CN210933132U - Axial positioning device and micro-injection pump - Google Patents

Abstract

The utility model provides an axial positioner and microinjection pump relates to the motor-driven tool field. The axial positioning device comprises a first driving piece, a second driving piece and an output rod, wherein the first driving piece is connected with the output rod, and the first driving piece is used for driving the output rod to move along the axial direction of the output rod so as to enable the output rod to be close to or separated from an object to be positioned. The second driving piece is connected with the output rod, and the end part of the output rod is provided with a fixing structure which is fixedly connected with an object to be positioned; the second driving piece is used for driving the output rod to rotate, the fixing structure can be in mutual abutting joint with the object to be positioned along the axial direction of the output rod in the rotating process of the output rod, and the fixing structure is used for fixing the output rod and the object to be positioned. The micro-injection pump is provided with the axial positioning device. The utility model discloses the axial positioning device who has alleviated and the technical problem who easily produces great return stroke error when having had the clearance and then having leaded to the object return stroke of undetermining in the junction between the object of undetermining of existence among the prior art.

Description

Axial positioning device and micro-injection pump

Technical Field

The utility model belongs to the technical field of the motor-driven tool technique and specifically relates to an axial positioner and micro-injection pump are related to.

Background

The micro-injection pump is a novel pump force instrument, and can realize the accurate control of the flow and the flow speed of fluid, for example, a small amount of liquid medicine is accurately, micro, uniformly and continuously pumped into a body. Existing micro syringe pumps include a base, a clamp, a syringe, and a linear motion module. Wherein, the syringe includes pipe shaft and piston push rod.

The clamp and the linear motion module in the micro-injection pump are both installed on the base, the tube body of the injector is fixed on one side of the base by the clamp, and the linear motion module is located on the base and opposite to the position of the clamp. One end of the piston push rod is provided with a rubber plug and is sleeved in the tube body, the other end of the piston push rod is flaky and is exposed outside the tube body, and the plane of the other end of the piston push rod is vertical to the axial direction of the piston push rod. The output end of the linear motion module is provided with a groove matched with the other end of the piston push rod, and the other end of the piston push rod is positioned in the groove and can be abutted against the side wall of the groove. Because the other end of the piston push rod is positioned in the groove, the output end of the linear motion module can drive the piston push rod to move along the axial direction of the piston push rod, and then liquid can be sucked into the pipe body or the liquid in the pipe body can be pushed out.

When the injector needs to send out a fixed amount of liquid and pump in a fixed amount of liquid, the piston push rod is positioned to a preset position. In the above positioning process, the piston rod should move a certain displacement along its axis, and correspondingly, the output end of the linear motion module should output a certain displacement. But there is the clearance between the other end of piston push rod and the recess, when needs switch piston push rod direction of motion, when needing piston push rod return stroke promptly, because the existence of above-mentioned clearance, the piston push rod can not follow linear motion module and move immediately, and then can lead to the piston push rod to produce great return stroke error.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an axial positioning device to there is the clearance and then easily produces the technical problem of great return stroke error when leading to the object return stroke of undetermining in the axial positioning device who alleviates existence among the prior art and the junction between the object of undetermining.

The utility model provides an axial positioning device, which comprises a first driving piece, a second driving piece and an output rod;

the first driving piece is connected with the output rod and used for driving the output rod to move along the axial direction of the output rod so as to enable the output rod to be close to or separate from an object to be positioned;

the second driving piece is connected with the output rod, and the end part of the output rod is provided with a fixing structure which is fixedly connected with an object to be positioned; the second driving piece is used for driving the output rod to rotate, the fixing structure can be in mutual abutting joint with the object to be positioned along the axial direction of the output rod in the rotating process of the output rod, and the fixing structure is used for fixing the output rod and the object to be positioned.

Further, the fixing structure is an external thread or an internal thread.

Further, the axial positioning device also comprises a trigger assembly and a switch;

the output rod and the switch are both connected with the trigger assembly, and the switch is connected with the second driving piece; the trigger assembly is used for opening the switch when the fixed structure is locked with the object to be positioned.

Furthermore, the axial positioning device also comprises a movable support, and the trigger assembly comprises a first meshing component, a second meshing component, a synchronous component and an elastic component;

a bearing is arranged at one end of the output rod, which is far away from the fixed structure, and the output rod is connected with the movable support through the bearing;

the first meshing part and the second meshing part are sleeved on the output rod, and the first meshing part is connected with the output shaft of the second driving part;

the first meshing part and the second meshing part both comprise two ends, a plurality of convex teeth which are circularly arranged are arranged at one end of the first meshing part and one end of the second meshing part, and the convex teeth on the second meshing part are meshed with the convex teeth on the first meshing part;

one end of the second meshing component, which is far away from the convex teeth, is provided with a groove, and the depth direction of the groove is parallel to the axial direction of the output rod; the synchronous piece penetrates through the output rod along the direction vertical to the axial direction of the output rod and is positioned in the groove;

the elastic piece comprises two ends, the elastic piece is sleeved on the output rod, one end of the elastic piece is connected with the second meshing piece, and the other end of the elastic piece is fixed on the output rod;

the switch is arranged on the movable support, a trigger lever is arranged on the switch, and the second meshing part is abutted to the trigger lever on the switch.

