JP4702657B2 - Fluid pressure control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid pressure control device capable of controlling the pressure of a fluid flowing through a fluid passage by displacing a spool valve under the drive action of a linear electromagnetic actuator.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a reciprocating motion device that moves an object electromagnetically, an electromagnetic valve that energizes an exciting coil and imparts a linear motion to a movable iron core by its magnetic force is known. Although this solenoid valve has a simple structure, it contains an iron core inside the excitation coil, so it is difficult to improve the electrical response, and the excitation coil is not energized. However, since thrust cannot be generated, there is a problem that its use is limited.
[0003]
Therefore, the applicant of the present invention provides a movable magnet type electromagnetic actuator that is capable of generating a steady-state thrust in a short time without applying a large voltage at the time of power generation, unlike a conventional electromagnetic solenoid. (See Japanese Patent Application No. 2000-217304).
[0004]
[Problems to be solved by the invention]
The present invention has been made in connection with the above proposal, and controls the pressure of the pressure fluid derived from the output port with high accuracy by improving the responsiveness of the valve switching unit under the driving action of the linear electromagnetic actuator. An object of the present invention is to provide a fluid pressure control device capable of performing the above.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises an annular excitation coil, a yoke that surrounds the periphery of the excitation coil, and pole teeth are disposed opposite to the center hole or both ends of the excitation coil, A drive unit having a cylindrical permanent magnet that is movably disposed in the axial direction inside or outside the central hole of the exciting coil and is magnetized in the radial direction; and a shaft that is integrally displaced with the permanent magnet;
Under the driving action of the drive unit, a valve switching unit that switches a communication state between a plurality of holes formed in the sleeve by displacing the spool valve integrally with the shaft;
A block body connected to the valve switching portion and formed with passages respectively communicating with the plurality of holes;
It is characterized by providing.
[0006]
In this case, a displacement sensor for detecting the displacement amount of the spool valve and a pressure sensor for detecting the pressure of the pressure fluid derived from the passage communicating with the output port may be selectively provided, or both may be provided. .
[0007]
In addition, a hollow portion penetrating the shaft may be formed, and the shaft and the spool valve may be connected approximately coaxially by a wire member disposed in the hollow portion.
[0008]
According to the present invention, by disposing a linear electromagnetic actuator as the drive unit, the displacement amount (stroke amount) of the drive unit can be set larger than that of a conventionally known electromagnetic valve, and the drive unit The thrust does not decrease corresponding to the amount of displacement, and a constant thrust can be maintained at an arbitrary position.
[0009]
As a result, the opening amount of the spool valve of the valve switching unit can be set large and with high accuracy, and the controllability can be enhanced by improving the responsiveness of the spool valve.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the fluid pressure control device according to the present invention will be described below and described in detail with reference to the accompanying drawings.
[0011]
In FIG. 1, reference numeral 10 indicates a fluid pressure control device according to an embodiment of the present invention.
[0012]
The fluid pressure control device 10 includes a base portion 12 and a casing 14 having a rectangular cross section attached to the base portion 12. The internal space of the casing 14 is integrally connected to the drive unit 16 made of a linear electromagnetic actuator and the drive unit 16 coaxially, and communicates with each other under the displacement action of the spool valve 18 disposed therein. It is shown from the port block (block body) 24 formed with a plurality of passages 22a to 22c communicating with each port (described later) of the valve switching unit 20, and the port block 24. A control unit 28 is provided that detects a fluid pressure led to an external fluid device that does not perform and performs feedback control by introducing the detection signal.
[0013]
The drive unit 16 is spaced apart by a predetermined distance along the axial direction, and supports the hollow shaft 32 via the substantially cylindrical first and second bearing members 30a, 30b so as to be displaceable along the axial direction. A first housing 34a and a second housing 34b, an annular coil (excitation coil) 36 disposed between the first housing 34a and the second housing 34b and wound around a bobbin (not shown); A yoke 40 having a pair of pole teeth 38a, 38b opposed to each other on both ends along the axial direction of the center hole of the coil 36 and surrounding the periphery, and the center in the center hole of the coil 36 And a cylindrical permanent magnet 42 that is movably disposed along the axial direction of the hole and is magnetized along the radial direction (see FIG. 6).
