JPH08215926A - Broach cutter and method for working crankshaft by the same - Google Patents

Abstract

PURPOSE: To prevent the same portion of a workpiece from being twice worked and the life of a broach cutter from being early reduced with unnecessary working by providing a space having no broach segment between a roughing broach segment and finishing broach segment. CONSTITUTION: In a second process, first, second, fourth and fifth journals 131 , 132 , 134 and 135 are worked respectively by broach cutters 8e, 8d, 8b and 8a. Then, the fourth journal 134 has been completely worked already in the first process. However, a space 8n' for the broach cutter 8b located in the fourth journal 134 is previously provided in front of a finishing broach segment 8n. Thus, while the broach segment 8n for finishing other broach cutters 8a, 8d, 8e finishes the first, second and fifth journals 131 , 132 and 135 , the fourth journal 134 is not worked by the broach cutter 8b since the space 8n' is located in the fourth journal 134 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broach cutter for machining a crankshaft of an engine and a method for machining a crankshaft using the broach cutter.

[0002]

2. Description of the Related Art Conventional crankshafts have crankshaft mirrors that are used to cut pins and journals. However, as the number of engine types and production decreases in recent years, crankshaft mirrors Is not a good way to improve productivity. Under these circumstances, research on machining a crankshaft using a turn broach machine has recently been advanced, but the turn broach machine exhibits high productivity for a single work due to the structure of the machine. However, because it is not versatile,
Each time the work changes, the work such as changing the broach cutter is required, and it takes a lot of time to change the setup.

[0003]

Conventional engines include 4-cylinder engines and 6-cylinder engines. The crankshafts of these engines have the same main journal diameter, width, and inter-journal pitch, and have longitudinal dimensions. Although the shape is increased / decreased by the number of cylinders, the conventional turn broach machine has a structure in which the broach cutter cannot be moved in the longitudinal direction of the work, so the same broach cutter has a crankshaft of a 4-cylinder engine and a 6-cylinder engine. The engine crankshaft cannot be machined. In order to improve such a problem, even when the structure in which the broach cutter can be moved in the longitudinal direction of the work is adopted, the following problems occur in the conventional broach cutter.

FIG. 1A shows a crankshaft of a 4-cylinder engine, and FIG. 1B shows a crankshaft of a 6-cylinder engine. A broach cutter b for processing a crankshaft a of a 4-cylinder engine is used. When processing the crankshaft c of a cylinder engine, there are two steps. First, in the first step, after processing the portion shown in (b) of FIG. 1, the broach cutter b is moved in the longitudinal direction of the work to perform the second step. When the part shown in (c) of FIG. 1 is processed in the process, the part d of (c) of FIG. 1 is processed twice by the broach cutter b, and the diameter of the processed part becomes smaller than necessary. In addition, wasteful processing may cause problems such as shortening the life of the broach cutter early. The present invention has been made to improve such problems, and has high versatility,
Moreover, it is an object of the present invention to provide a broach cutter that does not process the same portion twice and a method for machining a crankshaft using the broach cutter.

[0005]

In order to achieve the above object, the present invention provides a turn broach machine for simultaneously processing a plurality of crankshaft journals by a plurality of broach cutters attached to a broach drum.
At least one of the broach cutters is provided with a space without a broach segment between the broach segment for roughing and the broach segment for finishing.

Further, in a turn broaching machine for simultaneously processing a plurality of journals of a crankshaft with a plurality of broach cutters attached to a broach drum, at least one of the broach cutters is provided with a broach segment for roughing and a finishing broach. A space without a broach segment is provided between the broach segments, and the first
When a plurality of crankshaft journals are machined at the same time in the process, when the broach drum is moved in the longitudinal direction of the crankshaft to carry out the second and subsequent processes, a space is provided in the already processed journal part. The broach cutter is positioned to perform the processing after the second step.

[0007]

[Operation] With the above configuration, for example, the crankshaft of a 4-cylinder engine and the crankshaft of a 6-cylinder engine have the same main journal diameter, width, and pitch between journals, and the longitudinal dimension increases or decreases by the number of cylinders. It becomes possible to process different crankshafts with the same broach cutter. In addition, at least one of the broach cutters should be provided with a space without a broach segment between the broach segment for roughing and the broach segment for finishing, and when the multiple journals of the crankshaft are machined in the first step, When the drum is moved in the longitudinal direction of the crankshaft to perform the processing after the second step, by positioning the broach cutter with a void in the already processed journal portion,
It is possible to prevent the same place from being processed twice.

