JP4807682B2 - Torque tool - Google Patents

Description

  The present invention relates to a torque tool for performing a torque operation such as fastening or unfastening a screw such as a driver or a wrench.

  Such a torque tool has a torque transmission mechanism equipped with a so-called torque limiter that transmits torque in a range less than a set torque value using the biasing force of the spring and does not transmit torque when the set torque value is exceeded. The torque limiter uses a toggle mechanism (for example, see Patent Documents 1, 2, and 4), uses a cam and a ball (for example, see Patent Document 3), uses a circumferential cam and a cam follower ( For example, there are those using a recess and a ball (for example, see Patent Document 6).

  In any of these Patent Documents 1 to 6, the spring urging force, that is, the set torque value is adjusted by adjusting the position of the spring seat that receives one end of the spring back and forth using a continuous screw system. ing. Patent Document 1 discloses a technique that makes it easy to adjust to a binary set torque value in particular, and it is easy to cope with the necessity of changing the fastening torque value between winter and summer in gas pipe piping construction. is doing. In other words, as described in Patent Documents 2 to 6, setting binary values in a stepless adjustment range avoids that individual differences are likely to cause variations in accuracy.

The present applicant has previously provided a torque driver using a torque limiter as shown in FIG. 5 so that the torque tool can be applied to inspections such as a torque value at the time of fastening and looseness of fastening. This is provided with recesses b and c having a depth corresponding to a binary set torque value on a circumferential cam a connected to a bit, and to which recesses b and c a cam follower e biased by a spring d is applied. Therefore, the cam follower e gets over the recessed portions b and c engaged by the resistance at the time of the fastening operation, thereby causing a difference in the amount of pushing back with respect to the spring d when the idle operation is performed. Can be selected as a binary value. Screws fastened with the selected set torque value can be released with the same set torque value. This means that when the fastening operation is performed with the same set torque value for the screw that has been fastened, the screw starts to loosen by the time when the set torque value is reached, that is, when the cam follower e gets over the recesses b and c and becomes empty. Whether the fastening torque has not reached the set torque value or the subsequent looseness will be detected, and the operator will be able to detect whether or not the cam follower e gets over the recesses b and c and feels empty. Easy to judge. Further, if the fastening operation is re-executed with the same set torque value for the screw that has been subjected to the fastening operation, no further fastening operation is performed, and the cam follower e immediately passes over the recesses b and c and becomes an empty operation. It can be easily determined that the fastening has been performed at least at the set torque value or not, depending on whether or not the cam follower e is over-operated over the recesses b and c without causing the fastening operation to be re-operated.
JP-A-8-90441 JP 2001-71278 A JP 2000-190246 A JP 2003-326474 A JP 2003-33373 A JP 2005-131753 A

  By the way, in order to inspect the set torque value at the time of such fastening for the quality control of the object and the safety management of the object, people and the environment using the torque tool, the torque setting with the torque tool must be performed correctly. Is indispensable, and the purpose of the inspection is spoiled if there is any error. In addition, the more the number of fastening points where binary values are mixed, and the more the work site is located on the tower of the transmission line, the height around the outside of the building, or the environment with danger and tension, such as the electric shock environment, the more the torque setting work is. It is desirable that it is simple and does not cause errors.

  However, if the torque can be set steplessly by the continuous screw operation described in Patent Documents 2 to 6, the main scale or the secondary scale may be used, and the torque setting operation is complicated, easy and performed in a short time. It is difficult, and as Patent Document 1 points out, there is a problem that individual differences are likely to occur in the torque setting.

  In Patent Document 1, binary torque value setting by continuous screw operation is received at an upper value corresponding position by an upper limit pin by an upper limit side, and operation to a lower value side is lower limit. Although it is performed by receiving at the position corresponding to the lower value by the pin, it is not possible to restrict the torque setting between the upper value and the lower value, and it is not possible to restrict the difference between individuals. Moreover, since the setting operation of the torque value is a continuous screw operation, the operation position may be easily shifted when the operation member interferes with others, so that the reliability is lacking. In the configuration in which the screw operation portion is covered with an end face plate like the one described in Patent Document 1, an operation for attaching and detaching the end face plate is attached every time the torque value is set, so that the torque value cannot be switched quickly. Instead of this, even when a lock means for the set torque position is provided, the trouble of locking and unlocking is required.

  The previous thing by the applicant shown in FIG. 5 does not have a problem like the thing of the patent document 1. FIG. However, if a predetermined torque value is satisfied when the tightened screw is operated and inspected on the tightening release side, that is, on the loose side, or on the tightening side, that is, on the tightening side, the cam follower e moves over the recesses b and c to perform the idle operation. Will be transferred to. Therefore, in order to repeat the inspection with the same torque value, the next inspection cannot be performed unless the original torque setting state, that is, the cam follower e is returned to the position where the cam follower e is engaged with the original concave portion b or the concave portion c. Cut in half.

  The main object of the present invention is to provide a torque tool that can be easily and quickly, accurately and stably switching torque values, and can be used repeatedly without change in the set state. The purpose is to ensure continuity of use without returning operation when the set torque value is satisfied in the inspection.

