JPS6284939A - Automatic clamping device - Google Patents

Abstract

PURPOSE:To make it possible to clamp an output shaft at a regular torque by providing a casing whose interior acts as a cylinder hole, a transfer shaft having a piston to which a socket wrench is fixed and a spring between the cylinder hole and piston. CONSTITUTION:An output shaft 43 projected from a speed reducer 37 downward is led into a casing 42, equipped with a torque detector 44, and also connected to a rotary shaft 46 at the lower end. And the rotary shaft 46 is fixed with a boss section 50a, of which the internal peripheral face is formed a key way 49 to be engaged with a key 48, and connected to a spring receiving plate 50 acting as a piston by means of key connection. This spring receiving plate 50 is fitted to the lower half section 42a of the casing of which the interior acts as a cylinder hole and usually forced to be lowered by the spring 51 equipped around the boss section 50a between a thrust bearing 47 and the spring receiving plate 50.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an automatic tightening device, and more particularly to an automatic tightening device that automatically tightens bolts and nuts arranged at equal pitches on the same circumference to a specified torque. .

[Technical background of the invention and its problems]

Generally, steam valves used in steam turbine plants are very large, and the steam valve itself is a pressure vessel, so the bolts and nuts that are attached to the upper part of the steam valve body and used to tighten the bolts are very large. For this reason, the tightening of the bolt cage cannot be easily automated (conventionally, it has been done manually, and steam leakage may occur between the steam valve body and the top cover due to uneven tightening torque). . Further, when tightening the bolts after heating them with a bolt heater, the bolts and the like become hot, so manual tightening operations are often dangerous.

Therefore, as a means to eliminate the above-mentioned drawbacks, an automatic tightening device that automatically tightens large bolts and the like has been developed. FIG. 5 shows a conventional automatic tightening device, where 1 is a main column, 2 is an arm, 3 is a slide arm, 4 is a torque generator, 5 is a coupling, and 6 is a socket wrench. The automatic tightening device is installed so that the central axis of the main column 1 is located at the center of the virtual circle of the upper cover of the steam valve body in which bolts and the like are arranged at equal pitches on the same circumference, and the main column 1 is rotated. At the same time, the arm 2 is moved up and down to prevent the slide arm 3 from expanding and contracting, so that the socket wrench 6 attached to the tip of the slide arm 3 is fitted with a predetermined bolt, etc., and the socket wrench 6 is rotated by the torque generator 4 for tightening work. Do this. When tightening to a specified torque is completed, the arm is moved up and down and the main column 1 is rotated to perform the next bolt tightening operation.

The automatic tightening device performs the tightening work of bolts arranged at equal pitches on the same circumference as described above, but after the tightening work, the socket wrench 6 is moved from one bolt to the next one each time. It is necessary to move the arm 2 up and down, which causes problems in that it takes a long time to work, has poor operability, and is not efficient.

(Objective of the Invention) Therefore, the object of the present invention is to solve the problems of the above-mentioned prior art, and to improve the workability of automatically tightening bolts and nuts arranged at equal pitches on the same circumference with a specified torque. This provides an excellent automatic tightening device.

[Summary of the invention]

In order to achieve the above object, the present invention fixes a torque generating device to the tip of an arm that is fitted onto a rotatable main column, rotates together with the main column, and is extendable and retractable in the horizontal direction, and is connected to the torque generating device. In an automatic tightening device that performs bolt and nut tightening work by rotating a socket wrench, the torque generating device is composed of a drive motor and a torque transmitting device, and this torque transmitting device has a casing with a cylinder hole inside, and an upper end. a transmission shaft having a piston to which the output shaft of the drive motor is connected and a socket wrench is fixed to the lower end; hydraulic means for pushing up the piston of the transmission shaft; and between one end of the cylinder hole and the piston. It is characterized by being equipped with a spring that presses down the transmission shaft so that it fits with the socket wrench or bolt when the spring force is accumulated. Bolts, etc. can be tightened continuously by simply turning the upper F8 button.

[Embodiments of the invention]

Hereinafter, a first embodiment of the automatic e-tightening device according to the present invention will be described.
This will be explained with reference to FIGS. 4 to 4. Note that the same reference numerals are used for parts that are the same as in the prior art.

