JP6993095B2 - Torque Wrench - Google Patents

Description

The present invention relates to a torque wrench provided with a ratchet mechanism.

As the ratchet mechanism of the conventional torque wrench, there are a mechanism shown in FIG. 6 (for example, Patent Document 1) and a mechanism shown in FIG. 7 (for example, Patent Document 2).

In the ratchet mechanism shown in FIG. 6, the engaging member 4A is rotatable about the shaft portion 5A. Then, the spring 3A urges the engaging member 4A toward the ratchet ring 1A, so that the tip portion of the engaging member 4A meshes with the ratchet teeth 2A of the ratchet ring 1A. At this time, the engaging member 4A prevents the ratchet ring 1A from rotating in the direction of the arrow D1. When the ratchet ring 1A rotates in the direction of the arrow D2, the tip of the engaging member 4A moves along the ratchet teeth 2A, so that the spring 3A expands and contracts, and the engaging member 4A rotates about the shaft portion 5A. Move. When the torque wrench shown in FIG. 6 is rotated in the direction of arrow D3 to tighten the fastening member such as a bolt, a force for rotating the ratchet ring 1A in the direction of arrow D1 is generated by the reaction force from the fastening member. Since the engaging member 4A remains engaged with the ratchet teeth 2A, the ratchet ring 1A receives the load F1 when the ratchet ring 1A tries to rotate in the direction of the arrow D1 with the shaft portion 5A as a fulcrum.

On the other hand, in the ratchet mechanism shown in FIG. 7, a part of the engaging member 4A and the spring 3A are arranged side by side and housed in the guide groove 6A. The spring 3A urges the engaging member 4A toward the ratchet ring 1A, so that the tip of the engaging member 4A meshes with the ratchet teeth 2A of the ratchet ring 1A. At this time, the engaging member 4A prevents the ratchet ring 1A from rotating in the direction of the arrow D1. When the ratchet ring 1A rotates in the direction of the arrow D2, the tip of the engaging member 4A moves along the ratchet teeth 2A, so that the spring 3A expands and contracts, and the engaging member 4A slides along the guide groove 6A. Move. When the torque wrench shown in FIG. 7 is rotated in the direction of arrow D3 to tighten the fastening member such as a bolt, a force for rotating the ratchet ring 1A in the direction of arrow D1 is generated by the reaction force from the fastening member. Since the engaging member 4A remains in mesh with the ratchet teeth 2A, it abuts on the wall surface 7A of the guide groove 6A to receive the load F2 when the ratchet ring 1A tries to rotate in the direction of the arrow D1.

Japanese Unexamined Patent Publication No. 2001-179650 Japanese Unexamined Patent Publication No. 2004-255539

However, in the ratchet mechanism shown in FIG. 6, since the engaging member 4A rotates about the shaft portion 5A, the working space of the engaging member 4A must be larger than that of the ratchet mechanism shown in FIG. This causes a problem that it is difficult to reduce the size of the torque wrench.

Further, as described above, when the fastening member is tightened, the shaft portion 5A receives the load F1, so that the shaft portion 5A may be damaged.

On the other hand, in the ratchet mechanism shown in FIG. 7, since the engaging member 4A only slides along the guide groove 6A, it is necessary to take a wider working space for the engaging member 4A as compared with the ratchet mechanism shown in FIG. There is no problem, and there is an advantage that the torque wrench can be easily miniaturized.

However, in the ratchet mechanism shown in FIG. 7, the engaging member 4A abuts on the wall surface 7A of the guide groove 6A and continues to receive the load F2, so that the wall surface 7A of the guide groove 6A is easily worn. In particular, the region R shown in FIG. 7 is likely to be worn.

FIG. 8 shows the ratchet mechanism after the region R of FIG. 7 is worn. As shown in FIG. 8, the wear surface W is generated by the wear of the region R of FIG. 7. In this state, when a load F2 is applied to the engaging member 4A, the tip portion of the engaging member 4A is displaced in the direction toward the wear surface W, so that the engaging member 4A tends to tilt with respect to the guide groove 6A. do. As a result, the contact area between the engaging member 4A and the guide groove 6A is reduced, and the load F2 (bending stress) is repeatedly applied to the engaging member 4A, which may cause the engaging member 4A to bend or break. There is.

Therefore, an object of the present invention is to provide a torque wrench that can easily reduce the size of the ratchet mechanism and suppress deformation or breakage of parts of the ratchet mechanism.

