CN114837911B - Quantitative pump for aseptic filling - Google Patents

Abstract

The present invention discloses a metering pump for aseptic filling, which solves the technical problem in the prior art that the plunger of the metering pump is stuck in the plunger cavity and cannot slide after high-temperature cleaning. The metering pump comprises a pump body and a plunger, wherein the pump body is provided with a plunger cavity, and the plunger is slidably installed in the plunger cavity, and the plunger cavity comprises a positive pressure isolation cavity and a sterilization cavity distributed from top to bottom, and the sterilization cavity and the positive pressure isolation cavity are isolated by an air seal, and the side wall of the sterilization cavity is provided with a sterilizing gas inlet and a sterilizing gas outlet from top to bottom, and the side wall of the positive pressure isolation cavity is provided with a sterile air inlet, and the upper end of the positive pressure isolation cavity is provided with an opening, and the metering pump also includes a cooling cavity surrounding the outside of the positive pressure isolation cavity and used for accommodating a cooling liquid, and the cooling cavity is located between the opening and the sterile air inlet, and the cavity wall of the cooling cavity is connected with a liquid inlet pipe and a liquid outlet pipe.

Description

A quantitative pump for aseptic filling

[Technical field]

The invention relates to a filling device, in particular to a quantitative pump for aseptic filling.

[Background technology]

The existing quantitative pump for filling includes a pump body and a plunger. The pump body is provided with a plunger cavity. The plunger is slidably installed in the plunger cavity. One end of the plunger cavity is provided with an opening. When the plunger moves away from the opening, the material can be sucked into the plunger cavity from the opening. Then the plunger moves toward the opening to push the material in the plunger cavity out for filling. Since the cross-sectional area of the plunger cavity is constant, the movement distance of the plunger can be set to achieve the effect of sucking in quantitative material, thereby realizing quantitative filling.

After the metering pump has been used for a period of time, the plunger cavity needs to be cleaned at high temperature. During the high-temperature cleaning process, the pump body and the plunger will undergo thermal expansion and deformation, that is, the plunger cavity will shrink due to the thermal expansion of the pump body. As a result, the plunger will be stuck in the plunger cavity and unable to slide, thereby affecting the normal use of the metering pump.

[Summary of the invention]

The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a metering pump for aseptic filling, which can not only improve the safety of aseptic filling production and avoid material contamination and deterioration, but also quickly reduce the temperature of the pump body and the plunger before filling so that the plunger and the pump body return to normal, thereby ensuring that the metering pump can be used normally.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

A metering pump for aseptic filling comprises a pump body and a plunger, wherein the pump body is provided with a plunger cavity, the plunger is slidably mounted in the plunger cavity, the plunger cavity comprises a positive pressure isolation cavity and a sterilization cavity distributed from top to bottom, the sterilization cavity and the positive pressure isolation cavity are isolated by an air seal, the side wall of the sterilization cavity is provided with a sterilizing gas inlet and a sterilizing gas outlet from top to bottom, the side wall of the positive pressure isolation cavity is provided with a sterile air inlet, the upper end of the positive pressure isolation cavity is provided with an opening, the metering pump also comprises a cooling cavity surrounding the outside of the positive pressure isolation cavity and used to accommodate a cooling liquid, the cooling cavity is located between the opening and the sterile air inlet, and the cavity wall of the cooling cavity is connected with a liquid inlet pipe and a liquid outlet pipe.

In the above-mentioned metering pump for aseptic filling, the metering pump also includes a cooling jacket sleeved on the outside of the pump body, the cooling cavity is formed between the cooling jacket and the outer peripheral side of the pump body, and the liquid inlet pipe and the liquid outlet pipe are arranged on the cooling jacket.

In the above-mentioned metering pump for aseptic filling, an upper limit step and a lower limit step are provided on the outer peripheral side of the pump body, and the cooling jacket is clamped between the upper limit step and the lower limit step.

In the above-mentioned metering pump for aseptic filling, the upper end of the cooling jacket is welded to the upper limit step, and the lower end of the cooling jacket is welded to the lower limit step.

In the above-mentioned metering pump for aseptic filling, an annular groove is provided on the outer peripheral side of the pump body, and the annular groove cooperates with the cooling jacket to form the cooling cavity, and the outer surface of the cooling jacket is flush with the outer surface of the lower limit step.

