CN108274396B - A low-speed liquid flow control device and method for optical polishing slurry supply - Google Patents

Abstract

The present invention relates to a low-speed liquid flow control method for optical polishing slurry supply. The device used includes: a liquid storage tank, which is used for storing slurry; a liquid-dipping pipe, which extends into the interior of the liquid storage tank, and the liquid-dipping pipe is connected with a three-way valve, and the three-way valve is connected to the three-way valve. The valve is also connected with the air filter valve; the three-way valve is alternately directed to the dip tube and the air filter valve; the pump, one end of the pump is connected with the three-way valve, and the other end of the pump is connected with a pipeline, The pipeline is used for conveying the slurry, and the pump is used for controlling the flow rate of the slurry; the nozzle is arranged at the other end of the pipeline. The device and method provided by the invention save costs, improve the utilization rate of the slurry, and facilitate the realization of low-speed supply.

Description

A low-speed liquid flow control device and method for optical polishing slurry supply

technical field

The invention relates to the technical field of optical polishing slurry supply devices, in particular to a low-speed liquid flow control device for optical polishing slurry supply and a low-speed liquid flow control method for optical polishing slurry supply.

Background technique

During the grinding and polishing of optical components, the pressure and relative velocity generated by the grinding head are transmitted to the surface of the workpiece through the abrasive, thereby realizing material removal. The abrasive is formulated in the form of a suspension or solution and used in the grinding or polishing process, which is called abrasive or polishing liquid. The processing accuracy of the chemical components is relatively high, reaching the sub-micron level, so there is a very high requirement for the stability of the material removal rate. Among them, the change of the concentration of abrasive particles in the slurry directly affects the change of the material removal rate. During the supply process, once the slurry settles, it will greatly affect the optical polishing efficiency.

The supply of the slurry is generally powered by a pump, and the slurry is directly supplied to the surface of the workpiece through a serpentine tube. Existing technical solution: increase the slurry supply speed, so that the liquid moving at a high speed scours the settled abrasive, and the abrasive is entrained and transported. This conveying method requires the use of excess slurry, which will greatly increase the processing cost. Especially for large-diameter components (meter-scale diameter, requiring several liters of slurry), silicon carbide and other superhard materials (with diamond as abrasive), the use of this method is obviously limited.

Due to the increased supply rate, the actual amount of slurry used is much greater than the processing demand. To solve this problem, a circulation system can be added to realize the reuse of the slurry, but it will increase the risk of the slurry being contaminated, and it is very likely to produce scratches on the optical surface, which will affect the optical quality. In addition, the use of the circulation system and the residual liquid in the circulation system also increase the cost accordingly.

Switchable gas and liquid release and delivery devices, systems and methods are disclosed in the prior art, the devices comprising: a cartridge configured to include one or more chambers, wherein one or more odorous substances are contained in the respective chambers a housing configured to include a compartment to hold the cartridge; an opening to allow the one or more odorous substances to be dispensed from the device to an external environment; and one or more transfer channels formed in the compartment and the opening wherein each of the one or more delivery channels is configured to facilitate the odorant from the corresponding chamber to the opening; and an actuator switch disposed in the corresponding delivery channel and operable to be based on The applied signal is moved between an open position and a closed position to selectively allow passage of the odorant from the corresponding transport path. Although this technical solution can switch the gas or liquid source for supply, it cannot avoid the mixing between different transported substances, cannot automatically generate alternating air-liquid columns, cannot form the form of micro-circulation, and is difficult to use for suspension slurry supply.

The prior art discloses a pipeline for conveying a suspension, the pipeline includes: a PPH plastic layer, a steel pipe layer and a magnet layer; the PPH plastic layer is fixed on the inner side wall of the steel pipe layer; the magnet layer is fixed on the inner wall of the steel pipe layer. The outer side wall of the steel pipe layer; wherein, the suspended matter in the suspension has the property of being able to be adsorbed by the magnetic force of the magnet, and when the suspension is transported by the pipeline, the suspended matter in the suspension is in the magnet. Under the action of the magnetic force of the layer, it is attached to the surface of the PPH plastic layer to form a protective layer. The technical solution of the above-mentioned pipeline for conveying the suspension is in the form of the magnet layer adsorbing the ferromagnetic suspension to reduce sedimentation. However, most of the abrasive particles used for optical surface polishing do not have ferromagnetic properties, and the abrasives often require high purity, and it is not suitable to add auxiliary substances with ferromagnetic properties, which makes this technical solution difficult to apply to optical polishing. in the process.

