CN101829381B - Disposable insulin injection pen with adjustable metering - Google Patents

Abstract

The invention relates to a disposable adjustable metering insulin injection pen which is convenient to use and carry, and comprises a pen cap, a needle head, an injection tube, an injection sleeve, a positioning fixture block, a screw rod, a nut tube, a fixed tube, a coil tube, a clutch tube, a scale positioner and a button, wherein a piston is arranged in the injection tube, and a medicament is pre-filled in the injection tube; the insulin injection pen integrates insulin and an injection pen, so that a patient does not need to replace an injection tube and can discard the injection tube after use.

Description

Disposable adjustable dose insulin injection pen

technical field

The invention relates to an insulin injection pen, in particular to a one-time adjustable insulin injection pen.

Background technique

Diabetics or other patients who need to self-medicate often need to inject themselves with liquid medicine on different occasions. It is inconvenient for ordinary patients to use old-style disposable syringes and cannot effectively achieve accurate medication.

In the Chinese patent CN201055550Y published on May 7, 2008, a "pain-free insulin injection pen" is disclosed, which mainly includes an ejection box, a needle holder, a clutch key, an ejection spring, an injection needle, a needle cover and a touch metering device Composition, the ejection box is a cuboid or cylinder, the box is equipped with a touch metering device and a clutch key, the reed on the clutch key is matched with the sliding needle clip locking groove in the ejection box, and the needle clip is connected to the ejection box through the ejection spring. The boxes are connected, and the needle holder is used to insert and fix the injection needle. The injection needle is ejected into the skin by the ejection spring during injection; the touch metering device is composed of a touch probe and a dose card. The protruding knife edge of the touch probe corresponds to the dose card. The probe and the piston The rods are interconnected.

Chinese patent CN100453128C authorized on January 21, 2009 discloses an "insulin syringe", which can be used only as a piston advancement device with a rotating shaft to remove the vertical load applied to the rotating shaft, thus improving durability ; The automatic insulin injector includes a syringe, it has a water injector containing insulin inside it, and a piston inserted into the rear end of the water injector to provide the discharge pressure of insulin for the water injector, and a syringe receiving The housing of the space, the syringe receiving space has a partition wall formed at its rear end, a rotating shaft having a non-circular cross-section and a predetermined length, a power supply device for rotating the rotating shaft at a predetermined speed, a power supply for the piston to advance by pushing the piston A push plate assembly of power, the push plate assembly has a disc portion formed with external threads on its outer peripheral surface, and an engaging hole axially combined with a rotating shaft at its central portion, the rotating shaft passes through the engaging hole, and the rotating shaft passes through The engagement hole can move back and forth; and a hollow cylindrical push plate housing, which is inserted into the syringe receiving space at the rear end of the syringe to allow the piston to pass therethrough, the inner peripheral surface of the push plate housing forms internal threads, and the disc portion Engages the external threads of the disc, causing the disc-shaped part to helically move back and forth.

The above-mentioned two kinds of patent solutions related to syringes either have the problem of large size, inconvenient portability, or inconvenient use.

Contents of the invention

The purpose of the present invention is to solve the problems of large size, inconvenient portability or inconvenient use in existing insulin syringes, and provide a disposable adjustable metering insulin injection pen that is easy to use and portable.

