CN113110626B - Rectangular transparent adjustable venturi - Google Patents

Abstract

The present application relates to the field of aerospace technology, in particular to a rectangular transparent adjustable venturi. A rectangular transparent adjustable venturi includes a venturi casing, an adjustment component and a sliding member; the sliding member is arranged in the venturi casing, and a flow is formed between the sliding member and the side wall of the venturi casing. The two ends of the corresponding flow channel are respectively provided with an inlet end and an outlet end on the venturi shell; one end of the adjustment assembly is connected to the sliding piece, and the adjustment assembly can drive the sliding piece to move along the axis perpendicular to the flow channel. to change the cross-sectional area of the runner. The flow channel of the present application is formed between the sliding piece and the side wall of the venturi casing. When the sliding piece is driven to move in a direction perpendicular to the axis of the flow channel, a wide range of flow regulation can be achieved.

Description

Rectangular transparent adjustable venturi

technical field

The present application relates to the field of aerospace technology, in particular to a rectangular transparent adjustable venturi.

Background technique

When the adjustable cavitation Venturi adjusts the flow, it adopts the method of moving the valve core, specifically, the moving valve core changes the annular area formed between the valve core and the throat, so as to achieve the purpose of adjusting the flow rate; however, using this kind of Due to the structure, it is difficult to adjust the flow in a wide range and to observe the flow of the liquid inside the venturi.

Therefore, there is an urgent need for a rectangular transparent adjustable cavitation venturi to solve the technical problems existing in the prior art to a certain extent.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide a rectangular, transparent and debuggable venturi, to a certain extent, to solve the technical problem that the existing venturi is difficult to achieve a wide range of flow regulation.

The present application provides a rectangular transparent adjustable venturi, including a venturi casing, an adjustment component and a sliding member;

The sliding member is arranged in the venturi shell, and a flow channel is formed between the sliding member and the side wall of the venturi shell; the two ends corresponding to the flow channel are respectively located in the venturi shell. The upper opening is provided with an inlet end and an outlet end;

One end of the adjusting assembly is connected with the sliding member, and the adjusting assembly can drive the sliding member to move in a direction perpendicular to the axis of the flow channel to change the cross-sectional area of the flow channel.

In the above technical solution, a see-through member is further included; the see-through member is arranged on the casing and is arranged corresponding to the flow channel.

In the above technical solution, further, the see-through member includes an observation window and an anti-leakage ring;

The observation window is fixed on the venturi casing by the first fastening bolt, and is arranged corresponding to the flow channel;

The leak-proof ring is arranged between the observation window and the venturi casing, and is used for sealing the observation window on the venturi casing.

In the above technical solution, further, an electric cylinder is also included; the electric cylinder includes a servo drive motor, a motor housing and a ball screw;

The motor housing has an accommodating space, and the ball screw is connected with the output shaft of the servo drive motor and placed in the accommodating space;

The fixing part of the adjusting assembly is sleeved on the ball screw.

In the above technical solution, further, it also includes a control unit;

The control unit includes a PLC controller, a servo drive motor encoder, and a servo drive motor controller electrically connected to the PLC controller;

The servo drive motor controller is electrically connected to the servo drive motor, the receiving end of the servo drive motor encoder is electrically connected to the servo drive motor, and the transmitter end is electrically connected to the servo drive motor controller;

The PLC controller can transmit a preset command signal to the servo drive motor controller, and the servo drive motor controller that receives the preset command signal is used to control the motion of the servo drive motor to make the adjustment The assembly moves in a direction perpendicular to the axis of the flow channel;

The servo drive motor encoder is used to record the running speed and rotation direction of the output shaft of the servo drive motor, and can feed back the recorded running speed data and rotation direction data to the servo drive motor controller.

In the above technical solution, further, a reset component is also included; the reset component is electrically connected to the PLC controller;

The reset assembly includes a magnetic ring and at least three magnetic limit switches arranged on the motor housing at intervals, and the position of the magnetic limit switch close to the venturi housing is the origin position;

the magnetic ring is arranged on the fixing part;

When the fixed part moves in a direction perpendicular to the axis of the flow channel, the magnetic ring will trigger different actions of the magnetic limit switches, and the PLC controller can receive the action signals of the magnetic limit switches , and transmits a preset command signal to the servo drive motor controller according to the action signal, so as to reset the fixed part to the indicated origin position.

