A needle valve device

Abstract

This utility model relates to a needle-type dispensing valve device, including a dispensing valve body and a one-way throttle valve. The dispensing valve body includes a dispensing valve seat, a needle, a piston block, and a spring assembly. The dispensing valve seat has a piston chamber and a glue flow channel. The piston block divides the piston chamber into an upper chamber and a lower chamber. An inlet and outlet are provided on the outer wall of the middle part of the dispensing valve seat. An inlet is provided on the lower part of the dispensing valve seat, and an outlet is provided at the bottom of the dispensing valve seat. Both the inlet and outlet are connected to the glue flow channel. The upper end of the needle extends upward into the lower chamber and connects with the piston block. The lower end of the needle extends downward into the glue flow channel and cooperates with the outlet. The one-way throttle valve has a first valve port and a second valve port. The first valve port is connected to the inlet and outlet, and the second valve port is used to connect to an external air source. The one-way throttle valve can control the flow rate of gas from the first valve port to the second valve port. This pin-type dispensing valve device can prevent water droplets from forming at the end of the dispensing valve, thus improving the dispensing effect.

Description

Technical Field

[0001] This utility model relates to the field of dispensing technology, specifically to a needle-type dispensing valve device. Background Technology

[0002] The dispensing valve is the most important working component of a dispensing machine. A dispensing machine is an automated machine that controls fluid through dispensing valves, applying fluid droplets or coatings to the surface or interior of a product. Currently, the ejector-type dispensing valve has become one of the mainstream types due to its simple structure and fast response. Its working principle is to control the movement of the ejector pin pneumatically to open and close the dispensing circuit: when air is introduced, the ejector pin moves upward to open the dispensing valve; when air is cut off, the spring pushes the ejector pin back to close the dispensing valve.

[0003] Chinese utility model patent CN206911646U discloses a pin-type dispensing valve, which includes a valve body 100. The valve body 100 has an upper cavity 1 and a lower cavity 2. A striking pin 3 (i.e., a push pin) is disposed in the upper cavity 1. The lower part of the striking pin 3 is inserted into the lower cavity 2, and the tip of the striking pin 3 seals the dispensing port 12 of the dispensing valve. A first sealing ring 4 and an elastic component 5 are fitted onto the striking pin 3. The first sealing ring 4 is located in the lower cavity 2, and the elastic component 5 is located in the upper cavity 1 and partially placed in the lower cavity 2, so that the elastic component 5 contacts the first sealing ring 4 to press the first sealing ring 4. The lower cavity 2 is provided with an adhesive flow channel 11, which is located below the first sealing ring 4 and connects to the inlet 10 and outlet 12 on the adhesive valve body. This allows the adhesive to enter through the inlet 10 and flow out through the adhesive flow channel 11 and outlet 12. However, during the process of the spring assembly pushing the ejector pin downwards to close the adhesive valve when the air is cut off, the accelerated motion of the ejector pin under the action of the spring applies a large ejector pin pressure (pressure = spring pressure x ejector pin area) to the adhesive. The combined effect of this ejector pin pressure and the inlet pressure causes a sudden increase in the adhesive pressure in the adhesive flow channel, triggering adhesive spraying. This results in a sudden increase in the volume of the end adhesive dot, manifesting as a water droplet shape (this phenomenon is particularly noticeable in applications using ejector-type stop valves for dispensing low-viscosity adhesives). This leads to an excessively large end adhesive dot width / dispensing line width (>150%), affecting the overall dispensing effect. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a needle-type dispensing valve device, which can prevent water droplet-like glue dots from appearing at the end of the dispensing valve, thereby improving the dispensing effect. The technical solution adopted is as follows:

[0005] A needle-type dispensing valve device includes a dispensing valve body; the dispensing valve body includes a dispensing valve seat, a needle, a piston block, and a spring assembly. The dispensing valve seat has a piston chamber and a glue flow channel, with the glue flow channel located below the piston chamber. The piston block is movable up and down within the piston chamber and divides the piston chamber into an upper chamber and a lower chamber. An inlet / outlet communicating with the lower chamber is provided on the middle outer wall of the dispensing valve seat. An glue inlet is provided on the lower outer wall of the dispensing valve seat, and a glue outlet is provided at the bottom of the dispensing valve seat. Both the glue inlet and outlet are connected to the glue... The liquid flow channel is connected; the upper end of the ejector pin extends upward into the lower cavity and connects with the piston block, and the lower end of the ejector pin extends downward into the adhesive flow channel and cooperates with the adhesive outlet; the characteristic is that: the ejector pin type dispensing valve device further includes a one-way throttle valve, the one-way throttle valve is installed on the outside of the dispensing valve body, the one-way throttle valve has a first valve port and a second valve port, the first valve port is connected and communicated with the inlet and outlet air ports, and the second valve port is used to connect to an external air source; the one-way throttle valve can control the flow rate of gas from the first valve port to the second valve port.

