JP4702350B2 - Bolt tightening device - Google Patents

Description

  The present invention relates to a bolt fastening device.

Conventionally, as this type of bolt tightening device, there are a guide for passing the supplied bolt, a holding portion for holding the bolt at a position facing the bolt hole, and a socket for tightening the bolt after releasing the held bolt. Have been proposed (for example, see Patent Document 1). In this device, the holding part that holds the bolt is expanded on both sides, so that the held bolt is released and inserted into the bolt hole.
JP-A-62-58874

  However, in the above-described bolt fastening device, when there is not enough space in a part around the bolt hole, the holding portion cannot be expanded on both sides. For this reason, the bolt cannot be inserted into the bolt hole when the object for tightening the bolt has a complicated shape. At this time, it is conceivable to keep the holding part away from the object to a position where it can expand on both sides, attach an extension guide and pass the bolt, or attach a magnet to the socket tip and use the magnetic attraction force. The posture of the bolt changes inside, and a non-magnetic bolt or a relatively heavy bolt falls without being attracted. For this reason, since the bolt is not inserted into the bolt hole with high accuracy, a tightening failure may occur.

  The main purpose of the bolt tightening device of the present invention is to enable a bolt to be inserted into a bolt hole with high accuracy even when there is not enough space around the bolt hole.

  The bolt tightening device of the present invention employs the following means in order to achieve the main object described above.

The bolt tightening device of the present invention comprises:
A guide for passing the supplied bolt through the inner space surrounded by the inner wall surface, a holding portion formed on the inner wall surface of the guide for holding the bolt at a position facing the bolt hole, and pushing out the held bolt A bolt fastening device comprising a socket for fastening to the bolt hole,
The guide has a movable part that can be partially expanded when the socket pushes out the bolt,
The holding portion is formed on the inner wall surface of the movable portion of the inner wall surface of the guide, and protrudes inward from the inner wall surface to partially support the lower surface of the head of the bolt and the head. The bolt is held by being cantilevered by a screw portion supporting portion that receives from the side a force acting on the center of gravity of the bolt supported by the portion supporting portion.

  In the bolt tightening device of the present invention, the guide has a movable part that can be partially expanded when the socket pushes the bolt held by the holding part, and the holding part is movable among the inner wall surfaces of the guide. Formed on the inner wall surface of the head portion, projecting inwardly from the inner wall surface and partially supporting the lower surface of the head of the bolt, and the force acting on the center of gravity of the bolt supported using the head support portion as a fulcrum The bolt is held at a position facing the bolt hole by cantilevering the bolt with the screw portion supporting portion received from the side. For this reason, even if the entire guide does not expand, the bolt can be tightened only by partially expanding. Therefore, even when there is not enough space around a part of the bolt hole, the bolt can be inserted into the bolt hole with high accuracy and tightened.

  In such a bolt tightening device according to the present invention, the holding portion is disposed between the head support portion and the screw portion support portion obliquely downward from the end of the head support portion toward the center of the internal space. It is good also as what has the formed inclined surface. In this case, the pressing force applied to the bolt when the socket pushes out the bolt is received as a force in the direction of expanding the guide through the inclined surface, so that the movable part can be expanded relatively easily.

  Further, in the bolt tightening device of the present invention, the bolt is formed on a part of the inner wall surface of the guide on the upstream side of the holding portion, so that the supplied bolt is held by the holding portion. A posture adjusting unit that adjusts the posture may be provided. If it carries out like this, a volt | bolt can be hold | maintained to a holding | maintenance part with sufficient precision. In this case, the posture adjusting unit is formed on a part of the inner wall surface facing the inner wall surface provided with the holding unit among the inner wall surface on the upstream side of the holding unit, and the head of a bolt passing through the guide. It is good also as what is a level | step-difference part which protrudes inside so that the lower surface of a part may contact | abut partially. In this way, the tip of the bolt is directed to the side opposite to the side where the holding portion is provided until it passes through the guide and reaches the holding portion. Troubles that cannot be maintained can be prevented.

  Alternatively, in the bolt tightening device of the present invention, the guide is formed by combining two substantially semi-cylindrical members so as to form a substantially cylindrical internal space, and one of the two members is It is the said movable part which can be expanded, and the said holding | maintenance part is good also as what is formed in the inner wall face of this one member. In this way, the head support portion can support approximately half the circumference of the head of the bolt, so that the bolt can be stably held. Further, the holding part can be formed relatively easily.

