CN211132487U

CN211132487U - Low-resistance syringe with variable sealing degree

Info

Publication number: CN211132487U
Application number: CN201921988696.8U
Authority: CN
Inventors: 何杰; 陈乾龙; 文赵飞; 韩伟强
Original assignee: Zhejiang Runqiang Medical Instruments Co ltd
Current assignee: Zhejiang Runqiang Medical Instruments Co ltd
Priority date: 2019-11-18
Filing date: 2019-11-18
Publication date: 2020-07-31
Anticipated expiration: 2029-11-18

Abstract

The utility model relates to a low-resistance syringe with variable sealing degree, which comprises a needle cylinder and a piston rod, wherein a piston assembly is arranged in the needle cylinder, the piston assembly comprises a piston head and a piston core, the piston core is in linkage fit with the piston rod, sealing ribs are circumferentially arranged on the outer wall of the piston head, an annular neck is circumferentially formed on the cavity wall of a piston inner hole, an annular groove matched with the annular neck is circumferentially formed on the piston core, the annular neck is embedded in the annular groove, a gap exists between the annular neck and the annular groove, the piston head and the piston core are matched, and because of the existence of the gap between the annular neck and the annular groove, when in an initial position, the piston head and the inner wall of the needle cylinder are not tightly attached, so that the push-pull is easy, and when in the push-pull, because of the wedge surface fit between the annular neck and the annular groove, thereby make annular rib and cylinder inner wall closely laminate, guarantee the reliability of sealed.

Description

Low-resistance syringe with variable sealing degree

Technical Field

The utility model belongs to the field of medical equipment, concretely relates to changeable low resistance syringe of leakproofness.

Background

In order to ensure sealing of the existing injector, two sealing ribs are arranged in the circumferential direction of a piston, and the sealing ribs and the inner wall of a needle cylinder have large frictional resistance, so that an operator needs to push the piston with large force, and in order to reduce the frictional force between the piston and the inner wall of the needle cylinder, the sealing ribs with deformation are adopted at present, although the resistance between the sealing ribs and the piston is reduced, the sealing contact surface between the sealing ribs and the piston is small in area, so that when a sealing ring deforms, the sealing cannot be guaranteed, and the sealing reliability is reduced.

SUMMERY OF THE UTILITY MODEL

To the deficiency that prior art exists, the utility model aims to provide a changeable low resistance syringe of leakproofness.

In order to achieve the above purpose, the utility model provides a following technical scheme: the utility model provides a changeable low resistance syringe of degree of tightness, it includes cylinder and piston rod, be equipped with piston assembly in the cylinder, piston assembly establishes including piston head and the cover that has the piston hole piston core in the piston hole, piston core and piston rod linkage cooperation, piston head outer wall circumference is equipped with sealing rib, circumference forms annular neck on the chamber wall of piston hole, the circumference of piston core forms the annular groove with annular neck looks adaptation, the annular neck inlays to be established in the annular groove, and there is the clearance between the two, during initial state, constitute clearance fit between sealing rib and the cylinder inner wall, during operating condition, sealing rib forms sealedly with the cylinder inner wall under the piston core action drives, and the degree of tightness is decided by thrust.

The gap is between 0.1 and 0.3 mm.

The upper side and the lower side of the annular neck are both inclined planes.

The bottom end of the piston core is sunken to form a fixing cavity for connecting a piston rod.

The top end of the piston rod is provided with a connector, and the connector is sleeved in the fixed cavity of the piston core.

The piston core is provided with an upper shoulder, the piston head is correspondingly provided with a lower shoulder, the lower shoulder is positioned at the lower side of the upper shoulder, and a gap exists between the upper shoulder and the lower shoulder.

The top of the piston head forms a sealing surface having a curvature.

The position of the sealing rib is located outside the annular neck.

The utility model has the advantages that: utilize the cooperation of piston head and piston core, because the existence in clearance between annular neck and the annular groove, thereby when initial position, closely laminate not between piston head and the cylinder inner wall, lead to the resistance between piston and the cylinder lower, it is comparatively laborsaving when the push-and-pull piston rod, and when the push-and-pull, because the scarf cooperation between annular neck and the annular groove, thereby can make the push-and-pull in-process, annular groove extrusion annular neck, thereby make annular rib closely laminate with the cylinder inner wall, guarantee sealed reliability.

Drawings

Fig. 1 is a cross-sectional view of embodiment 1 of a piston assembly of the present invention.

Fig. 2 is a schematic sectional view of a piston head according to embodiment 1.

Fig. 3 is a schematic sectional view of a piston core according to embodiment 1.

Fig. 4 is a cross-sectional view of embodiment 2 of the piston assembly.

Fig. 5 is a schematic sectional view of a piston head according to embodiment 2.

