JPH0352523Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The invention relates to a liquid pump for administering parenteral liquids, such as saline, medicinal solutions, and nutrient solutions, into living organisms. In particular, the present invention relates to a tube guide structure for a liquid feeding pump that positions and guides a liquid feeding flexible tube (hereinafter simply referred to as a tube) attached to a finger type peristaltic liquid feeding pump to a housing.

(Prior Art) Many types of liquid delivery devices have been known as liquid delivery means for administering parenteral fluids into living bodies, but the present invention is based on a finger-type peristaltic liquid delivery pump (hereinafter referred to as (simply referred to as a liquid transfer pump). This liquid feeding pump is normally constructed as shown in FIGS. 3 to 5. In FIG. 3, a pump section 4 is provided on the front surface of the casing 1, in which a plurality of fingers 3, which will be described later, are mounted within a rectangular support frame 2. Further, a groove 5 is formed in the front surface of the support frame 2 in the vertical direction and passes approximately through the center of the support frame 2 in the width direction. It's becoming like that. Further, a clamp member 6 for clamping and closing the attached tube is provided at the upper part of the groove 5, and a pressure sensor 7 is provided at the lower part of the groove 5 for detecting the pressure of the liquid flowing inside the tube. and,
A bubble sensor 8 is provided to detect bubbles generated in this liquid.

On the other hand, a door 10 is rotatably attached to one side of the front surface of the casing 1 via a hinge 9, and a door 10 that is aligned with the finger 3 is provided on the surface of the door 10 facing the casing 1. A pressure plate 11 is provided at the position to press the tube mounted in the groove 5 against the finger 3. The upper and lower ends of this pressure plate 11 are connected to the door 10 by bolts 12 and 13, respectively.
It is attached movably in a direction perpendicular to the inner surface of the door 10. In addition, one end of the pair of springs 14 and 15 is attached to the door 10, and the other end of the spring 14, 15
The pressure plate 11 is biased in a direction so as to come into contact with the heads of the bolts 12 and 13. This door 1 again
A protrusion 16 is provided at the upper part of the inner surface of the door 10. The protrusion 16 engages with the clamp member 6 and pushes it open when the door 10 is rotated toward the housing 1 and closed.

The pump section 4 is constructed as shown in FIGS. 4 and 5. A pair of upper and lower frames 17 and 18 fixed at right angles to the inner front surface of the housing 1
A support shaft 21 is rotatably attached to the front surface of the housing 1 through bearings 19 and 20, respectively, and a plurality of shafts, for example,
Twelve eccentric cams 22 are fixed with sequentially shifted phases. Further, between these eccentric cams 22 and the front surface of the housing 1, a plurality of the fingers 3 having a shape as shown in FIG. 5 are provided corresponding to the eccentric cams 22, respectively. The finger shaft 3 is provided parallel to the front surface of the housing 1 between 18 and 18.
It is rotatably supported by a. Further, one end of these fingers 3 can be fitted into the support frame 2, and a U-shaped groove 3b that engages with the eccentric cam 22 is formed at the other end. and eccentric cam 2
2, the finger 3 swings around the finger shaft 3a, and the finger 3 sequentially presses the pressure plate 11.
approach or leave. The finger 3 is the pressure plate 11
The tip of finger 3 and pressure plate 11 when approaching
The distance between them is 2 mm to 3 mm, and the tube 23 held between them is compressed and the conduit is closed. Further, a stepping motor 24 is fixed on the upper frame 17, and a pulley 25 is attached to the drive shaft of the stepping motor 24. A timing belt 27 is provided between the pulley 26 fixed near the upper end of the support shaft 21 and this pulley 25.
is being strung up.

In the conventional finger type peristaltic liquid pump configured as described above, the rotational driving force of the stepping motor 24 is transmitted to the support shaft 21 via the timing belt 27, and the rotational driving force of the stepping motor 24 is transmitted to the support shaft 21, and the pump is attached to the support shaft 21 sequentially with a phase shift. The plurality of eccentric cams 22 are rotated. As a result, a plurality of fingers 3 are respectively engaged with the outer periphery of the eccentric cam 22 via the U-shaped grooves 3b.
is swung, and starts moving forward sequentially from the top to pressurizing plate 1.
The tube 23 is sandwiched between the tube 23 and the tube 23.
The occlusion site is moved along the longitudinal direction. and the tube 23 along the longitudinal direction of the tube 23.
The liquid inside is forced to move downward.