In the above-mentioned metering pump for aseptic filling, the cooling jacket comprises a left half jacket and a right half jacket which are independently processed and formed, and the left half jacket and the right half jacket are welded to form the cooling jacket.

In the above-mentioned metering pump for aseptic filling, the liquid inlet pipe is located above the liquid outlet pipe.

In the above-mentioned metering pump for aseptic filling, the pump body includes an upper pump body and a lower pump body, the positive pressure isolation chamber is arranged in the upper pump body, the sterilization chamber is arranged in the lower pump body, the upper pump body is sealed and installed on the top of the fixed plate, the lower pump body is sealed and installed on the bottom of the fixed plate, and the fixed plate is provided with a through hole for the plunger to pass through.

In the above-mentioned metering pump for aseptic filling, the bottom and top of the sterilization chamber are respectively provided with a first through-hole and a second through-hole, the plunger includes a rod portion and a plunger head provided at the upper end of the rod portion, the rod portion passes through the first through-hole and the second through-hole, the plunger head is located in the positive pressure isolation chamber, and the air seal is a pan-seal ring provided between the first through-hole and the rod portion and between the second through-hole and the rod portion.

In the above-mentioned metering pump for aseptic filling, the sterilization chamber is used to contain sterilizing gas, and the sterilizing gas is gasified hydrogen peroxide or high-temperature water vapor.

Beneficial effects of the present invention:

1. When the metering pump for aseptic filling in the present invention is used, sterile air is first continuously introduced into the positive-pressure isolation chamber. Since the plunger is always sealed with the plunger chamber, the sterile air is encapsulated in the space below the plunger in the positive-pressure isolation chamber. As the amount of sterile air increases, the air pressure in the positive-pressure isolation chamber will gradually increase, and then sterilizing gas is continuously introduced into the sterilization chamber through the sterilizing gas inlet, and the air pressure in the positive-pressure isolation chamber is kept greater than the air pressure in the sterilization chamber. At this time, the sterilizing gas in the sterilization chamber cannot penetrate into the positive-pressure isolation chamber under the action of the pressure difference, thereby preventing the sterilizing gas from entering the positive-pressure isolation chamber and destroying the material; the sterilizing gas in the sterilization chamber flows downward under the action of the pressure difference and sterilizes and disinfects the rod portion of the plunger rod located in the sterilization chamber, and then is discharged from the sterilizing gas outlet. By sterilizing and disinfecting the rod portion of the plunger rod in the sterilization chamber, bacteria can be prevented from entering the positive-pressure isolation chamber. The positive pressure isolation chamber is formed by the sterilizing gas, thereby preventing bacteria from contaminating the material. It can be seen that the gas sterilization barrier formed by the sterilizing gas and the positive pressure isolation barrier formed by the sterile air can form a permanent sterile isolation for the plunger cavity above the plunger for holding the material, thereby improving the safety of aseptic filling production and avoiding contamination and deterioration of the material; in addition, the metering pump in the present invention also includes a cooling chamber surrounding the outside of the positive pressure isolation chamber and used to accommodate a coolant, the cooling chamber is located between the open port and the sterile air inlet, and the cavity wall of the cooling chamber is connected with a liquid inlet pipe and a liquid outlet pipe, so that after the high-temperature cleaning is completed, by passing the coolant into the cooling chamber, the pump body and the plunger can be quickly cooled down, so that the pump body and the plunger can be restored to normal before filling, thereby ensuring that the metering pump can be used normally; finally, when filling the material, the material can also be cooled down by the coolant to maintain a certain temperature of the material.

2. The metering pump also includes a cooling jacket sleeved on the outside of the pump body, a cooling cavity is formed between the cooling jacket and the outer peripheral side of the pump body, and a liquid inlet pipe and a liquid outlet pipe are arranged on the cooling jacket. Compared with processing the cooling cavity by one-piece molding, this design can facilitate the processing and molding of the cooling cavity, thereby reducing the processing difficulty and manufacturing cost.

3. The outer circumference of the pump body is provided with an upper limit step and a lower limit step, and the cooling jacket is clamped between the upper limit step and the lower limit step. This design can position the cooling jacket in the up and down directions to facilitate the later fixed connection between the cooling jacket and the pump body.

