JP2003260397A - Apparatus and method of discharging fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems that the high speed shut-down and start-up of the discharge of a fluid are impossible, the flow passage is clogged by the compression breaking of a powdery fluid and the characteristics of the powdery fluid is changed in a conventional liquid discharge apparatus. <P>SOLUTION: The fluid discharge apparatus and method by which the high speed shut-down and start-up of the discharge of the fluid are enabled and the clogging of the flow passage by the compression breaking of the powdery fluid and the change of the characteristics of the liquid are prevented is realized by rotating a piston shaft 6 to measure the distance (δ) between a discharge side end face 35 which is a reference surface of the piston shaft 6 and a surface 37 opposite to a cylinder and a rotation angle of the piston shaft 6, storing the relation between the distance (δ) and the rotation angle, calculating the correction value of the distance (δ) to the rotation angle and adjusting the distance (δ) between the piston shaft 6 and the cylinder based on the correction value to control the distance (δ) to a desired value. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended for quantitatively discharging / blocking various liquids such as adhesives, cream solders, greases, paints, hot melts, etc. in the production process in the fields of electronic parts, home appliances and the like. Or C
The present invention relates to a fluid ejecting apparatus and a fluid ejecting method for uniformly and highly accurately ejecting and blocking a phosphor material or the like on a display surface such as an RT and a PDP. Or medicine,
The present invention relates to a fluid ejection device and a fluid ejection method for ejecting / blocking a liquid used in foods in a fixed amount.

[0002]

2. Description of the Related Art Liquid ejecting devices (dispensers) have been used in various fields, but with the recent needs for miniaturization and high recording density of electronic parts, a small amount of fluid material can be used with high accuracy. In addition, there is a demand for a technique for stable discharge control.

For example, surface mounting (Surface Mo)
For example, in the field of unt Technology,
In the trend of high-speed mounting, miniaturization, high density, high quality, and unmanned, the problems of the dispenser can be summarized as follows. High accuracy of discharge amount, miniaturization of discharge amount once, and discharge time That is, it is possible to cut off and start high-speed discharge, and to cope with highly viscous powder fluid.

Conventionally, dispensers of air pulse type, screw groove type, micropump type using an electromagnetic strain element, etc. have been put to practical use in order to discharge a minute flow rate of liquid. Among these dispensers, an air pulse type dispenser is widely used, and the technique is introduced, for example, in “Automation Technology '93 .25 Vol. 7”.

An air pulse type dispenser as shown in FIG. 6 applies a fixed amount of air supplied from a constant pressure source to the container 200 (cylinder) in a pulsed manner to increase the pressure of the air 202 in the cylinder 200. Is ejected from the nozzle 201.

[0006]

However, the air pulse type dispenser has a drawback that it has poor responsiveness.

This drawback is due to the compressibility of the air 202 contained in the cylinder 200 and the nozzle resistance when passing the air pulse through the narrow gap. That is, in the case of the air pulse system, the cylinder volume: C,
Nozzle resistance: R, time constant of fluid circuit determined by: T = RC
Is large, it is necessary to allow for a time delay of, for example, about 0.07 to 0.1 seconds after the input pulse is applied to start ejection.

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

In this case, however, when the fluid is shut off, the gap between the members that move relative to each other becomes zero, and the powder having an average particle diameter of several microns to several tens of microns is mechanically pressed and destroyed. Due to various problems that occur as a result, it is often difficult to apply it to the application of an adhesive agent, a conductive paste, a phosphor, or the like in which powder is mixed.

For the same purpose, a screw groove type dispenser which is a viscous pump has already been put into practical use. In the case of the thread groove type, it is possible to select a pump characteristic that does not easily depend on the nozzle resistance. Therefore, continuous coating can obtain a preferable result, but intermittent coating is not good because of the characteristics of a viscous pump. Therefore, in the conventional thread groove type, (1) an electromagnetic clutch is interposed between the motor and the pump shaft to connect or disconnect the electromagnetic clutch when the discharge is turned on or off. Alternatively, (2) a DC servo motor is used to start or stop the rapid rotation.

