CN103722702B - Non-return quantitative constant-pressure injection device - Google Patents

Abstract

The invention discloses a non-reverse quantitative and constant pressure injection device, which includes a nozzle body, a valve core mechanism, an injection cylinder, a hydraulic system and a controller. The nozzle body is provided with a flow channel and a liquid inlet for the nozzle body The opening or closing spool mechanism is installed in the nozzle body, the injection cylinder includes a cylinder body and a hydraulic rod with a first piston at the front end, and the hydraulic rod with the first piston extends into the flow channel of the nozzle body , the hydraulic system is connected with the oil cylinder body to drive the injection cylinder, characterized in that: the injection device also includes a hydraulic rod stroke control device, and both the hydraulic system and the hydraulic rod stroke control device are electrically connected to the controller. The invention has simple structure and high reliability, and can realize intermittent, quantitative and constant pressure injection.

Description

Anti-reverse quantitative and constant pressure injection device

technical field

The invention relates to the field of injection devices, in particular to a non-reverse quantitative and constant pressure injection device.

Background technique

The injection device is used for fluid injection and is suitable for many occasions, such as high-pressure injection in the hydraulic field, quantitative injection in chemical production, and so on. In the prior art, injection devices often use timing injection to perform injection. At this time, to achieve quantitative injection, it is necessary to ensure uniform feeding (ie, quantitative feeding under one cycle). However, in many cases, it is impossible to maintain uniform feeding or the feeding time is uncertain, resulting in different injection volumes each time, that is, quantitative injection cannot be achieved. Therefore, as a technical index and requirement, quantitative injection needs complicated mechanisms to realize in the prior art.

For example, Chinese patent CN102431134A discloses an injection device, which mainly includes an injection frame, a cylinder part mounted on the injection frame, a freely rotating and advancing and retreating injection part installed in the cylinder, a motor for injection, and a A movement direction conversion unit that converts the rotary motion generated by the driving of the injection motor into rotary linear motion, and the metering motor. Though this device can realize quantitative injection, structure is also very complicated, and the accuracy of metering is not high.

For the injection device in the prior art, it is necessary to close the nozzle during feeding to prevent the fluid from flowing out of the nozzle under non-injection conditions, so a valve body needs to be provided in the injection device. For example, Chinese patent CN102207215A discloses a water-saving check valve, which includes a nozzle body, a valve core and a spring. A waterway is arranged in the nozzle body, and the inner hole surface of the waterway includes a sealing section and a water-saving section. A sealing ring is arranged outside the valve core. The spring pushes against the spool so that the spool is subject to elastic force. If the water flow in the waterway is flowing forward and the water pressure is greater than the elastic force, the valve core moves so that the sealing ring is located in the water-saving section, and the sealing ring is radially expanded and deformed by the water pressure to reduce the gap between the outer periphery of the sealing ring and the inner surface of the water-saving section. Cross-sectional area; otherwise, the seal ring is located in the seal segment, and the seal ring seals the internal bore surface of the segment. The non-return function and the water-saving function of the check valve share a bracket and a sealing ring, which can reduce material consumption, reduce manufacturing costs, shorten the axial length of the valve core, reduce occupied space, and simplify the structure of the valve core. Since the direction of the valve core is consistent with the nozzle body, that is, the waterway, the structure can realize the function of saving water. But this check valve also has the following problems that cannot be solved. 1. When the liquid needs to be completely sealed, this water-saving check valve cannot realize this function; Reduce the water flow area to achieve water-saving function. When the use environment is such as high liquid temperature, or the liquid is corrosive, the sealing ring is also easy to damage, and this device is not suitable; 3. Since the valve core is axially closed Yes, the flow path in the valve needs to bypass the valve core, so the flow path is more curved and complicated, and the resistance is large.

Contents of the invention

The technical problem to be solved by the present invention is to provide a non-return quantitative and constant pressure injection device with simple structure and high reliability, which can realize intermittent, quantitative and constant pressure injection at the same time.

The technical solution of the present invention is to provide a non-return quantitative and constant pressure injection device with the following structure, including a nozzle body, a valve core mechanism, an injection cylinder, a hydraulic system and a controller. The nozzle body is provided with flow channels and Liquid inlet, the spool mechanism used to open or close the nozzle body is installed in the nozzle body, the injection cylinder includes a cylinder body and a hydraulic rod with a first piston at the front end, and the hydraulic cylinder with the first piston The rod extends into the flow channel of the nozzle body. The hydraulic system is connected with the cylinder body to drive the injection cylinder. The injection device also includes a hydraulic rod stroke control device. Both the hydraulic system and the hydraulic rod stroke control device are connected with the control electrical connection.

