Open type remaining needle fixing length angle selecting device

Abstract

The invention discloses an open type remaining needle fixing length angle selecting device, and belongs to the field of remaining needle production equipment. The needle fixing length angle selecting device comprises a bearing table, the bearing table is in butt joint with the indwelling needle assembly line, and a feeding piece, an angle positioning mechanism, an overturning inserting piece and a length positioning mechanism are further sequentially arranged on one side of the bearing table in the direction of the indwelling needle assembly line. The feeding piece can clamp the remaining needle at the top end of the bearing table to the inclined groove and the positioning groove, the overturning inserting piece can clamp the remaining needle in the inclined groove and the positioning groove and is inserted into the needle base after being overturned, and the angle positioning mechanism positions the tip angle of the remaining needle. The length positioning mechanism elastically ejects the remaining needle in the needle seat and limits the ejection length, length fixing is achieved, the remaining needle is fixed in length and angle, and the follow-up overall assembly process and precision improvement are ensured.

Description

Technical Field

[0001] This invention relates to the field of indwelling needle production equipment technology, and more specifically, to an open-type indwelling needle length selection angle device. Background Technology

[0002] An indwelling needle, also called a cannula, is a special infusion needle that can remain in a blood vessel for a period of time (usually 72-96 hours). As a Class III medical device implanted in a blood vessel and in direct contact with human tissue and blood, its manufacturing process demands extremely stringent requirements. Therefore, most processes must be completed on high-precision automated equipment to minimize human error and contamination. Examples include precisely inserting the steel needle into the cannula, bonding / thermal fusion of the cannula to the needle hub, and installing the fixation wings.

[0003] In the assembly process of steel needles and needle holders, firstly, the angle of the cross section of the tip of the steel needle is prone to be inconsistent, which indirectly reduces the assembly accuracy; secondly, the length of the shaft section of the exposed needle holder of the steel needle has a high precision, and the tolerance distance should generally be within ±0.1mm. However, the precision of traditional manufacturing processes is limited and cannot meet the aforementioned process requirements. Therefore, we propose an open-type indwelling needle length selection angle device to solve the above problems. Summary of the Invention

[0004] In view of the above-mentioned problems in the existing technology, the purpose of the present invention is to provide an open-type indwelling needle length selection angle device.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows: an open-type indwelling needle length selection angle device, comprising a receiving platform, the receiving platform being connected to the indwelling needle assembly line, the hollow indwelling needle being mounted on the top of the receiving platform, and a feeding component, an angle positioning mechanism, a flipping insertion component, and a length positioning mechanism being sequentially arranged on one side of the receiving platform along the direction of the indwelling needle assembly line. The angle positioning mechanism, along the assembly line direction, includes a fixed angle plate, a limiting plate, and a positioning plate in sequence. The fixed angle plate has a groove on its top surface, which flares outward and slopes downward at the end facing the limiting plate, with the slope matching the slope of the indwelling needle tip. The limiting plate is vertically fixed to the outside of the fixed angle plate and connects to the groove. The top of the limiting plate has a recessed limiting groove to limit the indwelling needle to the middle of the groove along the assembly line direction. The positioning plate has a positioning groove on its top surface, which, along with the groove, simultaneously supports the indwelling needle and always maintains the slope of the indwelling needle tip in contact with the slope of the groove. The feeding component can clamp the indwelling needle at the top of the receiving platform onto the inclined groove and positioning groove. The flipping insert can clamp the indwelling needle in the inclined groove and positioning groove, and after flipping, insert the indwelling needle into the needle holder positioned in the assembly line. The needle holder has a sliding cavity coaxial with the indwelling needle, and a push rod is slidably connected in the sliding cavity. The top surface of the push rod contacts the bottom surface of the inserted indwelling needle. The length positioning mechanism includes a base, a top rod, a mating block, and a wedge. The bottom end of the top rod is spring-connected to the base, and the top end points vertically to the center of the bottom surface of the needle seat and contacts the bottom surface of the push rod. The slope and height of the wedge are consistent with the slope and height of the tip of the indwelling needle. The mating block and the wedge are pneumatically closed to form a groove.

[0006] Furthermore, the feeding component includes a first dual-axis motion assembly and a first pneumatic finger. The first dual-axis motion assembly drives the first pneumatic finger to move in the assembly line direction and in a direction perpendicular to the ground. The receiving platform is a U-shaped plate, and the length of the U-shaped opening is greater than the width of the first pneumatic finger.

