TWI407016B - A fluid transfer pump - Google Patents

Abstract

A fluid transfer pump comprises a cylinder having a suction opening and a discharge opening, a plunger provided within the cylinder movable to and fro in a direction of an axis line of the cylinder, and a membrane-like sealing member for sealing a gap between the cylinder and the plunger, wherein the plunger is driven to and fro for carrying out suction operation and discharge operation alternately, so that fluid is sucked through the suction opening, then the sucked fluid is discharged through the discharge opening, wherein the suction opening is provided on a side portion of the cylinder so that a fluid transfer pump is provided which has an extremely small accumulation rate of fluid, and has good fluid displacement characteristic.

Description

Liquid transport pump

The present invention relates to a liquid transport pump comprising: a cylinder having a suction port and a discharge port; and a plunger that is rotatably driven inside the cylinder to be disposed along a direction of the axis thereof; and a film shape The sealing member seals the gap between the cylinder and the plunger, and drives the plunger back and forth to alternately perform the suction operation and the discharge operation to discharge the transfer target liquid sucked from the suction port from the discharge port. In particular, it relates to a liquid suitable for a liquid containing a precipitated substance, for example, a transport of a resist liquid for producing a liquid crystal substrate.

A mechanism for supplying a resist liquid for producing a liquid crystal substrate to a liquid crystal substrate manufacturing apparatus has conventionally used a liquid transport pump including a cylinder having a suction port and a discharge port, and a plunger. It can be driven back and forth in the direction of its axis inside the cylinder; and a sealing member that seals the gap between the cylinder and the plunger. In the liquid transport pump, the sealing member uses an O-ring. However, if an O-ring is used, problems such as particles, leakage, or short service life due to abrasion are severe, so the inventors made a liquid. In place of the O-ring, a film-like sealing member described in the product catalog CAT. No. BFS1-061 (hereinafter referred to as Non-Patent Document 1) of Fujikura Rubber Industry Co., Ltd. is used.

FIG. 7 is a partial cross-sectional view showing the front side of the conventional liquid transfer pump 10 described in the film-like sealing member of Non-Patent Document 1. Fig. 7(A) shows the state in which the plunger 5 is at the bottom dead center, and Fig. 7(B) shows the state in which the plunger 5 is at the top dead center.

As shown in FIG. 7 , the conventional liquid transport pump 10 includes a cylinder 20 , a plunger 5 , and a film-like sealing member 6 . At the top of the cylinder block 20, the suction port 320 and the discharge port 330 are bored so as to be parallel to the axis J1, respectively. The liquid transport pump 10 is used in a stand-up state, and the plunger 5 is driven back and forth to alternately perform the suction operation and the discharge operation to discharge the resist liquid sucked from the suction port 320 from the discharge port 330.

The film-like sealing member 6 is composed of a lid-like body containing a flexible material (refer to FIG. 2), and is in a state in which the opening end portion 62 of the lid-shaped body is fixed to the inner circumferential surface of the cylinder block 20 by The body portion 63 of the cap body covers the upper portion of the plunger 5. Further, by folding back the gap G between the cylinder 20 and the plunger 5, a U-shaped folded portion 61 having a U-shaped cross section is formed, and the gap G is sealed by the U-shaped folded portion 61. As the plunger 5 is driven back and forth, the U-shaped folded portion 61 moves in the gap G in the same direction as the driving direction. At this time, since the U-shaped folded portion 61 moves so as to roll along the gap G, the wear loss is small, and no liquid or gas leaks at all.

However, since the film-shaped sealing member 6 is very narrow in its U-shaped folded portion 61, the resist liquid is liable to stay therein. The retained resist liquid is finally gelled or precipitated, and is one of the factors of the impurity contained in the resist liquid supplied to the liquid crystal substrate manufacturing apparatus. In the liquid crystal substrate manufacturing apparatus, it is required to supply a high-purity resist liquid, and a liquid transport pump which requires a good liquid replacement property, that is, a liquid transport pump which requires an extremely low liquid retention rate.

