EP3408589A1

EP3408589A1 - Installation for the automated straightening of a spark plug electrode and associated automated straightening method

Info

Publication number: EP3408589A1
Application number: EP17706579.4A
Authority: EP
Inventors: Guilhem ROUSSEAU
Original assignee: Manufacture Francaise De Bougies
Current assignee: Manufacture Francaise De Bougies
Priority date: 2016-01-28
Filing date: 2017-01-27
Publication date: 2018-12-05
Anticipated expiration: 2037-01-27
Also published as: CA3011895C; CA3011895A1; ES2841301T3; FR3047250A1; US11156357B2; WO2017129915A1; US20180335207A1; EP3408589B1; FR3047250B1

Abstract

Installation (5) for the automated straightening of an electrode (12) of a spark plug (1) inside a receptacle (10) containing a fusible combustible substance (11) in the solidification phase, comprising: – a detection system (6) able to detect an initial position of the electrode inside the receptacle; – a mobile gripping system (7) able to grasp and move the electrode; – a control system connected to the said detection system for controlling it in terms of detection and receiving the said initial position and to the said gripping system for controlling it in terms of gripping and of movement, starting from a rest configuration as far as an initial configuration in which the said gripping system grasps the electrode in its initial position and then as far as a final configuration in which the said gripping system has straightened the electrode vertically. The present invention finds an application in the field of spark plug production lines.

Description

The present invention relates to an automated straightening installation of a candle wick inside a receptacle containing a fusible combustible material in the solidification phase, and to the associated automated straightening method.

The invention is in the field of candle production lines shaped to fill the fusible fuel material receptacles and place wicks inside the receptacles, each candle thus comprising a receptacle containing a fusible fuel material and a wick.

In a conventional manner, the fusible combustible material, generally of the natural wax or paraffin wax type, is introduced into the receptacle in liquid form, with the presence of the wick generally supported at its lower end by a support placed in the bottom of the receptacle, then the Fusible fuel material cures to being completely frozen or solid, thereby immobilizing the wick taken in the solid fusible combustible material.

Referring to Figure 1 which illustrates a candle 1 comprising a receptacle 10 containing a fusible combustible material 1 1 and a wick 12 carried by a support 13 placed in the bottom 14 of the receptacle 10, it is conventionally observed a sag of the wick 12 , in particular as a result of gravity, as solidification of the fusible combustible material 1 1 takes place.

Such collapse consists of a deflection of the wick 12 which no longer extends along a vertical central axis 15 of the receptacle 10, leading to a decentering of its upper part, so that this upper part of the wick 12 (which protrudes in part of the level of the fuse combustible material 1 1) approaches the walls of the receptacle 10. If the wick 12 is immobilized in such a collapsed position, it is customary for the manufacturer to remove the candle 1 which becomes unsellable for aesthetic reasons but especially of decrease in the duration of burning of the wick 12.

Referring to Figure 2, which illustrates the same candle 1 as Figure 1, it is preferable that the wick 12 is erected vertically within the receptacle 10, and more specifically in the center of the receptacle 10, so that the wick 12 extends along the vertical central axis 15 of the receptacle 10.

In order for the wick to be immobilized in such a vertical central position, at the end of the solidification of the combustible fusible material, several solutions are known. A first solution, known from US 7,736,145, is to use a dip tube within which is positioned the wick, the dip tube being supported by a bearing bearing on the edges of the receptacle. However, such a solution is particularly complex because it is necessary to manually place each wick in the tube, not to mention that it uses a first pouring combustible material fuse with the present plunger tube until complete solidification, then a second payment combustible material fuse without the dip tube.

A second solution, known in particular from documents US 2009/0092938, US 3,799,492, DE 36 20 607 and US 6 090 331, consists in using an upper bumper resting on the edges of the receptacle and traversed in its center by the upper end of the wick, such an upper stopper being provided to limit or block the movement of the wick at its high end. However, on a candle production line, at a higher or lower rate, it is difficult to manually position one by one each upper stopper on the receptacle while passing the wick through the center of the upper bumper, with a very limited benefit in terms of cost and efficiency.

A third solution, known from DE 23 28 267, consists of pneumatic means adapted to emit directed air flow to straighten the wick. However, such a pneumatic solution is not very accurate to replace a wick in the center of its receptacle, and is unsuitable for vertically straightening a sag lock.

The present invention aims to solve these disadvantages, providing an automated and effective solution to obtain vertically upright wicks in the center of the receptacles, and which is suitable for a high-speed candle production line.

