Rotary control valve and plunger pump

Abstract

The utility model discloses a rotary control valve and a plunger pump, the rotary control valve comprises a valve core and a second driving mechanism for driving the valve core to rotate around the axis of the valve core, and the valve core is provided with a conical section with a conical structure; the valve further comprises a second communicating hole formed in the valve element, one hole opening of the second communicating hole is located in the side face of the conical section, the other hole opening of the second communicating hole is located in the end face of the valve element, and the hole opening in the side face is located between the end face and the end, with the smaller diameter, of the conical section. The plunger pump comprises the rotary control valve. The rotary control valve is used for the plunger pump, is particularly used for switching the communication state of a plunger cavity on the plunger pump and an inlet / outlet, and has the characteristic of reliable sealing.

Description

Technical Field

[0001] The utility model relates to the technical field of fluid conveying equipment, in particular to a rotary control valve and a plunger pump. Background Art

[0002] In the food industry, medical industry, chemical industry, pharmaceutical industry, daily necessities industry, etc., plunger pumps are used for precise fluid delivery functions for the purpose of filling and adding materials, and are particularly suitable for quantitative delivery of viscous liquids.

[0003] Taking the use of a plunger pump to achieve the purpose of filling as an example, a filling machine is provided in the patent application document with patent application number CN201611206459.2, whose structural components include a plunger pump, a first cylinder, a first switch device and a second switch device, etc. When working, the first cylinder drives the plunger in the plunger pump to move in the plunger pump body, and controls the connection state of the plunger cavity in the plunger pump with the first liquid holding device and the second liquid holding device respectively through the first switch device and the second switch device. The above switch devices include baffles, springs and support plates. The specific working process of the filling machine is: the cylinder can control the piston to move in the plunger pump body, thereby changing the piston in the plunger pump cylinder. Air pressure, when the piston is away from the first liquid holding device, the air pressure in the plunger pump body is low, the first switch device is opened, and the liquid in the first liquid holding device is sucked into the plunger pump body. When the piston located in the plunger pump body moves close to the first liquid holding device, the air pressure in the plunger pump cylinder becomes high, and the liquid in the cylinder is pressed into the second liquid holding device through the connecting pipe. The second switch device is opened, and the liquid can be input from the liquid outlet into the bottle to be filled. The specific working process of the switch device is: the liquid pressure acts on the baffle and pushes the baffle to move to open the connecting hole. During this process, the spring supported on the support plate is compressed; when the liquid pressure becomes smaller, the spring rebounds to push the baffle to move in the opposite direction and block the connecting hole.

[0004] Plunger pumps play an important role in the precise delivery of liquids in various industries. It is necessary to further optimize the plunger pumps so that they can better serve various industries. Utility Model Content

[0005] In view of the above technical problem of optimizing the plunger pump, the utility model provides a rotary control valve and a plunger pump. The rotary control valve is used for the plunger pump, specifically for switching the connection state between the plunger cavity and the inlet and outlet of the plunger pump, and the rotary control valve has the characteristic of reliable sealing.

[0006] In view of the above problems, the rotary control valve and plunger pump provided by the utility model solve the problems through the following technical points: the rotary control valve comprises a valve core and a second driving mechanism driving the valve core to rotate around the valve core axis, and the valve core has a conical section with a cone structure;

[0007] It also includes a second connecting hole arranged on the valve core, one of the openings of the second connecting hole is located on the side of the tapered section, and the other opening of the second connecting hole is located on the end face of the valve core, and the position of the opening on the side is located between the end face and the end with the smaller diameter of the tapered section.

[0008] The specific application of this scheme can be: installed on the pump body of the plunger pump, as a switching module for switching the connection state between the plunger cavity on the plunger pump and the suction hole and discharge hole of the plunger pump, it can be specifically set to set a mounting cavity on the pump body, the suction hole and the discharge hole on the pump body are connected with the mounting cavity, and the connection position of the suction hole on the mounting cavity and the connection position of the discharge hole on the mounting cavity are located at the same axial position of the mounting cavity but at different circumferential positions, and the valve core is installed in the mounting cavity; the orifice of the second connecting hole located on the end face is connected with the front end of the plunger cavity, and the valve core can rotate in the mounting cavity, through the The rotation changes the position of the orifice of the second communicating hole on the side surface, so that the conduction states of the orifice of the second communicating hole on the side surface and the suction hole and the discharge hole are mutually converted. For example, when the valve core rotates under the action of the second driving mechanism so that the second communicating hole connects the suction hole and the plunger cavity, the plunger in the plunger cavity performs a fluid suction action, and the fluid from the suction hole can be sucked in at this time. When the valve core rotates under the action of the second driving mechanism so that the second communicating hole connects the discharge hole and the plunger cavity, the plunger in the plunger cavity performs a fluid extrusion action, and the fluid in the plunger cavity can be extruded toward the discharge hole, thereby achieving the purpose of fluid delivery.

