JPS6293087A - Joining method for shaft stock - Google Patents

Abstract

PURPOSE:To improve a joining accuracy by setting the inclined angle of the joining face of a shaft stock within the range given by a specified equation and by joining the shaft stock by the electron beam welding from one direction. CONSTITUTION:The inclination theta to the plane vertical to the shaft center of the shaft stock 2 of one part between a set of shaft stocks to be fixed by abutting is regulated within the range given by the equation (I). Then, the electron beam welding is performed by fixing the shaft stock 2 and the joining counterpart shaft stock 2 and by moving an electron beam gun 1 relatively from one direction. With this method, the bending angle of the shaft center of the joining shaft stock after welding can be regulated within practical + or -0.3 deg., etc. without taking into consideration the special constraint nor finishing allowance. Consequently the accuracy in welding junction of the shaft stock is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for joining shaft members made of steel such as forged steel.

[Prior art]

Conventionally, as a method for joining shaft members, arc welding is a well-known technique. However, in order to prevent welding distortion, especially angular deformation, welding methods have been adopted in which the shaft material is welded while being restrained using a special restraint jig, and the finishing allowance for the material has been increased. is the current situation.

In addition, we offer shielded arc welding, gas shielded arc welding,
Saf'mercy? In the arc 2 type welding process, the amount of deformation after welding is large, and in the case of multi-layer welding, the amount of deformation is not constant, so complete welding is performed from one or two directions without rotating the shaft material. When joining by welding, it is extremely difficult to ensure that both axes of the shaft members to be joined are straight after welding, even if the above constraint method is employed. In particular, it has been practically difficult to apply this method without increasing the finishing machining allowance, especially when joining shaft members that are not axially symmetrical, such as crankshafts, where center runout must be strictly controlled.

On the other hand, electron beam welding is originally known as a welding method that causes less deformation. However, when welding from one direction, bending still occurs at the welded parts of both shaft members, and depending on the welding conditions, it may bend toward the electron beam gun side or the opposite side, and the amount of bending is different for each.

Therefore, when joining shaft materials that are not axially symmetrical, such as crankshafts that require strict control of core runout, if the finishing machining allowance is not increased, this tends to result in poor dimensional accuracy due to bending deformation. There was a problem with becoming.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned conventional problems, and includes restraining both shaft members to be joined to each other,
The object of the present invention is to provide a method for joining shaft members by electron beam welding, which can control the bending of the shaft center within an allowable range without incurring finishing allowances.

[Structure of the invention]

The shaft member joining method according to the present invention is a shaft member joining method in which the shaft members are butted and fixed and joined by electron beam welding by moving an electron beam gun relatively from one direction. When machining the joint surfaces in advance, the joint surfaces of the shaft members on both sides are inclined at an angle within the range given by the following equation.

1000 2π 1000 2π Here, as shown in Fig. 1, ωImax is the maximum penetration width (dragon) from the surface on the electron beam gun side to 2 wall thickness, 01
m1n is the minimum penetration width from the surface on the electron beam gun side to 1/2 wall thickness (dragon), ωOmax is the maximum penetration width on the side opposite to the electron beam gun (dragon), and ω0m1n is 1 from the surface on the opposite side to the electron beam gun. This is the minimum penetration width (dragon) up to /2 wall thickness, and this welding shape is a constant determined by the steel type, plate thickness, welding conditions, etc. to be subjected to electron beam welding. Further, electron beam welding is performed by the electron beam gun 1 in the direction of the arrow.

By regulating the inclination angle θ of the joint surface of the shaft material within the above range, it is possible to actually confirm that the bending of the shaft center after welding is within the practical range of ±0.3°. It was done.

[Example 1] Hereinafter, one embodiment of the present invention will be described based on the drawings.

As representative examples of welding conditions, we selected four welding conditions that result in the welded shape of ■, ■, ■, and ■ in Table 1, and as shown in Figure 2, welded the joint surface 3 of the shaft material 2 before welding. , so that the inclination angle θ with respect to the plane perpendicular to the axis of the shaft member 2 changes in the range of −0.4° to +0.8°, and for each combination of these welding conditions and the inclination angle of the joint surface, As shown in FIG. 3, the bending angle α of the shaft center of the shaft member 4 after welding was measured.

