Sealing structure between hollow bolt and plunger sleeve of constant-pressure oil outlet valve

Abstract

The invention provides a sealing structure between a hollow bolt and a plunger sleeve of an isobaric oil outlet valve, which comprises the hollow bolt, the hollow bolt is provided with a central accommodating hole, the peripheral side of the central accommodating hole is provided with a sealing end face, the sealing end face is annular, and an avoiding space is reserved between a ring where the sealing end face is located and the central accommodating hole; the interior of the plunger sleeve extends inwards in the circumferential direction to form an annular table corresponding to the sealing end face, the sealing end face can be tightly pressed on the surface of the side, close to the inner wall of the plunger sleeve, of the annular table, and when the sealing end face abuts against the annular table, the annular table and / or the sealing end face can deform. The sealing end face and the avoiding space are arranged at the end of the hollow bolt, so that the sealing end face can be tightly pressed on the side, close to the inner wall of the plunger sleeve, of the annular table, the pressure borne by the annular table of the plunger sleeve can be far away from the center, stress is dispersed, the deformation degree of a center hole of the plunger sleeve is reduced, and the service life of the plunger sleeve is prolonged. Therefore, the plunger is prevented from being blocked while the sealing condition is met.

Description

Technical Field

[0001] The present invention belongs to the field of diesel engine parts, and particularly relates to a sealing structure between an isobaric oil outlet valve hollow bolt and a plunger sleeve. Background Art

[0002] Diesel engines control parameters such as the residual pressure, injection timing, injection law, and speed characteristics of the high-pressure system through the oil outlet valve. The oil outlet valves of some diesel engines are installed in the inner hole bolts, and the edge of the inner hole bolt is sealed with the plunger sleeve to prevent high-pressure oil from leaking out through the gap between the hollow bolt and the plunger sleeve during operation. In the prior art, in order to cope with the high-temperature and high-pressure working environment, an annular copper gasket is provided between the end of the hollow bolt and the plunger sleeve, so that the end face of the hollow bolt tightly presses on the copper gasket. By applying a pre-tightening force to the copper gasket, the copper gasket is deformed to complete the sealing. However, in actual installation, in order to maintain a good sealing effect, the hollow bolt usually needs to be tightened with a relatively large torque. During the process of tightening the hollow bolt, it is easy to cause cracks in the copper gasket, affecting the sealing effect and even resulting in the scrapping of parts. Moreover, when the pre-tightening force of the existing sealing structure is too large, the parts are deformed, resulting in a reduction in the clearance between the plunger and the plunger sleeve, which is likely to cause the plunger to get stuck. Summary of the Invention

[0003] In view of this, the present invention aims to provide a sealing structure between an isobaric oil outlet valve hollow bolt and a plunger sleeve to improve the product yield rate and avoid the plunger from getting stuck with the plunger sleeve.

[0004] To achieve the above object, the technical solution of the present invention is realized as follows:

[0005] A sealing structure between an isobaric oil outlet valve hollow bolt and a plunger sleeve, comprising

[0006] A hollow bolt, which includes a central accommodation hole. One end of the hollow bolt is provided with a sealing portion, and the sealing portion is disposed on the periphery of the central accommodation hole. The sealing portion includes a sealing end face, and the sealing end face is annular. There is a clearance space between the ring where the sealing end face is located and the central accommodation hole;

[0007] A plunger sleeve, which extends inwardly along the circumference to form a ring platform corresponding to the sealing end face. The sealing end face can tightly press on the surface of the ring platform close to the inner wall of the plunger sleeve, and when the sealing end face abuts against the ring platform, the ring platform and / or the sealing end face can be deformed.

[0008] Furthermore, an avoidance surface is provided inside the sealing end face, and the clearance space is formed by the avoidance surface and the plane where the sealing end face is located.

[0009] Further, the fuel outlet valve is placed in the central accommodation hole, and a strength maintaining section is left between the edge of the central accommodation hole near the avoidance space and the fuel outlet valve.

[0010] Further, the avoidance inclined surface is conical, and an included angle of 8° - 10° is provided between its generatrix and the plane where the sealing end face is located.

[0011] Further, the width of the sealing end face is 0.8 - 1 mm.

[0012] Further, the material of the hollow bolt is 40Cr steel.

[0013] Further, the hollow bolt is first machined from 40Cr steel to obtain a semi-finished product; the semi-finished product is placed in a furnace body at 850 °C for 1 hour for quenching and then cooled to room temperature in kerosene; then it is placed in a furnace at 570 °C for 1 hour for tempering, and finally placed in a room temperature environment and left to cool to room temperature.

[0014] Compared with the prior art, the sealing structure between the equal-pressure fuel outlet valve hollow bolt and the plunger sleeve of the present invention has the following advantages:

[0015] The present invention adopts a sealing end face and an avoidance space are arranged at the end of the hollow bolt, so that the sealing end face can tightly press against the inner side of the ring platform near the inner wall of the plunger sleeve, so that the pressure received by the ring platform part of the plunger sleeve can be far away from the central part, so that the stress is dispersed, reducing the deformation degree of the central hole of the plunger sleeve, and thus avoiding plunger jamming while meeting the sealing conditions;

[0016] The inclined avoidance surface is adopted to avoid weakening the strength of the end of the hollow bolt due to the relatively narrow sealing end face at the edge;

[0017] By arranging a strength maintaining section at the end of the hollow bolt, it is avoided to reduce the wall thickness of the hollow bolt at the position where the fuel outlet valve is installed and at the same time avoid the connection reliability between the fuel outlet valve and the hollow bolt. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 is a schematic diagram of the overall structure of the cooperation between the hollow bolt and the plunger sleeve in this embodiment;

[0020] Figure 2 is Figure 1 the enlarged schematic diagram at A in

[0021] Figure 3 is a schematic diagram of the sealing part structure of the hollow bolt.

[0022] Description of the reference numerals in the drawings:

[0023] 1 - Hollow bolt; 11 - Sealing part; 111 - Sealing end face; 112 - Avoidance face; 12 - Avoidance space; 13 - Strength retention section; 2 - Plunger sleeve; 21 - Ring platform; 3 - Delivery valve. Detailed implementation manners

[0024] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0025] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0027] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0028] The sealing structure between the equal-pressure delivery valve 3, the hollow bolt 1 and the plunger sleeve 2 according to the present invention includes a hollow bolt 1 and a plunger pair. The hollow bolt 1 is provided with a central accommodation hole, the delivery valve 3 is placed in the central accommodation hole, and the hollow bolt 1 is connected to the plunger sleeve 2 of the plunger pair. More specifically, the inner wall of the plunger sleeve 2 is provided with a thread that cooperates with the hollow bolt 1, so that the hollow bolt 1 can be screwed with the plunger sleeve 2, and the delivery valve 3 is communicated with the internal space of the plunger sleeve 2 through the central accommodation hole.

[0029] One end of the hollow bolt 1 is provided with a sealing portion 11, and the sealing portion 11 is placed on the periphery of the central receiving hole. The sealing portion 11 includes a sealing end face 111 and a relief face 112. The sealing end face 111 is annular, and the relief face 112 is placed inside the sealing end face 111 and is conical. There is an angle of 8° - 10° between its generatrix and the plane where the sealing end face 111 is located, so that the relief face 112 and the plane where the sealing end face 111 is located enclose a relief space 12, and the relief space 12 is placed between the ring where the sealing end face 111 is located and the receiving hole, while avoiding the outer wall of the hollow bolt 1 from being too thin and ensuring the structural strength of the hollow bolt 1. There is a strength maintaining section 13 between the edge of the receiving hole near the relief space 12 and the oil outlet valve 3, so that the oil outlet valve 3 is completely placed inside the hollow bolt 1, ensuring the connection strength between the hollow bolt 1 and the oil outlet valve 3.

[0030] A ring platform 21 corresponding to the sealing end face 111 extends circumferentially inward inside the plunger sleeve 2 of the plunger pair. Since the relief space 12 is placed inside the sealing end face 111, the sealing end face 111 can tightly press on the surface of the ring platform 21 on the side close to the inner wall of the plunger sleeve 2. Further, the sealing end face 111 can tightly press on the surface of the ring platform 21 away from the plunger side. And when the sealing end face 111 abuts against the ring platform 21, and a pre-tightening force is continuously applied to the hollow bolt 1, the ring platform 21 and / or the sealing end face 111 can deform under pressure, so that the surfaces of the sealing end face 111 and the ring platform 21 are in close contact with each other to complete the sealing. In this embodiment, in order to ensure the sealing effect and material strength, the width of the sealing end face 111 is 0.8 - 1 mm.

[0031] In this embodiment, the hollow bolt 1 is made of a metal material with certain elasticity. More specifically, the material of the hollow bolt 1 is 40Cr steel. During the production process, the 40Cr steel raw material is machined through rough machining and finish machining and other processes to determine the workpiece size to obtain a semi-finished product. Then, the semi-finished product is placed in a furnace at 8500° for 1 hour and then cooled to room temperature in kerosene to complete quenching; then it is placed in a furnace at 570° for 1 hour, and finally placed in a room temperature environment and left to cool to room temperature to complete tempering, so that the elastic properties of the material of the hollow bolt 1 can meet the requirements.

[0032] During the use process, the hollow bolt 1 and the plunger sleeve 2 of the plunger pair are connected. When the sealing end face 111 contacts the upper surface of the ring platform 21, the hollow bolt 1 is continuously rotated, so that the sealing end face 111 tightly presses on the ring platform 21. During this process, the sealing portion 11 of the hollow bolt 1 and the plunger sleeve 2 deform under pressure. However, since the sealing end face 111 is far from the plunger center, the stress of the deformation of the plunger sleeve 2 is dispersed, and the central hole of the ring platform 21 expands outward, thus avoiding jamming during the movement of the plunger.

[0033] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A sealing structure between a hollow bolt and a plunger sleeve of an isobaric oil outlet valve, characterized in that: include A hollow bolt, comprising a central receiving hole, a sealing portion being provided at one end of the hollow bolt, and the sealing portion being disposed on the peripheral side of the central receiving hole, the sealing portion comprising a sealing end face, and the sealing end face being annular, and an escape space being left between the ring where the sealing end face is located and the central receiving hole; The plunger sleeve has an annular platform corresponding to the sealing end face extending inwardly along the circumferential direction inside thereof, and the sealing end face can be tightly pressed against the surface of the annular platform close to the inner wall of the plunger sleeve, and when the sealing end face abuts against the annular platform, the annular platform and / or the sealing end face can be deformed.

2. The sealing structure between the hollow bolt and the plunger sleeve of the isobaric oil outlet valve according to claim 1, characterized in that: An avoidance surface is provided inside the sealing end surface, and the avoidance space is formed by the avoidance surface and the plane where the sealing end surface is located.

3. The sealing structure between the hollow bolt and the plunger sleeve of the isobaric oil outlet valve according to claim 1, characterized in that: The oil outlet valve is placed in the central accommodating hole, and a strength retaining section is reserved between the edge of the central accommodating hole close to one end of the avoidance space and the oil outlet valve.

4. The sealing structure between the hollow bolt and the plunger sleeve of the isobaric oil outlet valve according to claim 2, characterized in that: The avoidance slope is conical, and an angle of 8°-10° is set between its generatrix and the plane where the sealing end surface is located.

5. The sealing structure between the hollow bolt and the plunger sleeve of the isobaric oil outlet valve according to claim 1, characterized in that: The width of the sealing end surface is 0.8-1 mm.

6. The sealing structure between the hollow bolt and the plunger sleeve of the isobaric oil outlet valve according to claim 1, characterized in that: The hollow bolt is made of 40Cr steel.

7. The sealing structure between the hollow bolt and the plunger sleeve of the isobaric oil outlet valve according to claim 6, characterized in that: The hollow bolt is first machined from 40Cr steel to obtain a semi-finished product; the semi-finished product is placed in a furnace at 8500° for 1 hour for quenching, and then placed in kerosene to cool to room temperature; then placed in a furnace at 570° for 1 hour for tempering, and finally placed in a room temperature environment to stand and cool to room temperature.

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