Flexible ring fitting device

The flexible ring fitting device includes a flexible ring disposition mechanism 10 for disposing a flexible ring R relative to an annular groove G of a workpiece W and flexible ring assembly mechanisms 421 and 422 including an arm portion 424 rotating while pushing the flexible ring R along the outer periphery of the workpiece W. The flexible ring assembly mechanisms 421 and 422 are movable with respect to the workpiece W and include an elastic body 51 urging the arm portion 424 of the flexible ring assembly mechanisms 421 and 422 so as to press the arm portion 424 with respect to the workpiece W.

This application is based on and claims the benefit of priority from Japanese Patent Application No. 2018-023515, filed on 13 Feb. 2018, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a flexible ring fitting device.

Related Art

Known in the related art are devices fitting a flexible O-ring into a groove of a columnar workpiece that has an outer peripheral surface where the groove (annular groove) is formed (see, for example, Patent Documents 1 and 2). In the devices, a rod-shaped member rotating along the outer peripheral surface of the workpiece is rotated while the O-ring is pressed against the workpiece. The O-ring is fitted into the groove of the workpiece as a result.

Patent Document 1: Japanese Examined Patent Application Publication No. H02-11384

SUMMARY OF THE INVENTION

In the devices according to the related art that are described in Patent Documents 1 and 2, the rod-shaped member (arm portion) rotates about the axial center of the workpiece having a predetermined diameter. Accordingly, no O-ring can be fitted into a groove of a workpiece having a diameter different from the predetermined diameter. In other words, the devices according to the related art are configured to be capable of fitting O-rings simply with respect to workpieces having one type of diameter.

Besides, even in a case where O-rings are fitted with respect to the workpieces having one type of diameter by means of the devices according to the related art, it is not easy to fit the O-ring into the workpiece groove without a positional relationship in which the axial center of rotation of the arm portion and the axial center of the workpiece coincide with each other.

An object of the present invention is to provide a flexible ring fitting device capable of fitting a flexible ring in response to workpieces having different diameters and capable of fitting the flexible ring even in the event of a positional relationship in which the axial center of rotation of an arm portion and the axial center of a workpiece are misaligned from each other.

In order to achieve the above object, the present invention provides a flexible ring fitting device (such as a flexible ring fitting device1to be described later) fitting a flexible ring (such as an O-ring R to be described later) into an annular groove (such as a groove G to be described later) of a workpiece (such as a workpiece W to be described later) having the annular groove in an outer periphery of the workpiece. The flexible ring fitting device includes a flexible ring disposition mechanism (such as an O-ring supply rail10and an O-ring temporary placement table47to be described later) for disposing the flexible ring relative to the annular groove of the workpiece and a flexible ring assembly mechanism (such as a rotating portion main body421, a diameter direction moving portion422, and an arm portion424to be described later) including an arm portion rotating while pushing the flexible ring along the outer periphery of the workpiece. The flexible ring assembly mechanism is movable with respect to the workpiece and the flexible ring assembly mechanism includes an elastic body (such as a spring51to be described later) urging the arm portion of the flexible ring assembly mechanism so as to press the arm portion with respect to the workpiece.

According to the present invention, the flexible ring assembly mechanism moves and performs pressing so as to perform pressing with respect to the workpiece against the urging force of the elastic body. As a result, even in a case where the diameter of the workpiece is large or small or even in a case where the center of the workpiece is misaligned from the axial center of rotation of the arm portion, it is possible, by means of the expansion and contraction of the elastic body, for the arm portion to fit the flexible ring into the annular groove of the workpiece with an appropriate pressing force after a movement to an appropriate position following the peripheral surface of the flexible ring positioned on the outer peripheral surface of the workpiece and subsequently fitted into the annular groove of the workpiece W. In other words, the flexible ring fitting device is capable of fitting the flexible ring into the annular groove of the workpiece by flexibly responding to workpieces having various diameters.

