JP2007136584A - Rotation power transmission mechanism in screw driving machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation power transmission mechanism, making a tool compact, and preventing damages and meshing failure of a gear part 22 of a driving gear 13. <P>SOLUTION: In a screw driving machine, a driver bit 4 having a polygonal section is connected to an impact piston 3, the lower part of the driver bit 4 is fitted in a central through hole 14 of the driving gear 13 disposed below an impact cylinder to move in the axial direction, and after the impact piston 3 has been actuated in the axial direction of the driver bit 4 by compressed air to impact a drive screw, thereby driving the screw into a material to be driven by a predetermined amount, the driver bit 4 is rotated with the driving gear 13, to screw the drive screw into the material to be driven. Rotation-transmitting rollers 15, respectively engaged with at least two sides of the driver bit 4, are disposed inside the through hole 14 of the driving gear 13, and the bearing parts of the rotating shafts 17 of the rollers 15 are formed inside the gear part 22 of the outer periphery of the driving gear 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a screw driving machine, and more particularly to a rotational power transmission mechanism that transmits rotation of a driving gear that rotates using compressed air to a driver bit when screwed after impact.

  In general, a screw driving machine is provided with a driving mechanism of a driving screw and a screw tightening mechanism, and a driver bit having a polygonal cross section is coupled to a driving piston that is slidably accommodated in a vertical direction in the driving cylinder. The lower part is fitted in a through hole in the center of the driving gear disposed at the lower part of the hitting cylinder so as to be movable in the axial direction, and the hitting mechanism is operated by the compressed air supplied to the hitting cylinder, so that the hitting piston is connected to the shaft of the driver bit. After driving the driving screw in the direction to drive the driven material to the extent that the head is lifted, the driver bit is rotated together with the driving gear by the screw tightening mechanism using the compressed air as a driving source. The driving screw is screwed into the material to be driven.

  By the way, in the conventional screw driving machine, as shown in FIG. 2 of Patent Document 1, the height of the drive gear is required for the stroke of the steel ball, so that the height of the drive gear itself is increased. I had to.

  Although it has been considered that the driving gear is provided with a roller that engages with the side surface of the driver bit, the roller is disposed at the lower part (or upper part) of the driving gear, so that the entire roller and the driving gear are arranged. The height does not decrease.

On the other hand, there is also an idea that a roller is provided inside the central through hole of the drive gear that allows the driver bit to pass therethrough. The bearing hole of the rotation shaft of the roller is made to penetrate the side surface of the drive gear, and in this case, the end surface of the rotation shaft may be prevented from protruding from the outer gear portion (tooth portion) of the drive gear. According to this, the overall height falls within the height of the drive gear, so the overall height is low.
Japanese Patent No. 3520442

  However, if the bearing hole of the rotating shaft of the roller is penetrated to the outer peripheral surface of the drive gear, the end of the rotating shaft slightly protrudes from the surface of the gear portion, or the strength of the gear portion is insufficient. There are inconveniences such as poor meshing when meshing with other gears and damage to the gear part during rotation.

  On the other hand, if the length of the bearing hole does not reach the outer peripheral surface of the drive gear, it is very difficult to support the rotating shaft of the roller.

  The present invention solves the above-mentioned problems, enables the downsizing of the tool by reducing the overall height of the tool, and does not damage the gear portion of the drive gear or cause poor meshing with other gears. It is an object of the present invention to provide a rotational power transmission mechanism in a screw driving machine.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a driver bit having a polygonal cross section is coupled to a striking piston accommodated in a striking cylinder so as to be slidable in the vertical direction, and the lower portion of the driver bit is striking the striking part. The drive gear is located in the lower part of the cylinder and fitted in the central through hole so that it can move in the axial direction. The compressed air supplied to the blow cylinder operates the strike piston in the axial direction of the driver bit and strikes the drive screw. In the screw driving machine in which the driver bit is rotated together with the drive gear using the compressed air as a drive source after the predetermined amount is driven into the driven material, and the driving screw is screwed into the driven material. Arranged on the inside are rotation transmission rollers respectively engaged with at least two side surfaces of the driver bit, and bearing portions of the rotation shafts of the respective rollers Characterized in that formed on the inside of the gear portion of the outer periphery of the drive gear.

  According to a second aspect of the present invention, the bearing portion forms a storage groove for rotatably storing the rotary shaft and the roller from an end surface of the drive gear, and a stopper for preventing the rotary shaft from falling is provided on the storage groove. It is characterized by being fixed.

