Pipe connecting structure for a pipe-type modular wiper apparatus

Abstract: A pipe connecting structure a pipe-type modular wiper apparatus including: a bracket (3) to which a wiper motor (2) is fastened; and a bracket (5) to which a wiper shaft (4) is fastened and which is, via a pipe member (6), integrally connected to the bracket (3) to which a wiper motor is fastened. The pipe member (6) is integrally fastened to the brackets (3, 5) by integrally inserting a pipe nut (15) into an insertion hole (6a) formed at a position at which the pipe member is connected to the bracket in such a manner that a bolt (13) is, in a thread manner, inserted from the bracket side in a state where the bracket is brought into contact with a head portion of the pipe nut (15) projecting over the pipe member in such a manner that a recess-groove shape fastening groove portion (3c) is formed in a portion of the bracket to which the pipe member is fastened, the pipe member is fitted to the fastening groove portion so as to be tightened by the bolt (13), the fastening groove portion has a depth with which the pipe member can be fitted by a degree larger than the half of the pipe member and two introduction surfaces (3b) of the fastening groove portion through which the pipe member is introduced are made to be parallel surfaces facing a direction of a tangent of the outer circumference of the pipe member.

Description: BACKGROUND OF THE INVENTION Field of the Invention: The present invention relates to a pipe connecting structure for a pipe-type modular wiper apparatus for use in a vehicle such as an automobile, a bus or a track or the like. Description of the Related Art: There has been available a modular wiper apparatus structured in such a manner that a bracket to which the wiper motor is fastened and another bracket to which the wiper shaft is fastened are connected to each other by a pipe member. In a modular wiper apparatus of the type described above, the pipe member and the bracket are connected to each other in such a manner that a cylindrical projection to be inserted into the inner surface of the pipe member is formed on the bracket. Furthermore, the above-described projection is inserted into the pipe member at the end portion of the pipe member before a rivet is inserted into a hole formed at a position which corresponds to the projection and the pipe member so as to be riveted. However, the structure of this type necessarily encounters a problem of generation of a gap which will be formed between the inner surface of the pipe member and the projection of the bracket and that between the rivet, the pipe member and the hole formed in the bracket. Therefore, the wiper apparatus suffers from an undesirable play, causing a problem to be taken place in that, for example, the range which is wiped out by the wiper blade is undesirably changed and/or noise is generated. A pipe nut is sometimes employed for the purpose of fixing another member to the pipe member. The pipe nut in this case is employed as shown in Fig. 4 in such a manner that: a head portion 15a having the lower surface curved along the outer surface of the pipe member and the upper surface formed into a flat shape is formed on the top outer surface portion of a cylindrical member; and a female thread 15c is formed in the lower inner surface of the above-described cylindrical member. In this case, the pipe nut 15 is first inserted into a hole formed in the pipe member 6, and then a tool (omitted from illustration) is used in such a manner that a male thread formed on the tool is engaged with the female thread 15c of the pipe nut 15 so as to tighten them. After this process, the tool is pulled together with the female thread 15c. As a result, the intermediate portion of the pipe nut 15 is deformed into a flange shape so that the pipe nut 15 is fixedly secured to a portion within the hole formed in the pipe member 6 while preventing generation of undesirable play around the hole formed in the pipe member. It might therefore be feasible to employ a structure using the above-described pipe nut 15 as shown in Fig. 5 in such a manner that the bracket 16 is positioned to contact with the flat surface of the head portion 15a of the pipe nut 15 fastened to the pipe member 6 before a bolt 13 is screwed so that the pipe member 6 and the bracket 16 are connected to each other. The above-described structure encounters no problem when load is applied in the axial direction of the bolt because the load can be received by the bolt. However, strength exhibited is unsatisfatory when load is applied from a direction deviated from the axial direction of the bolt. Therefore, undesirable play takes place, causing a necessity to arise in that the strength is further improved. A structure of the type shown in Figure 5 is described in Japanese Utility Model Publication No. JP-U-87217/86. SUMMARY OF THE INVENTION To this end an object of the present invention is to provide a pipe connecting structure for a pipe-type modular wiper apparatus capable of overcoming the above-described problems. According to the present invention there is provided a pipe connecting structure for a pipe-type modular wiper apparatus comprising a bracket to which a wiper motor is fastened, a bracket to which a