[0006] When the ejector-type dispensing valve device is needed for dispensing, the external air supply flows in from the second valve port of the one-way throttle valve, then flows out from the first valve port, and then enters the lower chamber of the piston chamber through the inlet and outlet ports. Since the one-way throttle valve does not control the flow rate of gas from the second valve port to the first valve port, the one-way throttle valve can achieve normal air intake. When the intake air pressure is greater than the elastic force of the spring assembly, the piston block rises in the piston chamber (at this time the spring assembly is compressed), which drives the ejector pin to rise, so that the bottom end of the ejector pin disengages from the dispensing port, realizing the instantaneous opening of the dispensing valve. The glue can flow from the glue inlet port into the glue channel and then flow out from the glue outlet port to realize the dispensing work. When the ejector-type dispensing valve device is needed to stop the glue flow, after the air pressure at the air inlet is cut off, the gas in the lower chamber flows in from the first valve port of the one-way throttle valve and then flows out from the second valve port. When the air pressure at the inlet is less than the elastic force of the spring assembly, the spring assembly returns to its original state and applies force to the piston block, causing the bottom end of the ejector pin to move down to close the glue outlet, thus achieving the glue stop operation. Since the one-way throttle valve can control the flow rate of gas from the first valve port to the second valve port, the gas in the lower chamber flows out slowly. Therefore, the residual air pressure in the lower chamber applies an upward force to the piston block to slow down the descent speed of the piston block and the ejector pin, so that the bottom end of the ejector pin descends to the glue outlet more slowly. This effectively prevents the glue in the glue channel from being subjected to excessive pressure momentarily, which could cause spraying. This avoids the problem of the glue dot at the end changing abruptly and appearing as a water droplet during the glue stop process, reducing the width of the glue dot at the end / the width of the glue line (<120%), resulting in good glue dispensing effect and eliminating the need for glue overflow scraping.

[0007] In a preferred embodiment of this utility model, the one-way throttle valve includes a throttle valve seat, a one-way valve, and a flow regulating valve. The throttle valve seat has a first valve port and a second valve port on its two sides, respectively. The throttle valve seat contains a first gas flow channel and a second gas flow channel. The two ends of the first gas flow channel and the two ends of the second gas flow channel are connected to the first valve port and the second valve port, respectively. The one-way valve is installed on the first gas flow channel and is used to prevent gas from flowing from the first valve port to the second valve port. The flow regulating valve is installed on the second gas flow channel. During gas intake, the one-way valve does not restrict flow, and gas can simultaneously flow in from the first gas flow channel and the second gas flow channel through the second valve port, and then out from the first valve port. Thus, the one-way throttle valve can achieve normal gas intake. After gas is cut off, the one-way valve in the first gas flow channel prevents gas from flowing out, and the gas in the lower cavity can only flow to the second valve port through the inlet / outlet port, the first valve port, and the second gas flow channel. The flow regulating valve controls the flow rate of the gas in the second gas flow channel.

[0008] As another preferred embodiment of this utility model, the one-way throttle valve includes a throttle valve seat, a switching valve, and a flow regulating valve. The throttle valve seat has a first valve port and a second valve port on its two sides, respectively. The throttle valve seat contains a first gas flow channel and a second gas flow channel. The two ends of the first and second gas flow channels are connected to the first and second valve ports, respectively. The switching valve is installed on the first gas flow channel; the flow regulating valve is installed on the second gas flow channel. During gas intake, the switching valve opens, allowing gas to simultaneously flow into the second valve port through the first and second gas flow channels, and then out through the first valve port. This enables normal gas intake through the one-way throttle valve. After gas is cut off, the switching valve closes, and the gas in the lower cavity can only flow through the inlet / outlet, the first valve port, and the second gas flow channel to the second valve port. The flow regulating valve controls the flow rate of the gas in the second gas flow channel.