[0009] The conical section is a section on the valve core with a diameter at one end larger than the other end, and the diameter of the conical section changes linearly at each position along its axis. The valve core can be installed on the pump body by directly installing it in the installation cavity. In this application, the installation cavity needs to be processed into a hole section that can accommodate the conical section and fit with the conical section. The conical section is embedded in the hole section, coaxial with the hole section, and can rotate in the hole section with its own axis as the rotation axis. Since the opening of the second connecting hole on the conical section rotates in the hole section, the openings of the drainage hole and the suction hole on the installation cavity are located on the hole section and are aligned with the second connecting hole on the conical section. The orifices of the two communicating holes are located at the same axial position of the valve core, so as to switch the connection state between the plunger cavity and the suction hole and the discharge hole when the valve core rotates; when the following structure with a sleeve is adopted, the sleeve can be regarded as an inner lining on the mounting cavity, and the tapered hole section on the sleeve cooperates with the tapered section, and the second communicating hole is connected with the suction hole and the discharge hole through the corresponding connecting channel. In this way, the cavity wall of the mounting cavity fits well with the outer wall of the sleeve, so that the pump body is used as the pressure-bearing structure outside the sleeve, and the sleeve is set as an inner lining layer, which optimizes the performance of the plunger pump by exerting the functions of friction reduction and physical isolation of the medium.

[0010] In summary, this solution provides a technical solution that can be used to switch the connection state between the plunger cavity on the plunger pump and the inlet and outlet of the plunger pump. The switching of the above connection state is not limited by the action of the plunger pump and the position of the plunger. Different from the traditional spring-based unidirectional conduction control solution, this solution does not increase the load of the plunger, and at the same time, the functions of the discharge hole and the inlet hole can be replaced with each other.

[0011] When this solution is applied to quantitative delivery of viscous fluid that needs to be pressurized in advance before injection into the plunger pump, compared with the one-way conduction control solution based on the spring, the pressure of the flow path is not likely to cause unplanned changes in the conduction state between the plunger cavity and the suction hole and the discharge hole, so this solution has the characteristic of reliable control of the connection state;

[0012] The positions of the two orifices of the tapered section and the second connecting hole on the valve core are set to achieve: the orifice of the second connecting hole located on the end surface only rotates during the rotation of the valve core, and the first connecting hole connecting the plunger cavity and the orifice is easily processed on the valve body, and the second connecting hole and the plunger cavity are always kept in a state of being connected; during the entire use process, the valve core realizes that the orifice on the side surface is connected with the suction hole or the discharge hole at different rotation angles. During the process of the plunger performing fluid extrusion, the orifice on the end surface of the second connecting hole is the inlet orifice, and the orifice on the side of the tapered section is the outlet orifice. In this way, the tapered section is supported by the pump body toward the large end of the tapered section, and can pass the fluid The pressure exerted by the valve body on the valve core enables the valve core to move toward the end of the hole section / conical hole section with a smaller diameter, and with the help of this pressure, the axial sealing of the valve core and the matching surface of the hole section / conical hole section is achieved, while avoiding the pressure change in the flow path causing the stability of the valve core to be affected or causing unnecessary force on the second drive mechanism; after the corresponding matching surfaces of the valve core and the sleeve, and the valve core and the pump body are worn, the valve core can effectively maintain the state of the tapered section and the hole section / conical hole section conical surface in contact with each other under the fluid pressure or under other forces toward the small end of the tapered section, thereby reducing the possibility of fluid leakage through the suction hole and the discharge hole through the outer periphery of the valve core, so the structural setting of the rotary control valve makes it have the characteristics of reliable sealing.

[0013] As a further technical solution of the rotary control valve:

[0014] When the above scheme is implemented, the tapered section can be arranged between the two ends of the valve core or at the end of the valve core. When it is located between the two ends, if the large end of the tapered section faces the front end of the valve core, the opening of the second communication hole on the end surface is arranged on the front end surface of the valve core. When it is located at the end of the valve core, the large end of the tapered section is located at the end of the valve core. If the tapered section is located at the front end of the valve core, the opening of the second communication hole on the end surface is arranged on the front end surface of the valve core. When the rotary control valve is installed on the pump body, the large end of the tapered section is preferably used as an end of the tapered section that penetrates into the pump body. Since the tapered hole section / hole section can provide radial constraints for the valve core after the valve core is installed, in order to simplify the structure of the valve core and shorten the length of the second communication hole, it is set as follows: the end with a larger diameter of the tapered section is located at the end of the valve core. In addition, in order to facilitate the setting of the first communication hole that is always connected to the second communication hole, the opening of the second communication hole on the end surface can be used to rotate at the same position during the rotation of the valve core. Therefore, it is further set that the opening on the end surface is located on the end and is coaxial with the valve core.

