Medicine injection device capable of adjusting dosage

Abstract

The invention discloses a dosage-adjustable medicine injection device, and particularly relates to the technical field of medicine injection.The dosage-adjustable medicine injection device comprises a main body shell, an upper base is coaxially installed in an inner cavity of one end of the main body shell, a metering adjuster is slidably inserted into an opening of the other end of the main body shell, and an adjusting outer cylinder of the metering adjuster coaxially sleeves one end of the upper base; an adjusting inner cylinder of the metering adjuster is in threaded connection with a spiral push rod, a linear groove of the spiral push rod is in linear sliding connection with a converter, the converter is provided with a fixing step matched with an annular adjuster step of the metering adjuster, the upper base is provided with a one-way gear ring matched with an elastic pawl of the stopper, and the stopper is in threaded connection with the spiral push rod. According to the adjustable dose medicine injection device, the structure of an existing adjustable dose medicine injection device is simplified, meanwhile, certain injection precision is guaranteed, and the adjustable dose medicine injection device is simple and reliable in structure and convenient to produce.

Description

Technical Field

[0001] The invention belongs to the technical field of drug injection, and in particular relates to a drug injection device with adjustable dosage. Background Art

[0002] Common adjustable-dose drug injection devices on the market (such as insulin injection pens) are used in conjunction with cartridges. There are reusable injection pens (replaceable cartridges) and disposable injection pens (cartridges and injection pens are directly assembled together and discarded after use). The cartridge is filled with a fixed amount of medicine (such as 3 ml), and the injection pen can be set to a different dose each time as needed.

[0003] At present, there are some new drug injection needs in the market (such as GLP-1 weight loss drugs), and the minimum single injection dose is generally 0.1-0.2ml, which does not require too high precision. Since the minimum single injection dose of insulin injection pens is relatively small, generally 0.01ml, and the precision is relatively high, the insulin injection pen has more parts, complex structure, complex assembly, easy failure, high production cost, and is not suitable for a large number of adjustable dose drug injection needs.

[0004] Therefore, a novel drug injection device with adjustable dosage is needed. Summary of the invention

[0005] In order to solve the above problems, the present invention discloses a drug injection device with adjustable dosage.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A drug injection device with adjustable dosage, comprising a main body shell, wherein an upper base is coaxially mounted in an inner cavity at one end of the main body shell, and a metering regulator is slidably inserted into an opening at the other end of the main body shell, wherein an outer wall at one end of the upper base is provided with a plurality of uniformly distributed linear grooves, and the linear grooves are parallel to the axis of the upper base, an adjusting outer cylinder of the metering regulator is coaxially outer-arranged with one end of the upper base, and a plurality of elastic arm end protrusions of the adjusting outer cylinder are adapted to the linear grooves, an adjusting inner cylinder of the metering regulator is threadedly connected with a spiral push rod, a linear groove of the spiral push rod is linearly slidably connected with a converter, and an annular protrusion on the outer end edge of the converter is slidably adapted to the end ring of the metering regulator The groove is provided on the outer wall of the metering regulator, and the main body shell is provided with an observation window adapted to the annular indicator groove; the inner cavity at one end of the main body shell mounted on the upper base is coaxially connected with a medicine bottle holder, and the medicine bottle holder is filled with a cartridge bottle, and the end of the spiral push rod pointing to the cartridge bottle is provided with a push rod disk adapted to the built-in piston of the cartridge bottle.

[0008] As a preferred technical solution of the present invention, the adjusting inner cylinder is coaxially inserted into the upper base, and the adjusting inner cylinder extends an adjuster tooth that is adapted to the built-in base tooth of the upper base, and a sealing protrusion is provided at one end of the spiral groove of the spiral push rod away from the push rod disk.

[0009] As a preferred technical solution of the present invention, the main body shell is a hollow main body shell, the lower base is coaxially fixedly installed in the inner cavity of the hollow main body shell, and the inner cavity of the lower base is provided with a push-locking component linearly slidably connected to the linear groove, and the upper base is coaxially clamped with the lower base.