With the above structure, the present invention has the following advantages compared with the prior art: with the present invention, when storing material, the fluid material enters from the liquid inlet, and the valve core mechanism radially seals the flow channel, relying on the pressure generated by the fluid in the flow channel Slowly push out the hydraulic rod with the first piston (the hydraulic system does not provide pressure at this time, and the injection cylinder is in an empty state), when the hydraulic rod moves to the stroke control device of the hydraulic rod, the hydraulic system is turned on for injection. Since the hydraulic rod stroke control device controls the injection at a specific position, the injection volume is constant each time (a predetermined amount can be set), realizing intermittent and quantitative injection, while simplifying the product structure and high reliability.

As an improvement, the spool mechanism includes a main spool and a spring. On the nozzle body, the flow channel extends radially upward to form a spool channel. One end of the spring is fixed on the spool channel, and the other end is connected to the main valve. On the spool, the left end surface of the main spool is a conical surface, which is in line contact with the nozzle body. The movement direction of the main spool is located in the radial direction of the flow channel. An internal pressure chamber is set on the inner wall of the nozzle body opposite to the spool channel. A diversion hole is set on the main valve core, the diversion hole includes a radial section and a communication section, the radial section communicates with the internal pressure chamber, the communication section communicates with the flow channel, the pressure of the spring is greater than the injection The resistance of the first piston when the cylinder is empty. With this design, the fluid is sealed according to the pressure of the fluid under the action of the spring force supported by the main valve core at its lower end. When feeding, the fluid will enter from the connecting section of the diversion hole and flow through the radial section. Entering the internal pressure chamber, the pressure of the spring is greater than the resistance of the first piston when the injection cylinder is empty, and the pressure of the fluid will push the first piston away, making it reach the position set by the stroke control device of the hydraulic rod under the action of the fluid. This design cleverly utilizes hydraulic pressure to achieve non-return sealing. The left end surface of the main valve core is designed as a conical surface, and the contact with the valve body is a line contact. Good; and when the oil cylinder is injected, the hydraulic pressure of the fluid increases, so that the fluid entering the internal pressure chamber can push the main valve core, so that the nozzle port is connected with the flow channel to realize injection.

As an improvement, the internal pressure chamber is a stepped chamber with a large outside and a small inside. The area of the end of the main valve core is larger than the size of the small opening of the stepped chamber and smaller than the large opening of the stepped chamber. Under the action of the spring, the end of the main valve core is against the large mouth of the stepped chamber. The step surface between the mouth and the small mouth. When feeding, the contact area between the fluid in the internal pressure chamber and the contact end surface of the main valve core is the size of the small opening. When injecting, under the action of strong pressure, the spring is pushed away, and the contact surface between the fluid in the internal pressure chamber and the main valve core is instantly increased. The contact area greatly increases the force on the main valve core, which is beneficial to the opening of the valve core.

As an improvement, the communication section is obliquely connected to the radial section from top to bottom, and the end communicating with the radial section is the upper end. This design is mainly to facilitate the reduction of hydraulic loss when the fluid enters the internal pressure chamber, and the fluid in the internal pressure chamber can flow out from the communication section smoothly without the phenomenon of fluid accumulation.

As an improvement, the hydraulic rod travel control device includes a first travel switch and a second travel switch, the first travel switch is installed in the nozzle body and is located on the rear side of the first piston, and the second travel switch is installed Between the nozzle body and the oil cylinder body, and on the hydraulic rod, a touch block matching with the second travel switch is provided, and the touch block can touch the second travel switch during the travel of the hydraulic rod. In this way, the amount of fluid is controlled by the first stroke switch to achieve quantitative injection. When the first piston pushes against the front end of the nozzle body, the touch block on the hydraulic rod just touches the second stroke switch, thereby controlling the hydraulic system to stop working.

As an improvement, the injection device further includes an overflow valve, and the overflow valve is connected with the hydraulic system and located on a pipeline where the hydraulic system supplies liquid to the cylinder body. Through the overflow valve, the hydraulic system can supply liquid to the cylinder body at constant pressure to meet the requirements of constant pressure injection.

Description of drawings

Fig. 1 is a schematic structural diagram of a non-reverse quantitative and constant pressure injection device of the present invention.

