JP2018176361A - Torque wrench - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque wrench in which a ratchet mechanism can be easily miniaturized, and deformation and rupture of a component of the ratchet mechanism can be suppressed.SOLUTION: A torque wrench (1) of the present invention includes a ratchet ring (60) and an engaging member (70). The ratchet ring is rotatable with respect to a head (30), and a ratchet tooth (62) is formed on an outer circumferential surface of the ratchet ring. The engaging member linearly moves between a first position for engaging with the ratchet tooth and a second position for releasing engagement with the ratchet tooth. The engaging member is energized toward the first position by a spring. A pair of guide parts (51 and 52) and a housing part (53) are formed in the head. A pair of guide parts guide the engaging member in the movement direction of the engaging member. The housing part houses a part of the engaging member and a spring, and has a width wider than an interval of the pair of guide parts.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a torque wrench having a ratchet mechanism.

  As a ratchet mechanism of the conventional torque wrench, there exist a mechanism (for example, patent document 1) shown in FIG. 6, and a mechanism (for example, patent document 2) shown in FIG.

  In the ratchet mechanism shown in FIG. 6, the engagement member 4A is pivotable about the shaft 5A. Then, the spring 3A biases the engaging member 4A toward the ratchet ring 1A, whereby the tip end portion of the engaging member 4A meshes with the ratchet teeth 2A of the ratchet ring 1A. At this time, the engagement 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, whereby the spring 3A expands and contracts, and the engaging member 4A rotates around the shaft 5A. Move. When the torque wrench shown in FIG. 6 is rotated in the direction of arrow D3 to fasten a fastening member such as a bolt, a reaction force from the fastening member generates a force for rotating the ratchet ring 1A in the direction of arrow D1. Since the engaging member 4A remains in mesh with the ratchet teeth 2A, the engaging member 4A receives the load F1 when the ratchet ring 1A tries to rotate in the direction of the arrow D1 with the shaft 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 accommodated in the guide groove 6A. The spring 3A biases the engaging member 4A toward the ratchet ring 1A, whereby the tip end portion of the engaging member 4A meshes with the ratchet teeth 2A of the ratchet ring 1A. At this time, the engagement 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, whereby 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 fasten a fastening member such as a bolt, a reaction force from the fastening member generates a force for rotating the ratchet ring 1A in the direction of arrow D1. Since the engaging member 4A remains meshed with the ratchet teeth 2A, by abutting on the wall surface 7A of the guide groove 6A, the engaging member 4A receives the load F2 when the ratchet ring 1A tries to rotate in the direction of the arrow D1.

JP 2001-179650 A JP 2004-255539 A

  However, in the ratchet mechanism shown in FIG. 6, since the engaging member 4A pivots about the shaft 5A, the working space of the engaging member 4A must be larger than that of the ratchet mechanism shown in FIG. As a result, there is a problem that it is difficult to miniaturize the torque wrench.

  Furthermore, as described above, since the shaft 5A receives the load F1 when the fastening member is tightened, the shaft 5A may be damaged.

  On the other hand, in the ratchet mechanism shown in FIG. 7, since the engagement member 4A only slides along the guide groove 6A, it is necessary to make the operation space of the engagement member 4A wider than the ratchet mechanism shown in FIG. Has the advantage that it is easy to miniaturize the torque wrench.

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

  FIG. 8 shows the ratcheting mechanism after the area R of FIG. 7 has been worn. As shown in FIG. 8, the worn surface W is generated by wearing the region R of FIG. 7. In this state, when the load F2 is applied to the engaging member 4A, the tip of the engaging member 4A is displaced in the direction toward the wear surface W, whereby the engaging member 4A is inclined with respect to the guide groove 6A. Do. Thereby, the contact area of the engaging member 4A and the guide groove 6A decreases, and the load F2 (bending stress) is repeatedly applied to the engaging member 4A, which may cause the engaging member 4A to be bent or broken. There is.

  Then, an object of this invention is to provide the torque wrench which can be made easy to miniaturize a ratchet mechanism, and can suppress a deformation | transformation and a fracture | rupture of the components of a ratchet mechanism.

