JP6714229B2 - Liquid ejector - Google Patents

Description

The present invention relates to a liquid ejection device that pressurizes and ejects liquid.

In Patent Documents 1 and 2, the plunger pump is driven so that the liquid is sucked into the plunger pump, and then the liquid is pressurized and discharged from the nozzle. By alternately driving the pair of plunger pumps, the liquid is ejected while maintaining the pressure when ejecting the liquid from the nozzles substantially constant.

JP, 09-264261, A JP, 2008-019823, A

By alternately driving a pair of plunger pumps, it is possible to suppress fluctuations in the pressure of the liquid ejected from the nozzle, but when ejecting the liquid from the nozzle, the pressure of the liquid may fluctuate due to various factors. There is. Therefore, there is room for further improvement in suppressing the pressure fluctuation of the liquid.

The liquid ejection device of the present invention includes a pair of plunger pumps, a regulating valve, a pressure sensor, and a controller. Plunger pump, by the reciprocating motion of the plunger performs suction and ejection unloading of liquid alternately. The adjusting valve adjusts the pressure of the liquid alternately supplied from the pair of plunger pumps to discharge the liquid. The pressure sensor detects the pressure of the liquid supplied to the regulating valve. The controller controls the drive of the regulating valve based on the detection result of the pressure sensor. Of the pair of plunger pumps, when one plunger pump switches from the discharge state toward the reference position and the other plunger pump moves from the reference position and switches to the discharge state, both plunger pumps are the same. It is in a discharge state.

When the pressure detected by the pressure sensor is higher than the reference pressure, the controller drives the regulating valve to reduce the pressure of the liquid. When the pressure detected by the pressure sensor is lower than the reference pressure, the controller drives the regulating valve to increase the pressure of the liquid. As a result, the pressure of the liquid discharged from the adjusting valve can be changed along the reference pressure, and the pressure of the liquid discharged from the adjusting valve can be made substantially constant.

The regulating valve has a lower disc, an upper disc, a motor, and a power transmission mechanism. The lower disc allows liquid to pass through. The upper disc changes the cross-sectional area of the liquid flow path formed between the upper disc and the lower disc by moving with respect to the lower disc. The motor is driven by the controller. The power transmission mechanism converts the rotational movement of the motor into a linear movement and transmits it to the upper disc. The power transmission mechanism has a spring, a piston, and an amplification mechanism. The spring biases the upper disc away from the lower disc. The piston receives the rotational movement of the motor and makes a linear movement. The amplifying mechanism amplifies the moving force of the piston through the power transmitting liquid that comes into contact with the piston to move the upper disc in a direction approaching the lower disc against the biasing force of the spring.

According to the present invention, by adjusting the pressure of the liquid with the adjusting valve, it becomes easy to suppress the fluctuation of the pressure of the liquid discharged from the nozzle.

It is a schematic diagram showing the structure of a liquid ejection device. It is a schematic diagram showing the internal structure of a regulating valve. It is an enlarged view showing a part of structure of a regulating valve. It is a figure explaining operation|movement of a pair of plunger pump. It is a figure which shows the SEM image of a cellulose nanofiber.

The structure of the liquid ejection device according to the embodiment of the present invention will be described with reference to FIG.

The liquid ejection device 1 has a pair of plunger pumps 2. The pair of plunger pumps 2 have the same structure. Hereinafter, the structure of each plunger pump 2 will be described.

The motor 10 receives electric power from a power source (not shown) and rotates. A reduction mechanism 11 is connected to the output shaft 10a of the motor 10, and the reduction mechanism 11 reduces the rotation speed of the motor 10 to increase the torque. The reduction mechanism 11 has a drive pulley 12, and the rotational force of the motor 10 is transmitted to the drive pulley 12 via the reduction mechanism 11.

