FR2599647A1 - Process for manufacturing a gear-change lever and lever obtained - Google Patents

Abstract

The invention relates to a gear-change lever. According to the invention, it comprises a sphere 5 provided, at a position under the lower part, with a tubular lever body 4 and a short tubular connection part 6 under the sphere, which together form a unit. The invention applies especially to the motor-vehicle industry.

Description

The present invention relates to a method
manufacturing a gear shift lever.

All mature vehicles and machines
per engine available traditionally employ a
gearshift lever having construction such
than that shown in Figure 10 for example.

To form the lever shown in Figure 10, a
plastic sphere 102 is first attached to a surface
outer of a relatively short metal base tube 101
which extends directly forward, while fixing the
plastic sphere 102 to a lever retainer
(not shown), and a lever body 103 made of solid metal
is fully connected to the top of the tube
base 101 using welding means. Then a
screw 105 is attached to the upper end of the body
lever 103 to install the button 104 on the screw 105 and
then a pivot in metal tube 106 is integrally
connected to the bottom of the base tube 101 by
application of a welding medium to allow the
change rod 107 to be connected to pivot 106.

However, this change lever manufactured by
the conventional process described above is subjected to a
number of difficult problems which are
described below.

As the body 103 of the lever is substantially made
in a full round rod, when this lever is operated
of change which is connected to a predetermined part
gear change, vibrations produced by the
engine and transmission mechanism are directly
transmitted to the lever, thereby forcing this lever to vibrate,
itself, continuously and slightly.

Structurally, like the main components of any conventional shift lever
three units comprising a base tube 101, a sphere 102
and the body 103 of the lever you need a lot of
component parts and however the welding process is
essential to connect the body 103 of the lever and the base tube 101. Conversely, the welded part produced by the welding process easily causes a reduction in its mechanical strength during its period of use.

 In addition, given the large number of parts required, the assembly and control operations include many methods.

 Furthermore-, as the body 103 of the lever is itself made of a full round bar, each piece is of a specific weight and therefore, one cannot easily achieve a light construction.

 The main objective of the present invention is a new manufacturing method as well as a new construction of a gearshift lever having a light weight and a greater mechanical resistance, by sequentially applying processes comprising the following v d first, an expanded tubular part is formed in one end of a tube made of plastic and / or metal, which is then treated by a contraction means so that it can be converted into an elliptical shape and a connected part which are then respectively cold forged on the spherical parts and connected before possibly forming a hollow lever for changing into a plastic or metal tube.

 Another subject of the present invention is a new manufacturing process as well as a new construction of a gearshift lever making it possible to safely remove a large number of parts making it up and numerous control processes during the assembly operation thanks to the minimum number of welding and assembly processes that are required, by integrally forming the tubular lever body at the upper part and at the spherical / connected parts at the lower part, by applying the construction method of the invention.

 Another subject of the present invention is a new manufacturing process and a new construction of a gearshift lever which cannot undergo even the slightest vibration by effectively absorbing the vibrations of the engine and of the transmission mechanism thanks to the hollow part, by forming a hollow gear shift lever by applying a cold forging process.

 Another object of the present invention is a new manufacturing process as well as a new construction of a gearshift lever having a smooth surface, an extremely high dimensional precision, free from the need for applying finishing and modification processes. after completion of all the processes, and having a satisfactory appearance, by applying the construction process with a means of cold forging.

 Another subject of the present invention is a new manufacturing process as well as a new construction of a speed change lever allowing the regular expansion of the tubular shape when one end of the tube is expanded by a means forming a punch through a number of methods accomplished to sequentially dilate the diameter of the tube.

 Another subject of the present invention is a new manufacturing process as well as a new construction of a speed change lever allowing the tube pivot to be easily welded and the mechanical resistance to increase appreciably by forming a tapered part. along the surface edge of the connected part to force the thickness of the connected part to increase substantially at the same time, by applying pressure on the lateral surface of the connected part connected to the sphere in the tilted condition and in the direction the axis of the tube.

The invention will be better understood, and other objects, characteristics, details and advantages thereof will appear more clearly during the explanatory description which follows, given with reference to the appended schematic drawings given solely by way of example illustrating several embodiments of the invention and in which
- Figure 1 is a perspective view of a gear shift lever manufactured by the method according to the invention;
- Figure 2 is a sectional view showing the preliminary step of the first stage of the tube expansion process;
- Figure 3 is a sectional view showing the first stage of the tube expansion process;
- Figure 4 is a sectional view showing the preliminary step of the second stage of the tube expansion process;
- Figure 5 is a sectional view showing the second stage of the tube expansion process;
- Figure 6 is a sectional view showing the method of forming the proximal intermediate sphere of elliptical shape;
- Figure 7 is a sectional view showing the method of forming the sphere;
- Figure 8 is a sectional view showing the method of forming the tapered portion;
- Figure 9 is an enlarged sectional view showing the complete gear shift lever with cold forging process reflecting one of the preferred embodiments of the present invention; and
- Figure 10 is an exploded schematic view of a conventional gear shift lever.

 Referring now to the accompanying drawings, one of the preferred embodiments of the present invention will be described below.

