Half-hole cutting tool and cutting method for motorcycle engine box body

Abstract

The invention discloses a half-hole cutting tool for a motorcycle engine box and a cutting method. The cutting tool comprises a tool bar and a tool disc. A connecting part is arranged at one end of the cutter bar, and a mounting hole matched with the connecting part is formed in the middle of the cutter head; the connecting part of the cutter bar is arranged in the mounting hole in a sleeving manner, the end part of the cutter bar extends out of the cutter head, and the cutter head can rotate under the action of external force, is located at a locking station after rotating to a certain angle, and is located at an unlocking station after rotating reversely; the rotating direction of the cutter head rotating to the locking station is opposite to the rotating direction of the cutter head and the cutter bar, when the cutter head is located at the locking station, the mounting hole of the cutter head is in clamping fit with the middle of the connecting part of the cutter bar, the mounting hole and the tail end of the connecting part are crossed, and the tail end of the connecting part compresses and positions the cutter head; when the cutterhead is located at the unlocking station, the mounting hole of the cutterhead rotates to the initial position and corresponds to the connecting part, and the cutterhead can be pulled out of the connecting part of the guide rod under the action of external force.

Description

Technical Field

[0001] The present invention relates to the field of machining motorcycle engine cases, and particularly to a semi-hole cutting tool and a cutting method for a motorcycle engine case. Background Art

[0002] The engine case is a very important component in a motorcycle engine, and a transmission system is installed inside. Among them, in order to make the structure compact, an arc-shaped relief space for installing a gear needs to be provided beside the transmission gear in some engine cases, and this relief space forms an arc-shaped semi-hole in the case (that is, only the side with the cutting part needs to be cut to form a semi-hole). During the machining process, due to the complex shape of the case, the machining position of the arc-shaped semi-hole to be machined is limited, and there are protrusions beside the part to be cut, so that the cutting tool can only extend into the tool from the external through hole adjacent to the arc-shaped semi-hole on the outer side of the case for machining (usually the two holes are arranged vertically and are in the shape of a stepped hole). If the diameter of the arc-shaped semi-hole to be machined is quite different from the diameter of this through hole and is much larger than the through hole to be inserted, the conventional cutting tool cannot form a large-diameter arc-shaped semi-hole after the cutting tool performs cutting. For example, the existing eccentric reverse boring tool can only cut and machine stepped holes with a small difference in upper and lower hole diameters and is not suitable for cutting holes with a large difference in upper and lower hole diameters; the parachute-type tool can be closed before cutting, open when it rotates to a certain speed, and then close and retract the tool after machining, but when this tool is used for cutting and machining a product with a single-side arc surface and a cutting thickness greater than 10 mm, there will be uneven force and serious tool damage.

[0003] In view of the above problems, the applicant desires to design a cutting tool and a cutting method that can pass through a smaller external through hole, cut inside the case, and form an arc-shaped semi-hole. Summary of the Invention

