KR101205869B1 - Metering pump - Google Patents

Abstract

The present invention relates to a metering pump, and because the reciprocating motion of the pumping shaft is forced through the connecting rod, the reciprocating motion and the reciprocating cycle of the pumping shaft and the diaphragm can be accurately implemented without errors. The metering pump according to the present invention includes a drive motor having a drive shaft, an eccentric shaft formed around an eccentric point from the center of the drive shaft of the drive motor, a working oil part having an inlet and a discharge port, and one side of the operating oil chamber. It comprises a diaphragm to form, a pumping shaft fixed to one surface of the diaphragm and a linear connecting rod and a connecting rod having one end hinged to the pumping shaft and the other end hinged to the eccentric shaft.

Description

Metering pumps {METERING PUMP}

The present invention relates to a metering pump, and more particularly, by adopting a structure in which an eccentric shaft is additionally formed on the drive shaft of the motor to periodically reciprocate the diaphragm of the metering pump, and the eccentric shaft and the diaphragm are coupled using a connecting rod. The present invention relates to a metering pump that can transmit powerful driving force to a diaphragm and accurately realize the reciprocating cycle of the diaphragm.

In general, the metering pump is a pump that reciprocates the diaphragm by reciprocating motion of the plunger operated by the driving force of the driving motor to generate suction and discharge of the fluid.

The reciprocating movement of the diaphragm repeatedly changes the pressure of the pump head, and the change of the pressure causes the suction and discharge of the fluid, thereby causing the pumping operation of the metering pump.

1 is a view showing the structure of a conventional metering pump. As shown in FIG. 1, in the conventional metering pump, the eccentric cam 6 is connected to the drive shaft 5 of the motor, and the eccentric cam 6 contacts the power transmission frame 9a by the guide 9b. When the guided power transmission frame 9a is pushed, the pumping shaft 8 in contact with the power transmission frame 9a is moved to reciprocate the diaphragm (not shown). When the eccentric cam is retracted, the pumping shaft is returned by the restoring force of the spring 7.

However, this conventional metering pump has the following problems.

As the pumping shaft is moved forward by the power transmission frame directly contacting the eccentric cam, the pumping shaft can be precisely moved forward. However, the pumping shaft is driven by the restoring force of the spring. There is a problem in the quantitative transfer of fluid because it is not made properly, such as delay. Therefore, it is troublesome to select the spring in consideration of the viscosity of the fluid to be transferred and to replace the spring when the fluid is changed.

In addition, the eccentric cam contacts the power transmission frame and transmits power. The rounded contact portion of the eccentric cam and the power transmission frame continuously changes the force transmission direction, whereas the power transmission frame is movable only horizontally by the guide. Wear between the guide and the power transmission frame is inevitably deteriorated, there is a problem that must be reduced durability.

The present invention has been made to solve the problems of the prior art as the present invention forcibly moving the reciprocating motion of the pumping shaft through the connecting rod can accurately implement the reciprocating motion and reciprocating cycle of the pumping shaft and diaphragm without error There is an advantage.

An object of the present invention described above is a drive motor having a drive shaft, an eccentric shaft formed around an eccentric point from the center of the drive shaft of the drive motor, a working oil chamber having a suction port and a discharge port, and one side of the operating oil chamber. It is achieved by a metering pump including a diaphragm to be formed, a pumping shaft fixed to one surface of the diaphragm, and a connecting rod having one end hinged to the pumping shaft and the other end hinged to the eccentric shaft.

In order to achieve the above object, the discharge side check ball receiving portion and the discharge side check ball accommodation portion provided in the discharge side check ball accommodation portion and the discharge side check ball accommodation portion formed on the outer side of the discharge port of the operating oil chamber portion and the discharge side check ball A first sensor for sensing the advancement state of the diaphragm and a pressurizing means for pressurizing the discharge port, and a second sensor for detecting a distance from which the discharge side check ball rises from the discharge port, and receiving a signal from the first sensor and the second sensor. It further comprises a control unit for controlling the operation of the drive motor, the inner diameter of the discharge side check ball receiving portion is preferably formed larger than the diameter of the discharge side check ball.

Further, in order to achieve the above object, the suction side check ball receiving portion and the suction side check ball receiving portion which is formed inside the suction port of the operating fluid chamber and the first side for detecting the reverse state of the diaphragm And a second sensor for sensing a distance from the suction port by a sensor and the suction side check ball, and a controller configured to control the operation of the driving motor by receiving a signal from the first sensor and the second sensor. The inner diameter of the check ball accommodation portion is preferably formed larger than the diameter of the suction side check ball.

