Patent Description:
Conventionally, devices inserting an electric wire into a rubber plug are known. For example, Patent Literature <NUM> discloses a rubber plug insertion device including an electric wire holding member holding an electric wire, a rubber plug holding member having a rubber plug accommodation hole corresponding to an outer size of a rubber plug, a rubber plug supply tube supplying the rubber plug to the rubber plug holding member, and a rubber plug holding driving mechanism causing the rubber plug accommodation hole and the electric wire to get closer to each other. Patent Literature <NUM> provides a further rubber plug holding device according to the prior art.

There are various types of rubber plugs, and outer sizes thereof are not the same. However, for a conventional rubber plug insertion device as described in Patent Literature <NUM>, a rubber plug holding member corresponding to an outer size of a rubber plug needs to be prepared, which requires a preparation time period and is costly. Actual insertion requires a replacement step of replacing the rubber plug holding member in accordance with the type of the rubber plug or requires rubber plug insertion devices provided in a number corresponding to the number of the types of the rubber plugs.

The present invention made in light of the above-described points has an object of providing a rubber plug holding device capable of holding a rubber plug of any of types having different outer sizes, and an electric wire insertion device including such a rubber plug holding device and inserting an electric wire into a rubber plug.

A rubber plug holding device according to the present invention includes a plurality of first clamp members located around a predetermined central line so as to form a space inner thereto in which a cylindrical rubber plug is allowed to be located; a first support member supporting the plurality of first clamp members; and a first actuator driving the plurality of first clamp members. The plurality of first clamp members include three or more first rubber plug contact portions that are on the space inner thereto and are to be in contact with an outer circumferential surface of the rubber plug. The first support member supports the first clamp members such that the first rubber plug contact portions get closer to, or farther from, the central line. The first actuator drives the first clamp members such that the first clamp members pivot around the first support member such that the first rubber plug contact portions get closer to, or farther from, the central line in a radial direction.

With the above-described rubber plug holding device, the first actuator is driven to cause the three or more first rubber plug contact portions to get closer to, or farther from, the rubber plug located in the space inner to the first clamp members. Such a rubber plug holding device allows the three or more first rubber plug contact portions to be in contact with the outer circumferential surface of the rubber plug located in the inner space, regardless of the outer diameter of the rubber plug. Therefore, the rubber plug holding device holds any rubber plug having any of various outer diameters.

In a preferred embodiment of the rubber plug holding device according to the present invention, the first clamp members are provided in the number of three or more.

With such a rubber plug holding device, the first clamp members get closer to the rubber plug in at least three directions set along the circumferential direction. Therefore, the rubber plug is held stably.

In the rubber plug holding device according to the present invention, the first support member includes a plurality of first pivoting shafts each extending parallel to the central line and respectively supporting the first clamp members such that the first clamp members are pivotable. The first actuator pivots the plurality of first clamp members about the plurality of first pivoting shafts respectively. The plurality of first clamp members each include a first inner side surface that is on the space formed inner to the plurality of first clamp members and is structured such that different regions of the first inner side surface along a circumferential direction of the first pivoting shaft have different distances from the first pivoting shaft. The first rubber plug contact portions are provided at the first inner side surfaces and get closer to, or farther from, the central line by the first clamp members pivoting about the first pivoting shafts.

In such a rubber plug holding device, the first rubber plug contact portions are provided at the first inner side surfaces of the first clamp members, and the different regions of each of the first inner side surfaces along the circumferential direction of the first pivoting shaft have different distances from the first pivoting shaft. Therefore, mere pivoting of the first clamp members by the first actuator causes the first rubber plug contact portions to get closer to, or farther from, the central line. This simplifies the structure of the rubber plug holding device.

In a preferred embodiment of the rubber plug holding device, the first actuator includes a rotatable driving shaft. The rubber plug holding device further includes a first pulley including a ring portion having an outer engageable portion in an outer side surface thereof and an inner engageable portion in an inner side surface thereof, the first pulley being rotatable about the central line, and a transfer mechanism engageable with the outer engageable portion of the first pulley and the driving shaft of the first actuator, the transfer mechanism transferring a rotation of the driving shaft to the first pulley. The first clamp members each include a first engageable portion located inner to the ring portion in a radial direction and engageable with the inner engageable portion, the first clamp members pivoting about the first pivoting shafts by the first pulley rotating.

With such a rubber plug holding device, the first clamp members are pivoted by a simple structure of the first pulley including the outer engageable portion receiving the rotation force of the first actuator and the inner engageable portion transferring the rotation force of the first actuator to the first clamp members.

In a preferred embodiment according to the present invention, the rubber plug holding device further includes a plurality of second clamp members located around the central line so as to form a space inner thereto, in which the rubber plug is allowed to be located; a second support member supporting the second clamp members; and a second actuator driving the second clamp members. The plurality of second clamp members include three or more second rubber plug contact portions located at different positions, in a direction in which the central line extends, from those of the first rubber plug contact portions, the three or more second rubber plug contact portions being to be in contact with the outer circumferential surface of the rubber plug. The second support member supports the second clamp members such that the second rubber plug contact portions get closer to, or farther from, the central line. The second actuator drives the second clamp members such that the second rubber plug contact portions get closer to, or farther from, the central line.

Such a rubber plug holding device holds a stepped rubber plug, including portions having different outer sizes, in a preferred manner. Namely, the portion having a first outer diameter is clamped by the first clamp members and the portion having a second outer diameter is clamped by the second clamp members. Thus, the stepped rubber plug is held in a more preferred manner.

An electric wire insertion device according to the present invention inserts an electric wire into a through-hole of a rubber plug, the through-hole being along an axis of the rubber plug. The electric wire insertion device includes any one of the above-described rubber plug holding devices. The electric wire insertion device includes a rubber plug supply opening in communication with the space formed inner to the plurality of first clamp members, the rubber plug being supplied through the rubber plug supply opening; and an electric wire transportation device transporting the electric wire along the central line.

Such an electric wire insertion device includes the rubber plug holding device capable of holding any of rubber plugs having various outer diameters, and therefore, inserts an electric wire into any of rubber plugs having various outer diameters.

In a preferred embodiment according to the present invention, the electric wire insertion device further includes a detection device detecting whether or not the rubber plug is at a predetermined position, along the central line, at which the first clamp members are capable of grasping the rubber plug; and a controller connected with the first actuator and the detection device. The controller includes a first controller causing the first actuator to operate such that the first rubber plug contact portions get closer to the central line when the detection device detects that the rubber plug is at the predetermined position.

With such an electric wire insertion device, the rubber plug is grasped after the rubber plug is confirmed to be at the predetermined position at which the first clamp members are capable of grasping the rubber plug. Therefore, the rubber plug is held more certainly.

In a preferred embodiment according to the present invention, the electric wire insertion device further includes a wall against which a front end, in a rubber plug advancing direction, of the supplied rubber plug collides such that the rubber plug stops at a predetermined position, along the central line, at which the plurality of clamp members are capable of grasping the rubber plug.

With such an electric wire insertion device, the rubber plug collides against the wall to stop at the predetermined position at which the first clamp members are capable of grasping the rubber plug. Therefore, the rubber plug is held more certainly.

