JP2534491B2 - Detecting and adjusting device for tightening torque in tightening tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is, for example, driven by an air motor or an electric motor to fasten a nut with a predetermined torque, so-called
The present invention relates to a tightening torque detecting and adjusting device for a tightening tool such as a nut runner.

[Conventional technology]

Maintains a constant tightening torque in the nut runner,
That is, as a means for detecting the reaction force at the time of tightening, for example,
There is a structure shown in FIG. 7 and FIG.

This nut runner 100 is a speed reducer driven by an air motor 101.
The main shaft 103 is rotated via 102, and a nut (not shown) that fits into a socket attached to the tip of the main shaft 103 is also rotated.
Is a housing 10 that houses the air motor 101 and the speed reducer 102.
5 is rotatably supported by a mounting plate 106 and a support arm 107, and a swing lever 110 is attached to the casing 105 directly or to an air supply pipe 108 attached to the casing 105.
A spring receiver 111 is provided in 110 in parallel with the housing 105, and a pressing spring 113 is arranged between spring cases 112 attached to the support arm 107. In addition, 114 is a pressure air supply port.

The reaction force of the rotational torque applied to the main shaft 103, that is, the rotational force applied to the housing 105 is supported by the pressing spring 113, and when a tightening torque equal to or larger than the set tightening force is generated, the housing is 105 is a pressing spring 113 together with the swing lever 110.
Rotate against. This rotation is detected by appropriate means, and the supply of pressurized air is stopped.

In this case, the larger the length of the rocking lever 110, the weaker the pressing force of the pressing spring 113 and the easier the fine adjustment of the reaction force.

[Problems to be solved by the invention]

The swing lever 110 is attached to the casing 105,
The rotation of 105 is directly supported by the pressing spring 113, and the length of the rocking lever 110 is limited.

Therefore, the pressing spring 113 requires a considerable pressing force, has a large size, and is difficult to finely adjust.

Further, a so-called multi-shaft nut runner has recently been demanded for fastening a large number of nuts at the same time. For this reason,
When a large number of the nut runners are arranged side by side, the rocking lever 110 protrudes, which interferes with the projecting levers. Therefore, it is difficult to arrange a large number of the nut runners in close proximity.

In view of such a point, the present invention is capable of detecting a reaction force applied to the housing at the time of tightening with a small-sized device, and further, tightening in a tightening tool capable of easily performing fine adjustment of the tightening force. An object of the present invention is to provide a device for detecting and adjusting the applied torque.

[Means for solving problems]

In order to achieve the above object, the tightening torque detecting and adjusting device in the tightening tool of the present invention accommodates a drive source that rotates a main shaft by a drive source and receives the tightening torque applied to the main shaft as its reaction force. In a tightening torque detection and adjustment device for a tightening tool that detects the rotation of the housing and adjusts the tightening torque, the housing is rotatably supported on the fixed side of the tightening tool. Attaching a swing lever to this housing, disposing a main cylinder equipped with a main piston on the fixed side of the tightening tool facing the swing lever, and communicating with the main cylinder via a hydraulic oil circuit, A sub-cylinder having a sub-piston having a smaller diameter than the main piston is provided, a discriminating member for detecting movement of the sub-piston is provided, and rotation of the housing is prevented when a tightening torque is applied. So that the secondary piston moves A spring for urging in a direction opposite to the direction of the slave piston that, characterized in that arranged adjustably its urging force.

[Work]

Rotational force due to the tightening reaction force applied to the housing is applied to the sub piston through the hydraulic oil circuit. At this time, since the auxiliary piston has a smaller diameter than the main piston and the hydraulic oil circuit is used to pressurize the auxiliary piston, the pressing force applied to the auxiliary piston is very small, and therefore the auxiliary piston is biased. The spring can be made smaller, the overall size of the device can be reduced, and the tightening torque can be easily adjusted.

〔Example〕

1 to 4 show an example in which the present invention is applied to a nut runner as a tightening tool in relation to the first embodiment.