  In order to achieve the above object, the torque tool of the present invention includes a tool main body equipped with a torque working tool such as a bit or a wrench or a mounting portion thereof on the rotation axis thereof, and a torque working tool using the tool main body or the mounting thereof. A torque transmission mechanism having a torque limit function that transmits a rotation operation to a portion until a set torque value by a spring force is reached and when the set torque value is exceeded, the transmission is cut off and a blank operation is performed. Torque value set by switching the receiving position of the spring seat that receives one end to multiple stages with stepwise rotation and advance / retreat by the exposed operation member so that it can be manually operated outside the rear end of the torque transmission mechanism built-in part of the tool body Is provided with a torque switching mechanism for switching between a plurality of stages.

  In such a configuration, the torque limit function of the torque transmission mechanism can be used to perform fastening with a screw or nut at the set torque value, whether or not the set torque value has been fastened, and whether there is any subsequent slack Can be inspected. Since the torque is set in a plurality of stages, it is suitable for applications where the set torque value is specified. In particular, the set torque value can be switched to multiple discontinuous steps with stepwise rotation and advance / retreat by immediately manually operating the operating member exposed at the rear end of the torque transmission mechanism built-in part of the tool body. Therefore, the switching operation is accompanied by different operations such as rotation and advancement / retraction of the operation member, so that the switching state is not easily changed by interference with the other, and the stability can be ensured. In addition, the switching state can be easily visually recognized by the difference between the rotational position of the operating member with respect to the tool body and the advance / retreat position, especially the difference of the advance / retreat position, and the confirmation of the change becomes simple and clear as the set torque value to be switched is small. .

The torque transmission mechanism includes a cam that is provided in the tool body and rotates integrally with the torque working tool or its mounting portion, and a cam follower that is pressed against the cam by the bias of the spring, and the torque switching mechanism is a torque that switches to the rear surface of the spring seat. Depending on the value, concave portions with different depths are arranged in the circumferential direction, and according to the rotational position, one type of concave portion faces the receiving portion at a fixed position on the rear end side of the torque transmission mechanism built-in portion of the tool body. Depending on its type, it can be received at different advancing / retreating positions, and the operation member can move in and out of the receiving part of the recessed part by advancing and retracting action with contraction and extension of the spring, and change the type of the recessed part facing the receiving part by rotating operation. In a further configuration,
The torque transmission mechanism increases the torque value by pushing back the cam follower against the spring as the cam follower rotates relative to the torque transmission operation. When the torque reaches the set torque value, the torque transmission is cut off and the torque transmission is cut off. The torque limit function for shifting to the position can be surely exhibited, and the torque switching mechanism is a fitting in which the recess corresponding to the set torque is received by the receiving part by moving the spring seat against the spring by the operating member. If the spring seat is rotated by the operating member in its advanced state, the concavity facing the receiving portion is switched to another type, and the operating member is moved to the spring seat at the switching position. When retreating, the recessed part after switching fits with the receiving part and is received and can be switched to the torque value corresponding to the type of the recessed part. State is not easily varied by fits fits urged by a spring in the rotational direction specifying positions of the recess and the receiving portion even if others simply interfere with the operation member.

There are two types of recesses, three in the circumferential direction, and three in the circumferential direction.
Two types of recesses can be used to set binary torque values, and three in the circumferential direction and the same type of recesses fit into the three receiving portions in the circumferential direction. The rotation angle for switching the torque value is as small as 60 °.

In a further configuration, the recess is formed to open to the outer periphery of the spring seat, and the receiving portion is a claw portion protruding inward from the inner periphery of the peripheral wall of the tool body.
Since the recess is open to the outer periphery of the spring seat, the torque value can be switched by fitting with a simple receiving portion that protrudes from the inner periphery of the peripheral wall of the tool body.

The cam trough of the torque transmission mechanism rises gently on the fastening release operation side and rises rapidly on the fastening operation side.
While gradually increasing the torque value to the set torque value in the inspection operation to the engagement release side, the torque value at the time of engagement or the degree of looseness can be determined depending on when the engagement release starts, that is, the start of loosening. In the inspection operation, if there is a loosening, the fastening proceeds immediately or early, and if there is no loosening, the fastening does not proceed and the set torque value is reached immediately or early and the idle operation is performed.

The cam valley is repeatedly formed with the same depth and shape at the mountain boundary in the circumferential direction of the cam.
When the inspection operation satisfies the set torque value and shifts to the empty operation, the cam follower enters the next concave portion of the cam and falls into the valley by the urging force of the spring and is stabilized, so that the next inspection operation can be performed immediately.

