JP2002355593A - Apparatus and method for discharging fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method for discharging a fluid, by which the gap between a shaft and a housing is controlled with high precision and further the discharge quantity of the fluid is controlled with high precision. SOLUTION: The gap is controlled by controlling current so that the actual current flowing through an electromagnetic striction element is equal to the target current flowing through the electromagnetic striction element based on the difference between the actual position in the axial direction of shaft 6 and the target position in the axial direction of the shaft, which is the target value of the gap (δ).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention can be used in production processes in the fields of electronic parts, home electric appliances, etc., and includes adhesives, cream solders, phosphors, greases, paints,
TECHNICAL FIELD The present invention relates to a fluid ejection device and a fluid ejection method for ejecting and shutting off various liquids such as hot melts, medicines, and foods in a fixed amount.

[0002]

2. Description of the Related Art Liquid ejecting apparatuses (dispensers) have been used in various fields, but with the recent demand for miniaturization and high recording density of electronic components, a minute amount of fluid material can be dispensed with high precision. There is a demand for a technique for stably controlling discharge.

For example, a surface mounting technology (Surface)
For example, in the field of Mount Technology, the problems of dispensers in the trends of high-speed mounting, miniaturization, high-density, high-quality, and unmanned can be summarized as follows. And minimizing the amount of one discharge, shortening the discharge time, that is, being able to cut off and start high-speed discharge, and being able to cope with high-viscosity powder fluid.

Conventionally, dispensers of an air pulse type, a screw groove type, a micro pump type using an electromagnetic strain element, and the like have been put to practical use in order to discharge a very small amount of liquid.

[0005]

Among the above-mentioned prior arts, an air pulse type dispenser as shown in FIG. 6 is widely used.
93.25, No. 7, etc. ". The dispenser according to this method causes a constant amount of air supplied from a constant pressure source to be applied to the container 200 (cylinder) in a pulsed manner, and causes a constant amount of liquid corresponding to a rise in the pressure in the cylinder 200 to be discharged from the nozzle 201. Things.

However, the air pulse type dispenser has a drawback that the response is poor.

[0007] This disadvantage is due to the compressibility of the air 202 sealed in the cylinder and the nozzle resistance when passing the air pulse through a narrow gap. That is, in the case of the air pulse method, the cylinder volume: C and the nozzle resistance:
Time constant of the fluid circuit determined by R: T = RC is large, and for example, 0.07 to 0.1
A time delay of about a second must be expected.

In order to eliminate the drawbacks of the air pulse method, a needle valve is provided at the inlet of the discharge nozzle.
A dispenser that opens and closes a discharge port by moving a small-diameter spool constituting the needle valve at high speed in an axial direction has been put to practical use.

However, in this case, when the fluid is shut off, the gap between the relatively moving members becomes zero, and the powder having an average particle diameter of several to several tens of microns is mechanically pressed and destroyed. Due to various inconveniences that occur as a result, it is often difficult to apply the method to application of an adhesive material, a conductive paste, or a phosphor mixed with powder.

[0010] For the same purpose, a screw groove type dispenser which is a viscous pump has already been put to practical use. In the case of the thread groove type, a pump characteristic that is hardly dependent on the nozzle resistance can be selected, so that a preferable result can be obtained in the case of continuous application. Therefore, in the conventional screw groove type, (1) an electromagnetic clutch is interposed between the motor and the pump shaft to turn on and off the discharge.
At the time of FF, this electromagnetic clutch is connected or released. Or (2) using a DC servomotor,
Rapid rotation start or rapid stop is performed.

However, since the response is determined by the time constant of the mechanical system in any of the above cases, the high-speed intermittent operation is limited. In addition, the responsiveness is better than that of the air pulse method, but the limit is about 0.05 seconds even in the shortest time.

In addition, since there are many uncertainties in the rotation characteristics of the pump shaft during transient response (at the start and stop of rotation), it is difficult to strictly control the flow rate, and the coating accuracy is limited.

In order to discharge a very small amount of fluid, a micropump using a laminated piezoelectric element has been developed. For this micro pump, a mechanical passive discharge valve or suction valve is usually used.

However, such a valve is constituted by a spring and a ball, and the above-mentioned pump, which opens and closes a discharge valve and a suction valve by a pressure difference, has a high viscosity rheological fluid of tens of thousands to hundreds of thousands centipoise of poor fluidity. It is extremely difficult to perform intermittent discharge with high flow rate accuracy and high speed (0.1 seconds or less).