[0015] It also includes a sleeve, which is sleeved on the outside of the tapered section, and has a tapered hole section that fits the tapered section;

[0016] Two communication channels are arranged on the side wall of the sleeve, and the two communication channels are located at the same axial position of the sleeve and at different circumferential positions;

[0017] When the valve core rotates relative to the sleeve around the axis of the valve core, the second communicating hole can be rotated as follows:

[0018] The orifice located on the side of the tapered section is docked with any one of the connecting channels and staggered with the other connecting channel. In this solution, the sleeve is used to be fixedly connected to the mounting cavity on the valve body, and a static seal is set on the mating surface with the mounting cavity to realize the axial sealing function. The mating surface between the tapered section and the tapered hole section is a dynamic sealing surface to realize the axial sealing of the outer periphery of the valve core. It is set to also include the sleeve and install the valve core in the sleeve. Compared with directly installing the valve core on the pump body, the sleeve can be manufactured separately as a part on the pump body. For example, the pump body is made of stainless steel material to provide good pressure bearing capacity, and the sleeve is made of composite materials, polymer materials or metal materials with good wear resistance and the inner hole wall surface that can be easily processed into a smooth wall surface. In this way, when the valve core rotates and moves relative to the sleeve, the good wear resistance of the sleeve and the good matching accuracy of the valve core and the sleeve can effectively guarantee the performance and life of the plunger pump, and the performance and life of the plunger pump are guaranteed by the fluid isolation of the sleeve and the pressure resistance of the pump body. In specific implementation, the better application is that the pump body is made of stainless steel material, the plunger and valve core are made of ceramic material, and the sleeve is made of polymer material resistant to organic solvents.

[0019] In specific application, when it is not necessary to pressurize the fluid upstream of the suction hole or the pressurized pressure is low, it is easy to maintain the axial sealing of the gap between the sleeve and the valve core during fluid suction and extrusion through the matching state of the sleeve and the valve core, and prevent the fluid in the suction hole from directly entering the discharge hole from the gap. However, when it is necessary to pressurize the fluid upstream of the suction hole to a higher pressure, such as during the plunger suction process, the fluid may still enter the discharge hole from the suction hole through the gap. In order to solve this problem, a certain positive pressure can always be maintained between the tapered hole section and the tapered section to prevent the fluid in the suction hole from directly entering the discharge hole from the gap or axial leakage through the gap. A pre-tightening structure is also included, which acts on the valve core and is used to apply a force relative to the sleeve to the valve core, and the direction of the force is: toward the side with a smaller diameter of the tapered section. In this solution, the pre-tightening structure is used to provide the valve core with a continuous force toward the small end of the tapered hole section, and the force is used to maintain the positive pressure between the tapered hole section and the tapered section, thereby avoiding the axial leakage and the problem that the fluid in the suction hole directly enters the discharge hole from the gap. A preferred application is that the tapered hole section and the tapered section have the same size.

[0020] The pre-tightening structure includes a retaining ring fixed on the valve core, and the pre-tightening structure also includes an elastic member clamped between the end of the retaining ring and the end of the sleeve and in a compressed and deformed state. This scheme is a specific implementation method of the pre-tightening structure, specifically: the compressed elastic member provides thrust for the retaining ring, and after the thrust is transmitted to the valve core through the retaining ring, the valve core obtains a force to move toward the small end of the tapered hole section. In this scheme, the elastic member can be a metal elastic pad. Other applications also include setting an elastic member between one end of the valve core that penetrates into the pump body and the pump body, but this method needs to consider the influence of the fluid on the elastic member, which is not conducive to the selection of the elastic member and the ability to maintain performance.

[0021] As a technical solution that can effectively protect the valve core and facilitate the installation of the clamping ring when the valve core is made of ceramic material, the elastic member is an elastic gasket, and a flat gasket is arranged between the elastic member and the sleeve;

[0022] An annular groove coaxial with the valve core is arranged on the side surface of the valve core, and the clamping ring is installed in the annular groove. The clamping ring can be an elastic retaining ring for shaft.

[0023] The second connecting hole is composed of an axial hole and a radial hole connected in series, wherein the opening of the axial hole is located on the end face of the valve core, and the opening of the radial hole is located on the side face of the tapered section. This solution provides a specific second connecting hole structure, which is a technical solution that is convenient to process, simple in structure, and easy to ensure processing accuracy.

