WO2019179199A1

WO2019179199A1 - Elastic piston connecting structure, and high-pressure pumping system and method

Info

Publication number: WO2019179199A1
Application number: PCT/CN2018/125089
Authority: WO
Inventors: 罗凤玲
Original assignee: 惠州海卓科赛医疗有限公司
Priority date: 2018-02-12
Filing date: 2018-12-28
Publication date: 2019-09-26
Also published as: CN108591047A

Abstract

An elastic piston connecting structure, comprising an elastic piston body (10) which is received in the wall of a piston cavity, and a connecting component (20) fixedly connected to a push rod. The end wall at the rear side of the piston body (10) is sunken inwards to form a blind hole (11). The connecting component (20) is provided with a connecting rod (21) embedded into the blind hole, and the periphery of the connecting rod (21) is provided with a flange (22) which protrudes outwards in the radial direction. The outer diameter of the flange (22) is greater than the inner diameter of the blind hole (11). The flange (22) is snap-fitted into the blind hole (11) to form an inverted-snap fit structure, so that the connecting component (20) and the piston body (10) are stably connected, and connecting and assembly are easy and efficient. Also provided are a high-pressure pumping system having the elastic piston connecting structure, and a high-pressure pumping method.

Description

Elastic piston connecting structure, high pressure pumping system and method

Technical field

The invention relates to the technical field of medical instruments, in particular to an elastic piston connecting structure, a high pressure pumping system and a method.

Background technique

In prior art medical high pressure pumping systems, the piston is typically a cylindrical piston that is received and slidably coupled in the wall of the piston chamber, the piston reciprocating to provide power to pump fluid into and out of the pump chamber. The piston reciprocates by the push-pull movement of the push rod. The piston acts as a flexible member, and is connected with the push rod through a rigid connecting member. In the prior art, the common connection between the flexible member and the rigid member is mainly a screw connection. Bonding, welding, welding, and interference fit connections, etc., all of the above connection methods have the problems of complicated assembly and connection, and need to assist in the use of specific tools.

Summary of the invention

The technical problem to be solved by the present invention is to provide an elastic piston connecting structure with simple structure and convenient assembly, a high-pressure pumping system having the elastic piston connecting structure, and a high-pressure pumping method for fluid pumping by a high-pressure pumping system.

The technical solution adopted to solve the above technical problem: an elastic piston connecting structure comprising an elastic piston body received in a wall of a piston chamber and a connecting member fixedly connected with the push rod, a rear side wall of the piston body The recesses form a blind bore, the connecting member has a connecting rod embedded in the blind bore, the outer edge of the connecting rod has a radially outwardly convex flange, the outer diameter of the flange being larger than the inner diameter of the blind bore.

Preferably, the flange has a triangular or quadrangular cross-sectional shape.

Preferably, the bottom end surface in the blind hole is a plane, and the contact end surface of the connecting rod end and the bottom end surface is a plane.

Preferably, an annular groove is provided on the side wall of the blind hole.

Preferably, an annular groove is provided at the bottom of the side wall of the blind hole.

Preferably, the flange is mated to the annular groove.

Preferably, the front side and the rear side of the circumferential side wall of the piston body respectively form a front side inclined wall and a rear side inclined wall to constitute a recessed area at a central portion of the circumferential side wall of the piston body.

A technical solution adopted to solve the above technical problem: a high pressure pumping system comprising the above-described elastic piston connecting structure.

A technical solution adopted to solve the above technical problem: a high-pressure pumping method, wherein a fluid pumping method is performed by the pumping system, and a contact end surface of the connecting rod end contacts a bottom end surface of a blind hole of the piston body To push the piston body forward; the flange of the end of the connecting rod is inverted on the inner wall of the blind hole to pull the piston body to move backward.

Preferably, when the piston body moves forward, the contact end surface of the connecting rod end and the bottom end surface of the blind hole of the piston body is subjected to a pressure of 400 MPa or less; when the piston body moves backward, the end of the connecting rod The flange is inverted on the inner wall of the blind hole to pull the piston body to move, so that the degree of vacuum generated in the piston cavity is 0 to -0.1 MPa.

[Advantageous effect] In the elastic piston connecting structure, the outer diameter of the flange of the connecting rod end portion is larger than the inner diameter of the blind hole of the piston body, so that the flange buckle is buckled in the blind hole and the inner wall of the blind hole is pressed and deformed to form an inverted structure. Thereby, the connecting rod and the piston body form a limiting structure in the axial direction and the radial direction, so that a stable connection is formed between the connecting member and the piston body, so that the connecting rod and the piston body are prevented from falling off during the movement of the piston, and the The connection assembly is simple and efficient; Moreover, the possibility of contaminants generated by the conventional connection method due to bonding, welding, welding and the like is effectively avoided, and the use risk of the medical device is reduced.

DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings and embodiments;

1 is a schematic structural view of an embodiment of the present invention;

2 is a partial cross-sectional structural view of an embodiment of the present invention.

detailed description

1 and 2, the elastic piston connecting structure of the present invention comprises a piston body 10 elastically received in a wall of a piston chamber and a connecting member 20 connected to a rear end portion of the piston body 10, wherein the connecting member 20 is connected to the push rod The push rod reciprocates, thereby driving the piston body 10 to reciprocate.

