JPH075951Y2 - Nut tightening device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a nut tightening device for tightening a nut on a bolt protruding from a shaft of a shock absorber or the like.

(Prior Art) A nut tightening device for automatically tightening a nut on a bolt protruding from a shaft of an automobile part such as a shock absorber is known. In this nut tightening device, for example, as shown in FIG. 3, a tightening socket 2 is provided on a rotary shaft 1 that rotates in conjunction with a drive mechanism (not shown) such as a motor so as to be movable back and forth in the axial direction. 2 is urged downward by a spring 3. Reference numeral 4 is a work such as a shock absorber, and a bolt 5 is projectingly provided on the work 4. Then, the engaging hole 6 is engaged with the nut 7 that is engaged with the engaging hole 6 of the tightening socket 2 or the nut 7 that is previously screwed into the bolt 5, and the tightening nut 2 is tightened by the rotation of the rotating shaft 1. Thus, the nut 7 is fastened to the bolt 5.

However, when the nut 7 is tightened, the work 4 integrated with the bolt 5 is also rotated, and the nut 7 cannot be tightened. Therefore, conventionally, the air cylinder 8 is provided with a detent member 9, and the detent member 9 is pressed against the side wall of the work 4 to detent the work 4.

(Problems to be solved by the invention) By the way, as described above, it is necessary to provide the rotation preventing device for pressing the side wall of the work 4 separately from the nut tightening device
There is a problem that the device becomes large and a large installation space is required, and it is difficult to prevent the rotation when the work is a round shaft.

The present invention has been made in view of the above circumstances, and the purpose thereof is to provide a nut that can surely prevent rotation of a work without providing a rotation prevention device for a work separately from a tightening device, and can reduce the size of the device. To provide a tightening device.

[Structure of the Invention] (Means and Actions for Solving the Problem) In order to achieve the above object, this invention has a rotation restricting portion at the tip of a bolt projecting from a workpiece, and a nut is attached to the bolt. A nut tightening device for tightening a nut in a state where the rotation of the bolt is restricted by the rotation restricting part when screwing, the device main body and the drive mechanism provided in the main body rotate together with the work and And a revolving shaft that can move forward and backward, and rotatably support the revolving shaft provided at the tip of the revolving shaft and allow the device body to move in the axial direction of the revolving shaft and non-rotatably support it. And a tightening socket which is formed in a tubular shape and is rotatably provided on the head so as to be spaced from the rotary shaft and coaxial with the rotary shaft, and which has a nut engaging hole into which a nut is fitted at a tip end portion thereof. , And interlocking gears that allowed to transfer rotatably provided serial head rotation of the rotary shaft to the clamping socket,
Positioned on the same axis as the rotating shaft, movable forward and backward with respect to the tightening socket and restricted in rotation, the tip of the head is located in the nut engagement hole of the tightening socket and is engaged with the rotation restricting portion of the bolt. It is provided with a rotation stopping member for restricting the rotation of the mating bolt.

Then, when the nut is fastened to the bolt, the tightening socket is rotated and the nut is tightened with respect to the bolt in a state where the anti-rotation member engages with the rotation restricting portion at the tip of the bolt to prevent the bolt from turning.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1 and FIG. 2, 10 is a main body of the apparatus, and the main body 10 is provided with a rotary shaft 11. This rotating shaft 11
Is a shaft portion 13 directly connected to a drive mechanism 12 such as a motor,
It is composed of a cylindrical portion 14 fitted to 13 so as to be movable in the axial direction. The shaft portion 13 is provided with a slit 13a in the axial direction,
A pin 1 radially inserted into the tubular portion 14 is inserted into the slit 13a.
5 penetrates. The tubular portion 14 is non-rotatable with respect to the shaft portion 13 and is movably connected only in the axial direction. Further, a spring 16 is fitted on the rotating shaft 11 to constantly urge the tubular portion 14 downward.

A head 17 is provided at the tip of the cylindrical portion 14 of the rotary shaft 11. The head 17 is divided into an upper chamber 19 and a lower chamber 20 by a partition wall 18, and the cylindrical portion 14 is provided inside the upper chamber 19.
And a drive gear 21 integrated with the. This driving guy 21
Is supported by the head 17 by a thrust bearing 22, and the lower chamber 20 is provided with a driven gear 25 supported by a radial bearing 24 with respect to a guide shaft 23 fixed to the head 17. The drive gear 21 and the driven gear 25 are provided coaxially, and they are interlocked by an interlocking gear 26 pivotally supported by the partition wall 18.

Further, the driven gear 25 is integrally provided with a projecting tube 28 projecting downward from the opening 27 of the head 17, and the projecting tube 28 has a tightening socket fixed by a fixing pin 29.
30 are provided. An engaging hole 31 is provided at a lower end portion of the tightening socket 30 so as to engage with a nut 7 screwed to a bolt 5 protruding from the work 4 such as a shock absorber.

