JPH04111709A - Crank shaft processing method - Google Patents

Abstract

PURPOSE:To prevent drop of the accuracy by fixing a rest device supporting a crank shaft from movement in the longitudinal direction, and in this condition processing the crank shaft by one pass in the case of a V6 engine, and by two passes in the case of a V8 engine. CONSTITUTION:Because two connecting rods are installed simultaneously when assembling a V8 engine, a pin 1a' of a crank shaft 1' of the V8 engine has a width approx. two times as large as the pin 1a of crank shaft 1 of a V6 engine, so that the crank shaft 1',1 is process in two passes for the V8 engine while in one pass for V6 engine. In processing the crank shaft 1 of V6 engine, all pins 1a can be processed without shifting the two rest devices 2, 2' on the left and right. In processing the crank shaft 1' of V8 engine, the journal 1b of the crank shaft 1' is borne by the righthand rest device 2' at No.1 processing stage, by the left and right rest devices 2, 2' at No.1 and No.3 stages, and by the left-hand rest device 2 at the No.4 stage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a method for machining a crankshaft used in an internal combustion engine.

[Conventional technology]

Conventionally, crankshafts used in internal combustion engines are machined using crankshaft mirrors, but the pin width of crankshafts used in V-6 and V-8 engines is approximately Since the difference is twice as much, conventionally, when these crankshafts were machined using the same crankshaft mirror, the following machining method was used.

(1) As shown in Fig. 9 (a) and (b), similar to the cutter b for machining the crankshaft a used in ■ type 6 cylinder engine (hereinafter simply referred to as V6 engine), V type 8 cylinder engine (hereinafter simply referred to as the 8 engine) A method of machining a crankshaft a' by increasing the outer diameter of a cutter b'.

(2) As shown in Figures 10 (a) and (b), cutter b for machining the crankshaft a of a V6 engine or cutter adapter C according to the width of the installed cutter adapter C.
' and attached it to the V8 engine crankshaft a.
A method of machining by attaching cutter b' for machining '.

(3) As shown in Figure 11 (a), cutter b has the same width as cutter b used to process the crankshaft a of the V5 engine.
A method of first machining the crankshaft a' of a V8 engine using ', and then moving the rest d in the longitudinal direction with respect to the cutter b' to machine the remaining parts.

[Problem to be solved by the invention]

However, if the outside diameter of the cutter b' used to process the crankshaft a' of the ■8 engine is increased as in the machining method (1) above, the cutter b will be heavy, making it difficult to change the setup such as replacing the cutter. Additionally, the cutter itself also has the disadvantage of being expensive.

In addition, when machining the crankshaft a' of a V8 engine by attaching the cutter b' to the cutter adapter C', which has a width smaller than the crankshaft a1 of the V6 engine, as in method (2) above, the rigidity decreases. There are some problems that prevent high-precision machining.

Furthermore, when the rest d is moved during machining as in the machining method (3) above, the machining accuracy may be lowered.

This invention was made for the purpose of improving the above-mentioned problems, and the crankshaft of the V6 engine is one-pass, and the
An 8-engine crankshaft is intended to provide a method of machining a crankshaft in which the crankshaft is machined in two passes.

[Means and operations for solving the problem] In order to achieve the above object, the present invention provides two methods for processing a crankshaft.
A rest device that supports the crankshaft when machining a V6 engine crankshaft and a V8 engine crankshaft using a crankshaft mirror equipped with a base cutter head and two rest devices that support the crankshaft. With the position of the crankshaft fixed in the longitudinal direction, the crankshaft of the V6 engine is machined in one pass, and the crankshaft of the 8 engine is machined in two passes.

This makes it possible to process the crankshaft of a V8 engine using a cutter that processes the crankshaft of a V6 engine.

〔Example〕

An embodiment of the present invention will be described in detail with reference to the drawings.

The pin 1a' of the crankshaft 1' used in the V8 engine is approximately twice as wide as the pin 1a of the crankshaft 1 of the V6 engine because two conrods (not shown) are installed at the same time. In this invention, by utilizing this point, the crankshaft 1 of the V6 engine is
is one pass, and ■8 engine crankshaft 1
′ is processed in two passes.

In other words, when machining the crankshaft of a V6 engine, the first step is to support the journal 1b of the crankshaft 1 by the right rest device 2' as shown in FIG. The first bin 1a1 is cut by the left cutter 3 attached to the unit (not shown).
Then, a third pin la3 is processed using a right cutter 3' attached to a right cutter unit (not shown).

The crankshaft mirror used in the processing method of this invention includes two 4-cutter units that grip both ends of the workpieces 1 and 1', two cutter units that can simultaneously process the workpieces 1 and 1', and the workpiece 1.1. 2.2'.

After the first step is completed as described above, in the second step, the journal 1b of the crankshaft 1 is supported by the right rest device 2' and the left rest device 2, and the journal 1b is supported by the right rest device 2'. The left cutter 3 attached to the spindle unit is used to process the second bin 1a2, and the right cutter 3' attached to the right spindle unit is used to process the fifth pin 1a5.

