JP5154508B2 - Differential gear assembly apparatus and method - Google Patents

Description

  The present invention relates to an apparatus and method for assembling a differential gear constituting a differential device of an automobile or the like.

  As shown in FIG. 11, the differential gear includes a differential case (hereinafter referred to as a differential case) A, a pair of side gears B and a pair of pinion gears C disposed inside the differential case A, and a pinion shaft D. . The pair of side gears B are arranged in a side gear mounting hole A2 inside the differential case A with side surfaces facing each other via a side gear thrust washer E (hereinafter simply referred to as a washer E), and a pair of pinion gears C Is arranged with a pinion gear thrust washer F (hereinafter simply referred to as a washer F) inside the differential case A with the tooth surfaces facing each other. The pinion shaft D is inserted into the inner periphery of the pair of pinion gears C and the pinion shaft insertion hole A3 provided in the differential case A, and the straight pin G is crimped and fixed to the end of the pinion shaft D. The cross section (cross section in the direction perpendicular to the axis) of the pinion shaft D forms an oval shape in which a flat portion is formed by cutting out a portion facing the diameter direction. The inner peripheral surface of the pinion gear C forms a cylindrical surface that is slightly larger in diameter than the pinion shaft D, so that the pinion gear C can freely rotate on the outer periphery of the pinion shaft D. The inner peripheral surface of the washer F has an oval shape similar to the outer periphery of the pinion shaft D, whereby the washer F is engaged with the outer peripheral surface of the pinion shaft D in the circumferential direction, and the outer periphery of the pinion shaft D is Rotation is regulated.

  For example, Patent Document 1 discloses an assembling apparatus and assembling method for automatically assembling the above differential gear.

JP 11-33846 A

  In assembling the differential gear, first, a pair of side gears B are arranged in the differential case A with the tooth surfaces B2 facing each other in the vertical direction (see FIG. 12). The pinion gear C is carried in toward the vertical middle portion of the pair of side gears B, and each pinion gear is engaged with both the pair of side gears B. At this time, if the pinion gear C is translated in the horizontal direction (that is, along the chain line indicated by X in FIG. 12) and is to be carried into the differential case, the pinion gear C interferes with the lower edge of the opening A1 of the differential case A. (See the dotted arrow in FIG. 12). For this reason, in Patent Document 1, the pinion gear is carried into the differential case in a state where the arm holding the pinion gear is tilted with respect to the horizontal direction and the pinion gear is tilted with respect to the horizontal direction. As described above, in order to move the arm in an inclined state, a large-scale device and complicated control are required, resulting in an increase in cost. Further, if the pinion gear is merely brought into contact with the side gear, the crest portions of the gear tooth surfaces may come into contact with each other, and the gears may not mesh well.

  The problem to be solved by the present invention is to carry the pinion gear into the differential case with a simple mechanism without interfering with the edge of the opening of the differential case.

  Another problem to be solved by the present invention is to securely mesh the pinion gear and the side gear when the pinion gear is mounted.

  In order to solve the above problems, the present invention provides a differential gear assembling apparatus in which a pair of side gears and a pair of pinion gears are mounted inside a differential case, and the pair of side gears are respectively placed at predetermined positions inside the differential case. The side gear carry-in means that is arranged with the central axes thereof aligned and the tooth surfaces facing each other, the side gear holding means that holds the pair of side gears at predetermined positions in the differential case, and the pair of pinion gears, And a pinion gear carry-in means for meshing with the pair of side gears, and the pinion gear carry-in means translates the guide in a direction perpendicular to the central axis direction with a guide holding the pinion gear. And a holding portion that holds the guide while allowing movement in the central axis direction. There is provided a Lugia assembly apparatus.

  Thus, by holding the guide of the pinion gear carrying means while allowing the movement of the pair of side gears in the central axis direction, the pinion gear is translated in the direction perpendicular to the central axis direction, and one side gear is moved. The pinion gear can be moved in the direction of the central axis by the reaction force received from the side gear when it is brought into contact with. As a result, even when the pinion gear is carried in from a position offset from the predetermined position in the central axis direction, the pinion gear can be guided to the predetermined position by contacting the side gear, so that it interferes with the opening of the differential case. The pinion gear can be installed without doing so.

