Tool repair equipment

Abstract

This invention provides a tool repair device that aims to extend the lifespan of cutting tools through repair. [Solution] The tool repair device 1 for repairing a cutting tool 2 equipped with a cutting edge 21 made of cemented carbide material comprises an additive molding unit 3 including a powder material supply device 31 and a beam irradiation device 32, a tool mounting unit 11 that supports the cutting tool 2 so as to be movable relative to the additive molding unit 3, and an additive molding control unit 100 that controls the supply of powder material and beam irradiation by the additive molding unit 3 to the repair area R of the cutting edge 21 to form a build-up layer in the repair area R. The additive molding control unit 100 has a molding path control unit that controls the molding path so that the build-up start point 201 and build-up end point 202 in the repair area R are located outside the cutting edge area r1 of the cutting edge 21.

Description

Technical Field

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[0001] The present invention relates to a tool repair device.

Background Art

[0002] From the viewpoint of extending the service life of tools, etc., the demand for cutting tools using superhard materials is increasing, while due to the high cost of the materials, suppression of manufacturing costs and maintenance costs is required. For example, in Patent Document 1, a toothing tool for skiving is composed of an annular cutting edge portion and an annular support edge portion connected coaxially, and the forming material of the cutting edge portion is made of a harder material than the support edge portion, and it is proposed to reduce the usage amount of the hard material.

[0003] [[ID=!15]] Also, in Patent Document 2, in a cylindrical hob alloy in which a superhard material chip serving as a cutting edge is brazed to a cylindrical hob, the brazed joint surface of the superhard material chip is formed into a shape having protrusions or holes, etc. so that it can be fitted with unevenness, and a configuration for enhancing the peel resistance of the brazed portion is disclosed.

Prior Art Documents

Patent Documents

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Such cutting tools are generally used while resharpening the worn cutting edge, and are discarded when the amount of wear increases or chipping occurs. In cases where the cutting edge and tip are provided as separate parts, as in Patent Documents 1 and 2, the support blade and base metal can be reused, but the part made of cemented carbide is discarded. Furthermore, reuse requires processes such as joining an annular member that will become the cutting edge to the support blade and machining the cutting edge, or manufacturing a tip with a concave and concave fitting shape and brazing it to the base metal.

[0006] Therefore, in order to extend the lifespan of cutting tools made of cemented carbide, repair of the cutting edge is being considered. Although Patent Document 1 describes repair using additive manufacturing, forming a high-hardness repair layer with stable quality is not easy, and no concrete studies have been conducted to date.

[0007] This invention has been made in view of the above problems, and aims to provide a tool repair device for extending the lifespan of cutting tools through repair. [Means for solving the problem]

[0008] One aspect of the present invention is, A tool repair device for repairing cutting tools equipped with cutting edges made of cemented carbide, Additive molding section including powder material supply device and beam irradiation device, A tool mounting portion that supports the cutting tool so as to be movable relative to the added molding portion, The system includes an additive molding control unit that supplies powder material and irradiates a beam onto the area to be repaired of the cutting edge to form a build-up layer. The tool repair device includes a molding path control unit that controls the molding path so that the start point and end point of the buildup in the repair area are located outside the cutting edge area of ​​the cutting edge. [Effects of the Invention]

[0009] According to one aspect of the present invention, repair is performed on the area to be repaired on the cutting edge caused by the use of a cutting tool by forming a build-up layer by additive molding. In this process, the molding path is set so that the start and end points of the build-up are located outside the cutting edge region of the cutting edge. As a result, no discontinuities are formed in the build-up layer that becomes the cutting edge region, and the quality of the cutting edge region after repair is stabilized. Therefore, it becomes possible to repair cutting edges made of cemented carbide with stable quality, and the lifespan of the cutting tool can be extended. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of the tool repair device according to Embodiment 1 of the present invention. [Figure 2] This is a perspective view of the main part of the cutting tool in Embodiment 1, viewed from the direction of the central axis. [Figure 3] Figure 2 shows a partial perspective view of the cutting tool and a schematic diagram illustrating the wear state of the cutting edge. [Figure 4] This is a schematic diagram illustrating the repair method using the tool repair device shown in Figure 1. [Figure 5] Figure 2 is a diagram illustrating the manufacturing process of the cutting tool. [Figure 6] Figure 2 is a flowchart showing the process of reusing cutting tools after use. [Figure 7] This is a flowchart illustrating the repair method using the tool repair device shown in Figure 1. [Figure 8] This is a schematic diagram illustrating the additive molding method in the repair method shown in Figure 7. [Figure 9] Figure 1 shows a schematic diagram illustrating the configuration of the additive molding section in the tool repair device and a schematic diagram illustrating the additive molding method using it. [Figure 10] This is a schematic diagram illustrating another example of a repair method using the tool repair device shown in Figure 1. [Figure 11] This is a schematic diagram illustrating another example of a repair method using the tool repair device shown in Figure 1. [Modes for carrying out the invention]