Now, in the field of circuit formation, which is becoming increasingly more precise and ultra-fine in recent years, or in the fields of forming electrodes and ribs for picture tubes such as PDPs and CRTs, applying sealing materials for liquid crystal panels, and manufacturing processes for optical discs and the like. There are strong demands for fine coating technology as follows.

After the continuous application, the application can be stopped quickly, and the continuous application can be started rapidly after a short time. For that purpose, it is ideal that the flow rate can be controlled, for example, on the order of 0.01 second.

Able to handle powder fluid. For example, there should be no problems such as powder compression, breakage, and clogging of the flow channel due to mechanical interruption of the flow channel.

In order to respond to various recent demands related to the above-mentioned minute flow rate application of a high-viscosity fluid / powder fluid, the present inventors provide a relative linear motion and a rotational motion between a piston and a cylinder. In addition, an application device that provides a fluid transport device by rotating motion, changes the relative gap between the fixed side and the rotating side by using linear motion, and controls the discharge amount of fluid, “Fluid supply device and fluid supply method” (Japanese Patent Application 2000)
188899).

The present invention is a further improvement of the above proposal and provides a fluid discharge device and a fluid discharge method capable of controlling a gap between a shaft and a housing with high precision and controlling a fluid discharge amount with high precision. It is to provide.

[0020]

In order to achieve the above object, the present invention is configured as follows.

According to the first aspect of the present invention, an electromagnetic distortion element having one movable end and the other fixed end, a housing for accommodating the electromagnetic distortion element, and the electromagnetic distortion element with respect to the housing. A supporting device for supporting the device so as to be relatively rotatable and movable in the axial direction, a rotating device for rotating the electromagnetic strain element, a shaft fastened to a movable end of the electromagnetic strain element, and the shaft and the housing. A pump chamber formed of: a suction port and a discharge port of a fluid that communicates with the outside of the pump chamber and the pump chamber; a pumping device that pumps the fluid flowing into the pump chamber to a discharge port side; In order to increase or decrease the fluid resistance between the pump chamber and the discharge port, a fluid discharge device that controls a discharge amount of the fluid by changing a gap between the shaft and the housing by driving the electromagnetic distortion element, Up A plurality of displacement sensors for measuring the gap between the shaft and the housing, and an average value of the measured values of the gap measured by the plurality of displacement sensors is determined, and the average value is calculated in the axial direction of the shaft. A converter for converting the position into a position, position command generating means for outputting a target value of the gap between the shaft and the housing as a target position in the axial direction of the shaft, and the target position and the output from the converter. A position controller that outputs a target drive signal of the electromagnetic distortion element based on a difference from an actual position, a drive signal detector that detects an actual drive signal of the electromagnetic distortion element, and the actual drive signal is the target drive signal. A fluid ejection device is provided, wherein the clearance between the shaft and the housing can be controlled by a drive signal controller that controls drive signals to be equal.

According to a second aspect of the present invention, the converter includes the same number of amplifiers as the displacement sensors for converting the outputs of the plurality of displacement sensors into data indicating the axial position of the shaft, An adder for adding data output from the plurality of amplifiers, and an amplifier for multiplying the output from the adder by 1 / (the number of the amplifiers) and outputting an average value of the outputs of the plurality of amplifiers The fluid discharge device according to the first aspect, comprising:

According to the third aspect of the present invention, the magnetostrictive element having the movable end on the side to which the shaft is fastened and the fixed end on the other side is rotated relative to the housing housing the electrostrictive element. And by moving in the axial direction, to the discharge port side of the fluid that communicates with the outside of the pump chamber formed by the shaft and the housing, to pump the fluid flowing into the pump chamber, In order to increase or decrease the fluid resistance between the pump chamber and the discharge port, a fluid discharge method for controlling a discharge amount of the fluid by changing a gap between the shaft and the housing by driving the electromagnetic distortion element. Measuring the gap between the shaft and the housing with a plurality of displacement sensors, determining an average value of the measured values of the gap measured by the plurality of displacement sensors, and calculating the average value in the axial direction of the shaft. The target position of the gap between the shaft and the housing is output as a target position in the axial direction of the shaft, and the electromagnetic distortion is calculated based on a difference between the target position and the converted actual position. By outputting a target drive signal of the element, detecting an actual drive signal of the electromagnetic distortion element, and controlling the drive signal so that the actual drive signal is equal to the target drive signal, the distance between the shaft and the housing is reduced. A fluid discharge method is provided wherein the gap is controlled.