The rear end wall of the piston body 10 is concavely formed with a blind hole 11 having a cylindrical shape. The end of the connecting member 20 is axially extended to form a connecting rod 21, and the connecting rod 21 is also cylindrical, and the diameter of the connecting rod 21 is Slightly greater than or equal to the diameter of the blind hole 11, the connecting rod 21 is embedded in the blind hole 11, and the outer edge of the end of the connecting rod 21 extends radially outward to form a flange 22, and the diameter of the flange 22 is larger than the preferred size of the blind hole 11. The ground diameter is buckled in the blind hole 11 by the flange 22 and the inner wall of the blind hole 11 is pressed and deformed to form an inverted structure, so that a stable connection is formed between the connecting member 20 and the piston body 10. Preferably, the blind hole 11 is provided with an annular groove 12 for fitting the flange 22. The cross-sectional shape of the flange 22 can be designed as a triangle, a quadrangle or the like, and accordingly, the shape of the annular groove 12 is also adaptively adjusted. Of course, the blind hole 11 can also be a smooth, straight cylindrical channel, ie without an annular groove 12.

The bottom end surface of the blind hole 11 is a flat surface. Correspondingly, the contact end surface of the end portion of the connecting rod 21 and the bottom end surface is also a flat surface. The piston body 10 is driven to move back and forth in the piston chamber wall by the connecting rod 21. The contact end surface of the end of the connecting rod 21 is in contact with the bottom end surface of the blind hole 11 of the piston body 10 to push the piston body forward, preferably, the connection. The contact end surface of the end of the rod 21 is subjected to a pressure of 400 MPa or less; the flange 22 at the end of the connecting rod 21 is moved backward by the inverted structure fitting to pull the piston body 10, preferably, when the piston body 10 moves backward, the piston chamber The degree of vacuum generated is from 0 to -0.1 MPa.

Preferably, the front side and the rear side of the circumferential side wall of the piston body 10 respectively form a front side inclined wall 13 and a rear side inclined wall 14, which are disposed on the circumferential side of the piston body due to the arrangement of the front side inclined wall 13 and the rear side inclined wall 14. The central portion of the wall will form a recessed region 15, and when the piston body 10 is received in the wall of the piston chamber, the central portion of the piston body 10 is not in contact with the wall of the piston chamber, wherein the maximum diameter of the front oblique wall 13 is larger than the diameter of the piston chamber wall. The maximum diameter refers to the diameter of the end portion of the front inclined wall 13 toward the front side of the piston body, so that the piston body is received in the wall of the piston chamber, and the front inclined wall 13 can form an elastic abutting contact with the wall surface of the piston chamber wall. The end portion of the side inclined wall 14 protrudes outwardly and has a protrusion 16 having a maximum diameter larger than a diameter of the piston chamber wall, so that the piston body is received in the piston chamber wall, and the protrusion 16 on the rear side inclined wall 14 can Forming an elastic abutting contact with the wall surface of the piston chamber wall.

Due to the presence of the recessed portion 15, the rear side portion of the piston body 10 has a large amount of elastic deformation in the radial direction. When the connecting rod 21 is fitted into the blind hole 11 of the piston body 10, the energy of the rear side portion of the piston body 10 is A slight deformation is locally generated outward so that the flange 22 at the end of the connecting rod 21 can be inserted into the annular groove 12 of the blind hole 11 very smoothly and quickly; when the piston body 10 is elastically received in the wall of the piston chamber, The protrusion 16 of the rear inclined wall 14 is in elastic contact with the piston chamber wall, so that the rear side portion of the piston body 10 is deformed radially inwardly, thereby clamping and holding the connecting rod 21, so that the piston body 10 and the connecting member 20 is more tightly connected to form an integral body.

The high pressure pumping system of the present invention comprises the above described elastic piston connection structure.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments, and can be made without departing from the spirit of the invention within the scope of the knowledge of those skilled in the art. Various changes.

Claims

An elastic piston connecting structure, comprising: an elastic piston body received in a wall of a piston chamber and a connecting member fixedly connected with the push rod, wherein a rear side wall of the piston body is concavely formed with a blind hole, The connecting member has a connecting rod embedded in the blind hole, the outer edge of the connecting rod has a radially outwardly convex flange, the outer diameter of the flange being larger than the inner diameter of the blind hole.
The elastic piston joint structure according to claim 1, wherein the flange has a triangular or quadrangular sectional shape.
The elastic piston connecting structure according to claim 1, wherein a bottom end surface of the blind hole is a flat surface, and a contact end surface of the connecting rod end portion and the bottom end surface is a flat surface.
The elastic piston connecting structure according to claim 1, wherein an annular groove is provided on a side wall of the blind hole.
The elastic piston connecting structure according to claim 4, wherein an annular groove is provided at a bottom of the side wall of the blind hole.
The elastic piston connecting structure according to claim 4 or 5, wherein the flange is fitted to the annular groove.
The elastic piston connecting structure according to claim 1, wherein a front side wall and a rear side of the circumferential side wall of the piston body respectively form a front side inclined wall and a rear side inclined wall to be in the middle of the circumferential side wall of the piston body. The area forms a recessed area.
A high pressure pumping system comprising the resilient piston connection structure of any of claims 1-7.
A high-pressure pumping method, characterized in that, by the pumping system of claim 8, the contact end surface of the connecting rod end contacts the bottom end surface of the blind hole of the piston body to push the piston The body moves forward; the flange of the end of the connecting rod is inverted on the inner wall of the blind hole to pull the piston body to move backward.
The high-pressure pumping method according to claim 9, wherein when the piston body moves forward, the contact end surface of the end portion of the connecting rod and the bottom end surface of the blind hole of the piston body is subjected to a pressure of 400 MPa or less; When the body moves backward, the flange of the end of the connecting rod is inverted on the inner wall of the blind hole to pull the piston body to move, so that the degree of vacuum generated in the piston cavity is 0 to -0.1 MPa.