is variable and Ao is fixed. Further, the flow velocity of the fluid in the gap and the flow path is expressed as Vs (am/5ee), and the flow velocity at the discharge port 5 is expressed as Vo (cm/5ee). The relationship between these fluid pressures and opening areas is as follows.

First, if the flow rate of the fluid is Qf (cm'/5ee), then there is a relationship of Qf=As-Vs=Ao-Vo, and this flow rate Qf is expressed as in the following equation.

Qf=As −Ps−Pc ・2g γf=Ao
・Pc-Po ・2gγf...
(1) Here, g is the gravitational acceleration, γf is the specific gravity of the fluid, and is the Po valve O. Therefore, P c −K−P s / (1+ (A o / A
s)')...(2). Here, K indicates a coefficient.

In this way, the flow rate Qf is determined by the opening area As of the gap and flow path.
The relationship between the control pressure Pc and the opening area As is as shown in equation (2).

On the other hand, in the solenoid section 10, the solenoid coil 1
The current I (A) flowing through the plunger 13 and the stroke St (am) of the spool 6 connected thereto have a substantially linear proportional relationship as shown in FIG. 5(a). The gap and opening area As of the flow path are inversely proportional to the stroke of the spool 6, and the flow rate Qf is inversely proportional to the stroke St of the spool 6, as shown in FIG. 5(b). Set to . As a result, the flow rate Q
f is inversely proportional to the current I flowing through the solenoid coil 12, as shown in FIG. 5(C).

Further, as described above, the opening area As of the gap and the flow path is determined with respect to the stroke St of the spool 6, and the control pressure Pc is determined with respect to the stroke St of the spool 6 based on the above equation (2) as shown in FIG. ) is set so that the relationship is inversely proportional to that shown by the solid line.

As a result, the sixth
The spool 60 changes as shown by the solid line in figure (a).
Depending on the stroke St, the opening area As changes as shown by the broken line in FIG. 6(b), and the control pressure Pc changes as shown by the solid line.

Therefore, as shown in FIG. 6(C), the control pressure Pc is inversely proportional to the current ■. Thus, a fluid control valve is constructed in which the control pressure Pc changes linearly with respect to the current I of the solenoid coil 12.

In addition, as shown by the dashed line in FIG. 6(a), if the stroke of the plunger 13, that is, the stroke St of the spool 6 does not change linearly with respect to the current ■ of the solenoid coil 12, the By appropriately adjusting the relationship between the spool 60 stroke St and the opening area As of the gap and flow path in FIG.
) The relationship between the current I and the control pressure Pc can be made linear. That is, even if the relationship between the current I of the solenoid coil 12 and the stroke of the plunger 13 is not linear due to the characteristics of the solenoid section 10, if the two are in a stable relationship, the above-mentioned gap and flow will be maintained with respect to the stroke St of the spool 6. By appropriately changing the shape of the opening 21c so that the opening area As of the passage changes, the desired control pressure -
Current (Pc-I) characteristics can be obtained. Similarly, the flow rate-current (Qf-1) characteristic is also the stroke St of the spool 6.
By appropriately setting the shape of the opening 21c according to the flow rate, desired characteristics can be set, for example, linear flow characteristics can be achieved.

To explain the operation of the fluid control valve of this embodiment, when the solenoid coil 12 is not energized, the plunger 13 is in a position separated from the core 10c by the biasing force of the compression spring 16. Therefore, the spool 6 is in the initial position shown in FIG. 1, the supply port 3 communicates with the fluid chamber 9, and the opening area of the gap and flow path is at its maximum.

Next, when the solenoid coil 12 is energized and current is supplied, the plunger 13 is sucked into the core 10c and stopped at a position balanced with the biasing force of the compression spring 16. When the current applied to the solenoid coil 12 is increased, the core 10
The suction force of the plunger 13 due to c increases, and the plunger 1
3 stops at a position even closer to the core 10c. That is,
As the current of the solenoid coil 12 increases, the moving distance of the plunger 13 in the direction of the core 10c, that is, the stroke of the plunger 13 and the spool 6 described above increases, and as the current of the solenoid coil 12 decreases, the stroke of the plunger 13 and the spool 6 increases. becomes small. As a result, the fifth
Stroke-current (St-I) characteristics as shown in FIG. 6(a) or FIG. 6(a) are obtained.

In order to ensure such characteristics in the solenoid section 10, various measures can be taken such as forming the core 10c in a tapered shape and forming the plunger 13 in an inverted tapered shape, but these are well known. Therefore, the explanation will be omitted. In any case, according to this embodiment, in FIG. 6(a) -
Even if the 5t-I characteristic is not necessarily linear as shown by the dotted chain line, the desired Pc-I characteristic or Qf-I characteristic can be obtained by appropriately changing the shape of the opening 21c as described above. Therefore, there is no need to take complicated measures to obtain linear characteristics for the solenoid section 10.