[0011] (Embodiment 1) Embodiment 1 of the tool repair device will be described with reference to the drawings. [1. Overview of the tool repair device] As shown in FIG. 1, the tool repair device 1 of this embodiment is a device for repairing a cutting tool 2 made of a cemented carbide material, and mainly includes an additive forming unit 3 and a tool mounting unit 11. The tool repair device 1 can further include a removal processing unit 4 and a measurement unit 5. A cutting tool 2 including a blade body 22 having a cutting edge 21 and a tool body 23 is attached to the tool mounting unit 11 and is supported so as to be relatively movable with respect to the additive forming unit 3 and the removal processing unit 4, respectively. The relative position between the cutting tool 2 and the additive forming unit 3 or the removal processing unit 4 and the operations of each unit can be controlled by a control device 6.

[0012] The additive forming unit 3 employs, for example, laser metal deposition (LMD), which is one of the directed energy deposition methods. The additive forming unit 3 includes a powder material supply device 31, a beam irradiation device 32, etc., and irradiates a laser beam serving as a heat source while injecting a powder material containing a cemented carbide material, and adds the melted material to the forming surface to obtain an additive formed object.

[0013] The removal processing unit 4 is configured using a grinding device or the like, and can perform relative movement with respect to the cutting edge 21 provided on the blade body 22 of the cutting tool 2 to perform removal processing. The removal processing unit 4 is used when removing the cutting edge 21 of the cutting tool 2 prior to repair by the additive forming unit 3. Further, the additive formed object formed on the cutting edge 21 by the repair can also be the object of the removal processing. The measurement unit 5 is used to measure the wear state of the cutting edge 21. The measurement result by the measurement unit 5 can be stored in a storage unit 61 provided in the control device 6.

[0014] The control device 6 drives each part of the device via the drive unit 62 based on the measurement results of the measurement unit 5, various information stored in the storage unit 61, and the like. The control device 6 is provided with an additional shaping control unit 100 and a removal processing control unit 200, the details of which will be described later, and the repair of the cutting tool 2 using the additional shaping unit 3 and the removal processing unit 4 is controlled.

[0015] [2. Cutting tool to be repaired] As shown in Fig. 2, in the tool repair device 1 of this embodiment, the cutting tool 2 to be repaired includes an annular blade body 22 in which a plurality of cutting edges 21 made of cemented carbide are formed on the outer peripheral surface. A plurality of cutting edges 21 are provided on one end side of the blade body 22 in the direction of the central axis C, and the annular portion 24 on the other end side is attached to the tool body 23 (see Fig. 1). The cutting tool 2 is, for example, a tooth cutting tool for creating teeth such as gears. Specifically, a skiving cutter for gear skiving is mentioned, and it can perform skiving by being relatively fed with respect to a workpiece (not shown) while rotating relative to the central axis C.

[0016] Hereinafter, as an example, a skiving cutter for gear skiving will be described. However, the tooth cutting tool as the cutting tool 2 may be a hob cutter for hob machining. Note that the cutting tool 2 is not limited to a tooth cutting tool, and may be a cutting tool such as a cutting insert or a cutting drill that has a cutting edge 21 made of cemented carbide and is used for cutting.

[0017] In Fig. 2, in the blade body 22 of the cutting tool 2, a plurality of cutting edges 21 are arranged annularly to form a gear-shaped annular blade portion. Each cutting edge 21 of the annular blade portion has an outer edge on the outer peripheral side at the end face portion in the direction of the central axis C as the cutting edge r, and the inner peripheral side as the blade root. When viewed from the direction of the central axis C, each cutting edge has a tapered outer shape that becomes wider from the cutting edge side toward the blade root side, and is integrally joined on the blade root side.

