HK1085691B - Tightening torque measuring unit and bolt or nut tightening device - Google Patents

Description

Fastening torque measuring device and bolt or nut fastening machine

Technical Field

The present invention relates to a device for measuring a tightening torque of a bolt or nut tightening machine and a tightening machine capable of displaying the torque.

Background

The tightening torque of a conventional bolt or nut tightening machine is adjusted and confirmed by tightening a torque adjustment dial (see reference numeral 10 in fig. 24) and a manual torque wrench provided in a tightening machine body.

Specifically, first, a torque adjustment dial (10) is set to be slightly lower than a desired tightening torque value, and a bolt or a nut (hereinafter, representatively referred to as a "nut") is tightened.

The principle is to set a target torque value by a torque adjustment dial (10) by utilizing the fact that the tightening torque of the tightening machine shown in the X diagram of fig. 22 and the load current of the tightening machine shown in the Y diagram are in a nearly proportional relationship. When the load current reaches a target value, the motor of the tightening machine is stopped. The actual tightening torque at this time is an error from the value set on the adjustment dial due to the gear efficiency of the speed reducer built in the tightening machine body.

The worker tightens the nut using the torque wrench with the torque indicator and confirms the actual tightening torque.

The torque adjustment dial (10) is set so that the actual tightening torque value of the tightening machine becomes a desired torque value by repeating the operation of the torque adjustment dial (10), the tightening of the nut by the tightening machine, and the tightening of the torque wrench several times.

Nuts used for large-sized metal frame structures such as bridges are large-sized, and it is a heavy burden to manually tighten a torque wrench. Further, there are many problems in safety in an operation environment where it is difficult to use a torque wrench, such as inconvenience and footing at a high place.

Therefore, as shown in fig. 24, a tightening torque measuring tool (9) attached to a tightening machine body (1) has been proposed.

The principle that the fastening torque of the X diagram of fig. 22 is approximately proportional to the distortion of the fastening machine shown in the Z diagram is utilized.

A tightening machine body (1) has a 1 st output shaft (12) and a 2 nd output shaft (13) which are coaxially rotated in opposite directions, and in order to perform a normal tightening operation, a tightening socket (21) is attached to the 1 st output shaft (12), a reaction force receiver (22) is attached to the 2 nd output shaft (13), the tightening socket (21) is engaged with a nut N, and the reaction force receiver (22) is brought into contact with a protrusion (not shown) such as another nut near the nut N to perform tightening.

The tightening torque measuring tool (9) is used by being connected between the 1 st output shaft (12) of the tightening machine body (1) and the tightening socket (21). The tightening torque measuring tool (9) has a prismatic hole (92) into which a prismatic shaft part (12a) of a 1 st output shaft (12) of a tightening machine body (1) is fitted at the base end of a central shaft part (91), and has a prismatic shaft (93) at the tip end thereof, which is fitted to the base end of a tightening socket (21).

A distortion measuring instrument (47) is attached to the surface of a central shaft part (91) of a tightening torque measuring tool (9), and a circuit board, a torque display part and a battery (none of which are shown) are provided around the shaft part (91).

In the torque adjustment and confirmation of the tightening machine equipped with the tightening torque measuring tool (9), first, as described above, the torque adjustment dial (10) provided in the tightening machine body (1) is set to be slightly lower than a desired torque value.

A reaction force bracket (22) is mounted on a 2 nd output shaft (13) of a tightening machine body (1), a tightening socket (21) is engaged with a nut N, and the nut N is tightened by abutting the reaction force bracket (22) against a protrusion near the nut.

When the value of the current flowing through the motor of the fastening machine reaches a predetermined value, the motor is stopped, and the fastening torque corresponding to the amount of distortion of the shaft part (91) of the fastening torque measuring tool (9) at that time is displayed on the display part.

The torque adjustment dial (10) is set so that the operation of the torque adjustment dial (10) and the tightening of the nut are repeated several times, and the actual tightening torque value displayed on the display unit of the tightening machine becomes a desired torque value.

In this way, since the desired torque value can be set by operating the torque adjustment dial by observing the actual tightening torque value displayed on the display unit, the worker does not have to tighten with the torque wrench to measure the tightening torque.

Therefore, the problems of labor burden, danger, and the like of the tightening work using the torque wrench are solved.

The tightening torque measuring tool (9) is of a single shaft type, and the reaction force receiver (22) must be attached to the 2 nd output shaft (13) of the tightening machine body (1).

When the fastening socket (21) is directly attached to the 1 st output shaft (12) of the fastening machine body (1), the reaction force bracket arm (20) of the reaction force bracket (22) may be extended only by the length of the fastening socket (21) in the direction along the socket.

However, when the tightening torque measuring tool (9) is inserted between the tightening machine body (1) and the tightening socket (21), the reaction force bracket arm (20a) must be extended to the length of the tightening torque measuring tool (9). Thus, the distance between the 2 nd output shaft (13) of the tightening machine body (1) which is subjected to the tightening reaction force and the tip of the reaction force bracket arm (20a) which abuts against the partner member which actually receives the tightening reaction force becomes longer. At this time, the reaction force acting on the reaction force cantilever (20a) acts greatly so as to tilt the cantilever. Therefore, when the nut is fastened, the axes of the fastening machine body (1), the fastening torque measuring tool (9), and the fastening socket (21) which should be aligned on a straight line on the extension line of the axis of the nut are unstable, and there is a possibility that the fastening torque in a state of being inclined with respect to the axis of the nut, that is, an incorrect torque value is displayed.

When the torque adjustment of the fastener body (1) is completed, the fastening torque measuring tool (9) is generally removed, and the fastening socket (21) is directly connected to the fastener body (1) to perform the fastening operation. At this time, the reaction force bracket (22) also needs to be replaced with one having a short cantilever length. And the torque transmission efficiency varies due to the length of the cantilever. That is, when the tightening torque measuring tool (9) is set or removed, an error occurs in the value of the tightening torque.

The invention aims to provide a torque measuring device and a torque display fastening machine, wherein the value of fastening torque when the torque measuring device is installed on and removed from a fastening machine main body does not generate errors as much as possible.