As described above, the spool 6 slides in the cylinder hole 2a according to the current applied to the solenoid coil 12, and the spool 6 slides through the cylinder hole 2a.
and the fluid chamber 9 of the flow path formed by the gap between the end portion of the land portion 7 and the end surface 7b of the land portion 7 and the land portion 7 and the opening portion 21c.
The opening area increases or decreases. That is, when the current applied to the solenoid coil 12 increases, the gap and opening 2
1c is shielded by the land portion 7 in order from the stopper 2c side, and the opening area of the flow path to the fluid chamber 9 is reduced. When the end surface 7b of the runt portion 7 exceeds the end of the opening 21c on the core 10c side, communication with the supply port 3 is cut off, and the pressure inside the fluid chamber 9 becomes approximately atmospheric pressure. Therefore, the flow rate and pressure of the fluid supplied from the control port 4 to other control devices, that is, the control pressure, are controlled by the current flow to the solenoid coil 12, as shown in FIGS. 5(c) and 6(c), respectively. decreases as .

Next, when the current applied to the solenoid coil 12 decreases, the attraction force of the plunger 13 by the core 10c decreases, so that the plunger 13 and, in turn, the spool 6 move toward the plug body 2c, and the fluid chamber 9 in the gap and flow path is moved. The opening area increases, and the flow rate and control pressure of fluid supplied to the control port 4 increase as shown in FIGS. 5(C) and 6(C). When the opening area becomes sufficiently larger than the opening area of the discharge port 5, the control pressure of the control port 4 becomes approximately equal to the supply pressure of the supply port 3.

In other words, the opening area of the opening 21c is expressed by the above-mentioned formula P c
= K − P s / (1+ (A o / A
s) In 2), the end of the cylinder 21 and the end surface 7 of the land portion 7 are calculated from the opening area As that satisfies P
b is set to be equal to or larger than the value obtained by subtracting the area of the gap between

The fluid control valve of this example is shown in Fig. 5(e) and Fig. 6(c).
It has the characteristics shown in , and is applied to various devices such as internal combustion engines as a proportional electromagnetic pressure control valve.

For example, it is disposed in a hydraulic control circuit of an electronically controlled automatic transmission and is used for various controls. Alternatively, if the shape of the opening 21c is set so that the characteristics shown in FIG. 5(c) and the characteristics shown in FIG. It is also possible to use it as a valve.

7 to 9 show other embodiments of the opening 21c formed in the cylindrical body 21 of FIG. 1, which constitute another embodiment of the fluid control valve of the present invention. That is, according to the present invention, as explained in the embodiment of FIG.
By changing the shape of 1c, fluid control valves with various control pressure-current characteristics or flow rate-current characteristics can be constructed.

For example, as shown in FIG. 7, the land portion 7 and the annular groove 2b
The opening area for the fluid chamber 9 of the flow path formed by the gap between the land portion 7 and the opening portion 121C is maximum at the initial position of the spool 6, but gradually decreases as the spool 6 slides. After the land portion 7 reaches the cylindrical body 121, it is set to decrease rapidly, and the plunger 13
It is set so that it becomes the minimum at the position where it is attracted to 0c.

In the embodiments shown in FIGS. 8 and 9, the cylindrical body 21 and the second cylindrical body 22 shown in FIG. 321c
is formed.

Therefore, in these embodiments, the gap described above in the embodiments of FIGS. 1 and 7 does not exist.

In FIG. 8, the opening 221C is set so that the opening area of the flow path to the fluid chamber 9 gradually increases as the spool 6 slides, and increases rapidly after reaching a predetermined distance. In FIG. 9, the opening 321C has an elliptical shape, and is set so that the opening area of the flow path to the fluid chamber 9 is maximized at an intermediate position of the sliding distance of the spool 6.

FIG. 10 shows still another embodiment of the fluid control valve of the present invention, in which the supply pressure Ps is applied to the control chamber 41 through a throttle 31 having an opening area As fixed on the upstream side of the fluid control valve 100.
The fluid control valve 100 is configured to introduce the fluid into the fluid control valve 100 and discharge it to the fluid control valve 100. Fluid control valve 100 is connected to supply port 3. of the fluid control valve of FIG. A first port 51 and a second port 52 are provided in place of the control port 4 and discharge port 5, and the rest of the configuration is the same as that in FIG. 1. This first port 51 corresponds to a discharge port when viewed from the control room 41 side,
The fluid in the control chamber 41 is introduced into the fluid N9 through the first port 51 through the annular groove 2b and the opening 21c of the cylindrical body 21, and is discharged through the second port 52. Therefore,
The fluid on the discharge side of the control chamber 41 is controlled according to the opening area of the flow path with respect to the fluid chamber 9, which increases or decreases as the spool 6 slides. This embodiment is substantially the same as the embodiment shown in the figure, and can ensure the characteristics shown in FIGS. 5 and 6 regarding the fluid in the control chamber 41.

In each of the above embodiments, the discharge port 5 and the second port 52 are under atmospheric pressure, and the end face 7a side of the land portion 7 and the core 10c side of the plunger 13 are communicated with the atmosphere, but for example, the control fluid is oil In this case, they may be connected together to an oil reservoir via a drain passage, or may be configured to be buried in oil under atmospheric pressure. Further, in each of the above embodiments, an electromagnetic solenoid is used to configure the proportional electromagnetic control valve, but the spool 6 may be driven by, for example, a step motor and controlled using the number of steps as a parameter. Alternatively, a diaphragm actuator can be used as the drive device for the spool 6,
For example, it is also possible to use the intake pipe negative pressure of an internal combustion engine as the driving source.