In a preferred embodiment according to the present invention, the electric wire insertion device further includes a controller connected with the first actuator. The controller includes a setter setting a type of the rubber plug to be supplied, a storage storing a position of the first actuator for each of types of the rubber plug, and a second controller controlling the first actuator based on the setting performed by the setter and the position stored on the storage, to control positions of the first rubber plug contact portions with respect to the central line.

With such an electric wire insertion device, for holding the rubber plug, the first rubber plug contact portions are moved to preferred positions defined in accordance with each of types of the rubber plug. Therefore, the rubber plug of the set type is grasped certainly.

In a preferred embodiment according to the present invention, the electric wire insertion device further includes a controller connected with the first actuator. The controller includes a storage and a second controller. The storage stores a pre-insertion position as a position of the first actuator before the electric wire is inserted into the rubber plug and a post-insertion position as a position of the first actuator after the electric wire is inserted into the rubber plug. The second controller controls the first actuator based on the pre-insertion position and the post-insertion position stored on the storage, to control positions of the first rubber plug contact portions with respect to the central line.

In general, the outer diameter of the rubber plug is changed by an electric wire being inserted into the rubber plug. The electric wire insertion device stores the pre-insertion position as the position of the first actuator before the electric wire is inserted into the rubber plug, and the post-insertion position as the position of the first actuator after the electric wire is inserted into the rubber plug, separately from each other. Therefore, even if the outer diameter of the rubber plug is changed by the insertion of the electric wire, the first actuator is moved to the post-insertion position, so that the electric wire is inserted into the rubber plug smoothly.

In a preferred embodiment of the electric wire insertion device according to the present invention, the first rubber plug contact portions at the post-insertion positions are located farther from the central line than the first rubber plug contact portions at the pre-insertion positions.

In general, the outer diameter of the rubber plug is increased by an electric wire being inserted into the rubber plug. With the electric wire insertion device according to the present invention, even if the outer diameter of the rubber plug is increased by the insertion of the electric wire, the first rubber plug contact portions are moved to the post-insertion positions farther from the central line than the pre-insertion positions, so that the electric wire is inserted into the rubber plug smoothly.

In a preferred embodiment according to the present invention, the electric wire insertion device further including a moving device moving the rubber plug holding device parallel to the central line.

Such an electric wire insertion device locates the rubber plug at a position, in a direction in which the electric wire is inserted, that is preferred for the insertion of the electric wire.

In a preferred embodiment according to the present invention, the electric wire insertion device further includes a controller connected with the electric wire transportation device and the moving device. The controller includes a third controller and a fourth controller. The third controller controls the electric wire transportation device to transport the electric wire from an area outside the rubber plug holding device toward the space formed inner to the plurality of first clamp members, to insert the electric wire into the rubber plug. The fourth controller controls the moving device after the electric wire transportation device starts inserting the electric wire into the rubber plug, to move the rubber plug holding device in a transportation direction of the electric wire, and controls the moving device after the rubber plug holding device is moved in the transportation direction of the electric wire, to move the rubber plug holding device in a direction opposite to the transportation direction of the electric wire.

With such an electric wire insertion device, along with the transportation of the electric wire, the rubber plug is once moved in the transportation direction of the electric wire. As a result, buckling of the electric wire is suppressed in the initial stage of the process of inserting the electric wire into the rubber plug. Then, while the electric wire is transported, the rubber plug is moved in a direction opposite to the transportation direction of the electric wire. Thus, the electric wire is inserted into the rubber plug.

A rubber plug holding device according to the present invention holds a rubber plug of any of various types having different outer sizes.

First, a rubber plug will be described. <FIG> is a perspective view showing an example of rubber plug <NUM>. As shown in <FIG>, the rubber plug <NUM> according to an example has a cylindrical shape that is axially asymmetrical. The rubber plug <NUM> includes a long diameter portion 5a and a short diameter portion 5b. The long diameter portion 5a has a diameter longer than that of the short diameter portion 5b. The rubber plug <NUM> has a through-hole 5c running through the rubber plug <NUM> along the axis thereof. The shape of the rubber plug <NUM> shown here is merely an example, and there is no limitation on the shape of the rubber plug <NUM>.

<FIG> shows an example of form of use of the rubber plug <NUM>. As shown in <FIG>, the rubber plug <NUM> is, for example, attached to a covered electric wire <NUM> (hereinafter, referred to as the "electric wire <NUM>"). The electric wire <NUM> has a tip to be inserted into the through-hole 5c of the rubber plug <NUM>. The electric wire <NUM> is inserted into the through-hole 5c from an opening on the long diameter portion 5a side and is taken out from an opening on the short diameter portion 5b side. Then, the cover of the tip of the electric wire <NUM> is peeled off, and a crimp terminal <NUM> is crimped to the tip. At this point, the crimping of the crimp terminal <NUM> causes the rubber plug <NUM> to be secured to the electric wire <NUM>. In addition, an assembly of the electric wire <NUM>, the rubber plug <NUM> and the crimp terminal <NUM> is inserted into a housing <NUM> provided therefor. As shown in <FIG>, the rubber plug <NUM> is in contact with an inner circumferential surface of the housing <NUM> to prevent entrance of moisture into the housing <NUM>. The rubber plug <NUM> is a water-proof rubber plug.

<FIG> is a schematic cross-sectional view of a rubber plug supply device <NUM> and an electric wire insertion device <NUM> according to an embodiment. The electric wire insertion device <NUM> inserts the electric wire <NUM> into the through-hole 5c of the rubber plug <NUM>. The rubber plug supply device <NUM> supplies the rubber plug <NUM> to the electric wire insertion device <NUM>. In the following description, the left side and the right side of <FIG> will be described as the front side and the rear side, respectively. The left side, the right side, the up side and the down side of the rubber plug supply device <NUM> and the electric wire insertion device <NUM> as seen from the front side will be described as the left side, the right side, the up side and the down side. In the figures referred to below, the front side, the rear side, the left side, the right side, the up side and the down side will be represented by F, Rr, L, R, U and D, respectively. It should be noted that the directions mentioned in the following description are defined merely for the sake of convenience, and do not limit the present invention in any way.

As shown in <FIG>, the rubber plug supply device <NUM> includes a plurality of transportation tubes <NUM> and a tube selector <NUM>. Rubber plugs <NUM> are each directed by a parts feeder (not shown) such that the long diameter portion 5a is on the front side in an advancing direction thereof, and are transported in the transportation tubes <NUM>. The rubber plugs <NUM> are transported in the transportation tubes <NUM> by, for example, compressed air. In this embodiment, the plurality of transportation tubes <NUM> are provided side by side in an up-down direction. The tube selector <NUM> moves the plurality of transportation tubes <NUM> in the up-down direction. One of the plurality of transportation tubes <NUM> is positioned by the tube selector <NUM> so as to face a rubber plug supply opening <NUM> of the electric wire insertion device <NUM>. As a result, the one transportation tube <NUM> is connected with the rubber plug supply opening <NUM>. The rubber plug <NUM> in the transportation tube <NUM> connected with the rubber plug supply opening <NUM> is supplied to the electric wire insertion device <NUM>. It should be noted that there is no specific limitation on the structure of the rubber plug supply device <NUM>. For example, the plurality of transportation tubes may be located in a circumferential direction, and the tube selector may rotate the plurality of transportation tubes in the circumferential direction.

