FR3074709A1 - HAND TOOL FOR RECTIFYING THE DIAMETER OF A POSITIONING ELEMENT SUCH AS A CENTERING PIONE - Google Patents

Abstract

The invention relates to a tool (2) hand for grinding the diameter of a positioning element (100), such as a centering pin, the tool comprising: - a milling cutter (3), comprising a cylindrical body (30), one free end of which forms a cutting head (32); a tubular guide (4) having a centering portion (40) intended to be positioned on a base (102) of the positioning element, and a guide portion (42) for guiding translation of the body (30) of the cutter (3).

Description

Hand tool for rectifying the diameter of a positioning element such as a centering pin

The invention relates to the field of hand tools. More specifically, it relates to a hand tool allowing an operator to easily reduce the diameter of a centering pin or equivalent. The invention finds a very advantageous application in the field of motor vehicle assembly, but is not however limited to this particular field.

Motor vehicle assembly lines today involve the assembly of numerous parts comprising one or more positioning elements such as centering pins (also called indexing pilots). Such elements are provided to cooperate with orifices of complementary shape formed in the structure intended to accommodate the part concerned.

Figures 1a, 1b and 1c show an example of mounting a rear light unit 10 on the body 1 of a motor vehicle. As can be seen in FIG. 1b, the optical unit 10 is designed to be fixed to a reception structure 12 (generally known by the name of fire housing), integral with the body 1 of the vehicle. As shown in FIG. 1 c, which is a detailed view of FIG. 1b, the structure 12 comprises an opening 120 cooperating with a centering pin 100 of the optical unit 10. In order to facilitate its insertion, the centering pin 100 can present at its free end a portion of frustoconical shape or equivalent shape.

When mounting a part such as the optical unit described above, it may happen that the centering pin or pins present on the part have dimensions that are too large to be able to cooperate with the openings made in the receiving structure, for example. example because modifications to the part occurred after mass production had already started. In such a case, the assembly operators are forced to touch up the centering pins by hand using a knife, in order to reduce the diameter of the centering pins and bring this diameter to a suitable value. However, this work is relatively slow and imprecise, since it is carried out without a template. There is therefore a need for a hand tool making it possible to carry out such alterations more efficiently.

The object of the present invention is to remedy the drawbacks of the state of the art, and more particularly those described above, by proposing a hand tool, allowing the diameter of a plastic part such as a centering pin quickly and precisely.

To this end, the invention relates to a hand tool for the rectification of the diameter of a positioning element, such as a centering pin, the tool comprising:

- a cutter, comprising a cylindrical body having an axis of symmetry, one free end of which forms a cutting head;

- a tubular guide, comprising a centering part, intended to be positioned on a base of the positioning element, and a guide part intended to ensure the guiding in translation of the body of the cutter.

Thus, thanks to the guide which can be positioned directly on the element to be touched up, this guide ensuring the guiding in translation of the cutter manually actuated by an operator, the tool according to the invention allows manual rectification of the diameter of an element. plastic material such as a centering pin much more precisely and quickly than according to known manual methods. In addition, the tool according to the invention allows considerable gains in terms of repeatability, and therefore of quality, the final result no longer being dependent on the operator.

In one embodiment, the cutting head has a plurality of teeth, preferably two to four teeth, each tooth having a cutting edge.

In one embodiment, the teeth are regularly distributed around the axis of symmetry of the body.

In one embodiment, each cutting edge is oriented in an oblique direction relative to the axis of symmetry of the body, and preferably included in a radial plane relative to the axis of symmetry of the body.

In one embodiment, the radially internal ends of the cutting edges are inscribed in a circle of diameter equal to the final diameter of the positioning element, that is to say its diameter after rectification.

In one embodiment, the radially outer ends of the cutting edges are inscribed in a circle with a diameter greater than the initial diameter of the positioning element, that is to say its diameter before grinding.

In one embodiment, the free end of the teeth forms a translational stop surface of the cutter.

In one embodiment, the guide portion of the guide has an internal cylindrical shape, of internal diameter allowing the insertion and the guiding in translation of the body of the cutter in the guide.

In one embodiment, the positioning part of the guide has a shape complementary to the base of the positioning element, for example a frustoconical shape.

In one embodiment, the tool comprises a grip handle, connected to the body of the cutter by a connecting rod.

The present invention will be better understood on reading the detailed description which follows, given with reference to the appended drawings, in which:

- Figures 1a, 1b and 1c, already described, illustrate an example of arrangement of a rear optical unit on the body of a vehicle being assembled;

- Figure 2 is a general view of a tool according to the invention and a centering pin to be manually adjusted;

- Figure 3 is a partial sectional view of the tool of Figure 2;

- Figures 4a and 4b are views of the cutter of Figure 2;

- Figures 5a to 5c illustrate different stages of implementation of a tool according to the invention.

Figures 1a to 1c, already described, illustrate an example of use of a tool 2 according to the invention, an embodiment of which will be described below, in relation to Figures 2, 3, 4a, 4b , and 5a to 5c.

As shown in Figure 2, the tool according to the invention has two elements: a guide 4 and a cutter 3. In the example of Figure 2, the tool 2 is provided to correct the diameter of the centering pin 100 fitted to an optical unit 10, as shown in FIGS. 1 a to 1 c. In the example, the centering pin 100 comprises a base 102 of frustoconical shape, and a centering head 104, of generally cylindrical shape, of diameter A. The junction between the base 102 and the centering head is formed by a shoulder 106.