  SUMMARY OF THE INVENTION The present invention is a torque wrench having a handle operated by a user and a head pivotable relative to the handle, the ratchet having a ratchet ring and an engagement member. The ratchet ring is rotatable relative to the head, and ratchet teeth are formed on the outer circumferential surface of the ratchet ring. The engagement member linearly moves between a first position engaged with the ratchet teeth and a second position disengaged from the ratchet teeth. The engagement member is biased toward the first position by a spring.

  The head is formed with a pair of guide portions and a housing portion. The pair of guide portions guides the engagement member in the movement direction of the engagement member. The accommodating portion accommodates a part of the engaging member and the spring, and has a width larger than the distance between the pair of guide portions.

  According to the present invention, when the guide portion is worn due to the friction with the engaging member, the engaging member can be inclined with respect to the moving direction of the engaging member using the space in the housing portion. . Thereby, it can suppress that a bending stress generate | occur | produces in an engaging member, and can suppress that an engaging member bends or fractures | ruptures.

  The engagement member can be configured by an engagement portion engaged with the ratchet teeth and a pair of arms integrally formed with the engagement portion. Here, the pair of arm portions is disposed at a predetermined interval in the rotational axis direction of the ratchet ring, and a spring is disposed between the pair of arm portions. By providing the pair of arms, it becomes easy to form a space for disposing the spring.

  The diameter of the spring can be made 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 the biasing force of the spring can be easily adjusted. In addition, by enlarging the spring, the spring can be disposed along the housing portion, and the position of the spring in the housing portion can be stabilized.

  The torque wrench of the present invention can be provided with a first cover that covers the ratchet ring, a second cover that covers the housing, and a ring member. Since both ends of the ring member are free ends, they can be deformed radially inward. Here, the first cover is positioned on the head and the second cover is directed to the head by engaging the ring member with the head and the second cover by the restoring force when the ring member is deformed radially inward. Can be energized. Thus, the first cover and the second cover can be attached to the head using only the ring member.

It is a disassembled perspective view of the torque wrench of this embodiment. It is a top view of the torque wrench of this embodiment. It is AA sectional drawing in FIG. It is a BB sectional view in FIG. It is a top view of the torque wrench of this embodiment, Comprising: It is a figure which shows the state after abrasion of a part of guide groove. It is a top view of the conventional ratchet mechanism. It is a top view of the other conventional ratchet mechanism. FIG. 8 is a view showing a state after a part of the guide groove is worn away in the ratchet mechanism of FIG. 7;

  FIG. 1 is an exploded perspective view of the torque wrench of the present embodiment. The torque wrench 1 is used to tighten or loosen a fastening member such as a bolt. The torque wrench 1 has a handle 20 operated by the user and a head 30 rotatable relative to the handle 20. The handle 20 and the head 30 are connected by the 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 disposed in the handle 20 operates to rotate the handle 20 relative to the head 30. Thus, 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, the detailed description is 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 accommodated in the recess 40. The guide groove 50 accommodates the engagement member 70 and the spring 71.

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

  FIG. 3 is a cross-sectional view of the torque wrench 1 shown in FIG. Here, although FIG. 2 omits a first head cover 81, a second head cover 82, and a snap ring 90 described later, FIG. 3 also shows the first head cover 81, the second head cover 82, and the snap ring 90. .

  As shown in FIG. 3, the diameter d1 of the first hole 32 is the largest, and the diameter d3 of the third hole 36 is the smallest. The diameter d 2 of the second hole 34 is smaller than the diameter d 1 of the first hole 32 and larger than the diameter d 3 of the third hole 36. In the first hole 32, a groove 32a extending in the circumferential direction of the first hole 32 is formed. At the boundary between the first hole 32 and the second hole 34, a first step 33 formed of a plane perpendicular to the rotation axis C of the ratchet ring 60 is formed. At the boundary between the second hole 34 and the third hole 36, a second step 35 formed of 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 34 and extends from the second hole 34 to the outside of the second hole 34. The guide groove 50 has a pair of guide portions 51, 52 disposed substantially in parallel, and a storage 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 engagement member 70, and the engagement member 70 can slide relative to the guide portions 51 and 52. . Thus, the pair of guide portions 51 and 52 can move the engagement member 70 along the predetermined direction. The guide portion 51 is a portion to which the engaging member 70 abuts, as described later, and the area of the region in which the guide portion 51 is formed is larger than the area of the region in which the guide portion 52 is formed. A part of the engagement member 70 and the spring 71 are accommodated in the accommodation 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 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 along 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 accommodated in the recess 40, the upper surface of the second head cover 82 and the upper surface of the head 30 are positioned in the same plane. Do.