As shown in <FIG>, the electric wire insertion device <NUM> includes a rubber plug holding device <NUM>, a clamp moving device <NUM>, an electric wire transportation device <NUM>, a detection device <NUM>, and a controller <NUM> (see <FIG>). <FIG> is a perspective view of the electric wire insertion device <NUM>. <FIG> is a vertical cross-sectional view of the electric wire insertion device <NUM>. <FIG> is a rear view of the electric wire insertion device <NUM>. The rubber plug holding device <NUM> holds the rubber plug <NUM> supplied by the rubber plug supply device <NUM>. As shown in <FIG>, the rubber plug holding device <NUM> includes a plurality of first clamp members <NUM> and a plurality of second clamp members <NUM>. The plurality of first clamp members <NUM> clamp the shorter diameter portion 5b of the rubber plug <NUM>. The plurality of second clamp members <NUM> are partially located to the front of the plurality of first clamp members <NUM>, and clamp the long diameter portion 5a of the rubber plug <NUM>.

As shown in <FIG> and <FIG>, the plurality of first clamp members <NUM> are located around a predetermined central line CL so as to form a space S1 inner thereto, in which the cylindrical rubber plug <NUM> may be located. The central line CL matches the axis of the rubber plug <NUM> in the state where the rubber plug <NUM> located in the inner space S1 is clamped by the plurality of first clamp members <NUM>. The plurality of first clamp members <NUM> are located along a circumferential surface of a circle centered around the central line CL. As shown in <FIG>, the plurality of first clamp members <NUM> are four first clamp members <NUM> in this embodiment. The plurality of first clamp members <NUM> are located at an interval of <NUM> degrees. It is sufficient that there are two or more first clamp members <NUM>, and there is no further limitation on the number of the first clamp members <NUM>. In the case where, for example, there are three first clamp members <NUM>, the three first clamp members <NUM> may be located at an interval of <NUM> degrees. In the case where, for example, there are six first clamp members <NUM>, the six first clamp members <NUM> may be located at an interval of <NUM> degrees. The plurality of first clamp members <NUM> do not need to be located at an interval of an equal angle, and a part of, or all of, the angles between the plurality of first clamp members <NUM> may be different.

As shown in <FIG>, the plurality of first clamp members <NUM> each include a first cylindrical portion 31a, a first engageable portion 31b, a first arm portion 31c, and a first tip portion 31d. The first cylindrical portion 31a is cylindrical and extends in a front-rear direction. A shaft 32a of a support member <NUM> described below is pivotably inserted into the first cylindrical portion 31a. The shaft 32a is inserted into the first cylindrical portion 31a, so that the first clamp member <NUM> is pivotable about the shaft 32a. The first engageable portion 31b is provided on an outer circumferential surface of the first cylindrical portion 31a. The first engageable portion <NUM> has gear teeth formed therein.

The first arm portion 31c extends from the first cylindrical portion 31a toward the central line CL. Hereinafter, the direction from the first cylindrical portion 31a toward the central line CL will be referred to also as the "inner circumferential direction", and a direction opposite thereto will be referred to also as the "outer circumferential direction". The tip portion 31d is provided at an inner circumferential end of the first arm portion 31c. As shown in <FIG>, the tip portion 31d extends long in the front-rear direction. The above-described space S1, in which the rubber plug <NUM> is to be located, is formed inner to the plurality of tip portions 31d. In this embodiment, a rear end of the space S1 forms the rubber plug supply opening <NUM>, to which the rubber plug <NUM> is supplied. The rubber plug supply opening <NUM> is in communication with the space S1, which is formed inner to the plurality of first clamp members <NUM>. It should be noted that the rubber plug supply opening of the electric wire insertion device does not need to be defined by ends of the plurality of first clamp members <NUM>, and may be provided separately from the above-described ends.

As shown in <FIG>, the tip portion 31d has a first inner side surface 31e facing the space S1 inner to the plurality of first clamp members <NUM>. The first inner side surface 31e is provided so as to face the central line CL. As shown in <FIG>, the first inner side surface 31e is structured such that different regions thereof along a circumferential direction of the shaft 32a have different distances from the shaft 32a. The first inner side surface 31e is non-arcked, or arcked as centered about a position different from the shaft 32a, as seen in the front-rear direction. The first inner side surface 31e includes a first rubber plug contact portion 31e1, which is to be in contact with an outer circumferential surface of the rubber plug <NUM>. The first rubber plug contact portion 31e1 faces the space S1 inner to the plurality of first clamp members <NUM>. Therefore, the pivoting of the first clamp member <NUM> about the shaft 32a causes the first rubber plug contact portion 31e1 to get closer to, or farther from, the central line CL.

As shown in <FIG> and <FIG>, the rubber plug holding device <NUM> includes the support member <NUM>, a first actuator <NUM>, a first pulley <NUM>, and a first belt <NUM>. The support member <NUM> supports the plurality of first clamp members <NUM>. The support member <NUM> includes a plurality of the shafts 32a each extending parallel to the central line CL. As described above, the plurality of shafts 32a are respectively inserted into the cylindrical portions 31a of the first clamp members <NUM>. The plurality of shafts 32a respectively support the first clamp members <NUM> such that the first clamp members <NUM> are pivotable.

The first actuator <NUM> drives the plurality of first clamp members <NUM> via the first pulley <NUM> and the first belt <NUM>. The first actuator <NUM> is a stepping motor in this embodiment. The first actuator <NUM> includes a driving shaft 33a rotatable about the front-rear direction acting as an axial direction thereof. A first motor pulley 33b is secured to the driving shaft 33a. The first belt <NUM>, which is endless, is wound around the first motor pulley 33b. In this embodiment, the first belt <NUM> is a timing belt having a groove, engageable with a gear of the pulley, formed therein.

The first pulley <NUM> includes an annular ring portion 34a, around which the first belt <NUM> is to be wound. The first ring portion 34a has a rotation center matching the central line CL. The first pulley <NUM> is rotated about the central line CL. The first ring portion 34a includes an outer gear 34a1 in an outer circumferential surface thereof, and an inner gear 34a2 in an inner circumferential surface thereof. The first belt <NUM> is in engagement with the outer gear 34a1 of the first pulley <NUM>. The first belt <NUM> is also in engagement with the driving shaft 33a of the first actuator <NUM> via the first motor pulley 33b. The first belt <NUM> and the first motor pulley 33b act as an example of transfer mechanism that transfers the rotation of the driving shaft 33a to the first pulley <NUM>. It should be noted that the transfer mechanism that transfers the rotation of the driving shaft 33a to the first pulley <NUM> is not limited to a belt and a pulley. When the driving shaft 33a is rotated by a certain rotation angle, the first pulley <NUM> is rotated by an angle corresponding to the rotation angle.