The present invention has been made to solve the problem, and an object of the present invention is to provide a liquid transport pump which is excellent in liquid replacement characteristics and has excellent liquid retention characteristics.

In order to solve the above problems, the invention of the first aspect is a liquid transport pump 1 including a cylinder 2 including a suction port 32 and a discharge port 33, and a plunger 5 which is inside the cylinder 2 Driving back and forth along the direction of its axis J1; and a film-like sealing member 6 for sealing the gap G between the cylinder 2 and the plunger 5; and driving the plunger 5 back and forth to perform the suction operation and the discharge The operation is such that the transfer target liquid sucked from the suction port 32 is discharged from the discharge port 33, and the suction port 32 is provided on the side surface of the cylinder 2.

In the invention of the second aspect, the suction port 32 is formed in a range R in which the gap G is formed when the plunger 5 reaches the top dead center position.

In the invention of the third aspect, the suction port 32 is provided such that the axis J0 of the suction port 32 is inclined by a predetermined angle θ of 90 degrees or less with respect to the axis J1 of the cylinder 2.

In the invention of the fourth aspect, the suction port 32 is provided such that the axis J0 of the suction port 32 is inclined by a predetermined angle Φ of not less than 90 degrees with respect to the straight line J2 orthogonal to the axis J1 of the cylinder 2.

In the invention of the fifth aspect, the film-like sealing member 6 is formed of a lid-like body containing a flexible material, and the opening end portion 62 of the lid-shaped body is fixed to the inner circumferential surface of the cylinder block 2. In a state in which the upper portion of the plunger 5 is covered by the body portion 63 of the cap-shaped body, and the U-shaped folded portion 61 formed by folding back the gap G between the cylinder 2 and the plunger 5 is sealed. The gap G is formed.

In the invention of the aspect 6, the axis J1 of the cylinder 2 is arranged parallel to the vertical line and used.

According to the present invention, when the plunger 5 is driven downward, the resist liquid is ejected from the suction port 32. Since the suction port 32 is provided on the side surface of the cylinder block 2, the discharge flow flows down while forming a vortex along the inner wall of the cylinder block 2. Further, the circulation flow is performed by washing in the U-shaped folded portion 61. Thereby, the retention of the resist liquid in the U-shaped folded portion 61 disappears, and the liquid replacement characteristics are improved. In this way, it is possible to provide a liquid transport pump which is excellent in liquid displacement characteristics and has extremely low liquid retention.

Hereinafter, the best mode for carrying out the invention will be described with reference to the accompanying drawings. Fig. 1 is a partial cross-sectional view showing the front side of the liquid transport pump 1 of the present invention, wherein Fig. 1(A) shows the state in which the plunger 5 is at the bottom dead center, and Fig. 1(B) shows the plunger 5 at the top dead center. status. Fig. 2 is a perspective view showing the appearance of the film-like sealing member 6, and Fig. 3 is a partial cross-sectional view showing the plane of the liquid transport pump of the present invention.

Further, although the case where the liquid is a resist liquid is exemplified below, it is of course possible to use a liquid other than the resist liquid.

As shown in FIG. 1, the liquid transport pump 1 of the present invention includes a cylinder 2, a plunger 5, and a film-like sealing member 6.

The cylinder 2 includes a substantially bowl-shaped upper side cover 3 having an ear portion 31, and a substantially bowl-shaped lower side cover 4 having an ear portion 41 as well. The upper side cover 3 and the lower side cover 4 are attached between the respective ear portions 31 and the ear portion 41, and the ear portion 31 is clamped by the bolt 42 in a state where the opening end portion 62 of the film-like sealing member 6 is sandwiched. 41 is integrated with each other to form a cylinder body.