[0018] The cutting edge 21 has a rake face 21a formed on the end face in the direction of the central axis C, with a front relief face 21b on the tapered, narrower side, and a pair of side relief faces 21c on both sides of the rake face 21a. In this case, the boundary between the rake face 21a and the front relief face 21b becomes the cutting edge r, and the area on the cutting edge side of the boundary between the rake face 21a and the relief faces (front relief face 21b and the pair of side relief faces 21c) that contributes to the cutting process will hereafter be referred to as the cutting edge region. If the area on the cutting edge side that contributes to the cutting process is only the boundary that becomes the cutting edge r, then the cutting edge region coincides with the cutting edge r. Furthermore, a portion of the boundary between the rake face 21a and the side relief faces 21c that continues from the corners at both ends of the cutting edge r and is located on the base side of the cutting edge will hereafter be referred to as the base region.

[0019] When the cutting tool 2 is used for gear skiving from its pre-use state as shown in Figure 2, wear and tear occur on the edges of each cutting edge 21 of the blade body 22, including the cutting edge region, rendering it unusable for machining. At this point, as shown in Figure 3, a predetermined area including the worn area is designated as the repair area R, and repairs can be performed on the repair area R using the additive molding part 3 (see Figure 1).

[0020] [3. Repair area of ​​cutting tools] Figure 3 schematically shows examples of the basic shape (A) representing the pre-use state, i.e., the normal state, and the worn state (B1) and (B2) representing the post-use state, i.e., the worn state, for one of the multiple cutting edges 21 of the blade body 22 and one of the cutting edges 21 viewed from the direction of the central axis C. The worn state (B1) is the state in which wear has occurred, and the worn state (B2) is the state in which chipping has occurred.

[0021] In the basic shape (A), the end face of the cutting edge 21 in the direction of the central axis C has a tapered outer shape surrounded by a straight cutting edge ridge 25a. In contrast, in the worn shape (B1) after use due to gear skiving, the outer shape of the end face of the cutting edge 21 recedes inward relative to the cutting edge ridge 25a due to wear, and the contour line 25b changes to a non-linear shape. In this embodiment, the entire area where this wear has occurred is designated as the repair area R that requires repair, and repair is performed using the added molding part 3. Prior to this, the removal processing part 4 is used to perform pre-processing on the repair area R.

[0022] In the worn shape (B1), the repair area R corresponds to the area enclosed by the cutting edge ridge 25a in the basic shape (A) before use. The repair using the add-on molding part 3 involves building up the material in the repair area R up to the position of the cutting edge ridge 25a.

[0023] Furthermore, as shown in the worn shape after use (B2), even when the cutting edge 21 is almost worn, a chip 26 may occur on a part of the cutting edge 21. In this case as well, the entire area along the cutting edge ridge line 25a shall be designated as the repair area R that requires repair, and repair shall be carried out using the added molding part 3 and the removal processing part 4. Note that "chip" refers to brittle damage to the tool, and includes chipping, breakage, and fracture.

[0024] [4. Overview of Repair Methods] As shown in Figure 4, which illustrates an example of the worn shape (B1), specifically, the removal processing unit 4 performs removal processing on the area to be repaired R so that the new contour line 25c follows the cutting edge ridge line 25a. Preferably, the outer shape of the end face of the new cutting edge 21 is similar to the basic shape (A), with the contour line 25c receding inward relative to the cutting edge ridge line 25a. The operation of the removal processing unit 4 before repair is controlled by the pre-repair processing control unit 210 in the removal processing control unit 200 of the control device 6 (see Figure 1).

[0025] Subsequently, the additive molding unit 3 forms a build-up layer 20 using the LMD method on the repair area R that has been removed. The build-up layer 20 can be composed of, for example, multiple layers. The molding path is set so that the build-up start point 201 and build-up end point 202 in the repair area R are outside the cutting edge area (for example, the area r1 shown enclosed by a dotted line frame in the figure). Build-up repair is performed according to the set molding path, and the number of layers and the thickness of each layer are adjusted so that the outer shape of the end face of the cutting edge 21 after repair is again at the position of the cutting edge ridge line 25a of the basic shape (A). The operation of the additive molding unit 3 is controlled by the additive molding control unit 100 and the molding path control unit 110 of the control device 6 (see Figure 1).