Disclosure of Invention

A tightening torque measuring device (4) of the present invention has an inner shaft (31) connectable to a 1 st output shaft (12) of a tightening machine body (1), an outer shaft (32) connectable to a 2 nd output shaft (13), a tightening socket (21) provided at the tip of the inner shaft (31), a reaction force bracket (22) provided at the tip of the outer shaft (32), a distortion measuring instrument (47) provided on the outer shaft (32), a circuit board (7) for converting the distortion detected by the distortion measuring instrument into a corresponding tightening torque, and a display unit (5) for displaying the tightening torque.

Since the tightening torque is displayed on the display unit (5) of the tightening torque measuring device (4), the torque measuring operation by tightening the torque wrench with a torque indicator is not required.

Since the reaction force bracket (22) is provided in the tightening torque measuring device (4), the length of the reaction force bracket arm (20) of the reaction force bracket (22) can be reduced as compared with the case where the reaction force bracket (22) is attached to the tightening machine body (1). Therefore, the operation of the tightening reaction force falling reaction force bracket (22) can be reduced, and the accurate tightening torque can be measured by aligning the axial centers of the tightening machine body (1), the tightening torque measuring tool (9), and the tightening socket (21) on a straight line on the extension line of the axial center of the nut.

When the tightening torque measuring device (4) is detachably attached to the tightening machine body (1), the tightening torque measuring device (4) can be removed from the tightening machine body (1) after the tightening torque of the tightening machine body (1) is correctly set, and the tightening socket (21) and the reaction force bracket (22) can be directly attached to the tightening machine body (1). That is, the tightening operation can be performed with reduced weight by making the tightening machine as small as possible to subtract a part of the tightening torque measuring device (4).

If the tightening machine is provided with the torque measuring function of the tightening torque measuring device (4) without the need to attach and detach the tightening torque measuring device (4) to and from the tightening machine body (1), the tightening operation can be performed while confirming the tightening torque without requiring the attachment and detachment of the tightening torque measuring device (4).

Drawings

Fig. 1 is an exploded front view of a tightening torque measuring device.

Fig. 2 is a sectional view of the tightening torque measuring device.

Fig. 3 is a sectional view of the tightening torque measuring device attached to the tightening machine body.

Fig. 4 is an exploded perspective view of the fastening torque measuring apparatus main body.

Fig. 5 is a sectional view of the fastening torque measuring apparatus main body.

Fig. 6 is a sectional view taken along line a-a of fig. 5.

Fig. 7 is a sectional view of the display portion and the push switch on the circuit board.

Fig. 8 is an exploded front view of the tightening torque measuring device of embodiment 2.

Fig. 9 is a sectional view of the tightening torque measuring apparatus according to embodiment 2.

Fig. 10 is a sectional view of the tightening torque measuring device attached to the tightening machine body.

Fig. 11 is an exploded front view of the tightening torque measuring device of embodiment 3.

Fig. 12 is a sectional view of the tightening torque measuring apparatus according to embodiment 3.

Fig. 13 is a sectional view of the tightening torque measuring device connected to the tightening machine body.

Fig. 14 is a front view of the fastening torque measuring device according to embodiment 4 removed from the fastening device main body.

Fig. 15 is a sectional view of the fastening torque measuring device according to embodiment 4 taken out of the fastening device main body.

Fig. 16 is a sectional view showing a state where a tightening torque measuring device is attached to a tightening machine body.

Fig. 17 is a front view of the fastening torque measuring device according to embodiment 5 removed from the fastening device main body.

Fig. 18 is a sectional view of the fastening torque measuring device according to embodiment 5 taken out of the fastening device main body.

Fig. 19 is a sectional view showing a state where the socket device is directly connected to the fastener body.

Fig. 20 is a diagram showing the first half of the operation flow.

Fig. 21 is a diagram showing the latter half of the operation flow.

Fig. 22 is a diagram showing a relationship between fastening torque, load current, and distortion amount.

Fig. 23 is a sectional view of main parts of the torque display fastening machine of the other embodiment.

Fig. 24 is an explanatory view of the use of the tightening torque measuring tool of the present example.

Detailed Description

The present invention will be specifically described below with reference to the illustrated examples.

[ 1 st embodiment (FIGS. 1 to 7) ]

Fig. 1 and 2 show a state in which the tightening torque measuring device (4) is removed from the fastening machine body (1) and the tightening torque measuring device (4) is separated into the device body (3) and the socket device (2). Fig. 3 shows a state in which the tightening torque measuring device (4) is attached to the tightening machine body (1).

A cylindrical 1 st output shaft (12) is coaxially disposed on the inner side and a cylindrical 2 nd output shaft (13) is disposed on the outer side of the front end of the fastener body (1). The 1 st output shaft (12) and the 2 nd output shaft (13) are connected to the planetary gear speed reduction mechanism (11) so as to be rotated in opposite directions to each other.

The planetary gear reduction mechanism (11) is operated by a motor (not shown) built in the fastener body (1).

The tightening machine body (1) has a torque adjustment dial (see reference numeral 10 in fig. 24) for adjusting the tightening torque. The dial adjusts the tightening torque based on the principle that the value of the current flowing through the motor and the tightening torque are approximately proportional to each other.

Ridges (15) and grooves (16) extending in the axial direction are formed on the inner surface of the 1 st output shaft (12) so as to be staggered with each other in the circumferential direction.

The 2 nd output shaft (13) extends slightly outward from the 1 st output shaft (12), and a plurality of protruding pieces (17) protrude at equal intervals at the front end edge. A retaining bolt (18) of the relative fastening torque measuring device (4) is screwed to the front end of the 2 nd output shaft (13).

The tightening torque measuring device (4) is composed of a device body (3) and a socket device (2).

In a normal fastening operation, the socket device (2) is directly connected to the fastener body (1) and used.

The socket device (2) is composed of a fastening socket (21) and a reaction force bracket (22).

The reaction force bracket (22) is formed by a reaction force bracket arm (20) protruding on the outer periphery of the enlarged part of the cylindrical member (23) with the front end side enlarged and perpendicular to the axial center of the cylindrical member (23).

A circumferential groove (29) into which the tip of the retaining bolt (18) of the fastener body (1) can enter is formed in the base end of the tubular member (23) of the reaction force bracket (22).

A peripheral wall (27) is formed on the reaction force bracket (22) at a position slightly more forward than the circumferential groove (29), and a notch (28) into which the protruding piece (17) on the 2 nd output shaft (13) of the tightening machine body (1) can be fitted is opened in the peripheral wall (27).