[0008]

Embodiment An embodiment of the present invention will be described in detail with reference to the drawings shown in FIG. FIG. 2 shows a turn broaching machine using the broaching cutter of the present invention. An indexing slide unit 3 which is movable in the longitudinal direction of the bed 1 by an NC servomotor 2 is provided on the bed 1. On both ends of the index slide unit 3, there are provided a pair of index slides 5 which are simultaneously moved by the index drive motor 4 in a direction orthogonal to the moving direction of the index slide unit 3. A broach drive unit 6 is installed on one of the cutting slides 5, and a broach receiving unit 7 is installed on the other cutting slide 5, and a broach cutter 8 is provided between the broach driving unit 6 and the broach receiving unit 7. Both ends of the broach drum 9 attached to are supported,
The broach drum 9 is rotated by a broach drive motor 10 provided on the broach drive unit 6 side.

On the other hand, a broach cutter 8 for processing a crankshaft 12 of a 4-cylinder engine and a crankshaft 13 of a 6-cylinder engine is attached to the broach drum 9. The broach cutter 8 for processing the crankshaft 12 of the 4-cylinder engine has five locations 8a to 8e on the broach drum 9 at the same pitch as the _first to fifth journals 12 _{1 to} 12 ₅ as shown in FIG.
These broach cutters 8a to 8e are attached and have broach segments 8 ₁ to 8 _n divided into a plurality of pieces in the circumferential direction as shown in FIG. These broach segments 8 ₁ to 8 _n are sequentially arranged in the rotational direction of the broach drum 9 from roughing to finishing, and each journal 12 _{1 to} 12 ₅ while the broach drum 9 makes almost one rotation. Can be finished at the same time.

A crankshaft 1 of a four cylinder engine
When the crankshaft 13 of the 6-cylinder engine is processed by the broach cutter 8 for processing 2, the broach segment 8b for processing the sixth journal 13 ₆ so as not to process the same portion twice is shown in FIG. Other brooch cutters 8a, 8d, 8e for finishing brooch segment 8
As shown in FIG. 5A, a void 8n 'is provided at the position n, and a finishing broach segment 8n is attached to the rear of the void 8n'.

Next, the operation will be described. When machining the crankshaft 12 of a four-cylinder engine, FIG.
As shown in FIG.
Install the broach cutter 8a~8e at five positions in accordance with the pitch of the fifth journal 12 ₁ to 12 _5, during the broach drive unit 6 and lingering charge unit 7 turns broaching machine to indicate this broach drum 9 in FIG. 2 The broach drive motor 10 of the broach drive unit 6 rotates the broach drum 9 almost once, and the broach cutters 8a to 8e rotate the first journal 12 ₁ to the fifth journal 1 of the crankshaft 12.
Process up to ₂₅ at the same time. As a result, in the case of the crankshaft 12 of a 4-cylinder engine, the machining of the first journal 12 ₁ to the fifth journal 12 ₅ is completed in one step.

On the other hand, when machining the crankshaft 13 of a 6-cylinder engine using the broach cutter 8,
The unused third broach cutter 8c is previously removed. And in the first step, the third of the crankshaft 13,
4th, 6th journals 13 ₃ , 13 ₄ , 13 ₆ and 7th
The journals 13 to ₇ are processed as shown in FIG. At this time, the third, fourth and seventh journals 13 ₃ , 1
Broach cutters 8e, 8d, 8 for processing 3 ₄ , 13 _7.
As shown in FIG. 5B, the broach drum 9 is further rotated after the processing of the third, fourth, and seventh journals 13 ₃ , 13 ₄ , and 13 ₇ is completed. The sixth journal 13 ₆ is finished by the finishing broach segment 8n provided behind the cavity 8n 'as shown in FIG. When the processing of the first step is completed as described above, the broach drum 9 is once retracted, and then the NC slide motor 2 moves the indexing slide unit 3 to the right, and the remaining first, second and 4, the 5th journal 13 ₁ ,
The broach cutters 8a, 8b, 8d, and 8e are indexed to positions where 13 ₂ , 13 ₄ , and 13 ₅ can be machined, and the rotational direction position of the broach cutter 8 is returned to the origin to start the second process.

In the second step, the broach cutters 8e, 8d,
The first, second, fourth, and fifth journals 13 ₁ , 13 ₂ , 13 ₄ , and 13 ₅ are respectively processed by 8b and 8a as shown in (b) of FIG. The fourth journal 13 ₄ has been processed. However, since the broach cutter 8b located in the fourth journal 13 ₄ has a space 8n 'previously provided in front of the finishing broach segment 8n, the other broach cutters 8a, 8d, 8e.
The finishing broach segment 8n has the first, second and fifth journals 13 ₁ , 13 ₂ as shown in FIG.
While finishing the 13 _5, for broach cutter 8b is the voids 8n 'as shown at (h) in FIG. 5 in the position of the fourth journal 13 _4, fourth journal 13 ₄ is not processed.