[0007] Furthermore, the flipping insert includes a flipping table, a rotating shaft, a first pneumatic gripper, a second pneumatic gripper, and a second dual-axis motion assembly. The rotating shaft is rotatably connected to the flipping table, and a gear is coaxially fixed on the outside of the flipping table. A push cylinder and a rack are also fixed on the outer wall of the flipping table. The bottom surface of the rack is slidably connected to the flipping table through a pulley, and the top surface meshes with the gear. The output end of the push cylinder is fixedly connected to the rack. The first pneumatic gripper can grip the bottom end of the indwelling needle. The outer wall of the rotating shaft is recessed into a plane to be fixed with the first pneumatic gripper.

[0008] Furthermore, the second dual-axis motion assembly drives the second pneumatic gripper to move in the assembly line direction and in a direction perpendicular to the ground.

[0009] Furthermore, a clamping component is provided below the second pneumatic gripper. The clamping component is used to hold the indwelling needle inserted into the needle holder and to dock with the length positioning mechanism under the rotation of the indexing plate in the external assembly line.

[0010] Furthermore, the clamping component includes a connecting spring, a connecting pin, and clamping arms. The clamping arms include two arms and are hinged at one end to form a V-shape via the connecting pin. The connecting spring is connected to the inner side of the two clamping arms respectively. Each clamping arm has a clamping platform fixed at one end near the needle seat. The outer end of the clamping platform has a V-shaped clamping groove to frictionally fix the indwelling needle.

[0011] Furthermore, the length positioning mechanism also includes a lead screw module and a second pneumatic finger. The lead screw module is used to drive the second pneumatic finger to move in a direction perpendicular to the ground. The mating block and the wedge block are respectively fixed to the two ends of the second pneumatic finger. The bottom surface of the mating block is flush with the bottom surface of the wedge block. The side of the mating block opposite to the wedge block is a plane so as to fit with the inclined surface of the wedge block to form a V-groove.

[0012] Furthermore, the length positioning mechanism also includes a horizontal cylinder, a vertical cylinder, and an auxiliary clamping piece. The horizontal cylinder is fixed to the base platform, and the vertical cylinder is fixed to the output end of the horizontal cylinder. The horizontal cylinder can drive the auxiliary clamping piece to move in the assembly line direction. The auxiliary clamping piece is fixed to the output end of the vertical cylinder through a connecting platform. The top of the auxiliary clamping piece has a slot to limit the top of the indwelling needle.

[0013] Furthermore, after the indwelling needle is inserted into the needle holder by the flipping inserter, the tip of the indwelling needle is positioned higher than the bottom surface of the wedge.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention uses the angle positioning mechanism and the length positioning structure to work together. The two are connected by the flipping insert. The indwelling needle is connected to the receiving table from the external assembly line flow channel, and then the feeding part clamps it into the angle positioning mechanism to form a closed loop, and finally realizes the synchronous positioning of the angle of the indwelling needle and the length of the exposed needle seat. (2) For the positioning of the indwelling needle angle, the indwelling needle is supported at both ends by the inclined groove and the positioning groove, and then the indwelling needle is limited to a certain range in the middle of the inclined groove by the limiting groove. At the same time, since the indwelling needle is placed by the first pneumatic finger at the position where its tip corresponds to the slope of the inclined groove, the design of the inclined groove and its corresponding slope can ensure that after the indwelling needle rolls freely under gravity within the limiting range, the inclined surface of the tip fits exactly with the slope of the inclined groove, thus realizing the positioning of the tip angle of the indwelling needle. (3) For the positioning of the length of the indwelling needle, the top rod connected to the base is pushed upward by means of elastic connection, and then the bottom end of the indwelling needle in the needle seat is pushed upward synchronously by means of push rod. At the same time, the wedge block and the mating block located above the indwelling needle are closed to form a groove to ensure that the tip of the indwelling needle is always in contact with the inclined surface of the wedge block, and is positioned after the tip contacts the bottom of the groove of the wedge block and the mating block, so as to determine the exposed length of the indwelling needle. (4) The entire device can be seamlessly connected to the indwelling needle assembly line. By using the indwelling needle with fixed length and fixed angle, the subsequent overall assembly process and accuracy can be improved. (5) Compared with traditional visual CCD detection, the fixed needle length angle selection device of the present invention does not require the intervention of online algorithms and other equipment, has a lower cost, and the positioning method of traditional mechanical structure is more stable and practical than CCD online angle and height selection. Attached Figure Description

