JP5420928B2 - Impact tool - Google Patents

Description

  The present invention relates to an impact tool such as an impact driver that generates a rotational impact force on an anvil protruding forward of a housing.

In an impact tool such as an impact driver, a spindle that is rotated by a motor in a housing, and a front end of the spindle that is coaxially supported on the housing via a metal bearing in front of the spindle and has a bit insertion hole forward of the housing. A protruding anvil and a striking mechanism that transmits the rotation of the spindle to the anvil as a rotational striking force are provided, and the striking mechanism that accompanies the rotation of the spindle can impart a rotating striking force to the anvil (see Patent Document 1). ).
In addition, a bearing hole for fitting the tip of the spindle is formed in the rear end shaft center of the anvil, and a connection hole for connecting the bearing hole and the inner peripheral surface of the metal bearing to communicate with each other is formed in the anvil. The grease which is formed in the radial direction and accumulates in the bearing hole is supplied to the inner peripheral surface of the metal bearing through the connection hole so as to achieve lubrication between the anvil and the metal bearing.

JP 2003-231067 A

  Since the bearing hole provided in the anvil often has a mortar shape at the bottom of the drilling process, the amount of grease stored is relatively small. Therefore, even if the connection hole is connected to the bottom portion, the grease is not sufficiently supplied from the connection hole to the inner peripheral surface of the metal bearing, and there is a possibility that the lubricity is lowered and the durability is lowered. . Therefore, it is conceivable to extend the bearing hole forward, but since the insertion hole for the bit is formed in front of the bearing hole, if the depth of the insertion hole is secured and the bearing hole is lengthened, the total length of the anvil will be increased. Elongation will be hindered.

  Therefore, an object of the present invention is to provide a striking tool that can maintain compactness while ensuring sufficient lubrication between an anvil and a metal bearing.

In order to achieve the above object, the invention according to claim 1 includes the spindle, an anvil, and a striking mechanism, and the front end of the spindle is fitted coaxially into a bearing hole formed on the rear surface of the anvil. A ring-shaped outer groove facing the inner peripheral surface of the metal bearing is formed on the outer periphery of the anvil, and a connection hole is formed in the anvil in the radial direction for connecting the bearing hole and the outer groove to communicate with each other. This is a striking tool that allows the grease accumulated in the bearing hole to be discharged into the outer groove through the connection hole, and is a ring that protrudes forward from the front end of the fitted spindle to the front end that becomes the bottom of the bearing hole. In this configuration, a deep bottom portion is continuously provided, and a connection hole is connected to the deep bottom portion.
According to a second aspect of the present invention, in the configuration of the first aspect, the deep bottom portion protrudes beyond the rear end of the insertion hole until it overlaps the outside of the insertion hole. .
According to a third aspect of the present invention, in the configuration of the second aspect, when the rear end of the insertion hole becomes a taper portion tapered toward the rear side, the overlap with the insertion hole in the deep bottom portion is provided. The inner peripheral side of the portion has a tapered shape that is inclined along the tapered portion.
According to a fourth aspect of the present invention, there is provided a spindle that is rotated by a motor in a housing filled with grease, is coaxially supported on the housing via a metal bearing in front of the spindle, and has a bit insertion hole. An anvil having a front end protruding forward of the housing and a striking mechanism for transmitting rotation of the spindle to the anvil as a rotational striking force are provided, and a fitting portion is provided for fitting the anvil and the spindle coaxially. A striking tool in which a receiving groove is formed on the inner peripheral surface of the metal bearing, wherein the fitting portion and the receiving groove are in communication with each other and grease that collects in the fitting portion can be supplied to the receiving groove. with the provision to said anvil, said communication passage, a first communication passage extending axially forwardly of said anvil, extending radially outward of said first communication passage and connected the anvil And second communication path, as a third communication path that is recessed in a ring shape to the outer peripheral surface of said second communicating passage and leads said anvil, said third communication passage, radially outward of said insertion hole It is characterized by having been arranged in.
According to a fifth aspect of the present invention, there is provided a spindle that is rotated by a motor in a housing filled with grease, is coaxially supported on the housing via a metal bearing in front of the spindle, and has a bit insertion hole. An anvil having a front end protruding forward of the housing and a striking mechanism that transmits rotation of the spindle to the anvil as a rotational striking force, and the front end of the spindle is coaxial with a bearing hole formed on the rear surface of the anvil. A striking tool that is fitted and formed with a receiving groove on the inner peripheral surface of the metal bearing, and a ring-shaped deep bottom portion protruding forward from the front end of the fitted spindle at the front end of the bearing hole. Provided, the front end of the deep bottom portion and the receiving groove are connected to each other, and the grease accumulated in the bearing hole can be supplied to the receiving groove.

According to the first aspect of the present invention, since a large amount of grease is stored in the deep bottom portion, sufficient lubrication is ensured between the anvil and the metal bearing through the connection hole, and suitable durability is obtained. Can do. Further, since the deep bottom can be formed without interfering with the bit insertion hole, it is not necessary to lengthen the entire length of the anvil, and compactness can be maintained. Furthermore, the formation of the deep bottom part leads to a lighter anvil.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the volume of the deep bottom portion can be further increased without changing the positional relationship between the bearing hole, the insertion hole, and the connection hole. The amount of storage can be increased.
According to the third aspect of the present invention, in addition to the effect of the second aspect, the volume of the deep bottom portion can be increased as much as possible between the insertion hole and the lubricity and weight reduction. Improvement can be expected.