However, in any of the above cases, the responsiveness is determined by the time constant of the mechanical system, so there are restrictions on high-speed intermittent operation. The responsiveness is better than that of the air pulse method, but the limit is about 0.05 seconds even in the shortest time.

Further, since there are many uncertain factors in the rotational characteristics during the transient response of the pump shaft (at the time of starting and stopping the rotation), it is difficult to strictly control the flow rate, and the coating accuracy is limited.

Therefore, a micropump using a piezoelectric element has been developed for the purpose of supplying a minute amount of fluid. For this micropump, a mechanical passive discharge valve and suction valve are usually used.

However, such a valve is composed of a spring and a ball, and in a pump using the above-mentioned piezoelectric element that opens and closes the discharge valve and the suction valve by a pressure difference, the fluidity is poor, and several tens to several hundreds of Pa · s. It is extremely difficult to intermittently discharge the highly viscous rheological fluid with high flow rate and high speed (0.1 seconds or less).

However, in the field of circuit formation, which is becoming increasingly precise and ultra-fine in recent years, or in the formation of electrodes and ribs for video tubes such as PDPs and CRTs, coating of sealing materials for liquid crystal panels, and manufacturing processes for optical disks and the like. In the field, the following demands are increasing for fine coating technology.

After the continuous coating, the coating should be stopped quickly, and the continuous coating should be able to start rapidly after a short time. For that purpose, it is ideal that the flow rate can be controlled on the order of 0.01 seconds, for example.

Capable of handling powdered fluids. For example, there should be no troubles such as powder squeezing, breakage, or flow path clogging due to mechanical blockage of the flow path.

In order to meet various demands in recent years relating to the minute flow rate application of the above-mentioned high-viscosity fluid / powder fluid, the present inventors have made a relative linear motion and a rotary motion between the piston and the cylinder, respectively. In addition to being provided by an independent actuator, a fluid transport means is provided by a rotary motion, and a linear movement is used to change the relative gap between the fixed side and the rotary side to control the discharge amount of the fluid. And fluid supply method "is being applied for in Japanese Patent Application No. 2000-188899.

The present invention is a further improvement of the above-mentioned application, and a fluid ejecting apparatus and a fluid ejecting method capable of controlling the clearance between the shaft and the cylinder with high accuracy and the fluid ejection amount with higher accuracy. The purpose is to provide.

[0020]

In order to achieve the above object, a fluid discharge device of the present invention comprises a displacement sensor for detecting the position of the piston shaft in the direction of the piston axis, and an angle for detecting the rotation angle of the piston shaft. A detector, a correction amount memory generation that stores a relationship between a signal detected by the displacement sensor and a signal detected by the angle detector and outputs a correction amount signal of a position in the piston axis direction corresponding to the rotation angle of the piston shaft. Means, the actual position signal generating means for subtracting the correction amount signal output from the correction amount storage generating means from the detection signal of the displacement sensor and outputting the actual position signal of the piston shaft, and the piston based on the target value of the gap. Position command generating means for outputting a target value signal in the piston axis direction of the shaft, and the target of the piston axis direction driving means from the difference between the target value signal and the actual position signal. And position control means for outputting a motion signal,
The gap is constituted by drive signal detection means for detecting the actual drive signal of the piston axial direction drive means and drive signal control means for controlling the drive signal so that the actual drive signal becomes equal to the target drive signal. It is characterized by controlling. Further, the axial driving means may be an electromagnetic strain element.

Further, in the fluid discharge method of the present invention, the piston shaft is rotated, the gap between the discharge side end face of the piston shaft and the discharge side end face between the cylinders and the rotation angle of the piston shaft are measured, and the rotation angle is determined. Is stored, the correction amount of the gap at the rotation angle of the piston shaft is calculated from the relation, and the gap between the piston shaft and the cylinder is adjusted based on the correction amount to obtain the desired gap. Is set to a value of.