[0010] As a preferred technical solution of the present invention, the push-locking assembly includes: an inner ring tooth connector coaxially fixedly installed in the inner cavity of the lower base, an anti-rotation part coaxially slidably installed in the inner cavity of the lower base and linearly slidably connected to the linear groove, the anti-rotation part coaxial sleeve is provided with a spring that presses against the inner ring tooth connector, and the anti-rotation part is provided with an outer ring tooth that is adapted to be plugged into the inner ring tooth connector.

[0011] As a preferred technical solution of the present invention, the lower base is threadedly connected to the medicine bottle holder, the edge of the cartridge bottle presses the anti-rotation part, and when the cartridge bottle is detached from the anti-rotation part, the outer ring teeth of the anti-rotation part are separated from the inner ring teeth of the inner ring tooth connector.

[0012] As a preferred technical solution of the present invention, the medicine bottle holder is provided with a split pen cap, which includes: a pen cap upper cover whose inner wall annular protrusion is inserted into the annular groove of the medicine bottle holder, and the pen cap upper cover is coaxially connected to the pen cap lower cover by interference fit.

[0013] As a preferred technical solution of the present invention, a dial adapted to the observation window is attached to the outer wall of the hollow main body shell, and the dial is provided with an observation port adapted to the annular indicator groove.

[0014] As a preferred technical solution of the present invention, the main body shell is an integrated main body shell, and the upper base is coaxially clamped in the inner wall of the integrated main body shell, the integrated main body shell is linearly slidably connected to the linear groove, and the medicine bottle holder is coaxially clamped with the integrated main body shell.

[0015] As a preferred technical solution of the present invention, the medicine bottle holder is coaxially mounted with an integrated pen cap, and the annular protrusion on the inner wall of the integrated pen cap is inserted into the annular groove of the medicine bottle holder.

[0016] As a preferred technical solution of the present invention, the outer wall of the integrated main body shell is provided with a scale adapted to the annular indicator groove.

[0017] The beneficial effects of the present invention are:

[0018] 1. The two embodiments of the present application simplify the structure of the existing adjustable-dose drug injection device (such as an insulin injection pen), while ensuring a certain adjustable-dose drug injection accuracy. The structure is simple, reliable, and easy to produce, and meets the needs of a large number of low-precision adjustable-dose drug injections;

[0019] 2. Both embodiments of the present application are provided with a blocking protrusion on the spiral push rod, which limits the set dose to be no greater than the remaining dose in the cartridge bottle when adjusting the injection dose at a single time, and intuitively displays the dose of the remaining liquid medicine in the cartridge bottle, thereby improving the convenience of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0021] Figure 2 It is an overall cross-sectional view of the first embodiment of the present invention;

[0022] Figure 3 Embodiment 1 of the present invention Figure 2 The enlarged view of point A in the middle;

[0023] Figure 4 Embodiment 1 of the present invention Figure 2 The enlarged view of point B in the middle;

[0024] Figure 5This is a structural schematic diagram of one angle of a metering regulator according to an embodiment of the present invention;

[0025] Figure 6 This is a schematic structural diagram of a metering regulator from another angle according to an embodiment of the present invention;

[0026] Figure 7 This is a schematic structural diagram of an upper base according to a first embodiment of the present invention;

[0027] Figure 8 This is a schematic structural diagram of an upper base and a stopper according to a first embodiment of the present invention;

[0028] Fig. 9 This is a schematic structural diagram of a screw push rod and a converter according to a first embodiment of the present invention;

[0029] Fig.10 This is a schematic structural diagram of a spiral push rod and a push rod disk according to an embodiment of the present invention;

[0030] Fig.11 An exploded view of a blocker and a push-lock assembly according to a first embodiment of the present invention;

[0031] Fig.12 This is a schematic structural diagram of an inner ring gear connector according to an embodiment of the present invention;

[0032] Fig.13 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention;

[0033] Fig.14 is an overall cross-sectional view of the second embodiment of the present invention;

[0034] Fig.15 It is a schematic structural diagram of the integrated main body shell of the second embodiment of the present invention.