[0024] The present solution also relates to a plunger pump, comprising a plunger pump body, the plunger pump body comprising a pump body provided with a suction hole and a discharge hole, and further comprising a switching module mounted on the pump body, the switching module being used to switch the connection state between the plunger cavity on the plunger pump body and the suction hole and the discharge hole, the switching module comprising the rotary control valve as described in any one of the above;

[0025] The pump body is provided with an installation cavity, the liquid suction hole and the liquid discharge hole are both connected to the installation cavity, and the valve core is installed in the installation cavity;

[0026] The orifice of the second connecting hole located on the end face is connected to the front end of the plunger cavity, and the valve core can rotate in the installation cavity. Through the rotation, the opening of the second connecting hole located on the side surface and the conduction state of the suction hole and the discharge hole are mutually converted. This scheme is a plunger pump including the rotary control valve, and a specific application is: the suction hole and the discharge hole are located on a pair of opposite sides of the plunger cavity, so that when the valve core rotates 180°, the switching of the connection state between the plunger cavity and the suction hole and the discharge hole can be realized; a step hole is provided on the pump body, and a section of the step hole is used as the installation cavity, and the position of the valve core in the step hole is positioned by the step surface on the step hole. The hole section at the front end of the step hole is used as the first connecting hole and is used for the connection between the installation cavity and the plunger cavity. A sleeve having the tapered hole section is provided in the installation cavity, and the tapered section is installed in the sleeve. The sleeve is fixed in the installation cavity, and a retaining ring of the valve core and the outer end of the sleeve are provided. Elastic part; the plunger of the plunger pump is driven by a first drive mechanism of a stepper motor or a servo motor, so that the first drive mechanism is used to drive the plunger to move slightly with an appropriate stroke under the switching module to achieve the re-sucking of the extruded fluid, avoid the phenomenon of viscous fluid hanging on the wall at the front end of the liquid outlet pipe connected to the liquid outlet hole, ensure the fluid output accuracy of the plunger pump and reduce unnecessary waste of fluid. The second drive mechanism adopts a mechanism that can well control the rotation angle of the valve core, and specifically, a servo motor or stepper motor with a small volume and high angle control accuracy can be adopted. The valve core and the second drive mechanism adopt a tooth transmission with a fixed transmission ratio. Without considering the volume of the second drive mechanism, the second drive mechanism can also be pneumatic, hydraulic, etc.

[0027] The utility model has the following beneficial effects:

[0028] This solution provides a technical solution that can be used to switch the connection state between the plunger cavity on the plunger pump and the inlet and outlet of the plunger pump. The switching of the above connection state is not limited by the action of the plunger pump and the position of the plunger. Different from the traditional spring-based unidirectional conduction control solution, this solution does not increase the load of the plunger and can make the functions of the discharge hole and the inlet hole interchangeable.

[0029] When this solution is applied to quantitative delivery of viscous fluid that needs to be pressurized in advance before injection into the plunger pump, compared with the one-way conduction control solution based on the spring, the pressure of the flow path is not likely to cause unplanned changes in the conduction state between the plunger cavity and the suction hole and the discharge hole, so this solution has the characteristic of reliable control of the connection state;

[0030] The positions of the two orifices of the tapered section and the second connecting hole on the valve core are set to achieve: the orifice of the second connecting hole located on the end surface only rotates during the rotation of the valve core, and the first connecting hole connecting the plunger cavity and the orifice is easily processed on the valve body, and the second connecting hole and the plunger cavity are always kept in a state of being connected; during the entire use process, the orifice on the side of the valve core is connected with the suction hole or the discharge hole at different rotation angles, and during the process of the plunger performing fluid extrusion, the tapered section is supported by the pump body toward the large end of the tapered section, and can be pressed by the pressure exerted on the valve core by the fluid The force enables the valve core to move toward the end of the hole section / conical hole section with a smaller diameter, and with the help of the pressure, the axial sealing of the valve core and the matching surface of the hole section / conical hole section is achieved, while avoiding the pressure change in the flow path causing the stability of the valve core to be affected or causing unnecessary force on the second drive mechanism; after the corresponding matching surfaces between the valve core and the sleeve, and the valve core and the pump body are worn, the valve core can effectively maintain the state of the tapered section and the hole section / conical hole section The conical surface is in contact with the state, reducing the possibility of fluid leakage from the suction hole and the discharge hole through the outer periphery of the valve core. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a front view of a specific embodiment of the plunger pump described in this scheme;

[0032] Figure 2 for Figure 1 a side view of the structure shown;

[0033] Figure 3 for Figure 2 The structure shown is a cross-sectional view obtained by cutting along the AA direction;

[0034] Figure 4 for Figure 3 A partial enlarged view of section A is shown.

