JPH01187381A - Plunger pump - Google Patents

Abstract

PURPOSE:To prevent a plunger from coming into contact with a fed fluid directly as well as to make improvements in durability by making a pressure variation being produced in a cylinder by reciprocation of the plunger act on the fed fluid via a specified partition wall. CONSTITUTION:When a crankshaft 5 of a plunger pump 1 is rotated, a plunger 14 reciprocates in a cylinder 13 via a connecting rod 8 and a piston 6. If this plunger 14 reciprocates, by way of example, lubricating oil in the cylinder 13 is compressed, and the pressure acts on a fluid in a fluid passage 12 via a partition wall 23. In consequence, an intake valve body 19 is closed while a discharge valve body 22 is opened, so that the fluid in the fluid passage 12 is discharged out of the discharge valve body 22. At this time, since the plunger is isolated from the fed fluid by the partition wall 23, any solid body in the fed fluid can be prevented from being bitten between the plunger 14 and the cylinder 13.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a reciprocating sliding plunger pump for pumping fluids such as cement milk, medicinal solutions, and fluid foods.

(Prior art) Generally, this type of plunger pump has a suction valve element and a discharge valve element in a fluid passage, and a cylindrical cylinder in which a plunger is housed in the fluid passage between the two valve elements so as to be able to slide back and forth. By reciprocating the plunger, the suction valve body and the discharge valve body are alternately opened and closed by pressure fluctuations in the cylinder, so that the fluid in the fluid passage is sucked from the suction valve body and discharged from the pressure valve body. However, if the fluid being fed contains solids such as cement milk, the solids may get caught between the plunger and the cylinder, causing premature wear of the plunger. I had a problem with it.

In order to solve these drawbacks, there are some devices in which the plunger has a small outer peripheral surface made of ceramic to prevent the plunger from wearing out.

(Problems to be Solved by the Invention) As described above, in the reciprocating sliding type plunger pump of the conventional structure in which the outer peripheral surface of the plunger is formed of ceramics, first of all, ceramics are brittle and easily chipped. There was a problem that the method was expensive and the entire device was expensive.

Moreover, even if the outer circumferential surface of the plunger is made of ceramic, it is not possible to prevent solid objects from getting caught between the plunger and the cylinder, and the inner circumferential surface of the cylinder wears out, causing the plunger to deteriorate. There was also the problem that the work was more extensive and expensive than replacing it.

The present invention was proposed in view of such problems, and an object of the present invention is to provide a pump that is inexpensive and has excellent durability.

(Means for Solving the Problems) In order to achieve the above object, the plunger pump according to the present invention includes a suction valve body and a discharge valve body in a fluid passage, and a fluid passage between the two valve bodies. A cylindrical cylinder housing a plunger in a reciprocally slidable manner faces the cylinder, and a partition wall formed in a spherical shape with an elastically deformable thin film is placed in the cylinder or fluid passage ahead of the top dead center of the plunger. It is characterized in that it is provided in a state where it is partitioned off from both valve body side fluid passages.

(Function) When the plunger slides back and forth inside the cylinder, high pressure is created in the cylinder due to the forward movement, and when this pressure acts on the fluid in the fluid passage through the partition wall that seals the fluid, the suction valve body Since the discharge valve body opens at the same time as the valve closes, fluid is discharged and fed from the discharge valve body.

Next, when the plunger moves back and the cylinder becomes negative pressure,
This negative pressure is transmitted to the fluid in the fluid passage through the partition wall, the discharge valve element is closed, and the suction valve element is opened, so that the fluid to be fed is sucked into the partition wall portion.

Even when the plunger is driven back and forth, the partition wall keeps the plunger isolated from the fluid to be fed, so solids in the fluid to be fed get caught between the plunger and the cylinder. is prevented.

(Example) Hereinafter, an example of a plunger pump according to the present invention will be described based on the drawings.

Fig. 1 shows a partially cutaway side view of the plunger pump.
and a pump head 3 attached to the left end of the pump casing 2.

A crankcase 4 is formed in the right half of the pump casing 2. A crankshaft 5 is rotatably supported on the side wall of the crankcase 4, and a piston 6 is provided at the right end of the crankcase 4. A sleeve 7 is attached which slidably accommodates the.

The piston 6 and the crankshaft 5 are connected by a connecting rod 8, and driven by a drive device consisting of a motor, a speed reducer (both not shown), etc., which meshes with a driven gear 9 attached to the crankshaft 5. When the gear 10 is rotationally driven, the crank motion of the crankshaft 5 causes the piston 6 to slide from side to side in the figure via the connecting rod 8.