According to a fourth aspect of the present invention, when an average value of the measured values of the gap measured by the plurality of displacement sensors is determined, and the average value is converted into an actual position in the axial direction of the shaft. The outputs of the plurality of displacement sensors are converted to data indicating the axial position of the shaft by the same number of amplifiers as the displacement sensors, and the data output from the plurality of amplifiers are added. The fluid discharge method according to the third aspect, wherein the output value is 1 / the number of the amplifiers, and the average value of the outputs of the plurality of amplifiers is output.

[0025]

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

An example in which a fluid ejection device and a fluid ejection method according to an embodiment of the present invention are applied to a dispenser for surface mounting electronic components will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a first actuator. In this embodiment, as an example of an axial driving device,
In order to supply a high-viscosity fluid intermittently at a high speed with a very small amount and high precision, a giant magnetostrictive element is used which has high positioning accuracy, high responsiveness, and a large generated load. In the following description, the movable end of the electromagnetic distortion element is defined as the front side, and the other fixed end of the electromagnetic distortion element is defined as the rear side.

Reference numeral 2 denotes a central axis driven by the first actuator 1. The first actuator 1 is housed in a housing 3. A front main shaft 5 concentrically connected to the lower end of the center shaft 2 is supported by a housing 4 fixed to the lower end of the housing 3 so as to be rotatable and slightly movable in the axial direction. Reference numeral 6 denotes a piston (shaft) which is detachably attached to the front-side main shaft 5 and a plurality of bolts 7 and which is housed in a cylinder 8 fixed to the lower end of the housing 4, and 9 is formed on a relative movement surface between the piston 6 and the cylinder 8. Radial grooves for pumping fluid to the discharge side
Reference numeral 10 denotes a fluid seal disposed between the vicinity of the upper end of the piston 6 and the cylinder 8.

Between the piston 9 and the cylinder 8, there is formed a pump chamber 11 for obtaining a pumping action by the relative rotation of the screw groove 9 and its opposing surface. Further, a suction hole 12 communicating with the pump chamber 11 is formed in the cylinder 8. Reference numeral 13 denotes a discharge nozzle mounted on the lower end of the cylinder 8, and reference numeral 14 denotes a discharge unit including the discharge nozzle 13 described later.

Reference numeral 15 denotes a second actuator which gives a relative rotational movement between the piston 6 and the cylinder 8. The motor rotor 16 is fixed to the rear main shaft 17, and the motor stator 18 is housed in a housing 19. The rear-side main shaft 17 is integrally and concentrically connected to the upper end of the center shaft 2.

Reference numeral 20 denotes a cylindrical giant magnetostrictive rod composed of giant magnetostrictive elements, and reference numeral 21 denotes a magnetic field coil for applying a magnetic field in the longitudinal direction of the giant magnetostrictive rod 20. Reference numerals 22 and 23 denote upper and lower permanent magnets for applying a bias magnetic field to the giant magnetostrictive rod 20, which are arranged so as to grip and support the giant magnetostrictive rod 20 in the middle. The upper and lower permanent magnets 22 and 23 apply a magnetic field to the giant magnetostrictive rod 20 in advance to increase the operating point of the magnetic field. The magnetic bias can improve the linearity of the giant magnetostriction with respect to the strength of the magnetic field. . Reference numeral 24 denotes a rear yoke of a magnetic circuit which is arranged on the rear side of the giant magnetostrictive rod 20 and is integrated with the rear main shaft 17. The front-side main shaft 5 also serves as a yoke material of the magnetic circuit, and is disposed on the front side of the giant magnetostrictive rod 20. Reference numeral 25 denotes a cylindrical yoke member disposed on the outer peripheral portion of the magnetic field coil 21.

