JPH02102383A - Volume adjustable reciprocation pump - Google Patents

Abstract

PURPOSE:To make it possible to reduce or increase a minute amount of volume by providing a movable partition wall which furnishes a suction port and an exhaust port to a cylindrical container in which a reciprocating piston is installed, and converting the moving amount of the piston responding to the volume converted by the movement of the movable partition wall. CONSTITUTION:In a cylindrical container 1 whose one end is opened, a piston 2 is installed to reciprocate freely, and a movable partition wall 3 is installed to the opening end to move freely. The piston 2 is reciprocated by a driving device 5 through a piston rod 4, while a connecting rod 6 to move the movable partition wall, to which a rack 7 is engraved, is provided at the outer side of the movable partition wall 3, and by rotating a pinion 8 to gear with the rack 7 with a knob 10 furnishing a braking function, the movable partition wall 3 is moved through the connecting rod 6 to move the movable partition wall. In this case, the rotation angle variation of the knob 10 is detected by an encoder 9, the driving device 5 is controlled by a control device 11 responding to the detection signal, and the stroke length of the piston rod 4 is controlled.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a reciprocating pump, and more particularly to a reciprocating pump that is capable of increasing and decreasing the flow rate until the piston reaches a constant speed. be.

[Conventional technology]

Reciprocating pumps, which are well known in the past, repeatedly draw in and discharge fluid by moving a piston back and forth from side to side.Increasing or decreasing the flow rate is achieved by increasing or decreasing the repeated cycles of the reciprocating motion. This is usually sufficient for applications requiring specific flow rates. Also,
Reciprocating pumps are also ideally used for applications such as extracting equal amounts of different fluids, which is the original use of reciprocating pumps.

Regarding the use of drawing out equal amounts of the different fluids mentioned above, the prior art will be explained with reference to FIG. To store fluid in the chamber 63, move the piston 61 to the left in the figure and drain the fluid in the chamber 63 to the discharge port 68.
The fluid is discharged from the chamber 62, and the fluid is sucked in through the suction port 65 provided in the chamber 62. Next, in order to store fluid in the chamber 63, the piston 61 is moved to the right in the figure, the fluid in the chamber 62 is discharged from the discharge port 66, and the operation of sucking the fluid through the suction port 67 that opens into the chamber 63 is repeated. In order to increase the flow rate, which is a pump function, for example, it is possible to increase the flow rate by speeding up the repetition cycle.

[Problem that the invention seeks to solve]

However, if the desired flow rate is on the order of double or triple the previous flow rate, it can be easily changed by speeding up the repeat cycle by 2 or 3 times the previous volume. If you wish to increase the flow rate by 1.0% or 3%, theoretically it should be possible to increase the repeat cycle time by a small amount, but in reality, This is extremely difficult to realize due to equipment backlash and the like.

The present invention reduces the volume by 1.0% or 3.0% of the previous volume of the pump.
The object of the present invention is to provide a reciprocating pump that can easily increase or decrease the amount by 0%.

[Means for solving problems]

In order to achieve the above object, the reciprocating pump with adjustable volume according to the present invention includes a piston that reciprocates within a container, and has a fluid inlet and an outlet on one or both sides of the container. The present invention is characterized in that a movable partition wall is provided, and a control means is provided for controlling the amount of movement of the piston in accordance with the amount of movement of the movable partition wall.

[Effect]

The adjustable volume reciprocating pump according to the present invention is a reciprocating pump equipped with a reciprocating piston, and is provided with a movable partition having fluid intake and discharge ports on one or both sides of the container. Accordingly, a control means is provided for changing the volume of the container by moving the movable partition wall and controlling the moving distance of the piston according to the changed volume.
This allows the flow rate of the pump to be increased or decreased by a minute amount compared to the previous flow rate while keeping the reciprocating speed of the piston constant.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

Figure 1 shows the first embodiment, Figure 2 shows the second embodiment, and
Examples will be described based on the drawings.

In the figure, 1 is a cylindrical container with one end open.
A piston 2 is loosely fitted into the cylindrical container l so that it can freely reciprocate, and a movable partition wall 3 is loosely fitted into the cylindrical container 1 at the open end so that it can move freely. The open end is closed.