The present invention is a torque wrench having a handle operated by the user and a head rotatable with respect to the handle, including a ratchet ring and an engaging member. The ratchet ring is rotatable with respect to the head, and ratchet teeth are formed on the outer peripheral surface of the ratchet ring. The engaging member linearly moves between a first position that engages the ratchet tooth and a second position that disengages the ratchet tooth. The engaging member is urged toward the first position by a spring.

A pair of guide portions and accommodating portions are formed on the head. The pair of guide portions guide the engaging member in the moving direction of the engaging member. The accommodating portion accommodates a part of the engaging member and the spring, and has a width wider than the distance between the pair of guide portions. The accommodating portion allows the engaging member to tilt due to wear of one of the guide portions that receives the load from the engaging member among the pair of guide portions.

According to the present invention, when the guide portion is worn due to friction with the engaging member, it is possible to allow the engaging member to tilt with respect to the moving direction of the engaging member by utilizing the space in the accommodating portion. .. As a result, it is possible to suppress the generation of bending stress in the engaging member, and it is possible to suppress the engaging member from bending or breaking.

The engaging member can be composed of an engaging portion that engages with the ratchet teeth and a pair of arm portions that are integrally formed with the engaging portion. Here, the pair of arms are arranged at predetermined intervals in the direction of the rotation axis of the ratchet ring, and a spring is arranged between the pair of arms. By providing the pair of arms, it becomes easy to form a space for arranging the springs.

The diameter of the spring can be larger than the width of each arm in the direction in which the pair of guides face each other. As a result, the size of the spring can be increased, and it becomes easy to adjust the urging force of the spring. Further, by increasing the size of the spring, the spring can be arranged along the accommodating portion, and the position of the spring in the accommodating portion can be stabilized.

The torque wrench of the present invention may be provided with a first cover that covers the ratchet ring, a second cover that covers the accommodating portion, and a ring member. Since both ends of the ring member are free ends, they can be deformed inward in the radial direction. Here, by engaging the ring member with the head and the second cover by the restoring force when the ring member is deformed inward in the radial direction, the first cover is positioned on the head and the second cover is directed toward the head. Can be urged. This makes it possible to attach the first cover and the second cover to the head using only the ring member.

It is an exploded perspective view of the torque wrench of this embodiment. It is a top view of the torque wrench of this embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 2 is a cross-sectional view taken along the line BB in FIG. It is a top view of the torque wrench of this embodiment, and is the figure which shows the state after a part of the guide groove is worn. It is a top view of the conventional ratchet mechanism. It is a top view of another conventional ratchet mechanism. It is a figure which shows the state after a part of the guide groove is worn in the ratchet mechanism of FIG.

FIG. 1 is an exploded perspective view of the torque wrench of the present embodiment. The torque wrench 1 is used for tightening and loosening fastening members such as bolts. The torque wrench 1 has a handle 20 operated by the user and a head 30 rotatable with respect to the handle 20. The handle 20 and the head 30 are connected by a connecting shaft 21, and rotate relative to the connecting shaft 21. When the tightening torque of the fastening member reaches the set torque, the toggle mechanism arranged in the handle 20 operates, so that the handle 20 rotates with respect to the head 30. As a result, the user of the torque wrench 1 can recognize that the tightening torque of the fastening member has reached the set torque. Since the toggle mechanism is a known mechanism, detailed description thereof will be omitted.

The head 30 is formed with a hole 31, a recess 40, and a guide groove 50. The hole 31 accommodates the ratchet ring 60, the first head cover 81, and the retaining ring 90. The second head cover 82 is housed in the recess 40. The guide groove 50 accommodates the engaging member 70 and the spring 71.

The hole 31 is composed of three hole portions 32, 34, 36 having different diameters from the upper end to the lower end into which the ratchet ring 60 is inserted. Specifically, the first hole portion 32, the second hole portion 34, and the third hole portion 36 are formed in order from the upper end to the lower end of the hole 31.

FIG. 3 is a sectional view taken along the line AA of the torque wrench 1 shown in FIG. Here, in FIG. 2, the first head cover 81, the second head cover 82, and the retaining ring 90, which will be described later, are omitted, but in FIG. 3, the first head cover 81, the second head cover 82, and the retaining ring 90 are also shown. ..