For this purpose, it proposes an automated straightening installation of a candle wick inside a receptacle containing a fusible combustible material in solidification phase, said installation comprising:

a detection system capable of detecting an initial position of the wick inside the receptacle;

- A mobile gripping system adapted to grasp and move the wick relative to the receptacle;

a control system connected, on the one hand, to said detection system to drive it in detection and to receive said initial position of the wick relative to the receptacle and, on the other hand, to said gripping system for driving it in gripping and moving, from a rest configuration to an initial configuration in which said gripping system grasps the bit in its initial position and then to a final configuration wherein said gripping system has vertically straightened the wick within the receptacle.

Thus, the invention proposes, in place of known solutions of upper bumper or dip tube or air flow, to let the wick collapse naturally and to straighten vertically by means of a gripping system controlled by a control system, after having located or detected the initial position of the wick that has been depressed by the detection system; it being understood that if, in the initial position, the wick is not collapsed and is erected vertically, then the control system does not pilot any recovery operation by the gripping system.

According to one characteristic, the installation comprises a system for holding the candle receptacle in a fixed position during detection by the detection system and during gripping and moving the gripping system.

In a first variant, the receptacle may be fixed during detection by the detection system, then the receptacle is moved before being held stationary during gripping and moving the gripping system.

In a second variant, the receptacle moves continuously during the detection by the detection system and during the gripping and moving of the gripping system, so that the control system integrates this continuous movement to precisely control the system. detection and gripping system.

According to another characteristic, the gripping system comprises a gripper adapted for gripping the bit and attached to a mobile manipulator in a vertical direction and in at least one horizontal direction.

Depending on the size of the clamp, relative to the dimensions of the candle, the manipulator can be movable in a single horizontal direction or be movable in two orthogonal horizontal directions. In a particular embodiment, the gripping system is equipped with a device for regulating a force exerted vertically on the bit so as to allow vertical draft of the bit with controlled effort.

In a particular embodiment, the detection system comprises at least one detector chosen from the following group: a laser rangefinder, an ultrasonic rangefinder, a radar rangefinder, one or more infrared or visible cameras.

In general, the detection system is a non-contact system, so that this detection system does not come into contact with the wick which, by definition, is light and bathes in a fluid combustible material (not yet fixed or solid) , so that the detection system does not move the wick so as not to interfere with the handling of the gripping system to straighten the wick.

According to a possibility of the invention, the detection system comprises a movable rangefinder relative to the receptacle of the candle to scan the entire candle to detect the initial position of the wick.

According to another possibility of the invention, the rangefinder is movable horizontally.

The present invention also relates to an automated straightening station candle wicks disposed in successive rows in a horizontal transverse direction and conveyed in translation in a horizontal longitudinal direction, wherein the station comprises several automated straightening facilities according to the invention.

In such a station, an installation can be used for the straightening of several adjacent candles in the row (by moving the detection system and the gripping system from one candle to the other), and the control system can be common to the different installations.

The invention also relates to a candle manufacturing line comprising at least one automated straightening station according to the invention.

Advantageously, the production line comprises at least two automated straightening station according to the invention, these automated straightening stations being separated by a candle conveying system.

In this way, the straightening of the strands can be done at several distinct moments during the solidification phase of the material fuse fuel, for example at the beginning of solidification and in the middle of solidification; the conveying speed, the spacing between the stations and the rate of solidification of the combustible fuse material being parameters to be taken into account for straightening the wicks at the right times so that, once the fusible combustible material has solidified, the wicks are erected; vertically in the receptacles of the candles.

The invention further relates to a method for automated straightening of a candle wick inside a receptacle containing a fusible combustible material in solidification phase, said method comprising the following steps:

by means of a detection system, detecting an initial position of the wick inside the receptacle;

- By means of a mobile gripping system, grasp the wick in its initial position and move said wick to its upright within the receptacle.