The cam of the torque transmission mechanism is a circumferential cam, and the cam follower and spring act on the circumferential cam from the direction perpendicular to the rotational axis of the torque working tool or its mounting part, and the torque transmission mechanism built-in part of the tool body is the cam built-in part. In a further configuration, a grip portion extending from the cam to the one side and an auxiliary grip portion extending from the cam built-in portion to the opposite side are provided.
The torque transmission mechanism built-in portion of the tool body extends from the circumferential cam located on the rotational axis of the torque tool to the side to form a grip portion, and cooperates with the auxiliary grip portion that extends to the opposite side to form the T of the rotational axis. Even if the torque work tool is a bit by gripping the character portion, it can be rotated with a press from a short distance on the rotation axis. In addition, even when the torque switching mechanism is operated by the operating member exposed at the rear end of the torque transmission mechanism built-in portion, the operating member is pushed against the spring and the spring seat is advanced to move away from the receiving portion. An operation member that shifts to a rotational operation for switching the torque value, and subsequently operates a series of operations for receiving the spring seat at the torque value switching position on the receiving portion by releasing the push-in operation with the T-shaped portion gripped by one hand and the other hand. It can be done within a short distance on the same axis.

In a further configuration in which the cam follower is provided at the tip of the slider that advances and retreats in the torque transmission mechanism built-in part of the tool body, and the spring is operated between the rear part of the slider and the spring seat,
A long spring is moved between the slider and the spring seat by utilizing the length ensured for stable advancement and retraction of the slider, and it is easy to obtain a linear spring characteristic.

In a further configuration in which the slider rolls on the inner periphery of the torque transmission mechanism built-in part and contacts and moves back and forth at the contact part,
Friction between the slider and the torque transmission mechanism built-in portion of the tool body can be reduced, and stable torque performance can be exhibited over a long period of time.

The spring is working both inside and outside, in a further configuration,
By making the spring characteristics of the two springs different, the setting range of the spring characteristics necessary for the low torque value side and the high torque value side is increased, and the degree of freedom in design is increased.

  For this purpose, it is preferable that the spring having a small spring diameter has a smaller wire diameter and a longer spring length than a spring having a large spring diameter.

The tool body and the operating member are made of resin, the torque working tool or its mounting part and the cam are connected via resin, and the tool working body other than the torque working part of the torque working tool is covered with resin. In the further configuration in which a metal shim is applied to the inner periphery of the slider's advance / retreat range of the torque transmission mechanism built-in part,
The surface of the torque working tool other than the torque working part is covered with resin to achieve electrical insulation. For this reason, the tool body with a built-in torque transmission mechanism is made of resin. Wear is reduced by contact with a metal shim provided on the inner periphery of the steel, and stable torque characteristics can be ensured over a long period of time.

  Further objects and features of the present invention will become apparent from the following detailed description and drawings. Each feature of the present invention can be used alone or in combination in various combinations as much as possible.

  According to the torque tool of the present invention, a plurality of set torque values are specified in order to perform fastening with a screw or nut at a set torque value and to check whether the set torque value is tightened or there is no subsequent looseness. The set torque value can be switched by the immediate operation of the operating member exposed at the rear end of the torque transmission mechanism built-in part, and the switching can respond to the occasional rotation of the operating member. This is due to the accompanying discontinuous operation, and the switching state is less likely to fluctuate due to interference with other operation members, and stability can be ensured. In addition, the switching state can be intuitively determined by the difference in the advance / retreat position of the operation member, and misuse can be prevented.

  The torque transmission mechanism that reliably exerts the torque limit function by the cam and the cam follower biased by the spring, and the recess and the receiving part corresponding to the set torque are fitted by externally operating the spring seat with the operating member. This is a system that switches the receiving state by mating to a receiving state in which the recess and the receiving part corresponding to other set torque values are fitted. With the torque switching mechanism that is not easily changed by the biased fit, the high torque function is stably exhibited, and the work required can be reduced by reducing the considerations required for the work.

  While the two types of recesses correspond to the binary torque value setting, the same type of recesses fit with the three receiving portions in the circumferential direction so that they can be stably received in a balanced manner in the circumferential direction. Since the rotation angle for torque value switching is as small as 60 °, it is convenient for switching.

  The recess is open to the outer periphery of the spring seat, and is fitted to a simple receiving portion that protrudes from the inner periphery of the peripheral wall of the tool body so that it can be switched, so that the torque value can be switched and the structure is simplified.

  It is convenient because the torque value at the time of fastening or the degree of looseness can be judged by the point at which the inspection operation begins to loosen due to the shape of the concave rising to the fastening release operation side, and suddenly to the fastening operation side of the recess If there is a slack in the inspection operation due to the rising shape, the fastening proceeds immediately or early, and if there is no slack, the fastening does not proceed immediately and reaches the set torque value immediately or early, and the empty operation can be determined in a short time.

  In the inspection operation, when the set torque value is satisfied and the operation shifts to the empty operation, the next inspection operation can be immediately performed because the cam follower enters the next recess of the cam, and the workability is improved.

  Even if the grip part formed by the torque transmission mechanism built-in part of the tool body and the auxiliary grip part cooperate to grip the T-shaped part of the torque working tool or the rotation axis of the mounting part, the torque working tool is a bit. The torque operation is improved because the rotation operation can be stably performed without shaking accompanied by play from a short distance on the rotation axis and the pressing without escape. Further, the operation member is moved against the spring to move the push spring seat forward and away from the receiving portion to shift to the torque operation to switch the torque value. The switching operation can be performed easily and quickly without any play or run-out between the T-shaped portion gripped by one hand and the operation member operated by the other hand on the same coaxial distance, thereby improving workability.