The tightening tool 1 is configured such that a drive source 2 such as an air motor and a speed reducer 3 are housed in a housing 4 and a main shaft 5 is rotated. Also, a socket 9 that is rotatably supported by the mounting plate 8 and that fits into a nut is detachably mounted at the tip.

Reference numeral 20 denotes a mechanism for detecting and adjusting a reaction force applied to the housing 4 at the time of tightening, that is, a tightening torque. A main body 21 attached via the main body 21, a detection mechanism 22 connected to the main body 21, and a swing lever 23 attached to the housing 4 so as to face the main body 21.

The main body 21 has a main cylinder 29 formed on a bolster 24 attached to the mounting lever 11, and a main piston is attached to the main cylinder 29.
25 is inserted, the swing lever 23 is attached to the rotary cylinder 26, the rotary cylinder 26 is rotatably supported by the fixed cylinder 10 via the bearing 27, and is fixed to the housing 4 with screws 28. To be done.

The swing lever 23 is provided opposite to the main piston 25, and forms a curved contact surface 23a so as to press the main piston 25 when the housing 4 rotates.

Reference numeral 30 in the drawing denotes a hydraulic oil rotation that connects the main cylinder 29 having the main piston 25 and the sub cylinder 31 having the sub piston 31a.

The detection mechanism 22 includes a sub cylinder 31 including a sub piston 31a.
And a spring receiver 33 that is in contact with the sub piston 31a and is biased by a spring 32.
The spring 32 and the spring receiver 33 are housed in a cylindrical body 34, and the cylindrical body 34 is connected to the bolster 24 by a coupling 35.

Reference numeral 36 denotes a support plate for supporting the spring 32, which is moved by a nut 37 screwed to the tubular body 34 via a connecting bar 38, so that the spring 32
Allow the urging force of to be adjusted arbitrarily.

A striker 40 is projectingly provided on the spring receiver 33 outside the cylindrical body 34, and the striker 40 is provided with a determination member 41 such as a limit switch or a proximity switch.

Since the diameter of the sub piston 31a is smaller than that of the main piston 25, the pressure applied to the main piston 25 can be supported by a smaller biasing force.

By rotating the main shaft 5 in the above configuration, a nut (not shown) is rotated through the socket 9 to perform the tightening work.

At this time, the housing 4 receives a reaction force, the swing lever 23 contacts the main piston 25, the sub piston 31a faces the main piston 25 via the hydraulic fluid circuit 30, and the sub piston 31a is a spring.
It is biased by a predetermined pressure by 32, and therefore the reaction force of the rotation of the main shaft 5 is supported by the spring 32 and the housing 4 does not rotate, so that the nut is securely tightened.

That is, the reaction force against the tightening torque is supported by the spring 32. Therefore, by appropriately setting the biasing force of the spring 32, the magnitude of the tightening torque can be selected to a predetermined value.

Further, since the reaction force is supported through the hydraulic oil circuit 30, it is determined by the ratio between the diameter of the main piston 25 and the diameter of the sub piston 31a.

In the present invention, since the diameter of the sub piston 31a is smaller than the diameter of the main piston 25, the supporting force P of the spring 32 is However, A: area of the main piston B: area of the sub piston F: reaction force Therefore, the sub piston 31a can be supported by a weak force due to the ratio of both piston areas (hereinafter, referred to as hydraulic differential mechanism), The spring 32 can be made small and the tightening torque can be easily adjusted.

Note that the reaction force exceeds the set pressure of the spring 32 and the auxiliary piston 31a
When is shifted, the striker 40 operates the discriminating member 41 and stops the drive source 2. It is also possible to give a signal to the operator.

 Next, FIGS. 5 and 6 show a second embodiment.

Reference numeral 20 denotes a reaction force at the time of tightening, that is, a mechanism for detecting and adjusting the tightening torque, and the main body 41 and the detection mechanism 42 are connected by a flexible tube 43 forming a part of a hydraulic fluid circuit. In the same way as the previous example, the main body 41 is the bolster 44 and the main piston 45.
The main cylinder 29 having the above is formed, and the connection screw 47 of the flexible tube 43 is formed at the outlet side of the differential oil circuit 46.