[0035] List of Figure Symbols:

[0036] 101. Hollow main body shell; 102. Integrated main body shell;

[0037] 2. Upper base; 201. Base clamping teeth; 202. One-way gear ring;

[0038] 3. Screw push rod; 301. Linear groove; 302. Blocking protrusion;

[0039] 4. Metering regulator; 401. Adjustment outer cylinder; 402. Elastic arm; 403. Adjustment inner cylinder; 404. Regulator latch; 405. Regulator step;

[0040] 5. Converter; 501. Fixed step;

[0041] 6. Blocker; 7. Push rod plate;

[0042] 8. Press-lock assembly; 801. Inner ring gear connector; 802. Anti-rotation part; 803. Spring;

[0043] 9. Medicine bottle holder; 10. Cartridge bottle; 11. Piston;

[0044] 12. Split pen cap; 121. Upper pen cap cover; 122. Lower pen cap cover;

[0045] 13. Dial; 14. Integrated pen cap; 15. Lower base. DETAILED DESCRIPTION

[0046] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0047] See also Figure 1-15 ,

[0048] Embodiment 1

[0049] A drug injection device with adjustable dosage comprises a hollow main body shell 101, wherein an upper base 2 is coaxially mounted in the inner cavity at one end of the hollow main body shell 101, and a metering regulator 4 is slidably inserted into the opening at the other end of the hollow main body shell 101. A plurality of uniformly distributed linear grooves are arranged on the outer wall at one end of the upper base 2, and the linear grooves are parallel to the axis of the upper base 2. An adjusting outer cylinder 401 of the metering regulator 4 is coaxially disposed on one end of the upper base 2, and the end protrusions of a plurality of elastic arms 402 of the adjusting outer cylinder 401 are adapted to the linear grooves. An adjusting inner cylinder 403 of the metering regulator 4 is threadedly connected with a screw push rod 3, and a converter 5 is linearly slidably connected to the linear groove 301 of the screw push rod 3. The screw push rod 3 is provided with two linear grooves 301 parallel to its own axis. The annular protrusion at the outer end edge of the converter 5 is slidably adapted to the end annular groove of the metering regulator 4, and the converter 5 is provided with a fixed step 501 adapted to the annular regulator step 405 of the metering regulator 4. The converter 5 can move linearly relative to the metering regulator 4 under the constraint of the end ring groove of the metering regulator 4, so as to separate the fixed step 501 from the regulator step 405. After the fixed step 501 is separated from the regulator step 405, the metering regulator 4 can rotate relative to the converter 5. A blocker 6 is coaxially mounted in the inner cavity of one end of the upper base 2 away from the converter 5, and the upper base 2 is provided with a one-way gear ring 202 adapted to the elastic pawl of the blocker 6, and the blocker 6 is threadedly connected to the screw push rod 3.

[0050] Blocker 6 has two functions:

[0051] 1. During injection, the screw push rod 3 cannot rotate during the movement, but its thread can drive the blocker 6 to rotate. The blocker 6 has a thread inside that matches the push rod, and an elastic pawl is provided on the edge. When the blocker 6 rotates, the elastic pawl moves from one groove of the one-way gear ring 202 to another groove, generating a prompt sound;

[0052] 2. When the screw push rod 3 is assembled with the medicine bottle holder 9, it can only move toward the cartridge bottle 10. The reason is that once there is a force in the opposite direction (such as the elastic force of the piston 11) pushing it, the screw push rod 3 has a tendency to drive the blocker 6 to rotate. The elastic pawl of the blocker 6 is restricted by the one-way gear ring 202 and cannot rotate in the opposite direction (ratchet and pawl mechanism design), so the reverse movement of the screw push rod 3 is restricted.

[0053] The inner cavity of one end of the hollow main body shell 101 mounted on the upper base 2 is coaxially connected to the medicine bottle holder 9, and the medicine bottle holder 9 is filled with a cartridge bottle 10. The external thread of the injection end of the medicine bottle holder 9 is used to install an injection needle (similar to the existing insulin injection pen needle). The end of the spiral push rod 3 pointing to the cartridge bottle 10 is installed with a push rod disk 7 adapted to the built-in piston 11 of the cartridge bottle 10. The medicine bottle holder 9 is provided with an observation hole for observing the use of the liquid medicine in the transparent cartridge bottle 10.

