A medical negative pressure generator of the throttle type

Abstract

This invention discloses a gas-saving medical negative pressure generator, comprising a negative pressure generator valve body, a piston assembly, and a jet pump. The piston assembly includes a throttling device that automatically limits the driving flow rate based on changes in driving gas pressure. The throttling device includes a small piston with a small slide valve and an elastic component. The small piston is positioned within the piston assembly via the elastic component. One side of the small piston is connected to the driving gas, and the other side abuts against the elastic component and is open to the atmosphere. When the driving gas pressure is too high, the pressure overcomes the force of the elastic component, pushing the small piston to reduce the opening of the gas inlet connected to the jet pump by driving the slide valve. When the gas pressure is within the normal range, the elastic component drives the small piston to reset, restoring the opening of the gas inlet connected to the jet pump. This gas-saving medical negative pressure generator can ensure that the negative pressure generator meets performance requirements under low-pressure driving conditions; under high-pressure driving conditions, it can automatically limit the driving flow rate while meeting the performance requirements of the negative pressure generator, reducing driving gas consumption and waste.

Description

Technical Field

[0001] This invention relates to negative pressure suction technology, and more specifically to a medical negative pressure generator. Background Technology

[0002] In the field of medical negative pressure suction surgery, negative pressure is used as the driving force for surgical suction to remove waste fluids during surgery. There are generally two types of negative pressure sources for negative pressure suction: one is a tubular negative pressure source provided by a medical central suction system, and the other, when a tubular negative pressure source is unavailable, is a negative pressure source generated by a negative pressure generator using compressed gas. The negative pressure source is connected to the negative pressure suction device, which then performs the negative pressure suction surgery.

[0003] The compressed gas used to drive negative pressure generators is the same compressed gas used in anesthesia machines and ventilators. To broaden their applicability, anesthesia machines and ventilators use compressed gases with a wide permissible pressure range, between 0.28 and 0.6 MPa. For example... Figure 1 As shown, the size of the driving gas flow channel of the existing medical negative pressure generator is fixed, and the size of the nozzle of the negative pressure generator is also fixed. According to the principle of gas dynamics, a large driving gas pressure results in a large side gas consumption, and a low driving gas pressure results in a small side gas consumption.

[0004] To ensure the negative pressure output performance of the negative pressure generator meets the requirements of negative pressure suction, it is usually designed for low driving gas pressure. Based on this design, when used at high driving gas pressure, according to gas dynamics principles, the higher the driving gas pressure and the larger the driving gas flow rate, the more driving gas is consumed. Within the aforementioned pressure range of 0.28–0.6 MPa, the gas consumption will be more than double, resulting in significant waste of driving gas. To ensure economical gas consumption at high driving gas pressure, the driving gas pressure is too low and the driving flow rate is insufficient at low driving pressure, resulting in insufficient negative pressure generated by the generator to meet the requirements of negative pressure suction. Summary of the Invention

[0005] To address the problems existing in negative pressure generators, the present invention aims to provide a gas-saving medical negative pressure generator that can ensure the performance requirements of the negative pressure generator when driven by low gas pressure; and when driven by high gas pressure, it can automatically limit the driving flow rate to reduce the consumption and waste of driving gas while meeting the performance requirements of the negative pressure generator.

[0006] To achieve the above objectives, the present invention provides a gas-saving medical negative pressure generator, comprising a negative pressure generator valve body, a piston assembly, and a jet pump. The differential piston assembly and the jet pump are respectively disposed in the negative pressure generator valve body. The piston assembly is provided with a throttling device that automatically limits the driving flow rate according to changes in driving gas pressure. The throttling device includes a small piston with a small slide valve and an elastic component. The small piston is disposed in the piston assembly through the elastic component. One side of the small piston is connected to the driving gas, and the other side abuts against the elastic component and is open to the atmosphere. When the driving gas pressure is too high, the gas pressure overcomes the force of the elastic component, pushing the small piston to drive the slide valve to reduce the opening of the gas passage connecting to the jet pump. When the gas pressure is within the normal range, the elastic component drives the small piston to reset, restoring the opening of the gas passage connecting to the jet pump.

[0007] Furthermore, the piston assembly is a differential piston assembly.