4. The upper end of the cooling jacket is welded to the upper limit step, and the lower end of the cooling jacket is welded to the lower limit step. This design can not only achieve the respective sealed connection between the two ends of the cooling jacket and the upper limit step and the lower limit step, but also improve the installation reliability of the cooling jacket.

5. An annular groove is provided on the outer circumference of the pump body, and the annular groove cooperates with the cooling sleeve to form a cooling cavity, and the outer surface of the cooling sleeve is flush with the outer surface of the lower limit step. This design can improve the appearance of the quantitative pump.

6. The cooling jacket includes a left half and a right half that are independently processed and formed, and the left half and the right half are welded to form the cooling jacket. This design makes it easy to put the cooling jacket on the outside of the pump body, thereby reducing the difficulty of assembling the cooling jacket.

7. The liquid inlet pipe is located above the liquid outlet pipe. This design allows the coolant to flow smoothly into the liquid outlet pipe, thereby improving the cooling efficiency.

8. The pump body includes an upper pump body and a lower pump body. The positive pressure isolation chamber is arranged in the upper pump body, and the sterilization chamber is arranged in the lower pump body. The upper pump body seal is installed on the top of the fixed plate, and the lower pump body seal is installed on the bottom of the fixed plate. The fixed plate is provided with a through hole for the plunger to pass through. Such a design can not only realize the fixed installation of the quantitative pump on the frame, but also improve the installation stability of the quantitative pump.

9. The bottom and top of the sterilization chamber are respectively provided with a first through hole and a second through hole. The plunger includes a rod and a plunger head provided at the upper end of the rod. The rod passes through the first through hole and the second through hole. The plunger head is located in the positive pressure isolation chamber. The gas seal is a pan-seal ring provided between the first through hole and the rod and between the second through hole and the rod. Such a design can improve the sealing performance and service life of the gas seal, thereby preventing the sterilizing gas from leaking from the first through hole and the second through hole.

These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings.

【Brief Description of the Drawings】

The present invention will be further described below in conjunction with the accompanying drawings:

FIG1 is a cross-sectional view of a metering pump for aseptic filling in a preferred embodiment of the present invention;

FIG2 is a cross-sectional view of a Variseal seal ring in a preferred embodiment of the present invention;

FIG3 is a partial enlarged schematic diagram of A in FIG1 ;

4 is a cross-sectional view of the cooperation between the metering pump for aseptic filling and the filling rotary valve in the preferred embodiment of the present invention.

Description of the drawings:

010, valve body; 011, valve cavity; 0111, feed port; 0112, side discharge port; 0113, bottom discharge port; 020, valve core; 021, valve stem; 022, valve head; 0221, discharge channel; 100, pump body; 110, upper pump body; 111, upper limit step; 112, lower limit step; 113, annular groove; 120, lower pump body; 121, upper limit ring; 122, lower limit ring; 123, upper clamping block; 124, lower end plate; 125, lower clamping block; 130, positive Pressure isolation chamber; 131, sterile air inlet; 132, open; 140, sterilization chamber; 141, sterilization gas inlet; 142, sterilization gas outlet; 143, first perforation; 144, second perforation; 200, plunger; 210, rod; 220, plunger head; 300, fixing plate; 310, through hole; 400, air sealing member; 410, body; 420, elastic rubber ring; 430, mounting ring; 500, cooling jacket; 510, liquid inlet pipe; 520, liquid outlet pipe; 600, cooling chamber.

[Specific implementation method]

The technical solutions of the embodiments of the present invention are explained and described below in conjunction with the drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the present invention.