[0004] Aiming at the above deficiencies existing in the prior art, the purpose of the present invention is to provide a semi-hole cutting tool and a cutting method for a motorcycle engine case, so as to solve the problems that the cutting tool in the prior art cannot perform single-side cutting on a hole with a large diameter and has a high tool damage rate during cutting.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A semi-hole cutting tool for a motorcycle engine case, comprising a tool shank and a tool disc; one end of the tool shank is provided with a connecting portion, and a mounting hole matching the connecting portion is provided in the middle of the tool disc; the connecting portion of the tool shank is sleeved in the mounting hole, and the end portion extends out of the tool disc; a plurality of cutting tools are mounted on the tool disc, the cutting tools are located on two opposite sides of the tool disc, and the distance between the outer sides of the cutting tools on both sides is greater than the width of the tool disc; the tool disc can rotate under the action of an external force and is in a locked position after rotating to a certain angle, and is in an unlocked position after rotating in the reverse direction; the rotation direction of the tool disc to the locked position is opposite to the rotation direction of the tool disc and the tool shank, and when the tool disc is in the locked position, the mounting hole of the tool disc is clamped and matched with the middle part of the connecting portion of the tool shank, and the ends of the mounting hole and the connecting portion are in a crossed shape, and the end of the connecting portion presses and positions the tool disc; when the tool disc is in the unlocked position, its mounting hole rotates back to the initial position, corresponding to the connecting portion, and the tool disc can be pulled out from the connecting portion of the guide rod under the action of an external force. In this way, when cutting the case, first fix the end of the tool shank far from the connecting portion on the cutting machine tool, then fix the engine case to be processed on the opposite side of the tool shank, and adjust the position of the engine case so that the small hole beside the part to be cut corresponds to the tool shank, and then move the engine case or the tool shank so that the tool shank passes through the small hole, and the connecting portion extends out of the small hole and is placed beside the part to be cut. After the tool shank and the engine case to be cut are adjusted in place, the tool disc can be installed. When installing the tool disc, align the mounting hole of the tool disc with the connecting portion of the tool shank and insert it on the connecting portion, so that the middle part of the connecting portion corresponds to the mounting hole, and the end portion extends out of the mounting hole, and then rotate the tool disc until it cannot rotate. The mounting hole of the tool disc is clamped with the middle part of the connecting portion, the end is placed outside the mounting hole and is in a crossed shape with the mounting hole, and the tool disc is rotated to the locked position to achieve locking. After the tool disc is locked, start the cutting machine tool, and the main shaft of the cutting machine tool drives the tool shank and the tool disc to rotate together to complete the cutting of the tool disc. After the cutting is completed, after rotating the tool disc in the reverse direction, the relative position between the mounting hole and the connecting portion of the tool disc changes, and the mounting hole corresponds to the connecting portion, so that under the action of an external force, the tool disc can be taken out from the tool shank. The tool disc and the tool shank are detachably connected, so that during assembly, only the tool shank needs to pass through the small hole, without considering the size of the tool disc, so that it can meet the requirement that the cutting tool passes through the small hole and then cuts the large hole. At the same time, the locking and separation operations between the tool disc and the tool shank are relatively convenient, which is convenient for popularization and can be applied to the cutting of other parts. In addition, since the middle part between the tool disc and the connecting portion is tightly fitted after rotation, and the end of the connecting portion of the tool shank is in a crossed shape with the mounting hole and is closely attached to the end face of the tool disc, it can form a pressing and fixing of the tool disc. At the same time, the locking rotation direction is opposite to the rotation direction of the tool disc during cutting. During the cutting process, the cutting force is in the same direction as the locking direction, so that during cutting, the tool disc and the tool shank are getting tighter and will not fall off, and the safety factor of cutting is high. The tool disc is not a conventional disc shape, but the lengths of two of its sides are longer than the lengths of the other two opposite sides, so that it is convenient to assemble in a limited space and will not interfere with the part to be cut.

[0006] Further, the outer diameter of the connecting portion is smaller than that of the tool shank body, and it is composed of a connecting section and a positioning section; the connecting section is cylindrical, the positioning section is a double-sided flat-cut cylinder, and the positioning section is composed of a first positioning section and a second positioning section. The first positioning section is adjacent to the connecting section, and two clamping grooves are circumferentially spaced on the first positioning section; the mounting hole is composed of a circular sleeve hole and a fillet rectangular hole, and two oppositely arranged clamping blocks are provided on one side of the fillet rectangular hole close to the circular sleeve hole. The two clamping blocks and the two straight sides of the fillet rectangular hole together form a through hole for the positioning section of the connecting portion to pass through; the diameter of the circular sleeve hole is greater than or equal to the diameter of the connecting section. After the tool disc rotates to the locking position, the first positioning section of the connecting portion is clamped and fitted between the two straight sides of the fillet rectangular hole, the second positioning section of the connecting portion extends out of the fillet rectangular hole, and the fillet rectangular hole and the second positioning section are in a cross shape. In this way, the two clamping grooves in the middle of the connecting portion are spaced apart and are on both sides of the diameter line of the circumference where they are located. After rotation, the positions of the clamping grooves are stuck between the two long sides of the fillet rectangular hole, that is, the distance between the two clamping grooves is equal to the distance between the two long sides of the fillet rectangular hole. And the two clamping grooves are the clamping grooves opened on the first positioning section, and the distance between the two clamping grooves is smaller than the distance between the two corresponding positions of the second positioning section. Therefore, after being clamped in the fillet rectangular hole at the clamping grooves, the extended second positioning section corresponds to the distance between the two positions opposite to the two clamping grooves, and this distance is greater than the distance between the two clamping grooves and the distance between the two long sides of the fillet rectangular hole. Therefore, the two opposite sides of the second positioning section extend beyond the long sides of the fillet rectangular hole and together with the end face of the tool shank body form the clamping and positioning of the tool disc. The clamping blocks are arranged at the two rounded edges of the fillet rectangular hole and form a through hole with the two straight sides of the fillet rectangular hole, that is, the clamping blocks and the two straight sides together form a through hole that matches the positioning section. Since the positioning section is a double-sided flat-cut cylinder and the end face is in the shape of a fillet rectangle, the through hole is also a fillet rectangle and shares the same side with the two straight sides of the fillet rectangular hole, and the length of the straight side is slightly smaller than the two straight sides of the fillet rectangular hole. Thus, both the first positioning section and the second positioning section can pass through the through hole, and after the first positioning section passes through the through hole and corresponds to the fillet rectangular hole, after rotating a certain angle, it can be clamped and fitted with the two straight sides of the fillet rectangular hole.

