JP3223684B2 - Chemical injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid injector.
More specifically, the present invention relates to a drug solution injection device for continuously injecting various drug solutions into a human body at a constant pressure.

[0002]

2. Description of the Related Art A conventional chemical liquid injection device is a syringe pump type (Japanese Patent Application Laid-Open No. 59-11867, Japanese Unexamined Patent Application Publication No.
Japanese Patent Application Laid-Open No. Hei 12-16772, Japanese Patent Application Laid-Open No. 5-42209), and a balloon pressure type (Japanese Patent Application Laid-Open No. Hei 3-170163).

In the syringe pump type, the rotation of the electric motor is reduced by gears or the like, and the plunger inserted into the syringe is moved linearly at low speed. That is, a feed screw rod parallel to the axial direction of the syringe is rotatably installed inside a base box in which a syringe and a plunger are detachably set, and a motor, a reduction gear, a power supply, and a computer for rotating the screw rod are provided. A control circuit and the like are similarly built in. A control panel is provided on the surface of the base box.

On the other hand, in the balloon pressure utilization type, a cylindrical body penetrates the diameter of a spherical shell housing, and an elastic membrane sleeve is mounted on the outer periphery of the cylindrical body. A chemical solution is introduced between the sleeve and the cylinder, and the sleeve expands spherically in the spherical shell. Then, while maintaining a constant pressure by the elastic restoring force of the sleeve, the chemical solution in the sleeve is guided from the inside of the cylindrical body to the outside by the tube.

[0005]

However, in the former, a syringe containing a chemical is set on the surface of a base box containing a power supply, a motor, gears, and the like, so that the entire device is large and expensive, and the syringe containing a chemical is made. There is a drawback that the entire device is not disposable because it is used only after replacement.

On the other hand, the latter has a problem that flow controllability is poor. That is, the balloon pressure type has the disadvantage that the internal pressure fluctuates greatly at the beginning and end of the effective stroke as shown by the line b in FIG. 8, and the flow rate fluctuation due to sliding resistance and external pressure is large.

The present invention has solved the above-mentioned problems and has attained various conditions that none of the above-mentioned types of chemical liquid pumps could achieve, namely, low cost, simple structure, suitable for disposable use, and superior flow control performance. It is an object of the present invention to provide a drug solution injector that satisfies all of the above conditions.

[0008]

Means for Solving the Problems In order to solve the above problems, the constitution of the present invention is as follows. That is, the first configuration of the present invention comprises a drug solution container, a drive unit, a drive source, and a pressure control valve connected to a drug solution outlet of the drug solution container via a tube, and the drive unit includes: A housing provided on the base end side of the drug solution container and one of a pair of male and female screw members screwed together concentrically with the axis of the drug solution container are rotated by the drive source, and one of the screw members is rotated. A screw mechanism for linearly moving the gasket from the base end toward the distal end in the liquid medicine container in the axial direction, wherein the drive source is rotatable in the housing and coaxial with the liquid medicine container. A spring take-up drum supported above, a spring take-up reel rotatably supported in the housing with an axis parallel to the axis of the spring take-up drum, and one end fixed to the spring take-up drum The other end is spring-wound Is secured to the reel, it is to include a constant force spring that is biased to wind around naturally to the spring take-up reel side or drum side with no external forces.

In a second configuration, in addition to the first configuration, the chemical solution container portion and the driving portion are detachably connected by mounting means, and the mounting portion is formed on a housing of the driving portion. A male screw portion formed on the outer periphery of a cylindrical portion having substantially the same diameter as the chemical solution container, and a retaining solution formed on an outer periphery of a base end portion of the chemical solution container, so that the chemical solution is prevented from falling outside in the proximal direction. A nut is attached to the outer periphery of the container, and the nut is screwed into the male screw portion to attach the drive unit to the liquid medicine container.

In a third configuration, in addition to the first configuration, the screwing mechanism includes a male screw rod integral with the spring winding drum and a female screw portion screwed to the male screw rod at a base end inner periphery. And a hollow rod provided with a coupling portion detachably coupled to the gasket at the distal end thereof, and a rotation preventing stopper for preventing rotation of the hollow rod.