[0026] Thus, during additive molding, the build-up start point 201 and build-up end point 202 are positioned outside the cutting edge region r1 of the cutting edge 21, allowing the build-up layer 20 to be uniformly formed in the cutting edge region r1, thereby stabilizing the quality of the repaired cutting edge 21. Here, the molding path is set such that the build-up start point 201 and build-up end point 202 are positioned in the cutting edge region (for example, the region r2 enclosed by a dashed frame in the figure), which is a part of the lateral boundary of the rake face 21a on the cutting edge side. The cutting edge region r2 only needs to be set closer to the cutting edge than the cutting edge region r1, but preferably it can be set even closer to the cutting edge, for example, closer to the cutting edge than the line that divides the rake face 21a into the cutting edge side and the cutting edge side.

[0027] Here, as shown in Figure 5, the blade body 22 of the cutting tool 2 is constructed as an integrally sintered product using, for example, a cemented carbide material. Specifically, in step (1), an annular molded body 221 is pre-sintered, in step (2), the pre-sintered body 222 is cut into the shape of the blade body 22, and then in step (3), it is sintered at a predetermined sintering temperature. In step (4), each cutting edge 21 of this sintered body 223 is finished using a grinding tool 41, and then in step (5), the finished cutting edges 21 are coated with, for example, DLC (diamond-like carbon), to obtain a blade body 22 covered with a coating film 224. The grinding tool 41 in step (4) can be constructed as, for example, a grinding wheel with a diamond grinding wheel on its grinding surface.

[0028] The cemented carbide material used to form the blade body 22 is a hard material mainly composed of WC (tungsten carbide), for example. Examples of hard materials mainly composed of WC include sintered composite materials such as WC-Co alloys. WC-Co alloys are cemented carbide alloys containing WC particles and Co as a binder, and their material properties are adjusted by the particle size of the WC particles and the Co content. Generally, it is known that the smaller the particle size of the WC particles, or the lower the Co content, the higher the hardness and lower the toughness.

[0029] Note that the configuration of the blade body 22 shown in Figure 5 is just one example, and it may be an integrally sintered product without coating. Furthermore, it is not limited to an integrally sintered product of cemented carbide; for example, the base material may be formed from another material such as steel, and the surface of the base material may be coated with DLC or the like. Alternatively, the surface of a base material formed from another material such as steel may be coated with cemented carbide.

[0030] As shown in Figure 6, which illustrates the flow after tool manufacturing, cutting tools 2 made from cemented carbide are expensive. For example, after being used in gear skiving (step S1), they are reused after being reground according to the amount of wear (steps S2, S3). However, conventionally, when the amount of wear increased and exceeded a specified amount (i.e., wear amount > specified amount), as shown by the dotted arrow in Figure 6, they were deemed unusable and had to be discarded (step S5). Therefore, in this embodiment, repair is performed by additive molding using the tool repair device 1 shown in Figure 1 (step S4). This makes it possible to extend the lifespan of tools by repairing them without discarding them even when the amount of wear exceeds a specified amount.

[0031] [5. Configuration of the tool repair device] In Figure 1, the tool repair device 1 can be configured as a composite processing machine in which a removal processing unit 4 is attached to an additive manufacturing apparatus that includes a tool mounting section 11 to which a cutting tool 2 is attached, and a powder material supply device 31 and a beam irradiation device 32 which form an additive molding section 3. The powder material supply device 31 includes an injection nozzle 311 and a powder material storage section 312, and the beam irradiation device 32 includes a melting beam irradiation section 321 and a melting beam generation section 322, etc. Note that the configuration of each part of the additive manufacturing apparatus shown in the figure is schematic, and an example of the configuration of the additive molding section 3 will be described later.

[0032] The removal section 4 only needs to process the area R to be repaired before repair into a predetermined shape using the cutting edge 21 of the cutting tool 2. The processing method before repair is not particularly limited and can be appropriately selected from processing methods such as grinding, cutting, laser melting, laser ablation, and wire electrical discharge. Here, for example, a grinding device can be used, and by providing a grinding tool 41 similar to the one used in step (4) of Figure 5 described above, it can also be used for finishing after the build-up layer 20 has been formed by the repair. It is also possible to perform the processing before repair and the finishing process using different methods.

