JP2020019099A - Fastening torque generation mechanism and hydraulic pulse wrench - Google Patents

Abstract

To provide a fastening torque generation mechanism which enables a communication passage for allowing communication between a high pressure chamber and a low pressure chamber to be provided easily with high accuracy.SOLUTION: A fastening torque generation mechanism includes: an oil cylinder 11 filled with a hydraulic oil; a spindle 12 which is inserted into the oil cylinder 11 so as to be able to relative rotation; and blades 13 attached to the spindle 12. In the fastening torque generation mechanism, the oil cylinder 11 is rotated relative to the spindle 12 and the blades 13 and a partition wall 11c provided on an inner surface of the oil cylinder 11 to form a high pressure chamber HR and a lower pressure chamber LR in the oil cylinder 11 to apply impact torque to the spindle 12. The fastening torque generation mechanism further includes a communication passage P for allowing communication between the high pressure chamber HR and the lower pressure chamber LR. At least a part of the communication passage P is formed by a different member 15 fixed to the oil cylinder 11.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a tightening torque generating mechanism for generating a tightening torque for tightening or loosening bolts and nuts, and a hydraulic pulse wrench using the same.

  Patent Literature 1 discloses a hydraulic pulse wrench provided with a tightening torque generating mechanism. The tightening torque generating mechanism includes an oil cylinder filled with hydraulic oil, a main shaft rotatably inserted into the oil cylinder, and a pair of blades mounted on the main shaft. The oil cylinder is relatively rotated with respect to the main shaft, and a high pressure chamber and a low pressure chamber are formed in the oil cylinder by the blades and the partition provided on the inner surface of the oil cylinder, so that the oil cylinder is intermittent. It is designed to provide a tightening torque.

JP 2000-117650 A

  By the way, in order to smoothly perform the relative rotation of the oil cylinder, a communication passage communicating the high-pressure chamber and the low-pressure chamber is provided in the partition wall, so that hydraulic oil flows from the high-pressure chamber to the low-pressure chamber. However, if the flow amount of the hydraulic oil is large, the pressure difference between the high-pressure chamber and the low-pressure chamber becomes small, and a sufficiently large impact torque cannot be obtained. On the other hand, when the flow amount of the hydraulic oil is small, the rotation of the oil cylinder may be hindered by the pressure of the hydraulic oil in the high-pressure chamber, and the relative rotation of the oil cylinder may not be smoothly performed. Therefore, it is important to provide the communication passage with high accuracy. However, since the partition is located on the inner surface side of the oil cylinder, the operation is extremely difficult. In order to improve workability, a hole is provided separately extending between the inside and outside of the oil cylinder, and this hole is used as a work hole for forming a communication passage.However, this method includes an oil cylinder and an oil cylinder. This is applicable only when the cylinder case is separate from the cylinder case, and cannot be applied to the cylinder case-integrated oil cylinder as seen in recent years.

  Therefore, an object of the present invention is to provide a tightening torque generating mechanism that can easily and accurately provide a communication path that connects a high-pressure chamber and a low-pressure chamber.

  In order to solve the above problem, a tightening torque generating mechanism of the present invention includes an oil cylinder 11 filled with hydraulic oil, a main shaft 12 inserted rotatably with respect to the oil cylinder 11, and a main shaft 12. A high-pressure chamber HR and a low-pressure chamber LR in the oil cylinder 11 by the blade 13 and a partition wall 11c provided on the inner surface of the oil cylinder 11. Forming a tightening torque generating mechanism for applying an impact torque to the main shaft 12, further comprising a communication path P that communicates between the high-pressure chamber HR and the low-pressure chamber LR, and at least a part of the communication path P Is characterized by being constituted by a separate member 15 fixed to the oil cylinder 11.

  Further, an adjusting member 16 for making the flow passage area of the communication passage P variable is further provided, and at least a part of the communication passage P is constituted by another member 15 and the adjusting member 16. The adjustment member 16 may be adjacent.

  A hydraulic pulse wrench according to the present invention includes any one of the above-described tightening torque generating mechanisms.

  In the tightening torque generating mechanism according to the present invention, at least a part of the communication path is formed by a separate member fixed to the oil cylinder, so that the communication path can be provided simply and accurately. That is, since it is a part separate from the oil cylinder, machining is easy and accuracy can be easily obtained. In addition, since the hole accuracy on the oil cylinder side may be rough, the production of the oil cylinder is also simplified.

