JP4352181B2 - Piston pump movable seal liquid leakage prevention device - Google Patents

Description

  The present invention relates to a liquid leakage prevention device that prevents liquid leakage from a reciprocating piston and cylinder seal, such as an ultrahigh pressure piston pump.

Conventionally, as a device for preventing liquid leakage of a movable seal portion of a piston pump, elastic rubber, plastic, a metal ring or the like has been mainly used. (For example, see Patent Document 1)
JP 11-51193 A

In the case of the conventional piston pump movable seal part liquid leakage prevention device as described above, in recent years, liquid super-high pressure of 3,000 kgf / cm ² or more has been required, and when elastic rubber or plastic is used. The higher the pressure is, the more elastic it is, so it tightens strongly, so the frictional resistance increases, and even at an ultra-high pressure of 3,000 kgf / cm ² or more, there is a metal ring with little elasticity, When tightened to the point where the ultra-high pressure liquid does not leak, there was a problem of seizure (galling) due to intense movement.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a liquid leakage prevention device for a movable seal portion of a piston pump that does not leak even at an ultrahigh pressure.

  According to the present invention, there is provided a liquid leakage prevention device for a movable seal portion of a piston pump, a piston that reciprocates in the cylinder, a ring that prevents liquid leakage between the cylinder and the piston, and a holding screw that holds the ring. In the device for preventing liquid leakage of the movable seal portion of the piston pump provided with the above-described ring, the ring is one in which two types of piston side rings and a plurality of cylinder side rings are alternately incorporated.

  The piston side ring is a trapezoidal ring with a frustoconical outer slope on both sides with a thin outer diameter and a thick inner diameter, and the cylinder side ring has a thickness on the outer diameter side. Is a trapezoidal ring with a frustoconical inner slope with both rule surfaces having a large inner diameter and a smaller inner diameter. Further, the ring is not limited to metal as long as it has low elasticity and is slippery.

In the seal part where the piston pump is reciprocatingly moved, a high-pressure liquid flows from the pressurizing chamber to the working chamber and the frustoconical action inner slope, and stress is applied to the frustoconical inner slope of the ring holding screw. Since the ring has an inclined surface (angle), the ring on the piston side is tightened by a stress proportional to the pressure on the piston side on the piston side and the cylinder side ring on the cylinder side. Because of the above configuration, even if the cylinder swells with very high ultra-high pressure liquid and the inner diameter is slightly changed, two types of rings are forcedly applied with liquid pressure and slope, and the piston side ring is tightened in proportion to the liquid pressure. Since it is pressed against the piston side and the cylinder side ring is spread and pressed against the cylinder side, even if it is an ultra-high pressure of 3,000 kgf / cm ² or more, the ring will be proportional to the liquid pressure without excessive tightening, so even if it moves violently Prevents liquid leakage without seizing.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view in which a part of a movable seal portion liquid leakage prevention device for a piston pump showing an embodiment of the present invention is cut away. FIG. 2 is an enlarged cross-sectional view of the seal portion. FIG. 3 is an enlarged perspective view in which a part of the piston side ring is cut away. FIG. 4 is an enlarged perspective view in which a part of the cylinder side ring is cut away. In the figure, reference numeral 1 denotes a cylinder, which is provided with a circular hole 1a and a female screw 1c for a ring insertion hole 1b. A cylindrical piston 2 reciprocates in the hole 1a of the cylinder 1. Reference numeral 3 denotes a piston-side ring, which is made of phosphor bronze, gun metal, or the like. The outer diameter side is narrow, the inner diameter side is wide, both side surfaces are frustoconical outer slopes, and the cross section is trapezoidal. Reference numeral 4 denotes a cylinder-side ring, which is made of a stainless material or the like, and both side surfaces are frustoconical inner slopes and the cross section is trapezoidal.

  Reference numeral 8 denotes a ring holding screw for lightly screwing into the female screw 1c of the cylinder 1, and has a male screw portion 8a, a ring holding portion 8b, and an inclined surface 8c that presses against the piston side ring 3, and the inclined surface 8c is in a truncated cone shape. It is formed on the slope. Reference numeral 9 denotes an extra space formed between the cylinder 1 and the ring holding screw 8, and reference numeral 5 denotes a pressurizing chamber formed between the cylinder 1 and the piston 2. Reference numeral 6 denotes a working chamber into which ultrahigh pressure liquid enters from between the cylinder 1 and the piston 2, and 7 denotes a working inner slope. The ring holding screw 8 is shaped like a flange joint, and the inner diameter is formed so that the piston 2 can be inserted. The outer diameter of the ring holding portion 8b is the same as the outer diameter of the cylinder side ring 4. , 8d is the outer periphery of the flange.

Next, a method for assembling the liquid seal prevention device for the movable seal portion of the piston pump configured as described above will be described with reference to FIG.
First, it inserts so that the outer slope of the piston side ring 3 may match the action inner slope 7 of the insertion hole 1b of the cylinder 1. Next, two cylinder-side rings 4 and three piston-side rings 3 are assembled, and a ring holding screw 8 is screwed in so that the inserted piston 2 is not subjected to excessive resistance.

To explain the function of the invention, a sealing portion of the piston pump is reciprocated, infiltrates the high pressure liquid to the working chamber 6 from the pressurizing chamber 5, stress ring flows into the frustoconical working in slope 7 Because the ring has an inclined surface (angle) on the truncated cone-shaped inner inclined surface 8c of the holding screw 8, the piston side ring 3 is on the piston 2 side and the cylinder side ring 4 is on the cylinder 1 side with a stress proportional to the pressure. Because of this configuration, even if the cylinder swells with a very high ultra-high pressure liquid and the inner diameter is slightly changed, two types of rings can be used for the piston pressure ring in proportion to the liquid pressure. 3 is pressed against the tight piston 2 side, the cylinder-side ring 4 is pressed against the spreading cylinder 1 side, work is liking the two rings as in conjunction with excessive pressures without tighten friction resistance It is seizure (scuffing) leaks prevention device can be obtained for less.

Embodiment 2. FIG.
FIG. 5 is a longitudinal sectional view of a piston pump of different diameters showing Embodiment 2 of the present invention. Reference is made to Japanese Unexamined Patent Application Publication No. 2004-218619 super high pressure different diameter piston pump for explaining the incorporation of the movable seal portion leakage preventing device of the present invention. In the figure, the piston side ring 3 and the cylinder side ring 4 are shown in the first embodiment. Is the same. 11a is a different diameter cylinder front portion, and 11b is a different diameter cylinder rear portion. The inner diameter of the different diameter cylinder rear portion 11b is larger than the inner diameter of the different diameter cylinder front portion 11a. 12a is a piston front part with a different diameter, and 12b is a piston rear part with a different diameter. The piston side ring 3 and the cylinder side ring 4 are assembled into the piston side ring 3 and the cylinder side ring 4 in 11a at the cylinder rear portion 11b having a large inner diameter and a cylinder front portion having a small inner diameter.

  The piston pump of different diameter incorporating the present invention is not pressurized at the tip of the piston, the piston rear portion of the different diameter, the piston front portion 12a having a different diameter from 12b is a small cylinder, and its small cross-sectional area is the piston rear portion 12b having a different diameter. The area subtracted from the cross-sectional area is tapered, and since the pressure is applied at the tapered portion, the drag is dispersed. Since the cross-sectional area of the piston rear part 12b having a different diameter with respect to the pressurized area is large, the piston can be pushed with a large force, so that the liquid can be pushed out at an ultrahigh pressure.

  The fact that the piston can reciprocate means that there is even a slight gap between the piston and the cylinder. In addition, since the thermal expansion coefficient of the circumference of the cylinder is larger than the piston due to compression heat, etc., and the cylinder may swell even slightly even at ultra-high pressure, this invention is used to push out the liquid better at ultra-high pressure. If the movable seal part leakage prevention device is incorporated into a piston pump with a different diameter, the ring has a slope (angle) even if the cylinder has a slight bulge and diameter change. As a result, the efficiency of the piston pump with a different diameter is improved.

  When this invention is incorporated into a piston pump of a different diameter and used for fuel injection in a diesel engine, ultra-high pressure fuel injection can be performed more than ever, and at this time fuel is soaring, fuel efficiency is good and exhaust gas is clean. . In addition, compared to conventional ultra-high hydraulic pumps with the same amount of extrusion, the hydraulic equipment is simple and compact, and even when used as an ultra-high hydraulic pump, seaweed, oysters, rust, It is easy and easy to remove and clean paint with ultra-high water pressure.

  It is sectional drawing which notched a part of movable seal part liquid leak prevention apparatus of the piston pump which shows one Embodiment of this invention.   It is an expanded sectional view of the movable seal part of this invention.   It is the expansion perspective view which notched a part of piston side ring of this invention.   It is the expansion perspective view which notched a part of cylinder side ring of this invention.   It is a longitudinal cross-sectional view of the piston pump of different diameter which shows Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 1a Piston insertion hole 1b Ring insertion hole 1c Female thread 2 Piston 3 Piston side ring 3a Piston side ring outer slope 4 Cylinder side ring 4a Cylinder side ring slope 5 Pressurizing chamber 6 Working chamber 7 Working slope 8 Ring holding screw 8a Male thread 8b Ring retainer 8c Slope inside ring retainer 8d Flange outer periphery 9 Spare space 11 Different diameter cylinder 11a Different diameter cylinder front 11b Different diameter cylinder rear 12a Different diameter piston front 12b Different diameter piston rear

Claims (1)

Piston pump movable seal part liquid leakage prevention device comprising a cylinder, a piston that reciprocates in the cylinder, a ring that prevents liquid leakage between the cylinder and the piston, and a holding screw that holds the ring. in, the ring is a piston-side ring and cylinder-side ring which is slant both sides, the piston-side ring and a plurality of said side faces a plurality of said sides is a frustoconical outer slope is frustoconical in slope A seal part in which cylinder side rings are alternately assembled is formed, a pressurizing chamber is formed between the cylinder and the outer peripheral part of the piston, and an inner working slope and a working chamber are in contact with the seal part on the pressurizing chamber side is formed and a high pressure liquid from the pressure chamber causes flow into the working slope through the working chamber, the piston-side phosphorus by high pressure liquid having flown There undergoing stress, pressure chamber movable sealing unit leakage preventing device of a piston pump, wherein the ring tightens without being tightened excessive in conjunction with the fluid pressure.

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