[0009] As a preferred embodiment of this utility model, the dispensing valve seat is provided with a vertically oriented guide hole, which is located between the piston chamber and the adhesive flow channel. The upper and lower ends of the guide hole are connected to the piston chamber and the adhesive flow channel, respectively. The middle part of the ejector pin is located in the guide hole and is in sealed contact with the inner wall of the guide hole. Thus, the guide hole can be used to guide the middle part of the ejector pin, allowing the ejector pin to move smoothly up and down relative to the dispensing valve seat.

[0010] As a further preferred embodiment of this utility model, a first annular sealing groove is provided on the outer wall of the middle part of the ejector pin, and a first sealing ring is provided in the first annular sealing groove. The first sealing ring makes sealing contact with the inner wall of the guide hole. The first sealing ring is used to completely seal the gap between the middle part of the ejector pin and the inner wall of the guide hole, which helps to ensure the airtightness of the piston chamber.

[0011] As a preferred embodiment of this utility model, a second annular sealing groove is provided on the outer wall of the piston block, and a second sealing ring is provided in the second annular sealing groove. The second sealing ring is in sealing contact with the inner wall of the piston cavity. The second sealing ring is used to completely seal the gap between the piston block and the inner wall of the piston cavity, which helps to ensure the airtightness between the lower cavity and the upper cavity.

[0012] Generally, the dispensing valve body also includes a stroke adjusting screw and a limiting block. The stroke adjusting screw is installed on the top of the dispensing valve seat via a threaded connection, and the limiting block is installed at the lower end of the stroke adjusting screw and located above the piston block. The spring assembly uses a spring, which is sleeved on the limiting block 16 and located between the dispensing valve seat and the piston block. With this structure, the height position of the limiting block can be adjusted by turning the stroke adjusting screw to limit the upper side of the piston block, thereby adjusting the stroke of the piston block and the ejector pin.

[0013] Compared with the prior art, this utility model has the following advantages:

[0014] This needle-type dispensing valve device uses a one-way throttle valve at the air inlet and outlet of the dispensing valve body. The one-way throttle valve allows for normal air intake and slows down the air output after the air is cut off. This allows the residual air pressure in the lower chamber to apply an upward force to the piston block, thereby slowing down the descent speed of the piston block and the needle. This allows the bottom of the needle to slowly descend to the dispensing port, effectively preventing excessive pressure on the glue in the glue channel. This avoids the problem of the end glue dot suddenly changing into a droplet shape during the glue stopping process, reducing the width of the end glue dot / dispensing line width (<120%), resulting in good dispensing effect and eliminating the need for glue overflow scraping. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the preferred embodiment of the needle-type dispensing valve device of this utility model.

[0016] Figure 2 yes Figure 1 The diagram shows the working principle of the needle-type dispensing valve device. Detailed Implementation

[0017] like Figures 1-2As shown, this needle-type dispensing valve device includes a dispensing valve body 1 and a one-way throttle valve 2. The dispensing valve body 1 includes a dispensing valve seat 11, a needle 12, a piston block 13, and a spring assembly 14. The dispensing valve seat 11 is provided with a piston chamber 1101 and a glue flow channel 1102, with the glue flow channel 1102 located below the piston chamber 1101. The piston block 13 is movable up and down in the piston chamber 1101 and divides the piston chamber 1101 into an upper chamber 11011 and a lower chamber 11012. The middle outer wall of the dispensing valve seat 11 is provided with an air inlet / outlet 1103 communicating with the lower chamber 11012. The lower outer wall of the dispensing valve seat 11 is provided with a glue inlet 1104, and the bottom of the dispensing valve seat 11 is provided with a glue outlet 11. 05. The glue inlet 1104 and glue outlet 1105 are both connected to the glue flow channel 1102; the upper end of the ejector pin 12 extends upward into the lower cavity 11012 and is connected to the piston block 13, and the lower end of the ejector pin 12 extends downward into the glue flow channel 1102 and cooperates with the glue outlet 1105; the one-way throttle valve 2 is installed on the outside of the dispensing valve body 1. The one-way throttle valve 2 has a first valve port 201 and a second valve port 202. The first valve port 201 is connected to the air inlet and outlet 1103, and the second valve port 202 is used to connect to an external air source; the one-way throttle valve 2 can control the flow rate of gas from the first valve port 201 to the second valve port 202, but does not control the flow rate of gas from the second valve port 202 to the first valve port 201.