  The communication path further includes an adjustment member for changing a flow path area, and at least a part of the communication path is configured by another member and an adjustment member, and the another member and the adjustment member are adjacent to each other. Even in this case, the communication path can be easily and accurately provided. In addition, since the flow path area of the communication path can be changed using the adjustment member with reference to the communication path prepared by another member, the operation of adjusting the flow path area can be easily performed.

It is a sectional view showing the hydraulic pulse wrench provided with the tightening torque generating mechanism concerning the embodiment of the present invention. FIG. 4 is a cross-sectional view of the tightening torque generation mechanism in a direction orthogonal to the axial direction of the main shaft. FIG. 4 is a cross-sectional view of a tightening torque generating mechanism showing a state where a high-pressure chamber and a low-pressure chamber are formed. FIG. 4A is an exploded perspective view in section showing an oil cylinder, a fixing member (liner) and an adjusting member, and FIG. 4B is a sectional perspective view showing a state in which FIG. 4A is assembled.

  Next, an embodiment of a tightening torque generating mechanism 10 of the present invention and a hydraulic pulse wrench 1 having the same will be described in detail with reference to the drawings. FIG. 1 shows a sectional view of a hydraulic pulse wrench 1. The hydraulic pulse wrench 1 includes a grip portion 2 and a main body casing 3 extending at an upper end of the grip portion 2 in the front-rear direction. The grip 2 is provided with an air supply port 4 and an operation lever 5. Further, for example, a vane type air motor 6 is housed in a rear portion of the main body casing 3, and a tightening torque generating mechanism 10 is housed in a front portion of the air motor 6.

  The tightening torque generating mechanism 10 includes an oil cylinder 11 in which hydraulic oil is filled, a main shaft 12 inserted to be rotatable relative to the oil cylinder 11, and a blade 13 attached to the main shaft 12. .

  The oil cylinder 11 includes a bottomed cylindrical cylinder body 11a whose one end is closed, and an end plate 11b which closes the other end of the cylinder body 11a. In general, the oil cylinder is covered by a separate cylinder case, but the oil cylinder 11 also has the function of a cylinder case. In other words, it is an oil cylinder integrated with a cylinder case. The end plate 11b is connected to the rotor 6a of the air motor 6, and the oil cylinder 11 is driven to rotate by the air motor 6. The inside of the oil cylinder 11 is filled with hydraulic oil.

  The main shaft 12 is rotatably held by the bottom of the cylinder body 11a and the end plate 11b. The tip of the main shaft 12 protrudes from the oil cylinder 11 and further protrudes from the main body casing 3. A mounting portion 12a for mounting a socket (not shown) for turning a bolt or a nut or the like is formed at the protruding tip portion. On the other hand, a groove 12b for accommodating the blade 13 is formed on the base end side located in the oil cylinder 11 (see FIG. 2). Further, a spring mounting hole 12c is formed for mounting a spring 14 for urging the blade 13 inserted into the slot 12b.

  Two blades 13 are provided, and are inserted into the slot 12b so that the phases are different from each other by 180 degrees in the circumferential direction of the main shaft 12. The pair of blades 13, 13 are urged by a spring 14 in a direction protruding from the main shaft 12, and are always slidably in contact with the inner surface of the oil cylinder 11, and are freely retractable according to the inner surface shape of the oil cylinder 11. It has been.

  FIG. 2 is a cross-sectional view of the tightening torque generating mechanism 10 in a direction orthogonal to the axial direction of the main shaft 12. As shown in the drawing, the inner surface shape of the cylinder body 11a is a cocoon shape or a roughly gourd shape with a narrowed center. The constricted portion is formed by a pair of partition walls 11c, 11c protruding toward the center of the cylinder body 11a (the center of the main shaft 12). Further, a seal protrusion 11d is provided at a position advanced by about 90 degrees in the circumferential direction from the partition wall 11c toward the center of the cylinder body 11a (center of the main shaft 12). The main shaft 12 is also provided with a main shaft side seal projection 12d protruding toward the inner surface (radially outward direction) of the cylinder body 11a at a position advanced by about 90 degrees in the circumferential direction from the slot 12b. The partition 11c and the main shaft side seal protrusion 12d are in close contact with each other in an oil-tight state, and the seal protrusion 11d and the tip end surface of the blade 13 are in close contact with each other in an oil-tight state. It is to be divided into. The innermost surface F1 with which the tip surface of the blade 13 slides is constituted by, for example, a tip surface of a rib 11e provided annularly on the inner surface side of the cylinder body 11a. The innermost surface F1 has a substantially oval shape (substantially track shape) formed by arranging a plurality of (three) circles while slightly displacing them in parallel with a virtual line connecting the seal protrusions 11d. , The partition wall 11c and the seal protrusion 11d.