Reference numeral 42 denotes a reaction force at the time of tightening, that is, a mechanism for detecting and adjusting the tightening torque.The connecting cylinder 51 forming the auxiliary cylinder 50 having the auxiliary piston 50a, the spring 52 and the spring receiver 53 are provided. Connected to the housing 54 to be stored by a coupling 55,
The other end of the flexible tube 43 is connected to the connecting tube 51. As a result, the main cylinder 29 and the sub cylinder 50 are connected via the hydraulic oil circuit 46 and the flexible tube 43.

The other structure is the same as that of the above-described embodiment, and the same parts are designated by the same reference numerals and the description thereof is omitted.

According to the present embodiment, the device 42 for detecting and adjusting the tightening torque can be provided at an appropriate place, and the tightening torque can be easily adjusted.

FIG. 6 is a schematic explanatory diagram in which this embodiment is applied to a multi-axial nut runner.

Attach the required number of tightening tools 1a, 1b ... 1n to the mounting plate 60 at the predetermined positions, and attach the bolsters to each tightening tool.
44n and the detection mechanisms 42a, 42b ... 42n are flexible tubes 43a, 43
It is connected by b ... 43n and all the detection mechanisms are centrally arranged in the required places, so that the tightening torque at the time of tightening each tightening tool can be detected and adjusted centrally.

〔The invention's effect〕

According to the present invention, the rotational force of the housing due to the reaction force generated when the nut or the like is tightened is detected by using the hydraulic circuit, and the hydraulic circuit has a large-diameter piston and a small-diameter auxiliary piston. Since the hydraulic differential mechanism is used, the mechanism of the device can be simplified and the spring can be made smaller than the conventional method of directly supporting the rotational force of the housing by the spring. In addition, the tightening torque can be easily adjusted.

[Brief description of drawings]

1 to 4 relate to the first embodiment, FIG. 1 is an overall front view showing a part in a vertical section, FIG. 2 is a longitudinal section of a detecting device, and FIG. 3 is a fastening tool in FIG. FIG. 4 is a sectional view taken along line I-I of FIG. 1 in which the tightening tool is omitted, and FIGS. 5 and 6 relate to the second embodiment.
FIG. 5 is an overall vertical cross-sectional view of the detection device, FIG. 6 is a schematic explanatory view in which this embodiment is applied to a multi-axis nut runner, FIGS. 7 and 8 relate to a conventional example, and FIG. 8 is a sectional view taken along line II-II in FIG. 1 is a tightening tool, 2 is a drive source, 4 is a housing, 5 is a spindle, 23 is a swing lever, 25 and 45 are main pistons, 29 is a main cylinder, 30,
43 and 46 are hydraulic oil circuits, 31 and 50 are sub cylinders, 31a and 50a are sub pistons, and 41 is a discriminating member.

Claims (1)

(57) [Claims] 1. A main shaft (5) is rotated by a drive source (2),
A tightening tool (1) adapted to detect the tightening torque applied to the main shaft (5) from the rotation of a housing (4) accommodating a drive source (2) receiving the reaction force and to adjust the tightening torque. )
In the tightening torque detecting and adjusting device in, the housing (4) is rotatably supported on the fixed side of the tightening tool (1), and a swing lever (23) is attached to the housing (4). , A main cylinder (29) provided with a main piston (25, 45) is disposed on the fixed side of the tightening tool (1) facing the swing lever (23), and the main cylinder (29) and hydraulic oil A sub-cylinder (31,50) provided with a sub-piston (31a, 50a) having a diameter smaller than that of the main piston (25,45), which communicates with each other through a circuit (30,43,46), is provided. A determination member (41) for detecting the movement of the (31a, 50a) is provided, and the sub-pistons (31a, 50a) are arranged so as to prevent the housing (4) from rotating when a tightening torque is applied. In the direction opposite to the direction in which the auxiliary piston (3
A tightening torque detecting and adjusting device for a tightening tool, wherein springs (32, 52) for urging the springs (1a, 50a) are arranged so that the urging force can be adjusted.