A timing belt 14 is engaged with the drive pulley 12 and the driven pulley 13, and the driven pulley 13 rotates as the timing belt 14 moves according to the rotation of the drive pulley 12. The driven pulley 13 is connected to the ball screw 15, and the ball screw 15 rotates (forward or reverse) in the direction of arrow D1 according to the rotation of the driven pulley 13. Here, the reduction mechanism 11 and the ball screw 15 are supported by the holder 16.

A nut 17 meshes with the ball screw 15, and the nut 17 moves in the axial direction of the ball screw 15 according to the rotation of the ball screw 15. Here, the moving direction of the nut 17 can be changed by changing the rotating direction of the ball screw 15. For example, the nut 17 can be moved in the direction of arrow D2 by rotating the ball screw 15 in the normal direction. Further, the nut 17 can be moved in the direction of the arrow D3 by reversing the ball screw 15.

A slider 18 is fixed to the nut 17. By engaging the linear guide 19, the slider 18 can move in the same direction as the moving direction of the nut 17. A plunger 20 is connected to the slider 18 via a plunger support (not shown). By moving the slider 18, the plunger 20 moves in the same direction as the moving direction of the slider 18. Specifically, the plunger 20 moves in the direction of arrow D4 or the direction of arrow D5.

The tip portion 21 of the plunger 20 is inserted into the pressure chamber 31 of the pressure cylinder 30. Here, in FIG. 1, the internal structure of the pressurizing cylinder 30 is shown. A sealing member 32 is arranged between the outer peripheral surface of the plunger 20 and the inner wall surface of the pressurizing chamber 31.

The pressurizing cylinder 30 has a suction port 33 for sucking the liquid, and a tank (not shown) for storing the liquid is connected to the suction port 33 via a pipe (not shown). This allows the liquid in the tank to move to the suction port 33 via the pipe. A check valve 33 a is arranged in the suction port 33, and the suction port 33 is connected to the pressurizing chamber 31 via a communication passage 34. As a result, the liquid sucked from the suction port 33 can be guided to the pressurizing chamber 31 via the communication passage 34. By disposing the check valve 33a, the liquid moves only in the direction from the suction port 33 toward the pressurizing chamber 31.

The pressurizing cylinder 30 has a delivery port 35 for delivering the liquid, and the delivery port 35 is connected to the pressurizing chamber 31 via a communication passage 36. As a result, the liquid in the pressurizing chamber 31 moves through the communication passage 36 and is guided to the delivery port 35.

A branch pipe 40 is connected to the pair of plunger pumps 2 described above. The branch pipe 40 has two suction ports 41 and one delivery port 42. One suction port 41 is connected to the delivery port 35 of the pressurizing cylinder 30 in the one plunger pump 2, and the other suction port 41 is connected to the delivery port 35 of the pressurizing cylinder 30 in the other plunger pump 2. Has been done. Since the check valve 35 a is arranged at the delivery port 35, the liquid moves only in the direction from the delivery port 35 toward the suction port 41.

A regulating valve 100 is connected to the outlet 42 of the branch pipe 40. The adjusting valve 100 adjusts the pressure of the liquid supplied from the delivery port 42 to discharge the liquid having a substantially constant pressure. The specific structure of the adjusting valve 100 will be described later.

When the plunger 20 moves in the direction of the arrow D4 while the liquid is stored in the pressurizing chamber 31, the liquid in the pressurizing chamber 31 is compressed and the pressure in the pressurizing chamber 31 rises. As a result, the pressurized liquid can be moved from the pressurizing chamber 31 to the adjusting valve 100. After the liquid is delivered from the pressurizing chamber 31, when the plunger 20 moves in the direction of the arrow D5, the liquid supplied to the suction port 33 moves in the communication passage 34 by the suction force accompanying the movement of the plunger 20. It moves to the pressurizing chamber 31. As a result, the liquid can be contained in the pressurizing chamber 31.

As described above, the plunger 20 alternately moves in the directions of the arrow D4 and the arrow D5 to suck the liquid into the pressurizing chamber 31 (referred to as a sucking process) and to send the liquid from the pressurizing chamber 31 to adjust the valve. The step of ejecting the liquid from 100 (referred to as the ejection step) can be alternately performed.