Furthermore, the synchronous piece is cylindrical, and the sum of the distance between the tooth top and the tooth bottom of the convex teeth on the second meshing piece and the radius of the synchronous piece is less than or equal to the depth of the groove on the second meshing piece.

Furthermore, the convex teeth on the second meshing piece comprise a first inclined surface and a second inclined surface, the top ends of the first inclined surface and the second inclined surface are in butt joint, and the top ends of the first inclined surface and the second inclined surface are in butt joint with each other to form tooth tops of the convex teeth on the second meshing piece;

when the output rod is close to an object to be positioned, the first inclined surface can support the convex teeth of the first meshing part; the minimum included angle between the first inclined surface and the horizontal plane is smaller than or equal to the minimum included angle between the second inclined surface and the horizontal plane.

Furthermore, the trigger assembly further comprises a first baffle and a second baffle, the first baffle is sleeved on the output rod, and the first baffle is positioned between the second meshing component and the elastic component;

the second baffle is fixed on the output rod, and the other end of the elastic piece is abutted against the second baffle.

Further, the axial positioning device also comprises a gear; the second driving piece is arranged on the movable support, and an output shaft of the second driving piece penetrates through the movable support to be connected with the gear;

gear teeth are arranged at the other end of the first meshing component, and the gear is meshed with the gear teeth on the first meshing component.

Furthermore, the axial positioning device also comprises a fixed support, the first driving piece is arranged on the movable support, and an output shaft of the first driving piece is connected with the fixed support;

the fixed support is provided with a hole, and the other end of the output rod penetrates through the hole in the fixed support and is exposed outside the fixed support.

Furthermore, the axial positioning device also comprises a guide piece, the guide piece comprises two ends, and one end of the guide piece is fixed on the fixed support; the other end of the guide piece penetrates through the movable support and is exposed out of the movable support, and the movable support can move on the guide piece under the driving of the first driving piece.

Furthermore, the length of the fixed structure is smaller than the depth of a thread groove on the object to be positioned, and one end of the fixed structure, which is far away from the object to be positioned, is provided with a butting part.

Furthermore, the fixing structure is a bulge, can extend into a cylindrical groove on an object to be positioned and is abutted against a convex strip on the side wall of the cylindrical groove when the output rod rotates;

the distance between one end of the output rod close to the protrusion and the protrusion is equal to the distance between the convex strip and the bottom of the cylindrical groove.

The utility model provides an in be provided with in the micro-injection pump as above-mentioned any one of technical scheme axial positioner.

The utility model provides an axial positioning device and microinjection pump can produce following beneficial effect:

the utility model provides an axial positioning device includes first driving piece, second driving piece and output rod, and first driving piece is connected with the output rod, and the second driving piece is connected with the output rod, and the tip of output rod has and is connected fixed knot structure with the object of awaiting the location. Before an object to be positioned is positioned to a preset position, the output rod and the object to be positioned need to be fixed, and then the output rod is used for driving the object to be positioned to move to the preset position. After the output rod is used for driving the object to be positioned to move, the output rod is separated from the object to be positioned. In the process of fixing the output rod and the object to be positioned and in the process of separating the output rod and the object to be positioned, the object to be positioned is positioned in the axial direction of the output rod.

In the positioning process, the first driving piece is started firstly to enable the output rod to be close to the object to be positioned, and then the second driving piece is started simultaneously or sequentially to enable the output rod to rotate. When the output rod rotates, the fixing structure on the output rod can be abutted to the object to be positioned, and at the moment, the fixing structure can fixedly connect the output rod to the object to be positioned. Then the second driving piece is closed, the first driving piece drives the output rod to output a preset displacement, and finally the object to be positioned can be positioned to a preset position. When an object to be positioned needs to move reversely, the first driving piece is used for driving the output rod to move reversely, and the fixed structure fixedly connects the output rod to the object to be positioned, so that in the process of switching the movement direction of the object to be positioned, a gap enabling the output rod to be abutted against the object to be positioned again does not exist between the output rod and the object to be positioned, and the object to be positioned can synchronously move reversely along with the output rod so as to enable the object to be positioned to be far away from the preset position.

When the output rod is separated from the object to be positioned, the second driving piece is started firstly, so that the output rod reversely rotates, then or simultaneously the first driving piece is started, at the moment, the fixing structure is not abutted to the object to be positioned any more, and the fixing structure is separated from the object to be positioned. And then the second driving piece is closed, the first driving piece drives the output rod to move along the direction away from the object to be positioned, and finally the output rod and the object to be positioned can be separated.