Accordingly, a circuit from the giant magnetostrictive rod 20 to the giant magnetostrictive rod 20 again through the upper permanent magnet 22, the rear yoke 24, the yoke material 25, the front main shaft 5, and the lower permanent magnet 23, A closed loop magnetic circuit for controlling the expansion and contraction of the giant magnetostrictive rod 20 is formed. The center shaft 2 is made of a non-magnetic material so as not to affect the magnetic circuit. That is, by the giant magnetostrictive rod 20, the upper and lower permanent magnets 22, 23, and the magnetic field coil 21,
A giant magnetostrictive actuator (that is, a first actuator 1) that can control the axial expansion and contraction of the giant magnetostrictive rod 20 by a current applied to the magnetic field coil is provided.

The giant magnetostrictive material is an alloy of a rare earth element and iron. For example, bFe ₂ , DyFe ₂ , SmFe _{2 and the} like are known, and their practical use has been rapidly advanced in recent years.

The rear main shaft 17 is supported by a bearing 26 at the lower end of the housing 19 and at the rear side (upper end) of the housing 3.
And is rotatably supported by a rear housing 27 fixed to the housing.

Reference numeral 28 denotes the front-side main shaft 5 and the bearing sleeve 2.
9 is a bias spring mounted between the two. This bearing sleeve 29 is also rotatably supported by the housing 4 with respect to the housing 4. The giant magnetostrictive rod 20 is pressed by upper and lower members, that is, the front main shaft 5 and the rear yoke 24 via the upper and lower bias permanent magnets 22 and 23 by the axial load applied from the bias spring 28. It is grasped. As a result, the compressive stress is always applied to the giant magnetostrictive rod 20 in the axial direction, so that when a repetitive stress is generated, the defect of the giant magnetostrictive element which is weak against the tensile stress is solved.

Front spindle 5 integrated with piston 6
Is accommodated in the bearing sleeve 29 regulated by the bearing 30 so as to be movable in the axial direction.

The rotational power of the central shaft 2 transmitted from the motor 15 is transmitted to the front main shaft 5 by a rotation transmission key 31 provided between the central shaft 2 and the front main shaft 5. This rotation transmission key 31 transmits the rotational power,
It has a square cross-sectional shape that is free in the axial direction, and a recess 5 a having a substantially identical cross-sectional shape of the front main shaft 5.
To be fitted inside.

With the above configuration, the rotational power of the motor 15 is transmitted only to the central shaft 2 and the front main shaft 5, and no torsional torque is generated in the giant magnetostrictive element, which is a brittle material.

Reference numeral 32 denotes a motor 1 as a second actuator.
5 is an encoder for detecting rotational position information of the rear-side main shaft 17 disposed at the upper part of the main spindle 5.

Reference numerals 33 and 34 denote a first displacement sensor and a second displacement sensor for detecting an axial displacement of the front main shaft 5 (and the piston 6).

With the above configuration, in the fluid discharge device of the present embodiment, the piston 6 of the pump can simultaneously and independently control the rotational movement and the linear movement with minute displacement.

Furthermore, in the above embodiment, since the giant magnetostrictive element is used for the first actuator 1, the giant magnetostrictive rod 2
0 (and the piston 6) to move linearly.
It can be given from outside without contact.

Since the input current applied to the giant magnetostrictive element is proportional to the displacement, the axial positioning control of the piston 6 can be performed even with open loop control without a displacement sensor. However, if the position detection device as in the present embodiment, that is, the first displacement sensor 33 and the second displacement sensor 34 are provided and the feedback control is performed, the hysteresis characteristics of the giant magnetostrictive element can be improved, and the positioning can be performed with higher accuracy. .

In the present embodiment, the size of the gap on the discharge-side thrust end face of the piston 6 is arbitrarily controlled using the axial positioning function of the piston 6 while maintaining the steady rotation state of the piston 6. Can be. By using this function, the section of any flow passage from the suction hole 12 to the discharge nozzle 13 is cut off /
Can be opened. The principle will be described with reference to FIG.

In FIG. 2, reference numeral 35 denotes a discharge end face of the piston 6, and reference numeral 36 denotes a discharge plate fastened to the discharge end face of the cylinder 8. A thrust groove 38 for sealing is formed in a relative movement surface between the discharge side end surface 35 of the cylinder 8 and the opposing surface 37. An opening 39 of the discharge nozzle 13 is formed at the center of the facing surface 37 of the discharge side end surface 35.

The radial groove 11 already described with reference to FIG. 1 is a known groove known as a spiral groove hydrodynamic bearing, and is also used as a screw groove pump.