  A long spring is made to work between the slider and the spring seat by making effective use of the length secured for stable advancement and retraction of the slider, and it is easy to obtain linear spring characteristics.

  Friction between the slider and the torque transmission mechanism built-in part of the tool body can be reduced by rolling contact, and stable torque performance can be exhibited over a long period of time.

  By using different spring characteristics of the two springs, the setting range of the spring characteristics necessary for the low torque value side and the high torque value side is increased, design flexibility is increased, and a spring with a small spring diameter is It is preferable that the wire diameter is smaller and the spring length is larger than a spring having a larger spring diameter.

  The surface of the torque tool other than the torque working part is covered with resin to achieve electrical insulation. For this reason, the built-in part of the torque transmission mechanism of the tool body made of resin is the inner periphery of the slider's advance / retreat range. Wear is reduced by contact with a metal shim provided on the surface, ensuring stable torque characteristics over a long period of time, and improving the life and reliability.

  Hereinafter, a torque tool according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4 for an understanding of the present invention. However, the following description is a specific example of the present invention and does not limit the contents described in the claims.

  The torque tool of the present embodiment is an example of a torque driver with a bit 1 as shown in FIGS. 1, 2, and 3, but the present invention is not limited to this, and a wrench A tool main body 5 equipped with a torque working tool 2 such as a bit 1 or a wrench or its mounting portion 3 on the rotation axis 4 thereof, and a torque working tool using the tool main body 5. A torque transmission mechanism 7 having a torque limit function that transmits a rotation operation to 2 or its mounting portion 3 until a set torque value by the spring force of the spring 6 is reached and cuts the transmission when the set torque value is exceeded and shifts to a blank operation. Provided by the operating member 9 exposed so that the receiving position of the spring seat 8 for receiving one end of the spring 6 can be manually operated outside the rear end of the torque transmitting mechanism built-in portion 5a of the tool body 5. It is provided with a torque switching mechanism 11 for switching the stepwise rotation back and forth and the set torque value by switching a plurality of stages with a multiple stage.

  In such a torque tool, the torque limit function of the torque transmission mechanism 7 can be used to perform fastening with a screw or nut at a set torque value, and whether or not the set torque value has been fastened, there is a subsequent looseness. You can inspect for it. In any case, since the torque is set in a plurality of stages, it is suitable for applications where the set torque value is specified. In particular, the set torque value is determined in a plurality of non-continuous steps involving stepwise rotation and advance / retreat by immediately manually operating the operation member 9 exposed at the rear end of the torque transmission mechanism built-in portion 5a of the tool body 5. Switching can be done easily, quickly and accurately. In short, since the operation member 9 is exposed to the outside, the set torque value can be switched by an immediate operation and the workability is improved. In addition, the switching operation of the set torque value is accompanied by a discontinuous abnormal operation such as rotation and advancement / retraction of the operation member 9, so that the switching state is less likely to change due to interference with others, ensuring stability and necessary for work. Workability can be improved by reducing unnecessary considerations. Moreover, the setting torque value is switched according to the difference between the rotation position and the advance / retreat position of the operation member 9 with respect to the tool body 5, in particular the difference between the advance / retreat positions indicated by the solid line and the virtual line in FIG. Even if there is no error, it can be easily recognized, and as the set torque value to be switched is as small as two values as in this embodiment, the confirmation of the switching becomes simple and clear and the operator can intuitively. Therefore, it is possible to prevent the fastening with an incorrect set torque value and the use for the inspection. Although the difference in the rotational position of the operation member 9 with respect to the tool body 5 is difficult to understand, it can be made clear by an index or the like.

  As shown in FIGS. 1A and 4, the torque transmission mechanism 7 is provided in the tool body 5 and rotates integrally with the torque working tool 2 or its mounting portion 3, and a spring 6 is attached to the cam 12. The torque follower 13 is provided with a pressure-contacted cam follower 13, and the torque switching mechanism 11 is provided with recesses 8a, 8b,... Having different depths in the circumferential direction according to the torque value to be switched to the rear surface of the spring seat 8, and according to the rotational position. One kind of the recesses 8a, 8b,... Faces the receiving portion 14 at a fixed position on the rear end side of the torque transmission mechanism built-in portion 5a of the tool body 5 as shown in FIGS. The operation member 9 is moved in the direction A shown in FIG. 1 (a) accompanied by contraction and extension of the spring 6 so as to be received at an advance / retreat position depending on the depth depending on the type of the recesses 8a, 8b. Recesses 8a and 8b and receiving part 1 To perform the entry and exit of the recess 8a which faces the receiving portion 14 by the rotation operation in the B direction shown in FIG. 4, and to switch the type of 8b.

