Suction device

Abstract

To provide a suction device that is able to efficiently recover residual liquid by reducing an amount of liquid to be turned into mist.SOLUTION: The present invention relates to a suction device 1 for collecting a liquid remaining in a workpiece, and the suction device includes a collection tank 10, a negative pressure generator 20, and a recovery unit 30. The collection tank 10 has: a collection cylinder 12 having a plurality of holes 121; a lead-in pipe 11; a drain pipe 13; an outer cylinder 14 defining an annular space communicating with the plurality of holes 121; and an exhaust pipe 15. The negative pressure generator 20 includes a suction pipe 21, a compressed-air supply pipe 22, and a discharge pipe 23. A negative pressure is generated by an air flow generated by the compressed air; and air in a flow passage from the inside of the workpiece to the exhaust pipe 15 is sucked to suck the liquid in the workpiece and the mist formed by atomizing the liquid, thereby collecting them in the collection cylinder 11, and the liquid and the mist not having been collected are discharged from the discharge pipe 23. The recovery unit 30 recovers the liquid and the mist that have not been collected.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a suction device. [Background technology]

[0002] Conventionally, there are known devices that remove liquid from a workpiece after polishing, cleaning, inspection, etc., using the liquid. For example, the liquid suction machine disclosed in Patent Document 1 is equipped with a negative pressure device and sucks the liquid from a container to perform the extraction work.

[0003] Liquid recovery devices that utilize negative pressure in this way include devices that use an ejector to suck and recover residual liquid into a small centrifuge, as well as devices that use a breath slider to suck and collect residual liquid into a tank and then recover the uncollected liquid using an exhaust cleaner. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5020281 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although a device using a small centrifuge can separate air and liquid, the tank capacity is small, so the collected liquid must be frequently discarded, which impedes production efficiency.

[0006] On the other hand, in a device that uses a breath slider and exhaust cleaner, if the breath slider is placed on the tank inlet side, the sucked liquid will be turned into mist (micro-mist) by the supplied air. Also, because positive pressure is applied inside the tank, the mist passes through without accumulating in the tank, and most of it is collected by the exhaust cleaner. This causes the exhaust cleaner element to become clogged in a short period of time, reducing collection capacity.

[0007] In view of the above-mentioned problems, an object of the present invention is to provide a suction device that can reduce the amount of liquid that turns into mist and efficiently collect remaining liquid. [Means for solving the problem]

[0008] The present invention provides a suction device (1) for collecting liquid remaining inside a workpiece, and includes a collection tank (10), a negative pressure generator (20), and a recovery section (30).

[0009] The collection tank has a cylindrical collection tube (12) extending vertically and having a plurality of holes (121) connecting the inside and outside of the cylinder, an inlet pipe (11) connecting the inside of the work to the inside of the collection tube via the top side of the collection tube, a drain pipe (13) discharging liquid from the inside of the collection tube to the outside via the bottom side of the collection tube, an outer tube (14) surrounding the radial outside of the collection tube and forming an annular space connected through the plurality of holes, and an exhaust pipe (15) connecting the annular space to the outside.

[0010] The negative pressure generating device has a suction pipe (21) connected to the exhaust pipe, a supply pipe (22) through which compressed air supplied from the outside flows in, and a discharge pipe (23) connecting the suction pipe and the supply pipe with the outside.

[0011] The negative pressure generating device generates negative pressure by discharging the airflow generated by the compressed air that has been introduced into the discharge pipe, and by sucking in the air inside the flow path that leads from inside the workpiece to the exhaust pipe, it sucks in the liquid and mist that has been broken down into fine particles that remain inside the workpiece, and collects the sucked in liquid and mist in a collection tube.In addition, the liquid and mist that has been sucked in from the suction pipe without being collected in the collection tube is discharged from the discharge pipe together with the airflow.

[0012] The recovery section has a recovery pipe (31) that communicates with the discharge pipe, and recovers the liquid and mist that have not been collected in the collection tube and have flowed in from the recovery pipe.

[0013] In this invention, by locating a negative pressure generator downstream of the collection tank, the strong negative pressure generated by the negative pressure generator is deliberately routed through a complex flow path inside the collection tank, preventing the residual liquid inside the workpiece from being directly exposed to the strong negative pressure. By using the collection tank as a buffer space in this way, the suction liquid is prevented from turning into mist, allowing the residual liquid to be efficiently collected in the collection tube and outer tube. This also has the effect of reducing the amount of liquid or mist contained in the airflow reaching the collection body in the collection section, suppressing contamination of the element (the collection body described below), reducing the frequency of element replacement and contributing to production efficiency. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a configuration diagram of a suction device according to an embodiment. [Figure 2] 1 is a perspective view of a suction device according to one embodiment. [Figure 3] FIG. 2 is a partial cross-sectional front view of the periphery of a collection tank of a suction device according to one embodiment. [Figure 4] 1(a) is a diagram illustrating the configuration of a suction device according to Comparative Example 1. FIG. 1(b) is a diagram illustrating the configuration of a suction device according to Comparative Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a suction device according to an embodiment will be described with reference to the drawings.

