Liquid removal system and liquid removal method

Abstract

The present invention provides a liquid removal system and a liquid removal method. A bottomed hole (40) formed in a block (32) has a constant diameter portion (44) with a diameter defined by D ho . As a blow nozzle (14) inserted into the bottomed hole (40), one is selected for which an inner diameter is given as D in , and an outer diameter is given as D out , and an area ratio S ra represented by the following equation (1) falls within a range of 3 to 10. S ra ={(π / 4)D ho 2 ‑ (π / 4)D out 2} / (π / 4)D in 2 …(1) The blow nozzle (14) is inserted into the bottomed hole (40) so that an insertion length (L) thereof is greater than or equal to one fourth of a depth (H) of the constant diameter portion (44), and a compressed gas is discharged from the blow nozzle (14) at a discharge pressure greater than or equal to 0.05 MPa.

Description

[0001] This application is a divisional application of the following patent application:

[0002] Application Number: 201810354571.3

[0003] Application date: April 19, 2018

[0004] Invention Title: Liquid Removal Method Technical Field

[0005] The present invention relates to a liquid removal method for removing liquid retained in a bottomed orifice. Background Technology

[0006] So-called mechanical connections are widely used, in which one component is connected to a predetermined component via a fastening component such as a screw or bolt. For this connection to be made, a bottomed screw hole or bolt hole (hereinafter also referred to as a "connection hole") is formed in the predetermined component into which the fastening component enters.

[0007] Many components are cleaned to remove debris after machining processes such as forming connection holes and before mechanical connection is performed. For this purpose, cleaning fluid is retained in the connection holes. If mechanical connection is performed with such cleaning fluid retained in the connection holes, there is a concern that rust may form on the fastening components and the inner walls of the connection holes. To avoid this, a so-called dewatering process is performed to remove the cleaning fluid from the connection holes. Japanese Patent No. 5123744 discloses an air-blowing device and a method for removing foreign objects for the purpose of performing this dewatering process. Summary of the Invention

[0008] For example, Japanese Patent No. 5123744 Figures 3 to 5 As shown, in this technology, an air nozzle is inserted from the bottom of a connecting hole, with the bottom of the connecting hole facing upwards, and compressed air is blown vertically upwards. Therefore, in order to remove foreign matter formed on the vertically upward-facing upper surface from the connecting hole, the orientation of the workpiece needs to be changed so that its upper surface faces downwards.

[0009] Incidentally, in Japanese Patent No. 5123744, the cylinder block is exemplified as a workpiece having such a connecting hole formed therein. However, it is difficult and troublesome to manually change the posture of such a heavy object. Therefore, it is possible to consider setting up a posture changing mechanism. However, in this case, the construction of the cleaning equipment becomes complicated, and it creates inconvenience in terms of increased capital investment.

[0010] The main objective of this invention is to provide a liquid removal method that does not require changing the orientation of the workpiece.

[0011] Another object of the present invention is to provide a liquid removal method that can remove liquid from a bottomed orifice using a simple construction.

[0012] According to an embodiment of the present invention, a liquid removal method is provided for removing liquid from a bottomed orifice having a constant diameter portion formed in a workpiece by compressed gas, the liquid removal method comprising:

[0013] In the insertion step, the air nozzle is inserted into the bottom hole. The air nozzle has an inner diameter D. in and outer diameter D out And where the diameter of the constant diameter portion with the bottom hole is given as D ho When, its area ratio S is expressed by the following equation (1) ra Falling within the range of 3 to 10; and

[0014] S ra = {(π / 4)D ho 2 - (π / 4)D out 2} / (π / 4)D in 2 …(1)

[0015] The removal step involves expelling compressed gas from the blow nozzle into the bottom hole, thereby removing the liquid that has entered the bottom hole to the outside of the bottom hole.