A surface of the arm portion of the flexible ring assembly mechanism in contact with the flexible ring is inclined toward a tip. Accordingly, it is possible to press the flexible ring on the inclined surface in fitting the flexible ring into the annular groove of the workpiece by pressing the flexible ring with the arm portion. Accordingly, an excessive pressing force can be prevented from acting on the flexible ring from the arm portion either in a case where the diameter of the workpiece is large or in a case where the diameter of the workpiece is small. When the arm portion rotates, the flexible ring abuts against the inclined surface. Accordingly, the flexible ring can be smoothly guided to the annular groove of the workpiece. In a case where the flexible ring fitting device is further reduced in size, it is possible to narrow the movement range of the arm portion moved by the elastic body.

The flexible ring fitting device includes a pressing mechanism including a flexible ring holding mechanism (such as an O-ring holding shaft426to be described later) for fitting a part of the flexible ring into the annular groove of the workpiece. The pressing mechanism moves along with the flexible ring assembly mechanism. Accordingly, it is possible for the arm portion to push the other part of the flexible ring into the annular groove of the workpiece with the flexible ring partially fitted in the annular groove of the workpiece, and thus the other part of the flexible ring can be reliably fitted into the annular groove of the workpiece by the arm portion.

According to the present invention, it is possible to provide a flexible ring fitting device capable of fitting a flexible ring in response to workpieces having different diameters and capable of fitting the flexible ring even in the event of a positional relationship in which the axial center of rotation of an arm portion and the axial center of a workpiece are misaligned from each other.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention will be described in detail with reference to accompanying drawings. A flexible ring fitting device1is used so that a rubber-based O-ring R, which is a flexible ring, is fitted into a groove G (annular groove G). The groove G extends in the circumferential direction of a workpiece W and goes around. Each groove G is formed in the outer peripheral surface of a longitudinal end portion of the workpiece W. The workpiece W, which has a cylindrical shape, is a pipe member (pipe) interconnecting cases such as a crankcase and a differential case in a vehicle.FIG. 1is a perspective view illustrating the flexible ring fitting device1.

In the following description, the direction in which the rotary shafts of a pair of rotary cylinders41(described later) extend (substantially leftward-rightward direction inFIG. 1in which the rotary cylinder41on the left side and the rotary cylinder41on the right side are interconnected inFIG. 1) is defined as a leftward-rightward direction. In addition, the direction from an O-ring supply rail10(described later) toward a workpiece holding unit48(left oblique forward downward direction inFIG. 1) is defined as a forward direction and the direction that is opposite to the forward direction (right oblique rearward upward direction inFIG. 1) is defined as a rearward direction. In addition, the direction from a base plate101toward the O-ring supply rail10(upward direction inFIG. 1) is defined as an upward direction and the direction that is opposite to the upward direction (downward direction inFIG. 1) is defined as a downward direction. The flexible ring fitting device1has a symmetrical configuration. Accordingly, the following description will focus on the right side and description of the left side will be omitted.

As illustrated inFIG. 1, the flexible ring fitting device1is provided with the O-ring supply rail10, a flexible ring assembly portion30, and a spring51(seeFIG. 3), which are disposed on the rectangular flat plate-shaped base plate101.

Specifically, the pair of rotary cylinders41facing each other in the leftward-rightward direction is disposed on the base plate101. Each of the rotary cylinders41is supported by a cylinder support member102so as to be movable in the forward-rearward direction with respect to the base plate101.

The O-ring supply rail10is disposed between the pair of rotary cylinders41. The O-ring supply rail10has a rectangular plate shape. Both ends of the O-ring supply rail10in the leftward-rightward direction are respectively fixed to a pair of support plates44and are supported with a positional relationship in which the longitudinal direction of the O-ring supply rail10coincides with the upward-downward direction. In this configuration, a pair of O-ring transport spaces45extending in the longitudinal direction of the O-ring supply rail10is formed in the O-ring supply rail10. In the O-ring transport space45, the O-ring R is transported from the upper end portion of the O-ring supply rail10to the lower end portion of the O-ring supply rail10.