In the positioning process, the utility model provides an all can fixed connection between output rod and the object of awaiting positioning, can be locked between output rod and the object of awaiting positioning promptly, therefore there is not the clearance when output rod links together with the object of awaiting positioning, can not cause great return stroke error when the object return stroke of awaiting positioning. In addition, the second driving piece is utilized to drive the output rod to reversely rotate, the fixed structure can be separated from the object to be positioned, and then the separation process between the output rod and the object to be positioned can be realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural view of an object to be positioned and an axial positioning device according to a first embodiment of the present invention;

FIG. 2 is a schematic structural view of the axial positioning device of FIG. 1;

FIG. 3 is a front view of the axial positioning device of FIG. 2;

FIG. 4 is a sectional view A-A of FIG. 3;

FIG. 5 is a schematic diagram of the trigger assembly and switch of FIG. 2;

FIG. 6 is a schematic structural diagram of the trigger assembly of FIG. 5;

FIG. 7 is a schematic view of the output rod and the elastic member of FIG. 6;

FIG. 8 is a schematic view of the first and second engagement members of FIG. 6;

FIG. 9 is another schematic structural view of the first and second engagement members of FIG. 6;

FIG. 10 is a schematic structural view of the movable bracket and the fixed bracket of FIG. 2;

FIG. 11 is a schematic view of the second engagement member of FIG. 6;

FIG. 12 is a schematic view of the engagement of the first and second engagement members of FIG. 6;

FIG. 13 is a rear view of the axial positioning device of FIG. 3;

fig. 14 is a schematic structural view of an object to be positioned and an output rod according to a second embodiment of the present invention;

FIG. 15 is a schematic view of the object to be positioned and the output rod of FIG. 14 connected together;

fig. 16 is a side view of the object to be positioned in fig. 14.

Icon: 1-an object to be positioned; 10-thread groove; 11-convex strips; 2-a first driving member; 3-a second driving member; 4-an output rod; 40-an abutment; 41-a contact piece; 5-a trigger component; 50-a first engagement member; 51-a second engagement member; 510-a groove; 52-a synchronizing member; 53-a resilient member; 54-a bearing; 55-convex teeth; 550-a first inclined plane; 551-second inclined plane; 56-a first baffle; 57-a second baffle; 6-a switch; 60-trigger lever; 7-a movable support; 8-gear; 9-fixing a bracket; 90-a guide; 91-spring.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The first embodiment is as follows:

as shown in fig. 1-4, the present embodiment provides an axial positioning device including a first driver 2, a second driver 3, and an output rod 4. The first driving piece 2 is connected with the output rod 4, and the first driving piece 2 is used for driving the output rod 4 to move along the axial direction of the output rod 4 so as to enable the output rod 4 to approach or separate from the object 1 to be positioned.

The second driving piece 3 is connected with the output rod 4, and the end part of the output rod 4 is provided with a fixing structure which is fixedly connected with the object 1 to be positioned; the second driving piece 3 is used for driving the output rod 4 to rotate, the fixing structure can be abutted against the object 1 to be positioned in the axial direction of the output rod 4 in the rotating process of the output rod 4, and the fixing structure is used for fixing the output rod 4 and the object 1 to be positioned.

Taking the object 1 to be positioned as a piston push rod in a syringe in a micro syringe pump as an example, when the syringe in the micro syringe pump needs to send a certain amount of liquid, the piston push rod needs to be positioned to a preset position, as shown in fig. 1, at this time, the piston push rod can be positioned in the axial direction of the output rod 4, and then the first driving member 2 is started, and the first driving member 2 can drive the output rod 4 to approach the piston push rod. After the first driving element 2 is started, the second driving element 3 is started, or the second driving element 3 is started while the first driving element 2 is started, and after the second driving element 3 is started, the output rod 4 can be driven to rotate on the piston push rod. In the process of rotation of the output rod 4, the fixing structure on the output rod 4 can be abutted against the piston push rod along the axial direction of the output rod 4, at the moment, the output rod 4 is locked with the piston push rod, and the piston push rod cannot be separated from the output rod 4 along the axial direction of the output rod 4.

The first driving piece 2 is continuously utilized to drive the output rod 4 to move along the axial direction of the output rod, and finally the piston push rod connected with the output rod 4 can be positioned to a preset position. When the piston push rod needs to be switched to the movement direction, the first driving piece 2 can be started first, and the first driving piece 2 can drive the output rod 4 to move reversely. At this time, because the output rod 4 is fixedly connected to the piston push rod by the fixing structure, in the process of switching the motion direction of the piston push rod, a gap enabling the output rod 4 to be abutted against the piston push rod again does not exist between the output rod 4 and the piston push rod, and the piston push rod can synchronously move reversely along with the output rod 4 so as to enable the piston push rod to be far away from the preset position. In the process of carrying out motion positioning on the object 1 to be positioned, the output rod 4 and the object 1 to be positioned are always fixedly connected, namely, the output rod 4 and the object 1 to be positioned can be locked. Therefore, when the output rod 4 is connected with the object 1 to be positioned, no gap exists, and a large return error cannot be caused when the object 1 to be positioned returns.