  The ratchet ring 60 has an angular drive 61, ratchet teeth 62, and a shaft 63, and can rotate around the rotation axis 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, and are disposed inside the second hole 34 to engage with the engagement member 70 accommodated in the guide groove 50. The angular drive 61 is provided on one end face of the main body of the ratchet ring 60 in the direction of the rotation axis C, and a socket (not shown) is attached to the angular drive 61. The shaft portion 63 is provided on the other end surface of the main body of the ratchet ring 60 in the direction of the rotation axis 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 rotation shaft C abuts on the second step portion 35 of the hole 31.

  The engagement member 70 is a U-shaped member in which a part of a rectangular parallelepiped is cut away. Specifically, the engagement member 70 has an engagement portion 70a that engages with the ratchet teeth 62, and a pair of arm portions 70b and 70c integrally provided at both ends of the engagement portion 70a. The pair of arm portions 70 b and 70 c 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 disposed between the pair of arms 70 b and 70 c. By providing the pair of arms 70b and 70c, a space for disposing the spring 71 can be formed between the pair of arms 70b and 70c. As a result, in the housing portion 53, an arrangement space for the spring 71 can be easily formed.

  The diameter of the spring 71 is larger than the width of each arm 70b, 70c in the direction in which the pair of guides 51, 52 oppose each other. As shown in FIG. , 70c project outward from the space formed between them. The diameter of the spring 71 may be equal to or less than the width of each of the arm portions 70 b and 70 c described above.

  As shown in FIG. 4, the engagement member 70 is accommodated 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 engagement portion 70 a Thus, the spring 71 biases the engagement member 70 toward the ratchet teeth 62.

  The shape of the engagement member 70 is not limited to the above-described shape. That is, as long as the engaging member 70 can be engaged with the ratchet teeth 62 by receiving the urging force of the spring 71, the engaging member 70 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 disposed at a position covering 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 accommodated in the first hole 32 of the hole 31, and the lower surface of the first head cover 81 shown in FIG. 1 abuts on the first step 33 of the hole 31. Prevent the ratchet ring 60 from coming off. Here, the angular drive 61 protrudes from the opening formed inside the first head cover 81.

  The second head cover 82 covers the guide groove 50, is used to prevent the engagement 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 32 of the hole 31.

  In addition, a concave groove 85 is formed on the second side surface 84 of the second head cover 82. The groove 85 is positioned on an extension of the groove 32 a of the first hole 32 in a state where the second head cover 82 is embedded in the recess 40. A snap ring 90 is engaged with the groove 32 a of the first hole 32 and the groove 85 of the second head cover 82.

  The retaining ring 90 is used to prevent the first head cover 81 from being removed from the hole 31 and to prevent the second head cover 82 from being removed from the recess 40, and has a ring shape whose both ends are free ends. It is an elastic body. The retaining ring 90 is reduced in diameter when pressed inward in the circumferential direction, and generates a restoring force that is deformed outward in the circumferential direction. Then, the retaining ring 90 engages with the groove 32 a of the first hole 32 and the groove 85 of the second head cover 82 by this restoring force. At this time, the retaining ring 90 positions the first head cover 81 in the first hole 32 of the hole 31 in order to abut on the first head cover 81 installed in the first step portion 33.

  In addition, 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 is The first side surface 83 is pressed against the side surface 42 of the recess 40. This can prevent the second head cover 82 from coming off the recess 40.