In the above technical solution, further, three magnetic limit switches are provided, and the three magnetic limit switches are respectively an upper limit switch, a warning limit switch and a lower limit switch;

The warning limit switch is arranged between the upper limit switch and the lower limit switch; the lower limit switch corresponds to the origin position;

The servo drive motor controller can respectively control the servo drive motor to move at a first speed and a first rotational direction to move the magnetic ring toward the upper limit switch, the servo drive motor to move at the first speed and a second rotational direction to move the magnet ring toward the warning limit switch and the servo drive motor to move at a second speed and the second rotational direction to move the magnet ring toward the lower limit switch When the magnetic ring moves to the origin position, the fixing part is reset.

In the above technical solution, further, the reset assembly further includes a limit block disposed between the electric cylinder and the venturi casing;

A first accommodating part, a second accommodating part and a third accommodating part are sequentially opened inside the limiting block from the end part close to the electric cylinder to the end part close to the venturi housing, and the third accommodating part the accommodating part communicates with the flow channel;

the first accommodating part, the second accommodating part and the third accommodating part are stepped;

The adjusting part of the adjusting assembly passes through the first accommodating part, the second accommodating part and the third accommodating part in sequence, and is connected with the sliding element.

In the above technical solution, further, it also includes an inlet pipe connection member;

The inlet pipe connection member includes an inlet pipe joint, a first gasket and a first leak-proof ring;

The inlet pipe joint is disposed on the venturi shell corresponding to the inlet end;

the first anti-leakage ring is arranged between the inlet pipe joint and the inner side wall of the venturi casing;

The first gasket is disposed between the inlet pipe joint and the outer side wall of the venturi housing.

In the above technical solution, further, it also includes an outlet pipe connection member;

The outlet pipe connection member includes an outlet pipe joint, a second gasket and a second leak-proof ring;

The outlet pipe connector is disposed on the venturi casing corresponding to the outlet end;

The second leak-proof ring is arranged between the outlet pipe joint and the inner side wall of the venturi casing; the second gasket is arranged between the outlet pipe joint and the venturi casing. between the outer walls.

Compared with the prior art, the beneficial effects of the present application are:

The application provides a rectangular transparent adjustable venturi, including a venturi casing, an adjustment component and a sliding member;

The sliding member is arranged in the venturi shell, and a flow channel is formed between the sliding member and the side wall of the venturi shell; the two ends corresponding to the flow channel are respectively located in the venturi shell. The upper opening is provided with an inlet end and an outlet end;

One end of the adjusting assembly is connected with the sliding member, and the adjusting assembly can drive the sliding member to move in a direction perpendicular to the axis of the flow channel to change the cross-sectional area of the flow channel.

Specifically, the flow channel of the present application is formed between the sliding piece and the side wall of the venturi casing. When the sliding piece is driven to move in a direction perpendicular to the axis of the flow channel, a wide range of Flow regulation.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific embodiments or the prior art will be briefly introduced below. The drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic plan view of a rectangular transparent adjustable venturi provided by the application at a first viewing angle;

Fig. 2 is the enlarged view of A structure in Fig. 1;

3 is a schematic structural diagram of a venturi casing in a rectangular transparent adjustable venturi provided by the application;

4 is a schematic structural diagram of removing the venturi casing in the rectangular transparent adjustable venturi provided by the application;

FIG. 5 is a schematic plan view of the rectangular transparent adjustable venturi provided by the present application in a second viewing angle.

Reference number:

100-venturi housing; 101-adjustment assembly; 102-slider; 103-flow channel; 104-contraction section; 105-transition section; 106-expansion section; 107-fixed part; 108-adjustment part; 109- 110-observation window; 111-first anti-leakage ring; 112-first fastening bolt; 115-motor housing; 116-slot; 117-ball screw; 118-reset assembly; 119-upper limit switch; 120-warning limit switch; 121-lower limit switch; 124-limit block; 128-inlet pipe connection member; 129-inlet pipe joint; 130-first gasket; 131-second leakproof ring; 132 - outlet pipe connection member; 133 - outlet pipe joint; 134 - second gasket; 135 - third leakage prevention ring; 136 - fourth leakage prevention ring; 137 - fifth leakage prevention ring; 138 - second fastening bolt ; 139 - the third tightening bolt; 140 - the fourth tightening bolt; 141 - the sixth anti-leakage ring; 142 - adjusting rod; 143 - connecting block.

Detailed ways

The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, but not all of the embodiments.

The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Thus, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the application as claimed, but is merely representative of selected embodiments of the application.

Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limitations on this application. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood in specific situations.

The following describes a rectangular transparent adjustable venturi provided by the present application with reference to FIGS. 1 to 5 .

The present application provides a rectangular transparent adjustable venturi, including a venturi casing 100, an adjustment assembly 101 and a sliding member 102;

The sliding member 102 is disposed in the venturi housing 100, and a flow channel 103 is formed between the sliding member 102 and the side wall of the venturi housing 100; The venturi casing 100 is provided with an inlet end and an outlet end;

One end of the adjusting assembly 101 is connected with the sliding member 102 , and the adjusting assembly 101 can drive the sliding member 102 to move in a direction perpendicular to the axis of the flow channel 103 to change the cross-sectional area of the flow channel 103 .

Specifically, the flow channel 103 formed between the sliding member 102 and the side wall of the venturi casing 100 in the present application is a rectangular structure, and when the sliding member 102 is driven along the axis perpendicular to the flow channel 103 When moving in the direction, a wide range of flow regulation can be achieved, and even a super large flow regulation ratio can be achieved. When the sliding member 102 is very close to the side wall of the venturi housing 100 and fits slightly, a small flow regulation can be achieved. .

Specifically, the inner side wall of the venturi casing 100 cooperates with the sliding member to form an adjustable minimum flow area to control the flow.

More specifically, the flow channel 103 has a constricting section 104 , a transition section 105 and an expanding section 106 connected in sequence.

In addition, the drive shaft of the existing cavitation control venturi and the direction of the fluid outlet are on the same straight line, and the direction of the fluid inlet and the fluid outlet are often 90 degrees. However, this 90-degree curved structure, Once the pressure drop is large, cavitation cannot occur in the transition section 105, and the downstream pressure will have an impact on the transition section 105, which will lead to unstable upstream pressure and a certain deviation in flow control. In this application, the inlet end and the outlet end are relatively set , that is, the flow channel 103 formed by the inlet end and the outlet end is a straight flow channel 103, there is no bending, it will not cause too much pressure drop loss, the upstream pressure is relatively stable, and the flow control accuracy is improved.

In this embodiment, in order to be able to observe the flow rate of the liquid in the flow channel 103 at any time, and to observe whether the cavitation phenomenon occurs at any time, so as to facilitate the analysis of the flow field of the inner flow channel 103 of the Venturi tube, the rectangular transparent adjustable Venturi The tube further includes a see-through member 109 ; the see-through member 109 is arranged on the casing and is arranged corresponding to the flow channel 103 .

Wherein, the see-through member 109 includes an observation window 110 and a first anti-leakage ring 111; the observation window 110 is fixed on the venturi casing 100 by the first fastening bolt 112, and is connected with the flow The first anti-leakage ring 111 is disposed between the observation window 110 and the venturi casing 100 to seal the observation window 110 to the venturi casing 100 superior.

Specifically, since the interior of the venturi is closed, it is difficult to observe the phenomenon of internal liquid flow; the present application provides a transparent venturi suitable for testing experiments. During the experiment, the flow field information of cavitation phenomenon can be obtained through video recording equipment , which can be used for mechanistic studies. In the same way, it is also possible to directly judge whether cavitation occurs inside the adjustable venturi from the direction of image processing by means of machine vision, and even visually judge whether cavitation occurs inside the venturi.

Specifically, the observation window 110 is made of Parm board, which integrates the advantages of high strength, high toughness, high thickness, high transparency, etc. The observation window 110 made of Parm board can withstand up to several In addition, the observation window 110 made of Pam plate not only has a certain thickness, but also has the advantage of high transparency, so that the operator can clearly observe the venturi from the outside. Internal fluid flow and cavitation.

Further, the observation window 110 is preferably circular.

Specifically, the number of the first fastening bolts 112 is set in multiples, preferably 15, which can be obtained through repeated tests. On the one hand, the 15 first fastening bolts 112 can withstand the fluid pressure for the observation window 110. The pressure, on the other hand, fastens the viewing window 110 and the venturi housing 100.

Specifically, the first anti-leakage ring 111 cooperates with the observation window 110 and the venturi casing 100 to prevent fluid leakage inside the adjustable venturi and achieve a sealing effect.

In this embodiment, the adjusting assembly 101 includes an adjusting rod 142 , an adjusting portion 108 is formed on the end of the adjusting rod 142 close to the venturi housing 100 , and a fixing portion is formed on the end close to the electric cylinder 107.