The fastening socket (21) enlarges the tip of a barrel shaft part (21a) rotatably housed in a barrel member (23) of a reaction force bracket (22), and a nut engagement hole (24) is formed in the enlarged part.

The proximal end of a cylindrical shaft portion (21a) of the fastening socket (21) protrudes from a cylindrical member (23) of the reaction force holder (22), and concave strips (26) and convex strips (25) extending in the axial direction of the fastening socket (21) are formed on the outer peripheral surface of the protruding portion so as to be staggered in the circumferential direction. The concave strips (26) and the convex strips (25) can be embedded on the convex strips (15) and the concave strips (16) on the inner surface of the 1 st output shaft (12) of the fastening machine body (1).

When the open ring (22a) provided on the inner surface of the front end of the cylindrical member (23) of the reaction force bracket (22) is removed, the fastening socket (21) can be pulled out forward relative to the reaction force bracket (22). Therefore, the fastening sockets with different sizes of the nut engaging holes (24) can be replaced.

The device main body (3) has a cylindrical inner shaft (31) and a cylindrical outer shaft (32) that rotatably and coaxially houses the inner shaft (31).

The base end of the inner shaft (31) protrudes from the base end of the outer shaft (32), and concave strips (36) and convex strips (35) extending in the axial direction are formed on the outer peripheral surface of the protruding portion in a staggered manner in the circumferential direction. The concave strips (36) and the convex strips (35) can be embedded on the convex strips (15) and the concave strips (16) on the inner surface of the 1 st output shaft (12) of the fastening machine body (1).

A circumferential groove (38) into which the tip of the retaining bolt (18) of the fastening machine body (1) can be fitted is formed in the outer periphery of the base end of the outer shaft (32), and a cutout (37) into which the protruding piece (17) on the 2 nd output shaft (13) of the fastening machine body (1) is fitted is formed in the thick portion on the tip side of the circumferential groove (38).

The front end of the outer shaft (32) is formed with a size to be fitted to the base end of the tubular member (23) of the reaction force bracket (22), a retaining bolt (30) screwed to a circumferential groove (29) of the tubular member (23) is provided at the front end, and protruding pieces (39) to be fitted to notches (28) of the tubular member (23) are provided at the front end edge at equal intervals in the circumferential direction.

The outer shaft (32) is provided with 2 peripheral walls (32e, 32f) protruding from both end sides, and one peripheral wall (32e) is smaller in outer diameter and larger in wall thickness than the other peripheral wall (32 f). A hole (32c) for preventing a cylindrical sleeve (49) from falling off is formed in the peripheral surface of the small-diameter peripheral wall (32e), and 4 small screw holes (32g) are formed in the large-diameter peripheral wall (32f) so as to penetrate the peripheral wall and be equally spaced in the circumferential direction.

A distortion measuring instrument (47) is attached to the surface of the outer shaft (32) at the center between the peripheral walls (32e, 32 f).

In the embodiment, X-shaped distortion measuring instruments (47) are attached to the outer shaft (32) at 4 positions at equal intervals in the circumferential direction.

The distortion measuring instrument (47) is covered with a protective layer (48) that surrounds the outer shaft (32) in one turn.

Between the peripheral walls (32e, 32f), 2 blocks (41, 41) of the same shape on the outer shaft (32) are disposed facing each other with the outer shaft (32) therebetween.

The inner surface of the block (41) is formed in an arc shape along the outer shaft (32), and the outer surface is formed in an arc shape having a diameter slightly smaller than the outer diameter of the peripheral wall (32f) having a larger diameter than the inner diameter of the 2 peripheral walls (32e, 32f) of the outer shaft (32).

A groove (41a) for avoiding collision with the protective layer (48) is formed in the inner surface of the block (41).

A circumferential groove (42) and a W-shaped recess (43) extending in the axial direction across the circumferential groove (42) are formed on the outer periphery of the block (41).

The circumferential groove (42) serves as a passage through which wiring (not shown) connecting the distortion measuring devices (47) and circuit boards (7, 71) described later passes.

A box (44) is mounted on each W-shaped recess (43), and the box (44) accommodates a battery V.

Screw holes (41b) are formed in the end faces of the respective blocks (41, 41) so as to correspond to the 4 small screw holes (32g) of the large-diameter peripheral wall (32f) of the outer shaft (32), and the respective blocks (41, 41) are fixed to the peripheral wall (32f) by 2 small screws (40 b).

2 circuit boards (7, 71) are arranged between the two end faces of the blocks (41, 41) facing each other.

The circuit boards (7, 71) are supported by the end edges of the boards being fitted into grooves (45, 45) formed in the facing end surfaces of the blocks (41, 41).

A display unit (5) for displaying a tightening torque value corresponding to the amount of distortion of the distortion measuring device (47) and a push switch (6) for energizing the circuit boards (7, 71) are disposed on one of the circuit boards (7).

The display unit (5) of the embodiment is a 4-digit display, each digit display surface (51) can display the numbers from '0' to '9' by using 4 vertical and 3 horizontal light bars (52, 52a), and a point unit (53) for displaying the light (point) is arranged at the lower right of each digit display surface. An LED (not shown) is disposed at each of the bright light bars (52) (52a) and the point portion (53).

A cylindrical sleeve (49) is covered over 2 peripheral walls (32e, 32f) on the outer shaft (32), and a front end unthreaded part (40a) of a small screw (40) penetrating and screwed into one end of the peripheral wall of the sleeve is fitted into an engagement hole (32c) in the small-diameter peripheral wall (32 e). The peripheral wall (32e) does not have a screw thrust of the small screw (40) applied thereto.

A window 49a is opened in the cover 49 corresponding to the display part 5 and the button switch 6 on the circuit board 7, and the button switch 6 can be operated from the outside of the cover 49.

The 4-position distortion measuring instrument (47) on the outer shaft (32) forms a bridge circuit (not shown) on the circuit board (7), and a fastening torque value corresponding to the average distortion amount of the 4 positions of the outer shaft (32) to which the distortion measuring instrument (47) is attached is displayed on the display unit (5).

As shown in fig. 3, the fastening socket (21) and the reaction force bracket (22) of the socket device (2) are connected to the inner shaft (31) and the outer shaft (32) of the device body (3), thereby constituting a fastening torque measuring device (4).