The suction port 32 and the discharge port 33 are bored in the upper side cover 3. The suction port 32 is passed through the side surface of the upper side cover 3. Further, the suction port 32 is bored in a range R in which the gap G is formed when the plunger 5 reaches the top dead center position. Further, the suction port 32 is bored such that its axis J0 is inclined by a predetermined angle θ with respect to the axis J1 of the cylinder 2. The angle θ is 90 degrees or less, and the minimum value of the angle θ is an angle at which the elliptical arc of the suction port 32 at least partially overlaps the flange portion of the sealed film-like sealing member 6 (refer to FIGS. 3(A) and (B)). At the same time, as shown in FIG. 3(C), the suction port 32 is bored such that its axis J0 is inclined by a predetermined angle Φ with respect to a straight line J2 orthogonal to the axis J1 of the cylinder 2. The optimum range of the angle Φ is a range in which the hole centered on the axis J0 has a tangential relationship with the inner circumference of the cylinder 2 (which belongs to the hole, and the line parallel to the axis J0 becomes a tangent to the inner circumference of the cylinder 2) (Refer to Figure 3(D)). The discharge port 33 is attached to the top of the upper side cover 3 and is bored in a direction parallel to the axis J1. Further, a direction switching valve or the like (not shown) may be provided, and the suction port 32 may be in the form of a discharge port.

A vacuum extraction port 43 and a rod hole 44 are bored in the lower cover 4 . The vacuum extraction port 43 is connected to the vacuum pump 73 at a position below the lower cover 4 . By vacuum-decompressing the chamber below the cylinder 2 via the vacuum pump 73, the outer peripheral surface of the head 51 and the inner peripheral surface of the cylinder 2 are improved in adhesion to the film-like sealing member 6, and the gas can be more effectively prevented from entering the upper chamber. . The rod hole 44 is a through hole provided in such a manner that the rod 53 is slidably passed through, and is bored at the bottom of the lower side cover 4.

The plunger 5 includes a head 51, a seat plate 52, and a rod 53. The head 51 covered by the film-like sealing member 6 is coupled to the rod 53 via a seat plate 52 by a bolt 54. The rod 53 that penetrates the rod hole 44 connects the other end to a driving device (not shown). Thereby, the plunger 5 can be moved back and forth inside the cylinder 2.

The film-like sealing member 6 is composed of a lid-like body containing a flexible material. As the flexible material, for example, a rubber is coated on a strong polyester cloth, and the film-like sealing member 6 is followed by sealing the gap G. That is, in a state where the opening end portion 62 is fixed to the inner circumferential surface of the cylinder 2, the upper portion of the plunger 5 is covered by the body portion 63 of the lid body. Then, the gap G between the cylinder 2 and the plunger 5 is folded back to form a U-shaped folded portion 61 having a U-shaped cross section, whereby the gap G is sealed by the U-shaped folded portion 61.

The liquid transport pump 1 having such a configuration is used in an upright state, and the plunger 5 is driven back and forth to alternately perform a suction operation and a discharge operation, and the resist liquid is sucked into the cylinder 2 from the suction port 32, and The inhaled resist liquid is discharged from the discharge port 33.

When the plunger 5 is driven downward, the resist liquid supplied through the inspection valve 71 is discharged from the suction port 32. This discharge flow system flows down while forming a vortex along the inner wall of the cylinder 2. Further, the circulation flow is performed by washing in the U-shaped folded portion 61. Thereby, the retention of the resist liquid in the U-shaped folded portion 61 disappears, and the liquid replacement characteristics are improved.

The resist liquid that has flowed into the cylinder 2 is pressurized by driving the cylinder 5 upward, is discharged from the discharge port 33, and is supplied to the liquid crystal substrate manufacturing apparatus (not shown) via the inspection valve 72.

As the plunger 5 is driven back and forth, the U-shaped folded portion 61 moves in the gap G in the same direction as the driving direction. At this time, since the U-shaped folded portion 61 moves so as to roll along the gap G, the wear loss is small and there is no leakage of liquid or gas at all.