[0016] In the insertion step, the insertion length of the air nozzle into the bottom hole is set to be greater than or equal to one-quarter of the depth of the constant diameter portion; and

[0017] In the removal step, the discharge pressure of the compressed gas from the blowing nozzle is set to be greater than or equal to 0.05 MPa.

[0018] In equation (1), the denominator is the opening area of ​​the discharge port of the blowing nozzle, and the numerator is the horizontal cross-sectional area of ​​the gap formed between the inner wall of the bottomed orifice and the outer wall of the blowing nozzle. Since liquid is removed through this gap, the horizontal cross-sectional area of ​​this gap can be considered, in other words, as the horizontal cross-sectional area of ​​the liquid removal channel. More specifically, according to the invention, the ratio between the opening area of ​​the discharge port for discharging compressed gas and the horizontal cross-sectional area of ​​the liquid removal channel falls within the range of 3 to 10, and the insertion length of the blowing nozzle into the bottomed orifice and the discharge pressure of the compressed gas are appropriately set. By defining the discharge conditions in this way, liquid can be easily removed from the bottomed orifice even when the bottomed orifice is opened in an upward-facing manner.

[0019] More specifically, in this case, the liquid can be removed from the upward-opening bottomed orifice without changing the workpiece's orientation. Therefore, since no orientation-changing mechanism is required, the liquid can be removed from the bottomed orifice using a simple construction. Furthermore, increased capital investment can be avoided.

[0020] Needless to say, the constant π / 4 in equation (1) can be canceled out. In other words, equation (1) can be modified in the following way.

[0021] S ra = (D ho 2 - D out 2 ) / D in 2

[0022] Although it is preferable to have the discharge pressure of the compressed gas from the blowing nozzle as high as possible during the removal step, obtaining compressed gas with excessively high discharge pressure is not easy. Furthermore, in this case, the investment capital is high due to the need to provide pressure-resistant structures for the supply lines, etc. Therefore, it is preferable to set the discharge pressure to less than or equal to 0.5 MPa.

[0023] Furthermore, since the discharge pressure is greater than or equal to 0.05 MPa, it is sufficient to set the period for discharging compressed gas to 1 to 20 seconds.

[0024] As an air blowing nozzle, a straight tube with a constant inner diameter and a constant outer diameter is preferred; in other words, a cylinder. Air blowing nozzles with this simple shape are easy to manufacture. Therefore, costs can be reduced.

[0025] In the insertion step, preferably, the insertion length of the blowing nozzle into the bottom hole is set to be greater than or equal to half the depth of the constant diameter portion. In this case, the discharge pressure can be set to a lower pressure, or the period of discharge of compressed gas can be shorter.

[0026] According to the present invention, the ratio between the opening area of ​​the discharge port for discharging compressed gas and the horizontal cross-sectional area of ​​the liquid removal channel falls within the range of 3 to 10. Simultaneously, the discharge conditions when the compressed gas is discharged, such as the insertion length of the blowing nozzle into the bottom hole and the discharge pressure of the compressed gas, are appropriately set. As a result, even if the bottom hole is opened upwards, the liquid inside the bottom hole can be easily removed.

[0027] Therefore, there is no need for a posture-changing mechanism or similar device to change the posture of the workpiece forming the bottom hole so that the opening of the bottom hole is oriented downwards. Thus, liquid can be removed from the bottom hole using a simple mechanism.

[0028] The above and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which preferred embodiments of the invention are shown by way of illustrated examples. Attached Figure Description

[0029] Figure 1 This is a system construction diagram of an air blowing device for performing the liquid removal method according to this embodiment;

[0030] Figure 2 It is a display Figure 1 An enlarged perspective view of the main component with the air nozzle inserted into the bottom hole;

[0031] Figure 3 It is a display Figure 1 An enlarged vertical cross-sectional view of the main component with the air nozzle inserted into the bottom hole;

[0032] Figure 4 It is displayed in the area ratio S ra A graph showing whether water is removed when the quotient (insertion length of the air nozzle / depth of the constant diameter portion) is changed; and

[0033] Figure 5 It is the display area ratio S ra A graph showing whether water is removed when the compressed air discharge pressure is changed. Detailed Implementation

[0034] Preferred embodiments of the liquid removal method according to the present invention will be presented and described in detail below with reference to the accompanying drawings.

