JPS6322065Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a wrench used to tighten a bolt or nut with an appropriate axial force and to display the axial force.

Prior Art When fastening a bolt or nut, axial force (tensile force) acts on the threaded shaft of the bolt and it will break when it reaches its plastic limit, so it is necessary to prevent such breakage and fasten with a predetermined axial force. For example, an axial force display device that detects and displays when the axial force approaches a set value is disclosed in Japanese Patent Publication No. 58-34264.
Although it has been generally known since before this application, a separate device detects and displays the axial force after tightening using a normal wrench, and therefore the operation is difficult. However, it is troublesome and time-consuming, so it lacks practicality.

Technical Issues Therefore, in the present invention, the wrench itself for tightening bolts and nuts has the function of displaying the tightening axial force so that the bolts and nuts can be tightened with the appropriate axial force. The technical challenge is to be able to display the fastening axial force in the field.

Means for solving the problem In order to solve the above technical problem, the present invention
It is a wrench for tightening bolts or nuts, and a sliding ring 3 is provided at the tip of the wrench body 1 so that it can slide freely relative to the wrench body, and when an axial force is applied to the sliding ring 3 by tightening a screw. A clamping piece 6 integral with the sliding ring 3 is provided to clamp the washer 26 whose diameter expands due to a compressive load from both sides, and a movable clamping piece 7 is provided that expands around the pivot pin 9 as a fulcrum. A lever 10 is integrally extended to the free end of the lever 10.
A proximity switch S is provided at the end and an arm 13 protruding from the sliding ring 3, which is composed of two contact pieces 12 and 12' facing each other so as to be variable in distance and distance by expanding the movable clamping piece 7, and the wrench body 1 is provided with a display 14 operated by a proximity switch S.

Embodiment FIG. 1 shows an embodiment of the fastening axial force display wrench according to this invention, in which 1 is a wrench body, and a fastening part 2 made of a hexagonal square body is provided at the tip in a replaceable manner. ing. This fastening portion 2 will be described later.

The sliding ring 3 is attached to the outer periphery of the tip of the wrench body 1 so as to be slidable relative to the body 1. This sliding ring 3 is constructed by providing a circumferential groove 4 on the outer periphery of the tip of the wrench body 1, and a guide pin 5 protruding from the inner circumferential surface of the sliding ring 3 is loosely fitted into and locked in the circumferential groove 4. It is rotatably mounted relative to the A clamping piece 6 and a movable clamping piece 7, which are provided opposite to each other around the fastening portion 2, are attached to this sliding ring 3. The clamping piece 6 is fixed integrally with the sliding ring 3 by a fixing screw 8, and the movable clamping piece 7 is provided so as to be swingable about a pivot pin 9 as a fulcrum.
A portion projecting rearward from the pivot portion is a lever 10. This lever 10 is provided with a spring 11 to apply elasticity to the movable clamping piece 7 in the direction of diameter reduction.

The proximity switch S is a contact piece 1 provided at the end of the lever 10.
2 and a contact piece 12' provided on an arm 13 protruding from the sliding ring 3, and when both the contact pieces 12, 12' reach a predetermined close position, the electric circuit 15 of the indicator 14 is closed. It is used for display. The contact piece 12' is connected to a current-carrying ring 17 which is fitted and attached to the circumference of the main body 1 via an insulator 16. 18 is a power source.

A handle 19 for tightening operation is provided at the rear end of the wrench body 1, but in the case of an electric type, a drive section 20 with a built-in motor is provided instead of this handle, and the display 14' is also connected to the drive section 20. It is attached to the casing or main body 1, etc.

Various types of fastening parts 2 are used depending on the shape of the bolt or nut to be fastened. Fig. 1 shows a bolt 21 having a square hole 23 in its head 22, into which a square body (fastening part 2) attached non-rotatably to the tip of the wrench body 1 is fitted, and the handle When the wrench body 1 is rotated by the operation 19, the bolt 21 is fastened.

5 and 6 show a case in which the fastening portions 2', 2'' are fitted into square nuts 24, 25 from the outside.

Operation In FIG. 1, the fastening part 2 of the wrench body 1 is inserted into the head square hole 23 of the bolt 21 to be fastened, and at the same time the opposing clamping pieces 6 and 7 are brought into contact with the outer periphery of the axial force display washer 26. Set to . In this state, when the wrench body 1 is rotated in the screw fastening direction to fasten the bolt 21, the washer 26 expands in the diametrical direction as the axial force becomes stronger due to the action of the wedge-shaped tapered surface. When the washer 26 expands in diameter, the clamping pieces 6 and 7 in contact with its outer periphery are pushed apart, so when the set axial force is reached, the proximity switch S operates and the indicator 14 (or 14') is activated. . The clamping piece 6 is integrated with the sliding ring 3 and does not open or close by itself, but when the washer 26 expands in diameter, the clamping piece 6 acts as a pedestal and holds the washer with the opposing movable clamping piece 7. This is done reliably, and the pushing force due to diameter expansion is transmitted to the movable clamping piece 7. Therefore, the bolt 21 is fastened simultaneously with proper axial force, and this can be confirmed on the display 14.

Fig. 5 shows a case where the circumferential body part 24a that is integral with the nut 24 expands in diameter.
The figure shows a case where a separate axial force indicating washer 26' is attached to the nut 25.

Effects of the invention This invention consists of the above-mentioned structure,
The fastening part provided at the tip of the wrench body is fitted into the bolt or nut to be fastened, and the axial force display washer is held between a clamping piece and a movable clamping piece provided oppositely around the fastening part. When the wrench body is rotated by the wrench tightening operation, the washer expands in diameter at the same time as tightening, pushing both clamping pieces apart, and the proximity switch operates the indicator with the set axial force, and the appropriate axial force is applied. Compared to the conventional method of measuring with a measuring device after tightening, the work can be done quickly, and at the same time, it is convenient because the appropriate axial force can be confirmed on the display. It is easy to operate and handle, and has a simple structure.
It can be implemented at low cost.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional side view of the wrench according to the present invention, showing the state of use, and Figs. 2, 3, and 4 show lines AA, B-B, and C-C in Fig. A sectional view, FIG. 5 is a longitudinal sectional side view of a fastening portion showing a second embodiment, and FIG. 6 is a longitudinal sectional side view of a fastening portion showing a third embodiment. DESCRIPTION OF SYMBOLS 1... Wrench body, 2... Fastening part, 3... Sliding ring, 4... Peripheral groove, 5... Guide pin, 6... Clamping piece, 7... Movable clamping piece, 9... Pivotal pin , 10...
...Lever, 12, 12'... Contact piece, 14, 14'...
...Display, S...Proximity switch.

Claims (1)

[Scope of utility model registration request] A wrench for tightening bolts or nuts,
A sliding ring 3 is provided at the tip of the wrench body 1 so that it can slide freely relative to the wrench body, and a washer 26 that expands in diameter due to a compressive load when an axial force is applied to the sliding ring 3 by tightening a screw is attached from both sides. A clamping piece 6 that is integral with the sliding ring 3 and a movable clamping piece 7 that expands around the pivot pin 9 as a fulcrum are provided, and the movable clamping piece 7
A lever 10 is integrally extended to the free end of the lever 1.
0 end and an arm 13 protruding from the sliding ring 3 are provided with a proximity switch S consisting of two contact pieces 12 and 12' facing each other so as to be variable in distance by expanding the movable clamping piece 7, and the wrench Proximity switch S to main body 1
A tightening axial force display wrench for bolts and nuts, characterized in that it is provided with an indicator 14 that operates at .