Patent ID: 12214415

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described usingFIGS.1to8.

FIG.7is a partial schematic view of a vehicle200including a hub unit bearing (a bearing unit)1. The present invention can be applied to any of a hub unit bearing for a driving wheel and a hub unit bearing of a driven wheel. InFIG.7, the hub unit bearing1is for a driving wheel and the hub unit bearing1includes an outer ring2, a hub3, and a plurality of rolling elements6. The outer ring2is fixed to a knuckle201of a suspension device using bolts or the like. A wheel (and a braking rotating body)202is fixed to a flange (a rotating flange)3A provided on the hub3using bolts or the like. Furthermore, the vehicle200can have the same support structure as described above with respect to the hub unit bearing1for the driven wheel.

A rotary forging device100which is a target in this embodiment is, for example, used to form a caulking part10of the hub unit bearing1shown inFIG.8.

As shown inFIG.1, the rotary forging device100includes a frame11, a spherical concave seat12, a spherical seat13with a shaft, a forming pressing die14, a rotating body15, a support table16, a load application apparatus17, and an outer ring drive apparatus18.

It should be noted that, in the following description of this embodiment, an upward/downward direction refers to the upward downward directions inFIGS.1to6. Here, the upward/downward direction inFIGS.1to6does not necessarily coincide with an upward/downward direction at the time of processing.

The frame11constitutes an outer form of the rotary forging device100and has a reference axis α disposed in the upward/downward direction (a vertical direction). A head case26which constitutes an outer form together with the frame11is fixed to an upper surface of the frame11.

The spherical concave seal (a spherical concave seat and a concave seat body)12has a hole portion12ahaving a swing shaft20of the spherical seat13with a shaft disposed therein and is constituted in an annular shape as a whole. The spherical concave seat12is fixed to an upper inside of the frame11. The spherical concave seat12has a spherical concave portion (a concave surface, a spherical surface, and a spherical concave surface)19having a central axis coaxial with the reference axis α. The spherical concave portion19is an axially lower surface and is disposed facing downward. The spherical concave portion19has an opening corresponding to the hole portion12aand is constituted in an annular shape (a circular annular shape) as a whole. The spherical concave portion19has a surface which smoothly extends in a circumferential direction about a central axis thereof over the entire circumference.

The spherical seat13with a shaft (a swing member and a swing body) has the swing shaft (a shaft)20and a spherical convex surface seat (a spherical convex seat and a convex seat body)21coaxially fixed to a lower aid portion of the swing shaft20. A central axis of the swing shaft20is coaxial with a central axis of the spherical convex surface seat21. The spherical convex surface seat21has a spherical convex portion (a convex surface, a spherical surface, and a spherical convex surface)22constituted in a partially spherical shape. The spherical convex portion22has an outer diameter dimension larger than that of the swing shaft20. The spherical convex portion22is an axially upper surface and is disposed facing upward. The spherical convex portion22is constituted in an annular shape (a circular annular shape) as a whole. The spherical convex portion22has a surface which smoothly extends in a circumferential direction about a central axis thereof over the entire circumference.

Such a spherical seat13with a shaft is disposed inside the frame11and the head case26. The spherical seat13with a shaft is disposed in a state in which an axis of rotation β that is a central axis thereof is inclined by a predetermined angle θ with respect to the reference axis α. The spherical convex surface seat21is spherically fitted to the spherical concave seat12. The spherical alignment of the spherical convex portion22with respect to the spherical concave portion19allows the spherical seat13with a shaft to rotate (swingingly rotate) about the reference axis α and to revolve about the axis of rotation β. In one example, a predetermined angle θ for caulking can be set to 10 degrees or more and 30 degrees or less or 15 degrees or more (for example, 15 degrees or more and 30 degrees or less). In one example, a predetermined angle θ can be 15 degrees as a swing angle that is an angle of the axis of rotation (β) with respect to the reference axis (α). In another example, a predetermined angle θ can be 5, 10, 12, 14, 16, 18, 20, 25, 30, or 35 degrees.