  That is, according to the present invention, a step of arranging a pair of side gears at predetermined positions inside the differential case in a state where the respective central axes coincide with each other and the tooth surfaces face each other, and a direction orthogonal to the central axis And moving the pinion gear in the direction of the central axis by the reaction force received from the one side gear by further pushing the pinion gear in the parallel movement direction. Thus, the differential gear assembly method may include a step of bringing the pinion gear into contact with the other side gear.

  The differential gear assembling apparatus described above can be configured, for example, such that the guide is translated in the horizontal direction by the drive unit and the guide is held by the holding unit while balancing so as to cancel the gravity of the guide. . Thereby, the guide holding the pinion gear can be moved in a direction perpendicular to the horizontal direction with a small reaction force due to contact with the side gear.

  Further, if the pair of side gears are rotatably held by the side gear holding means and at least one of the side gears can be driven to rotate, the pinion gear in which one of the side gears is driven to rotate is brought into contact with the side gear. Thus, even when the crests of the tooth surfaces come into contact with each other, the phases of the tooth surfaces can be shifted and the two gears can be reliably engaged. Further, the pinion gear is rotated by meshing with one of the rotationally driven side gears, and the pinion gear and the other side gear are brought into contact with the other side gear held rotatably. Engage reliably.

  As shown in FIG. 11, a side gear thrust washer E is mounted between the pair of side gears B and the differential case A, and a pinion gear thrust washer F is mounted between the pair of pinion gears C and the differential case A, respectively. Installed. In the differential gear assembling process, there is a risk that the washer may not be mounted due to an assembly error, or a plurality of washers may be mounted on one gear. Therefore, after arranging the pair of side gears at predetermined positions inside the differential case, the pair of side gears are pulled away from each other, and based on the distance between the pair of side gears, the side gears are placed between the side gears and the differential case. If it is confirmed whether or not the thrust washer for use is properly attached, it is possible to prevent a situation in which an erroneous assembly of the side gear thrust washer is overlooked. That is, if the washer is not attached, the measured distance between the side gears will be larger than the distance between the side gears when the washer is attached normally (predetermined value). If the washer is excessively attached, the distance between the side gears The measurement distance becomes smaller than a predetermined value. At this time, the distance between the pair of side gears may be measured directly, or indirectly, for example, the distance between the clamp shafts that pulls the side gear away from each other may be measured.

  Similarly, a pair of pinion gears are pushed in directions approaching each other by guides, meshed with both of the pair of side gears, and the distance between the guides is measured in this state, and each pinion gear is measured based on the measured distance. If it is confirmed whether or not the pinion gear thrust washer is properly mounted between the gear case and the differential case, it is possible to prevent the mistake of assembling the pinion gear thrust washer from being overlooked. That is, if the washer is not attached, the measurement distance between the guides is smaller than the distance between the guides when the washer is normally attached (predetermined value). If the washer is excessively attached, the distance between the guides The measurement distance becomes larger than a predetermined value.

  As described above, according to the present invention, the pinion gear can be carried into the differential case with a simple mechanism without interfering with the opening of the differential case. In addition, when the pinion gear is mounted, the pinion gear and the side gear can be reliably meshed.

It is sectional drawing which shows a side gear mounting process. It is sectional drawing which shows a side gear mounting process. It is sectional drawing which shows a side gear mounting process. (A) is sectional drawing which shows a pinion gear mounting process, (b) is the same top view. It is sectional drawing which shows a pinion gear mounting process. (A) is sectional drawing which shows a pinion gear mounting process, (b) is the same top view. (A) is sectional drawing which shows a pinion gear mounting process, (b) is the top view, (c) is an axial orthogonal direction sectional view of a dummy shaft and a 2nd clamp shaft. It is a top view which shows a pinion shaft insertion process. (A) is sectional drawing which shows a pinion shaft insertion process, (b) is the same top view. (A) is sectional drawing which shows a pinion shaft insertion process, (b) is the same top view. It is a disassembled perspective view of a differential gear. It is sectional drawing which shows a mode that a pinion gear is carried in in a differential case from a horizontal direction.

