JPH08200236A - Carbide plunger for high pressure pump - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a plunger for a high-pressure pump such as a clout pump by applying a super-hard material to a sliding portion to improve wear resistance and a manufacturing method thereof. [Structure] A cylinder (1) made of an ultra-hard material is arranged in the sliding friction portion of the plunger, and a shaft (2) made of a high-tensile material is provided inside the
One end of the shaft (2) is connected to the power transmission temporal (3), the other end is provided with a screw (21), and the central part is provided with a parallel part (23). The power transmission temporal (3) and the pump chamber temporal (4) are provided with spanner hooks (33, 44), and the pump chamber temporal (4)
Comprises an internal thread (41) which fits into the thread (21). Attach seat packing (6) and O-ring (5) Attach the cylinder (1) by tightening the power transmission side head (3) and the pump chamber side head (4) with screws (21, 41).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes a high wear resistance property and a high compression resistance property of a super hard material to screw a super hard material cylindrical body to a worn portion of a plunger for a high pressure pump such as a grout pump. The present invention relates to a long-life plunger for a high-pressure pump, which is fastened by.

[0002]

2. Description of the Related Art Conventionally, plungers for high-pressure pumps are made of heat-treated steel, those made by heat-treating the surface of heat-treated steel with hard chrome plating, and the surface hardening treatment of superhard materials such as by melting. Some of them have been made by precision finishing the surface, but they are not satisfactory in terms of longevity due to abrasion damage of sliding friction parts with packing and bearings.

[0003]

In any of the plungers used conventionally, the sliding friction portion with the packing and the bearing is not worn and damaged for a long time, and maintenance is expensive. Also, even if the pump is worn or damaged during operation, it may be difficult to interrupt work for the procedure, and the machine may become overworked, hindering the progress of work, and maintenance at the work site is easy. There are some inconveniences that you cannot do. SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, the present invention aims to extend the wear resistance of a blanker to prolong its service life and to provide an inexpensive manufacturing method thereof. In order to achieve the above purpose, conventionally, as an application of the super hard material, there is a super hard material surface build-up, but the characteristics of the super hard material build-up are normal abrasion resistance of the super hard material. The wear resistance is considerably lower than the wear resistance, and even if there is some material improvement, at present, the wear resistance for achieving the purpose is far inferior. The use of normal cemented carbide, that is, cemented carbide or fine ceramics, is considered to be the best solution for the problem.The conventional attempt to utilize cemented carbide was to manufacture the entire plunger with cemented carbide. Has the drawback that it is not possible to easily screw the mounting part. If only the mounting part is made of steel, braze or shrink fit the steel etc. to the cemented carbide and screw the steel part etc. Had to be produced. The drawback in this case is that the strength problem due to the distribution of thermal stress remains. Further, when a cemented carbide is used, its specific gravity is about twice that of steel, so there is a weight problem. Of course, since a large amount of expensive cemented carbide is used and the processing cost is also high, it becomes a fairly high-priced product. In order to solve the above-mentioned problem of thermal stress, it is conceivable to use an Elinvar alloy or the like having a thermal expansion coefficient that is slightly equal to that of the cemented carbide, instead of steel, but this results in a more expensive product. Regarding the use of fine ceramics, it has excellent corrosion resistance as well as abrasion resistance, and its specific gravity is smaller than that of steel, so the weight problem is an exception, but it is rather preferable. Is difficult to achieve, and has a lower tensile strength and fracture toughness than cemented carbide,
Grindability is also poor. Therefore, when joining other materials such as steel to the mounting portion, there is a drawback that they must be mechanically joined by a method such as shrink fitting and screwing. In addition, the material price is high and the processing cost is high, so the product is considerably more expensive than cemented carbide. As described above, it is intended to solve the problems by the following (a), (b), (c) and (d) by utilizing the wear resistance of the super hard material (such as a cemented carbide and fine ceramics). (A) The super-hard material has a characteristic that it has a large compressive strength and a comparatively small tensile strength. (B) In the case of using a cemented carbide among the superhard materials, reduce the weight by saving the material. (C) Since the ultra-hard material itself is expensive, the amount used should be reduced to reduce the price. (D) Since super-hard materials have poor machinability such as grinding, the man-hours should be reduced by reducing the size of the machining process.