The purpose of the present invention is achieved in this way: a disposable adjustable metering insulin injection pen, including a pen cap, a needle, an injection tube with a built-in piston and pre-loaded medicament, an injection sleeve, a positioning block, a screw, a nut tube, a fixed tube, Coil tube, clutch tube, scale locator and button, where the insulin injection in the injection tube is injected by the pharmaceutical factory and sealed with a piston; two sides of the screw are respectively cut off part of the thread along the axial direction to form two parallel sections, and the front end of the screw is a pressure head The screw rod passes through the guide hole in the center of the positioning block and is coupled with the internal thread of the nut tube. The inner wall of the guide hole has a pair of side walls that match the two cut surfaces of the screw rod respectively, so that the guide hole and the screw rod slide in the axial direction. And can not be relatively rotated; the fixed tube inner wall is provided with annular rib to separate the fixed tube inner wall into a front section and a rear section, and the rear section inner wall is provided with a spiral rib, and the outer diameter of the tube body of the nut tube slides with the inner diameter of the annular rib Matched and the tube body extends to the rear section of the fixed tube, the front end of the nut tube is located in the front section of the fixed tube and a pair of elastic ratchets are arranged symmetrically and stretched elastically in the radial direction, and the front section of the fixed tube is close to the ring stop The ribs are provided with a number of ratchets annularly distributed along the inner wall of the front section of the fixed pipe. The ratchets are matched with the elastic ratchet so that the nut tube can only drive the screw to move forward in one direction, that is, the nut tube can only move forward relative to the fixed tube. Forward (one-way) rotation but not reverse rotation - equivalent to the principle of ratchet and ratchet, the elastic ratchet is located between the positioning block and the ring rib of the fixed tube, the injection of the built-in piston The sleeve is inside the injection sleeve, the front end of the injection sleeve matches the thread of the needle head, and the inner wall of the rear end of the injection sleeve is provided with symmetrical buttonholes, and the positioning block is provided with two elastic buckles that are respectively buckled into the buttonholes The feet make the positioning block and the injection sleeve mutually fixed, and the positioning block extends forward and two tile-shaped elastic clips that are stretched out are respectively snapped into the grooves on the inner wall of the front section of the fixing tube to fix the The tube and the positioning block are fixed to each other so that the injection sleeve, the positioning block and the screw cannot rotate relative to the fixed tube; The clutch tube in the tube covers the nut tube, and the front end of the inner wall of the coil tube is provided with a boss extending into the guide groove extending in the axial direction on the outer surface of the nut tube, and the front side of the annular protruding ring on the outer surface of the end of the clutch tube is provided with several For the end face teeth protruding forward, the rotating tube is provided with a tooth groove matching each end face tooth, and a clutch spring is provided between the clutch tube and the coil tube; the positioning coupling rib protruding from the front end of the scale positioner is inserted into the end of the clutch tube The positioning coupling groove of the inner wall enables the scale locator and the clutch tube to rotate synchronously. The outer wall of the scale locator is provided with a ring-shaped rib, and the inner wall of the coil tail is provided with a ring-shaped rib. The inner diameter of the ring-shaped rib is smaller than the ring limit The outer diameter of the position bar, the scale positioner is provided with a radially protruding elastic arm chuck, and a number of axial scale positioning grooves are set along the annular inner wall at the position of the coil corresponding to the elastic arm chuck, and the coil is relative to the scale. When the locator rotates, the clips of the elastic arms are respectively stuck in different scale positioning grooves in sequence. counterbore The card slot matches the ring card table; the fixed tube has a window to observe the scale engraved on the outer surface of the coil tube and along the direction of the spiral groove;

The thread of the screw rod is right-handed, and the spiral groove on the outer surface of the coiled pipe is left-handed;

When in use, first pull out the pen cap that is set outside the injection sleeve. At this time, under the action of the clutch spring, the end face teeth of the clutch tube are separated from the tooth grooves in the coil tube, and the clutch formed by the clutch tube and the coil tube is in a disengaged state; Rotate the rotating handle of the coiled tube protruding from the tail of the fixed tube in the forward direction, and the elastic ratchet at the front end of the nut tube is coupled with the ratchet of the fixed tube in reverse so that the scale positioning groove in the coiled tube is relative to the spring arm chuck of the scale positioner Sliding, every time the elastic arm chuck slides through a graduated positioning groove, the coiled tube will drive the clutch tube to move outward in the axial direction by one measurement unit, observe the scale on the surface of the coiled tube through the window of the fixed tube, and stop turning the rotating handle until the required injection volume , to complete the metering adjustment, if the coil is rotated too much in the forward direction, you can rotate the coil in the opposite direction to reach the appropriate dosage. The force is greater than the friction between the scale positioning groove and the spring arm clamp of the scale positioner, and there is a certain pressure in the injection tube, so it will not drive the screw to rotate, but only make the scale positioning groove relative to the scale positioner. The chuck slides, so the injection volume can be adjusted repeatedly before injection; after the injection volume is adjusted accurately, press the end face of the button by hand to overcome the pressure of the clutch spring so that the end face teeth on the clutch tube mesh with the tooth grooves of the coil tube, and the coil tube reversely rotates to drive The clutch tube and the nut tube rotate to push the screw rod forward to extrude the piston in the injection tube to inject the injection into the human body from the needle.