As shown in <FIG>, the first engageable portion 31b of the first clamp member <NUM> is located inner to the first ring portion 34a in a radial direction. The first engageable portion 31b includes gear teeth, and is in engagement with the inner gear 34a2 of the first ring portion 34a. With this structure, the rotation of the first pulley <NUM> causes the first clamp members <NUM> to pivot about the shafts 34a. When the driving shaft 33a of the first actuator <NUM> is rotated by a certain rotation angle, the first clamp members <NUM> are pivoted about the shafts 32a by an angle corresponding to the rotation angle of the driving shaft 33a via the first motor pulley 33b, the first belt <NUM> and the first pulley <NUM>. As can be seen, in the case where the first pulley <NUM> including the outer gear 34a1 receiving the rotation force of the first actuator <NUM> and the inner gear 34a2 transferring the rotation force of the first actuator <NUM> to the first clamp members <NUM> is used, the first clamp members <NUM> are pivoted with a simple structure. With such a structure, first clamp members <NUM> are located inner to the first ring portion 34a in the radial direction. Therefore, the entirety of the mechanism driving the first clamp members <NUM> by the first actuator <NUM> is made compact.

In this embodiment, the first rubber plug contact portion 31e1 is provided at each first inner side surface 31e of the first clamp member <NUM>, and different regions of the first inner side surface 31e along the circumferential direction of the shaft 32a have different distances from the shaft 32a as the pivoting center of the first inner side surface 31e. Therefore, mere pivoting of the first clamp members <NUM> causes the first rubber plug contact portions 31e1 to get closer to, or farther from, the central line CL. With such a structure, the rubber plug holding device <NUM> according to this embodiment is simple and compact.

A plurality of second clamp members <NUM> and a mechanism that drives the plurality of second clamp members <NUM> are structured in substantially the same manner as the plurality of first clamp members <NUM> and the mechanism that drives the plurality of first clamp members <NUM>. The plurality of second clamp members <NUM> are located side by side with the plurality of first clamp members <NUM> in a direction in which the central line CL extends. In this embodiment, the positions of the plurality of second clamp members <NUM> in the front-rear direction partially overlap the positions of the plurality of first clamp members <NUM> in the front-rear direction.

In this embodiment, the shafts 32a of the support member <NUM> extend parallel to the central line CL. The shafts 32a of the support member <NUM> also supports the second clamp members <NUM> such that the second clamp members <NUM> are pivotable. In this embodiment, the first clamp members <NUM> and the second clamp members <NUM> share the support members (in this embodiment, the shafts 32a) to decrease the number of components. It should be noted that the rubber plug holding device may include a second support members supporting the second clamp members in addition to the support members supporting the first clamp members.

As shown in <FIG>, there are four second clamp members <NUM> in this embodiment. It should be noted that there is no limitation on the number of the second clamp members <NUM>. As shown in <FIG>, second arm portions 41c of the second clamp members <NUM> are located outer in the circumferential direction to the first tip portions 31d, of the first clamp members <NUM>, extending in the front-rear direction. The second arm portions 41c extend forward. Tip portions 41d connected to front ends of the second arm portions 41c are located to the front of front ends of the first clamp members <NUM>. The tip portions 41d each include a second rubber plug contact portion 41e1, which is to be in contact with the long diameter portion 5a of the rubber plug <NUM>. The second rubber plug contact portion 41e1 is located at a position different from that of the first rubber plug contact portion 31e1 (see <FIG>) in the direction in which the central line CL extends. In more detail, the plurality of second rubber plug contact portions 41e1 are provided to the front of the plurality of first rubber plug contact portions 31e1. The plurality of second rubber plug contact portions 41e1 are structured so as to be in contact with the long diameter portion 5a of the rubber plug <NUM>.

In this embodiment, the second clamp members <NUM> including the second rubber plug contact portions 41e1 are only partially located at positions shifted from the positions of the first clamp members <NUM>. Alternatively, the second clamp members <NUM> may be entirely located at positions shifted from the positions of the first clamp members <NUM>.

As shown in <FIG>, like the plurality of first clamp members <NUM>, the plurality of second clamp members <NUM> are located around the central line CL so as to form a space S2 inner thereto, in which the cylindrical rubber plug <NUM> may be located. A second actuator <NUM> pivots the second clamp members <NUM> via a second motor pulley 43b, a second belt <NUM>, and a second pulley <NUM>. The second actuator <NUM> is also a stepping motor in this embodiment. The second actuator <NUM>, the second motor pulley 43b, the second pulley <NUM> and the second belt <NUM> are respectively structured in substantially the same manner as the first actuator <NUM>, the first motor pulley 33b, the first pulley <NUM> and the first belt <NUM>, Rotation of a driving shaft 43a of the second actuator <NUM> causes the second clamp members <NUM> to pivot about the shafts 32a. An inner side surface of each of the second clamp members <NUM> is structured such that different regions of the inner side surface along the circumferential direction of the shaft 32a have different distances from the shaft 32a. Therefore, the pivoting of the second clamp members <NUM> about the shafts 32a causes the second rubber plug contact portions 41e1 provided at the inner side surfaces of the second clamp members <NUM> to get closer to, or farther from, the central line CL.

As shown in <FIG> and <FIG>, the clamp moving device <NUM> supports the rubber plug holding device <NUM> from below. The clamp moving device <NUM> moves the rubber plug holding device <NUM> parallel to the central line CL (in this embodiment, in the front-rear direction). The clamp moving device <NUM> includes a base plate <NUM>, a pair of guide rails <NUM>, and a movement actuator <NUM> (see <FIG>). The base plate <NUM> supports the rubber plug holding device <NUM>. The pair of guide rails <NUM> extend in the front-rear direction. The base plate <NUM> are in engagement with the pair of guide rails <NUM> so as to be slidable therewith in the front-rear direction. The movement actuator <NUM> moves the base plate <NUM> along the pair of guide rails <NUM>. There is no specific limitation on the type of the movement actuator <NUM>. In this embodiment, the movement actuator <NUM> is a stepping motor. In this embodiment, the clamp moving device <NUM> is capable of moving the rubber plug holding device <NUM> by <NUM> in the front-rear direction. It should be noted that there is no limitation on the distance by which the clamp moving device <NUM> is capable of moving the rubber plug holding device <NUM>.

The electric wire transportation device <NUM> transports the electric wire <NUM> along the central line CL. Before the electric wire <NUM> is inserted into the rubber plug <NUM>, the electric wire transportation device <NUM> transports the electric wire <NUM> from the front side to the rear side with respect to the rubber plug holding device <NUM>. After the electric wire <NUM> is inserted into the rubber plug <NUM>, the electric wire transportation device <NUM> transports the electric wire <NUM> forward to separate the electric wire <NUM> from the rubber plug holding device <NUM>. As shown in <FIG>, the electric wire transportation device <NUM> includes an electric wire guide <NUM> guiding the electric wire <NUM>. The electric wire guide <NUM> is provided to the front of the rubber plug holding device <NUM>. The electric wire guide <NUM> includes a top member 61U and a bottom member 61D. The top member 61U and the bottom member 61D are flat plate-like. The top member 61U and the bottom member 61D are structured such that one thereof or both thereof are movable in the up-down direction. The electric wire transportation device <NUM> includes a guide actuator <NUM> (see <FIG>) moving one of, or both of, the top member 61U and the bottom member 61D in the up-down direction.

