JPH0440802Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a crankshaft used in an engine or other prime mover, in which an R-shaped portion at both ends of a pin portion and an R-shaped portion of a shoulder portion connected to the pin portion are used. The present invention relates to a cutter device for simultaneous cutting, and in particular to a cutter device for a crankshaft that facilitates the formation of cutting edges and the replacement of cutters, and can dramatically extend the life of the cutters.

[Conventional technology]

Conventionally, when cutting the R-shaped parts formed at both ends of the pin part of a crankshaft, the side wall of the shoulder part connected to the pin part and the R-shaped part of the shoulder part were cut at the same time in order to increase work efficiency. It is customary to perform machining, and various cutter devices for performing such simultaneous cutting have been proposed.

Fig. 7 shows a cutter of a so-called integral molding type, and this cutter has two cutting edges, that is, an R-shaped part 2 formed at the end of the pin part 1 shown in Fig. 9, a side wall 3 of the shoulder part, and an R-shaped part of the shoulder part. Shape part 5
A chip 8 is formed by integrally forming a first cutting edge 4 (so-called 1st R-shaped portion) and a second cutting edge 7 (so-called 2nd R-shaped portion) so as to match the cross-sectional shape of
It is brazed to the handle body 10 along the weld line 9, and when the tip 8 is advanced in the direction of arrow a through the handle body 10 while rotating the pin part 1, at first,
The cutting blade 7 cuts the side wall 6 of the balance weight, then the cutting blade 4 cuts the side wall 3 of the shoulder part,
Finally, the cutting edge 4 and the cutting edge 7 are connected to the pin portion 1, respectively.
The R-shaped portion 2 of the shoulder portion and the R-shaped portion 5 of the shoulder portion are cut.

[Problem that the invention aims to solve] However, this integrally molded cutter has each cutting edge 4,
Since the cutting edge 7 has an R-shaped portion, it is difficult to form the cutting edge, and in particular, forming the second cutting edge 7 connected to the first cutting edge 4 requires a highly accurate technique. Therefore, the cutting edge of the katsuta was only formed by a limited number of experts.

Additionally, during cutting, if chipping occurs on the first cutting edge 4 and the cutting edge is missing, the entire cutting edge including the second cutting edge 7 must be ground or replaced, and as a result, There was a problem in that the second cutting edge 7, which could still be fully used, was ground needlessly, resulting in a significant shortening of the life of the cutter as a whole.

In order to avoid the above problems, a method has been proposed in which a plurality of chips are combined to form a cutter (see Japanese Utility Model Publication No. 61-980). This katsuta is
For example, as shown in the attached FIG. 8, two daruma-shaped chips 12 and two full-shaped chips 13 are placed one on top of the other as shown, and are implanted on the outer periphery of a disc 14.

However, in this combination cutter, it is necessary to form each corner 15, 16 of the daruma-shaped tip 12 to fit respectively the R-shaped portions 2 and 5 of the corresponding crankshaft, so it is difficult to manufacture the daruma-shaped tip 12 itself. There is also the problem that it is difficult.

In view of the above-mentioned problems, the present invention aims to provide a crankshaft cutter device in which the cutting edge is easy to form and there is no need to re-grind or replace the entire cutter due to partial breakage of the cutting edge. Consider it a technical issue.

[Means to solve the problem]

The means of the present invention for solving the above-mentioned problems is to removably hold the cutter in a plurality of holes drilled in the holder, and to form an R-shaped part of the crankshaft pin part and an R-shaped part of the shoulder part connected to the pin part. In a crankshaft cutter device that simultaneously cuts the crankshaft pin part and the shoulder part, the cutter is formed with a cutting edge that matches each R-shaped part of the crankshaft pin part and the shoulder part at the tip of the cutter body having a uniform circular cross section. The holes that hold each cutter are arranged symmetrically and obliquely with respect to the vertical plane that bisects the holder horizontally, and the cutting edge of each cutter is placed on the side of the holder. The cutting edge is fixed in the hole so as to be able to move forward and backward into the hole while protruding symmetrically outward from the cutter body, and the cutting edge is connected to a flat end surface diagonally intersecting at an acute angle of nearly 90 degrees to the center line of the cutter body. This crankshaft cutter device is characterized in that it is formed with an edge that intersects with the outer surface of the main body.