  A differential gear assembling apparatus (hereinafter simply referred to as “assembling apparatus”) according to an embodiment of the present invention is for assembling a differential gear shown in FIG. Hereinafter, a differential gear assembling method using the assembling apparatus (hereinafter simply referred to as “assembling method”) will be described together with the structure of the assembling apparatus. In the present embodiment, a case is shown in which assembly is performed in a state where the differential case A is arranged so that the penetrating direction of the side gear mounting hole A2 is the vertical direction.

  The assembly method of this embodiment is performed through a side gear mounting process, a pinion gear mounting process, and a pinion shaft insertion process.

  In the side gear mounting step, the pair of side gears B and washers E are carried into the differential case A by appropriate side gear carrying means (arms or the like). Inside the differential case A, the pair of side gears B are arranged in a state in which the respective central axes in the vertical direction coincide with each other and the tooth surfaces B2 face each other, and are respectively held rotatably by the side gear holding means. Specifically, as shown in FIG. 1, a first clamp shaft 21 as one side gear holding means is inserted from above into the upper side gear mounting hole A2 of the differential case A. The side gear B is clamped and held. The first clamp shaft 21 is connected to a driving device (not shown), and the upper side gear B can be rotationally driven by the first clamp shaft 21. On the other hand, the lower side gear B is mounted in the lower side gear mounting hole A2 of the differential case A (in this case, the lower side gear mounting hole A2 serves as the other side gear holding means). Then, as shown in FIG. 2, the second clamp shaft 22 is inserted into the inner periphery of the lower side gear mounting hole A <b> 2 and the side gear B from below. The second clamp shaft 22 has a U-shaped cross section formed at a clamp portion 22a capable of expanding and reducing the outer peripheral surface, an extending portion 22b extending upward from the clamp portion 22a, and an upper end of the extending portion 22b. And a groove 22c. In the state shown in FIG. 2, the upper end portion of the second clamp shaft 22 reaches the upper side from the center of the pinion shaft insertion hole A3, and the clamp portion 22a is arranged on the inner periphery of the lower side gear B. By expanding the diameter of the clamp portion 22a in this state, the inner peripheral surface of the lower side gear B can be clamped (see FIG. 3). The groove 22c extends in the penetrating direction (left-right direction in FIG. 2) of the opening A1 of the differential case A, and the groove width is set larger than the diameter of the dummy shaft 31 described later. The second clamp shaft 22 is provided so as to be freely rotatable. Accordingly, in a state where the lower side gear B is clamped by the clamp portion 22a, the lower side gear B can freely rotate together with the second clamp shaft 22, and in a state where the clamp by the clamp portion 22a is released, the lower side gear B B is freely rotatable on the outer periphery of the second clamp shaft 22.

  At this time, a washer E is mounted between the upper and lower side gears B and the differential case A, but the washer E is not mounted due to an assembly error, or a plurality of washers E are stacked on one side gear B. There is a risk of wearing. Therefore, as shown in FIG. 3, the upper side gear B is pulled up by the first clamp shaft 21, and the lower side gear B is clamped by the second clamp shaft 22 and pulled down. By measuring the vertical distance L between the shaft 21 and the second clamp shaft 22 by the measuring means 23, it can be confirmed whether or not the washer E is normally attached. If the washer E is not attached, the vertical distance L is larger than a predetermined value, and if the washer E is excessively attached, the vertical distance L is smaller than a predetermined value. When the attachment confirmation of the washer E is completed, the clamp of the lower side gear B by the clamp portion 22 a of the second clamp shaft 22 is released, and the side gear B can freely rotate on the outer periphery of the second clamp shaft 22.

  Next, in the pinion gear mounting step, the pair of pinion gears C and washers F are mounted at predetermined locations inside the differential case A by the pinion gear carry-in means. In the present embodiment, as shown in FIG. 4, the pinion gear carry-in means includes guides 31 and 32 provided on both sides of the opening A1 of the differential case A in the penetration direction (left and right sides in the drawing), and guides 31 and 32. The drive unit 33 that translates in a direction orthogonal to the central axis direction of the side gear (horizontal direction in the present embodiment) and the guides 31 and 32 are allowed to move in the central axis direction of the side gear (vertical direction in the present embodiment). And a holding portion (not shown) for holding.