The branch pipe 40 is provided with a pressure sensor 43 for detecting the pressure of the liquid moving from the suction port 41 to the delivery port 42. The pressure detected by the pressure sensor 43 is transmitted to the controller 50. Here, the alternate long and short dash line shown in FIG. 1 represents electrical connection.

The controller 50 controls the drive of the adjustment valve 100 based on the pressure detected by the pressure sensor 43. Specifically, when the pressure detected by the pressure sensor 43 is lower than a predetermined reference pressure (predetermined value), the controller 50 drives the adjustment valve 100 to control the pressure of the liquid moving the adjustment valve 100. By increasing the pressure, the pressure of the liquid discharged from the adjusting valve 100 is increased. As a result, the pressure of the liquid discharged from the adjusting valve 100 can be brought close to the reference pressure.

On the other hand, when the pressure detected by the pressure sensor 43 is higher than the predetermined reference pressure, the controller 50 drives the adjusting valve 100 to reduce the pressure of the liquid moving in the adjusting valve 100, thereby reducing the adjusting valve. The pressure of the liquid discharged from 100 is reduced. As a result, the pressure of the liquid discharged from the adjusting valve 100 can be brought close to the reference pressure. As described above, by controlling the drive of the adjustment valve 100, when the liquid is continuously discharged from the adjustment valve 100, the pressure of the liquid can be easily kept constant.

When controlling the drive of the regulating valve 100, a predetermined pressure range can be set instead of the above-mentioned reference pressure. The predetermined pressure range is a range defined by an upper limit value (pressure) and a lower limit value (pressure). Here, when the pressure detected by the pressure sensor 43 is higher than the upper limit value of the pressure range, the controller 50 can drive the adjustment valve 100 to reduce the pressure of the liquid. Further, when the pressure detected by the pressure sensor 43 is lower than the lower limit value of the pressure range, the controller 50 can drive the adjustment valve 100 to increase the pressure of the liquid. Thereby, the pressure of the liquid discharged from the adjusting valve 100 can be maintained within the predetermined pressure range.

Further, in the present embodiment, the rotational force of the motor 10 is transmitted to the ball screw 15 via the speed reduction mechanism 11, the drive pulley 12, the timing belt 14 and the driven pulley 13, but the present invention is not limited to this. That is, any structure may be used as long as the rotational force of the motor 10 can be transmitted to the ball screw 15.

Next, the structure of the adjusting valve 100 will be described with reference to FIGS. 2 and 3. FIG. 2 is a schematic view showing the internal structure of the adjusting valve 100, and FIG. 3 is an enlarged view showing the structure of a part of the adjusting valve 100.

A seat 101 is connected to the branch pipe 40, and a lower disk 102 is arranged on the upper surface of the seat 101. The liquid from the branch pipe 40 passes through the sheet 101 and the lower disc 102. As shown in FIG. 3, on the upper surface of the lower disk 102, a convex portion 102a protruding upward is formed. An impact ring 103 is arranged around the outside of the convex portion 102 a, and the impact ring 103 is fixed to the upper surface of the lower disc 102.

The lower disc 102 and the impact ring 103 are fixed to the inner peripheral surface of the sleeve 104. A body 105 is arranged on the outer peripheral surface of the sleeve 104. The sleeve 104 and the body 105 are respectively formed with passages 104a and 105a for guiding the liquid to the outside of the regulating valve 100. The liquid passes through the passages 104a and 105a and is discharged from the regulating valve 100.

An upper disc 106 is arranged above the lower disc 102. The lower end portion of the upper disc 106 is separated upward from the convex portion 102a of the lower disc 102. In the present embodiment, the pressure of the liquid passing through the adjusting valve 100 can be adjusted by adjusting the clearance formed between the lower end of the upper disc 106 and the convex portion 102a. This principle will be described later.

