JP5506344B2 - Torque wrench and screw tightening method using it - Google Patents

Description

The present invention, for example, uses a torque wrench that prevents over-tightening without noticing neck breakage of the head portion when, for example, an LA terminal with an electric wire is screwed and connected to the mating connection side with a bolt or nut . The present invention relates to a screw tightening method .

  FIG. 4 shows a main part of one form of a conventional torque wrench (see Patent Document 1).

  In this torque wrench 41, a pressing shaft 8 biased by a spring 7 in a handle 42 is connected to a lever 10 by a toggle link 9, and a head (not shown) is provided on the lever 10 and a pin is attached to the handle 42. When the screw tightening torque of the head portion reaches a specified value, the toggle link 9 rotates against the spring bias, and the head portion is bent with respect to the handle portion 42. A click sound is generated to alert the operator.

  FIG. 5 shows another form of the torque wrench (see Patent Document 2).

  The torque wrench 44 is biased by a handle portion 45, a head portion 46 that is pivotally connected to the handle portion 45 by a shaft portion, a compression coil spring 47 provided in the handle portion, and a coil spring 47. It comprises a toggle roller 48, an arc-shaped groove 49 that engages with the toggle roller 48 in the head portion 46, and a roller guide surface 51 having a radius that gradually increases around a shaft portion (pin) 50 following the groove 49. is there.

  The tightening torque of the screw component 52 is defined by the length of the coil spring 47. When the operator turns the handle 45 clockwise to tighten the screw 52 from the state shown in FIG. It escapes from the groove 49 against the urging force of the spring 47, and the handle 45 rotates (swings) at a large angle as shown by a chain line, thereby detecting that the operator has reached the specified tightening torque. This prevents overtightening (overtorque).

  FIG. 6 shows a main part of a conventional torque limiter type torque wrench (see Patent Document 3).

  The torque wrench 54 is engaged with the groove 14 having a circular arc cross section of the clutch plate 12 in a state where the plurality of steel balls 13 are rotatably held by the holding plate 15, and the holding plate 15 is slid to the shaft portion 16. It is freely engaged and urged by a compression coil spring (not shown) toward the clutch plate 12, and a head part (not shown) is connected to the shaft part 16, and the screw tightening torque of the head part is When the specified value is reached, the steel ball 13 escapes from the groove 14 and rolls on the clutch plate surface, and the clutch plate 12 idles to prevent overtightening.

JP 2001-121445 A (FIG. 1) Utility Model Registration No. 3060909 (FIG. 3) Japanese Patent Laying-Open No. 2005-131753 (FIG. 4)

  However, in the conventional torque wrench 41 of FIG. 4, for example, in order to make the operator sense that the tightening torque is satisfied by the neck break and click sound at a relatively small angle of the head portion, There is a concern that an unsatisfactory worker may not be able to perceive a neck break of the head part or that the noise in the work area is large, so that the tightening operation may be continued as it is and the screw may be over-tightened.

  Further, in the torque wrench of FIG. 5, when the specified screw tightening value is reached, the handle 45 rotates at a large angle (90 ° at the maximum) in the tightening direction, which is useless for tightening work. There was concern that workability could be reduced over time. Further, since the roller guide surface 51 having a fan-shaped diameter is provided on the head portion 46, the base side of the head portion 46 is enlarged, and the swing angle of the head portion 46 is larger than the neck fold angle of the torque wrench 41 of FIG. Since it is large and not constant, there is a concern that it is difficult to dispose a sensor for detecting neck breakage (for detecting specified torque) on the base side of the head portion 46, for example.

In view of the above points, the present invention makes it possible for the operator to reliably detect that the screw tightening torque has been satisfied, and without adding unnecessary man-hours during normal (normal) screw tightening operations. An object of the present invention is to provide a torque wrench capable of disposing a sensor for detecting neck breakage on the base side of the head part while preventing enlargement of the base part of the head part and a screw tightening method using the torque wrench .

