JP2014030872A - Fastening device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fastening device which is simple in positioning control of a nut runner.SOLUTION: A fastening device includes: a rotating shaft 2; a nut runner 4 which is mounted in a state movable in a radial direction with respect to the rotating shaft 2; a drive part 3 which rotates the nut runner 4 around the rotating shaft 2 by rotationally driving the rotating shaft 2; and a guide part 5 which can abut against the nut runner 4 in the radial direction. The nut runner 4 is arranged coaxially with fastening points (bolt holes A-A) by abutting the nut runner 4 against the guide part 5 and arranging the rotating shaft 2 at a predetermined rotation angle by the drive part 3.

Description

  The present invention relates to a fastening device for fastening a fastening member at a predetermined fastening location.

  For example, in the assembly process of an automobile engine, various parts are assembled to the engine body using a plurality of bolts. In such a process, a tightening device that automatically tightens bolts at a plurality of fastening locations may be used.

  For example, Patent Literature 1 below discloses a fastening device in which a nut runner is provided so as to be movable along X, Y, and Z axes. This clamping device detects the form of the conveyed workpiece with a sensor, and controls the control unit that receives the detection signal to place the nut runner at a necessary position (work fastening position).

JP-A-6-143058

  However, the tightening device that positions the nut runner by the three-axis control as described above has an advantage that the nut runner can be arranged at any fastening location, but has a problem that the control of the nut runner becomes complicated. In particular, when assembling components (for example, oil seal retainers) in which the fastening points are arranged in a substantially arc shape, it is possible to assemble using the above-described three-axis control tightening device, but it is necessary. Since the control is complicated as described above, a tightening device with simpler control is required.

  The problem to be solved by the present invention is to provide a tightening device in which the positioning control of the nut runner is simple.

  The tightening device according to the present invention made to solve the above-described problem is a tightening device for tightening a fastening member to a plurality of fastening locations, and is movable in the radial direction with respect to the rotating shaft and the rotating shaft. A nut runner mounted in a stable state, a drive unit that rotates the rotary shaft to rotate the nut runner around the rotary shaft, and a guide portion that can contact the nut runner in the radial direction of the rotary shaft. The nut runner is arranged coaxially with each fastening portion by being brought into contact with the portion and by arranging the rotation shaft at a predetermined rotation angle by the drive portion.

  Thus, in the fastening device according to the present invention, the nut runner is positioned in the radial direction of the rotation shaft (hereinafter simply referred to as “radial direction”), and the rotation shaft is arranged at a predetermined rotation angle by the drive unit. By positioning the nut runner in the circumferential direction of the rotating shaft (hereinafter simply referred to as “circumferential direction”), the nut runner is arranged coaxially with each fastening portion. At this time, the positioning of the nut runner in the radial direction is performed by bringing the nut runner into contact with the guide portion in the radial direction, thereby eliminating the need for radial positioning control. As a result, when the workpiece is assembled, the nut runner can be arranged coaxially with each fastening point only by controlling the circumferential position of the nut runner with respect to the rotating shaft, that is, the rotational angle of the rotating shaft. The nut runner positioning control can be simplified as compared with the case of the axis control.

  In the tightening device as described above, when the rotation shaft is arranged at a predetermined rotation angle (the same angle as the fastening portion) while the nut runner is in contact with the guide portion, the nut runner is arranged coaxially with the fastening portion. It is necessary to design the shape of the guide part. However, even if the guide portion is designed to satisfy such a condition, the position of the nut runner and each fastening portion may be shifted due to various factors when an actual fastening device is installed. For example, when the nut runner is horizontally arranged, the nut runner is inclined by gravity, and the position of the nut runner and each fastening portion may be slightly shifted. Or if the place of a fastening part is changed even a little by a vehicle type change, it cannot respond with the guide part of the same shape. In these cases, it is necessary to change the shape of the guide part. However, if the guide part is formed as a single part, the shape cannot be changed at all. Invite. Therefore, if the guide part is composed of a plurality of guide members fixed to the guide base and the fixing position of each guide member with respect to the guide base can be adjusted, the nut runner and the fastening part can be connected with the weight of the nut runner or the vehicle type change. Even if there is a slight misalignment between the two, it can be dealt with by adjusting the position of each guide member, so that it is not necessary to manufacture a new guide part.

  In addition, when the number of fastening locations is 3 or less, the guide portion can be formed in an arc shape, but when the number of fastening locations is 4 or more, unless each fastening location is arranged on a complete arc, A nut runner cannot be positioned at all fastening points with a single arcuate guide. For this reason, when there are four or more fastening points on a trajectory slightly deviated from the arc, when the guide part is configured with one part, the guide part needs to have a complicated shape (for example, an elliptical arc shape or a polygonal shape). is there. On the other hand, if the guide portion is constituted by a plurality of guide members as described above, each guide portion can be formed into a simple arc shape.

  As described above, according to the tightening device of the present invention, since the nut runner can be positioned at the fastening position without requiring complicated control such as three-axis control, positioning control of the nut runner can be simplified.