[Effect]

This invention separates and removably fixes multiple cutters that match the shape of each R-shaped part of the crankshaft to the holder, so even if a cutter becomes damaged, only the broken cutter can be re-ground or replaced. This eliminates the need to re-grind or replace all the cutters when a part of the cutting edge breaks off, as in the case of conventional methods.In addition, the cutting edge of each cutter uses the edge of the sloped surface formed at the end of the cutter body. So,
Easy to form cutting edges.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings. Note that the reference numerals for each part of the crankshaft are the same as those used in explaining the conventional technology, and the explanation thereof will be omitted.

Figures 1 to 6 show an embodiment of the present invention, and the cutter device of the present invention has four independent cutters as shown in the plan view in Figure 1 and the side views in Figures 2 and 3. pin-shaped cutlet (or straight pin)
21, 21, 22, 22, and a block-shaped holder 23 that detachably holds these cutters in predetermined positions and directions.

Each cutter 21, 21, 22, 22 has a cutter body 24 of uniform circular cross section made of tool steel (see Fig. 5), and one end of this cutter body 24 is attached at an angle of 90 degrees to the cutter center line 25. A flat end surface 26 is formed which intersects said centerline 25 at a slightly smaller angle, and the edge where said end surface 26 intersects with the outer surface 27 of the cutter body forms a cutting edge 28 .

Further, the outer part on the opposite side of the cutter main body 24 has a fifth
As shown in the figure, about half of the total length of the cutter is chamfered, and the chamfered part is cutter 21, 2.
It serves as a locking surface 29 when fixing 1, 22, 22 to the holder 23.

The holder 23 is formed into a substantially rectangular block shape as shown in FIG. 1, and is integrally manufactured using a strong material such as forged steel. In addition, there are four cutters 2 near the tip of the holder 23.
1, 21, 22, and 22 are drilled, and the four diagonal holes 30
passes through the holder 23 in the vertical direction.

The inner diameter of each diagonal hole 30 is approximately equal to the outer diameter of each cutter body 24, and
2, 22 into each diagonal hole 30, the outer edges of the cutting edges 28, 28 of each pair of cutters 21, 22 on the left and right sides of the holder 23 are aligned with the pin portion 1 to be machined, as shown in FIG. R of R-shaped part 2 and shoulder part
The relative positions of the diagonal holes 30 are set accurately to match the cross-sectional shape of the shaped portion 5.
In addition, during cutting, each of the left and right side surfaces 33, 32, 34 of the left and right sides and the tip side of the holder 23 is arranged so that they do not come into contact with the opposing side walls 3, 3 of the shoulder and the side walls 6, 6 of the balance weight. ，
Stepped portions 33a and 32a are provided on 32, respectively, so that the width dimensions l ₁ and l ₂ between the side surfaces 33 and 32 and between the side surfaces 33a and 32a are changed to the dimension L ₁ between the side walls 6 of the balance weight and the side wall 3 of the shoulder. , 3 is set slightly smaller than the dimension L ₂ between the holders 23 and the outer edge of the cutting blade 28 of each cutter is
3, 33a, 32, 32a, and 34, each diagonal hole 30 is inclined in the left-right direction and the front-back direction (see FIGS. 2 and 3).
Further, the left and right sets of diagonal holes 30 are arranged symmetrically with respect to a vertical plane 36 that equally divides the holder 23 in the left and right direction.

A ladder-shaped recess 41 is formed in the end surface 35 on the tip side of the holder 23, and screw holes 37 are formed from the slope 41a of the recess 41 toward the inside of the holder 23. The screw holes 37, 37 pass through the diagonal hole 30 on the distal end side of the holder 23. Further, screw holes 38, 38 are bored horizontally from the outer surface 31 on the rear side of the holder 23 toward the inside of the holder 23, and the screw holes 38, 38 pass through the diagonal holes 30 on the rear side of the holder 23. are doing.

Although not shown here, each screw hole 3
A set screw is screwed into each cutter 7, 37, 38, 38.
2 into the diagonal hole 30.

Further, the holder 23 is provided with a stepped bolt hole 39 that vertically passes through the holder 23, and the stepped bolt hole 39 serves to fix the holder 23 to the handle body 40.