In a fourth configuration, in addition to the first configuration, the screwing mechanism is a prism that is integral with the spring take-up drum, and is externally movably inserted in the prism in an axially movable manner, and is coupled to the gasket at a tip portion. A hollow screw rod provided with a coupling portion, and a female screw member screwed to the hollow screw rod and fixed to the housing.

A fifth configuration according to any one of the first to fourth configurations, further comprises manually rotating the spring winding drum or reel to wind the constant load spring around the spring winding drum or reel. That is, a winding means is provided.

The sixth configuration is, in addition to any one of the first to fifth configurations, further provided with a brake means, wherein the brake means is provided with a first pulley fixed concentrically with the spring winding drum, and a first pulley.
A second pulley fixed concentrically to the spring take-up reel with the outer circumferential surface facing the pulley, and a second pulley which is concentrically fixed to the spring take-up reel, is capable of moving back and forth to a side where the outer circumferential surfaces approach each other at the boundary between the first and second pulleys And a wedge member.

In a seventh configuration, in addition to the first to sixth configurations, the pressure control valve comprises first, second, and third members in the longitudinal direction of the valve rod in order, and the first member has a valve hole. , A valve seat, a first recess, and a fluid outlet are provided. The second member is provided with a valve stem through hole, a second recess on the first recess side, and a third recess on the opposite side. The three members are provided with a fourth recess and a pilot hole on the third recess side and a valve stem through-hole corresponding to the valve seat. Between the first and second members, a first diaphragm interposed between the first and second members and fixed through the valve stem in a fluid-tight manner, and the second and third members. A second diaphragm interposed and liquid-tightly fixed to the other end of the valve stem;
A compression spring interposed between the diaphragm and the bottom of the third recess.

[0015]

In the state in which the chemical solution container and the drive unit are assembled, the constant load spring is wound around the spring winding drum by the winding means, and then released, the winding drum wound around the winding reel is rotated. Can be The rotation of the spring winding drum is converted into linear motion of the gasket by the screw member of the screwing mechanism, and the gasket advances from the base end of the chemical solution container to the distal end side to push out the chemical solution. At this time, the rotation torque of the spring winding drum and the screw advancing mechanism is constant, and the flow rate is determined by the rotation torque. Further, since the liquid medicine is injected through the pressure control valve, the supply pressure of the liquid medicine becomes substantially constant. As a result, a minute amount of injection can be performed for a long time. Since the pushing force in the linear direction is increased by the screwing mechanism, there is an advantage that a high extrusion pressure can be obtained.

When the chemical solution container and the drive unit are attached by the attaching means, only the chemical solution container portion can be discarded after use, and can be disposable. Then, the liquid medicine container is filled with the liquid medicine in advance, and the connector such as the connector at the tip of the liquid medicine container can be sterilized by sealing it with a cap or the like, so that it is possible to transport and store only the liquid medicine container part with the liquid medicine filled and sterilized. is there. Furthermore, when the drive unit is mounted during use, the screwing mechanism is reversed by the winding means, and the gasket is retracted in the chemical solution container, so that the chemical solution can be filled in the chemical solution container at the time of use.

[0017]

Embodiments of the present invention will be described below based on one embodiment shown in the drawings. In FIG. 1, the liquid medicine injection device P of the present embodiment basically includes a liquid medicine container section 10 and a drive section 30, which are separate units, and are characterized in that they are detachably connected by a nut 21. is there.

The chemical solution container 10 includes a chemical solution container 11 and a gasket 12. The chemical liquid container 11 has a mounting portion 11b such as a connector formed at the narrowed end of a cylindrical body 11a made of glass, plastic or the like with both ends opened.
As shown in FIG. On the outside of the base end portion of the chemical solution container 11, a retaining ridge 11 protruding outward in the radial direction.
c is formed. The gasket 12 has a plurality of O-ring 12b on the outer periphery of the gasket main body 12a made of synthetic resin umbrella-shaped member polypropylene and Po triethylene like is mounted, the male threaded portion of the hollow rod 32b which will be described later on the inner circumferential 3
A female screw portion 12c screwed with 2d is formed, and is inserted into the base end of the chemical solution container 11 in a liquid-tight and slidable manner.