As shown in the figure: 1. Nozzle body, 2. Hydraulic system, 3. Controller, 4. Runner, 5. Liquid inlet, 6. Cylinder body, 7. First piston, 8. Hydraulic rod, 9. Main Spool, 10, spring, 11, spool channel, 12, internal pressure chamber, 13, diversion hole, 14, first stroke switch, 15, second stroke switch, 16, touch block, 17, overflow valve , 18, the second piston, 19, limit column, 20, one-way valve.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the non-return quantitative and constant pressure injection device of the present invention includes a nozzle body 1, a valve core mechanism, an injection cylinder, a hydraulic system 2 and a controller 3, and the nozzle body 1 is provided with a flow channel 4 and The liquid inlet 5, the spool mechanism used to open or close the nozzle body 1 is installed in the nozzle body 1, the injection cylinder includes a cylinder body 6 and a hydraulic rod 8 with a first piston 7 at the front end. The hydraulic rod 8 with the first piston 7 extends into the flow channel 4 of the nozzle body 1, the hydraulic system 2 is connected with the cylinder body 6 for driving the injection cylinder, and the injection device also includes a hydraulic rod stroke control device, Both the hydraulic system 2 and the stroke control device of the hydraulic rod are electrically connected to the controller 3 .

The spool mechanism includes a main spool 9 and a spring 10. On the nozzle body 1, the flow channel 4 extends radially to form a spool passage 11. One end of the spring 10 is fixed on the spool passage 11, and the other end Connected to the main spool 9, the left end surface of the main spool 9 is a conical surface, which is in line contact with the nozzle body 1, and the movement direction of the main spool 9 is located in the radial direction of the flow channel 4, opposite to the spool channel 11 An internal pressure chamber 12 is provided on the inner wall of the nozzle body 1, and a guide hole 13 is provided on the main valve core 9. The guide hole 13 includes a radial section and a communication section, and the radial section communicates with the internal pressure chamber 12. , the communication section communicates with the flow channel 4, and the pressure of the spring 10 is greater than the resistance of the first piston 7 when the injection cylinder is empty.

The internal pressure chamber 12 is a stepped chamber with a large outside and a small inside. The area of the end of the main valve core 9 is larger than the size of the small mouth of the stepped chamber and smaller than the size of the large mouth of the stepped chamber. Under the action of the spring 10, the end of the main valve core 9 is against the stepped chamber. The stepped surface between the large mouth and the small mouth. The stepped surface refers to the surface where the large mouth and the small mouth of the stepped cavity meet, that is, the surface that the end of the main valve core is against in the attached drawing.

The communication section is obliquely connected to the radial section from top to bottom, and the end communicating with the radial section is the upper end.

The hydraulic rod stroke control device includes a first stroke switch 14 and a second stroke switch 15, the first stroke switch 14 is installed in the nozzle body 1, and is located on the rear side of the first piston 7, the second stroke switch The travel switch 15 is installed between the nozzle body 1 and the oil cylinder body 6, and a touch block 16 matched with the second travel switch 15 is provided on the hydraulic rod 8, and the touch block 16 can be touched during the travel of the hydraulic rod 8 Touch the second travel switch 15. The distance from the first travel switch to the main spool is the injection amount divided by the cross-sectional area of the flow channel plus the thickness of the first piston. The first travel switch is close to the wall of the flow channel so as not to affect the sliding of the first piston.

The injection device also includes an overflow valve 17 , which is connected to the hydraulic system 2 and located on the pipeline where the hydraulic system 2 supplies fluid to the cylinder body 6 .

The other end of the hydraulic rod 8 is provided with a second piston 18, and the end surface area of the second piston 18 is larger than the end surface area of the first piston 7. This design improves the injection pressure of the first piston and increases the nozzle pressure. injection pressure.

The inner wall in the spool passage 11 is provided with a limit post 19, and the installation depth of the stop post 19 (the depth in the spool passage) is equal to the length of the main spool; a spring is provided in the spool passage 11 Guide bushing or rod for guiding the spring.

A liquid inlet pipe is provided at the liquid inlet, and a one-way valve 20 is provided at the lower end of the liquid inlet pipe, so as to prevent the reverse flow of the fluid.

Working process of the present invention is as follows:

In the material storage stage, when the external liquid enters the flow channel through the liquid inlet, at this time, the main valve core is at the top under the action of the spring force, the valve core seals the flow channel of the fluid, and the controller sends out a signal For the hydraulic system (a hydraulic pump is used in this embodiment), the hydraulic pump is in a stop state and does not provide pressure to the hydraulic system. With more and more fluid, the left end of the flow channel is sealed by the valve core, and the fluid can only go to the right of the flow channel. Lateral movement pushes the first piston to move to the right; since the hydraulic pump is unloaded, the hydraulic oil on the right side of the cylinder body returns to the oil tank through the pipeline.

