AU2017348773B2

AU2017348773B2 - Tangential machining element

Info

Publication number: AU2017348773B2
Application number: AU2017348773A
Authority: AU
Inventors: Richard BOISSON
Original assignee: Bartec Group
Current assignee: Bartec Group
Priority date: 2016-10-27
Filing date: 2017-10-17
Publication date: 2023-01-05
Anticipated expiration: 2037-10-17
Also published as: WO2018078241A1; AU2017348773A1; FR3058080B1; ZA201902538B; FR3058080A1; CN109937104A

Abstract

This tangential machining element (2) comprises a front face (4); a rear face (5); a machining face (11) linking the front face (4) to the rear face (5), the machining face (11) comprising a first machining portion (14) comprising machining ribs (14.2) substantially parallel to each other, and a second machining portion (15) comprising a machining surface (15.1) that is substantially planar; a first lateral face (16) and a second lateral face (17), the intersection between the first lateral face (16) and the machining face (11) defining a machining edge (18) comprising a first edge portion (18.2) defined by the machining ribs (14.2) and configured to form a thread on a part to be machined and to move the part to be machined relative to the tangential machining element (2) in a direction of movement, and a second edge portion (18.3) defined by the machining surface (15.1) and configured to trim the thread formed by the first edge portion (18.2) and to reduce the external diameter of at least a portion of the part to be machined.

Description

Tangential machining element

The present invention concerns a tangential machining element intended to equip a machining head and configured to machine a workpiece by material removal, and more particularly to reduce the diameter of a workpiece, such as a reinforcing bar. The discussion of the background to the invention herein is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any aspect of the discussion was part of the common general knowledge as at the priority date of the application. Where any or all of the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components. A machining device for reducing the diameter of a workpiece, also known as a peeling or scalping device, includes in a known manner: - a machining head including a plurality of tangential machining elements, each tangential machining element including a machining surface which is substantially planar and which defines at least in part one machining edge configured to reduce the external diameter of an end portion of the workpiece, and - a support element intended to support and hold the workpiece, the support element being mounted movable in translation relative to the machining head according to a direction of displacement parallel to the direction of extension of the workpiece. Such a machining device may further include a maneuvering member intended to be handled by an operator and configured to displace the support element according to the direction of displacement. Thus, such a machining device requires the presence of an operator throughout the entire step of machining the workpiece, in order to ensure in particular an advance of the support element, and therefore of the workpiece, towards the machining head. However, the result obtained using such a machining device is strongly related to the skill of the operator. Indeed, an irregular advance of the workpiece necessarily induces surface defects on the machined portion of the workpiece. As a result, a «catch-up» step is often provided after the machining step in order to correct the surface defects obtained using such a machining device.

To overcome these drawbacks, numerically controlled machining devices have been developed. A numerically controlled machining device enables more particularly automatic control of the advance of the support element towards the machining head, and therefore the obtainment of a part with a smooth surface condition. Nonetheless, the manufacturing costs of such a numerically controlled machining device are much higher than the manufacturing costs of a conventional machining device, which induces a significant increase in machining costs of the workpiece. The technical problem underlying the invention is therefore to provide a tangential machining element that is economical and simple in structure, while ensuring a regular machining and at lower costs of a workpiece. To this end, the present invention concerns a machining head including a plurality of tangential machining elements and configured to machine a workpiece by material removal, the tangential machining elements being angularly shifted from each other and being configured to extend tangentially relative to the workpiece, each tangential machining element including: - a front face, - a rear face which is opposite to the front face and which is configured to abut against a stop surface belonging to the machining head, - a machining face connecting the front face to the rear face, the intersection between the front face and the machining face defining a cutting edge, the machining face including: - a first machining portion extending from the cutting edge and along the cutting edge, the first machining portion including a beveled surface, also called a lead chamfer, extending from and along the cutting edge and the machining ribs substantially parallel to each other, and - a second machining portion extending between the first machining portion and the rear face, the second machining portion including a machining surface which is substantially planar, - a machining edge including at least: - a first edge portion, also called a drive portion, defined in part by the machining ribs of the first machining portion, the first edge portion being configured to form a thread on the workpiece and to displace the workpiece relative to the tangential workpiece according to an axial direction of displacement, and - a second edge portion, also called a cutting portion, defined in part by the machining surface of the second machining portion, the second edge portion being configured to reduce the external diameter of at least a portion, and for example an end portion, of the workpiece at a predetermined value.