According to the present invention, the fluid discharge amount of the fluid discharge device can be accurately controlled, and the fluid discharge device and method can be realized in which the flow path is not clogged due to the crushing damage of the powder fluid and the characteristic of the fluid is not changed.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the fluid ejecting apparatus and the fluid ejecting method of the present invention are applied to a surface mounting dispenser for electronic parts will be described below with reference to FIGS.

In FIG. 1, reference numeral 1 is a first actuator (electromagnetic strain element) which is an axial driving means, and more specifically, it supplies a high viscosity fluid at high speed intermittently in a minute amount and with high accuracy. In addition, a giant magnetostrictive element is used which has high positioning accuracy, high responsiveness, and large load. In the following description, the movable end of the giant magnetostrictive element is the front side (lower side in FIG. 1) and the other fixed side of the giant magnetostrictive element is the rear side (upper side in FIG. 1).

Reference numeral 2 is a central shaft driven by the first actuator 1. The first actuator 1 is housed in the housing 3. A front side main shaft 5, which is concentrically connected to the lower end of the central shaft 2, is supported by a housing 4 fixed to the lower end of the housing 3 so as to be rotatable and capable of slightly moving in the axial direction. A piston shaft 6 is detachably attached to the front main shaft 5 and a plurality of bolts 7, and is housed in a cylinder 8 fixed to the lower end of the housing 4, and 11 is formed on the relative moving surface of the piston shaft 6 and the cylinder 8. Radial groove for pumping the fluid to the discharge side, 1
Reference numeral 0 denotes a fluid seal arranged between the upper end of the piston shaft 6 and the cylinder 8.

A pump chamber 9 is formed between the piston shaft 6 and the cylinder 8 to obtain a pumping action by the relative rotation of the radial groove 11 and its opposing surface.
The piston shaft 6, the cylinder 8, the pump chamber 9, and the radial groove 11 constitute a fluid pressure feeding means. Reference numeral 13 is a discharge nozzle attached to the lower end of the cylinder 8, and 14 is a discharge portion including the discharge nozzle 13 (details will be described later).

Reference numeral 15 is a second actuator, which is a motor which is a rotating means for providing a relative rotational movement between the piston shaft 6 and the cylinder 8. The motor rotor 16 is the rear side spindle 1.
7 and the motor stator 18 is fixed to the housing 1
It is stored in 9. The rear main shaft 17 is integrally and concentrically connected to the upper end of the central shaft 2.

Reference numeral 20 is a cylindrical giant magnetostrictive rod composed of giant magnetostrictive elements, and 21 is 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, and are arranged so as to support and hold 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 enhance the operating point of the magnetic field, and 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 side yoke of a magnetic circuit which is arranged on the rear side of the giant magnetostrictive rod 20 and which is integrated with the rear side main shaft 17. The front-side main shaft 5 also functions as a yoke material of the magnetic circuit, and is arranged on the front side of the giant magnetostrictive rod 20. Reference numeral 25 denotes a cylindrical yoke member arranged on the outer peripheral portion of the magnetic field coil 21.

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

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

Reference numeral 28 denotes the front side main shaft 5 and the bearing sleeve 2.
9 is a bias spring mounted between the two. Similarly, the bearing sleeve 29 is rotatably supported on the housing 4 by a bearing 30. Due to the axial load applied from the bias spring 28, the giant magnetostrictive rod 20 is gripped in such a manner that it is pressed by the upper and lower members, that is, the front main spindle 5 and the rear yoke 24, via the upper and lower bias permanent magnets 22 and 23. Has been done. As a result, the compressive stress is always applied to the giant magnetostrictive rod 20 in the axial direction, so that the defect of the giant magnetostrictive element, which is weak against tensile stress, is eliminated when repeated stress is generated.

