Manual deburring tool

Abstract

The invention relates to a manual deburring tool (1) comprising:-a consumable hard alloy plate (10) having a deburring edge (12), and-a housing (20) configured to be manually grasped and having an inner cavity (22) for receiving the plate, the housing (20) comprising a body (25) and a cover (27) removably attached to the body, and a housing (20) arranged in the cavity (22) to enable insertion and removal of the plate (10) into the cavity (22), the housing comprising at least one opening (26) which opens into the cavity and exposes the deburring edge (12).

Description

Technical Field

[0001] The invention relates to the technical field of hand tools for deburring and conditioning workpiece surfaces, for example by trimming edges or rounding corners. Background Art

[0002] The background art includes in particular documents CH-A-479 358, US-A1-2018 / 250843, US-A1-2021 / 213544 and US-A1-5 054 201.

[0003] Finishing of workpieces, especially raw metal workpieces, involves several manual adjustment operations, including deburring, trimming edges or even chamfering or rounding. Deburring is the process of removing excess metal or burrs from a workpiece. This type of defect can appear on a workpiece after machining operations such as milling or turning. Trimming edges is an operation designed to remove unwanted protrusions from the surface of the workpiece, while rounding aims to eliminate cutting ridges.

[0004] Until now, when manually adjusting a workpiece, the operator used a carbide plate to remove the burrs resulting from the previous operation. However, the use of a carbide plate has proven to be neither suitable for the operator nor for the workpiece on which the finishing operation is to be carried out. In fact, the operator is exposed to the risk of cuts when using this plate, and there is a risk of impacts and scratches on the workpiece, which affects the quality of the workpiece and the delivery time. In addition, in the absence of the appropriate tool, the operator may be led to use other tools that are not validated in the tool library, resulting in non-compliance with quality rules. This applies in particular to the manufacture of workpieces in the aerospace field, such as turbine workpieces. In fact, turbine workpieces can be very large and the manual adjustment operations of these workpieces can be long and delicate.

[0005] The object of the present invention is to provide a hand tool for deburring and adjusting the surface of a workpiece making it possible to avoid damage to the workpiece, the risk of cutting the operator and the consequences of such a situation. Summary of the invention

[0006] In fact, the present invention proposes a manual deburring tool, comprising:

[0007] - a consumable carbide plate having a deburred edge, and

[0008] - a housing configured to be manually gripped and comprising an inner cavity for accommodating a plate, the housing comprising a body and a cover removably attached to the body so as to enable the plate to be inserted into the cavity and removed from the cavity, the housing comprising at least one opening leading to the cavity and exposing the deburred edge of the plate.

[0009] When using the hand tool according to the invention, the operator is no longer in direct contact with the carbide plate, but with the housing. In fact, when the housing is closed, i.e. when the cover is closed, only the or each deburred edge of the carbide plate is exposed through the opening. In this way, the housing provides protection for the operator, who no longer directly grips the carbide plate, but the housing enclosing the plate. Furthermore, since only the deburred edge of the plate remains exposed, the risk of collision with the surface of the workpiece to be finished is significantly reduced.

[0010] Different features according to the invention which may be employed together or separately:

[0011] - the tool comprises a plurality of openings;

[0012] - The depth of the opening is between 2 mm and 8 mm;

[0013] - the dimensions of the opening are smaller than the dimensions of the plate, except for the thickness of said plate;

[0014] - The dimensions of the cavity are adjusted to the dimensions of the plate;

[0015] - the body comprises two guides and the cover comprises two lateral longitudinal flanges adapted to cooperate with the guides by means of a sliding connection;

[0016] - the housing comprises a recess adapted to cooperate with a lug on the cover;

[0017] -The shell has a breaking strength between 35J / m 2 Up to 52J / m 2 Between, preferably between 44 J / m 2 Up to 48J / m 2 Made of plastic material between;

[0018] - the outer surface of the housing comprises a knurled portion defining a plastic structure having an arithmetic mean roughness between 0.2 μm and 0.3 μm;

[0019] The invention also relates to a method for deburring a workpiece with the aid of a hand tool as described above, the workpiece comprising a ridge on which a burr is present, the method comprising the following steps:

[0020] - bringing one of the edges of the plate into contact with the ridge through one of the openings, and

[0021] -Move the edge of the plate in contact with the ridge along the ridge.

