JP4127328B2 - Crankshaft machining cutter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a throw-away tip seating portion in a crankshaft machining cutter in which a cutting edge is constituted by a rough cutting tip and a finishing cutting tip.
[0002]
[Prior art]
One of the processes for manufacturing a crankshaft, which is a main component of an automobile engine or the like, is a process of side surface processing of both ends of a pin journal and a process of shallow groove processing generally referred to as an undercut. Conventionally, the machining of this part has been performed in two steps: a step of milling the side surface of the pin journal using a crankshaft mirror, and a step of subsequent finishing and grooving by turning. However, in the turning process, the indexing work of the pin journals having different phases is troublesome, and since the process is divided into two processes, an extra machine device, an installation place, an operation person, etc. are required. Therefore, a request to consolidate these and increase the processing efficiency was born.
[0003]
As a relatively new technique that satisfies such requirements, a technique has been developed that enables both side surface processing and groove processing of both ends of a pin journal with a single cutter. For example, Japanese Utility Model Laid-Open No. 6-57513 discloses a cutter device for a crankshaft mirror. This cutter is composed of a rough blade tip that simultaneously performs rough machining on both side surfaces of both ends of the pin journal and groove processing of the tip, and a finishing blade tip that is partially replaced. A finishing blade is formed as a cutting blade for side processing on the finishing blade tip, and the finishing blade is used for finishing.
[0004]
This type of cutter is usually configured such that a throw-away tip (hereinafter referred to as a tip) is placed on the cutter body in a standing insert state, and is screwed and fixed using a countersunk hole drilled in the center of the tip. Yes. As exemplified in the above publication, in many of the prior arts, the chip is directly assembled and fixed to the chip seating portion cut out in the cutter body.
[0005]
Next, the positional relationship between the finishing blade tip and the rough blade tip will be described with reference to FIG. As shown in this figure, the finishing blade tip 4 is placed with its tip retracted from the coarse blade tip 3 in the radial direction of the cutter body 1, and the finishing blade tip 4 is provided in the width direction of the cutter body 1. The blade 20 is placed so as to protrude slightly outward from the coarse blade tip 3. The rough edge tip 3 performs groove processing after processing the side surface of the pin journal. The finishing blade 20 provided in the finishing blade tip 4 finishes by sweeping the side surface that the coarse blade tip 3 has processed in advance.
[0006]
In order to obtain a good finished surface, the countersink 20 is usually placed flat against the side work surface. At this time, if the blade length of the countersink blade 20 is longer than necessary, the distance for rubbing with the processed surface becomes too long, and the processed surface is roughened against the purpose, and the life of the chip is reduced and the vibration is generated. Will be invited. In order to prevent this, it is necessary to leave a predetermined blade length and delete further cutting blades so that they are not in contact with each other. Conventionally, as shown in the figure, this has been realized by forming a cutting edge portion to be non-contact with a step surface that is uniformly low.
[0007]
[Problems to be solved by the invention]
As described above, the finishing blade tip in the side finishing of the pin journal should slightly protrude from the rough blade tip in the width direction of the cutter body so as to ensure a set fine cutting depth. Furthermore, a particularly high accuracy is required for the width accuracy between the finishing blade tips arranged on both side surfaces of the cutter body. On the other hand, with regard to grooving as well, the cutting load of each cutting edge is made uniform by maintaining good radial runout accuracy of the tip of the rough blade, chip chipping, chip life reduction, vibration generation, machining surface It is necessary to suppress deterioration and the like.
[0008]
In order to obtain such a high precision chip assembly accuracy, the above-described direct-fixed type crankshaft machining cutter has to improve both the accuracy of the cutter body and the single chip. In other words, the manufacturing accuracy is directly reflected in the chip incorporation accuracy and there is no adjustment method. Moreover, there is also a problem that when the chip defect occurs, the cutter body is damaged.