The cutter 3 comprises a body 30, of generally cylindrical shape with an axis of symmetry X, and one free end of which forms a cutting head 32. At the opposite end of the cutting head 32, the body 30 is connected to a handle 36 by means of a connecting rod 34. As shown in FIGS. 4a and 4b, which are respectively front and perspective views of the cutter 3, the cutting head 32 has a plurality of teeth 38 ( in the example, four teeth 38, regularly distributed around the axis of symmetry X of the body 30). Each tooth 38 has a face 380 included in a radial plane relative to the axis of symmetry X of the body 30 and defining a cutting edge 382. The cutting edges 382 are in an oblique direction relative to the axis of symmetry X of the body 30, so that the geometric surface defined by the rotation of the cutting edges 382 constitutes a truncated cone of larger diameter C (of value greater than the value of the diameter A, which corresponds to the initial diameter of the element to rectify), and of smaller diameter B (which corresponds to the final diameter of the element to be rectified, that is to say the desired diameter after rectification). The angle formed by each cutting edge 382 with the axis of symmetry X (which corresponds to the half-angle at the top of the truncated cone mentioned above) will be between 45 ° and 60 °, and is in the example equal to 45 °.

The guide 4 is tubular in shape and comprises a centering part 40 and a guide part 42. The centering part 40 is intended to be positioned on the centering pin 100, by form cooperation with the base 102 of the centering pin 100. To this end, the centering part 40 of the guide 4 has an internal shape complementary to that of the base 102, in the example a frustoconical shape. Note that the centering part 40 of the guide 4 can be adapted to the shape of the base of the element whose diameter is to be corrected, whether this shape is of circular, rectangular, square section, etc. The guide part 42 is intended to receive and guide in translation the body 30 of the cutter 3. For this purpose, the guide part 42 has a cylindrical shape with an internal diameter E close to the external diameter D of the body 30 of the cutter 3 , so as to allow the body 30 to be inserted into the guide 4, with a clearance allowing correct guiding of the cutter 3, as shown in FIG. 3. This clearance will also be sufficient to allow the rotation of the body 30 inside the guide part 42.

FIGS. 5a to 5c represent the first steps in implementing a tool according to the invention. The first step, illustrated by FIGS. 5a and 5b, consists in positioning the guide 4 on the element whose diameter must be manually corrected, in the example the centering pin 100 previously described. This positioning is done simply by fitting the guide 4 (and more precisely the guide part 42 thereof) on the base 102 of the centering pin 100. Once the guide in position, the operator can insert the body 30 of the cutter 3 (and therefore the cutting head 32 thereof) in the guide 4, the start of this step being shown in Figure 5c. Once the body 30 of the cutter 3 inserted in the guide 4, the operator can drive the cutter 3 in rotation, clockwise, by means of the handle 36. At the same time as it drives the cutter 3 in rotation , the operator must drive it in translation forward (that is to say towards the centering pin 100). When it is no longer possible for the operator to drive the cutter 3 forwards, that is to say when the free ends 384 of the teeth 38 are in contact with the shoulder 106 of the pin centering 100, then the rectification operation is completed. The diameter of the centering pin 100 has been reduced from the value A to the value B. The operator can remove the cutter 3 and the guide 4 and carry out another touch-up.

The milling cutter and the tool guide according to the invention will advantageously be made of a metallic material, such as steel, and preferably a steel suitable for cutting tools with regard to the milling cutter.

Claims (10)

1. Hand tool (2) for rectifying the diameter of a positioning element (100), such as a centering pin, the tool comprising: - a milling cutter (3), comprising a cylindrical body (30) having an axis of symmetry (X), one free end of which forms a cutting head (32); - a guide (4) of tubular shape, comprising a centering part (40), intended to be positioned on a base (102) of the positioning element, and a guide part (42) intended to ensure the guiding in translation of the body (30) of the cutter (3). 2. Tool (2) according to claim 1, wherein the cutting head comprises a plurality of teeth (38), preferably two to four teeth (38), each tooth (38) having a cutting edge (382) . 3. Tool (2) according to claim 2, wherein the teeth (38) are regularly distributed around the axis of symmetry (X) of the body (30). 4. Tool (2) according to the preceding claim, wherein each cutting edge (382) is oriented in an oblique direction relative to the axis of symmetry (X) of the body (30), and preferably included in a plane radial with respect to the axis of symmetry (X) of the body (30). 5. Tool (2) according to the preceding claim, wherein the radially internal ends of the cutting edges (382) are inscribed in a circle of diameter (B) equal to the final diameter of the positioning element (100), c ' that is to say its diameter after rectification. 6. Tool (2) according to the preceding claim, wherein the radially outer ends of the cutting edges (382) are inscribed in a circle of diameter (C) greater than the initial diameter (A) of the positioning element (100) , i.e. its diameter before rectification. 7. Tool (2) according to one of claims 2 to 6, wherein the free end (384) of the teeth (38) forms a stop surface in translation of the cutter (3). 8. Tool (2) according to one of the preceding claims, in which the guide part (42) of the guide (4) has a cylindrical internal shape, of internal diameter (E) allowing the insertion and the guiding in translation of the body (30) of the cutter (3) in the guide (4). 9. Tool (2) according to one of the preceding claims, in which the positioning part (40) of the guide (4) has a shape complementary to the base (102) of the positioning element (100), for example a frustoconical shape. 5 10. Tool (2) according to one of the preceding claims, comprising a handle (36) for gripping, connected to the body (30) of the cutter (3) by a connecting rod (34).