As shown in FIG. 3, the diameter d1 of the first hole portion 32 is the largest, and the diameter d3 of the third hole portion 36 is the smallest. The diameter d2 of the second hole portion 34 is smaller than the diameter d1 of the first hole portion 32 and larger than the diameter d3 of the third hole portion 36. The first hole portion 32 is formed with a groove portion 32a extending in the circumferential direction of the first hole portion 32. At the boundary between the first hole portion 32 and the second hole portion 34, a first step portion 33 formed of a plane orthogonal to the rotation axis C of the ratchet ring 60 is formed. At the boundary between the second hole portion 34 and the third hole portion 36, a second step portion 35 formed by a plane orthogonal to the rotation axis C of the ratchet ring 60 is formed.

The guide groove 50 is connected to the second hole portion 34 and extends from the second hole portion 34 toward the outside of the second hole portion 34. The guide groove 50 has a pair of guide portions 51, 52 arranged substantially in parallel, and an accommodating portion 53 forming a space S1 having a width wider than the distance between the pair of guide portions 51, 52 (see FIG. 2). ..

The distance between the pair of guide portions 51 and 52 is set to a value slightly larger than the thickness of the engaging member 70 so that the engaging member 70 can slide with respect to the guide portions 51 and 52. .. As a result, the pair of guide portions 51 and 52 can move the engaging member 70 along a predetermined direction. As will be described later, the guide portion 51 is a portion where the engaging member 70 is brought into contact with the guide portion 51, and the area of the region where the guide portion 51 is formed is larger than the area of the region where the guide portion 52 is formed. A part of the engaging member 70 and the spring 71 are accommodated in the accommodating portion 53 (in other words, the space S1).

The recess 40 is formed on the upper surface of the head 30 and is connected to the first hole portion 32 described above. The bottom surface 41 of the recess 40 is formed in the same plane as the first step portion 33, and the guide groove 50 is formed on the bottom surface 41 of the recess 40. The side surface 42 of the recess 40 is formed in a shape that follows the outer shape of the second head cover 82. The depth of the recess 40 is substantially equal to the thickness of the second head cover 82, and when the second head cover 82 is housed in the recess 40, the upper surface of the second head cover 82 and the upper surface of the head 30 are located in the same plane. do.

The ratchet ring 60 has a square drive 61, ratchet teeth 62, and a shaft portion 63, and is rotatable about a rotation shaft C in the hole 31. The ratchet teeth 62 are formed on the outer peripheral surface of the main body of the ratchet ring 60, are arranged inside the second hole portion 34, and engage with the engaging member 70 accommodated in the guide groove 50. The square drive 61 is provided on one end surface of the ratchet ring 60 in the direction of the rotation axis C, and a socket (not shown) is mounted on the square drive 61. The shaft portion 63 is provided on the other end surface of the ratchet ring 60 in the direction of the rotation shaft C, and is inserted into the third hole portion 36. Of the main body of the ratchet ring 60, the other end surface of the rotating shaft C abuts on the second step portion 35 of the hole 31.

The engaging member 70 is a U-shaped member obtained by cutting out a part of a rectangular parallelepiped. Specifically, the engaging member 70 has an engaging portion 70a that engages with the ratchet tooth 62, and a pair of arm portions 70b, 70c integrally provided at both ends of the engaging portion 70a. The pair of arm portions 70b and 70c are arranged at predetermined intervals in the direction of the rotation axis C of the ratchet ring 60.

The spring 71 is an elastic body and is arranged between the pair of arm portions 70b and 70c. By providing the pair of arm portions 70b and 70c, it is possible to form a space for arranging the spring 71 between the pair of arm portions 70b and 70c. This facilitates the formation of a space for arranging the spring 71 in the accommodating portion 53.

The diameter of the spring 71 is larger than the width of each arm portion 70b, 70c in the direction in which the pair of guide portions 51, 52 face each other, and as shown in FIG. 2, a part of the spring 71 is a part of the arm portion 70b. , 70c project outward from the space formed between them. The diameter of the spring 71 may be smaller than or equal to the width of each of the arm portions 70b and 70c described above.

As shown in FIG. 4, the engaging member 70 is housed in the guide groove 50 together with the spring 71, one end of the spring 71 abuts on the guide groove 50, and the other end of the spring 71 abuts on the engaging portion 70a. As a result, the spring 71 urges the engaging member 70 toward the ratchet teeth 62.