The proximal end of an inner shaft (31) of a tightening torque measuring device (4) is fitted to a 1 st output shaft (12) of a tightening machine main body (1), the proximal end of an outer shaft (32) of the device (4) is inserted into a cylindrical 2 nd output shaft (13) of the tightening machine main body (1), and a protruding piece (17) on the 2 nd output shaft (13) is fitted into a notch (37) on the outer shaft (32).

Thus, the 1 st output shaft (12), the inner shaft (31) of the device body (3), and the fastening socket (21) are connected to be integrally rotatable, and the 2 nd output shaft (13), the outer shaft (32) of the device body (3), and the reaction force receiver (22) of the socket device (2) are connected to be integrally rotatable in the opposite direction to the rotation of the 1 st output shaft (12).

As described above, in the torque adjustment and confirmation of the tightening machine equipped with the tightening torque measuring device (4), the torque adjustment dial (10) provided in the tightening machine body (1) is first set to be slightly lower than a desired torque value.

A push switch (6) of a fastening torque measuring device (4) is pushed to supply electricity to circuit boards (7, 71).

A reaction force bracket (22) is attached to the 2 nd output shaft (13) of the tightening machine body (1), and a tightening socket (21) is engaged with a nut so that the reaction force bracket (22) abuts against a protrusion near the nut.

When the motor of the fastening machine body (1) is operated, the reaction force bracket (22) prevents the 2 nd output shaft (13) from rotating, so that only the 1 st output shaft (12) rotates. That is, the fastening socket (21) is rotated to fasten the nut.

When the current value flowing through the motor of the fastening machine reaches a predetermined value, the motor is stopped, and at this time, a distortion measuring device (47) at 4 detects the distortion of an outer shaft (32) of a fastening torque measuring device (4), and the average value of the distortion is displayed on a display part (5) as the fastening torque.

The reaction force bracket (22) can be used in the same manner when the tightening torque measuring device (4) is attached to and removed from the tightening machine body (1), and it is not necessary to prepare 2 types of reaction force brackets (22) having different cantilever lengths as in the prior art.

In the embodiment, the connection between the outer shaft (32) to which the distortion measuring instrument (47) is attached and the tightening machine body (1), and the connection between the outer shaft (32) and the socket device (2) are performed by fitting convex strips and concave strips extending in the axial direction with each other, or fitting protruding strips (17, 39) and notches (37, 28), that is, fitting convex strips and concave strips extending in the axial direction with each other. Therefore, when the nut is tightened, the outer shaft (32) does not cause a large error in the amount of distortion in the circumferential direction passing through each distortion measuring instrument (47). However, since the reliability of the measurement is lowered when the screw thrust of the retaining bolts (18, 30) is applied to the outer shaft (32), in the embodiment, the distortion amount is measured by the distortion measuring instrument (47) disposed at 4 positions at equal intervals in the circumferential direction of the outer shaft (32), and the average value of the measured distortion is displayed to improve the reliability of the measurement.

The distortion measuring instrument (47) is attached to the outer shaft (32), and is not limited to 4 positions as in the embodiment, but may be a multiple of 2 such as 2, 4, 6 positions, and the like. The greater the number of the distortion measuring instruments (47), the higher the measurement accuracy of the tightening torque can be made.

The distortion measuring instrument is preferably installed at 4 points from the perspective of the circumference of the outer shaft (32) of the tightening torque measuring device (4) and the accuracy required for the tightening torque of the bolt/nut, which is suitable for the size of the bolt-nut tightening machine used for worker support.

The torque measurement accuracy of the distortion measuring instrument is not necessary when the distortion measuring instrument is set to 6 or more, and the reliability of the torque measurement of the distortion measuring instrument is unstable when the distortion measuring instrument is set to 2.

Since the tightening torque is displayed on the display unit (5) of the tightening torque measuring device (4) as described above, it is not necessary to perform tightening work using a torque wrench with a torque indicator as in the prior art.

The reaction force bracket arm (20) is provided so as to protrude outward from the same position as the nut at the outer peripheral portion of the reaction force bracket (22) covering the tightening socket (21), and therefore the tightening reaction force acting on the reaction force bracket arm (20) does not act so as to fall down the tightening torque measuring device (4) or the tightening machine body (1). Therefore, the fastening torque measuring device (4) and the fastening torque measuring device (4) can be made to be aligned with the axis of the nut to fasten the nut, and the fastening torque value can be displayed on the display unit (5) as accurately as possible.

The torque adjustment dial (10) may be set by repeating the operation of the torque adjustment dial (10) of the tightening machine body (1) and the tightening of the nut several times so that the actual tightening torque value displayed on the display unit (5) of the tightening torque measuring device (4) becomes a desired torque value.

The reaction force bracket (22) can be used in the same manner when the tightening torque measuring device (4) is attached to and removed from the tightening machine body (1), and it is not necessary to prepare 2 kinds of reaction force brackets (22) having different cantilever lengths as in the prior art.

After the reliability of torque setting is confirmed by performing the above-described operation on a plurality of nuts, the tightening torque measuring device (4) is taken out from the tightening machine body (1), and the socket device (2) of the tightening torque measuring device (4) is directly connected to the tightening machine body (1). Specifically, the concave strips (26) and convex strips (25) at the base end of the fastening socket (21) of the socket device (2) are fitted to the convex strips (15) and concave strips (16) of the 1 st output shaft (12) of the fastening machine body (1), the base end of the reaction force bracket (22) is fitted to the 2 nd output shaft (13), and the projecting strips (17) on the 2 nd output shaft (13) are engaged with the notches (28) on the reaction force bracket (22).

As described above, if the socket device (2) is directly connected to the tightening machine body (1), the nut can be tightened by reducing the weight of the device body (3) of the tightening torque measuring device (4) and the torque of the tightening machine body (1) can be adjusted, so that the nut is tightened with a set torque and the rotation of the tightening socket (21) is automatically stopped.

The inner shaft (31) of the device body (3) of the tightening torque measuring device (4) of the embodiment is formed in a cylindrical shape to reduce the weight, and can be retracted into the inner shaft (31) even if the bolt is left for a surplus length (the bolt tip protrudes from the nut top surface) in the nut tightening.