As illustrated inFIG. 2, an O-ring temporary placement table47is provided on the lower side of the lower end portion of the O-ring supply rail10.FIG. 2is an enlarged perspective view illustrating the workpiece holding unit48of the flexible ring fitting device1.

The O-ring temporary placement table47has a horizontal plate-shaped portion471having a horizontal upper surface and a back wall portion472rising in the upward direction from the rear portion of the horizontal plate-shaped portion471. In this configuration, the O-ring R that has fallen in the downward direction from the lower end portion of the O-ring supply rail10abuts against the upper surface of the horizontal plate-shaped portion471and is prevented from falling in the downward direction. At that position, the O-ring R abuts against the upper surface of the horizontal plate-shaped portion471and the back wall portion472. As a result, the O-ring R is supported by the upper surface of the horizontal plate-shaped portion471and the back wall portion472with a positional relationship in which the axial center of the O-ring R is oriented substantially in the forward-rearward direction as illustrated inFIG. 2. The O-ring R that is supported as described above is disposed relative to the groove G of the workpiece W. More specifically, the O-ring R is disposed so as to directly face the groove G. It should be noted that the O-ring R may not directly face the groove G of the workpiece W insofar as the O-ring R is relative to the groove G.

The workpiece holding unit48is provided on the front side of the lower end portion of the O-ring supply rail10. The workpiece holding unit48is provided with a lower side support portion481and an upper side support portion482. A lower side recessed portion483(seeFIG. 5) recessed downwards in a V shape is formed in the upper surface of the lower side support portion481. An upper side recessed portion (not illustrated) recessed upwards in a V shape is formed in the lower surface of the upper side support portion482. By the upper surface of the lower side support portion481approaching and being disposed in proximity to the lower surface of the upper side support portion482, a through hole is formed by the lower side recessed portion483and the upper side recessed portion (not illustrated). As illustrated inFIG. 2, in this through hole, the columnar workpiece W is held so as to be immovable with respect to the base plate101with the workpiece W sandwiched by the lower side support portion481and the upper side support portion482.

The flexible ring assembly portion30and the spring51are provided in the rotating portion42of the rotary cylinder41. Specifically, the rotating portion42is provided with a rotating portion main body421as illustrated in the drawings includingFIGS. 2 and 3. The flexible ring assembly portion30has a diameter direction moving portion422and an arm portion424.FIG. 3is an enlarged perspective view illustrating the configuration of the spring51of the flexible ring fitting device1and the vicinity of the spring51.

The rotating portion main body421has a columnar outer shape and is connected, so as to be integrally rotatable, to the rotary shaft (not illustrated) of the rotary cylinder41with a positional relationship in which the rotating portion main body421is coaxial with the rotary shaft (not illustrated) of the rotary cylinder41. A guide groove4211extending in the diameter direction of the rotating portion main body421is formed at the diameter position of the rotating portion main body421. The diameter direction moving portion422is disposed in the guide groove4211so as to be movable in the diameter direction of the rotating portion main body421in the guide groove4211.

The diameter direction moving portion422has a moving portion base portion4221fitted in the guide groove4211and sliding with respect to the rotating portion main body421in the guide groove4211, a substantially elliptical base portion protruding portion4222protruding from the moving portion base portion4221, and the arm portion424further protruding from a longitudinal end portion of the protruding end surface of the base portion protruding portion4222.

The moving portion base portion4221has a rectangular shape. One end portion of the moving portion base portion4221is capable of abutting against a retainer4214fixed by a pin4213to one end portion of the guide groove4211by the moving portion base portion4221moving in the guide groove4211. The other end portion of the moving portion base portion4221abuts against one end portion of the spring51as an elastic body constituted by a compression spring. The other end portion of the spring51abuts against a spring abutting portion4215fixed to the rotating portion main body421in the other end portion of the guide groove4211. As a result, the spring51urges the diameter direction moving portion422in the direction toward the retainer4214, that is, the direction in which the arm portion424is pressed with respect to the workpiece W held by the workpiece holding unit48.