  As a result, the torque transmission mechanism 7 increases the torque value by pushing the cam follower 13 against the spring 6 against the spring 6 in accordance with the relative rotation of the cam follower 13 interlocked with the torque transmission operation by the tool body 5, and becomes the set torque value. The torque limit function that overcomes the valley and cuts off the torque transmission to shift to the empty operation is surely demonstrated. In the illustrated example corresponding to the set torque value, the torque switching mechanism 11 moves the spring seat 8 against the spring 6 against the spring 6 by the operating member 9, and in the example shown in FIG. 4 can be removed as shown in FIG. 4, and when the spring seat 8 is rotated by the operating member 9 in its advanced state, the recess 8a facing the receiving portion 14 is separated. When the operation member 9 is switched back with the spring seat 8 at the switching position, the recessed portion 8b after switching is different in depth from the receiving portion 14 in the illustrated example. It can be received by being fitted deeper than the previous time, and can be switched to a torque value corresponding to the type of the recess 8b. Further, these torque value setting states can be easily achieved by the engagement of the recesses 8a and 8b and the receiving portion 14 urged by the spring 6 at a specific position in the rotational direction even if another member simply interferes with the operation member 9. It is not fluctuated. As a result, the torque transmission mechanism 7 that reliably exerts the torque limit function by the cam 12 and the cam follower 13 biased by the spring 6 and the spring seat 8 that receives the spring 6 are externally operated by the operation member 9 to set In the method of switching the receiving state due to the fitting of the recess 8a corresponding to the torque value and the receiving portion 14 to the receiving state where the recess 8b corresponding to the other set torque value and the receiving portion 14 are fitted, A high torque function is stabilized by the torque switching mechanism 11 that is not easily changed by the engagement of the recesses 8a, 8b and the receiving portion 14 urged by the spring 6 even if another member simply interferes with the operation member 9. It can be used to reduce work-related considerations and improve workability.

  In this embodiment, two types of recesses 8a and 8b are provided corresponding to binary torque value switching. However, as shown in FIGS. 1 (b) and 4, three are arranged alternately in the circumferential direction. Corresponding to this, there are three receiving portions 14 in the circumferential direction. Thus, two types of recesses 8a and 8b correspond to the binary torque value setting, and three recesses 8a and 8b are arranged in the circumferential direction, and the recess 8a is represented in FIG. As shown, the recesses 8a or 8b of the same kind are fitted with the receiving portions 14 having three in the circumferential direction so that they are stably received in a balanced manner at three locations in the circumferential direction, and the rotation angle for switching the torque value is 60. It becomes smaller with °. Further, as shown in FIGS. 1A and 1B, the recesses 8a and 8b are formed so as to be opened on the outer periphery of the spring seat 8, and the receiving portion 14 is a claw portion protruding inward from the inner periphery of the peripheral wall of the tool body 5. It is as. As described above, the recesses 8a and 8b are open to the outer periphery of the spring seat 8, so that the recesses 8a and 8b are fitted to the simple receiving portion 14 protruding in a claw shape from the inner periphery of the peripheral wall of the tool body 5 so as to be switchable. The torque value can be switched, and the configuration is simplified. The set torque value to be switched is a binary value of 3 N · m and 16 N · m, but is not limited to this.

  The trough 12a of the cam 12 of the torque transmission mechanism 7 has a shape that rises gently on the fastening release operation side C and rises abruptly on the fastening operation side D, as shown in FIGS. As a result, while gradually increasing the torque value to the set torque value in the inspection operation to the engagement release side C, the torque value at the time of engagement or the subsequent This is convenient because the degree of looseness can be determined. In addition, in the inspection operation to the fastening side, if there is a loosening, the fastening proceeds immediately or early, and if there is no loosening, the fastening does not proceed and the set torque value is reached immediately or early and the idle operation is performed, so it can be judged in a short time. . Moreover, the valley 12a of the cam 12 is repeatedly formed in the circumferential direction of the cam 12 with the same depth and shape with the mountain 12b as a boundary. Accordingly, when the inspection operation at one valley 12a satisfies the set torque value and shifts to the empty operation after exceeding one mountain 12b, the cam follower 13 has entered the next valley 12a of the cam 12 and the spring 6 Because of this urging force, it falls into the next valley 12a and stabilizes, so that the next inspection operation can be performed immediately and workability is improved.