SUMMARY OF THE INVENTION

In order to solve the above problems in the prior art, embodiments of the present invention provide a low-speed liquid flow control device for optical polishing slurry supply and a low-speed liquid flow control device for optical polishing slurry supply method.

In the present invention, the abrasives and polishing liquids mentioned in the background art are collectively referred to as polishing slurry, or simply referred to as slurry.

In a first aspect, the low-speed liquid flow control device for optical polishing slurry supply provided by the present invention includes: a liquid storage tank for storing the slurry; and a dip tube, the dip tube extending into the storage tank Inside the liquid tank, and the dipping pipe is connected with a three-way valve, and the three-way valve is also connected with an air filter valve; the three-way valve alternately points to the dipping pipe and the air filter valve; the pump, the pump One end of the pump is connected with the three-way valve, and the other end of the pump is connected with a pipeline, the pipeline is used to transport the slurry, and the pump is used to control the flow rate of the slurry; a nozzle, the nozzle is arranged on the pipeline the other end of the .

In the present invention, the cycle delay relay is used to control the two-position three-way valve, so that the three-way valve can automatically and periodically switch between the two states, so the "three-way valve" in the present invention can also be referred to as "3/2-way valve with delayed cycle function". In the present invention, the air filter valve is a filter screen with holes in the middle, or a valve connected with an air filter. The purpose of the air filter valve is to ensure that the incoming air does not contain large particles of impurities and avoid affecting the optical surface. Grinding or polishing can achieve this effect.

In some embodiments, the pump is selected from one of a peristaltic pump, a self-priming pump, or a diaphragm pump.

In some embodiments, the low-speed liquid flow control device further includes an agitator located inside the liquid storage tank.

In some embodiments, the three-way valve includes a solenoid valve and a time control switch.

In some embodiments, the material of the pipe includes, but is not limited to, one of PU, TPU, EVA, and PVC. Further preferably, the pipe is a polyurethane pipe (PU pipe).

In a second aspect, the present invention also provides a low-speed liquid flow control method for supplying optical polishing slurry, which is performed by using the low-speed liquid flow control device provided by the present invention, comprising the steps of:

S1. The liquid storage tank is filled with slurry, the three-way valve points to the air filter valve, the pump is in a closed state, and there is no object in the pipeline for transportation;

S2. Open the three-way valve, and the three-way valve alternately points to the drain pipe and the air filter valve;

S3. Adjust the speed of the pump.

In the present invention, the cycle delay relay controls the three-way valve to switch in two states (the three-way valve alternately points to the dip tube and the air filter valve, that is, the three-way valve is in "pointing to the dip tube" and "pointing to the air filter". Alternately switch between the valve ", "pointing to the dip tube" means that the three-way valve is in the state where the common end is connected to the dip tube, and "pointing to the air filter valve" means that the three-way valve is at the common end and the air filter valve. connected state).

In some embodiments, the step S2 includes: opening a three-way valve, the three-way valve is directed to the dip tube and held for a period of time t1, and the three-way valve is directed to the air filter valve and held for a period of time t2 .

In some embodiments, t1≤3s, t2≥0.5s. t1 should not be too large to ensure that the aspect ratio of the droplets in the tube is close to 1 and that a sufficiently significant microcirculation is generated. t2 should not be too small, otherwise, the amount of air entering the pipe is not enough to separate two adjacent droplets.

The present invention does not need a clear restriction on the value of t1/t2, and the effective supply rate of the slurry can be adjusted by setting the ratio of t1/t2. Preferably, in some embodiments, 0.1≤t1/t2≤3.