The groove at the front section of the fixed pipe is an annular groove surrounding the inner wall of the fixed pipe, and an axial positioning groove is provided on the outer wall of the positioning block to match the axial positioning rib at the corresponding inner wall of the fixed pipe to match the positioning block with the inner wall of the fixed pipe. Circumferential positioning between the fixed tubes - that is, the fixed tube and the positioning block cannot be rotated relative to each other, and the two elastic feet of the positioning block inserted into the annular groove will axially position the positioning block and the fixed tube . The advantage is that it is easy to install.

Two tile-shaped clamping feet are provided at the tail of the injection sleeve, and the two clamping feet are respectively located between the two elastic clamping feet protruding forward of the positioning block, so that the two tiles The sheet-shaped clamping feet and the two tile-shaped elastic clamping feet can roughly form a ring.

The teeth on the front side of the annular protruding ring protruding forward on the outer surface of the end of the clutch tube are serrations.

The front end of the mandrel of the button is a pointed end, and the pointed end is against the bottom of the counterbore of the scale positioner. The advantage is that the friction force between the button and the scale locator is reduced when the button is pressed, so that the button and the finger are relatively stationary during the process of pressing the button by hand and will not rotate with the scale locator.

The tail of the injection cannula is provided with a ring-shaped rib to be inserted into the ring-shaped groove on the inner wall of the front section of the fixed tube.

Due to the adoption of the technical solution described in the present invention, when the patient injects insulin, there is no need to install the injection, and the pen cap can be removed directly to adjust the injection volume, which is very convenient to use; and the rotating handle can be adjusted forward and reverse repeatedly during use. , The combination of the scale locator and the scale positioning groove makes the adjustment process precise; after use, cover the pen cap, the overall appearance of the pen is not only easy to carry but also helps to protect personal privacy.

Description of drawings

The present invention will be further described below in conjunction with drawings and embodiments.

Fig. 1 is a three-dimensional exploded view of a specific embodiment of the present invention.

Fig. 2 is a perspective enlarged view of another angle of the positioning block in Fig. 1 .

Fig. 3 is a perspective enlarged view of another angle of the injection cannula in Fig. 1 .

Fig. 4 is a perspective view when the positioning block in Fig. 2 is installed on the injection cannula in Fig. 3 .

FIG. 5 is an enlarged perspective view of the scale positioner in FIG. 1 from another angle.

Fig. 6 is a perspective view from another angle of Fig. 5 .

Fig. 7 is an enlarged perspective view of the screw rod in Fig. 1 at another angle.

Fig. 8 is a perspective enlarged view of another angle of the nut tube in Fig. 1 .

Fig. 9 is a perspective enlarged view of another angle of the clutch tube in Fig. 1 .

Fig. 10 is a perspective enlarged view from another angle after half of the clutch tube in Fig. 9 is cut off.

Fig. 11 is a three-dimensional enlarged view of another angle after cutting off half of the nut tube in Fig. 1 when it is installed in the fixed tube.

Fig. 12 is a perspective view of the pen cap used in the embodiment of Fig. 1 .

Fig. 13 is a perspective enlarged view from another angle after cutting half of the fixing tube in Fig. 1 .

Fig. 14 is a perspective enlarged view from another angle after cutting half of the coiled tube in Fig. 1 .

Fig. 15 is an enlarged view along the axial direction when the scale positioner in Fig. 1 is installed at the tail of the coil.

Fig. 16 is a sectional view cut along the axis after the parts in Fig. 1 are installed together (the hatching is not drawn in the figure).

Fig. 17 is a sectional view along the line H-H of Fig. 16 (hatching is drawn at the end of the figure).

Fig. 18 is a partially enlarged view of part A in Fig. 16 with hatching added.

Fig. 19 is a partially enlarged view of part B in Fig. 17 with hatching added.

Fig. 20 is a partial enlarged view of part C in Fig. 17 with hatching added.

Fig. 21 is a partial enlarged view of part D in Fig. 17 with hatching added.

