JPH07208325A - No-valve reciprocation piston pump - Google Patents

Abstract

PURPOSE:To provide a reciprocating piston pump having no valve by carrying out a second relative repetitive operation for communicating or breaking an intake port and a discharging port with each other reciprocally in synchronism of a cylinder and a piston with first relative repetitive operation for increasing/ decreasing the capacity of a pump chamber. CONSTITUTION:When cycle operation of a piston 14 is reciprocally repeated opposing to a cylinder 10, fluid corresponding to the capacity of a pump chamber 20 corresponding to the axial line direction stroke of a piston 14 opposing to the cylinder 10 per cycle is sucked in the pump chamber 20 through a hole 22, or it is discharged from the pump chamber 20 outward the pump chamber 20 through a hole 24. During relative cycle operation between the cylinder 10 and the piston 14, relative repetitive operation for increasing/decreasing the capacity of the pump chamber 20 is carried out in relation to the cylinder 10 and the piston 14, and simultaneously second relative repetitive operation is carried out in synchronism therewith so as to reciprocally communicate and break an inlet port which is constituted by the hole 22 and a straight line groove 26 and an outlet port which is constituted by the hole 24 and the straight line groove 26 with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump, and more particularly, to a reciprocating piston pump in which a cylinder and a piston fitted to each other relatively reciprocate to perform a pumping action.

[0002]

2. Description of the Related Art In a reciprocating piston pump in which a cylinder and a piston fitted to each other reciprocate relative to each other to perform a pumping action, a pump chamber defined by the cylinder and the piston is In the process of increasing its volume, it is in communication with the fluid inlet passage, while it is blocked from the fluid outlet passage, and in the process of decreasing its volume, it is in communication with the fluid outlet passage, while it is in communication with the fluid outlet passage. So as to be disconnected from each other, the fluid inlet passage and the fluid outlet passage are reciprocally communicated with or shut off from each other in synchronization with the relative reciprocal movement between the cylinder and the piston. In the conventional reciprocating piston pump, the selective communication and blocking between the pump chamber and the fluid inlet passage and the fluid outlet passage are performed at the boundary between the fluid inlet passage and the pump chamber and between the fluid outlet passage and the pump chamber. This is achieved by a valve device such as a check valve provided at the boundary portion or a slide valve driven in synchronization with the relative reciprocal movement between the cylinder and the piston.

[0003]

SUMMARY OF THE INVENTION The present invention provides a valveless reciprocating piston pump which does not require special valve means such as a check valve and a slide valve which are conventionally incorporated in the reciprocating piston pump. Is an issue.

[0004]

SUMMARY OF THE INVENTION According to the present invention, the above object is to define a pump chamber having a cylinder and a piston, the volume of which is repeatedly increased and decreased by a relative repetitive motion between them. A pump that sucks fluid into the pump chamber through a suction port when the volume of the pump chamber increases and discharges fluid from the pump chamber through a discharge port when the volume of the pump chamber decreases. In the device, the suction port and the discharge port are partially connected or blocked by the alignment or non-alignment of the first passage portion provided in the cylinder and the second passage portion provided in the piston. A second relative repetition in which the cylinder and the piston reciprocally connect or block the suction port and the discharge port in synchronization with a first relative repeated movement for increasing or decreasing the volume of the pump chamber. It is achieved by a pump and performs dynamic.

[0005]

According to the above structure, the intake port and the discharge port are reciprocally synchronized with each other in synchronization with the first relative repetitive motion in which the cylinder and the piston increase and decrease the volume of the pump chamber. By performing the second relative repetitive motion of communicating or blocking, the cylinder and the piston are also used as the valve element, and the pump chamber and the fluid inlet passage and the fluid outlet passage are provided without requiring any special valve element or valve member. Reciprocal communication or blocking between can be achieved.

The pump of the present invention having such a structure has a simple structure, and the discharge amount can be easily and highly accurately according to the loci of the first and second relative repetitive motions between the cylinder and the piston. Further, it is variably controlled, and is particularly suitable for a pump that conveys a small amount of fluid with high accuracy.

[0007]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 attached herewith is a schematic perspective view showing an exploded view of one embodiment of a valveless reciprocating piston pump according to the present invention, and FIG. 2 includes AA and BB of FIG. It is sectional drawing which looked at the cross section of the pump by a plane in the arrow C direction. In these figures, 10 is a cylinder having a cylindrical cylinder chamber 12 closed at one end in the illustrated embodiment,
Reference numeral 14 denotes a piston whose cylindrical outer peripheral surface 16 tightly slidingly engages with the cylindrical inner peripheral surface of the cylinder chamber 12. In the cylinder chamber 12, a variable volume pump chamber 20 is defined, one axial end of which is closed by an inner end surface 18 of the piston 14.