The front main shaft 5 integrated with the piston shaft 6 is accommodated in a bearing sleeve 29 regulated by a 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 spindle 5 by a rotation transmission key 31 provided between the central shaft 2 and the front main spindle 5. This rotation transmission key 31 has a rectangular cross-sectional shape that transmits rotational power to the front-side main shaft 5 but is free in the axial direction, and has a recess 5a having substantially the same cross-sectional shape of the front-side main shaft 5. Is fitted inside.

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

Reference numeral 32 is a motor 1 which is a second actuator.
5 is an encoder (angle detector) for detecting the rotational position information of the rear side main shaft 17 arranged on the upper part of FIG.

Reference numeral 33 is a displacement sensor for detecting the axial displacement of the front side main shaft 5 (and the piston shaft 6).

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

Further, in the present embodiment, since the giant magnetostrictive element is used for the first actuator 1, the giant magnetostrictive rod 2 is used.
Power for linearly moving 0 (and the piston shaft 6) can be applied from the outside in a non-contact manner.

Since the input current applied to the giant magnetostrictive element is proportional to the displacement, the axial positioning control of the piston shaft 6 is possible even by open loop control without a displacement sensor.
However, if the position detecting device as in this embodiment, that is, the displacement sensor 33 is provided and feedback control is performed,
Since the hysteresis characteristic of the giant magnetostrictive element can be improved, positioning control with higher accuracy can be performed.

In the present embodiment, the axial positioning function of the piston shaft 6 is used to set the size of the clearance between the discharge side thrust end face of the piston shaft 6 and the piston shaft 6 in a steady rotation state. Can be controlled. By using this function, the powder fluid can be blocked / opened in a mechanically non-contact state in any section of the flow passage from the suction port 12 to the discharge nozzle 13.

The principle will be described with reference to FIG. 2, which is a detailed view of the discharge section 14. In FIG. 2, 35 is an end face of the piston shaft 6 on the discharge side, 36 is a component of the cylinder 8,
The discharge plate is fastened to the discharge-side end surface of the cylinder 8. The discharge side end surface 35 of the piston shaft 6 and the facing surface 3
A thrust thrust groove 38 is formed on the relative moving surface of 7. An opening 39 of the discharge nozzle 13 is formed in the center of the facing surface 37 of the discharge side end surface 35. Opening 3
Reference numeral 9 is a discharge port.

The radial groove 11 which has already been described with reference to FIG. 1 is a known one known as a spiral groove dynamic pressure bearing, and is a fluid pumping means also used as a screw groove pump.

The sealing thrust groove 38 is also known as a thrust dynamic pressure bearing. Here, 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 characteristic of the seal pressure Ps with respect to the gap δ when the spiral groove type thrust groove is used under the conditions of the following Table 1. 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 the radial groove can be selected in a wide range by selecting the radial gap, the groove depth and the groove angle, like the thrust groove. However, qualitatively, the pumping pressure Pr of the radial groove does not depend on the size of the air gap at the shaft tip (that is, the size of the gap δ).

When the gap ∂ of the thrust groove for sealing is sufficiently large, for example, when the gap δ = 15 μm, the generated seal pressure is small and Ps <1 Pa.

With the piston shaft kept rotating, the end face of the rotating shaft is brought closer to the facing surface on the fixed side. Gap δ <10.0μ
At m, the seal pressure Ps becomes larger than the pumping pressure Pr of the radial groove, and the outflow of fluid to the discharge port side is blocked.

FIG. 2 shows a state in which the outflow of this fluid is blocked. In FIG. 2, the fluid in the vicinity of the opening 39 of the discharge nozzle is subjected to centrifugal pumping action (see parallel arrow in FIG. 2) by the thrust groove 38, so that the vicinity of the opening 39 is negative pressure (atmospheric pressure). Below). Due to this effect, the fluid remaining inside the discharge nozzle 13 after being blocked is again sucked into the pump. As a result, no fluid lump is formed due to surface tension at the tip of the discharge nozzle, and stringing and drooping are eliminated.

In the embodiment of the present invention, the fluid discharge state is turned on and off by moving the rotary shaft (piston shaft) in the axial direction by, for example, only about 5 to 10 μm.
Can be controlled freely.