It is the clamping device which concerns on one Embodiment of this invention, and is the side view seen from the I direction of FIG. It is a front view of the above-mentioned clamping device seen from the II direction of FIG. It is a front view for demonstrating the fastening procedure by the said fastening apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A tightening device 1 according to an embodiment of the present invention is for tightening fastening members (bolts or nuts) at a plurality of fastening locations arranged in a substantially arc shape, for example, an oil seal retainer for an engine body. Used in the assembly process. As shown in FIGS. 1 and 2, the fastening device 1 includes a rotating shaft 2, a drive unit 3, a nut runner 4, a guide unit 5, a guide base 6a, and a base plate 6b. The drive unit 3 and the guide base 6a are fixed to a base plate 6b, and the rotary shaft 2 and the nut runner 4 can be rotated with respect to them. The base plate 6b is slidable in the axial direction of the rotary shaft 2 by a slide portion (not shown). In the following description, the axial direction of the rotating shaft 2 is referred to as “axial direction”, and the radial direction of the rotating shaft 2 is referred to as “radial direction”.

  The rotating shaft 2 is attached to the base plate 6b via the bearing 2a and the support portion 2b, and is supported rotatably with respect to the base plate 6b. The drive unit 3 is composed of, for example, a servo motor, and rotationally drives the rotary shaft 2 so that the angle can be controlled based on a command from a control unit (not shown).

  The nut runner 4 includes a main body portion 4a, a socket 4b provided at the tip (right end in FIG. 1) of the main body portion 4a, and a guide receiving portion 4c provided on the outer periphery of the main body portion 4a. The main body 4a is provided with a drive motor (not shown) that rotationally drives the socket 4b. The drive motor rotationally drives the socket 4b with a predetermined torque based on a command from the control unit. The guide receiving portion 4c is, for example, a bearing having an inner ring fixed to the outer periphery of the main body portion 4a, an outer ring rotatable with respect to the inner ring, and rolling elements (for example, balls) disposed between the inner ring and the outer ring. Consists of. In addition, the guide receiving portion 4c may be formed of a ring-shaped component made of resin or metal, and the outer peripheral surface thereof may be in sliding contact with the guide portion 5.

  The nut runner 4 and the rotating shaft 2 are disposed so that the axes are parallel to each other. Further, in the illustrated example, the nut runner 4 and the rotating shaft 2 are disposed so that the axis is horizontal. The rotating shaft 2 and the main body 4 a of the nut runner 4 are connected via a parallel link 7. Thereby, the nut runner 4 can be rotated together with the rotating shaft 2 while maintaining a state parallel to the rotating shaft 2, and can be moved in the radial direction with respect to the rotating shaft 2. The nut runner 4 is urged in the radial direction by the urging means. In the illustrated example, an urging means is constituted by a spring 8 disposed in a compressed state between the rotary shaft 2 and the main body 4 a of the nut runner 4, and the nut runner 4 is urged in the outer diameter direction by the spring 8.

The guide part 5 is provided so as to surround the outer periphery of the rotating shaft 2. Specifically, as shown in FIG. 3, the guide portion 5 is provided so as to surround the outer periphery of a plurality of fastening locations (bolt holes A _{1 to} A ₅ ) arranged side by side in a substantially arc shape. The guide receiving portion 4c is arranged at a position where it can abut from the inner diameter side. In the example of illustration, the guide part 5 is made into the substantially circular arc shape which opened the downward direction. The guide portion 5 is composed of a plurality of guide members 5a. In the present embodiment, the guide portion 5 is composed of two guide members 5a and 5b. Each of the guide members 5a and 5b has an arc shape. The shape of the inner peripheral surface of the guide portion 5, particularly the shape of the portion that contacts the guide receiving portion 4 c, is arranged at the circumferential position of each fastening portion while the guide receiving portion 4 c is in contact with the inner peripheral surface of the guide portion 5. (See the chain line in FIG. 3), the nut runner 4 is designed so that the radial position of the nut runner 4 matches the radial position of each fastening point.

  The guide members 5a and 5b are fixed to the guide base 6a (see FIG. 2). In the present embodiment, through holes 5c and 6a1 are formed in both circumferential ends of the guide members 5a and 5b and the guide base 6a, and the guide members 5a and 5b are connected to the guide base 6a with bolts 9 through these through holes. It is fixed (see FIG. 3). Each guide member 5a, 5b can be fixed at a fixed position with respect to the guide base 6a. In the present embodiment, the through holes 5c and 6a1 formed in the guide members 5a and 5b and the guide base 6a are long holes. By loosening the bolts 9, the fixing positions of the guide members 5a with respect to the guide base 6a are set. Adjustable.

  The slide portion slides the nut runner 4 in the axial direction. In the present embodiment, the configuration shown in FIG. 1, that is, the rotary shaft 2, the drive portion 3, the nut runner 4, the guide portion 5, the guide base 6a, and the base plate 6b and the like can be slid in the axial direction integrally by the slide portion based on a command from the control portion.