Figures 1 and 2 show the overall structure of the automatic tightening device.A main column 1 is mounted on a base 11 that is placed on the upper surface of the upper lid of the steam valve body, and rotates through bearings 12, 13, and 14. It is possible to install it upright. Arm 2 is attached to the main pillar 1 above.
A cylindrical arm support part 2 whose upper and lower ends are closed
a is fitted, a spring receiving plate 15 is provided on the main column 1 in this arm support portion 2a, and this spring receiving plate 15
A spring 16 is installed around the main column 1 between the main column 1 and the lower end wall of the arm support section 2a.

Therefore, the arm support portion 2a has a spring 16
It is constantly being subjected to a downward force due to the spring force. Further, one end of a hydraulic vibrator 17 that supplies hydraulic oil for moving the arm support portion 2a upward is connected to the upper end wall of the arm support portion 2a, and the other end of this hydraulic vibrator 17 has a servo valve (not shown) inside. ) is connected to an oil tank 18 with a Roughly speaking, an O-ring 19 for sealing between the main column 1 and the arm support part 2a is attached to the inner peripheral surface of the upper end wall of the arm support part 2a. In addition, the arm support portion 2a
A plurality of keys 20 protruding inward are integrally formed on the inner circumferential surface of the lower end wall, and a key groove 21 that engages with the keys 20 is formed on the outer circumferential surface of the main column 1 by a predetermined length in the 1111 line direction. It is formed by Due to this key connection, the arm support portion 2a rotates together with the main column 1. Furthermore, a stopper 22 is provided at the upper end of the main column 1 to limit the upward movement of the arm support 2a, and this stopper 22 has an arm position detector 23 provided on the side wall of the arm support 2a. One end is fixed. Further, in order to rotate the main column 1, a worm wheel 1a is integrally formed at the lower part of the main column 1, and this worm wheel 1a meshes with a worm 25 rotated by an electric motor 24. In addition, the main pillar 1
The rotational position of is detected by a rotational position detector 27 supported on the base 11 via a bracket 26.

On the other hand, on the side wall of the arm support section 2a, the arm support section 2a is
An arm portion 2b constituting the arm 2 is formed to extend in the horizontal direction. This arm portion 2b is also formed into a cylindrical shape like the arm support portion 2a, and a slide and an id 7-3 that extend and contract in the horizontal direction are fitted therein. A spring receiving plate 2 is attached to the slide arm 3 in the arm portion 2b.
8 is provided, and this spring receiving plate 28 and arm portion 2b
A spring 29 is installed between the slide arm 3 and the tip wall to urge the slide arm 3 to contract. Further, one end of a hydraulic vibrator 30 that supplies hydraulic oil for extending the slide arm 3 is connected to the base end wall of the arm portion 2b, that is, the side wall of the arm support portion 2a.
The other end is connected to an oil tank 31 having a servo valve (V not shown) inside, and the above 7-arm part 21c.
') A plurality of 1-32 are integrally formed on the inner peripheral surface of the tip wall, and the key groove 33 that engages the keys 3-51 passes through the guide groove of the slide arm 3 to the outer peripheral surface of the slide arm 3. In addition, a drive motor 34 of a torque generator 4 for tightening bolts and nuts is attached to the tip of the slide arm 3. One end of a slide arm position detector 35 provided on the side wall of the arm portion 2b is fixed via a bracket 36.

Further, a reducer 37 is provided at the lower end of the drive motor 34, and the reducer 37 is further provided with a torque transmission v device 38 to which a socket wrench 6 is attached. Further, one end of a hydraulic vibrator 39 that supplies hydraulic oil for moving the socket wrench 6 up and down is connected to the torque transmission device 38, and the other end of this hydraulic vibrator 39 has a nervo valve (not shown) inside. It is connected to an oil tank 40 provided therein.

The oil tank 40 and the aforementioned oil tanks 18 and 31 are each fixed to the side wall of the arm portion 2b, and the servo valve provided in each tank, the 7-arm position detector 23, and the rotational position Various signals from the detector 27, the linear arm position detector 35, and the detector (not shown) in the socket wrench 6 are input to a control box 41 fixed to the side wall of the arm portion 2b, and the cotton drawing process is performed. It looks like this.