A nut 21 is externally inserted around the outer periphery of the chemical solution container 11, and an engaging ridge 22 protruding radially inward is formed on the distal end side of the chemical solution container, and is engaged with the retaining ridge 11c. The liquid medicine container 11 is configured so as not to come out from the base end portion.

In FIGS. 1 and 3, the drive unit 30 has a housing 31. An intermediate cylindrical portion 31b having substantially the same diameter as the intermediate tube portion 31b, which is concentric with the medical solution container 11 on the side of the main body 31a of the housing 31 and is close to the chemical solution container. Are formed in order. A male screw 31d is formed on the outer periphery of the intermediate cylindrical portion, and the nut 21 is screwed into the male screw 31d to form the mounting means 20, and the driving unit 30 is detachably connected to the chemical liquid container 11. The intermediate cylindrical portion 31b and the main body of the housing are connected to each other with screws B1 or the like.

In the housing body 31a, a chemical solution container 1 is provided.
A spring take-up drum 41 is rotatably supported by a support hole on the same axis as 1. A spring take-up reel 42 is rotatably supported by the housing with an axis parallel to the axis of the spring take-up drum. One end of the constant load spring 43 is fixed to the spring take-up drum 41, and the other end is connected to the spring take-up reel 4.
2 and is urged to naturally wind around the spring take-up reel without applying any external force. This constant load spring is a spiral spring wound with a thin plate-like spring material. In addition, the winding force (in other words, the rotating torque of the winding drum generated at the time of rewinding) has a characteristic that it is constant over the entire effective rotational speed as shown by the line a in FIG.
Note that the line c is based on a known mainspring.

In FIG. 1, the screwing mechanism 32 is connected to the inside of the spring winding drum 41 coaxially. That is, the male screw rod 32a is connected to the spring winding drum concentrically, and the tip of the male screw rod is located substantially concentrically within the housing tip cylindrical portion 31c. A hollow rod 3 is provided on the outer circumference of the male screw rod 32a.
2b is arranged, and the female screw portion 32c formed on the inner periphery of the base end portion is screwed to the male screw rod. A male screw portion 32 d is formed on the outer periphery of the distal end portion of the hollow rod, and is screwed with the female screw portion 12 c of the gasket 12. Hollow rod 32b
As shown in FIGS. 1 and 6, an anti-rotation groove 32f which is long in the axial direction is formed on the side surface, and an anti-rotation stopper 32e which fits long in this groove is fixed to the inner surface of the housing distal end cylindrical portion 31c. . Therefore, when the male screw rod 32a rotates, the hollow rod 32b advances and retreats in the axial direction without rotating, and moves the gasket 12 in the chemical solution container 11 in the axial direction.

At the center of the male screw rod 32a, preferably,
A hexagonal hole 44a is formed along the axis. And
When the hexagon wrench 44b is inserted into the hexagonal hole and manually rotated, the constant load spring 43 can be wound around the winding drum 41. The hexagonal hole and the hexagonal wrench constitute a winding means 44 described in the claims.

Further, a brake means 45 is provided.
That is, in FIG. 4, a first pulley 45a concentrically fixed to the spring take-up drum 41, and a first pulley 45a concentrically fixed to the spring take-up reel 42 with the outer circumferential surface facing the first pulley. 2 pulleys 45b, the first and second pulleys 45a, 4
It comprises a stopper 45c having a wedge member 45f which can move forward and backward to the side where the outer circumferential surfaces approach each other at the boundary of 5b. The stopper is passed through a through hole formed in the housing body 31a. This stopper is knob 45
d, barrel 45 e, consists of a spring 4 5 g was interposed between the wedge portion 45f and the wedge portion and the housing. And, normally wedge portion 45f is the pulleys 45a by the urging force of the spring 4 5 g, fitted between 45b, the drum 41 taken up by the wedge action does not rotate.

