DESC:FIELD OF INVENTION

The present invention relates to a system used in automobile assembly line for wheel nut torquing on different automobile models. In particular, the present invention relates to a multi-spindle system used on automobile assembly line. More particularly, the present invention relates to a Three PCD (Pitch-Centre-Distance) Single Wheel Multi Spindle System for wheel nut torquing of different automobile models.

BACKGROUND OF THE INVENTION

The automobile wheels include a predetermined number of holes for tightening the wheels on the wheel discs of the vehicles. The wheel-discs include a corresponding number of drilled or bored and tapped holes of the same size machined at a predetermined pitch circle diameter (PCD) by mounting the wheel disc on a dividing index table, which is rotated and located to make these holes of predetermined size at a predefined PCD. This indexing and rotating is continued till all the holes are drilled or bored and tapped on the wheel discs.

The use of multi-spindle systems on vehicle assembly-lines is well-known in modern automobile industry. Such multi-spindle systems are generally used in automobile assembly-lines for operations like wheel nut torquing. These multi-spindle systems are especially employed for drilling, tapping, boring and tightening and unscrewing of fasteners, e.g. screws or bolts on the wheels in automotive assembly lines. Such multi-spindle systems used in automotive industry normally function by locating a plurality of tool spindles provided on the periphery of a predetermined pitch circle diameter corresponding to the holes required to be drilled on the wheel discs.

From the production-quality point of view, the wheel-nut torqueing using an electrical tool was mandatory and also a critical joint to maintain the standardized and quality process of torqueing 5 joints simultaneously. Moreover, eliminating the second PCD was not a solution, since the prior-art multi-spindle systems model have to be continued for export productions.
Operator dependency would have increased with single tool torqueing for 5 joints on each wheel. There are total 4 sets of 5 joint on each wheel, i.e. 10 joints on the LHS and 10 joints on the RHS.

To plan a new system for additional PCD would have cost about Rs.75 lacs (Rs.1.05 Crores after taxation). Therefore, it is quite logical to modify the existing system for maintaining the quality of deliverable.

PRIOR ART

US 3848488A discloses multi-spindle hand screwing device or brace for tightening and unscrewing the wheel screw fastenings of motor vehicles. It comprises essentially a drive motor, a transmission unit, the adjusting device and the five screw spindles. Further, drive motor drives via a transmission unit a plurality of screw spindles provided at their free ends with a screwing implement and with the interposition in each case of a claw or dog coupling which automatically disengages at a predetermined torque and each screw spindle having a universal joint shaft having two joints, and the spindle end provided with the screwing implement being guided parallel in each case by a radially movable slide member which can be moved by a drive unit common to all the slide members.

However, the multi-spindle drilling system disclosed in US Patent 3,848,488 includes a complex multi-spindle system with common central pinion with other slide members.

Further, this prior art discloses arrangement of central gear and pinion on flywheel which increases overall weight of the system and along with cost. It does not throw light on integration of another PCD with existing two PCD.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:
An object of the present invention is to provide a simply configured multi-spindle system for automotive assembly lines.

Another object of the present invention is to provide a light-weight multi-spindle system for automotive assembly lines.

Still another object of the present invention is to provide a cost-effective multi-spindle system for automotive assembly lines.

Yet another object of the present invention is to provide a three-pitch circle diameter (3-PCD) assembling system for automotive assembly lines.

A further object of the present invention is to provide a 3-PCD, single wheel diameter assembling system for automotive assembly lines.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a modular multi-spindle system for wheel nut torquing for different models on an automobile assembly line, the system is a 3-PCD (Pitch-Centre-Distance) single wheel multi-spindle system comprising:

• a front plate made in a pentagonal configuration with five triangular arms extending away from a substantially circular central portion;

• a pivot bracket each fitted at either end of the respective arms of the pentagonal front plate;

• a corresponding universal coupling is fixed on each pivot bracket by means of a respective pivot pin for suspending a respective spindle therebetween; and
• each spindle couples a respective pair of larger stroke cylinder and smaller stroke cylinder fitted back to back;

wherein the multi-spindle system is adjustable for configuring a predefined pitch circle diameter (PCD) by varying the lengths of the outer larger stroke cylinders and the inner smaller stroke cylinders for the purpose of wheel balancing or changing tyres on an automotive assembly line of different automobile models.