Next, a description will be given of a liquid transport pump 1A according to another embodiment of the present invention. Fig. 4 is a partial cross-sectional view showing the plane of the liquid transport pump 1A according to another embodiment of the present invention.

As shown in FIG. 4, the liquid transport pump 1A includes an upper side cover 3A instead of the upper side cover 3 of the liquid transport pump 1. Since the configuration other than the upper lid body 3A is the same as that of the liquid transport pump 1, the description thereof will be omitted.

The upper side cover 3A is provided with a suction port 32A having the same shape as the suction port 32 of the liquid transport pump 1 at a position symmetrical with respect to the center. With this configuration, the resist liquid ejected from the suction ports 32 and 32A during the suction operation is swirled in the same direction as the arrow W2 in Fig. 4, so that the eddy current is compared with the case where the suction port is one. The speed is increased to improve the above effects.

Further, a liquid transport pump 1B according to another embodiment of the present invention will be described. Fig. 5 is a partial cross-sectional view showing a liquid transport pump 1B according to still another embodiment of the present invention. Fig. 5(A) is a partial cross-sectional view showing the front side, and Fig. 5(B) is a partial cross-sectional view showing the front side.

As shown in FIG. 5, the liquid transport pump 1B is provided with an upper side cover 3B instead of the upper side cover 3 of the liquid transport pump 1. The configuration other than the upper lid body 3B is the same as that of the liquid transport pump 1, and the description thereof will be omitted.

The upper side cover 3B is provided with a suction port 32B on its side surface. Its axis J0 is 90 degrees to the axis J1 of the cylinder. Further, the straight line J2 orthogonal to the axis J1 of the cylinder is 0 degrees. With this configuration, as shown by an arrow W3 in FIG. 5(B), the resist liquid discharged from the suction port 32B at the time of the suction operation is distributed to both sides, and flows down along the inner wall of the cylinder to form a vortex. Then, the eddy current systems on the opposite sides collide with each other on the opposite side to the suction port 32B, and merge upward (refer to Figs. 5(C) and (D)). This result is the same as that of the liquid transport pump 1, and since the U-shaped folded portion 61 is stirred, the liquid replacement characteristics are improved.

Specifically, the liquid replacement test was performed with the plunger 5 at the top dead center.

In a state where the resist liquid is filled in the cylinder, the liquid is supplied from the suction port 320 of Fig. 7(B) at a pressure of 0.05 MPa, and is discharged from the discharge port 330, and the plunger is stopped, even if it takes 5 minutes. When 10 liters of the liquid replacement cleaning solution was continuously supplied, the resist liquid accumulated in the U-shaped folded portion could not be completely replaced.

The same liquid replacement test was carried out in the embodiment of Fig. 5, and the resist liquid accumulated in the U-shaped folded portion was completely replaced by continuously flowing 4 liters of the liquid replacement cleaning solution for 2 minutes.

By discharging (cleaning) the retentate, saving the replacement liquid, and shortening the required time, the liquid replacement property can be improved, and the productivity of the liquid crystal substrate can be improved. Further, if the retentate enters the liquid crystal, it becomes a failure, and since the replacement liquid (washing liquid) is small, it contributes to the cost reduction, and the environment is also good, and the required time is shortened, and the maintenance such as regular cleaning is shortened. The shutdown time of the liquid crystal substrate manufacturing apparatus can improve productivity.

In each of the above embodiments, the cylinder 2 is disposed such that the axis J1 is perpendicular, but the cylinder 2 can be disposed horizontally on the axis J1.

Fig. 6 is a schematic view showing an embodiment in which the cylinder 2 is disposed horizontally on the axis J1.