[0007] Further, the cutter head includes a cutter head body and a cutter mounting portion distributed clockwise along the outer edge of the cutter head body. The cutter head body is in the shape of a rounded rectangle, and the cutter mounting portions are arranged on the two rounded sides of the cutter head body; a cutting tool is provided on the rotation azimuth side of each cutter mounting portion, and the outer ends of all the cutting tools are on the same circumference, and the diameter of the circumference where the outer ends are located is equal to the diameter of the semi-hole to be cut. In this way, the cutter head body is in the shape of a rounded rectangle, and the cutter mounting portions are arranged on the two rounded sides, extending outward from the rounded sides and integrally formed with the cutter head body, so that the width of the two straight sides of the cutter head is less than the distance between the other two cutter mounting portions. Therefore, when taking or rotating, it can be grasped at the two straight sides of the cutter head body, which is convenient to grasp and is conducive to installation and rotation operations. At the same time, there is a certain clearance space at the wide side of the cutter head, which can also adapt to the cutting of round holes or arc-shaped concave surfaces in a smaller space. The cutting tools are evenly distributed and the outer ends are on the same circumference, which can meet the requirements of cutting round holes or arc surfaces.

[0008] Further, there are four cutter mounting portions, which are distributed in pairs on the rounded sides of the cutter head body. The outer edges of all the cutter mounting portions are on the same circumference, and the center of the circumference where the outer edges of the cutter mounting portions are located overlaps with the center of the mounting hole. In this way, the cutter mounting portions and the cutting tools fixed on them are evenly distributed, which is convenient for manufacturing and cutting. The distances from the outer edges of the cutter mounting portions to the center of the mounting hole are equal. At the same time, the cutter mounting portions are circumferentially distributed around the center of the mounting hole, and each cutter mounting portion is evenly stressed during cutting and is not easily deformed or damaged.

[0009] Further, the cross-sectional width of the cutter mounting portion is greater than the cross-sectional width of the cutting tool, and the cutting tool is fixed by welding or detachably mounted on the cutter mounting portion. In this way, except for the protruding part, the rest of the cutting tool is closely attached to the cutter mounting portion. During the cutting process, almost all the cutting forces generated will be transmitted to the cutter mounting portion. The cutting tool and the cutter mounting portion together bear the cutting forces generated during cutting, and the overall rigidity is relatively high, and it is not easily deformed or damaged during the cutting process.

[0010] Further, the thickness of the cutter head body is 14.9 - 15.2 mm, the thickness of the cutter mounting portion is 11.1 - 11.3 mm, and the width is 12 - 14 mm. In this way, the cutter mounting portion and the cutter head body are relatively thick and have high strength. At the same time, the width of the cutter mounting portion is wider than that of a conventional cutter head, and the overall strength and rigidity are higher, which can meet the requirements of unilateral cutting, have a long service life, and can meet the long-term cutting needs.

[0011] A method for cutting a semi-hole of a motorcycle engine case includes the following steps: S1, designing and manufacturing a semi-hole cutting tool according to the design requirements of the engine case, the semi-hole cutting tool being as described above; S2, fixedly installing the opposite side of the connecting part on the tool shank on the main shaft of the cutting machine tool; S3, fixing the engine case to be machined on the four-axis turntable under the cutting station of the cutting machine tool, and after controlling the four-axis turntable to rotate, rotating the side of the engine case where the part to be cut is located to the upper side, and at the same time controlling the four-axis turntable to move left and / or right and / or forward and backward, so that the through hole beside the part to be cut on the engine case corresponds to the tool shank fixed on the cutting machine tool; S4, installing the cutter head, controlling the lifting mechanism of the cutting machine tool to drive the main shaft and the tool shank to move downward until the tool shank passes through the through hole on the engine case and then stops moving, and then aligning the mounting hole on the cutter head with the tool shank and sleeving it on the tool shank until the end of the tool shank extends out of the cutter head and then rotating the cutter head. After the cutter head rotates into place, the mounting hole of the cutter head is clamped tightly with the middle part of the connecting part, and the end of the tool shank is in a crossed shape with the mounting hole, and the cutter head is pressed tightly and fixed on the tool shank; S5, starting the main shaft to rotate, and the tool shank and the cutter head perform unilateral cutting on the corresponding position of the engine case under the drive of the main shaft until the cutting stops after reaching the design requirements; S6, rotating the cutter head in the reverse direction, making the tool shank correspond to the mounting hole, then pulling the cutter head downward to remove the cutter head from the tool shank, driving the lifting mechanism of the cutting machine tool to drive the main shaft and the tool shank to rise, and withdrawing the tool shank from the engine case to complete the cutting. In this way, after fixing, rotating, and aligning the engine case, the cutter head and the tool shank are fixed together. This method of first corresponding the tool shank with the through hole on the engine case and then installing the cutter head enables the cutter head to avoid the shielding part, correspond to the part to be cut, and be placed on one side of the part to be cut. At the same time, the cutter head does not need to adapt to the through hole, and compared with the parachute-type tool, it has higher rigidity and can meet the requirements of unilateral cutting.