In this embodiment, an electric cylinder is also included, preferably a servo electric cylinder. Compared with a conventional stepping motor, the function of the servo electric cylinder is to convert rotary motion into linear motion. The servo electric cylinder is a modular product that integrates the servo drive motor and the lead screw. It converts the rotary motion of the servo drive motor into linear motion, while retaining the greatest advantages of the servo drive motor: the precise speed, number of revolutions, torque The control is converted into precise speed, displacement, thrust control, and finally high-precision linear motion control can be realized. In this embodiment, in order to save space, a foldable electric cylinder is preferably used, in which the belt drive of the synchronous pulley is added.

Specifically, the electric cylinder includes a servo drive motor, a motor housing 115 and a ball screw 117; the motor housing 115 has a accommodating space in it, the ball screw 117 and the output shaft of the servo drive motor connected and placed in the accommodating space; the fixing part 107 of the adjusting assembly 101 is sleeved on the ball screw 117 .

In the actual working process, a servo control system can be used to control the electric cylinder, thereby realizing accurate adjustment of the position, state and orientation of the adjustment assembly 101, wherein the servo control system is a prior art, which is briefly described here as follows: The servo control system mainly relies on pulses for positioning. When the servo drive motor receives one pulse, it will rotate the angle corresponding to one pulse, thereby realizing the displacement of the ball screw 117; further, the pulses received by the servo drive motor and The formation between the pulses fed back by the servo drive motor can realize a closed-loop system, so as to precisely control the rotation of the servo drive motor, thereby realizing the accurate adjustment of the adjustment component 101; under normal circumstances, the repeated positioning accuracy of the adjustment component 101 can reach 0.002mm. At the same time, the servo drive motor can also achieve fast response. When the lead screw is 2mm and the rated speed of the motor is 3000 rpm, the adjustment speed can reach 100mm/s, and the motor speed can be increased to 6000 rpm under special circumstances. Minutes, the maximum adjustment speed can reach 200mm/s.

In this embodiment, it also includes a control unit; the control unit includes a PLC controller, a servo drive motor encoder, and a servo drive motor controller electrically connected to the PLC controller; the servo drive motor controller is connected to the The servo drive motor is electrically connected, the receiving end of the servo drive motor encoder is electrically connected with the servo drive motor, and the transmitter end is electrically connected with the servo drive motor controller; the PLC controller can send the servo drive motor to the servo drive. The drive motor controller transmits a preset command signal, and the servo drive motor controller that receives the preset command signal is used to control the motion of the servo drive motor, so that the adjustment assembly 101 is perpendicular to the flow channel 103 The axis direction movement of the servo drive motor; the servo drive motor encoder is used to record the operation speed and rotation direction of the output shaft of the servo drive motor, and can feed back the recorded operation speed data and rotation direction data to the servo drive motor controller. .

In this embodiment, a reset assembly 118 is also included; the reset assembly 118 is electrically connected to the PLC controller; the reset assembly 118 includes a magnetic ring and at least three spaced apart on the motor housing 115 the magnetic limit switch, and the position of the magnetic limit switch close to the venturi casing is the origin position; the magnetic ring is arranged on the fixing part 107;

When the fixing part 107 moves in a direction perpendicular to the axis of the flow channel 103, the magnetic ring will trigger different actions of the magnetic limit switches, and the PLC controller can receive the magnetic limit switches. action signal, and transmits a preset command signal to the servo drive motor controller according to the action signal, so as to reset the fixing part 107 to the shown origin position.

In this embodiment, there are three magnetic limit switches, and the three magnetic limit switches are respectively an upper limit switch 119 , a warning limit switch 120 and a lower limit switch 121 ;

The warning limit switch 120 is disposed between the upper limit switch 119 and the lower limit switch 121; the lower limit switch 121 corresponds to the origin position;

The servo drive motor controller can respectively control the servo drive motor to move at a first speed and a first rotation direction to make the magnetic ring move towards the upper limit switch 119, and the servo drive motor to move at the first speed. speed and second rotational direction to move the magnet ring toward the warning limit switch 120 and the servo drive motor to move at a second speed and the second rotational direction to move the magnet ring toward the lower limit The position switch 121 moves, and when the magnetic ring moves to the origin position, the fixing portion 107 is reset.