A guide member 107 for guiding the upper disc 106 in the vertical direction is arranged between the upper disc 106 and the sleeve 104. A first cylinder 108 is arranged on the upper surfaces of the sleeve 104, the body 105, and the guide member 107. A recess 108a for accommodating the return rod 109 is formed in the first cylinder 108, and a through hole 108b through which the shaft portion 109a of the return rod 109 penetrates is formed in the bottom surface of the recess 108a. The upper end of the upper disc 106 is connected to the lower end of the shaft 109a.

A spring 110 is arranged in the recess 108a. The upper end of the spring 110 is in contact with the flange portion 109b of the return rod 109, and the lower end of the spring 110 is in contact with the bottom surface of the recess 108a. Since the spring 110 is housed in the recess 108a in a compressed state, it biases the return rod 109 upward.

The upper end surface of the return rod 109 is connected to the master piston 111. The master piston 111 is housed inside the second cylinder 112, and is vertically movable inside the second cylinder 112. A piston 113 is housed inside the second cylinder 112. The liquid L is contained in the space formed between the lower end of the piston 113 and the upper end surface of the master piston 111. The liquid L is used to transmit power between the piston 113 and the master piston 111.

The upper end of the piston 113 is connected to the lower end of the ball screw 114. A part of the ball screw 114 is engaged with the rotation stopper 115, and the rotation stopper 115 prevents the rotation of the ball screw 114. The rotation stopper 115 is fixed to the inner peripheral surface of the third cylinder 116.

A nut 117 is arranged above the third cylinder 116. Since the bearing mechanism is arranged between the nut 117 and the third cylinder 116, the nut 117 is rotatable with respect to the third cylinder 116. The nut 117 is connected to the motor 118 and rotates by receiving power from the motor 118. The drive of the motor 118 is controlled by the controller 50.

The screw portion formed on the inner peripheral surface of the nut 117 is engaged with the ball screw 114, and the ball screw 114 receives the rotational force of the nut 117 and moves in the vertical direction. The ball screw 114 penetrates the motor 118 and projects above the motor 118. A sensor dog 119 is fixed to an upper end portion of the ball screw 114 protruding from the motor 118, and the sensor dog 119 moves in the vertical direction together with the ball screw 114. The position sensor 120 detects the position of the sensor dog 119 and outputs the detection result to the controller 50.

Next, the operation of the regulating valve 100 will be described.

When the controller 50 causes the motor 118 to rotate in the normal direction, the rotational force of the motor 118 is transmitted to the nut 117 and the nut 117 rotates in one direction. The ball screw 114 moves downward as the nut 117 rotates. Here, since the ball screw 114 is engaged with the rotation stopper 115, the ball screw 114 moves downward without rotating together with the nut 117.

Since the piston 113 is connected to the lower end of the ball screw 114, when the ball screw 114 moves downward, the piston 113 also moves downward. The lower end of the piston 113 is in contact with the liquid L, and the piston 113 moves downward to push the liquid L downward. Since the liquid L is in contact with the master piston 111, the downward moving force of the piston 113 is transmitted to the master piston 111 via the liquid L. As a result, the master piston 111 moves downward.

Here, the diameter of the master piston 111 is larger than the diameter of the piston 113, and the liquid L is in contact with the entire upper surface of the master piston 111. As a result, the downward moving force of the piston 113 can be amplified and transmitted to the master piston 111.

Since the lower end surface of the master piston 111 is connected to the return rod 109, when the master piston 111 moves downward, the return rod 109 moves downward. Here, the return rod 109 is given an urging force of the spring 110, but the return rod 109 moves downward against the urging force of the spring 110 by receiving the pressing force from the master piston 111. ..

Since the upper disc 106 is connected to the lower end of the return rod 109, when the return rod 109 moves downward, the upper disc 106 also moves downward. As a result, the clearance between the lower end of the upper disc 106 and the convex portion 102a of the lower disc 102 is narrowed. Since this clearance defines the cross-sectional area of the flow passage through which the liquid passes, the pressure of the liquid passing through the flow passage can be increased by narrowing the clearance.