Here, when the stopper 45c is pulled out, the winding drum 41 can freely rotate, and the winding drum is rotated by the rewinding force of the constant load spring 43. Then, as shown in FIG. 7, the male screw rod 32a rotates in the same direction, the hollow rod 32b moves forward, and the gasket 12 moves forward toward the tip end of the chemical liquid container 11. As a result, the liquid medicine in the liquid medicine container is discharged.

In the chemical solution outlet 11b of the chemical solution container,
As shown in FIGS. 14 and 15, the pressure control valve 50 is connected via the tube 1. The valve box 50A of the valve includes first, second, and third members 51, 52, 53 in the longitudinal direction of the valve rod 54 in order.
Consists of The first member 51 includes a valve hole 51a and a valve seat 51.
b, a first recess 51c and a fluid outlet 51d are provided,
The second member 52 has a valve stem through hole 52 a and the first recess 51.
The second recess 52b of the c side, and the third recess 52c and the air hole 52d opposite is provided, the fourth recess 53 b and the pilot hole 5 in the third recess 52c side in the third member 53
3a is provided.

The valve rod 54 penetrates through the valve rod through-hole 52a correspondingly to the valve seat 51b, and the other end thereof is the third or fourth valve rod.
It is in the recesses 52c, 53b. The first diaphragm 55 is interposed between the first and second members 51 and 52 and is fixed in a liquid-tight manner through the valve rod 54. The second diaphragm 56 is interposed between the second and third members 52 and 53 and is fixed to the other end of the valve rod 54 in a liquid-tight manner. The compression spring 5 is disposed between the second diaphragm 56 and the bottom of the third recess 52c.
7 are interposed.

In FIG. 15, the pressure (for example, 1.5 kgf / cm ^{2 at first} ) from the chemical solution injector P is guided to the pressure control valve 50. At this time, the valve rod 54 is pushed up by the compression spring 57 to open the valve, and flows toward the injection needle 3. However, since the pressure in the fourth recess 53b immediately rises (the injection needle becomes a kind of capillary action restrictor), the first recess 51c
The pressure becomes larger than the value obtained by adding the force of the spring 57 to the pressure, and the valve rod 54 is pushed downward to close the valve. If the flow of the injection needle 3 continues, the pressure in the second and third recesses 52b and 52c decreases, so that the valve rod 54 rises again by the force of the spring 57 to open the valve. Hereinafter, this operation is repeated, and it is compared with the exit 51d.
For example, a pressure of 0.5 kgf / cm ² is maintained. This pressure control valve has a simple structure, is obtained at low cost, and is suitable for disposable use. Further, if the valve stem through-hole 52a is a through hole, the valve stem 54 does not contact and does not friction, and the operation is accurate. Moreover, the second and third recesses 52b and 52c do not touch the chemical.

In the above embodiment, the following materials are suitable for each part. Male thread rod 32a, hollow rod 32
b: metal (iron, brass), ABS resin, nylon, polyacetal resin, polyethylene, polycarbonate resin, etc., housing 31: ABS resin, polyethylene resin, etc., nut 21: ABS resin, polyethylene resin,
Gasket 12 such as nylon; polyethylene resin; O-ring 12b: natural rubber, synthetic rubber (butyl rubber, butadiene rubber, silicon rubber, fluorine rubber); cap C: natural rubber, butyl rubber, polyethylene resin.

In the chemical liquid injector having the above-mentioned configuration and the following specifications, for example, an internal pressure of 600 mHg could be constantly generated. The chemical solution container has an inner diameter of 50 mm, the same cross-sectional area of 19.6 cm ² , a capacity of 60 cc, and a male screw rod 32 a having eight rotations and a stroke of 31 mm.

FIG. 14 shows the use state of the chemical injection device of the above embodiment. As shown in FIG.
, A pressure control valve 50 and a flow rate controller 2 are interposed in the middle thereof, a puncture needle 3 is attached to the tip, and a human body is punctured. The flow rate of the drug solution extruded from the drug solution injector is controlled by the flow rate controller 2, so that a small amount of continuous injection is effectively performed for a long time. Or the same figure (B)
As shown in FIG.
And insert it into the human body.