[0015] Figure 1 This is a perspective view of the angle selection part in the fixed needle length angle selection device of the present invention; Figure 2 This is a partial structural schematic diagram of the angle positioning mechanism of the present invention; Figure 3 This is a rear view of the angle selection section in the fixed needle length angle selection device of the present invention; Figure 4 This is a perspective view of the fixed needle length portion in the fixed needle length selection angle device of the present invention; Figure 5 This is an isometric structural diagram of the fixed needle length portion in the fixed needle length angle selection device of the present invention; Figure 6 This is a front view of the fixed needle length portion in the fixed needle length selection angle device of the present invention; Figure 7 This is a partial structural schematic diagram of the clamping component of the present invention; Figure 8 This is a schematic diagram of the internal structure of the needle holder of the present invention.

[0016] In the diagram: 1. Receiving platform; 2. Feeding component; 201. First dual-axis motion assembly; 202. First pneumatic finger; 3. Angle positioning mechanism; 301. Fixed angle plate; 302. Limiting plate; 303. Positioning plate; 304. Inclined groove; 305. Limiting groove; 306. Positioning groove; 4. Flipping insert; 401. Flipping table; 402. Rotating shaft; 403. First pneumatic gripper; 404. Second pneumatic gripper; 405. Second dual-axis motion assembly; 406. Gear; 407. Rack; 408. 409. Push cylinder; 5. Pulley; 6. Length positioning mechanism; 7. Base platform; 8. Push rod; 9. Mating block; 10. Wedge block; 11. Lead screw module; 12. Second pneumatic finger; 13. Horizontal cylinder; 14. Vertical cylinder; 15. Auxiliary clamp; 16. Slot; 17. Indwelling needle; 18. Needle seat; 19. Slide cavity; 10. Push rod; 11. Clamping piece; 12. Connecting spring; 13. Connecting pin; 14. Clamping arm; 15. Clamping platform; 16. Clamping groove; Detailed Implementation The present invention will be further described below with reference to specific embodiments.

[0017] In this embodiment, the open-type indwelling needle 6 needle length selection angle device is actually a combination of an angle positioning mechanism 3 and a length positioning structure. Both are located in a loop in the actual assembly line of the indwelling needle 6. They are connected by a flipping insert 4. The indwelling needle 6 docks with the receiving table 1 from the external assembly line flow channel, and then is clamped into the angle positioning mechanism 3 by the feeding part 2, thus forming a closed loop, and finally realizing the synchronous positioning of the angle of the indwelling needle 6 and the length of the exposed needle seat 7.

[0018] The following section provides a detailed explanation of the implementation structure of each step in the actual assembly line sequence.

[0019] Firstly, regarding the feeding process, in this embodiment, as follows: Figure 1 As shown, the feed component 2 specifically includes a first dual-axis motion assembly 201 and a first pneumatic finger 202. The first dual-axis motion assembly 201 drives the first pneumatic finger 202 to move in the assembly line direction and perpendicular to the ground direction. The receiving platform 1 is a U-shaped plate, and the length of the U-shaped opening is greater than the width of the first pneumatic finger 202. The sufficiently long opening ensures that the first pneumatic finger 202 does not interfere with the receiving platform 1 when clamping and placing the indwelling needle 6. The first dual-axis motion assembly 201 can be referenced. Figure 1 The choice between pneumatic slides or servo screws is not limited to these in practice. The corresponding structures are quite common in this field and will not be elaborated on here.