[0033] The tool mounting section 11 includes a spindle 12 that supports the cutting tool 2 so as to be rotatable around the central axis C, and a moving device (not shown). The spindle 12 is provided so as to be relatively movable in three orthogonal axes with respect to the injection nozzle 311 of the powder material supply device 31 and the melting beam irradiation section 321 of the beam irradiation device 32, and can supply powder or irradiate beam onto any part of the cutting tool 2. The same applies when processing is performed by the removal processing section 4; for example, it is provided so as to be relatively movable in three orthogonal axes with respect to the grinding tool 41 of the grinding device. The Z axis in the three orthogonal axes is an axis parallel to the central axis C, and the X and Y axes are axes perpendicular to the Z axis.

[0034] Prior to repair by additive molding, the measurement unit 5 measures the amount of wear and the size of chipping, which indicate the wear state of the cutting edge 21. The configuration of the measurement unit 5 is not particularly limited, but it is sufficient if it is equipped with a camera, light source, etc., to acquire images for observing the state of the cutting edge 21 of the cutting tool 2, and is configured to calculate the amount of wear and the size of chipping by performing image processing and calculation processing. The measurement unit 5 can be configured as a separate device from the composite processing machine including the additive molding unit 3 and the removal processing unit 4, and the measured shape data is sent to the control device 6 and used to determine whether repair is necessary and to determine the repair area R including the worn part.

[0035] The control device 6 includes a storage unit 61 that stores shape information such as shape data corresponding to the normal state of the cutting tool 2, for example, the state before use, and measurement data from the measurement unit 5. The control device 6 also includes an additive molding control unit 100 that controls the operation of the additive molding unit 3, and a removal processing control unit 200 that controls the operation of the removal processing unit 4.

[0036] The additive molding control unit 100 uses the area to be repaired R, which includes the worn portion of the cutting edge 21, as the molding surface, and performs powder material supply and beam irradiation by the additive molding unit 3 to perform repair with a build-up layer 20. Specifically, the molding path control unit 110 controls the molding path by the additive molding unit 3. The removal processing control unit 200 has a pre-repair processing control unit 210, and preferably removes and flattens the surface of the area to be repaired R prior to the formation of the build-up layer 20 by the additive molding unit 3.

[0037] [6. Repair methods for cutting tools] Figure 7 shows a flowchart illustrating the method for repairing a cutting tool 2 using the tool repair device 1. As shown in Figure 6 above, the used cutting tool 2 is reused after being used for gear machining, etc., while the cutting edge 21 is resharpened, and then the cutting edge 21 is repaired as needed. In this case, first, the wear state of the cutting edge 21 is measured using the measuring unit 5, and shape data measuring the amount of wear and the size of chipping is acquired (measurement step S11). The acquired shape data is stored in the storage unit 61 of the control device 6.

[0038] Here, as shown in Figure 4 above, when wear occurs to the cutting edge ridge 25a in the normal state of the cutting edge 21, the amount of wear corresponds to the amount of recession of the contour line 25b on the outer shape of the end face of the worn cutting edge 21. The measurement unit 5 can, for example, identify the contour line 25b based on the acquired image, calculate the amount of recession of each part relative to the cutting edge ridge 25a, and output it as shape data indicating the wear state of each part.

[0039] The control device 6, for example, compares the maximum wear amount value based on shape data with a predetermined specified value to determine whether or not the wear condition requires repair (wear condition determination step S12). If the maximum wear amount exceeds the allowable wear amount, it is determined that the wear condition requires repair by additive molding, and the process proceeds to the next step. If the wear amount is within the allowable range, this flow is terminated.

[0040] Next, the control device 6 performs pre-repair processing control based on the measured amount of wear in the pre-repair processing control unit 210 of the removal processing control unit 200 (pre-repair processing step S13). The pre-repair processing control unit 210 determines the area to be repaired R, including the worn part, from the shape data of the cutting edge 21, and compares the measured shape data with the shape data of the cutting edge ridge line 25a stored in the storage unit 61 to determine the shape after removal processing.

