JP2005066802A - Torque wrench - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and light fluid working type torque wrench capable of providing continuous torque by continuously rotating a driving shaft through a drive plate of a ratchet mechanism to be engaged with a coupler of a cylinder mechanism and increasing rotating speed of the driving shaft, and accordingly finishing fastening work of a fastening member within a short period of time. <P>SOLUTION: This fluid working type torque wrench 200 is devised to fasten the fastening member so as to be made contact with an end part of the driving shaft by rotating the driving shaft through the cylinder mechanisms 203 A, B provided in a housing 202 and the ratchet mechanism driven by the cylinder mechanisms and is devised to continuously rotate the driving shaft by providing the two cylinder mechanisms and the ratchet mechanisms of the same structure as each other in the housing and alternately working the two cylinder mechanisms and the ratchet mechanisms. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement in a fluid operated torque wrench used when fastening a fastening member such as a bolt or a nut with a constant or prescribed torque (rotational moment).

  A torque wrench operated by a fluid such as oil obtains torque by converting a reciprocating motion of a piston rod in a cylinder into a circular motion.

  Conventionally, as such a fluid-operated torque wrench, for example, a power wrench as disclosed in Patent Document 1 and shown in FIG. 5 is known. The power wrench 100 includes a cylinder mechanism 103 and a ratchet mechanism 104 in which a power wrench main body 101 is provided in a housing 102. The cylinder mechanism 103 includes a piston 108 having a piston rod 107 that reciprocates in the cylinder 105 and provided with a joint 106 at an operating end, and a spring 109 provided to return the piston rod 107. Yes. On the other hand, the ratchet mechanism 104 includes a drive plate 110 that engages with the joint 106, a drive pawl 112 that is coupled to the drive plate 110 and has a pawl 111, and a plurality of teeth 113 that can mesh with the pawl 111 of the drive pawl 112. Is composed of a ratchet 114 provided on the outer periphery, and a drive shaft 115 inserted into the ratchet 114.

According to the power torque wrench 100, the fluid is flowed as indicated by the arrow N ₁ through the passage 116 in the cylinder 105, the piston rod 107 of the cylinder 105 begins to forward movement in the direction indicated by the arrow N ₂ Accordingly, the drive plate 110 engaged with the joint 106 provided at the operating end of the piston rod 107 performs an arc motion as indicated by a dotted line with the center O _{1 of the} ratchet 114 as a fulcrum, and torque is generated by the arc motion. Is transmitted to the ratchet 114 via the drive pawl 112. As a result, the drive shaft 115 is tightened is wound fastening members bolts and nuts or the like in contact with the end of the drive shaft 115 is rotated in a direction (not shown) indicated by the arrow N _3.

  However, as described above, the power wrench 100 obtains torque by converting the forward movement of the piston rod 107 of the cylinder mechanism 103 into an arcuate movement via the ratchet mechanism 104, and only when the piston 108 is pushed out. Is involved in the generation of torque and is not involved in the generation of torque at the time of return, so that the circular motion becomes intermittent, and the rotational speed of the drive shaft 115 becomes slow, and along with this the time for tightening work etc. There was a disadvantage that it took.

In addition, the power wrench 100 has a problem in that the cylinder 105 has a double structure of the cylinder bush 105a and the support bush 105b, so that it takes time to manufacture the cylinder 105 and increases the manufacturing cost. Further, fluid such as oil may leak from the joint 117 between the cylinder bush 105a and the support bush 105b.
Japanese Patent Laid-Open No. 7-164339

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to continuously rotate a drive shaft through a drive plate of a ratchet mechanism that engages with a joint of a cylinder mechanism, thereby driving the drive shaft. Since a continuous torque can be obtained by increasing the rotation speed of this, a small and lightweight fluid-operated torque wrench that can complete the fastening operation of the fastening member in a short time is provided.

  The object of the present invention is to rotate a drive shaft via a cylinder mechanism provided in a housing and a ratchet mechanism driven by the cylinder mechanism, and to tighten a fastening member abutted on an end of the drive shaft. In the fluid actuated torque wrench, two cylinder mechanisms and ratchet mechanisms having the same structure are arranged in parallel in the housing, and the two cylinder mechanisms and ratchet mechanisms are operated alternately, thereby driving the drive shaft. This is accomplished by providing a fluid operated torque wrench characterized by being continuously rotated.