  When the oil cylinder 11 is rotationally driven by the air motor 6, the tightening torque generating mechanism 10 having the above-described configuration causes the blade 13 to rotate the oil cylinder 11 via hydraulic oil (not shown) filled in the oil cylinder 11. The force is transmitted, and the main shaft 12 rotates. The bolts and nuts are tightened using this rotation. When the bolts and nuts are tightened to some extent and the tightening load becomes large, the rotation of the main shaft 12 becomes slow. On the other hand, since the oil cylinder 11 keeps rotating, the relative rotational position between the main shaft 12 and the oil cylinder 11 changes. In the process, the partition wall 11c comes into close contact with the main shaft side seal protrusion 12d, and the tip end surface of the blade 13 comes into close contact with the seal protrusion 11d. That is, the interior of the oil cylinder 11 reaches a specific position partitioned into four rooms in the rotation direction (FIG. 3). Then, the hydraulic oil sealed in the room is compressed by the blade 13 approaching relatively (the high-pressure chamber HR is formed). On the other hand, in the room on the opposite side of the high pressure chamber HR across the blade 13, the hydraulic oil is not compressed, and this room becomes the low pressure chamber LR. Since the oil cylinder 11 rotates at a high speed, the high-pressure chamber HR and the low-pressure chamber LR are continuously formed in a short time. As a result, intermittent tightening torque (pulse impact torque) is applied to the main shaft 12 via the blade 13.

  Incidentally, the tightening torque generating mechanism 10 includes a communication path P that connects the high-pressure chamber HR and the low-pressure chamber LR, and an adjusting unit R that changes the flow passage area of the communication path P. Part of the communication path P is constituted by a through hole 11c1 provided in the partition wall 11c. However, since the through hole 11c1 is located on the inner surface side of the oil cylinder 11, it is difficult to form the through hole 11c1 with high accuracy. Therefore, in the tightening torque generating mechanism 10 of the present invention, the liner 15 which is a separate component from the oil cylinder 11 is used.

  As shown in FIG. 4, the cylindrical liner 15 is provided with a communication hole 15a penetrating in a direction orthogonal to the axial direction. The opening area of the communication hole 15a is, for example, large enough to restrict the operating oil flowing from the high-pressure chamber HR to the low-pressure chamber LR to a certain degree, that is, a pressure difference between the high-pressure chamber HR and the low-pressure chamber LR is equal to or greater than a certain value. It is a size that can occur, and is at least smaller than the through hole 11c1. The opening area of the through hole 11c1 is set to a size that does not cause a constant pressure difference between the high-pressure chamber HR and the low-pressure chamber LR. The shape of the communication hole 15a is a shape included in the through hole 11c1 (see FIG. 4B). Specifically, the through hole 11c1 has a substantially rectangular shape, and the communication hole 15a has a substantially elliptical shape.

  The liner 15 communicates with the through hole 11c1, is inserted into an insertion hole 11c2 provided in the partition 11c so as to open in the axial direction of the oil cylinder 11, and is fixed so as not to move. Specifically, a non-circular (elliptical) rotation stopper 15b is provided on the rear end side of the liner 15, and the rotation in the insertion hole 11c2 is restricted. The movement in the axial direction is restricted by the end plate 11b. When the liner 15 is inserted into the communication hole 15a, the through hole 11c1 of the partition wall 11c communicates with the communication hole 15a, and the communication hole 15a forms a part of the communication passage P.

  As described above, by adjusting the flow passage area and the shape of the communication passage P by the communication hole 15a of the liner 15, the through hole 11c1 can be formed roughly. Therefore, the manufacture of the oil cylinder 11 becomes easy. For example, the through hole 11c1 can be formed by casting. Further, since the liner 15 is a separate member from the oil cylinder 11, the communication hole 15a forming a part of the communication path P can be formed easily and accurately.