Among the figure 101, needle head, 1, injection sleeve, 113, annular clamping rib, 11, 12, clamping foot, 111, 121, buckle hole, 2, positioning clamping block, 21, 22, elastic clamping foot, 23, axial direction Positioning groove, 102, injection tube, 103, piston, 33, pressure head, 32, thread, 3, screw rod, 31, cut surface, 41, guide groove, 4, nut tube, 5, fixed tube, 51, window, 61 , spiral groove, 6, coil pipe, 62, rotary handle, 10, clutch spring, 7, clutch tube, 71, step down, 72, end tooth, 8, scale locator, 81, positioning coupling rib, 9, button, 91, ring card platform, 92, pointed head, 93, end face; 24, elastic buckle foot, 25, guide hole, 26, axial groove, 82, elastic arm chuck, 83, annular limit rib, 80, sink Hole, 42, 43, elastic ratchet, 44, internal thread, 73, boss, 52, ratchet, 53, spiral rib, 54, groove, 55, axial positioning rib, 74, positioning coupling groove, 56, Annular draw-in groove, 57, annular retaining rib, 63, annular rib, 64, tooth groove, 65, scale positioning groove, 66, annular convex rib, 410, end, 89, draw-in groove.

Detailed ways:

As shown in Figure 1, the disposable adjustable metering insulin injection pen includes a pen cap (Figure 12), a needle 101, an injection tube 102 with a built-in piston 103, an injection sleeve 1, a positioning block 2, a screw rod 3, and a nut tube 4. Fixed tube 5, coiled tube 6, clutch tube 7, scale positioner 8, button 9, and clutch spring 10, wherein the pharmaceutical factory uses piston 103 to seal the tail after injecting insulin injection into injection tube 102.

As shown in Figure 7, the three-dimensional enlarged view of another angle of the screw, the overall appearance of the screw is "T" shape, the front end is a pressure head 33, and the two sides of the screw are respectively cut off part of the thread along the axial direction to form two parallel cut surfaces 31, The surface of the screw between the two cut surfaces 31 is the thread 32 .

See that the center of the positioning block shown in Figure 2 has a guide hole 25, the size of this guide hole 25 matches the screw rod in Figure 7, and the screw rod penetrates the guide hole 25 through the below of the positioning block in Figure 2 when the two are installed. The outer wall of the positioning block in Fig. 2 is provided with an axial positioning groove 23, two tile-shaped elastic clamping feet 21 and 22 protruding forward, and two elastic buckle feet 24 (only one is observed in the figure), Combined with the injection cannula shown in Figure 3, two tile-shaped clamping feet 11 and 12 with button holes 111 and 121 protrude from the tail of the injection cannula, and the two elastic buckle feet 24 in Figure 2 are buckled in respectively. In the two buttonholes 111 and 121 in Fig. 3, two tile-shaped elastic clip feet 21, 22 and two tile-shaped clip feet 11, 12 are roughly ring-shaped (its outer wall is roughly a cylindrical surface), and its The appearance is shown in Figure 4, wherein the axial positioning groove 23 matches the axial positioning rib 55 in Figure 13; the axial positioning groove 23 on the outer wall of the positioning block can also use the axial groove 26 behind the elastic buckle foot 24 Instead, the size of the axial positioning rib in FIG. 13 should be equivalent to the axial groove 26 at this time.

The scale locator shown in Fig. 5 and Fig. 6 is provided with a positioning coupling rib 81, an annular limiting rib 83, four elastic arm clips 82 and a counterbore 80 at the rear end, and the counterbore 80 is provided with an annular slot ( See the draw-in groove 89 in Fig. 21), some positioning coupling ribs 81 protruding from its front end match with the positioning coupling groove 74 at the rear part of the clutch tube in Fig. 10; The scale positioning groove 65 is used in conjunction with it. When the scale locator is stationary and the coil rotates, the clips of each elastic arm roll into the adjacent scale positioning groove respectively, so that the rotation of the coil becomes a segmented (stage) rotation, and also When the present invention realizes metering adjustment by rotating the coil, it is segmented (stage) adjustment-relative to continuous stepless adjustment; see Figure 15, it can be roughly clearly observed that the scale positioning groove 65 and The interaction between the elastic arm chucks 82 on the scale positioner.