In order to achieve the above object, a torque wrench according to claim 1 of the present invention includes a torque wrench portion having a handle portion for tightening operation and a neck-type head portion, and orthogonal to the torque wrench portion. The torque wrench includes an idling torque limiter portion coupled to the head portion and having a screw engaging portion at a tip, and a sensor provided outside the handle portion to detect neck breakage of the head portion. The screw tightening set torque of the torque limiter unit is set larger than the screw tightening set torque of the unit , and the switch unit of the sensor is arranged to face the side surface opposite to the neck bending direction, When the screw tightening torque reaches the torque tightening set torque of the torque wrench portion, the head breaks, creating a gap between the switch portion and the side surface of the head portion, and the switch portion is turned on. , Screw connected to the sensor Characterized in that to operate the lamp or buzzer order controller.

  With the above configuration, an operator engages a screw part (for example, a socket or the like) with a screw part (such as a bolt head or nut) temporarily tightened by turning the handle part in the tightening direction. When the screw tightening standard value, i.e., the torque tightening set torque of the torque wrench part, is reached, the head part breaks and the torque limiter part It is idled and the tightening force is not transmitted to the screw engaging part, and further tightening is prevented, and the screw parts are securely fastened with the set screw tightening torque (torque within the screw tightening standard) of the torque limiter part. .

The internal structure of the torque wrench part and the torque limiter part is an existing one, and the torque wrench part includes, for example, a spring member for torque regulation in the handle part, a spring-biased toggle link for neck folding, and a toggle link The torque limiter unit is connected to the head unit, for example, in a cylindrical torque limiter main body, and connected to the head unit. A torque limiting clutch portion that follows the first portion, a torque regulating spring member that biases the clutch portion, and the screw engagement portion that is coupled to the shaft portion that continues from the clutch portion.
In addition, the sensor detects the neck breakage of the head and, for example, operates the lamp or buzzer of the screw tightening controller via an electric wire from the sensor to notify the operator that the screw tightening torque has met the specified value. Can do. As the sensor, a contact type or non-contact type switch for the side surface of the head unit can be used. The sensor can be installed because the base side of the head part is compact and the neck folding angle of the head part is constant.

  The torque wrench according to claim 2 is the torque wrench according to claim 1, wherein a screw tightening set torque of the torque wrench portion is set to a screw tightening standard median value, and a screw tightening set torque of the torque limiter portion is set to a screw tightening standard. It is set near the upper limit value.

  With the above configuration, the screw part is tightened with the torque tightening standard median torque at the torque wrench, and at the same time the neck breaks, but even if the neck break cannot be detected, the screw part is near the upper screw tightening standard at the torque limiter ( It is securely tightened with a torque slightly lower than the upper limit value or a value between the screw tightening standard median value and the upper limit value.

A screw tightening method using a torque wrench according to claim 3 includes: a torque wrench portion having a handle portion for tightening operation and a neck-type head portion; and a head portion connected perpendicularly to the torque wrench portion. And an idling torque limiter having a screw engaging portion at the tip, and a sensor provided on the outside of the handle for detecting neck breakage of the head, and setting the screw tightening of the torque wrench A torque wrench in which the screw tightening set torque of the torque limiter portion is set to be larger than the torque, and the switch portion of the sensor is arranged to face the side surface of the head portion opposite to the neck folding direction, is used. A screw tightening method in which the handle portion is rotated and screw parts are screwed by the screw engaging portion, and the head is bent when the screw tightening torque reaches the screw tightening set torque of the torque wrench portion. Let The switch portion is turned on by creating a gap between the head portion and the side surface of the head portion, thereby turning on the lamp of the screw tightening controller previously connected to the sensor and tightening to the operator. The completion is notified.

With the above configuration, an operator engages a screw part (for example, a socket or the like) with a screw part (such as a bolt head or nut) temporarily tightened by turning the handle part in the tightening direction. When the screw tightening standard value, i.e., the torque tightening set torque of the torque wrench part, is reached, the head part breaks and the torque limiter part It is idled and the tightening force is not transmitted to the screw engaging part, and further tightening is prevented, and the screw parts are securely fastened with the set screw tightening torque (torque within the screw tightening standard) of the torque limiter part. .
In addition, the sensor detects the neck breakage of the head and, for example, operates the lamp or buzzer of the screw tightening controller via an electric wire from the sensor to notify the operator that the screw tightening torque has met the specified value. Can do. As the sensor, a contact type or non-contact type switch for the side surface of the head unit can be used. The sensor can be installed because the base side of the head part is compact and the neck folding angle of the head part is constant.