[0035] First, refer to Figure 1 A blowing apparatus for performing the liquid removal method according to the invention is briefly described. The blowing apparatus 10 includes a compressor 12 as a source of compressed air (compressed gas), a blowing nozzle 14 for discharging compressed air, and a supply line 16 through which the compressed air supplied from the compressor 12 flows to the blowing nozzle 14. The compressor 12, for example, supplies so-called factory air.

[0036] In the supply line 16, a filter 18, a pressure regulator 20, a flow meter 22, and a switching valve 24 are sequentially arranged from the upstream side. Once opened, the switching valve 24 remains open until a preset time has elapsed in the timer 26. Unless otherwise stated, the switching valve 24 is closed upon activation of the timer 26.

[0037] In this configuration, the air nozzle 14 is supported by a fitting (not shown) on the lower end surface of the support 28. A pressure gauge 30 is arranged inside the support 28 in the supply line 16, and the discharge pressure of the compressed air discharged from the air nozzle 14 is indicated by the pressure gauge 30.

[0038] like Figure 2 and 3 As shown, in this invention, the air-blowing nozzle 14 has an inner diameter D in and outer diameter D out It is made of a constant straight tube (cylinder). Although copper can be cited as a suitable material for blowing nozzles 14 having this shape, the invention is not particularly limited to this feature.

[0039] The support 28 can be moved in the front-back, left-right, and up-down directions by three actuators (not shown). At this time, the support 28 is guided by a guide rail (not shown).

[0040] exist Figure 1 In the image, the block 32, which serves as the workpiece, is displayed together with the support 28. (Example) Figures 1 to 3 As shown, a bottomed hole 40 is formed on the upper surface of the block 32 by drilling. The bottomed hole 40 includes: a tapered portion 42 that decreases in diameter in a tapered shape; and a constant diameter portion 44 having a constant diameter. Furthermore, the bottomed hole 40 is a screw hole with a threaded portion (not shown) formed on the inner wall of the constant diameter portion 44 and extending vertically downward toward the lower surface of the bottomed hole 40. Figure 2 and 3 In the diagram, the letter H represents the depth of the constant diameter portion 44 with the bottom hole 40, more specifically, the distance from the opening to the boundary between the tapered portion 42 and the constant diameter portion 44, and the letter L represents the insertion length of the blowing nozzle 14. Further, in Figure 2 and 3 In the middle, variable D ho It is the diameter of the constant diameter portion 44 (i.e., the opening diameter).

[0041] In this case, the insertion length L is defined as the distance from the opening of the bottom hole 40 to the distal end of the blowing nozzle 14. Thus, for example, the statement "insertion length L is one-quarter of the depth H of the bottom hole 40" implies that the distal end (exhaust port) of the blowing nozzle 14 is located at one-quarter of the depth H of the constant diameter portion 44. From this fact, it can be understood that as the calculated value of (insertion length L / depth H of the constant diameter portion 44) becomes closer to 1, the distal end of the blowing nozzle 14 is closer to the boundary between the tapered portion 42 of the bottom hole 40 and the constant diameter portion 44.

[0042] Next, a liquid removal method according to this embodiment will be described. In the liquid removal method, liquid W pre-reserved in the bottom hole 40 is removed from the bottom hole 40 by compressed air discharged from the blowing nozzle 14.

[0043] In this case, the blowing nozzle 14 is selected with a predetermined area ratio S relative to the horizontal cross-sectional area of ​​the bottom hole 40. ra The air blowing nozzle. More specifically, the air blowing nozzle 14 has an inner diameter D. in and outer diameter D out The area ratio S is expressed by the following equation (1). ra It falls within the range of 3 to 10.

