EP1324840A1

EP1324840A1 - Device for straightening the body and/or structures of a damaged motor vehicle

Info

Publication number: EP1324840A1
Application number: EP01978520A
Authority: EP
Inventors: Alain Couturier
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-10-11
Filing date: 2001-10-10
Publication date: 2003-07-09
Anticipated expiration: 2021-10-10
Also published as: WO2002030588A1; ATE302073T1; DE60112778T2; FR2815003B1; AU2002210627A1; FR2815003A1; EP1324840B1; US6973816B2; ES2247174T3; DE60112778D1; US20040000185A1

Abstract

A device for straightening the body and the structures of a damaged vehicle, includes a master cylinder filled with hydraulic fluid, wherein moves a master piston under the action of a rotary member actuated by a motor. A slave cylinder is connected to the master cylinder through a flexible conduit extending from said master cylinder, and is designed to be connected by some means to the body or to the structure to be straightened. The slave cylinder receives a slave piston, driven in translation inside the slave cylinder under the action of the hydraulic fluid, so as to be urged to strike the neighbourhood of the end of said slave cylinder connected to the body or to the structure, by being subjected to a return force tending to bring it back to its initial position.

Description

DEVICE FOR STRAIGHTENING THE BODY AND / OR STRUCTURES OF AN ACCIDENTED MOTOR VEHICLE

The present invention relates to a device for straightening and in particular restoring the bodywork or structures of damaged motor vehicles.

Traditionally, such reconditioning is carried out using hydraulic cylinders, integrating into various known systems such as the bracket, the vector system or even the jacking tower.

The installation of this type of system is long and tedious and requires to bear on the vehicle, or to securely fix the vehicle on the straightening system. Such a system is for example described in document EP-A-0 192 15 291.

The object of the present invention is to simplify these straightening and reconditioning operations, in particular by means of a portable device, capable of developing significant power. Such a system is reversibly fixed to the vehicle and can be oriented in a direction such that the straightening forces are exerted precisely in the desired direction. It is intended to enable traction or pressure forces to be produced without long and difficult handling of the structures in question, and without requiring the fixing of the vehicle, the mass of the latter being sufficient to prevent any displacement of 5 this during the straightening action.

Thus, the device according to the present invention comprises: "a transmitting cylinder, filled with hydraulic fluid, in which a transmitting piston moves under the action of a rotary member actuated in 0 rotation by means of a motor;

"a portable receiving cylinder, connected to the sending cylinder by means of a flexible conduit, said receiving cylinder being intended to be connected by any means to the bodywork or to the structure to be straightened and receiving a piston moving in translation within said cylinder under the action 5 of the hydraulic fluid, in order to strike the vicinity of the end of said receiving cylinder connected to the bodywork or to said structure. Advantageously, the frequency of movement or striking of the piston within the portable receiving cylinder is between 50 and 100 shots per second.

In addition, and according to an advantageous characteristic of the invention, the rotary member consists of a cam with a non-circular profile, of a connecting rod associated with a crankshaft, or of an equivalent member. It is intended to transform a rotary movement into an alternative translational movement.

In addition, in order to increase the speed of the piston, and therefore the impact power, the diameter of the portable receiving cylinder is less than the diameter of the sending cylinder. The increase in speed of the piston within the receiving cylinder takes place in the same proportion as the difference in effective sections.

According to an advantageous characteristic of the invention, the emitting cylinder communicates with at least one hydraulic fluid accumulation chamber, the accumulation volume of which is adjustable by means of a piston, the stroke of which is limited with a threaded rod, said piston closing off access to said accumulation chamber in the absence of external stress, under the action of compressed air or a calibrated spring.

According to another variant of the invention, said piston of the accumulation chamber is static, and is therefore not subjected to the action of compressed air or any calibrated spring. In this configuration, it becomes possible to adjust the quantity of hydraulic fluid capable of remaining in the receiving cylinder, so as to constitute a stop against which the receiving piston abuts when it is subjected to the restoring force tending to return to its original position.

The manner in which the invention can be implemented and the advantages which result therefrom will emerge more clearly from the example, of an embodiment which follows, given by way of nonlimiting indication in support of the appended figures.

Figure 1 is a schematic representation of the rotary member, in this case constituted by a cam, intended to illustrate the linear speed of the emitting piston as a function of the angular coordinates of the rotary member.