[0012] Further, when installing the cutter head, the cutting tools on both sides of the cutter head are correspondingly arranged on one side of the part to be cut of the engine case. In this way, the cutting tools of the cutter head are located on one side of the part to be cut of the case, and there is no interference between the cutting tools and the part to be cut, and the cutting and assembly requirements can be met. Description of the Drawings

[0013] Figure 1 Schematic diagram of the split structure of the tool shank and the cutter head in the embodiment; Figure 2 For Figure 1 Schematic diagram of the sectional structure of A-A in Figure 3 Schematic diagram of the structure of the cutter head in the embodiment; Figure 4 For Figure 3 Schematic diagram of the sectional structure of B-B in Figure 5 Schematic diagram of the assembled state of the tool shank and the cutter head in the embodiment; Figure 6 Schematic three-dimensional structure diagram of the tool shank in the embodiment; Figure 7 Schematic connection structure diagram between the tool disc and the guide rod in the locked state in the embodiment; Figure 8 Schematic installation diagram of the tool shank and the tool disc before cutting in the embodiment. Detailed implementation manners

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Components of the embodiments of the present invention described and illustrated herein can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0015] It should be noted that like reference numerals and letters refer to like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the product of the invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance. In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined. In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0016] Such as Figures 1-7As shown in the figure, the semi-hole cutting tool for a motorcycle engine housing disclosed in this embodiment includes a tool shank 1 and a tool disc 2. One end of the tool shank 1 is provided with a connecting portion 12, and a mounting hole 24 matching the connecting portion 12 is provided in the middle of the tool disc 2. The connecting portion 12 of the tool shank 1 is sleeved in the mounting hole 24, and the end portion extends out of the tool disc 2. Four cutting tools 23 are mounted on the tool disc 2. The cutting tools 23 are located on two opposite sides of the tool disc 2, and the distance between the outer sides of the cutting tools 23 on both sides (shown as L1 in the figure) is greater than the width of the tool disc 2 (shown as L2 in the figure). The tool disc 2 can rotate under the action of an external force and is in the locked position after rotating to a certain angle, and is in the unlocked position after rotating in the reverse direction. The rotation direction of the tool disc 2 when it rotates to the locked position is opposite to the rotation direction of the tool disc 2 and the tool shank 1. When the tool disc 2 is in the locked position, the mounting hole 24 of the tool disc 2 is clamped and matched with the middle part of the connecting portion 12 of the tool shank 1, and the ends of the mounting hole 24 and the connecting portion 12 are in a cross shape, and the end of the connecting portion 12 presses and positions the tool disc 2. When the tool disc 2 is in the unlocked position, its mounting hole 24 rotates back to the initial position and corresponds to the connecting portion 12, and the tool disc 2 can be pulled out from the connecting portion 12 of the guide rod under the action of an external force. In this way, when cutting the housing, first fix the end of the tool shank 1 away from the connecting portion 12 on the cutting machine tool, then fix the engine housing 3 to be machined on the opposite side of the tool shank 1, and adjust the position of the engine housing so that the small hole beside the part to be cut corresponds to the tool shank 1. Then move the engine housing or the tool shank 1 so that the tool shank 1 passes through the small hole, and the connecting portion 12 extends out of the small hole and is placed beside the part to be cut. After the tool shank 1 and the engine housing to be cut are adjusted in place, the tool disc 2 can be installed. When installing the tool disc 2, make the mounting hole 24 of the tool disc 2 correspond to the connecting portion 12 of the tool shank 1 and insert it on the connecting portion 12 so that the middle part of the connecting portion 12 corresponds to the mounting hole 24, and the end portion extends out of the mounting hole 24. Then rotate the tool disc 2 until it cannot rotate. The mounting hole 24 of the tool disc 2 is clamped with the middle part of the connecting portion 12, and the end is placed outside the mounting hole 24 and is in a cross shape with the mounting hole 24. The tool disc 2 is rotated to the locked position to achieve locking. After the tool disc 2 is locked, start the cutting machine tool. The main shaft of the cutting machine tool drives the tool shank 1 and the tool disc 2 to rotate together to complete the cutting of the tool disc 2. After the cutting is completed, after rotating the tool disc 2 in the reverse direction, the relative position between the mounting hole 24 and the connecting portion 12 of the tool disc 2 changes, and the mounting hole 24 corresponds to the connecting portion 12. Thus, under the action of an external force, the tool disc 2 can be taken out from the tool shank 1. The tool disc 2 and the tool shank 1 are detachably connected. Thus, during assembly, only the tool shank 1 needs to pass through the small hole, without considering the size of the tool disc 2, so that it can meet the requirement that the cutting tool 23 passes through the small hole and then cuts the large hole. At the same time, the locking and separation operations between the tool disc 2 and the tool shank 1 are relatively convenient, which is convenient for popularization and can be applied to the cutting of other parts.In addition, since there is an interference fit after the middle part between the cutter head 2 and the connecting part 12 rotates, and the end of the connecting part 12 of the cutter bar 1 is cross-shaped with the mounting hole 24 and is in close contact with the end face of the cutter head 2, it can form a pressing and fixing of the cutter head 2. At the same time, the locking rotation direction is opposite to the rotation direction of the cutter head 2 during cutting. During the cutting process, the cutting force is in the same direction as the locking direction. Therefore, during cutting, the cutter head 2 and the cutter bar 1 become tighter and will not fall off, and the safety factor of cutting is high. The cutter head 2 is not a conventional disc shape, but the lengths of its two sides are longer than the lengths of the other two opposite sides, so that it can be easily assembled in a limited space and will not interfere with the part to be cut.