[0041] Specifically, as shown in Figure 4 above, if wear occurs across the entire cutting edge 21, the entire contour line 25b is treated as the repair area R and removed. Then, the contour line 25c after removal is set based on the maximum amount of wear so that the entire worn area due to wear is removed. At this time, the contour line 25c recedes inward to conform to the outer shape of the cutting edge ridge line 25a, which is the reference shape data of the cutting edge 21, resulting in a tapered, approximately similar shape. Furthermore, the amount of surface removal of the worn repair area R is controlled so that the amount of receding from the cutting edge ridge line 25a across the entire contour line 25c is approximately a constant amount corresponding to the maximum amount of wear.

[0042] As a result, the surface of the repair area R after removal is flattened, the contour line 25c becomes straight, and additional molding to the repair area R in the next process is facilitated. In this way, by removing the entire worn part, a minute step is formed that will become the molding surface during additional molding, surrounding the outside of the new contour line 25c. Depending on the wear condition of each part of the repair area R, it is not always necessary for the entire surface of the repair area R to be flattened, and some of the worn parts may remain. For example, if the wear of a part with the maximum wear amount is large, removing the entire part will increase the amount of material removed, and the build-up layer 20 formed in the next process will be thicker, so the shape after removal can be appropriately set within a range where the impact on quality is suppressed.

[0043] Subsequently, the control device 6, in the additive molding control unit 100, uses the repair area R, which has undergone pre-repair processing, as the molding surface and performs additive molding using the additive molding unit 3. At this time, the molding path control unit 110 first sets the molding path for the build-up layer 20 to be added to the repair area R (molding path setting step S14). Next, build-up repair is performed on the repair area R using the additive molding unit 3, for example, forming a multi-layered build-up layer 20 outside the contour line 25c after removal processing (additive molding step S15). After that, if necessary, finishing processing after repair is performed using the removal processing unit 4 (additive molding step S16), and a coating can be applied (coating step S17).

[0044] As shown in Figure 8, specifically, the molding path control unit 110 sets the build-up start point 201 and the build-up end point 202 so that neither is located in the cutting edge region r1. Preferably, they are located in the blade base region r2, which is further away from the cutting edge region r1 of the cutting edge 21. For example, it is desirable to set the build-up start point 201 at the end of the repaired area R closest to the blade base in the blade base region r2. In this case, the molding path proceeds toward the cutting edge side along the contour line 25c after removal processing, passes through the cutting edge region r1, and returns to the blade base side opposite the build-up start point 201. This is the first layer (I), and it is folded back at the blade base end. For the second layer (II), additive molding is performed in the reverse direction. This is repeated for the third layer (III) and beyond, and additive molding is performed until the thickness of the build-up layer 20 reaches the position of the cutting edge ridge line 25a of the basic shape. Here, for example, three layers of additive molding are performed from the inside to the outside within a plane parallel to the rake face 21a, with the end near the blade (where it overlaps with the turning point of the first layer) being designated as the build-up termination point 202. It is also possible to fold back again from the end near the blade and further layering in a direction perpendicular to the rake face 21a (the direction of the central axis C in Figure 2). In this case as well, the path is set so that the final build-up termination point 202 is in the blade base region r2.

[0045] Next, a specific method for performing build-up repair on the fabricated surface of the repair area R using the powder material supply device 31 and beam irradiation device 32 of the additive fabrication unit 3 will be described. As shown in Figure 9, the beam irradiation device 32 may be provided integrally with the main melting beam irradiation unit 321 and may include an auxiliary beam irradiation unit 323 that has a preheating and heat retention function for the fabricated surface B. Note that the configuration of the additive fabrication unit 3 is just one example, and for example, instead of the auxiliary beam irradiation unit 323, a heater with preheating and heat retention may be provided on the fabricated surface B side, or the auxiliary beam irradiation unit 323 may be provided independently.

[0046] In the beam irradiation device 32, an auxiliary beam irradiation unit 323 is coaxially positioned outside the melting beam irradiation unit 321. An auxiliary beam generation unit 324 is connected to the auxiliary beam irradiation unit 323. As a result, the auxiliary beam ABM is irradiated in a ring shape outside the melting beam MBM, which is irradiated in a circular shape from the melting beam generation unit 322 through the melting beam irradiation unit 321. In addition, the injection nozzle 311 of the powder material supply device 31 is positioned near the beam irradiation device 32 and is connected to piping leading to the storage unit 312 where the powder material is stored and the gas cylinder 313 filled with high-pressure gas. Although only one injection nozzle 311 is shown here, multiple nozzles may be evenly arranged outside the beam irradiation device 32. In either case, the irradiation angle of the beam irradiation device 32 and the injection angle of the injection nozzle 311 are adjusted to intersect.