  Further, the above object of the present invention is that the cylinder mechanism is constituted by a joint that reciprocates in the cylinder and has a piston rod at an operating end, and a spring that returns the piston rod. A drive plate that engages with the joint, a drive pawl connected to the drive plate via a drive pawl spring, a ratchet that meshes with the drive pawl, and the drive shaft that is inserted into the ratchet. This is accomplished effectively by providing a fluid operated torque wrench characterized by:

  According to the torque wrench according to the present invention, the rotational speed of the drive shaft can be increased, so that the drive shaft can be continuously rotated. As a result, a continuous torque can be obtained, so that even a small and light torque wrench can be used to fasten fastening members such as bolts and nuts in a short time and leak fluid such as oil. Can be prevented.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side sectional view of a fluid-operated torque wrench (hereinafter referred to as “the present torque wrench”) 200 according to the present invention (a cross-sectional view taken along the line Y-Y in FIG. 2), and FIG. FIG. 3 is a sectional view taken along the line ZZ in FIG. 1, and FIG. 4 is an enlarged view of a portion indicated by a circle R in FIG. The torque wrench 200 includes two cylinder mechanisms 203A and 203B having the same structure and two ratchet mechanisms 204A in a single housing 202 having a common torque wrench body 201 as shown in FIGS. , 204B, and the other components are the same as those of the conventional power wrench 100 described above, except that the mechanism A, B is formed in parallel to form a dual drive mechanism. Since the two mechanisms A and B of the torque wrench 200 are the same as each other, the mechanism A will be described below.

  The cylinder mechanism 203A is provided in the housing 202 and drives a drive plate 213A, which will be described later. The cylinder 205A, a piston 208A having a piston rod 207A having a joint 206A at its operating end, and a piston rod 207A are returned. It consists of a spring 209A. A nipple 210A for supplying high-pressure oil is provided at one end of the cylinder 205A, and a hydraulic unit (not shown) is connected to the tip of the nipple 210A via a hydraulic hose.

  The piston 208A reciprocates in the cylinder 205A by the high-pressure oil that has flowed in. A seal ring (O-ring) 211A for sealing the inside of the cylinder 205A is provided on the outer periphery of the piston 208A. A joint 206A provided at the operating end of the piston rod 207A is engaged with the tip of the drive plate 213A. The joint 206A transmits the reciprocating motion of the cylinder mechanism 203A to the ratchet mechanism 204A, and the ratchet mechanism 204A converts the reciprocating motion into an arc motion.

  The ratchet mechanism 204A transmits drive in one direction of the drive plate 213A to the drive shaft 214, and includes a drive plate 213A, a drive pawl 215A, a ratchet 216A, and a drive shaft 214. The drive shaft 214 is inserted into a hollow rotary shaft 220 that is inserted across two ratchet mechanisms 204A and 204B having the same structure as will be described later.

Drive plate 213A is engaged with the fitting 206A described above, rotates the ratchet 216A, is drivingly supported in the direction indicated its base is an arrow _{N 4} to a drive shaft 214 via the ratchet 216A.

As shown in FIG. 4, the drive pawl 215A has a plurality of claws 217A, and these claws 217A are formed so as to be able to mesh with teeth 218A provided on the outer periphery of the ratchet 216A. ratchet 216A are rotated in the direction indicated by the arrow _{N 4} the center _{O 2} as a fulcrum.

  A drive pawl spring 219A is embedded at the upper end of the drive pawl 215A and connected to the drive plate 213A. By providing this drive pawl spring 219A, the claw 217A is released from the tooth 218A of the ratchet 216A when the piston 208A reaches the limit position P (A) and the pressure becomes zero.

  The drive shaft 214 is inserted into a rotation hole (spline hole) 221 formed inside the hollow rotary shaft 220 as shown in FIG. This drive shaft 214 has a stop portion (spline) 222 adapted to the stop hole 221, and a bolt or a nut (not shown) is brought into contact with this end portion and is rotated together with the drive shaft 214 to be tightened. It is done.

  Next, the operation of the torque wrench 200 configured as described above will be described.

When high pressure oil is supplied to the cylinder 205A of the cylinder mechanism 203A via the nipple 210A, the piston 208A is pushed out toward the ratchet mechanism 204A, and the joint 206A provided at the tip of the piston rod 207A moves forward. This forward motion is transmitted to the drive plate 213A via the joint 206A, where it is converted into a circular motion. This arc motion is transmitted to the ratchet 216A via the drive pawl 215A, and the ratchet 216A rotates counterclockwise by a predetermined angle α (about 30 ° in the present embodiment) as shown in FIG. There tightened by turning the fastening member is rotated in the direction indicated by the arrow N _4.

  When the piston 208A reaches the limit position P (A) of the pushing limit, an external hydraulic unit (not shown) is operated so that the flow of high-pressure oil is transferred from the cylinder 205A to the cylinder mechanism 203B of the other mechanism B. Can be switched to. At the same time as the flow of the high-pressure oil is switched from the cylinder mechanism 203A to the cylinder mechanism 203B, the pressure state of the piston rod 207A is released and the pressure becomes zero, so the piston rod 207A is returned to the original position by the spring force of the spring 209A.