The sealing thrust groove 38 is also known as a thrust dynamic pressure bearing. The seal pressure that can be generated by the thrust bearing is determined by the rotational angular velocity, the inner and outer diameters of the thrust bearing, the groove depth, the groove angle, the groove width and the ridge width, and the like.

The curve (a) in the graph of FIG. 3 shows the characteristics of the sealing pressure Ps with respect to the gap δ when a spiral groove type thrust groove is used under the conditions shown in Table 1 below. The curve (b) in the graph of FIG. 3 is an example showing the relationship between the pumping pressure of the radial groove and the gap δ at the tip of the shaft when there is no axial flow. The pumping pressure of this radial groove can be selected in a wide range by selecting the radial gap and the groove depth and groove angle, similarly to the thrust groove. However, qualitatively, the pumping pressure Pr of the radial groove does not depend on the size of the gap at the tip of the shaft (that is, the size of the gap δ).

When the gap δ of the sealing thrust groove is sufficiently large, for example, when the gap δ is 15 μm, the generated pressure is small, that is, P <0.1 kg / mm ² .

While the shaft is being rotated, the end surface of the rotating shaft is brought closer to the fixed facing surface. When the gap δ <10.0 μm, the sealing pressure becomes larger than the pumping pressure Pr of the radial groove, and the outflow of the fluid to the discharge port side is shut off.

FIG. 2 shows a state in which the outflow of the fluid is shut off. The fluid near the opening 39 of the discharge nozzle is subjected to the centrifugal pumping action (see the arrow in FIG. 2) by the thrust groove 38. The pressure near the opening 39 is negative pressure (atmospheric pressure or lower). Due to this effect, after shutting off, the fluid remaining inside the discharge nozzle 13 is sucked into the pump again. As a result, a fluid mass due to surface tension is not formed at the tip of the discharge nozzle, and stringing and dropping are eliminated.

In the embodiment of the present invention, ON and OFF of the discharge state of the fluid can be freely controlled by moving the rotation axis in the axial direction, for example, only about 5 to 10 μm.

To summarize the points of the embodiment of the present invention, the sealing pressure by the thrust groove increases rapidly when the gap δ becomes small, whereas the pumping pressure of the radial groove changes extremely with the change of the gap δ. He takes advantage of his insensitivity.

Incidentally, both the radial groove and the thrust groove may be formed on either the rotating side or the fixed side.

When a powder fluid such as an adhesive containing fine particles is applied, the minimum value δmin of the gap δ may be set to be larger than the fine particle diameter φd. That is, δmin> φd (1) In order to obtain a larger gap δ for the same generated pressure, the rotational speed may be increased.

As an example, Table 1 shows the rotation speed N, the viscosity coefficient μ of the fluid, the depth hg of the thrust groove for sealing, and the radius RO.
And Ri, specific setting values of the groove angle α with respect to the direction perpendicular to the axial direction, the groove width bg, and the width br of the ridge between adjacent grooves are shown. RO is the outer diameter of the thrust groove 38 (that is, the outer diameter of the disk of the thrust groove 38 in FIG. 3), and Ri is the inner diameter of the thrust groove 38 (that is, the inner diameter of the disk of the thrust groove 38 in FIG. 3). is there.

[0057]

[Table 1]

In this embodiment, the giant magnetostrictive element is used for the axial driving device. However, in a pump handling a small flow rate, the stroke of the gap δ for forming the “non-contact seal” is at most a few. The order may be on the order of 10 microns, and the limit of the stroke of the magnetostrictive element such as the giant magnetostrictive element and the piezo element does not matter.

When a high-viscosity fluid is discharged, a large discharge pressure is expected to be generated by the pumping action of the radial groove. In this case, since the first actuator 1 is required to have a large thrust against high fluid pressure, it is preferable to use an electromagnetic strain type actuator capable of easily producing a force of several hundred to several thousand N. Since the magnetostrictive element has a frequency response of several MHz or more, the main axis can be linearly moved with high response. Therefore, the discharge amount of the high-viscosity fluid can be controlled with high response and high accuracy.

Further, when a giant magnetostrictive element is used for the axial driving device, the conductive brush can be omitted as compared with the case where a piezoelectric element is used, so that the load on the motor (an example of a rotating device) can be reduced and the overall structure can be reduced. Is extremely simple, the moment of inertia of the moving part can be minimized, and the diameter of the dispenser can be reduced.