[0044] S ra = {(π / 4)D ho 2 - (π / 4)D out 2} / (π / 4)D in 2

[0045] = (D ho 2 - D out 2 ) / D in 2 …(1)

[0046] The opening area SA1 of the discharge port is calculated from the denominator (π / 4)D in 2 Calculated. On the other hand, the gap formed between the inner wall of the bottom hole 40 and the outer wall of the air nozzle 14, in other words, by Figure 2 The horizontal cross-sectional area SA2 represented by the mid-section line is derived from the molecule {(π / 4)D} ho 2 - (π / 4)D out 2} is obtained. This gap serves as a liquid removal channel. Essentially, the molecule in equation (1) represents the horizontal cross-sectional area of ​​the liquid discharge channel, while the area ratio S ra This represents the ratio of the horizontal cross-sectional area SA2 of the liquid removal channel to the opening area SA1 of the discharge port.

[0047] If the area is greater than S ra If the area is less than 3, then liquid W is less likely to be removed from the bottom hole 40 because the area of ​​the liquid removal channel is smaller. Furthermore, if the area is greater than S... ra If the area ratio is greater than 10, the blowing pressure becomes insufficient due to the smaller compressed air supply area. Therefore, under the same conditions, liquid W is not easily removed from the bottom hole 40. More preferably, the area ratio S ra It is set to 5 to 9.

[0048] Next, the insertion step is performed. More specifically, by operating the actuator described above, the support 28 is moved, the position of the air nozzle 14 is aligned with the position of the bottom hole 40, and the air nozzle 14 is lowered into the bottom hole 40. As a result, the distal end of the air nozzle 14 selected as described above is inserted into the bottom hole 40, as... Figure 2 and 3 As shown. In this case, if the insertion length L of the air nozzle 14 is too small, the liquid W near the bottom may remain there instead of being removed from the bottom hole 40 because the compressed air discharged from the air nozzle 14 has difficulty reaching the bottom of the bottom hole 40. To avoid this, the insertion length L is set to be greater than or equal to one-quarter of the depth H of the constant diameter portion 44.

[0049] More preferably, the insertion length L is set to be greater than or equal to half the depth H of the constant diameter portion 44. In this case, since the distal end (discharge port) of the blowing nozzle 14 is placed closer to the bottom of the bottom hole 40, the liquid W near the bottom of the bottom hole 40 can be easily removed.

[0050] Next, the removal step is performed. More specifically, the switching valve 24 is opened simultaneously with the operating timer 26. Therefore, compressed air supplied from the compressor 12 begins to flow through the supply line 16. As demand arises, the pressure of the compressed air is regulated by the pressure regulator 20 during the flow. The compressed air is discharged from the blowing nozzle 14 using its pressure, which is regulated as described above as the discharge pressure. The flow rate of the compressed air is controlled by the flow meter 22, and the discharge pressure of the compressed air is indicated by the pressure gauge 30.

[0051] When compressed air is discharged from the blow nozzle 14 in this manner, the liquid W retained in the bottom hole 40 is pushed out by the compressed air. In other words, the liquid W is removed from the bottom hole 40.

[0052] If the discharge pressure of the compressed air is too low, the liquid W will be difficult to remove from the bottom hole 40 due to the low pressure applied to it. Therefore, the discharge pressure of the compressed air is preferably set to be greater than or equal to 0.05 MPa. Furthermore, the maximum supply pressure of air in a typical factory is approximately 0.5 MPa. Within this range, the discharge pressure of the compressed air is sufficient. More specifically, the discharge pressure of the compressed air can be set in the range of 0.05 to 0.5 MPa.

[0053] After a predetermined period has elapsed since compressed air began to be discharged from the air nozzle 14, timer 26 is activated to close the switching valve 24. Thus, the discharge of compressed air is terminated. The period from the start to the end of discharge is referred to as the "discharge time." Assuming a discharge pressure of 0.05 to 0.5 MPa, this discharge time is sufficient to fall within the range of 1 to 20 seconds.