[0016] In this embodiment, an injector for an internal combustion engine is assumed as the workpiece W. In manufacturing the fuel injection nozzle of the injector, the nozzle is processed and assembled through processes such as (1) electric discharge machining, (2) fluid polishing, (3) cleaning, and (4) a flow rate test using test oil to simulate the engine installation state.

[0017] In steps (2) to (4), pressure is applied to the workpiece W to inject the polishing liquid, cleaning liquid, and inspection oil, respectively. However, because the nozzle holes of the fuel injection nozzles are minute, liquid remains inside the workpiece W after processing and inspection are completed. Therefore, it is necessary to perform an operation to suction and recover the liquid from inside the workpiece. The suction device of this embodiment allows this operation to be performed efficiently.

[0018] (One embodiment) An outline of a suction device according to one embodiment is shown in Fig. 1. The suction device 1 collects liquid remaining inside the workpiece W, and includes a collection tank 10, a negative pressure generator 20, and a recovery unit 30.

[0019] Negative pressure generator 20 receives a supply of compressed air from an external device and generates an air flow (air current) in the direction of the arrow (Figure 1). Workpiece W is located at the most upstream point of this air current and is the starting point of the air current. The inside of workpiece W is connected to collection tank 10, which releases liquid including mist. Collection tank 10 collects the liquid and mist and is connected to negative pressure generator 20, which releases any liquid and mist that was not captured. Negative pressure generator 20 is connected to collection section 30, which collects the liquid and mist that was not collected and releases the air current that does not contain liquid and mist further downstream.

[0020] The negative pressure generator 20 generates this airflow, but the negative pressure generator 20 is not directly connected to the workpiece W, but is connected to the collection tank 10 and is located downstream of the collection tank 10. As shown in FIG. 2, which will be described later, the collection tank 10 discharges the collected liquid Lq (including the re-merged mist, the same applies below) via a separate route. As will be described later, the collection unit 30 collects the liquid not collected by the collection tank 10.

[0021] The appearance of one embodiment is shown in Figure 2. Collection tank 10 has one airflow inlet (inlet pipe 11), one airflow outlet (drain pipe 13), and one liquid outlet (exhaust pipe 15). Negative pressure generator 20 has two airflow inlets (suction pipe 21, supply pipe 22) and one airflow outlet (discharge pipe 23). Collection unit 30 has one airflow inlet (collection pipe) and one outlet (not shown).

[0022] In FIG. 2, the flow directions of the airflow and liquid are indicated by three types of arrows. In the suction device 1 of this embodiment, as described below, a negative pressure is generated by the compressed air flow, which powerfully suctions the remaining liquid inside the workpiece W. As a result, as a result of suction, some of the remaining liquid inside the workpiece W separates from the liquid surface and becomes liquid mist, which is carried away by the airflow. For this reason, the flow of the airflow containing the liquid and mist is indicated by a solid arrow as the "wet airflow Aw," while the flow of the airflow not containing the liquid and mist is indicated by a dashed arrow as the "dry airflow Ad." The dry airflow Ad includes the compressed air and the airflow resulting from the collection of the liquid and mist from the wet airflow Aw. The discharge direction of the liquid collected in the collection tank is indicated by a graphic arrow as the "collected liquid Lq."

[0023] The internal structure of the collection tank 10 is shown in Figure 3. The collection tank 10 has an inlet pipe 11, a collection tube 12, a drain pipe 13, an outer tube 14, and an exhaust pipe 15. The inlet pipe 11 communicates with the inside of the collection tube 12 via the top side of the collection tube 12 from the inside of the workpiece W, and causes the wet airflow Aw containing residual liquid and mist from inside the workpiece W to flow directly into the collection tube 12 of the collection tank 10. The driving source of the airflow is the negative pressure generator 20 located downstream of the exhaust pipe 15, as described above.

[0024] The collection tank 10 has a double structure in which an outer cylinder 14 encloses the collection cylinder 12, and the wet airflow Aw is first drawn into the collection cylinder 12. The cross-sectional flow path area of ​​the cylindrical portion of the collection cylinder 12 is relatively larger than the cross-sectional flow path area inside the piping that connects the inside of the workpiece W to the inlet pipe 11 and the cross-sectional flow path area inside the inlet pipe 11. Therefore, when the wet airflow Aw flows from the inlet pipe 11 into the collection cylinder 12, the negative pressure weakens relatively due to Bernoulli's theorem (principle), slowing the flow rate of the airflow, and mist particles that have separated from the liquid tend to rejoin the liquid. This allows the liquid and mist to be collected inside the collection cylinder 12.

