JPH0519961U - Dispensing device - Google Patents

Abstract

(57) [Summary] [Purpose] The dispensing unit amount is not affected by the heat generation of the motor, so that the dispensing unit amount does not change and the dispensing unit amount is maintained at a predetermined value to reduce the number of assembling steps and separate for the motor. Eliminates the brake of. [Structure] Rotating shaft 5 for vertically moving motor 3 in and out
Is provided with a spherical body 8 as a pressing portion, and an upper end of the piston 20 is provided with a ball receiver 22a as a pressing receiving portion that receives a pressing force from the pressing portion, and the piston is urged in the direction of the rotation axis. Instead of being connected to the shaft, the pressure receiving portion is in contact with the pressure portion in a concavo-convex relationship with only a small contact area.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dispensing device for dispensing target liquids such as blood samples and reagents.

[0002]

[Prior Art]

 The dispenser not only has a large number of liquids to be dispensed, but also can freely respond to changes in the dispensed volume, increasing the dispense efficiency and shortening the time required for dispensing. Instead, it is important to be able to withstand repeated use over a long period of time and to secure an accurate dispensing unit amount. In the conventional dispenser, a piston housed in a cylinder is operated by a rotating shaft that moves in and out of a drive motor to perform dispensing, and the piston is connected to the rotating shaft.

[0003]

[Problems to be solved by the device]

 However, in the conventional dispenser, the piston is connected to the rotating shaft, so heat is transferred from the rotating shaft heated by the heat of the motor to the piston and the cylinder, and the effect of this heat causes the cylinder to expand and contract. However, there is a drawback that the dispensing unit amount changes and the dispensing becomes inaccurate.Because a bearing, coupling, etc. are required to connect the piston to the rotary shaft, assembly is troublesome. In addition, in order to perform dispensing accurately, the rotating shaft must be able to be stopped in a stable state, but for that purpose it is necessary to attach a separate brake etc. to the motor. There was a problem that there was.

In view of such problems of the related art, an object of the present invention is to not be affected by heat generation of a motor, and therefore, the dispensing unit amount can be maintained at a predetermined value without changing. The purpose is to reduce the number of assembly steps and provide a dispensing device that does not require a separate brake for the motor.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is a dispensing device for operating a piston housed in a cylinder by a rotary shaft of a drive motor that can freely move in and out, wherein a tip end of the rotary shaft is provided with a pressing portion. , The piston is provided with a pressing force receiving portion for receiving a pressing force from the pressing portion, the piston is biased in the direction of the rotation axis, and the pressing portion and the pressing force receiving portion have a concave-convex relationship and only a small contact area. It is characterized by contacting with.

[0006]

[Action]

 The dispensing device according to the present invention is provided with a pressing portion at the tip of the rotating shaft and a pressing receiving portion for receiving a pressing force from the pressing portion on the piston, and the piston is biased in the direction of the rotating shaft. Since it is not connected to the shaft and the pressure receiving part is in contact with the pressure part with only a very small contact area, there is almost no heat transfer from the motor to the piston, and there is no influence of expansion and contraction due to heat, and accurate Since it can be poured and the pressure receiving portion is in contact with the pressure portion in a concave-convex relationship, the piston and the rotating shaft can be easily assembled, and a separate brake is not required for the motor.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a main part of a dispensing device according to an embodiment of the present invention, and FIG. 2 is a plan view showing a frame in a broken manner.

The dispensing device 1 according to the present embodiment has a drive motor 3 having a rotating shaft 5 that moves up and down freely, and a rotating shaft 5 that pushes and lowers and a compression spring 15 moves upward. A piston 20 urged in the direction of the rolling shaft 5 and a cylinder 10 for accommodating the piston 20 so as to be movable up and down are provided, and a dispensing nozzle 35 is assembled in communication with the cylinder 10. The piston 20 is operated by the drive motor 3 for dispensing. The rotary shaft 5 is provided with a convex spherical body 8 serving as a pressing portion, and the piston 20 has a concave shape that receives a pressing force from the spherical body 8. Is provided with a ball receiver 22a as a pressure receiving portion, the piston 20 is biased toward the rotating shaft 5 and is not connected to the rotating shaft 5, and the ball receiver 22a is always in contact with the spherical body 8 only in a small area. The motor 3 to the piston 20 There is almost no heat transfer to the sphere 8, and the ball receiver 22a makes contact with the sphere 8 in a concave-convex relationship to give a pushing force, so that the piston 20 and the rotary shaft 5 can be easily assembled, and a separate brake is required for the motor 3. Not.