  Further, the cam 12 of the torque transmission mechanism 7 is a circumferential cam as shown in FIGS. 1 (a), 2 (b) and 4, and is shown in FIGS. 1 (a), 2 (a) and 2 (b). Thus, the cam follower 13 and the spring 6 act on the outer peripheral cam surface of the cam 12 from the direction perpendicular to the rotational axis 4 of the torque working tool 2 or its mounting portion 3, and the torque transmission mechanism built-in portion 5a of the tool body 5 is the cam built-in portion 5b. A grip portion 21 extending to one side is formed, and an auxiliary grip portion 22 extending to the opposite side from the cam built-in portion 5b is provided. Thus, the torque transmission mechanism built-in portion 5a of the tool body 5 extends from the cam 12 located on the rotation axis 4 of the torque working tool 2 to the side to form the grip portion 21, and the auxiliary grip portion 22 extends to the opposite side. 1A, 2A, 2B, and 3 with the rotational axis 4 in cooperation with the torque work tool 2 with the bit 1 as shown in the figure. Even if there is a play from a short distance on the rotation axis and a pressing without escape, the rotation operation can be stably performed without a vibration accompanied by a pressure from a short distance on the rotation axis 4 and the torque work is improved. Further, in order to perform the torque value switching operation in the torque switching mechanism 7 by the operating member 9 exposed at the rear end portion of the torque transmission mechanism built-in portion 5a, the operating member 9 is pushed against the spring 6 and the spring seat 8 is advanced. The T-shaped portion gripped with one hand is moved to a rotational operation for switching the torque value away from the receiving portion 14 and the operation of receiving the spring seat 8 at the torque value switching position on the receiving portion 14 by subsequent release of pushing. 23 and the operation member 9 operated by the other hand can be easily and quickly performed without any play or run-out between a short distance on the same axis 24 shown in FIGS. 1 (a), 2 (a) and 2 (b). Workability is improved.

  Further, as shown in FIGS. 1A and 4, the cam follower 13 is pivotally supported by a shaft 26 at the tip of the slider 25 that moves forward and backward in the torque transmission mechanism built-in portion 5 a of the tool body 5. A spring 6 is acted between the rear part and the spring seat 8. As a result, the long spring 6 can be moved between the slider 25 and the spring seat 8 by utilizing the length ensured for the stable advance and retreat of the slider 25, so that it is easy to obtain a linear spring characteristic and can be made compact. The slider 25 contacts the inner periphery of the torque transmission mechanism built-in portion 5a with the front and rear rolling contact portions 27 and 28 so as to advance and retreat. Thereby, friction between the slider 25 and the torque transmission mechanism built-in portion 5a of the tool body 5 can be reduced, and a stable torque performance can be exhibited for a long time. The front rolling contact portion 27 is supported by a shaft 29 on the side where the slider 25 is pressed against the inner periphery of the torque transmission mechanism built-in portion 5a during the inspection operation to the fastening release side C, as shown in FIGS. 4, the reaction force acting on the cam follower 13 by the inspection operation to the fastening release side C is received by rolling contact with the inner periphery of the torque transmission mechanism built-in portion 5a. 1 (a) and 1 (c) and FIG. 4, the rear rolling contact portion 28 is a simple ball group that is fitted in a groove 31 formed on the outer periphery of the rear portion of the slider 25 without any gap in the circumferential direction. In the entire circumference of the rear part of the 25, it comes into rolling contact with the inner circumference of the torque transmission mechanism built-in part 5a. These rolling contact portions 27 and 28 may be configured in any manner, and may be provided on the side of the torque transmission mechanism built-in portion 5a of the tool body 5, but the slider 25 side is easier to provide.

  Further, as shown in FIG. 1 (a), the spring 6 has two inner and outer double springs 6a and 6b acting on them, so that the spring characteristics of the two springs 6a and 6b are made different from each other, so The setting range of the spring characteristics necessary for the torque value side is increased, and the degree of freedom in design is increased. For this purpose, as shown in FIGS. 1A and 4, it is preferable that the spring 6a having a small spring diameter has a smaller wire diameter and a longer spring length than the spring 6b having a large spring diameter. By acting between the concave portion 32 of the slider 25 and the concave portion 33 of the spring seat 8 and the spring 6b acting between the rear end surface of the slider 25 and the front end surface of the spring seat 8, play is possible regardless of the length. And works according to the set spring characteristics. The slider 25 has a key groove 25a shown in FIGS. 1 (a) and 4, and this key groove 25a is fitted so as to be fitted with the key portion 5d on the inner periphery of the torque transmission mechanism built-in portion 5a so as to be guided straight. .

  Finally, in the torque tool according to the present embodiment, the tool body 5 and the operation member 9 are made of resin, and the torque working tool 2 or its mounting portion 3 and the cam 12 are connected via a resin. An insulating tool covered with resin is used except for the torque working portion 2a, and a metal shim 34 is applied to the inner periphery of the slider 25 of the torque transmission mechanism built-in portion 5a in the tool body 5 in the advance / retreat range. Thus, if the surface other than the torque working portion 2a of the torque working tool 2 is covered with resin, electrical insulation is achieved and the safety of the torque work that may cause an electric shock can be ensured. Although the tool body 5 is made of resin in spite of the fact that it is built in, the slider 25 comes into contact with a metal shim 34 provided on the inner periphery of the advance / retreat range to reduce wear and to provide stable torque over a long period of time. The characteristics can be ensured, and the lifetime and reliability can be improved. In particular, since the both contacts are the rolling contacts described above, the effect is great.