See the fixed pipe shown in Figure 13, the inner wall of the fixed pipe is provided with an annular retaining rib 57, wherein the inner wall of the rear section is provided with a spiral rib 53, and the front side of the annular retaining rib 57 is provided with a number of ratchets 52 evenly distributed along the circumference of the pipe wall. There is a window 51 on the surface of the tube for observing the scale on the surface of the inner coil of the fixed tube.

See the nut tube shown in Figure 8, its front end is provided with two elastic ratchets 43 to match the ratchets 52 on the nut tube in Figure 13, the relationship between the two is shown in Figure 11: ratchets 52 and elastic ratchets 42 The relationship is equivalent to a ratchet mechanism, so that the nut tube can only rotate in one direction relative to the fixed tube. It can also be seen from FIG. 11 that an annular groove 54 is also provided on the inner wall of the fixed pipe.

See the clutch tube shown in Figure 9, its tail is provided with a drop step 71 and a convex ring with end teeth 72, and the inner wall of the clutch tube is provided with a boss 73; the front end of the clutch tube in Figure 9 is facing the tail end of the nut tube in Figure 8 , and make the boss roughly facing the guide groove and forcibly press it in to make the boss 73 fall into the guide groove 41. In addition to guiding and synchronizing the two in the circumferential direction, between the boss and the guide groove , It can also prevent the clutch tube from being separated from the nut tube in the axial direction.

The tail of the clutch tube shown in Figure 9 is also provided with a positioning coupling groove 74 to match the positioning coupling rib 81 in Figure 5, so that the clutch tube and the scale positioner can rotate synchronously.

Also be provided with annular rib 63 and tooth groove 64 in the coiled pipe shown in Fig. 14, clutch spring is arranged between this annular rib 63 and the step-down 71 of the clutch tube among Fig. 9 (see Fig. 16 or 17 ), tooth groove 64 is matched with face tooth 72 on Fig. 9, and face tooth 72 is sawtooth actually.

Returning to Fig. 1, when installing the disposable adjustable metering insulin injection pen, first put the injection tube 102 (medicine and piston pre-installed by the pharmaceutical factory) into the injection tube along the tail of the injection tube 11, and thread the right end of the screw rod 3 through the injection tube. After passing through the guide hole in the center of the positioning block 2, it is threadedly coupled with the nut tube 4 to the root, and then the two elastic clamping feet 21 and 22 of the positioning clamping block are respectively facing between the two clamping feet 11 and 12 of the injection casing Press it in between, so that the two buckle feet on the positioning block respectively buckle the two button holes 111 and 112 of the injection sleeve (so that the injection sleeve and the positioning block are connected together as shown in Figure 4), and then Put the left end of the fixed tube 5 into the right end of the injection sleeve 1 and press it in, so that the annular rib 113 on the injection sleeve is forcibly pressed into the annular groove 56 of the fixed tube 5 (see the annular groove 56 in Figure 13 ) so that both Axially fixed, at the same time the two clamping feet 111 and 121 of the injection sleeve stretch outwards and extend into the annular groove 54 in Figure 13 (as shown in Figure 18) to further make the axial fixation of the two more firm, and the positioning clamp The axial positioning groove 23 of the block slides into the axial positioning rib 55 shown in Figure 13 so that the injection sleeve and the positioning block are fixed in the circumferential direction relative to the fixed tube, then the coiled tube 6 is screwed into the fixed tube, and then the coiled tube Put the clutch spring 10 into the right end, put the clutch tube 7 along the right end of the coil until the boss in the clutch tube enters the guide groove 41 of the nut tube (the positions of the clutch tube and the nut tube are shown in Figure 17), Press the scale locator 8 to the right end of the coiled tube again, so that the positioning coupling rib of the scale locator is inserted into the positioning coupling groove of the clutch tube until the annular limiting rib 83 shown in Figure 21 crosses the annular convex rib 66 of the coiled tube (annular convex rib 66 limit the axial direction of the scale locator), and finally the button 9 is forced into the counterbore 80 of the scale locator (see Figure 21, so that the ring card platform 91 of the button falls into the slot 89 of the scale locator Make the button and the scale positioner be axially limited and positioned, at this time, the tip 92 of the button is in point contact with the bottom of the counterbore 80 so that the friction force between the two is relatively small when they rotate with each other), and the needle is screwed into the front end of the injection sleeve The screw thread can be used, and after use, cover the injection sleeve with the pen cap shown in Figure 12 to make it into a pen shape (of course, the needle can also be taken out and stored in addition before being inserted into the pen cap).

