JP2960380B2 - Angle wrench - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle wrench for tightening a screw by using an angle method. In particular, the resolution of a fastening angle at the time of measuring an angle can be enhanced to improve the accuracy of an angle measurement value. The present invention relates to an angle wrench configured as described above.

[0002]

2. Description of the Related Art For example, a preset type torque wrench or the like has been known as a screw tightening machine used for fastening a screw with a predetermined torque value. In the screw tightening work with such a preset torque wrench, the seat surface of the screw,
If the friction coefficient between the seat surface and the surface of the object to be tightened changes, the applied torque value will not be an accurate screw tightening force (axial force). A defect such as the inability to perform screw tightening occurs.

[0003] In order to solve such a problem, immediately after the tightening torque detecting means such as a toggle link in the preset type torque wrench operates (the point at which snug torque is generated), the torque wrench is rotated and tightened. It is known to employ an angle method in which a torque wrench is rotated while detecting an angle to perform screw tightening (including additional tightening) at a predetermined rotational tightening angle.

As shown in FIG. 5, an axial force characteristic diagram at the time of screw tightening using this angle method shows that when a screw is tightened by a torque wrench, a screw tightening force is further applied after the screw to be tightened is seated. , Reaches the snag torque generation point (snag axial force),
By rotating the torque wrench by a predetermined angle (θ ₁ ) with the snug torque generating point as a base point, the tightening reaches a tightening completion point (specified tightening axial force), thereby performing screw tightening with high tightening accuracy. Things.

In other words, in the screw tightening operation using the angle method,
Since the screw tightening management can be performed based on the axial force that does not receive the frictional force, it is possible to perform the screw tightening management with high accuracy compared to the normal torque method affected by the frictional force. There are features.

[0006] In a torque device for performing screw tightening using such an angle method, the tightening angle of the torque device from a predetermined base point (snagle torque generation point) to a tightening completion point. It is necessary to detect (manage) the rotation angle at which the rotation is performed. For this purpose, for example, as shown in FIG. 6, when the screw tightening force reaches the snag torque generation point by screw tightening by the torque wrench main body 1, a rotary encoder for detecting an angle, a photo sensor, a geomagnetic sensor, or the like is used. It is necessary to operate the angle sensor 2 to detect the angle from the snug torque generation point to the specified tightening completion point.

As described above, in order to operate the angle sensor 2, the rotor 3 corresponding to the stator 4 of the angle sensor 2, which is integrally connected to the torque wrench main body 1, must be positioned so as not to rotate. Therefore, in the conventional example of FIG. 6, the flexible shaft 5 directly connected to the rotor 3
Is fixed non-rotatably to the base 7 via a base fixing body 6 made of a magnet or the like.

[0008]

As described above, in the angle detector used in the conventional torque device adopting the angle method, the stator 4 side of the angle sensor 2 is directly fixed to the torque wrench main body 1. Also, the rotor 3 of the encoder 2 is
It is non-rotatably connected to one end of the flexible shaft 5 which is non-rotatably positioned on the base 7, and based on the rotation angle generated between the rotor 3 and the stator 4, from the point of snag torque generation during screw tightening operation. In this configuration, the angle up to the specified tightening completion point is detected.

For this purpose, it is conceivable to use, for example, a rotary encoder or a photosensor as the angle sensor. However, when the rotary encoder is used, particularly, in the case of a rotary encoder having a high resolution, the outer shape becomes large, and Therefore, the operability of the angle wrench deteriorates. In the case of using a photo sensor, the rotation angle generated between the rotor 3 and the stator 4 and the screw rotation angle of the torque wrench body 1 are equal to each other, and the angular resolution is low. Thus, the angle display by the angle detection output output from the angle detector becomes coarse, and not only the visibility of the detected angle is poor, but also the display accuracy is poor.

When the geomagnetic sensor is used, it is possible to cope with a tightening operation in the horizontal direction, but normal operation of the geomagnetic sensor cannot be expected when tightening in the vertical direction.

The present invention has been made in view of such a conventional problem, and has an angle sensor such as a rotary encoder which is not restricted in a screw tightening direction such as a horizontal direction or a vertical direction. A first object is to increase the angle resolution of the angle sensor and increase the accuracy of the angle display value.

Further, in the present invention, an angle sensor to be provided in the head portion of the torque wrench is provided on the lower surface (ratchet shaft, projecting side surface) of the head portion to eliminate the projecting member on the upper surface of the head portion. It is a second object of the present invention to facilitate the workability of screw tightening at a place having a dimensional restriction on the upper part of the head.