2a

In other words, the second edge portion is configured to roll a portion of the workpiece at a predetermined diameter. Such a configuration of the tangential machining element enables, after contacting the workpiece with the machining head by the operator, ensuring a regular and automatic advance of the workpiece because of the creation of a thread on the latter via the first edge portion, this thread being then removed by the second edge portion which also allows reducing the diameter of the workpiece to the desired value. The advance per revolution of the workpiece or the machining element may be easily adapted by changing the thread pitch, that is to say by changing the configuration of the machining ribs.

Thus, the tangential machining element according to the present invention allows ensuring an automatic advance on an initially manual machining device, and also eliminates the need to have either a hydraulic thrust, or a mechanical screwdriver or an axis driven by a numerical control to ensure the advance of the workpiece or the machining head. The result is a simpler, more robust and less expensive machining device. It should be noted that the tangential machining element according to the present invention may be used to reduce the diameter of a workpiece, before performing a subsequent thread, for example by rolling or deformation, on the machined portion using such a tangential machining element. Furthermore, the fact of forming a thread at first on the workpiece allows obtaining, through a single machining passage, a large decrease in the diameter of the workpiece thanks to the formation of multiple shavings obtained in particular from the furrows formed by the thread and then the screeding of the threads. 1s Consequently, the tangential machining element according to the present invention enables the making of a stepped tool enabling a very deep and fast shaving take-up. In addition, the presence of the beveled surface on the first machining portion also contributes to the formation of the multiple shavings obtained, and therefore to the possibility of obtaining a large decrease in the diameter of the workpiece in a single machining passage. The tangential machining element may further have one or more of the following features, considered alone or in combination. According to an embodiment of the invention, the second edge portion is configured to screed the thread formed by the first edge portion. According to an embodiment of the invention, the tangential machining element includes a first lateral face and a second lateral face opposite to the first lateral face, the intersection between the first lateral face and the machining face defining the machining edge. According to an embodiment of the invention, the machining surface and the tops of the machining ribs extend substantially in a same extension plane. According to an embodiment of the invention, the rear face is beveled. According to an embodiment of the invention, the front face is substantially planar, and the rear face is substantially planar and inclined with respect to the front face. According to an embodiment of the invention, the first lateral face is beveled. According to an embodiment of the invention, the second lateral face is substantially planar, and the first lateral face is substantially planar and inclined with respect to the second lateral face.