[0054] exist Figure 4 The diagram shows, in graphical form, the effect when water is pre-retained in the bottom hole 40 and the area ratio S ra The system checks whether water is removed from the bottom hole 40 when the insertion length L is changed in various ways. Furthermore, the compressed air discharge pressure is set to 0.05 to 0.5 MPa, and the discharge time is set to 1 to 20 seconds. Then, after blowing air, the system determines whether "water residue" occurs when the block 32 is flipped upside down and droplets fall from the block; otherwise, it determines whether "water has been removed." Figure 4 In the diagram, "water residue" is indicated by ▲, and "water removed" is indicated by 〇. Furthermore, the horizontal axis indicates the value of (insertion length L / depth H of constant diameter portion 44).

[0055] Furthermore, in Figure 5 The diagram shows the area ratio S in the form of a graph. ra And whether water is removed from the bottom hole 40 when the discharge pressure is changed in various ways. The setting of the discharge time and the criteria used to determine whether water has been removed are the same as those mentioned above. Furthermore, in the same way as mentioned above, Figure 5 The symbols “▲” and “〇” indicate the water residue and water removal status, respectively.

[0056] refer to Figure 4 and 5 When the area ratio S obtained from the above equation (1) ra When the value is 3 to 10 and the insertion length L is greater than or equal to one-quarter of the depth H of the constant diameter portion 44, it is clear that water is removed from the bottom hole 40 by setting the discharge pressure from 0.05 to 0.5 MPa and the discharge time from 1 to 20 seconds.

[0057] Therefore, when another component is connected (mechanically linked) to the block 32 by threading a screw into the bottom hole 40 (screw hole), rust can be avoided on the screw or the inner wall of the bottom hole 40 due to water remaining in the bottom hole 40. More specifically, the block 32 and the other component can be connected together with sufficient strength. Furthermore, hygienic conditions can be achieved because no water (liquid) remains.

[0058] Furthermore, according to this embodiment, it has a constant outer diameter D out and constant inner diameter D in A straight tube (cylinder) can be used as the air nozzle 14. The air nozzle 14 with this simple shape is easy to manufacture, thereby reducing costs.

[0059] Furthermore, according to this embodiment, even if the air-blowing nozzle 14 is inserted into the bottomed hole 40 formed in the upper surface with its discharge port facing downwards, the liquid W can be reliably removed from the bottomed hole 40 by setting the discharge conditions as described above. Therefore, it is not necessary to change the posture of the workpiece so that the opening of the bottomed hole 40 faces downwards. Thus, a posture-changing mechanism is not required. Therefore, the construction of the air-blowing device 10 can be simplified, and increased equipment investment can be avoided.

[0060] The present invention is not particularly limited to the embodiments described above, and various modifications can be made without departing from the essence and spirit of the invention. For example, the bottom hole 40 is not limited to a screw hole, but can be a simple hole in which no threaded portion is formed. Furthermore, the bottom hole 40 may consist only of a constant diameter portion 44.

[0061] Furthermore, instead of compressed air, different gases such as compressed nitrogen can be used. Similarly, in this case, by setting the discharge conditions as described above, liquid W can be removed from the bottom hole 40.