[0013]

In order to achieve the first and second objects, in the first aspect, a sensor base is fixed to a ratchet shaft projecting surface of a preset type torque wrench head, and the sensor base is fixed. A sensor gear is axially supported on the base, an angle sensor corresponding to the sensor gear is fixed, and a ring gear having a gear portion formed on the outer peripheral surface outside the ratchet shaft is concentric with the ratchet shaft. Rotatably support the ratchet shaft,
Further, the present invention is characterized in that the gear portion is an angle wrench gear-coupled to the sensor gear via a speed increasing gear having a gear ratio smaller than the gear ratio of the gear portion.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIGS. 1 and 2 show a side view and a bottom view of an angle wrench obtained by assembling a preset type torque wrench with an angle sensor. FIGS. 3 and 4 show a sectional view and a plan view of the angle sensor. Show. The preset type torque wrench 11
The wrench handle 12 includes a wrench handle 12 and a head 13 that is pivotally supported at the tip of the wrench handle 12. The head link has a well-known structure in which a ratchet shaft 14 protrudes from the head. A socket 17 that is engaged with a fastening screw 16 that is fastened to the body 15 to be fastened is fitted to the tip of the ratchet shaft 14. In addition, on the outer upper surface of the wrench handle 12, snag torque detecting means interlocking with a toggle link mechanism provided inside the wrench handle 12 such as a microswitch 18 or a voltage of snag torque is set first. A case 20 containing a torque sensor or the like that outputs a signal when the voltage exceeds the voltage, a display unit 19 that displays an angle by an output from an angle sensor described later, and the like are mounted and supported.

Reference numeral 21 denotes a sensor base fixed to the lower surface of the head portion 13, that is, the expendable side surface of the ratchet shaft 14 via a mounting screw 22, and the sensor base 21 includes an idle gear 23 (additional gear). Speed gear) and the angle sensor gear 24 meshed with the idle gear 23.
It is rotatably supported via a support shaft 25 and a support shaft 26. Further, an angle sensor 27 for detecting the rotation of the angle sensor gear is arranged near the outer peripheral surface of the angle sensor gear 24.

Reference numeral 28 denotes a ring gear rotatably supported on the outer peripheral surface of the ratchet shaft 14 via a bearing 29. The gear portion 30 formed on the outer peripheral surface of the ring gear 28 The gear 23 is engaged. A cylindrical inner case 32 is fitted on the outer peripheral surface of the cylindrical portion 31 of the ring gear 28,
As shown in FIG. 7, the inner case 32 reduces the resilient pressure of the ring spring 34 when a part of the balls 33 disposed and supported at equal intervals in the circumferential direction of the inner case 32, for example, at three places. The ring gear 28 is resiliently engaged into a recess 35 formed on the outer peripheral surface of the cylindrical portion 31 and receives the ring gear 28.
The inner case 32 can be removed from the ring gear 28 by releasing the engagement between the ball 33 and the recess 35 against the elastic force of the ring spring 34. A pin 36 protruding inward is fixed to the inner case 32, and the pin 36 is locked in a concave portion formed on the lower edge of the cylindrical portion 31,
The inner case 32 is non-rotatably engaged with and held by the ring gear 28.

Reference numeral 37 denotes a cylindrical outer case which is slidable on the outer surface of the inner case 32 in the axial direction of the case and is fitted non-rotatably in the circumferential direction of the inner case 32. , This outer case 37
A resilient spring 38 for pressing the outer case 37 in the axial direction with respect to the inner case 32 is interposed between the inner case 32 and the inner case 32. A ring-shaped friction member 39 made of rubber or the like is attached to a lower edge of the outer case 37. Reference numeral 40 denotes a guide pin projecting in the diametrical direction at the lower end of the inner case 32. The guide pin 40 is a long hole 4 formed in the axial direction on both sides of the outer case 37.
1 and guides the sliding of the outer case 37 in the axial direction while preventing the outer case 37 from being detached from the inner case 32.

The operation of the present embodiment has been described above. Next, the operation will be described. In the preset type torque wrench 11 before screw tightening, the ring gear 28 attached to the preset type torque wrench 11 is used. Tube part 3
1 outer case 37 and inner case 32
Inner case 32 of an angle reference structure composed of a combination of
And the ball 33 is engaged into the recess 35 of the ring gear 29 by the elastic pressure of the ring spring 34 and the pin 3
By locking the ring 6 with the ring gear 28, the angle reference structure is attached to the preset torque wrench 11. In the mounted angle reference structure, the outer case 37 is pushed down below the inner case 32 under the elastic pressure of the elastic pressure spring 38. Then, in order to tighten the fastening screw 16 using the preset type torque wrench 11, the socket 17 provided on the preset type torque wrench 11 is put on the head of the fastening screw 16, and When the set type torque wrench 11 is rotated and the operation proceeds, the fastening screw 16 is
Sit at 5. In this seating, the outer case 3
The frictional member 39 formed on the lower edge of the
Because the elastic member 8 is pressed against the surface of the member 15 under the elastic pressure of 8, the rotation of the angle reference structure is prevented by the pressing force. Therefore, the angle reference structure is fixed so as not to rotate together with the preset type torque angle wrench 11 without rotating.