Next, how to assemble the cutter device of the present invention and how to use the cutter will be explained. When assembling the cutter device, first use the cutters 21, 21, 2.
2 and 22 by a certain length into each diagonal hole 30 to cut the cutting edge 28 of each cutter 21, 21, 22, 22.
Adjust the vertical position so that the protruding length of Katsuta 21, 21, 2
2 and 22 are fixed.

Next, the attachment bolt 42 is screwed into the bolt hole 39 to fix the cutter device 43 to the handle body 40 (see FIG. 6).

In addition, in the above explanation, it was explained that the cutting edge 28 is formed on each cutter and then fixed to the holder 23, but the cutting edge 28 may be formed after the cutters 21 and 22 are fixed to the holder 23. This makes it easier to adjust the protruding length of the cutter.

Furthermore, if the protrusion length of each cutter is uniformly increased or decreased,
Other crankshafts with different crankpin lengths can be similarly cut.

Here, while rotating the crankshaft C around the center line 44 of the pin part, move the handle body 40 along the arrow a.
When driven forward in the direction, first the cutters 22, 22
cut the side walls 6, 6 of the balance weight, and the cutters 21, 21 cut the side walls 3, 3 of the shoulder at the same time, and finally cut the R-shaped parts 5, 5 of the shoulder part and the R-shaped part of the pin part at the position of the imaginary line. The shaped parts 2, 2 are cut at the same time, and the machining is completed.

It should be noted that the means for fixing the cutters 21, 22 to the holder 23, etc. are not limited to the above embodiments, and it goes without saying that various other deflections may be applied without departing from the gist of the present invention.

[Effect of idea]

As described above, the cutter device of the present invention exhibits the following excellent effects.

() Separate cutters are provided for each R-shaped part of the pin part and shoulder part and are removably fixed to the holder, so if some of the cutters become worn or damaged, the entire cutter can be ground or replaced as before. There's no need. Therefore, the life of the entire cutter can be dramatically extended.

() For the same reason as in paragraph (), it is easy to replace the cutter.

() Since the cutting edge of the cutter utilizes the edge of the inclined surface formed at the end of the round pin-shaped cutter, the cutting edge can be easily formed without requiring difficult processing techniques unlike conventional products.

() By uniformly increasing or decreasing the protruding length of each cutter, it becomes possible to cut other crankshafts with different crankpin lengths, expanding the range of application of the device. I can do it.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention,
Figure 1 is a plan view, Figure 2 is a - in Figure 1.
The arrow view from the direction, Fig. 3 is − in Fig. 2.
4 is an explanatory diagram showing the arrangement of the cutting blades of the cutter, FIG. 5 is a side view of the cutter, and FIG. 6 is an explanatory diagram of the cutting procedure using the cutter device of the present invention. , FIG. 7 is an explanatory diagram of a conventional integrally molded cutter, FIG. 8 is an explanatory diagram of a conventional combination cutter, and FIG. 9 is a side view showing a portion of a general crankshaft. In the figure, 1 is a pin part, 2 and 5 are R-shaped parts, 21,
22 is a cutter, 23 is a holder, 24 is a cutter body, 26 is an end surface, 27 is an outer surface of the cutter body, 2
8 is a cutting blade, 30 is an oblique hole, and 43 is a cutter device.

Claims (1)

[Claims for Utility Model Registration] A cutter is removably held in a plurality of holes drilled in the holder, and the R-shaped portion of the crankshaft pin portion and the R-shaped portion of the shoulder portion connected to the pin portion are simultaneously connected. In a crankshaft cutter device for cutting, the cutter has a cutting edge that matches each R-shaped portion of the crankshaft pin portion and the shoulder portion formed at the tip of the cutter body having a uniform circular cross section, The holes that hold each cutter are arranged symmetrically and obliquely to the vertical plane that bisects the holder in the left and right direction, and the cutting edge of each cutter extends outward from the side of the holder. It is fixed in the hole so as to be able to move forward and backward into the hole in a symmetrical state, and the cutting edge has a flat end face obliquely intersecting at an acute angle of nearly 90 degrees with respect to the center line of the cutter body, and an outer surface of the cutter body. A crankshaft cutter device characterized in that it is formed of edges that intersect.