Hereinafter, the procedure for bolting the workpiece W (oil seal retainer) to the engine body (not shown) with the fastening device 1 having the above-described configuration will be described with reference to FIG. The workpiece W is provided with bolt holes A _{1 to} A ₅ in which fastening members (bolts, not shown in the present embodiment) to be fixed are arranged in a substantially arc shape. In the state shown in FIG. 3, the workpiece W is disposed at a predetermined position of the engine body, and the bolts are temporarily tightened in the respective bolt holes A _{1 to} A ₅ . In FIG. 3, the workpiece W and the guide portion 5 are indicated by solid lines, the guide receiving portion 4 c of the nut runner 4 is indicated by a chain line, and other members are not shown. The center of the rotating shaft 2 is indicated by O.

First, while the guide receiving portion 4c of the nut runner 4 is urged by the spring 8 in the outer diameter direction and is brought into contact with the inner peripheral surface of the guide portion 5, the driving portion 3 rotates the rotating shaft 2 to obtain a predetermined rotation angle θ. Stop at ₁ . Thereby, the nut runner 4 is positioned in the radial direction and the circumferential direction, and is arranged coaxially with the bolt hole A ₁ of the workpiece W. In this state, the entire device including the nut runner 4 by the slide portion is slid axially forward, thereby fitting the socket 4b of the nut runner 4 to the bolt holes A ₁ to temporarily tightened by bolts, by rotating the socket 4b bolt Tighten. At this time, the nut runner 4 can be slid while reliably maintaining the state of positioning with respect to the bolt hole A ₁ by sliding the nut runner 4 together with the nut runner 4 in contact with the guide portion 5.

After tightening of the bolt bolt holes A ₁ is completed to retract the entire apparatus including a nut runner 4 by the sliding part. Then, while maintaining the state of being contact with the guide receiving portion 4c of the nut runner 4 by the guide portion 5, the rotary shaft 2 is rotated by the driving unit 3, the circumferential direction of the circumferential positions of the bolt holes A ₂ nutrunner 4 Stop at a rotation angle θ ₂ that matches the position. Thus, the nut runner 4 is disposed in the bolt hole A ₂ and coaxially with the workpiece W. In this state, the entire device including the nut runner 4 by the slide portion is slid forward, tighten the bolt of the bolt hole A _2. Thereafter, the assembly of the workpiece W is completed by tightening the bolts of the bolt holes A _{3 to} A _{5 in} the same manner.

  As described above, by positioning the nut runner 4 in the radial direction by contacting the guide portion 5, only the circumferential position of the nut runner 4, that is, the rotation angle of the rotary shaft 2 can be controlled when the workpiece W is assembled. Therefore, for example, the positioning control of the nut runner 4 can be greatly simplified as compared with the case of the three-axis control.

  Moreover, when it is necessary to change the shape of the guide part 5 due to circumstances such as a positional shift of the socket 4b due to the horizontal arrangement of the nut runner 4 and a position change of the bolt hole of the work W accompanying a vehicle type change, This can be dealt with by loosening the bolts 9 fixing the guide members 5a and the guide base 6a and adjusting the fixing positions of the guide members 5a with respect to the guide base 6a. Thereby, since it is not necessary to manufacture a new guide part, cost reduction is achieved.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the case where the guide portion 5 is configured by the two guide members 5a is shown. However, the guide portion 5 is not limited to this, and the guide portion 5 is configured by three or more guide members connected in the circumferential direction. Also good. In addition, when it is not necessary to adjust the fixed position of the guide part 5 with respect to the guide base 6a, the guide part 5 may be constituted by one component.

  Moreover, in said embodiment, although the case where the inner peripheral surface of guide member 5a, 5b was made into circular arc shape was shown, not only this but elliptical arc shape and polygonal shape are good. Moreover, you may vary the curvature radius of each guide member 5a, 5b.

  Moreover, although the case where the rotating shaft 2 and the nut runner 4 were horizontally arranged was shown in said embodiment, you may arrange | position not only to this but the direction inclined with respect to the horizontal direction, for example, a perpendicular direction.

  Moreover, although the case where the workpiece | work W was an oil seal retainer was shown in said embodiment, not only this but the some fastening location (bolt hole) will be arrange | positioned along with the substantially circular arc shape. The fastening device according to the present invention can be applied.

1 clamping device 2 the rotary shaft 3 driving unit 4 nut runner 4a body portion 4b socket 4c guide receiving portion 5 the guide portion 5a guide member 6a guide base 6b base plate 7 parallel link 8 Spring A ₁ to A ₅ bolt hole (engagement portion)
W Work

Claims (3)

A fastening device for fastening fastening members to a plurality of fastening locations,
A rotating shaft, a nut runner attached in a state of being movable in a radial direction with respect to the rotating shaft, a drive unit for rotating the nut runner around the rotating shaft by rotationally driving the rotating shaft, and the rotating shaft A guide portion capable of contacting the nut runner in the radial direction of
A tightening device that places the nut runner coaxially with each fastening portion by bringing the nut runner into contact with the guide portion and arranging the rotation shaft at a predetermined rotation angle by the drive portion.   The fastening device according to claim 1, wherein the guide portion includes a plurality of guide members fixed to a guide base, and the fixing position of each guide member with respect to the guide base can be adjusted.   The fastening device according to claim 2, wherein each of the plurality of guide portions has an arc shape.

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