[0008] Furthermore, the differential piston assembly includes a slide valve, which includes a piston forming a large end and a piston rod forming a small end. A central hole is formed inside the slide valve. An air inlet is provided at a corresponding position on the piston rod, communicating with the central hole. A large countersunk hole for accommodating a throttling device is formed at the end of the piston rod, and an air outlet is provided on the large section of the piston rod corresponding to the large countersunk hole, leading to the outside.

[0009] Furthermore, the valve body is provided with a switch cavity extending along a first direction. One end of the switch cavity is a piston cavity that mates with the large end of the slide valve, and the other end is a slide valve cavity that mates with the small end of the slide valve. The slide valve cavity is provided with an air inlet cavity and an air outlet cavity. An air inlet is provided on the side of the air inlet cavity. The valve body is provided with a jet pump cavity arranged along a second direction.

[0010] Furthermore, the small piston is cylindrical, with one end being the piston part and a raised frustum at the end, and the other end being the small valve core of the slide valve. A countersunk hole is provided in the center, and a venting groove is provided between the piston part and the small valve core. A venting hole is provided in the venting groove and communicates with the countersunk hole on the piston rod.

[0011] Furthermore, the elastic component is a spring.

[0012] The air-saving medical negative pressure generator provided by this invention introduces a throttling device and innovatively sets it in the differential piston assembly of the negative pressure generator. This effectively achieves automatic limitation of the driving flow rate according to changes in driving air pressure. When the driving air pressure is too high, it can reduce the opening of the air inlet connected to the jet pump to reduce the flow rate. When the air pressure is within the normal range, it can reset and restore the opening of the air inlet connected to the jet pump, which can effectively overcome the problem of excessive flow rate at high driving air pressure.

[0013] In practical applications, the air-saving medical negative pressure generator provided by this invention can also appropriately increase the driving flow rate when the driving air pressure is low, thereby improving the performance of the negative pressure generator when the driving air pressure is low, thus improving the performance of the medical negative pressure generator and expanding its application range.

[0014] The gas-saving medical negative pressure generator provided by this invention can be directly implemented based on the existing medical negative pressure generator in practical applications, without affecting the overall shape and installation size of the existing medical negative pressure generator. It is low in cost and highly practical. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0016] Figure 1 This is a structural diagram of an existing linked medical negative pressure generator;

[0017] Figure 2 This is a structural example diagram of the thrift-type medical negative pressure generator in an embodiment of the present invention;

[0018] Figure 3 This is a structural example diagram of the valve body cross-section in an embodiment of the present invention;

[0019] Figure 4 This is an assembly example diagram of the slide valve assembly in an embodiment of the present invention;

[0020] Figure 5 This is an example diagram of the thrift-type medical negative pressure generator in a low-pressure driven working state in an embodiment of the present invention;

[0021] Figure 6 This is a schematic diagram illustrating the working principle of the thrift-type medical negative pressure generator in the low-pressure driven state in an example of the present invention.

[0022] Figure 7 This is an example diagram of the thrift-type medical negative pressure generator in the high-pressure driven working state in an embodiment of the present invention;

[0023] Figure 8 This is a schematic diagram illustrating the working principle of the thrift-type medical negative pressure generator in the high-pressure driven state in an example of the present invention. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0025] Based on the fixed nozzle size design of existing medical negative pressure generators, this invention, without affecting the overall shape and installation dimensions of existing medical negative pressure generators, innovatively introduces a throttling device that automatically limits the driving flow rate according to changes in driving gas pressure. This throttling device ensures that the negative pressure generator meets performance requirements when it is in a low-pressure driving state; and when the negative pressure generator is in a high-pressure driving state, it automatically limits the driving flow rate while meeting the performance requirements of the negative pressure generator, thereby reducing driving gas consumption and waste.

[0026] Furthermore, since this throttling device overcomes the problem of excessive flow rate at high driving air pressure, it can also appropriately increase the driving flow rate at low driving air pressure, thereby improving the performance of the negative pressure generator at low driving air pressure, thus enhancing the performance of the medical negative pressure generator and expanding its application range.