In order to achieve the above object, it is preferable that the diaphragm is formed convex toward the working oil chamber and the outer side of the central part is concave.

According to the present invention, since the accurate reciprocating motion of the diaphragm is secured without the delay time by using the connecting rod, the quantitative transfer of fluid is completely realized.

In addition, even if the type of fluid to be transferred is different, since the quantitative transfer of the fluid is realized regardless of the type of fluid, there is no need to replace a specific part of the metering pump according to the type of fluid.

In addition, when the air is sucked in the inlet for sucking the fluid in the metering pump, the inhaled air is prevented from being discharged through the discharge port, thereby preventing the occurrence of an accident by discharging air rather than the intended fluid.

1 is a view showing the structure of a conventional metering pump.
2 is a view briefly showing a part of the configuration of the metering pump according to the first embodiment of the present invention,
3 is a perspective view briefly illustrating a connection configuration of an eccentric shaft and a pumping shaft of a metering pump according to a first embodiment of the present invention;
4 is a cross-sectional view briefly showing the internal configuration of the metering pump according to the first embodiment of the present invention,
5 is a view showing the configuration of a metering pump according to a second embodiment of the present invention,
6 is a view showing a part of the metering pump according to the second embodiment of the present invention,
7 is a view showing a state in which air is sucked in the metering pump according to the second embodiment of the present invention,
FIG. 8 is a diagram comparing the size of a flow path around a discharge port in an advanced state of a diaphragm and a comparison target diaphragm which are commonly used in the first and second embodiments of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration of the metering pump according to a preferred embodiment of the present invention.

2 is a view schematically showing a part of the configuration of the metering pump according to the first embodiment of the present invention, Figure 3 is a simplified configuration of the connection between the eccentric shaft and the pumping shaft of the metering pump according to the first embodiment of the present invention Figure 4 is a perspective view, Figure 4 is a simplified cross-sectional view showing the internal configuration of the metering pump according to the first embodiment of the present invention.

As shown in Figures 2 and 3, the metering pump according to a preferred embodiment of the present invention is a diaphragm forming a surface of the operating oil chamber 10, the operating oil chamber 10, the suction port 20 and the discharge port 30 is formed 15, a pumping shaft 40 coupled to the diaphragm 15, a driving motor (not shown), an eccentric shaft 55 formed on the driving shaft 50 of the driving motor, an eccentric shaft 55, and a pumping shaft 40. It comprises a connecting rod 60 and the control unit 70 for connecting the.

The working oil compartment 10 is a suction port 20 and a discharge port 30 are formed as a space in which the fluid sucked through the suction port 20 for the fixed quantity transfer. The suction side check ball accommodating part 21 is formed inside the suction port 20, and the discharge side check ball accommodating part 31 is formed outside the discharge port 30. Each of the suction port 20 and the discharge port 30 is provided with a suction side check ball 22 and a discharge side check ball 32 for closing the suction port 20 and the discharge port 30. One surface of the working oil compartment 10 is composed of a diaphragm 15 to be retracted.

The suction port 20 of the operating oil chamber part 10 is connected to the suction side check ball accommodation part 21, and the suction side check ball accommodation part 21 is positioned at the suction side check ball 22 for closing the suction port 20. The suction side check ball restricting portion 23 is formed inside the suction port 20 of the seal portion 10. The suction side check ball retainer 23 has a passage formed so that the suctioned fluid passes but the suction side check ball 22 does not pass, so the suction side check ball 22 is connected to the suction port 20 side. Prevents the tube 24 from closing. The inner diameter of the suction side check ball accommodating part 21 is larger than the diameter of the suction side check ball 22 so that a gap is formed between the suction side check ball accommodating part 21 and the suction side check ball 22.

The discharge port 30 of the working oil compartment 10 is connected to the discharge side check ball accommodation part 31, and the discharge side check ball 32 for closing the discharge port 30 is positioned at the discharge side check ball accommodation part 31. The discharge side check ball constraining portion 33 is formed outside the discharge port 30 of the? The discharge side check ball constraining portion 33 has a passage formed therein so that the discharged fluid passes, but the discharge side check ball 32 does not pass, so that the discharge side check ball 32 is connected to the discharge port 30 from the discharge side connection pipe ( 34) prevent closure. The inner diameter of the discharge side check ball accommodating part 31 is larger than the diameter of the discharge side check ball 32 so that a gap is formed between the discharge side check ball accommodating part 31 and the discharge side check ball 32.