The piston 2 described above is connected to a driving means 5 via a piston rod 4.
It is made to reciprocate by. Although a power cylinder or the like using air pressure or oil pressure can be used as the drive means 5, this embodiment will be explained using an example of an electric drive means. The piston rod 4, which is driven left and right by the driving means 5, is driven by, for example, a rack carved on the piston rod 4 and a pinion rotated by a pulse motor or the like, which is not shown in the drawings.

A movable bulkhead moving link 6 with a hook 7 carved therein is provided on the outer side of the movable bulkhead 3, and a pinion 8 that meshes with the rack 7 is equipped with a brake mechanism to prevent accidental rotation. This rotation moves the movable bulkhead 3 via the movable bulkhead moving link 6 on which the rack 7 is carved.

The change in the rotation angle of the knob 10 described above is converted into an electric signal by the encoder 9 and supplied to the control means 11. The control means 11 controls the pulse motor of the drive means 5, etc., and controls the piston rod 4. This is the part that calculates the optimum stroke length of and issues a reciprocating command to the driving means 5.

The encoder 9 described above is preferably a position pulse conversion method using an optical or magnetic method, but it is also possible to use an analog voltage (resistance) change and A/D conversion method. It is also possible to convert the movement of the movable bulkhead moving link 6 directly into an electrical signal using a linear encoder.

Then, the control means 11 controls the initially set piston 2.
The driving means 5 is reset by adding or subtracting the movement of the movable bulkhead moving link 6 to the horizontal position by the rack 7, which is converted into an electric signal, to the reciprocating length signal. do.

At this time, instead of the above-mentioned configuration of the rack and pinion meshing, a thread is carved into the connecting rod 6 for moving the movable bulkhead, and a pole screw is formed between the connecting rod 6 and the movable bulkhead 3. The movable partition wall 3 may be moved by rotating the movable partition wall 3.

In this example as well, if a knob 10 equipped with a brake mechanism is provided to prevent the encoder 9 from rotating inadvertently, the same effects as in the case of a rack and pinion can be obtained.

Although not particularly shown, the mechanical stop to the movable partition wall 3 at one end of the piston 2 and the cylindrical container 1 and the other end wall 1' of the piston 2 and the cylindrical container 1 is achieved by adding a magnetic material to the piston 2. The cylindrical portion of the cylindrical container 1 is made of a non-magnetic material and a limit detector of a magnetic type or the like is attached to prevent damage to the device, and is also used to command reversal of the reciprocating motion of the piston 2.

A vernier mechanism such as a gear down mechanism is installed between the pinion 8, encoder 9, and knob 10 to improve the accuracy of adjustment settings, and a brake mechanism is also installed to prevent the adjusted position from moving (not shown). ).

Reference numeral 12 denotes a rail member such as an O-ring fitted into a groove bored on the outer periphery of the piston 2, and the chambers 15 and 16 inside the cylindrical container 1 partitioned by the piston 2 are separated by the sealing member.
The liquids are kept from mixing with each other.

Similarly, 13 is a sealing member such as an O-ring fitted into a groove bored on the outer periphery of the movable partition wall 3, and 14 is a sealing member provided on the end wall 1' through which the piston rod 4 of the cylindrical container 1 is inserted. Ta0
The sealing member 1314 prevents the fluid inside the cylindrical container 1 from leaking to the outside.

Reference numeral 17 denotes an indicator, which indicates the amount of movement of the flexible bulkhead 3 by the rack 7 and pinion 8 of the movable bulkhead moving link 6;
The amount of change in volume according to the amount of movement of the movable partition wall 3 may be converted and displayed.

18 and 19 are an inlet line and an outlet line respectively provided on the end wall 1' of the cylindrical container 1;
Reference numeral 1 denotes an inlet line and an outlet line connected to the movable bulkhead 3 through flexible tubes or the like. Check valves 22a, 22b, 22c, and 22d are provided in each of the inlet lines 18, 20 and outlet lines 19, 21 described above. Moreover, the above-mentioned check valves 22a, 22
b, 22c, and 22d can be replaced with three-way solenoid valves or the like depending on the purpose.

Next, the calibration of the reciprocating pump in this example will be explained.