According to the first aspect of the present invention, when the screw tightening torque is satisfied, the torque wrench portion is broken at a small angle, and when the operator continues tightening without noticing it, the torque limiter portion is idled. Thus, the screw tightening is forcibly completed, so that the screw tightening operation can be reliably performed with a normal torque without human error. Also, in normal (normal) work, the tightening can be detected by a small neck fold operation of the torque wrench, so the screw wrench can be operated with less man-hours without turning the torque wrench at a larger angle than necessary. Can be done well.
In addition, by using a sensor that detects the neck breakage of the torque wrench to notify the lamp that the tightening torque has reached the specified level, the tightening operation can be performed in a short time before tightening with the torque limiter. Can be completed with. Since there is no protrusion (roller guide surface) as in the prior art (FIG. 5) on the base side of the head part, the head part is compact and the head part has a constant neck folding angle, a sensor can be installed.

  According to the second aspect of the present invention, even when the screw component is tightened satisfactorily with a normal (normal) screw tightening operation with a torque of the standard median value and then tightened, the screw component with a torque near the upper limit of the standard is maintained. Can be tightened well, so that the screw tightening quality can be kept good.

According to the third and fourth aspects of the invention, when the screw tightening torque is satisfied, the torque wrench portion is broken at a small angle, and when the operator continues tightening without noticing it, the torque limiter portion is Since the screwing is forcibly completed by idling, the screwing operation can be reliably performed with a normal torque without human error. Also, in normal (normal) work, the tightening can be detected by a small neck fold operation of the torque wrench, so the screw wrench can be operated with less man-hours without turning the torque wrench at a larger angle than necessary. Can be done well.
In addition, by using a sensor that detects the neck breakage of the torque wrench to notify the lamp that the tightening torque has reached the specified level, the tightening operation can be performed in a short time before tightening with the torque limiter. Can be completed with. Since there is no protrusion (roller guide surface) as in the prior art (FIG. 5) on the base side of the head part, the head part is compact and the head part has a constant neck folding angle, a sensor can be installed.

1 is a front view showing an embodiment of a torque wrench according to the present invention. It is a top view perspective view similarly showing a torque wrench and a screwing process using the same. It is a front view perspective view which similarly shows a torque wrench and a screwing process. It is principal part sectional drawing which shows one form of the conventional torque wrench. It is the top view which made the cross section the part which shows the other form of the conventional torque wrench. It is principal part sectional drawing which shows the other form of the conventional torque wrench.

  1 to 3 show an embodiment of a torque wrench according to the present invention.

  As shown in FIG. 1, the torque wrench 1 is composed of a horizontal neck-foldable torque wrench portion 2 and a vertical idling torque limiter portion 3 connected to a head 4 of the torque wrench portion 2. The torque limiter portion 3 is provided with a socket (screw engaging portion) 5 for engaging a screw component.

  The torque wrench portion 2 is an existing one. For example, as in the conventional example of FIG. 4, a torque regulating compression coil spring (spring member) 7 disposed inside a hollow cylindrical handle 6 and a spring 7, a short pressing shaft 8 urged by 7, a lever 10 connected to the pressing shaft 8 via a toggle link 9, and a tip of the lever 6 provided integrally with the tip of the lever 10. And a head portion 4 that is rotatably supported on the side.

  The head part 4 is provided with a connecting convex part (not shown) having a square cross section, for example, facing downward, and a ball plunger (not shown) for retaining is provided on the outer surface of the connecting convex part. . The connecting convex portion is engaged with a connecting concave portion (not shown) provided on the upper portion of the torque limiter portion 3, and the ball plunger is engaged with a hole on the inner surface of the connecting concave portion.