[0054] The outer wall of the metering regulator 4 is provided with an annular indicator groove, and the hollow main body shell 101 is provided with an observation window adapted to the annular indicator groove. The outer wall of the hollow main body shell 101 is fitted with a dial 13 adapted to the observation window, and the dial 13 is provided with an observation port adapted to the annular indicator groove. The scale corresponding to the annular indicator groove is observed through the observation port of the dial 13.

[0055] The regulating inner cylinder 403 is coaxially inserted into the upper base 2, and the regulating inner cylinder 403 extends a regulator latch 404 adapted to the built-in base latch 201 of the upper base 2. When adjusting the single injection dose, the metering regulator 4 is rotated, and several elastic arms 402 on the metering regulator 4 cooperate with the linear grooves of the upper base 2. After the metering regulator 4 stops rotating, its elastic arms 402 and the bottom of the linear groove are automatically aligned, and a clicking sound is generated when the elastic arms 402 slide between the linear grooves. The single minimum injection dose is the moving distance of the metering regulator 4 when the elastic arm 402 rotates through a single linear groove; the single maximum injection dose is the moving distance of the metering regulator 4 when the regulating inner cylinder 403 is rotated until the regulator latch 404 is stuck to the base latch 201. A blocking protrusion 302 is provided at one end of the spiral groove of the spiral push rod 3 away from the push rod disk 7. After multiple injections, when the metering regulator 4 rotates and contacts the blocking protrusion 302 of the spiral push rod 3, the metering regulator 4 cannot rotate, indicating that the liquid medicine in the cartridge bottle 10 is about to be used up.

[0056] The lower base 15 is coaxially fixedly installed in the inner cavity of the hollow main body shell 101, and the inner cavity of the lower base 15 is provided with a press-locking component 8 linearly slidably connected to the linear groove 301, and the upper base 2 is coaxially clamped with the lower base 15.

[0057] The press-lock assembly 8 includes: an inner ring gear connector 801 coaxially fixedly installed in the inner cavity of the lower base 15, an anti-rotation member 802 coaxially slidably installed in the inner cavity of the lower base 15 and linearly slidably connected to the linear groove 301, the anti-rotation member 802 is coaxially sleeved with a spring 803 that presses against the inner ring gear connector 801, and the anti-rotation member 802 is provided with an outer ring gear that is adapted to be plugged with the inner ring gear connector 801. The lower base 15 is threadedly connected to the medicine bottle holder 9, the edge of the cartridge bottle 10 presses the anti-rotation member 802, and when the cartridge bottle 10 is separated from the anti-rotation member 802, the outer ring gear of the anti-rotation member 802 is separated from the inner ring gear of the inner ring gear connector 801.

[0058] The medicine bottle holder 9 is provided with a split pen cap 12, which includes: a pen cap upper cover 121 whose inner wall annular protrusion is inserted into the annular groove of the medicine bottle holder 9, and the pen cap upper cover 121 is coaxially connected with a pen cap lower cover 122 by interference fit.

[0059] Working principle:

[0060] When in use, the medicine bottle holder 9 is rotated and tightened to the lower base 15, so that the edge of the cartridge bottle 10 presses the anti-rotation piece 802, and the outer ring teeth of the anti-rotation piece 802 are inserted into the inner ring teeth of the inner ring tooth connector 801, and the anti-rotation piece 802 and the spiral push rod 3 cannot rotate, and the spiral push rod 3 can only move linearly relative to the anti-rotation piece 802. Then, the needle connected to the cartridge bottle 10 is screwed on the medicine bottle holder 9, and then the metering regulator 4 is rotated so that the annular indicator groove of the metering regulator 4 points to the corresponding scale of a single injection. At this time, the metering regulator 4 is rotated relative to the converter 5, and the metering regulator 4 is rotated. The metering regulator 4 moves spirally relative to the screw push rod 3, and the converter 5 moves linearly relative to the screw push rod 3. Then the converter 5 is pressed, and at this time, the fixed step 501 of the converter 5 and the regulator step 405 of the metering regulator 4 are engaged, and the metering regulator 4 and the converter 5 cannot rotate relative to each other, and the metering regulator 4 and the screw push rod 3 cannot move relative to each other. These three parts (the screw push rod 3, the metering regulator 4 and the converter 5) can only move linearly along the axial direction of the screw push rod 3. Under the pressure, the screw push rod 3 pushes the piston 11 in the cartridge bottle 10 through the push rod disk 7 to perform injection;