The base portion protruding portion4222is molded integrally with and provided in the longitudinal middle portion of the moving portion base portion4221. The arm portion424is molded integrally with and provided in the base portion protruding portion4222. As illustrated in the drawings includingFIG. 4, a rectangular notch4241is formed at a part of the tip portion of the arm portion424. An O-ring holding shaft426passes through the rectangular notch4241when a part of the O-ring R is fitted into the groove G of the workpiece W, which will be described later.

As illustrated in the drawings includingFIG. 4, the part of the tip portion of the arm portion424that lacks the notch4241and abuts against the O-ring R as will be described later has an inclined surface4242inclined so as to become tapered toward the tip that is an extending end. By the rotary cylinder41being driven in this configuration, the arm portion424rotates while pushing the O-ring R along the outer periphery of the workpiece W with the inclined surface4242abutting against the O-ring R. As a result, the O-ring R is fitted into the groove G of the workpiece W.FIG. 4is an enlarged upper perspective view illustrating a state where the O-ring R and the like are away from the workpiece # in the flexible ring fitting device1.

The O-ring holding shaft426is provided on the rear side of the workpiece holding unit48. The O-ring holding shaft426is configured such that the O-ring holding shaft426can be driven by a spring (not illustrated), a cylinder (not illustrated), or the like and moved integrally with the rotary cylinder41in the forward-rearward direction with a positional relationship in which the longitudinal direction of the O-ring holding shaft426is oriented in the forward-rearward direction. The O-ring holding shaft426moves in the forward direction and fits a part of the O-ring R into the groove G of the workpiece W.

Next, an operation for fitting the O-ring R into the groove G of the workpiece W with the flexible ring fitting device1configured as described above will be described. First, the O-ring R falls from the lower end portion of the O-ring supply rail10and is supported by the O-ring temporary placement table47. Next, the rotary cylinder41moves in the forward direction with respect to the base plate101and the O-ring R is moved in the forward direction by the arm portion424. Then, the O-ring R has a positional relationship in which the O-ring R is pinched by the arm portion424and the workpiece W as illustrated inFIGS. 5 to 7.FIG. 5is an enlarged front perspective view illustrating a state where the O-ring R is pressed against the workpiece in the flexible ring fitting device1.FIG. 6is an enlarged upper perspective view illustrating the state where the O-ring R is pressed against the workpiece W in the flexible ring fitting device1.FIG. 7is an enlarged lateral perspective view illustrating the state where the O-ring R is pressed against the workpiece W in the flexible ring fitting device1.

At this time, the forward movement of the rotary cylinder41terminates and stops. Simultaneously with the movement of the arm portion424and the rotary cylinder41, the O-ring holding shaft426moves in the forward direction and abuts against a part of the O-ring R. Then, the O-ring R is partially fitted into the groove G. Then, the O-ring holding shaft426continues to press the O-ring R fitted in the groove G with respect to the workpiece W and the O-ring R is held in this state. In this manner, the O-ring holding shaft426moves simultaneously with the arm portion424and the rotary cylinder41, and thus it is possible to achieve cycle time improvement in fitting the O-ring R into the groove G of the workpiece W.

Next, the rotary cylinder41is driven and the arm portion424rotates by 270 degrees about the rotary shaft of the rotating portion main body421. As illustrated inFIG. 8, at this time, the O-ring R and the workpiece W are pressed by the arm portion424in the direction toward the axial center of rotation of the arm portion424.FIG. 8is an enlarged lateral perspective view illustrating a state where the O-ring R is fitted in the groove G of the workpiece W as a result of rotation of the arm portion424in the flexible ring fitting device1.

In a case where the diameter of the workpiece W is large or small and the center of the workpiece W is misaligned from the axial center of rotation of the arm portion424, the diameter direction moving portion422moves along the guide groove4211against the urging force of the spring51such that the arm portion424is moved by the reaction force of the pressing to a position following the outer peripheral surface of the workpiece W, more specifically, a position following the peripheral surface of the O-ring R positioned on the outer peripheral surface of the workpiece W and subsequently fitted into the groove G of the workpiece W. As a result, the O-ring R is pressed and fitted by the arm portion424with no extremely strong pressing force acting on the O-ring R as illustrated inFIG. 8.