Typically, the larger stroke cylinder is fitted the outer end of the respective spindle and the smaller stroke cylinder is fitted at the inner end of the respective spindle.

Typically, the pairs of outer larger stroke cylinder and inner smaller stroke cylinder are mutually congruent or fitted back to back inside the spindle and disposed along the axis thereof.

Typically, a respective bearing housing is fitted with an extension of extended end thereof on one side of the front plate on each of the spindles.

Typically, each bearing housings passes through the front plate and the other end thereof along with a respective suspension rod is fitted on a suspension bracket to facilitate the suspension of the entire multi-spindle system by means of a connector under the top suspension of automotive assembly line.

Typically, the spindles are adjustable on three different predefined pitch center diameters (PCDs) for catering to different vehicle models, preferably at 114.3 mm, 140 mm and 160 mm PCD for tightening of different wheels of the corresponding pitch center diameters by adapting to the wheels disc size to be assembled on the assembly line.

Typically, one of the predefined PCD is adjusted by pneumatically displacing the pairs of larger and smaller cylinders disposed inside each spindle of the system.

Typically, the spindles are adjusted at the first pitch center diameter (PCD) for tightening of the wheels on the wheels disc size of the corresponding vehicle model, preferably a Sports Utility Vehicle (SUV) model to be assembled on the assembly line.

Typically, the spindles are adjusted at the second pitch center diameter (PCD) for tightening of the wheels on the wheels disc size of the corresponding vehicle model, preferably a Multipurpose Vehicle (MPV) model to be assembled on the assembly line.

Typically, the spindles are adjusted at the third pitch center diameter (PCD) for tightening of the wheels on the wheels disc size of the corresponding vehicle model, preferably a Light Commercial Vehicle (LCV) model to be assembled on the assembly line.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings, wherein:

Figure 1 shows a perspective view of a three-PCD single-wheel multi-spindle system configured in accordance with the present invention and positioned on the right-hand side (RHS) of the automotive assembly line.

Figure 2 shows a perspective view of a three-PCD single-wheel multi-spindle system configured in accordance with the present invention and positioned on the left-hand side (LHS) of automotive assembly line.

Figure 3 shows a side-view of the arrangement of five cylinders of the three-PCD single-wheel multi-spindle system of Figure 2.

Figure 4 shows front-view of the arrangement of cylinders of the three-PCD single-wheel multi-spindle system of Figure 2.

Figure 5 shows a perspective view of a three-PCD single-wheel multi-spindle system configured in accordance with the present invention and positioned on the RHS during tightening of a wheel of the vehicle being manufactured on the automotive assembly line.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1 shows a perspective view of a three-PCD single-wheel multi-spindle system 100 configured in accordance with the present invention and suspended from the conventional suspension arrangement 10 and positioned on RHS of automotive assembly line (not shown) for final tightening or loosening bolts on wheels of the vehicle.

Figure 2 shows a perspective view of a three-PCD single-wheel multi-spindle system 100 configured in accordance with the present invention and suspended from the conventional suspension arrangement 10 and positioned on LHS of the automotive assembly line (not shown).