The method of use is shown in Figures 16 and 17. According to the direction of the right view, when the rotating handle 62 is turned clockwise, the coiled pipe moves to the right under the interaction of the spiral groove and the spiral rib of the fixed pipe (at this time, the end face teeth 72 of the clutch pipe and the The cog groove 64 of the coiled pipe is separated—the clutch is in a disengaged state—as shown in Figures 16 and 17), and the elastic ratchet 42 at the front end of the nut tube is coupled with the ratchet 52 of the fixed pipe in reverse so that the rotating handle, scale The locator, the clutch tube, and the rotation transmitted to the coil are stopped, and the rotary handle rotates relative to the scale locator; when the excessive adjustment needs to turn the rotary handle 62 counterclockwise, due to the elastic ratchet 42 of the nut tube and the ratchet of the fixed tube The positive friction force of 52 is greater than the friction force between the scale positioning groove of the coil and the elastic arm chuck of the scale positioner, so that the nut tube is stationary and the coil and the scale positioner slide and rotate in stages; after the metering adjustment is completed, hand pressure The end surface 93 of the button overcomes the pressure of the clutch spring to make the end tooth 72 on the clutch tube mesh with the tooth groove 66 of the coil, and the coil rotates counterclockwise under the inward force, and the clutch tube also counterclockwise through the interaction between the end tooth and the tooth groove. Rotate clockwise, the boss in the clutch tube drives the nut tube to rotate counterclockwise through the guide groove (at this time, the elastic ratchet of the nut tube and the ratchet of the fixed tube are positively coupled, so that it can be forcibly rotated), and the nut tube passes through the thread Coupled to make the screw rotate and move forward to push and squeeze the piston in the injection tube to inject the injection into the human body from the needle.

During the process of adjusting the measurement, the user can observe the unit scale of 0-60 on the surface of the coil from the window of the fixed tube.

Because the connection between the injection cannula and the fixed tube, between the button and the scale positioner, and between the scale positioner and the coil is forcibly engaged, and cannot be pulled out after being forcedly engaged, so when the screw is pushed to the When the bottom of the injection tube is completely squeezed out, the screw cannot be retracted because the elastic ratchet of the nut tube engages with the ratchet of the fixed tube in reverse, so it is not reusable and is disposable.

For ease of observation, there is no section line in each section in Fig. 16 and 17, but in Fig. 18, 19, 20, 21, section lines are drawn on the corresponding part products.

Claims (6)

