METHOD FOR CONTROLLING THE HEAT TREATMENT OF A WHEEL SPIN BOWL

Abstract

The present invention relates to a method for controlling the heat treatment of a wheel hub of a motor vehicle, this hub having undergone quenching (1) as a heat treatment, characterized in that it comprises the steps of placing (3) the wheel hub on an axis of rotation, placing (4) an eddy current measuring probe in the hub of the wheel hub, rotating (5) the hub of the hub around the measuring probe, acquiring (6) the measurement signal from the measuring probe during the rotation of the hub, processing (7) this measurement signal to determine the quench thickness, and concluding that the quench thickness is deemed compliant if this thickness is between a non-zero minimum thickness and a predetermined maximum thickness. Figure 1

Description

Title of the invention: METHOD FOR CONTROLLING THE HEAT TREATMENT OF A WHEEL SPINDLE BOWL

[0001] The present invention relates to the control of the heat treatment of mechanical parts.

[0002] More particularly, the invention relates to a method for controlling the heat treatment of a wheel spindle bowl which has undergone quenching.

[0003] Certain mechanical parts for automobiles such as wheel spindle bowls are heat treated to improve their mechanical strength. These spindle bowls undergo, for example, quenching and tempering.

[0004] However, this heat treatment sometimes presents defects. It is therefore necessary to carry out checks after this operation in order to verify the conformity of the production.

[0005] So-called destructive tests render the part unusable because it is, for example, cut out. Furthermore, these destructive testing operations are long, the consumables used for cutting are expensive and cutting requires precision to succeed in this test. In addition, if a large number of parts are taken, this penalizes the cost of the test.

[0006] The invention aims to resolve the drawbacks of the prior art and provides according to the invention a method for controlling the heat treatment of a motor vehicle wheel spindle bowl, this bowl having undergone quenching as heat treatment, characterized in that it comprises the steps of: - placement of the wheel spindle on an axis of rotation, - placement of an eddy current measuring probe in the bowl of the wheel spindle, -rotation of the rocket bowl around the measuring probe, - acquisition of the measurement signal from the measuring probe during rotation of the bowl, - processing of this measurement signal to determine the thickness of the quenching, - conclusion that the thickness of the quenching is considered compliant if this thickness is between a non-zero minimum thickness and a predetermined maximum thickness.

[0007] The technical effect is to enable rapid and reliable measurement of the quenching thickness of the wheel spindle bowl and to avoid destructive testing.

[0008] Various additional features may be provided, alone or in combination:

[0009] In one embodiment, if the quenching thickness is not deemed to be compliant, the The wheel spindle is removed to a space dedicated to non-compliant parts.

[0010] In one embodiment, if it is non-compliant, the evacuated wheel spindle is cut and its quench thickness defect analyzed.

[0011] In one embodiment, beyond a determined number of consecutive checks deemed non-compliant, an alert is issued and the check process stopped.

[0012] In one embodiment, the determined number of consecutive checks deemed non-compliant is equal to three.

[0013] The invention also relates to a device for controlling the heat treatment of a vehicle wheel spindle bowl, characterized in that it comprises: - a rotation axis configured to receive the wheel spindle, - an eddy current measuring probe, - means for moving the measuring probe configured to place this probe in the bowl of the wheel spindle, - means of acquiring the signal from the measuring probe, - means for processing this measurement signal configured to determine the thickness of the hardening of the wheel spindle bowl, - processing means configured to conclude that the thickness of the quenching is compliant if this thickness is between a predetermined non-zero minimum thickness and a predetermined maximum thickness.

[0014] In one embodiment, this heat treatment control device further comprises means for counting the number of consecutive controls deemed non-compliant and alert means configured to be triggered when the number of consecutive controls deemed non-compliant reaches a predetermined number.

[0015] In one embodiment, this heat treatment control device comprises means for displaying the measurement of the thickness of the quenching.

[0016] Other features and advantages will appear on reading the following description of a particular, non-limiting embodiment of the invention, given with reference to the figures in which:

[0017] [Fig.l]: this figure schematically represents the steps of the control method of the invention.

[0018] [Fig.l] illustrates the heat treatment control method of the invention.

[0019] In this example, the mechanical part whose heat treatment is to be checked is a wheel spindle bowl. This spindle bowl has undergone a quenching step (block 1) and may also have subsequently undergone a tempering step (block 2). The tempering may be induction tempering.

[0020] In order to carry out the check, the wheel spindle is first placed on a rotation axis (block 3). The rotation axis and the bowl axis are the same. The rotation axis is motorized to allow the wheel spindle to rotate.

[0021] Then an eddy current measuring probe is placed in the bowl of the wheel spindle (block 4).