[0035] The reference numerals in the figure are respectively: 1. first driving mechanism, 2. transmission mechanism, 3. plunger pump body, 31. suction hole, 32. pump body, 33. discharge hole, 34. first connecting hole, 35. plunger, 4. switching module, 41. second driving mechanism, 42. valve core, 43. second connecting hole, 44. retaining ring, 45. elastic member, 46. sleeve. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the embodiments, but the present invention is not limited to the following embodiments:

[0037] Embodiment 1:

[0038] like Figures 1 to 4 As shown, the rotary control valve comprises a valve core 42 and a second driving mechanism 41 driving the valve core 42 to rotate around the axis of the valve core 42, wherein the valve core 42 has a conical section with a conical structure;

[0039] It also includes a second connecting hole 43 arranged on the valve core 42, one of the openings of the second connecting hole 43 is located on the side of the tapered section, and the other opening of the second connecting hole 43 is located on the end face of the valve core 42, and the position of the opening on the side is between the end face and the end with a smaller diameter of the tapered section.

[0040] The specific application of this scheme can be: installed on the pump body 32 of the plunger pump, as a switching module 4 for switching the connection state between the plunger cavity on the plunger pump and the suction hole 31 and the discharge hole 33 of the plunger pump, it can be specifically set to set a mounting cavity on the pump body 32, the suction hole 31 and the discharge hole 33 on the pump body 32 are both connected with the mounting cavity, and the connection position of the suction hole 31 on the mounting cavity and the connection position of the discharge hole 33 on the mounting cavity are located at the same axial position of the mounting cavity but at different circumferential positions, and the valve core 42 is installed in the mounting cavity; the orifice of the second connecting hole 43 located on the end face is connected with the front end of the plunger cavity, and the valve core 42 can rotate in the mounting cavity, and through the rotation , changing the position of the orifice of the second connecting hole 43 on the side surface, so that the conduction states of the orifice of the second connecting hole 43 on the side surface and the suction hole 31 and the discharge hole 33 are mutually converted. For example, when the valve core 42 is rotated to the second connecting hole 43 under the action of the second driving mechanism 41 to connect the suction hole 31 with the plunger cavity, the plunger 35 in the plunger cavity performs a fluid suction action, and the fluid from the suction hole 31 can be sucked in at this time. When the valve core 42 is rotated to the second connecting hole 43 under the action of the second driving mechanism 41 to connect the discharge hole 33 with the plunger cavity, the plunger 35 in the plunger cavity performs a fluid extrusion action, and the fluid in the plunger cavity can be extruded toward the discharge hole 33, thereby achieving the purpose of fluid transportation.

[0041] The conical section is a section on the valve core 42 where the diameter of one end is larger than the other end, and the diameter of each position of the conical section along its axis changes linearly. The valve core 42 can be installed on the pump body 32 by directly installing it in the installation cavity. In this application, the installation cavity needs to be processed into a hole section that can accommodate the conical section and fit with the conical section. The conical section is embedded in the hole section, coaxial with the hole section, and can rotate in the hole section with its own axis as the rotation axis. Since the opening of the second connecting hole 43 on the conical section rotates in the hole section, the openings of the drainage hole 33 and the suction hole 31 on the installation cavity are located on the hole section and are aligned with the hole of the second connecting hole 43. The opening is located at the same axial position of the valve core 42, so as to switch the connection state between the plunger cavity and the suction hole 31 and the discharge hole 33 when the valve core 42 rotates; when the following structure with a sleeve 46 is adopted, the sleeve 46 can be regarded as an inner lining on the mounting cavity, and the tapered hole section on the sleeve 46 cooperates with the tapered section, and the second connecting hole 43 is connected with the suction hole 31 and the discharge hole 33 through the corresponding connecting channel. In this way, the cavity wall of the mounting cavity fits well with the outer wall of the sleeve 46, so that the pump body 32 is used as the pressure-bearing structure outside the sleeve 46, and the sleeve 46 is set as an inner lining layer, and the performance of the plunger pump is optimized by exerting the functions of friction reduction and physical isolation of the medium.

[0042] In summary, this solution provides a technical solution that can be used to switch the connection state between the plunger chamber on the plunger pump and the inlet and outlet of the plunger pump. The switching of the above connection state is not limited by the action of the plunger pump and the position of the plunger 35. Different from the traditional spring-based unidirectional conduction control solution, this solution does not increase the load of the plunger 35, and at the same time, the functions of the discharge hole 33 and the inlet hole can be replaced with each other.

[0043] When this solution is applied to quantitative delivery of viscous fluid that needs to be pressurized in advance before injection into the plunger pump, compared with the unidirectional conduction control solution based on the spring, the pressure of the flow path is not likely to cause unplanned changes in the conduction state between the plunger cavity and the suction hole 31 and the discharge hole 33, so this solution has the characteristic of reliable control of the connection state;