An electric wire insertion hole 61a (also see <FIG>) is formed by the top member 61U and the bottom member 61D at an interface at which the top member 61U and the bottom member 61D contact each other. The electric wire insertion hole 61a is located on the central line CL. The movement of one of, or both of, the top member 61U and the bottom member 61D in the up-down direction allows the electric wire insertion hole 61a to have a size corresponding to any of various diameters of the electric wire <NUM>. Hereinafter, decrease in the distance between the top member 61U and the bottom member 61D will be referred to also as "closing the electric wire guide <NUM>", and increase in the distance between the top member 61U and the bottom member 61D will be referred to also as "opening the electric wire guide <NUM>". The electric wire <NUM> is inserted into the electric wire insertion hole 61a to be transported along the central line CL. The electric wire transportation device <NUM> includes an electric wire clamp <NUM> and a transportation shaft <NUM> (see <FIG>; not shown in any of <FIG>). The electric wire <NUM> is transported by a rotation of the transportation shaft <NUM>.

The electric wire clamp <NUM> is located along the central line CL on the rubber plug holding device <NUM> side with respect to the transportation shaft <NUM>. The electric wire clamp <NUM> is located between the transportation shaft <NUM> and the electric wire guide <NUM>. In this embodiment, the electric wire clamp <NUM> includes a pair of holding members 63U and 63D facing each other in the up-down direction. The electric wire transportation device <NUM> includes a clamp actuator <NUM> (see <FIG>) moving the pair of holding members 63U and 63D in the up-down direction to open and close the electric wire clamp <NUM>. When the electric wire clamp <NUM> is closed, the electric wire <NUM> is grasped. When the electric wire clamp <NUM> is opened, the electric wire <NUM> is released from the grasped state. It should be noted that the electric wire clamp <NUM> merely needs to grasp and release the electric wire <NUM>, and there is no limitation on the structure thereof. The electric wire clamp <NUM> is supported by a moving device (not shown) moving the electric wire clamp <NUM> in the front-rear direction.

As shown in <FIG>, the electric wire transportation device <NUM> includes a wall 61b (also see <FIG>), against which a front end, in the advancing direction, of the rubber plug <NUM> supplied is to collide. The wall 61b is provided such that the rubber plug <NUM> stops at a predetermined position, along the central line CL, at which the first clamp members <NUM> and the second clamp members <NUM> are capable of grasping the rubber plug <NUM>. The wall 61b is located to the front of the first rubber plug contact portions 31e1 and the second rubber plug contact portions 41e1 in the advancing direction of the rubber plug <NUM>. In this embodiment, the wall 61b is a rear end surface of the flat plate-like electric wire guide <NUM>. It should be noted that the wall against which the rubber plug <NUM> is to collide may be provided separately from the electric wire guide. Hereinafter, the predetermined position of the rubber plug <NUM> will be referred to also as the "clamp position" of the rubber plug <NUM>.

The detection device <NUM> detects whether or not the rubber plug <NUM> is at the clamp position. There is no specific limitation on the structure of the detection device <NUM>. In this embodiment, the detection device <NUM> includes an optical sensor. As shown in <FIG>, the detection device <NUM> includes a light projector <NUM> and a light receiver <NUM>. The light projector <NUM> is located above a gap between the rubber plug holding device <NUM> and the wall 61b of the electric wire guide <NUM>. The light projector <NUM> radiates light toward the gap. In <FIG>, letter Ax refers to an optical axis of the light to be radiated by the light projector <NUM>. The light receiver <NUM> is located below the gap between the rubber plug holding device <NUM> and the wall 61b of the electric wire guide <NUM>. The light receiver <NUM> is located on the optical axis Ax of the light to be radiated by the light projector <NUM>. The positions of the light projector <NUM> and the light receiver <NUM> may be opposite to those described above. Alternatively, the light projector <NUM> and the light receiver <NUM> may face each other in any of different directions around the central line CL, for example, in a left-right direction.

In the state where the rubber plug <NUM> is not at the clamp position, the light receiver <NUM> receives the light radiated by the light projector <NUM>. In the state where the rubber plug <NUM> is at the clamp position, the light radiated by the light projector <NUM> is blocked by the rubber plug <NUM> and does not reach the light receiver <NUM>. Whether or not the rubber plug <NUM> is at the clamp position is determined based on whether or not the light receiver <NUM> receives the light from the light projector <NUM>. The detection device <NUM> sends a signal indicating whether or not the rubber plug <NUM> is at the clamp position to the controller <NUM>.

The electric wire insertion device <NUM> includes the controller <NUM> controlling operations of various components. <FIG> is a block diagram of the electric wire insertion device <NUM>. As shown in <FIG>, the controller <NUM> is connected with the first actuator <NUM>, the second actuator <NUM>, the movement actuator <NUM>, the guide actuator <NUM>, the clamp actuator <NUM> and the transportation shaft <NUM>, and controls the operations thereof. The controller <NUM> is also connected with the detection device <NUM>, and receives a signal from the detection device <NUM>. The controller <NUM> is further connected with an operation panel <NUM>, by which a user makes various settings. The controller <NUM> and the rubber plug supply device <NUM> may or may not be connected with each other.

There is no specific limitation on the structure of the controller <NUM>. The controller <NUM> may include, for example, a central processing unit (hereinafter, referred to as the "CPU"), a ROM storing, for example, a program to be executed by the CPU, a RAM, and the like. Each of the portions of the controller <NUM> may be realized by software or hardware. Each of the portions may be a processor or a circuit. As shown in <FIG>, the controller <NUM> includes a setter <NUM>, a first position storage <NUM>, a second position storage <NUM>, a signal receiver <NUM>, a clamp instructor <NUM>, a first clamp controller <NUM>, a second clamp controller <NUM>, a transportation controller <NUM>, a moving position storage <NUM>, and a movement controller <NUM>. The controller <NUM> may include further processors, which are not shown or described herein.

The setter <NUM> sets the type of the rubber plug <NUM> to be supplied. In this embodiment, the electric wire insertion device <NUM> is supplied with various types of rubber plugs <NUM> having different shapes and various types of electric wires <NUM> having different diameters in correspondence with the rubber plugs <NUM>. The diameters of the long diameter portion 5a and the short diameter portion 5b vary in accordance with the type of the rubber plug <NUM>. The setting of the type of the rubber plug <NUM> by the setter <NUM> may be performed automatically based on information from an upper-level system connected with the electric wire insertion device <NUM> or may be performed by the user.

The first position storage <NUM> stores the position of the first actuator <NUM> in correspondence with each type of the rubber plug <NUM>. It should be noted that data to be stored on the first position storage <NUM> merely needs to correspond to the positions of the first rubber plug contact portions 31e1 with respect to the central line CL, and merely needs to be a physical amount equivalent to the positions of the first rubber plug contact portions 31e1 with respect to the central line CL. In this embodiment, the first position storage <NUM> stores a rotation position of the first actuator <NUM>. Such a stored position of the first actuator <NUM> corresponds to the diameter of the short diameter portion 5b of the rubber plug <NUM>.