[0009]
In order to solve the above-described problems, a technique has been proposed in which a chip is mounted on a cartridge having a fine adjustment mechanism, and this cartridge is incorporated into a cutter body. However, since the cartridge incorporates a fine adjustment screw or the like, the size of the cartridge main body becomes large, and the storage space provided in the cutter main body for storing this must be large, and the width is thin. The cutter has a problem that the rigidity is lowered. In addition, the fine adjustment work using the cartridge actually requires considerable skill and requires a long time.
[0010]
On the other hand, with regard to the shape of the finishing blade tip, since the conventional finishing blade tip as described above has a rake face and a seating face fixed to one side, the number of cutting edges that can be used is small. It was an economy.
[0011]
[Means for Solving the Problems]
The present invention has been made in view of the above-described problems. A throwaway tip is placed and fixed in a standing insert state on both side surfaces of a peripheral portion of a disc-shaped cutter body. In the crankshaft machining cutter in which the away tip is constituted by a combination of a rough blade tip and a finishing blade tip, the seat portion of the throwaway tip includes a receiving piece that supports the throwaway tip in the radial direction of the cutter body, Rotating the cutter from the seating surface on which the finishing blade tip is seated is formed on the bottom plate that is formed with the bottom plate that is supported in the width direction of the cutter body, and is the seating portion of the finishing blade tip that is shorter than the coarse blade tip. projection projecting outward of the forward side is attached, said floor plate by pressing by the projection holding frame is fixed to the cutter body Is intended to symptom, by processing corrected by removing receiving the frame and floor plate from the cutter body, it is intended to as a chip embedded accuracy can be easily ensured. In addition, parts with slightly different dimensional accuracy are prepared in advance and can be dealt with by replacing the parts. At the same time, when a chip defect occurs, damage to the cutter body is avoided by preventing damage around the chip from spreading outside the receiving piece and the base plate.
[0012]
Further, the floor plate in the seating portion of the finishing blade tip is provided with a projection protruding outward from the seating surface, and the floor plate is fixed to the cutter body by pressing the projection with a holding piece. It provides a new fixing method for small parts that are difficult to fix.
[0013]
According to a second aspect of the present invention, a presser piece fastening screw is inserted into the presser piece, and an O-ring is externally inserted into the presser piece fastening screw at a position between the presser piece and the cutter body. It is intended to prevent the presser piece clamping screw, such as chips and dust, from entering the threaded portion.
[0014]
In a finishing blade tip that has a rectangular flat plate shape and is mounted in a standing insert state together with a rough blade tip on a crankshaft machining cutter, the main edge line that serves as a side cutting edge of the finishing blade tip has a desired cutting edge from the tip corner. It is preferable that a blade is provided in the blade length, and the rear end thereof is subjected to cutting blade removal along the main ridgeline, and the width of cutting blade removal formed on the finishing blade tip is separated from the tip corner side. more preferably be formed to be wider according to the finishing blade tip, a small notch is provided at the rear end of Sarae blade, the cutting edge removal, that is the starting point of the notch Particularly preferred . Specifically, the cutting blade removal is performed by chamfering or stepping.
[0015]
It is formed finish blade tip as described above, by the axial rake angle and the radial rake angle is set to a negative angle, setting flat and Sarae blade to the side working surface, the finishing edge chips Relief occurs in the portion excluding the blade, and does not come into contact with the machined surface. Moreover, a wide flat surface is secured on the rectangular flat plate surface of the finishing blade tip, and the seating stability is not impaired even when the front and back surfaces are reversed. The cutting edge shape is also a shape that can be used by reversing the front and back. In addition, the notch provided when setting the cutting edge length of the cutting edge is designed to absorb the manufacturing variation of the starting point of cutting edge removal that occurs when there is no notch in the notch. This is to ensure that it can be set.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 to FIG. 10 show an embodiment of the present invention. FIG. 1 is a perspective view in which a substantially quarter of the cutter body 1 is taken out. The cutter body 1 has a disc shape, but has an outer ring shape because the center portion is removed as a large hollow circle. A plurality of throw-away chips (hereinafter referred to as chips) 2 are arranged on both side surfaces so as to sandwich the cutter body and are detachably mounted on the inner peripheral edge of the ring. The tip 2 is composed of a combination of a rough blade tip 3 and a finishing blade tip 4, and is configured so that several finishing blade tips 4 are mixed in the majority of the rough blade tips 3. The tip 2 is mounted in an insert state from both side surfaces of the cutter body 1, but in this figure, the seating portion of the finishing blade tip 4 is drawn with some parts disassembled for understanding of the configuration. .