Because a gap exists at the joint between the axial positioning device and the object 1 to be positioned in the prior art, the connection relationship between the prior axial positioning device and the object 1 to be positioned is unstable. The fixing structure in the axial positioning device provided by the embodiment can fix the output rod and the object 1 to be positioned, and the connection stability between the output rod and the object 1 to be positioned is improved. Therefore, the axial positioning device provided by the embodiment also solves the problem that the connection relationship between the axial positioning device and the object 1 to be positioned is unstable in the prior art.

Therefore, the axial positioning device provided by the embodiment alleviates the technical problem that a gap exists at the joint between the axial positioning device and the object to be positioned 1 in the prior art, so that a large return error is easily generated when the object to be positioned 1 returns.

In addition, the axial positioning device provided by this embodiment can realize the automatic connection process between the output rod 4 and the object 1 to be positioned by using the first driving element 2 and the second driving element 3, and can also automatically separate the output rod 4 from the object 1 to be positioned. Compared with the process of manually connecting and separating the output rod 4 and the object 1 to be positioned in the prior art, the axial positioning device provided by the embodiment can save labor and labor.

The output rod 4 in the axial positioning device provided by this embodiment can also be separated from the object 1 to be positioned, that is, the output rod 4 can also be unlocked from the object 1 to be positioned. When the unlocking is needed, the second driving piece 3 can be rotated reversely to drive the output rod 4 to rotate reversely, and then the locking between the output rod 4 and the object 1 to be positioned can be released. Meanwhile, the first driving piece 2 drives the output rod 4 to move reversely along the axial direction of the output rod 4, so that the output rod 4 and the object 1 to be positioned can be separated.

Wherein, the fixing structure can be an external thread or an internal thread. When the fixing structure is an external thread, a thread groove 10 can be arranged on the object 1 to be positioned, and the thread in the thread groove 10 is matched with the external thread. When the fixing structure is an internal thread, a thread matched with the internal thread can be arranged on the upper outer side wall of the object 1 to be positioned.

Further, when the fixing structure is an external thread or an internal thread, the first driving member 2 may be an electric push rod, and the second driving member 3 may be a motor. In the process of positioning the object 1 to be positioned to the preset position, when the object 1 to be positioned and the output rod 4 need to be connected and locked, the first driving piece 2 and the second driving piece 3 are started.

The fixing structure can enable the connection mode between the output rod 4 and the object 1 to be positioned to be a thread connection mode capable of self-locking, and compared with a mode of utilizing groove butting in the prior art, the thread connection mode does not enable the object 1 to be positioned to generate return errors due to gaps during return. Therefore, the axial positioning device provided by the embodiment can improve the positioning precision of the object 1 to be positioned.

In addition, in the embodiment, the connection locking of the object 1 to be positioned and the output rod 4, the motion positioning of the object 1 to be positioned and the separation between the object 1 to be positioned and the output rod 4 can be realized by using one motor, one electric push rod and the output rod 4, so that the return error of the object 1 to be positioned can be reduced, and the device can be adapted to a miniaturized instrument with low load capacity requirement.

As shown in fig. 2 and 5, the axial positioning device provided in this embodiment further includes a trigger assembly 5 and a switch 6. The output rod 4 and the switch 6 are both connected to the triggering assembly 5. The triggering assembly 5 is used to open the switch 6 when the fixed structure is locked with the object 1 to be positioned.

Further, the switch 6 is connected to a control system for controlling the second driving member 3 to be turned on or off, and when the switch 6 is turned on, the control system controls the second driving member 3 to be turned off. A control system such as a programmable logic controller. After the second driving element 3 is closed, the output rod 4 stops rotating. The control system may then also control the first drive member 2 to push the output rod 4 to move a distance equal to the distance between the object 1 to be positioned and the predetermined position.

As shown in fig. 2 and 10, the axial positioning device provided in this embodiment further includes a movable bracket 7. As shown in fig. 2, 5 and 6, the triggering assembly 5 includes a first engaging member 50, a second engaging member 51, a synchronizing member 52 and an elastic member 53. Wherein, the bearing 54 is installed on the one end of output rod 4 far away from fixed knot structure, passes through bearing 54 between output rod 4 and the movable support 7 and connects. The first engaging piece 50 and the second engaging piece 51 are sleeved on the output rod 4, and the first engaging piece 50 is connected with the output shaft of the second driving piece 3.

As shown in fig. 8 and 9, each of the first engaging member 50 and the second engaging member 51 includes two ends, one end of the first engaging member 50 and one end of the second engaging member 51 are provided with a plurality of teeth 55 arranged in a circular shape, and the teeth 55 of the second engaging member 51 are engaged with the teeth 55 of the first engaging member 50. The end of the second engaging member 51 facing away from the teeth 55 is provided with a groove 510, and the depth direction of the groove 510 is parallel to the axial direction of the output rod 4.