[ 2 nd embodiment (FIGS. 8 to 10) ]

Fig. 8 and 9 show a state in which the tightening torque measuring device (4) is removed from the fastening machine body (1), and the tightening torque measuring device (4) is separated into the device body (3), the tightening socket (21), and the reaction force receiver (22). Fig. 10 shows a state in which the tightening torque measuring device (4) is attached to the tightening machine body (1).

The fastening machine body (1) is the same as the aforementioned embodiment 1.

The device body (3) of the tightening torque measuring device (4) differs from the embodiment 1 in the tip end portions of the inner shaft (31) and the outer shaft (32), and the other portions are the same.

The front end of the outer shaft (32) of the device body (3) forms a short polygonal shaft part (32a), and in the embodiment, forms a hexagonal shaft part.

The front end side of the inner shaft (31) of the device main body (3) is closed, and a polygonal shaft part (32a) of the outer shaft (32) is rotatably penetrated, and a prism shaft (31a) is arranged at the front end in a protruding way.

The fastening socket (21) has a nut engaging hole (24) coaxially opened at the tip end and a prism hole (2a) opened at the base end, and a prism shaft (31a) at the tip end of an inner shaft (31) of the device body (3) is detachably fitted in the prism hole (2 a).

The reaction force bracket (22) is formed by arranging a reaction force bracket cantilever (20) on the periphery of the ring part (22b) in a protruding way.

The ring part (22b) is integrally and rotatably fitted to a polygonal shaft part (32a) of an outer shaft (32) of the device body (3). The locking bolt (22c) for retaining is screwed on the ring part (22b) through the hole.

The reaction force bracket arm (20) extends from the ring portion (22b) to the front end of the fastening socket (21) and is bent at a substantially right angle on the outside.

In comparison with the embodiment 1, the reaction force bracket arm 20 of the reaction force bracket 22 has a length that forms only the length of the fastening socket 21 in the direction along the axial center of the fastening socket 21. Therefore, the stability that the axial centers of the fastening socket (21), the device body (3), and the fastener body (1) are aligned on a straight line during fastening is reduced. However, compared with the conventional example shown in fig. 24 in which the reaction force bracket (22) is attached to the tightening machine body (1) further inside than the tightening torque measuring tool (9) connected to the tightening machine body (1), the length of the reaction force bracket arm (20) in the axial direction of the tightening socket (21) can be shortened, and the stability at the time of tightening is better than that of the conventional example.

The socket device (2) according to embodiment 1 can be directly attached to the fastener body (1) by removing the device body (3) from the fastener body (1), and a normal nut tightening operation can be performed.

Example 3 (FIGS. 11 to 13)

Fig. 11 and 12 show a state in which the tightening torque measuring device (4) is removed from the fastening machine body (1), and the tightening torque measuring device (4) is separated into the device body (3), the tightening socket (21), and the reaction force receiver (22). Fig. 13 shows a state in which the tightening torque measuring device (4) is attached to the tightening machine body (1).

The installation relationship of the device body (3), the fastening socket (21), and the reaction force receiver (22) is the same as in embodiment 2.

The fastening machine body (1) and the device body (3) are different from the embodiments 1 and 2.

The 2 nd output shaft (13) of the fastening machine main body (1) is a polygonal shaft part (13a) formed at the front end part. A1 st output shaft (12) of the fastener body (1) is provided with a polygonal shaft portion (13a) which closes the front end side and which rotatably penetrates the 2 nd output shaft (13), and a prism (12a) is provided at the front end thereof in a protruding manner.

An engagement hole (32b) into which a polygonal shaft part (13a) of a 2 nd output shaft (13) of a fastening machine body (1) is fitted is opened at the base end of an outer shaft (32) of the device body (3). A screw-on anti-slip fastening bolt (32d) is passed through the peripheral wall of the engagement hole (32 b).

A prism hole (32b) into which a prism shaft (12a) at the tip of a 1 st output shaft (12) of a fastener body (1) is fitted is formed at the base end of an inner shaft (31) of the device body (3).

A ring part (22b) of a reaction force bracket (22) is fitted to a polygonal shaft part (32a) of an outer shaft (32) of an apparatus body (3) so as to be integrally rotatable, and a prism shaft (31a) of an inner shaft (31) is fitted to a prism hole (2a) of a fastening socket (21) to perform a normal nut fastening operation.

Example 4 (FIGS. 14 to 16)

Fig. 14 and 15 show a state in which the tightening torque measuring device (4) is removed from the tightening machine body (1), and fig. 16 shows a state in which the tightening torque measuring device (4) is attached to the tightening machine body (1).

The fastening torque measuring device (4) and the fastening machine body (1) are mounted in the same manner as in the above-described embodiments 1 and 2.

A nut engagement hole (24) is formed in an inner shaft (31) of a tightening torque measuring device (4) by enlarging the tip end thereof.

A snap ring (22e) for preventing the inner shaft (31) from coming off is provided at the front end of the inner surface of the outer shaft (32). The inner shaft (31) can be replaced by a nut engaging hole (24) having a different size.

The outer periphery of the tip end of an outer shaft (32) of a tightening torque measuring device (4) is formed in a spline shape with ridges and grooves extending in the axial direction being staggered in the circumferential direction.

A reaction force bracket (22) is attached to the tip of the outer shaft (32).

The reaction force bracket (22) is formed by arranging a reaction force bracket cantilever (20) outwards in a ring part (22b) which is embedded at the front end of the outer shaft (32). Concave strips and convex strips which are clamped on the convex strips and the concave strips of the outer shaft (32) are formed on the inner surface of the ring part (22b), and the outer shaft (32) and the reaction force support (22) rotate integrally.

The snap ring (22d) can be removed and the reaction force bracket (22) can be pulled out from the outer shaft (32).

As described above, if the convex and concave strips of the reaction force bracket (22) are fitted to the spline-like concave and convex strips on the outer periphery of the tip of the outer shaft (32), the reaction force applied to the reaction force bracket arm (20) can be applied uniformly to the entire circumference of the outer shaft (32), and the distortion of the outer shaft (32) can be detected as accurately as possible by the distortion measuring instrument (47) without causing variations.

In the case of embodiment 4, when the torque setting of the tightening machine body (1) is completed and the normal nut tightening operation is performed, the tightening torque measuring device (4) may be removed and the socket device (2) shown in fig. 1 may be attached to the tightening machine body (1).

