CZ79093A3 - Electronic torque-limiting wrench - Google Patents

Abstract

The first end of the body (1) is provided with a replaceable handle (15) s accumulator (14). It is located in the central part of the body (1) connection socket (13), instrument panel (11), evaluation and an indicator circuit (12) and an instrument knob (10). IN the other end of the body (1) is rotatably supported by the bearing (9) a strain gauge sensing member (3) is disposed therein the spindle (2), the inner end of which is supported by a roller (6) located in the body (1) and on the other hand a cage (4) which is together with the pull direction switch (5) located on the bolt (8) screwed in the inner end of the spindle (2). Between the pull direction switch (5) and the cage (4) are positioned spring (7). Between body (1), strain gauge a roller parallelepiped by a member (3) and a bearing (9) (16).

Description

The invention relates to an electronic torque wrench with a control roller freewheel with electronic sensing and torque evaluation, and an optical and acoustic indication of the achievement of a predetermined torque. It is intended for tightening screw connections to exact torque.

BACKGROUND OF THE INVENTION

From commercially available materials, electronic torque wrenches are designed as conventional ratchet wrenches and a sensing member is inserted between the attachment and the ratchet. The sensor is connected by a cable to the instrument box, which is also a source of power supply. and where the output signal is also processed.

There are known electronic torque wrenches with external power supply without ratchet or freewheel, only with torsion bar.

The above-mentioned types are low precision (approx. ± 10% of the set value as they derive the torque from the beam bending), mechanically low resistance, handling of the lead-in cable makes tightening of the screw connection difficult and can only be tightened in one direction. Use for tightening soft joints is annoying because of the necessity of replacing the wrench on the bolt and nut.

An electronic torque wrench according to US Patent No. 4,60.8,872 is known where alternative battery power is contemplated, but only as a variant, which is tied to the type of sensing member because of the low battery capacity. The described device uses a freewheel, but only for unidirectional retraction of the screw connection, the mechanical and electronic parts are not integrated into one unit.

SUMMARY OF THE INVENTION

The above drawbacks are substantially eliminated by the electronic torque wrench of the present invention, which consists of a torque wrench body 1, a roller freewheel 16, an instrument panel 11, an evaluation and indication circuit 12 and an accumulator 14, wherein the roller freewheel 16 consists of a strain gauge sensor. 3, cage 4, pull direction switch 5, rollers <2, springs 7, bolt S, bearings 9 and spindle 10, wherein the freewheel 16 is a reversible reversible direction and forms with the torque wrench body 1 by the instrument panel Π, the evaluation and the indicating circuit 12 is a single unit and the strain gauge sensor 3 is a semiconductor with a circular cross-section.

The high sensitivity semiconductor strain gauge sensor with low current consumption directly crushes torque and can be used as a power supply without the need for power cables. Achieving the set torque value is indicated acoustically and optically. The torque is sensed with high precision by a semiconductor strain gauge sensor, converted into an electrical signal, which is evaluated in other circuits. The accuracy of the sensed signal is also increased, since errors due to friction or fatigue of the material are eliminated and the durability and durability of the sensing member is increased.

Exemplary embodiment

According to the present invention, two prototypes were produced. The body of the electronic torque wrench was made of aluminum, the other mechanical parts of heat-treated steel. For optical indication were used LEDs, alternatively LED and LCD display. A miniature piezoelectric loudspeaker with high sensitivity was used for acoustic indication. The power source was a 9V / 110 mAh NiCd battery. The prototypes have been tested in service repairs of passenger cars and have confirmed the advantages of this device according to the invention, ease of operation and unambiguous acoustic and optical indication of reaching the set torque values.

Overview of the figure in the drawing

The illustration shows the torque wrench electronically. Roller coupling arrangement 16 is shown in detail.

-3List of Reference Marks

1) Torque wrench body

2) spindle

3) Strain gauge sensor

4) cage

5) retract direction switch

6) roller

7) spring

8) screw

9) bearing

10) instrument knob

11) instrument panel

12) evaluation and indication circuit

13) connection socket

14) accumulator

15) interchangeable handle

16) roller parallel

Claims (6)

1) Electronically a torque wrench, characterized in that it consists of a torque wrench body (1), a freewheel (16), an instrument panel (11), an evaluation and indication circuit (12) and an accumulator (14). 2) An electronic torque wrench according to claim 1, characterized in that the cylindrical parallel (16) consists of a strain-gauge sensor (3). cages (4). pull direction switch (5), rollers (6), springs (7). the bolt (8), the bearing (9) and the spindle (2). 3) An electronic torque wrench according to n / cc, characterized in that the freewheel (16) is reversible with the possibility of changing the direction of rotation. 4) The electronic torque wrench according to claim 1, characterized in that the torque wrench body (1), the freewheel (16), the instrument panel (11), the evaluation and indication circuit (12) form one compact unit. 5) An electronic torque wrench according to claim 1, wherein the strain gauge sensor is a semiconductor. 6) The electronic torque wrench according to claim 1, characterized in that the strain gauge sensor (3) is of circular cross-section.