In summary of the points of the embodiment of the present invention, the sealing pressure due to the thrust groove rapidly increases as the gap δ becomes smaller, whereas the pumping pressure in the radial groove as the gap δ changes. It takes advantage of the fact that it is extremely insensitive.

Both the radial groove and the thrust groove may be formed on either the rotating side or the fixed side.

When applying a powdery fluid such as an adhesive containing fine particles, the minimum value δmin of the gap δ may be set larger than the fine particle diameter φd.

[0053]

[Formula 1]

That is, the conditions shown in the above equation (1) may be set.

Here, having the same seal pressure Ps,
In order to obtain a larger gap δ, the rotation speed of the piston shaft may be increased.

As an example, in Table 1, the rotational speed N of the piston shaft, the viscosity coefficient μ of the fluid, and the groove depth h of the thrust groove for sealing are shown.
Specific values of g, radii RO and Ri, the groove angle α with respect to the direction orthogonal to the axial direction, the groove width bg, and the width br of the ridge between adjacent grooves are shown. Note that 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 the present embodiment, the giant magnetostrictive element is used in the axial drive device. However, in a pump handling a minute flow rate, the stroke of the gap δ for forming the "non-contact seal" is at most several. It may be on the order of 10 μm, and the stroke limit of an electromagnetic strain element such as a giant magnetostrictive element or a piezo element does not matter.

When discharging a high-viscosity fluid, it is expected that a large discharge pressure will 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 force against a high fluid pressure, an electromagnetic strain type actuator that can easily generate a force of several hundred to several thousand N is preferable. Since the electromagnetic strain 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. Since it is extremely simple, the moment of inertia of the moving part can be minimized and the dispenser can be made smaller in diameter.

Next, a method for controlling the clearance δ between the piston shaft 6 (FIG. 2) and the housing 8 (FIG. 2) with high accuracy will be described with reference to FIGS. 4 and 5.

FIG. 4 is a block diagram showing the control configuration.
33 is a displacement sensor (see also FIG. 1). Reference numeral 109 is an amplifier for converting the output of the displacement sensor 33 into data indicating the axial position of the piston shaft. The subtractor 110, which is the actual position signal generating means, outputs a value obtained by subtracting the output value of the correction amount storing / generating means 113 described below from the output value of the amplifier 109 as the actual position signal.

Reference numeral 100 is a position command generating means for outputting a target value of the gap δ between the piston shaft 6 (FIG. 2) and the housing 8 (FIG. 2) as a target position in the axial direction of the shaft, and the subtracter 10
1 is a subtracter 110 from the output value of the position command generating means 100.
The output value of 1 is subtracted and output to the position control amplifier 102 as an example of the position control means. The position control amplifier 102 outputs a target current value flowing through the electromagnetic strain element as an example of a target drive signal of the electromagnetic strain element based on an output value of the subtractor 101 according to a preset arithmetic expression. As an example of the arithmetic expression, there may be a case where proportional control in which a coefficient is simply applied, proportional control, integral control for integrating an input, and differential control for differentiating an input are added.

Reference numeral 105 is a current detector as an example of drive signal detecting means for detecting the actual drive signal of the electromagnetic distortion element, which detects the actual current flowing through the electromagnetic distortion element, and the subtracter 103 is based on the output of the position control amplifier 102. The output of the current detector 105 is subtracted, and the current control amplifier 10 serving as drive signal control means
Output to 4. 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 becomes equal to the target drive signal.

Reference numeral 15 is a motor (see also FIG. 1) which is a second actuator for rotating the piston shaft, and 32 is an encoder (FIG. 1) for detecting the rotation angle of the motor 15.
See also). The motor 15 is driven by the motor driving device 111. Reference numeral 112 is a counter that counts the signals output from the encoder 32 and outputs the rotation angle of the motor 15.