The controller 2 includes, for example, a tube 1
If a pipe having a fine inner diameter of 10 to 50 μm is installed in the middle of the process, the outflow speed of the drug solution in the drug solution injector decreases, and the time for injecting the drug solution into the human body can be lengthened. The length of the pipe is 1 cm or more, and the outer diameter is 5 to 500 times the inner diameter. If the length of the pipe exceeds 30 mm, using a case in which the fine inner diameter pipe is stored in a crimped structure,
The length of the tube 1 is preferably reduced. Flow controller 2
Japanese Patent Application Laid-Open No. 2-1116 filed by the present applicant
No. 0 or JP-A-3-140163, and a metal pipe, a synthetic resin pipe, a glass pipe, or the like may be used.

FIG. 9 shows a second embodiment of the present invention, in which an outer flange 11d is provided at a base end of a chemical solution container, and this is connected to a housing 31a of a drive section by a screw B1. Other configurations are substantially the same as those of the first embodiment, and therefore, the same components are denoted by the same reference numerals and description thereof is omitted. In this embodiment, it is also possible to make the chemical solution container unit 10 and the drive unit 30 inseparable and to dispose the entire chemical solution injection device disposable.

FIG. 10 shows a third embodiment of the present invention. The present embodiment is different from the first embodiment in that the gasket 12 is formed of a rubber-like elastic body, and that the screwing mechanism 33 and the connection portion between them are different. That is, the prism 33a is coupled concentrically with the spring winding drum 41, and a hexagonal hole is formed concentrically with this prism. As the cross-sectional shape of the prism, an arbitrary polygon of about triangular to octagonal is used. A hollow male screw rod 33b is extrapolated around the outer periphery of the prism. The cross-sectional shape of the cavity of this hollow male screw rod is similar to the cross-sectional shape of the prism, and does not rotate independently of each other, but always rotates in the same direction,
Axial movement is allowed. And the female screw member 33c screwed around the outer periphery of the hollow male screw rod is
It is fixed to the cylindrical portion 31b of the housing.

Accordingly, the drum 41 rotates and the prism 33
When a is also rotated, the hollow male screw rod 33b rotates in the same direction, and advances in the axial direction by being screwed with the female screw member 33c integrated with the casing.

At the end of the hollow male screw rod 33b, a cap-shaped coupling portion 33d is formed, which fits into an engaging concave portion 12d formed in the gasket 12 by elastic deformation, and
There are gaps so that they can rotate with each other. Thus, the hollow male screw rod 33b is detachably attached to the gasket 12.

In this embodiment, the hollow male screw rod 33b is used.
Moves forward while rotating, and pushes the gasket 12 toward the distal end of the chemical solution container. As a result, the chemical solution can be discharged at a constant pressure.

The gasket 12 of this embodiment does not use an O-ring, but the gasket itself is formed of a rubber-like elastic material such as natural rubber or butyl rubber. An annular ridge 12e that plays a similar role
Is formed.

The connector 1 of the chemical solution container according to the present invention.
The shape of 1b is arbitrary, and for example, the following can be exemplified. In the example of FIG. 12, the coupling portion is a luer tip 11e, and a female connector D coupled to the luer tip 11e is used. Further, a puncture needle (not shown) may be directly connected to the luer tip.

In the example shown in FIG. 13, the connecting portion is a mouth 11d of a tightening type, which includes a double-ended needle 6 having a connecting means (luer tip) on the distal end side, and a double-ended needle and a puncture needle 7. Or a double-ended metal needle 8
Can be attached.

The advantages of each embodiment of the present invention are as follows. In each embodiment, the chemical solution container unit 10 and the driving unit 30
Is a separate body, and the chemical solution container portion 10 is an inexpensive one composed of the container 11 and the gasket 12, so that only the chemical solution container portion can be disposable after use.

As shown in the chemical solution container section 10 of FIG.
If the gasket 12 is sealed after filling the drug solution container 11 with the drug solution, sterilization can be performed in that state, so that the sterility of the drug solution can be guaranteed. In addition, it is possible to make a prefill for transporting and storing the liquid medicine in a state in which the liquid medicine container is filled with the liquid medicine. In this case, the chemical liquid container 10 and the drive unit 30 can be easily used only by connecting them with the nut 21 at the time of use. In particular, in the first and third embodiments, the coupling can be performed only by tightening the nut 21.