1 to 4 , the metering pump for aseptic filling in the preferred embodiment includes a pump body 100 and a plunger 200. A plunger cavity is provided in the pump body 100. The plunger 200 is slidably installed in the plunger cavity. The pump body 100 includes an upper pump body 110 and a lower pump body 120. The upper pump body 110 is sealed and installed on the top of the fixed plate 300, and the lower pump body 120 is sealed and installed on the bottom of the fixed plate 300. The plunger cavity includes a positive pressure isolation cavity 130 and a sterilization cavity 140 distributed from top to bottom. The sterilization cavity 140 is used to accommodate sterilization gas. The sterilization gas is vaporized hydrogen peroxide or high-temperature water vapor, preferably vaporized hydrogen peroxide with a lower temperature. The positive pressure isolation chamber 130 is arranged in the upper pump body 110, and the side wall of the positive pressure isolation chamber 130 is provided with a sterile air inlet 131, and the upper end of the positive pressure isolation chamber 130 is provided with an opening 132, which is connected to the bottom discharge port of the filling rotary valve. The sterilization chamber 140 is arranged in the lower pump body 120, and the side wall of the sterilization chamber 140 is provided with a sterilization gas inlet 141 and a sterilization gas outlet 142 from top to bottom. A through hole 310 is provided on the fixed plate 300, and the through hole 310 connects the positive pressure isolation chamber 130 and the sterilization chamber 140. The bottom of the sterilization chamber 140 is provided with a first through hole 143 connected to the outside, and the top of the sterilization chamber 140 is provided with a second through hole 144 connected to the through hole 310.

The plunger 200 includes a rod 210 and a plunger head 220 threadedly connected to the top of the rod 210. The rod 210 passes through the first through hole 143, the second through hole 144 and the through hole 310 so that the plunger head 220 is located in the positive pressure isolation chamber 130. An air seal 400 is provided between the rod 210 and the first through hole 143 and between the rod 210 and the second through hole 144, respectively. The air seal 400 provided at the second through hole 144 isolates the sterilization chamber 140 from the positive pressure isolation chamber 130, and the air seal 400 provided at the first through hole 143 isolates the sterilization chamber 140 from the outside, so as to prevent the sterilization gas in the sterilization chamber 140 from leaking.

In order to improve the sealing performance and service life of the gas seal 400, the gas seal 400 in this embodiment is preferably a pan seal ring, and the gas seal 400 includes a body 410, an elastic rubber ring 420 and a mounting ring 430 convexly arranged on the outer peripheral side of the body 410, and the upper and lower end surfaces of the body 410 are respectively provided with annular V-shaped grooves, and the elastic rubber ring 420 is clamped in the V-shaped groove, and the elastic rubber ring 420 protrudes from the end surface of the body 410, and the inner wall of the lower pump body 120 is convexly provided with an upper limit ring 121 and a lower limit ring 122 The above-mentioned sterilization chamber 140 is formed between the upper limiting ring 121 and the lower limiting ring 122, an upper clamping block 123 is provided between the upper limiting ring 121 and the fixed plate 300, and a lower clamping block 125 is provided between the lower limiting ring 122 and the lower end plate 124, wherein the mounting ring 430 of the air sealing member 400 provided at the second through hole 144 is clamped and fixed between the upper limiting ring 121 and the upper clamping block 123, and the mounting ring 430 of the air sealing member 400 provided at the first through hole 143 is clamped and fixed between the lower limiting ring 122 and the lower clamping block 125.

In addition, the metering pump also includes a cooling jacket 500 mounted on the outside of the pump body 100, the cooling jacket 500 is located between the opening 132 and the sterile air inlet 131, and a cooling chamber 600 is formed between the cooling jacket 500 and the outer peripheral side of the upper pump body 110, the cooling chamber 600 surrounds the outside of the positive pressure isolation chamber 130 and is used to accommodate cooling liquid, and the cooling jacket 500 is connected with a liquid inlet pipe 510 and a liquid outlet pipe 520, both of which are connected to the cooling chamber 600, and the liquid inlet pipe 510 and the liquid outlet pipe 520 are located above the liquid outlet pipe 520 to facilitate the smooth flow of cooling liquid into the liquid outlet pipe 520, thereby improving the cooling efficiency; in addition, compared with processing the cooling chamber by one-piece molding, such a design can facilitate the processing and molding of the cooling chamber 600, thereby reducing the processing difficulty and manufacturing cost.