  Further, in the bolt tightening device of the present invention, the bolt is used for tightening a bolt having a head portion including a crown portion into which the socket can be fitted and a flange portion having an outer diameter larger than the crown portion. It is good. In this way, even if the protrusion margin from the inner wall surface of the guide of the head support portion is reduced, the bolt can be pushed out relatively easily because the socket abuts against the collar portion of the bolt and the socket fits into the top of the head.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a block diagram showing an outline of the configuration of a nut runner 10 as an embodiment of the present invention, and FIG. The nut runner 10 according to the embodiment is used when, for example, a case and a housing of an automatic transmission are automatically tightened with a hexagonal bolt with a collar, and can be moved up and down to a bolt tightening position by a lifting mechanism (not shown). . As shown in FIG. 1, the nut runner 10 is mounted on a guide 20 that guides and holds a bolt B supplied from a bolt supply device (not shown) to a position opposed to a predetermined bolt hole, and is attached to an upper portion of the guide 20. A bolt setter 60 connected to the supply device, and a socket 70 that is inserted into the guide 20 via the bolt setter 60 and is fitted to the bolt B held by the guide 20 and fastened to the bolt hole.

  As shown in FIG. 1, the guide 20 includes a case 22 having an inner cylindrical shape, a left semi-cylindrical left guide 30, and a right semi-cylindrical right guide 40. The distal end side of the right guide 40 can be expanded from the support portion 42 with the support portion 42 as a fulcrum. The guide 20 forms a substantially cylindrical bolt passage 20 a by the internal space of the case 22, the left guide 30 and the right guide 40. The left guide 30 includes a spring receiver 30a formed on the base end side with respect to the support portion 32, a spring 34 that is disposed on the spring receiver 30a and biases the distal end of the left guide 30 to the closed side (right direction in the figure), And a holding portion 50 that is formed at the tip and holds the bolt B. On the other hand, the right guide 40 includes a spring receiver 40a formed on the base end side from the support portion 42, and a spring 44 that is disposed on the spring receiver 40a and biases the distal end of the right guide 40 toward the closed side (left direction in the figure). And a stepped portion 54 formed near the approximate center in the longitudinal direction. Further, when the left guide 30 receives a force greater than the urging force of the spring 34 outwardly, the left guide 30 expands leftward in the figure with the support portion 32 as a fulcrum, and the right guide 40 outwards the spring 44. When a force greater than the urging force is received, the support portion 42 is expanded in the right direction in the drawing with the support portion 42 as a fulcrum.

  As shown in FIGS. 1 and 2, the holding portion 50 includes a head support portion 50 a that protrudes inward from the left guide 30 and is formed in a half ring shape, and extends from the end of the head support portion 50 a to the center of the bolt passage 20 a. The inclined surface 50b is formed in a tapered shape obliquely downward, and a screw portion support portion 50c formed in a semi-cylindrical shape from the lower end of the inclined surface 50b to the tip of the left guide 30 is formed. FIG. 3 shows how the holding unit 50 holds the bolt B. As shown in FIG. 3, the head support portion 50a partially supports the peripheral edge of the lower surface of the collar portion of the bolt B, and the screw portion support portion 50c supports the screw portion of the bolt B from the side. Thereby, when the head support 50a is used as a fulcrum, the screw B support 50c receives a force (shown by an arrow) that causes the center of gravity (shown by a black circle) of the bolt B to move directly below the fulcrum. Can be supported in a cantilevered state in such a manner that it is caught by the head support 50a.

  As shown in FIG. 1, the stepped portion 54 abuts against the lower surface of the collar portion of the bolt B passing through the bolt passage 20 a, so that the direction of the tip of the bolt B is opposite to the holding portion 50. Is to adjust. For this reason, even if the bolt B passes through the bolt passage 20a in the posture like the bolt B (1), the bolt B is adjusted to the posture like the bolt B (2). It is possible to prevent troubles that are caught on the part support part 50a and the inclined surface 50b and cannot be normally held. Note that the position where the stepped portion 54 is formed is not limited to the vicinity of the approximate center in the longitudinal direction of the right guide 40, and is a bolt that is upstream of the tip of the bolt B reaching the holding portion 50 and that has undergone posture adjustment. What is necessary is just to obtain | require and set distance from which the front-end | tip of B does not face the holding | maintenance part 50 again by experiment.

  The bolt setter 60 is supplied from the bolt supply port 60b connected to a bolt supply device (not shown) and a substantially cylindrical socket passage 60a that penetrates up and down and communicates with the bolt passage 20a of the guide 20 and through which the socket 70 passes. And a bolt supply path 60c for feeding to a joining portion (shown by a white circle) that joins with the socket passage 60a. By connecting the socket passage 60a and the bolt passage 20a of the bolt setter 60, the supplied bolt B reaches the holding portion 50 of the guide 20 from the bolt supply port 60b, and the socket 70 moves from above to below.