[0017] Specifically, the engine housing 3 referred to in this embodiment is the left engine housing or the right engine housing. The part to be cut is a cube and is located inside the engine housing 3. On one side of the part to be cut 31 and on the engine housing 1, there is a through hole (not marked in the figure), and this through hole is the through hole through which the cutter bar 1 is to pass. The diameter of the through hole is small, while the diameter of the circumference where the cutting semi-hole of the part to be cut is located is 88 mm, and the thickness to be cut is relatively large. On the opposite side of the through hole in the engine housing through which the cutter bar 1 is passed, there is a protrusion. The protrusion is adjacent to the part to be cut and is partially staggered, so that the cutting tool cannot extend from this side to cut the part to be cut, and can only enter from one side of the through hole for cutting. Of course, in specific applications, for other equipment openings where there is interference with the placement position of such a cutting tool and it can only be placed from the other side, and the tool placement space is limited, at the same time, it can also be applied to the cutting of existing stepped holes and large holes.

[0018] Furthermore, the outer diameter of the connecting portion 12 is smaller than that of the cutter bar body 11, and it consists of a connecting section 121 and a positioning section; the connecting section 121 is cylindrical, the positioning section is a double-sided flat-cut cylinder, and the positioning section consists of a first positioning section 122 and a second positioning section 123. The first positioning section 122 is adjacent to the connecting section 121, and two clamping grooves 122a are circumferentially spaced on the first positioning section 122; the mounting hole 24 consists of a circular sleeve hole 241 and a rounded rectangular hole 242. On one side of the rounded rectangular hole 242 close to the circular sleeve hole 241, two oppositely arranged clamping blocks 243 are provided. The two clamping blocks 243 and the two straight edges of the rounded rectangular hole 242 together form a through hole for the positioning section of the connecting portion 12 to pass through; the diameter of the circular sleeve hole 241 is greater than or equal to the diameter of the connecting section 121. After the cutter disc 2 rotates to the locking position, the first positioning section 122 of the connecting portion 12 is clamped and fitted between the two straight edges of the rounded rectangular hole 242, and the second positioning section 123 of the connecting portion 12 extends out of the rounded rectangular hole 242, and the rounded rectangular hole 242 and the second positioning section 123 are in a cross shape. In this way, the two clamping grooves 122a in the middle of the connecting portion 12 are spaced apart, on both sides of the diameter line of the circumference where they are located. After rotation, the positions of the clamping grooves 122a are stuck between the two long sides of the rounded rectangular hole 242, that is, the distance between the two clamping grooves 122a is equal to the distance between the two long sides of the rounded rectangular hole 242. And the two clamping grooves 122a are the clamping grooves 122a opened on the first positioning section 122, and the distance between the two clamping grooves 122a is smaller than the distance between the two corresponding positions of the second positioning section 123. Therefore, after being clamped in the rounded rectangular hole 242 at the clamping grooves 122a, the protruding second positioning section 123 corresponds to the distance between the two positions opposite to the two clamping grooves 122a. This distance is greater than the distance between the two clamping grooves 122a and the distance between the two long sides of the rounded rectangular hole 242. Therefore, the two opposite sides of the second positioning section 123 extend beyond the long sides of the rounded rectangular hole 242, and together with the end face of the cutter bar body 11, they form a clamping and positioning for the cutter disc 2. The