[0025] Collection tube 12 is a cylindrical hollow member extending in the vertical direction, and has a large number of holes 121 that connect the inside and outside of the cylinder. In this embodiment, the cylindrical portion of the collection tube is made of a material such as stainless steel punched metal, in which the large number of holes 121 form openings with a diameter of about 1 mm, and the opening rate is over 20%.

[0026] The wet airflow Aw drawn into the collecting cylinder 12 passes through the numerous holes 121 from the inside to the outside and then flows into the outer cylinder 14. At this time, the liquid and mist contained in the wet airflow Aw remain inside the collecting cylinder 12 and become collected liquid Lq, which is then discharged from the collecting cylinder 12 and the collecting tank 10 through the drain pipe 13. As shown in Fig. 3, two drain pipes 13 are provided in this embodiment. That is, one drains the liquid from inside the collecting cylinder 12 to the outside via the bottom side of the collecting cylinder 12, and the other drains the liquid collected below the outer cylinder 14 and discharges it to the outside.

[0027] On the other hand, the wet airflow Aw that passes through the multiple holes 121 has liquid and mist collected, resulting in a relatively lower liquid and mist content. However, this airflow passes through holes 121 with a flow path cross-sectional area much smaller than the flow path cross-sectional area of ​​collection tube 12, which causes the Bernoulli effect described above to work in reverse, relatively increasing the negative pressure and increasing the airflow velocity. For this reason, the wet airflow Aw that has flowed into collection tube 12 does not immediately change into dry airflow Ad, and it is thought that liquid and mist, including newly generated mist, are generated as they pass through holes 121 due to the negative pressure created by negative pressure generator 20 and the microscopic increase in flow velocity associated with fluctuations in the flow path cross-sectional area.

[0028] The outer cylinder 14 of the collection tank 10 surrounds the outside of the collection cylinder 12 in the radial direction, forming an annular space 141 that communicates through a number of holes 121, and is connected to an exhaust pipe 15 that connects the annular space 141 to the outside. As shown in FIG. 3, the annular space 141 has a zigzag shape when viewed from the front, thereby increasing the flow path length. As the wet airflow Aw moves along the zigzag flow path, the liquid and mist contained in the wet airflow Aw are gradually collected by adhering to the wall surfaces, and are discharged from the bottom of the outer cylinder 14 into the drain pipe 13. In this way, most of the liquid and mist are collected from the wet airflow Aw before it passes through the exhaust pipe 15, and the wet airflow Aw becomes almost a dry airflow Ad (FIG. 3).

[0029] The negative pressure generator 20 has a suction pipe 21 that communicates with the exhaust pipe 15, a supply pipe 22 that receives compressed air supplied from the outside, and a discharge pipe 23 that connects the suction pipe 21 and the supply pipe 22 to the outside. The negative pressure generator 20 generates negative pressure by causing the compressed air that flows in from the supply pipe 22 to suddenly increase in volume in an environment of relatively low atmospheric pressure, generating a strong airflow, and discharging the airflow toward the discharge pipe 23 (Venturi mechanism). In this embodiment, the negative pressure generator 20 is a so-called breath slider.

[0030] With this configuration, air inside the flow path from inside the workpiece W to the exhaust pipe 15 is strongly sucked in, and the liquid remaining inside the workpiece and the mist that has been separated from the liquid surface and turned into fine particles are forcibly sucked in, and the sucked liquid and mist are collected in the collection tube 12 as described above. In addition, the liquid and mist that pass through neither the collection tube 12 nor the outer tube 14 without being collected and that are sucked in from the suction pipe 21 are discharged from the discharge pipe 23 together with the airflow.

[0031] The collection unit 30 has a collection pipe 31 communicating with the discharge pipe 23 and a collection body made of a sponge-like porous body (not shown), and passes through the collection body to absorb and collect the liquid and mist that is not captured by the collection tube 12 or the outer tube 14 and is discharged from the negative pressure generator via the collection pipe 23. This collection body is replaced periodically. In this embodiment, the collection unit 30 is an exhaust cleaner, and the collection body is a so-called element.

[0032] Figure 4 shows a suction device of a comparative example. Below, the effects of this embodiment, which is representative of this embodiment, will be explained in comparison with the comparative example. Comparative example 1 in Figure 4(a) is an example of a suction device that uses the ejector and small centrifuge introduced in the first paragraph of paragraph 0003. While this method is capable of separating air and liquid, the tank capacity of the small centrifuge is small, so the tank quickly fills up, necessitating frequent disposal of the liquid and reducing production efficiency.

