GB2193693A - Vehicle wheel suspension assembling and alignment - Google Patents

Abstract

A vehicle wheel suspension alignment adjustment process in which, before a suspension sub- assembly comprising a pair of spaced apart wheel attaching members (a), a subsidiary frame (2a) and component members of the suspension, is assembled to a vehicle body (1), a sub-assembly attaching position of the vehicle body is measured, a deviation of the attaching position thereof from a reference position thereof is detected, and an alignment adjustment taking this deviation into account of the sub-assembly is carried out so that the resultant adjusted alignment has a predetermined value under the condition that the sub-assembly is thereafter assembled to the vehicle body. This process makes it unnecessary to carry out alignment adjustment of the suspension on a completed vehicle. <IMAGE>

Description

SPECIFICATION Vehicle suspension alignment This invention relates to adjustment of wheel alignment of the wheel suspension of motor vehicles.

It has been a case hitherto that assembling a wheel suspension to a motor vehicle body has been carried out in such a manner that, as disclosed in Kokai Publication Sho 60 (1985)-71530 (Japanese Utility Model Registration), firstly, component members for a wheel suspension are so attached to a subsidiary frame that an alignment thereof has a predetermined value, and there is obtained a suspension sub-assembly, and this suspension sub-assembly is then assembled to a vehicle body on an assembly line. However, this can be inconvenient in that it sometimes happens that there is a deviation of the attached subassembly from a reference position therefor.

This deviation causes a displacement in wheel alignment and consequently thereafter it becomes inevitable that a wheel alignment adjustment of the suspension has to be carried out on the assembled complete car. It may be that this wheel adjustment work has to be carried out within a pit in a bad working environment so that a heavy burden is imposed on a worker. Much skill and much time are required, inhibiting improved productivity of completed cars.

According to the present invention there is provided a vehicle wheel suspension alignment adjustment process in which, before a suspension sub-assembly comprising a pair of spaced apart wheel attaching members, a subsidiary frame and component members of the suspension, is assembled to a vehicle body, a sub-assembly attaching position of the vehicle body is measured, a deviation of the attaching position thereof from a reference position thereof is detected, and an alignment adjustment taking this deviation into account of the sub-assembly is carried out so that the resultant adjusted alignment has a predetermined value under the condition that the sub-assembly is thereafter assembled to the vehicle body.This suspension alignment adjustment process makes it unnecessary to carry out alignment adjustment of-a suspension on a complete car, so that productivity can be improved.

The invention also provides an alignment apparatus, for carrying out an alignment adjustment before a suspension sub-assembly comprising spaced apart wheel attaching members attached to a subsidiary frame through suspension component members, is assembled to a vehicle body, wherein there is provided, on a machine base, clamp means for clamping and setting the subsidiary frame in position, simulation means whereby the suspension component members may be set in position in relation to the subsidiary frame at the same positions as those obtained at the time of actually assembling of the subassembly to the vehicle body, and detecting means for detecting alignment.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a top plan view of a suspension assembly line; Figure 2 is a perspective view of measuring equipment provided at a measuring station in the assembly line of Figure 1; Figure 3 is a front view of adjustment equipment provided at an alignment adjustment station in the assembly line of Figure 1; Figure 4 is a top plan view taken on line IV--IV in Figure 3; Figure 5 is a side view taken on line V-V in Figure 3; Figure 6 is a front view on a larger scale of an important portion of the adjustment equipment; Figure 7 is a side view, partly in section, of the portion of Figure 6;; Figure 8 is a side view on a larger scale of steering positioning equipment; Figure 9 is a perspective view of a portion at one side of a vehicle of a front suspension of the vehicle; Figure 10 is a rear view of the suspension portion shown in Figure 9; Figure 11 is a perspective view of a portion at one side of a rear suspension of the vehicle; and Figure 12 is a rear view of the suspension portion shown in Figure 11.

Referring to Figure 1, numerals 1 denote vehicle bodies, numerals 2 denote front suspension sub-assemblies, and numeral 3 denotes rear suspension sub-assemblies. The vehicle bodies are conveyed one-by-one by, for example, a hanger conveyor, into, and positioned at, an assembling station 5 provided in a vehicle body conveying passage 4. Front and rear sub-assemblies 2, 3 are assembled to the vehicle bodies from below by an assembling jig 6 disposed at the station 5.

As shown in Figures 9 and 10, the front suspension is a doublewishbone type having a knuckle arm b supporting a wheel hub and brake disk assembly a, an upper arm c, a lower arm d, a shock absorber unit e and a radius rod f. As assembled to the vehicle body 1, this front suspension sub-assembly 2 is associated with a subsidiary frame 2a (Figures 3, 4, 5, 6, 7, and 8) which is bolted to front portion of the vehicle body 1 and which is provided thereon with an engine E and the suspension component members just mentioned, excluding the upper arm c which constitutes part of the vehicle body 1, a tie rod g connected to a steering mechanism compris ing a steering gear housed in a portion of a rear beam of the subsidiary frame 2a, and a drive shaft h.

As shown in Figures 11 and 12, the rear suspension is a double wishbone type having a knuckle arm b supporting a wheel hub and brake disk assembly a, an upper arm c, a pair of lower arms d1, d2, a shock absorber unit e and a trailing arm i. As assembled to the vehicle body 1, this suspension sub-assembly 3 is associated with a subsidiary frame 3a which is bolted to a rear portion of the vehicle body 1 and which is provided thereon with the rear suspension component members just mentioned, excluding the upper arm c which constitutes part of the vehicle body. It will be understood that in the completed vehicle each wheel hub and brake disk assembly a serves as a wheel attaching member.

The sub-assemblies 2, 3 are conveyed into the assembling jig 6 through respective suspension conveying passages 7, 8. Then these sub-assemblies 2, 3 are assembled to the vehicle body 1, the subsidiary frames. 2a, 3a being bolted to the vehicle body 1 at predetermined positions. Each bolt insertion opening made in each of the subsidiary frames 2a, 3a is made comparatively so large in diameter as to provide an allowance of displacement from a position of an attaching opening made in the vehicle body 1. Thus each of these subsidiary frames 2a, 3a may be bolted at a given attaching position to the vehicle body 1 that has been calculated from a reference opening in the vehicle body 1.

The upper arm c is previously attached to the vehicle body 1. If it is attached to a position deviated or dislocated from a reference position, then even if each of the subsidiary frames 2a, 3a is attached correctly at a reference position, there results an error in wheel alignment when the sub-assembly is assembled to the vehicle body. For preventing this, in the illustrated example, a measuring station 9 is provided in the vehicle body conveying passage 4 upstream of the assembling station 5.

At the measuring station 9 there are disposed two laterally spaced-apart measuring devices 10 for the front suspension. Each of the devices includes, as shown in Figure 2, pins 10b, 10b for inserting into subsidiary frame attaching openings of the vehicle body 1 and an engaging member 10c for engaging a knuckle joint portion of the upper arm c.

These pins 10b, 10b and the engaging member 10c are provided on an elevating frame 10a so as to be individually movable in two directions crossing one another at right angles. Similarly, there are disposed two laterally spaced-apart measuring devices (not illustrated) for the rear suspension, each of which has the same construction as the measuring devices for the front suspension. Respective moved amounts of these pins 10b, 10b and the engaging member 10c are inputted to a computer 10d for detecting respective deviations of the subsidiary frame attaching openings and the upper arm c from their respective reference positions.Additionally, alignment adjustment stations 11, 12 are provided in the suspension conveying passages 7, 8 so that an alignment adjustment of each sub-assembly may be carried out, based on the deviation data, at each of these alignment adjustment stations 11, 12.

At the alignment adjustment station 11 on the front suspension conveying passage 7, there is provided the adjustment equipment 13 shown in Figures 3 to 5.

The equipment 13 includes, on a machine base 14, a lift 15 for lifting upwards the subassembly 2 conveyed thereinto; four clamps 16 situated at the front, rear, left and right for holding in a predetermined position the subsidiary frame 2a of the lifted-up sub-assembly 2; left and right knuckle supports 17 that can be brought into abutment with the respective lower arms d and that then serving to push upwards and support the respective knuckle arms b, in relation to the subsidiary frame 2a, at the same swung movement positions as those obtained at the time of actually assembling the sub-assembly to the vehicle body; and left and right knuckle positioning devices 18 each having an engaging member 18a for being inserted from above into and in engagement with a joint portion which is an upper end of each knuckle arm b.

Each engaging member 18a is adjustable in position, in accordance with a position for attaching the upper arm attached to the vehicle body, by means of a cross slider 18b. Thus, by the knuckle supports 17 and the knuckle positioning devices 18, there is established such a simulation arrangement that the knuckle arm b may be so held in relation to the subsidiary frame 2a as to have the same position as obtained at the time of actually assemblying the sub-assembly to the vehicle body.

Additionally, there is provided, on the machine base 14, two first detecting devices 19, 19 for detecting toe-in/toe-out and camber which are located to face the left and right wheel hub and brake disk assemblies a, a; two second detecting devices 20, 20 for detecting caster which are located to face the left and right knuckle arms b, b; and the steering positioning equipment 21 (Figure 8) for detecting a neutral positon of the steering mechanism and for serving to keep this mechanism at the neutral position.

In more detail and with reference to Figures 6 and 7, each of the clamps 16 includes a receiving seat 16b having a positioning pin 1 6a for the subsidiary frame 2a and is moved to rise and fall by a piston and cylinder arrangement 16c. A clamp arm 16e moved by a piston and cylinder arrangement 16d is at tached to the receiving seat 16b. Each clamp 16 is operated in such a manner that, under the condition that the sub-assembly 2 is lifted up by the lift 15, the receiving seat 16b of the clamp is raised. The lift 15 is then lowered so that the subsidiary frame 2a is received on the receiving seat 16b. Thereafter the clamp arm 16e is closed to hold the subsidiary frame 2a at the predetermined position.

The knuckle support 17 on each side includes a guide block 1 7b which is moved upwards and downwards by a piston and cylinder arrangement 17a. An abutment seat 17c which is brought into abutment with a lower surface of the lower arm d is provided on the guide block 17b, through a bearing 17d, so as to be movable freely in the front and rear directions.

The knuckle positioning device 18 on each side includes a machine frame 1 4a that is upright on the machine base 14 and that is pm vided with a slider 1 8d which is movable downwards to a predetermined position by operation of a toggle lever 18c. The engaging member 1 8a is attached through the cross slider 18b, which comprises a first movable member 18b1 movable for adjustment in the front and rear directions and a second movable member 1 8b2 movable for adjustment in the left and right directions, to a lower end of a rod 18e extending vertically downwards from the slider 18d. By the cross slider 18b, the engaging member 18a is adjustable in position in any of front, rear, left and right directions.Reference 1 8f denotes a piston and cylinder arrangement for upwardly moving the slider 18d.

The first detecting device 19 on each side includes a detecting head 1 9c facing the wheel hub and brake disk assembly a and supported so as to be movable forwards and rearwards on a slide base 19b. This base 19b is moved to advance and retreat by a piston and cylinder arrangement 1 9a in relation to the wheel hub and brake disk assembly a side. Attached to the head 19c are a centering pin 19d for mounting into an axle centre of the assembly a; a pair of front and rear toe-in/toe-out detecting elements 19e, 19e, each comprising a non-contact type distance sensor; and a pair bf upper and lower camber detecting elements 19f, 19f, each comprising also a non-contact type distance sensor.Under the condition that the head 1 9c is positioned in relation to the assembly a by the centering pin 19d, the distance in relation to a wheel attaching standard surface a1 of the assembly a may be measured by each element 19e, 19f, and thereby the toe-in/toe-out may be calculated from the difference between the measured values obtained by the pair of detecting elements 19e, 19e, and the camber may be calculated from the difference between the measured values obtained by the pair of camber detecting elements 19f, 19f.

The second detecting device 20 on each side includes a caster detecting element 20d comprising a non-contact type distance sensor. The element 20d is attached to a detecting head 20c which is moved, to advance and retreat to and from a position facing a caster measuring surface b1 (Figure 9) on the front face of the knuckle arm b, by a piston and cylinder arrangement 20a and a guide bar 20b. In this way the distance in relation to the measuring surface b1 may be measured by the detecting element 20d, and the caster may be calculated from this measured value.

The steering positioning equipment 21 includes, as shown in Figure 8, a socket 21a for engaging a pinion shaft j which is situated on an input side of the steering shaft and projects from a rear beam of the subsidiary frame 2a, a motor 21b for turning the socket 21a in regular and reverse directions, and a detecting device 21 c for detecting a turning angle of the socket 21a.

In'more detail, on the machine frame 14a there is provided a swingable frame 21e which is swingably moved between an upper escaped position and a lower operative position by a piston and cylinder arrangement 21d. The motor 21b with a reduction gear is mounted on the swingable frame 21e. A splined shaft 21 g connected through a torquelimiter 21f to the motor 21b extends downwards through a guide sleeve 21e' extending from the swingable frame 21 e. The socket 21a is connected to a lower end of the shaft 219 so as to be movable upwards and downwards. A gear 21h having teeth which are equal in number to the serrations of the pinion shaft j is attached to an upper end portion of the shaft 21.An approximation switch 21i is attached to a position of the swingable frame 21e that faces a circumferential surface of the gear 21 h so as to constitute the detecting device 21 c, the number of the teeth of the gear 21h passing across the front of surface of the switch 21i being counted by a counter connected to the switch 21 i, whereby the turning angle of the socket 21a may be detected.

References 21j denote each of lock rings which are provided on the lower end portion of the guide sleeve 21e' so as to be in two upper and lower stages whereby the socket 21a is retained resiliently at its two upper and lower positions by these rings 21j, 21j, and thus the socket 21a may be brought into engagement with the pinion shaft j when moved downwards manually to its lower position.

The adjustment procedures using the adjustment apparatus described are as follows: Firstly, the subsidiary frame 2a of the subassembly 2 is lifted up by the lift 15 and is held at its predetermined position in position by the respective clamps 16. Thereafter, the knuckle arm b on each side is pushed upwards by each knuckle support 17, to its swung position obtained at the time when the vehicle body weight is applied thereto, that is, the same position thereof obtained when the sub-assembly is actually assembled to the vehicle body. Thereafter, the engaging member 18a of each knuckle positioning device 18 is lowered by operation of the toggle lever 18c, and is brought into engagement with the joint portion, which is to be jointed with the upper arm c, of the upper end of each knuckle arm b.At this stage, in accordance with any deviation in any of front, rear, left and right directions, of the attaching position of the upper arm c to the vehicle body from a reference position, that has been previously detected by the measuring devices 10, the first movable member 18b, and/or the second movable member 18b2 of the cross slider 18b are moved for adjustment. In this way, the positional relation of the engaging member 18a with the subsidiary frame 2a is set to be equal to the positional relation of the knuckle joint portion of the upper arm c actually attached to the vehicle body with the subsidiary frame 2a.

Also in this way, the knuckle arm b constituting one of the suspension component members is held at the same position, in relation to the subsidiary frame 2a, as that obtained at the time of actually assembling thereof to the vehicle body. Thereafter, the neutral position of the steering mechanism is detected by the steering positioning equipment 21, and thereby the steering mechanism is set in this neutral position.

This detecting and keeping of the neutral position is carried out as follows. The socket 21a is brought into engagement with the pinion shaft j, and by operation of the motor 21b, the socket 21a is turned to a lock position thereof on one side, the shaft j being locked by movement of a rack of the steering mechanism, moved in conjunction with the shaft j, to one stroke end. Thereafter the socket 21a is turned to a lock position thereof on the other side of the shaft j now being locked by movement of the rack to its other stroke end.A turning angle 6 of the socket 21a between the two lock positions is detected by the detecting device 21c, and then the socket 21 a is turned in reverse through an angle 6/2 from the lock position on the other side by operation of the motor 21b controlled by a control mechanism (not illustrated).

When the phase of the serration of the pi- nion shaft j is detected from the position of the teeth of the gear 21 h, constituting the detecting device 21c, and when the socket 21a is turned in reverse through the angle 6/2 as explained above, if the serration of the shaft j is not positioned at a predetermined phase which is connectable to the steering shaft with the steering wheel set in a straight running position, the socket 21a is further turned within the range of an angle of one pitch of the serration, and when the serration becomes the desired predetermined phase, the turning of the socket 21 a is stopped, and this position is made the neutral position of the steering mechanism.

Thereafter, the toe-in/toe-out, camber and the caster of the left and right wheels are detected by the first and second detecting devices 19, 20, and the toe-in/toe-out adjustment is carried out by expansion and contraction operations of the tie rods g so that the toe-in/toe-out of each of the wheels is made equal to that of the other wheel, and in addition the adjustment of the camber and that of the caster are carried out by operations of the lower arm d and the radius rod f.

It can be that the deviation of the subsidiary frame attaching opening of the vehicle body 1 from the reference position becomes so large that the opening cannot be met with the opening of the bolt insertion opening of the subsidiary frame 2a, and the subsidiary frame 2a cannot be attached to the vehicle body at its reference position. In this case, the position of the engaging member 18a and the aimed adjustment of the alignment are calculated by the computer 10d, while taking the deviation of the attaching position of the subsidiary frame 2a into account, and an adjustment operation basing on the calculated resultant values is carried out.

The alignment adjustment at the alignment adjustment station 11 provided on the front suspension conveying passage 7 has now been explained.

Almost the same adjustment arrangment, but one not needing steering positioning equipment, is provided also at the alignment adjustment station 12 provided on the rear suspension conveying passage 8. At this station 12 the knuckle arm b of the rear suspension is set in position in accordance with a deviation of the attached position of the rear upper arm c to the vehicle body 7 from a reference position that has been measured at the measuring station 9, so that an alignment adjustment is performed.