  As shown in FIG. 4B, the guide 31 includes a dummy shaft 31a, a support portion 31b that accommodates the dummy shaft 31a on the inner periphery, and a cylinder 31c that advances the dummy shaft 31a. Like the pinion shaft D shown in FIG. 11, the dummy shaft 31a has an oval transverse cross-sectional shape in which a portion opposed in the diametrical direction is cut out (in the drawing, it is represented by a cylinder for simplification). The maximum outer diameter of the dummy shaft 31a (the outer diameter of the arc portion) is formed slightly smaller than the inner peripheral surface of the pinion gear C, whereby the dummy shaft 31a can hold the pinion gear C so as to be freely rotatable. it can. The outer peripheral surface of the oval mold of the dummy shaft 31a is fitted with the inner peripheral surface of the oval mold of the washer F, whereby the rotation of the washer F on the outer periphery of the dummy shaft 31a is restricted. The dummy shaft 31 a is provided so as to be able to protrude from the support portion 31 b by the operating shaft 31 c 1 of the cylinder 31 c and is provided so as to be completely separable from the guide 31. The support portion 31b has a curved support surface 31b1 following the spherical surface portion C3 (that is, washer F) of the pinion gear C at the tip portion, and the tip portion of the dummy shaft 31a protrudes from the support surface 31b1. . The guide 32 does not have a dummy shaft, the operating shaft 32c1 of the cylinder 32c protrudes from the support surface 32b1 of the support portion 32b, and the outer peripheral surface of the operating shaft 32c1 has an oval cross-sectional shape. Since the other structure of the guide 32 is the same as that of the guide 31, description is abbreviate | omitted.

  The holding portion is configured by a mechanism that acts to cancel the weight of the guides 31 and 32 via a balance cylinder or a spring. For this reason, when a vertical force is applied to the guides 31 and 32, the guides 31 and 32 move up and down while maintaining the axial direction horizontal.

  A pinion gear C and a washer F are attached to the tip of the dummy shaft 31a of the guide 31 and the tip of the operating shaft 32c1 of the guide 32, respectively, and the pair of pinion gears C is located outside the opening A1 of the differential case A. The planes C2 are arranged to face each other in the horizontal direction. At this time, in a state where the phase of the flat surface portion of the oval inner peripheral surface of the washer F matches the phase of the flat surface portion of the oval outer peripheral surface of the dummy shaft 31a (for example, a state where the flat surface portion is arranged vertically) Both are fitted. The height of the central axis of the pinion gear C is higher than the height of a predetermined position to be mounted in the differential case (that is, the height of the pinion shaft insertion hole A3, indicated by X in FIG. 4A). As a result, the lower end portion of the pinion gear C is disposed above the lower edge of the opening A1 of the differential case A. Then, the clamp shaft 21 is driven to rotate, and the upper side gear B arranged in the differential case A is rotated in the horizontal plane, so that the guides 31 and 32 are moved parallel to each other in the horizontal direction by the drive unit 33. Then, the tooth surface C2 of the pinion gear C is brought into contact with the tooth surface B2 of the upper side gear B (see FIG. 5). In this way, by causing the pinion gear C to contact while rotating the upper side gear B, even if the crests of the tooth surfaces B2 and C2 of both gears contact each other, the phases of both tooth surfaces are shifted and the teeth are shifted. The surface B2 and the tooth surface C2 can be reliably meshed with each other. Thereby, the pinion gear C rotates in the vertical plane on the outer periphery of the dummy shaft 31 a of the guide 31 as the side gear B rotates.

  At this time, the pinion gear C receives a downward reaction force from the upper side gear B because the tapered tooth surface C2 of the pinion gear C abuts on the tapered tooth surface B2 of the upper side gear B. Accordingly, when the guides 31 and 32 are pushed forward, the guides 31 and 32 holding the pinion gear C are pushed into the inner side of the differential case A and are pushed down while maintaining the axial direction horizontal, and the teeth of the pinion gear C are The lower part of the surface C2 contacts the tooth surface B2 of the lower side gear B. Thus, by rotating the pinion gear C and bringing it into contact with the lower side gear B, the tooth surface C2 of the pinion gear C and the tooth surface B2 of the lower side gear B can be reliably engaged with each other. The side gear B on the side rotates in the direction opposite to the side gear B on the upper side in the horizontal plane as the pinion gear C rotates (see FIG. 6A). In the present embodiment, the lower side gear B is held so as to be freely rotatable. However, the present invention is not limited to this. For example, the second clamp shaft 22 is rotationally driven in a state where the lower side gear B is clamped. Thus, the lower side gear B may be rotationally driven in the opposite direction to the upper side gear B.