The control device having the above-mentioned configuration controls the gap δ between the piston shaft 6 (FIG. 2) and the housing 8 (FIG. 2) to an arbitrary value.

Next, a method of correcting a variation in the detected value of the displacement sensor 33 depending on the rotation angle of the motor 15 will be described.

While the first actuator 1 is not driven (the current supply is cut off), the motor 5 is rotated,
The rotation angle output from the counter 112 and the amplifier 119
The relationship between the output position data of the shaft and the axial position data is stored in the correction amount storage / generation means.

As an example, when the number of pulses per rotation of the encoder 32 is 4000 pulses and stored at 10 pulse intervals, 360 ÷ 4000 × 10 = 0.9.
Can be stored at intervals. Here, the position of 0 ° is set to a position where the Z phase of the encoder 32 is turned on, or
After the position where the phase is turned on is set to 0 °, an offset may be added to set an arbitrary position to 0 °.

The counter 112 stored in this way
The average value of the axial position data of the shaft output from the amplifier 119 for each rotation angle output is calculated, and a value obtained by subtracting the average value from the stored position data is stored as a correction amount.

FIG. 5 is a waveform diagram for explaining the effect of this embodiment. As can be seen from FIG. 2, the displacement sensor cannot directly measure the gap δ between the discharge-side end surface 35 of the piston shaft 6 and the facing surface 37 due to mechanical constraints, so that the displacement sensor is located at a position away from the piston shaft 6. It is arranged. Therefore, since the displacement of the rotation of the piston shaft due to mechanical error is measured, the output of the amplifier 109 (FIG. 4) of the displacement sensor 33 (FIG. 4) is relative to the rotation angle of the piston shaft.
The waveform (displacement sensor output A) is as shown in FIG. This amplitude is 10 to 10 μm in the case of the present embodiment.
There is a degree. Therefore, when the position control is performed in this state, the piston shaft moves in the axial direction by 10 to 10 depending on the rotation angle.
It will move about several μm. In the present embodiment, the correction amount storage / generation means 113 subtracts the above-described correction amount (correction amount B in FIG. 5) from the output of the amplifier 109 of the displacement sensor 33 to obtain the displacement amount A in FIG. It becomes like -B, and the fluctuation of the measurement value of the displacement sensor 33 can be canceled.

That is, the front side main shaft 5 and the piston shaft 6 in FIG. 1 are integrated shafts, and the position of the flange surface (reference surface of the integrated shaft) of the front side main shaft 5 is measured by the displacement sensor 33. However, by performing the above control, it is possible to eliminate the influence of the shake of the rotation of the piston shaft due to a mechanical error, and it is possible to more accurately control the fluid discharge amount of the fluid discharge device.

[0073]

According to the fluid ejecting apparatus and method of the present invention, the gap between the shaft and the housing is measured by the displacement sensor, the rotation angle of the electromagnetic strain element is detected by the angle detector, and the rotation of the electromagnetic strain element is detected. The relationship between the angle and the measured value of the displacement sensor is stored, the correction amount of the measured value of the displacement sensor according to the rotation angle of the electromagnetic strain element is calculated and output from the relationship, and the corrected amount is subtracted from the measured value of the displacement sensor. Output as a real position signal, the target value of the gap between the shaft and the housing as a target position signal in the axial direction of the shaft, and the target drive signal of the electromagnetic distortion element based on the difference between the target position signal and the real position signal. Is output, the actual drive signal of the electromagnetic distortion element is detected, and the drive signal is controlled so that the actual drive signal becomes equal to the target drive signal, whereby the gap is controlled.

Therefore, the following effects can be obtained. 1. High-speed discharge cutoff of fluid and high-speed discharge can be started. 2. No troubles such as clogging of the flow path due to crushing of the powder and changes in the fluid characteristics will occur. 3. Furthermore, the pump of the present invention can also have the following features.

High-speed application of high-viscosity fluid is possible.

It is possible to discharge an extremely small amount with high accuracy.