Example 5 (FIGS. 17 to 19)

Fig. 17 shows a state where the tightening torque measuring device (4) is removed from the fastening machine body (1). Fig. 18 shows a state in which the tightening torque measuring device (4) is attached to the tightening machine body (1).

The 5 th embodiment is implemented in a fastening machine for fastening a bolt B having a shearing or reaction receiving end T and a nut N, as shown in fig. 18.

The fastening torque measuring device (4) and the fastening machine body (1) are mounted in the same manner as in embodiment 1.

A socket device (2) detachably connected to the front end of a device body (3) is composed of a nut engaging socket (21b) engaged with a nut, and a bolt end engaging socket (22b) rotatably disposed in the socket (21b) and engaged with a bolt end T.

A recessed part (29a) such as a hole or a circumferential groove into which the tip of the retaining bolt (18) of the tightening machine body (1) or the retaining bolt (30) of the tightening torque measuring device (4) can be inserted is formed in the base end part of the nut engaging socket (21 b).

A peripheral wall (27a) is formed on the nut engaging socket (21b) slightly ahead of the recess (29a), and a notch (28a) into which a protruding piece (17) on the 2 nd output shaft (13) of the fastening machine body (1) or a protruding piece (39) of the device body (3) can be fitted is opened in the peripheral wall (27 a).

On the outer peripheral surface of the base end of the bolt distal end engagement socket (22b), concave strips (26a) and convex strips (25a) extending in the circumferential direction are formed in a staggered manner in the circumferential direction. The concave strips (26a) and the convex strips (25a) can be engaged with the convex strips (15) and the concave strips (16) on the inner surface of the 1 st output shaft (12) of the fastening machine body (1) or the convex strips (33) and the concave strips (34) on the front end of the inner shaft (31) of the device body (3).

As shown in fig. 18, the fastening torque measuring device (4) is configured by connecting the nut engagement socket (21b) and the bolt end engagement socket (22b) of the socket device (2) to the inner shaft (31) and the outer shaft (32) of the device body (3). Then, as described above, the tightening torque measuring device (4) is connected to the tightening machine body (1).

In fig. 18, a reference numeral (100) denotes a spring, which is disposed between a convex portion (31c) on the inner surface of an inner shaft (31) of the device body (3) and the bolt distal end engagement socket (22b) and functions to urge the bolt distal end engagement socket (22b) forward and abut against an inner peripheral step portion (21c) of the nut engagement socket (21 b).

The bolt end T is engaged with the bolt end engagement socket (22b), and the nut N is engaged with the nut engagement socket (21b), so that the tightening machine is operated.

When the 2 nd output shaft (13) of the fastening machine body (1) rotates, the nut engagement socket (21b) of the socket device (2) also rotates via the outer shaft (32) of the device body (3) to fasten the nut (N).

The tightening reaction force is received by the bolt B by engaging the 1 st output shaft (12) of the tightening machine body (1), the inner shaft (31) of the device body (3), and the bolt end of the socket device (2) with the socket (22B).

As the tightening progresses, the amount of protrusion of the bolt shaft from the nut N increases, but the bolt tip engagement socket (22b) retreats against the spring (100), and therefore the tightening is not hindered.

When the bolt/nut is tightened by torque before shearing the bolt end T, the bolt end engagement socket (22b) engaged with the bolt end T becomes a reaction force receiver.

When the bolt tip T is sheared, a nut engagement socket (21b) engaged with the nut N becomes a reaction force receiver.

Fig. 19 shows a state in which the socket device (2) is directly connected to the fastener body (1). The normal fastening operation after the fastening torque setting is performed in the state of fig. 19. A spring (100) for biasing the bolt distal end engagement socket (22b) is abutted against a planetary gear support bracket (11a) of the fastening machine body (1) and the like.

Fig. 22 shows the relationship between the torque generated in the tightening machine during the nut tightening, the amount of distortion of the tightening machine, specifically, the outer shaft (32) of the apparatus main body (3) of the relative tightening torque measuring apparatus (4), and the load current of the tightening machine. When the tightening machine is started and tightening of the bolt is started, the torque generated by the tightening machine (tightening torque of the bolt) gradually increases, and in proportion thereto, the load current of the tightening machine also gradually increases.

When a constant torque is introduced into the bolt and the current supply to the tightening machine is stopped, the torque introduced into the bolt is maintained (see the broken line in fig. 22), and the generated torque and the load current of the tightening machine are rapidly reduced. Therefore, the amount of distortion of the tightening torque measuring device (4) proportional to the torque generated by the tightening machine also decreases rapidly. That is, it is not necessary to detect the amount of distortion after the bolt is fastened until the fastening of the bolt at the rear is started.

The applicant therefore proposes in the present invention: after the tightening torque is maintained at a high level, the tightening torque measuring device (4) cuts off the power supply to the distortion sensor bridge circuit, and the LED of the display unit (5) is energized only when necessary, so that unnecessary current consumption is eliminated, and the life of the battery V mounted on the tightening torque measuring device (4) is prolonged. It is also proposed that: the control circuit formed on the circuit board (7, 71) of the fastening torque measuring device (4) can be operated by 1 push-button switch (6), thereby reducing the arrangement space of the push-button switch (6) on the circuit board (7).

Generally, the control circuit requires 2 or more operation switches for the power switch and the set (reset) switch. When a control circuit of the CPU is mounted, the CPU power supply is set to be normally On (standby power) in advance, or after the power supply is set to be On, if the setting switch is not pressed, the CPU [ bridge power supply On + auto zero (described later) ] cannot be set. However, if 2 or more switches are mounted on the circuit board (7), the number of components increases and the area of the circuit board (7) becomes large. Further, if the CPU power supply is set to be constant On, the battery consumption increases. Therefore, in this embodiment, a forced self-hold circuit is provided outside the CPU, and while the button switch (6) is On, the power is supplied to the CPU and a self-hold command is output by the CPU, and the power is continuously supplied even if the switch is Off. At the same time, an On/Off recognition input port of the push switch (6) is provided, and when the push switch (6) is On, a switch On signal is input to the port, so that the power supply On and setting can be used as well.