On the other hand, when the controller 50 causes the motor 118 to rotate in the reverse direction, the operation reverse to the operation described above is performed. That is, the nut 117 rotates in the other direction in response to the reverse rotation of the motor 118, and the ball screw 114 moves upward. As a result, the piston 113 moves upward together with the ball screw 114. Here, since the return rod 109 is biased by the spring 110, when the piston 113 moves upward, the master piston 111 receives the biasing force of the spring 110 via the return rod 109 and moves upward. To do. The liquid L moves according to the movement of the piston 113 and the master piston 111.

As a result, the lower end portion of the upper disc 106 moves in a direction away from the convex portion 102a of the lower disc 102, and the clearance between the lower end portion of the upper disc 106 and the convex portion 102a of the lower disc 102 expands. By widening the clearance, the pressure of the liquid passing through the flow path can be reduced.

The controller 50 controls the drive of the motor 118 based on the detection results of the pressure sensor 43 and the position sensor 120 so that the pressure of the liquid discharged from the adjustment valve 100 becomes substantially constant. Here, the controller 50 can grasp the current liquid pressure based on the detection result of the pressure sensor 43. Further, the controller 50 can grasp the state of the regulating valve 100 (that is, the above-mentioned clearance) based on the detection result of the position sensor 120. By grasping these, the controller 50 controls the drive of the motor 118 and adjusts the position of the upper disk 106 (that is, the above-mentioned clearance), so that the pressure of the liquid discharged from the adjustment valve 100 is substantially constant. Can be

According to the adjusting valve 100 of the present embodiment, for example, emulsification processing or crushing processing can be performed. In the emulsification treatment, when the liquid containing fat globules passes through the clearance between the lower end of the upper disc 106 and the convex portion 102a of the lower disc 102, the fat globules are destroyed and minute fat globules are generated ( (See FIG. 3). In the crushing process, for example, when the liquid containing the raw material fibers passes through the clearance between the lower end portion of the upper disc 106 and the convex portion 102a of the lower disc 102, the raw material fibers are broken and fine fibers are generated ( (See FIG. 3).

In the present embodiment, the motor 118 is driven based on the detection result of the pressure sensor 43 to change the clearance between the lower end of the upper disc 106 and the convex portion 102a of the lower disc 102. It is possible to suppress clogging of the liquid inside the container. When the liquid is clogged inside the adjustment valve 100, the pressure of the liquid rises. Therefore, the liquid clogging can be suppressed by expanding the clearance as described above. For example, when a liquid containing raw material fibers is used, it is possible to prevent the raw material fibers from clogging inside the adjusting valve 100.

Next, a method of driving the pair of plunger pumps 2 will be described.

In each plunger pump 2, the suction process and the discharge process described above are alternately repeated. Specifically, when the pair of plunger pumps 2 are driven, when one of the plunger pumps 2 performs the discharge process, the other plunger pump 2 performs the suction process. Further, when the discharge process is performed by the other plunger pump 2, the suction process is performed by the one plunger pump 2. In this way, by driving the pair of plunger pumps 2, it is possible to continuously discharge the liquid from the adjusting valve 100 while keeping the pressure of the liquid discharged from the adjusting valve 100 substantially constant.

FIG. 4 is a timing chart showing a discharge process and a suction process in the pair of plunger pumps 2. In FIG. 4, the horizontal axis represents time and the vertical axis represents the position of the plunger 20. Here, of the pair of plunger pumps 2, one plunger pump 2 is referred to as a first plunger pump 2, and the other plunger pump 2 is referred to as a second plunger pump 2.

At time t0, the plunger 20 of the first plunger pump 2 is at the reference position, and the plunger 20 of the second plunger pump 2 is at the discharge position. After time t0, the plunger 20 of the first plunger pump 2 moves in the direction of the arrow D4 shown in FIG. 1, and at time t1, the plunger 20 of the first plunger pump 2 reaches the discharge position. In the second plunger pump 2, the plunger 20 is at the discharge position from time t0 to time t1.