Specifically, in this embodiment, the limit position is reached through the cooperation of the three magnetic limit switches (the upper limit switch 119 , the warning limit switch 120 and the lower limit switch 121 ), and the main function is to adjust the venturi. After the task is performed, the adjustment component 101 can be accurately reset to zero, thereby establishing a benchmark, avoiding the accumulation of errors caused by multiple uses, and facilitating multiple use.

In order to ensure the repeatability of the venturi control and the accuracy of the origin return, the upper limit switch 119, the warning limit switch 120 and the lower limit switch 121 are installed in the groove 116 on the upper part of the electric cylinder; the principle of the magnetic limit switch is The ball screw 117 in the electric control cylinder is fixedly connected with the fixed part 107 of the adjustment assembly 101, and the ball screw 117 is equipped with a magnetic ring, so the magnetic ring and the fixed part 107 move synchronously, and the magnetic ring moves to the position of the magnetic limit switch. When it is near, the magnetic field strength here increases, and the magnetic limit switch is closed by the magnetic action; when the magnetic ring is far away from the magnetic limit switch, the magnetic field strength decreases, and the magnetic limit switch is disconnected. The specific working process is as follows: when the current task is completed or the origin return instruction is received, the fixed part 107 of the adjustment component 101 starts to quickly approach the upper limit switch 119 at a constant speed, and after the magnetic ring touches the upper limit switch 119, the adjustment component The fixed part 107 of 101 stops and moves rapidly in the opposite direction at a constant speed until the magnetic ring hits the warning limit switch 120, the warning limit switch 120 is closed, and the moving speed of the fixed part 107 of the adjusting assembly 101 becomes slower, in a way. The constant low-speed downward limit switch 121 moves closer until it hits the lower limit switch 121, and the fixed part 107 of the adjustment assembly 101 stops moving, which is the origin (the position of the lower limit switch 121 is the origin). Since the return to the origin is approached at a constant low speed to the lower limit switch 121 serving as the origin each time, the accuracy can be improved.

It can detect whether the three limit magnetic switches work normally each time when returning to the origin. If the fixed part 107 of the adjustment assembly 101 moves to the corresponding position, the PLC does not receive the signal returned by the magnetic limit switches, indicating that there is a problem with the sensor. , the fixed part 107 of the adjustment assembly 101 stops moving, and the PLC control panel will report an error.

More specifically, through the cooperation of software and hardware, the three magnetic limit switches can provide different control schemes for the same flow adjustment process in order to further improve the control accuracy. The following three control schemes that can be implemented are given in this application:

In the first control scheme, every time the fixing portion 107 of the adjusting assembly 101 starts to work, according to the above-mentioned movement method, the fixing portion 107 of the adjusting assembly 101 quickly reaches the upper magnetic limit switch, then reaches the warning limit switch 120, and then reaches the upper magnetic limit switch. It reaches the lower limit switch 121 at a constant low speed and returns to the origin.

When receiving the adjustment flow command, the PLC sends corresponding pulses at a certain frequency, so that the fixed part 107 of the adjustment component 101 reaches the corresponding position; when the flow adjustment command is received again, that is, when the flow size needs to be changed again, in order to improve the control Accuracy, the magnetic limit switch will be used again here, the fixed part 107 of the adjustment assembly 101 will again reach the upper limit switch 119 at a constant and fast speed, then reach the warning limit switch 120, and then reach the lower limit switch 121 at a constant low speed, returning to the origin , and then the number of pulses is cleared. Then, the fixed part 107 of the adjustment component 101 is moved to the corresponding position by sending a certain number of pulses through the PLC control board.

To sum up, the magnetic limit switch as hardware is used to assist in returning to the origin, so that the fixing portion 107 of the adjusting assembly 101 reaches the target position again.

In the second control scheme, after the power is turned on, the fixed part 107 of the adjustment component 101 is moved to the origin as described above. When receiving the adjustment flow command, the PLC sends corresponding pulses at a certain frequency, so that the fixed part 107 of the adjustment component 101 reaches the origin. Corresponding position; when the command of flow change is received again, through the logic operation and four arithmetic operations of the PLC control board, determine which magnetic limit switch is the closest to the present, and then approach the magnetic limit switch at a constant low speed, When the switch detects the fixed part 107 of the adjustment assembly 101, the fixed part 107 of the adjustment assembly 101 stops, and the pulse number in the PLC control board is changed to the pulse number corresponding to the magnetic limit switch. The reason for this operation is that when the fixed part 107 of the adjustment assembly 101 is in different positions, it corresponds to different pulse numbers. For example, the lower limit switch 121 is used as the origin, and the corresponding pulse number is 0. The remaining two magnetic limit switches are set in advance. The position of the position switch is calibrated. The calibration method is as follows: the fixed part 107 of the adjustment assembly 101 starts from the origin and approaches the warning limit switch 120 at a constant low speed. When the warning limit switch 120 is close to closing, the fixed part 107 of the adjustment assembly 101 Stop the movement and record the number of pulses at this time. This number of pulses corresponds to the actual position of the warning limit switch 120; similarly, the upper limit switch 119 is calibrated, and its position corresponds to a certain number of pulses.