The motor 3 includes a fixed nut 4 protruding downward and a rotary shaft 5 screwed to the fixed nut 4 and movable up and down. The support plate 6 made of aluminum fixed to the common frame 2 penetrates the motor 3. The fixing nut 4 is inserted through the hole, and is supported and incorporated by the supporting plate 6. The rotary shaft 5 has a male screw 5a engraved on the outer periphery thereof, and a sphere 8 as a pressing portion is fitted to the tip of the rotary shaft 5. The motor 3 is driven to rotate in the reverse direction and to rotate in the normal direction to move up and down in FIG. The piston 20 is pushed down during the lowering operation. The common frame 2 is provided with a power connector 9 for the motor at the top, and a sensor 36 for detecting the pressure in the cylinder 10 is attached to the side surface at a position substantially corresponding to the cylinder 10. The motor 3 is provided with an origin confirmation sensor 3a.

The cylinder 10 is configured by combining an upper divided body 11 and a lower divided body 16, and is fixed to the common frame 2. The upper divided body 11 has a cylindrical portion 12 that straightly guides a piston rod 22 that is slidably fitted, and an accommodating recess 13a that accommodates a piston, and a piston accommodating portion 13 having an outer diameter larger than that of the cylindrical portion 12. Are integrally formed, the lower end surface is provided with an annular groove 13b, and the compression spring 15 is wound around the outer periphery of the cylindrical portion 12. is recieving. The lower split body 16 includes a housing recess 16a corresponding to the housing recess 13a of the upper partition 11, a through hole 17 at the bottom of the housing recess 16a, and a screw hole 18 following the through hole 17, The upper end surface, which is a mating surface with the split body 11, is flat.

The housing recess 13a forming the piston housing chamber on the side of the upper split body 11 has an inner diameter larger than that of the housing recess 16a of the lower split body 16, and serves as an inner peripheral surface of the housing recess 13a of the upper split body 11. The predetermined gap with the outer peripheral surface of the piston body 21 exceeds twice the thickness of the elastic diaphragm 25, and the inner peripheral surface of the accommodating recess 16a and the outer peripheral surface of the piston main body 21 that constitute the piston accommodating chamber on the lower split body 16 side. The predetermined gap between and is larger than the thickness of the elastic diaphragm 25.

The piston 20 integrally includes a piston body 21 at the lower end, which has a predetermined gap between the piston 20 and the accommodation recess, and is vertically movably accommodated in the accommodation recess, and a piston rod 22 having a diameter smaller than that. All of them have a circular cross section, and a ball receiver 22a, which is a conical concave pressure receiving portion, is formed at the upper end of the piston rod 22, and this ball receiver 22a separates the sphere 8 from the tip of the rotary shaft 5. A spring bearing plate 23 having an outer diameter larger than that of the cylindrical portion 12 is fitted to the outer periphery of the upper end of the compression spring 15 under the pressing force, and the lower surface of the flange 23a formed on the spring bearing plate 23 extends from the upper end of the compression spring 15. It is receiving push-up force.

FIG. 3A is an enlarged sectional view showing the elastic diaphragm, and FIG. 3B is a plan view thereof. The elastic diaphragm 25 is made of a tapered cup-shaped synthetic rubber-based material that expands upward in a natural state, has an annular projection 27 integrally at the edge of the upper end flange 26, and has a lower surface of the upper end flange 26 in the cylinder. 10 is brought into contact with the flat upper end surface of the lower divided body 16, the ring-shaped ridge 27 is fitted into the annular groove 13b of the upper divided body 11, and the upper end flange 26 is attached to the lower end surface of the upper divided body 11 and the lower divided body. It is attached so as to be sandwiched between the upper end surface of 16 and.