[0022] Advantageously, the workpiece is a workpiece of an aircraft turbomachine, in particular a rotor drum. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other objects, features and advantages of the present invention will become apparent from the following description given with reference to the accompanying drawings, in which:

[0024] - Figure 1 shows a perspective view of a manual deburring tool according to an embodiment of the present invention;

[0025] - Figure 2 A perspective view showing a cemented carbide plate for a manual deburring tool according to an embodiment of the present invention;

[0026] - Figure 3 shows a side view of a workpiece being finished using a manual deburring tool according to the present invention;

[0027] - Figure 4a is a cross-sectional view of a housing of a manual deburring tool according to an embodiment of the present invention;

[0028] - Figure 4b is a side view of a housing of a manual deburring tool according to an embodiment of the present invention;

[0029] - Figure 5 A top view of a housing of a manual deburring tool according to an embodiment of the present invention is shown (without a cover);

[0030] - Figure 6a is a side view of a cover of a manual deburring tool according to an embodiment of the present invention;

[0031] - Figure 6b is a cross-sectional view of a cover of a manual deburring tool according to an embodiment of the present invention;

[0032] - Figure 6c is a top view of a cover of a manual deburring tool according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] refer to Figure 1 The present invention relates to a hand tool 1 for deburring and adjusting the surface of a workpiece P. The definition of deburring is given in the preamble of this specification and is not repeated here. Adjusting the surface of a workpiece refers to any operation aimed at modifying the surface of a workpiece, including trimming edges or rounding corners, the definitions of trimming edges or rounding corners also being given in the preamble of this specification.

[0034] The hand tool 1 comprises a consumable carbide plate 10 having a deburred edge 12. These enable any finishing operation to be carried out, such as those seen above. Figure 3It is shown how to perform workpiece finishing using the hand tool 1. The carbide plate 10 is consumable and can therefore be replaced after wear or damage (eg due to wear of the deburred edge of the carbide plate).

[0035] Preferably, the cemented carbide plate 10 is a silicon cemented carbide plate.

[0036] The plate 10 has, for example, the general shape of a truncated pyramid, so that the deburring edge 12 of the plate 10 is inclined. In this embodiment, the bottom of the truncated pyramid corresponds to the lower surface of the plate, while the plane in which the pyramid is truncated corresponds to the upper surface of the plate. It should be noted that the terms "lower" and "upper" are not restrictive in the context of the present invention and are only used to describe the invention with reference to the embodiments shown in the accompanying drawings. Preferably, the lower surface of the plate is a lower surface that faces the bottom of the cavity of the hand tool 1. As can be seen from the figure, the deburring edge 12 is more precisely inclined outwardly from the upper surface towards the lower surface. This will be discussed further below.

[0037] exist Figure 3 In the example shown, the workpiece P is an aircraft turbine rotor, more specifically a rotor drum, which is shown here in a partial axial section. Typically, the drum has a generally annular shape around an axis and comprises a disk D interconnected by an annular web V. The disk comprises at its periphery a pocket AL for mounting a blade root, the web comprising an annular lip L extending radially outwards. The hand tool 1 is used to remove burrs located at a ridge A or to round off a ridge located, for example, in the connection area of ​​the web to the disk, as shown in the figure.

[0038] The hand tool 1 also includes a housing 20 configured for manual gripping. The housing 20 includes an inner cavity 22 for accommodating the cemented carbide plate 10. According to one embodiment of the present invention, the size of the cavity 22 is adjusted to the size of the cemented carbide plate 10 so that there is little or no gap between the plate 10 and the cavity 22. When there is no gap between the plate 10 and the cavity 22, the plate 10 is fixedly or immovably held in the cavity 22. The housing 20 also includes a body 25 and a cover 27 removably attached to the body to enable the cemented carbide plate 10 to be inserted into the cavity 22 and removed from the cavity 22.

[0039] According to the present invention, the housing 20 includes at least one opening 26 (in Figure 4b ), at least one opening 26 leads to the cavity 22 and exposes the deburred edge 12 of the cemented carbide plate. That is, advantageously, the housing includes a plurality of openings 26, so that the deburred edge of the plate can be further exposed. As previously mentioned, the deburred edge 12 is inclined outward from the upper surface toward the lower surface, so that when the plate 10 is in the cavity 22 and the lower surface of the plate 10 contacts the bottom of the cavity 22, the deburred edge 12 is closer to the opening 26 than other parts of the plate 10.

[0040] exist Figure 1 and Figure 5 In the embodiment shown, the body 25 is in the shape of a parallelepiped. The cavity 22 can be positioned so that one or more of the side surfaces of the cavity 22 are adjacent to or located at one or more side walls 21a, 21b, 21c, 21d of the body 25. By varying the distance between the side surfaces of the cavity and the facing side walls 21a, 21b, 21c, 21d of the body, the depth of the opening 26 can be varied. In fact, the depth of the opening corresponds to the distance separating the side surface where the opening of the cavity is located from the outer surface of the side wall of the body to which said opening leads. Each side surface of the cavity defines the inner surface of the housing, while for each side wall of the body, the outer surface corresponds to the outer surface of the housing.