[0022] The rotation axis then rotates the wheel spindle, more precisely the bowl around the eddy current measuring probe, in a very short time (block 5). For example, the cycle time is 0.2 seconds.

[0023] During rotation of the wheel spindle bowl around the eddy current measuring probe, the measuring signal from the probe is acquired (block 6) and processed (block 7) to determine the thickness of the quench. The processing is preferably digital processing.

[0024] A display of the measurement of the quenching thickness can be provided on a screen to allow an operator to follow this measurement (block 8).

[0025] The measurement of the quenching thickness is then compared with the thickness thresholds (block 9). If the quenching thickness is between a predetermined minimum non-zero thickness and a maximum thickness, then in conclusion, the quenching thickness is judged to be compliant (block 10). If the quenching thickness is not between these thresholds, this quenching thickness is judged to be out of tolerance and the wheel spindle to be non-compliant.

[0026] The non-compliant wheel spindle is then removed (block 11) into a space dedicated to non-compliant parts. The non-compliant wheel spindle is then cut and its quench thickness defect analyzed (block 12).

[0027] It is also provided that beyond a determined number of consecutive checks deemed non-compliant, an alert is issued and the control process stopped. For example, if there are three consecutive parts out of tolerance, the control process is stopped and an alert is issued to call an operator.

[0028] This control method can be implemented by a device for controlling the heat treatment of a vehicle wheel spindle bowl. In accordance with the method described above, this device comprises:

[0029] -a rotation axis configured to receive the wheel spindle. This rotation axis is driven by a motor, for example an electric motor, in order to rotate the bowl of the wheel spindle once the probe is placed in the bowl.

[0030] - an eddy current measuring probe,

[0031] - means for moving the measuring probe configured to place this probe in the bowl of the wheel spindle,

[0032] - means for acquiring the signal from the measuring probe,

[0033] - means for processing this measurement signal configured to determine the thickness of the wheel spindle bowl temper,

[0034] - processing means configured to conclude that the thickness of the quenching is compliant if this thickness is between a non-zero minimum thickness and a predetermined maximum thickness.

[0035] The device may also comprise means for displaying the measurement of the thickness of the quenching.

[0036] The device may also comprise means for evacuating a wheel spindle deemed defective, for example an evacuation chute.

[0037] The device may also comprise means for counting the number of consecutive checks deemed non-compliant and alert means configured to be triggered when the number of consecutive checks deemed non-compliant reaches a predetermined number.

[0038] The invention has the advantages of ensuring continuous production without heat treatment defects, saving cycle time, avoiding unnecessary and lengthy checks when cutting rockets and consequently allowing a saving of time and parts because these rocket cutting operations are long and particularly consume cutting discs. Thus, machine downtimes will be less frequent.

Claims

Claims

1. Method for controlling the heat treatment of a motor vehicle wheel spindle bowl, this bowl having undergone quenching as heat treatment (1), characterized in that it comprises the steps of: - placing (3) the wheel spindle on an axis of rotation - placing (4) an eddy current measuring probe in the bowl of the wheel spindle, - rotation (5) of the spindle bowl around the measuring probe, - acquisition (6) of the measuring signal from the measuring probe during rotation of the bowl, - processing (7) of this measuring signal to determine the thickness of the quenching, - conclusion that the thickness of the quenching is considered compliant if this thickness is between a predetermined minimum non-zero thickness and a maximum thickness.

2. Method according to claim 1, characterized in that if the quenching thickness is not deemed to be compliant, the wheel spindle is evacuated (11) into a space dedicated to non-compliant parts.

3. Method according to claim 2, characterized in that the evacuated wheel spindle is cut and its quench thickness defect analyzed.

4. Method according to one of the preceding claims, characterized in that beyond a determined number of consecutive checks deemed non-compliant, an alert is issued and the control process stopped.

5. Method according to the preceding claim, characterized in that the determined number of consecutive checks deemed non-compliant is equal to three.

6. Device for controlling the heat treatment of a vehicle wheel spindle bowl, characterized in that it comprises: - a rotation axis configured to receive the wheel spindle, - an eddy current measuring probe, - means for moving the measuring probe configured to place this probe in the wheel spindle bowl, - means for acquiring the signal from the measuring probe, - means for processing this measuring signal configured to determine the thickness of the quenching of the wheel spindle bowl, - processing means configured to conclude that the thickness of the quenching is compliant if this thickness is between a non-zero minimum thickness and a predetermined maximum thickness.

7. Heat treatment control device according to the preceding claim, characterized in that it further comprises means for counting the number of consecutive checks deemed non-compliant and alert means configured to be triggered when the number of consecutive checks deemed non-compliant reaches a predetermined number.

8. Heat treatment control device according to claim 6 or claim 7, characterized in that it comprises means for displaying the measurement of the thickness of the quenching.

Images