The first position storage <NUM> also stores a position of the first actuator <NUM> before the electric wire <NUM> is inserted into the rubber plug <NUM> (hereinafter, referred to as the "pre-insertion position") and a position of the first actuator <NUM> after the electric wire <NUM> is inserted into the rubber plug <NUM> (hereinafter, referred to as the "post-insertion position") in correspondence with each type of the rubber plug <NUM>. When the electric wire <NUM> is inserted, the diameter of the rubber plug <NUM> is generally increased. Therefore, in order to insert the electric wire <NUM> smoothly into the rubber plug <NUM>, the post-insertion positions of the first rubber plug contact portions 31e1 are set. The first rubber plug contact portions 31e1 at the post-insertion positions are farther from the central line CL than the first rubber plug contact portions 31e1 at the pre-insertion positions.

The second position storage <NUM> stores similar data on the second clamp member <NUM> as stored on the first position storage <NUM>. The second position storage <NUM> stores a pre-insertion position and a post-insertion position of the second actuator <NUM> in correspondence with each type of the rubber plug <NUM>.

The signal receiver <NUM> receives a signal from the detection device <NUM>. When the detection device <NUM> detects that the rubber plug <NUM> is at the clamp position, the clamp instructor <NUM> causes the first actuator <NUM> and the second actuator <NUM> to operate such that the first rubber plug contact portions 31e1 and the second rubber plug contact portions 41e1 get closer to the central line CL. This operation may be performed immediately after the detection device <NUM> detects that the rubber plug <NUM> is at the clamp position, or may be performed after an elapse of a time period for confirmation.

The first clamp controller <NUM> controls the first actuator <NUM> based on the setting by the setter <NUM> and the pre-insertion position and the post-insertion position stored on the first position storage <NUM> to control the positions of the first rubber plug contact portions 31e1 with respect to the central line CL. Similarly, the second clamp controller <NUM> controls the second actuator <NUM> based on the setting by the setter <NUM> and the pre-insertion position and the post-insertion position stored on the second position storage <NUM> to control the positions of the second rubber plug contact portions 41e1 with respect to the central line CL.

The transportation controller <NUM> controls the electric wire transportation device <NUM> to transport the electric wire <NUM> from an area outside the rubber plug holding device <NUM> toward the space S1 formed inner to the plurality of first clamp members <NUM> and the space S2 formed inner to the plurality of second clamp members <NUM>. As a result, the electric wire <NUM> is inserted into the rubber plug <NUM>. After the electric wire <NUM> is inserted into the rubber plug <NUM>, the transportation controller <NUM> controls the electric wire transportation device <NUM> to move the electric wire <NUM> inserted into the rubber plug <NUM> forward (direction in which the electric wire <NUM> is separated from the rubber plug holding device <NUM>).

The moving position storage <NUM> stores the position, in the front-rear direction, at which the rubber plug holding device <NUM> is to be located by the clamp moving device <NUM>. The moving position storage <NUM> stores an initial position, at which the rubber plug holding device <NUM> is to be located before the electric wire <NUM> is inserted, in correspondence with each type of the rubber plug <NUM>. The moving position storage <NUM> stores the position to which the rubber plug holding device <NUM> is to move in the transportation direction of the rubber plug <NUM> after the electric wire <NUM> starts inserted into the rubber plug <NUM>, and the position to which the rubber plug holding device <NUM> is to move in the direction opposite to the transportation direction of the rubber plug <NUM> after that, in correspondence with each type of the rubber plug <NUM> or each type of the electric wire <NUM>. It should be noted that these positions may be fixed regardless of the type of the rubber plug <NUM> or the type of the electric wire <NUM>. The fixed positions may be, for example, front and rear stroke ends of the clamp moving device <NUM>.

The movement controller <NUM> controls the operation of the clamp moving device <NUM>. In more detail, the movement controller <NUM> controls the clamp moving device <NUM> to locate the rubber plug holding device <NUM> at the initial position defined for each type of the rubber plug <NUM>. After the electric wire <NUM> starts inserted into the rubber plug <NUM> by the electric wire transportation device <NUM>, the movement controller <NUM> controls the clamp moving device <NUM> to move the rubber plug holding device <NUM> in the transportation direction of the electric wire <NUM>. After the rubber plug holding device <NUM> is moved in the transportation direction of the electric wire <NUM>, the movement controller <NUM> controls the clamp moving device <NUM> to move the rubber plug holding device <NUM> in the direction opposite to the transportation direction of the electric wire <NUM>. The positions, in the front-rear direction, to which the rubber plug holding device <NUM> is to be moved by these operations are based on the positions stored on the moving position storage <NUM>. These operations will be described below.

Hereinafter, a process of inserting the electric wire <NUM> into the rubber plug <NUM> will be described. <FIG> is a flowchart showing a process of inserting the electric wire <NUM> into the rubber plug <NUM>. As shown in <FIG>, in step S01 of the process of inserting the electric wire <NUM> into the rubber plug <NUM>, the type of the rubber plug <NUM> is selected.

In step S02, the rubber plug supply device <NUM> supplies the rubber plug <NUM> to the electric wire insertion device <NUM>. As a result of step S02, the rubber plug <NUM> is moved forward until colliding against the wall 61b of the electric wire guide <NUM>. The position of the rubber plug <NUM> when the rubber plug <NUM> collides against the wall 61b of the electric wire guide <NUM> is the clamp position. The rubber plug <NUM> is caused to collide against the wall 61b to stop at the clamp position certainly. Then, in step S03, whether or not the rubber plug <NUM> has reached the clamp position is determined based on the signal from the detection device <NUM>. In the case where the rubber plug <NUM> has not reached the clamp position (NO in step S03), the process returns to step S03, where the determination is repeated. In the case where the rubber plug <NUM> has reached the clamp position (YES in step S03), the rubber plug <NUM> is clamped in step S04. As can be seen, in this embodiment, after being confirmed to have reached the clamp position, the rubber plug <NUM> is clamped. Therefore, the rubber plug <NUM> is held more certainly.

For clamping the rubber plug <NUM>, the driving shaft 33a of the first actuator <NUM> is rotated by the rotation angle stored on the first position storage <NUM>. As a result, the first clamp members <NUM> are pivoted in a direction of arrow R1 in <FIG>. When the first clamp members <NUM> are pivoted in the R1 direction, as shown in <FIG>, the first rubber plug contact portions 31e1 are moved in a direction of arrow R2 to get closer to the central line CL. When the driving shaft 33a of the first actuator <NUM> is rotated by the rotation angle stored on the first position storage <NUM>, the first rubber plug contact portions 31e1 reach the pre-insertion positions. As a result, the short diameter portion 5b of the rubber plug <NUM> is held by the plurality of first clamp members <NUM>. As can be seen, the first clamp members <NUM> are driven so as to cause the first rubber plug contact portions 31e1 to get closer to the central line CL, so that the rubber plug <NUM> of any type having any of various outer diameters is held. In more detail, the type of the rubber plug <NUM> is set in step S01 and the position of the first actuator <NUM> is controlled in accordance with the type of the rubber plug <NUM> in step <NUM>, so that the rubber plug <NUM> of any type having any of various outer dimeters is held.