  When high pressure oil is supplied to the cylinder 205B of the cylinder mechanism 203B via the nipple 210B, the piston 208B is pushed out to the ratchet mechanism 204B side as in the mechanism A described above, and the joint provided at the tip of the piston rod 217B 206B moves forward. This forward motion is transmitted to the drive plate 213B via the joint 206B, where it is converted into a circular motion. This arc motion is transmitted to the ratchet 216B via the drive pawl 215B, the ratchet 216B rotates counterclockwise by a predetermined angle α, rotates the drive shaft 214, and rotates and tightens the fastening member.

  When the piston 208B reaches the limit position P (B) of the pushing limit, an external hydraulic unit (not shown) is operated, whereby the flow of high-pressure oil is transferred from the cylinder 205B to the other cylinder mechanism 203A. Can be switched. As in the mechanism A described above, the flow of the high-pressure oil is switched from the cylinder mechanism 203A to the cylinder mechanism 203B. At the same time, the piston rod 207B is released from the pressurized state and the pressure becomes zero. Is returned to the original position.

  In the torque wrench 200, the two shafts A and B alternately perform the above-described operations so that the drive shaft 214 continuously performs an arc motion, so that the rotational speed of the drive shaft 214 is almost doubled. Since a continuous torque can be obtained, a fastening member such as a bolt or a nut can be fastened quickly. Accordingly, even when a large number of fastening members have to be fastened in an extremely narrow place, such as a tightening work of a connecting bolt of a segment in underground tunnel construction, for example, the work can be easily performed.

  Further, since the cylinders 205A and 205B according to the torque wrench 200 are not a double structure of the cylinder bush and the support bush as in the conventional power wrench 100, the labor involved in the manufacturing is saved, and the manufacturing cost is reduced. Furthermore, the effect that fluid such as oil does not leak is obtained.

  Furthermore, although the case where the drive shaft rotates counterclockwise has been described, the rotation direction can be reversed by inserting the drive shaft from the opposite side, that is, the drive shaft is rotated clockwise. Therefore, it is possible to provide a torque wrench that can be used even when a fastening member such as a tightened bolt or nut is loosened.

The case where the fluid flowing into the torque wrench 200 is high-pressure oil has been described above. However, the present invention is not limited to such high-pressure oil, and any fluid such as low-pressure oil or water can be applied.

It is a sectional side view (YY section arrow view figure of FIG. 2) of the torque wrench which concerns on this invention. FIG. 2 is a sectional view taken along the line XX in FIG. It is a YY cross-sectional arrow view of FIG. FIG. 2 is an enlarged view of a portion indicated by a circle R in FIG. 1. It is a sectional side view of the conventional fluid actuated torque wrench.

Explanation of symbols

100, 200 Torque wrench 101, 201 Torque wrench body 102, 202 Housing 103, 203A, 203B Cylinder mechanism 104, 204A, 204B Ratchet mechanism 105, 205A, 205B Cylinder 106, 206A, 206B Joint 107, 207A, 207B Piston rod 108, 208A, 208B Piston 109, 209A, 209B Spring 210A, 210B Nipple 211A, 211B Seal ring (O-ring)
212A, 212B Joint shaft 110, 213A, 213B Drive plate 115, 214 Drive shaft 112, 215A, 215B Drive pawl 114, 216A, 216B Ratchet 111, 217A, 217B Provided on claw 113, 218A, 218B ratchet provided on drive pawl Teeth 219A, 219B Drive paw spring 220 Hollow rotary shaft 221 Stop hole 222 Stop part P (A), P (B) Limit position

Claims (2)

  A fluid-operated torque is configured such that a drive shaft is rotated via a cylinder mechanism provided in the housing and a ratchet mechanism driven by the cylinder mechanism, and a fastening member abutted on the end of the drive shaft is tightened. In a torque wrench, two cylinder mechanisms and ratchet mechanisms having the same structure are arranged in parallel in the housing, and the two drive shaft mechanisms and the ratchet mechanisms are operated alternately so that the drive shaft is continuously rotated. A fluid-operated torque wrench characterized by The cylinder mechanism includes a cylinder, a piston having a piston rod that reciprocates in the cylinder and has a joint at an operating end thereof, and a spring that returns the piston rod, and the ratchet mechanism includes: A drive plate engaged with the joint; a drive pawl connected to the drive plate via a drive pawl spring; a ratchet engaged with the drive pawl; and the drive shaft inserted into the ratchet. The fluid actuated torque wrench according to claim 1, wherein:

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