 In FIG. 1, the gear shift lever 1 is integrally formed by combining methods and components according to sequential steps described below. By applying a cold forging process by a press operation, the spherical part 5 is fixed to the lower part of the tubular body 4 of the lever, the upper tube part 3 of which bends against the base 2 by a specific angle O such as 15 to 20O for example, the short tubular connection part 6 being fixed to the lower part of the spherical part 5 and the tapered part 7 being fixed to the lower surface of the connection part 6 respectively.

 The short tubular pivot 8 is fixed to the tapered part 7, by welding means.

 The tubular body 4 of the lever is provided with a tapered configuration, its lower part being of a larger diameter than its upper part. The upper end of the tubular body 4 is provided with a thread 9.

 The sphere 5 of the gearshift lever 1 is kept pivoting by means of the lever (not shown). The pivot 8 arranged at the lower end of the entire unit is connected to the change rod, while the button is fixed to the thread 9 at the upper end of the entire unit, so that it can obtain, for use, a complete gearshift lever.

 The step-by-step process for manufacturing the shift lever 1 will now be described below.

 As shown in Figure 2, first, the first forgings 11 having a specific surface configuration necessary for the first stage of the tube expansion process is formed. The tube 13 is then completely inserted into the cylindrical hole 12 provided in the flat-bottom forged part 11.

 The tube 13 is made of plastic or metal and of a specific length.

 Then, as shown in FIGS. 2 and 3, the expanded part of tube 15 of the first stage is formed at the part of the upper edge of the tube 13 by inserting the first punch 14 into this part.

 After having formed the dilated part of the first stage 15, the tapered end part 16 is formed between the tube 13 and the part 15.

 The position at which the first stage expanded tube part 15 is formed corresponds to the position of the sphere 5 of the complete gear change lever 1 shown in FIG. 1.

 The first forged part 11 is provided with an ejection pin as required.

 Then, as shown in FIG. 4, the second forged part 18 is formed for the position higher than the position which corresponds to the tapered end part 16, the second forged part 18 being provided with a surface 17 necessary for placing in the process of expanding the tube of the second stage having a diameter of the hole larger than that of the surface 10 necessary to accomplish the process of expanding the tube of the first stage. The tube 13 is then completely inserted into the cylindrical hole 19 provided at the bottom of the second forged part 18.

 Then, as shown in FIGS. 4 and 5, the second punch 20 with a diameter larger than the external diameter of the first punch 14 is inserted, from the opening of the expanded portion of the first stage 15, to form the expanded portion of the second stage 21 with a diameter larger than that of the dilated part of the first stage 15 at the upper edge of the tube 13. The process described above completes the first process.

 The preferred embodiment thus comprises the method of expanding the first stage tube shown in Figures 2 and 3 and the method of expanding the second stage tube shown in Figures 4 and 5. The implementation of these methods facilitates the method of expanding the tube by sequentially expanding the tube 13 by sequentially increasing the diameters of the means forming punches 14 and 20.

 It is needless to say that the ejection pins can be provided for the first forged part 11 and the second forged part 18 if this is necessary.

 Then, as shown in FIG. 6, the first mold 24 composed of two units comprising a lower mold 22 and an upper mold 23, facing each other, at the central part of the expanded part of the tube of the second stage 21, is formed.

 The lower mold 22 and the upper mold 23 are respectively provided with surfaces 25 and 26 giving an intermediate elliptical shape close to the sphere 5 shown in FIG. 1 so that they can be split into two parts between the two molds. The upper mold 23 is provided with the surface 27 of the connected part close to the connection part 6 shown in Figure 1, while the surface 27 is formed with the surface 26 to give the intermediate elliptical shape.

 Then, the tube 13 is completely inserted through the hole 28 of the lower mold 22. Then, the upper mold 23 which is movable against the stationary lower mold 22 is pressed to force the expanded part of the tube of the second stage 21 of FIG. 5 to deform and finally, the intermediate elliptical part 29 and the connected part 30 in FIG. 6 are respectively treated by a contraction means. This completes the second process.

 Then, as shown in FIG. 7, a second mold 33, formed of a pair of molds comprising a lower mold 31 and an upper mold 32 which face the central part of the intermediate elliptical part 29, is formed.

 The lower mold 31 and the upper mold 32 are respectively provided with spherical surfaces 34 and 35 corresponding to the sphere 5 of FIG. 1 so that they can be divided into two parts between the two molds.

The upper mold 32 is provided with a surface 36 compatible with the connection part 6 shown in FIG. 1 in connection with the spherical surface 35.

 Then, the tube 13 is completely inserted into the hole 37 of the lower mold 31. Then, the upper mold 32 which is movable against the stationary lower mold 31 is pressed to force the intermediate elliptical part 29 and the connected part 20 of FIG. 6 to deform respectively before possibly treating the sphere 5 and the connection part 6 of FIG. 7 by application of a contraction means. This completes the third process.

 Then, as shown in FIG. 8, the third mole 40 composed of a pair of molds comprising the lower mold 38 and the upper mold 39 which face each other, at the central part of FIG. 5, is formed.