[0014]
The yoke 40 is mounted flush with the outer peripheral surfaces of the first and second housings 34a, 34b and is connected to one end side along the axial direction of the outer yoke 44, and an outer yoke 44 serving as an outer peripheral casing. An L-shaped first pole tooth 38a, an L-shaped second pole tooth 38b connected to the other end side of the outer yoke 44 along the axial direction, and spaced apart from the first pole tooth 38a by a predetermined distance; Have
[0015]
The coil 36 and the yoke 40 wound around the bobbin are integrally assembled as a coil assembly, and are fixed to the first and second housings 34a and 34b via a plurality of screw members, respectively.
[0016]
The first and second pole teeth 38 a and 38 b are disposed on both ends of the center hole of the coil 36, but may be disposed opposite to both ends on the outside of the coil 36. In this case, the permanent magnet 42 may be arranged outside the coil 36 so as to be movable along the axial direction of the coil 36.
[0017]
A holder 46 that holds a permanent magnet 42 is connected to the outer peripheral surface of the shaft 32, and a back yoke 48 is provided in an annular space inside the permanent magnet 42.
[0018]
The shaft 32 is formed with a hollow portion 50 penetrating therethrough. One end portion of the hollow portion 50 is locked to the end portion of the shaft 32 and the other end portion is connected to a spool valve 18 described later. Is disposed. The holder 46 and the permanent magnet 42 function as a mover that is displaced integrally with the shaft 32.
[0019]
The permanent magnet 42 is preferably set to a length extending between a pair of pole teeth 38a and 38b, and when one end of the permanent magnet 42 reaches one moving end in the central hole of the coil 36. In addition, the other end of the permanent magnet 42 may be set close to the opposite pole tooth 38a (38b), or a part thereof may have a length facing each other. Further, the back yoke 48 is not necessarily provided, but it is desirable to set the length so that most of the permanent magnet 42 can cover any moving position.
[0020]
As shown in FIG. 3, the valve switching unit 20 includes a cylindrical valve body 54 that is coaxially connected to one end of the first housing 34 a, and an annular recess 56 formed in the center, and the valve chamber of the valve body 54. 58, and a first to third hole portion 60a formed so as to surround the spool valve 18 and communicated with respective passages 22a to 22c of the port block 24 described later. ˜60c.
[0021]
Between the sleeve 62 and the valve body 54, seal members 64 that respectively surround the first to third holes 60a to 60c are mounted via annular grooves. The valve body 54 is formed with a breathing port 68 for supplying and discharging air in the valve chamber 58 via passages 66 a and 66 b communicating with the valve chamber 58.
[0022]
One end portion of the spool valve 18 is engaged with an end portion of the wire member 52 via a locking member 70, and a sensor scale 74 constituting a displacement sensor 72 is connected to the other end portion. Thus, by connecting the spool valve 18 and the shaft 32 by the wire member 52, an error (coaxial deviation) between the axis of the spool valve 18 and the axis of the shaft 32 is absorbed by the wire member 52. The coaxiality of the axis line and the axis line of the shaft 32 can be substantially matched.
[0023]
At the connection part of the valve body 54 to the port block 24, a pressure fluid supply port 76a communicating with the first hole 60a of the sleeve 62 and an output port 76b communicating with the second hole 60b adjacent to the first hole 60a. And a pressure fluid discharge port 76c communicating with the third hole 60c adjacent to the second hole 60b, respectively, and the connecting portion is a gasket 78 interposed between the valve body 54 and the port block 24. (See FIG. 1).
[0024]
The port block 24 includes a first passage 22a that communicates with the pressure fluid supply port 76a, a second passage 22b that communicates with the output port 76b, and a third passage 22c that communicates with the pressure fluid discharge port 76c. It is formed. A two-port solenoid valve 80 functioning as a switching valve is connected to the output port 76b, and the pressure adjusted to a desired pressure from the output port 76b to an external fluid device (not shown) under the switching action of the solenoid valve 80. A fluid is derived.
[0025]
On one side of the valve body 54, as shown in FIG. 2, a pressure sensor 82 for detecting the pressure value of the pressure fluid led out from the output port 76b through the second passage 22b of the port block 24 has a screw member. The detection signal from the pressure sensor 82 is fixed to the base unit 12 and introduced into the control unit 28 including the circuit board 84.
[0026]
Further, at the end of the valve body 54, as shown in FIG. 1, the amount of displacement of the spool valve 18 is detected by detecting the amount of displacement of the sensor scale 74 that is displaced integrally with the spool valve 18 by the sensor head 86. A displacement sensor 72 for deriving a detection signal corresponding to the above to the control unit 28 is connected.
[0027]
The fluid pressure control device according to the embodiment of the present invention is basically configured as described above. Next, the operation and effect of the fluid pressure control device will be described.