The cylinder 10 is provided with a pair of holes 22 and 24 which are circumferentially spaced from each other at the same axial position and which are open to the inner peripheral surface of the cylinder. The piston 14 has an outer peripheral surface 1 from its inner end surface facing the pump chamber 20.
6 there is provided a linear groove 26 extending axially over an axial distance corresponding to the axial stroke of the relative reciprocating motion between the cylinder and the piston, which linear groove 26. When it reaches the end position of the axial stroke, which is fully pushed into the cylinder 10 as shown in the drawing, the hole 2 is formed at one end on the side just separated from the inner end face 18.
It is designed to be consistent with 2. Since the holes 22 and 24 are at the same axial position as described above, when the piston 14 is rotated in the circumferential direction with respect to the cylinder 10 and the linear groove 26 of the piston comes to a position aligned with the hole 24 of the cylinder, a straight line is formed. The one end of groove 26 is just aligned with hole 24.

In the following, for convenience of description, the cylinder 10 is fixed, and the piston 14 is reciprocally moved with respect to the cylinder 10. However, the relationship between them is that the piston 14 is fixed and the cylinder 10 is piston 14. It is the same even when the reciprocating motion is relatively performed. 28 schematically shows an arm member for driving the piston 14 when the cylinder 10 is fixed and the piston 14 is repeatedly moved as described above.

FIG. 3 is a perspective view similar to FIG. 1, showing four states in the process of performing the pump operation of one cycle by the pump shown in FIGS. The state shown in FIG. 3A is the same as the state shown in FIG. Arm 2 starting from this state
When 8 is axially driven from the position a to the position b by drive means not shown in the figure, the piston 14 increases the volume of the pump chamber 20 and moves upward in the figure relative to the cylinder 10. To move. Meanwhile, the linear groove 2 of the piston
6 remains aligned with the bore 22 in the cylinder. Therefore, if the hole 22 is connected to an arbitrary fluid inlet passage (not shown), the fluid is sucked into the pump chamber 20 through the straight groove 26 from the hole 22 as the volume of the pump chamber 20 increases. To be done. Therefore, in this case, the hole 22 and the linear groove 26 form each part of the suction port in the pump.

The state where the arm 28 reaches the position b is shown in FIG.
B of FIG. From this state, when the arm 28 is driven toward the position c in the direction of rotating around the central axis of the pump, the linear groove 26 is out of alignment with the hole 22, and the hole 2
Match with 4. This state is shown in FIG. 3C. From this state, the arm 28 moves the piston 14 into the cylinder chamber 12
When the pump chamber 20 is axially driven toward the position d in the pushing direction, the volume of the pump chamber 20 decreases with the linear groove 26 and the hole 24 aligned with each other. Therefore, at this time, the hole 24
Is connected to a fluid outlet passage not shown in the figure, the fluid in the pump chamber 20 is discharged toward the fluid outlet passage through the linear groove 26 and the hole 24. Therefore, in this case, the linear groove 26 and the hole 24 form each part of the discharge port of the pump. The state in which the arm 28 reaches the d position is shown in D of FIG.

When the arm 28 is driven from the state shown in FIG. 3D to the position a in the direction in which the arm 28 rotates about the central axis of the pump, the linear groove 26 of the piston is caused by the rotation of the piston 14 accompanying the rotation. The alignment with the hole 24 is removed, the alignment with the hole 22 is performed again, and the state shown in FIG. 3A is restored. In this way, the piston 14 moves relative to the cylinder 10 in the states A, B, C of FIG.
When such a cycle movement is repeated repeatedly, with the process of relatively moving via D as one cycle, the fluid corresponding to the volume of the pump chamber 20 corresponding to the axial stroke of the piston 14 with respect to the cylinder 10 in each cycle. Is sucked into the pump chamber 20 through the hole 22 and discharged from the pump chamber 20 to the outside of the pump chamber through the hole 24. During the relative cyclic movement between the cylinder and the piston, the cylinder and the piston perform the first relative repetitive movement to increase or decrease the volume of the pump chamber 20, and at the same time, the hole 2 is synchronized therewith.
2 and the linear groove 26 and the outlet port defined by the hole 24 and the linear groove 26 perform a second relative reciprocal motion for reciprocal communication and interruption, thereby causing the cylinder and the piston. Besides, reciprocal communication and blocking of the inlet port and the outlet port with respect to the pump chamber is achieved without the need for a special valve member or valve element.

