Plunger device for liquid transfer pump
Technical Field
The utility model relates to a ration moves the liquid field, especially relates to a plunger device for moving liquid pump.
Background
With the rapid development of science and technology, the liquid transfer work of laboratories such as biology, chemistry, environment, medicine research and development, food and the like, and units such as hospitals, disease control, blood stations and the like is becoming routine, and in the face of more complicated research objects and increasing sample quantity, an automatic liquid transfer system (or a liquid transfer workstation) in the market becomes increasingly popular, wherein a plunger liquid transfer pump is a basic component of the liquid transfer workstation.
The plunger liquid-transfering pump in the prior art has the following problems in use: 1. the air leakage is caused by expansion and contraction caused by the movement of the piston, so that the liquid transfer is inaccurate; 2. the piston moves for a long time, causing wear of the seals and thus inaccurate pipetting.
SUMMERY OF THE UTILITY MODEL
To the above problem, the utility model provides a plunger device for move liquid pump, this plunger device has solved the gas tightness problem among the prior art.
In order to achieve the above object, the utility model provides a plunger device for liquid-transfering pump, include: the suction head adapter comprises a piston cylinder body, a piston assembly and a suction head adapter, wherein a piston channel is formed on the inner wall of the piston cylinder body, the piston assembly is slidably mounted in the piston cylinder body, and the piston cylinder body is connected with the suction head adapter; the piston assembly comprises a piston rod and a piston head assembly, the piston head assembly is mounted at the end of the piston rod, and the suction head adapter is used for being connected with a suction head;
the piston head assembly includes a piston head and a piston head seal that is compression fit between the piston head and the piston rod, the piston head seal imparting a tendency for the piston head to expand radially toward the piston rod.
In the prior art, the reciprocating time of the piston head in the piston cavity is too long, heat is generated, expansion with heat and contraction with cold are caused, meanwhile, the conventional piston cylinder body and the piston head are made of different materials, so that the specific heat capacity is different, and a gap is generated between the piston head and a piston channel after expansion with heat and contraction with cold, and air leakage is caused; meanwhile, long-term reciprocating motion causes surface abrasion of the piston head and inner wall abrasion of the piston cylinder body, and can also cause a gap between the piston head and the piston channel, thereby causing air leakage. Therefore, the inventor adopts the design, the piston head sealing ring is added between the piston head and the piston rod, the piston head is expanded outwards from the inside, and the effect of tensioning the piston head and the piston channel is further achieved.
In one embodiment, the number of piston head sealing rings is at least 2.
With the above design, the piston head can be expanded outward symmetrically. In one embodiment, 2 piston head sealing rings are arranged along the axial direction of the piston rod in sequence.
Adopt above-mentioned design, can effectively make the piston head outwards expand, make the surface of piston head and the inner wall laminating of piston cylinder body.
In one embodiment, a piston head sealing groove is formed in the end portion of the piston rod, the piston head sealing groove is arranged around the piston rod, and the piston head sealing ring is installed in the piston head sealing groove.
By adopting the design, a proper installation position can be reserved for the piston head sealing ring at the end part of the piston rod.
In one embodiment, the piston head sealing groove is annular, and the piston rod is axially perpendicular to an annular plane of the piston head sealing groove.
In one embodiment, the piston head is trapezoidal in cross-section and faces the suction head adapter with a smaller end face.
In one embodiment, a mounting groove for mounting the piston rod is formed in the piston head, the inner diameter of an opening end of the mounting groove is larger than the inner diameter of a closed end of the mounting groove, and the closed end of the mounting groove is in interference fit with the piston rod.
By adopting the design, the position of the piston head, which is contacted with the piston head sealing ring, namely the opening end of the mounting groove, is thinner than the closed end of the mounting groove, so that the piston head sealing ring can effectively expand the piston head outwards, and the piston head is not expanded outwards because the opening end of the mounting groove is too thick; meanwhile, the interference fit enables the piston rod and the piston head to be tightly connected, and the piston rod and the piston head cannot be separated in the reciprocating motion process.
In one embodiment, the mounting position of the piston head sealing ring corresponds to the open end of the mounting groove.
By adopting the design, one side of the piston head opposite to the closed end of the mounting groove can be effectively expanded outwards, and the air tightness is realized while the piston head assembly is ensured to smoothly move in a reciprocating manner.
Compared with the prior art, the utility model discloses following beneficial effect has:
the utility model discloses a plunger device for pipetting pump, this plunger device have solved the gas tightness problem among the prior art.
Drawings
FIG. 1 is a schematic view showing the construction of a piston assembly, an elastic member, and a suction head driving rod according to an embodiment;
the device comprises a piston cylinder body 1, a piston rod 21, a piston head sealing groove 211, a piston head 221, a mounting groove 2211 and a piston head sealing ring 222, wherein the piston cylinder body 21 is a piston rod.
Detailed Description
In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "coupled" to another element, it can be directly coupled to the other element or intervening elements may also be present.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
The source is as follows:
reagents, materials and equipment used in the present example are all commercially available sources unless otherwise specified; unless otherwise specified, all the experimental methods are routine in the field.
Examples
A plunger device for a pipette pump.
The plunger device comprises a piston cylinder body 1, a piston assembly and a suction head adapter, wherein a piston channel is formed on the inner wall of the piston cylinder body 1, the piston assembly is slidably mounted in the piston cylinder body 1, the piston cylinder body 1 is connected with the suction head adapter, and the suction head adapter is used for being connected with a suction head.
The piston assembly comprises a piston rod 21 and a piston head assembly, the piston head assembly is installed at the end of the piston rod 21 and comprises a piston head 221 and a piston head sealing ring 222, the section of the piston head 221 is trapezoidal, and a smaller end face faces the direction of the suction head adapter, a mounting groove 2211 for installing the piston rod 21 is formed in the piston head 221, the inner diameter of the opening end of the mounting groove 2211 is larger than that of the closed end of the mounting groove 2211, the closed end of the mounting groove 2211 is in interference fit with the piston rod 21, the piston head sealing ring 222 is installed between the piston and the piston rod 21 in an extrusion mode, the installation position of the piston head sealing ring 222 corresponds to the opening end of the mounting groove 2211, the number of the piston head sealing ring is not less than 2, the piston head sealing ring is axially arranged along the piston rod 21, the piston head 221 has a tendency of radial expansion towards the piston rod 21, a piston head sealing groove 211 surrounding the end of the piston rod 21 is formed in the piston head sealing groove 222, the piston head sealing groove 211 is in an annular shape, and the piston rod 21 is axially perpendicular to the annular plane of the piston head sealing groove 211; in this embodiment, the number of the piston head sealing rings 222 is 4, 4 piston head sealing rings 222 are sequentially and axially arranged along the piston rod 21, and the piston head sealing rings 222 are arranged at the opening end of the installation groove 2211.
The piston head sealing ring 222 is added between the piston head 221 and the piston rod 21 of the plunger device, the opening end of the mounting groove 2211 of the piston head 221 is expanded outwards from the inside, the closed end of the mounting groove 2211 is in interference fit with the piston rod 21, and the effect of tensioning the piston head 221 and the piston channel is further achieved.
All possible combinations of the technical features of the above embodiments may not be described for the sake of brevity, but should be considered as within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.