Since the same button switch (6) is used as both an On/Off switch and a setting switch of the power supply, the On/Off switch and the setting switch are distinguished by different On times [ the time for which the button switch (6) is continuously pressed ]. In the embodiment, the power source On is a long press set to 1 second or more, and a short press set to 1 second or less (the shortest time recognizable to the CPU or more) is set. The power supply is set to On by a short-press of the push switch (6) while the power supply is held On by self. The power supply Off is a circuit for releasing the self-hold circuit by setting the On time to 3 seconds or more, and cuts Off all power supplies (including the CPU power supply) while leaving the button switch (6).

By setting the power On time to 1 second and the power Off time to 3 seconds, not only is the setting distinguished from the setting of a short press of the button switch (6), but also On or Off caused by malfunction of the power supply is effectively prevented.

Fig. 20 and 21 are flowcharts of the operation of the control circuit.

It is judged in step 1 from the start whether or not the push switch is pressed (6). If no, return to before step 1. If yes, the process proceeds to step 2(S2) to start supplying power to the CPU on the circuit board (7).

When the CPU is started to be supplied with power, the process proceeds to step 3(S3), and it is judged whether or not the time for pressing the push switch 6 is 1 second or more. If not, the process proceeds to step 4(S4), and power supply to the CPU is terminated, and the process returns to the step 1. If so, the process proceeds to step 5(S5) to self-hold the CPU power supply, and power supply to the LED of the display unit 5 is started in step 6 (S6).

Then, the process shifts to a data setting operation, and in step 7(S7), the display unit (5) displays "0" for only 1 digit and all the other digits are set to Off. In step 8(S8), power supply to the bridge circuit constituted by the distortion measuring instrument (47) and the analog amplifier circuit for amplifying the signal is started. With a slight time lag, in step 9(S9), the analog value of the voltage output from the bridge circuit of the distortion measuring instrument (47) at the time of torque 0 (zero) is converted into a digital value, and "auto-zero" is performed by converting the value obtained by subtracting the analog value into a torque value. The auto zero (S9) is a function generally carried by a torque measuring device and automatically corrects a variation in voltage output from a bridge of a distortion measuring device (47) when the torque is 0 (zero) due to disturbance such as temperature.

Then, in step 10(S10), it is judged whether or not the tightening torque exceeds the desired torque value, and if so, before returning to step 10(S10), if so, step 11(S11) is performed to measure the torque, and the tightening torque gradually rising is displayed on the display unit (5). The level at which the torque measurement starts is preferably about 10% of the freeze torque of the fastener body (1), but if malfunction can be prevented, it is preferable to be as close to 0 (zero) as possible.

It is then determined whether a torque peak is detected in step 12(S12), and if so, the power supply to the bridge circuit is ended in step 13(S13) before returning to step 12 (S12). However, the display unit (5) is kept in a state of displaying the peak value.

It is then judged in step 15(S15) whether or not the push button switch (6) is pressed, and if not, it is returned to before step 15 (S15).

If yes in step 15(S15), the process proceeds to step 16(S16) and it is determined whether or not the time for pressing the push switch (6) is 3 seconds or longer. If not, the process returns to step 7(S7) to prepare for the next torque measurement.

If yes in step 16(S16), the power supply to the display unit (5) is terminated in step 17 (S17).

The self-hold of the CPU power is then ended at step 18(S18), and it is judged at step 19(S19) whether the pressing of the push button switch (6) is released, and before returning to step 19(S19) if it is, and before returning to step 1(S1) if it is.

As described above, the power supply is supplied to the bridge of the distortion measuring instrument (47) only for the time necessary for measurement, whereby the battery V can be suppressed from being consumed, and the Joule heat generated by the current flowing through the bridge of the distortion measuring instrument (47) can be suppressed as much as possible. Further, the operation for both the power supply On and the auto zero is constituted by the "1 second or more press" of the button switch (6) in the state where the CPU power supply is not self-held.

Further, the automatic zero setting for the torque measurement 2 times or later is performed by the "3 second or less pressing" of the push switch (6), the power supply Off operation is performed by the "3 second or more pressing" of the push switch (6) in the state of self-holding of the CPU power supply, and 3 kinds of switching functions are provided by 1 push switch (6). Thus, compared with 3 switches, the switch arrangement area can be reduced, and the pressing error of the switch can be prevented.

In the above, the judgment reference of the pressing time of the button switch (6) is set to 1 second and 3 seconds, but the judgment reference is not limited to this, and any judgment reference may be set as long as the worker does not feel too short or too long.

In each of the above embodiments, the socket device (2) is detachably connected to the fastener body (1) on the premise that the socket device (2) is removed from the fastener body (1) if the fastening torque is set, but it is needless to say that the fastening work of the bolt and the nut can be performed when the socket device (2) is attached to the fastener body.

Next, a torque display tightening machine in which a distortion measuring instrument (47) is provided on an output shaft of the tightening machine will be described with reference to fig. 23.

A1 st output shaft (12) is projected from a planetary carrier (11a) of a planetary gear reduction mechanism (11) of a fastener, and a 2 nd output shaft (13) is projected from a ring gear (11b) of the planetary gear reduction mechanism (11).

The 1 st output shaft (12) may be integrated with the planetary carrier (11a), or may be integrally rotatably coupled by the planetary carrier (11a) and the spline engagement (12 a).

The 2 nd output shaft (13) may be integrated with the ring gear (11b), or may be integrally rotatably coupled by making a notch (37) in the 2 nd output shaft (13) and fitting a plurality of protruding pieces (17) protruding toward the tip end side of the ring gear (11 b).

A fastening socket (21) having a nut engaging hole (24) is formed at the tip of the 1 st output shaft (12), and a reaction force receiver (22) is provided at the tip of the 2 nd output shaft (13).

Although the reaction force bracket (22) and the 2 nd output shaft (13) may be integrated, in the embodiment, the reaction force bracket (22) and the 2 nd output shaft (13) are formed separately in consideration of easy assembly and replacement of the reaction force bracket (22) which is easily damaged. The reaction force bracket (22) is attached to the 2 nd output shaft (13) by the same connection structure as that of the reaction force bracket (22) and the outer shaft (32) of the tightening torque measurement device (4) according to the aforementioned embodiment 4.