  The torque limiter portion 3 is also an existing one. For example, referring to the conventional example of FIG. 6, a clutch plate (clutch portion) 12 having the coupling recess and a plurality of steel balls 13 inside the torque limiter portion main body 11. Is held rotatably, and a steel ball holding plate (clutch portion) 15 in which a steel ball 13 is engaged with a groove 14 having a circular arc cross section of the clutch plate 12 and the steel ball holding plate 15 are slidable in the axial direction. A torque limiter body having an engaged shaft portion 16 and a compression coil spring (spring member) (not shown) that is disposed around the shaft portion 16 and biases the steel ball holding plate 15 toward the clutch plate 12. 11 is provided with a socket 5 for engaging a screw component connected to a shaft portion 16 projecting downward from the torque limiter portion main body 11.

  It is also possible to use a disc spring or the like (not shown) instead of the compression coil spring. It is also possible to use a clutch plate instead of the steel ball holding plate 15 without using the steel ball 13 and limit the torque by using the frictional force of the upper and lower clutch plates 14 and 15. The internal structures of the torque limiter unit 3 and the torque wrench unit 2 can be set as appropriate. 2 and 3, a screw component (not shown) is temporarily fastened with a rod-like temporary fastening bit (not shown) in advance before the final tightening with the torque wrench 1.

  As shown in FIGS. 1 and 2, the torque wrench portion 2 of this example is provided with a sensor (switch) 17 for detecting neck breakage (for detecting a specified torque) on the tip side of the handle portion 6 on the base side of the head portion 4. The sensor 17 is electrically connected to the simplified screw tightening controller 19 shown in FIG.

  As shown in FIG. 2, the sensor 17 is formed in a substantially L shape by a fixing portion 20 to the handle portion 6 and a switch portion 21 close to the head portion 4, and a spring-biased contact 22 of the switch portion 21. Is elastically in contact with the side surface 4a of the head portion 4, and is in a switch-off state, for example.

  2, the handle 4 of the torque wrench 2 is rotated clockwise (clockwise) as indicated by the arrow A, so that the head 4 is bent in the direction of the arrow B with the specified torque (at the same time, clicking with a click). 3), a gap is formed between the side surface 21a of the switch portion 21 and the side surface 4a of the head portion 4, and the contact 22 is displaced in the direction of arrow B (the direction of neck breakage) to switch on, and the screw shown in FIG. The lamp 23 of the tightening controller 19 is turned on and the buzzer 24 sounds to notify the operator of the completion of tightening.

  2, reference numeral 25 denotes a switching lever that reverses the tightening direction of the head portion 4. In FIGS. 2 and 3, reference numeral 26 denotes a work that requires screw tightening (for example, a bus bar for fusible link connection). Or a fuse box or the like in which the terminal LA terminal 28 of the electric wire 27 on the wire harness side is fastened to the terminal with bolts or nuts which are screw parts. In FIG. 3, reference numeral 29 denotes a reset button. When tightening the bolt, the nut is fixed in the fuse box 26, and when tightening the nut, the bolt is fixed in the fuse box 26.

  As an example, the standard value of the tightening torque of the M5 screw is 2.9 to 3.9 Nm (3.4 ± 0.5 Nm). In this case, the tightening torque of the torque wrench portion 2 is 3.4 Nm. The tightening torque of the torque limiter unit 3 is set to 3.8 Nm. These set values may have a width. For example, the tightening set torque of the torque wrench unit 2 is 3.3 to 3.6 Nm, and the tightening set torque of the torque limiter unit 3 is 3.7 to 3.8 Nm. To do. In any case, the tightening torque of the torque limiter unit 3 is set higher than the tightening torque of the torque wrench unit 2.

  In this way, the tightening torque of the first-stage torque wrench section 2 is set to be small (to the standard median value), and the tightening torque of the second-stage torque limiter section 3 is set to be large (slightly lower than the upper limit of the standard). 2 and 3, the operator is not aware of the turning operation of the torque wrench portion 2 when the head portion 4 is bent or the screw tightening controller 19 is notified. Even if the torque limiter section 3 continues, the torque limiter section 3 idles with the tightening torque within the standard of + α when the head section 4 is broken, and further tightening is forcibly stopped. In addition to being prevented, the tightening of the screw is stably and reliably performed with a torque within a standard slightly higher than the standard median value.