Figure 3 shows a detailed side-view of the arrangement of five cylinders of the three-PCD single-wheel multi-spindle system of Figure 2. It includes a pentagonal configuration of sets of spindles and cylinder mechanisms. The cylinders of different lengths are positioned "Back to Back", i.e. one cylinder of smaller stroke and the other cylinder of larger stroke for each spindle. Therefore, there are total 5 number of spindles 122, 124, 126, 128, 130, so these includes in all 5 cylinders of larger stroke 102, 104, 106, 108, 110 and 5 cylinders 112, 114, 116, 118, 120 of smaller stroke fitted inside the existing (e.g. EME5I-20J) spindles 122, 124, 126, 128, 130, as seen in this figure. The complete multi-spindle system 100 is completed via the front plate 140, as described in detail in the following with reference to Fig. 4. The multi-spindle system in these figures is configured for 114.3 mm, 140 mm and 160 mm PCD respectively, which relate to the applicant’s different vehicle models. However, the idea underlying the present invention is applicable to tightening of wheels having any pitch circle diameter (PCD), which can be easily configured by varying the lengths of the larger 102, 104, 106, 108, 110 and smaller stroke cylinders 112, 114, 116, 118, 120 shown here.

Figure 4 shows detailed front-view of the arrangement of cylinders of the three-PCD single-wheel multi-spindle system of Figure 2. The front plate 140 carries a plurality of pivot brackets (5 here) 150 at the outer ends of the system 100, i.e. at the outer diameter (e.g. O.D. of 799.3 mm here). Each of these pivot brackets 150 is used for fixing a corresponding universal coupling 152 by means of a respective pivot pin 154. This universal coupling 152 couples a respective larger stroke cylinder 102, 104, 106, 108, 110 congruent to a respective smaller stroke cylinder 112, 114, 116, 118, 120 on the respective spindle 122, 124, 126, 128, 130. A plurality of bearing housings 160 with a respective extension 162 is fitted on one side (on RHS in figure) of the front plate 140 on each of the spindles 122, 124, 126, 128, 130. The bearing housings 160 pass through the front plate 140 and their other ends 164 along with a respective suspension rod 172 are fitted on a suspension bracket 170 for suspending the whole multi-spindle system 100 by means of a connector 174 (see Fig. 1) under the existing top suspension 10 of the vehicle assembly line (not shown).

Figure 5 shows a perspective view of a three-PCD single-wheel multi-spindle system 100 positioned on RHS of the wheel disc W of a vehicle 200 being manufactured on the automotive assembly line. Accordingly, the outer ends of larger stroke cylinders of each spindle are fitted to the anvil end of existing fixture. This anvil end of existing fixture in turn is connected to the tool housing, which slides when the cylinders are operated. By selectively operating the cylinders, the multiple spindle system 100 can be adapted to the desired wheels disc size to be assembled on the vehicle assembly line. By activating the inner cylinders 112, 114, 116, 118, 120, the first or smaller PCD of 114.3 mm is configured to enable the tightening of wheels for a sports utility vehicle SUV model. By keeping both sets of inner 112, 114, 116, 118, 120 and outer cylinders 102, 104, 106, 108, 110 at home position facilitates to achieve the second PCD of 120 mm for Multipurpose vehicle (MPV) models. Whereas, activating the outer cylinders 102, 104, 106, 108, 110 configures the third or larger PCD of 160 mm for light commercial vehicle (LCV) model.

Therefore, this multi-spindle system can be used for different types of vehicles, i.e. vehicles having different wheel sizes, thus it substantially reduces the cost of wheel tightening machinery. It also makes the wheel tightening process quicker than the existing systems. The system 100 also includes additional stopper for positive positioning to achieve accuracy.

The important difference of the multi-spindle system 100 with the prior art described above is that in this system 100, the desired PCD is achieved by means of the pneumatic cylinder displacement, whereas in the prior art this was achieved by means of a motorized concept driven by a single shaft.

So, the present invention utilizes the pneumatic principle for its operation as against the electrical operation employed in the prior art. Moreover, the multi-spindle system 100 can bear higher torque reactions during wheel torquing. Thus, it is easier to configure and more accurate than the existing systems.

TECHNICAL ADVANTAGES & ECONOMIC SIGNIFICANCE

This multi-spindle system configured in accordance with the present invention has the following advantages:

• Reduces the cycle time to do it manually using single tool for 3rd PCD.

• Offers a world class manufacturing standard established 1st Time in OEM.

• Reduces costs.