When the preset wrench 11 is further rotated to apply a screw tightening force, the wrench 11 is fixed in the rotation direction via an angle reference structure frictionally fixed to the surface of the workpiece 15. The angle sensor gear 24 meshed with the ring gear 28 is provided with the preset type torque wrench 1.
It is rotated according to one rotation angle. By displaying the rotation angle of the preset torque wrench 11 after the snug torque generation point due to the rotation of the preset torque wrench 11 on the display unit 19, the bias of the preset torque wrench 11 after the snug torque generation point is displayed. The angle of orientation can be measured.

Therefore, in this embodiment, the gear ratio of the ring gear 28 is smaller than that of the ring gear 28 between the ring gear 28, which is fixed in the rotational direction with the workpiece 15, and the angle sensor gear 24 corresponding to the angle sensor 27. Since the angle sensor 27 and the ring gear 28 are gear-coupled to each other by interposing the idle gear 23 formed at the gear ratio, the angular resolution can be increased. Visibility and display accuracy are improved. The angle sensor 27 and the angle sensor gear 24 related to the angle sensor 27 are provided with a preset type torque wrench 1.
1 is supported on the lower side of the head portion 13, that is, on the protruding side of the ratchet shaft 14, and there is no protruding portion on the upper side of the head portion 13. Therefore, particularly, the preset torque wrench 11 is used. At the screw tightening work site, when there is a dimensional restriction on the upper part of the head portion 13 of the preset type torque wrench 11, smooth screw tightening work can be performed without impairing the workability of screw tightening.

[0022]

As described above, according to the angle wrench of the present invention, since the angle resolution can be improved when the screw is tightened by adopting the angle method, the display accuracy of the angle display can be improved. Further, at the screw tightening work site, the screw tightening work can be smoothly performed even if there is a dimensional restriction above the head portion of the angle wrench.

[0023] Further, by changing the gear ratio between the ring gear and the sensor gear, it is possible to freely select the angular resolution.

[Brief description of the drawings]

FIG. 1 is an overall side view showing an angle wrench according to the present invention.

FIG. 2 is a bottom view of FIG. 1;

FIG. 3 is an enlarged cross-sectional view showing a main structure of an angle wrench according to the present invention.

FIG. 4 is an explanatory plan view of FIG. 3;

FIG. 5 is a characteristic diagram showing a relationship between a tightening axial force and a tightening rotation angle during screw tightening.

FIG. 6 is a structural explanatory view of a conventional torque wrench employing an angle method.

FIG. 7 is an enlarged view of a main part of an embodiment according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Preset type torque wrench 12 ... Wrench handle 13 ... Head part 14 ... Ratchet shaft 15 ... Fastened object 16 ... Fastening screw 17 ... Socket 18 ... Micro switch 19 ... Display part 20 ... Case 21 ... Sensor base 22 ... Mounting Screw 23 ... Idle gear 24 ... Sensor gear 25 ... Support shaft 26 ... Support shaft 27 ... Angle sensor 28 ... Ring gear 29 ... Bearing 30 ... Gear part 31 ... Cylinder part 32 ... Inner case 33 ... Ball 34 ... Ring spring 35 ... Recess 36 ... Pin 37: Outer case 38: Resilient spring 39: Friction member 40: Guide pin 41: Slot

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B25B 23/14 610 B25B 23/142

Claims (1)

(57) [Claims] 1. A sensor base (21) is fixed to a projecting surface of a ratchet shaft (14) of a preset type torque wrench head, and a sensor gear (2) is fixed to the sensor base (21).
4) a ring gear that supports the angle sensor (27) corresponding to the sensor gear (24), and further has a gear portion (30) on the outer peripheral surface outside the ratchet shaft (14). (28) is rotatably supported on the ratchet shaft (14) concentrically with the ratchet shaft (14), and the gear portion (30) has a gear ratio smaller than the gear ratio of the gear portion. An angle wrench characterized by being gear-coupled to the sensor gear (24) via a speed increasing gear.