[0041] Preferably, the depth of the opening 26 is between 2 mm and 8 mm. A minimum depth of 2 mm ensures that the deburring edge 12 is sufficiently recessed relative to the outer surface of the housing. At the same time, this also means a wall thickness of 2 mm, which also gives the housing 20 good mechanical strength. A depth of up to 8 mm allows a hand tool 1 of appropriate dimensions to be kept at hand while ensuring access to the deburring edge 12. In fact, the greater the depth of the opening 26, the greater the other dimensions of the opening 26 must be in order to keep the deburring edge 12 accessible from the workpiece P, and the worse the operability of the hand tool 1 according to the invention.

[0042] In the embodiment presented, the tool 1 comprises a plurality of openings 26. However, this is not necessary and it would not go beyond the scope of the invention if the tool had only one opening.

[0043] However, when the tool has multiple openings, the tool can be optimally positioned relative to the surface of the object to be processed by the tool. In addition, having multiple openings reduces the need to move the plate once the first edge of the plate is worn due to use, because all edges of the plate opposite the openings will wear during use.

[0044] For example, the openings may be arranged on three of the four edges of the housing of the tool 1 .

[0045] Advantageously, the dimensions of the opening 26 are smaller than those of the cemented carbide plate 10 , except for the thickness of said cemented carbide plate, which prevents the plate 10 from coming out of the housing after being inserted into the cavity. In particular, the width and length of the opening 26 are smaller than those of the plate 10 .

[0046] Still according to Figure 1In the embodiment shown, the inner cavity 22 for receiving the plate comprises an inlet 23 extending transversely to the side walls of the cavity, through which the plate 10 can be inserted. Alternatively, a slot can be used to allow the cemented carbide plate 10 to be inserted sideways. However, this solution is less attractive because it requires additional means for closing the cavity 22. The inlet 23 is closed by a cover 27. In Figure 1 In the embodiment, the cover 27 is appropriately positioned for inserting the plate 10 into the cavity 22. That is, the position of the cover 27 can vary. In this regard, the body 25 includes two guides 28a, 28b with which the longitudinal edges 27a, 27b of the cover can cooperate. Figure 4a In the example shown, the guides 28a, 28b take the form of parallelepiped recesses in the side walls 21b, 21d of the housing. Figure 1 As can be seen, guides 28a, 28b are formed along the side walls 21b and 21d and the edges of the inlet 23. Thus, the cover 27 is in sliding connection with the body 25, so that the cover 27 moves from a proximal position, in which the cover 27 completely covers the cavity 22, thereby closing the housing 20, to a distal position, in which the inlet 23 is completely free, and then the housing 20 is opened, passing through a series of intermediate positions.

[0047] When the cover 27 completely covers the cavity 22, the deburring edge 12 is the only part of the plate 10 that is exposed through the opening 26, as previously described. Thus, by using the hand tool 1 according to the invention, the risk of cutting the operator and damaging the workpiece to be finished is greatly reduced, if not eliminated. In fact, the surface treated by the operator is protected by the housing 20. In addition, if the hand tool 1 comes into contact with another surface of the workpiece during the finishing operation, the other surface is the surface protected by the housing 20, since the housing 20 covers a large part of the plate 10. As already mentioned, the depth of the opening 26 is between 2 mm and 8 mm, so that the deburring edge 12 is recessed from the outer surface of the housing 20.

[0048] Figure 5 The arrangement of the cavity 22 and other elements located inside the housing 20 is shown in more detail. As already noted, in the illustrated embodiment, the cavity 22 is located in the immediate vicinity of one or more of the side walls 21a, 21b, 21c, 21d. In this case, the cavity 22 is located in the immediate vicinity of the side walls 21a, 21b and 21d. The cavity 22 includes a bottom 220 against which the cemented carbide plate 10 rests.

[0049] On the right side of the housing, Figure 5 As shown, the solid portion 24 is adjacent to the cavity 22. The solid portion 24 comprises a recess 24a in which a lug 27c located on the surface of the cover 27 facing the interior of the housing 20 is intended to be received. Figure 6a and Figure 6b An example of an arrangement of the lug 27c relative to the cover is shown in . This arrangement makes it possible to limit the displacement of the cover 27 and even lock the cover 27 relative to the housing 20. The locking occurs once the cover is in the proximal position, i.e. when the cover completely closes the cavity 22. The locking makes the tool easier to use, because the locking ensures that the cover cannot be reopened during use, regardless of the position of the tool.

[0050] Reference now Figure 6c The cover 27 may further include an opening 27d that enables an operator to grasp the cover 27 and enables the cover 27 to slide along the guides 28a, 28b. Figure 1 As can be better understood, when the cover is in the proximal position and closes the cavity 22, the opening 27d is positioned facing the solid portion 24, thus enabling an associate to easily and securely grasp the cover.

[0051] Advantageously, the housing 20 is made of a material having a breaking strength between 35 J / m 2 Up to 52J / m 2 Between, preferably between 44 J / m 2 Up to 48J / m 2 This makes the housing stronger and reduces wear. For example, ACCURA Gray plastic can achieve this breaking strength. Other plastics with breaking strengths within the above ranges can also be used. It should be noted that ACCURA Gray plastic can be used for additive manufacturing methods. Therefore, the housing 20 of the hand tool 1 according to the present invention can be manufactured by additive manufacturing. Other plastic materials that can be used for additive manufacturing or conventional manufacturing and have the aforementioned breaking strength can be obtained by those skilled in the art.

[0052] As shown in the figure, the housing 20 can be produced by knurling, which defines a plastic structure 29 with an arithmetic mean roughness between 0.2 μm and 0.3 μm. The knurling is understood here as an alternation of convex parts and valleys, and the arithmetic roughness of the knurling is defined as the characteristic depth, i.e. the difference between the top of the convex part and the bottom of the valley. Increasing the surface roughness of the housing 20 by the knurling gives the housing 20 anti-slip properties. This improves the operator's grip on the hand tool while avoiding the risk of cuts. In fact, the anti-slip coating improves the grip between the personal protective equipment worn by the operator and the housing 20.

[0053] A method for deburring a workpiece using a hand tool 1 as described above is described hereinafter. A workpiece P is provided, comprising a ridge A at which there is a burr resulting from a previous turning or milling step on the workpiece. The method comprises a step in which one of the edges of a cemented carbide plate is brought into contact with the ridge A through one of the openings 26, and then comprises a further step in which the edge of the plate in contact with the ridge is moved along the ridge. In this way, the ridge A rubs or slides against one of the deburring edges 12 of the hand tool 1 to remove the burr. Therefore, it is both simple and safe for the operator to use the hand tool according to the invention.

[0054] The configurations shown in the figures are merely possible examples of the present invention and are not intended to be any limitation of the present invention. On the contrary, the present invention encompasses all variations in shape and design that can be imagined by a person skilled in the art.

Claims

1. A manual deburring tool (1), comprising: - a consumable cemented carbide plate (10) having a deburred edge (12), and - a housing (20) configured to be manually grasped and having an inner cavity (22) for accommodating the plate, the housing (20) comprising a body (25) and a cover (27) removably attached to the body to enable the plate (10) to be inserted into and removed from the cavity (22), the housing comprising at least one opening (26) leading to the cavity and exposing the deburred edge (12) of the plate.

2. The hand tool (1) according to claim 1, wherein: The depth of the opening (26) is between 2 mm and 8 mm.

3. The hand tool (1) according to claim 1 or 2, wherein: The dimensions of the opening (26) are smaller than the dimensions of the plate (10), except for the thickness of the plate.

4. The hand tool (1) according to any one of the preceding claims, wherein: The dimensions of the cavity (22) are adjusted to the dimensions of the plate (10).

5. The hand tool (1) according to claim 4, wherein: The body (25) comprises two guides (28a, 28b) and the cover (27) comprises two lateral longitudinal flanges (27a, 27b) adapted to cooperate with the guides (28a, 28b) by means of a sliding connection.

6. The hand tool (1) according to claim 4 or 5, wherein: The housing (20) includes a recess (24a) adapted to cooperate with a lug (27c) on the cover.

7. The hand tool (1) according to any one of the preceding claims, wherein: The shell (20) has a breaking strength between 35 J / m 2 Up to 52J / m 2 Between, preferably between 44 J / m 2 Up to 48J / m 2 Made of plastic material.

8. The hand tool (1) according to any one of the preceding claims, wherein: The outer surface of the housing (20) includes a knurled portion, which defines a plastic structure (29) with an arithmetic mean roughness between 0.2 μm and 0.3 μm.

9. A method for deburring a workpiece (P) comprising a ridge (A) where a burr is present, by means of a hand tool (1) according to any one of the preceding claims, the method comprising the following steps: - bringing one of the edges of the plate (10) into contact with the ridge (A) through one of the openings (26), and - moving the edge of the plate in contact with the ridge along the ridge.

10. The method according to the preceding claim, wherein: The workpiece is a workpiece of an aircraft turbomachine, in particular a rotor drum (P).

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