[0044] The positions of the two orifices of the tapered section and the second connecting hole 43 on the valve core 42 are set to achieve: the orifice of the second connecting hole 43 located on the end surface only rotates during the rotation of the valve core 42, and the first connecting hole 34 connecting the plunger cavity and the orifice is easily processed on the valve body, and the second connecting hole 43 is always kept in a state of being connected to the plunger cavity by using the first connecting hole 34; during the entire use process, the orifice on the side of the valve core 42 is connected to the suction hole 31 or the discharge hole 33 at different rotation angles, and during the process of the plunger 35 performing fluid extrusion, the orifice on the end surface of the second connecting hole 43 is the inlet orifice, and the orifice on the side of the tapered section is the outlet orifice. In this way, the tapered section is supported by the pump body 32 toward the large end of the tapered section, and can pass the fluid The pressure exerted by the valve body on the valve core 42 enables the valve core 42 to move toward the end of the hole section / conical hole section with a smaller diameter, and with the help of this pressure, the valve core 42 and the hole section / conical hole section mating surface are axially sealed, while avoiding the pressure change in the flow path causing the stability of the valve core 42 to be affected or causing unnecessary force on the second drive mechanism 41; after the valve core 42 and the sleeve 46, and the valve core 42 and the pump body 32 corresponding mating surfaces are worn, the valve core 42 can effectively maintain the state of the tapered section and the hole section / conical hole section tapered surface in contact with each other under fluid pressure or under other forces toward the small end of the tapered section, thereby reducing the possibility of fluid leakage through the suction hole 31 and the discharge hole 33 through the periphery of the valve core 42, so the structural setting of the rotary control valve makes it have the characteristics of reliable sealing.

[0045] Embodiment 2:

[0046] This embodiment is further refined on the basis of embodiment 1:

[0047] In the specific implementation of the above scheme, the tapered section can be arranged between the two ends of the valve core 42 or at the end of the valve core 42. When it is located between the two ends, if the large end of the tapered section faces the front end of the valve core 42, the opening of the second communication hole 43 on the end surface is arranged on the front end surface of the valve core 42. When it is located at the end of the valve core 42, the large end of the tapered section is located at the end of the valve core 42. If the tapered section is located at the front end of the valve core 42, the opening of the second communication hole 43 on the end surface is arranged on the front end surface of the valve core 42. When the rotary control valve is installed on the pump body 32, the large end of the tapered section is preferably As one end of the tapered section penetrates into the pump body 32, since the tapered hole section / hole section can provide radial constraint for the valve core 42 after the valve core 42 is installed, in order to simplify the structure of the valve core 42 and shorten the length of the second connecting hole 43, it is set as follows: the end with a larger diameter of the tapered section is located at the end of the valve core 42. In addition, in order to facilitate the setting of the first connecting hole 34 that is always connected to the second connecting hole 43, the orifice of the second connecting hole 43 on the end surface can be rotated at the same position during the rotation of the valve core 42. Therefore, it is further set that the orifice on the end surface is located on the end and is coaxial with the valve core 42.

[0048] Embodiment 3:

[0049] This embodiment is further refined on the basis of embodiment 1:

[0050] It also includes a sleeve 46, which is sleeved on the outside of the tapered section, and has a tapered hole section that fits the tapered section;

[0051] The side wall of the sleeve 46 is provided with two communication channels, and the two communication channels are located at the same axial position of the sleeve 46 and at different circumferential positions;

[0052] When the valve core 42 rotates relative to the sleeve 46 around the axis of the valve core 42, the second communication hole 43 can be rotated as follows:

[0053] The orifice located on the side of the tapered section is butted against any one of the communicating channels and is staggered with another communicating channel. In the present solution, the sleeve 46 is used to be fixedly connected with the mounting cavity on the valve body, and a static seal realizing an axial sealing function is arranged on the mating surface with the mounting cavity, and the mating surface between the tapered section and the tapered hole section is a dynamic sealing surface realizing an axial sealing of the outer periphery of the valve core 42, and it is arranged to also include the sleeve 46 and install the valve core 42 in the sleeve 46. Compared with directly installing the valve core 42 on the pump body 32, the sleeve 46 can be manufactured separately as a part on the pump body 32. For example, the pump body 32 is made of stainless steel material to provide good pressure bearing capacity, and the sleeve 46 is made of a composite material, a polymer material or a metal material with good wear resistance and an inner hole wall that can be easily processed into a smooth wall. In this way, when the valve core 42 rotates and moves relative to the sleeve 46, the good wear resistance of the sleeve 46 and the good matching accuracy of the valve core 42 and the sleeve 46 can effectively guarantee the performance and life of the plunger pump, and the performance and life of the plunger pump are guaranteed by the fluid isolation of the sleeve 46 and the pressure resistance of the pump body 32. In specific implementation, it is preferred that the pump body 32 is made of stainless steel, the plunger 35 and the valve core 42 are made of ceramic material, and the sleeve 46 is made of a polymer material resistant to organic solvents.