It should be noted that in the embodiment shown in FIGS. 1-3, the piston projects laterally from which the first and second relative reciprocating movements between the cylinder and the piston are clearly illustrated. Although the structure driven by the arm 28 is used, the driving mechanism for performing the first and second relative repetitive movements between the cylinder and the piston is a driving mechanism connected to the upper end surface of the piston. It will be appreciated that various other configurations may be provided, such as a mechanism for reciprocating the rod in the axial direction and rotating the rods at opposite ends of the reciprocating movement in opposite directions.

Although not generally preferred as the preferred embodiment shown in FIGS. 1 to 3, depending on other constraints, two linear grooves 26 are provided in parallel and one of them is a hole. Even if a port structure is used in which the state of being aligned with 22 and the other being out of alignment with the hole 24 and the state of being out of alignment with one of the holes 22 and the other being in alignment with the hole 24 are reciprocally repeated. Good.

FIG. 4 is a view similar to FIG. 3 showing another embodiment of the pump according to the present invention. In FIG. 4, parts corresponding to the parts shown in FIG. 3 are designated by the same reference numerals as in FIG. In this embodiment, the piston 14 extends arcuately from its inner end surface 18 along its outer peripheral surface over an axial distance corresponding to the axial stroke of the relative reciprocating motion between the cylinder and piston. A pair of existing curved grooves 30 and 32 are provided. In the state shown in FIG. 4A, the curved groove 30 is aligned with the hole 22 of the cylinder at the end on the side remote from the inner end surface 18 of the piston, and therefore the hole 2
2 is connected to a fluid inlet passage which is not shown in the figure, the pump chamber 20 now has a curved groove 30 and a bore 2.
2 and communicates with the fluid inlet passage. Starting from this state, the driving locus 3 in which the arm 34 provided on the piston 14 is substantially circular by the driving means not shown in the drawing.
When driven along 6, the piston 14 moves the cylinder 10
On the other hand, at the same time as being driven axially upward in the figure, at first, as viewed from above, the pump is driven in the clockwise direction and then in the counterclockwise direction, so that the curved groove 30 corresponds thereto. When the curved groove 30 is formed along the arcuate locus, the curved groove 30 maintains alignment with the hole 22 and reaches the state shown in FIG. 4B. Therefore, during this time, the fluid is sucked into the pump chamber 20 through the hole 22 and the curved groove 30 through the inlet fluid passage (not shown). Therefore, in this case, the hole 2
2 and the curved groove 30 constitute each part of the suction port of the pump.

When the arm 24 is further driven along the locus 36 from the state shown in FIG. 4B, the curved groove 30 is out of alignment with the hole 22, and immediately after that, the curved groove 32 is aligned with the hole 24. In this case, if the bore 24 is connected to a fluid outlet passage not shown, the pump chamber 20 now communicates with the fluid outlet passage via the curved groove 32 and the bore 24.

When the arm 34 is further driven along the locus 36 from the state shown in FIG. 4B, the piston 14 is axially driven downward in the figure with respect to the cylinder 10 and, at the same time, the pump is driven from above. As seen, it is driven counterclockwise first and then clockwise. Therefore, the curved groove 3
When 2 is formed in an arc shape corresponding to that, the curved groove 32 is kept aligned with the hole 24, and the pump chamber 20
Is kept in communication with the fluid outlet passage through the curved groove 32 and the hole 24. Therefore, in this case, the curved groove 32 and the hole 24 form each part of the discharge port of the pump.

Thus, as the arm 34 is driven along the locus 36, the fluid in the pump chamber 20 is curved in the curved groove 32 and the hole 2.
When the piston 14 descends while being discharged to the fluid outlet passage via 4 the pump eventually reaches the state shown in D of FIG. When the arm 34 is further driven along the locus 36, the curved groove 32 is out of alignment with the hole 24,
Immediately thereafter, the curved groove 30 aligns with the hole 22 again, and the pump returns to the state shown in FIG. 4A. Thus, also in the embodiment shown in FIG. 4, one cycle of the pump is carried out through the states shown in A, B, C and D. Also in this case, the relative repetitive motion between the cylinder and the piston is the first relative repetitive motion for increasing or decreasing the volume of the pump chamber 20, and the hole 22 and the curved groove 3.
0 pump suction port, curved groove 32 and hole 24
It will be clear that a combined second relative reciprocating movement for reciprocally connecting and blocking the discharge port of the pump consisting of

In the embodiment shown in FIG. 4, the driving locus of the arm 34 for performing the above-mentioned first and second relative repetitive motions in combination between the cylinder and the piston is a substantially circular locus. As a result, the driving means for the arm 34 may simply rotate, and may be simpler than the relative driving means between the cylinder and the piston in the embodiment shown in FIG. Will be understood.