wiper shaft is rotatably coupled, a pipe member extending between said brackets and connecting means for connecting each bracket to the pipe member, whereby each connecting means comprises a pipe nut having a head and a bolt having a head and a shaft which is arranged to engage said nut and to tighten the head portion of the nut towards the corresponding bracket to locate the bracket between the head of the bolt and the head portion of the nut (Pipe connecting structure of the type disclosed in JP-U-87217/86 and shown in fig. 5 of the present patent), characterised in that each bracket is shaped to define a fastening groove portion whose bottom groove portion is adapted to locate between the head of the bolt and the head portion of the nut, the fastening groove portion having a depth larger than the radius of the pipe member, whereby the pipe member is received in said groove portion to a depth which exceeds said radius. Further developments in line with claim 1 are referred to in the dependent claims. The invention will be described now by way of example only, with particular reference to the accompanying drawings. In the drawings: BRIEF DESCRIPTION OF THE DRAWINGS Accompanying drawings illustrate embodiments of the present invention of a pipe connecting structure for a pipe-type modular wiper apparatus according to the present invention, where Fig. 1 is a perspective view which illustrates a wiper apparatus,; Fig. 2 is a cross-sectional view taken along line Y-Y of Fig. 1; Figs. 3A, 3B and 3C are respectively a plan view, a side elevational view and a front elevational view; Fig. 4 is a partial front elevational cross sectional view which illustrates a pipe nut; and Fig. 5 is a cross-sectional view which illustrates an essential portion of a conventional structure. DESCRIPTION OF PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. Referring to the drawings, a pipe-type modular wiper apparatus 1 is constituted by integrally connecting an aluminum die-cast first bracket 3 and an aluminum die-cast second bracket 5 to each other by using a steel pipe member 6. A wiper motor 2 is attached to the aluminum die-cast first bracket 3, while a wiper shaft 4 is rotatably attached to the aluminum die-cast second bracket 5. Furthermore, a wiper link 8 is interposed between a motor arm (omitted from illustration) provided for the motor shaft 4 of the wiper motor 2 and a link arm 7 provided for the wiper shaft 4. In addition, another wiper link 11 is interposed between the link arm 7 and a link arm 10 of a wiper shaft 9 provided for the first bracket 3. As a result of this, when the wiper motor 2 is rotated, the two link arms 7 and 10 are reciprocated, causing the wiper shafts 4 and 9 to be rotated. Therefore, the surface of the window can be wiped out as desired. The pipe member 6 for integrally connecting the above-described two brackets 3 and 5 to each other is, by tightening, connected to each of the brackets 3 and 5 by using pipe nuts 15. The pipe member 6 is connected to the first bracket 3 by virtue of the connecting structure according to the present invention which is arranged as follows: That is, the first bracket 3 has a pipe fitting groove 3c which is formed into a semicircular arc in such a manner that a lower portion is faced to a downwardness and the upper portion is a bottom groove, the pipe member 6 is fitted to the pipe fitting groove 3c. Two nut fitting grooves 3a are arranged on the bottom groove portion of the pipe fitting groove 3c in the form of the cylindrically in the longitudinal direction, so as to constitute two pipe member connecting portions in the axial direction of the pipe fitting groove 3c. Thus the fastening groove portion comprises the pipe fitting groove 3c and the nut fitting groove 3a. The above-described fastened groove portions are structured in such a manner that they cause the pipe member 6, which is arranged to be fitted within the above-described pipe fitting groove 3c, to be fitted further deeply over the radius position of the pipe member 6. In addition, the opposite ends of the pipe member 6 are open so that water which inserted in pipe member 6 can flow from their ends. Furthermore, the two introducing surfaces 3b of the pipe fitting groove 3c, through wich the pipe member 6 is inserted, are structured in such manner that they open in substantially parallel to each othe while facing the direction of tangent K of the outer circumference of the pipe 6. And a pair of ribs 3d, 3d are formed on the upper surface of the first bracket 3, especially on the upper surface of the pipe fitting groove 3c, the ribs 3d, 3d contribute the increase of the strength of the bracket 3. On the other hand, a first bracket connecting portion of the pipe member 6 has an insertion hole 6a at a position confronting the bottom portion of the nut fitting groove 3a. A leading portion of the pipe nut 15 is inserted into the above-described insertion hole 6a while a tool is used to engage a pipe nut thread portion 15c and cause it to deform an insertion intermediate portion 15b so that it is folded back and bent to form a flange shape along the inner surface of the pipe member 6. As a result, the pipe member 6 is held by the above-described insertion intermediate portion 15b and a head portion 15a of