The present embodiment has the following effects. In the present embodiment, the flexible ring fitting device1fitting an O-ring as a flexible ring into the annular groove G of the workpiece W having the annular groove G in the outer periphery of the workpiece W is provided with a flexible ring disposition mechanism for disposing the O-ring relative to the annular groove G of the workpiece W and the rotating portion main body421, the diameter direction moving portion422, and the arm portion424as a flexible ring assembly mechanism having the arm portion424rotating while pushing the O-ring along the outer periphery of the workpiece W. The flexible ring assembly mechanism is provided with an elastic body that urges the arm portion424of the flexible ring assembly mechanism so as to press the arm portion424with respect to the workpiece W and is movable with respect to the workpiece W.

As a result, the diameter direction moving portion422moves along the guide groove4211against the urging force of the spring51. As a result, even in a case where the diameter of the workpiece W is large or small or even in a case where the center of the workpiece W is misaligned from the axial center of rotation of the arm portion424, it is possible, by means of the expansion and contraction of the spring51, for the arm portion424to fit the O-ring R into the groove G of the workpiece W with an appropriate pressing force after a movement to an appropriate position following the peripheral surface of the O-ring R positioned on the outer peripheral surface of the workpiece W and subsequently fitted into the groove G of the workpiece W. In other words, the flexible ring fitting device1is capable of fitting the O-ring R into the groove G of the workpiece W by flexibly responding to the workpieces W having various diameters.

The surface of the arm portion424of the flexible ring assembly mechanism that is in contact with the flexible O-ring R has the inclined surface4242inclined toward the tip. As a result, it is possible to press the O-ring R on the inclined surface4242in fitting the O-ring R into the groove G of the workpiece W by pressing the O-ring R with the arm portion424. Accordingly, an excessive pressing force acts on the O-ring R from the arm portion424neither in a case where the diameter of the workpiece W is large nor in a case where the diameter of the workpiece W is small and it is possible to push and drift the O-ring R toward the groove G. When the arm portion424rotates, the O-ring R abuts against the inclined surface4242. Accordingly, the O-ring R can be smoothly guided to the groove G of the workpiece W. In a case where the flexible ring fitting device1is further reduced in size, it is possible to narrow the movement range of the diameter direction moving portion422moved by the spring51.

Also provided is a pressing mechanism having the O-ring holding shaft426as a flexible ring holding mechanism for fitting a part of the O-ring into the groove G of the workpiece W. The O-ring holding shaft426of the pressing mechanism moves along with, for example, the arm portion424as the flexible ring assembly mechanism. As a result, it is possible for the arm portion424to push the other part of the O-ring R into the groove G of the workpiece W with the O-ring R partially fitted in the groove G of the workpiece W, and thus the other part of the O-ring R can be reliably fitted into the groove G of the workpiece W by the arm portion424.

The present invention is not limited to the above-described embodiment. Modifications, improvements, and the like within the scope of achieving the object of the present invention are included in the present invention. For example, the configuration of each part of the flexible ring fitting device is not limited to the configuration of each part of the flexible ring fitting device1according to the present embodiment. In other words, each configuration such as the flexible ring disposition mechanism, the flexible ring assembly mechanism, the elastic body, the inclined surface, the flexible ring holding mechanism, and the pressing mechanism is not limited to each configuration such as the O-ring supply rail10, the O-ring temporary placement table47, the rotating portion main body421, the diameter direction moving portion422, the arm portion424, the spring51, the inclined surface4242, and the O-ring holding shaft426according to the present embodiment. Accordingly, the flexible ring fitting device may lack the O-ring holding shaft426insofar as, for example, the O-ring R can be held. Although the moving portion base portion4221is retained by the retainer4214fixed by the pin4213in the present embodiment, the present invention is not limited to this configuration. For example, the pin4213may retain the moving portion base portion4221without the retainer4214being provided.

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