clamping blocks 243 are arranged at the two rounded edges of the rounded rectangular hole 242 and form a through hole with the two straight edges of the rounded rectangular hole 242, that is, the clamping blocks 243 and the two straight edges together form a through hole that matches the positioning section. Since the positioning section is a double-sided flat-cut cylinder and the end face is in a rounded rectangular shape, the through hole is also a rounded rectangle and shares the same side with the two straight edges of the rounded rectangular hole 242, and the length of the straight edge is slightly smaller than the two straight edges of the rounded rectangular hole 242. Thus, both the first positioning section 122 and the second positioning section 123 can pass through the through hole. And after the first positioning section 122 passes through the through hole and corresponds to the rounded rectangular hole 242, after rotating a certain angle, it can be clamped and fitted with the two straight edges of the rounded rectangular hole 242.

[0019] Furthermore, the cutter head 2 includes a cutter head body 21 and four tool mounting parts 22. The cutter head body 21 is in the shape of a rounded rectangle. The tool mounting parts 22 are arranged on the two rounded edges of the cutter head body 21 and are integrally formed with the cutter head body 21. On the cutting rotation azimuth side of each tool mounting part 22 (i.e., the same side as the circumferential rotation direction of the cutter head body 21), a cutting tool 23 is provided. The outer ends of all the cutting tools 23 are on the same circumference, and the diameter of the circumference where the outer ends are located is equal to the diameter of the semi-hole to be cut. In this way, the cutter head body 21 is in the shape of a rounded rectangle, and the tool mounting parts 22 are arranged on the two rounded edges and extend outward from the rounded edges, being integrally formed with the cutter head body 21, so that the width of the two straight edges of the cutter head 2 is smaller than the distance between the other two tool mounting parts 22. Thus, when grasping or rotating, it can be grasped at the two straight edges of the cutter head body 21, which is convenient for grasping and is conducive to installation and rotation operations. At the same time, there is a certain clearance space at the wide edge of the cutter head 2, which can also adapt to the cutting of round holes or arc-shaped concave surfaces in a smaller space. The cutting tools 23 are evenly distributed, and the cutting edges are arranged in the radial direction, which can meet the cutting requirements.

[0020] Furthermore, there are four tool mounting parts 22, which are distributed in pairs on the rounded edges of the cutter head body 21. The outer edges of all the tool mounting parts 22 are on the same circumference, and the center of the circumference where the outer edges of the tool mounting parts 22 are located overlaps with the center of the mounting hole 24. In this way, the tool mounting parts 22 and the cutting tools 23 fixed on them are evenly distributed, which is convenient for manufacturing and cutting. The distances between the outer edges of the tool mounting parts 22 and the center of the mounting hole 24 are equal. At the same time, the tool mounting parts 22 are circumferentially distributed around the center of the mounting hole 24, and each tool mounting part 22 is evenly stressed during cutting and is not easily deformed or damaged.

[0021] Furthermore, the cross-sectional width of the tool mounting part 22 is greater than the cross-sectional width of the cutting tool 23, and the cutting tool 23 is fixed by welding or detachably mounted on the tool mounting part 22. In this way, except for the protruding part, the rest of the tool is in close contact with the tool mounting part 22. During the cutting process, almost all the cutting forces generated will be transmitted to the tool mounting part 22. The cutting tool 23 and the tool mounting part 22 together bear the cutting forces generated during cutting, and the overall rigidity is relatively high, and it is not easily deformed or damaged during the cutting process.