Similarly, the large diameter portion 5a of the rubber plug <NUM> is held by the plurality of second clamp members <NUM>. The plurality of second clamp members <NUM> allow the rubber plug <NUM> to be held in a preferred manner even though the rubber plug <NUM> is stepped. It should be noted that even in the case where the rubber plug <NUM> is not stepped, the rubber plug <NUM> is held by the rubber plug holding device <NUM> including the second clamp members <NUM>, needless to say.

In step S05, the rubber plug holding device <NUM> is moved by the clamp moving device <NUM> to the initial position stored on the moving position storage <NUM>. The rubber plug holding device <NUM> is movable parallel to the central line CL, and therefore, the rubber plug <NUM> is located at a position suitable for the insertion of the electric wire <NUM>. The initial position may be, for example, a position at which the rubber plug <NUM> is close to, or contacts, the electric wire guide <NUM>.

In step S06, the electric wire transportation device <NUM> is driven to insert the electric wire <NUM> into the electric wire insertion hole 61a of the electric wire guide <NUM>. At this point, the top member 61U or the bottom member 61D may be moved to open the electric wire guide <NUM>. After that, the electric wire guide <NUM> may be closed. The operation in step S02 through S05 and the operation in step S06 may be performed in an opposite order or at the same time.

In step S07, the electric wire <NUM> starts transported rearward by the electric wire transportation device <NUM>. The electric wire <NUM> is guided by the electric wire guide <NUM> to be inserted into the through-hole 5c of the rubber plug <NUM>. When a predetermined time period elapses after step S07, the rubber plug holding device <NUM> is moved rearward by the clamp moving device <NUM> in step S08. At this point, the electric wire clamp <NUM> is also moved rearward by a moving device (not shown). During these operations, the rearward transportation of the electric wire <NUM> is continued. As a result of the rearward movement of the rubber plug <NUM> and the rearward movement of the electric wire clamp <NUM>, the position of the electric wire guide <NUM> guiding the electric wire <NUM> is relatively moved from the vicinity of the rubber plug <NUM> toward a middle position between the electric wire clamp <NUM> and the rubber plug <NUM>. Therefore, the distance between the electric wire clamp <NUM> and the electric wire guide <NUM> is shortened. Along with this, the length of a portion of the electric wire <NUM> that is between the electric wire clamp <NUM> and the electric wire guide <NUM> (free electric wire length) is shortened. When the free electric wire length of the electric wire <NUM> is shortened, the buckling tolerance of the electric wire <NUM> is improved. As a result, the buckling of the electric wire <NUM> is suppressed.

When a predetermined time period elapses after step S08, the first clamp members <NUM> and the second clamp members <NUM> are moved to the post-insertion positions in step S09. This weakens the clamp on the rubber plug <NUM> by the rubber plug holding device <NUM> to permit the rubber plug <NUM> to expand outward in the circumferential direction. As a result, the electric wire <NUM> is inserted into the through-hole 5c smoothly.

The above-described control suppresses rattling of the rubber plug <NUM> in the held state. With a conventional rubber plug insertion device for which a rubber plug holding member is prepared for each type of the rubber plug, the size of the rubber plug holding member needs to be set to be larger in consideration that the outer size of the rubber plug is increased by the insertion of the electric wire. Therefore, with the conventional rubber plug insertion device, the rubber plug rattles significantly before the electric wire is inserted. With the rubber plug holding device <NUM> according to this embodiment, the pre-insertion positions of the first rubber plug contact portions 31e1 are set independently from the post-insertion positions thereof. This suppresses the rattling of the rubber plug <NUM> before the electric wire <NUM> is inserted. Therefore, the electric wire <NUM> is inserted into the rubber plug <NUM> more certainly. This is applicable to the second clamp members <NUM>.

In step S10, the rubber plug holding device <NUM> is moved forward by the clamp moving device <NUM>. As a result of the forward movement of the rubber plug holding device <NUM> and the continuing rearward movement of the electric wire <NUM>, the electric wire <NUM> is inserted into the rubber plug <NUM> completely. The operations in steps S08 through S10 may be performed in a different order except that the operation in step S10 needs to be performed after the operation in step S08.

In step S11, the rearward transportation of the electric wire <NUM> is stopped. In step S12, the rubber plug holding device <NUM> is driven to be opened, and the rubber plug <NUM> is released from the held state. In step S13, the electric wire guide <NUM> is opened. As a result, the electric wire <NUM> having the rubber plug <NUM> attached thereto is released from the held state. The operation in step S12 and the operation in S13 may be performed in an opposite order or at the same time.

In step S14, the electric wire <NUM> having the rubber plug <NUM> attached thereto is transported forward by the electric wire transportation device <NUM>. Thus, the process of inserting the electric wire <NUM> into the rubber plug <NUM> is finished. The above-described process is a preferred example, and the process of inserting the electric wire <NUM> into the rubber plug <NUM> is not limited to this.

An embodiment of the present invention is described above. The above-described embodiment is merely an example. Various other embodiments are available.

The following embodiments (first and second modifications) are not according to the invention and are present for illustration purposes only.

<FIG> is a perspective view of a main part of the rubber plug holding device <NUM> according to a first modification. <FIG> does not show a part of the components. As shown in <FIG>, the rubber plug holding device <NUM> according to this modification includes two first clamp members 131A and 131B (hereinafter, referred to simply as the "clamp members"; this is applicable to a second modification). The two clamp members 131A and 131B face each other in the up-down direction in this embodiment. It should be noted that the direction in which the two clamp members 131A and 131B face each other is not limited to the up-down direction.

Although not shown, the rubber plug holding device <NUM> includes an actuator moving the clamp members 131A and 131B in the up-down direction. When the actuator moves the bottom clamp member 131A upward and the top clamp member 131B downward, the clamp members 131A and 131B clamp the rubber plug <NUM>.

As shown in <FIG>, the clamp member 131A has an inner side surface 131A1 having a V shape as seen in the front-rear direction. In the state of being held by the rubber plug holding device <NUM>, the rubber plug <NUM> is in contact with, and supported by, two rubber plug contact portions 131A2 of the inner side surface 131A1. The two rubber plug contact portions 131A2 are located in two inclining surfaces of the inner side surface 131A1 having the V shape as seen in the front-rear direction, and extend in the front-rear direction.

A bottom surface 131B1 of the clamp member 131B is flat. Therefore, in the state of being held by the rubber plug holding device <NUM>, the rubber plug <NUM> is in contact with a single rubber plug contact portion 131B2 of the bottom surface 131B1. The rubber plug contact portion 131B2 extends in the front-rear direction.

The rubber plug holding device <NUM> according to this modification also holds the rubber plug <NUM> with the axis of the rubber plug <NUM> matching a predetermined central line CL set in the rubber plug holding device <NUM>. In other words, as long as including three or more rubber plug contact portions to be in contact with the outer circumferential surface of the cylindrical rubber plug <NUM>, the rubber plug holding device holds the rubber plug <NUM> in a preferred manner by two clamp members. In this embodiment not according to the invention, the three or more rubber plug contact portions are the two rubber plug contact portions 131A2 of the clamp member 131A and the single rubber plug contact portion 131B2 of the clamp member 131B. Although not shown, a plurality of second clamp members may have substantially the same structure.