Next, the above embodiment for controlling the gap δ between the shaft 6 and the housing 8 with high accuracy will be described with reference to FIGS.

FIG. 4 is a block diagram showing a control configuration.
Reference numerals 33 and 34 denote first and second displacement sensors (see FIG. 1) which are arranged at positions 180 ° apart from each other. 109,
Reference numeral 110 denotes an amplifier for converting the outputs of the displacement sensors 33 and 34 into data indicating the position of the shaft in the axial direction. The data output from the amplifiers 109 and 110 are added by the adder 111, 1
/ 2 times. That is, the output of the amplifier 112 is an average value of the outputs of the amplifiers 109 and 110. At this time, when two displacement sensors 33 and 34 are used, the output data of two amplifiers 109 and 110 are averaged, but when three or more displacement sensors are used, three or more amplifiers are used. Will be averaged.

Numeral 100 denotes a position command generating means for outputting a target value of the gap δ between the shaft 6 and the housing 8 as a target position in the axial direction of the shaft.
The output value of the amplifier 112 is subtracted from the output value of 0 and output to the position control amplifier 102 as an example of the position controller. The position control amplifier 102 is based on the output value of the subtractor 101,
A target current value to be supplied to the magnetostrictive element as an example of a target drive signal of the magnetostrictive element is output by a preset arithmetic expression. Examples of the arithmetic expression include a proportional control that simply multiplies a coefficient, and an integral control for integrating an input or a differential control for differentiating an input in addition to the proportional control.

Reference numeral 105 denotes a current detector for detecting an actual current flowing through the electromagnetic distortion element, which is an example of a drive signal detector for detecting an actual drive signal of the electromagnetic distortion element.
Reference numeral 3 denotes a current detector 105 based on the output of the position control amplifier 102.
Is subtracted and output to the current control amplifier 104. The current control amplifier 104 controls the current so that the output of the subtractor 103 becomes zero. The current control amplifier 104 functions as an example of a drive signal controller that controls the drive signal so that the actual drive signal is equal to the target drive signal.

With the above configuration, the gap δ between the shaft 6 and the housing 8 is controlled to an arbitrary value.

FIG. 5 is a waveform chart for explaining the effect of the present embodiment. As can be seen from FIG. 1, the displacement sensors 33, 34
Cannot be measured directly between the shaft 6 and the housings 3, 4 and 8, and is therefore located at a position distant from the shaft 6. Therefore, since the rotation deviation is measured, the output of the amplifier 109 of the first displacement sensor 33 and the output of the amplifier 110 of the second displacement sensor 34 are different from the rotation angle of the shaft 6.
The waveform is as shown in FIG. This amplitude is about 10 to several tens [mu] m in this embodiment. Therefore, when only one displacement sensor is used, the shaft 6 moves in the axial direction by about 10 to several tens μm depending on the rotation angle. In the present embodiment, by averaging the output of the amplifier 109 of the first displacement sensor 33 and the output of the amplifier 110 of the second displacement sensor 34, fluctuations in the measured values of the respective displacement sensors 33 and 34 can be canceled. .

The fluid discharge device according to the above-described embodiment houses the electromagnetic strain element as an example of the first actuator 1 having the movable end on the front side and the other fixed end on the rear side, and the above-described electromagnetic strain element. The housings 3, 4, 8 and a magnetic field coil 21 as an example of a supporting device for supporting the electrostrictive element relatively rotatably and axially movable with respect to the housings 3, 4, 8; Permanent magnets 22 and 23, a rotating device as an example of a second actuator 15 for rotating the electromagnetic distortion element, a shaft 6 fastened to the front side of the electromagnetic distortion element, A pump chamber 11 formed by the housing 8 and a pump chamber 1
1 is a fluid suction hole 1 communicating the outside of the pump chamber 11 with the pump chamber 11.
2, a discharge nozzle 13, a radial groove 9 which is an example of a pumping device for pumping the fluid flowing into the pump chamber 11 toward the discharge nozzle, and a fluid resistance between the pump chamber 11 and the discharge nozzle 13. In order to increase or decrease the amount of the fluid, a gap δ between the shaft 6 and the housing 8 is changed by driving the electromagnetic strain element to control the discharge amount of the fluid. And the average value of the measured values of the gap δ measured by the two displacement sensors 33 and 34 is determined. A converter that converts the actual position in the axial direction (the amplifier 1 as an example)
09, 110, an adder 111 and an amplifier 112. ) And the gap δ between the shaft 6 and the housing 8
Position command generating means 100 for outputting the target value of the shaft 6 as a target position in the axial direction of the shaft 6, and a target current flowing to the electromagnetic distortion element based on a difference between the target position and the actual position output from the converter. A position control amplifier 102 as an example of a position controller that outputs a current, a current detector 105 that detects an actual current flowing through the electromagnetic distortion element, and a current that controls the current so that the actual current becomes equal to the target current. With the current control amplifier 104 as an example of a controller,
And the gap 8 between the housing 8 and the housing 8 can be controlled.