The elastic diaphragm 25 has a bottom surface 28 serving as a back surface fixed to the lower end surface of the piston body 21, and when the piston 20 descends, the tapered side portion 29 together with the piston body 21 fits in the housing recess 16 a of the lower split body 16. When the piston 20 is housed, the side part 29 is housed in the housing recess 13a of the upper split body 11 together with the piston body 21 by bending and deforming as shown by the chain double-dashed line in FIG.

The nozzle 35 is attached by screwing a male screw at the upper end into a screw hole 18 of the lower divided body 16 of the cylinder 10, and a continuous central hole 35 a over the entire length has a small through hole 17 in the cylinder 10. A pipette that is not shown and is exchangeable is airtightly fitted to the outer periphery of the tapered lower end, and the liquid to be dispensed is sucked into the pipette for use.

The dispensing device 1 according to the present embodiment is provided with two rods 31 used for supporting the entire bracket 30 in FIGS. 1 and 2. The rod 31 has an upper end fixed to the support plate 6 and a lower end fixed to the overhanging portion 16b of the lower split body 16 and is arranged in parallel with the piston 20 and the nozzle 35. The sliding body 37 is penetrated through two bearings 30a. The bracket 30 has a compression spring 32 wound around the outer circumference of the rod 31 between the lower end, the upper surface of the protruding portion 16b of the lower split body 16 and the lower surface of the sliding body 37, and is directed upward with respect to the entire dispensing device 1. And is slidable along the rod 31.

Then, in the dispensing device 1, the upper surface of the overhanging portion 16b of the lower divided body 16 is located at a position with a predetermined gap from the lower end surface of the sliding body 37, and the bracket 30 is provided with the robot 40 shown in FIG. When it is fixed to a predetermined position of the device, the entire device is urged downward by the compression spring 32 and supported by the bracket 30, and the entire device escapes upward against the urging force of the compression spring 32. The spring 32 acts as a buffer.

FIG. 4 is a perspective view showing an embodiment when the dispensing device according to the present invention is attached to a robot and used. The robot 40 as a moving machine includes a first arm 42 rotatably mounted on a main pillar 41 standing on a base 46, and a first arm 42 connected to the first arm 42 via a joint 43. The second arm 44 and the vertical member 45 fixed to the tip of the second arm 44 are provided, and the flat plate-shaped cover 47 on the back side of the vertical member 45 is removed, and the vertical member 45 is not shown. The bracket 30 is detachably fixed to a predetermined position of the lifting / lowering body with a small bolt (not shown), and the plate A and the plate B are installed on the base plate 46 within the reach of the vertical member 45. A large number of cells (not shown) are arranged in rows and columns.

Next, the operation of the dispensing apparatus will be described by taking as an example the case of dispensing a sample in a predetermined cell on the plate A side to a large number of cells on the plate B in FIG. With the piston 20 set to the fully lowered position shown in FIG. 1 and the dispensing device 1 being raised, the robot 40 is moved to a position directly above a predetermined cell on the plate A side. At this time, the elastic diaphragm 25 has a cup shape in a substantially natural state, and the tapered side portion 29 is accommodated in a predetermined gap in the accommodation recess 16 a of the lower split body 16.

The robot 40 lowers the dispensing device 1 to a position where the tip of a pipette (not shown) fitted in the nozzle 35 reaches the sample in the cell directly below. By rotating the motor 3 in the reverse direction, the rotary shaft 5 is raised and the piston 20 is raised by the urging force of the compression spring 15 accordingly, and a predetermined amount of sample is pipetted while the sensor 36 detects the pressure in the cylinder 10. Inhale. At this time, the elastic diaphragm 25 is doubled by bending the side portion 29 as shown by a chain double-dashed line in FIG. 1, and is accommodated in a predetermined gap in the accommodation recess 13a of the upper divided body 11.