[0020] Then, as Figure 2 As shown, the first pneumatic finger 202 clamps the indwelling needle 6 onto the fixed angle plate 301 and the positioning plate 303 of the angle positioning structure. In this embodiment, the top surface of the fixed angle plate 301 has an inclined groove 304. The inclined groove 304 flares outward and slopes downward at the end facing the limiting plate 302, with the slope of the inclined groove being consistent with the slope of the tip of the indwelling needle 6. A vertical limiting plate 302 is also fixed to the outside of the fixed angle plate 301. The top of the limiting plate 302 has a limiting groove 305 recessed to limit the indwelling needle 6 in the middle of the inclined groove 304 along the assembly line direction. The top surface of the positioning plate 303 has a positioning groove 306. The positioning groove 306 and the inclined groove 304 support the indwelling needle 6 synchronously and always keep the slope of the tip of the indwelling needle 6 in contact with the slope of the inclined groove 304. As can be seen, the present invention first uses the inclined groove 304 and the positioning groove 306 to support both ends of the indwelling needle 6, and then the limiting groove 305 limits the indwelling needle 6 within a certain range in the middle of the inclined groove 304. Simultaneously, since the position where the indwelling needle 6 is clamped by the first pneumatic finger 202 is exactly where its tip corresponds to the slope of the inclined groove 304, the design of the inclined groove 304 and its corresponding slope can ensure that after the indwelling needle 6 rolls freely under gravity within the limiting range, the inclined surface of its tip is exactly in contact with the slope of the inclined groove 304, thereby achieving the positioning of the tip angle of the indwelling needle 6.

[0021] After the indwelling needle 6 is positioned at an angle, the flipping insert 4 clamps the indwelling needle 6 into the inclined groove 304 and the positioning groove 306, and after flipping, the indwelling needle 6 is inserted into the needle holder 7 positioned in the assembly line. The structure of the needle holder 7 can be referred to Figure 7 As shown, in this embodiment, the flipping insert 4 includes a flipping table 401, a rotating shaft 402, a first pneumatic gripper 403, a second pneumatic gripper 404, and a second dual-axis motion assembly 405. The rotating shaft 402 is rotatably connected to the flipping table 401, and a gear 406 is coaxially fixed to the outside of the flipping table 401. A push cylinder 408 and a rack 407 are also fixed to the outer wall of the flipping table 401. The bottom surface of the rack 407 is slidably connected to the flipping table 401 via a pulley 409, and its top surface meshes with the gear 406. The output end of the push cylinder 408 is fixedly connected to the rack 407. The first pneumatic gripper 403 can grip the bottom end of the indwelling needle 6. The outer wall of the rotating shaft 402 is recessed into a plane to be fixed with the first pneumatic gripper 403. The second dual-axis motion assembly 405 drives the second pneumatic gripper 404 to move in the assembly line direction and in a direction perpendicular to the ground.

[0022] First, the first pneumatic gripper 403 grips the indwelling needle 6 at a fixed angle. Then, by pushing the output of the cylinder 408, the rack 407, which slides with the pulley 409 of the tilting table 401, is moved. The gear 406, which meshes with the rack 407, can drive the rotating shaft 402 to rotate 90° to dock with the second pneumatic gripper 404 above. After the second pneumatic gripper 404 servo-grips the indwelling needle 6 on the first pneumatic gripper 403, it is bidirectionally moved by the second dual-axis motion assembly 405 to meet the assembly position requirements of the needle holder 7 below, that is, the indwelling needle 6 is inserted into the needle holder 7. The structural design of the second dual-axis motion assembly 405 is the same as that of the first dual-axis motion assembly 201, and will not be described in detail here.

[0023] At this time, the assembly of the indwelling needle 6 and the needle seat 7 relies solely on the displacement of the second dual-axis motion component 405, and the accuracy cannot reach the required tolerance of ±0.1mm. In order to further precisely control the length of the exposed needle seat 7 of the indwelling needle 6, this embodiment also provides a clamping member 8 below the second pneumatic gripper 404. The clamping member 8 is used to clamp the indwelling needle 6 inserted into the needle seat 7 and dock with the length positioning mechanism 5 under the rotation of the indexing plate in the external assembly line, and rotate and shift to achieve seamless docking.

[0024] Regarding the subsequent process of determining the needle length, in this embodiment, as follows: Figure 4 , Figure 5 and Figure 6As shown, the length positioning mechanism 5 includes a base 501, a push rod 502, a mating block 503, and a wedge 504. The bottom end of the push rod 502 is spring-connected to the base 501, and its top end points vertically to the center of the bottom surface of the needle seat 7 and contacts the bottom surface of the push rod 702. The slope and height of the wedge 504 are consistent with the slope and height of the tip of the indwelling needle 6. The mating block 503 and the wedge 504 are pneumatically closed to form a groove. Figure 8 As shown, the needle holder 7 has a sliding cavity 701 coaxial with the indwelling needle 6, and a push rod 702 is slidably connected within the sliding cavity 701. The top surface of the push rod 702 contacts the bottom surface of the inserted indwelling needle 6. Figure 7 As shown, the clamping member 8 includes a connecting spring 801, a connecting pin 802, and a clamping arm 803. The clamping arm 803 includes two arms and is hinged to one end in a V-shape by the connecting pin 802. The connecting spring 801 is connected to the inner side of the two clamping arms 803 respectively. Each clamping arm 803 has a clamping platform 804 fixed at one end near the needle seat 7. The outer end of the clamping platform 804 is provided with a V-shaped clamping groove 805 to frictionally fix the indwelling needle 6.

