Patent Publication Number: US-2015069754-A1

Title: Hose attaching structure

Description:
TECHNICAL FIELD 
     The present disclosure relates to an improvement in hose attaching structures for attaching a hose to a working apparatus. 
     BACKGROUND 
     Among the conventionally-known hose attaching structures for attaching a hose to a working apparatus, such as a water pump, is one which is designed to attach a hose to a water pump via a hose nipple. Examples of such a hose nipple includes one that is attached to a water pump using a claw, and one that is attached to a water pump through screw or threaded coupling engagement. One example of such a hose attaching structure is disclosed in Japanese Patent Application Laid-open Publication No. HEI-2- 199295 (hereinafter referred to as “the relevant patent literature”).    
     In the hose attaching structure disclosed in the relevant patent literature, a hose is attached to a suction opening section formed in a horizontal direction of the water pump. The suction opening section of the water pump has a female threaded (i.e., internally-threaded) portion, and a hose nipple having the hose attached thereto has a male thread (i.e., externally-threaded) portion formed on one end portion thereof. The male threaded portion of the hose nipple is screwed into the female threaded portion of the suction opening of the water pump. 
     However, when the hose nipple, having the hose attached thereto, is to be screwed into the suction opening of the water pump, the hose nipple would tilt due to the weight of the hose, and thus it would be difficult to bring the male and female thread portions into appropriate meshing engagement with each other. Therefore, some improvement has to be made in order to threadedly couple the hose nipple, having the hose attached thereto, to the suction opening section of the water pump. 
     SUMMARY 
     In view of the foregoing problems, it is preferable to provide an improved technique for readily threadedly couple a hose nipple, having a hose attached hereto, to a working apparatus without being adversely influenced by the weight of the hose. 
     In order to accomplish the above, one aspect of the present disclosure provides an improved hose attaching structure for attaching a hose to a working apparatus, which comprises: a hose nipple having the hose attached thereto; and an annular hose coupling connected to the hose nipple, the hose coupling having, on the inner peripheral surface thereof, a non-threaded portion and a female threaded portion to be screwed onto a male threaded portion formed on a distal end portion of a nozzle of the working apparatus, the non-threaded portion being located on a distal end portion of the inner peripheral surface of the hose coupling to be inserted over the nozzle and having such an inner diameter that the non-threaded portion is fittable over the male threaded portion of the nozzle. The hose nipple connected with the hose coupling is threadedly coupled to the nozzle through meshing engagement between the female threaded portion of the hose coupling and the male threaded portion of the nozzle. 
     Because the non-threaded portion is formed on a distal end portion of the inner peripheral surface of the hose coupling to be inserted over the nozzle and has such an inner diameter that the non-threaded portion is fittable over the male threaded portion of the nozzle, the non-threaded portion functions as a guide for appropriately positioning the hose coupling relative to the nozzle. Namely, the non-threaded portion guides the hose coupling in such a manner that the respective axes of the hose coupling and the nozzle are brought into alignment. Thus, the present disclosure can greatly facilitate positioning of the hose coupling relative to the nozzle, preventing mutual clinging or biting between the male and female threaded portions and thus permits appropriate meshing engagement and tightening between the male and female threaded portions without being influenced by the weight of the hose. As a result, the present disclosure can readily threadedly couple the hose nipple, coupled with the hose coupling and having the hose attached thereto, to the nozzle of the working apparatus. 
     In an embodiment, the non-threaded portion is located closer than the female threaded portion to the distal end of the hose coupling, and the inner diameter of the non-threaded portion is substantially equal to the outer diameter of the male threaded portion of the nozzle so that, when the female threaded portion and the male threaded portion are in meshing engagement with each other, the male threaded portion is covered with the non-threaded portion. Because the non-threaded portion of the hose coupling covers the male threaded portion of the nozzle, the male threaded portion and the female threaded portion can be protected from muddy water and dirt and dust that would otherwise enter through a proximal end portion of the male threaded portion. 
     The following will describe embodiments of the present invention, but it should be appreciated that the present invention is not limited to the described embodiments and various modifications of the invention are possible without departing from the basic principles. The scope of the present invention is therefore to be determined solely by the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain preferred embodiments of the present invention will hereinafter be described in detail, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a sectional view of a working apparatus employing an embodiment of a hose attaching structure of the present invention; 
         FIG. 2  is a view showing in enlarged scape principal sections of the working apparatus shown in  FIG. 1 ; 
         FIG. 3  is a view explanatory of behavior of a conventionally-known example of a hose attaching structure; and 
         FIG. 4  is a view explanatory of the embodiment of the hose attaching structure shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a sectional view of a working apparatus  10  which employs an embodiment of a hose attaching structure of the present invention. The working apparatus  10  is, for example, a water pump. This water pump  10  includes: an engine  11 ; a case  21  provided on a cylinder block  12  of the engine  11 ; a suction nozzle  40  provided in a suction opening section  22  of the case  21 ; and a discharge nozzle  25  provided in a discharge opening section  24  of the case  21 . 
