JP2019030911A - Welded component, gear, and transmission gear - Google Patents

Abstract

To provide a gear in which concentration of stress onto a corner part thereof can be alleviated even if the corner part receives thermal effect due to electron beam welding.SOLUTION: A main gear 10 has a corner R part 13 in an incident direction EB of electron beam which is radiated at the time of electron beam welding. The corner R part 13 is formed into a stepped shape. The corner R part 13 of a stepped shape has: a relief part 11 which is concaved in a circular arc shape in the incident direction EB of electron beam; and stress concentration part 12 which is so formed as to be smoothly continued from the relief part 11, and is curved in a concave form. Further, the stress concentration part 12 is deeper with respect to the incident direction EB of electron beam than the relief part 11, that is, a diameter of R thereof is so formed as to be larger.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a member to be welded, a gear, and a transmission gear.

  Conventionally, as one of the welding methods, the thermoelectrons emitted by heating the filament in vacuum are accelerated to a beam by a high voltage, and this high-speed electron beam is squeezed with an electromagnetic lens (base material to be welded). Electron beam welding (EBW) is known in which welding is performed using impact heat generated at the time of collision with a member). This electron beam welding is characterized in that welding can be performed to a deep part in a narrow range on a member to be welded, as compared with other welding methods.

  Here, Patent Document 1 discloses a method of manufacturing a transmission gear in which a synchronization clutch gear is inserted into a main gear and integrated by electron beam welding. More specifically, according to this manufacturing method, first, the clutch gear is inserted into the outer peripheral joint surface of the main gear, and then, the contact surface of the main gear that rises perpendicularly from the outer peripheral joint surface and the back side joint surface of the clutch gear. Are welded by electron beam welding, and the clutch gear is integrated with the main gear.

JP 2004-11816 A

  By the way, in the welded portion of the transmission gear (main gear), there is a corner portion (a portion where the outer peripheral joint surface and the contact surface intersect) in the incident direction of the electron beam. ) May be affected by the heat of electron beam welding. In that case, the corner R portion, which is a relief shape, is deformed by heat, so that the portion may become a stress concentration portion.

  In particular, transmission gears require a welding depth that satisfies the torque transmission strength. For example, if there is no allowance in the weldable range (welding depth) due to layout or manufacturing requirements, etc. There is a possibility that the heat effect of electron beam welding is applied to the corner R portion due to the welding depth variation of the beam welding. In such a case, there is a concern that the corner R portion, which is a high stress generation site, is deformed due to the heat effect of electron beam welding to become a stress concentration site, and breakage occurs starting from the deformation site.

  The present invention has been made to solve the above problems, and even if the corner is affected by heat by electron beam welding, the member to be welded can alleviate stress concentration at the corner. An object is to provide a gear and a transmission gear.

  A member to be welded according to the present invention is a member to be welded having a corner portion in the incident direction of the electron beam irradiated during electron beam welding, and the corner portion has a relief portion recessed in the incident direction of the electron beam, and a relief portion. And a stress concentration alleviation part formed so as to be continuously concavely curved from the part.

  According to the member to be welded according to the present invention, since the corner of the member to be welded has a stepped shape including the relief portion and the stress concentration relaxation portion, the relief portion is heated by the electron beam during electron beam welding. Even if it is affected, it is possible to prevent the thermal effect from reaching the stress concentration relaxation part. Therefore, when the member to be welded is incorporated into an apparatus after being welded and used, high stress is concentrated on the corner (escape portion) by the stress concentration relaxation portion formed to be concavely curved. This can be prevented. As a result, even if the corner portion (relief portion) is affected by heat due to electron beam welding, the stress concentration on the corner portion (relief portion) can be reduced.

  The gear according to the present invention is a gear having a corner portion in the incident direction of the electron beam irradiated during electron beam welding, and the corner portion is continuous from the escape portion recessed in the incident direction of the electron beam and the escape portion. And a stress concentration relaxation portion formed so as to be curved in a concave shape.

  According to the gear according to the present invention, since the corner portion of the gear has a stepped shape including the relief portion and the stress concentration relaxation portion, the relief portion was affected by heat due to the electron beam during electron beam welding. However, it is possible to prevent the thermal effect from reaching the stress concentration relaxation part. Therefore, when the gear is welded and then incorporated into a device, high stress is concentrated on the corner (relief portion) by the stress concentration relaxation portion formed to be concavely curved. Can be prevented. As a result, even if the corner portion (relief portion) is affected by heat due to electron beam welding, the stress concentration on the corner portion (relief portion) can be reduced.