1. Disposable insulin injection pen with adjustable dosage, comprise the cap for brush, syringe needle, built-in piston pre-installed the injection pipe of medicament, injection sleeve pipe, positioning wedged block, screw rod, nut pipe, stationary pipes, coil, clutch pipe, scale locator and button, it is characterized in that screw rod both sides vertically respectively cut-out screw thread form two tangent planes be parallel to each other, screw front end is pressure head, screw rod is coupled with the internal thread of nut pipe through after the pilot hole of positioning wedged block central authorities, and the inwall of described pilot hole has pair of sidewalls to match with two tangent planes of screw rod respectively, it is leading portion and back segment that stationary pipes inwall is provided with annular block reinforcement by stationary pipes internal wall separates, described back segment inwall is provided with spiral bar, the pipe shaft external diameter of nut pipe and the internal diameter of described annular block reinforcement slide and to match and this pipe shaft extends to the back segment of described stationary pipes, the front end of nut pipe is positioned at the leading portion of stationary pipes and arranges a pair symmetrical and radially elasticity sour jujube head of bending and stretching of elasticity, stationary pipes leading portion arranges the some ratchets along stationary pipes leading portion inwall annular spread near described annular block reinforcement place, described ratchet and described elasticity sour jujube head match and make nut pipe screw rod can only be driven to move forward along single direction rotation, this elasticity sour jujube head is between described positioning wedged block and the annular block reinforcement of described stationary pipes, the injection pipe box of built-in piston is in described injection sleeve pipe, injection sleeve pipe front end and syringe needle screw thread match, the tail end inwall of injection sleeve pipe has symmetrical button hole, positioning wedged block is provided with two elastic buckles pin buckled into respectively in described button hole and makes to interfix between positioning wedged block and injection sleeve pipe, to interfix between stationary pipes and positioning wedged block in the groove that the elasticity card base that positioning wedged block stretches out forward two tiles outwards snaps in described stationary pipes leading portion inwall respectively, the spiral bar that coil outer wall has helicla flute and described stationary pipes back segment inwall matches, nut pipe is stated in the clutch pipe box residence being positioned at coil, and coil inwall front end is provided with boss stretches in the direction recess that described nut tube outer surface extends vertically, on front side of the annular convex ring of clutch pipe distal outer surface, some end-tooths stretched out forward are set, be provided with the teeth groove matched with each end-tooth in coil, between described clutch pipe and coil, be provided with brake spring, make scale locator and clutch pipe can synchronous rotary in the location coupling slot that location that scale locator front end face stretches out coupling muscle inserts clutch pipe inner wall at end, the outer wall of scale locator is provided with annular stop muscle, coil afterbody inwall is provided with annular convex rib, the internal diameter of this annular convex rib is less than the external diameter of described annular stop muscle, scale locator is provided with radially-protruding elastic arm dop, coil to should elastic arm dop position annularly inwall some axial scale locating slots are set, scale locator tail end face is provided with the counterbore of inner wall belt draw-in groove, the mandrel outer surface that button front end is stretched out is provided with the annular chuck matched with the draw-in groove of described counterbore, stationary pipes have form can observe be engraved in coil outer surface and along helicla flute trend scale,

Described screw flight is dextrorotation, and the helicla flute of described coil outer surface is left-handed;

During use, the cap for brush be enclosed within outside injection sleeve pipe is extracted, now, under the effect of brake spring, the end-tooth of clutch pipe is separated with the teeth groove in coil, rotate forward the rotary handle of the coil stretching out stationary pipes afterbody, the elasticity sour jujube head of nut pipe front end and the ratchet reverse coupled of stationary pipes and the scale locating slot in coil is slided relative to the elastic arm dop of scale locator, elastic arm dop often slips over a scale locating slot coil and just drives clutch pipe outwards to move a measurement unit vertically, the scale on coil surface is observed until the rotary handle that stops operating after required injection volume by the form of stationary pipes, complete metering to regulate, injection volume regulates accurately, hand button end face, the pressure overcoming brake spring makes the end-tooth on clutch pipe engage with the teeth groove of coil, and coil reversely rotates and drives clutch pipe, nut pipe rotate and make the piston in screw rod driven forward extruding injection pipe that injection is injected in human body from syringe needle.

2. Disposable insulin injection pen with adjustable dosage according to claim 1, it is characterized in that the groove of described stationary pipes leading portion is the annular groove around stationary pipes inwall, the axial location muscle that the outer wall of described positioning wedged block is provided with axial location groove inwall place corresponding to stationary pipes matches.

3. Disposable insulin injection pen with adjustable dosage according to claim 1 or 2, it is characterized in that described injection sleeve pipe afterbody is provided with the card base of two tiles, and described two card bases lay respectively between two elasticity card bases that described positioning wedged block stretches out forward, and the elastic card bottoms of the card base of two tiles and two tiles is circularized.

4. Disposable insulin injection pen with adjustable dosage according to claim 1 or 2, is characterized in that the end-tooth stretched out forward on front side of the annular convex ring of described clutch pipe distal outer surface is sawtooth.

5. Disposable insulin injection pen with adjustable dosage according to claim 1 or 2, it is characterized in that the mandrel front end of described button is tip, this tip props up the bottom of the counterbore of described scale locator.

6. Disposable insulin injection pen with adjustable dosage according to claim 1 or 2, is characterized in that described injection sleeve pipe afterbody is provided with annular snap muscle and snaps in the annular slot of stationary pipes leading portion inwall.