In addition to the prefilled type, the present invention can be used as an in-use filling type in which the empty chemical solution container unit 10 and the driving unit 30 are connected in advance. In this case, the gasket 12
From the state where it is advanced into the chemical solution container 11,
When the winding drum 41 is wound up using 4b or the like, the gasket 12 gradually retreats, so that the chemical solution can be filled in the chemical solution container 11. The second embodiment is suitable for such usage.

The drive section 30 is mainly composed of a constant load spring 43 and mechanical components such as a take-up drum 41, a take-up reel 42, a screwing mechanism 32 and the like. Can be manufactured at a low price.

Since the liquid medicine is pushed out with a constant torque by the constant load spring 43, the fluctuation of the flow rate is small, the discharge pressure is high, and the constant amount of the liquid medicine can be administered by maintaining the constant pressure by the pressure control valve 50. In addition, by combining with the flow rate controller 2, it is possible to perform a long-time, minute continuous injection.

It can have both functions of a storage container for a chemical solution and an injection device.

The present invention is not limited to the examples and embodiments described above, but includes various modifications without departing from the spirit and scope of the claims.

[0048]

According to the present invention, a medicinal solution injection is inexpensive, has a simple structure, is suitable for disposable use, has a flow control performance that is as accurate as that of a syringe pump, and is capable of both pre-filling and in-use filling. Equipment can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II of FIG.

FIG. 3 is a sectional view taken along line III of FIG. 1;

FIG. 4 is a sectional view taken along line IV of FIG. 1;

FIG. 5 is a bottom view of FIG. 1;

FIG. 6 is a sectional view taken along the line VI of FIG. 1;

FIG. 7 is a partial longitudinal sectional view during operation.

FIG. 8 is a torque (output) characteristic diagram of a constant load spring and the like.

FIG. 9 is a partial longitudinal sectional view of a second embodiment of the present invention.

FIG. 10 is a longitudinal sectional view of a third embodiment of the present invention.

FIG. 11 is a vertical cross-sectional view of a third embodiment during an extrusion operation.

FIG. 12 is a cross-sectional view showing an example of the chemical solution container 11 and a coupling.

FIG. 13 is a cross-sectional view showing another example of the chemical solution container 11 and a coupling.

FIG. 14 is an explanatory diagram of a use state of the present invention.

FIG. 15 is a cross-sectional view of the pressure control valve 50.

[Description of Signs] 10 Chemical liquid container portion 11 Chemical liquid container 11a Cylindrical main body 11b Connector or other mounting portion 11c Retaining ridge 12 Gasket 12a Lid main body 12b O-ring 12c Female screw portion 12d Engagement concave portion 12e Annular ridge 20 Mounting means 21 Nut 22 Engagement ridge 30 Drive unit 31 Housing 31a Main body 31b Intermediate cylindrical part 31c Tip cylindrical part 31d Male screw 32 Threading mechanism 32a Male screw rod 32b Hollow rod 32c Female screw part 32d Male screw part 32e Rotation prevention stopper 32f Rotation prevention groove 33 Screw advance mechanism 33a Square pillar 33b Hollow male screw rod 33c Female screw member 40 Drive source (constant pressure spring) 41 Spring take-up drum 42 Spring take-up reel 43 Constant load spring 44 Hoisting means 44a Hexagon hole 44b Hex wrench 45 Brake means 45a 1 pulley 45b 2nd pulley 45c stopper 45d knob 45e barrel 45f wedge 4 5 g spring 50 pressure control valve 50A valve box 51 first member 51a valve hole 51b valve seat 51c first recess 51d fluid outlet 52 second members 52a valve stem through hole 52b first 2 recess 52c third recess 52d air hole 53 third member 53a pilot hole 53b fourth recess 54 valve stem 54a valve body 54b rod body 55 first diaphragm 56 second diaphragm 57 compression spring