The 2 nd output shaft (13) is provided with a distortion measuring instrument (47), a circuit board (7), a display unit (5), and a battery (not shown). The mounting structure is the same as the structure in which the distortion measuring instrument (47), the circuit board (7), the display unit (5), and the battery (not shown) are mounted on the outer shaft (32) in the fastening torque measuring device.

The ring gear (11b) and the 2 nd output shaft (13) are disengaged from each other by fitting a pin (12b) disposed so as to penetrate the ring gear (11b) perpendicularly to the axial center of the ring gear (11b) into a recess (12d) such as a hole or a circumferential groove of a fitting portion (12c) of the 2 nd output shaft (31) toward the tip of the ring gear (11 b).

The end of a cylindrical sleeve (44) covering the circuit board (7) or the like covers the pin (12b) at the tip of the internal gear (11b) so as not to pull out the pin (12 b).

In the torque indicating fastener shown in fig. 23, if the 1 st output shaft (12) is not integrated with the planetary carrier (11a) and the 2 nd output shaft (13) is integrated with the planetary carrier (11a), the same is almost the same as the embodiment shown in fig. 14, 15, and 16, but in order to avoid a misunderstanding that the fastening torque measuring device (4) is detachably attached to the fastener main body (1) as an essential configuration of the present invention, an additional description is made in fig. 23.

The above description is illustrative of the invention and should not be taken as limiting or narrowing the scope of the claims. The respective configurations of the present invention are not limited to the above-described embodiments, and various modifications are naturally possible within the technical scope described in the claims.

For example, the fastening socket (21) of the embodiment has a nut engagement hole (24) at the tip, but is not limited thereto. It is needless to say that the fastening socket (21) of the present invention includes a hexagonal shaft or a polygonal shaft that is engaged with a mating bolt or nut, such as a hexagonal shaft that is engaged with a hexagonal hole of a hexagonal hole bolt, provided at the tip of the fastening socket (21) in a protruding manner.

In the embodiment, the fastening torque measuring device (4) is provided with not only the distortion measuring device (47) but also the circuit board (7) and the display unit (5) on the outer shaft (32), but the invention is not limited thereto, and the circuit board (7) and the display unit (5) may be disposed at an appropriate place on the fastening machine or at an appropriate place other than the fastening machine. When wiring is performed on the side of the distortion measuring instrument (47), the side of the circuit board (7) and the side of the display unit (5), signals cannot be transmitted infinitely.

Claims (12)

1. A tightening torque measuring device 4 detachably connected to a bolt or nut tightening machine body 1, the tightening machine body 1 having a 1 st output shaft 12 and a 2 nd output shaft 13 coaxially rotatable in opposite directions,

the method is characterized in that: the tightening torque measuring device (4) has an inner shaft (31) connectable to a 1 st output shaft (12) of a tightening machine body (1), an outer shaft (32) connectable to a 2 nd output shaft (13), one of a tightening socket (21) and a reaction force holder (22) is provided at the tip of the inner shaft (31), the other is provided at the tip of the outer shaft (32), a distortion measuring instrument (47) is provided on the outer shaft (32), and the device has a circuit board (7) for converting the amount of distortion detected by the distortion measuring instrument into a corresponding amount of tightening torque, and a display unit (5) for displaying the amount of tightening torque.

2. The tightening torque measuring device according to claim 1, characterized in that: the tightening torque measuring device (4) is a socket device (2) detachably connected to a device main body (3) including an inner shaft (31) and an outer shaft (32), and the socket device (2) is composed of a reaction force bracket (22) formed by projecting a reaction force bracket arm (20) on a cylindrical member (23), and a tightening socket (21) rotatably fitted to the cylindrical member (23) of the reaction force bracket (22).

3. The tightening torque measuring device according to claim 1, characterized in that: the fastening socket (21) is detachably attached to a ridge shaft (31a) projecting from the front end of the inner shaft (31), and the reaction force bracket (22) is detachably attached to the outer shaft (32).

4. The tightening torque measuring device according to claim 2, wherein: the connection of the two shafts (12, 13) of the tightening machine body (1) and the two shafts (31, 32) of the device body (3), and the connection of the two shafts (31, 32) of the device body (3) and the tightening socket (21) and the reaction force bracket (22) are performed by fitting of a convex portion and a concave portion which are separated and engaged in the direction along the axis of the tightening torque measuring device (4).

5. The tightening torque measuring device according to claim 1, characterized in that: the outer shaft (32) is provided with 2 peripheral walls (32e, 32f) at intervals, a distortion measuring instrument (47) is attached to the outer shaft (32) between the peripheral walls (32e, 32f), a display part (5), a circuit board (7), a push-button switch (6) and a battery V are accommodated between the peripheral walls (32e, 32f), the display part is covered by a cylindrical sleeve (49) which is inserted on the outer shaft (32) across the 2 peripheral walls (32e, 32f), and the positions of the display part (5) and the push-button switch (6) are set corresponding to a window part (49a) provided on the cylindrical sleeve (49).

6. The tightening torque measuring device according to claim 1, characterized in that: the distortion measuring instruments (47) are arranged at a multiple of 2 at approximately equal intervals in the circumferential direction of the outer shaft (32).

7. The tightening torque measuring device according to claim 1, characterized in that: the control circuit can be operated by 1 long or short press time of the push switch (6).

8. The tightening torque measuring device according to claim 1, characterized in that: the circuit board (7) has a function of cutting off the power supply to the bridge circuit and the analog amplification circuit of the distortion measuring device after the fastening torque of the bolt or the nut is measured and before the automatic zero setting operation before the next fastening torque is measured.

9. The tightening torque measuring device according to claim 1, characterized in that: the circuit board (7) and the display unit (5) are disposed on the outer shaft (32).

10. The tightening torque measuring device according to claim 1, characterized in that: the outer end of the inner shaft (31) is formed as a fastening socket (21), and the reaction force bracket (22) is attached to the outer end of the outer shaft (32).

11. The tightening torque measuring device according to claim 10, wherein: the inner shaft (31) is detachable from an outer shaft (32) which can be replaced with another inner shaft (31) having a nut engagement hole (24) of a different size.

12. A bolt or nut tightening machine comprising a tightening torque measuring device (4) according to any one of claims 1 to 11, and a bolt or nut tightening machine body (1) having a 1 st output shaft (12) and a 2 nd output shaft (13), the tightening torque measuring device (4) being detachably connected to the body (1).