 The lower mold 38 had the upper mold 39 are respectively provided with spherical surfaces 41 and 42 compatible with the external configuration of the sphere 5 so as to be able to divide into two parts between the two molds. The upper mold 39 is provided with the connection surface 43 compatible with the external configuration of the connection part 6 and with the tapered surface 44 compatible with the tapered part 7 of FIG. 1 in connection with the spherical surface 42.

 Then, the upper mold 39 which is movable against the stationary lower mold 38 is pressed to force the lateral surface of the connection part 6 to deform in the tilted condition and in the direction of the axis before possibly forming the tapered part 7 along the edge surface of the connection portion 6 to allow the thickness of the connection portion 6 to increase as shown in Figures 8 and 9. This completes the fourth method relating to the preferred embodiment of the present invention.

 We now refer to FIG. 9. By implementing the method described above, supposing that the thickness of the lower part of the sphere 5 and of the connection part 6 is respectively "t1" and " t2 ", the thickness of part 6 can be increased to be greater than the other.

 The tube 13 below the sphere 5 shown in FIG. 7 is first treated by several contraction methods (not shown) before being possibly deformed to the predetermined configuration shown in FIGS. 8 and 9.

 More particularly, the lower part 5 is treated in a tapered shape by a contraction means before possibly making the significantly tapered tubular lever body 4 that can be seen in FIG. 9.

 Then, a threading process is applied to the end of the tubular lever body 4 before forming the threaded part 9 shown in Figure 9 and finally, the body 4 is bent at a specific angle e to complete the formation of the change lever speed 1 shown in figure 1.

 In FIG. 1, the pivot 8 is integrally welded to the lower part of the tapered part 7. As previously mentioned, as the connection part 6 and the tapered part 7 have a sufficient thickness respectively and also thanks to the presence of the tapered portion 7, the welding operation can be easily performed. In particular, the fact of providing sufficient thickness significantly improves the mechanical strength of these basic members.

 Likewise, since the thickness of the threaded part 9 is also sufficient thanks to a similar processing means, the thread 9 can constantly maintain its predetermined strength.

 In addition, the tube 13 made of a plastic or metallic material, is contracted into a hollow change lever 1 by application of a cold forging process as previously mentioned. This method allows the manufacturer to produce new gearshift levers that are considerably lighter in weight than all conventional gearshift levers, however, welding or assembly processes can be saved significantly.

 The shifting lever reflecting the preferred embodiment of the present invention employs a considerably smaller number of parts than all conventional shifting levers, thereby resulting in a reduced number of control methods and more, providing a satisfactory aspect.

 In particular, according to the preferred embodiment, the hollow gearshift lever 1 is provided. The hollow construction allows the lever to effectively absorb the vibrations of the engine and of the transmission mechanism of motor-driven vehicles and the like. , which effectively prevents lever 1 from undergoing even the slightest vibrations while the engine and transmission mechanism are driven.

The shift lever according to the present invention is terminated by the cold forging process which gives a smooth surface and high dimensional accuracy of the finished products.

 As a result, neither a finishing method nor a modification method is necessary for the shift lever derived from the present invention.

 It is needless to say that the lower molds 22, 31 and 38 are respectively provided with ejection pins, as necessary.

Claims (6)

 1.- Method for manufacturing a gearshift lever, characterized in that it comprises  a first stage method where a punch means is inserted into one end of a plastic or metal tube of a predetermined length and then an expanded part of the tube is formed in a position corresponding to the spherical part of the lever body which is treated;;  a second stage process in which the surfaces of an intermediate sphere close to the sphere of the lever which is processed and a connected part close to the connector part are formed separately in a first mold means composed of two molds comprising molds lower and upper which face the central part of the expanded tube part and before possibly treating the intermediate sphere and the connected part by application of a contraction means by pressure process executed by said mold means; and  a third stage process in which the surfaces of the sphere corresponding to the sphere of the lever which is processed and the interconnected part corresponding to the connection part are formed separately in a second mold means composed of two molds comprising lower molds and upper which face the central part of said intermediate sphere near the sphere of the lever being treated before possibly treating said sphere and the connection part by application of a contraction means by a pressure process carried out by said means forming mold.  2.- Method according to claim 1, characterized in that the method of the first stage consists of a number of steps which sequentially expand the tube by gradually widening the diameter of the punching means.  3.- Method according to claim 1, characterized in that it further comprises a process in four stages in which, following the process of the third stage, the surface of the edge of the connection part is pressed in tilted condition and in the direction of the axis, before forming the tapered portion on the edge surface of the connection portion - to force the thickness of the connection portion to increase substantially at the same time.  4.- Gear shift lever characterized in that it comprises a sphere (5) provided in the position below the lower part of a tubular body (4) of the lever and a short tubular connection part (6) below said sphere, which are integrally connected to each other to form a unit.  5. A lever according to claim 4, characterized in that the aforementioned connection part (6) is of appreciable thickness thanks to the application of a compression means.  6.- Lever according to claim 4, characterized in that the lower end part of the connection part (6) is integrally connected to a tapered part (7) inclined in the direction of the axis to form a unit.