[0033] Comparative Example 2 in Figure 4(b) is an example of a suction device that uses the breath slider and exhaust cleaner introduced in the latter part of paragraph 0003. The components in this example are the same as those in this embodiment. That is, the tank corresponds to the collection tank 10, the breath slider corresponds to the negative pressure generator 20, and the exhaust cleaner corresponds to the recovery device 30. In order to suction and recover the residual liquid inside the workpiece W as efficiently as possible, the connection order of the tank and breath slider is reversed from that of this embodiment, that is, in this embodiment, the order is workpiece W, negative pressure generator 20, and collection tank 10.

[0034] However, with this configuration, the residual liquid being sucked in is directly exposed to a strong negative pressure, which makes the liquid prone to misting. Furthermore, because a strong positive pressure is also applied to the tank downstream of the breath slider, the mist passes through without accumulating in the tank, and almost all of it easily reaches the exhaust cleaner downstream of the tank, where it is collected. This causes the exhaust cleaner element to clog in a short period of time, reducing collection capacity. For this reason, there has been a demand for suction devices that use negative pressure to prevent the collected liquid from becoming misted.

[0035] In view of the above-mentioned problems, in this embodiment, the negative pressure generator 20 is disposed downstream of the collection tank 10, and the strong negative pressure generated by the negative pressure generator 20 is deliberately routed through a complex flow path inside the collection tank 10, so that the residual liquid inside the workpiece W is not directly exposed to the strong negative pressure. By using the collection tank 10 as a buffer space in this way, the suction liquid is prevented from turning into mist, and the residual liquid can be efficiently collected in the collection tube 12 and outer tube 14. This also has the effect of reducing the amount of liquid or mist that reaches the collection unit 30, which reduces the frequency of element replacement in the collection unit 30 and contributes to improved production efficiency.

[0036] (Other embodiments) In the above embodiment, an example of sucking liquid remaining inside an injector of an internal combustion engine is shown, but the workpiece is not limited to the above example, and the present invention can be applied to any workpiece that has a complex or narrow internal structure and is likely to retain liquid required for the process.

[0037] In the above-described embodiment, an example was shown in which the flow path inside the outer cylinder is a meandering flow path as shown in Fig. 3. However, the flow path inside the outer cylinder is not limited to the above-described example, and any flow path may be used as long as it is long, for example, the flow path spirals upward around the outside of the collecting cylinder and reaches the exhaust pipe.

[0038] In the above embodiment, an example was shown in which a member such as a punched metal was used as the collection tube having a plurality of holes. However, the collection tube is not limited to the above example, and any structure capable of collecting liquid and mist may be used, such as a rolled metal mesh with a low opening ratio.

[0039] In the above embodiment, an example was shown in which a device such as an exhaust cleaner incorporating a porous sponge (element) was used as the collection unit. However, the collection unit is not limited to the above example, and any device capable of collecting uncaptured liquid and mist may be used.

[0040] In the above-described embodiment, the components are arranged in the layout relationship shown in Fig. 2. However, the layout of the components is not limited to the above example, and can be designed as appropriate depending on the convenience of the installation location, etc.

[0041] As such, the present disclosure is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit of the present disclosure. [Explanation of symbols]

[0042] 1 suction device, 10 collection tank, 11 inlet pipe, 12 collection tube, 121 hole 13 drainage pipe, 14 outer cylinder, 15 exhaust pipe, 20 negative pressure generator, 21 suction pipe 22 supply pipe, 23 discharge pipe, 30 recovery section, 31 recovery pipe

Claims

[Claim 1] A suction device (1) for collecting liquid remaining inside a workpiece, a collecting tank (10) having a cylindrical collecting tube (12) extending vertically and having a plurality of holes (121) communicating the inside and outside of the cylinder; an inlet pipe (11) communicating from the inside of the work to the inside of the collecting tube via the top side of the collecting tube; a drain pipe (13) discharging liquid from the inside of the collecting tube to the outside via the bottom side of the collecting tube; an outer tube (14) surrounding the radial outside of the collecting tube and forming an annular space communicating with the plurality of holes; and an exhaust pipe (15) communicating the annular space with the outside. a negative pressure generating device (20) having a suction pipe (21) communicating with the exhaust pipe, a supply pipe (22) through which compressed air supplied from the outside flows in, and a discharge pipe (23) through which the suction pipe and the supply pipe communicate with the outside, which generates negative pressure by discharging an airflow generated by the compressed air that flows in toward the discharge pipe, and which sucks in air from inside the workpiece inside a flow path leading to the exhaust pipe, thereby sucking in liquid and mist that has been atomized from the liquid remaining inside the workpiece, collecting the sucked liquid and mist in the collecting tube, and discharging the liquid and mist that have not been collected in the collecting tube and are sucked from the suction pipe together with the airflow from the discharge pipe; a collection section (30) having a collection pipe (31) communicating with the discharge pipe and collecting liquid and mist that have flowed in from the collection pipe without being collected by the collection tube; A suction device comprising:

Images