In this way, when the piston 6 slides left and right, the movement of the piston 6 is transmitted through the coupling 11 to the fluid passage 1, which will be described later.
2, and the plunger 14 is slidably driven.

The pump head 3 has a suction port 15 formed on the lower surface of the pump head 3 as shown in FIGS. 1 and 2.
A fluid passage 12 is formed in the shape of a crank, and communicates with a discharge port 16 formed in the upper part of one side of the pump head 3. In the fluid passage 12 near the suction port 15, there is a ball 17 and a valve in contact with the fluid passage 12. Suction valve body 1 consisting of seat 18
9 is provided, and a discharge valve body 22 consisting of a ball 20 and a valve seat 21 with which it comes into contact is provided in the fluid passage 12 near the discharge port 16.

Further, the fluid passage 1 between the suction valve body 19 and the discharge valve body 22
A part of the fluid passage 12 is branched out from the cylinder 2 so as to communicate with the cylinder 13 which slidably houses the plunger 14.

A partition wall 23 is formed between the branched fluid passage 12 and the cylinder 13, and as shown in FIG. The peripheral edge portion 23a is clamped and fixed between the cylinder forming block 24 and the partition wall forming block 25 attached to the left end surface of the pump head 3 to form the fluid passage 1.
It is configured to partition the two parts and the inside of the cylinder 13.

The cylinder 13 separated from the fluid passage 12 by the partition wall 23 is filled with lubricating oil.

In the plunger pump 1 configured as described above, when the crankshaft 5 is rotationally driven by the drive device and the plunger 14 slides back and forth inside the cylinder 13 via the connecting rod 8 and the piston 6, the cylinder Lubricating oil 29 in 13 is compressed, and this pressure acts on the fluid in fluid passage 12 via partition wall 23 .

When the pressure of the fluid in the fluid passage 12 becomes high, the suction valve body 19 closes and the discharge valve body 22 opens, and the fluid in the fluid passage 12 is discharged and fed from the discharge valve body 22.

Next, when the inside of the cylinder 13 becomes negative pressure due to the return movement of the plunger 14, this negative pressure is transferred to the fluid passage 12 through the partition wall 23.
Contrary to what was described above, the discharge valve body 2
2 is closed, the suction valve body 19 is opened, and the fluid to be fed is sucked from the suction valve body 19 into the partition wall 23 portion.

Since the plunger 14 is kept isolated from the fluid to be fed by the partition wall 23 even when the plunger 14 is driven back and forth, the solids in the fluid to be fed are separated from the plunger 14 and the cylinder 13. This prevents them from getting caught in between.

Further, the lubricating oil filled in the plunger 14 partitioned by the partition wall 23 maintains smooth sliding of the plunger 14 and prevents the cylinder 13 and the plunger 14 from being worn out.

(Effects of the Invention) As described above, the present invention allows the pressure fluctuations generated in the cylinder due to the reciprocating motion of the plunger to act on the fluid to be delivered through the partition wall in which the fluid is sealed in an elastic membrane material. Therefore, there is no need to use an expensive plunger pump such as a ceramic plunger, and the entire device can be made cheaper.

Moreover, since the plunger does not come into direct contact with the fluid to be fed, solid matter contained in the fluid to be fed will not get caught between the plunger and the cylinder, thereby preventing wear on the plunger and cylinder as much as possible. can greatly improve its durability.

Furthermore, even if a blockage occurs on the discharge side and the pressure of the fluid to be delivered increases abnormally, this abnormally high pressure is relieved by the elastic diaphragm and the pressure transmission fluid sealed inside, and acts on the plunger. Therefore, abnormally high pressure is prevented from acting directly on the drive device that drives the plunger, and the durability of the drive device can be greatly improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially cutaway side view of a plunger pump, and FIG. 2 is a longitudinal sectional side view of the pump head. ■...Plunger pump, 12...Fluid passage, 13
...Cylinder, 14...Plunger, 19...Suction valve body, 22...Discharge valve body, 23...Dividing wall.

Claims (2)

[Claims] (1) A suction valve body and a discharge valve body are provided in the fluid passage, and a cylindrical cylinder that houses a plunger so as to be able to slide back and forth is faced in the fluid passage between the fluid passage and the re-valve body, and the top dead center of the plunger is A plunger pump characterized in that a partition wall formed in a spherical shape and made of an elastically deformable thin film is provided in a cylinder or a fluid passage further forward to partition the inside of the plunger side cylinder and both valve body side fluid passages. (2) The plunger pump according to claim 1, wherein the plunger side cylinder partitioned by a partition wall is filled with lubricating oil.