As described above, when the plunger 20 of the first plunger pump 2 moves from the reference position toward the discharge position, the liquid is sent out from the pressurizing chamber 31 of the pressurizing cylinder 30 toward the adjusting valve 100, and the adjusting valve The liquid starts to be ejected from 100. Then, while the plunger 20 of the first plunger pump 2 is stopped at the discharge position, the liquid is continuously discharged from the adjustment valve 100.

After time t1, the plunger 20 of the first plunger pump 2 is maintained at the discharge position. On the other hand, after the time t1, the plunger 20 of the second plunger pump 2 moves from the discharge position toward the reference position, and at the time t2, the plunger 20 of the second plunger pump 2 reaches the reference position. From time t2 to time t3, the plunger 20 of the second plunger pump 2 is stopped at the reference position.

After time t3, the plunger 20 of the second plunger pump 2 moves in the direction of arrow D5 shown in FIG. 1 to move from the reference position toward the suction position. At time t4, the plunger 20 of the second plunger pump 2 reaches the suction position. From time t4 to time t5, the plunger 20 of the second plunger pump 2 is stopped at the suction position.

As described above, as the plunger 20 of the second plunger pump 2 moves from the reference position toward the suction position, the liquid is sucked into the pressurizing chamber 31 of the pressurizing cylinder 30, and the liquid is stored in the pressurizing chamber 31. To be done. The liquid continues to be sucked into the pressurizing chamber 31 while the plunger 20 of the second plunger pump 2 is stopped at the suction position.

After time t5, the plunger 20 of the second plunger pump 2 moves in the direction of arrow D4 shown in FIG. 1 to move from the suction position toward the reference position. Then, at time t6, the plunger 20 of the second plunger pump 2 reaches the reference position.

From time t6 to time t7, the plunger 20 of the second plunger pump 2 stops at the reference position. After time t7, the plunger 20 of the second plunger pump 2 moves from the reference position toward the discharge position by moving in the direction of arrow D4 shown in FIG. At time t8, the plunger 20 of the second plunger pump 2 reaches the discharge position. After time t8, the plunger 20 of the second plunger pump 2 stops at the discharge position.

As described above, by moving the plunger 20 of the second plunger pump 2 from the reference position toward the discharge position, liquid is sent out from the pressurizing chamber 31 of the pressurizing cylinder 30 toward the adjusting valve 100, and the adjusting valve The liquid starts to be ejected from 100. Then, while the plunger 20 of the first plunger pump 2 is stopped at the discharge position, the liquid is continuously discharged from the adjustment valve 100.

The plunger 20 of the first plunger pump 2 is stopped at the discharge position from time t1 to time t8. After time t8, the plunger 20 of the first plunger pump 2 moves in the direction of arrow D5 shown in FIG. 1 to move from the discharge position toward the reference position. Then, at time t9, the plunger 20 of the first plunger pump 2 reaches the reference position.

After time t8, the first plunger pump 2 performs the same operation as the operation of the second plunger pump 2 from time t1 to time t7. After time t8, the second plunger pump 2 performs the same operation as the operation of the first plunger pump 2 from time t1 to time t8. As described above, as the operation of each plunger pump 2, the operation of the first plunger pump 2 from time t0 to time t9 and the operation of the second plunger pump 2 from time t2 to time t7 alternate. To be done.

According to the present embodiment, while the plunger 20 of the first plunger pump 2 is stopped at the discharge position and liquid is being discharged from the regulating valve 100, that is, from the time t1 to the time t8 shown in FIG. The plunger 20 of the two-plunger pump 2 moves from the discharge position to the suction position and then moves to the discharge position.