[0027] Specifically, the throttling device in this solution mainly consists of a small piston with a small slide valve and a corresponding elastic component. The small piston is mounted on the piston assembly of the medical negative pressure generator via the elastic component, and is connected to the air inlet of the jet pump. One side of the small piston is connected to the driving gas, and the other side abuts against the elastic component and is open to the atmosphere. When the driving gas pressure is too high, the pressure overcomes the force of the elastic component, pushing the small piston to actuate the slide valve, reducing the opening of the air inlet connected to the jet pump. When the gas pressure is within the normal range, the elastic component drives the small piston to reset, restoring the opening of the air inlet connected to the jet pump, allowing the negative pressure generator to return to normal operation.

[0028] Therefore, the following specific example will be used to illustrate this solution.

[0029] This example uses a negative pressure generator structure with linkage control, by adding a throttling device to the differential piston that can automatically limit the drive flow according to pressure changes.

[0030] See Figure 2 The diagram shown is a structural example of the seasonal medical negative pressure generator given in this example.

[0031] As shown in the figure, this thrift-type medical negative pressure generator is mainly composed of the following components: negative pressure generator valve body 1, slide valve 2, cylinder head 3, small piston 4, spring 5, small end cap 6, several sealing rings 7, and jet pump 8.

[0032] See further Figure 3 The diagram shows a structural example of valve body 1 in this example. Valve body 1 is a block with an internal cavity. The upper part of valve body 1 is a horizontally penetrating switch cavity 1-1. One end of the switch cavity has a larger diameter and is the piston cavity 1-11, while the other end has a smaller diameter and is the slide valve cavity 1-12.

[0033] Furthermore, the slide valve cavity is provided with an inlet chamber 1-13 and an outlet chamber 1-14. The inlet chamber 1-13 is located near the piston chamber 1-11. Each chamber is provided with a sealing ring groove 1-16 for placing the corresponding sealing ring 7, so that when the slide valve 2 is in place, it can form an independent cavity for sealing and isolation.

[0034] Furthermore, in this example, an air inlet 1-15 is provided on the side of the air inlet chamber 1-13 for connecting an external driving air source.

[0035] Furthermore, in this example, the lower part of the valve body 1 is a vertically open jet pump chamber 1-2. The upper part of this jet pump chamber 1-2 communicates with the air outlet chamber 1-14. An air intake port (i.e., a negative pressure port) 1-3 is provided on the side of the middle part of the jet pump chamber 1-2.

[0036] Combination Figure 4 As shown, for the valve body 1 structure described above, the slide valve 2 in this example is a double-section cylinder. The large end is the piston 2-1, and the piston 2-1 is provided with a sealing ring groove for placing the corresponding sealing ring 7. The small end is the piston rod 2-2, the center is a multi-section central through hole 2-3, the side near the large end is the throttling orifice 2-3a, and the piston rod 2-2 is provided with a radial air inlet hole 2-21 that communicates with the central hole 2-3 in the middle position.

[0037] Furthermore, the piston rod 2-2 side of this slide valve 2 has a large countersunk hole with external threads; the large hole section on the piston rod 2-2 side is provided with a small air outlet hole 2-22 leading to the outside.

[0038] Furthermore, in this example, a radial hole 2-5 can be provided at the connection between piston 2-1 and piston rod 2-2, communicating with the central hole 2-3.

[0039] In this example, valve cover 3 is a screw cover with external threads on one side and a countersunk hole in the center, and an end cover with a center hole on the other side, which is the control port 3-1.

[0040] In this example, the small piston 4 is adjustablely positioned in the large countersunk hole of the piston rod 2-2 on the slide valve 2 via a spring 5 and a small end cap 6, forming a slide valve assembly 9 with the slide valve 2. Figure 4 As shown.

[0041] Specifically, the small piston 4 is cylindrical, with one end being piston 4-1, which has a sealing groove for accommodating the corresponding sealing ring 7; at the same time, the end of piston 4-1 has a raised frustum; the other end of the small piston 4 is a slide valve core 4-2, which has a countersunk hole in the center, and there is a venting groove between piston 4-1 and small valve core 4-2, with a venting hole 4-3 in the groove that communicates with the countersunk hole of the valve core.

[0042] In this example, spring 5 is a columnar helical spring to ensure a stable and reliable elastic force.

[0043] In this example, the small end cap 6 is preferably made of screw cap, with an external thread on one side having a central countersunk hole 6-1, and a circular end cap on the other side, with a small hole 6-2 on the end cap communicating with the countersunk hole 6-1.