According to an embodiment of the invention, the tangential machining element further comprises a mounting face intended to be mounted on a holding device belonging to the machining head, the mounting face being opposite to the machining face. According to an embodiment of the invention, the mounting face includes a bearing surface intended to bear against a complementary bearing surface provided on the holding device, the bearing surface being substantially parallel to the machining surface. According to an embodiment of the invention, the mounting face includes a clamping surface configured to cooperate with a clamping element belonging to the holding device. According to an embodiment of the invention, the clamping surface is beveled. According to an embodiment of the invention, the mounting face includes a clamping groove opening into the front face and defining the clamping surface. According to an embodiment of the invention, the tangential machining element has a parallelepiped general shape. According to an embodiment of the invention, the tangential machining element is elongated and extends according to a direction of extension, the cutting edge extending according to the direction of extension of the tangential machining 2o element and the machining edge extending transversely to the direction of extension of the tangential machining element. According to an embodiment of the invention, each machining rib has a substantially triangular cross-section. According to an embodiment of the invention, the workpiece is elongated and extends according to a direction of extension. The workpiece may be a metal bar, and for example a reinforcing bar, also called a concrete reinforcing bar. The present invention further concerns a machining head including a plurality of tangential machining elements according to the present invention. According to an embodiment of the invention, the tangential machining elements are angularly shifted from each other, and are configured to extend tangentially relative to a workpiece. According to an embodiment of the invention, the machining head includes N tangential machining elements which are arranged in such a way that the machining ribs of two adjacent tangential machining elements are axially shifted by a predetermined distance equal to about 1/N*p, N being an integer larger than or equal to 2 and p being the thread pitch intended to be formed on the workpiece. For example, when the machining head includes four tangential machining elements, the machining ribs of two adjacent tangential machining elements are axially shifted by a quarter of a pitch, that is to say a quarter of the thread pitch formed on the workpiece. The present invention also concerns a machining device including: - a machining head according to the present invention, and - a support element intended to support and hold a workpiece, the support element being movably mounted relative to the machining head according to a direction of displacement. According to an embodiment of the invention, the support element is a support carriage. According to an embodiment of the invention, the direction of displacement is substantially parallel to the direction of extension of the workpiece. According to an embodiment of the invention, the machining device further includes at least one guide element configured to guide the support element during a displacement, according to a direction of displacement, of the support element relative to the machining head. Anyway, the invention will be better understood using the description that follows with reference to the appended schematic drawings representing, as a non limiting example, an embodiment of this tangential machining element. Figure 1 is a perspective view of a tangential machining element according to the present invention. Figure 2 is a side view of the tangential machining element of Figure 1. Figure 3 is a front view of the tangential machining element of Figure 1. Figure 5 is a schematic view of a machining device including a plurality of tangential machining elements of Figure 1. Figure 6 is a front view of a machining head belonging to the machining device of Figure 4. Figure 7 is a perspective view of a holding device belonging to the machining head of Figure 5 and equipped with the tangential machining element of Figure 1. Figure 8 is a sectional view of the holding device of Figure 6. Figures 1 to 4 represent a tangential machining element 2 configured to machine a workpiece 3 by material removal. The workpiece 3 may be for example a metal bar, such as a reinforcing bar. The tangential machining element 2 is elongated and extends in a direction of extension De. The tangential machining element 2 has more particularly a parallelepiped general shape, and thus includes six faces opposed in pairs. The tangential machining element 2 includes in particular a front face 4, also called cutting face, extending according to the direction of extension De, and a rear face 5 opposite to the front face 4 and also extending according to the direction of extension De. According to the embodiment represented in the figures, the front face 4 is planar, and the rear face is beveled, that is to say it is inclined with respect to the front face 4. The tangential machining element 2 also includes a mounting face 6 connecting the front face 4 to the rear face 5 and extending in the direction of extension De. The mounting face 6 includes a bearing surface 7 which is substantially planar and extends over the entire length of the mounting face 6. The bearing surface 7 advantageously has a rectangular general shape. The mounting face 6 also includes a clamping groove 8 which opens into the front face 4 and which extends over the entire length of the mounting face 6. The clamping groove 8 defines more particularly a clamping surface 9, which may for example be beveled. The tangential machining element 2 further includes a machining face 11 opposite to the mounting face 6. The machining face 11 connects the front face 4 to the rear face 5 and extending according to the direction of extension De. The intersection between the front face 4 and the machining face 11 defines a cutting edge 12 extending according to the direction of extension De, whereas the intersection between the rear face 5 and the machining face 11 defines a rear edge 13 also extending according to the direction of extension De. The machining face 11 more particularly includes a first machining portion 14 2o extending from and along the cutting edge 12. According to the embodiment represented in the figures, the first machining portion 14 includes a beveled surface 14.1 extending from and along the cutting edge 12, and machining ribs 14.2 substantially parallel to each other. The machining ribs 14.2 may for example be slightly inclined with respect to the direction of extension De. According to the embodiment represented in the figures, each machining rib 14.2 has a substantially triangular cross-section. In addition, the machining face 11 includes a second machining portion 15 extending between the first machining portion 14 and the rear face 5. The second machining portion 15 more particularly includes a machining surface 15.1 which is advantageously planar and substantially parallel to the bearing surface 7. According to the embodiment represented in the figures, the machining ribs 15.2 are disposed between the beveled surface 14.1 and the machining surface 15.1, and the tops 14.3 of the machining ribs 14.2 extend in the same extension plane as the machining surface 15.1. In addition, the tangential machining element 2 includes a first lateral face 16 extending transversely to the direction of extension De, and a second lateral face 17 opposite to the first lateral face 16 and also extending transversely to the direction of extension De. According to the embodiment represented in the figures, the second lateral face 17 is planar and extends perpendicularly to the machining surface 7, and the first lateral face 16 is beveled, that is to say it is inclined with respect to the second lateralface 17. The intersection between the first lateral face 16 and the machining face 11 defines more particularly a machining edge 18 including successively from front to the rear: - an edge portion 18.1 defined in part by the beveled surface 14.1, the edge portion 18.1 being configured to reduce the external diameter of an end portion of the workpiece 3, - an edge portion 18.2 defined in part by the machining ribs 14.2 of the first machining portion 14, the edge portion 18.2 being configured to form a thread 19 on the workpiece 3 and to displace the workpiece 3 relative to the tangential machining element 2 in a direction of displacement Dd, and - an edge portion 18.3 defined in part by the machining surface 15.1 of is the second machining portion 15, the edge portion 18.3 being configured to screed the thread 19 formed by the edge portion 18.2 and to reduce the external diameter of the end portion of the workpiece 3. In use conditions, the edge portion 18.1, the edge portion 18.2 and the edge portion 18.3 are configured to respectively generate a first shaving, a second shaving 2o and a third shaving. Such a tangential machining element 2 is more particularly intended to equip a machining device 21, as schematized in Figure 5. The machining device 21, also called a peeling or scalping device, includes in particular a machining head 22 provided with a plurality of tangential machining elements 2 angularly shifted from each other in a regular manner, and a support element 23, such as a support carriage, intended to support and hold a workpiece 3. According to an embodiment of the invention, the support element 23 is mounted movable in translation relative to the machining head 22 according to a direction of displacement Dd substantially parallel to the direction of extension of the workpiece 3, and is therefore configured to be displaced in the direction of the machining head 22. According to another embodiment of the invention, the machining head 22 could be mounted movable in translation relative to the support element 23 according to a direction of displacement Dd substantially parallel to the direction of extension of the workpiece 3, and therefore be configured to be displaced in the direction of the support element 23. Furthermore, according to an embodiment of the invention, the machining head 22 could be rotatably movable about an axis of rotation, and the support element 23 could be configured to immobilize the workpiece 3 in rotation. According to another embodiment of the invention, the machining head 22 could be rotatably immobile, and the support element 23 could be configured to rotatably drive the workpiece 3 according to the axis of extension of the latter. According to the embodiment represented in the figures, the machining head 22 includes four tangential machining elements 2. However, the machining head 22 could of course include less than four or more than four tangential machining elements 2. As shown in Figure 6, the machining head 22 includes a plurality of holding devices 24 each including a holding block 24.1, and a clamping element 24.2 fastened to the respective holding block 24.1 and configured to clamp a tangential machining element 2 against the respective holding block 24.1. As shown more particularly in Figures 7 and 8, the rear face 5 of a tangential machining element 2 is configured to abut against a stop surface 25 provided on the respective holding block 22.1, and the bearing surface 7 of a tangential machining element 2 is configured to bear against a complementary bearing surface 26 provided on the respective holding block 22.1. Furthermore, the clamping surface 9 of a tangential machining element 2 is configured to cooperate with the clamping element 24.2 of the respective holding device 24. It goes without saying that, the invention is not limited to the sole embodiment of this tangential machining element, described hereinabove as an example, but it 2o encompasses all variants thereof.

Claims

The claims defining the invention are as follows:

1. A machining head including a plurality of tangential machining elements and configured to machine a workpiece by material removal, the tangential machining elements being angularly shifted from each other and being configured to extend tangentially relative to the workpiece, each tangential machining element including: - a front face, - a rear face which is opposite to the front face and which is configured to abut against a stop surface belonging to the machining head, - a machining face connecting the front face to the rear face, the intersection between the front face and the machining face defining a cutting edge, the machining face including: - a first machining portion extending from the cutting edge and along the cutting edge, the first machining portion including a beveled surface extending from and along the cutting edge and machining ribs substantially parallel to each other, and - a second machining portion extending between the first machining portion and the rear face, the second machining portion including a machining surface that is substantially planar, - a machining edge including at least: - a first edge portion, defined in part by the machining ribs, the first edge portion being configured to form a thread on the workpiece and to displace the workpiece relative to the tangential machining element according to a direction of displacement, and - a second edge portion, defined in part by the machining surface, the second edge portion being configured to reduce the external diameter of at least a portion of the workpiece.

2. The machining head according to claim 1, wherein the second edge is configured to reduce the external diameter of an end portion of the workpiece.

3. The machining head according to claim 1 or 2, wherein the second edge portion is configured to trim the thread formed by the first edge portion.

4. The machining head according to any one of claims 1 to 3, wherein the machining surface and the tops of the machining ribs extend substantially in a same extension plane.

5. The machining head according to any one of claims 1 to 4, wherein each tangential machining element further comprises a mounting face intended to be mounted on a respective holding device belonging to the machining head, the mounting face being opposite to the respective machining face.

6. The machining head according to claim 5, wherein the mounting face includes a bearing surface intended to bear against a complementary bearing surface provided on the respective holding device, the bearing surface being substantially parallel to the machining surface.

7. The machining head element according to claim 5 or 6, wherein the mounting face includes a clamping surface configured to cooperate with a clamping element belonging to the respective holding device.

8. The machining head according to any one of claims 1 to 7, wherein each tangential machining element has a parallelepiped general shape.

9. The machining head according to any one of claims 1 to 8, wherein each tangential machining element is elongated and extends in a direction of extension, each cutting edge extending according to the direction of extension of the respective tangential machining element and each machining edge extending transversely to the direction of extension of the respective tangential machining element.

10. The machining head according to any one of claims 1 to 9, which includes N tangential machining elements which are arranged in such a way that the machining ribs of two adjacent tangential machining elements are axially shifted by a predetermined distance equal to about 1/N*p, N being an integer larger than or equal to 2 and p being the thread pitch intended to be formed on the workpiece.

11. A machining device including: - a machining head according to any one of claims 1 to 10, and - a support element intended to support and hold a workpiece, the support element being movably mounted relative to the machining head according to a direction of displacement.