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

[Brief description of drawings]

FIG. 1 is a sectional view showing a fluid ejection device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a discharge part of the fluid discharge device according to the embodiment of the present invention.

FIG. 3 is a diagram showing a graph of a discharge principle of the fluid discharge device according to the embodiment of the present invention.

FIG. 4 is a block diagram showing a control configuration of the fluid ejection device according to the embodiment of the present invention.

FIG. 5 is a waveform diagram illustrating effects of the fluid ejection device according to the embodiment of the present invention.

FIG. 6 is a diagram showing a conventional fluid discharge device.

[Explanation of symbols]

1 Axial direction driving means (electromagnetic strain element or giant magnetostrictive element) 2 central axis 3 housing 4 housing 5 Front side spindle 6 Piston shaft 8 cylinders 9 pump room 11 radial groove 12 suction port 13 Discharge nozzle 14 Discharge part 15 Motor (rotating means) 20 giant magnetostrictive rod 29 Bearing sleeve 30 bearings 31 Rotation transmission key 32 encoder (angle detector) 33 displacement sensor 35 Discharge end face of piston shaft 36 Discharge plate 38 Thrust groove 39 opening 100 Position command generating means 101 Subtractor 102 Position control amplifier (position control means) 103 Subtractor 104 current control amplifier (driving signal control means) 105 Current detector (driving signal detecting means) 110 subtractor (actual position signal generating means) 113 correction amount memory generating means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Teruo Maruyama             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 4D075 AC06 AC07 AC84 DB13 DC18                       DC21 DC24 EA35                 4F033 AA01 AA14 BA03 BA06 CA01                       DA01 EA01 GA00 NA01                 4F041 AA02 AA05 AB01 BA02 BA34

Claims (3)

[Claims] 1. A rotating means for relatively rotating a piston shaft and a cylinder accommodating the piston shaft, a piston axial direction driving means for giving a relative displacement in the piston axial direction between the piston shaft and the cylinder, and the piston shaft. And a pump chamber formed by the cylinder, a suction port and a discharge port for a fluid communicating from the pump chamber to the outside, and the fluid introduced into the pump chamber from the suction port to the discharge port side by pressure. And a gap between the discharge side end surface of the piston shaft and the discharge side end surface between the cylinders by the piston axial driving means in order to increase or decrease the fluid resistance between the pump chamber and the discharge port. In a fluid discharge device that controls the discharge amount of the fluid by changing the displacement of the piston shaft in the direction of the piston axis; Angle detector for detecting the rotation angle of the piston shaft, and a relationship between the signal detected by the displacement sensor and the signal detected by the angle detector is stored to correct the position of the piston shaft in the axial direction corresponding to the rotation angle of the piston shaft. A correction amount memory generating means for outputting an amount signal, and a real position signal generating means for subtracting the correction amount signal output from the correction amount memory generating means from a detection signal of the displacement sensor to output an actual position signal of the piston shaft. Position command generating means for outputting a target value signal in the piston axis direction of the piston shaft from the target value of the gap, and a target drive signal of the piston axis direction driving means from the difference between the target value signal and the actual position signal. Position control means for outputting, drive signal detection means for detecting an actual drive signal of the piston axial direction drive means, and the actual drive signal becomes equal to the target drive signal And a drive signal control means for controlling the drive signal to control the gap. 2. The fluid ejection device according to claim 1, wherein the piston axial driving means is an electromagnetic strain element. 3. A piston shaft and a cylinder are relatively moved in the axial direction of the piston shaft to adjust a gap between a discharge side end face of the piston shaft and a discharge side end face between the cylinders.
In a fluid discharge method of stopping or starting discharge of fluid from a discharge port provided in the cylinder, the piston shaft is rotated, the gap and a rotation angle of the piston shaft are measured, and the relation of the gap to the rotation angle is measured. Storing the correction amount of the gap at the rotation angle of the piston shaft from the relationship, and adjusting the gap between the piston shaft and the cylinder based on the correction amount,
A fluid discharge method, wherein the gap is set to a desired value.