Rolling grinder in which the rollers and shaft are pressed together

Abstract

The present invention relates to a method for manufacturing a rolling grinder (1) having at least one grinding or polishing surface (1a, 1b) for grinding and / or polishing cutting tools, the rolling grinder (1) being substantially formed from two rollers (2), a grip body (3) disposed between the rollers (2) and rotatably disposed relative to the rollers (2), and a shaft (5) rotatably supported within the grip body (3). According to the present invention, each of the rollers (2) is connected to the shaft (5) in a frictionally engaging manner to facilitate easy and accurate operation of the rolling grinder overall.

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a rolling grinder having at least one grinding or polishing surface for grinding and / or polishing cutting tools, the rolling grinder being substantially formed from two rollers, a grip body being positioned between the rollers and rotatable relative thereto, and a shaft being rotatably supported in the grip body. [Background technology]

[0002] Such a rolling grinder is known, for example, from EP 3278926 A1. This rolling grinder is intended to bring its grinding or polishing surface into contact with the cutting edge of the cutting tool to be ground and to move along the cutting edge in a rolling motion over a flat base. The grinding or polishing surface of the end face rotates along a grinding plane arranged perpendicular to the base and removes material from the cutting edge.

[0003] In the rolling grinder known from EP 3278926 A1, the roller and the grinding or polishing wheel are bolted to the shaft so that the rolling grinder can be easily disassembled into its individual parts. When removing the grinding or polishing wheel from the shaft, the user must hold the roller firmly, otherwise it will come off the shaft. As the rolling grinder can be disassembled, cleaning is easier, but handling is more difficult for the user.

[0004] The invention is based on the task of improving known rolling grinders to such an extent that their operation according to their intended use becomes user-friendly and generally easier. Summary of the Invention

[0005] To solve this problem, the present invention provides a method for manufacturing a rolling grinder according to claim 1. The method according to the invention serves to manufacture a rolling grinder having at least one grinding or polishing surface for grinding and / or polishing cutting tools, the rolling grinder being substantially formed of two rollers, a grip body arranged between the rollers and rotatably arranged relative to the rollers, and a shaft rotatably supported in the grip body. According to the invention, each roller is connected to the shaft in a frictionally engaging manner. This means that the rollers, the grip body and the shaft form an integral unit and ideally cannot be detached from each other without causing damage. As a result, the rolling grinder according to the invention can be manufactured with little effort and is overall user-friendly, since the components of the rolling grinder are held together in a constrained manner.

[0006] Preferred further embodiments are the subject of the dependent claims.

[0007] It can be advantageous if one or both of the rollers are connected to the shaft only in a frictionally engaging manner. Due to this exclusive frictional connection between each roller and the shaft, in particular no separate fastening means are required. This reduces the number of components required and therefore the effort required to manufacture the rolling grinder.

[0008] It may be useful if one or both of the rollers are connected to the shaft by a press fit. After press-fitting, an interference fit is formed at the junction of the roller and the shaft. This means that the longitudinal and transverse forces are transferred in a frictional engagement manner. This allows to create a cylindrical interference fit between the roller and the shaft. To achieve the longitudinal press-fit, the roller is pressed onto the shaft under high axial force (e.g. using a hydraulic press). The average surface roughness of the roller and / or shaft is preferably in the range of Rz 3-10 μm. To facilitate the press-fitting, the shaft and / or the roller are preferably provided with an insert bevel or chamfer.

[0009] It may be useful to have one or both of the rollers connected to the shaft with a temperature difference relative to the shaft, for example by heating the rollers and / or cooling the shaft prior to assembly. This allows the rollers to expand and the shaft to contract, joining the two parts without or with significantly reduced force. Subsequent temperature equalization adjusts the press while still maintaining most of the surface roughness, resulting in a much tighter fit than an axial press fit.

[0010] It may prove practical if one or both of the rollers are fitted onto or inserted into the shaft. In a preferred embodiment, the rollers have holes, in particular through holes, and the shaft has a support section that fits into the holes. In this respect, the rollers form the "female" component and the shaft forms the "male" component. However, it is also possible for the shaft to form the "female" component, have holes and have support sections that fit into the holes, with the rollers as the "male" component.