Further, the guide shaft 23 fixed to the head 17 is provided with a guide hole 32 in the axial direction, and a rotation preventing member 33 is provided inside the guide hole 32.
Has been inserted. A slit 34 is provided in the anti-rotation member 33 in the axial direction, and a pin 35 protruding from the guide shaft 23 penetrates the slit 34. Therefore, the detent member 33 cannot rotate with respect to the guide shaft 23 and is movably supported only in the axial direction. A biasing spring 36 is interposed between the upper end surface of the detent member 33 and the upper end surface of the guide hole 32 to bias the detent member 33 downward. An engaging portion 37 formed of a concave groove is provided at the lower end portion of the rotation preventing member 33, and the engaging portion 37 is non-rotatable with the rectangular protrusion 5a as a rotation restricting portion provided at the tip of the bolt 5 so as to project. Is adapted to engage with.

Further, a guide pin 38 is provided on the side wall of the head 17 so as to project laterally. On the other hand, the main body 10 facing the guide pin 38 is provided with a guide hole 39 formed of an elongated hole,
The guide pin 38 is engaged with the guide hole 39. The head 17 is non-rotatably held so as to be movable only in the vertical direction.

Next, the operation of the nut tightening device configured as described above will be described. When the rotating shaft 11 of the tightening device is lowered while the nut 7 is engaged with the engaging hole 31 of the tightening socket 30, the guide pin 38 projecting from the head 17 slides inside the guide hole 39 while the head 17 slides inside the guide hole 39. 17 descends. Then, the nut 7 engaged with the engaging hole 31 of the tightening socket 30.
Contacts the tip of the bolt 5, and the downward biasing force of the spring 16 keeps the nut 7 pressed against the bolt 5. Further, since the detent member 33 provided inside the tightening socket 30 is also pressed downward by the biasing spring 36, the engaging portion 37 of the detent member 33 engages with the protrusion 5a of the bolt 5. That is, the anti-rotation member 30 and the bolt 5 are in a non-rotatably connected state.

When the rotating shaft 11 is rotated by the drive mechanism 12 in this state, this rotational force is transmitted in the order of the drive gear 21, the interlocking gear 26 and the driven gear 25, and the rotational force of the driven gear 25 is transmitted to the tightening socket 30. . Therefore, the nut 7 engaged with the tightening socket 30 is rotated, and the nut 7 is tightened to the bolt 5. At this time, the rotational force of the nut 7 is transmitted to the work 4 via the bolt 5, but since the protrusion 5a of the bolt 5 is engaged with the rotation preventing member 30 fixed to the head 17, the rotation force of the work 4 is reduced. The bolt 5 does not rotate, and the nut 7 can be securely tightened.

In this way, the locking member 33 is provided inside the tightening socket 30.
By disposing the detent member 33 coaxially with the bolt 5, an unreasonable external force is not applied to the bolt 5 when the nut 7 is tightened.

In the above-described embodiment, the bolt is provided with the projection and the rotation preventing member is provided with the concave groove so as to be engaged, but conversely, the bolt may be provided with the concave groove and the rotation preventing member may be provided with the projection.

[Effect of the Invention] As described above, according to the present invention, a special bolt having a rotation restricting portion at the tip portion is adopted, and when the nut is screwed into the bolt, the rotation restricting portion of the bolt is prevented. The nut can be reliably tightened with respect to the bolt by providing the rotation stopping member that engages with the rotation restricting portion and restricts the rotation of the bolt in the engagement hole of the tightening socket. Further, by engaging the bolt itself and restricting the rotation of the bolt, no force in the rotating direction acts between the work and the bolt when tightening the nut to the bolt fixed to the work. , It is possible to tighten the nut with a desired tightening torque even on a work with relatively low rigidity, and even when the bolt is simply screwed into the work and not fixed, tightening the nut with the rotation of the bolt restricted Is possible. In addition, there is no need to provide a separate detent device,
There is an effect that the size of the entire device can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view of a nut tightening device showing an embodiment of the present invention, FIG. 2 is a vertical cross-sectional side view during nut tightening, and FIG. 3 is a side view of a conventional nut tightening device. 10 …… Main body, 11 …… Rotary shaft, 12 …… Drive mechanism, 17 …… Head, 30 …… Tightening socket, 33 …… Rotation prevention member.

Claims (1)

[Scope of utility model registration request] 1. A nut for tightening a nut having a rotation restricting portion at the tip of a bolt projecting from a workpiece and restricting the rotation of the bolt by the rotation restricting portion when the nut is screwed onto the bolt. The tightening device includes a main body of the apparatus, a rotary shaft which is provided in the main body and rotates in association with a drive mechanism and which can advance and retreat with respect to the work, and a rotary shaft which is provided at a tip end portion of the rotary shaft to rotate the rotary shaft. A head that is freely supported and that is supported by the device body such that the rotation shaft is allowed to move in the axial direction and is not rotatable, and that is formed in a tubular shape and is separated from the rotation shaft and coaxial with the rotation shaft. A tightening socket having a nut engaging hole on the head, which is rotatably mounted on the head, and into which the nut is fitted; and a rotation of the rotary shaft, which is rotatably mounted on the head, transmitted to the tightening socket. Interlocking gear, which is coaxial with the rotating shaft, is movable forward and backward with respect to the tightening socket and is rotationally restricted, and the tip of the head is located in the nut engaging hole of the tightening socket. And a rotation stopping member that engages with the rotation restricting portion of the above and restricts the rotation of the bolt, and the nut tightening device.