  The socket 70 has a fitting hole 70a that can be fitted to the top of the bolt B at the tip, and is connected to a rotary drive mechanism (not shown) and an elevator mechanism (not shown). For this reason, the socket 70 can rotate in the direction in which the bolt B is tightened, or can move up and down while rotating or without rotating. When the socket 70 is lowered while rotating toward the bolt B held by the holding portion 50, the fitting hole 70a is fitted to the top of the bolt B. Further, when the socket 70 is further lowered in the fitted state, the bolt B can be pushed out from the holding portion 50 and tightened into the bolt hole. Details of this tightening operation will be described later.

  In the nut runner 10 of the embodiment thus configured, the bolt B supplied from the bolt supply device passes through the bolt supply passage 60c, the socket passage 60a, and the bolt passage 20a, and after the posture is adjusted by the step portion 54, It is held by the holding part 50 so as to be arranged on the same axis. Further, when the nut runner 10 is lowered to a position facing the bolt hole by a lifting mechanism (not shown), a part of the tip of the threaded portion of the bolt B is inserted into the bolt hole, and the socket 70 is lowered while rotating so that the fitting hole 70a is formed. The bolt B is fitted to the top of the head. Thereby, the preparation for fastening the bolt B to the bolt hole is completed.

  Next, the bolt tightening operation of the nut runner 10 according to the embodiment thus configured will be described. 4-6 is explanatory drawing which shows a mode that the nut runner 10 of an Example clamp | tightens the workpiece | work W1 and the workpiece | work W2 with the volt | bolt B. FIG. FIG. 4 is an explanatory diagram showing a state where preparation for bolt tightening is completed. As shown in the figure, in this embodiment, a work W1 in which a female screw hole a1 is formed, a through hole a2 formed at a position corresponding to the female screw hole a1, and a wall surface H rising from the upper surface of the work W2 are formed. The workpiece W2 is tightened with a bolt B. Here, the female screw hole a1 and the through hole a2 are collectively referred to as a bolt hole A. Since there is only a slight gap between the wall surface H of the workpiece W2 and the guide 20, the guide 20 cannot be expanded in the right direction in the figure. FIG. 5 is an explanatory view showing a state in which the socket 70 starts to push out the bolt B from the holding portion 50. As described above, since the bolt B is cantilevered so as to be hooked on the head support 50a of the holding part 50, as shown in the drawing, the support of the head support 50a is supported by the pressing force of the socket 70. Is removed and the bolt B moves downward. At this time, since the bolt B moves along the inclined surface 50b, the pressing force applied to the bolt B from the socket 70 acts as a force for pushing the left guide 30 outward through the inclined surface 50b (illustrated by a white arrow). When this force exceeds the urging force of the spring 34, the left guide 30 expands (illustrated by a black arrow), and tightening of the bolt B into the bolt hole A is started. FIG. 6 is an explanatory diagram showing a state in which the tightening of the bolt B to the bolt hole A has progressed. As the tightening of the bolt B proceeds and the bolt B gradually descends, the left guide 30 gradually expands in the left direction in the figure. After the flange portion of the bolt B reaches the end of the inclined surface 50b, the side surface of the socket 70 comes into contact with the apex of the holding portion 50 (see FIG. 2), and the left guide 30 is opened with a certain opening amount as shown in the figure. Maintain the expanded state. When the tightening of the bolt B is completed, the socket 70 rises. When the side surface of the socket 70 does not contact the holding portion 50, the left guide 30 is returned to the original position by the urging force of the spring 34. On the other hand, since the right guide 40 is not applied with a force greater than the urging force of the spring 44 until the bolt B is pushed out and tightening is completed, the right guide 40 expands and contacts the wall surface H. There is no. In this way, when the bolt B is pushed out of the holding portion 50 and tightened into the bolt hole A, only the left guide 30 of the guide 20 expands, so that there is only a slight gap between the guide 20 and the wall surface H of the workpiece W2. Even if not, the bolt B can be inserted into the bolt hole A with high accuracy and tightened.