[0018]
2 and 3 show one mounting portion of the coarse blade tip 3. The cutter body 1 is provided with a notch step portion 5 in which a chip mounting component is accommodated and a chip pocket 6 for promoting chip outflow.
[0019]
The rough blade tip 3 has a substantially rectangular flat appearance, and a countersink 7 is drilled symmetrically from the front and back surfaces at the center of the flat plate surface. When the tip fastening screw 8 inserted into the countersink 7 is screwed into a screw hole provided in the cutter body 1, the coarse blade tip 3 is fastened and fixed.
[0020]
Two side surfaces of the long edge side of the rough blade tip 3 forming a substantially rectangular flat plate have a parallelogram shape, and an arc cutting edge is formed at an acute corner. In the vertical insert, the side surface becomes the rake face 9 at the time of cutting. If this rough blade tip 3 is rotated 180 ° on the same rake face, the other sharp corner is used as a cutting edge. Further, if the front and back sides are reversed with respect to the flat plate surface, the surface on the back side of the rake face 9 can be used as a rake face by mounting on the other side face of the cutter body 1.
[0021]
In the radial direction of the cutter body 1, a receiving piece 10 that supports the coarse blade tip 3 is disposed, and is detachably fixed to the cutter body 1 by a receiving piece fastening bolt 11. Further, in the width direction of the cutter body 1, the floor plate 12 is sandwiched between the rough blade tip 3 and the cutter body 1, and the floor plate 12 is formed as a seating portion of the coarse blade tip 3. The floor plate 12 is provided with a through hole 13 through which the chip fastening screw 8 can pass and a stepped hole 14 separately. A small screw 15 is inserted into the stepped hole 14 and screwed into the cutter body 1, whereby the floor plate 12 is detachably fixed to the cutter body 1.
[0022]
4 to 6 show one mounting portion of the finishing blade tip 4. The cutter body 1 is provided with a notch step portion 5 in which a chip mounting component is accommodated and a chip pocket 6 for promoting chip outflow.
[0023]
The finishing blade tip 4 is a substantially rectangular flat plate, and a countersink 7 is drilled symmetrically from the front and back surfaces at the center of the flat plate surface. The finishing blade tip 4 is fastened and fixed by screwing the tip fastening screw 8 inserted into the countersink 7 with the screw hole provided in the cutter body 1. The two side surfaces on the long side of the finishing blade tip 4 forming a substantially rectangular flat plate have a rectangular shape, and arc corners are formed at the two corners at the top. In the vertical insert, the side surface is a rake face 9 at the time of cutting, and the arc corner side is a cutting edge portion used for cutting. The other two corners are formed in a chamfered shape.
[0024]
The radial cutter body 1 receives frame 10 for supporting a finishing blade Chi-up 4 is arranged, by receiving piece fastening bolt 11 is removably secured to the cutter body 1. In the width direction of the cutter body 1, a floor plate 12 is sandwiched between the finishing blade tip 4 and the cutter body 1 to form a seating portion for the finishing blade tip 4. A through hole 13 is drilled in the floor plate 12 so that the chip fastening screw 8 can pass therethrough. Further, the floor plate 12 is provided with a protrusion 16 that protrudes outward from the seating surface on which the finishing blade tip 4 is seated on the front side in the rotational direction of the cutter body 1 .