[0047] As a result, the powder material sprayed from the injection nozzle 311 along with high-pressure inert gas is irradiated with both the molten beam MBM and the auxiliary beam ABM. The molten beam MBM is controlled to a temperature that can melt the powder material and form a molten pool MP, while the auxiliary beam ABM is controlled to have a wider irradiation range outward than the molten beam MBM and to a predetermined temperature at which the powder material does not melt. At this time, the additive molding control unit 100 controls the relative scanning and output of the molten beam MBM and the auxiliary beam ABM with respect to the molding surface B. In this process, each layer of the build-up layer 20 is continuously formed from the build-up start point 201 to the build-up end point 202, as set by the build-up path control unit 110.

[0048] This diagram shows the state in which the first layer L1 of the build-up layer 20 is being fabricated on the repair area R, which will be the fabricated surface B, and the second layer L2 is being fabricated on top of it. Each layer consists of multiple beads that are formed in a streaky pattern in the direction of movement as the molten beam MBM moves in the direction indicated by the white arrows in the diagram, after the powder material has been melted so that the molten pool MP expands. The layers in front of the molten pool MP in the direction of movement are preheated by the auxiliary beam ABM, and the layers below and behind the molten pool MP are kept warm by the auxiliary beam ABM, contributing to quality stabilization.

[0049] When forming a build-up layer 20 by additive molding in a repair area R, there is always a build-up start point 201 and a build-up end point 202. For example, if the first layer L1 shown in the figure has a build-up start point 201 in the middle, one of the sides of the build-up start point 201 will not form a continuous bead with respect to the build-up start point 201. Also, a step will be formed at the connection point from the first layer L1 to the second layer L2. In such areas, it is not easy to standardize the conditions for additive molding, making it difficult to create a homogeneous layer, and there is a risk that the quality after repair will not be stable.

[0050] In this embodiment, the molding path is set such that the build-up start point 201 and the build-up end point 202 are located away from the cutting edge region r1 where stable quality is required, for example, in the cutting base region r2, and build-up repair is performed. This stabilizes the quality of the build-up layer 20 made of high-hardness material. Furthermore, by performing pre-repair processing, the molded surface B is flattened, and the build-up layer 20 formed on the molded surface B becomes of a uniform thickness, making it easier to form a homogeneous layer. Therefore, the discarding of cutting tools 2 made of cemented carbide material can be avoided, and they can be used for a longer period while being repaired, thus extending their lifespan.

[0051] (Modified version of Embodiment 1) As shown in Figure 10, which illustrates a repair example in the worn shape (B2), even when chipping 26 occurs due to chipping or the like, the entire area corresponding to the cutting edge ridge 25a can be designated as the repair area R, similar to the worn shape (B1). Similarly, the repair area R is subjected to removal processing by the removal processing unit 4 so that a new contour line 25c follows the shape of the cutting edge ridge 25a, preferably a similar shape.

[0052] Specifically, the entire repair area R of the cutting edge 21 is receded inward from the cutting edge ridge 25a, and the molded surface B (see Figure 9) surrounding the outside of the new contour line 25c is removed and flattened so that it becomes a minute step of a predetermined width and depth corresponding to the size of the chip 26. Subsequently, a build-up layer 20 can be formed on the flattened repair area R by the additional molded part 3 in the same manner as the worn shape (B1).

[0053] In this case, although the worn area due to the chip 26 is part of the cutting edge ridge 25a, if only the part including the chip 26 is removed, there is a risk that a difference in quality will occur between the repaired and unrepaired parts, resulting in unstable quality after repair. Therefore, depending on the size of the chip 26 (for example, the depth from the cutting edge ridge 25a), the removal process is performed so that a new contour line 25c is formed with the entire worn area removed.