[0028]
As shown in FIG. 3, the state where the pressure fluid discharge port 76c and the output port 76b communicate with each other by the annular recess 56 of the spool valve 18 will be described as an initial position. In the initial position, the pressure fluid supply port 76a and the output port 76b are not in communication, and no pressure fluid is supplied to an external fluid device (not shown).
[0029]
First, the principle of operation of the linear electromagnetic actuator that functions as the drive unit 16 will be described with reference to FIG.
[0030]
For example, when the permanent magnet 42 is magnetized in the radial direction so that the outer side is the S pole and the inner side is the N pole, and the coil 36 is energized in the direction indicated by the symbol in FIG. Depending on the direction of the current, one pole tooth 38a of the yoke 40 becomes the S pole, and the other pole tooth 38b becomes the S pole. In this case, an attractive force is generated between the N pole generated on the pole teeth 38b of the yoke 40 and the S pole on the outer surface of the permanent magnet 42 opposed thereto, while the S pole generated on the pole teeth 38a of the yoke 40 Since repulsive force acts between the S poles of the permanent magnets 42, these forces become axial thrusts acting on the permanent magnets 42, and the permanent magnets 42 pass through the center hole of the coil 36 in the axial direction (see FIG. 6) (in the direction of arrow B).
[0031]
Further, when the coil 36 is energized in the reverse direction, the N pole and the S pole generated in the pole teeth 38a and 38b of the yoke 40 are opposite to those described above. Therefore, the thrust acting on the permanent magnet 42 is also in the reverse direction (FIG. 6). Arrow A direction), and the permanent magnet 42 moves in the opposite direction.
[0032]
In a state where the permanent magnet 42 is moved to one end or the other end in the central hole of the coil 36 by energizing the coil 36, even if the energization to the coil 36 is released, the permanent magnet 42 is It is held at the moving position. Therefore, an object to be driven (for example, the shaft 32) is connected to the permanent magnet 42 and the permanent magnet 42 is driven by energizing the coil 36 in either forward or reverse direction. The permanent magnet 42 can be driven and positioned at two positions, which are the movement positions of the permanent magnet 42.
[0033]
Further, when a cylindrical back yoke 48 along the permanent magnet 42 is disposed inside the cylindrical permanent magnet 42, the one pole tooth 38 a in the yoke 40 reaches the inside of the back yoke 48 through the permanent magnet 42. Since the magnetic path reaching the other pole tooth 38b again through the permanent magnet 42 is formed, the magnetic resistance can be reduced and the thrust and magnetic attraction force of the permanent magnet 42 can be further increased. As described above, the thrust and the magnetic attractive force can be adjusted depending on how the back yoke 48 is arranged.
[0034]
Thus, in the initial position, the shaft 32 is displaced along the arrow B direction integrally with the permanent magnet 42 functioning as a mover under the drive action of the linear electromagnetic actuator which is the drive unit 16, thereby the shaft The displacement is transmitted to the spool valve 18 through the wire member 52 disposed in the hollow portion 50 of the 32. Accordingly, the spool valve 18 is displaced rightward in FIG. 3, and the output port 76b and the pressure fluid supply port 76a communicate with each other via the annular recess 56 of the spool valve 18, and the pressure fluid supply port 76a The supplied pressure fluid is led out from the output port 76b (see FIG. 4).
[0035]
In this case, when the spool valve 18 is slidably displaced along the sleeve 62 fixed to the valve body 54 under the driving action of the drive unit 16, the sleeve 62 is formed in the sleeve 62 depending on the positional relationship between the sleeve 62 and the spool valve 18. The opening amount of the 1st hole part 60a and the 3rd hole part 60c which were made changes. Accordingly, by setting the opening width of the first hole portion 60a communicating with the pressure fluid supply port 76a and the opening width of the third hole portion 60c communicating with the pressure fluid discharge port 76c to a predetermined width, output is achieved. The pressure of the pressure fluid led out from the port 76b can be adjusted to a desired pressure (see FIG. 5).
[0036]
In this case, the pressure sensor 82 detects the pressure of the pressure fluid led out from the output port 76 b to the external fluid device side, and the displacement sensor 72 detects the displacement amount of the spool valve 18. A detection signal corresponding to the pressure value detected by the pressure sensor 82 and a detection signal corresponding to the amount of displacement detected by the displacement sensor 72 are respectively introduced into the control unit 28, and the detection signal and a preset setting are set. Each value is compared, and a command signal is derived from the control unit 28 to the drive unit 16 so that the deviation becomes zero, and feedback control is performed (see FIG. 7).