[0011] It may be useful if a stepped shaft is used as the shaft, which has a central section and two support sections which are stepped at the ends. For the axial positioning of the rollers on the shaft, a central section, for example in the form of a shoulder, is preferred as a position limit.

[0012] It can be advantageous if one of the rolling bearings and the rollers, and optionally a spacer element, is arranged on each support section, preferably the rolling bearing being axially supported with its inner ring on the central section of the shaft and / or the spacer element being axially fixed between the rolling bearing and the roller. In this respect, the central section of the shaft is used as a position limit for the rollers on the shaft. This arrangement allows the position of the rollers relative to the shaft to be set particularly accurately.

[0013] It may be useful if the rolling bearing is fixed to the grip body by its outer ring in a frictionally and / or form-locking manner, so that the position of the shaft relative to the grip body can be precisely adjusted.

[0014] It may be useful if one or both of the rollers have the grinding or polishing surface permanently arranged thereon, preferably at the end face, which is preferably formed integrally with the roller or permanently connected thereto, and which is particularly preferably formed as a coating, in particular as a ceramic coating. In this variant, the number of components of the rolling grinder is reduced to a minimum, which facilitates production and user handling.

[0015] However, it may be convenient if a grinding or polishing wheel with said grinding or polishing surface is attached, preferably removably, to one or both of said rollers. This variant is particularly suitable for experienced users who wish to use exchangeable grinding or polishing wheels. This broadens the range of applications of the rolling grinder.

[0016] Preferably, the grip body has at least one of the following features: - the grip body is made of plastic and / or metal and / or wood, preferably oak, walnut, beech or spruce, preferably in one piece; The grip body is configured as a cylinder, preferably a hollow cylinder.

[0017] An independent aspect of the invention relates to a rolling grinder comprising two rollers and a grip body disposed therebetween, the rollers being connected in a frictionally engaging manner to a shaft rotatably supported within the grip body, the rollers having grinding or polishing surfaces on their end faces.

[0018] Further preferred embodiments result from the combinations of features disclosed in the claims, the description and the drawings. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 shows a perspective exploded view of a rolling grinder according to a first embodiment, which can be manufactured by the method according to the invention. [Diagram 2] FIG. 2 shows a perspective exploded view of a rolling grinder according to a second embodiment, which can be manufactured according to the method according to the invention. [Diagram 3] FIG. 3 shows a schematic diagram of a rolling grinder according to a first embodiment of the invention in an assembled state. [Figure 4] FIG. 4 shows a schematic diagram of a rolling grinder according to a second embodiment of the invention in an assembled state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0021] First embodiment (FIGS. 1 and 3)—Roller with integral grinding / polishing surface

[0022] In a first embodiment of the invention, described below with reference to Figures 1 and 3, the rolling grinder 1 is made up of a total of 10 or 12 components, including two rollers 2, a grip body 3 (optionally with two bearing sleeves not shown), two spacer elements 4, a shaft 5, two rolling bearings 6 (each counting as one component), and two rubber rings 8 arranged on the edges of the rollers 2 to form the running surface of the rollers 2.

[0023] Each roller 2 is substantially configured as a cylindrical disk made of stainless steel and includes a circumferential annular groove in the cylindrical shell surface 2a, in which a rubber ring 8 is held in a form-fitting manner. The thickness or axial length of the roller 2 is, for example, in the range from 2 to 10 mm, in particular about 8 mm, and the outer diameter (excluding the rubber ring 8) is, for example, in the range from 40 to 60 mm, in particular about 54 mm. The rubber ring 8 preferably has an elliptical cross section, the main axis of which is preferably arranged parallel to the shell surface 2a of the roller 2. An integrally formed grinding or polishing surface 1a, 1b is located on the intended end face of each roller 2. The transition from the circumferential side 2a provided with the annular groove to the end face of the roller 2 is rounded or chamfered, the radius of curvature of the rounding being in the range from 0.5 to 2 mm, in particular about 1 mm. The side of the roller 2 intended to face the grip body 3 has a central opening 2b, by means of which the roller 2 fits onto a shaft 5 which will be described below.