Fig. 6 is a schematic cross-sectional view of a syringe.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In the present application, unless expressly stated or limited otherwise, the terms "connected" and "fixed" are to be construed broadly, e.g., "fixed" may be fixedly connected or detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In addition, descriptions in the present application as to "first", "second", and the like are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit to the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

As shown in the figure, the utility model provides a changeable low resistance syringe of leakproofness, it includes cylinder 3 and piston rod 4, be equipped with piston assembly in the cylinder, it establishes including piston head 1 and the cover that has the piston hole piston core 2 in the piston hole 15, piston rod and piston core linkage cooperation, piston head outer wall circumference is equipped with sealing rib 12, circumference forms annular neck 13 on the chamber wall of piston hole, the circumference of piston core forms the annular groove with annular neck looks adaptation, the annular neck inlays to be established in the annular groove 21, and there is the clearance between the two.

In the initial state, the sealing ribs and the inner wall of the needle cylinder form clearance fit, in the working state, the sealing ribs and the inner wall of the needle cylinder form sealing under the driving of the action of the piston core, and the sealing degree is determined by thrust.

Due to clearance fit in the initial state, the piston and the needle cylinder have low resistance, so that labor is saved when the piston rod is pushed and pulled.

The annular groove is provided with a conical concave peripheral surface, and the concave conical angle of the annular groove is 140 degrees. And the upper and lower both sides of annular neck are the inclined plane, and inlay and establish in this annular groove 21 to make piston core and piston head realize linkage fit, and the piston core adopts the plastics that have certain hardness, and the piston head adopts the rubber spare, consequently there is the condition of pressure in the cylinder inside, when the push-and-pull piston core, this piston core can be with the force on the annular neck of piston head, thereby make the piston head extrude to the outside, improve the sealing performance between sealing rib and the cylinder inner wall, thrust is big more, sealing performance is better.

The gap is between 0.1mm and 0.3mm, preferably 0.1mm, so that the rubber can freely change in size, and the pushing and pulling of the rubber are labor-saving in the absence of pressure.

The bottom end of the piston core is recessed to form a fixed cavity 22 for connection to the piston rod, and an inner shoulder 23 is formed at the entrance of the fixed cavity to prevent the piston rod from coming out when inserted into the fixed cavity.

The piston core is provided with an upper shoulder 24, the piston head is correspondingly provided with a lower shoulder 14, the lower shoulder is positioned at the lower side of the upper shoulder, a gap exists between the upper shoulder and the lower shoulder, and the linkage reliability between the piston core and the piston head can be ensured due to the cooperation between the upper shoulder and the lower shoulder.

The top of the piston head forms a sealing surface 11 having a curvature.

Example 1 discloses a seal face with a sharp tip, while example 2 discloses a seal face with a rounded arc.

The position of the sealing rib is positioned on the outer side of the annular neck, and the sealing rib directly acts on the sealing rib by utilizing the action of the annular neck, so that the sealing reliability between the sealing rib and the inner wall of the needle cylinder is ensured.

The piston assembly is slidably and sealingly connected within the barrel, and a forward chamber is formed within the barrel at the forward end of the piston assembly and a rearward chamber is formed within the barrel at the rearward end of the piston assembly.

The examples should not be construed as limiting the present invention, but any modifications made based on the spirit of the present invention should be within the scope of the present invention.

Claims

1. The utility model provides a changeable low resistance syringe of leakproofness, its includes cylinder and piston rod, be equipped with piston assembly in the cylinder, its characterized in that: piston assembly establishes including piston head and the cover that has the piston hole piston core in the piston hole, piston core and piston rod linkage cooperation, piston head outer wall circumference is equipped with sealed rib, circumference forms annular neck on the chamber wall of piston hole, the circumference of piston core forms the annular groove with annular neck looks adaptation, the annular neck inlays to be established in the annular groove, and there is the clearance between the two, during initial state, constitute clearance fit between sealed rib and the cylinder inner wall, during operating condition, sealed rib is sealed with the cylinder inner wall formation under the piston core action drives, and the degree of sealing is decided by thrust.

2. A variable seal low drag syringe of claim 1 wherein: the gap is between 0.1 and 0.3 mm.

3. A variable seal low drag syringe of claim 1 wherein: the upper side and the lower side of the annular neck are both inclined planes.

4. A variable seal low drag syringe of claim 1 wherein: the bottom end of the piston core is sunken to form a fixing cavity for connecting a piston rod.

5. A variable seal low drag syringe of claim 4 wherein: the top end of the piston rod is provided with a connector, and the connector is sleeved in the fixed cavity of the piston core.

6. A variable seal low drag syringe of claim 1 wherein: the piston core is provided with an upper shoulder, the piston head is correspondingly provided with a lower shoulder, the lower shoulder is positioned at the lower side of the upper shoulder, and a gap exists between the upper shoulder and the lower shoulder.

7. A variable seal low drag syringe of claim 1 wherein: the top of the piston head forms a sealing surface having a curvature.

8. A variable seal low drag syringe of claim 1 wherein: the position of the sealing rib is located outside the annular neck.