  In the gear according to the present invention, it is preferable that the relief portion is formed in an arc shape and the stress concentration relaxation portion is formed so as to be smoothly continuous from the relief portion. If it does in this way, processing of a relief part and a stress concentration relaxation part can be performed comparatively simply. That is, it is possible to relatively easily form a shape that can effectively exhibit the functions of the relief portion and the stress concentration relaxation portion.

  In the gear according to the present invention, it is preferable that the stress concentration relaxation portion is formed deeper than the escape portion with respect to the incident direction of the electron beam. In this way, even if the corner (relief) is affected by the heat of electron beam welding and deforms, for example, it is possible to more effectively relieve stress concentration on the corner (relief). Become.

  A transmission gear according to the present invention includes any one of the above gears and a coupling integrated with the gear by electron beam welding.

  According to the transmission gear according to the present invention, any of the above gears and the coupling are integrated by electron beam welding. Therefore, as described above, even when the gear and the coupling are subjected to electron beam welding, even if the corner portion (relief portion) of the gear is affected by heat due to electron beam welding, the transmission gear is incorporated into the transmission. When being used, it becomes possible to alleviate the stress concentration on the corner (relief) of the gear.

  According to the present invention, even if a corner is affected by heat due to electron beam welding, stress concentration on the corner can be reduced.

It is sectional drawing which shows the structure of the transmission gear which concerns on embodiment. It is a figure which shows the strength analysis result of the corner part of the transmission gear (main gear) which concerns on embodiment. It is sectional drawing which shows the structure of the transmission gear which has a comparative example (it has the corner | angular R part of the conventional shape). It is a figure which shows the state (endurance test result) of the weld part after the endurance test of the transmission gear which has a corner R part of the related art which concerns on a comparative example. It is a figure which shows the state (endurance test result) of the welding part after the other endurance tests of the transmission gear which has a corner R part of the related art which concerns on a comparative example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted. Here, a transmission gear (main gear) used in a manual transmission of an automobile will be described as an example of a member to be welded.

  First, the configuration of the transmission gear 1 according to the embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view showing the configuration of the transmission gear 1.

  As described above, the transmission gear 1 is a gear used for a manual transmission of an automobile, and includes a gear (hereinafter referred to as “main gear”) 10 and a coupling (hereinafter referred to as “clutch”) integrated with the main gear 10 by electron beam welding. 20).

  The main gear 10 includes a disc-shaped main body portion 15 having a predetermined thickness in the axial direction and having a tooth portion 14 on the outer peripheral portion, and a cylindrical cylindrical portion 16 protruding from the main body portion 15 in the axial direction. Yes. A shaft hole 17 penetrating in the axial direction is formed in the main gear 10, and the main shaft is inserted into the shaft hole 17 when incorporated in the transmission.

  The clutch gear 20 has a main body portion 22 having a spline 21 formed on the outer peripheral portion, and a cone portion 23 protruding from the main body portion 22 in the axial direction. The clutch gear 20 is formed with a through hole that can be fitted onto the cylindrical portion 16 of the main gear 10.

  When welding the main gear 10 and the clutch gear 20, first, the clutch gear 20 is fitted into the cylindrical portion 16 of the main gear 10. An electron beam is incident from a direction parallel to the axial direction of the main gear 10 (incident direction EB in FIG. 1), and the outer peripheral surface of the cylindrical portion 16 of the main gear 10 and the main body portion 22 (through hole) of the clutch gear 20. The joint surface (welded portion) with the inner peripheral surface of the steel plate is welded over the entire periphery. In this way, the main gear 10 and the clutch gear 20 are integrated by electron beam welding.

  As described above, when electron beam welding is performed on the main gear 10 and the clutch gear 20, the electron beam is incident from the incident direction EB parallel to the axial direction of the main gear 10. Therefore, a corner (hereinafter also referred to as “corner R portion”) 13 defined by the side surface of the main body portion 15 of the main gear 10 and the outer peripheral surface of the cylindrical portion 16 is positioned in front of the incident direction EB of the electron beam. . The corner R portion 13 is a portion where stress is concentrated when the corner R portion 13 is incorporated in a transmission.