The forming pressing die14is attached to an axially lower portion of the spherical convex surface seat21coaxially with the spherical seal13with a shaft and in an attachable and detachable manner. The forming pressing die14has a surface portion to be processed23on the axially lower surface. In one example, the surface portion to be processed23has a circular annular shape. The coaxiality of the forming pressing die14with respect to the spherical seat13with a shaft is achieved by internally fitting a convex portion (a boss portion)24provided at a central portion of an upper surface of the forming pressing die14into a concave portion25provided at a central portion of a lower surface of the spherical convex surface seat21without rattling.

The rotating body15is supported inside the head case26by a bearing device27to be able to rotate about the reference axis α. The rotating body15can be rotationally driven by a rotating body drive apparatus having an electric motor for the rotating body (not shown) as a drive source. In one example, the rotating body15has one holding hole28inclined by the same angle θ as the axis of rotation β of the swing shaft20with respect to the reference axis α in an circumferential direction of a radially outer portion thereof. An axially upper portion of the swing shaft20is rotatably supported inside the holding hole28via a rolling bearing29. In this state, the swing shaft20is prevented from being displaced axially downward with respect to the holding hole28, that is, falling off from the holding hole28.

In this embodiment, as the rolling bearing29, something having an axial load support ability in addition to a radial load support ability, specifically, an self-aligning roller bearing is used. In the self-aligning roller bearing, a plurality of spherical milers32that are rolling elements are disposed between an inner circumferential surface of an outer ring30and an outer circumferential surface of an inner ring31. The self-aligning roller bearing can support a radial load and an axial load acting between the outer ring30and the inner ring31. Furthermore, even when central axes of the outer ring30and the inner ring31are inclined, a characteristic in which the spherical rollers32can be smoothly rolled between the inner circumferential surface of the outer ring30and the outer circumferential surface of the inner ring31, that is, a self-alignment property is provided. Since various kinds of more specific constitutions of such a self-aligning roller bearing are known in the related art, a description thereof will be omitted. It should be noted that a deep groove ball bearing, an angular contact ball bearing, and the like can also be used as the rolling bearing29.

In one example, the holding hole28is a stepped hole configured by connecting a large diameter hole on an upper side in an axial direction thereof to a small diameter hole on a lower side in the axial direction thereof via a step surface33facing the upper side in the axial direction thereof. The outer ring30is internally fitted into the large diameter hole of the holding hole28and an axially lower end surface of the outer ring30is in contact with the step surface33of the holding hole28. Thus, the outer ring30is prevented from being displaced downward in the axial direction with respect to the holding hole28. Furthermore, the axially upper portion of the swing shaft20is internally fitted (inserted) to be able to be relatively displaced in the axial direction with respect to the inner ring31. A nut35screwed to a male screw portion34provided in the axially upper portion of the swing shaft20is in contact with an axially upper end surface of the inner ring31. Thus, the swing shaft20is prevented from being displaced downward in the axial direction with respect to the inner ring31. By adopting such a constitution, the swing shaft20is prevented from being displaced downward in the axial direction with respect to the holding hole28.

By changing a positional relationship between the spherical convex portion22and the spherical concave portion19concerning an axial position of the swing shaft20by adjusting a screwing position (an amount of screwing) of the nut35with respect to the male screw portion34, a gap (an engagement margin) present in a spherical surface engaging portion between the spherical convex portion22and the spherical concave portion19is adjusted and an appropriate gap can be obtained. It should be noted that, in this embodiment, the spherical seat13with a shaft, the rotating body15, the bearing device27, and the rolling bearing29correspond to a pressing die support part.

The support table16is disposed inside the frame11and below the forming pressing die14. Furthermore, the support table16is provided to be able to move in the upward/downward direction along the reference axis α with respect to the frame11. A receiving die (a holder)36is fixed to an upper surface of the support table16. In one example, the receiving die36has a bottomed cylindrical shape with an open upper end and is disposed coaxially with the reference axis α. The receiving die36can hold a workpiece coaxially via a work adapter37. The work adapter37is coaxial with the receiving die36in an attachable and detachable manner. The work adapter37is a jig having a shape corresponding to a type of workpiece and can hold a workpiece coaxially. The coaxiality of the work adapter37with respect to the receiving die36can be achieved by internally fitting a convex portion (a boss portion)38provided on a central portion of an upper surface of a bottom plate portion in the receiving die36into the concave portion39provided in a central portion of a lower surface in the work adapter37without rattling.