The shape of the engaging member 70 is not limited to the shape described above. That is, the engaging member 70 only needs to be able to engage with the ratchet teeth 62 by receiving the urging force of the spring 71, and can be formed into various shapes (for example, a rectangular parallelepiped) as long as it has this function.

The first head cover 81 is formed in a ring shape and is arranged at a position that covers a part of the ratchet ring 60 to prevent the ratchet ring 60 from coming out of the hole 31. Specifically, the first head cover 81 is housed in the first hole portion 32 of the hole 31, and the lower surface of the first head cover 81 shown in FIG. 1 abuts on the first step portion 33 of the hole 31. The ratchet ring 60 is prevented from coming off. Here, the square drive 61 projects from the opening formed inside the first head cover 81.

The second head cover 82 covers the guide groove 50 and is used to prevent the engaging member 70 and the spring 71 from coming out of the guide groove 50, and has a first side surface 83 and a second side surface 84. The first side surface 83 is formed along the side surface 42 of the recess 40. That is, the curvatures of the first side surface 83 and the side surface 42 are substantially the same. The second side surface 84 is formed with the same curvature as the first hole portion 32 of the hole 31.

Further, a concave groove 85 is formed on the second side surface 84 of the second head cover 82. The groove portion 85 is located on an extension line of the groove portion 32a of the first hole portion 32 in a state where the second head cover 82 is embedded in the recess 40. The retaining ring 90 engages with the groove portion 32a of the first hole portion 32 and the groove portion 85 of the second head cover 82.

The retaining ring 90 is used to prevent the first head cover 81 from coming off the hole 31 and the second head cover 82 from coming off from the recess 40, and has a ring shape having both ends free ends. It is an elastic body. When the retaining ring 90 is pressed inward in the circumferential direction, the diameter is reduced, and a restoring force that deforms outward in the circumferential direction is generated. Then, the retaining ring 90 engages with the groove portion 32a of the first hole portion 32 and the groove portion 85 of the second head cover 82 by this restoring force. At this time, since the retaining ring 90 comes into contact with the first head cover 81 installed in the first step portion 33, the first head cover 81 is positioned in the first hole portion 32 of the hole 31.

Further, when the retaining ring 90 is engaged with the groove 85 of the second head cover 82 housed in the recess 40, the restoring force of the retaining ring 90 acts on the second head cover 82, so that the second head cover 82 The first side surface 83 is pressed against the side surface 42 of the recess 40. This makes it possible to prevent the second head cover 82 from coming off the recess 40.

The operation of the ratchet mechanism when the torque wrench 1 is used will be described.

In FIG. 2, the engaging member 70 is engaged with the ratchet tooth 62 by the urging force of the spring 71. In the state shown in FIG. 2, when the handle 20 is rotated in the direction of the arrow X, the reaction force from the fastening member acts on the ratchet ring 60, so that the engaging member 70 receives the load F2 from the ratchet teeth 62 and guides it. It abuts on the portion 51. As a result, the ratchet mechanism of the torque wrench 1 is locked, the rotational force of the handle 20 in the arrow X direction is transmitted to the fastening member, and the fastening member rotates in the arrow Z direction (tightening direction).

On the other hand, in the state shown in FIG. 2, when the handle 20 is rotated in the Y direction of the arrow, the engaging member 70 moves along the ratchet teeth 62. When the engaging member 70 abuts on the crest of the ratchet tooth 62, the ratchet tooth 62 causes the spring 71 to contract by pushing the engaging member 70 toward the inside of the space S1. At this time, the engagement member 70 and the ratchet tooth 62 are disengaged. When the ratchet ring 60 further rotates in the same direction and the engaging member 70 gets over the mountain portion of the ratchet tooth 62, the engaging member 70 moves to the valley portion of the ratchet tooth 62 by the urging force of the spring 71. Engage with the ratchet tooth 62 again. When the handle 20 is rotated in the Y direction of the arrow in this way, the engagement position of the engaging member 70 with respect to the ratchet teeth 62 changes, the ratchet mechanism is in an unlocked state, and the engaging member 70 is along the guide groove 50. Reciprocating motion (linear motion). At this time, the rotational force of the handle 20 in the arrow Y direction is not transmitted to the fastening member, and the fastening member does not rotate in the tightening direction.

In this way, when the handle 20 is rotated alternately in the arrow X direction and the arrow Y direction, the ratchet ring 60 is intermittently rotated in the arrow Z direction, and the fastening member is rotated in the arrow Z direction (tightening direction). Can be done.