(1) First, the movable bulkhead 3 loosely fitted on the open side of the cylindrical container l is rotated to a predetermined initial position by rotating the knob 10, and the movable bulkhead 3 is moved through the pinion 8 and the rack 7. Move 3 to match.

(2) Next, the control means 11 generates a signal with an initial value such as a pulse for a predetermined distance of movement of the piston 2, and supplies it to the drive means 5.

(2) Next, rotate the knob 10 to move the movable partition wall 3 by the desired volume increase. This can be done by actually measuring the number of rotations of the knob 10 and the moving distance of the movable partition wall 3 in terms of volume and marking them in advance.

■ Under the above conditions, operate the reciprocating pump and
stops the pump at its initial value and the most extreme movement position.

■ At this time, a signal for the desired increase in volume is added to the initial value signal of the movement distance of the piston 2 of the control means 11 using a cylinder-type volume measuring means in the discharge line 21 provided on the movable bulkhead 3, and the reciprocating The dynamic pump is started, and the fluid remaining in the chamber 16 is measured by the volume measuring means. This makes it possible to know the relationship between the increased movement of the piston 2 and the corresponding increased volume.

Further, the above operation may be performed by moving the piston 2 until the movement of the piston 2 is detected as a limit of movement by a limit detector.

■ If the above measured value is different from the desired value, return the reciprocating pump operation settings to the initial state and turn knob 1.
The best calibration can be achieved by rotating the movable partition wall 3 by a certain amount and starting over from step (2) above. Depending on the application, the above-mentioned confirmation work may be performed each time the device is used to achieve optimal calibration.

It is preferable that the adjustment means described above, including the control means 11, be manufactured and added in advance as a microcomputer element.

The following table shows specific examples of adjustable numerical values in this embodiment.

In the case of an initial cylindrical container with a volume of 500 cm, FIG. 2 shows a second embodiment of the present invention. The embodiment allows for significant volume increases and decreases.

In the figure, 30 is a cylindrical body with both ends open, and the cylindrical body 30
Therein is a piston rod 32 actuated by a drive means 33.
The piston 31 is loosely fitted to be able to reciprocate through the
Movable partition walls 34 and 35, which are movable, are loosely fitted into the open ends of the cylindrical body 30, respectively.

The reciprocating movement of the piston rod 32 by the driving means 33 described above is performed by, for example, driving a rack and pinion (not shown) directly connected to the piston rod 32 with a pulse motor (not shown) or the like.

Further, a sealing member 36 such as an O-ring is fitted into the outer circumferential groove of the piston 32 to prevent the fluids in the compartments 39 and 40 divided by the piston 32 from sliding against each other, and similarly, the movable partition wall 34. A sealing member 37, 37' such as an O-ring or the like is inserted into the outer peripheral groove of 35, and an O-ring 38 or the like is also fitted into the insertion portion of the piston rod 32 of the movable partition wall 34 to prevent the fluid inside the cylindrical body from leaking to the outside. There is.

Reference numeral 41 denotes a control means, which controls the pulse motor of the drive means 33 described above, and 42, 4.
Reference numeral 3 denotes a movable partition moving link (hereinafter simply referred to as a link) fixed to the movable partition walls 34 and 35 in order to move the movable partition walls 34 and 35, respectively;
Racks 44 and 45 are respectively engraved at the tips of 2.43, and the connecting rods 42, 43 are bent or the like so that the racks 44, 45 at the tips thereof face each other,
A pinion 46 that engages both racks 44, 45 at the same time is provided, and a knob 48 is rotated to rotate the pinion 46, and a connecting rod 42, 43 is provided with a rack 44, 45 that engages with the pinion 46. are simultaneously moved in opposite directions, and the respective movable bulkheads are simultaneously moved in a direction toward or away from each other via the connecting rods 42,42.

47 is an encoder which converts the change in rotation angle of the pinion 46 into an electric signal and supplies it to the control means 41, calculates the optimum stroke length of the piston rod 32 accordingly, and issues a reciprocating command to the drive means 33. Do it like this.

The encoder 47 described above is preferably a position pulse conversion method using an optical type or a magnetic type, but an analog voltage (
Resistance) variation and A/D conversion methods can also be used. Also,
It can also be used in the same way if the movement of the connecting rods 42, 43 via the racks 44, 45 is directly converted into electrical signals by a linear encoder. Then, the control means 41 adjusts the rack 44 to the initially set reciprocating length signal of the piston 31.
．． The driving means 33 is controlled again by adding or subtracting the changed movement of the connecting rods 42 and 43 to an arbitrary position in the horizontal direction via the electric signal 45 into an electric signal.