The first modification may be carried out in a further modified form. <FIG> is a perspective view of a main part of a rubber plug holding device <NUM> according to the second modification. Like <FIG> does not show a part of the components. As shown in <FIG>, the rubber plug holding device <NUM> according to this modification includes two clamp members 231A and 231B. The two clamp members 231A and 231B face each other in the up-down direction.

As shown in <FIG>, the clamp member 231A has an inner side surface 231A1 having a V shape as seen in the front-rear direction. In the state of being held by the rubber plug holding device <NUM>, the rubber plug <NUM> is in contact with, and supported by, two rubber plug contact portions 231A2 of the inner side surface 231A1.

In this modification, the top clamp member 231B is identical to the bottom clamp member 231A. The top clamp member 231B is located at a position rotated by <NUM> degrees from the bottom clamp member 231A about the central line CL. The V-shaped inner side surface 231A1 of the clamp member 231A and a V-shaped inner side surface 231B1 of the clamp member 231B face each other. In the state of being held by the rubber plug holding device <NUM>, the rubber plug <NUM> is in contact with two rubber plug contact portions 231B2 of the inner side surface 231B1.

As described above, the rubber plug holding device <NUM> according to this modification includes the two clamp members 231A and 231B each including two rubber plug contact portions to be in contact with the cylindrical rubber plug <NUM>. In this embodiment, the two clamp members 231A and 231B respectively have the two rubber plug contact portions 231A2 and the two rubber plug contact portions 231B2. The rubber plug holding device <NUM> having such a structure also holds the rubber plug <NUM> with the axis of the rubber plug <NUM> matching a predetermined central line CL set in the rubber plug holding device <NUM>. Such a structure allows the axis of the rubber plug <NUM> to match the central line CL by simpler control than with the rubber plug holding device <NUM> according to the first modification. Although not shown, a plurality of second clamp members may have substantially the same structure.

As described in the first modification and the second modification, the plurality of first clamp members may have the same shape as each other, or may have different shapes from each other. The plurality of clamp members are not limited to having any specific shape as long as having a total of three or more rubber plug contact portions to be in contact with the rubber plug. This is applicable to the plurality of second clamp members.

The above-described embodiment does not limit the present invention unless otherwise specified. For example, in another preferred embodiment, the number of the first clamp members may be three. Alternatively, the number of the first clamp members may be five or more. It is preferred that the first clamp members are provided in the number of three or more. In the case where the number of the first clamp members is three or more, the first clamp members get closer to the rubber plug <NUM> in at least three directions set along the circumferential direction. Therefore, the rubber plug <NUM> is held stably. This is applicable to the plurality of second clamp members.

In the above-described embodiment, the rubber plug holding device <NUM> includes the plurality of first clamp members <NUM> and the plurality of second clamp members <NUM>. The rubber plug holding device does not need to include the second clamp members. Alternatively, the rubber plug holding device may further include a plurality of third clamp members or a plurality of fourth clamp members (or a plurality of further clamp members).

In the above-described embodiment, the mechanism that receives a driving force of the first actuator <NUM> to drive the first clamp members <NUM> such that the rubber plug contact portions 31e1 get closer to, or farther from, the central line CL at the same time is the first pulley <NUM> including the inner gear 34a2. The mechanism that drives the plurality of first clamp members in a synchronized state is not limited to such a mechanism. For example, the mechanism that drives the plurality of first clamp members in a synchronized state may include a plurality of gears that are each coupled with one first clamp member and are engaged with each other. This is applicable to the second clamp members <NUM>.

In the above-described embodiment, the first rubber plug contact portions 31e1 get closer to, or farther from, the central line CL by an action of the first inner side surfaces 31e, different regions of which have different distances from the pivoting axis. The mechanism that causes the first rubber plug contact portions 31e1 to get closer to, or farther from, the central line CL is not limited to such a mechanism. For example, the first clamp members may get closer to, or farther from, the central line along a direction normal to the circumferential direction. This is applicable to the second clamp members <NUM>.

In the above-described embodiment, the first actuator <NUM> is a stepping motor, the rotation position of which is recognizable. The first actuator <NUM> is not limited to this. The first actuator may be, for example, a servo motor, the rotation position of which is feedback-controllable. Alternatively, the first actuator <NUM> may merely need to move or pivot the first clamp members until the first clamp members contact the rubber plug and stop. The first actuator is not limited to an electric motor, and may be, for example, an air-driven actuator. The first actuator is not limited to including a rotatable driving shaft, and may be, for example, like a cylinder including an extendable rod. This is applicable to the other actuators including the second actuator <NUM> and the movement actuator <NUM>.

In the above-described embodiment, the central line CL extends in a horizontal direction. The central line CL does not need to extend in the horizontal direction. For example, the central line of the rubber plug holding device may extend in a vertical direction or any other direction. There is no limitation on the form of installation of the electric wire insertion device.

In the above-described embodiment, the electric wire <NUM> is transported to be inserted into the rubber plug <NUM>. The rubber plug holding device <NUM> may be moved together with the rubber plug. Alternatively, both of the electric wire <NUM> and the rubber plug <NUM> may be moved.

In the above-described embodiment, the detection device <NUM> detecting that the rubber plug <NUM> has reached the clamp position includes the optical sensor. There is no limitation on the detection system of the detection device. The detection device may include, for example, an image recognition device, a contact switch or the like. It is not needed to detect that the rubber plug <NUM> has reached the clamp position. For example, elapse of a predetermined time period may be considered to indicate that the rubber plug <NUM> has reached the clamp position.

The above-described control on the electric wire insertion device <NUM> is a preferred example, and the control on the electric wire insertion device <NUM> is not limited to this. For example, the rubber plug holding device <NUM> may drive only the first clamp members <NUM> or the second clamp members <NUM> as necessary. In this case, it is preferred that the small diameter portion 5b of the rubber plug <NUM> may be grasped. For example, during the process of inserting the electric wire <NUM> into the rubber plug <NUM>, the rubber plug holding device <NUM> may be once released from the clamped state and re-grasped to have the electric wire <NUM> inserted thereto.

Claim 1:
A rubber plug holding device (<NUM>), comprising:
a plurality of first clamp members (<NUM>) located around a predetermined central line (CL) so as to form a space inner thereto in which a cylindrical rubber plug (<NUM>) is allowed to be located;
a first support member (<NUM>) supporting the plurality of first clamp members (<NUM>); and
a first actuator (<NUM>) driving the plurality of first clamp members (<NUM>), wherein:
the plurality of first clamp members (<NUM>) include three or more first rubber plug contact portions (31e1) that are on the space inner thereto and are to be in contact with an outer circumferential surface of the rubber plug (<NUM>),
the first support member (<NUM>) supports the first clamp members (<NUM>) such that the first rubber plug contact portions (31e1) get closer to, or farther from, the central line (CL),
characterized in that:
the first support member (<NUM>) includes a plurality of first pivoting shafts (32a) each extending parallel to the central line (CL) and respectively supporting the plurality of first clamp members (<NUM>) such that said first clamp members (<NUM>) are pivotable, and
the first actuator (<NUM>) drives the first clamp members (<NUM>) such that the first clamp members (<NUM>) pivot around the first pivoting shafts (32a) such that the first rubber plug contact portions (31e1) get closer to, or farther from, the central line (CL).