The diaphragm 15 is a configuration that changes the volume of the working oil compartment 10 while repeating deformation in the front and rear direction, and is formed of a synthetic resin material that can be deformed. The diaphragm 15 is formed on one surface of the working oil compartment 10, and the circumference of the diaphragm 15 is hydraulic It is fixed to the seal part 10. One surface of the diaphragm 15 forming one surface of the working oil compartment 10 has a structure in which the portion 17 adjacent to the edge of the diaphragm 15 is recessed inwardly, but the center portion 16 is relatively convexly protruding. to be.

The pumping shaft 40 is fixed to the rear of the diaphragm 15. Outside the pumping shaft 40, a guide 42 for guiding the linear movement of the diaphragm 15 in the horizontal direction is formed. The rear end of the pumping shaft 40 is formed with a coupling hole for coupling with the connecting rod 60 to be described later.

The driving motor generates a driving force for operating the diaphragm 15, and an eccentric shaft extends from an end of the driving shaft 50 at an end of the driving shaft 50 of the driving motor about a point away from the center of the driving shaft 50. 55 is formed.

The connecting rod 60 connects the eccentric shaft 55 formed on the drive shaft 50 and the pumping shaft 40 fixed to the diaphragm 15. One end of the connecting rod 60 is hinged to one end of the pumping shaft 40 by the pin 61 and the other end of the connecting rod 60 is the eccentric shaft 55 and the hinge formed at the end of the drive shaft 50. Combined. Since a specific configuration for coupling the connecting rod 60 and the pumping shaft 40 and the eccentric shaft 55 is well known, description thereof will be omitted.

Hereinafter will be described the operation of the metering pump according to the first embodiment of the present invention.

When the drive motor of the metering pump operates, the eccentric shaft 55 formed on the drive shaft 50 rotates.

When the eccentric shaft 55 rotates, the connecting rod 60 connected to the eccentric shaft 55 reciprocates back and forth.

When the connecting rod 60 reciprocates in the front-rear direction, the pumping shaft 40 connected to the front end of the connecting rod 60 reciprocates in the front-back direction, and the diaphragm 15 coupled to one end of the pumping shaft 40. Figure also performs the suction and discharge process of the fluid while reciprocating in the front and rear direction.

At this time, the forward and backward of the diaphragm 15 coincides with the forward and backward of the pumping shaft 40 to which the diaphragm 15 is coupled, and the forward and backward of the pumping shaft 40 is made by the movement of the connecting rod 60. The movement of the connecting rod 60 is precisely controlled by the eccentric shaft 55 formed on the drive shaft 50 of the drive motor. Therefore, since the movement of the diaphragm 15 is forcibly performed by the drive motor, the movement of the diaphragm 15 is completely controlled through the control of the drive motor without being affected by the viscosity of the fluid to be transferred. Therefore, when the viscosity of the fluid is large, the diaphragm does not return smoothly, and the metering pump of the present invention solves the problem of the conventional metering pump, which cannot carry out the metering of the fluid.

5 is a view showing the configuration of a metering pump according to a second embodiment of the present invention, Figure 6 is a view showing a part of the metering pump according to a second embodiment of the present invention, Figure 7 is a view of the present invention 2 is a view showing a state in which air is sucked in the metering pump according to the second embodiment.

As shown in Figure 5 and 6, the metering pump according to the second embodiment of the present invention is the same as most of the metering pump according to the first embodiment of the present invention shown in Figures 2 to 4, However, the difference is that the configuration around the discharge port 30 of the working oil chamber part 10 is different and the sensing means for detecting the position of the diaphragm 15 (first sensor 71) and the position of the discharge side check ball 32 The means (second sensor 72) is further formed. Therefore, in describing the configuration of the metering pump according to the second embodiment, the same configuration as that of the metering pump according to the first embodiment will be omitted for simplicity of description.

In the metering pump according to the second embodiment of the present invention, the pressurizing means 37 is provided between the discharge port 30 of the working oil chamber part 10 and the discharge side check ball restricting part 33. The pressurizing means 37 serves to bring the discharge side check ball 32 into close contact with the discharge port 30. The spring means 37 may be used. However, the pressing means 37 is not limited to a spring as a configuration for pushing the discharge side check ball 32 with a predetermined force, and various elastic bodies having a restoring force capable of pushing the discharge side check ball 32 may be used.

The first sensor 71 serves to detect the advancing state of the diaphragm 15 and is connected to the control unit 70. As the first sensor 71, an ultrasonic sensor for distance measurement may be used. That is, when the ultrasonic sensor 71 is formed at a position adjacent to the pumping shaft 40 coupled to the diaphragm 15, and the protrusion 45 facing the ultrasonic sensor is formed at a predetermined position of the pumping shaft 40, the pumping shaft When the 40 moves forward, the ultrasonic sensor measures the distance from the protrusion 45 formed on the pumping shaft 40 to detect the advance state of the diaphragm 15 and transmits the detected signal to the controller 70.