[0022] As Figure 1 、 Figure 3 、 Figure 4 shown, the thickness H1 of the cutter head body 21 is 15 mm, the thickness H2 of the tool mounting part 22 is 11 mm, and the width W1 is 13 mm. In this way, the tool mounting part 22 and the cutter head body 21 are relatively thick and have relatively high strength. At the same time, the width of the tool mounting part 22 is wider than that of the conventional cutter head 2, and the overall strength and rigidity are higher, which can meet the requirements of unilateral cutting, have a long service life, and can meet the long-time cutting needs.

[0023] This embodiment also provides a method for cutting a semi-hole of a motorcycle engine case, which includes the following steps: S1, designing and manufacturing a semi-hole cutting tool 23 according to the design requirements of the engine case, and the semi-hole cutting tool 23 is as described above (see Figures 1-7 shown); S2, fixedly installing the opposite side of the connecting portion 12 on the tool bar 1 on the main shaft of the cutting machine tool; S3, fixing the engine case to be machined on the four-axis turntable 4 under the cutting station of the cutting machine tool, and after controlling the four-axis turntable 4 to rotate, rotating the side of the engine case where the portion to be cut is located to the upper side, and at the same time controlling the four-axis turntable 4 to move in the four directions of left, right, front and back (i.e., moving in the X direction and the Y direction), so that the through hole beside the portion to be cut on the engine case corresponds to the tool bar 1 fixed on the cutting machine tool (as Figure 8 shown); S4, installing the cutter head 2, controlling the lifting mechanism of the cutting machine tool to drive the main shaft and the tool bar 1 to move downward until the tool bar 1 passes through the through hole on the engine case and stops moving after reaching the set position (the set position is the position where the first positioning section 122 on the tool bar corresponds to the portion to be cut), then aligning the mounting hole 24 on the cutter head 2 with the tool bar 1 and sleeving it on the tool bar 1. Until the end of the tool bar 1 extends out of the cutter head 2, then rotate the cutter head 2. After the cutter head 2 rotates in place, the mounting hole 24 of the cutter head 2 is clamped tightly with the middle part of the connecting portion 12, and the end of the tool bar 1 and the mounting hole 24 are in a crossed state, and the cutter head 2 is pressed tightly and fixed on the tool bar 1; S5, starting the main shaft to rotate, and the tool bar 1 and the cutter head 2 perform unilateral cutting on the corresponding position of the engine case under the drive of the main shaft until the cutting stops after reaching the design requirements; S6, manually rotating the cutter head 2 in the reverse direction, making the tool bar 1 correspond to the mounting hole 24, then pulling the cutter head 2 downward to remove the cutter head 2 from the tool bar 1, and then controlling the lifting mechanism to drive the main shaft and the tool bar 1 to rise, and withdrawing the tool bar 1 from the engine case to complete the cutting. In this way, after fixing, rotating, and aligning the engine case, then fixing the cutter head 2 and the tool bar 1 together. This method of first corresponding the tool bar 1 with the through hole on the engine case and then installing the cutter head 2 enables the cutter head 2 to avoid the shielding part and correspond to the portion to be cut, and is placed on one side of the portion to be cut. At the same time, the cutter head 2 does not need to adapt to the through hole, and has higher rigidity compared with the parachute-type tool, and can meet the requirements of unilateral cutting.

[0024] The four-axis turntable 4 adopted in this embodiment includes two spaced-apart supports 41, and a workpiece fixing plate 42 is provided between the two supports 41 and is connected to them. The support 41 can move in the X and Y directions under the drive of a sliding mechanism, and the workpiece fixing plate 42 is connected to a driving mechanism and can rotate and be positioned under the drive of the driving mechanism. At the same time, an operation opening is also provided in the middle of the workpiece fixing plate 42. When the engine case is being cut, one side of the through hole is at the upper end, and the portion to be cut is inside the operation opening. When installing and disassembling the cutter head 2, workers operate on the cutter head 2 from this operation opening.

[0025] Furthermore, when installing the cutter head 2, the cutters on both sides of the cutter head 2 are arranged correspondingly on one side of the to-be-cut part of the engine housing. In this way, the cutting cutter 23 of the cutter head 2 is located on one side of the to-be-cut part of the housing, and there is no interference between the cutting cutter and the to-be-cut part, which can meet the requirements of cutting and assembly.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Those of ordinary skill in the art should understand that any modifications or equivalent replacements made to the technical solutions of the present invention without departing from the spirit and scope of the present technical solution shall be covered by the scope of the claims of the present invention.

Claims

1. A half-hole cutting tool for a motorcycle engine case, characterized in that: The tool holder is a tool for cutting a piece of steel, and the tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel. The tool holder has a plurality of cutting tools, each of which is adapted to cut the piece of steel.