the pipe nut 15 so that the steel pipe nut 15 is integrally secured to the pipe member 6 in such a manner that the separation of the steel pipe nut 15 and the pipe member 6 are prevented. In this case, the intermediate portion 15b to be folded back and bent is receive and supported by the inner surface of the pipe fitting groove 3c through the pipe member 6, therefore the pipe member 6 is prevented to deform when the bolt is tightened, and the pipe member 6 is fixedly connected. Furthermore, the insertion intermediate portion 15b to be folded back and bent is arranged to cover the insertion hole 6a in the condition that the insertion intermediate portion 15b is forcibly inserted into the edge of the under the insertion hole 6a, accordingly, the pipe member 6 is fixedly connected in the axial direction as well as the vertical direction of the pipe nut 15. Then the intermediate portion 15b is directly received and supported by the portion of the bracket 3 while holding the pipe member 6. As described above, the pipe member 6 integrally including the pipe nut 15 is fitted within the nut filling groove 3a in such a manner that the head portion 15a projecting over the outer surface of the pipe member 6 is abutted against the bottom portion of the nut fitting groove 3a. Furthermore, a bolt 13 is driven into the thread portion 15c of the pipe nut 15. Therefore, the pipe member 6 and the first bracket 3 are fixedly connected to each other. When the pipe member 6 is connected to the first bracket 3 in the above-described structure according to the present invention, the pipe member 6 is fitted within the pipe fitting groove 3c in a state where the pipe nut 15 has been inserted into the pipe member 6. Then, the bolt 13 is driven from the bottom side of the nut fitting groove 3a so that the above-described connection is completed. Since the pipe member 6 thus connected is received by the pipe fitting groove 3c deeply in such a manner that the portion of the pipe member 6 exceeding its radius position is received, load given in the direction of the plate of the first bracket 3 and as well as load given in the axial direction of the bolt 13 can be effectively received by the first bracket 3. Therefore, a problem of separation of the pipe member 6 from the pipe fitting groove 3c can be prevented while maintaining satisfactory strength of the connection. According to the present invention, the pipe member 6 is deeply held by the pipe fitting groove 3c comprising the fastening groove portion in such a manner that the two introducing surface 3b of the pipe fitting groove 3c are arranged to form parallel surfaces facing the direction of tangent K of the outer circumference of the pipe member 6. Therefore, the undesirable undercut state of the portion including the fastening groove portion generated in the mold removal direction can be prevented at the time of molding the first bracket 3. As a result, an effect can be obtained in that the ordinary molding operation can be performed. As described above, the structure according to the present invention is arranged in such a manner that: the pipe nut 15 included in the pipe member 6 is employed; and the insertion intermediate portion 15b of the pipe member 6 is deformed to form a flange like shape along the inner surface of the pipe member 6 so that the pipe member 6 is held fixedly by the pipe nut 15. As a result, the leading portion of the bolt and the nut which is screwed by the bolt do not appear outside. Furthermore, no load acts in a direction in which the pipe member 6 is deformed in its radial direction. Therefore, an effect can be obtained in that the strength of the pipe member 6 can substantially by maintained and thereby satisfactory strength can be realized. Furthermore, the structure according to the above-described embodiment is arranged in such a manner that the position at wich the pipe member 6 fitted within the fastening groove portion is abutted and supported by the two introducing surfaces 3b, 3b of the pipe fitting groove 3a substantially aligns to the inner surface of the bracket (that is, the longitudinal line L of the pipe member 6 in the direction of the plate substantially aligns to the inner surface of the plate of the bracket). Therefore, load given in the direction of the plate surface is directly received by the plate surface of the bracket. Therefore, an effect can be obtained in that strength can be further improved. In addition, since the pipe fitting groove 3c according to this invention has an opening which faces downwardly any water which enters can drop from the groove and does not collect in it. Since the opposite ends of the pipe member 6 are open any water entering the pipe member 6 can flow out from those ends, and not collect in the pipe member 6. As a result, the pipe member and the bracket do not suffer from rust or corrosion. In this embodiment, the invention can be of course applied to the connecting portion between the first bracket 3 and the pipe member 6 as well as the connection portion between the second bracket 5 and the pipe member 6. As described above, since the present invention is structured as described above, the pipe member is connected to the bracket in such a manner that the pipe member is fitted within the fastening