The second sensor 72 serves to detect the degree to which the discharge side check ball 32 rises from the discharge port 30 and is connected to the controller 70. The second sensor 72 may be an ultrasonic sensor for distance measurement. That is, when the ultrasonic sensor 72 is installed at a predetermined position in the discharge passage toward the discharge side check ball 32, and the ultrasonic sensor measures the distance from the discharge side check ball 32, the discharge side check ball 32 is discharged ( The controller 70 may calculate the distance away from 30.

When the fluid is almost exhausted to the storage unit (not shown) that stores the fluid sucked by the metering pump, a situation may occur in which air is sucked from the storage unit into the working oil chamber 10. The metering pump of the second embodiment of the present invention is further provided with a pressurizing means 37, a first sensor 71, and a second sensor 72 for the purpose of detecting such a situation and taking necessary measures.

In the metering pump of this embodiment, the force for pressing the discharge side check ball 32 by the pressurizing means 37 for pressing the discharge side check ball 32 is " existed inside the working oil compartment 10 when the diaphragm 15 is advanced. Even when air is discharged through the discharge port 30, the degree to which the discharge side check ball 32 is almost in close contact with the discharge port 30 is appropriate. The state in which the discharge side check ball 32 is in close contact with the discharge port 30 means a state in which the discharge side check ball 32 maintains an interval of 1 millimeter or less from the discharge port 30. This setting interval is not limited to 1 millimeter, and an appropriate value may be selected in consideration of the amount of movement of the discharge side check ball 32 when the fluid is discharged, depending on the viscosity of the fluid to be conveyed. For example, if the discharge side check ball 32 rises by an average of 5 millimeters during the discharging process in an environment of conveying a fluid having a high viscosity, the pressing force of the pressurizing means causes the discharge side check ball 32 to be 2 millimeters at the time of air discharge. It can also be set to rise below.

Since the inner diameter of the discharge side check ball accommodating portion 31 formed in front of the discharge port 30 is formed larger than the diameter of the discharge side check ball 32, even if air is discharged through the discharge port 30, the air remains on the discharge side check ball 32. Since it passes through the gap between the discharge side check ball accommodating part 31 and the discharge side check ball 32 being pressurized by the pressurizing means 37, the discharge side check ball 32 hardly rises upward even if air passes. The state of close contact with the discharge port 30 is maintained. (See Figure 7)

Therefore, in this case, since the air is discharged instead of the fluid, the controller 70 determines that the metering pump is malfunctioning and takes warning measures.

Hereinafter will be described the operation of the metering pump according to the second embodiment of the present invention.

When the fluid is almost exhausted to the storage unit (not shown) that stores the fluid sucked by the metering pump, air is sucked into the working oil chamber unit 10 from the storage unit.

Air sucked into the working oil compartment 10 through the inlet 20 is discharged to the outlet 30 by the operation of the diaphragm 15.

The controller 70 detects that the diaphragm 15 is advanced by the first sensor 71 and at the same time that the discharge side check ball 32 is almost in close contact with the discharge port 30 by the second sensor 72. If the air is not a fluid is determined to be discharged through the discharge port 30 (that is, it is determined that a problem in the quantitative supply of the liquid) and the operation of the drive motor is stopped. The controller 70 may generate a warning signal at the same time as stopping the operation of the driving motor.

In addition, the additional function of the pressing means 37 for pressing the discharge side check ball 32 is as follows.

When the viscosity of the fluid conveyed by the metering pump is large, the fluid is discharged through the discharge port 3 and the discharge side check ball 32 is pushed upward and the discharge side check ball 32 upwardly descends. That is, the descending speed of the discharge side check ball 32 is related to the viscosity of the fluid. This is because the lowering of the discharge side check ball 32 is caused by the weight of the discharge side check ball 32. Therefore, when the viscosity of the fluid is large, since the discharge side check ball 32 descends slowly, the process of the diaphragm 15 retreating before the discharge side check ball 32 descends to block the discharge port 30 may be started. If the diaphragm 15 is retracted (ie, the fluid suction process is started) before the discharge side check ball 32 is lowered to block the discharge port 30, the discharged fluid flows back to the discharge port 30. This causes an error in the quantitative supply of fluid. However, since the metering pump of the present invention forcibly lowers the discharge side check ball 32 that is raised during the discharge process, the pressurizing means 37 of the discharge side check ball 32 discharges the check side before the retreat process of the diaphragm 15 starts. The ball 32 completely closes the discharge port 30.