[0037]
Note that which of the displacement sensor 72 and the pressure sensor 82 is set to be main is arbitrarily set by the user. For example, the displacement sensor 72 may be secondarily used as a limiter in which a desired displacement width is set, and the pressure sensor 82 may be primarily used.
[0038]
In the present embodiment, by using a linear electromagnetic actuator as the drive unit 16, the displacement amount (stroke amount) of the drive unit 16 can be set larger than that of a conventionally known electromagnetic valve, and driving is performed. The thrust does not decrease corresponding to the amount of displacement of the portion 16, and a constant thrust can be maintained at an arbitrary position.
[0039]
Therefore, in the present embodiment, the opening amount of the spool valve 18 of the valve switching unit 20 can be set large and with high accuracy, and the responsiveness of the spool valve 18 can be improved to improve the controllability.
[0040]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0041]
That is, the displacement amount (stroke amount) of the drive unit can be set larger than that of conventionally known solenoid valves, and the thrust does not decrease corresponding to the displacement amount of the drive unit. By maintaining a constant thrust at the position, the responsiveness of the valve switching unit can be improved, and the pressure of the pressure fluid derived from the output port can be controlled with high accuracy.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a partial vertical cross section of a fluid pressure control device according to an embodiment of the present invention.
FIG. 2 is a plan view of the fluid pressure control device shown in FIG.
FIG. 3 is an enlarged vertical cross-sectional view in which a part of a valve switching unit is omitted.
4 is an operation explanatory view showing a state in which the spool valve is displaced from the state of FIG. 3; FIG.
FIG. 5 is a schematic circuit configuration diagram of the fluid pressure control device shown in FIG. 1;
FIG. 6 is a partially omitted enlarged longitudinal sectional view showing an operation principle of a linear electromagnetic actuator as a driving unit.
FIG. 7 is an explanatory diagram of feedback control by a displacement sensor and a pressure sensor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Fluid pressure control device 16 ... Drive part 18 ... Spool valve 20 ... Valve switching part 22a-22c, 66a, 66b ... Passage 24 ... Port block 28 ... Control part 32 ... Shaft 36 ... Coil 38a, 38b ... Polar tooth 40 ... Yoke 42 ... Permanent magnet 44 ... Outer yoke 48 ... Back yoke 50 ... Hollow portion 52 ... Wire member 54 ... Valve body 56 ... Annular recess 58 ... Valve chamber 60a-60c ... Hole 62 ... Sleeve 72 ... Displacement sensor 76a ... Pressure fluid supply port 76b ... Output port 76c ... Pressure fluid discharge port 82 ... Pressure sensor 84 ... Circuit board

Claims (4)

An annular excitation coil, a yoke surrounding the excitation coil and having pole teeth opposed to both ends of the center hole or outside of the excitation coil, and along the axial direction in or outside the center hole of the excitation coil A drive unit having a cylindrical permanent magnet that is movably arranged and magnetized in the radial direction, and a shaft that is integrally displaced with the permanent magnet;
Under the driving action of the drive unit, a valve switching unit that switches a communication state between a plurality of holes formed in the sleeve by displacing the spool valve integrally with the shaft;
A block body connected to the valve switching portion and formed with passages respectively communicating with the plurality of holes;
With
The fluid pressure control device according to claim 1, wherein the shaft has a hollow portion that penetrates, and the shaft and the spool valve are connected substantially coaxially by a wire member disposed in the hollow portion. An annular excitation coil, a yoke surrounding the excitation coil and having pole teeth opposed to both ends of the center hole or outside of the excitation coil, and along the axial direction in or outside the center hole of the excitation coil A drive unit having a cylindrical permanent magnet that is movably arranged and magnetized in the radial direction, and a shaft that is integrally displaced with the permanent magnet;
Under the driving action of the drive unit, a valve switching unit that switches a communication state between a plurality of holes formed in the sleeve by displacing the spool valve integrally with the shaft;
A block body connected to the valve switching portion and formed with passages respectively communicating with the plurality of holes;
With
The drive unit has the yoke disposed outside the permanent magnet, the yoke has two different magnetic poles via the pole teeth , and the shaft has a hollow portion that passes therethrough. The valve is connected substantially coaxially by a wire member disposed in the hollow portion . The apparatus according to claim 1 or 2,
A fluid pressure control device comprising a displacement sensor for detecting a displacement amount of the spool valve. The apparatus according to claim 1 or 2,
A fluid pressure control device comprising a pressure sensor for detecting a pressure of a pressure fluid led out from a passage communicating with an output port.

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