  According to a third aspect of the present invention, the drive gear and the roller have substantially the same height.

  According to the first aspect of the present invention, the rotation transmission rollers that are respectively engaged with at least two side surfaces of the driver bit are arranged inside the through hole of the drive gear, and the bearing portions of the rotation shafts of the rollers are arranged in the above manner. Since it is formed between the inner surface of the through-hole and the gear portion on the outer periphery of the drive gear, the drive gear portion and the roller can be arranged at the same height, so that the overall height of the screw driving machine can be reduced, and the tool Can be made compact.

  In addition, since the transmission force of the rotational drive of the drive gear and the transmission force from the rotating shaft and roller to the driver bit are on the same plane, transmission loss can be reduced.

  Furthermore, since the diameter of the tip circle of the drive gear is increased, the number of intermediate gears from the power source such as an air motor to the drive gear can be reduced.

  According to the second aspect of the present invention, since the bearing portion of the rotary shaft of the roller can be constituted by the storage groove formed on the end face of the drive gear and the stopper for preventing the rotary shaft from being removed, the processing can be performed. It is simple and the mounting work of the rotating shaft is very simple, and the cost can be kept low.

  According to the invention which concerns on Claim 3, a drive gear and a roller can be arrange | positioned at the same height, Therefore The total height of a screwing machine can be made low and the compactization of a tool is attained.

  FIG. 1 is a longitudinal sectional view of a screw driving machine. This screw driving machine includes an impact mechanism and a screw tightening mechanism inside a tool body 1. The striking mechanism has a striking cylinder 2, a striking piston 3 slidably provided within the striking cylinder 2, and a driver bit 4 integrally coupled to the striking piston 3. The valve 6 is operated and the main valve 7 is opened, and compressed air is supplied into the striking cylinder 2 from an air chamber (connected to an air supply source) 8 that stores compressed air, and the driver bit 4 is driven. It is something to be made. The screw tightening mechanism (not shown) is for tightening the driver bit 4 with the power of the air motor. After driving a predetermined amount into the material to be driven, the main valve 7 opens and operates to supply a part of the compressed air flowing from the air chamber 8 to the air motor 11, and the rotational force of the air motor 11 is transmitted via the intermediate reduction gear 12. By transmitting the rotation to the drive gear 13 and transmitting the rotation of the drive gear 13 to the driver bit 4 and rotating it around the axis, the driving screw driven by the driver bit 4 is tightened.

  Such a striking mechanism and a screw tightening mechanism are known mechanisms as known from, for example, Japanese Patent Laid-Open Nos. 9-290376 and 9-141571.

  In the screw tightening mechanism, as shown in FIG. 2, two rotation transmission rollers 15 that engage with the opposite side surfaces of the driver bit 4 rotate inside the through hole 14 of the drive gear 13. Arranged freely.

  That is, as shown in FIGS. 3A to 3D and FIG. 4, the first end face of the drive gear 13 has two screw holes 16 and a rotary shaft 17 that is accommodated on the opposite sides. A storage groove 20 including one storage groove 18 and a second storage groove 19 for storing a part of the roller 15 is formed as an opening. The first storage groove 18 is formed inside the outer peripheral gear portion (tooth) 22, and the depth thereof is formed to be the same as or slightly deeper than the diameter of the rotating shaft 17.

  Further, the bottom of the second storage groove 19 is prevented from reaching the opposite end face of the drive gear 13. Further, a pair of arc-shaped projecting pieces 23 are formed on the inner edge of the through hole 14 of the drive gear 13 so as to protrude from the one end face on the side adjacent to and facing the storage groove 20. Further, a short cylindrical portion 29 is formed to protrude from the other end surface.