In the injection stage, when the fluid in the flow channel reaches the predetermined amount, the first piston touches the first travel switch at this time, the first travel switch sends a signal to the controller, the controller sends a signal to the hydraulic pump, and the hydraulic pump starts to work , the hydraulic pressure first passes through the overflow valve, so that the hydraulic pressure entering the piston is at a constant pressure, the constant pressure hydraulic pressure pushes the hydraulic rod, and the hydraulic rod then pushes the first piston to transfer the hydraulic pressure to the fluid in the flow channel, and the high-pressure fluid enters the pressure chamber through the diversion hole , the high-pressure fluid in the pressure chamber produces a downward pressure on the valve core, which can overcome the spring force and friction force on the valve core, and the valve core moves downward to the position of the limit post. At this time, the flow channel is completely Open and high pressure fluid is ejected through the nozzle.

As the fluid is sprayed out, the first piston and the hydraulic rod continue to move to the left. When the fluid in the flow channel is about to be emptied, the piston I moves to the far left, and the touch block on the hydraulic rod also touches the second travel switch. , touch the switch to transmit the signal to the controller, the controller controls the hydraulic pump to stop working, the hydraulic system does not provide pressure, the fluid in the flow channel becomes normal pressure, at this time, the valve core moves upward to the uppermost end under the action of the spring force , and block the fluid channel to complete the cycle.

Since the area of the end face of the second piston is larger than that of the end face of the first piston, the pressure generated by the fluid is greater than the pressure of the hydraulic system, so a pressure amplification effect is produced, which increases the injection pressure and injection speed of the nozzle.

The injection device has the functions of irregular timing, quantitative and constant pressure injection, and is especially suitable for when the inflow of liquid is not uniform, and the injection needs quantitative and constant pressure. .

The above is only an illustration of the preferred embodiments of the present invention, but should not be construed as a limitation on the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to vary. In a word, all kinds of changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

Claims (5)

1. A non-return quantitative and constant pressure injection device, comprising a nozzle body (1), a spool mechanism, an injection cylinder, a hydraulic system (2) and a controller (3), the nozzle body (1) is provided with a flow Road (4) and liquid inlet (5), the spool mechanism used to open or close the nozzle body (1) is installed in the nozzle body (1), and the injection cylinder includes the cylinder body (6) and the front end A hydraulic rod (8) with a first piston (7), the hydraulic rod (8) with the first piston (7) extends into the flow channel (4) of the nozzle body (1), the hydraulic pressure The system (2) is connected with the oil cylinder body (6) to drive the injection cylinder, and it is characterized in that: the injection device also includes a hydraulic rod stroke control device, and the hydraulic system (2) and the hydraulic rod stroke control device are both connected with the control Device (3) is electrically connected; The spool mechanism includes a main spool (9) and a spring (10). On the nozzle body (1), the flow channel (4) extends radially to form a spool passage (11), and the spring (10) ) one end is fixed on the spool passage (11), and the other end is connected to the main spool (9). The movement direction of the spool (9) is located in the radial direction of the flow channel (4), and the inner pressure chamber (12) is set on the inner wall of the nozzle body (1) opposite to the spool channel (11), and the main spool (9) is set A diversion hole (13), the diversion hole (13) includes a radial section and a communication section, the radial section communicates with the internal pressure chamber (12), and the communication section communicates with the flow channel (4) In communication, the pressure of the spring (10) is greater than the resistance of the first piston (7) when the injection cylinder is empty. 2. The non-return quantitative and constant pressure injection device according to claim 1, characterized in that: the internal pressure cavity (12) is a stepped cavity with a large outside and a small inside, and the end area of the main valve core (9) is larger than The size of the small mouth of the stepped chamber is smaller than the large mouth of the stepped chamber, and the end of the main valve core (9) is against the stepped surface between the large mouth and the small mouth of the stepped chamber under the action of the spring (10). 3. The non-return quantitative and constant pressure injection device according to claim 1, characterized in that: the communication section is connected to the radial section obliquely from top to bottom, and the end connected to the radial section is the upper end. 4. The non-return quantitative and constant pressure injection device according to claim 1, characterized in that: the hydraulic rod stroke control device includes a first stroke switch (14) and a second stroke switch (15), and the first stroke switch (15) A travel switch (14) is installed in the nozzle body (1), and is located at the rear side of the first piston (7), and the second travel switch (15) is installed between the nozzle body (1) and the cylinder body (6). between, and on the hydraulic rod (8) is provided with a touch block (16) matched with the second travel switch (15), the touch block (16) can touch the second travel switch (15) during the travel of the hydraulic rod (8) Travel switch (15). 5. The non-return quantitative and constant pressure injection device according to claim 1, characterized in that: the injection device also includes an overflow valve (17), and the overflow valve (17) is connected with the hydraulic system (2) It is connected with each other and is located on the pipeline where the hydraulic system (2) supplies liquid to the oil cylinder body (6).