The third control scheme is to return to the origin according to the above method after starting up. When receiving the regulation flow command, the PLC sends corresponding pulses at a certain frequency, so that the fixed part 107 of the regulation component 101 reaches the corresponding position. When the flow adjustment command is received again, that is, the flow rate needs to be changed again, the fixed part 107 of the adjustment assembly 101 will quickly approach the origin, and when approaching the origin, it will reach the lower limit switch 121 at a constant low speed, and then the lower limit The switch 121 is closed, the number of pulses is cleared, the PLC control board sends the corresponding number of pulses again, and the fixed part 107 of the adjustment component 101 moves to the corresponding position.

The premise that the third solution can be implemented is to use absolute positioning to record the number of pulses, that is, different positions correspond to different numbers of pulses. When the fixed part 107 of the adjustment component 101 is rapidly approaching the origin, the number of pulses recorded by the PLC control board will decrease rapidly. Small. When the number of pulses is lower than a certain value, the PLC control board can determine that the fixed part 107 of the adjustment component 101 is very close to the lower limit switch 121 at this time, so the output pulse frequency is changed, and the fixed part 107 of the adjustment component 101 will be constant The origin is reached at low speed, thereby improving the control accuracy.

To sum up, in order to improve the control accuracy and reduce the response time, that is, to improve the displacement accuracy and speed of the fixed portion 107 of the adjustment assembly 101, the conventional stepper motor is no longer used here, but an electric cylinder is used to drive the adjustment assembly. The fixed part 107 of 101, the electric cylinder is a linear motion mechanism combined with a high-precision servo drive motor and a high-precision ball screw, and the high-precision displacement control and fast response of the electric cylinder are used to achieve accurate flow control.

In the actual working process, the PLC controller transmits a preset command signal to the servo drive motor controller, where the preset command signal refers to a pulse command, and the servo drive motor controller drives the servo drive motor after receiving the pulse command. Rotating according to the corresponding speed and direction, the rotary motion of the servo drive motor is converted into the linear motion of the adjusting mechanism through the transmission mechanism and the ball screw 117 . Specific steps are as follows:

Step 100: Calculate the number of pulses that the PLC controller needs to transmit when a certain liquid flow rate needs to be adjusted, for example, when a certain liquid flow rate needs to be increased, that is, when a certain liquid flow rate needs to be increased. The cross-sectional area of the large critical flow channel 103 can be calculated by the relevant calculation formula of the venturi, and the moving distance of the adjustment part 108 can be calculated, and then the transmission ratio of the transmission mechanism, the pitch of the ball screw 117, etc. can be used to calculate the required rotation of the servo drive motor. angle or number of turns; then convert the rotation angle into the number of pulses that the corresponding servo drive motor driver needs to send, and finally convert the number of pulses from the servo drive motor driver to the number of pulses that the PLC controller needs to send through the conversion of the electronic gear ratio.

Step 200: The PLC controller sends a preset number of pulses, and the adjusting part 108 moves, thereby adjusting the cross-sectional area of the critical flow channel 103 and adjusting the flow rate of the liquid flow; the servo drive motor controller receives the pulse frequency and the number of pulses from the PLC controller After that, the servo drive motor driver sends a certain number of pulses at the corresponding pulse frequency, and the servo drive motor receives the pulse frequency and the number of pulses (wherein, the pulse frequency corresponds to the rotation speed of the servo drive motor, and the number of pulses corresponds to the rotation angle of the servo drive motor), The servo drive motor will rotate the corresponding angle at the speed corresponding to the pulse frequency. At this time, the rotation of the servo drive motor will be recorded by the servo drive motor encoder, and the encoder will feed back the recorded pulses to the servo drive motor driver; in this way , the pulse of the servo drive motor driver and the servo drive motor encoder echoes, because the pulse of the servo drive motor encoder matches the pulse of the rotation angle of the servo drive motor, which is equivalent to the formation between the servo drive motor driver and the servo drive motor. closed-loop control.