Figures 2 to 9 are schematic sectional representations of the device according to the invention under different operating phases. Figure 10 is a detailed schematic representation of a receiving cylinder provided with the receiving piston.

Figure 11 is a view similar to any of Figures 2 to 9, illustrating a second embodiment of the device according to the invention.

The device according to the invention is therefore very particularly described in relation to Figures 2 to 9. It is made of steel.

Basically, this first comprises a CE emitting cylinder, in which a PE emitting piston moves under the action of a rotary member.

In the example described, this consists of a cam C with a non-circular profile and, in particular, an ellipsoidal profile, which transforms a circular movement (that of the cam) into an alternating movement of the emitting piston PE. This cam is itself rotated by an electric or thermal motor (not shown) so as to induce the displacement of the PE piston in an alternating translational movement, and one of the ends of which comes to bear on the cam path . This cam C induces at each start of the cycle the thrust of the hydraulic fluid, and of the oil in this case contained by the device, by means of the emitting piston PE.

The system, as already said, is filled with a hydraulic fluid, in particular oil. On the other hand, oil cannot penetrate into the volume of rotation of the cam, the PE piston being for this purpose provided with an O-ring Jl.

This emitting cylinder communicates via a flexible conduit F with a portable receiving cylinder CR, intended to be fixed to the bodywork or to the structure to be straightened by any known means, and in particular by means of an anchoring piece.

A receiving piston PR slides within the receiving cylinder CR, and this under the action of the oil conveyed at this level by the flexible conduit F. It is therefore conceivable that taking into account the fact that the emitting cylinder CE and the flexible F are filled with oil, this oil is transmitted through the hydraulic hose F within the portable receiving cylinder CR by the displacements of the emitting piston PE, itself actuated by the cam C. At the end of the stroke, the receiving piston PR strikes the rear bottom FA of the receiving cylinder CR. As can be seen in FIG. 10, this receiving cylinder and the receiving piston have complementary shapes, such that the receiving piston is guided in its translation within the receiving cylinder. In order to avoid the introduction of oil into the translation chamber of said cylinder, the latter is provided at its two respective ends with O-rings J2 and J3, in a known manner.

The striking of the receiving piston on the rear bottom FA of the receiving cylinder generates a more or less powerful force, depending on the mass and the speed of the piston upon impact.

The receiving piston PR is then pushed back by a calibrated spring (not shown) or a compressed gas, so that it returns to its initial position of start of stroke, simultaneously leading to the return of the oil which had actuated it, which itself- same pushes back the emitting piston PE still pressing on the cam path, said cam C returning to its initial position. Each rotation of the cam causes an entire cycle of displacement of the respective pistons.

The number of cycles per second is a function of the speed of rotation of the cam. The higher the number of cycles per second, the higher the striking frequency, which can almost reach a continuum in terms of pressure or traction exerted on the structure to be straightened.

According to the invention, and as shown in FIG. 10, the receiving cylinder has two ends and in particular anchoring lugs respectively FP and FT depending on the nature of the action to be carried out at the level of the structure, the end FP intended to allow the exercise of pressure, and the end FT being intended to allow the exercise of traction.

The frequency of strikes, therefore cycles is advantageously between 50 and 100 strokes per second, causing a phenomenon of increase in the amplitude of the vibrations of the structure to be rectified when the period of the imposed vibrations or one of its harmonics becomes equal to the specific vibration period of the vehicle to be repaired, this resonance phenomenon participating very favorably in the recovery of the bodywork or damaged structures. According to an advantageous characteristic of the invention, the device also comprises means for adjusting the force generated by the striking of the receiving piston PR on the rear bottom FA of the receiving cylinder CR.

It is recalled that the cam C, driven in rotation by an electric or thermal motor, gives the emitting piston PE a uniformly varied rectilinear movement on the outward and return journey. The linear speed of the emitting piston PE is low at the start of the rotation of the cam C (close to the bottom dead center - Figure 1), increases in the middle of the race, to become weaker again at the end of the race (top dead center).

The stroke of the PE emitting piston as well as its diameter contribute to the fact that an amount of oil is displaced, much greater than the amount of oil necessary for the displacement of the receiving piston PR, the diameter of which is less than the diameter of the PE emitting piston. , which due to the differences in effective surfaces, increases in the same proportions the speed of the receiving piston PR.

It therefore suffices to choose the sector of the cam (FIG. 1) which will confer on the emitting piston PE, therefore via the oil, on the receiving piston PR at the time of impact the desired speed. The striking force of the receiving piston PR is proportional to the mass of the latter and to the square of its speed, so that it is adjustable.

To do this, the device comprises an oil accumulation chamber Al, communicating with the emitting cylinder CE. The volume of this chamber is adjustable by means of a threaded rod at the end of which a PI piston bears, capable of moving within this chamber. The stroke of the piston within the accumulation chamber A1 is therefore adjustable. In addition, one of the zones of said chamber, which cannot be filled with oil, is filled with a compressed gas or- incorporates a calibrated spring (not shown), intended to induce the plugging of said chamber by the piston. PI in the absence of external constraints.

Thus, if a moderate striking force of the receiving piston PR is desired, the threaded rod T is screwed to the maximum (FIG. 3) so as to prevent any displacement of the piston PI, and thus avoid the penetration of oil into the bedroom

Al. In this configuration, taking into account the fact that the oil volume is constant, and that it cannot therefore penetrate inside the accumulation chamber Al, the rotation of the cam C generates the thrust of the emitting piston PE, which in turn immediately induces the displacement of the oil at the level of the receiving piston PR, which thus comes to strike the rear bottom FA of the receiving cylinder at a fairly moderate speed ( Figure 4), since it corresponds to an area of the cam close to bottom dead center. In other words, according to this configuration, the sector involved in the cam gives low power to the piston PE, which in turn communicates a low speed to the piston PR, and consequently a low striking force.

The surplus oil expelled by the emitting piston PE is stored in a second accumulation chamber A2, also communicating with the emitting cylinder CE. In the absence of external stress, such as for example the thrust of the oil, this chamber A2 is also closed by a piston P2, maintained according to this shutter configuration either by a calibrated spring (not shown), but of constant return pressure greater than that of the spring acting on the piston PI, or by a gas compressed at a pressure greater than the pressure of the compressed gas acting on the piston PL In other words, the piston P2 requires oil pressure from the emitter cylinder greater than that capable of acting on the piston PI to generate its movement in the accumulation chamber A2, and as a corollary, the release of a temporary accumulation volume of the oil coming from said emitter cylinder CE. The calibration of the piston P2 is thus chosen so that it is greater than the force acting on the receiving piston PR by the calibrated spring or the compressed gas, so that the piston P2 cannot come into action before the receiving piston PR of the receiving cylinder came to strike the rear part FA of said receiving cylinder (Figure 5). In other words, the physical quantities governing the piston P2 are higher than those governing the return force of the receiving piston PR, which are themselves greater than those acting on the piston PI.

During the second phase of the cycle, the emitting piston PE goes down again, taking into account the movement of the cam track on which it rests, and allows the accumulation chamber A2, whose pressure generated by the piston P2 is very high , to empty itself (figure 6). The receiving cylinder CR, whose calibration of its return spring, or whose pressure of the compressed gas, are less than the corresponding physical quantities of the accumulation chamber A2, can then be emptied (FIG. 7). At the end of these various operations, cam C has completed its cycle and finds itself at its starting point, ready for a new cycle.

If, on the other hand, it is desired to have a greater striking force on the receiving piston, the threaded rod T is unscrewed (FIG. 8). Thus, the piston PI is immediately moved under the action of the oil expelled by the emitting piston PE, making it possible to store oil in the accumulation chamber Al until the piston PI abuts against the rod threaded (Figure 9), which induces the stop of its stroke. The accumulation chamber A1 comes into action first, because its return spring is calibrated the weakest, or the pressure of the compressed gas is the lowest compared to the corresponding physical quantities of the accumulation chamber A2 or of the receiving piston PR, as already specified above.

When the accumulation chamber A1 has stored an amount of oil corresponding to a low speed of the emitter piston, itself dependent on the position of the cam (see FIG. 1), the speed of the emitter piston increases, because corresponding to a area of the cam track where the speed is higher, and pushes the receiving piston PR, which in turn then strikes the bottom FA of the receiving cylinder CR, and this, at a higher speed than during the previous configuration, generating a greater strike force. The surplus oil expelled by the emitting piston PE is stored in the accumulation chamber A2, of which it is recalled that the setting of the return spring is greater or that the pressure of the compressed gas is higher.

In the second part of the cycle, the emitting piston PE goes back down and allows the accumulation chamber A2 to empty first, taking into account the characteristics of its return member (spring or compressed gas). Then comes the emptying of the cylinder. CR receiver, for the same reasons. Finally, there is the emptying of the accumulation chamber A1, taking into account the characteristics of its weakest return member.

The adjustment of the threaded rod T makes it possible, according to its position, to very precisely adjust the stroke of the piston PI in the accumulation chamber Al, and therefore to choose with precision the speed of the emitting piston PE as a function of the position of the cam C during the striking of the piston PR at the bottom FA of the receiving cylinder. We conceive in fact the number of infinite settings between the lowest speed, corresponding to a low lifting of the cam C, sufficient to induce the displacement of the receiving piston PR over its entire stroke, and the highest speed, corresponding to a greater lifting of the cam C, causing a maximum linear speed of movement of the sending piston PE, therefore of the receiving piston PR. This cam can be replaced by a crankshaft and a connecting rod connected to the PE emitting piston.

It can also be seen that the striking force can be varied in relation to the speed of the receiving piston, depending on the one hand, on the speed of rotation of the cam C, and on the other hand, on the adjustment of the volume of the accumulation chamber A1. One therefore proceeds by adjusting the accumulation chamber, by means of the threaded rod T, to select the striking force of the receiving piston. In addition, the speed of rotation of the cam C is also acted on, in order to determine the power or the striking force. This speed of rotation induces a more or less rapid displacement of the emitting piston PE and the receiving piston PR. As the striking force, as already mentioned depends on the mass of the PR piston, and the square of its speed, the more the speed increases the greater the striking force. This speed also influences the frequency of the shocks allowing the straightening.

The variation of the speed of the emitting piston PE can be obtained by various means, such as for example an electronic variator of the speed of the motor driving the cam C in rotation, or even by means of a speed variator with gears.

According to a variant of the invention illustrated in relation to FIG. 11, the piston PI of the accumulation chamber A1 is devoid of any restoring force. In other words, the zone of said chamber which is not accessible to oil does not have a calibrated spring or compressed gas, but communicates freely with the outside air. Said piston PI is therefore static during the operation of the device of the invention.

In fact, it simply comes to bear, under the action of the oil driven out by the emitting piston PE, or under the action of the oil driven out by the receiving piston PR during the action of the restoring forces generated at level of the latter by the calibrated return spring or by the compressed gas, at the free end of the threaded rod T, defining, as a function of the adjustment of the latter, a volume determined within the accumulation chamber Al.

In this way, taking into account the constant volume of the oil within the entirety of said device, the increase or decrease in the volume of oil within the accumulation chamber A1 has the effect of removing or bring the receiving piston PR closer to the striking zone FA, said receiving piston remaining permanently in contact with the oil, taking account of the abovementioned return forces to which it is subjected.

In other words, during the return phase of the receiving piston PR, that is to say after having struck against the bottom FA of the receiving cylinder CR, a more or less significant quantity of oil is likely to be maintained at within said receiving cylinder, capable of absorbing or even preventing the shock of the receiving piston against the upstream part PA of said receiving cylinder. This result proves to be of great importance in the operation and the durability of the device, taking into account the operating frequencies, and the feedback phenomena observed at such frequencies.

In addition, this embodiment of the invention makes it possible to maintain the adjustment of the striking force of the receiving piston PR on the bottom FA of the receiving cylinder CR. In fact, if said receiving piston PR is positioned in a zone relatively close to the bottom FA, due to the reduction in the available volume of the accumulation chamber A1, a slight displacement of the sending piston PE is necessary to push the receiving piston PR and hitting said bottom FA. This slight displacement of the emitting piston PE is generated by a sector of the cam C close to the bottom dead center. In other words, according to this configuration, the sector involved in the cam C confers a low speed to the sending piston PE, which in turn communicates a low speed to the receiving piston PR, and consequently a low striking force in FA.

If the volume of the accumulation chamber A1 is increased, the receiving piston PR away from the striking zone FA, so that a greater displacement of the sending piston PE is necessary, in order to push a sufficient quantity of oil so that the receiving piston PR strikes the bottom FA of the receiving cylinder CR. This greater displacement of the emitting piston PE is generated by a greater rotation of the cam C, and at the time of impact of the receiving piston PR on the bottom FA, the sector of the cam C in contact with the sending piston PE is located between the bottom dead center and the top dead center, giving the sending piston PE a faster speed. In other words, according to this configuration, the sector of the cam C involved at the time of the impact of the receiving piston PR in FA gives a high speed to the sending piston PE, which in turn communicates a high speed to the receiving piston PR , and as a corollary a significant striking force in AF.

We therefore proceed to a static adjustment of the piston PI, which does not undergo displacement during the operating cycle of the device.

We therefore understand the infinite number of settings between the two configurations described above, which allows the variation of the volume of the accumulation chamber Al by the action of the threaded rod T.

Claims

1. Device for straightening the bodywork and the structures of an accident vehicle, characterized in that it comprises: "a transmitter cylinder CE filled with hydraulic fluid, in which a piston transmitter PE moves under the action of a rotary member powered by a motor;

"a portable receiving cylinder CR, connected to the sending cylinder by means of a flexible conduit F extending from said sending cylinder, and being intended to be connected by any means to the bodywork or to the structure to be straightened, said receiving cylinder receiving a receiving piston PR, translating within the receiving cylinder under the action of the hydraulic fluid, in order to strike the vicinity of the end FA of said receiving cylinder connected to the body or to the structure, and being subjected to a force of reminder to return it to its original position.

2. Device for straightening the bodywork and the structures of an accident vehicle according to claim 1, characterized in that the restoring force tending to return the receiving piston PR to its original position is generated by air or compressed gas or a calibrated spring.

3. Device for straightening the bodywork and the structures of an accident vehicle according to one of claims 1 and 2, characterized in that the frequency of movement, and consequently the frequency of impacts generated by the receiving piston PR is between 50 and 100 shots per second.

4. Device for straightening the bodywork and the structures of an accident vehicle according to claim 3, characterized in that the frequency of displacement, and consequently the frequency of impacts generated by the receiving piston PR is granted to the resonance frequency of the structure to straighten or to one of its harmonics.

5. Device for straightening the bodywork and the structures of an accident vehicle according to one of claims 1 to 4, characterized in that the rotary member is constituted by a cam C with a non-circular profile or by a crankshaft associated with a connecting rod or an equivalent device, giving the emitting piston an alternative translational movement.

6. Device for straightening the bodywork and the structures of an accident vehicle according to one of claims 1 to 5, characterized in that the diameter of the receiving cylinder is less than the diameter of the emitting cylinder.

7. Device for straightening the bodywork and the structures of an accident vehicle according to one of claims 1 to 6, characterized in that the emitting cylinder CE communicates with at least one accumulation chamber Al of the hydraulic fluid, the volume of which is adjustable by means of a PI piston associated with a threaded rod T, said PI piston being in the absence of stress, maintained in the closed position of said accumulation chamber by air or compressed gas or a calibrated spring.

8. Device for straightening the bodywork and the structures of an accident vehicle according to claim 7, characterized in that the emitting cylinder CE communicates with a second accumulation chamber A2 also associated with a piston P2 maintained, in the absence of external stress, in the closed position of the accumulation chamber A2 by air or a compressed gas or a calibrated spring, these physical quantities being nevertheless higher than those exerting the restoring force of the receiving piston PR, they same superior to those of the means acting on the piston PI of the accumulation chamber Al.

9. Device for straightening the bodywork and the structures of an accident vehicle according to one of claims 1 to 6, characterized in that the emitting cylinder CE communicates:

On the one hand, with an accumulation chamber Al of the hydraulic fluid, the volume of which is adjustable by means of a piston PI associated with a threaded rod T, said piston PI not being subjected to any constraint other than that of the hydraulic fluid capable of penetrating within the volume which it defines within the accumulation chamber Al,

• and on the other hand with a second accumulation chamber A2 also associated with a piston P2 maintained, in the absence of external stress, in the closed position of said chamber by air or a compressed gas or a spring tared, these physical quantities being nevertheless higher than those exerting the restoring force of the receiving piston

PR.