[0024] The grip body 3 is a hollow wooden cylinder extending along a central axis X3 and having a cylindrical shell surface 3a, two parallel end faces 3b, and a cylindrical central hole 3c. In one variant, the central hole 3c (see FIG. 3) of the grip body 3 has two sections with different diameters, namely a central section with a smaller diameter and an end section with a larger diameter. At the end faces of the central section, two parallel outwardly directed bearing support sections 3d are formed for axially supporting the rolling bearings 6. These bearing support sections 3d determine the position of the roller 2 relative to the grip body 3. In another variant, the grip body 3 has a central hole 3a of uniform diameter. To fix the rolling bearings 6 described below, bearing sleeves (not shown) are inserted into the central hole 3a from each end face 3a of the grip body 3, which are supported by flanges on the end faces 3a of the grip body 3 and form the bearing support sections 3d on the base. The base of the bearing sleeve is provided with an opening for inserting the shaft 5. In the case of particularly high-quality constructions, the grip body 3 is manufactured in one piece from oak, walnut, beech or spruce. The outer diameter of the grip body 3 preferably corresponds to the outer diameter of the roller 2 (excluding the rubber ring 8) so that in the intended assembled state (see FIG. 3) the shell surface 3a of the grip body 3 and the shell surface 2a of the roller 2 are flush with each other. During the manufacture of the grip body 3, the moisture content of the wood should be as low as possible and not exceed 10%. The outer diameter of the grip body 3 is, for example, in the range 50-60 mm, in this case approximately 54 mm. The axial length of the grip body 3 is, for example, in the range 55 mm to 75 mm, in this case approximately 64 mm.

[0025] The shaft 5 is configured as a stepped shaft 5 having a central section 5a and end stepped bearing sections 5b.

[0026] The rolling bearing 6 is, for example, a commercially available ball bearing. The inner diameter of the inner ring of the rolling bearing 6 matches the outer diameter of the bearing section 5b of the shaft 5 and can be placed on it. The inner ring is thereby axially supported on the central section 5a of the shaft 5. The outer diameter and axial length of the rolling bearing 6 are adapted to the dimensions of the grip body 3. The rolling bearing 6 can therefore be precisely inserted into the central hole or bearing sleeve of the grip body 3 and axially supported by the outer ring of the bearing support section 3d.

[0027] The spacer element 4 is, for example, an annular disk or a cylindrical sleeve which can slide onto the bearing section 5b of the shaft 5 in order to be supported on the inner ring of the rolling bearing 6 and on the rollers 2. Depending on the actual dimensions of the grip body 3 and thus the gap dimensions between each roller 2 and the grip body 3, different types of spacer elements 4 having different axial lengths are provided in order to precisely adjust the distance between the rollers 2 mounted on the shaft 5.

[0028] In the assembled state, the shaft 5 and the spacer element 4, the rolling bearing 6 and the rollers 2 connected thereto have a common central or rotation axis X5.

[0029] The rolling grinder 1 is assembled from the above components by fitting the rolling bearings 6, the spacer elements 4 and the rollers 2 into the respective bearing sections 5b of the shaft 5 passing through the central hole 3c of the grip body 3, so that the inner ring of the rolling bearing 6 is supported on the central section 5a of the shaft 5 and the spacer elements 4 are fixed between the inner ring of the rolling bearing 6 and the inside of the rollers 2. The rollers 2 are then firmly and irremovably connected to the shaft 5 by a press fit, which creates an interference fit at the connection points. The outer ring of the rolling bearing 6 is fixed to the grip body 3 by a friction lock and, if necessary, by a snug-fit lock.

[0030] Second embodiment (FIGS. 2 and 4) - Roller with separate grinding / polishing roller

[0031] In a second embodiment of the present invention described below with reference to Figures 2 and 4, the rolling grinder 1 has substantially the same components and features as the rolling grinder 1 of the first embodiment, except for the differences described below.