Other characteristics and advantages of the present invention will appear on reading the detailed description below, of an example of non-limiting implementation, with reference to the appended figures in which:

- Figure 1, already described, is a schematic perspective view of a candle with the wick is collapsed;

- Figure 2, already described, is a schematic perspective view of a candle whose wick is straightened vertically;

- Figure 3 is a schematic perspective view of a portion of a candle manufacturing line according to the invention, with an automated straightening station framed by two conveyors;

FIG. 4 is a schematic perspective view of part of the automated straightening station of FIG. 3, zoomed on detection systems for automated straightening installations in accordance with the invention, where the detection systems are in a initial configuration at the beginning of the scan to detect the initial positions of the candle wicks;

FIG. 5 is a view similar to that of FIG. 4, in which the detection systems are in an intermediate configuration during the scanning; FIG. 6 is a view similar to that of FIG. 4, where the detection systems are in a final configuration at the end of the scanning;

FIG. 7 is a diagrammatic perspective view of a portion of the automated straightening station of FIG. 3, zoomed on detection systems and on a gripping system, where the gripping system has left a raised initial configuration and occupies a lowered configuration with its open clamp;

- Figure 8 is a view similar to that of Figure 7, wherein the gripping system is, with its closed gripper, in an initial configuration of seizure of a candle wick in its initial collapsed position;

- Figure 9 is a view similar to that of Figure 7, wherein the gripping system is, with its always closed clamp, in a final vertical straightening configuration of the wick; and

- Figure 10 is a view similar to that of Figure 7, wherein the gripping system is, with its open gripper, returned to a raised initial configuration.

With reference to FIG. 3, a candle making line 2 comprises at least one straightening station 3 framed by one or two conveyors 4, for example of the roller conveyor or conveyor belt type, which convey the candles 1 disposed in successive rows in a transverse direction Y horizontal, these rows of candles 1 being conveyed in translation in a longitudinal direction X horizontal and orthogonal to the transverse direction Y.

An inlet conveyor 4 conveys the rows of candles 1 at the inlet of the straightening station 3, and an output conveyor 4 conveys the rows of candles 1 at the outlet of the straightening station 3, or a single conveyor performs this conveying task. at the entrance and exit of the straightening station 3.

The candles 1 are as previously described with reference to FIGS. 1 and 2, in the sense that they each comprise a receptacle 10 containing a fusible combustible material 11 and a wick 12 carried by a support 13 placed in the bottom 14 of the receptacle 10. For each spark plug 1 at the inlet and the outlet of the straightening station 3, the fusible combustible material 1 1 is in the solidification phase, in other words the fusible combustible material 11 is still fluid, with the risk of sagging of the wick 12. as described above with reference to FIG. The straightening station 3 is designed to automatically straighten the collapsed wicks of incoming candles 1, row by row, in order to output candles 1 having their strands straightened vertically. It is obvious that this sagging of the wick may occur on all or part of the candles 1 of the treated row in the straightening station 3, or on any of the candles 1 of the treated row.

The straightening station 3 may be preceded by a spacing unit 8 capable of isolating the rows at the entrance of the straightening station 3, for example a blade separator, in order to feed the straightening station 3 with rows. candles sufficiently spaced from each other with respect to the duration of operations relative to straightening wicks.

The straightening station 3 comprises a system for aligning the row of candles 1 treated, otherwise called row aligner, which forms a system for holding each candle receptacle 1 in a fixed position in alignment in the transverse direction Y, during all the operations relating to the straightening of the locks.

For the straightening of the locks, the straightening station 3 comprises several automated straightening facilities 5, and in particular a straightening installation 5 every two candles 1 in the row, either

N straightening facilities 5 for rows of 2N candles 1.

In a more expensive variant and offering a shorter processing time, the straightening station 3 comprises as many straightening facilities 5 as candles 1 in a row. In a less expensive variant and offering a higher processing time, the straightening station 3 comprises a straightening installation 5 every three candles 1 in the row, or even every four candles or more.

With reference to FIGS. 4 to 10, a straightening installation 5 comprises at least one detection system 6 able to detect an initial position of the wick 12 inside the receptacle 10 of a candle 1; this initial position corresponding to the position of the wick 12 before the straightening operations, and this initial position may correspond to an undesired collapsed position or a vertically erect desired position.

It should be noted that the number of detection systems 6 may be different from the number of straightening installations 5 within a straightening station 3. In the example of FIGS. 4 to 10, the detection system 6 comprises an obstacle detector of the laser rangefinder type 60 movable in the transverse direction Y (in other words parallel to the row of candles 1) and placed in a raised manner relative to to the receptacles 10 of the candles 1, in order to scan the entirety of the candle to detect the initial position of the wick 12.

Alternatively, the laser rangefinder 60 is fixed and the candle 1 is movable in the transverse direction Y. In another variant, the detection system 6 comprises one or more infrared or visible cameras, the images of which will be the subject of a video processing to determine the initial position of the wick 12 relative to the receptacle 10.

In the illustrated example, the laser rangefinder 60 is movable in the transverse direction Y a distance provided to allow the laser rangefinder 60 to scan the entirety of two adjacent candles 1 in the row (or more depending on the number of laser rangefinders 60 provided in the straightening station 3).