In the two embodiments described above, the cylinder 10 has a cylinder chamber 12 closed at one end, and a single piston 14 is fitted in the cylinder chamber. However, in the pump according to the present invention, a pair of pistons 14 are fitted face-to-face from both ends of a cylinder having a cylinder chamber opened at both ends, and the structure of the suction port and the discharge port in the pump shown in FIG. 3 or FIG. It will be appreciated that may be configured as a twin pump incorporated for each piston.

[Brief description of drawings]

FIG. 1 is a perspective view showing an exploded view of one embodiment of a pump according to the present invention.

2 is a cross-sectional view of the pump shown in FIG. 1 taken along a plane including lines AA and BB taken in the direction of arrow C. FIG.

FIG. 3 is a perspective view showing four states of the pump shown in FIGS. 1 and 2 during one cycle of operation.

FIG. 4 is a view similar to FIG. 3 showing another embodiment of the pump according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Cylinder 12 ... Cylinder chamber 14 ... Piston 16 ... Piston outer peripheral surface 18 ... Piston inner end surface 20 ... Pump chamber 22, 24 ... Hole 26 ... Straight groove 28 ... Arm 30, 32 ... Curved groove 34 ... Arm 36 ... Arm Drive trajectory

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Claims (3)

[Claims] Claim: What is claimed is: 1. A pump chamber having a cylinder and a piston, the volume of which is repeatedly increased and decreased by a relative repetitive motion between them, and a suction port is formed in the process of increasing the volume of the pump chamber. Through the discharge port to discharge fluid from the pump chamber in the process of reducing the volume of the pump chamber, and the suction port and the discharge port are each one of them. Part is communicated with or cut off by the alignment or non-alignment of the first passage part provided in the cylinder and the second passage part provided in the piston, and the cylinder and the piston increase or decrease the volume of the pump chamber. A second relative repetitive motion that reciprocally connects or blocks the suction port and the discharge port in synchronism with the first relative repetitive motion. 2. The pump according to claim 1, wherein the first passage portions of the suction port and the discharge port are circumferentially spaced from each other at the same axial position of the cylinder. A pair of holes that open to the inner peripheral surface, wherein the second passage portion of each of the suction port and the discharge port is a passage common to both of the suction port and the discharge port from the inner end of the piston facing the pump chamber. A straight groove extending axially along the outer circumferential surface of the piston over an axial distance corresponding to the axial stroke of the first relative repetitive motion between the cylinder and the piston, And the first relative repetitive movement between the piston and the piston is a relative axial movement between the cylinder and the piston in a state where each one of the pair of holes and the linear groove are aligned, The cylinder The second relative repetitive motion between the pistons switches the linear groove from aligning with one of the pair of holes to aligning with the other and aligning with the other with aligning with the cylinder; A pump characterized by a relative rotational movement between the pistons. 3. The pump according to claim 1, wherein the first passage portions of the suction port and the discharge port are circumferentially spaced from each other at the same axial position of the cylinder. A pair of holes open to the inner peripheral surface, wherein the second passage portion of each of the suction port and the discharge port extends from the inner end of the piston facing the pump chamber along the outer peripheral surface of the piston. A pair of curved grooves extending arcuately over an axial distance corresponding to an axial stroke of the first relative repetitive motion between the cylinder and the piston, the between the cylinder and the piston The first relative repetitive movement is performed in a relative axial direction and a circumferential direction between the cylinder and the piston in a state where only one of the pair of curved grooves is aligned with the corresponding one of the pair of holes. Exercise The second relative repetitive movement between the cylinder and the piston is performed from a first state in which one of the pair of curved grooves is aligned with one of the pair of holes and the other of the pair of curved grooves is the pair of curved grooves. Relative axial and circumferential movement between the cylinder and the piston for switching to and from a second state aligned with the other of the bores and from the second state to the cylinder. The relative axial and circumferential movement for the first relative repetitive movement between the pistons and the relative axial direction for the second relative repetitive movement between the cylinder and the piston. Further, the circumferential movement is a relative rotational movement between the cylinder and the piston which are continuous with each other.