Table 1 Unit (+=-) Here, h is the wall thickness (+*m) of the shaft material welded part.

When the values of left type θc (min) and right type θc (max) in the above formula are calculated under these welding conditions, the values are as shown in Table 2.

Table 2 Table 3 shows the measurement results of the bending angle α of the shaft center after welding. .

[Margin below]

Table 3 Items marked with a circle in Table 3 have α within the range of ±0.3, and θ is calculated using the above formula, that is, θc(min) in Table 2.
) and θc (max), and α is within the range between ±0.
When θ exceeds 3 and is indicated by an X mark, it is outside the range of the above equation.

[Example 2] Next, in order to further confirm the above results with another specific example,
As shown in Figures 4(a) and 4(b), the diameter is 230 +
A 5F45 forged steel shaft material 5 with a length of 500 + u is
An example of joining by electron beam welding under the welding conditions (1) in Tables 1 and 2 will be described. The inclination angle θ of the joint surface is θ in Table 2.
c (max), θc (min) and median value (=-0,0
3°). Note that since the joint surface of the shaft member 5 is circular, a tab plate 6 is fitted around the outer periphery of the joint surface.
The joint surfaces were made into a rectangular shape with a fin angle of 50 mm, and electron beam welding was performed from the direction of the arrow with the joint surfaces aligned as shown in FIG. Table 4 shows the inclination angle θ of the welding surface and the bending angle α of the axis of the joined shaft member.

Table 4 As shown, if the inclination angle θ of the joint surface is within the range calculated using the above formula, the bending angle α of the axis of the joint material after welding can be kept within a practical range (±0.3). I can do it.

Therefore, as shown in FIG. 6, even when welding a shaft member such as the crankshaft 7 which is not axially symmetrical, it is possible to join the shaft member within a practical range of curvature of the shaft center.

〔Effect of the invention〕

According to the shaft member joining method of the present invention, as described above, 1. When electron beam welding the shaft + O from the - direction, special restraint is achieved by regulating the inclination angle of the joining surface within a predetermined range. The bending angle of the axial center of the joined shaft material after welding can be kept within a practical range without having to Therefore, (1) it is possible to easily perform welding and joining with high precision, and there is no need to increase the finishing allowance.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the penetration shape in the welded part, Fig. 2 is a side view of the shaft material before joining, Fig. 3 is a side view of the shaft material after welding, and Fig. 4 is a joint of another embodiment. The front shaft member is shown, and the same figure (a
) is a side view, FIG. 5(b) is a front view, FIG. 5 is a side view showing the state at the time of joining, and FIG. 6 is a side view showing another example of application. 1 is an electron beam gun, 2 and 5 are shaft members, 3 is a joining surface, 4 is a shaft material after welding, θ is an inclination angle of the joining surface, and α is a bending angle of the shaft center after joining. Patent applicant: Kobe Steel, Ltd. Figure 1 Figure 4 (a) YoS 411 (b). □ Presentation σ ■ Figure 6

Claims (1)

[Claims] 1. In a shaft member joining method in which the shaft members are butted and fixed and joined by electron beam welding from one direction, the inclination θ of the joint surfaces of the shaft members on both sides is set in the range given by the following formula. A method for joining shaft members, characterized by: (ω I min−ω0max)/1000×360°/
2π≦θ≦(ω I max−ω0min)/1000×
360°/2π Here, ω I max: Maximum penetration width (mm) from the surface on the electron beam gun side to 1/2 wall thickness ω I min: Minimum penetration width from the surface on the electron beam gun side to 1/2 wall thickness Penetration width (mm) ω0max: Maximum penetration width on the opposite side from the electron beam gun (m
m) ω0min: 1/2 from the surface opposite to the electron beam gun
Minimum penetration width to wall thickness (mm)