The load application apparatus17(shown in block diagrams only inFIGS.2,5, and6) is configured to move the support table16in the upward/downward direction. With the movement of the support table16, the forming pressing die14(and a measuring pressing die43which will be described later) is pressed against an object to be pressed supported by the support table16and a load in a direction of the reference axis α is applied to the object to be pressed. The load application apparatus17includes a hydraulic cylinder40, a hydraulic sensor41, and a control device42.

The hydraulic cylinder40includes a pair of hydraulic chambers and a piston provided between the pair of hydraulic chambers. In the hydraulic cylinder40, the piston moves on the basis of a differential pressure between the pair of hydraulic chambers. With the movement of the piston, the support table16moves in the upward/downward direction along the reference axis α. The hydraulic sensor41measures a differential pressure between the pair of hydraulic chambers. The control device42controls a position of the support table16in the upward/downward direction and a load applied to the object to be pressed in the direction of the reference axis α by controlling a differential pressure between the pair of hydraulic chambers. The differential pressure (the load) between the pair of hydraulic chambers using the control device42is controlled while confirming (feed backing) the differential pressure measured by the hydraulic sensor41. Furthermore, a set value of a load controlled by the control device42is defined by a differential pressure between a pair of hydraulic chambers×an area of a piston×a coefficient. The set value of the load is displayed on a display part of the control device42so that an operator or the like can confirm the set value. It should be noted that, although the coefficient is basically 1, the coefficient can be appropriately adjusted (changed) through calibration work which will be described later.

The outer ring drive apparatus18(shown in the block diagram only inFIG.2) is supported by the support table16. The cuter ring drive apparatus18is used to rotationally drive the outer ring2with respect to the hub3using an electric motor for the outer ring as a drive source when the caulking part10of the hub unit bearing1is formed.

In this embodiment, the control device42constitutes not only the load application apparatus17but also a rotating body drive apparatus (not shown) configured to rotationally drive the rotating body15and a part of the outer ring drive apparatus18and is constituted to perform drive control on these apparatus.

In the rotary forging device100in this embodiment, when the caulking part10is formed at an axially inner end portion of a hub ring7, as shown inFIGS.1and2, the hub ring7that is a workpiece and is an object to be pressed is held coaxially with the receiving die36(via (the work adapter37) in a state in which the hub ring7before the caulking part10is formed and other constituent elements constituting the hub unit bearing1are assembled. It should be noted that, in this state, the hub ring7is supported by the support table16via the work adapter37and the receiving die36. Furthermore, in this state, the outer ring2is rotated relative to the hub3using the outer ring drive apparatus18. On the basis of the rotation of the rotating body15, the spherical seat13with a shaft and the forming pressing die14swingingly rotate about the reference axis α. In this state, the support table16moves upward, and as shown in part (a) ofFIG.3, the surface portion to be processed23of the forming pressing die14is pressed against a cylindrical part9of the hub ring7. Thus, processing forces directed downward in the upward/downward direction and outward in the radial direction are applied from the forming pressing die14to the cylindrical part9. Furthermore, an application portion (a processing position) of a processing force changes continuously in a circumferential direction. Thus, as shown inFIG.3(a)toFIG.3(b), the cylindrical part9gradually plastically deforms outward in the radial direction to form the caulking part10and an axially inner end surface of the inner ring8is suppressed by the caulking part10.

Thus, when the caulking part10is formed, the forming pressing die14swingingly rotates as described above while rotating (revolving) about the axis of rotation β on the basis of a frictional force acting on a contact portion between the forming pressing die14and the cylindrical part9. That is to say, the contact of the forming pressing die14with respect to the cylindrical part9is a rolling contact. For this reason, the wear and the heat generation at a contact portion can be sufficiently minimized. Furthermore, the processing reaction force applied from the cylindrical part9to the forming pressing die14can be efficiently supported by the spherical concave seat12.

Incidentally, a load deviation may occur in the rotary forging device100in this embodiment as described above in some cases. This is caused by variations of the accuracy of the hydraulic sensor41, the sliding resistance of the piston of the hydraulic cylinder40, the weight of the support table16, or the like or is caused by changes with the passage of time thereof. That is to say, a set value of a load of the load application apparatus17(a set value of a load controlled by the control device42and a display value of a load displayed on the display part of the control device42) deviates from an actual load in the direction of the reference axis α applied to the object to be pressed. For this reason, in the rotary forging device100in this embodiment, in view of securing the processing accuracy of the workpiece, it is desirable to calibrate a set value (a display value) of a load of the load application apparatus17at the time of shipment, maintenance, or the like.