  Here, a case where a conventional guide expands on both sides will be described as a comparative example. FIG. 7 is an explanatory view showing a state in which the bolt B held by the holding portion 500 of the guide 200 of the comparative example is pushed out by the socket 70. In this guide 200, the holding portion 500 holds the bolt B by supporting the peripheral edge of the lower surface of the collar portion of the bolt B with the tapered inclined surfaces 500b and 510b over the entire circumference. As shown in the figure, when the socket 70 pushes out the bolt B, the left guide 300 is expanded in the left direction in the drawing by the pressing force of the socket 70 transmitted through the inclined surface 500b, and through the inclined surface 510b. The right guide 400 is expanded in the right direction in the figure by the transmitted pressing force of the socket 70. As described above, in the guide 200, the entire guide expands to the left and right sides (illustrated by black arrows). For this reason, when the wall surface H is formed on the workpiece W2 as described above, the guide 200 cannot be expanded and the bolt B cannot be inserted into the bolt hole A. At this time, the guide 200 can be expanded to the left and right sides while avoiding the wall H, that is, away from the workpiece W2 to a position exceeding the height of the wall H, the extension guide is attached, the bolt B is passed, and the socket 70 is fitted. It is also conceivable to use a magnetic attraction force by attaching a magnet to the joint hole 70a. However, since the posture of the bolt B changes in the extension guide, or the non-magnetic bolt B or the relatively heavy bolt B cannot be attracted and falls, the bolt B cannot be inserted into the bolt hole A with high accuracy. It may cause tightening failure.

  According to the nut runner 10 of the embodiment described above, since the holding portion 50 cantilever-supports the bolt B and only the left guide 30 on which the holding portion 50 is formed is expanded when the socket 70 pushes out the bolt B, Even if the guide 20 does not expand as a whole, the bolt B can be pushed out only by expanding the left guide 30. Thereby, even if there is an obstacle around the bolt hole A, the bolt B can be held in a state closer to the bolt hole A than the conventional one, and the bolt B is pushed out and tightened to the bolt hole A. Can do. As a result, even when there is not enough space around a part of the bolt hole A, the bolt B can be accurately inserted into the bolt hole A and tightened.

  Further, according to the nut runner 10 of the embodiment, the holding portion 50 receives the pressing force of the socket 70 as a force in the direction of expanding the guide 20 via the inclined surface 50b, so that the left guide 30 is expanded relatively easily. Can be opened.

  Furthermore, according to the nutrunner 10 of the embodiment, the step B is adjusted so that the tip of the bolt B faces the side opposite to the holding portion 50, so that the tip of the bolt B is caught by the holding portion 50 and cannot be normally held. Can be prevented.

  Furthermore, according to the nut runner 10 of the embodiment, the guide 20 is a combination of the left guide 30 and the right guide 40, and the holding portion 50 is formed on the left guide 30, so the head support portion 50a is a bolt. It becomes possible to support the substantially half circumference of the collar part of B, and can hold | maintain the volt | bolt B stably. Further, the holding part 50 can be formed relatively easily.

  Moreover, since the nut runner 10 of the embodiment is used for tightening the bolt B having the head composed of the top of the head and the collar, the collar B of the bolt B can be formed even if the protrusion margin of the head support 50a is reduced. Since the socket 70 is fitted to the top of the head, the bolt B can be pushed out relatively easily.

  In the nutrunner 10 according to the embodiment, the guide 20 has a two-part structure in which the left guide 30 and the right guide 40 are combined. However, the guide 20 may be divided into three parts, four parts, or more. At this time, it may be determined as appropriate in which of the divided guides the holding portion is formed. For example, a three-divided configuration may be adopted, and one of them may be formed with a holding portion, or may be formed with two. Further, a four-divided configuration may be adopted, and the two may be formed opposite to each other, or may be formed on two adjacent ones.

  Although the nut runner 10 according to the embodiment is configured to tighten the bolt B having the collar portion, the nut runner 10 may be configured to tighten the bolt B1 having no collar portion. FIG. 8 shows how the holding portion 520 holds the bolt B1. As shown, the head support portion 520a supports the lower surface of the head of the bolt B1, and the screw portion support portion 520c supports the screw portion of the bolt B1. At this time, each dimension is set so that there is a clearance between the head of the bolt B1 and the left guide 320 and the right guide 420 so that the fitting hole 700a of the socket 700 can be fitted to the head of the bolt B1. There is a need to. Moreover, it is good also as what forms the raised part 58 lower than the height of the head of a bolt in the upper part of the head support part 520a. As a result, when the socket 700 is fitted to the head of the bolt B1, the side surface of the socket 700 abuts against the raised portion 38 while fitting and the left guide 30 is slightly expanded, so that the socket 700 is fitted to the bolt B1. This makes it easy to push out the bolt B1.

  In the nut runner 10 of the embodiment, the holding portion 50 is formed such that the screw portion supporting portion 50c comes into surface contact with the screw portion of the bolt B. However, the holding portion 530 shown in FIG. 9 may be formed. As shown in the drawing, the inclined surface 530b may be formed large, and the bolt B may be abutted and supported as a screw portion support portion 530c whose line tip is in line contact with the screw portion of the bolt B.