In order to facilitate the fixing of the cooling jacket 500 on the outside of the pump body 100, an upper limit step 111 and a lower limit step 112 are provided on the outer peripheral side of the upper pump body 110 in this embodiment. After the cooling jacket 500 is mounted on the outside of the upper pump body 110, it is clamped between the upper limit step 111 and the lower limit step 112. Subsequently, the upper end of the cooling jacket 500 is welded and sealed to the upper limit step 111, and the lower end of the cooling jacket 500 is welded and sealed to the lower limit step 112. Thus, the cooling jacket 500 can be positioned in the upper and lower directions by the upper limit step 111 and the lower limit step 112, which facilitates the welding of the cooling jacket 500 and the upper pump body 110. In addition, the cooling jacket 500 and the upper pump body 110 are connected and sealed by welding, which can also improve the installation reliability of the cooling jacket 500 while ensuring the sealing performance.

In order to enable the cooling jacket 500 to be sleeved on the outside of the upper pump body 110, the cooling jacket 500 in this embodiment includes a left half jacket and a right half jacket that are independently processed and formed. After the left half jacket and the right half jacket are sleeved on the outside of the upper pump body 110, the two ends are butt-jointed and welded to form the cooling jacket 500.

In addition, in this embodiment, an annular groove 113 is provided on the outer circumference of the upper pump body 110, and the annular groove 113 cooperates with the cooling jacket 500 to form a cooling cavity 600, and the outer surface of the cooling jacket 500 is flush with the outer surface of the lower limit step 112. Such a design can not only improve the appearance of the metering pump, but also increase the capacity of the cooling cavity 600, thereby improving the cooling rate.

As shown in FIG4 , in order to explain in detail the use process of the metering pump for aseptic filling in this embodiment, the filling rotary valve used in conjunction with the metering pump includes a valve body 010 and a valve core 020. The valve body 010 is provided with a valve cavity 011. The valve core 020 is movably installed in the valve cavity 011. The side wall of the valve cavity 011 is provided with a feed port 0111 and a side discharge port 0112. The lower end of the valve cavity 011 is opened to form a bottom discharge port 0113. The bottom discharge port 0113 is connected to the open port 132. The valve core 020 includes a valve stem 021 and a valve head 022 installed at the bottom of the valve stem 021. A discharge channel 0221 is provided in the valve head 022. The discharge channel 0221 has an inlet and an outlet. The inlet is provided on the side of the valve head 022, and the outlet is connected to the bottom. The discharge port 0113 always remains connected. During filling, the valve core 020 is rotated to make the inlet and the feed port 0111 correspondingly connected, and the side discharge port 0112 is blocked by the valve head 022 at the same time. At this time, the plunger 200 of the metering pump moves downward to a set distance, so that the material flows into the positive pressure isolation chamber 130 through the feed port 0111 and the discharge channel 0221 into the space above the plunger head 220, that is, quantitative suction is achieved. Subsequently, the valve core 020 is rotated to make the inlet and the side discharge port 0112 correspondingly connected, and the feed port 0111 is blocked by the valve head 022 at the same time. At this time, the plunger 200 of the metering pump moves upward and pushes the material to be discharged from the side discharge port 0112 through the discharge channel 0221, thereby achieving quantitative filling.

Among them, it should be noted that when the metering pump for aseptic filling is used, sterile air is first continuously introduced into the positive pressure isolation chamber 130. Since the plunger head 220 is always sealed with the positive pressure isolation chamber 130, the sterile air will be encapsulated in the space below the plunger head 220 in the positive pressure isolation chamber 130. As the amount of sterile air increases, the air pressure in the positive pressure isolation chamber 130 will gradually increase, and then sterilizing gas will be continuously introduced into the sterilization chamber 140 through the sterilizing gas inlet 141, and the air pressure in the positive pressure isolation chamber 130 is kept greater than the air pressure in the sterilization chamber 140. At this time, the sterilizing gas in the sterilization chamber 140 cannot penetrate into the positive pressure isolation chamber 130 under the action of the pressure difference, thereby preventing the sterilizing gas from entering the positive pressure isolation chamber 130 and destroying the material; and the sterilizing gas in the sterilization chamber 140 flows downward under the action of the pressure difference and sterilizes and disinfects the part of the rod 210 located in the sterilization chamber 140, and then is discharged through the sterilizing gas outlet 142 is discharged, and by sterilizing and disinfecting the rod 210 in the sterilization chamber 140, bacteria can be prevented from entering the positive pressure isolation chamber 130, thereby preventing bacteria from contaminating the material. It can be seen that the gas sterilization barrier formed by the sterilizing gas and the positive pressure isolation barrier formed by the sterile air can form a permanent sterile isolation for the positive pressure isolation chamber 130 above the plunger head 220 for holding the material, thereby improving the safety of aseptic filling production and avoiding contamination and deterioration of the material; in addition, after the high-temperature cleaning of the metering pump in this embodiment is completed, by passing a coolant (such as cooling water) into the cooling chamber 600, the pump body 100 and the plunger 200 can be quickly cooled down, so that the pump body 100 and the plunger 200 can be restored to normal before filling, avoiding the plunger 200 from being stuck in the plunger cavity, thereby ensuring that the metering pump can be used normally; finally, when filling the material, the material can also be cooled down by the coolant to maintain a certain temperature of the material.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the contents described in the drawings and the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims (10)