• Good Return on Investment.

• Enables additional production volume.

• Reduces capital investment by saving of INR 75 lacs basic (Rs.1.05 Crores after taxation) for new system to meet the quality objective.

• Customer satisfaction enhanced.

• Quality interlocks added resulting to robust process.

• Eliminates operator’s fatigue thereby increases morale of the personnel.

• Enhances safety, therefor improves working environment.

• Establishes standardized process on the vehicle assembly line.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to imply including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention. The description provided herein is purely by way of example and illustration.

Although, the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person in the art would readily recognize that these embodiments can be applied with modifications possible within the spirit and scope of the present invention as described in this specification. Therefore, the skilled person can make innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies, in terms of their size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

While considerable emphasis has been placed on the specific features of the preferred embodiment described here, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiments without departing from the principles of the invention.

These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. ,CLAIMS:We claim:

1. A single wheel modular multi-spindle system for wheel nut torquing on an automobile assembly line, the system is a 3-PCD (Pitch-Centre-Distance) single wheel multi-spindle system comprising:

• a front plate made in a pentagonal configuration with five triangular arms extending away from a substantially circular central portion;

• a pivot bracket each fitted at either end of the respective arms of the pentagonal front plate;

• a corresponding universal coupling is fixed on each pivot bracket by means of a respective pivot pin for suspending a respective spindle therebetween; and

• each spindle couples a respective pair of larger stroke cylinder and smaller stroke cylinder fitted back to back;

wherein the multi-spindle system is adjustable for configuring a predefined pitch circle diameter (PCD) by varying the lengths of the outer larger stroke cylinders and the inner smaller stroke cylinders for wheel nut torqueing on an automotive assembly line of different automobile models.

2. Multi-spindle system as claimed in claim 1, wherein the larger stroke cylinder is fitted the outer end of the respective spindle and the smaller stroke cylinder is fitted at the inner end of the respective spindle.

3. Multi-spindle system as claimed in claim 2, wherein the pairs of outer larger stroke cylinder and inner smaller stroke cylinder are mutually congruent or fitted back to back inside the spindle and disposed along the axis thereof.

4. Multi-spindle system as claimed in claim 1, wherein a respective bearing housing is fitted with an extension of extended end thereof on one side of the front plate on each of the spindles.
5. Multi-spindle system as claimed in claim 1, wherein each bearing housings passes through the front plate and the other end thereof along with a respective suspension rod is fitted on a suspension bracket to facilitate the suspension of the entire multi-spindle system by means of a connector under the top suspension of the automotive assembly line.

6. Multi-spindle system as claimed in claim 1, wherein the spindles are adjustable on three different predefined pitch center diameters (PCDs), preferably at 114.3 mm, 140 mm and 160 mm PCD for catering to different vehicle models for tightening of different wheels of the corresponding pitch center diameters by adapting to the wheels disc size to be assembled on the assembly line.

7. Multi-spindle system as claimed in any one of the claims 1 to 6, wherein one of the predefined PCDs is adjusted by pneumatically displacing the pairs of larger and smaller cylinders disposed inside each spindle of the system.

8. Multi-spindle system as claimed in claim 7, wherein the spindles are adjusted at the first pitch center diameter (PCD) for tightening of the wheels on the wheels disc size of the corresponding vehicle model, preferably a Sports Utility Vehicle (SUV) model to be assembled on the assembly line.

9. Multi-spindle system as claimed in claim 7, wherein the spindles are adjusted at the second pitch center diameter (PCD) for tightening of the wheels on the wheels disc size of the corresponding vehicle model, preferably a Multipurpose Vehicle (MPV) model to be assembled on the assembly line.

10. Multi-spindle system as claimed in claim 7, wherein the spindles are adjusted at the third pitch center diameter (PCD) for tightening of the wheels on the wheels disc size of the corresponding vehicle model, preferably a Light Commercial Vehicle (LCV) model to be assembled on the assembly line.

Dated: this day of 30th June 2016. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT