GB2213753A

GB2213753A - Taper rolling apparatus

Info

Publication number: GB2213753A
Application number: GB8900479A
Authority: GB
Inventors: Alexander Ian Wilson
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-01-14
Filing date: 1989-01-10
Publication date: 1989-08-23
Anticipated expiration: 2009-01-10
Also published as: GB2213753B; GB8800791D0; GB8900479D0

Abstract

Taper rolling apparatus includes a movable carriage 26 for gripping a deformable blank 13 and drawing it between a pair of rolls 12, 14 whilst moving the rolls towards each other. So that the production rate can be increased, mechanical handling apparatus includes roller means 36 for feeding the blank 13 into the movable carriage 26 in one direction and roller means 38 for ejecting it from the carriage in another direction. <IMAGE>

Description

Taper rolling apparatus.

The invention relates to taper rolling apparatus, that is to say apparatus for producing hot rolled product of tapered form.

Single taper leaf springs are now widely used for vehicle suspensions, and when producing such a spring by hot rolling it is necessary to control the degree of taper very accurately, that is to say, in the case of a double ended leaf spring, from its mid-portion towards its opposite ends.

This is usually effected using apparatus of the kind in which a deformable blank is first fed between an open pair of rolls and is then drawn between the pair of rolls whilst the position of at least one of said rolls is simultaneously controlled in accordance with the linear movement of a movable carriage to which the deformable blank is clamped, the deformable blank being generally drawn between the rolls a number of times to reduce it to the required form. Various means are employed for controlling the position of said at least one of the rolls in accordance with the linear movement of the movable carriage, and may include for example a master profile remote from the rolls and/or may include digital data from input equipment such as punched tape or card defining a specified taper.A relatively large deformable blank may require to be drawn between the rolls a considerable number of times to bring it to the required form. On the other hand, a relatively small blank will require relatively fewer passes, for example it may require to be drawn between the rolls only twice or three times to bring it to the required form (or only once in some very rare cases).

Taper rolling apparatus as just described is invariably associated with automatic mechanical handling apparatus by means of which the deformable blanks are fed in turn from a furnace in which they have been heated to said rolling apparatus, and by means of which they are subsequently transferred from the rolling apparatus after having been brought to the required form. The drawbar for drawing the deformable blank between the rolls is invariably provided with a wedge arrangement between movable jaws of which a root end of said blank can be placed to be clamped by a clamping pressure applied in a direction normal to the clamped surfaces. (If the finished product is a double ended taper leaf spring, it is of course formed in two quite separate rolling operations and the root end referred to is a parallel portion of the blank intermediate its ends).Consequently, the mechanical handling apparatus referred to has included mechanism for grasping and lifting from between the movable jaws a deformable blank which has just been brought to the required form, further mechanism for grasping and lifting the next deformable blank delivered from a furnace which is to be lowered between the movable jaws of the wedge arrangement, and means for displacing the two grasping and lifting mechanisms either simultaneously or in sequence so that the just deformed blank is cleared before the next blank is brought into position above the opened wedge arrangement.

The mechanical handling apparatus which has been used heretofore has been reasonably satisfactory when the deformable blank has been of relatively large size since the fact that said blank has required a correspondingly large number of passes between the rolls to bring it to the required form has resulted in the mechanical handling sequence of operations just described taking a relatively small part of the total time to produce the tapered product. However, when the deformable blank has been of relatively small size and has required to be drawn between the rolls only a relatively few times to bring it to the required form the sequence of operations of such mechanical handling apparatus has been seen to occupy a significant part of the total time to produce the tapered product.The object of the invention is to provide mechanical handling apparatus for use with taper rolling apparatus of the kind described so that the production rate of hot rolled tapered products can be significantly increased, especially when such products are of relatively small size.

According to the invention, there is provided taper rolling apparatus including a pair of rolls, a movable carriage for gripping a deformable blank and drawing it between said rolls, control means for controlling the position of at least one of the rolls in accordance with the linear movement of the movable carriage, and mechanical handling apparatus by means of which the deformable blanks can be fed in turn to the movable carriage to be drawn between the rolls and by means of which they can be transferred from the apparatus after rolling, said mechanical handling apparatus including means for feeding a deformable blank into the movable carriage in one direction to be gripped before being drawn between the rolls and further means for ejecting it from the movable carriage in another direction, after rolling, in readiness for a further deformable blank being fed into said carriage.The mechanical handling apparatus will preferably include means for lowering a deformable blank into the movable carriage and further means for ejecting it rearwardly from the movable carriage after rolling. The further means referred to for ejecting the deformable blank rearwardly from the movable carriage, after rolling, will preferably include at least one pair of rotatable pinch rolls which can be brought into engagement with side surfaces of the blank. The pinch rolls may be mounted for rotation about vertical axes at the upper ends of respective mounting members slidably mounted in the carriage for movement towards or away from each other under the influence of respective hydraulic rams.

Means for gripping a deformable blank in the movable carriage may be constituted by at least one pair of movable jaws actuated by respective hydraulic rams. The jaws will preferably be acted on by respective wedges which, when the hydraulic rams are extended, are caused to slide along converging walls of the carriage to cause the jaws to apply a clamping pressure to the deformable blank in a direction normal to the clamped surfaces. The means for gripping a deformable blank may be constituted by two pairs of movable jaws in which case said two pairs of movable jaws may be located on opposite sides of a pair of pinch rolls and to enable the two pairs of jaws to be acted on by a single pair of hydraulic rams each ram may be connected to a wedge member having stepped surfaces which act against the respective jaws simultaneously.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which: - Figure 1 is a side elevation of taper rolling apparatus embodying the invention, Figure 2 is a plan view, Figure 3 is a view in the direction of arrow 3 in Figure 1, Figure 4 is a diagrammatic perspective view of a part of said taper rolling apparatus, Figure 5 is a view similar to Figure 4 but illustrating diagrammatically the way in which heated blanks are fed to the apparatus and subsequently removed therefrom after having been brought to the required tapered form, Figure 6 is a plan view of a part of the apparatus which will be referred to presently, and Figure 7 is a side view thereof, Figures 8, 9 and 10 are sectional views on the lines 8-8, 9-9 and 10-10 respectively in Figure 7, and Figure 11 is a view similar to Figure 6 and illustrating a possible modification which will be described.

Referring now to Figures 1 to 10 of the drawings, the taper rolling apparatus there illustrated includes a rolling mill generally indicated 10 having a pair of rolls 12 and 14 the positions of which can be very accurately controlled in equal and opposite manner in accordance with the linear movement of a movable carriage generally indicated 16 for drawing a deformable blank B between the rolls. The means for controlling the positions of the rolls are not shown in the drawings but the reduction and consequent elongation of the blank brought about during a notional two passes of the blank between the rolls is shown in chain-dotted lines at one end of the blank in Figure 4.

The movable carriage 16 for drawing the deformable blank between the rolls is provided with a wedge arrangement (see Figure 6) between movable jaws 18,18 of which a root end of the blank B can be placed, said root end in the case of a double ended taper leaf spring being a parallel portion of the blank intermediate its ends. The movable carriage is mounted for reciprocating sliding movement on guide surfaces of a machine bed generally indicated 20 in Figure 1 and is connected at 22 to a powerful hydraulic ram 24 by means of which the carriage can be traversed to and fro.

Referring now in particular to Figures 6 to 10, the movable jaws 18,18 are actuated by respective hydraulic rams 26,26 which are mounted, as shown, in the movable carriage, the arrangement being such that, when the rams are extended, wedges 27,27 are caused to slide along converging upstanding walls 28,28 of the movable carriage to cause the jaws to apply a clamping pressure to the deformable blank in a direction normal to the clamped surfaces. The wedges 27,27 are connected together for simultaneous movement by means of a rotatably mounted shaft 30 carrying a spaced pair of pinions 32,32 which mesh with respective toothed rack portions 34,34 of said wedges.

As shown, the movable carriage is open topped to allow a heated deformable blank to be lowered into position between the movable jaws 18,18 when the latter have been opened to receive it. The manner in which a heated blank is moved into position above the movable carriage and then lowered into position between said jaws is shown semidiagrammatically in Figure 5, the blank in this illustrated arrangement being fed over the rolls of the mill on rollers 36 from a furnace (not shown).

From the position in which it is shown in full lines in Figure 5, in which very precise position it will have been arrested by a precision stop arrangement indicated 37 in Figure 1, the deformable blank B is lowered to the level of the movable carriage by means of a jaw arrangement which can grasp the blank in that precise position and lower it into the movable carriage. To enable the blank to move vertically downwards from the position in which it is shown in full lines in Figure 5, the cantilever mounted rollers 36 on which it is shown to be resting can be moved laterally, as shown in chain-dotted lines in Figure 3, on a parallelogram linkage 35, under the control of a hydraulic ram 39.The jaw arrangement which can grasp the blank and lower it into the movable carriage when the rollers 36 have been moved laterally is also shown in Figure 3, being indicated 41 and shown in full lines in a lowered position in which the blank carried thereby will be located at the constant pass line between the pair of rolls 12 and 14. The jaw arrangement is vertically adjustable, by means not shown, in vertical guides (not shown). However, a deformable blank which has been brought to the required form between the rolls is not removed from the movable carriage in the reverse manner. Instead it is ejected rearwardly from the movable carriage, again as illustrated semi-diagrammatically in Figure 5.

Having been ejected rearwardly, the finished blank (or semi-finished blank in the case of a double ended leaf spring only one end length of which has yet been brought to the required taper form) is received on a roller table 38.

Mechanism by means of which a deformable blank can be ejected rearwardly from the movable carriage is illustrated in Figures 6 to 10 and is constituted by a pair of rotatable pinch rolls 40,40 which can be brought into frictional engagement with the side surfaces of the blank. As shown, the pinch rolls are mounted for rotation about vertical axes at the uper ends of respective mounting members 42,42, the latter being slidably mounted in the carriage for movement towards or away from each other under the influence of respective double acting hydraulic rams 44,44. The pinch rolls are mounted at the upper ends of respective spindles 46 (see Figure 9) which are carried in bearings 48 in the mounting members, the lower ends of said spindles being connected to respective hydraulic motors 50,50.

The arrangement is such that when a deformable blank has been worked to the required form between the rolls 12,14 the movable jaws can be released and the pinch rolls brought into frictional engagement with the side surfaces of the blank by the pressurisation of the hydraulic rams 44,44.

The pinch rolls will then eject the workpiece rearwardly from the carriage. When the workpiece has been ejected, the pinch rolls will be moved away from each other by the retraction of the hydraulic rams 44,44 in readiness for a further deformable blank being received in the carriage.

Thus there is provided a taper rolling apparatus by means of which the rate of production of at least relatively small sized products will be significantly increased with respect to taper rolling apparatus used hitherto. This is because a fresh heated blank can be lowered into position between the jaws of the wedge arrangement of the movable carriage as soon as the latter arrives back at the initial starting position following a final reduction pass of the previous deformable blank between the rolls. The fresh heated blank may be being lowered into position between the jaws of the wedge arrangement as the previous blank is being ejected. In fact, the previous blank can be ejected rearwardly of the movable carriage as soon as its final pass between the rolls has been completed and before the movable carriage has completed its return movement to its initial starting position.

Various modifications may be made. For example, in Figure 11 there is illustrated a possible modification of the movable carriage in which two pairs of jaws 18,18 and 19,19 are provided, the further pair of jaws 19,19 having been added immediately to the rear of the pinch rolls 40,40.

As shown, to enable the two pairs of jaws to be acted on by the single pair of hydraulic rams 26,26, each ram is connected to a wedge member 27 having stepped surfaces 29,29 which act against the respective jaw 18 and the respective jaw 19 simultaneously.

It will be understood that the mechanical handling apparatus by means of which the deformable blanks can be fed in turn to the movable carriage to be drawn between the rolls and by means of which they can be transferred from the apparatus after rolling can be modified in numerous ways, the one essential requirement being that, by virtue of the open topped form of the movable carriage, a fresh blank is able to be entered into the carriage in one direction simultaneously with or immediately following a just rolled blank being removed from the carriage in another direction. The route by which the fresh blank approaches the movable carriage before being entered into it is of no consequence. Obviously, it need not necessarily be fed over the rolls of the mill as in the illustrated embodiment.

Although it will almost certainly be preferable for the fresh deformable blank to be lowered into the movable carriage and for a rolled blank to be ejected rearwardly from the carriage, the possibility exists that feeding and subsequent ejection of the blanks to and from the carriage could be in the reverse direction.

Claims

CLAIMS:

1. Taper rolling apparatus including a pair of rolls, a movable carriage for gripping a deformable blank and drawing it between said rolls, control means for controlling the position of at least one of the rolls in accordance with the linear movement of the movable carriage, and mechanical handling apparatus by means of which the deformable blanks can be fed in turn to the movable carriage to be drawn between the rolls and by means of which they can be transferred from the apparatus after rolling, said mechanical handling apparatus including means for feeding a deformable blank into the movable carriage in one direction to be gripped before being drawn between the rolls and further means for ejecting it from the movable carriage in another direction, after rolling, in readiness for a further deformable blank being fed into said carriage.

2. Taper rolling apparatus according to claim 1, in which the mechanical handling apparatus includes means for lowering a deformable blank into the movable carriage and further means for ejecting it rearwardly from the movable carriage after rolling.

3. Taper rolling apparatus according to claim 2, in which the further means referred to for ejecting the deformable blank rearwardly from the movable carriage, after rolling, includes at least one pair of rotatable pinch rolls which can be brought into engagement with side surfaces of the blank.

4. Taper rolling apparatus according to claim 3, in which the pinch rolls are mounted for rotation about vertical axes at the upper ends of respective mounting members slidably mounted in the carriage for movement towards or away from each other under the influence of respective hydraulic rams.

5. Taper rolling apparatus according to any one of the preceding claims, in which means for gripping a deformable blank in the movable carriage are constituted by at least one pair of movable jaws actuated by respective hydraulic rams.

6. Taper rolling apparatus according to claim 5, in which the jaws are acted on by respective wedges which, when the hydraulic rams are extended, are caused to slide along converging walls of the carriage to cause the jaws to apply a clamping pressure to the deformable blank in a direction normal to the clamped surfaces.

7. Taper rolling apparatus according to any one of claims 1 to 4, in which the means for gripping a deforable blank are constituted by two pairs of movable jaws, said two pairs of movable jaws being located on opposite sides of a pair of pinch rolls and to enable the two pairs of jaws to be acted on by a single pair of hydraulic rams each ram is connected to a wedge member having stepped surfaces which act against the respective * > jaws simultaneously.

8. Taper rolling apparatus constructed, arranged and adapted to operate substantially as hereinbefore described, with reference to and as illustrated by Figures 1 to 10 or Figure 11 of the accompanying drawings.

9. Taper rolling apparatus constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated by Figures 1 to 10 or Figure 11 of the accompanying drawings.