In some embodiments, when the three-way valve points to the air filter valve, the object conveyed into the pipeline is a medium immiscible with the slurry in the liquid storage tank.

The beneficial effects of the present invention are: the low-speed liquid flow control device for optical polishing slurry supply and the low-speed liquid flow control method for optical polishing slurry supply provided by the present invention save costs and improve the utilization rate of the slurry , to facilitate the realization of low-speed supply.

Description of drawings

1 is a schematic diagram of interface distribution and surface tension according to an embodiment of the present invention;

2 is a schematic diagram of slurry transportation in a supply pipe according to an embodiment of the present invention;

3 is a schematic structural diagram of a low-speed liquid flow control device according to an embodiment of the present invention;

4 is a timing diagram of device operations and states according to an embodiment of the present invention.

In the figure, 100, low-speed liquid flow control device; 1, abrasive particles; 2, base fluid; 3, microcirculation; 5, contact angle; 8, air filter valve; 9, three-way valve; 10, dip tube; 11 , agitator; 12, liquid storage tank; 6, slurry; 7, air; 13, pump; 4, pipeline; 14, nozzle; 15, optical element.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

In the present invention, the abrasives and polishing liquids (that is, the mixture of abrasive particles and base liquid, which are divided into abrasives and polishing liquids according to their uses) mentioned in the background art are collectively referred to as polishing slurry, abbreviated as slurry.

3 is a schematic structural diagram of a low-speed liquid flow control device 100 according to an embodiment of the present invention, wherein the low-speed liquid flow control device 100 for supplying optical polishing slurry includes: a liquid storage tank 12, Used to store the slurry 6; the dip tube 10, the dip tube 10 extends into the interior of the liquid storage tank 12, and the dip tube 10 is connected with a three-way valve 9, and the three-way valve 9 is also connected with The air filter valve 8 is connected; the three-way valve is alternately directed to the dip tube and the air filter valve; the pump 13, one end of the pump 13 is connected with the three-way valve 9, and the other end of the pump 13 is connected with a Pipe 4, the pipe 4 is used to transport the slurry 6, the pump 13 is used to control the flow rate of the slurry; the nozzle 14, the nozzle 14 is arranged at the other end of the pipe 4, and guides the slurry 6 to the optical element 15 surfaces.

FIG. 1 is a schematic diagram of interface distribution and surface tension according to an embodiment of the present invention. Surface tension refers to the pulling force perpendicular to the boundary line caused by the unbalanced molecular attraction of the liquid surface layer. The inventors of the present invention have found through a large number of experimental studies that, due to the existence of the surface tension σ, the droplets of the base liquid 2 mainly composed of water form a contact angle 5 on the surface of the pipe wall of the pipe 4 . Without loss of generality, consider the process of liquid transportation from left to right as follows: there is a reverse resistance between the base liquid 2 droplet and the pipe 4, resulting in the bottom of the base liquid 2 droplet relative to the overall production of the base liquid 2 droplet. Right-to-left flow; with the upward trend of the contact angle, a microcirculation 3 is formed in the lower half of the base fluid 2 droplet. When the abrasive particles 1 slowly settle inside the droplets of the base liquid 2 , the microcirculation 3 plays the role of scouring and stirring, preventing the abrasive particles 1 from depositing to the bottom of the pipe wall of the pipe 4 . If a droplet-like form similar to the droplets of the base liquid 2 is not used, but a traditional continuous liquid flow is used, an effective microcirculation 3 cannot be formed inside the liquid at this time. Moreover, due to the wall resistance of the pipe 4, the flow rate of the bottom liquid is reduced, which is even more unfavorable to avoid the deposition of the abrasive particles 1.

2 is a schematic diagram of slurry transportation in a supply pipe according to an embodiment of the present invention. The present invention has found through a large number of experimental studies that the method for realizing the transportation of a large amount of slurry 6 includes: in a specific embodiment, using the pipeline 4 to supply the slurry 6, and in the pipeline 4, the form of alternating liquid flow of slurry 6 and air column is formed. Use the pump 13 as kinetic energy and control the flow rate. A nozzle 14 is inserted at the end of the pipe 4 to direct the slurry 6 to the surface of the optical element 15 .