groove portion of the bracket in a state where the pipe nut has been inserted and fitted to the pipe member. Then, the bolt is driven from the bracket side. Furthermore, the pipe member is held by the fastening groove portion deeply such that a portion larger than its half portion is held. As a result, load given to the pipe member in the axial direction of the bolt can, of course, be effectively received and as well as load given in the direction of the plate surface, which is perpendicular to the above-described direction, can also effectively be received by the plate surface of the bracket. Therefore, the strength of connection established between the pipe member and the bracket can significantly be improved without a necessity of providing an independent reinforcing means because the characteristics of the bracket are directly effectively utilized, the characteristics being characteristics that a bracket is strong in the direction of its plate surface. Therefore, the strength of the established connection can assuredly be improved by a simple structure while eliminating a necessity of increasing the overall weight. Furthermore, the pipe member is received by the fastening groove portion deeply by a large portion exceeding the half of the pipe member. In this state, the two introduction surfaces of the fastening groove portion for receiving the pipe member are formed into parallel surfaces facing the direction of the tangent of the outer circumference of the pipe member as an alternative to the conventional circular arc shape which is formed along the outer surface of the pipe member to be fastened. As a result, the pipe member can easily be inserted and as well as the undesirable undercut state of the fastening groove portion in the mold removable direction can be prevented. Therefore, an effect can be obtained in that the bracket can be easily molded because it can be molded by the ordinary molding method. Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been changed in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

Claims: A pipe connecting structure for a pipe-type modular wiper apparatus comprising a bracket (3) to which a wiper motor (2) is fastened, a bracket (5) to which a wiper shaft (4) is rotatably coupled, a pipe member (6) extending between said brackets (3, 5) and connecting means for connecting each bracket (3, 5) to the pipe member (6), whereby each connecting means comprises a pipe nut (15) having a head (15a) and a bolt (13) having a head and a shaft which is arranged to engage said nut (15) and to tighten the head portion (15a) of the nut (15) towards the corresponding bracket (3, 5) to locate the bracket (3, 5) between the head of the bolt (13) and the head portion (15a) of the nut (15), characterised in that each bracket (3, 5) is shaped to define a fastening groove portion (3a, 3c) whose bottom groove portion is adapted to locate between the head of the bolt and the head portion (15a) of the nut, the fastening groove portion (3a, 3c) having a depth larger than the radius of the pipe member (6), whereby the pipe member (6) is received in said groove portion (3a, 3c) to a depth which exceeds said radius. A pipe connecting structure for a pipe-type modular wiper apparatus according to claim 1, wherein said fastening groove portion (3a, 3c) of said bracket comprises a semi-circular pipe fitting groove (3c), for receiving said pipe member, and at least one cylindrical nut fitting groove (3a) for fitting the pipe nut head portion (15a). A pipe connecting structure for a pipe-type modular wiper apparatus according to claim 2, wherein the depth at which said pipe member (6) is fitted into said pipe fitting groove (3c) is arranged in such a manner that said pipe member (6) can be fitted by a degree larger than the half a cross-sectional area of of said pipe member (6). A pipe connecting structure for a pipe-type modular wiper apparatus according to claim 2, wherein said pipe fitting groove (3) has two introduction surfaces (3b) through which said pipe member (6) is introduced, said surfaces (3b) are substantially parallel surfaces facing in a direction of a tangent (K) to the outer circumference of said pipe member (6). A pipe connecting structure for a pipe-type modular wiper apparatus according to claim 2, wherein said pipe nut (15) has an insertion intermediate portion (15b) which receives a threaded portion of the bolt (13), said insertion portion (15b) being inserted into said pipe member and folded back and along the inner surface of said pipe member which said bolt tightens the bracket against the pipe member. A pipe connecting structure for a pipe-type modular wiper apparatus according to claim 2, the lower portion of said pipe fitting groove (3) formed on said bracket is open and the upper portion of said pipe fitting groove forms the nut fitting groove (3a) in the longitudinal direction of the pipe fitting groove. A pipe connecting structure for a pipe-type modular wiper apparatus according to claim 2, wherein either end of said pipe member (6) is open.

Inventors: HOSHINO TAKASHI, HOSHINO, TAKASHI
Applicants: MITSUBA ELECTRIC MFG CO, MITSUBA ELECTRIC MANUFACTURING CO., LTD.
Application year: 1991
Main classification: B60S1
IPC codes: B60S1, F16B9, F16B37, F16B5, F16B1