Here, at time t1, the plungers 20 of the pair of plunger pumps 2 are at the discharge position, and the discharge process by the second plunger pump 2 is switched to the discharge process by the first plunger pump 2. Further, at time t8, the plungers 20 of the pair of plunger pumps 2 are in the discharge position, and the discharge process by the first plunger pump 2 is switched to the discharge process by the second plunger pump 2. By driving the pair of plunger pumps 2 in this way, it is possible to suppress fluctuations in the pressure of the liquid when the liquid is continuously discharged from the regulating valve 100.

The liquid ejection device 1 of this embodiment can be used in various technical fields.

For example, in the fiber field, cellulose nanofibers are being developed. Here, by supplying the liquid containing the raw material fiber to the liquid discharge device 1, the raw material fiber can be crushed in the adjusting valve 100 to produce the cellulose nanofiber. FIG. 5 shows an SEM image of cellulose nanofibers produced by using a hardwood bleached pulp as a raw material fiber.

On the other hand, in the chemical industry, the emulsification step is performed in many processes, and as an example, silicone oil and water emulsions are used in a wide range of fields. By using the liquid ejecting apparatus 1 of the present embodiment, by ejecting silicon oil under a high pressure (for example, 150 MPa or more), an emulsion of silicon oil having a minute particle diameter can be generated, and the emulsion-containing liquid is transparent. Can give sex.

Further, the pigment-based paint (particles) is difficult to disperse in a medium such as water, but by ejecting the pigment-based paint under a high pressure using the liquid ejection device 1 of the present embodiment, the pigment-based paint is dispersed in the medium. Easy to disperse. Furthermore, when the pigment particles are dispersed in the ink liquid, the liquid ejection device 1 of this embodiment can be used. Here, by ejecting the pigment particles under high pressure, fine pigment particles can be generated and the pigment particles can be easily dispersed in the ink liquid. Further, when the particles used in cosmetics are made finer, the liquid ejection device 1 of the present embodiment can be used. By using the liquid ejection device 1 to eject cosmetic raw materials under high pressure, fine particles can be generated.

1: Liquid discharge device, 2: Plunger pump, 10: Motor, 11: Reduction mechanism,
12: drive pulley, 13: driven pulley, 14: timing belt, 15: ball screw,
17: Nut, 18: Slider, 19: Linear Guide, 20: Plunger,
30: pressure cylinder, 31: pressure chamber, 40: branch pipe, 43: pressure sensor,
50: controller, 100: adjusting valve

Claims (2)

A pair of plunger pumps that alternately suck and discharge the liquid by the reciprocating motion of the plunger,
An adjustment valve for discharging the liquid by adjusting the pressure of the liquid alternately supplied from the pair of plunger pumps,
A pressure sensor for detecting the pressure of the liquid supplied to the adjusting valve,
Based on the detection result of the pressure sensor, a controller for controlling the drive of the adjustment valve,
Have
Among the pair of plunger pumps, one of the plunger pumps switches from the discharge state toward the reference position, and the other plunger pump moves from the reference position to the discharge state at the timing of switching the pair of plunger pumps. same discharge state and Do Ri,
The adjusting valve is
A lower disk that allows liquid to pass through,
An upper disk that changes the cross-sectional area of the liquid flow path formed between the lower disk and the lower disk by moving with respect to the lower disk;
A motor driven by the controller,
A power transmission mechanism for converting the rotational movement of the motor into a linear movement and transmitting the linear movement to the upper disc,
The power transmission mechanism is
A spring for urging the upper disc in a direction away from the lower disc,
A piston that receives the rotational movement of the motor to make a linear movement;
An amplifying mechanism for moving the upper disk in a direction approaching the lower disk against the biasing force of the spring by amplifying the moving force of the piston via the power transmission liquid that contacts the piston. A liquid ejecting apparatus having: The controller is
When the pressure detected by the pressure sensor is higher than a reference pressure, the regulating valve is driven to reduce the pressure of the liquid,
The liquid ejecting apparatus according to claim 1, wherein when the pressure detected by the pressure sensor is lower than the reference pressure, the adjusting valve is driven to increase the pressure of the liquid.