Although not shown, the piston 31 and the movable partition wall 3435
For the mechanism and stop, a magnetic material is added to the piston 31, the cylindrical body 30 is made of a non-magnetic material, and a limit detector such as a magnetic type is attached to prevent the device from being damaged.

The above-mentioned movable bulkhead 34.35 rotates a pinion 46 by rotating a knob 48, and the movable bulkhead 34.35
By moving the connecting rods 42 and 43 fixed to the movable bulkheads 34 and 35, the movable bulkheads 34 and 35 are horizontally moved in mutually opposite directions. This is to improve the setting accuracy of the adjustment and to prevent the adjusted position of the movable bulkheads 42, 43 from being inadvertently moved by the brake mechanism.

Reference numeral 49 denotes an indicator which indicates the amount of movement of the movable bulkhead 34.35 by the rack 44.45 and pinion 46, and this indicator 49 cumulatively displays the amount of change in volume according to the movable bulkhead. Good too.

The driving means 33, control means 41, and indicator 49 described above can be easily constructed from ordinary semiconductors or their integrated circuits.

Inlet lines 50.52 and outlet lines 51.53 are connected to the movable bulkheads 34.35 by flexible tubes, respectively, and check valves 54a, 54b, 54c are connected to each of the lines, respectively. and 5
4d, and the above check valve may be a three-way solenoid valve depending on the purpose.

In the first embodiment configured as described above, by connecting the suction line 18.20 and the discharge line 19.21, a reciprocating pump capable of suctioning and discharging equal amounts of different fluids is constructed. Moreover, in the first embodiment, it is possible to use a reciprocating pump that can increase or decrease the volume by a small amount.

Furthermore, as an actual application of this embodiment, it is best to use it in combination with an ultrafiltration filter of an artificial kidney dialysis machine, taking advantage of the feature that the volume can be finely adjusted. That is,
This makes it easier to correct variations in the volume of a single filter, adjust the volume in the case of different types of filters, change the ultrafiltration rate, etc., which helps reduce cost and improve the ease of use of the device.

In the second embodiment, in addition to the applications already mentioned, the position of the piston 31 is initially set so that the volumes of the chambers 39 and 40 are not equal, but start from a position with a certain ratio, and the moving length of the piston is By changing the operation settings of the control means 41 and starting by moving only the length of the small volume chamber side, the pump becomes able to change the volume significantly without changing the discharge flow rate. . And the ratio is room 3
This pump also has the feature that it can be freely set on either the 9 side or the chamber 40 side. Furthermore, the pump is capable of finely adjusting the volume, making it highly flexible in use.

Furthermore, racks 44 and 45 do not have a common pinion,
By providing a single pinion for each rack, individual fine adjustment of the volume of the chambers 39, 40 is possible, making possible applications in many fields.

〔Effect of the invention〕

The adjustable volume reciprocating pump according to the present invention is a pump equipped with a reciprocating piston, and is provided with a movable partition wall provided with a fluid intake/discharge port on one or both sides of a cylindrical container. By moving the movable bulkhead a required amount, the volume inside the container is changed, and a control means is provided to control the amount of movement of the piston according to the changed volume, so the reciprocating speed of the piston can be kept constant. It is also possible to increase or decrease the volume by a small amount with \.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a first embodiment of the present invention, FIG. 2 is an explanatory diagram of the configuration of the second embodiment, and FIG. 3 is an explanatory diagram of a conventional device. 1.3O: Cylindrical container 2,31: Piston 5.33
: Drive means 3.34.35: Movable bulkhead 11.41
: Control means 9, 47: Encoder 10. 48: Knob 8, 46: Pinion 7, 44. 45: Rack

Claims (1)

[Claims] A piston that reciprocates within a container is provided, a movable partition having a fluid inlet and an outlet is provided on one or both sides of the container, and the piston moves according to the amount of movement of the movable partition. A reciprocating pump with adjustable volume, characterized in that it is provided with control means for controlling the volume.