In a specific embodiment, as the power, any pump that can generate suction pressure can be used. For example, the pump 13 is selected from one of a peristaltic pump, a self-priming pump or a diaphragm pump.

In a specific embodiment, the low-speed liquid flow control device 100 further includes a stirrer 11, and the stirrer 11 is located inside the liquid storage tank 12. Preferably, the stirrer is continuously stirred to keep the slurry 6 uniform. Consistent.

In a specific embodiment, the three-way valve 9 includes a solenoid valve and a time control switch, which are used to cyclically switch the states of the two-position three-way solenoid valve to form alternate delivery of droplets and air columns.

In a specific embodiment, the pipe 4 is a PU pipe.

In a second aspect, the present invention also provides a low-speed liquid flow control method for supplying optical polishing slurry, which is performed by using the low-speed liquid flow control device provided by the present invention, comprising the steps of:

S1. The liquid storage tank is filled with slurry, the three-way valve points to the air filter valve, the pump is in a closed state, and there is no object in the pipeline for transportation;

S2. Open the three-way valve, and the three-way valve alternately points to the drain pipe and the air filter valve;

S3. Adjust the speed of the pump.

In a specific embodiment, the step S2 includes: opening a three-way valve, the three-way valve is directed to the dip tube and held for a period of time t1, and the three-way valve is directed to the air filter valve and held for a period of time t2.

FIG. 4 is a timing diagram of device operations and states according to an embodiment of the present invention. In Fig. 4, from top to bottom, the first line is the operation of the three-way valve, the second line is the operation of the pump, and the third line is the pipeline state of the pipeline. Here, the pipeline state refers to the conveying state within the pipeline. In a specific embodiment, preferably, the device operation and state sequence diagram of an embodiment of the present invention can be specifically described as: first, the slurry 6 is stored in the liquid storage tank 12, and the agitator 11 is continuously stirred to keep the slurry Material 6 is uniform. In the normal state, the three-way valve 9 points to the air filter valve 8, the pump 1 is in the closed state, and there is no object in the PU pipe for transportation. Then, at time line L1 , the pump 13 is turned on, and the outside air is delivered in the conduit 4 via the air filter valve 8 . At the time line L2, the three-way valve 9 is opened, and the three-way valve 9 begins to point to the dip tube 10 and the air filter valve 8 alternately, that is, the first state and the second state are alternately switched, which can be specifically described as: when the three-way valve 9 The valve 9 points to the dip tube 10 and maintains for a period of time t1, which is recorded as the first state. At this time, the pipeline state is to transport slurry; when the three-way valve 9 points to the air filter valve 8 and maintains for a period of time t2, it is recorded as the second state. , at this time, the pipeline state is air delivery. The first state and the second state are alternately switched, and the pipeline 4 produces a liquid flow conveyed in sections, in the form of a section of slurry and a section of air arranged in a linear and periodic manner. That is, in the first state, the dip tube (10) is opened, and the air filter valve is kept closed, so that the slurry is fed into the pipeline by the pump; in the second state, the three-way valve closes the dip tube (10), keeping the With the air filter valve open, the pump delivers air into the pipeline. Preferably, in the present invention, a time relay is used to generate a cyclic delay, and the setting of the on-off time can be realized by adjusting the oscillation frequency, that is, adjusting the resistance value and capacitance value of the oscillator.

In the above process, preferably, the flow rate of the liquid supply can be adjusted by the following two methods:

(a) By adjusting the rotational speed of the pump 13, the flow rate of the slurry 6 can be adjusted; the control of the flow rate by the pump includes both the slurry and the air: the overall effect is to affect the rate at which the slurry is supplied to the workpiece surface.

(b) By adjusting the time ratio t1/t2 of the three-way valve 9 in the first state and the second state, the duty ratio of the slurry 6 in the pipeline 4 can be adjusted. The inventors of the present invention found that, in order to better ensure the same feeding rate, the flow rate of the liquid/gas is larger, and the abrasive is less likely to settle.