During the operation of detecting the initial position of the wick 12, the laser rangefinder 60 moves in the transverse direction Y by emitting a laser beam 61 directed in the longitudinal direction X. When the laser beam 61 intersects the wick 12 ( which forms an obstacle for the laser beam 61), the transverse coordinate in the direction Y of the wick 12 is directly deduced, and the wick in turn returns the light beam and the laser rangefinder 60 calculates the phase difference between the emission and the reception to deduce the longitudinal coordinate in the X direction of the wick 12. The initial position of the wick 12 thus corresponds to the combination of these transverse and longitudinal coordinates.

With reference to FIGS. 4 to 6, the laser rangefinder 60 starts the operation of detecting the initial position of the wick 12 of a candle 1, starting from a starting situation (as illustrated in FIG. 4) in which the laser beam 61 passes on one side (for example on the left) of the candle 1, then is displaced in translation in the transverse direction Y, until the laser beam 61 scans the candle 1 and cuts the wick 12 (as illustrated in FIG. 5), and ends the detection operation in an end situation (as illustrated in FIG. 6), in which the laser beam 61 passes on the other side (for example on the right) of the candle 1 . Referring to Figures 7 to 10, a straightening installation 5 further comprises a gripping system 7 movable able to grasp and move the wick 12 relative to the receptacle 10, to straighten vertically in the center of the receptacle 10, starting from the initial position detected by the detection system 6 during the detection operation described above. For the sake of clarity, in FIGS. 7 to 10, only a gripping system 7 of a straightening installation 5 is illustrated, the gripping systems 7 of neighboring straightening facilities 5 being not drawn.

Between the detection operation and the straightening operation implemented by the gripping system 7, each candle 1 (or row of candles 1) remains fixed. Alternatively, it is conceivable that each candle 1 (or row of candles 1) is moved in the longitudinal direction X is a given pitch in order to place the candle 1 (or row of candles 1) below the system of candles. gripping, either continuously without interruption of the movement of the candles 1.

The gripping system 7 comprises a gripper 70 adapted to grip the bit 12 and attached to a manipulator 71 movable in a vertical direction Z and in the transverse direction Y and / or the longitudinal direction X.

In the example illustrated, the clamp 70 is positioned directly above the receptacle 10 in a rest configuration (as illustrated in FIG. 7) and has a width equivalent to or greater than the thickness of the wick 12, and the manipulator is movable in the vertical direction Z and also in both the longitudinal direction X and in the transverse direction Y to be able to precisely bring the gripper to grasp the wick 2, then move the clamp at the center of the receptacle and finally raise the clamp in the vertical direction Z to vertically straighten the wick 12 in the center of the receptacle 10.

In a first variant not shown, the clamp is positioned directly above the receptacle 10 and has a width equivalent to or greater than the dimension of the receptacle in the longitudinal direction X (ie its diameter if the receptacle is cylindrical), and when the clamp is closed, it defines a nip parallel to the longitudinal direction X and located in a median plane (or central plane) of the receptacle 10 along the longitudinal X. Thus, when the clamp is closed and seized the wick 12, it is then necessary to move the clamp 70 in the longitudinal direction X to replace the wick 12 in the center, then to raise the clamp in the vertical direction Z to vertically straighten the wick 12 in the center of the receptacle 10. In this first variant , the manipulator is movable in the vertical direction Z and in the longitudinal direction X. However, if this clamp is to be used for another candle 1 neighbor in the row, it is necessary that the manipulator is also movable in the transverse direction Y so to be able to bring it above this other candle 1.

In a second variant not illustrated, the clamp is positioned directly above the receptacle 10 and has a width equivalent to or greater than the dimension of the receptacle in the transverse direction Y (ie its diameter if the receptacle is cylindrical), and when the clamp is closed on the wick in the initial position, it defines a nip parallel to the transverse direction Y and located in a median plane (or central plane) of the receptacle in this transverse direction. Thus, when the clamp is closed and has grasped the wick, it is then sufficient to move the clamp in the transverse direction Y to replace the wick 12 in the center, then to raise the clamp in the vertical direction Z to vertically straighten the wick in the center of the receptacle before opening the clamp. In this second variant, the manipulator is movable in the vertical direction Z and in the transverse direction Y. This mobility in the transverse direction Y thus makes it possible to then bring the clamp 70 on top of another candle 1 next to the row. .