By the operation of the robot 40, the dispensing apparatus 1 is lifted right above and then positioned right above a predetermined cell on the plate B side. When the pipette reaches a predetermined position in the cell by the operation of the robot 40, the dispensing device 1 is lowered to about the roller, and the motor 3 is rotated in the forward direction to lower the rotating shaft 5 and press the ball receiver 22a with the sphere 8. Then, the piston 20 is lowered to discharge a predetermined amount of liquid while the sensor 36 detects the pressure in the cylinder 10.

The robot 40 raises the dispensing device 1 right above and moves it to a position just above another predetermined cell on the plate B side. Repeat the above steps and to dispense the sample into a specified number of cells on the plate B side. Each of the above operations is performed by a computer (not shown) according to a predetermined program. During each of the above operations, the ball receiver 22a of the piston 20 is always in contact with the sphere 8 with only a small contact area and is not connected to the rotary shaft 5, so that the accurate unit amount is not affected by the heat generation of the motor 3. Since the pouring amount can be maintained and the ball receiver 22a is constantly in contact with the sphere 8 to give a pushing force, when the motor 3 is stopped, the frictional force between the female screw of the fixed nut 4 and the male screw 5a of the rotary shaft 5 The rotating shaft 5 can be stopped at a predetermined position in a stable state. Further, since it is sufficient that the sphere 8 and the sphere receiver 22a are in contact with each other in a concavo-convex relationship, the rotary shaft 5 and the piston 20 can be easily assembled.

It should be noted that the present invention is not limited to the above-described embodiment, and the sphere may be attached to the upper end of the piston instead of being attached to the tip of the rotary shaft, and a curved surface other than a spherical surface may be used instead of the sphere. The elastic diaphragm may be made of a metal, the elastic diaphragm may be made of metal, and the elastic diaphragm may be made of bellows instead of the cup. Various modifications are possible without departing from the scope of the invention.

[0024]

[Effect of the device]

 As described above, according to the present invention, the rotating shaft has the pressing portion at the tip thereof, the piston has the pressing receiving portion for receiving the pressing force from the pressing portion, and the piston is biased toward the rotating shaft. Since the pressure receiving part is not connected to the rotating shaft and is in contact with the pressing part with only a small contact area, it is possible to prevent the heat of the motor from being transferred to the piston via the rotating shaft, and the expansion due to heat There is an effect that accurate dispensing function is maintained without being affected by contraction, and the dispensing unit amount can be constantly maintained at a predetermined value. Further, according to the present invention, since the pressure receiving portion comes into contact with the pressure portion in a concavo-convex relationship, the piston and the rotary shaft can be easily assembled. You don't need a brake.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a main part of a dispensing device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a frame of a dispensing device according to an embodiment of the present invention in a cutaway manner.

3A and 3B show an elastic diaphragm according to an embodiment of the present invention, in which FIG. 3A is an enlarged sectional view and FIG. 3B is a plan view.

FIG. 4 is a perspective view showing a case where the dispensing apparatus according to the embodiment of the present invention is attached to a robot and used.

[Explanation of symbols]

 3 Motor 4 Fixing Nut 5 Rotating Shaft 8 Sphere (Pressing Section) 10 Cylinder 11 Upper Divided Body 13 Piston Housing 13a Housing Recess 15 Compression Spring 16 Lower Split 16a Housing Recess 20 Piston 21 Piston Body 22 Piston Rod 22a Ball Receiver Receiving part 23 Spring receiving plate 25 Elastic diaphragm 26 Top flange 27 Ring-shaped ridge 28 Bottom surface (rear side) 29 Side part 30 Bracket

Claims (1)

[Scope of utility model registration request] 1. A dispensing device for performing dispensing by operating a piston housed in a cylinder with a rotating shaft of a drive motor that can freely move in and out, wherein a tip of the rotating shaft is provided with a pressing portion, and the piston is provided with the pressing member. A pressing receiving portion that receives a pressing force from the portion, the piston is biased in the direction of the rotating shaft,
A dispenser, wherein the pressing portion and the pressing receiving portion are in contact with each other only in a minute contact area due to the concavo-convex relationship.