This makes it possible to prevent the fourth journal 13 ₄ processed in the first step from being reprocessed. When the second step is completed as described above, the broach drum 9 is retracted, the crankshaft 13 that has been machined is taken out, the crankshaft 13 to be machined next is carried in, and the above operation is repeated. It becomes possible to process the crankshaft 13 of the 6-cylinder engine with the broach cutter 8 which processes the crankshaft 12 of the engine.

In the above embodiment, when processing the crankshaft 13 of the 6-cylinder engine, the broach cutter 8 is used.
Although c has been removed, the broach cutter 8c can be machined without removing the broach cutter 8c from the broach drum 9 by providing a vacant space 8n 'in advance similarly to the broach cutter 8b. In the above embodiment, the crankshaft 12 of the 4-cylinder engine and the crankshaft 13 of the 6-cylinder engine are machined, but the main journal diameter, width and inter-journal pitch are the same, and the longitudinal dimension is the number of cylinders. If the crankshaft increases or decreases by
It is also possible to process crankshafts of engines other than the above cylinders.

[0016]

As described in detail above, the present invention has the same main journal diameter, width, and pitch between journals, and has the same longitudinal dimension as in a crankshaft of a 4-cylinder engine and a crankshaft of a 6-cylinder engine. Since the crankshaft that increases and decreases by the number of cylinders can be machined with the same broach cutter, the versatility is improved and the broach cutter can be broached with a broach cutter when the broach cutter is replaced every time the work changes. Since the same part of the work is not machined twice by providing a space without segments, the diameter of the machined part is reduced, and unnecessary machining shortens the life of the broach cutter early. It can be resolved. Further, by making the broach cutter movable in the longitudinal direction of the workpiece, the crankshaft of, for example, a 4-cylinder engine can be processed in one step, and the crankshaft of, for example, a 6-cylinder engine, can be processed in two steps, thus improving productivity. Improve further.

[Brief description of drawings]

1A to 1C are explanatory views showing a processing method using a conventional broach cutter.

FIG. 2 is a front view of a turn broach machine using a broach cutter according to an embodiment of the present invention.

FIG. 3 (a) is an explanatory diagram for processing a crankshaft of a 4-cylinder engine with the broach cutter according to the embodiment of the present invention. (B) It is an arrow view from the A direction of (a) of FIG.

FIG. 4 (a) is an explanatory view showing a first step in processing a crankshaft of a 6-cylinder engine with a broach cutter according to an embodiment of the present invention. (B) It is explanatory drawing which shows the 2nd process at the time of processing the crankshaft of a 6 cylinder engine with the broach cutter which becomes one Example of this invention.

5 (a) and 5 (b) are explanatory views showing a first step in processing a crankshaft of a 6-cylinder engine with a broach cutter according to an embodiment of the present invention. (C) and (d) FIG. 8 is an explanatory view showing a second step in processing a crankshaft of a 6-cylinder engine with a broach cutter according to an embodiment of the present invention.

[Explanation of symbols]

8 a to 8 e ... broach cutter 8 ₁ ... rough machining broach segments 8n ... finishing broach segments 8n '... cavity 9 ... brooch drum 12 ... 4 cylinder engine crankshaft 12 ₁ to 12 ₅ ... journal 13 ... 6-cylinder engine Crankshaft 13 _{1 to} 13 ₇ ... Journal.

Claims (2)

[Claims] 1. A crankshaft 1 having a plurality of broach cutters 8a to 8e attached to a broach drum 9.
Multiple journal 12 ₁ to 12 ₅ 2,13, 13 ₁ ~
In the turn broaching machine for simultaneously processing 13 ₇ , at least one of the broach cutters 8a to 8e is provided between the broaching segment 8 ₁ for roughing processing and the broaching segment 8n for finishing processing.
Broach cutter, characterized in that a cavity 8n 'no ₁ to 8 _n. 2. A crankshaft 1 having a plurality of broach cutters 8a to 8e attached to a broach drum 9.
Multiple journal 12 ₁ to 12 ₅ 2,13, 13 ₁ ~
In the turn broaching machine for simultaneously processing 13 ₇ , at least one of the broach cutters 8a to 8e is provided between the broaching segment 8 ₁ for roughing processing and the broaching segment 8n for finishing processing.
_When a plurality of journals 13 ₁ of the crankshaft 13 are simultaneously processed in the first step by providing a void 8 _n ′ having no ₁ to 8 _n , the broach drum 9 is moved to the crankshaft 1
When moving in the longitudinal direction of 3 and performing the processing after the second step,
A method for machining a crankshaft by a broach cutter, characterized in that a broach cutter 8b provided with a void 8n 'is positioned in a journal portion which has already been machined to perform the machining after the second step.