[0061] After multiple injections, the metering regulator 4 rotates to contact the blocking protrusion 302 of the spiral push rod 3, and the metering regulator 4 cannot rotate. The liquid medicine in the cartridge bottle 10 is about to run out. At this time, the medicine bottle holder 9 can be unscrewed to refill the cartridge bottle 10, and the spiral push rod 3 is spirally reset. At this time, the cartridge bottle 10 is separated from the anti-rotation part 802. Under the elastic force of the spring 803, the outer ring teeth of the anti-rotation part 802 are separated from the inner ring teeth of the inner ring tooth connector 801, and the anti-rotation part 802 can rotate together with the spiral push rod 3. Then, the push rod disk 7 is pressed, and the spiral push rod 3 rotates relative to the push rod disk 7. The spiral push rod 3 moves spirally relative to the blocker 6 and the upper base 2, and the spiral push rod 3 moves linearly relative to the converter 5. The spiral push rod 3 retracts into the hollow main body shell 101 and resets. Then the medicine bottle holder 9 and the lower base 15 can be rotated and tightened again.

[0062] Embodiment 2

[0063] In this embodiment, the structure of the drug injection device is basically the same as that of the first embodiment, except that:

[0064] The hollow main body shell 101 in the first embodiment is replaced by an integrated main body shell 102, and the upper base 2 is coaxially clamped in the inner wall of the integrated main body shell 102. The integrated main body shell 102 is directly connected to the linear groove 301 in a linear sliding manner, and the press-locking component 8 is not provided. The medicine bottle holder 9 is coaxially clamped with the integrated main body shell 102, and the medicine bottle holder 9 and the integrated main body shell 102 do not adopt the threaded connection of the first embodiment, wherein the annular protrusion of the medicine bottle holder 9 is clamped into the annular groove of the integrated main body shell 102.

[0065] The outer wall of the integrated main body shell 102 is provided with a scale adapted to the annular indicator groove, and the scale corresponding to the annular indicator groove can be observed through the observation window of the integrated main body shell 102 .

[0066] The split pen cap 12 in the first embodiment is replaced by an integrated pen cap 14 , and the medicine bottle holder 9 is coaxially mounted with the integrated pen cap 14 , and the annular protrusion on the inner wall of the integrated pen cap 14 is inserted into the annular groove of the medicine bottle holder 9 .

[0067] Working principle:

[0068] In this embodiment, the working principle of the drug injection device is basically the same as that of the first embodiment, except that:

[0069] Since the integrated main body shell 102 is directly connected to the linear groove 301 in a linear sliding manner, when the screw push rod 3 moves to the end of the stroke, that is, when the metering regulator 4 rotates and contacts the blocking protrusion 302 of the screw push rod 3, the screw push rod 3 cannot be spirally reset relative to the integrated main body shell 102. At the same time, since the integrated main body shell 102 and the integrated pen cap 14 have simple structures and are easy to produce, and the screw push rod 3 of this embodiment cannot be rotated and reset compared to the first embodiment, this embodiment is a disposable adjustable dose drug injection device.