[0025]
A pressing piece 17 is disposed adjacent to the front side of the floor plate 12 in the rotational direction of the cutter body 1 . One end of the presser piece 17 is brought into contact with the protrusion 16, and the protrusion 16 is pressed by the tightening force of the presser piece tightening screw 18 inserted into the presser piece 17 and screwed into the cutter body 1. The floor plate 12 is detachably fixed to the cutter body 1. The reason why different fixing methods are used for the floor plate 12 for the finishing blade tip 4 and the floor plate 12 for the rough blade tip 3 is that the difference between the cutting edge positions of the rough blade tip 3 and the finishing blade tip 4 described later, This is because the chip lengths are different, and a space for screwing cannot be secured on the floor plate 12 serving as the seating surface of the finishing blade chip 4 with a short chip length.
[0026]
An O-ring 19 is externally attached to the presser piece fastening screw 18 at a position between the presser piece 17 and the cutter body 1 so as to be in close contact with the presser piece 17 and the cutter body 1, and the presser piece tightening is performed. Prevent chips and dust from entering the screw hole of the screw 18.
[0027]
7 to 9 show the finishing blade tip 4. A countersink 20 for finishing the side surface when the crankshaft is processed is provided at two corners on the rake face 9 at the top. A notch 21 that is substantially perpendicular to the cutting edge is provided at the rear end of the cutting edge 20 so that the cutting edge 20 is set to a desired cutting edge length. At this time, the appropriate length of the cutting edge is determined in relation to the feed per rotation and the number of blades. If the cutting edge length is too long, the distance for the scrubbing without any cutting action will be excessive and the effect as a cutting edge will be diminished, resulting in deterioration of the machined surface, shortening of the chip life, generation of vibration, etc. Will be invited.
[0028]
A cutting edge removal 22 is provided along the ridgeline on the extended ridge of the blade 20, and the cutting edge is deleted. In addition to chamfering, the cutting edge removal 22 has a stepped shape as shown in the figure. The cutting edge removal 22 is formed so that its width gradually becomes wider as it is separated from the tip corner side. By making the starting point be in the space of the notch 21, the manufacturing variation of the starting point is absorbed into the notch 21, and the cutting edge length of the blade 20 is kept constant.
[0029]
Since the finishing blade tip 4 is basically a negative tip, both the axial rake angle and the radial rake angle are attached to the cutter body 1 at negative angles. Therefore, even if the cutting edge 20 is installed so as to be flat with respect to the processing surface, all the portions other than the cutting edge portion of the finishing blade tip 4 including the cutting edge removal 22 are evacuated, so Contact is avoided. In addition, the shape of the cutting edge removal 22 that gradually becomes wider as the distance from the tip corner side is increased, so that the area of the cutting edge removal 22 is minimized while the escape is surely performed. .
[0030]
The finishing blade tip 4 has a point-symmetric shape on the rake face 9 and a left-right symmetric shape in appearance from the flat plate surface, and a flat surface is ensured on the flat plate surface by making the cutting blade removal 22 as described above. Therefore, the front and back sides can be reversed without impairing the seating stability. The shape of the cutting edge is also a shape that can cope with inversion of front and back. That is, if the finishing blade tip 4 is rotated by 180 ° with respect to the same rake face 9, the other corner becomes the working cutting edge. At the same time as reversing the front and back of the flat plate surface, by attaching this to the other side surface of the cutter body 1, the back surface of the rake surface 9 can be used as a rake surface. It is possible to use four cutting edges.