[Effects of the Invention] Since the present invention is configured as described above, it has the following effects.

That is, according to the fluid control valve of the present invention, an opening having a predetermined shape is formed in the cylinder so that the sliding stroke of the spool and the opening area into the cylinder can be set in a predetermined relationship.
By simply forming an opening in a predetermined shape according to the relationship between the current flowing to the drive source to be connected and the sliding stroke of the spool, it is possible to ensure linear fluid pressure characteristics or flow rate characteristics with respect to the current flowing. . Therefore, there is no fear that the above-mentioned fluid characteristics will fluctuate due to rotational vibration of the fluid control valve, and stable fluid control can be performed even when installed in an automobile.

In particular, when a cylindrical body is fitted into a cylinder and its opening is shaped so that the opening area changes non-linearly along the axial direction, it is possible to obtain linear fluid pressure characteristics with respect to the sliding stroke of the spool. .

Further, in a fluid control valve in which a drive source is attached in the axial direction of the cylinder and a discharge port is bored in the radial direction of the cylinder, the entire device is compact and can be easily attached to the fluid passage.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of one embodiment of the fluid control valve of the present invention, FIG. 2 is a partially enlarged cross-sectional view of the cylinder, FIG. 3 is a partial perspective view of the land portion of the spool, and FIG. is an explanatory diagram showing the operating principle, and Fig. 5 is a diagram showing the operating characteristics.
Diagram (a) shows the spool stroke (s B and current (I)
Figure 5(b) is a characteristic diagram of the opening area (AS) of the opening into the cylinder, the flow 'M (Qf), and the spool stroke (St), and Figure 5(c) is the characteristic diagram of the flow rate ( Qf) and current N), FIG. 6 is a diagram explaining another operating characteristic of the fluid control valve according to the above embodiment, and FIG. 6(a)
is a characteristic diagram of the spool stroke (St) and current N),
Figure 6(b) shows the opening area (A) of the opening into the cylinder.
s), control pressure (Pc) and spool stroke (sB
and a characteristic diagram of control pressure (PC) and spool stroke (st), FIG. 6(c) is a characteristic diagram of control pressure (Pc) and current (I), and FIG. 7 is a characteristic diagram of the fluid control valve of the present invention. FIG. 8 is a partial sectional view showing another embodiment of the invention, FIG. 9 is a partial sectional view showing another embodiment of the same, and FIG. FIG. 3 is an overall configuration diagram showing another example of a control valve. 1...Valve part, 2...Cylinder. 2a... cylinder hole, 2b... annular groove. 2c... Plug body, 3... Supply port. 4...Control port, 5...Discharge port. 6...Spool, 7...Land portion. 7a, 7b... end face, 8... land portion. 9... Fluid chamber, 10... Solenoid section (drive source) 10c... Core, 12... Solenoid coil. 13...Plunger, 16...Compression spring 21 121.221,321...Cylinder body. 21c, 121c, 221c, 321c...opening 2
2... Second cylindrical body, 31... Diaphragm, 41... Control chamber 31... Diaphragm, 41... Control chamber. 51...first port, 52...second port. 100...Fluid control valve patent applicant Aisan Kogyo Co., Ltd.

Claims (3)

[Claims] (1) A cylinder, and a spool having at least one land that slides inside the cylinder, and the land opens and closes a port bored in the radial direction of the cylinder in response to sliding. In a fluid control valve for controlling supply and discharge of fluid into and out of a cylinder, the cylinder is provided with an opening having a predetermined shape that communicates with the port and opens into the cylinder, and the opening part communicates with the port and opens into the cylinder. A fluid characterized in that a land portion is arranged so as to overlap the opening portion, and the fluid is supplied and discharged into the cylinder through a flow path formed by at least the opening portion and the land portion. control valve. (2) A cylinder, and a spool having at least one land that slides inside the cylinder, and the land opens and closes a port bored in the radial direction of the cylinder in response to sliding. In a fluid control valve that controls supply and discharge of fluid into and out of a cylinder, an annular groove that communicates with the port and opens into the cylinder is formed on the inner surface of the cylinder, and the opening area into the cylinder extends at least in the axial direction. A cylindrical body having an opening whose shape changes non-linearly along the cylinder is fitted into the cylinder such that the opening faces the annular groove, and the spool is slidably housed in the cylindrical body. At the same time, the land portion is arranged so as to overlap with the opening portion according to the sliding of the spool, and the land portion is arranged to overlap with the opening portion, and the land portion is arranged to be connected to the inside of the cylinder through a flow path formed by at least the opening portion and the land portion. A fluid control valve that supplies and discharges the fluid. (3) A driving source for driving the spool is installed in the axial direction of the cylinder, and a discharge port communicating with the inside of the cylinder is bored in the radial direction of the cylinder. Item 2. The fluid control valve according to item 2.