Therefore, a dynamic load measuring device150will be described below usingFIGS.4to6. The dynamic load measuring device150is used to calibrate a set value (a display value) of a load of the load application apparatus17, that is, to perform a method of calibrating the rotary forging device100of this embodiment. It should be noted thatFIGS.4to6show a state in which the dynamic load measuring device150is assembled to the rotary forging device100.

The dynamic load measuring device150includes the measuring pressing die43, a guide stand44, a measuring shaft member45that is an object to be pressed, a linear motion ball bearing (a linear guide)46, a load cell adaptor47, and a load cell48.

The measuring pressing die (a pressing die and an inspection die)43is attached to the spherical convex surface seat21instead of the forming pressing die (the processing die). The measuring pressing die43is attached to an axially lower portion of the spherical convex surface seat21from which the forming pressing die14has been removed coaxially with the spherical seat13with a shall and in an attachable and detachable manner. The coaxiality of the measuring pressing die43with respect to the spherical seat13with a shaft is achieved by internally fitting a convex portion (a boss portion)24aprovided at a central portion of an upper surface of the measuring pressing die43into the concave portion25provided at a central portion of a lower surface of the spherical convex surface seat21without rattling. In one example, the measuring pressing die43has a spherical convex shape (a spherical convex surface) in which a distal end portion49that is an axially lower end portion has a center of curvature above the reference axis α. In this embodiment, the measuring pressing die43is made of steel and the distal end portion49is subjected to hardening heal treatment.

The guide stand44is fixed to the upper surface of the support table16. The guide stand44includes a top plate part50disposed horizontally above the receiving die36and a plurality of leg parts51which support a plurality of portions of an outer circumferential portion of the top plate part50in an circumferential direction thereof with respect to the upper surface of the support table16. The top plate part50includes a circular-ring-shaped outer circumferential plate part52constituting an outer circumferential portion thereof, a circular-ring-shaped bush support plate pan53internally supported by the outer circumferential plate pan52, and a cylindrical bush54internally fitted into and supported by the bush support plate part53. The bush54is disposed coaxially with the reference axis α. Furthermore, the bush54is made of steel and is subjected to hardening heat treatment to improve the wear resistance thereof.

The measuring shall member45is constituted in a circular columnar shape as a whole. The measuring shaft member45is disposed coaxially with the reference axis α via the linear motion ball bearing46inside the bush54in the radial direction thereof and is linearly guided in the direction of the reference axis α. The measuring shaft member45is constituted by connecting and fixing a main body part55which constitutes most except for an upper end portion thereof to a buffer part56which constitutes the upper end portion thereof. The main body part55is made of steel, is constituted in a circular columnar shape, and is subjected to hardening heat treatment to improve the wear resistance. The buffer part56is made of steel, is constituted in a cylindrical short shape, and is in a raw state without being subjected to hardening heat treatment. That is to say, the buffer part56is constituted of a metal softer than that of the distal end portion49of the measuring pressing die43. The measuring shaft member45has an outer circumferential surface having an outer diameter which is substantially the same as a diameter (a processing diameter) corresponding to a caulking part that is an object to be processed. For example, a ratio of the outer diameter of the outer circumferential surface to the processing diameter can be about 0.5, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, or more.

The linear motion ball bearing46has a plurality of balls which are disposed to freely rotate and a cylindrical holder (a ball retainer) which holds these balls between a cylindrical inner circumferential surface of the bush54and a cylindrical outer circumferential surface of the main body part55constituting the measuring shaft member45. The linear motion ball bearing46is prevented from falling from the inner side of the bush54in the radial direction thereof using a circular-ring-shaped suppression plate57fixed to a lower end surface of the bush54. The measuring shaft member45is linearly guided in the direction of the reference axis α using the linear motion ball bearing46so that the displacement of the measuring shaft member45in a direction orthogonal to the reference axis α and the inclination of the measuring shall member45with respect to the reference axis α are prevented. The linear motion ball bearing46is constituted to continuously surround an outer circumferential surface of the measuring shaft member45over the entire circumference. The linear motion ball bearing46can support a force from the outer circumferential surface of the measuring shall member45over the entire circumference. An axial support length (a distance of a support section, in the axial direction) Z1(FIG.5) of the linear motion ball bearing (the linear guide)46with respect to the outer circumferential surface of the measuring shaft member45is appropriately set. A ratio of the axial support length Z1to the processing diameter can be about 0.5, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, or more.