As shown in fig. 5 and 6, the synchronizer 52 is provided through the output rod 4 in a direction perpendicular to the axial direction of the output rod 4 and is located in the groove 510. As shown in fig. 7, the elastic member 53 includes two ends, the elastic member 53 is sleeved on the output rod 4, one end of the elastic member 53 is connected to the second engaging member 51, and the other end of the elastic member 53 is fixed on the output rod 4. As shown in fig. 5, the switch 6 is mounted on the movable bracket 7, the trigger lever 60 is provided on the switch 6, and the second engaging member 51 abuts against the trigger lever 60 on the switch 6.

When the output rod 4 and the object 1 to be positioned need to be fixed, as shown in fig. 1 and 2, the object 1 to be positioned is placed on the axial direction of the output rod 4, and then the first driving member 2 drives the movable support 7 to be close to the object 1 to be positioned. Because the bearing 54 is installed on one end of the output rod 4 far away from the fixed structure, the output rod 4 is connected with the movable support 7 through the bearing 54, and the first meshing piece 50 and the second meshing piece 51 are sleeved on the output rod 4, the first meshing piece 50 and the second meshing piece 51 can be driven by the movable support 7 to be close to the object 1 to be positioned.

At the same time, the second driving member 3 should be started, and since the first engaging member 50 is connected with the output shaft of the second driving member 3, as shown in fig. 2, the first engaging member 50 can be rotated by the second driving member 3. And because the convex teeth 55 on the second engaging member 51 are engaged with the convex teeth 55 on the first engaging member 50, the second engaging member 51 can be driven by the first engaging member 50 to rotate.

As shown in fig. 6, in the present embodiment, it is preferable that an abutting piece 41 is fixed to the output rod 4, the abutting piece 41 is located between the first engaging piece 50 and the bearing 54, and the abutting piece 41 abuts against a side of the first engaging piece 50 facing away from the second engaging piece 51.

The abutting piece 41 is used for preventing the first engaging piece 50 from sliding on the output rod 4 in a direction away from the second engaging piece 51, and the abutting piece 41 can make the rotating process of the first engaging piece 50 more stable.

As shown in fig. 4 and 5, the synchronizing member 52 is inserted through the output rod 4 in a direction perpendicular to the axial direction of the output rod 4, and the synchronizing member 52 is located in the recess 510 on the end of the second engaging member 51 facing away from the teeth 55, so that the synchronizing member 52 can restrict the second engaging member 51 from rotating synchronously with the output rod 4, preventing the second engaging member 51 from rotating on the output rod 4 relative to the output rod 4. Thus, after the second engaging member 51 is rotated, the output rod 4 can be rotated by the second engaging member 51.

The output rod 4 can now be moved both axially and also rotationally, so that the output rod 4 can be screwed into a threaded groove 10 in the object 1 to be positioned.

When the output rod 4 cannot move in the axial direction in the threaded groove 10 on the object 1 to be positioned, the rotation process of the output rod 4 is also limited, and the output rod 4 cannot rotate any further. Since the second engaging member 51 is restricted from rotating relative to the output shaft 4 by the synchronizing member 52, the second engaging member 51 cannot rotate any further, but the second driving member 3 still drives the first engaging member 50 to rotate, i.e., the first engaging member 50 still rotates, and the second engaging member 51 stops rotating.

In the present embodiment, as shown in fig. 4, the synchronizing member 52 has a space from the groove bottom of the groove 510 on the second engaging member 51, which allows the second engaging member 51 to slide on the output rod 4 in the axial direction of the output rod 4 without being hindered by the synchronizing member 52. And because the convex teeth 55 on the second engaging member 51 are engaged with the convex teeth 55 on the first engaging member 50, and the second engaging member 51 can slide on the output rod 4 along the axial direction of the output rod 4, the first engaging member 50 which still rotates pushes the second engaging member 51, so that the second engaging member 51 moves along the direction away from the first engaging member 50, at this time, the second engaging member 51 drives one end of the elastic member 53 to move together along the direction away from the first engaging member 50, and the second engaging member 51 compresses the elastic member 53.

Since the second engaging member 51 abuts against the trigger lever 60 of the switch 6, when the second engaging member 51 moves in a direction away from the first engaging member 50, the second engaging member 51 pushes the trigger lever 60 of the switch 6, and after the trigger lever 60 of the switch 6 is triggered, the first driving member 2 drives the output rod 4 to output a predetermined displacement.

The preset displacement of the output rod 4 should be equal to the distance between the object 1 to be positioned and the preset position.