Also in this embodiment, similarly to the conventional ratchet mechanism shown in FIG. 8, the guide portion 51 is repeatedly subjected to the load F2 from the engaging member 70, so that a part of the region of the guide portion 51 (the region shown by the diagonal line). ) R may wear.

FIG. 5 is a diagram showing a state after the region R shown in FIG. 2 is worn, and is a diagram corresponding to FIG. 2. The wear surface W is a wall surface generated by the wear of the region R. As shown in FIG. 5, when the engaging member 70 receives the load F2 from the ratchet teeth 62, the engaging member 70 is in a posture along the wear surface W, and is in the posture of the engaging member 70 shown in FIG. On the other hand, it will tilt.

In the present embodiment, since the space S1 is provided in the guide groove 50, the inclination of the engaging member 70 can be allowed as described above. As a result, the load F2 acting on the engaging member 70 can be received from the ratchet teeth 62 only on the wear surface W, and the bending stress can be suppressed from acting on the engaging member 70. Therefore, even if the torque wrench 1 is used after the region R is worn, it is possible to suppress bending or breakage of the engaging member 70, and it is possible to continue to maintain the function of the engaging member 70. Further, considering the bending of the engaging member 70, it is necessary to give the engaging member 70 toughness, but in the present embodiment, the compressive force of the wear surface W and the ratchet teeth 62 only acts on the engaging member 70. Therefore, it is not necessary to give the engaging member 70 toughness, and the hardness of the engaging member 70 can be improved.

Further, in the present embodiment, the spring 71 is arranged between the pair of arm portions 70b and 70c, and the spring 71 is housed in the space S1 wider than the distance between the pair of guide portions 51 and 52. Therefore, the diameter of the spring 71 can be increased, and the urging force of the spring 71 can be easily adjusted. Further, by increasing the diameter of the spring 71, the spring 71 can be arranged along the accommodating portion 53, and the position of the spring 71 in the space S1 can be stabilized.

Further, in the present embodiment, the first head cover 81 can be fixed to the hole 31 of the head 30 and the second head cover 82 can be fixed to the recess 40 only by the retaining ring 90. As a result, the number of parts can be reduced and the torque wrench 1 can be easily assembled as compared with the case where the two head covers 81 and 82 are individually fixed.

1: Torque wrench, 20: Handle, 30: Head, 40: Recess, 50: Guide groove,
60: ratchet ring, 70: engaging member, 71: spring, 81: first head cover,
82: 2nd head cover, 90: retaining ring, R: area, W: worn surface, S1: space

Claims (4)

A torque wrench having a handle operated by the user and a head rotatable with respect to the handle.
A ratchet ring having ratchet teeth formed on the outer peripheral surface and rotatable with respect to the head,
An engaging member that linearly moves between a first position that engages with the ratchet tooth and a second position that disengages the ratchet tooth.
A spring that urges the engaging member toward the first position,
A pair of guide portions formed on the head and guiding the engaging member in the moving direction of the engaging member.
The spring is formed on the head, is connected to an end portion of the guide portion that is separated from the ratchet ring in the moving direction of the engaging member, has a width wider than the distance between the pair of guide portions, and has a width wider than the distance between the pair of guide portions. And a containment unit
Have,
While the engaging member moves between the first position and the second position, the accommodating portion accommodates the end portion of the engaging member that is separated from the ratchet teeth in the moving direction. When the engaging member is in the first position, the inclination of the engaging member due to wear of one of the guide portions that receives the load from the engaging member among the pair of guide portions is determined. A torque wrench characterized by being tolerable. The engaging member is
An engaging portion that engages with the ratchet teeth,
A pair of arm portions integrally formed with the engaging portion and arranged at positions sandwiching the spring in the rotation axis direction of the ratchet ring.
The torque wrench according to claim 1, wherein the torque wrench is characterized by having. The torque wrench according to claim 2, wherein the diameter of the spring is larger than the width of each arm portion in the direction in which the pair of guide portions face each other. The first cover covering the ratchet ring and
A second cover that covers the housing and
It has both ends that are free ends, and by engaging with the head and the second cover by the restoring force when deformed inward in the radial direction, the first cover is positioned on the head and at the same time. A ring member that urges the second cover toward the head, and
The torque wrench according to any one of claims 1 to 3, wherein the torque wrench is characterized by having.

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