[0031]
FIG. 10 is a simplified cross-sectional view for explaining the positional relationship between the rough blade tip 3 and the finishing blade tip 4. The rough blade tip 3 drawn with imaginary lines is attached to the side surface of the cutter body 1 with a slight inclination from the tip end to the rear end, and the clearance is set. On the other hand, the finishing blade tip 4 is set so that the blade 20 is flat with respect to the side surface of the cutter body 1, but as described above, relief is given to other ridge lines and surfaces. In the radial direction of the cutter body 1, a rough blade tip 3 is disposed so as to protrude from the finishing blade tip 4, and side surface processing and shallow groove processing of the pin journal are performed. In the width direction of the cutter body 1, the finishing blade tip 4 is set to protrude laterally from the rough blade tip 3 by the amount of the finishing allowance. Since the cutting feed is sent toward the center of the cutter body 1, the finishing blade tip 4 follows the processed surface of the rough blade tip 3 by the arc cutting blade, and the finishing by the blade 20 is performed.
[0032]
In the present invention, the rough blade tip 3 and the finishing blade tip 4 are supported by the detachable receiving piece 10 and the floor plate 12, so that these parts can be replaced with other parts having different dimensions or added. By making corrections, it is possible to adjust the deflection accuracy between the cutting blades, the protruding amount of the finishing blade tip 4 with respect to the rough blade tip 3, the width between the left and right of the finishing blade tip 4, and the like.
[0033]
【The invention's effect】
According to the cutter for processing a crankshaft according to the present invention, the rigidity of the cutter body is impaired by detachably inserting a chip seating component of a compact size between the throw-away tip and the cutter body. Therefore, the function of adjusting the throw-away tip assembly accuracy can be provided by exchanging the tip seating component. Since the structure of the chip seating portion is simple, a desired assembly accuracy can be obtained in a relatively short time, and adjustment work can be performed even with the cutter attached to the machine.
[0034]
According to the finishing blade tip according to the present invention incorporated in the cutter for machining the crankshaft, it has a shape that can be turned upside down, so the number of cutting blades is twice that of the conventional finishing blade tip. Obtained and economical.
[Brief description of the drawings]
FIG. 1 is a partial perspective view showing an embodiment of a cutter for machining a crankshaft of the present invention.
FIG. 2 is a side view of a rough blade tip portion mounted in FIG. 1;
3 is a cross-sectional view taken along line AA in FIG.
4 is a side view of the finishing blade tip mounted in FIG. 1. FIG.
5 is a cross-sectional view taken along line BB in FIG.
6 is a cross-sectional view taken along the line CC of FIG.
FIG. 7 is a side view showing an embodiment of a finishing blade tip for machining a crankshaft of the present invention.
8 is a front view of FIG. 7. FIG.
9 is a perspective view of the finishing blade tip shown in FIG.
10 is a simplified cross-sectional view for explaining the relationship between the rough blade tip and the finishing blade tip shown in FIG. 1. FIG.
FIG. 11 is a simplified cross-sectional view for explaining the relationship between a conventional rough blade tip and a finishing blade tip.
DESCRIPTION OF SYMBOLS 1 Cutter body 3 Coarse blade tip 4 Finishing blade tip 9 Drake face 10 Receiving piece 12 Base plate 16 Protrusion 17 Pressing piece 19 O-ring 20 Cutting blade 21 Notch 22 Cutting blade removal

Claims (2)

A throw-away tip is placed and fixed in an insert state on both sides of the peripheral edge of the disc-shaped cutter body, and the throw-away tip is configured by a combination of a coarse blade tip and a finishing blade tip. and the crankshaft machining cutter, seat of the cutting insert, a receiving frame for supporting the cutting insert in the radial direction of the cutter body, are formed with at the floor plate for supporting the width direction of the cutter body, the crude A protrusion that protrudes outward in the rotational direction of the cutter from the seating surface on which the finishing blade tip is seated is attached to the base plate that serves as a seating portion of the finishing blade tip that is shorter than the blade tip. A cutter for crankshaft machining, wherein the floor plate is fixed to the cutter body by pressing with a pressing piece . The presser piece fastening screw is inserted into the presser piece, and an O-ring is externally inserted into the presser piece fastening screw at a position between the presser piece and the cutter body. Item 2. The crankshaft processing cutter according to Item 1.

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