In summary, the formed servo drive system is a closed-loop control system. The servo drive motor driver can directly sample the encoder feedback signal of the servo drive motor, and a position loop and a speed loop are formed inside, which can overcome the existing open-loop stepping. The motor has the phenomenon of missing pulses, and the present application makes the control performance more stable and reliable.

In this embodiment, the reset assembly 118 further includes a limit block 124 disposed between the electric cylinder and the venturi housing;

A first accommodating portion, a second accommodating portion and a third accommodating portion are sequentially opened inside the limiting block 124 from the end portion close to the electric cylinder to the end portion close to the venturi housing. Three accommodating parts communicate with the flow channel 103; the first accommodating part, the second accommodating part and the third accommodating part are stepped; the regulating part 108 of the regulating assembly 101 passes through the first accommodating part in sequence part, the second accommodating part and the third accommodating part, and are connected with the slider 102 .

Specifically, one end of the limit block 124 is fixed on the motor housing 115 by the third fastening bolt 139, and the other end of the limit block 124 is connected with the connection block 143 by the second fastening bolt 138, One end of the connecting block 143 is connected to the venturi casing 100 by a fourth fastening bolt 140 , and a sixth anti-leakage ring 141 is arranged between the connecting block 143 and the venturi casing 100 . The inner side wall of the block 143 is provided with a fourth leak-proof ring 136 at the connection with the limiting block 124 , and a fifth leak-proof ring 137 is provided at the connection between the limiting block 124 and the adjusting portion 108 . In this implementation In the example, the fourth anti-leakage ring 136, the fifth anti-leakage ring 137 and the sixth anti-leakage ring 141 are used to make the adjustment assembly 101, the venturi housing 100 and the electric cylinder in a sealed state to prevent liquid leakage. flow.

In this embodiment, an inlet pipe connection member 128 is also included; the inlet pipe connection member 128 includes an inlet pipe joint 129, a first gasket 130 and a second leak-proof ring 131;

The inlet pipe joint 129 is disposed on the venturi casing 100 corresponding to the inlet end and is adapted to the venturi casing 100. The inlet pipe joint 129 is used as a general interface and is connected with external pipes , as the inlet of the venturi housing 100 .

The second anti-leakage ring 131 is disposed between the inlet pipe joint 129 and the inner side wall of the venturi casing 100 to prevent fluid leakage inside the venturi casing 100 and achieve a sealing effect.

The first gasket 130 is disposed between the inlet pipe joint 129 and the outer side wall of the venturi housing 100 . The function of the first gasket 130 is to increase the tightening force and prevent the inlet pipe joint 129 from loosening.

In this embodiment, an outlet pipe connection member 132 is also included; the outlet pipe connection member 132 includes an outlet pipe joint 133, a second gasket 134 and a second leak-proof ring 131;

The outlet pipe fitting is disposed on the venturi casing 100 corresponding to the outlet end, and the function of the outlet pipe fitting 132 is to serve as a general interface to connect with the external pipeline, and to serve as a connection to the venturi casing 100 . Export.

The third anti-leakage ring 135 is disposed between the outlet pipe joint 133 and the inner side wall of the venturi casing 100 ; the third anti-leakage ring 135 prevents fluid leakage inside the venturi casing 100 to achieve sealing effect.

The second gasket 134 is disposed between the outlet pipe joint 133 and the outer side wall of the venturi housing 100 ; the second gasket 134 is used to increase the tightening force and prevent the outlet pipe joint 133 from loosening.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application. scope.

Claims (10)

