JPS6349568Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a variable stroke pump that can perform a plurality of operations with different strokes using a fluid pressure cylinder.

PRIOR ART

Pumps that utilize the stroke of a pump plunger include constant stroke pumps using cams or air cylinders, but they cannot be operated with multiple operations with different strokes. As a conventional variable stroke pump, a variable stroke pump using a screw, that is, one that converts the rotational force of a motor into thrust and movement in the thrust direction using a screw has been proposed.

[Problem that the invention attempts to solve]

Conventional screw-based variable stroke pumps require a stopper to prevent them from rotating relative to the rotation of the motor and a guide to obtain movement in the thrust direction, making the structure complex and requiring precision screws to improve accuracy. In addition, there were other problems, such as overloading and the intrusion of dirt into the threaded portion, which could cause jamming, and wear of the thread, causing changes in the stroke.

[Means for solving problems]

This idea was developed to solve the above problems, and by connecting multiple fluid pressure cylinders, it is a variable stroke pump that has a simple structure and can freely change the stroke in multiple stages with high precision. I will provide a.

The invention includes a first cylinder having a first piston connected to a pump plunger, and a second cylinder having a second piston connected to an extending rod to vary the stroke of the first piston.
a cylinder, a nut screwed to the other end of the rod extending from the second cylinder, a stopper for regulating movement of the nut, and supplying pressurized fluid to both ends of the first and second cylinders. The variable stroke pump is characterized in that it is equipped with a flow path for injecting or discharging the air.

[Effect]

In the variable stroke pump configured as described above, the second piston rod is rotated to change the threaded position of the nut.
A plurality of operations with different strokes can be performed by adjusting the stroke of the piston and the gap between it and the first piston, and supplying or discharging pressure fluid to the flow path. The stroke in each operation can be adjusted by adjusting the stroke of the second piston and the gap between it and the first piston.

〔Example〕

This invention will be explained below with reference to embodiments of the drawings. The drawings are cross-sectional views of the embodiments. In the drawing, reference numeral 1 designates a pump plunger that reciprocates within a pump cylinder 3 via a seal 2, sucks in liquid from a suction pipe 4, and discharges it to a liquid delivery pipe 5.
6 and 7 are check valves, and 8 is a pump casing.

The pump casing 8 includes a first cylinder 11
A first piston 13 and a second piston 14 having a larger diameter are provided so as to be able to reciprocate, respectively. The first piston 13 is provided with a rod 15, and the second piston 14 is provided with a rod 16. Further, at both ends of the first and second cylinders 11 and 12, there are flow paths 1 for supplying or discharging pressure fluid, respectively.
7, 18, 19, and 20 are provided.

The rod 15 is provided only on the pump casing 8 side of the first piston 13, and
The pump plunger 1 is connected to the pump plunger 1 by passing through a partition wall 21 on the pump casing 8 side. 22 is the first
This is a screw plug that is screwed onto the piston 13 of.

The rod 16 extends on both sides of the second piston 14 and is fixed by stops 23,24.
One end of the rod 16 connects the first and second cylinders 1
1 and 12, and extends into the first cylinder 11 so as to make the stroke of the first piston 13 variable. The other end of the rod 16 extends outwardly through a flange 26 attached to the end of the second cylinder 12, and a threaded portion 27 is formed in the protruding portion thereof, to which a nut 28 is screwed.

stopper 2 to restrict the movement of nut 28.
9 is attached to the flange 26. Natsuto 2
8 is provided with a hole 30, through which a pin (not shown) can be attached through a groove 31 formed in the stopper 29. 32 is a groove formed at the tip of the rod 16, 33 is a lockite, 34-3
6 is a bearing, and 37 to 44 are O-rings.

In the above configuration, since the first piston 13 is connected to the pump plunger 1 via the rod 15, the pump plunger 1 moves in unison with the movement of the first piston 13. The movement range of the first piston 13 is from the position where the piston 13 contacts the partition wall 21 to the position where the piston 13 contacts the left end of the rod 16, and reciprocates by supplying or discharging pressure fluid to the channels 17 and 18. The bulkhead 21 is fixed, but the rod 16 is connected to the second piston 1.
4, the stroke of the first piston 13 is variable.

To move the second piston 14, the flow path 1
By supplying or discharging pressure fluid to 9 and 20, it can be moved left and right. Pressure fluid is supplied to the flow path 19 from the position shown in the figure, and the piston 14
When is moved to the right, the amount of movement becomes L=H−h.