1. A metering pump for aseptic filling, comprising a pump body and a plunger, the pump body being provided with a plunger cavity, the plunger being slidably mounted in the plunger cavity, characterized in that the plunger cavity comprises a positive pressure isolation cavity and a sterilization cavity distributed from top to bottom, the sterilization cavity and the positive pressure isolation cavity are isolated by an air seal, the side wall of the sterilization cavity is provided with a sterilizing gas inlet and a sterilizing gas outlet from top to bottom, the side wall of the positive pressure isolation cavity is provided with a sterile air inlet, the upper end of the positive pressure isolation cavity is provided with an opening, the metering pump also includes a cooling cavity surrounding the outside of the positive pressure isolation cavity and used to accommodate a cooling liquid, the cooling cavity is located between the opening and the sterile air inlet, and the cavity wall of the cooling cavity is connected with a liquid inlet pipe and a liquid outlet pipe. 2. A metering pump for aseptic filling as described in claim 1, characterized in that the metering pump also includes a cooling jacket sleeved on the outside of the pump body, the cooling cavity is formed between the cooling jacket and the outer peripheral side of the pump body, and the liquid inlet pipe and the liquid outlet pipe are arranged on the cooling jacket. 3. A metering pump for aseptic filling as described in claim 2, characterized in that an upper limit step and a lower limit step are provided on the outer peripheral side of the pump body, and the cooling jacket is clamped between the upper limit step and the lower limit step. 4. A metering pump for aseptic filling as described in claim 3, characterized in that the upper end of the cooling jacket is welded to the upper limit step, and the lower end of the cooling jacket is welded to the lower limit step. 5. A metering pump for aseptic filling as described in claim 3, characterized in that an annular groove is provided on the outer peripheral side of the pump body, the annular groove cooperates with the cooling sleeve to form the cooling cavity, and the outer surface of the cooling sleeve is flush with the outer surface of the lower limit step. 6. A metering pump for aseptic filling as claimed in claim 3, characterized in that the cooling jacket comprises a left half jacket and a right half jacket which are independently processed and formed, and the left half jacket and the right half jacket are welded to form the cooling jacket. 7. A metering pump for aseptic filling as claimed in claim 1, characterized in that the liquid inlet pipe is located above the liquid outlet pipe. 8. A metering pump for aseptic filling as described in any one of claims 1 to 7, characterized in that the pump body comprises an upper pump body and a lower pump body, the positive pressure isolation chamber is arranged in the upper pump body, the sterilization chamber is arranged in the lower pump body, the upper pump body is sealed and installed on the top of the fixed plate, the lower pump body is sealed and installed on the bottom of the fixed plate, and the fixed plate is provided with a through hole for the plunger to pass through. 9. A metering pump for aseptic filling as described in any one of claims 1 to 7, characterized in that the bottom and top of the sterilization chamber are respectively provided with a first perforation and a second perforation, the plunger comprises a rod portion and a plunger head arranged at the upper end of the rod portion, the rod portion passes through the first perforation and the second perforation, the plunger head is located in the positive pressure isolation chamber, and the air seal is a pan-seal ring arranged between the first perforation and the rod portion and between the second perforation and the rod portion. 10. A metering pump for aseptic filling according to any one of claims 1 to 7, characterized in that the sterilization chamber is used to contain sterilizing gas, and the sterilizing gas is gasified hydrogen peroxide or high-temperature water vapor.