[0004]

In order to achieve the above object, a shaft (2) made of a high-tensile material is provided inside a cylindrical body (1) made of a superhard material such as cemented carbide or fine ceramics.
One end of the shaft (2) was connected to the power transmission side (3), and the other end was connected to the pump chamber side (4) where leakage prevention measures were applied, and was provided at one end of the shaft (2). The cylindrical body (1) is tightened and compressed by the screw (41) provided on the inner surface of the pump chamber temporal (4) meshing with the screw (21) by the pump chamber temporal (4) and the power transmission temporal (3). The fluctuation of the force received during the operation of the plunger due to the structure attached to the cylinder is absorbed by the compression elasticity of the ultra-hard material cylinder (1) and the tensile elasticity of the high-tensile material shaft (2), and the wear resistance of the ultra-hard material I took measures to extend the life.

[0005]

The concept of operation of the plunger constructed as described above is shown in FIGS. 9 and 10. In the discharging process, the plunger in the pump chamber receives the same pressure as the discharging pressure on the entire surface thereof, and the sliding portion between the packing and the bearing receives the sliding frictional resistance force. Further, in the suction process, the plunger in the pump chamber receives a negative pressure for sucking the liquid on the entire surface, and the sliding portion between the packing and the bearing receives the sliding frictional resistance force. Because of these
The axial force of the super-hard material cylindrical body (1) attached only to the sliding parts of the packing and the bearing is added by the compressive stress generated by tightening and the compressive force received in the discharge process, and the shaft (2) is expanded in the suction process. Cylinder (1) with a length equal to the length
, The compressive stress generated by tightening is reduced accordingly. Similarly, the forces act in the direction perpendicular to the axis of the cylindrical body (1), so that these forces are absorbed by the cylindrical body. The shaft (2) of high-strength material is subjected to the tensile force generated by tightening in the axial direction in the suction process and the tensile force received in the suction process, and in the discharging process, only the length of the cylindrical body (1) contracted in the axial direction. Since the shaft (2) contracts, the tensile stress generated during tightening decreases by an amount corresponding to the contracted length. Further, it is necessary to prevent loosening of screws and secure packing action, but these forces are mainly absorbed by the parallel portion (23) of the shaft (2).

[0006]

EXAMPLES Examples of the present invention will be described below. (B) Cemented Carbide V20
The shape is shown in [FIG. 5] using (JIS B4053). The length is set to the length of the sliding part where the packing and bearing slide when the blanker is activated, considering the mounting position of the blanker.The outer diameter is the same as the outer diameter of the conventional product, and the inner diameter is tightened during assembly. The safety and the force received during operation are set. Inner circumference (11, 12) of left and right ends and left and right end faces (1
4 and 15) have the same shape on the left and right sides and are set so that the left and right positions can be exchanged. As for the finishing degree of the surface, the outer peripheral surface (16) is precision lap finished, and the inner peripheral portion (1
Although the inner peripheral portion (13) except for 1, 12) was left as a burnt surface, it may be a rough ground surface. The other surfaces are upper to middle ground surfaces. As a result, the amount of material used is reduced, and therefore, the weight and the material cost are reduced, and the processing man-hour is also reduced. The above-mentioned cemented carbide material is not limited to cemented carbide V20, but a wide range of cemented carbide materials having a hardness of HRA84 or more and few burrows are used. When special consideration is required for corrosion resistance, etc., alumina-based or zirconia-based materials Fine ceramics such as silicon nitride and cermet may be used. (B) The materials of the shaft (2), the power transmission temporal (3), and the pump chamber temporal (4) are all SCM-440 heat-treated steel (JI
Although SG 4105) is used, it is not limited thereto, and a material suitable for the purpose may be selected and used from a wide range of materials such as carbon steel for machine structure, alloy steel, and stainless steel. (C) The shaft (2) has a tightening screw (21) at one end as shown in [Fig. 6], and the other end is integral with the power transmission temporal (3), or equal to or more than the screw (21). Capacity screw (2
0, 30), and a parallel part that is as long as possible and has a diameter smaller than the root diameter of the tightening screw (21) is provided at the center. The parallel portion absorbs the tensile force generated by tightening during assembly and the tensile force received by the plunger during operation, and the screw (2
Prevent loosening of 1, 41) and secure the packing action of the packing (6). (D) The power transmission temporal (3) is shown in FIG. Protrusion (31) for centering the cylindrical body (1), cylindrical body (1)
Has a pressure surface (32) to the
Deploy 3). If necessary, an inner screw (30) that meshes with the connecting screw (20) of the shaft (2) may be provided. (E) The pump chamber temporal (4) is formed in the shape of a cap nut as shown in [Fig. 7], and the inner screw (41) meshing with the tightening screw (21) of the shaft (2) is aligned with the center of the cylindrical body. A protrusion (42) for pressing, a pressing surface (43) to the cylindrical body (1), an O-ring groove (45), and a spanner hook (44) having a plurality of surfaces are provided. (F) Measures to prevent liquid leakage are a cap nut type of the pump chamber temporal (4), mounting of the O-ring (5) in the O-ring groove (45), and a pressurizing surface (43) of the pump chamber temporal (4). ) And the end face (14) of the cylindrical body (1), using a sheet packing (6) or the like. The O-ring (5) is a type 1 B-fixing O-ring (J
Although IS B2401) is used, other high pressure resistant ones may be used, and the sheet packing (6) is made of a tetrafluoroethylene resin sheet, but may be another resin sheet or a metal thin plate depending on the purpose. (G) When assembling the above-mentioned parts, when assembling, the screw (21) of the shaft (2) and the screw (4) of the pump chamber temporal (4)
1) and O-ring groove (43) and O-ring (5) are oiled and assembled as shown in FIG. (H) In the tightening compression of the cylindrical body (1), first, after tightening at a tightening torque set at room temperature, the entire body is heated to a set temperature and then tightened at the tightening torque set again to naturally cool. This heating and tightening is for reducing the torsional stress applied to the parallel portion (23) of the shaft (2), and in some cases, without heating. In the cemented carbide plunger for a high-pressure pump of the present invention, as shown in FIG. 8, the tightening screw (21) of the shaft (2) is on the power transmission side. ), And the other end of the shaft (2) may be integrally or screw-connected to the pump chamber temporal (4).

[0007]

The cemented carbide plunger for a high-pressure pump, which has been completed as described above, is used under the same operating conditions as the conventional product in which the surface of the heat-treated steel is plated with hard chrome.
Although it is twice as expensive, it can be expected to be several times more in terms of service life, so maintenance costs can be reduced. Therefore, by applying the present invention to this type of pump, the pump work cost can be significantly reduced, which is industrially beneficial.

[Brief description of drawings]

FIG. 1 is an assembly view of a cemented carbide plunger used in an embodiment of the present invention with a partial cross section.

FIG. 2 is a sectional view taken along the line AA ′ of FIG.

FIG. 3 is a sectional view taken along line BB ′ of FIG.

FIG. 4 is a sectional view taken along the line CC ′ in FIG.

FIG. 5 is a cross-sectional view of a superhard material cylindrical body (1) used in an example of the present invention.

FIG. 6 is a plunger shaft (2) used in an embodiment of the present invention.
And a partial sectional view of the power transmission head (3)

FIG. 7 is a sectional view of a pump chamber temporal portion (4) of the plunger used in the embodiment of the present invention.

FIG. 8 shows a carbide plunger of the present invention, which includes a tightening screw (2
1, 41) is an assembly drawing of a partial cross section of a carbide plunger provided on the power transmission temporal (3) side

FIG. 9 is an explanatory diagram of a discharge process in the operation of the carbide plunger of the present invention.

FIG. 10 is an explanatory diagram of a suction process in the operation of the carbide plunger of the present invention.

[Explanation of symbols]

 1 Super Hard Material Cylinder 2 Plunger Shaft 3 Power Transmission Temporal 4 Pump Chamber Temporal 5 O-Ring 6 Seat Packing 11 and 12 Inner Surface of Cylinder End 13 Internal Surface of Cylinder, but Excluding Both Ends 14, 15 Cylindrical End 16 Outer surface of cylindrical body 21,41 Tightening screw 21,34 Tightening screw 20,30 Virtual connection screw 23 Parallel part of shaft (2) 31,42 Protrusion 32,43 for mounting position alignment Pressure surface to cylindrical body (1) 33 , 44 Spanner hook 45 O-ring mounting groove

Claims (1)

[Claims] 1. A shaft (2) of a high tensile material is provided inside a cylindrical body (1) made of a cemented carbide or fine ceramics such as fine ceramics, and one end of the shaft (2) is a power transmission temporal (3). The other end is connected to the pump chamber temporal (4) respectively, and by the screw (41) provided on the inner surface of the pump chamber temporal (4) that meshes with the screw (21) provided at one end of the shaft (2). , The pump chamber side (4) and the power transmission side (3) are used to tighten and compress the cylinder, and the fluctuation of the force received during the operation of the plunger is suppressed by the compression elasticity and high strength of the super hard material cylinder (1). Cemented carbide plunger for high-pressure pumps, which absorbs by the tensile elasticity of the shaft (2) of the tension material.