The method of detecting that the air is sucked into the working oil compartment 10 is a second embodiment of the present invention for detecting whether the discharge side check ball 32 is in close contact with the discharge port 30 when the diaphragm 15 is advanced. In addition to the method of the metering pump according to the above, in the retraction process (fluid suction process) of the diaphragm 15 in the state in which the ultrasonic sensor is installed on the suction flow path, the suction check ball 22 rises from the suction port 20. May be used. That is, when air is sucked in from the suction port 20, the suction side check ball 22 only rises finely. That is, the suction side check ball 22 rises relatively large when the fluid is sucked in, but the suction side check ball 22 rises less when air is sucked in. That is, when the first sensor 71 detects the retraction of the diaphragm 15 and at the same time the second sensor 72 detects the rising distance of the suction side check ball 22, it is possible to detect whether the air is sucked in.

FIG. 8 is a diagram comparing the size of a flow path around a discharge port in an advanced state of a diaphragm and a comparison target diaphragm which are commonly used in the first and second embodiments of the present invention.

As shown in FIG. 8 (b), the diaphragm 15 of the metering pump according to the present invention has a shape in which the edge portion 17 is recessed inwardly. Therefore, the space of the working loss part 10, which is reduced when the diaphragm 15 is advanced, corresponds mainly to the center part, and the space of the edge part is less reduced. As a result, even when the diaphragm 15 shrinks, the cross-sectional area of the flow path 39 adjacent to the discharge port 30 is reduced slightly. Since the cross-sectional area of the flow path 39 is reduced, it is possible to prevent the fluid from being rapidly discharged at a high pressure during the discharge process and to prevent the rapid discharge, thereby minimizing the pulsation during the fluid discharge.

If excessive pulsation occurs when the fluid is discharged from the metering pump, it may change the working environment of the fluid. For example, in the case where the measuring gauge for measuring the water level is formed in the storage unit in which the discharged fluid is stored, if the pulsation of the discharged fluid is excessive, the value of the measurement of the water level in the storage unit causes an error, making it difficult to accurately measure the water level.

As shown in FIG. 8A, when the diaphragm 15 has no groove formed around the edge, when the diaphragm 15 is advanced, the cross-sectional area of the flow path adjacent to the discharge port 30 is greatly reduced, so that the fluid Is suddenly discharged and excessive pulsation occurs during the discharge of the fluid.

Preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art will be able to make various modifications, changes and additions within the spirit and scope of the present invention. And additions should be considered to be within the scope of the claims of the present invention.

Inlet port 20, outlet port 30, working oil compartment 10, diaphragm 15, pumping shaft 40, drive shaft 50, eccentric shaft 55, connecting rod 60, control unit 70

Claims (4)

A drive motor having a drive shaft;
An eccentric shaft formed about an eccentric point of the driving shaft of the driving motor;
A working oil chamber formed with a suction port and a discharge port;
A diaphragm forming one side of the working oil loss part;
A pumping shaft fixed to one surface of the diaphragm and linearly moving;
A connecting rod having one end hinged to the pumping shaft and the other end hinged to the eccentric shaft;
A discharge side check ball accommodating part formed outside the discharge port of the working oil chamber part;
A discharge side check ball provided in the discharge side check ball accommodation portion;
Pressurizing means formed on said discharge side check ball accommodating portion to press said discharge side check ball to said discharge port;
A first sensor detecting a forward state of the diaphragm;
A second sensor for sensing a degree in which the discharge side check ball rises from the discharge hole; And
A control unit for receiving a signal from the first sensor and the second sensor to control the operation of the drive motor,
The inner diameter of the discharge side check ball accommodation portion is larger than the diameter of the discharge side check ball metering pump. delete The method of claim 1,
A suction side check ball accommodating part formed inside the suction port of the working loss part;
A suction side check ball provided in the suction side check ball accommodating part;
A first sensor detecting a reverse state of the diaphragm; And
A second sensor for sensing a distance from which the suction side check ball rises from the suction port; And
A control unit for receiving a signal from the first sensor and the second sensor to control the operation of the drive motor,
The inner diameter of the suction side check ball accommodation portion is a fixed quantity pump, characterized in that formed larger than the diameter of the suction check ball. The method according to claim 1 or 3,
The diaphragm is a metering pump, characterized in that the central portion is formed convex toward the working oil chamber and the outer side of the central portion is formed concave.

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