When the output rod 4 is connected and locked or unlocked with the object 1 to be positioned, the first driving piece 2 drives the movable support 7 and the output rod 4 to move along the axial direction of the output rod 4 according to a preset movement speed, and the movement speed can be calculated according to the formula (1):

v＝P*n (1)

in the formula: p is the lead of the thread on the output rod 4, and n is the rotational speed of the output rod 4.

As shown in fig. 6, the synchronizing member 52 is cylindrical. The synchronizing member 52 may be a pin. Further, as shown in fig. 11, the sum of the pitch between the crest and the root of the convex teeth 55 of the second engaging member 51 and the radius of the synchronizing member 52 is smaller than or equal to the depth of the concave groove 510 of the second engaging member 51.

As shown in fig. 11, the distance between the tooth crest and the tooth bottom of the convex teeth 55 on the second meshing member 51 is denoted by H, the diameter of the synchronizing member 52 is denoted by d, and the depth of the groove 510 on the second meshing member 51 is denoted by H. The sum of the distance from the top to the bottom of the teeth 55 of the second engaging member 51 and the radius of the synchronizing member 52 is less than or equal to the depth of the groove 510 of the second engaging member 51, i.e. it can be expressed as formula (2):

when the formula (2) is satisfied, the depth of the groove 510 on the second engaging member 51 is deep enough not to be hindered by the synchronizing member 52 when the second engaging member 51 moves in the axial direction of the output rod 4.

Further, the width of the groove 510 on the second engaging member 51 is denoted by b, and b > d should be set so that the second engaging member 51 can smoothly move relative to the synchronizing member 52.

In the present embodiment, as shown in fig. 12, the convex teeth 55 on the second engaging member 51 include a first inclined surface 550 and a second inclined surface 551 whose tips meet each other, and the tip of the first inclined surface 550 and the tip of the second inclined surface 551 meet each other to form the tooth tip of the convex teeth 55 on the second engaging member 51. The first inclined surface 550 can support the spur 55 of the first engagement member 50 when the output rod 4 approaches the object 1 to be positioned. The minimum angle between the first inclined surface 550 and the horizontal plane is less than or equal to the minimum angle between the second inclined surface 551 and the horizontal plane.

As shown in fig. 12, the minimum angle between the first inclined surface 550 and the horizontal plane is α, and the minimum angle between the second inclined surface 551 and the horizontal plane is β, the direction indicated by the arrow in fig. 11 is the rotation direction of the first engaging member 50 and the second engaging member 51 when the output rod 4 approaches the object 1 to be positioned, and at this time, the first inclined surface 550 can support the convex teeth 55 of the first engaging member 50.

When the output rod 4 is locked with the object 1 to be positioned, the second engaging piece 51 can rotate in the direction of an arrow shown in fig. 11 under the driving of the first engaging piece 50, and when the output rod 4 is unlocked with the object 1 to be positioned and the first engaging piece 50 rotates in the direction opposite to the direction of the arrow shown in fig. 11, α is less than or equal to β, so that the first engaging piece 50 can provide enough supporting force to drive the second engaging piece 51 to rotate in the direction opposite to the direction of the arrow shown in fig. 11, and the first engaging piece 50 and the second engaging piece 51 cannot slide.

As shown in fig. 7, the trigger assembly 5 further includes a first baffle 56 and a second baffle 57, the first baffle 56 is sleeved on the output rod 4, and the first baffle 56 is located between the second engaging member 51 and the elastic member 53. The second shutter 57 is fixed to the output rod 4, and the other end of the elastic member 53 abuts against the second shutter 57.

Wherein the elastic member 53 may be a coil spring, and the first shutter 56 may slide on the output rod 4.

In this embodiment, the first baffle 56 can increase the force application area of the second engaging member 51 to the elastic member 53, so that the second engaging member 51 compresses the elastic member 53.

A pin shaft can be arranged on the output rod 4 below the second baffle 57 in a penetrating manner, and the pin shaft can prevent the second baffle 57 from moving on the output rod 4 along the direction close to the object 1 to be positioned.

As shown in fig. 2, the axial positioning device provided in this embodiment may further include a gear 8, the second driving member 3 is mounted on the movable bracket 7, and the output shaft of the second driving member 3 passes through the movable bracket 7 and is connected to the gear 8. As shown in fig. 8 and 9, gear teeth are provided on the other end of the first engaging member 50, and the gear 8 is engaged with the gear teeth on the first engaging member 50.

The gear 8 is used for driving the first engaging member 50 to rotate, so that the mounting position of the second driving member 3 can be more flexible.

As shown in fig. 13, the axial positioning device provided in this embodiment may further include a fixed bracket 9, the first driving member 2 is mounted on the movable bracket 7, and the output shaft of the first driving member 2 is connected to the fixed bracket 9. The fixed bracket 9 is provided with a hole, and the other end of the output rod 4 passes through the hole on the fixed bracket 9 and is exposed out of the fixed bracket 9.