     The engine  11  includes: a partition wall  13  of the cylinder block  12 ; a mechanical seal  15  provided in a support hole  14  of the partition wall  13 ; and a crankshaft  16  rotatably mounted on the mechanical seal  15 . The crankshaft  16  has an end portion  17  projecting into the case  21 , and a vane wheel  31  is connected to the end portion  17  of the crankshaft  16 . 
     A volute  32  is disposed within the case  21 , and the vane wheel  31  is covered with the volute  32 . The case  21  has an opening portion  26  closed with the partition wall  13  and the volute  32  is provided on the partition wall  13 , so that an in-case flow passage  33  is defined with the partition wall  13 , the case  21  and the volute  32 . The in-case flow passage  33  is formed in a substantially annular shape between the case  21  and the volute  32 . 
     The case  21  includes: a suction-side wall section  27  opposed to the partition wall  13 ; a suction passage section  28  communicating with the suction opening section  22  formed in the suction-side wall section  27 ; and an annular peripheral wall section  29  formed along the edge of the suction-side wall section  27 . 
     The suction nozzle  40  extends in a horizontal direction from the suction opening section  22  and has a male threaded portion  42  formed on its distal end portion. 
     Further, a hose nipple  52  having a hose  51  attached thereto is connectable to the suction nozzle  40  via a hose coupling  50  in a manner to be described in detail below. A seal member  34  is disposed on the distal end of the suction nozzle  40  in such a manner that it is sandwiched between the hose nipple  52  and the suction nozzle  40  when the hose nipple  52  is connected to the hose nipple  40  via the hose coupling  50 . 
     The following describe principal sections of the embodiment. As shown in  FIGS. 1 and 2 , the hose coupling  50  has on its inner peripheral surface  53 : a taper portion  54  formed on a distal end portion of the inner peripheral surface  53 ; a non-threaded portion  56  to be inserted onto the male threaded portion  42  of the suction nozzle  40 ; a female threaded portion  55  to be screwed onto the male threaded portion  42 ; a seal support portion  57  supporting the seal member  34 ; and a flange support portion  58  supporting a flange  52   a  of the hose nipple  52 . 
     Further, the hose coupling  50  has a handle section  59  such that the hose coupling  50  can be readily rotated by use of the handle section  59 . 
     The non-threaded portion  56  of the hose coupling  50  is located closer than the female threaded portion  55  to the distal end of the hose coupling  50  to be inserted over the suction nozzle  40 . Further, the taper portion  54  is located closer than the non-threaded portion  56  to the distal end of the hose coupling  50  to be inserted over the suction nozzle  40 . 
     The taper portion  54  is formed continuously with the non-threaded portion  56  in such a manner that it becomes gradually wider (i.e., greater in inner diameter) from one end of the non-threaded portion  56  toward the distal end of the hose coupling  50 . In  FIG. 2 , the taper portion  54  has a maximum inner diameter d1, the non-threaded portion  56  has an inner diameter d2 and the female threaded portion  56  has an inner diameter d3, and relationship among the inner diameters d1, d2 and d3 is d3&lt;d2&lt;d1. The trough diameter of the female threaded portion  55  is substantially equal to the inner diameter of the non-threaded portion  56 . 
     Further, in  FIG. 2 , the male threaded portion  42  of the suction nozzle  40  has an outer diameter D4, and the non-threaded portion  56  has an inner diameter d2 is substantially equal to or slightly greater than the outer diameter D4 of the male threaded portion  42 . Namely, the inner diameter d2 of the non-threaded portion  56  is set or chosen such that the non-threaded portion  56  is fittable over the male threaded portion  42 . Further, the non-threaded portion  56  has an axial length L1 that is set to correspond to an axial distance between two adjoining threads or more of the male threaded portion  42 . 
     Thus, when the hose coupling  50  is to be connected to the nozzle  40 , first, the taper portion  54  functions as a first guide for aligning the center of the distal end portion of the nozzle  40  and the center of the distal end portion of the hose coupling  50 . Then, the non-threaded portion  56  functions as a second guide for aligning the axis of the nozzle  40  and the axis of the hose coupling  50 . In this way, the female threaded portion  55  of the hose coupling  50  can be tightened over the male threaded portion  42  of the nozzle  40  easily and accurately. 
     The following describe behavior of a conventionally-known example of a hose attaching structure. (a) of  FIG. 3  shows a working apparatus  100  employing the conventionally-known hose attaching structure, which includes a nozzle  101  having a male threaded portion  102  formed on a distal end portion thereof. Further, an annular hose coupling  105  is connected to a hose nipple  104  having a hose  103  attached thereto. The hose coupling  105  has a taper portion  107  formed on a distal end portion of the inner peripheral surface  106  of the hose coupling  105 , and a female threaded portion  108  formed continuously with the taper portion  107 . 