  When the pinion gear C completely meshes with the upper and lower side gears B, the parallel movement of the guides 31 and 32 is stopped and the rotation of the clamp shaft 21 is stopped. At this time, the central axis of the pair of pinion gears C coincides with the height of the pinion shaft insertion hole A3 of the differential case A. Further, the spherical support surfaces 31b1 and 32b1 of the support portions 31b and 32b of the guides 31 and 32 are arranged in the opening A1 of the differential case A, and are arranged on a spherical surface obtained by extending the spherical inner peripheral surface of the differential case A ( (Refer FIG.6 (b)). In this state, the distance between the guide 31 and the guide 32, specifically, the horizontal distance S between the support portions 31b and 32b is measured by the measuring means 34, whereby the distance between the pinion gear C and the support portions 31b and 32b. It is possible to confirm whether or not each washer F is normally attached. If the washer F is not attached, the horizontal distance S is smaller than a predetermined value, and if the washer F is excessively attached, the horizontal distance S is larger than a predetermined value.

  From this state, the cylinder 31c of the guide 31 is actuated, the dummy shaft 31a is pushed out from the support portion 31b by the working shaft 31c1, and the working shaft 32c1 is moved backward at the tip of the dummy shaft 31a (see FIG. 7). At this time, the dummy shaft 31a is accommodated inside the spherical inner peripheral surface (extended spherical surface) of the differential case A, that is, between the support surfaces 31b1 and 32b1 of the guides 31 and 32. The central portion of the dummy shaft 31a is disposed on the inner periphery of the groove 22c of the second clamp shaft 22, and thus the central portion of the dummy shaft 31a is sandwiched between the second clamp shafts 22 from both sides in the horizontal direction (FIG. 7 ( c)).

  Subsequently, a pinion shaft insertion process is performed. From the state shown in FIG. 7, by rotating the second clamp shaft 22, the dummy shaft 31 a disposed on the inner periphery of the groove 22 c is rotated around the central axis of the side gear B. At this time, the upper side gear B is held so as to be freely rotatable together with the first clamp shaft 21, and the lower side gear B is freely clamped in the lower side gear mounting hole A 2 without being clamped by the second clamp shaft 22. Since it is held rotatably, when the dummy shaft 31a is rotated, the pair of pinion gears C and the pair of side gears B rotate together around the vertical central axis (the central axis of the side gear B). Thereby, since the dummy shaft 31a and the washer F rotate around the central axis in the vertical direction without rotating, the flat portions of the oval outer peripheral surface and the inner peripheral surface are maintained vertically. When the dummy shaft 31a rotates 90 °, the rotation of the second clamp shaft 22 is stopped (see FIG. 8). At this time, the inner peripheral surface C1 of the pair of pinion gears C, the inner peripheral surface of the pair of washers F, the dummy shaft 31a, and the pinion shaft insertion hole A3 of the differential case A are arranged coaxially.

  Thereafter, the guides 31 and 32 are moved backward, and the guide 31 from which the dummy shaft 31a is discharged is moved to one side in the penetration direction of the pinion shaft insertion hole A3 of the differential case A, and the dummy shaft 31a and the inner hole of the support portion 31b are moved. It arrange | positions on the same axis | shaft (refer FIG. 9). On the other side of the differential case A through the pinion shaft insertion hole A3, a pinion shaft supply unit 40 is provided. The pinion shaft supply unit 40 includes an accommodation unit 41 that accommodates the pinion shaft D on the inner periphery, and a push-out mechanism (not shown) that pushes the pinion shaft D out of the accommodation unit 41, and a pinion shaft insertion hole A 3 of the differential case A The pinion shaft D is arranged on the same axis. As described above, when the pinion shaft D is pushed out from the accommodating portion 41 with the guide 31 disposed on one side of the differential case A, the pinion shaft D is inserted into the inner periphery of the pinion gear C and the dummy shaft 31a is It is pushed out from the inner periphery of the pinion gear C and accommodated in the inner periphery of the support portion 31b (see FIG. 10).

  At this time, it is necessary to match the phase of the flat portion of the oval inner peripheral surface of the washer F attached to the pinion gear C with the phase of the flat portion of the oval outer peripheral surface of the pinion shaft D. In this embodiment, since the flat portion of the oval inner peripheral surface of the washer F is maintained in a vertically arranged state, if the phase of the flat portion of the oval outer peripheral surface of the pinion shaft D is matched to this, The pinion shaft D can be inserted through the inner periphery of the washer F without any trouble. As described above, the dummy shaft 31 a is returned to the guide 31 at the same time as the mounting of the pinion shaft D to the inner periphery of the pair of pinion gears C is completed. Thereafter, a straight pin G is press-fitted into a through hole provided at an end portion of the pinion shaft D, and the end portion of the straight pin G is crimped with a jig to complete a differential gear.

21 First clamp shaft 22 Second clamp shaft 31/32 Guide 31a Dummy shaft 31c Cylinder 32 Guide 32c Cylinder 32c1 Actuating shaft 33 Drive unit 40 Pinion shaft supply part A Differential case A1 Opening part A2 Side gear mounting hole A3 Pinion shaft insertion hole B Side gear B2 Tooth surface C Pinion gear C2 Tooth surface D Pinion shaft E Side gear thrust washer F Pinion gear thrust washer G Straight pin

Claims (8)

A differential gear assembly device in which a pair of side gears and a pair of pinion gears are mounted inside a differential case,
Side gear carry-in means for arranging a pair of side gears at predetermined positions inside the differential case with their central axes aligned and with their tooth surfaces facing each other; and the pair of side gears at predetermined positions in the differential case Side gear holding means for holding, and a pinion gear carrying means for carrying a pair of pinion gears into the differential case and meshing with the pair of side gears,
A pinion gear carrying means that holds the pinion gear; a drive unit that translates the guide in a direction orthogonal to the central axis direction; and a holding unit that holds the guide while allowing movement in the central axis direction. A differential gear assembling apparatus.   The differential gear assembling apparatus according to claim 1, wherein the guide is moved in parallel in the horizontal direction by the drive unit, and the guide is held by the holding unit while balancing so as to cancel the gravity of the guide.   3. The differential gear assembling apparatus according to claim 1, wherein the pair of side gears are rotatably held by the side gear holding means, and at least one of the side gears is rotatably driven. A step of arranging a pair of side gears at a predetermined position inside the differential case in a state where the respective central axes coincide with each other and the tooth surfaces face each other;
A step of translating the pinion gear in a direction perpendicular to the central axis and bringing it into contact with the tooth surface of one side gear;
A differential gear assembling method, further comprising: pushing the pinion gear further in the parallel movement direction, moving the pinion gear in the central axis direction by a reaction force received from one side gear, and bringing the pinion gear into contact with the other side gear. .   5. The differential gear assembling method according to claim 4, wherein the side gear and the pinion gear are engaged with each other by bringing a pinion gear into contact with the side gear while one side gear is rotationally driven.   The pinion gear is rotated by meshing with one of the rotationally driven side gears, and the pinion gear is meshed with the other side gear by bringing the pinion gear into contact with the other side gear held rotatably. The differential gear assembling method according to claim 5.   After the pair of side gears are arranged at predetermined positions inside the differential case, the pair of side gears are pulled away from each other, and based on the distance between the pair of side gears at this time, the side gear thrust is between each side gear and the differential case. The differential gear assembling method according to any one of claims 4 to 6, wherein it is confirmed whether or not the washer is properly attached.   A pair of pinion gears are pushed in a direction approaching each other by guides, meshed with both of the pair of side gears, and in this state, the distance between the guides is measured, and based on the measured distance, each pinion gear and the differential case A differential gear assembling method according to any one of claims 4 to 7, wherein it is confirmed whether or not a pinion gear thrust washer is properly mounted between the two.

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