  When the roller 15 is disposed in the storage groove 20, the roller 15 is attached to the center of the rotating shaft 17 and is disposed in the storage groove 20 in that state. Then, a stopper 24 for preventing the rotary shaft from being detached is fixed on the storage groove 20 with screws. The stopper 24 is a disk having a diameter substantially the same as a circle not including the tooth tip of the drive gear 13, and a cross-shaped opening 24 a and a screw insertion hole 25 are formed at the center. A presser claw 26 is formed on the inner edge of the opening 24 a corresponding to the storage groove 20. The stopper 24 is fixed to the screw hole 16 on the end face of the drive gear 13 by a fixing screw 28 inserted through the screw insertion hole 25. At this time, the rotary shaft 17 exposed to the first storage groove 18 of the storage groove 20 is pressed by the presser claw 26. Thereby, the bearing portion of the rotating shaft 17 is formed by the first storage groove 18 and the stopper 24, and the rotating shaft 17 does not come out of the storage groove 20. Finally, the bearing 27 is arranged around the short cylindrical portion 29 opposite to the circumference of the arc-shaped protruding piece 23 of the drive gear 13. Thereby, the drive gear 13 as shown in FIG. 5 is completed.

  The driver bit 4 has a shape with two cross sections, and is configured such that the opposite side surfaces thereof engage with the two rollers 15 when passing through the through hole 14 of the drive gear 13.

  According to the above configuration, if the drive gear 13 rotates, the roller 15 also rotates, so that the rotational force of the drive gear 13 is transmitted to the driver bit 4, and the driver bit 4 rotates to screw the driving screw into the driven material.

  As described above, the rotation transmission roller 15 that engages with the two side surfaces of the driver bit 4 is disposed inside the through hole 14 of the drive gear 13, so that the drive gear 13 and the roller 15 are at the same height. Therefore, the overall height of the screwdriver can be lowered, and the tool can be made compact.

  Further, since the bearing portion of the rotating shaft 17 of each roller 15 is formed inside the outer gear portion 22 of the drive gear 13, the gear portion 22 may be damaged or the meshing with other gears may be poor. There is no.

  Furthermore, since the transmission force of the rotational drive of the drive gear 13 and the transmission force from the rotating shaft 17 and the roller 15 to the driver bit 4 are on the same plane, transmission loss can be reduced.

  Furthermore, since the diameter of the tip circle of the drive gear 13 is increased, the number of intermediate gears from the power source such as an air motor to the drive gear 13 can be reduced.

  In addition, the bearing portion of the rotary shaft 17 can be constituted by a storage groove 20 formed on the end face of the drive gear 13 and a stopper 24 for preventing the rotary shaft from being removed, so that the machining is simple and the rotation is possible. The mounting operation of the shaft 17 is very simple, and the cost can be kept low.

  The number of rollers 15 is not limited to two. For example, when the cross-sectional area of the driver bit is hexagonal, the rollers may be engaged with every other side surface.

  Further, the predetermined amount after being driven into the driven material according to claim 1 is a level that does not cause a fastening failure when screwed in after being driven into the driven material, and the upper surface of the driven material The screw is about 3 to 15 mm in height.

It is a longitudinal cross-sectional view of a screwing machine. It is an expanded sectional view of the important section of the above-mentioned screw driving machine. (A), (b), (c), (d) is the top view of the drive gear which concerns on a rotational power transmission mechanism, respectively, and sectional drawing of an AA line, a BB line, and CC line. It is a disassembled perspective view of a drive gear. It is a perspective view of the drive gear after completion.

Explanation of symbols

2 Stroke cylinder 3 Stroke piston 4 Driver bit 13 Drive gear 15 Roller 18 First storage groove 22 Gear portion

Claims (3)

A driver bit having a polygonal cross section is coupled to a striking piston accommodated in a striking cylinder so as to be slidable in the vertical direction, and a lower portion of the driver bit is connected to a through hole in a center of a driving gear disposed at a lower portion of the striking cylinder. After being fitted in a movable manner in the axial direction and operating the striking piston in the axial direction of the driver bit by the compressed air supplied to the striking cylinder and striking the driving screw to drive a predetermined amount into the material to be driven, the compressed air is In a screw driving machine that rotates the driver bit together with the driving gear as a driving source to screw the driving screw into a workpiece.
Arranged inside the through hole of the drive gear are rotation transmission rollers respectively engaged with at least two side surfaces of the driver bit, and the bearing portion of the rotation shaft of each roller is located inside the outer gear portion of the drive gear. A rotational power transmission mechanism in a screw driving machine, characterized by being formed in   The bearing portion is characterized in that a storage groove for rotatably storing the rotary shaft and the roller is formed from an end surface of the drive gear, and a rotary shaft retaining stopper is fixed on the storage groove. The rotational power transmission mechanism in the screw driving machine according to claim 1.   The rotational power transmission mechanism in the screw driving machine according to claim 1 or 2, wherein the drive gear and the roller have substantially the same height.

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