Finally, the slurry 6 and air are transported to the nozzle and directed towards the optical workpiece surface 15 for grinding or polishing.

In a specific embodiment, t1≤3s, t2≥0.5s. t1 should not be too large to ensure that the aspect ratio of the droplets in the tube is close to 1 and that a sufficiently significant microcirculation is generated. t2 should not be too small, otherwise, the amount of air entering the pipe is not enough to separate two adjacent droplets.

The present invention does not need a clear restriction on the value of t1/t2, and the effective supply rate of the slurry can be adjusted by setting the ratio of t1/t2. Preferably, in a specific embodiment, 0.1≤t1/t2≤3.

In a specific embodiment, when the three-way valve points to the air filter valve, the object conveyed into the pipeline is not necessarily air, as long as the medium is immiscible with the slurry in the liquid storage tank. For example, castor oil can be used instead of air in applications using water as the base fluid.

In a specific embodiment, each droplet is isolated by air in the tube of the present invention, and is transported in the form of a section of air and a section of liquid. In addition, by adjusting the time ratio of the three-way valve 9 in the first state and the second state, the flow rate supplied by the slurry 6 is adjusted.

The beneficial effects of the present invention: in the case of low-speed supply of the slurry, the abrasive deposition phenomenon can be greatly reduced. To achieve near-net utilization of the slurry, the slurry in the liquid storage tank can be fully utilized.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Rear, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial, The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

The specific embodiments of the present invention described above do not limit the protection scope of the present invention. Any other corresponding changes and modifications made according to the technical concept of the present invention shall be included in the protection scope of the claims of the present invention.

What is described in the above-mentioned embodiments and specification is only to illustrate the principle and best embodiment of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have various changes and improvements, and these changes and improvements all fall within the scope of the present invention. within the scope of the claimed invention.

Claims (8)

1. a low-speed liquid flow control method for optical grinding and polishing slurry supply, is characterized in that, its use device comprises: liquid storage tank, for storing slurry; Inside the liquid storage tank, and the dipping pipe is connected with a three-way valve, and the three-way valve is also connected with the air filter valve; the three-way valve alternately points to the dipping pipe and the air filter valve; the pump, so One end of the pump is connected with the three-way valve, and the other end of the pump is connected with a pipeline, the pipeline is used to transport the slurry, and the pump is used to control the flow rate of the slurry; a nozzle, the nozzle is arranged at the The other end of the pipeline; the control method includes the following steps: S1. The liquid storage tank is filled with slurry, the three-way valve points to the air filter valve, the pump is in a closed state, and there is no object in the pipeline for transportation; S2, open the three-way valve, the three-way valve alternately points to the drain pipe and the air filter valve; open the three-way valve, the three-way valve points to the drain pipe and keeps for a period of time t1, the three-way valve points to the The air filter valve is kept for a period of time t2; when the three-way valve points to the air filter valve, the object transported into the pipeline is a medium immiscible with the slurry in the liquid storage tank; S3. Adjust the speed of the pump. 2 . The low-speed liquid flow control method for optical polishing slurry supply according to claim 1 , wherein the pump is selected from one of a peristaltic pump, a self-priming pump or a diaphragm pump. 3 . 3 . The low-speed liquid flow control method for optical polishing slurry supply according to claim 1 , further comprising a stirrer, and the stirrer is located inside the liquid storage tank. 4 . 4 . The low-speed liquid flow control method for optical polishing slurry supply according to claim 1 , wherein the three-way valve comprises a solenoid valve and a time control switch. 5 . 5 . The low-speed liquid flow control method for optical polishing slurry supply according to claim 1 , wherein the material of the pipe is one of PU, EVA, and PVC. 6 . 6 . The low-speed liquid flow control method for optical polishing slurry supply according to claim 5 , wherein the pipe is made of TPU. 7 . 7 . The low-speed liquid flow control method for optical polishing slurry supply according to claim 1 , wherein t1≦3s, and t2≧0.5s. 8 . 8 . The low-speed liquid flow control method for optical polishing slurry supply according to claim 1 , wherein 0.1≦t1/t2≦3. 9 .

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