[0044] In this example, the sealing ring 7 corresponds to the specifications of each sealing groove in this negative pressure generator, and each sealing groove is equipped with a matching sealing ring.

[0045] In this example, the jet pump 8 is preferably a gas-driven jet pump, including a nozzle 8-1 and a throat 8-2. The specific structural form is not limited here and can be determined according to actual needs.

[0046] Based on this, the thrift-type medical negative pressure generator in this example is assembled and set up (in conjunction with...). Figure 3-4 ):

[0047] See Figure 4 First, the small piston 4 is installed into the large countersunk hole of the piston rod of the slide valve 2. The spring 5 is sleeved on the protrusion at the end of the small piston 4, and the small end cap 6 is sleeved on the outside of the spring 5 and screwed into the slide valve 2 to give the spring 5 a certain loading force. Thus, a spring cavity is formed between the small piston 4 and the small end cap 6. Atmospheric pressure is introduced into the spring cavity on the back of the small piston 4 through the small hole 6-2 and the countersunk hole 6-1 on the small end cap 6, thus forming the slide valve assembly 9.

[0048] Next, the slide valve assembly 9 is installed into the horizontally penetrating switch cavity 1-1 at the top of the valve body 1; the valve cover 3 seals the outer opening of the large piston cavity 1-11 of the valve body 1; the outer end of the piston rod of the slide valve assembly 9 is allowed to pass through the switch cavity 1-1 to the atmosphere, and then the jet pump 5 is placed in the jet pump cavity 1-2, as follows. Figure 5 Or as shown in Figure 7.

[0049] The slide valve assembly 9, configured in this way, divides the piston chamber 1-11 of the switch cavity 1-1, forming a large piston chamber 3-2 between the outer side of the piston 2-1 and the valve cover 3. The large piston chamber 3-2 communicates with the control port 3-1. Furthermore, the inner side of the piston 2-1 is the piston rod chamber 2-10, which communicates with the intake chamber 1-13.

[0050] With this configuration, the piston's large chamber 3-2 and piston rod chamber 2-10, together with the slide valve 2, form a differential cylinder. The throttle orifice 2-3 controls the discharge volume. When the control port 3-1 is closed or open, it controls the left and right movement of the slide valve assembly 9, cutting off or opening the drive gas source, switching the negative pressure generator on and off, and linking it with the host equipment, such as... Figure 6 Or as shown in Figure 8.

[0051] The operating status of the thrifty medical negative pressure generator, based on this, is as follows:

[0052] See Figure 5 and Figure 6When the driving air source pressure in the gas-saving medical negative pressure generator is in the low pressure range, the air pressure acts on the small piston 4. The thrust generated by the pressure difference on both sides of the small piston 4 is insufficient to overcome the loading force of the spring 5 to push the small piston 4. The small piston 4 will maintain its original position. The driving air source enters the jet pump directly through the air inlet hole 2-21, the air vent 4-3, the air outlet hole 2-22, etc., and drives the jet pump to work normally.

[0053] See Figure 7 and Figure 8 When the driving air source pressure entering the air-saving medical negative pressure generator is in the high-pressure range, the pressure acts on the small piston 4. At this time, the thrust generated by the pressure difference on both sides of the small piston 4 is sufficient to overcome the loading force of the spring 5, pushing the small piston 4 to the right. Through the small valve core 4-2 on the small piston 4, the small valve core 4-2 gradually blocks the outlet orifice 2-22, automatically reducing the opening of the outlet orifice 2-22, reducing the flow area, and throttling the flow, thus reducing the driving airflow. Only after the driving air source is throttled through the outlet orifice 2-22 can it enter the jet pump and drive the jet pump to work.

[0054] In this state, the higher the driving air source pressure, the greater the rightward movement of the small piston 4, and the smaller the opening of the outlet orifice 2-22. The driving air source flow rate is kept stable within a certain range, unaffected by the driving air pressure, thus achieving the goal of saving driving gas when using high-pressure drive.

[0055] Based on this, in order to prevent the drive air source from being cut off, the stroke of the small piston 4 is limited by the small end cap 6 to ensure that the small air outlet 2-22 has a minimum opening.