That is, the two displacement sensors 33 and 34 are provided by the fluid discharge device and method according to the above embodiment.
Determine the average of the measured values of the gap δ measured by,
The average value is converted into an actual position in the axial direction of the shaft 6, and a target value of the gap δ between the shaft 6 and the housings 3, 4, 8 is output as a target position in the axial direction of the shaft 6, Based on the difference between the target position and the converted actual position, a target current flowing to the electromagnetic distortion element is output, and a real current flowing to the electromagnetic distortion element is detected, and the actual current becomes equal to the target current. Since the gap δ between the shaft 6 and the housings 3, 4, and 8 is controlled by controlling the current as described above, the following effects can be obtained. That is, high-speed discharge can be interrupted and high-speed discharge can be started, troubles such as clogging of the flow channel due to breakage of powder compression and changes in fluid characteristics do not occur, and the pump of the present embodiment further has the following features. Can be. High-speed application of high viscosity fluid is possible. Dispenses ultra-fine quantities with high precision.

Accordingly, this embodiment can be applied to, for example, application by a dispenser for applying an adhesive for surface mounting, PDP, CR, or the like.
If it is used for the application of a phosphor for a T display, the application of a sealing material for a liquid crystal panel, etc., the advantages can be fully exhibited, and the effect is enormous.

[0070]

According to the fluid discharging apparatus and method using the present invention, the average value of the measured values of the gap between the shaft and the housing measured by, for example, two displacement sensors at a plurality of locations is determined. Is converted to an actual position in the axial direction of the shaft, the target value of the gap is output as a target position in the axial direction of the shaft, and the electromagnetic distortion is calculated based on the difference between the target position and the converted actual position. The gap is controlled by outputting an actual drive signal of the element, detecting an actual drive signal of the electromagnetic distortion element, and controlling the drive signal so that the actual drive signal is equal to the target drive signal. ing. Therefore,
The following effects can be obtained.

1. High-speed discharge interruption and high-speed discharge start can be performed.

2. Clogging of flow path due to powder compression damage,
Troubles such as changes in fluid characteristics do not occur.

3. Further, the pump of the present invention can have the following features.

High-speed application of a high-viscosity fluid can be performed.

Ultra-small quantities can be ejected with high precision.

If the present invention is applied to, for example, application by a dispenser for applying an adhesive for surface mounting, application of a phosphor for a PDP or CRT display, application of a sealing material for a liquid crystal panel, etc., the advantages can be fully exhibited and the effect is remarkable. There is something.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a dispenser as a specific example of a fluid ejection device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a discharge section of the embodiment.

FIG. 3 is a graph illustrating the principle of the present invention.

FIG. 4 is a block diagram showing a control configuration of the embodiment of the present invention.

FIG. 5 is a waveform chart illustrating the effect of the embodiment of the present invention.

FIG. 6 is a view showing a conventional air pulse method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st actuator, 2 ... Center axis, 3 ... Housing, 4 ... Housing, 5 ... Front side main shaft, 5a ... Depression, 6 ... Piston (shaft), 7 ... Bolt, 8 ... Cylinder,
9: radial groove, 10: fluid seal, 11: pump chamber,
12: suction hole, 13: discharge nozzle, 14: discharge part, 15
... second actuator, 16 ... motor rotor, 17 ... rear spindle, 18 ... motor stator, 19 ... housing,
Reference numeral 20: giant magnetostrictive rod, 21: magnetic field coil, 22: upper permanent magnet, 23: lower permanent magnet, 24: rear yoke, 25: yoke material, 26: bearing, 27: rear housing, 28: Bias spring, 29 ... bearing sleeve, 3
0: bearing, 31: rotation transmission key, 32: encoder, 3
3. First displacement sensor, 34 Second displacement sensor, 35
... end face of piston on the discharge side, 36 ... discharge plate, 37 ...
Opposing surface, 38: thrust groove for sealing, 39: opening, 1
00: position command generating means, 101: subtractor, 102: position control amplifier, 103: subtractor, 104: current control amplifier, 105: current detector, 109, 110: amplifier, 1
11: adder, 112: amplifier.