The amount of movement of the second piston 14 can be adjusted by changing the threaded position of a nut 28 screwed onto the threaded portion 27 of the rod 16. In the position shown in the figure, insert the pin into the hole 30 through the groove 31 to fix the nut 28, insert the screwdriver into the groove 32, and rotate it to the right.The rod 16 cannot move because its left end is in contact with the piston 13. First, this causes the nut 28 to move to the right, which causes L to become smaller, and the strokes of the first piston 13 and the pump plunger 1 to become smaller. Natsuto 2
8 comes into contact with the stopper 29, L becomes zero and the stroke becomes zero.

Conversely, when the rod 16 is rotated to the left, L increases and the rod returns to the position shown in the figure. When the nut 28 is further rotated to the left, the rod 16 moves to the right while keeping the nut 28 in contact with the flange 26, and a gap X is formed between the first piston 13 and the rod 16 by the amount of movement to the right. . As X becomes larger, the strokes of the first piston 13 and the pump plunger 1 increase.

When pressure fluid is supplied to the flow path 20 in this state, the rod 16 is fixed and serves as a stopper for the first piston 13, so that the stroke of the first piston 13 is regulated by the gap X. In this state, flow path 1
When pressure fluid is supplied to 7, the first
piston 13 and pump plunger 1 can be moved.

Furthermore, when the supply of pressure fluid to the flow path 20 is stopped and the flow path 20 is opened, the second piston 14 is pushed by the first piston 13 and moves to the right, and moves by a certain distance by a stroke L. Therefore, the first piston 13 can move the X and L strokes by dividing them into two movements.

The reverse operation can be performed by supplying pressure fluid to the flow path 20.
If the pressure fluid is moved to the left by X, then the supply of pressure fluid to flow path 17 is stopped and opened, and pressure fluid is supplied to flow path 18, it is possible to move further by X.

If there is no need to separate the movement into two movements, use flow path 1.
7, 18 can be used to move left and right with a stroke of X+L. In this way, the flow paths 17 to 2
By combining the supply and release of pressure fluid to 0, different strokes can be performed, and each stroke can also be set arbitrarily. Further, the pump plunger includes a piston-shaped one.

The above explanation was based on the case of two cylinders and two pistons, but when the number of these is increased,
More complex movements can be created by combining each movement. Moreover, compressed air or other fluids can be used as the pressure fluid.

The variable stroke pump mentioned above can use the reciprocating motion of the fluid pressure cylinder directly as the reciprocating motion of the pump, so the drive unit has a simple structure, and even if the pump is overloaded, no unreasonable force will be applied to the drive unit. Once the load returns to normal, normal operation begins. The thrust of the pump can be freely set by adjusting the fluid pressure, and multiple cylinders can be operated with a single pressure fluid source. When the diameter of the second piston 14 is larger than that of the first piston 13, the pressure receiving area becomes larger and the thrust of the second piston 14 becomes larger when the fluid pressure is equal, so that it functions as a stopper for the first piston 13. do.

[Effect of idea]

According to this device, by connecting multiple fluid pressure cylinders, it is possible to perform multiple stages of operation with different strokes with a simple structure and operation, each stroke can be set arbitrarily, and excessive force is not applied even in the case of an overload.

[Brief explanation of drawings]

The drawing is a sectional view of the embodiment, in which 1 is a pump plunger, 8 is a pump casing, 11 is a first cylinder, 12 is a second cylinder, 13 is a first piston, 14 is a second piston, 15, 16 is a rod, 17 to 20 are channels, 28 is a nut, and 29 is a stopper.

Claims (1)

[Claims for Utility Model Registration] (1) A first cylinder having a first piston connected to a pump plunger, and a second cylinder connected to a rod extending so as to vary the stroke of the first piston. a second cylinder having a piston; a nut screwed to the other end of the rod extending from the second cylinder; a stopper for restricting movement of the nut; and both ends of the first and second cylinders. A variable stroke pump characterized by comprising a flow path for supplying or discharging pressure fluid to the pump. (2) The variable stroke pump according to claim 1, wherein the second piston has a larger diameter than the first piston. (3) The variable stroke pump according to claim 1 or 2, wherein the nut has a hole into which a pin is inserted through a groove in the stopper. (4) The variable stroke pump according to any one of claims 1 to 3, wherein the rod of the second piston has a groove at the externally protruding tip.