[0054] Furthermore, the powder material used when forming the build-up layer 20 by the additive molding section 3 may be the same as the material for the cutting edge 21, but preferably, a material with higher toughness than the material for the cutting edge 21 can be used. For example, when using the WC-Co alloy described above, the toughness can be adjusted by changing the particle size of the WC particles and the Co content, allowing for the formation of a build-up layer 20 with desired properties. In this way, the toughness of the cutting edge 21 after repair is increased, improving its chipping resistance.

[0055] (Other variations of Embodiment 1) As shown in Figure 11 as the wear shape (B3), if wear similar to the wear shape (B1) occurs but no wear occurs on the blade base side, the repair area R can be a part of the area corresponding to the cutting edge ridge 25a. In that case, the part on the blade base side where no wear has occurred is left, and the rest is removed by the removal processing section 4 in the same manner.

[0056] As a result, a new contour line 25c is formed in the repair area R after the removal process, from the cutting edge to the base of the cutting edge, and a minute step of a predetermined width and depth is formed surrounding the outside of this contour line, which becomes the molded surface B (see Figure 9). In this case as well, a build-up layer 20 can be formed by the additional molding part 3 on the minute step of the flattened repair area R.

[0057] When forming the build-up layer 20 on the worn area due to such wear, the powder material used may be the same material as the cutting edge 21 before repair, but a powder material with higher hardness can also be used. For example, when using the WC-Co alloy described above, the hardness can be adjusted by changing the particle size of the WC particles and the Co content, allowing for the formation of a build-up layer 20 with desired properties. In this case, the hardness of the repaired cutting edge 21 increases, improving its wear resistance.

[0058] The present invention is not limited to the embodiments described above, and can be applied to various embodiments without departing from its spirit. [Explanation of Symbols]

[0059] 1. Tool repair device 11 Tool mounting section 2 Cutting tools 21 cutting edge 3. Add-on molding part 31 Powder material supply device 32 Beam irradiation device 4 Removal processing section 5 Measurement Unit 6. Control device 100 Additive molding control unit 110 Molding Path Control Unit 200 Removal Processing Control Unit 210 Pre-repair processing control unit

Claims

1. A tool repair device for repairing cutting tools equipped with cutting edges made of cemented carbide, Additive molding section including powder material supply device and beam irradiation device, A tool mounting portion that supports the cutting tool so as to be movable relative to the added molding portion, The system includes an additive molding control unit that supplies powder material and irradiates a beam onto the area to be repaired, including the worn portion of the cutting edge, to form a build-up layer. The tool repair device includes a molding path control unit that controls the molding path so that the start point and end point of the buildup in the area to be repaired are located outside the cutting edge area of ​​the cutting edge.

2. Furthermore, it is equipped with a measuring unit for measuring the wear state of the cutting edge, The tool repair apparatus according to claim 1, wherein the additive molding control unit determines the area to be repaired based on the measurement data from the measurement unit.

3. moreover, A removal processing unit that moves relative to the cutting tool to perform removal processing on the cutting edge, A storage unit that stores reference shape data for the cutting edge in its normal state, Prior to the formation of the build-up layer, the system includes a pre-repair processing control unit that removes and flattens the surface of the area to be repaired using the removal processing unit, The tool repair device according to claim 2, wherein the pre-repair processing control unit controls the shape after removal processing to conform to the reference shape in a normal state, based on the measurement data from the measurement unit and the reference shape data.

4. The tool repair device according to claim 3, wherein the pre-repair processing control unit controls the amount of surface removal of the cutting edge so that the entire worn portion included in the area to be repaired is removed.

5. The area to be repaired includes the worn portion due to wear of the cutting edge, The tool repair device according to any one of claims 1 to 4, wherein the buildup layer is made of a powder material with higher hardness than the constituent material of the cutting edge.

6. The area to be repaired includes the worn portion due to chipping of the cutting edge, The tool repair device according to any one of claims 1 to 4, wherein the buildup layer is made of a powder material with higher toughness than the material used to construct the cutting edge.

7. The tool repair device according to any one of claims 1 to 4, wherein the cutting tool is a tool for skiving.

8. The tool repair device according to claim 7, wherein the cutting edge region is the cutting edge side of the boundary between the rake face and the flank face that contributes to cutting.

9. The tool repair device according to claim 7, wherein the molding path control unit controls the molding path so that the build-up start point and the build-up end point are located on the blade base side in the area to be repaired.

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