The load cell adaptor47is attached above a bottom plate portion of the receiving die36from which the work adapter37has been removed coaxially with the receiving die36and in an attachable and detachable manner. The load cell adaptor47can hold the load cell48coaxially. The coaxiality of the load cell adaptor47with respect to the receiving die36is achieved by internally fitting a convex portion (a boss portion)38provided at a central portion of an upper surface of the bottom plate portion of the receiving die36into the concave portion39aprovided at a central portion of a lower surface of the load cell adaptor47without rattling.

The load cell48is coaxially held above the load cell adaptor47. Therefore, the load cell48is disposed coaxially with the reference axis α. The load cell48has an input portion58having a spherical convex shape in which an upper surface of a central portion in the radial direction thereof protrudes further upward than the peripheral portion. The load cell48can measure a load in the direction of the reference axis α input from the input portion58. A lower surface (a flat surface orthogonal to the reference axis α) of the main body part55constituting the measuring shall member45is in contact with a central portion of the input portion58. Therefore, the load cell48can measure a load in the direction of the reference axis α input from the measuring shall member45. Such a load cell48generally includes a strain generating body (not shown) elastically deforming due to a load in the direction of the reference axis α input front the input portion58and a strain gauge (not shown) adhered to the strain generating body. The load cell48has a constitution in which an amount of elastic deformation of the strain generating body is converted into a voltage using the strain gauge and the load is measured. It should be noted that the measuring shaft member45is supported by the support table16via the load cell48, the load cell adaptor47, and the receiving die36. In one example, the load cell48has a short circular columnar shape. In other examples, the load cell48can have other shapes.

A method fix calibrating the rotary forging device100in this embodiment will be described below. First, as shown inFIGS.4and5, the dynamic load measuring device150is assembled to the rotary forging device100. The load application apparatus17moves the support table16upward while the spherical seat13with a shaft and the measuring pressing die43are swung and rotated about the reference axis α on the basis of the rotation of the rotating body15. Then, as shown inFIG.6, the distal end portion49of the measuring pressing die43comes in contact with an upper end surface of the measuring shaft member45and starts pressing the measuring pressing die43. At the same time, the measuring pressing die43starts the revolution thereof about the axis of rotation β. A force (an actual load) by which the measuring pressing die43presses the measuring shaft member45using the load application apparatus17is input from the measuring shaft member45to the input portion58of the load cell48.

Here, in order to accurately measure, using the load cell48, the force by which measuring pressing die43presses the measuring shaft member4using the load application apparatus17as a load in the direction of the reference axis α, it is necessary to input the load in the direction of the reference axis α from the measuring shaft member45to the central portion of the input portion58of the load cell48. In this regard, in this embodiment, a lower end surface of the measuring shaft member45is in contact with the central portion of the input portion58of the load cell48. Furthermore, the measuring shaft member45is guided to be linearly moved using the linear motion ball bearing46in the direction of the reference axis α. For this reason, the lower end surface of the measuring shaft member45which has been guided to be linearly moved can press the central portion of the input portion58of the load cell48substantially in the direction of the reference axis α even if an offset load is input from the distal end portion49of the measuring pressing die43to, the upper end surface of the measuring shaft member45. Therefore, the load application apparatus17can accurately measure the force by which the measuring pressing die43presses the measuring shaft member45as a load in the direction of the reference axis α using the had cell48.

Also, in this embodiment, the distal end portion49of the measuring pressing die43is formed to have a spherical convex shape having a center of curvature above the reference axis α. For this reason, the distal end portion49can press the central portion of the upper end surface of the measuring shaft member45. Therefore, it is difficult for an offset load to be input from the measuring pressing die43to the measuring shaft member45. In addition, it is difficult for an offset load to be input from the measuring shaft member45to the input portion58of the load cell48. Accordingly, the measurement accuracy of a load in the direction of the reference axis α using the load cell48can be improved.

Also, in this embodiment, the upper end portion of the measuring shaft member45is the buffer part56made of a metal softer than that of the distal end portion49of the measuring pressing die43. For this reason, when the distal end portion49of the measuring pressing die43starts pressing the upper end surface of the buffer part56, the deformation of the upper end surface of the buffer part56starts. After that, the upper end surface of the buffer part56has a shape in which the upper end surface matches (spherically engages with) the distal end portion49of the measuring pressing die43. As a result, it is more difficult for an offset load to be input from the measuring pressing die43to the measuring shaft member45. In addition, it is more difficult from an offset load to be input from the measuring shaft member45to the input portion58of the load cell48. Accordingly, the measurement accuracy of a load in the direction of the reference axis α using the load cell48can be improved.

In this embodiment, for example, a load of the load application apparatus17is set so that a set value (a display value) of the load is a predetermined value. The distal end portion49of the measuring pressing die43is pressed against the upper end surface of the measuring shaft member45while the measuring pressing die43is swung and rotated as described above on the basis of the set load. When the load in the direction of the reference axis α input to the input portion58of the load cell48is stabilized, a measurement value of a load using the load cell48is confirmed.

It should be noted that the measurement value of the load using the load cell48may not be stable in some cases. For example, the central portion of the upper end surface of the measuring shaft member45cannot be pressed by the distal end portion49of the measuring pressing die43due to a manufacturing error or an assembly error of constituent elements constituting the rotary forging device100or the dynamic load measuring device150. As a result, some offset load is input to the input portion58of the load cell48. When the measurement value of the load using the load cell48is not stable, an average value when the measuring pressing die43is swung and rotated once is confirmed as the measurement value of the load using the load cell48. If the confirmed measurement value of the load is different from the set value (the display value) of the load of the load application apparatus17, the set value (the display value) of the load of the load application mean17is caused (calibrated) to match the confirmed measurement value of the load by adjusting a coefficient of the load application apparatus17(the above-mentioned coefficient multiplied when a differential pressure measured using the hydraulic sensor41is converted into a load). Such calibration work is repeatedly performed an set values (display values) of a plurality of loads.

For example, as shown in Table 1 which will be described later, in a case in which the set values (display values) of the plurality of loads of the load application apparatus17deviate from the measurement value of the load using the load cell48, as shown in Table 2 which will be described later, a coefficient of the load application apparatus17is adjusted so that the set value (the display value) of the load in which the deviation has occurred matches the measurement value of the load using the load cell48.

TABLE 1Set value0 kN10 kN50 kN100 kN150 kN200 kN(display value)of load of loadapplicationapparatusSet value of load0 kN11 kN55 kN110 kN165 kN220 kNusing load cell

TABLE 2Set value0 kN10 kN50 kN100 kN150 kN200 kN(display value)of load of loadapplicationapparatusSet value of load0 kN10 kN50 kN100 kN150 kN200 kNusing load cell

In this embodiment, the load application apparatus17can accurately measure the force by which the measuring pressing die43presses the measuring shaft member45as a load in the direction of the reference axis α using the load cell48. For this reason, the set value (the display value) of the load of the load application apparatus17can be accurately calibrated using the measurement value of the load using the load cell48. Therefore, the caulking pan10can be finished into a desired shape using the rotary forging device100calibrated using the calibration method of this embodiment, and as a result, an appropriate range of a pre-pressure can be applied to the hub unit bearing1.

It should be noted that, when the present invention is carried out, for example, something described in Japanese Patent No. 4127266 can be used as the outer ring drive apparatus18constituting the rotary urging device. In this case, some of the constituent elements constituting the outer ring drive apparatus18can be used as some (the leg parts51, the outer circumferential plate part52, and the bush support plate part53) of the constituent elements constituting the guide stand44of the dynamic load measuring device150.

Also, when the present invention is carried out, the rotary forging device is not limited to a type in which the support table moves in the direction of the reference axis and may be a type in which the pressing die moves in the direction of the reference axis. Furthermore, a specific structure of the pressing die support pan constituting the rotary forging device is not limited, and for example, may not include a spherical surface seat.