  More specifically, the tool body 5 is made of Duracon resin (POM), and the operation member 9 and the connecting member 35 between the cam 12 and the mounting portion 3 are made of MC nylon, and the operation member 9 protrudes from the back of the spring seat 8. The shaft portion 36 is fitted into a non-through hole and fastened by a metal set screw 37, and the back portion of the mounting hole by the set screw 37 is filled with a cap 38 made of MC resin. The connecting member 35 is fitted to a downward shaft 39 of the cam 12 and connected by a metal shaft 41, and both ends of the connecting hole by the shaft 41 are finished to be flush with insulating caulk. Further, the mounting portion 3 is made of a metal one-touch holder with a click stopper made of a ball biased by a spring (not shown), and is connected to the lower end of the connecting member 35 by a metal shaft 43 so that the connection hole by the shaft 43 is insulated. The outer periphery of the mounting release sleeve 42 of the mounting portion 3 is covered with a cover tube 44 made of MC resin integrated with the mounting release sleeve 42 in a state where it is finished with the same coking and the upper end of the connecting member 35 is connected to the connecting member 35. Due to the fitting, the lower end extends below the mounting portion 3 so that the mounting portion 3 is not exposed to the outside. The bit 1 is also covered with a urethane resin cover 45 except for the torque working part 2a and the click engaging part to the mounting part 3 so that only the torque working part 2a is exposed.

  In addition, the spring seat 8 having the recesses 8 a and 8 b in the torque switching mechanism 11 and the receiving portion 14 are fitted in the direction of the shaft 24 having a large step in the direction of the axis 24, and the axis 24 Since large friction and impact occur due to the switching with relative rotation of the surroundings, hardened steel is also adopted for these to enhance wear resistance and impact resistance. For this purpose, the receiving portion 14 is fitted with a sleeve portion 46a as a hardened steel receiving ring 46 that fits on the outer periphery of the rear end of the torque transmitting mechanism built-in portion 5a of the tool body 5, and the shaft portion 36 of the spring seat 8 passes therethrough. The receiving portions 14 are formed at three locations in the circumferential direction on the inner periphery of the ring wall 46b. The receiving ring 46 is screwed with a metal set screw 53 in a state in which the receiving ring 46 is screwed without play by a screw-matching portion 52 with the inner periphery of the rear half of the MC resin cover ring 51, and the back insulating insulating caulking of the screw-fastening hole. The outer ring and the back of the receiving ring 46 are covered so as not to be exposed to the outside. The inner circumference of the front half of the cover ring 51 is screwed at the screw fitting portion 55 with the outer circumference of the rear half of the MC resin locking ring 54 fitted to the outer circumference of the middle portion of the torque transmission mechanism built-in portion 5a of the tool body 5. The circlip 56 locked at a predetermined position on the tool body 5 adjusts the attracting position of the receiving portion 14 with respect to the locking ring 54 locked via the slide ring 57, and by this adjustment, the receiving portion 14 and the recess 8a, The torque transmission mechanism 7 can exhibit a torque value corresponding to each fitting position with 8b. The adjustment position is screwed by a metal set screw 58, and the back of the screw hole is flush with an insulating caulk.

  Although the claw-shaped receiving part 14 is moved in the direction of the axis 24 to escape from the recesses 8a and 8b, it can be removed by rotation to some extent, and it satisfies moderate engagement and switching ease. In order to achieve this, there are slopes 14a on both sides in the rotational direction so that the concave parts 8a and 8b can easily get over in the rotational direction, and the deeper concave part 8b has in particular a countersunk face 8d that cooperates with the slope 14a. It is said. Further, in order to clearly indicate the torque switching state in the torque switching mechanism 11, the tool body 5 and the operating member 9 have outer periphery such as white facing each other at 3 N · m where the recess 8 a and the receiving portion 14 are engaged. Markers 59a and 59b as shown in FIGS. 1 (a) and 2 (b) are provided. As a result, the operator can intuitively feel that the set torque value is 3 N · m in the switching state in which the markers 59 a and 59 b face each other, and that the set torque value is 16 N · m otherwise.

  Further, on the upper surface of the cam built-in portion 5b in the torque transmission mechanism built-in portion 5a of the tool body 5, as shown in FIGS. 1 (a) and 2 (b), the cam 12 and the display board 61 bonded thereon are arranged. The lens cover 62 made of a transparent resin that can be seen through is fixed by screwing at the screw-in portion 63, and the upward shaft 39 a of the cam 12 and the downward direction are formed by the lens cover 62 and the lower wall of the torque transmission mechanism built-in portion 5 a. The shaft 39 is supported through metal oilless bushes 64 and 65, and is connected between the lower wall of the torque transmission mechanism built-in portion 5a and the lower surface of the cam 12, and to the lower wall of the torque transmission mechanism built-in portion 5a. Metal oil washers 66 and 67 are fitted between both the members 35 so as to prevent the resin members from sliding against each other to improve wear resistance. As a result, the torque tool according to the present embodiment can sufficiently withstand repeated use of about 80,000 times based on the experimental results of the inventors. The washer 67 between the lower wall of the torque transmission mechanism built-in portion 5a and the connecting member 35 is fitted to the inner periphery of the cylindrical wall 5c whose upper end of the connecting member 35 extends downward from the lower wall of the torque transmitting mechanism built-in portion 5a. Therefore, the structure is not exposed to the outside.