  In the nut runner 10 of the embodiment, the right guide 40 in which the holding portion 50 is not formed is also formed so as to be able to expand, but may be fixed to the case 22 so that it cannot be expanded.

  In the nut runner 10 of the embodiment, the inner diameter of the bolt passage 20a is reduced with the stepped portion 54 as a boundary. However, only a part where the stepped portion 54 is formed is raised and the inner diameter is reduced, and the downstream side is It may be substantially the same as the inner diameter on the upstream side.

  In the nut runner 10 of the embodiment, the step portion 54 that adjusts the posture of the bolt B is provided, but it may not be provided. Even in this case, if the angle of the inclined surface 50b of the holding part 50 is optimized, the trouble that the bolt B is caught on the holding part 50 can be reduced.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention is applicable to the automobile industry and the like.

It is a block diagram which shows the outline of a structure of the nut runner 10 of this invention. It is sectional drawing which shows the AA cross section of the guide 20 of FIG. It is explanatory drawing which shows a mode that the holding | maintenance part 50 hold | maintains the volt | bolt B. FIG. It is explanatory drawing which shows a mode that the bolt clamp | tightening preparation of the nut runner 10 was prepared. It is explanatory drawing which shows a mode that the socket 70 began pushing out the volt | bolt B from the holding | maintenance part 50. FIG. It is explanatory drawing which shows a mode that the fastening to the bolt hole A of the volt | bolt B advanced. It is explanatory drawing which shows a mode that the volt | bolt B hold | maintained with the holding | maintenance part 500 of the guide 200 of a comparative example is extruded with the socket 70. FIG. It is explanatory drawing which shows a mode that the holding | maintenance part 520 of a modification hold | maintains the volt | bolt B1. It is explanatory drawing which shows a mode that the holding | maintenance part 530 of a modification hold | maintains the volt | bolt B. FIG.

Explanation of symbols

  10 Nutrunner, 20, 200 guide, 20a Bolt passage, 22 Case, 30, 300, 320, 330 Left guide, 30a Spring receiver, 32 Support portion, 34 Spring, 40, 400, 420 Right guide, 40a Spring receiver, 42 Support Part, 44 spring, 50, 500, 520, 530 holding part, 50a, 520a, 530a head support part, 50b, 500b, 510b, 520b, 530b inclined surface, 50c, 520c, 530c screw part support part, 54 step part , 58 ridge, 60 bolt setter, 60a socket passage, 60b bolt supply port, 60c bolt supply passage, 70,700 socket, 70a, 700a fitting hole, A bolt hole, a1 female screw hole, a2 through hole, B, B1 bolt, H wall, W1, W2 Over click.

Claims (4)

A guide for passing the supplied bolt through the inner space surrounded by the inner wall surface, a holding portion formed on the inner wall surface of the guide for holding the bolt at a position facing the bolt hole, and pushing out the held bolt A bolt fastening device comprising a socket for fastening to the bolt hole,
The guide has a movable part that can be partially expanded when the socket pushes out the bolt,
The holding portion is formed on the inner wall surface of the movable portion of the inner wall surface of the guide, and protrudes inward from the inner wall surface to partially support the lower surface of the head of the bolt and the head. the force acting on the center of gravity of the supported said bolt part supporting portion as a fulcrum by a threaded portion supporting unit for receiving from the side held by cantilevered said bolt,
A posture adjusting unit that is formed on a part of the inner wall surface of the guide on the upstream side of the holding unit and adjusts the posture of the bolt so that the supplied bolt is held by the holding unit,
The posture adjusting unit is formed on a part of the inner wall surface facing the inner wall surface provided with the holding unit among the inner wall surface on the upstream side of the holding unit, and the lower surface of the head of the bolt passing through the guide A bolt tightening device which is a stepped portion that protrudes inward so as to partially abut . The holding portion has an inclined surface formed obliquely downward from an end of the head support portion toward the center of the internal space between the head support portion and the screw portion support portion. The bolt fastening device described. The guide is formed by combining two substantially semi-cylindrical members so as to form a substantially cylindrical internal space, and one of the two members is the expandable movable part,
The holding portion is formed by forming on the inner wall surface of the one member said claim 1 or 2 bolt clamping device according. The bolt according to any one of claims 1 to 3, wherein the bolt is used for tightening a bolt having a head portion including a crown portion into which the socket can be fitted and a flange portion having an outer diameter larger than the crown portion. Bolt tightening device.

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