[0054] Embodiment 4:

[0055] This embodiment is further refined on the basis of Embodiment 3:

[0056] In specific application, when it is not necessary to pressurize the fluid upstream of the suction hole 31 or the pressurized pressure is low, it is easy to maintain the axial sealing of the gap between the sleeve 46 and the valve core 42 during fluid suction and extrusion through the matching state of the sleeve 46 and the valve core 42, and prevent the fluid in the suction hole 31 from directly entering the discharge hole 33 from the gap. However, when it is necessary to pressurize the fluid upstream of the suction hole 31 to a higher pressure, such as during the suction process of the plunger 35, the fluid may still enter the discharge hole 33 from the suction hole 31 through the gap. In order to solve this problem, a certain positive pressure can always be maintained between the tapered hole section and the tapered section to prevent the fluid in the suction hole 31 from directly entering the discharge hole 33 from the gap or axial leakage through the gap. A pre-tightening structure is also included, which acts on the valve core 42 and is used to apply a force relative to the sleeve 46 to the valve core 42, and the direction of the force is: toward the side with a smaller diameter of the tapered section. In this solution, the pre-tightening structure is used to provide the valve core 42 with a continuous force toward the small end of the tapered hole section, and the force is used to maintain the positive pressure between the tapered hole section and the tapered section, thereby avoiding the axial leakage and the problem that the fluid in the suction hole 31 directly enters the discharge hole 33 from the gap. A preferred application is that the tapered hole section and the tapered section have the same size.

[0057] Embodiment 5:

[0058] This embodiment is further refined on the basis of Embodiment 4:

[0059] The pre-tightening structure includes a retaining ring 44 fixed on the valve core 42, and the pre-tightening structure also includes an elastic member 45 clamped between the end of the retaining ring 44 and the end of the sleeve 46 and in a compressed and deformed state. This scheme is a specific implementation method of the pre-tightening structure, specifically: the compressed elastic member 45 provides thrust for the retaining ring 44, and after the thrust is transmitted to the valve core 42 through the retaining ring 44, the valve core 42 obtains a force to move toward the small end of the tapered hole section. In this scheme, the elastic member 45 can be a metal elastic pad. Other applications also include setting an elastic member 45 between one end of the valve core 42 that penetrates into the pump body 32 and the pump body 32, but this method needs to consider the influence of the fluid on the elastic member 45, which is not conducive to the selection of the elastic member 45 and the ability to maintain performance.

[0060] Embodiment 6:

[0061] This embodiment is further refined on the basis of Embodiment 5:

[0062] As a technical solution that can effectively protect the valve core 42 and facilitate the installation of the clamp ring 44 when the valve core 42 is made of ceramic material, the elastic member 45 is an elastic gasket, and a flat gasket is provided between the elastic member 45 and the sleeve 46;

[0063] An annular groove coaxial with the valve core 42 is provided on the side surface of the valve core 42 , and the clamping ring 44 is installed in the annular groove. The clamping ring 44 can be an elastic circlip for a shaft.

[0064] Embodiment 7:

[0065] This embodiment is further refined on the basis of embodiment 1:

[0066] The second connecting hole 43 is composed of an axial hole and a radial hole connected in series, wherein the opening of the axial hole is located on the end face of the valve core 42, and the opening of the radial hole is located on the side of the tapered section. This solution provides a specific structural form of the second connecting hole 43, which is a technical solution that is convenient to process, simple in structure, and easy to ensure processing accuracy.

[0067] Embodiment 8:

[0068] This embodiment provides a plunger pump on the basis of Embodiment 1, including a plunger pump body 3, the plunger pump body 3 including a pump body 32 on which a suction hole 31 and a discharge hole 33 are provided, and also includes a switching module 4 installed on the pump body 32, the switching module 4 is used to switch the connection state between the plunger cavity on the plunger pump body 3 and the suction hole 31 and the discharge hole 33, the switching module 4 includes the rotary control valve as described in any one of the above;

[0069] The pump body 32 is provided with an installation cavity, the liquid suction hole 31 and the liquid discharge hole 33 are both connected to the installation cavity, and the valve core 42 is installed in the installation cavity;