However, according to the conventional liquid pump configured as described above, the tube 23 attached to the front surface of the housing 1 is inserted into the groove 5 formed in the upper and lower parts of the support frame 2 on the front surface of the housing 1. However, since there is no guide portion within the support frame 2, the tube 23 is curved and biased to one side, causing a problem in that the liquid may not be completely fed. In order to solve this problem, conventionally, as shown in FIG. 3, a fixed guide portion 28 has been provided approximately in the middle of the support frame 2 in the height direction, protruding from both sides toward the center. However, even in this case, the height of the guide portion 28 must be the same as that of the support frame 2. On the other hand, when the pressure plate 11 presses the tube 23 against the tip of the finger 3, there is some gap between the surface of the support frame 2 and the surface of the pressure plate 11 due to variations in the outer diameter and wall thickness of the tube 23. Occur. For this reason, the tube 23 sometimes ran onto the surface of the guide portion 28 and became blocked. Furthermore, in order to eliminate this drawback, as shown in FIG. 6, the fixed guide portion 28 is made to protrude from the surface of the support frame 2, and a recess 31 is formed on the surface of the pressure plate 11 at a position aligned with the guide portion 28. forming the guide part 2
There is also a method of fitting the tip of 8 into this recess 31. However, according to this method, the pressure plate 11
If the guide part 28 is pressed out of the correct position, the tip of the guide part 28 will not fit into the recess 31 and the pressure plate 11
The pressure plate 11 may tilt due to contact with the surface of the guide portion 28, and in extreme cases, the tip of the guide portion 28 may break.

(Problem to be solved by the invention) As mentioned above, according to the tube guide structure of the conventional liquid transfer pump, there is no guide part for the tube within the support frame where the finger is attached, so the tube is offset and the liquid is transferred. In addition, even if the guide portion is fixed to the support frame, there is a gap between the pressure plate and the guide portion, so the tube may enter the gap and become blocked. Furthermore, if the guide part is protruded and fixed to the support frame and a recess into which the guide part fits is formed in the pressure plate, the tube can be reliably positioned and guided, but if the pressure plate is displaced, the guide part will not be applied. There have been problems in that the pressure plate may come into contact with the surface of the pressure plate and the pressure plate may be tilted, or the tip of the guide portion may break.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a tube guide structure for a liquid pump that can reliably position and guide the tube with a simple structure.

[Structure of the invention] (Means for solving the problem) In order to achieve the above object, the present invention includes a plurality of eccentric cams rotatably supported in a housing, and rotation of the eccentric cams. and a pressure plate that clamps and presses the flexible tube between the fingers, and the fingers are sequentially operated by the rotation of the eccentric cam to sequentially move the flexible tube. A front surface is provided in a liquid feeding pump that moves liquid in the longitudinal direction of the tube by pressing and closing the tube at a plurality of different positions, and has an opening through which the finger of the housing projects through the tube. In the tube guide structure of the liquid pump for positioning and guiding the tube, a concave groove is formed in the front surface of the casing to vertically penetrate through approximately the center in the width direction of the opening and positioning and guiding the tube; the tube is inserted between the two protrusions in the opening, and the tips of the two protrusions are directed toward the pressure plate; The guide member is provided with a guide member that is movable toward and away from the pressure plate, and a biasing means that biases the guide member in the direction of the pressure plate.

(Function) According to the above configuration, the guide member provided in the support frame for positioning and guiding the tube is elastically in contact with the pressure plate, and therefore moves following the displacement of the pressure plate. As a result, the tips of the two protrusions of the guide member and the pressure plate are always in close contact with each other, the tube does not ride on the guide member, and the tube can always be reliably positioned and guided to the correct position.