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

  In FIG. 2, the engagement member 70 is engaged with the ratchet teeth 62 by the biasing force of the spring 71. In the state shown in FIG. 2, when the handle 20 is rotated in the direction of arrow X, the reaction force from the fastening member acts on the ratchet ring 60, so the engaging member 70 receives the load F 2 from the ratchet teeth 62 and guides It abuts on the part 51. As a result, the ratchet mechanism of the torque wrench 1 is locked, rotational force in the arrow X direction of the handle 20 is transmitted to the fastening member, and the fastening member is rotated 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 arrow Y direction, the engagement member 70 moves along the ratchet teeth 62. When the engaging member 70 abuts on the ridge of the ratchet tooth 62, the ratchet tooth 62 contracts the spring 71 by pushing the engaging member 70 toward the inside of the space S1. At this time, the engagement between the engagement member 70 and the ratchet teeth 62 is released. When the ratchet ring 60 further rotates in the same direction, and the engagement member 70 climbs over the ridge of the ratchet tooth 62, the engagement member 70 moves to the valley of the ratchet tooth 62 by the biasing force of the spring 71. It engages with the ratchet teeth 62 again. Thus, when the handle 20 is rotated in the arrow Y direction, the engagement position of the engagement member 70 with respect to the ratchet teeth 62 changes, the ratchet mechanism becomes unlocked, and the engagement member 70 is along the guide groove 50. Reciprocate (linear motion). At this time, the rotational force in the arrow Y direction of the handle 20 is not transmitted to the fastening member, and the fastening member does not rotate in the fastening direction.

  Thus, when the handle 20 is alternately rotated in the arrow X direction and the arrow Y direction, the ratchet ring 60 is intermittently rotated in the arrow Z direction to rotate the fastening member in the arrow Z direction (tightening direction). Can.

  Also in the present embodiment, as in the conventional ratchet mechanism shown in FIG. 8, the guide portion 51 repeatedly receives the load F2 from the engagement member 70 to partially cover the area of the guide portion 51 (the hatched area ) R may wear.

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

  In the present embodiment, since the space S1 is provided in the guide groove 50, as described above, the inclination of the engagement member 70 can be allowed. Thus, the load F2 acting on the engagement member 70 from the ratchet teeth 62 can be received only on the wear surface W, and the bending stress can be suppressed from acting on the engagement member 70. Therefore, even if the torque wrench 1 is used after the region R is worn, the occurrence of bending or breakage of the engagement member 70 can be suppressed, and the function of the engagement member 70 can be maintained. Further, in consideration of bending of the engagement member 70, it is necessary to make the engagement member 70 have toughness, but in the present embodiment, only the compressive force by the wear surface W and the ratchet teeth 62 acts on the engagement member 70. Thus, the need for the engagement member 70 to have toughness can be eliminated, and the hardness of the engagement member 70 can be improved.

  Further, in the present embodiment, the spring 71 is disposed between the pair of arm portions 70b and 70c, and the spring 71 is accommodated 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 biasing force of the spring 71 can be easily adjusted. Further, by enlarging the diameter of the spring 71, the spring 71 can be disposed along the housing 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 assembling of the torque wrench 1 is easy as compared to 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: engagement member, 71: spring, 81: first head cover,
82: Second head cover, 90: Retaining ring, R: Area, W: Wear surface, S1: Space

Claims (4)

A torque wrench having a handle operated by a user and a head rotatable relative to the handle, the torque wrench comprising:
Ratchet teeth are formed on the outer peripheral surface, and a ratchet ring rotatable relative to the head;
An engagement member linearly moving between a first position engaged with the ratchet teeth and a second position disengaged from the ratchet teeth;
A spring biasing the engagement member towards the first position;
A pair of guide portions formed on the head and guiding the engagement member in the movement direction of the engagement member;
A receptacle formed in the head and having a width greater than the distance between the pair of guides, and a part for receiving the part of the engagement member and the spring;
Torque wrench characterized by having. The engagement member is
An engagement portion that engages with the ratchet teeth;
A pair of arms formed integrally with the engagement portion and disposed at positions sandwiching the spring in the rotational axis direction of the ratchet ring;
The torque wrench according to claim 1, comprising:   The torque wrench according to claim 2, wherein a diameter of the spring is larger than a width of each of the arm portions in a direction in which the pair of guide portions face each other. A first cover covering the ratchet ring;
A second cover covering the housing portion;
The first cover is positioned on the head by engaging both the head and the second cover by having both end portions which are free ends, and by restoring force when deformed inward in the radial direction. A ring member for biasing the second cover toward the head;
The torque wrench according to any one of claims 1 to 3, comprising: