JPS5939170B2 - Fluid pressure driven fluid mixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-pressure-driven adjustment device for diluting a concentrated stock solution, and in particular, the invention relates to a water pressure-driven adjustment device for diluting a concentrated stock solution, and in particular, the invention relates to a water pressure-driven adjustment device for diluting a concentrated stock solution, and in particular, a concentrated dialysate for an artificial dialysis machine (stock solution) and a sterilized dilution water are mixed into a dilution water. The present invention relates to a dilution device that employs a pump system in which a piston is driven by pressure.

In an artificial kidney (hemodialysis machine), the dialysate used for hemodialysis is required to be maintained at a constant concentration and temperature. Conventionally, as a method of diluting the dialysate stock solution and adjusting the dialysate at a constant concentration, a metering pump is used to supply the dialysate stock solution and dilution water at a fixed ratio, respectively, to prepare the dialysate needed for dialysis treatment in advance. There are two methods: one is to prepare dialysate at a constant concentration during dialysis treatment, and the other is to continuously adjust dialysate at a constant concentration during dialysis treatment.The former method requires a large dialysate storage tank and there is a risk of contamination with bacteria during storage. In the latter case, there was a problem in that the concentration fluctuated slightly due to the characteristics of the pump.In order to overcome these problems, the applicant combined a four-way valve and an operating cylinder. A motion converting mechanism is provided at one end of the piston rod of the piston incorporated in the operating cylinder to displace in a direction perpendicular to the reciprocating motion of the piston rod. A pair of plungers are connected, pump chambers are configured symmetrically at the tips of these plungers, and the other end of the pinuton rod is extended outward, and the spool shaft of the four-way valve is extended parallel to this. The reciprocating displacement of the piston rod is transmitted to the spool shaft via the operating rod, so that switching control of the four-way valve is automatically performed, and the symmetrically arranged pump chambers are connected to the pump chambers, respectively. By operating the pump chamber and supplying the stock solution to the pump chamber and supplying dilution water to the pressure fluid supply system composed of a four-way valve and an operation cylinder, the dialysate stock solution can be adjusted arbitrarily to the dilution water that is supplied in a fixed amount. He developed a diluter that could supply a fixed amount at a ratio of In addition, the mechanical connection structure between the four-way valve and the operating cylinder was complicated, requiring precise design and time-consuming manufacturing.Therefore, the inventors of the present invention conducted extensive research. As a result, a pair of cylinders each having a fluid operating piston are provided, and a fluid supply port and a fluid discharge port are provided symmetrically at both ends of each cylinder, and one end of the piston rod of each cylinder is connected to a swing connecting rod pivoted at one point. One cylinder is pivotally connected to both end groups, and one cylinder is configured as a driving cylinder, and the other cylinder is configured as a driven cylinder, and a pressure fluid supply system is connected to the fluid supply port of one driving cylinder via a valve device, and the driven cylinder is By connecting another fluid supply system to the fluid supply port of the cylinder via a valve device, and further connecting a transfer pipe communicating with the mixing device to the fluid discharge port of both cylinders via the respective valve devices, If pressurized fluid is alternately supplied into two fluid chambers defined by the piston, the piston rod of the driven cylinder will reciprocate as the piston rod reciprocates to pump another fluid, and the two fluids will be mixed in the mixing device. It was found that proportional mixing control of can be easily achieved.

A general object of the present invention is to perform a pump operation by piston drive using the pressure of the fluid to be mixed, and to proportionally control the pump discharge amount by adjusting the stroke length of the piston drive. The present invention provides a fluid mixing device using a cylinder.

The main object of the present invention is to have a first cylinder connected to a pressure fluid supply system and a second cylinder connected to another fluid supply system, and one end of the piston rod of the first cylinder and the second cylinder, respectively. A fluid supply system and a fluid discharge system are connected to the fluid chambers defined by the pistons of each cylinder via valve devices, respectively, and the fluid chambers are connected to both ends of a swinging connecting rod pivoted at one point. The object of the present invention is to provide a fluid pressure single drive type fluid mixing device characterized in that a system is communicated with a mixing device.

Further, in the above-mentioned fluid pressure 1 drive type fluid mixing device, the first cylinder and the second cylinder each have two fluid chambers defined by a piston, and communicate with both fluid chambers of the first cylinder. A fluid supply system configured to alternately switch open and close a valve device provided in the pressure fluid supply system and a valve device provided in the discharge system to perform reciprocating motion of the pinuton, and communicate with both fluid chambers of the second cylinder. The valve device provided in the exhaust system and the valve device provided in the discharge system can each be configured with a check valve.

In the case of the above structure, a switch actuating member is provided at one end of the piston rod of the first cylinder, a pair of limit switches are provided at a predetermined distance apart in correspondence with the switch actuating member, and the valve is operated under the action of these limit switches. It is preferable that the device be configured to perform switching opening/closing control.

In the fluid mixing device according to the present invention, if the pivot portion of the swinging connecting rod connecting the piston rods of the first cylinder and the second cylinder is configured to be movably adjustable, it becomes possible to adjust the mixing ratio as desired.

Furthermore, by drilling a fluid hole in the second cylinder that is adjacent to the two fluid chambers and perpendicularly intersects with the shaft sealing part of the pinuton rod, dilution water can be supplied to the first cylinder, and stock solution can be supplied to the second cylinder. When used as a dilution mixing device for supplying liquid, it is preferable to prevent various damage to the shaft sealing portion of the stock solution in the second cylinder. The fluid mixing device according to the present invention is configured to include a plurality of cylinders (for example, three or four), which is more than two, so that the number of types of fluids commensurate with the number of cylinders can be mixed. You can also do that.

Next, embodiments of the fluid pressure-driven fluid mixing device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a system diagram showing the principle of the device of the present invention, in which reference numeral 10 indicates a first cylinder, 12 indicates a second cylinder,
The first cylinder 10 and the second cylinder 12 have two fluid chambers 10a defined by pistons 14 and 16, respectively.
10b, 12a, 12b, and fluid supply ports 18a, 18b and 20a, 20b and fluid discharge ports 22a, 22b and 24a, 24b corresponding to each fluid chamber.

Also, one end of the piston rods 26 and 28 inserted into the first cylinder 10 and the second cylinder 12 is pivoted to both ends of a swing connecting rod 30 which is pivoted at one point, so that the piston rods 26 and 28 alternately reciprocate. Configure to exercise.
In the first cylinder 10 and second cylinder 12 configured in this way, the fluid supply port 18a of the first cylinder 10,
A pressure fluid supply system 34 led out from the first fluid storage tank 32 is connected to 18b via valve devices 36a and 36b, and a pressure fluid supply system 34 led out from the second fluid storage tank 38 is connected to the fluid supply ports 20a and 20b of the second cylinder 12. A fluid supply system 40 led out is connected via valve devices 42a, 42b.

Furthermore, fluid discharge ports 22a and 22b of the first cylinder 10
A discharge pipe 46 is connected to the fluid discharge ports 24a, 24 of the second cylinder 12 via valve devices 44a, 44b.
A transfer pipe 50 is connected to b via valve devices 48a and 48b, and these discharge pipes 46 and 50 communicate with a mixing device 52.

By configuring in this way, for example, the fluid supply ports 18a, 18b and the fluid discharge port 22 of the first cylinder 10
The valve devices 36a, 36b and 44a, 44b for opening and closing the fluid chambers 10a and 22b are respectively constructed of electromagnetic valves, and when supplying pressure fluid to one fluid chamber 10a, the other fluid chamber 1
By controlling the opening and closing of the valve device to discharge fluid from 0b, the reciprocating motion of the piston 14 of the first cylinder 10 is transmitted to the piston rod 28 of the second cylinder 12 via the piston rod 26 and the swinging connecting rod 30. A pump operation is achieved by changing the volume of the two fluid chambers 12a and 12b provided in the second cylinder 12.

Therefore, in this case, the fluid supply port 20 of the second cylinder 12
It is preferable that the valve devices 42a, 42b and 48a, 48b, which control the opening and closing of the fluid discharge ports 24a, 20b and the fluid discharge ports 24a, 24b, are respectively constructed of check valves. Further, in the device of the present invention, the valve devices 36a, 36 in the first cylinder 10
b, 44a, 44b, a switch actuating member 54 is attached to one end of the piston rod 26 inserted into the first cylinder 10, and the switch actuating member 5
4, a pair of limit switches 56 and 58 are arranged at a required distance from each other, and these limit switches 5
Each valve device (electromagnetic valve) is configured to be alternately switched under the action of valves 6 and 58.

Furthermore, by configuring the fulcrum part A of the swing connecting rod 30 that connects the piston rods of the first cylinder 10 and the second cylinder 12 to be movable by the adjustment mechanism 60, the second piston rod can be moved.
By appropriately adjusting the stroke length of the piston 16 of the cylinder 12, the ratio of the flow rate of the fluid transferred via the second cylinder 1Z to the flow rate of the fluid transferred via the first cylinder 10 can be adjusted.

Therefore, with this configuration, when the fluid to be transferred is a stock solution and dilution water, the dilution ratio of the stock solution can be set arbitrarily. FIG. 2 shows an embodiment of the device in which the device of the present invention is applied to a device for adjusting dialysate used in an artificial dialysis device. One end of the piston rods 26 and 28 inserted into the first cylinder 10 and the second cylinder 12 is connected to the swing connecting rod 3, which is set to supply the liquid concentrate.
0, and the fulcrum A of this swing connecting rod 30 is connected to the feed screw 6.
The position can be changed by an adjustment mechanism 60 consisting of two parts.