(Example) Hereinafter, an example of the tube guide structure of a liquid transfer pump according to the present invention will be described with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 1 and 2.
In the figure, parts that are the same or equivalent to those of the conventional example shown in FIG. 4 are denoted by the same reference numerals, and explanations thereof will be omitted. The feature of this embodiment lies in the tube guide structure within the support frame 2 on the front surface of the housing 1, and other parts are the same as those of the conventional example. In FIG. 1, the movable guide plate 29 is rotatably attached at one end approximately at the longitudinal center of the finger shaft 3a.
The other end is bifurcated and protrudes toward the pressure plate 11. A tube 23 that is positioned and guided by a groove 5 shown in FIG. 3 is linearly fitted between the pair of protrusions 29a. The distance between the protrusions 29a is larger than the width of the tube 23 when it is held between the tip of the finger 3 and the pressure plate 11 and pressurized until it becomes flat. . Further, on the other end of the movable guide plate 29, on the surface opposite to the side on which the protrusion 29a is formed, there is a plate spring 3 whose one end is fixed to the housing 1.
0 is engaged, and the tip of the protruding portion 29a is biased in a direction to come into contact with the pressure plate 11. Note that the biasing force of the leaf spring 30 is smaller than the sum of the biasing forces of the springs 14 and 15 that press the pressure plate 11.
A sufficient pressing force against the fingers 3 can be ensured. A leaf spring 30 is the biasing means.

The movable guide plate 29 configured as described above is
Similar to the fixed guide 28 shown in FIGS. 3 and 4, the intermediate fingers 3 and the eccentric cams 22 corresponding to the fingers 3 are removed one by one and are rotatably attached to these parts. FIG. 2 is an external perspective view of this embodiment.

According to this embodiment, the movable guide plate 29 is rotationally biased by the leaf spring 30, and the tip of the protrusion 29a is always in close contact with the surface of the pressure plate 11, so that it follows the displacement of the pressure plate 11. Displaced. Therefore, the protrusion 2
The tube 23 held between the protrusions 29 and 9a
It is not caught between the tip of a and the pressure plate 11, and is always positioned and guided to the correct position.

In the above embodiment, a case has been described in which there are 12 fingers 3 and 12 eccentric cams 22, but it goes without saying that these numbers are not limited to 12. Further, the means for rotationally biasing the movable guide plate 29 is not limited to the leaf spring 30;
For example, it may be a coiled spring. Furthermore, the shape of the movable guide plate 29 and the means for engaging with the eccentric cam 22 are also
The design may be changed without departing from the spirit of the present invention.

[Effect of the invention] As explained above, according to the invention, the tips of the two protrusions of the guide member are always in contact with the pressure plate, so that the tube is not sandwiched between the guide member and the pressure plate. It is always positioned and guided in the correct position without being moved, and perfect liquid delivery can be performed.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing an embodiment of the tube guide structure of a liquid pump according to the present invention, Fig. 2 is an external perspective view of this embodiment, and Fig. 3 is a perspective view of a conventional liquid pump. , FIG. 4 is a longitudinal sectional view showing the main part of FIG. 3, FIG. 5 is a partially sectional plan view of FIG. 4, and FIG. 6 is a longitudinal sectional view showing an example of a conventional tube guide. 1... Housing, 2... Support frame (opening), 3...
Finger, 5... Concave groove, 11... Pressure plate, 22...
... Eccentric cam, 23 ... tube, 29 ... movable guide plate (guide member), 30 ... leaf spring (biasing means).

Claims (1)

[Scope of utility model registration request] A plurality of eccentric cams rotatably supported within a housing, a plurality of fingers that are respectively moved back and forth by the rotation of the eccentric cams, and a pressure plate that clamps and presses the flexible tube between the fingers. and liquid feeding for moving the liquid in the longitudinal direction of the tube by sequentially operating the finger by rotation of the eccentric cam to press and close the tube at a plurality of sequentially different positions on the tube. In the tube guide structure of the liquid pump, which is provided in the pump and positions and guides the tube to a front surface of the housing in which an opening from which the fingers protrude is formed, a tube guide structure is provided in the front surface of the housing in the width direction of the opening. A concave groove is formed that penetrates vertically through the center and guides the positioning of the tube, and has two protrusions, and the tube is inserted between the two protrusions in the opening. a guide member which is movable toward and away from the pressure plate with the tips of the two protrusions facing the pressure plate; A tube guide structure for a liquid feeding pump, characterized in that it is provided with a biasing means for biasing the fluid pump.