[0056] As can be seen from the above, the gas-saving medical negative pressure generator solution presented in this example integrates a small piston and a slide valve into the valve stem of the original negative pressure generator switching valve. The spring balances the gas pressure force, and when working at low driving gas pressure, the driving gas source is normally connected; when working at high gas pressure, the flow rate is gradually throttled according to the gas pressure, so that the driving gas flow rate is not affected by the driving gas pressure and is stabilized within a certain range, thus achieving the purpose of gas saving when driving at high gas pressure.

[0057] In practical applications, this invention employs an integrated control structure, which does not increase the original external installation dimensions or significantly increase costs. It stabilizes the driving gas flow rate of the negative pressure generator, ensuring the driving gas is unaffected by driving gas pressure. While guaranteeing the performance requirements for negative pressure suction, it maximizes the conservation of driving gas and energy. Furthermore, it can even further enhance the performance of negative pressure suction without consuming excessive energy.

[0058] In practical applications, compared to adding a pressure reducing valve at the inlet of the driving air source, the present invention avoids the problems of complex structure and large size of the negative pressure generator caused by adding a pressure reducing valve, which affects installation and use; at the same time, it also avoids the problems of increased production and maintenance costs caused by adding a pressure reducing valve.

[0059] Finally, it should be noted that the solutions provided by the present invention are not limited to the above-described embodiments, but can be modified and varied in various ways according to design needs and other factors within the scope of the appended claims or their equivalents, such as the structure, sealing ring form and position of the small piston in a manually operated negative pressure generator.

[0060] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A gas-saving medical negative pressure generator, comprising a negative pressure generator valve body, a piston assembly, and a jet pump, wherein the piston assembly and the jet pump are respectively disposed in the negative pressure generator valve body, characterized in that, The piston assembly includes a slide valve, which is equipped with a throttling device that automatically limits the drive flow rate according to changes in drive air pressure. The piston assembly includes a slide valve, which is a double-section cylinder with a piston at the large end, a piston rod at the small end, a multi-section central through hole at the center, a throttling orifice near the large end, and a radial air inlet hole communicating with the central hole at the middle of the piston rod; the piston rod side of the slide valve has a large countersunk hole, and the large hole section of the piston rod side has an air outlet hole leading to the outside. The throttling device includes a small piston with a small slide valve and an elastic component. The small piston is placed in the large countersunk hole of the piston rod on the slide valve through the elastic component, and cooperates with the slide valve to form a slide valve assembly. It is also configured to cooperate with the gas inlet that connects to the jet pump. One side of the small piston is connected to the driving gas, and the other side abuts against the elastic component and is open to the atmosphere. When the driving air pressure is too high, the air pressure acts on the small piston, and the air pressure overcomes the force of the elastic component, pushing the small piston to drive the slide valve to move in the first direction. The small valve core on the small piston gradually blocks the small air outlet, which will automatically reduce the opening of the air passage connecting to the jet pump, throttle the driving airflow, so that the throttled driving airflow enters the jet pump and drives the jet pump to work. When the air pressure is within the normal range, the elastic component drives the small piston to move and reset in the second direction. The small valve core on the small piston gradually opens the small air outlet, restoring the opening of the air passage connecting to the jet pump. This allows the air source to directly enter the jet pump, driving the jet pump to work normally.

2. The gas-saving medical negative pressure generator according to claim 1, characterized in that, The piston assembly is a differential piston assembly.

3. The gas-saving medical negative pressure generator according to claim 1, characterized in that, The valve body is provided with a switch cavity that extends through a first direction. One end of the switch cavity is a piston cavity that mates with the large end of the slide valve, and the other end is a slide valve cavity that mates with the small end of the slide valve. The slide valve cavity is provided with an air inlet cavity and an air outlet cavity. An air inlet is provided on the side of the air inlet cavity. The valve body is provided with a jet pump cavity that extends along a second direction.

4. The gas-saving medical negative pressure generator according to claim 1, characterized in that, The small piston is cylindrical, with one end being the piston part and a raised frustum at the end, and the other end being the small valve core of the slide valve. A countersunk hole is provided in the center, and a venting groove is provided between the piston part and the small valve core. A venting hole is provided in the venting groove, which communicates with the countersunk hole on the piston rod.

5. The gas-saving medical negative pressure generator according to claim 1, characterized in that, The elastic component is a spring.

Images