FIG. 3 shows a condensed configuration of the torque transmitting device 38, in which a casing 42 that can be divided into upper and lower parts approximately at the center is fixed to the lower end surface of the reducer 37. The speed reducer 37
The output shaft 43, which protrudes further downward, is guided into the casing 42.1. A torque detector 44 is attached to the L output shaft 43, and a rotating shaft 46 is connected to the output shaft 43 via a shaft coupling 45. The rotary shaft 46 is supported within the casing 42 by a thrust bearing 47, and a plurality of keys 48 are provided on the outer peripheral surface of the lower end of the rotary shaft 46 to protrude in the axial direction.

Further, for the rotation @46, a boss portion 50a having a key groove 49 formed on the inner circumferential surface that engages with the key 48 is fixed to the center of the upper surface, and a spring receiving plate 50 acting as a piston is connected by key coupling. ing. This spring receiving plate 5
0 is the lower half of the casing 4 whose inside acts as a silling hole.
2a, and is always held downward by a spring 51 mounted around the boss portion 50a between the thrust bearing 47 and the spring receiving plate 50. Further, a mounting shaft 5ob to which the socket wrench 6 is attached is fixed to the center of the surface of the spring receiving root 50+, and the lower end of this mounting shaft 50b projects downward from the casing 42. The rotating shaft 46 and the spring receiving plate including the boss portion 50a and the mounting shaft 50b are integrally connected and function as a transmission shaft for transmitting torque to the socket wrench. Further, the hydraulic vibrator 39 that supplies hydraulic oil is connected to the working chamber 52 formed between the spring receiving plate 50 and the lower end wall of the casing 42 . In addition, the spring receiving plate 50
O-rings 53 and 54 are attached to the outer peripheral surface and the inner peripheral surface of the lower end wall of the casing 42, respectively, to seal the working chamber 52.

In addition, a bolt or the like is attached to the lower end of the mounting shaft 50b.
A matching socket wrench 6 is fixed.

This socket wrench 6 is a plug-in type with the same structure as a normal small torque wrench, and has a recess 6a formed to match the shape of a bolt, etc., and a contact sensor 5 on the bottom of this recess 6a.
5 are provided.

Next, the operation of the present invention will be explained with reference to FIGS. 4A to 4C.

First, the center of the virtual circle of the upper cover (not shown) of the steam valve body, in which bolts etc. are arranged at equal pitches on the circumference, and the main pillar 1 of this device.
The apparatus is installed on the upper surface of the upper lid so that the center axis of the base 11 coincides with the center of the base 11, and the bolts and the like to be tightened are lightly tightened by hand in advance.

Next, the servo valve is operated in the working chamber 52 of the torque rotation device 38 to supply hydraulic oil from the hydraulic vibrator 39, and the spring receiving plate 50 is moved until the upper surface of the spring receiving plate 50, which acts as a piston, comes into contact with the lower end of the rotating shaft 46. push up. Next, hydraulic oil is supplied from the hydraulic vibrator 17 to push the arm 2 up to its upper limit. Furthermore, the main column 1 is rotated by the electric motor 24 to align the arm 2 with the center of a predetermined bolt or the like.

Press the start button and enter the data necessary to perform the work, such as the PCD of the bolt, the number of bolts, the tightening torque, and the number of grooves on the grooved nut. After checking the input data, the slide arm 3 is positioned. The slide arm position setting signal calculated from the circular pitch of the bolt, etc. and the position signal from the slide arm position detector 35 are compared and calculated in the control box 41, and a deviation signal is output until the arm position reaches the set value. .

The servo valve is activated by this deviation signal, and the hydraulic vibrator 30
A predetermined amount of hydraulic oil is supplied.

When the position of the slide arm 3 is determined, the hydraulic pressure in the working chamber 52 is lowered by the operation of the nervo valve, and the spring 51
The spring receiving plate 50 is lowered by the spring force, and the socket wrench 6 and bolt etc. at the lower end of the shaft 50b are engaged with each other. This fitted state is checked by a contact sensor 55 provided on the socket wrench 6. If the contact sensor 55 does not detect it, the fitted state is insufficient ZZ. For example, if the nut has six grooves, rotate the socket wrench at a slow speed by 360'/6=60' to connect the socket wrench 6 and the bolt. etc. to ensure a perfect mating condition.