In the third step, with the journal 1b of the crankshaft 1 supported by the left rest device 2', the remaining fourth pin 1a4 is removed by the left cutter 3 attached to the left spindle unit.
Then, the sixth pin 1a6 is machined using the right cutter 3' attached to the right spindle unit.

By machining as described above, the two left and right rest devices 2, 2' can machine all the pins 1a of the crankshaft 1 without moving their positions.

On the other hand, the crankshaft 1' used in the V8 engine is processed in four steps as shown in FIG.

That is, in the first step, half of the first pin 1a1 is processed using the left cutter 3 attached to the left spindle unit, and half of the second pin la2 is processed using the right cutter 3' attached to the right spindle unit.〇 Second step Now, the left cutter 3 of the left spindle unit processes the remaining half of the first pin 1a, and the right cutter 3' of the right spindle unit processes the remaining half of the third pin 1a30.

In the third step, the left cutter 3 of the left spindle unit processes the remaining half of the second pin 1a2, and the right cutter 3' of the right spindle unit processes the remaining half of the fourth pin la4.

In the fourth and final step, the left cutter 3 of the left spindle unit processes the remaining half of the third pin la3, and the right cutter 3' of the right spindle unit processes the remaining half of the fourth pin la4. In the first step, the rest device 2 on the right side
In the second and third steps, the left and right rest devices 2.2' support the journal 1b of the crankshaft 1', and in the fourth step, the left rest device 2 supports the journal 1b of the crankshaft 1'.

As a result, the position of the journal 1b can be selectively supported by clamping and unclamping operations without moving the positions of the left and right rest devices 2, 2' during processing.

The above is a method for machining the crankshaft 1.1' used in V6 and V8 engines, but the same method can be used to process the crankshaft used in 3-cylinder engines and 4-cylinder engines as shown in Figures 3 and 4. Crankshafts used in engines and VIO as shown in Figures 5 and 6.
We can also process crankshafts used in engines and V12 engines.

Also, Fig. 7 shows the machining status (1 pass) of the crankshaft 1 used in the V6 engine, and Fig. 8 shows the machining status of the crankshaft 1' used in the V8 engine! ! (2 passes) are shown respectively.

As is clear from these figures, when machining the crankshaft 1' of a V8 engine in two passes, the rest devices 2, 2'
The pitch of the left and right rest devices 2.2' is set so that the left and right rest devices 2.2' do not have to be moved in the longitudinal direction with respect to the left and right cutters 3.3'.

〔Effect of the invention〕

As described in detail above, this invention uses the same crankshaft miller to machine the crankshaft of a V6 engine in one pass, and the crankshaft of a V8 engine in two passes, making it possible to machine the crankshaft of a V6 engine in two passes. This eliminates problems such as the large size of the cutter used to process the crankshaft of a V8 engine, which makes setup changes difficult, and also allows the crankshaft to be processed without replacing the cutter adapter. It is also possible to eliminate problems such as a decrease in rigidity that affects machining accuracy.

Furthermore, since machining can be performed while the relative position of the rest device and the cutter in the longitudinal direction is fixed, it is possible to prevent a decrease in accuracy due to re-holding the workpiece, and
When machining an engine crankshaft, the machining load can be reduced by machining it in two passes, so that even larger crankshafts can be machined using a crankshaft mirror with a smaller capacity.

[Brief explanation of the drawing]

The drawings show an embodiment of the method of this invention, and FIG.
Figure 2 is a process diagram showing the process for machining the crankshaft for a 6-engine engine. Figure 3 is a process diagram for machining the crankshaft for a 3-cylinder engine. Figure 4 is a process diagram for machining a crankshaft for a 4-cylinder engine, Figure 5 is a process diagram for machining a crankshaft for a Vlo or 5-cylinder engine, and Figure 6 is a process diagram for machining a Vlo or 5-cylinder engine crankshaft. Process diagram for machining the crankshaft, Figure 7 is V6
A detailed view of an engine crankshaft being machined in one pass. Figure 8 is a detailed view of a V8 engine crankshaft being machined in two passes. Figure 9 (A).
(B), Figure 10 (A), (O) and Figure 11 (A),
(b) is an explanatory diagram showing a conventional processing method. 1.1' is the crankshaft, 22' is the rest device,

Claims (2)

[Claims] (1) The crankshaft of a V6 engine is manufactured by a crankshaft mirror equipped with two cutter heads for machining the crankshafts 1 and 1' and two rest devices 2 and 2' for supporting the crankshafts 1 and 1'. 1 and V8
When machining the engine crankshaft 1',
Rest devices 2, 2 that support the crankshafts 1, 1'
A crankshaft machining method characterized by machining the crankshaft 1 of a V6 engine in one pass, and the crankshaft 1' of a V8 engine in two passes, with the position of the crankshaft ' in the longitudinal direction fixed. . (2) In order to carry out the above machining method, the distance between the cutters 3, 3' provided in each cutter unit and the rest devices 2, 2' is set to a pitch that allows one-pass machining and two-pass machining. The method of processing a crankshaft according to claim 1.