The front and rear suspension sub-assemblies 2, 3 applied with the respective alignment adjustments as described above are, then, conveyed into the assembling station 5 and are assembled to the vehicle body 1, with the result that alignment adjustment working at the stage of the completed vehicle becomes unnecessary. Additionally, if, under the condition that the steering mechanism is set in its neutral position, the steering shaft, with its steering wheel set in its straight running position, is connected to the pinion shaft j, the left and right steering angles of the steering wheel become equal, and a steering angle adjustment at the stage of the completed car also becomes unnecessary.

With vehicle bodies manufactured by the same press lot, there takes place no change in a value of dispersion in attaching position of the upper arm c from the reference position. When, however, the vehicle bodies are manufactured by different press lots there can be caused varied dispersion in attaching position of the upper arm c. Therefore, it is necessary that measuring at the measuring station 9 and the alignment adjustments at the adjustment stations 11, 12 as described above are carried out, and based on the adjustment values, the alignment adjustments of the subsequent sub-assemblies 2, 3 are carried out.

In summary, prior to attaching the sub-assembly to the vehicle body the deviation of the suspension attaching position of the vehicle body from a reference position is measured, and an alignment adjustment of the suspension sub-assembly that takes this deviation into account is carried out, and thereafter the sub-assembly thus adjusted in wheel alignment is assembled to the vehicle body, so that wheel alignment adjustment after the completition of a vehicle becomes unnecessary, resulting in a large improvement in productivity.

Claims (8)

1. A vehicle wheel suspension alignment adjustment process in which, before a suspension sub-assembly comprising a pair of spaced apart wheel attaching members, a subsidiary frame and component members of the suspension, is assembled to a vehicle body, a sub-assembly attaching position of the vehicle body is measured, a deviation of the attaching position thereof from a reference position thereof is detected, and an alignment adjustment taking this deviation into account of the sub-assembly is carried out so that the resultant adjusted alignment has a predetermined value under the condition that the sub-assembly is thereafter assembled to the vehicle body.

2. A suspension alignment adjustment process as claimed in Claim 1, wherein the suspension component members are moved in relation to the subsidiary frame in accordance with the detected deviation and are set in the same positions as those obtained at the time of actually assembling the sub-assembly to the vehicle body, and under this condition the alignment adjustment is carried out.

3. A suspension alignment adjustment process as claimed in Claim 2, wherein when the sub-assembly is provided with a steering mechanism, a neutral position of the steering mechanism is detected, and under the condition that the steering mechanism is kept at its neutral position, the alignment adjustment including that of toe-in/toe-out is carried out.

4. A vehicle wheel suspension alignment process, substantially as hereinbefore described wih reference to the accompanying drawings.

5. An alignment apparatus for carrying out an alignment adjustment before a suspension sub-assembly comprising spaced apart wheel attaching members attached to a subsidiary frame through suspension component members, is assembled to a vehicle body, wherein there is provided, on a machine base, clamp means for clamping and setting the subsidiary frame in position, simulation means whereby the suspension component members may be set in position in relation to the subsidiary frame at the same positions as those obtained at the time of actually assembling of the subassembly to the vehicle body, and detecting means for detecting alignment.

6. An alignment adjustment apparatus as claimed in Claim 5, wherein the suspension component members are those of a double wishbone suspension having a pair of knuckle arms; wherein the simulation means comprises a pair of knuckle supporting means for pushing upwards and supporting respective knuckle arms in relation to the subsidiary frame, at the same swung-movement positions as those obtained at the time of actual assembling thereof to the vehicle body, and a pair of knuckle positioning means each having a positional adjustment engaging member for engaging a joint portion, which is to be attached to the upper arm, attached to the vehicle body, of an upper end of the knuckle arm on each side; and wherein the detecting means for alignment comprises the first detecting means for toe-in/toe-out and camber facing the wheel attaching member on each side, and two second detecting means for caster facing the respective knuckle arms.

7. An alignment adjustment apparatus as claimed in Claim 5 or 6, wherein there is provided, on the machine base, a steering positioning means which comprises a socket for engaging a pinion shaft situated on an input side of the steering mechanism assembled to the sub-assembly, a motor for turning the socket in regular and reverse directions thereof, and a detecting device for a turning angle of the socket.

8. An alignment apparatus for carrying out an alignment operation before a suspension sub-assembly is assembled to a vehicle body, substantially as hereinbefore described with reference to the accompanying drawings.