For the vertical movement of the manipulator 71, and therefore of the clamp 70, the manipulator 71 may comprise a pneumatic cylinder 72 advantageously equipped with a pressure regulator for regulating the force exerted vertically on the wick 12 when the clamp 70 is closed on the wick 12 and pulls it vertically.

For the transverse and / or longitudinal displacement of the manipulator 71, the manipulator 71 may comprise a motorized electrical system 73 single-axis or bi-axis, or tri-axis or mutli-axis.

In a variant not illustrated, the manipulator 71 is a robotic manipulator triaxis or multi-axis, so that the gripping system 7 forms a robotic gripper three-dimensional.

In order to control the straightening facilities 5, the straightening station 3 comprises a control system (not shown), in particular

Claims

of the microcontroller type, processor or computer terminal, which is connected to each detection system 6 and each gripping system 7, so that the control system provides the following sequences: - control of each detection system 6 (tripping control) laser beam 61 and moving control); receiving the measurement of the initial position of the wick relative to the receptacle made by each detection system 6; according to each measurement, candle by candle, control in gripping (opening / closing of the clamp 70) and in displacement (movement of the manipulator 71), from a rest configuration to an initial configuration in which the clamp 70 grasps the wick in its initial position and then to a final configuration in which the clamp 70 has vertically straightened the wick in the center of the receptacle 10. Of course the implementation example mentioned above has no character and other improvements and details can be made to the straightening facility, the straightening station and the production line, without departing from the scope of the invention where other types of gripping means can by For example, instead of a clamp and / or other types of non-contact detection means, for example, they can be made instead of a laser range finder. CLAIMS

1. Automatic straightening installation (5) of a wick (12) of candle (1) inside a receptacle (10) containing a combustible material fuse (1 1) in solidification phase, said straightening installation (5) ) including:

a detection system (6) able to detect an initial position of the wick (12) inside the receptacle (10);

- A gripping system (7) movable adapted to grasp and move the wick (12) relative to the receptacle (10);

a control system connected, on the one hand, to said detection system (6) to drive it in detection and to receive said initial position of the wick (12) relative to the receptacle (10) and, on the other hand, to said system gripper (7) for controlling it while grasping and moving, from a resting configuration to an initial configuration in which said gripping system (7) grasps the bit (12) in its initial position and then up to to a final configuration wherein said gripping system (7) vertically straightened the wick (12) within the receptacle.

2. straightening device (5) according to claim 1, comprising a system for holding the candle receptacle (10) in a fixed position during detection by the detection system (6) and during gripping and moving of the gripping system (7).

3. straightening device (5) according to claims 1 or 2, wherein the gripping system (7) comprises a clamp (70) adapted for gripping the wick (12) and attached to a manipulator (71) movable according to a vertical direction (Z) and in at least one horizontal direction (X; Y).

4. straightening installation (5) according to any one of the preceding claims, wherein the gripping system (7) is equipped with a device for regulating a force exerted vertically on the wick (12).

A straightening apparatus (5) according to any one of the preceding claims, wherein the detection system (6) comprises at least one detector selected from the following group: a laser range finder (60), an ultrasonic range finder, a radar telemeter, one or more infrared or visible cameras.

6. straightening installation (5) according to claim 5, wherein the detection system (6) comprises a rangefinder (60) movable relative to the receptacle (10) of the candle (1) to scan the entire candle (1) for detecting the initial position of the wick (12).

7. straightening installation (5) according to claim 6, wherein the rangefinder (60) is horizontally movable relative to the receptacle (10) of the candle.

8. Automatic straightening station (3) of the wicks (12) of candles (1) arranged in successive rows in a transverse direction (Y) horizontal and conveyed in translation in a longitudinal direction (X) horizontal, where said straightening station ( 3) comprises a plurality of automated straightening facilities (5) according to any one of the preceding claims.

9. Manufacturing line (2) of candles (1) comprising at least one automated straightening station (3) according to claim 8.

10. Manufacturing line (2) of spark plugs (1) according to claim 9, comprising at least two automated straightening stations (3), these automated straightening stations (3) being separated by at least one conveying system (4). candles (1).

1 1. A process for automated straightening of a wick (12) of candle (1) inside a receptacle (10) containing a fusible fuel material (1 1) in the solidification phase, said method comprising the following steps:

- by means of a detection system (6), detecting an initial position of the wick (12) inside the receptacle (10);

- By means of a gripping system (7) movable, grasp the wick (12) in its initial position and move said wick (12) to its upright within the receptacle.