  When the tightening set torque of the torque wrench 2 and the tightening set torque of the torque limiter 3 are the same, there is no problem with the tightening torque, but the torque limiter 3 Due to idling, the handle portion 6 of the torque wrench portion 2 rotates at a larger angle than the neck break during normal operation, and tightening workability decreases. By setting the tightening torque in two stages, it becomes possible to prevent over-tightening (over-torque) due to human error mechanically, and it is possible to guarantee a torque value that is inexpensive and does not rely on human hands.

  If a screw driver (not shown) is used instead of the socket 5, a screw can be tightened instead of a bolt. It is also possible to provide a contactless proximity switch in the switch portion 21 of the sensor 17.

  Further, for example, the sensor 17 of FIG. 2 is provided with a second switch having a second stroke (not shown) having a large stroke in addition to the above-described toucher 22, or a two-stage displacement type using the toucher 22. When the torque limiter unit 3 is idling, the switch is turned on to turn on the second lamp 30 of the screw tightening controller 19 shown in FIG. 3 and sound the buzzer 24 to complete the work to the operator. It is also possible to notify again.

  In addition to the torque wrench 1, the configuration of the present invention described above may be used as a screw tightening method or a screw tightening structure using the torque wrench 1, or as a screw tightening machine or a screw tightening device including the screw tightening controller 19. It is effective.

  The torque wrench according to the present invention can be used, for example, to connect an electric wire with a terminal of an automobile wire harness to a fuse box, an electric connection box or the like with a bolt or a nut without tightening.

DESCRIPTION OF SYMBOLS 1 Torque wrench 2 Torque wrench part 3 Torque limiter part 4 Head part 5 Socket (screw engaging part)
6 Handle 17 Sensor

Claims (4)

A torque wrench portion having a handle portion for tightening operation and a neck-foldable head portion, and an idling torque limiter that is coupled to the head portion perpendicular to the torque wrench portion and has a screw engaging portion at the tip. And a sensor provided on the outside of the handle for detecting neck breakage of the head portion , and the screw tightening set torque of the torque limiter portion is set larger than the screw tightening set torque of the torque wrench portion The sensor switch part is disposed opposite to the side surface of the head part opposite to the neck bending direction, and the screw tightening torque reaches the screw tightening set torque of the torque wrench part. Breaks the neck, creates a gap between the switch part and the side surface of the head part, turns on the switch part, and operates the lamp and buzzer of the screw tightening controller connected to the sensor. Characteristic torqueren .   The screw tightening set torque of the torque wrench part is set to a screw tightening standard median value, and the screw tightening set torque of the torque limiter part is set to the vicinity of the screw tightening standard upper limit value. A wrench. A torque wrench portion having a handle portion for tightening operation and a neck-foldable head portion, and an idling torque limiter that is coupled to the head portion perpendicular to the torque wrench portion and has a screw engaging portion at the tip. And a sensor provided on the outside of the handle for detecting neck breakage of the head portion, and the screw tightening set torque of the torque limiter portion is set larger than the screw tightening set torque of the torque wrench portion And a screw tightening method using a torque wrench in which the switch part of the sensor is arranged to face the side surface of the head part opposite to the neck bending direction,
The handle portion is rotated and screw components are screwed by the screw engaging portion, and when the screw tightening torque reaches the screw tightening set torque of the torque wrench portion, the head is bent, and the switch portion and the switch portion are The switch portion is turned on by creating a gap between the side surface of the head portion, and thereby the lamp of the screw tightening controller connected in advance to the sensor is turned on to notify the operator of the completion of tightening. A screw tightening method using a torque wrench characterized by the above. 4. The screw tightening method using a torque wrench according to claim 3, wherein a buzzer of the screw tightening controller is sounded simultaneously with the lamp to notify the operator of the completion of tightening.

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