In addition, in this example, the second
When the stock solution leaks from the shaft seal portion through which the piston rod 28 of the cylinder 12 is inserted, crystals of the components in the stock solution precipitate, causing deterioration of the shaft seal mechanism and causing the piston rod 2
8, the second cylinder 12
Fluid holes 64 and 66 are formed adjacent to the stock solution fluid chambers 12a and 12b and perpendicularly intersect with the shaft seal, and dilution water is allowed to flow through the fluid holes 64 and 66 to close the shaft seal. Make sure to wash it off. Also in the device of this embodiment configured in this way, the first cylinder 10 and the second cylinder 12 are provided with fluid supply ports 18a, 18b and 20a, 20b and fluid discharge ports 22a, 22b and 24a, 24b, respectively. By connecting the pressure dilution water supply system 68 to the cylinder 10 and connecting the stock solution supply 70 to the second cylinder 12, a dialysate having a constant dilution ratio can be easily prepared.

In this embodiment, the cross-sectional area of the first cylinder 10 is S, the cross-sectional area of the second cylinder 12 is S2, and each end of the piston rod 26 of the first cylinder 10 and the piston rod 28 of the second cylinder 12 is piston rod 26
, 28 to the fulcrum of the swing connecting rod 30 that interconnect them are respectively X and y, and furthermore, the stroke length of the piston 14 of the first cylinder 10 is L, the amount of liquid delivered per unit time of each cylinder is is as follows. However, N is the number of strokes within a metal time. From the above equations (1) and (2), the ratio of the discharge amounts of both cylinders is as follows.

Therefore, from equation (3), it is clear that by changing the fulcrum of the swing connecting rod 30, the mixing ratio of the fluids supplied from the first cylinder 10 and the second cylinder 12 can be set arbitrarily.

The fluid pressure-driven fluid mixing device according to the present invention can not only mix two or more different fluids at a constant ratio, but also adjust the mixing ratio arbitrarily with a simple operation. Dilution mixing with dilution water can also be smoothly achieved.

Furthermore, since the device of the present invention has a simple structure and operates using the pressure of the supplied fluid as a driving source, it not only reduces operating costs but also achieves stable fluid transfer control over a long period of time. be able to.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing the basic configuration of a fluid output drive type fluid mixing device according to the present invention, and FIG. 2 is a sectional view showing an embodiment of a cylinder which is a main part of the device according to the present invention. 10...First cylinder, 12...Second
Cylinder, 14, 16... Piston, 18, 2
0...Fluid supply port, 22, 24...Fluid discharge port, 26, 28...Piston rod, 3
0... Swinging connection rod, 32... First fluid storage tank, 34... Pressure fluid supply system, 36...
...Valve device, 38...Second fluid storage tank, 40...
... Fluid supply section, 42 ... Valve device, 44.
... Valve device, 46, 50 ... Discharge pipe, 4
8... Valve device, 52... Mixing device, 5
4... Switch operating member, 56, 58...
...Limit switch, 60...Adjustment mechanism, 6
2...Feed screw, 64, 66...Fluid hole, 68...Pressure dilution water supply system, 70...
...Still solution supply system.

Claims (1)

[Claims] 1. Consisting of a first cylinder connected to a pressure fluid supply system and a second cylinder connected to another fluid supply system, the first cylinder is connected to a pressure fluid supply system.
One end of the piston rod of the cylinder and the second cylinder is pivotally connected to both ends of a swinging connecting rod that pivots at one point, and fluid is supplied to the fluid chamber defined by the piston of each cylinder through a valve device. A fluid pressure-driven fluid mixing device, characterized in that a supply system and a discharge system are connected to each other, and the discharge system is communicated with a mixing device. 2. The first cylinder and the second cylinder each have two fluid chambers defined by a piston, and a valve device and a discharge system provided in a pressure fluid supply system communicating with both fluid chambers of the first cylinder. A valve device provided in the fluid supply system communicating with both fluid chambers of the second cylinder and a valve device provided in the discharge system are configured to perform reciprocating motion of the piston by alternately controlling the opening and closing of the valve devices provided in the second cylinder. 2. A fluid pressure-driven fluid mixing device according to claim 1, wherein said fluid mixing device comprises check valves. 3. A switch operating member is provided at one end of the piston rod of the first cylinder, a pair of limit switches are provided at a predetermined distance apart from the switch operating member, and switching opening/closing control of the valve device is performed under the action of these limit switches. A fluid pressure-driven fluid mixing device according to claim 2, which is configured to perform the following. 4. The fluid pressure drive according to any one of claims 1 to 3, wherein the pivot portion of the swing connecting rod that communicates the piston rods of the first cylinder and the second cylinder is configured to be movable and adjustable. Type fluid mixing device. 5. According to any one of claims 1 to 4, the second cylinder is provided with a fluid hole adjacent to the two fluid chambers and perpendicularly intersecting the shaft sealing portion of the piston rod. The fluid pressure driven fluid mixing device described.