[0018] In this embodiment, the dispensing valve seat 11 is provided with a vertically oriented guide hole 1106. The guide hole 1106 is located between the piston chamber 1101 and the adhesive flow channel 1102, and the upper and lower ends of the guide hole 1106 are connected to the piston chamber 1101 and the adhesive flow channel 1102, respectively. The middle part of the ejector pin 12 is located in the guide hole 1106. A first annular sealing groove 121 is provided on the outer wall of the middle part of the ejector pin 12, and a first sealing ring 122 is provided in the first annular sealing groove 121. The first sealing ring 122 is in sealing contact with the inner wall of the guide hole 1106. Thus, the guide hole 1106 can be used to guide the middle part of the ejector pin 12, so that the ejector pin 12 can move up and down smoothly relative to the dispensing valve seat 11. The first sealing ring 122 is used to completely seal the gap between the middle part of the ejector pin 12 and the inner wall of the guide hole 1106, which helps to ensure the airtightness of the piston chamber 1101.

[0019] In this embodiment, a second annular sealing groove 131 is provided on the outer side wall of the piston block 13, and a second sealing ring 132 is provided in the second annular sealing groove 131. The first sealing ring 122 is in sealing contact with the inner wall of the piston cavity 1101. The second sealing ring 132 is used to completely seal the gap between the piston block 13 and the inner wall of the piston cavity 1101, which helps to ensure the airtightness between the lower cavity 11012 and the upper cavity 11011.

[0020] In this embodiment, the dispensing valve body 1 further includes a stroke adjusting screw 15 and a limiting block 16. The stroke adjusting screw 15 is installed on the top of the dispensing valve seat 11 via a threaded connection. The limiting block 16 is installed at the lower end of the stroke adjusting screw 15 and is located above the piston block 13. The spring assembly 14 is a spring, which is sleeved on the limiting block 16 and located between the dispensing valve seat 11 and the piston block 13. With this structure, the height position of the limiting block 16 can be adjusted by turning the stroke adjusting screw 15, thereby limiting the upper side of the piston block 13 and thus adjusting the stroke of the piston block 13 and the ejector pin 12.

[0021] In this embodiment, the one-way throttle valve 2 includes a throttle valve seat 21, a one-way valve 22, and a flow regulating valve 23. The throttle valve seat 21 has a first valve port 201 and a second valve port 202 on both sides. The throttle valve seat 21 has a first gas flow channel 211 and a second gas flow channel 212. The two ends of the first gas flow channel 211 and the two ends of the second gas flow channel 212 are connected to the first valve port 201 and the second valve port 202, respectively. The one-way valve 22 is installed on the first gas flow channel 211 and is used to prevent gas from flowing from the first valve port 201 to the second valve port 202. The flow regulating valve 23 is installed on the second gas flow channel 212. During air intake, the one-way valve 22 does not restrict flow, and gas can simultaneously flow in from the first gas flow channel 211 and the second gas flow channel 212 through the second valve port 202, and then flow out from the first valve port 201. Thus, the one-way throttle valve 2 can achieve normal air intake. After the gas is cut off, the one-way valve 22 in the first gas flow channel 211 prevents the gas from flowing out. The gas in the lower cavity 11012 can only flow to the second valve port 202 through the inlet / outlet port 1103, the first valve port 201, and the second gas flow channel 212. The flow regulating valve 23 controls the flow rate of the gas in the second gas flow channel 212.

[0022] The working principle of this needle-type dispensing valve device is briefly described below:

[0023] When the ejector-type dispensing valve device is needed for dispensing, the gas supplied by the external air source flows in from the second valve port 202 of the one-way throttle valve 2, then flows out from the first valve port 201, and then enters the lower chamber 11012 of the piston chamber 1101 through the air inlet and outlet ports 1103. Since the one-way throttle valve 2 does not control the flow rate of gas from the second valve port 202 to the first valve port 201, the one-way throttle valve 2 can achieve normal air intake. After the intake air pressure is greater than the elastic force of the spring assembly 14, the piston block 13 rises in the piston chamber 1101 (at this time, the spring assembly 14 is compressed), which drives the ejector pin 12 to rise, so that the bottom end of the ejector pin 12 is separated from the dispensing port 1105, realizing the instantaneous opening of the dispensing valve. The glue can flow into the glue flow channel 1102 from the glue inlet port 1104 and then flow out from the glue outlet port 1105 to realize the dispensing work. When the ejector-type dispensing valve device needs to stop the glue flow, after the air pressure at the air inlet is cut off, the gas in the lower cavity 11012 flows in from the first valve port 201 of the one-way throttle valve 2 and then flows out from the second valve port 202. When the air pressure at the inlet is less than the elastic force of the spring assembly 14, the spring assembly 14 returns to its original state and applies a force to the piston block 13, causing the bottom end of the ejector pin 12 to move down to close the glue outlet 1105, thus achieving the glue-stopping operation. Because the one-way throttle valve 2 can control the flow rate of gas from the first valve port 201 to the second valve port 202, the lower cavity 11012... The gas in the lower cavity 11012 slowly flows out, so the residual gas pressure in the lower cavity 11012 exerts an upward force on the piston block 13 to slow down the descent speed of the piston block 13 and the ejector pin 12, so that the bottom end of the ejector pin 12 descends to the glue outlet 1105 more slowly, effectively preventing it from causing excessive pressure on the glue in the glue flow channel 1102 and causing spraying. This avoids the problem of the end glue point changing abruptly and appearing as a water droplet during the glue stopping process, reduces the width of the end glue point / glue line width (<120%), and the glue dispensing effect is good, so there is no need to do glue overflow scraping treatment.