1. a rectangular transparent adjustable venturi, is characterized in that, comprises venturi casing, adjustment assembly and slider; The sliding member is arranged in the venturi shell, and a flow channel is formed between the sliding member and the side wall of the venturi shell; the two ends corresponding to the flow channel are respectively located in the venturi shell. The upper opening is provided with an inlet end and an outlet end; One end of the adjusting assembly is connected with the sliding member, and the adjusting assembly can drive the sliding member to move in a direction perpendicular to the axis of the flow channel to change the cross-sectional area of the flow channel, and the flow channel includes Sequentially connected constriction, transition, and expansion. 2. The rectangular transparent adjustable venturi according to claim 1, further comprising a see-through member; The see-through member is arranged on the casing and is arranged corresponding to the flow channel. 3. The rectangular transparent adjustable venturi according to claim 2, wherein the see-through member comprises an observation window and a first anti-leakage ring; the observation window is fixed on the venturi casing by a first fastening bolt, and is arranged corresponding to the flow channel; The first anti-leakage ring is arranged between the observation window and the venturi casing, and is used for sealing the observation window on the venturi casing. 4. The rectangular transparent adjustable venturi according to claim 1, further comprising an electric cylinder; The electric cylinder includes a servo drive motor, a motor housing and a ball screw; The motor housing has an accommodating space, and the ball screw is connected with the output shaft of the servo drive motor and placed in the accommodating space; The adjustment assembly includes a fixing part, and the fixing part is sleeved on the ball screw. 5. The rectangular transparent adjustable venturi according to claim 4, further comprising a control unit; The control unit includes a PLC controller, a servo drive motor encoder, and a servo drive motor controller electrically connected to the PLC controller; The servo drive motor controller is electrically connected to the servo drive motor, the receiving end of the servo drive motor encoder is electrically connected to the servo drive motor, and the transmitter end is electrically connected to the servo drive motor controller; The PLC controller can transmit a preset command signal to the servo drive motor controller, and the servo drive motor controller that receives the preset command signal is used to control the motion of the servo drive motor to make the adjustment The assembly moves in a direction perpendicular to the axis of the flow channel; The servo drive motor encoder is used to record the running speed and rotation direction of the output shaft of the servo drive motor, and can feed back the recorded running speed data and rotation direction data to the servo drive motor controller. 6. The rectangular transparent adjustable venturi according to claim 5, further comprising a reset assembly; the reset assembly is electrically connected to the PLC controller; The reset assembly includes a magnetic ring and at least three magnetic limit switches arranged on the motor housing at intervals, and the position of the magnetic limit switch close to the venturi housing is the origin position; the magnetic ring is arranged on the fixing part; When the fixed part moves in a direction perpendicular to the axis of the flow channel, the magnetic ring will trigger different actions of the magnetic limit switches, and the PLC controller can receive the action signals of the magnetic limit switches , and transmits a preset command signal to the servo drive motor controller according to the action signal, so as to reset the fixed part to the indicated origin position. 7 . The rectangular transparent adjustable venturi according to claim 6 , wherein three magnetic limit switches are provided, and the three magnetic limit switches are respectively an upper limit switch, a warning limit switch and a lower limit switch; The warning limit switch is arranged between the upper limit switch and the lower limit switch; the lower limit switch corresponds to the origin position; The servo drive motor controller can respectively control the servo drive motor to move at a first speed and a first rotation direction, so that the magnetic ring moves toward the upper limit switch; the servo drive motor moves at the first speed speed and a second rotational direction to move the magnetic ring toward the warning limit switch and the servo drive motor to move at a second speed and the second rotational direction to move the magnetic ring toward the alert limit switch The lower limit switch moves, and when the magnetic ring moves to the origin position, the fixing part is reset. 8 . The rectangular transparent adjustable venturi according to claim 6 , wherein the reset assembly further comprises a limit block arranged between the electric cylinder and the venturi housing; 8 . A first accommodating part, a second accommodating part and a third accommodating part are sequentially opened inside the limiting block from the end close to the electric cylinder to the end close to the venturi housing, and the third accommodating part the accommodating part communicates with the flow channel; the first accommodating part, the second accommodating part and the third accommodating part are stepped; The adjustment assembly further includes an adjustment part, the adjustment part passes through the first accommodating part, the second accommodating part and the third accommodating part in sequence, and is connected with the sliding member. 9. The rectangular transparent adjustable venturi according to claim 1, further comprising an inlet pipe connection member; The inlet pipe connection member includes an inlet pipe joint, a first gasket and a second leak proof ring; The inlet pipe joint is disposed on the venturi shell corresponding to the inlet end; the second leak-proof ring is arranged between the inlet pipe joint and the inner side wall of the venturi casing; The first gasket is disposed between the inlet pipe joint and the outer side wall of the venturi housing. 10. The rectangular transparent adjustable venturi according to claim 1, further comprising an outlet pipe connection member; The outlet pipe connection member includes an outlet pipe joint, a second gasket and a third leak-proof ring; The outlet pipe fitting is disposed on the venturi casing corresponding to the outlet end; The third leak-proof ring is arranged between the outlet pipe joint and the inner side wall of the venturi casing; the second gasket is arranged between the outlet pipe joint and the venturi casing. between the outer walls.

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