2. The half-hole cutting tool for motorcycle engine case according to claim 1, characterized in that: The outer diameter of the connecting part is smaller than the outer diameter of the tool rod body, and is composed of a connecting section and a positioning section; the connecting section is cylindrical, the positioning section is a double-sided flat-cut cylinder, and the positioning section is composed of a first positioning section and a second positioning section, the first positioning section is adjacent to the connecting section, and two slots are circumferentially spaced on the first positioning section; the mounting hole is composed of a circular sleeve hole and a rounded rectangular hole, and two oppositely arranged clamping blocks are provided on the side of the rounded rectangular hole close to the circular sleeve hole, and the two clamping blocks together with the two straight sides of the rounded rectangular hole form a through hole for the positioning section of the connecting part to pass through; the diameter of the circular sleeve hole is greater than or equal to the diameter of the connecting section, and after the tool disc is rotated to the locking position, the first positioning section of the connecting part is clamped and fitted between the two straight sides of the rounded rectangular hole, the second positioning section of the connecting part extends out of the rounded rectangular hole, and the rounded rectangular hole and the second positioning section are cross-shaped.

3. The half-hole cutting tool for motorcycle engine case according to claim 1 or 2, characterized in that: The cutter disc includes a cutter disc main body and a tool mounting portion distributed in a clockwise direction along the outer edge of the cutter disc main body. The cutter disc main body is in a rounded rectangular shape, and the tool mounting portion is arranged on the two rounded sides of the cutter disc main body. A cutting tool is arranged on the rotational azimuth side of each tool mounting portion, and the outer ends of all cutting tools are on the same circumference, and the diameter of the circumference of the outer ends is equal to the diameter of the half hole to be cut.

4. The half-hole cutting tool for motorcycle engine case according to claim 3, characterized in that: There are four tool mounting parts, which are distributed in pairs on the rounded edges of the cutter disc body. The outer edges of all tool mounting parts are on the same circumference, and the center of the circumference of the outer edge of the tool mounting part overlaps with the center of the mounting hole.

5. The half-hole cutting tool for motorcycle engine case according to claim 3, characterized in that: The cross-sectional width of the tool mounting portion is greater than the cross-sectional width of the cutting tool, and the cutting tool is fixed by welding or detachably mounted on the tool mounting portion.

6. The half-hole cutting tool for motorcycle engine case according to claim 4 or 5, characterized in that: The thickness of the cutter disc body is 14.9-15.2 mm, the thickness of the cutter mounting portion is 11.1-11.3 mm, and the width is 12-14 mm.

7. A method for cutting a half hole of a motorcycle engine case, characterized in that: The method comprises the following steps: S1, designing and manufacturing a half-hole cutting tool according to the design requirements of an engine case, wherein the half-hole cutting tool is as described in any one of claims 1 to 6; S2, fixing the opposite side of the connecting portion on the tool bar on the spindle of a cutting machine; S3, fixing the engine case to be processed on a four-axis turntable under the cutting station of the cutting machine, and after controlling the four-axis turntable to rotate, rotating one side of the part to be cut on the engine case upward, and controlling the four-axis turntable to move left and right and / or forward and backward at the same time, so that the through hole next to the part to be cut on the engine case corresponds to the tool bar fixed on the cutting machine; S4, installing the cutter disc, controlling the lifting mechanism on the cutting machine to drive the spindle and the tool bar to move downward until the tool bar penetrates the cutting machine. After passing through the through hole on the engine case, stop moving, then align the mounting hole on the cutter disc with the cutter rod and put it on the cutter rod until the end of the cutter rod extends out of the cutter disc and then rotate the cutter disc. After the cutter disc is rotated into place, the mounting hole of the cutter disc is clamped with the middle part of the connecting part, and the end of the cutter rod is in a cross shape with the mounting hole, so that the cutter disc is pressed tightly against the cutter rod; S5, start the main shaft to rotate, and the cutter rod and the cutter disc are driven by the main shaft to perform unilateral cutting on the corresponding position of the engine case until the design requirements are met and stop cutting; S6, rotate the cutter disc in the opposite direction, so that the cutter rod corresponds to the mounting hole, pull the cutter disc downward, remove the cutter disc from the cutter rod, and then control the lifting mechanism to drive the main shaft and the cutter rod to rise, withdraw the cutter rod from the engine case, and complete the cutting.

8. The half-hole cutting method of a motorcycle engine case according to claim 7, characterized in that: When installing the cutter disc, the cutters on both sides of the cutter disc are arranged correspondingly on one side of the part to be cut of the engine case.

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