  Here, the corner R portion 13 of the main gear 10 will be described. As shown enlarged in the circle of FIG. 1, the corner R portion 13 is formed in a stepped shape. That is, the corner R portion 13 includes a relief portion 11 that is recessed in an arc shape in the electron beam incident direction EB, and a stress concentration relaxation portion 12 that is formed so as to be smoothly and continuously curved from the relief portion 11 into a concave shape. It is configured.

  Further, the stress concentration relaxation portion 12 is deeper than the escape portion 11 in the electron beam incident direction EB (same as the axial direction), that is, has a larger R diameter. Although a cross section is shown in FIG. 1, the corner R portion 13 is formed along the outer edge of the cylindrical portion 16 over the entire circumference of the cylindrical portion 16.

  Since the corner R portion 13 has the above-described configuration (stepped shape), even when the escape portion 11 in the electron beam incident direction EB is affected by heat due to the electron beam during electron beam welding, the heat The influence is prevented from reaching the stress concentration alleviating part 12. Therefore, when the main gear 10 is welded to the clutch gear 20 and incorporated in the transmission, the stress concentration relaxation portion 12 formed so as to be curved in a concave shape causes high stress to be generated at the corner R portion 13 (escape). Concentration on the part 11) is prevented. As a result, even if the corner R portion 13 (relief portion 11) is affected by heat due to electron beam welding, the stress concentration on the corner R portion 13 (relief portion 11) is alleviated.

  Subsequently, in order to confirm the effect of the corner R portion 13 having a stepped shape including the relief portion 11 and the stress concentration relaxation portion 12, strength analysis of the corner R portion 13 was performed. More specifically, assuming that the relief portion 11 of the corner R portion 13 is buried due to the heat effect of electron beam welding, the relief portion 11 is filled and the conventional (ie, the case where the stress concentration relaxation portion 12 is not provided). Then, the strength analysis was performed by simulating the shape where the stress tends to concentrate. The analysis result is shown in FIG. Here, FIG. 2 is a diagram showing the strength analysis result of the corner R portion 13 of the transmission gear 1 (main gear 10). Note that the shading in FIG. 2 indicates the strength of the applied stress, and the darker the color, the stronger the stress.

  As shown in FIG. 2, since stress is dispersed and relaxed in the R portion of the stress concentration relaxation portion 12, it was confirmed that high stress does not concentrate in the buried relief portion 11. Therefore, it was confirmed that even if the relief portion 11 of the corner R portion 13 is filled due to the heat effect of electron beam welding, the stress concentration on the corner R portion 13 (escape portion 11) can be alleviated.

  As a comparative example, an endurance test was performed on the transmission gear 100 in which the main gear 110 having the conventional corner R portion (that is, the corner R portion not having a stepped shape) 113 shown in FIG. went. The test results are shown in FIGS. Here, FIG. 3 is a cross-sectional view showing a configuration of a transmission gear 100 according to a comparative example (having a conventional-shaped corner R portion 113). FIG. 4 is a diagram showing a state of a welded part (endurance test result) after the endurance test of the transmission gear 100 according to the comparative example (having a conventional corner R portion 113). FIG. 5 is a diagram showing a state of a welded part (endurance test result) after another endurance test of the transmission gear 100 according to the comparative example (having a conventional-shaped corner R portion 113).

  As shown in FIG. 4, in the transmission gear 100 according to the comparative example (having the conventional-shaped corner R portion 113), the corner R portion 113 is deformed due to the heat effect of electron beam welding and an abnormal shape (projection shape) is formed. As a result, the abnormal shape became a stress concentration site and a crack occurred. Further, as shown in FIG. 5, in the transmission gear 100 according to the comparative example (having the conventional-shaped corner R portion 113), the corner R portion 101 is substantially buried due to the heat effect of electron beam welding, and the portion is Cracks occurred at the starting point.

  As described above, according to the main gear 10 according to the present embodiment, the corner R portion 13 has the stepped shape including the relief portion 11 and the stress concentration relaxation portion 12, so that the relief portion is affected by the heat effect of electron beam welding. Even when 11 is deformed, it is confirmed that stress is not concentrated in the escape portion 11 because the stress is dispersed and relaxed in the R portion of the stress concentration relaxation portion 12.