[0070] The orifice of the second connecting hole 43 located on the end face is communicated with the front end of the plunger cavity, and the valve core 42 can rotate in the installation cavity. Through the rotation, the conduction state of the orifice of the second connecting hole 43 located on the side and the suction hole 31 and the discharge hole 33 are converted to each other. The present invention is a plunger pump including the rotary control valve, and a specific application is as follows: the suction hole 31 and the discharge hole 33 are located on a pair of opposite sides of the plunger cavity, so that when the valve core 42 rotates 180°, the connection state between the plunger cavity and the suction hole 31 and the discharge hole 33 can be switched; a step hole is provided on the pump body 32, one section of the step hole is used as the installation cavity, and the position of the valve core 42 in the step hole is positioned by the step surface on the step hole, the hole section at the front end of the step hole is used as the first connecting hole 34 and is used for connecting the installation cavity with the plunger cavity, a sleeve 46 with the tapered hole section is provided in the installation cavity, the tapered section is installed in the sleeve 46, the sleeve 46 is fixed in the installation cavity, and an elastic member 45 is provided between the retaining ring 44 of the valve core 42 and the outer end of the sleeve 46; the plunger 35 of the plunger pump adopts a stepping motor or a servo motor The first driving mechanism 1 of the machine is driven, so that the first driving mechanism 1 is used to drive the plunger 35 to move slightly with a suitable stroke under the switching module 4, so as to realize the back suction of the extruded fluid, avoid the phenomenon of viscous fluid hanging on the wall at the front end of the liquid outlet pipe connected to the liquid outlet hole, ensure the fluid output accuracy of the plunger pump and reduce unnecessary waste of fluid. At the same time, the first driving mechanism 1 and the plunger 35 are driven by the transmission mechanism 2, and the transmission mechanism 2 adopts a ball screw structure to ensure the transmission accuracy of the plunger 35 for a long time. The second driving mechanism 41 adopts a mechanism that can well control the rotation angle of the valve core 42, and specifically, a servo motor or a stepper motor with a small volume and high angle control accuracy can be adopted. The valve core 42 and the second driving mechanism 41 adopt a tooth transmission with a fixed transmission ratio. Without considering the volume of the second driving mechanism 41, the second driving mechanism 41 can also adopt pneumatic, hydraulic and other forms.

[0071] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and the specific embodiments of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, other embodiments derived without departing from the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A rotary control valve, comprising a valve core (42) and a second drive mechanism (41) for driving the valve core (42) to rotate around an axis of the valve core (42), characterized in that: The valve core (42) has a conical section with a conical structure; It also includes a second communication hole (43) arranged on the valve core (42), one of the openings of the second communication hole (43) is located on the side surface of the tapered section, and the other opening of the second communication hole (43) is located on the end surface of the valve core (42), and the position of the opening on the side surface is between the end surface and the end of the tapered section with a smaller diameter.

2. The rotary control valve according to claim 1, characterized in that: The end of the tapered section with a larger diameter is located at the end of the valve core (42), and the orifice on the end surface is located at the end and is coaxial with the valve core (42).

3. The rotary control valve according to claim 1, characterized in that: It also includes a sleeve (46), which is sleeved on the outside of the tapered section, and has a tapered hole section that fits the tapered section; Two communication channels are provided on the side wall of the sleeve (46), and the two communication channels are located at the same axial position of the sleeve (46) and at different circumferential positions; When the valve core (42) rotates relative to the sleeve (46) around the axis of the valve core (42), the second communication hole (43) can be rotated to: The orifice located on the side of the tapered section is butted against any one of the communicating channels and is staggered with another communicating channel.

4. The rotary control valve according to claim 3, characterized in that: It also comprises a pre-tightening structure, which acts on the valve core (42) and is used to apply a force to the valve core (42) relative to the sleeve (46), wherein the direction of the force is towards the side of the tapered section with a smaller diameter.

5. The rotary control valve according to claim 4, characterized in that: The pre-tightening structure comprises a clamping ring (44) fixed on the valve core (42), and the pre-tightening structure also comprises an elastic member (45) clamped between the end of the clamping ring (44) and the end of the sleeve (46) and in a compressed and deformed state.

6. The rotary control valve according to claim 5, characterized in that: The elastic member (45) is an elastic gasket, and a flat gasket is provided between the elastic member (45) and the sleeve (46); An annular groove coaxial with the valve core (42) is provided on the side surface of the valve core (42), and the clamping ring (44) is installed in the annular groove.

7. The rotary control valve according to any one of claims 1 to 6, characterized in that: The second connecting hole (43) is composed of an axial hole and a radial hole connected in series, wherein the orifice of the axial hole is located on the end surface of the valve core (42), and the orifice of the radial hole is located on the side surface of the tapered section.

8. A plunger pump, comprising a plunger pump body (3), the plunger pump body (3) comprising a pump body (32) provided with a liquid suction hole (31) and a liquid discharge hole (33), and further comprising a switching module (4) mounted on the pump body (32), the switching module (4) being used to switch the connection state between the plunger cavity on the plunger pump body (3) and the liquid suction hole (31) and the liquid discharge hole (33), characterized in that: The switching module (4) comprises a rotary control valve according to any one of claims 1 to 7; The pump body (32) is provided with a mounting cavity, the liquid suction hole (31) and the liquid discharge hole (33) are both in communication with the mounting cavity, and the valve core (42) is mounted in the mounting cavity; The orifice of the second communicating hole (43) located on the end surface is communicated with the front end of the plunger cavity, and the valve core (42) can rotate in the installation cavity. Through the rotation, the conduction state of the orifice of the second communicating hole (43) located on the side surface and the suction hole (31) and the discharge hole (33) are mutually switched.

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