Claims

1. A liquid removal system comprising a workpiece and an air blowing device, the workpiece having a bottomed hole formed on its upper surface, the air blowing device removing water from the bottomed hole by blowing compressed gas into the bottomed hole, characterized in that, The bottomed hole has an opening and a constant diameter portion, the constant diameter portion communicating with the opening and extending in a vertically downward direction, the constant diameter portion having a constant diameter. The blowing device includes: a blowing nozzle that supplies the compressed gas flowing through the supply line to the bottomed orifice; An actuator that moves the air nozzle above the bottomed hole and lowers the air nozzle; and a pressure regulator, which is located in the supply line and regulates the pressure of the compressed gas discharged from the blowing nozzle. When the diameter of the constant diameter portion is given as D ho At that time, the air blowing nozzle has an inner diameter D in and outer diameter D out Such that when the bottom hole is inserted, the area ratio S, expressed by the following formula (1), is... ra Falling within the range of 3 to 10, S ra = {(π / 4)D ho 2 - (π / 4)D out 2 } / (π / 4)D in 2 …(1), The actuator sets the insertion length of the air-blowing nozzle into the bottomed hole to be greater than or equal to one-quarter of the depth of the constant diameter portion. The pressure regulator sets the discharge pressure of the compressed gas from the blowing nozzle to be greater than or equal to 0.05 MPa and less than or equal to 0.5 MPa.

2. The liquid removal system according to claim 1, characterized in that, The air nozzle has a constant inner diameter D. in and constant outer diameter D out Straight pipe.

3. The liquid removal system according to claim 1 or 2, characterized in that, The air blowing device includes a switching valve located in the supply line, and the switching valve closes 1 to 20 seconds after the compressed gas begins to be discharged from the air blowing nozzle, thereby terminating the discharge of the compressed gas.

4. The liquid removal system according to claim 1 or 2, characterized in that, The actuator sets the insertion length of the air nozzle into the bottomed hole to be greater than or equal to half the depth of the constant diameter portion.

5. The liquid removal system according to claim 1 or 2, characterized in that, The material of the air blowing nozzle is copper.

6. A liquid removal method for removing water retained in a bottomed hole by blowing compressed gas supplied from a blower nozzle inserted into the bottomed hole, the bottomed hole being formed on the upper surface of a workpiece, characterized in that... The bottomed hole has an opening and a constant diameter portion, the constant diameter portion communicating with the opening and extending in a vertically downward direction, the constant diameter portion having a constant diameter. When the diameter of the constant diameter portion is given as D ho At that time, the air blowing nozzle has an inner diameter D in and outer diameter D out Such that when the bottom hole is inserted, the area ratio S, expressed by the following formula (1), is... ra Falling within the range of 3 to 10, S ra = {(π / 4)D ho 2 - (π / 4)D out 2 } / (π / 4)D in 2 …(1), The liquid removal method includes: In the insertion step, without changing the posture of the workpiece, the air nozzle is inserted vertically from above through the opening, and the bottom of the bottom hole is opposite to the discharge port formed at the distal end of the air nozzle. as well as In the removal step, without changing the posture of the workpiece, compressed gas is discharged from the discharge port of the air nozzle, causing the compressed gas to reach the bottom of the bottomed hole. The compressed gas then pushes the water retained in the bottomed hole upwards through the space between the inner wall of the constant diameter portion and the air nozzle, towards the opening of the bottomed hole. This removes the water retained in the bottomed hole from the opening to the outside of the bottomed hole. In the insertion step, the insertion length of the air nozzle into the bottomed hole is set to be greater than or equal to one-quarter of the depth of the constant diameter portion, and In the removal step, the discharge pressure of the compressed gas from the blowing nozzle is set to be greater than or equal to 0.05 MPa and less than or equal to 0.5 MPa.

7. The liquid removal method as described in claim 6, characterized in that, With a constant inner diameter D in and constant outer diameter D out A straight tube is used as the blowing nozzle.

8. The liquid removal method as described in claim 6 or 7, characterized in that, The compressed gas is discharged for 1 to 20 seconds.

9. The liquid removal method as described in claim 6 or 7, characterized in that, In the insertion step, the insertion length of the air nozzle into the bottomed hole is set to be greater than or equal to half the depth of the constant diameter portion.

10. The liquid removal method as described in claim 6 or 7, characterized in that, In the insertion step, the discharge port of the air nozzle is positioned below the water surface, and the removal step is performed in this state.

Images