  As described above, according to the main gear 10 (member to be welded) according to the present embodiment, the corner portion 13 of the main gear 10 has a stepped shape including the relief portion 11 and the stress concentration relaxation portion 12. Even when the escape portion 11 is thermally affected by the electron beam during electron beam welding, the thermal effect can be prevented from reaching the stress concentration relaxation portion 12. Therefore, when the main gear 10 is welded to the clutch gear 20 and incorporated in the transmission, the stress concentration relaxation portion 12 formed so as to bend in a concave shape causes the high stress to be applied to the corner portion 13 (the relief portion). 11) can be prevented from concentrating. As a result, even if the corner portion 13 (relief portion 11) is affected by heat due to electron beam welding, the stress concentration on the corner portion 13 (relief portion 11) can be reduced.

  In particular, in the main gear 10 according to the present embodiment, the stress concentration relaxation portion 12 is deeper than the escape portion 11 in the electron beam incident direction EB (axial direction), that is, R is formed larger. Even if the portion 13 (the escape portion 11) is affected by the heat of electron beam welding and deforms, for example, it becomes possible to more effectively alleviate the stress concentration on the corner portion 13 (the escape portion 11).

  In the main gear 10 according to the present embodiment, the escape portion 11 is formed in an arc shape, and the stress concentration relaxation portion 12 is formed in an arc shape so as to smoothly continue from the escape portion 11. Processing of the stress concentration relaxation portion 12 can be performed relatively easily. That is, it is possible to relatively easily form a shape that can effectively exhibit the functions of the relief portion 11 and the stress concentration relaxation portion 12.

  Moreover, according to the transmission gear 1 which concerns on this embodiment, the main gear 10 and the clutch gear 20 which were mentioned above are integrated by electron beam welding. Therefore, as described above, when the main gear 10 and the clutch gear 20 are subjected to electron beam welding, even if the corner portion 13 (relief portion 11) of the main gear 10 is affected by heat due to electron beam welding, the transmission gear. When 1 is incorporated into a transmission and used, stress concentration on the corner 13 (escape portion 11) of the main gear 10 can be reduced.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above-described embodiment, the main gear 10 of the transmission gear 1 is described as an example of the member to be welded, but the member to be welded is not limited to the main gear of the transmission gear.

  In the above embodiment, the stepped corner R portion 13 is formed in a circular shape along the outer edge of the cylindrical portion 16 of the main gear 10. However, the shape in which the corner R portion 13 extends is limited to a circular shape. It can set arbitrarily according to a welding shape, without being done.

1 Transmission gear 10 Main gear (welded member)
11 relief part 12 stress concentration relaxation part 13 corner R part (corner part)
20 Clutch gear (coupling)
EB Electron beam incident direction

As shown in FIG. 4, in the transmission gear 100 according to the comparative example (having the conventional-shaped corner R portion 113), the corner R portion 113 is deformed due to the heat effect of electron beam welding and an abnormal shape (projection shape) is formed. As a result, the abnormal shape became a stress concentration site and a crack occurred. Further, as shown in FIG. 5, in the transmission gear 100 according to the comparative example (having the corner R portion 113 having the conventional shape), the corner R portion 113 is substantially buried due to the heat effect of electron beam welding, and the portion is Cracks occurred at the starting point.

Claims (5)

A welded member having a corner in the incident direction of an electron beam irradiated during electron beam welding,
The corner is
A relief portion recessed in the incident direction of the electron beam;
A stress concentration relaxation portion formed so as to be continuously concavely curved from the escape portion;
A member to be welded characterized by comprising: A gear having a corner in the incident direction of an electron beam irradiated during electron beam welding,
The corner is
A relief portion recessed in the incident direction of the electron beam;
A stress concentration relaxation portion formed so as to be continuously concavely curved from the escape portion;
The gear characterized by having. The escape portion is formed in an arc shape,
The gear according to claim 2, wherein the stress concentration relaxation part is formed so as to be smoothly continuous from the relief part.   The gear according to claim 3, wherein the stress concentration relaxation portion is formed deeper than the escape portion in the incident direction of the electron beam. The gear according to any one of claims 2 to 4,
A transmission gear comprising the gear and a coupling integrated by electron beam welding.

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