Continued on the front page (72) Inventor Teruo Maruyama 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 4D075 AC56 AC92 AC94 AC99 CA48 DA06 DB01 DC18 DC21 EA35 4F035 AA04 BA21 BB03 BB05 BC01 4F041 AA01 AB01 BA01

Claims (4)

[Claims] 1. An electrostrictive element having one movable end and the other fixed end, a housing for accommodating said electrostrictive element, and said electrostrictive element being rotatable and axially movable relative to said housing. A supporting device movably supporting the
A rotating device that applies rotation to the electromagnetic strain element, a shaft fastened to the movable end side of the electromagnetic strain element, a pump chamber formed by the shaft and the housing, and an outside of the pump chamber and the pump chamber. A suction port and a discharge port of the fluid to be communicated, a pumping device for pumping the fluid flowing into the pump chamber to a discharge port side, and a fluid resistance between the pump chamber and the discharge port to increase or decrease. A fluid ejection device that controls a discharge amount of the fluid by changing a gap between the shaft and the housing by driving the electromagnetic strain element, a plurality of displacement sensors that measure the gap between the shaft and the housing. A converter for determining an average value of the measured values of the gaps measured by the plurality of displacement sensors, and converting the average value to an actual position in the axial direction of the shaft; and the gap between the shaft and the housing. Position command generating means for outputting a target value as a target position in the axial direction of the axis; and outputting a target drive signal for the electromagnetic distortion element based on a difference between the target position and the actual position output from the converter. A position controller; a drive signal detector that detects an actual drive signal of the electromagnetic distortion element; and a drive signal controller that controls a drive signal so that the actual drive signal is equal to the target drive signal. A fluid discharge device configured to control the gap between the housing and the housing. 2. The converter according to claim 1, wherein said converter converts the outputs of said plurality of displacement sensors into data indicating the axial position of said shaft, and outputs the same number of amplifiers as said displacement sensors. 2. An adder for adding data to a plurality of amplifiers, and an amplifier for multiplying an output from the adder by 1 / (the number of the amplifiers) and outputting an average value of outputs of the plurality of amplifiers. The fluid ejection device according to claim 1. 3. An electrostrictive element having a movable end on the side to which the shaft is fastened and a fixed end on the other side is rotated relative to a housing for accommodating the electrostrictive element and moved in the axial direction. By pumping the fluid flowing into the pump chamber to the outside of the pump chamber formed by the shaft and the housing and to the discharge port side of the fluid that communicates with the pump chamber, the pump chamber and the discharge port In order to increase or decrease the fluid resistance between, in the fluid discharge method of controlling the discharge amount of the fluid by changing the gap between the shaft and the housing by driving the electromagnetic distortion element, The gap is measured by a plurality of displacement sensors, an average value of the measured values of the gap measured by the plurality of displacement sensors is obtained, and the average value is converted to an actual position in the axial direction of the axis. axis And outputting a target value of the gap between the housings as a target position in the axial direction of the shaft, and outputting a target drive signal of the electromagnetic distortion element based on a difference between the target position and the converted actual position. The gap between the shaft and the housing is controlled by detecting an actual drive signal of the electromagnetic distortion element and controlling the drive signal so that the actual drive signal is equal to the target drive signal. A fluid discharging method characterized by the above-mentioned. 4. An average value of the measured values of the gaps measured by the plurality of displacement sensors, and converting the average value to an actual position in the axial direction of the shaft, comprises: The output is converted to data indicating the axial position of the shaft by the same number of amplifiers as the displacement sensor, data output from the plurality of amplifiers is added, and the added value is 1 / the value of the amplifier. 4. The fluid discharging method according to claim 3, wherein an average value of outputs of the plurality of amplifiers is output by multiplying the number.