[0024] Furthermore, it should be noted that the names of the various parts of the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles of this utility model patent are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined by the claims, they should all fall within the protection scope of this utility model.

Claims

1. A needle-type dispensing valve device, comprising a dispensing valve body; the dispensing valve body includes a dispensing valve seat, a needle, a piston block, and a spring assembly; the dispensing valve seat has a piston chamber and a glue flow channel, the glue flow channel being located below the piston chamber; the piston block is movable up and down in the piston chamber and divides the piston chamber into an upper chamber and a lower chamber; the middle outer wall of the dispensing valve seat has an inlet and outlet port communicating with the lower chamber; the lower outer wall of the dispensing valve seat has an inlet port, and the bottom of the dispensing valve seat has an outlet port, both the inlet and outlet ports communicating with the glue flow channel; the upper end of the needle extends upward into the lower chamber and connects with the piston block, and the lower end of the needle extends downward into the glue flow channel and cooperates with the outlet port; characterized in that: The needle-type dispensing valve device also includes a one-way throttle valve, which is installed on the outside of the dispensing valve body. The one-way throttle valve has a first valve port and a second valve port. The first valve port is connected to the inlet and outlet air ports, and the second valve port is used to connect to an external air source. The one-way throttle valve can control the flow rate of gas from the first valve port to the second valve port.

2. The needle-type dispensing valve device according to claim 1, characterized in that: The one-way throttle valve includes a throttle valve seat, a one-way valve, and a flow regulating valve. The throttle valve seat has a first valve port and a second valve port on its two sides, respectively. The throttle valve seat has a first gas flow channel and a second gas flow channel. The two ends of the first gas flow channel and the two ends of the second gas flow channel are connected to the first valve port and the second valve port, respectively. The one-way valve is installed on the first gas flow channel and is used to prevent gas from flowing from the first valve port to the second valve port. The flow regulating valve is installed on the second gas flow channel.

3. The needle-type dispensing valve device according to claim 1, characterized in that: The one-way throttle valve includes a throttle valve seat, a switching valve, and a flow regulating valve. The throttle valve seat has a first valve port and a second valve port on its two sides, respectively. The throttle valve seat has a first gas flow channel and a second gas flow channel. The two ends of the first gas flow channel and the second gas flow channel are connected to the first valve port and the second valve port, respectively. The switching valve is installed on the first gas flow channel, and the flow regulating valve is installed on the second gas flow channel.

4. A needle-type dispensing valve device according to any one of claims 1-3, characterized in that: The dispensing valve seat is provided with a guide hole running vertically. The guide hole is located between the piston chamber and the adhesive flow channel. The upper end and the lower end of the guide hole are connected to the piston chamber and the adhesive flow channel, respectively. The middle part of the ejector pin is located in the guide hole and is in sealed contact with the inner wall of the guide hole.

5. The needle-type dispensing valve device according to claim 4, characterized in that: The outer wall of the middle part of the ejector pin is provided with a first annular sealing groove, and a first sealing ring is provided in the first annular sealing groove. The first sealing ring is in sealing contact with the inner wall of the guide hole.

6. A needle-type dispensing valve device according to any one of claims 1-3, characterized in that: The piston block has a second annular sealing groove on its outer side wall, and a second sealing ring is provided in the second annular sealing groove. The second sealing ring is in sealing contact with the inner wall of the piston cavity.

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