In one embodiment, a rotary forging device (100) includes pressing die support parts (13,15,27, and29), a support table (16), and a load application apparatus (17). The pressing die support parts (13,15,27, and29) can support any one selected from a forming pressing die (14) and a measuring pressing die (43) to be rotatable about a reference axis (α) and to freely rotate about an axis of rotation (β) inclined at a predetermined angle with respect to the reference axis (α). The support table (16) supports an object to be pressed disposed at a position facing a pressing die supported by the pressing die support parts (13,15,27, and29) in a direction of the reference axis (α). The load application apparatus (17) applies a load to the object to be pressed in the direction of the reference axis (α) by pressing the pressing die supported by the pressing die support parts (13,15,27, and29) against the object to be pressed supported by the support table on the basis of the relative movement between the pressing die support parts (13,15,27, and29) and the support table (16) in the direction of the reference axis (α).

In a dynamic load measurement method of the rotary forging device (100), the measuring pressing die (43) is supported by the pressing die support parts (13,15,27, and29). Furthermore, a measuring shaft member (45) that is an object to be pressed is disposed coaxially with the reference axis (α) and is linearly guided in the direction of the reference axis (α) while the measuring pressing die (43) is supported by the support table (16). After that, the load application apparatus (17) measures an actual load in the direction of the reference axis (α) applied to the measuring shaft member (45) in a state in which the measuring pressing die (43) is pressed against the measuring shall member (45) while the measuring pressing die (43) is rotated about the reference axis (α).

A dynamic load measuring device (150) of the rotary forging device (100) includes the measuring pressing die (43), the measuring shaft member (45), and a load measurement apparatus (48). The measuring pressing die (43) is supported by the pressing die support parts (13,15,27, and29). The measuring shaft member (45) is disposed coaxially with the reference axis (α) and linearly guided in the direction of the reference axis (α) while supported by the support table (16). The load measurement, apparatus (48) measures the actual load in the direction of the reference axis (α) applied to the measuring shaft member (45).

A linear motion ball bearing can be used to linearly guide the measuring shaft member (45) in the direction of the reference axis (α) with respect to the support table (16).

The load measurement apparatus (48) can be a load cell disposed between the support table (16) and the measuring shaft member (45).

A distal end portion of the measuring pressing die (43) pressed against an axial end portion of the measuring shaft member (45) when the actual load is measured can be set to have a spherical convex shape having a center of curvature above the reference axis (α).

An axial end portion of the measuring shaft member (45) which can press the distal end portion of the measuring pressing die (43) when the actual load is measured can be made of a metal softer than that of the distal end portion of the measuring pressing die (43).

In one embodiment, a method for calibrating a runny forging device includes measuring the actual load using the dynamic load measurement method for the rotary forging device (100) and calibrating a set value of a load of the load application apparatus (17) using the measured actual load.

In one embodiment, a hub unit hearing (1) includes a constituent element having a caulking pan (10). In a method for manufacturing the hub unit bearing (1), the caulking part (10) is formed using a rotary forging device (100) calibrated using the method for calibrating a rotary forging device.

In one embodiment, a vehicle that is a target of a manufacturing method includes a hub unit bearing (1). In a method for manufacturing a vehicle, the hub unit bearing (1) is manufactured using the above-mentioned method for manufacturing a hub unit bearing.

REFERENCE SIGNS LIST

1Hub unit bearing2Outer ring3Hub4a,4bOuter ring trajectory5a,5bInner ring trajectory6Rolling element7Hub ring8Inner ring9Cylindrical part10Caulking part11Frame12Spherical concave seat13Spherical seat with shaft14Forming pressing die15Rotating body16Support table17Load application apparatus18Outer ring drive apparatus19Spherical concave portion20Swing shaft21Spherical convex surface seat22Spherical convex portion23Surface portion to be processed24,24aConvex portion25Concave portion26Head case27Bearing device28Holding hole29Rolling bearing30Outer ring31Inner ring32Spherical roller33Step surface34Male screw portion35Nut36Receiving die37Work adapter38Convex portion39,39aConcave portion40Hydraulic cylinder41Hydraulic sensor42Control device43Measuring pressing die44Guide stand45Measuring shaft member46Linear motion ball bearing47Load cell adaptor48Load cell49Distal end portion50Top plate part51Leg part52Outer circumferential plate part53Bush support plate part54Bush55Main body part56Buffer part57Suppression plate58Input portion100Rotary forging device150Dynamic load measuring device