[0070] It should be noted that the above content merely illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A drug injection device with adjustable dosage, comprising a main body shell, characterized in that: An upper base (2) is coaxially mounted in the inner cavity at one end of the main body shell, and a metering regulator (4) is slidably inserted into the opening at the other end of the main body shell. An outer wall at one end of the upper base (2) is provided with a plurality of uniformly distributed linear grooves, and the linear grooves are parallel to the axis of the upper base (2). An adjusting outer cylinder (401) of the metering regulator (4) is coaxially disposed on one end of the upper base (2), and a plurality of elastic arms (402) of the adjusting outer cylinder (401) have end protrusions adapted to the linear grooves. An adjusting inner cylinder (403) of the metering regulator (4) is threadedly connected to a screw push rod (3), and a converter (5) is linearly slidably connected to the linear groove (301) of the screw push rod (3). An annular protrusion on the outer edge of the converter (5) is slidably adapted to the end ring groove of the metering regulator (4), and the converter (5) is provided with a ring that is adapted to the metering regulator (4). The upper base (2) is provided with a fixed step (501) adapted to the regulator step (405); a blocker (6) is coaxially mounted on the inner cavity of one end of the upper base (2) away from the converter (5), and the upper base (2) is provided with a one-way gear ring (202) adapted to the elastic ratchet of the blocker (6); the blocker (6) is threadedly connected to the spiral push rod (3); the inner cavity of one end of the main shell on which the upper base (2) is mounted is linearly slidably connected to the linear groove (301); the outer wall of the metering regulator (4) is provided with an annular indicating groove, and the main shell is provided with an observation window adapted to the annular indicating groove; the inner cavity of one end of the main shell on which the upper base (2) is mounted is coaxially connected to a medicine bottle holder (9), and the medicine bottle holder (9) is loaded with a cartridge bottle (10); the end of the spiral push rod (3) pointing to the cartridge bottle (10) is provided with a push rod disk (7) adapted to the built-in piston (11) of the cartridge bottle (10).

2. A drug injection device with adjustable dosage according to claim 1, characterized in that: The regulating inner cylinder (403) is coaxially inserted into the upper base (2), and the regulating inner cylinder (403) extends a regulator latch (404) adapted to the built-in base latch (201) of the upper base (2), and a blocking protrusion (302) is provided at one end of the spiral groove of the spiral push rod (3) away from the push rod disk (7).

3. A drug injection device with adjustable dosage according to claim 1, characterized in that: The main body shell is a hollow main body shell (101), the inner cavity of the hollow main body shell (101) is coaxially fixedly mounted with a lower base (15), and the inner cavity of the lower base (15) is provided with a press-locking assembly (8) linearly slidably connected to the linear groove (301), and the upper base (2) is coaxially clamped with the lower base (15).

4. A drug injection device with adjustable dosage according to claim 3, characterized in that: The push-lock assembly (8) comprises: an inner ring gear connector (801) coaxially fixedly mounted in the inner cavity of the lower base (15); an anti-rotation component (802) coaxially slidably mounted in the inner cavity of the lower base (15) and linearly slidably connected to the linear groove (301); the anti-rotation component (802) is coaxially sleeved with a spring (803) pressed against the inner ring gear connector (801); and the anti-rotation component (802) is provided with an outer ring gear adapted to be plugged into the inner ring gear connector (801).

5. A drug injection device with adjustable dosage according to claim 4, characterized in that: The lower base (15) is threadedly connected to the medicine bottle holder (9), the edge of the cartridge bottle (10) presses the anti-rotation component (802), and when the cartridge bottle (10) is separated from the anti-rotation component (802), the outer ring teeth of the anti-rotation component (802) are separated from the inner ring teeth of the inner ring tooth connector (801).

6. The adjustable dose drug injection device according to claim 3, characterized in that: The medicine bottle holder (9) is sleeved with a split pen cap (12), and the split pen cap (12) comprises: a pen cap upper cover (121) whose inner wall annular protrusion is inserted into an annular groove of the medicine bottle holder (9), and the pen cap upper cover (121) is coaxially connected to a pen cap lower cover (122) by interference fit.

7. The adjustable dose drug injection device according to claim 3, characterized in that: The outer wall of the hollow main body shell (101) is fitted with a dial (13) adapted to the observation window, and the dial (13) is provided with an observation port adapted to the annular indicator groove.

8. The adjustable dose drug injection device according to claim 1, characterized in that: The main body shell is an integrated main body shell (102), and the upper base (2) is coaxially clamped in the inner wall of the integrated main body shell (102), the integrated main body shell (102) is linearly slidably connected to the linear groove (301), and the medicine bottle holder (9) is coaxially clamped with the integrated main body shell (102).

9. The adjustable dose drug injection device according to claim 8, characterized in that: The medicine bottle holder (9) is coaxially mounted with an integrated pen cap (14), and the annular protrusion on the inner wall of the integrated pen cap (14) is inserted into the annular groove of the medicine bottle holder (9).

10. The adjustable dose drug injection device according to claim 8, characterized in that: The outer wall of the integrated main body shell (102) is provided with a scale adapted to the annular indicating groove.

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