  Practically used for various torque tools, the torque value can be switched easily and quickly and accurately, and the set state does not fluctuate.

The torque driver of this embodiment is shown, (a) is a cross-sectional view, (b) is a cross-sectional view of a torque switching mechanism, (c) is a cross-sectional view of a rear rolling contact portion of a slider having a cam follower, d) is a cross-sectional view of a front rolling contact portion of a slider having a cam follower. The torque driver of FIG. 1 is shown, (a) is a front view, (b) is a top view. It is a side view of the torque driver of FIG. It is a disassembled perspective view of the torque transmission mechanism and torque switching mechanism of the torque driver of FIG. It is a perspective view which shows the principal part of the torque transmission mechanism of the conventional torque driver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bit 2 Torque working tool 2a Torque working part 3 Mounting part 4 Rotating axis 5 Tool main body 5a Torque transmission mechanism built-in part 5b Cam built-in parts 6, 6a, 6b Spring 7 Torque transmitting mechanism 8 Spring seats 8a, 8b Recess 9 Operation member 11 Torque switching mechanism 12 Cam 13 Cam follower 14 Receiving part 21 Grip part 22 Auxiliary grip part 23 T-shaped part 24 Axis 25 Slider 27, 28 Rolling contact part 32, 33 Recess 34 Metal shim 35 Connecting member 44 Cover cylinder 45 Cover 46 Receiving ring 51 Cover ring 54 Lock ring

Claims (13)

A tool body equipped with a torque work tool such as a bit or a wrench or its mounting part on the axis of rotation, and the rotation operation of the tool body with respect to the torque work tool or its mounting part is transmitted until the set torque value by the spring force is reached. In a torque tool equipped with a torque transmission mechanism having a torque limit function that cuts transmission and shifts to empty operation when a set torque value is exceeded,
The receiving position of the spring seat for receiving one end of the spring is switched to a plurality of stages with stepwise rotation and advancing and retreating by an exposed operation member so that it can be manually operated outside the rear end of the torque transmission mechanism built-in part of the tool body. A torque tool provided with a torque switching mechanism for switching a set torque value in a plurality of stages. The torque tool according to claim 1, wherein the torque switching mechanism switches the set torque value in two stages. The torque transmission mechanism includes a cam that is provided in the tool body and rotates integrally with the torque working tool or its mounting portion, and a cam follower that is pressed against the cam by the bias of the spring, and the torque switching mechanism is a torque that switches to the rear surface of the spring seat. Depending on the value, concave portions with different depths are arranged in the circumferential direction, and according to the rotational position, one type of concave portion faces the receiving portion at a fixed position on the rear end side of the torque transmission mechanism built-in portion of the tool body. Claims 1, 2 wherein the operation member is received at a different advancing / retreating position depending on its type, and the operation member is moved in and out of the receiving portion of the recessed portion by an advancing / retreating operation, and the type of the recessed portion opposed to the receiving portion is switched by a rotating operation. The torque tool according to any one of the above. 4. The torque tool according to claim 3, wherein there are two types of recesses, and three recesses are alternately arranged in the circumferential direction, and there are three receiving portions in the circumferential direction. The torque tool according to any one of claims 3 and 4, wherein the concave portion is formed to open to the outer periphery of the spring seat, and the receiving portion is a claw portion protruding inward from the inner periphery of the peripheral wall of the tool body. The torque tool according to any one of claims 1 to 5, wherein the valley of the cam of the torque transmission mechanism rises gently toward the fastening release operation side and suddenly rises toward the fastening operation side. The torque tool according to claim 6, wherein a plurality of cam valleys are repeatedly formed in the circumferential direction of the cam with the same depth and shape with the mountain as a boundary. The cam of the torque transmission mechanism is a circumferential cam, and the cam follower and spring act on the circumferential cam from the direction perpendicular to the rotational axis of the torque working tool or its mounting part, and the torque transmission mechanism built-in part of the tool body is the cam built-in part. The torque tool according to any one of claims 1 to 7, further comprising an auxiliary grip portion extending from the cam built-in portion to the opposite side. 9. The cam follower according to claim 1, wherein the cam follower is provided at a tip portion of a slider that advances and retreats in the torque transmission mechanism built-in portion of the tool body, and a spring is operated between the rear portion of the slider and the spring seat. Torque tool. The torque tool according to claim 9, wherein the slider makes contact with the inner periphery of the torque transmission mechanism built-in portion at the rolling contact portion and advances and retreats. The torque tool according to any one of claims 1 to 10, wherein the spring is operated in an inner / outer double manner. The torque tool according to claim 11, wherein the spring having a small spring diameter has a smaller wire diameter and a larger spring length than a spring having a larger spring diameter. The tool body and the operating member are made of resin, the torque working tool or its mounting part and the cam are connected via resin, and the tool working body other than the torque working part of the torque working tool is covered with resin. The torque tool according to any one of claims 1 to 12, wherein a metal shim is applied to the inner periphery of the slider advance / retreat range of the torque transmission mechanism built-in portion.

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