     The hose nipple  104  and the hose coupling  105  are subjected to force in a direction of arrow A due to the weight of the hose  103 , so that they are slightly tilted relative to the nozzle  101 . When the hose coupling  105  is to be inserted over the nozzle  101 , the center of the distal end portion of the nozzle  101  and the center of the distal end portion of the hose coupling  105  are aligned with each other by the guide function of the taper portion  107 , but the hose nipple  104  and the hose coupling  105  stay tilted relative to the nozzle  101 . Thus, the female threaded portion  108  would undesirably cling to, or bite into, the male threaded portion  102 , so that the female threaded portion  108  and the male threaded portion  102  cannot be brought into appropriate meshing easily. 
     (b) of  FIG. 3  shows a state of the working apparatus  100  after the female threaded portion  108  and the male threaded portion  102  have been brought into meshing engagement with each other. In this state, the hose coupling  105  has been inserted deep onto the nozzle  40 . Because the female threaded portion  108  is formed from the distal end of the inner peripheral surface  106  of the hose coupling  105 , muddy water and dirt and dust may easily enter through a proximal end portion of the male threaded portion  102 . 
     Next, a description will be given about behavior of the embodiment of the hose attaching structure. (a) of  FIG. 4  shows the working apparatus  10  employing the embodiment of the hose attaching structure. The hose nipple  52  and the hose coupling  50  are subjected to force in a direction of arrow B due to the weight of the hose  51 , so that they are slightly tilted relative to the nozzle  40 . When the hose coupling  50  is to be inserted over the nozzle  40 , the center of the distal end portion of the nozzle  40  and the center of the distal end portion of the hose coupling  50  are aligned with each other by the guide function of the taper portion  54 . 
     (b) of  FIG. 4  shows a state of the embodiment where the hose coupling  50  has been inserted slightly over the nozzle  40 , from which time the non-threaded portion  56  is advanced along the male threaded portion  42  of the nozzle  40 . Thus, the axes of the nozzle  40  and the hose coupling  50  are guided into alignment. This arrangement can prevent the female threaded portion  55  from clinging to, or biting into, the male threaded portion  42 , so that the male threaded portion  42  and the female threaded portion  55  can be brought into appropriate meshing engagement with ease. 
     (c) of  FIG. 4  shows a state of the working apparatus  10  after the female threaded portion  55  and the male threaded portion  42  have been brought into meshing engagement. In this state, the hose coupling  50  has been inserted deep onto the nozzle  40 . Because the non-threaded portion  56  having the inner diameter substantially equal to the outer diameter of the male threaded portion  42  of the nozzle  40 , the male threaded portion  42  is covered with the non-threaded portion  56 , so that muddy water and dirt and dust can be prevented from entering through a proximal end portion of the male threaded portion  42  and consequently the male threaded portion  42  and the female threaded portion  55  can be protected from muddy water and dirt and dust. 
     The following summarizes the above-described embodiment of the hose attaching structure. As shown in  FIGS. 1 ,  2  and  4 , the non-threaded portion  56  is located in a distal end portion of the inner peripheral surface of the hose coupling  50  to be inserted over the nozzle  40 , and the inner diameter d2 of the non-threaded portion  56  is set or chosen such that the non-threaded portion  56  is fittable over the male threaded portion  42 . Thus, the non-threaded portion  56  of the hose coupling  50  functions as a guide for the hose coupling  50 . Because the hose coupling  50  is guided by the non-threaded portion  56  in such a manner that the axes of the hose coupling  50  and the nozzle  40  are aligned with each other, positioning of the hose coupling  50  and the nozzle  40  can be greatly facilitated and unwanted biting between the male and female threaded portions  42  and  55  can be prevented reliably. Thus, the male and female threaded portions  42  and  55  can be brought into appropriate meshing engagement without being adversely influenced by the weight of the hose  51 . As a result, the hose nipple  52  connected with the hose coupling  51  and having the hose  51  attached thereto can be readily screwed onto, or threadedly coupled to, the nozzle  40  of the working apparatus  10 . 
     Further, because the non-threaded portion  56  of the hose coupling  51  covers an end portion of the male threaded portion  42  of the nozzle  40 , the male and female threaded portions  42  and  55  can be protected from muddy water and dirt and dust. 
     Whereas the working apparatus to which is applied the embodiment of the hose attaching structure has been described above as a water pump, the working apparatus may be any other type of apparatus as long as the hose attaching structure has an annular hose coupling that is threadedly coupled to, or screwed onto, a nozzle of the working apparatus. Furthermore, whereas the embodiment of the hose attaching structure has been described above as applied to a suction nozzle, the present invention is not so limited, and it may be applied to a discharge nozzle. Further, whereas the embodiment of the hose attaching structure has been described above as applied to a nozzle extending in a horizontal direction, the present invention is not so limited, and it may be applied to a tilted nozzle or a nozzle extending in a vertical direction. 
     The hose attaching structure of the present disclosure is particularly well suited for attaching a hose to a nozzle of a water pump.