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kenji Himejima 3-9-3 Honjo Nishi, Kita-ku, Osaka-shi, Osaka Nissho Co., Ltd. (56) References JP-A-63-120871 (JP, A) JP-A-62-217975 (JP, A) JP-A-52-120592 (JP, A) JP-A-58-39242 (JP, U) JP-A-61-500007 (JP, A) JP-A-58-500649 (JP, A) , A) Special Table 1986-500415 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61M 5/145 A61M 5/20

Claims (7)

(57) [Claims] 1. A liquid medicine container comprising: a liquid medicine container, a driving unit having a screw member, a driving source having a spring, and a pressure control valve connected to a liquid medicine outlet of the liquid medicine container via a tube; Has a constricted distal end and an open proximal end, and has a tubular chemical solution container having a connector or the like formed at the distal end, and is slidably inserted into the proximal end lumen of the chemical solution container. The drive unit comprises a housing provided at a base end side of the chemical solution container, and one of a pair of male and female screw members that are screwed together and concentric with an axis of the chemical solution container. Is rotated by any of the screw members in the axial direction,
A screw mechanism for linearly moving the gasket from the base end toward the distal end in the liquid medicine container, wherein the drive source is rotatable within the housing and supported coaxially with the liquid medicine container. A take-up drum, a spring take-up reel rotatably supported in the housing with an axis parallel to the axis of the spring take-up drum, and one end fixed to the spring take-up drum and the other end being A chemical load injector fixed to a spring take-up reel and including a constant load spring biased so as to naturally wind around the spring take-up reel or the drum side without applying an external force. 2. The liquid medicine container part and the drive part are detachably connected by an attaching means, and the attaching means is
A male screw portion formed on the outer periphery of a cylindrical portion having substantially the same diameter as the liquid medicine container formed on the housing of the drive unit, and a retaining projection formed on the outer periphery of the base end portion of the liquid medicine container. 2. The liquid injector according to claim 1, further comprising a nut attached to an outer periphery of the liquid medicine container so as not to come out in the proximal direction, and screwing the nut to the male screw portion to attach the drive unit to the liquid medicine container. . 3. The screw advance mechanism includes a male screw rod concentrically fixed to the spring take-up drum, and a female screw part screwed to the male screw rod on a base end inner periphery, and the distal end has the female screw part. 2. The liquid injector according to claim 1, further comprising: a hollow rod having a connecting portion detachably connected to the gasket; and a rotation preventing stopper for preventing rotation of the hollow rod. 4. A hollow in which the screwing mechanism is provided with a prism fixed concentrically with the spring winding drum, and a coupling portion which is externally movably inserted in the prism and is connected to the gasket at a tip end thereof. 2. The liquid injector according to claim 1, comprising a screw rod and a female screw member screwed into the hollow screw rod and fixed to the housing. 5. A winding means for manually rotating the spring winding drum or reel to wind the constant load spring around the spring winding drum or reel. The drug solution injector according to any one of the above. 6. A spring take-up reel having brake means, wherein the brake means is provided with a first pulley fixed concentrically to the spring take-up drum, and an outer circumferential surface opposed to the first pulley. A second pulley fixed concentrically to the first and second pulleys; and a wedge member that is movable back and forth toward a side where outer circumferential surfaces approach each other at a boundary between the first and second pulleys. 6. The drug solution injection device according to any one of items 5 to 5. 7. The pressure control valve comprises first, second, and third members in the longitudinal direction of the valve stem,
The first member is provided with a valve hole, a valve seat, a first recess and a fluid outlet, and the second member is provided with a valve rod through hole, a second recess on the first recess side, and a third recess on the opposite side. A recess provided with a fourth recess and a pilot hole on the third recess side of the third member; and a valve stem through hole corresponding to the valve seat. A valve stem having the other end located in the third and fourth recesses; a first diaphragm interposed between the first and second members and fixed through the valve stem in a liquid-tight manner; A second diaphragm interposed between the second and third members and fixed to the other end of the valve rod in a liquid-tight manner; a compression spring interposed between the second diaphragm and the bottom of the third recess; The drug solution injector according to any one of claims 1 to 6, comprising: