Patent Publication Number: US-2019178146-A1

Title: Two-piece type oil jet assembly and method of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Korean Patent Application No. 10-2017-0170462 filed on Dec. 12, 2017, which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to an oil jet assembly. The oil jet assembly according to the present invention has an improved structure in which a valve part and a nozzle part are combined together in a two-piece form. 
     2. Description of the Related Art 
     Pistons used in gasoline engines, diesel engines, and high-performance engines are easily overheated during operation. In such a reciprocating engine, a pressure-driven oil jet is used to cool the lower portion of a piston. Such an oil jet is usually mounted on a bore below an engine block, and receives pressurized oil from an oil gallery. The oil jet also has a check valve, and discharges the oil through a tube when a certain pressure is reached. 
     The oil jet shown in  FIGS. 3 and 4  is manufactured in a one-piece form by a cutting process in an integrated manner. A fluid passage is disposed inside a cylindrical valve housing  12 ,′ an inlet is sealed with a ball  16 ,′ and a spring  14 ′ is interposed between the ball  16 ′ and a pin  18 ′ configured to seal the upper part of the passage. An outlet communicates with a tube  22 ,′ and a fastening ring  30 ′ configured to be fastened to an external component is coupled to the outer circumference of the middle portion of a body  12 .′ However, the one-piece type oil jet is manufactured by a cutting process, so that the manufacturing cost thereof is high and it is burdensome that the overall one-piece type oil jet must be re-manufactured in accordance with the type of vehicle when the type of vehicle is changed. 
     The oil jet  1 ′ shown in  FIG. 5  is manufactured in a two-piece form by a cutting process, and includes a valve part  10 ′ disposed on a right side and a cylindrical nozzle part  20 ′ disposed on a left side. The valve part  10 ′ is similar to that of  FIG. 4 . The nozzle part  20 ′ is fabricated by assembling a coupling ring  30 ′ and a tube  22 ′ together, and the threaded portion of the valve part  10 ′ is engaged with the threaded portion of the inside surface  32 ′ of the nozzle part  20 .′ However, the two-piece type oil jet  1 ′ is also manufactured by a cutting process, so that the manufacturing cost thereof is high and it is burdensome that the overall value part  10 ′ must be redesigned and re-manufactured in accordance with the type of vehicle when the type of vehicle is changed. 
     Meanwhile, as to patent documents regarding oil jets, Korean Patent Application Publication No. 10-2009-0043273 discloses a method of press-inserting a check valve into an oil inflow passage formed in an oil gallery, and Korean Patent Application Publication No. 10-2002-0019268 discloses a stopper for blocking the forward movement of a spring on the inner surface of a valve housing. However, these patents are intended to secure a smooth flow path for fluid, and do not address an overall method of manufacturing an oil jet and corresponding structural improvement. 
     SUMMARY 
     The present invention has been conceived to overcome the above-described problems, and an object of the present invention is to provide a manufacturing method in which a valve part and a nozzle part are separated from each other in the structure of an oil jet for a vehicle, the valve part is configured to be standardized, and the pressure of a spring can be accurately controlled. 
     In order to accomplish the above object, the present invention provides an oil jet assembly for injecting oil, introduced from an oil gallery of an engine block for a vehicle, to a piston, the oil jet assembly including: a nozzle part configured to function as a first piece, and adapted to include a head that has a cap and hollow cylindrical shape and that is configured such that the top surface thereof is closed, the bottom surface thereof is open, and a side surface thereof communicates with a tube for injecting oil; and a valve part configured to function as a second piece, and adapted such that the body thereof is formed using a retainer configured to be inserted into the open bottom surface of the head of the nozzle part, to have a hollow cylindrical shape, and to have open top and bottom surfaces, a spring is mounted inside the retainer, and a ball is inserted below the spring; wherein the nozzle part and the valve part are combined with each other. 
     The head and the retainer may be manufactured using a thin pipe made of steel material. 
     A bend bent inward may be formed along the periphery of the top surface of the retainer, a bend bent inward may be formed along the periphery of the bottom surface of the retainer, the bottom surface of the retainer may be open and form an entrance, and the inner surface of the bend of the bottom surface may provide a valve seat that comes into contact with the ball. 
     The retainer may be inserted into the head so that the top surface of the retainer is placed at a location adjacent to the bottom of the tube, and a predetermined portion of the retainer may extend below the bottom surface of the head and be exposed to the outside. 
     Furthermore, the present invention provides a method of manufacturing the two-piece type oil jet assembly, wherein the elastic modulus, pitch and number of turns of the spring are adjusted by means of an auto coiler so that the spring can accommodate valve opening pressure varying depending the type of vehicle, and the ball is inserted. 
     The bend of the bottom surface of the retainer may be formed by a rolling process, and the ball may be seated on the bend. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features, and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a sectional view showing an oil jet assembly according to an embodiment of the present invention with a nozzle part and a valve part separated from each other; 
         FIG. 2  is a sectional view of the oil jet assembly according to the embodiment of the present invention with the nozzle part and the valve part combined with each other; 
         FIG. 3  is a perspective view of an one-piece type oil jet according to an example of the prior art; 
         FIG. 4  is a partially sectional view of the one-piece type oil jet according to the example of the prior art; and 
         FIG. 5  is a view of a two-piece type oil jet according to another example of the prior art. 
     
    
    
     DETAILED DESCRIPTION 
     Some embodiments of the present invention will be described in detail below with reference to the exemplary drawings. It should be noted that the same reference symbols are assigned to the same components as much as possible even when they are shown in different drawings. In the following description of the embodiments, when it is determined that a detailed description of a related well-known function or configuration may make the gist of the present invention obscure, it will be omitted. 
     In the description of the components of each embodiment of the present invention, the terms “first,” “second,” “A,” “B,” “a,” “b,” etc. may be used. These terms are each used merely to distinguish a corresponding component from another component, but are not used to limit the natures or sequential positions of corresponding components. In some portion of the specification, when any component is described as “including” or “having” another component, this is not intended to exclude a third component, but is intended to include a third component, unless particularly described to the contrary. Furthermore, throughout the specification, when any component is described as being “connected,” “installed,” or “attached” to another component, it should be interpreted in a broad sense in such a manner that it is interpreted as including a case where the former component is directly connected, installed, or attached to the latter component and a case where the former component is connected, installed, or attached” to the latter component indirectly or via a third component. 
       FIG. 1  is a sectional view showing an oil jet assembly  1  according to an embodiment of the present invention with a nozzle part  10  and a valve part  20  separated from each other. 
     The head  12  of the nozzle part  10  has a cap and hollow cylindrical shape. The head  12  is configured such that the top surface thereof is closed, the bottom surface thereof is opened to accommodate the valve part  20 , and a side surface thereof communicates with a tube  14  and provides a fluid outlet. A fastening ring  16  is formed on the bottom surface of the head  12  in an integrated manner. The head  12  and the fastening ring  16  are fabricated using a thin pipe made of steel material. The nozzle part  10  is completed by fastening the tube  14  to the head  12 , for example, by performing drawing or welding after rolling molding. Alternatively, the head  12  and the fastening ring  16  may be fabricated by means of a forming process. In the present invention, the head  12  constituting the body of the nozzle part  10  is fabricated using a thin steel plate, which is advantageous for the lightening of weight. 
     The size and shape of the nozzle part  10  are shown as an example, and may vary depending on the type of vehicle. 
     Next, the valve part  20  has a hollow cylindrical shape. The valve part  20  is configured such that the body thereof is formed using a retainer  22  having open top and bottom surfaces and a spring S is mounted inside the retainer  22 . A ball  28  is inserted under the spring S. A bend  24  bent inward is formed along the periphery of the top surface of the retainer  22 , and the top surface of the retainer  22  is open and forms an exit  24   a.  A bend  26  bent inward is formed along the periphery of the bottom surface of the retainer  22 , and the bottom surface of the retainer  22  is open and forms an entrance  26   a.  The inner surface of the bend  26  provides a valve seat, and the ball  28  is pressed by the pressing force of the spring S and comes into contact with the valve seat. In  FIG. 1 , the entrance  26   a  of the valve part  20  is sealed. 
     The retainer  22  is fabricated using a thin pipe made of steel material. Furthermore, the valve part  20  is completed by inserting the ball  28  into the spring S and mounting the ball  28  and the spring S inside the retainer  22 , and thus design is simplified and fabrication is facilitated. When the valve part  20  is fabricated, the elastic modulus, pitch and number of turns of the spring S are adjusted, for example, by means of an auto coiler so that the spring S can accommodate valve opening pressure slightly varying depending on the type of vehicle, the ball  28  is inserted, the bend  26  is formed by means of a rolling process, and the ball  28  is seated on the bend  26 . 
       FIG. 2  is a sectional view of the oil jet assembly  1  according to the embodiment of the present invention with the nozzle part  10  and the valve part  20  combined with each other. 
     The valve part  20  is inserted into the nozzle part  10  so that the exit  24   a  of the retainer  22  is placed at a location adjacent to the bottom of the tube  14 . In this case, the valve part  20  and the nozzle part  10  are sealed together in such a manner that the outer circumference of the retainer  22  comes into contact with the inside of the lower portion of the head  12 . In order to secure the sealing, a gasket may be further installed. The portion of the retainer  22  up to height H is mounted in the bore of a block. An accommodation cup (not shown) configured to accommodate the retainer may be installed in the bore. Alternatively, the height of the head  12  may extend, and the bottom surface of the head  12  may be configured to extend below the ball  28 . 
     In the oil jet assembly  1  according to the present invention, the head  12  and the retainer  22  are fabricated using a thin pipe made of steel material, so that the thick wall of the conventional valve housing is removed and the oil jet assembly  1  can be simply assembled using two-piece parts, thereby enabling manufacturing cost to be reduced and also enabling a surrounding space to be decreased due to the compact volume of the oil jet assembly  1 . 
     Furthermore, complete products can be efficiently fabricated by standardizing a valve part in accordance with pressure and designing, fabricating a nozzle part in accordance with the type of vehicle, and then combining the valve and nozzle parts. 
     According to the present invention, the nozzle part and the valve part are fabricated using a thin steel plate material, and thus a lightweight product can be implemented. 
     Furthermore, the valve part is formed to fasten the spring and the ball by using a pipe-shaped material, and thus the manufacture thereof can be facilitated and a simple shape can be achieved. In particular, there can be applied a manufacturing technique for fastening the ball by means of a rolling process while measuring spring force so that the spring force is set within the range of management specifications. 
     Moreover, the valve part can be standardized and fabricated in accordance with pressure, the nozzle part can be designed and fabricated in accordance with the type of vehicle, and then the valve part and the nozzle part can be combined, thereby enabling a complete product to be efficiently manufactured. 
     While the embodiment of the present invention has been described as an example, this does not limit the scope of the present invention. Various alterations or modifications may be made to the present invention, and also fall within the scope of the present invention. The scope of the present invention extends to a range identical or equivalent to the attached claims.