As shown in fig. 13, the axial positioning device provided in this embodiment further includes a guiding element 90, the guiding element 90 includes two ends, and one end of the guiding element 90 is fixed on the fixing bracket 9. The other end of the guide 90 passes through the movable bracket 7 and is exposed out of the movable bracket 7, and the movable bracket 7 can move on the guide 90 by the driving of the first driving member 2.

The number of the guide members 90 may be three, and the connecting line between the three guide members 90 is triangular, so that the guide members 90 can make the process of the first driving member 2 driving the movable bracket 7 to move more stable.

Further, as shown in fig. 13, the guide 90 may be rod-shaped, and a spring 91 is sleeved on the guide 90, and the spring 91 is located between the fixed bracket 9 and the movable bracket 7.

The spring 91 on the guide 90 can provide a preload to the first driving member 2 to ensure that the load of the first driving member 2 is unidirectional during the movement, so as to prevent the return clearance generated inside the first driving member 2 from affecting the movement accuracy of the output rod 4.

As shown in fig. 1, in the present embodiment, preferably, the length of the fixing structure may be smaller than the depth of the thread groove 10 on the object 1 to be positioned, and an abutting portion 40 is disposed on one end of the fixing structure away from the object 1 to be positioned.

The fixing structure may be an external thread provided on the output rod 4, and the output rod 4 may be a round rod. The diameter of the threaded section on the output rod 4 may be smaller than the diameter of the unthreaded section, in which case the abutment 40 is the portion of the unthreaded section that protrudes above the threaded section.

Example two:

the axial positioning device provided by the present embodiment also includes a first driver 2, a second driver 3 and an output rod 4. The first driving piece 2 is connected with the output rod 4, and the first driving piece 2 is used for driving the output rod 4 to move along the axial direction of the output rod 4 so as to enable the output rod 4 to approach or separate from the object 1 to be positioned. The second driving piece 3 is connected with an output rod 4, and the end part of the output rod 4 is provided with a fixed structure which is fixedly connected with the object 1 to be positioned; the second driving piece 3 is used for driving the output rod 4 to rotate, the fixing structure can be abutted against the object 1 to be positioned in the axial direction of the output rod 4 in the rotating process of the output rod 4, and the fixing structure is used for fixing the output rod 4 and the object 1 to be positioned.

Unlike the first embodiment, as shown in fig. 14 to 16, the fixing structure in the present embodiment is a protrusion, the fixing structure can extend into a cylindrical groove on the object 1 to be positioned and abut against the protruding strip 11 on the sidewall of the cylindrical groove when the output rod 4 rotates, and the distance between one end of the output rod 4 close to the protrusion and the protrusion is equal to the distance between the protruding strip 11 and the bottom of the cylindrical groove.

The convex strip 11 in the cylindrical groove on the object 1 to be positioned is arc-shaped, and the arc-shaped convex strip 11 is arranged on the inner side wall of the cylindrical groove along the circumferential direction of the cylindrical groove. Further, the fixing structure may be a block-shaped protrusion.

When output rod 4 stretches into the columnar groove, fixed knot on output rod 4 constructs with the columnar groove in not being provided with the position of sand grip 11 relatively, and fixed knot constructs can not receive the hindrance of sand grip 11, can cross sand grip 11 and continue to stretch into the columnar groove, because the interval between output rod 4's the bellied one end of being close to and the arch equals the interval between sand grip 11 to the tank bottom in columnar groove this moment, output rod 4's the bellied one end of being close to can the butt on the tank bottom in columnar groove. After the second driving piece 3 drives the output rod 4 to rotate, the fixing structure on the output rod 4 can be opposite to the position of the convex strip 11, when the output rod 4 is moved in the direction away from the object 1 to be positioned, the fixing structure can abut against the convex strip 11, then the output rod 4 can be prevented from being separated from a cylindrical groove, the output rod 4 is connected with and fixed to the object 1 to be positioned at the moment, and a large gap cannot exist when the object 1 to be positioned returns.

When needing to make between output rod 4 and the object 1 of awaiting the location unblock, can make first driving piece 2 antiport, and then can make fixed knot construct with 11 position interlocks of sand grip and no longer mutual butt, restart second driving piece 3 antiport, and then can make between output rod 4 and the object 1 of awaiting the location separation.

The remaining features of the axial positioning device provided in this embodiment are the same as those of the axial positioning device provided in the first embodiment, and are not described herein again.

It can be seen that the axial positioning device provided in this embodiment and the axial positioning device in the first embodiment also include the first driving element 2, the second driving element 3 and the output rod 4, the output rod 4 is also provided with the fixing structure, and the fixing structure has the same function, so that the axial positioning device provided in this embodiment and the axial positioning device in the first embodiment can solve the same technical problem, and achieve the same technical effect.

Example three:

the micro syringe pump provided by the present embodiment includes the axial positioning device of the first embodiment, or includes the axial positioning device of the second embodiment. Therefore, the micro-syringe pump provided in the present embodiment and the axial positioning device in the first embodiment can solve the same technical problems and achieve the same technical effects.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims (13)

1. An axial positioning device is characterized by comprising a first driving piece, a second driving piece and an output rod;

the first driving piece is connected with the output rod and used for driving the output rod to move along the axial direction of the output rod so as to enable the output rod to approach or separate from an object to be positioned;

the second driving piece is connected with the output rod, and the end part of the output rod is provided with a fixing structure which is fixedly connected with an object to be positioned; the second driving piece is used for driving the output rod to rotate, the fixing structure can be abutted against an object to be positioned in the axial direction of the output rod in the rotating process of the output rod, and the fixing structure is used for fixing the output rod and the object to be positioned.

2. The axial positioning device of claim 1, wherein the securing structure is either male or female.

3. The axial positioning device of claim 2, further comprising a trigger assembly and a switch;

the output rod and the switch are both connected with the trigger assembly, and the switch is connected with the second driving piece; the trigger assembly is used for opening the switch when the fixed structure is locked with an object to be positioned.

4. The axial positioning device of claim 3, further comprising a movable bracket, wherein the trigger assembly comprises a first engagement member, a second engagement member, a synchronizing member, and an elastic member;

a bearing is arranged at one end of the output rod, which is far away from the fixed structure, and the output rod is connected with the movable support through the bearing;

the first meshing part and the second meshing part are sleeved on the output rod, and the first meshing part is connected with the output shaft of the second driving part;

the first meshing part and the second meshing part both comprise two ends, a plurality of convex teeth which are circularly arranged are arranged at one end of the first meshing part and one end of the second meshing part, and the convex teeth on the second meshing part are meshed with the convex teeth on the first meshing part;

a groove is formed in one end, away from the convex teeth, of the second meshing part, and the depth direction of the groove is parallel to the axial direction of the output rod; the synchronous piece penetrates through the output rod along the direction perpendicular to the axial direction of the output rod and is positioned in the groove;

the elastic piece comprises two ends, the elastic piece is sleeved on the output rod, one end of the elastic piece is connected with the second meshing piece, and the other end of the elastic piece is fixed on the output rod;

the switch is installed on the movable support, a trigger lever is arranged on the switch, and the second meshing part is abutted to the trigger lever on the switch.

5. The axial positioning device of claim 4, wherein the synchronizing member is cylindrical, and the sum of the pitch between the crest and the root of the teeth of the second engaging member and the radius of the synchronizing member is less than or equal to the depth of the groove of the second engaging member.

6. The axial positioning device of claim 4, wherein the teeth on the second engagement member comprise a first inclined surface and a second inclined surface with abutting top ends, and the abutting top ends of the first inclined surface and the second inclined surface are the top of the teeth on the second engagement member;

when the output rod is close to an object to be positioned, the first inclined surface can support the convex teeth of the first meshing part; the minimum included angle between the first inclined surface and the horizontal plane is smaller than or equal to the minimum included angle between the second inclined surface and the horizontal plane.

7. The axial positioning device of claim 4, wherein the trigger assembly further comprises a first baffle plate and a second baffle plate, the first baffle plate is sleeved on the output rod, and the first baffle plate is located between the second engaging member and the elastic member;

the second baffle is fixed on the output rod, and the other end of the elastic piece is abutted against the second baffle.

8. The axial positioning device of claim 4, further comprising a gear; the second driving piece is arranged on the movable support, and an output shaft of the second driving piece penetrates through the movable support to be connected with the gear;

gear teeth are arranged at the other end of the first meshing component, and the gear is meshed with the gear teeth on the first meshing component.

9. The axial positioning device as recited in claim 4, further comprising a fixed bracket, wherein the first driving member is mounted on the movable bracket, and an output shaft of the first driving member is connected with the fixed bracket;

the fixed support is provided with a hole, and the other end of the output rod penetrates through the hole in the fixed support and is exposed outside the fixed support.

10. The axial positioning device of claim 9, further comprising a guide member, the guide member including two ends, one of the ends of the guide member being secured to the fixed bracket; the other end of the guide piece penetrates through the movable support and is exposed out of the movable support, and the movable support can move on the guide piece under the driving of the first driving piece.

11. The axial positioning device as claimed in any one of claims 2 to 10, wherein the length of the fixing structure is smaller than the depth of the threaded groove on the object to be positioned, and an abutment portion is provided on an end of the fixing structure remote from the object to be positioned.

12. The axial positioning device of claim 1, wherein the fixing structure is a protrusion, and the fixing structure can extend into a cylindrical groove on the object to be positioned and abut against a protruding strip on the side wall of the cylindrical groove when the output rod rotates;

the distance between one end of the output rod close to the protrusion and the protrusion is equal to the distance between the convex strip and the bottom of the cylindrical groove.

13. A micro syringe pump having an axial positioning device as claimed in any one of claims 1 to 12 disposed therein.

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