Next, power is supplied to the drive motor 34, and the output shaft 43
, the socket wrench 6 is rotated via the rotating shaft/16 and the mounting shaft 50b. The tightening torque is detected by a torque detector 44 and compared with a set value. When the tightening torque reaches the set value, the drive motor 34 is powered off and the tightening work is completed. Further, when the work is completed, the servo valve is operated to increase the oil pressure in the working chamber 52, and the spring receiving plate 50 is pushed up until the upper surface of the spring receiving plate 50 comes into contact with the lower end of the rotating shaft 46.

This releases the fitted state between the socket wrench 6 and the bolt. The control box 41 counts the number of bolts that have been tightened, and when the number of bolts that have been tightened has not reached the initially set number, power is supplied to the electric motor 24 and the main column 1 and the arm 2 to the next bolt position. Then, the signal from the rotational position detector 27 is compared with the set value, and the rotational position of the main column 1 is finely adjusted until the set value is reached, and then the power to the electric motor 24 is turned off.

When the above operations are completed, the spring receiving plate 50 moves to the lowering operation described above, and the next tightening operation is performed. In this way, the tightening work is continued until the number of bolts that have been tightened reaches the initially set number, and when the number of bolts reaches the set value, all the work is completed.

[Effects of the Invention] As is clear from the above description, the present invention includes a rotatable main column that is fitted with a horizontally extendable arm, a drive motor and a torque transmission device are provided at the tip of this arm, and the torque transmission The device includes a casing with a cylinder hole inside, a transmission shaft having a piston to which a drive motor is connected to the upper end and a socket wrench is fixed to the lower end, hydraulic means for pushing up the piston of the transmission shaft, and the cylinder hole. The socket wrench can be moved up and down without moving the arm up and down. Multiple bolts can be tightened in succession by simply moving the arm, saving time in moving the arm up and down. For this reason, work efficiency during machine downtime is improved, and more efficient tightening work can be performed.

In the present invention, hydraulic pressure and spring force are used to move the arm up and down, but a screw structure may be used without using hydraulic pressure.

4. Explanation of Drawings Figure 1 is a partially sectional front view of the automatic tightening device according to the present invention, Figure 2 is a plan view of the automatic tightening device, and Figure 3 is a partially enlarged view of the tightening device described above. Cross-sectional front view, No. 4A
4C are flowcharts showing the operation of the automatic tightening device, and FIG. 5 is a partially sectional front view of the conventional automatic tightening device.

DESCRIPTION OF SYMBOLS 1... Main pillar, 2a... Arm support part, 2b... Arm part, 3... Slide arm, 6... Socket wrench, 11... Base, 15, 28.50... Spring receiving plate, 16, 29.51...Spring, 17
, 30° 39...Hydraulic vibe, 18.31.40...
・Oil tank, 20.32.48...Key, 21.33
．． 49...Keyway, 23...Arm position detector, 2
4... Electric motor, 25... Worm, 27... Rotation position detector, 34... Drives overnight, 35... Slide arm position detector, 37... Reducer, 38...・Torque transmission device, 41...control box, 42
...Casing, 43...Output shaft, 44...Torque detector, 45...Shaft coupling, 46...Rotating shaft, 4
7... Thrust bearing, 52... Working chamber, 55
...Touch sensor.

Applicant's agent @ Fuji - Male Figure 1 Figure 4A Figure 5

Claims (1)

[Scope of Claims] 1. A torque generating device is fixed to the tip of an arm that is fitted onto a rotatable main pillar, rotates together with the main pillar, and can be expanded and contracted in the horizontal direction, and a socket connected to the torque generating device. In an automatic tightening device that rotates a wrench to tighten bolts and nuts, the torque generating device is composed of a drive motor and a torque transmission device, and this torque transmission device has a casing with a cylinder hole inside and a drive A transmission shaft having a piston to which the output shaft of the motor is connected and a socket wrench fixed to the lower end, hydraulic means for pushing up the piston of the transmission shaft, and installed between one end of the cylinder hole and the piston. and a spring that presses down a transmission shaft so as to fit with the socket wrench or bolt when the spring force is accumulated. 2. The automatic tightening device according to claim 1, wherein the socket wrench is equipped with a contact sensor that detects the state of engagement with the bolt.