As shown in FIGS. 6(A) and (B), the discharge port must be disposed at the uppermost portion. Further, the suction port may be bored such that its axis J0 is parallel to the axis J3 of the discharge port as shown in FIG. 6(A), or as shown in FIG. 6(B), the axis J0 is opposed to the cylinder block 2. The axis J1 may be inclined at a certain angle θ and may be worn. Further, as shown in FIG. 6(C), the suction port is formed such that the axis J0 is inclined by a predetermined angle Φ with respect to the straight line J2 orthogonal to the axis J1 of the cylinder 2, and a vortex flow in one direction can be formed. In this case, it is preferable that the angular range α in which the eddy current is formed is substantially larger than 180 degrees. However, the inclination angle Φ may be 0 degrees. In this case, it is preferable to pierce the suction port on the opposite side of the discharge port.

The embodiments of the present invention have been described above, but the embodiments disclosed above are merely illustrative, and the scope of the present invention is not limited to the embodiments. The scope of the present invention is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope of the claims.

1, 1A, 1B, 10. . . Liquid transport pump

2, 20. . . Cylinder block

3, 3A, 3B. . . Upper side cover

31, 41. . . Ear

32, 32A, 32B, 320. . . suction point

33,330. . . Spit

4. . . Lower side cover

42. . . bolt

43. . . Vacuum suction port

44. . . Rod hole

5. . . Plunger

51. . . Nozzle

52. . . Base plate

53. . . Rod

54. . . bolt

6. . . Membrane sealing member

61. . . U-shaped foldback

62. . . Open end

63. . . Body part

71, 72. . . Check valve

73. . . Vacuum pump

G. . . gap

1(A) and 1(B) are partial cross-sectional views showing the front side of a pump for liquid transportation according to the present invention.

Fig. 2 is a perspective view showing the appearance of a film-like sealing member.

3(A), (B) and (C) are schematic views showing a pump for liquid transportation according to the present invention.

Fig. 4 is a partial cross-sectional view showing a plane of a pump for liquid transportation according to another embodiment of the present invention.

5(A), (B), (C), and (D) are partial cross-sectional views showing a liquid transport pump according to still another embodiment of the present invention.

6(A), (B) and (C) are schematic views showing a pump for liquid transportation according to still another embodiment of the present invention.

7(A) and 7(B) are partial cross-sectional views showing the front side of a conventional liquid transport pump.

1. . . Liquid transport pump

2. . . Cylinder block

3. . . Upper side cover

31, 41. . . Ear

32. . . suction point

33. . . Spit

4. . . Lower side cover

42. . . bolt

43. . . Vacuum suction port

44. . . Rod hole

5. . . Plunger

51. . . Nozzle

52. . . Base plate

53. . . Rod

54. . . bolt

6. . . Membrane sealing member

61. . . U-shaped foldback

62. . . Open end

71, 72. . . Check valve

73. . . Vacuum pump

G. . . gap

Claims (5)

A pump for liquid transportation, comprising: a cylinder having a suction port and a discharge port; a plunger that is provided to be driven back and forth in a direction of an axis of the cylinder; and a film-like sealing member; Sealing the gap between the side surface of the cylinder and the plunger; and driving the plunger back and forth to alternately perform the suction operation and the discharge operation to discharge the transfer target liquid sucked from the suction port from the discharge port; The suction port is provided on a side surface of the cylinder, and the suction port is provided in a range in which the gap is formed when the plunger reaches a top dead center position. The liquid transport pump according to claim 1, wherein the suction port is provided such that an axis of the suction port is inclined at a certain angle of 90 degrees or less with respect to an axis of the cylinder. The liquid transport pump according to claim 1 or 2, wherein the suction port is provided such that an axis of the suction port is inclined at a certain angle of less than 90 degrees with respect to a line orthogonal to an axis of the cylinder. The liquid transport pump according to claim 1, wherein the film-like sealing member is formed of a cap-shaped body containing a flexible material, and an open end portion of the cap-shaped body is fixed to an inner circumferential surface of the cylinder block. In a state, the plunger is covered by the body portion of the cap body, and the gap is sealed by a U-shaped folded portion formed by folding back the gap between the cylinder and the plunger. The liquid transport pump of claim 1, wherein the axis of the cylinder is disposed parallel to the vertical line.