[0025] As can be seen, for the fixed-length process, the push rod 502, which is elastically connected to the base 501, pushes upward, and then the push rod 702 drives the bottom end of the indwelling needle 6 in the needle seat 7 to push upward synchronously. At the same time, the wedge block 504 and the mating block 503 located above the indwelling needle 6 close to form a groove, ensuring that the tip of the indwelling needle 6 is always in contact with the inclined surface of the wedge block 504, and is positioned after the tip contacts the bottom of the groove of the wedge block 504 and the mating block 503, thus determining the exposed length of the indwelling needle 6. During this process, the two spring-connected clamping arms 803 of the clamping member 8 can make frictional contact with the indwelling needle 6, and the two V-shaped clamping platforms 804 can ensure that the upward process of the indwelling needle 6 can be stopped stably at any time, ultimately achieving the matching of the thickness of the inclined surface of the wedge block 504 with the tip length of the indwelling needle 6. For indwelling needles 6 with different tip lengths, only the model of the inclined surface of the wedge block 504 needs to be adjusted.

[0026] Specifically, for the process of closing the groove between the wedge block 504 and the mating block 503, the length positioning mechanism 5 further includes a lead screw module 505 and a second pneumatic finger 506. The lead screw module 505 is used to drive the second pneumatic finger 506 to move in a direction perpendicular to the ground. The mating block 503 and the wedge block 504 are respectively fixed to the two ends of the finger of the second pneumatic finger 506. The bottom surface of the mating block 503 is flush with the bottom surface of the wedge block 504. The side of the mating block 503 opposite to the wedge block 504 is a plane so as to fit with the inclined surface of the wedge block 504 to form a V-groove.

[0027] Similarly, to ensure the stability of the entire ejection process when the indwelling needle 6 is positioned in length with the inclined surface of the wedge block 504, this embodiment also includes a horizontal cylinder 507, a vertical cylinder 508, and an auxiliary clamping plate 509 on one side. The horizontal cylinder 507 is fixed to the base platform 501, and the vertical cylinder 508 is fixed to the output end of the horizontal cylinder 507. The horizontal cylinder 507 can drive the auxiliary clamping plate 509 to move in the assembly line direction. The auxiliary clamping plate 509 is fixed to the output end of the vertical cylinder 508 through a connecting platform. The top of the auxiliary clamping plate 509 has a slot 510 to limit the top of the indwelling needle 6.

[0028] In actual assembly lines, to prevent wear caused by hard contact between the tip of the indwelling needle 6 and the wedge block 504, servo control can be used to control the flipping insert 4 to insert the indwelling needle 6 into the needle holder 7, with the tip of the indwelling needle 6 positioned higher than the bottom surface of the wedge block 504. This ensures that each indwelling needle 6 is kept to a fixed length without being worn by hard contact.

[0029] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. An open indwelling needle length fixing and angle selecting device, comprising a receiving table, the receiving table is connected in the indwelling needle assembly line, the indwelling needle hollow is erected on the top end of the receiving table, characterized in that: The side of the receiving table along the direction of the indwelling needle assembly line is further provided with an infeed piece, an angle positioning mechanism, a turnover insertion piece and a length positioning mechanism in sequence, The angle positioning mechanism includes a fixed angle plate, a limiting plate and a positioning plate in sequence along the assembly line direction, the top surface of the fixed angle plate is provided with an inclined groove, the inclined groove is flared at one end facing the limiting plate and is inclined downward, the inclination gradient is consistent with the gradient of the tip of the indwelling needle, the limiting plate is vertically fixed outside the fixed angle plate and is connected with the inclined groove, the top end of the limiting plate is concave to form a limiting groove, so as to limit the indwelling needle in the middle of the inclined groove along the assembly line direction, the top surface of the positioning plate is provided with a positioning groove, the positioning groove supports the indwelling needle synchronously with the inclined groove, and the tip slope of the indwelling needle is always in contact with the slope of the inclined groove, The infeed piece can clamp and place the indwelling needle at the top end of the receiving table on the inclined groove and the positioning groove, the turnover insertion piece can clamp and place the indwelling needle in the inclined groove and the positioning groove, and after turning over, the indwelling needle is inserted into the needle seat in the assembly line, the needle seat is provided with a sliding cavity coaxial with the indwelling needle, and a push rod is slidably connected in the sliding cavity, the top surface of the push rod is in contact with the bottom surface of the indwelling needle after insertion, The length positioning mechanism includes a base, a top rod, a matching block and a wedge, the bottom end of the top rod is spring-connected with the base, the top end is vertically directed to the center of the bottom surface of the needle seat and is in contact with the bottom surface of the push rod, the inclination gradient and height of the wedge are consistent with the inclination gradient and height of the tip of the indwelling needle, and the matching block is pneumatically closed with the wedge to form a groove.

2. The open indwelling needle length fixing and angle selecting device according to claim 1, characterized in that: The infeed piece includes a first double-shaft movement assembly and a first pneumatic finger, the first double-shaft movement assembly drives the first pneumatic finger to move in the direction of the assembly line and perpendicular to the ground, the receiving table is a U-shaped plate, and the length of the U-shaped opening is greater than the width of the first pneumatic finger.

3. The open indwelling needle length fixing and angle selecting device according to claim 1, characterized in that: The turnover insertion piece includes a turnover table, a rotating shaft, a first pneumatic clamp jaw, a second pneumatic clamp jaw and a second double-shaft movement assembly, the rotating shaft is rotationally connected with the turnover table, a gear is coaxially fixed outside the turnover table, a push cylinder and a rack are further fixed on the outer wall of the turnover table, the bottom surface of the rack is slidably connected with the turnover table through a pulley, the top surface is engaged with the gear, the output end of the push cylinder is fixedly connected with the rack, the first pneumatic clamp jaw can clamp the bottom end of the indwelling needle, and the outer wall of the rotating shaft is concave to form a flat surface to fix the first pneumatic clamp jaw.

4. The open indwelling needle length fixing and angle selecting device according to claim 3, characterized in that: The second double-shaft movement assembly drives the second pneumatic clamp jaw to move in the direction of the assembly line and perpendicular to the ground.

5. The open indwelling needle length fixing and angle selecting device according to claim 4, characterized in that: A clamping piece is further arranged below the second pneumatic clamp jaw, which is used to clamp the indwelling needle inserted into the needle seat and to be connected with the length positioning mechanism under the rotation of the index plate in the external assembly line.

6. The open indwelling needle length fixing and angle selecting device according to claim 5, characterized in that: The clamping piece includes a connecting spring, a connecting pin and a clamping arm, the clamping arm includes two V-shaped arms hinged at one end by the connecting pin, the connecting spring is connected to the inner side of each clamping arm, and a clamping table is fixed at one end of each clamping arm close to the needle seat, a V-shaped clamping groove is formed at the outer end of the clamping table to frictionally fix the indwelling needle.

7. The open indwelling needle length fixing and angle selecting device according to claim 1, characterized in that: The length positioning mechanism further comprises a screw module and a second pneumatic finger, the screw module is used to drive the second pneumatic finger to shift in the direction perpendicular to the ground, the matching block and the wedge block are respectively fixed at the two ends of the second pneumatic finger, the bottom surface of the matching block is flush with the bottom surface of the wedge block, and the surface of the matching block opposite to the wedge block is a plane to form a V groove with the inclined surface of the wedge block.

8. The open indwelling needle length fixing and angle selecting device according to claim 7, characterized in that: The length positioning mechanism further comprises a horizontal air cylinder, a vertical air cylinder and an auxiliary clamping piece, the horizontal air cylinder is fixed with the base table, the vertical air cylinder is fixed on the output end of the horizontal air cylinder, the horizontal air cylinder can drive the auxiliary clamping piece to shift in the assembly line direction, the auxiliary clamping piece is fixed with the output end of the vertical air cylinder through a connecting table, and a clamping groove is arranged at the top end of the auxiliary clamping piece to limit the top end of the indwelling needle.

9. The open indwelling needle length fixing and angle selecting device according to claim 1, characterized in that: The top height of the indwelling needle tip is higher than the bottom height of the wedge block after the indwelling needle is inserted into the needle seat by the turnover insert.

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