  The adjusting means R includes an adjusting member 16 inserted into the liner 15 having a cylindrical shape, and an adjusting screw 17 for adjusting an axial position of the adjusting member 16 (see FIG. 1). More specifically, as shown in FIG. 4A, the adjusting member 16 has a substantially columnar shape having substantially the same diameter as the inner diameter of the liner 15, and communicates with the communication hole 15a of the liner 15 on the outer periphery. A concave groove 16a forming a part of P is provided. This concave groove 16a is continuous in the circumferential direction (annular). The adjusting member 16 is connected (screwed) to an adjusting screw 17 provided on the front side in the axial direction of the adjusting member 16, the axial position is changed by turning the adjusting screw 17, and the communication hole 15 a and the groove 16 a are formed. , That is, the flow path area of the communication path P can be adjusted (variable). The adjusting member 16 is also provided with a non-circular (elliptical) rotation stopper 16b on the rear end side, so that rotation in the liner 15 is restricted. In other words, the liner 15 also functions as a fixing member for fixing the adjusting member 16 to the oil cylinder 11.

  The adjusting member 16 is provided with a side hole 16c communicating with the communication passage P and a shaft hole 16d communicating with the side hole 16c, separately from the concave groove 16a. The side hole 16c and the shaft hole 16d apply hydraulic oil pressure to a piston 21 located downstream via a relief valve 20, and operate a pilot valve 23 by a rod 22 arranged at the back of the piston 21 to thereby control the air motor 6 This is a passage for supplying hydraulic oil to a so-called shut-off valve mechanism S that shuts off air supply to the engine (see FIG. 1).

  As described above, the specific embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and can be implemented with various modifications within the scope of the present invention. For example, in the above embodiment, the cylinder case-integrated oil cylinder 11 is used, but the cylinder case and the oil cylinder may be separate bodies. In addition, although a cylindrical liner is used as the separate member 15, components having various shapes such as an arc-shaped cross section and a semi-circular cross section can be adopted. Further, the separate member 15 may be provided outside the partition 11c (upstream of the through hole 11c1) instead of inside the partition 11c (downstream of the through hole 11c1). It is preferable that the separate member 15 and the adjustment member 16 are adjacent to each other (the adjustment member 16 is located on the upstream side or the downstream side of the separate member 15). If a valve mechanism is used, the separate member 15 and the adjustment member 16 do not necessarily have to be adjacent to each other. Further, the communication hole 15a may be provided by a groove instead of a hole. As for the concave groove 16a, the flow path may be secured by providing a hole in the adjusting member 16 instead of the groove.

DESCRIPTION OF SYMBOLS 1 Hydraulic pulse wrench 2 Gripping part 3 Main body casing 4 Air supply port 5 Operating lever 6 Air motor 6a Rotor 10 Tightening torque generating mechanism 11 Oil cylinder 11a Cylinder main body 11b End plate 11c Partition wall 11c1 Through hole 11c2 Insertion hole 11d Seal protrusion 11e Rib 12 Main shaft 12a Mounting portion 12b Slot 12c Spring mounting hole 12d Main shaft side seal protrusion 13 Blade 14 Spring 15 Another member (liner)
15a Communication hole 15b Rotation stop 16 Adjustment member 16a Depressed groove 16b Rotation stop 16c Side hole 16d Shaft hole 17 Adjustment screw 20 Relief valve 21 Piston 22 Rod 23 Pilot valve HR High pressure chamber LR Low pressure chamber P Communication passage R Adjusting means S Shut-off valve Mechanism F1 Innermost surface

Claims (3)

An oil cylinder filled with hydraulic oil,
A spindle inserted rotatably relative to the oil cylinder;
With a blade attached to the main shaft,
The oil cylinder is relatively rotated with respect to the main shaft, and a high pressure chamber and a low pressure chamber are formed in the oil cylinder by the blade and a partition provided on the inner surface of the oil cylinder, thereby providing a tightening torque for applying a striking torque to the main shaft. A torque generating mechanism with
It further comprises a communication passage for communicating the high-pressure chamber and the low-pressure chamber,
A tightening torque generating mechanism, wherein at least a part of the communication passage is formed by a separate member fixed to the oil cylinder. Further comprising an adjusting member for making the flow passage area of the communication passage variable,
At least a part of the communication passage is configured by another member and an adjusting member,
The tightening torque generating mechanism according to claim 1, wherein the separate member and the adjusting member are adjacent to each other. A hydraulic pulse wrench provided with the tightening torque generating mechanism according to claim 1.

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