[0032] Whereas in the first embodiment the grinding and polishing surfaces 1a, 1b are integrally formed with the roller 2 on the end faces and are therefore an integral part of the rolling grinder 1, the rolling grinder 1 according to the second embodiment of the invention comprises a separate grinding and polishing wheel 7 with the grinding and polishing surfaces 1a, 1b formed on its end faces. The grinding and polishing wheel 7 can be removably connected to the roller 2 or to the shaft 5 by screwing an integrally formed threaded socket 7b into a corresponding mating thread. Unlike the first embodiment, the roller 2 is not chamfered or rounded on its outwardly facing end faces, so that the shell surface 7a of the grinding and polishing wheel 7 is flush with the shell surface 2a of the respective adjacent roller 2. Instead, the grinding and polishing wheel 7 is chamfered or rounded at the transition between the shell surface 7a and the respective grinding or polishing surface 1a, 1b. The radius of curvature at the end faces of the grinding or polishing wheel 7 is, for example, in the range of 0.5 mm to 2 mm, preferably about 1 mm. [Explanation of symbols]

[0033] 1. Rolling Grinder 1a Grinding surface 1b Polished surface 2. Laura 2a Shell surface or circumferential side 2b opening 3 Grip body 3a Shell Surface 3b End face 3c hole 3d Support Section 4 Spacer Elements 5 Shaft 5a Central Section 5b Bearing section 6. Rolling Bearings 7 Grinding and polishing wheels 7a Shell Surface 7b Threaded Socket 8 Rubber Ring U-Base X1 Rotary / Central Axis Rolling Grinder X3 Rotating / Central Axis Grip Body X5 Shafts, rolling bearings, rotating / central axes of grinding and polishing wheels, if applicable

Claims

1. A method for manufacturing a rolling grinder (1) having at least one grinding or polishing surface (1a, 1b) for grinding and / or polishing cutting tools, comprising the steps of: The rolling grinder (1) is substantially formed of two rollers (2), a grip body (3) disposed between the rollers (2) and rotatably disposed relative to the rollers (2), and a shaft (5) rotatably supported within the grip body (3); Each of said rollers (2) is connected to a shaft (5) in a frictionally engaging manner; A method, characterized in that each of said rollers (2) is connected to said shaft (5) by a press fit.

2. 2. The method according to claim 1, characterized in that one or both of the rollers (2) are connected to the shaft (5) in a frictionally engaging manner only.

3. 3. A method according to any one of claims 1 to 2, characterized in that one or both of the rollers (2) are connected to the shaft (5) with a temperature difference relative to the shaft (5).

4. Method according to any one of the preceding claims, characterized in that one or both of the rollers (2) are plugged or inserted into the shaft (5).

5. 5. The method according to claim 1, characterized in that as the shaft (5) a stepped shaft (5) is used having a central section (5a) and two end stepped support sections (5b).

6. 6. The method according to claim 5, characterized in that a rolling bearing (6) and one of the rollers (2) is arranged on each support section (5b), and the rolling bearing (6) is axially supported on the central section (5a) of the shaft (5) with an inner ring of the rolling bearing (6).

7. 7. The method according to claim 6, characterized in that the rolling bearing (6) is fixed to the grip body (3) by an outer ring of the rolling bearing (6) in a frictionally engaging and / or form-locking manner.

8. one or both of said rollers (2) have thereon said grinding or polishing surface (1a, 1b) permanently arranged, preferably on an end face of said roller (2), said grinding or polishing surface (1a, 1b) is preferably integrally formed with or permanently connected to said roller (2); 8. The method according to claim 1, wherein the grinding or polishing surface (1a, 1b) is particularly preferably formed as a coating, in particular as a ceramic coating.

9. 9. The method according to any one of the preceding claims, characterized in that a grinding or polishing wheel (7) with said grinding or polishing surface (1a, 1b) is attached, preferably removably, to one or both of said rollers (2).

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