It is a partial longitudinal cross-sectional view of an impact driver. It is a partial longitudinal cross-sectional view of the example of a change of an impact driver.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, an impact driver 1 as an example of an impact tool is formed by assembling left and right half housings 3 and 3, and a main body housing 2 that houses a motor 4, and a front (see FIG. 1 and is provided with a spindle 7, a striking mechanism 8, and a hammer case 6 having a bell-shaped cross section for accommodating an anvil 9. A handle (not shown) with a battery pack serving as a power source attached to the lower end is extended below the main body housing 2. Further, an extended portion 10 that covers the lower portion is formed in a lower portion of the hammer case 6 in the main body housing 2, and a light unit 11 facing the front of the anvil 9 is mounted in the extended portion 10. ing.

An output shaft 5 of the motor 4 is pivotally supported by a gear case 12 assembled to the main body housing 2, and a pinion 13 protruding into the hammer case 6 is fitted thereon. In the hammer case 6, the spindle 7 holds two planetary gears 15, 15 that revolve in the internal gear 14 and mesh with the pinion 13, and the rear end portion is a ball bearing 16 that is supported by the gear case 12. Is supported coaxially with the output shaft 5.
A pair of flanges 17 and 17 are radially extended at the rear end of the anvil 9 in the hammer case 6, and the striking mechanism 8 is externally mounted on the front end of the spindle 7 and is attached to the flanges 17 and 17 of the anvil 9. A hammer 18 that engages and a coil spring 19 that biases the hammer 18 forward are provided. The hammer 18 is a ball that fits between grooves 20 and 20 formed on the inner surface of the hammer 18 and the outer surface of the spindle 7. It has a well-known structure connected to the spindle 7 through 21 and 21.

The anvil 9 is supported at its middle by a metal bearing 22 held at the front end of the hammer case 6, and a small-diameter portion 24 protruding from the front end of the spindle 7 is fitted into a bearing hole 23 formed in the rear shaft center. It is combined.
A bit insertion hole 25 (not shown) is formed at the front end of the anvil 9 protruding from the hammer case 6, and balls 26, 26 and a sleeve 27 for retaining the bit inserted into the insertion hole 25 are attached. Etc. are provided.

  On the other hand, in the anvil 9, a ring-shaped deep bottom portion 28 is formed at the front end of the bearing hole 23 so as to protrude forward from the small diameter portion 24 inserted therein. The deep bottom portion 28 protrudes until the front end overlaps the outside of the taper portion 29 beyond the rear end of the taper portion 29 formed at the bottom of the bit insertion hole 25 and tapering backward. A connection hole 30 is formed between the deep bottom portion 28 and the insertion hole 25. The connection hole 30 is formed in a radial direction of the anvil 9 with an end portion on the center side communicating with the front end of the deep bottom portion 28, and is opened in an outer groove 31 that is recessed in a ring shape on the outer peripheral surface of the anvil 9. To do. A ring-shaped receiving groove 32 is also provided in the inner peripheral surface of the metal bearing 22 and overlaps with the outer groove 31 of the anvil 9 in the anvil axial direction. Therefore, the deep bottom portion 28 of the bearing hole 23 communicates with the receiving groove 32 of the metal bearing 22 through the connection hole 30 and the outer groove 31.

  In the impact driver 1 configured as described above, when the motor 4 is driven by operating a switch trigger (not shown) provided on the handle, the rotation of the output shaft 5 is transmitted to the spindle 7 via the planetary gears 15 and 15. The spindle 7 is rotated. Since the spindle 7 rotates the hammer 18 via the balls 21 and 21 and rotates the anvil 9 with which the hammer 18 is engaged, the spindle 7 can be tightened with a bit attached to the tip of the anvil 9. When the screw tightening progresses and the load on the anvil 9 increases, the hammer 18 repeatedly engages and disengages the flanges 17 and 17 of the anvil 9 to apply an intermittent rotational striking force, thereby performing additional tightening.

  The grease filled in the hammer case 6 accumulates in the deep bottom portion 28 from the bearing hole 23, is discharged into the outer groove 31 through the connection hole 30 by centrifugal force accompanying the rotation of the anvil 9, and communicates with the metal bearing. 22 is supplied to the receiving groove 32. Therefore, lubrication between the outer peripheral surface of the anvil 9 and the inner peripheral surface of the metal bearing 22 is maintained.

  Thus, according to the impact driver 1 of the said form, the ring-shaped deep bottom part 28 which protrudes ahead rather than the small diameter part 24 of the spindle 7 fitted in the front end used as the bottom of the bearing hole 23 is provided continuously. By connecting the connection hole 30 to the deep bottom portion 28, a large amount of grease is stored in the deep bottom portion 28. Therefore, sufficient lubrication is ensured between the anvil 9 and the metal bearing 22 through the connection hole 30, and suitable durability can be obtained. Further, since the deep bottom portion 28 can be formed without interfering with the bit insertion hole 25, it is not necessary to lengthen the entire length of the anvil 9, and compactness can be maintained. Furthermore, the formation of the deep bottom portion 28 leads to the weight reduction of the anvil 9.

  In particular, here, the deep bottom portion 28 protrudes beyond the rear end of the insertion hole 25 until it overlaps the outside of the insertion hole 25, so that each of the bearing hole 23, the insertion hole 25, and the connection hole 30. Without changing the positional relationship, it is possible to increase the volume of the deep bottom portion 28 and increase the amount of grease stored.

In the above embodiment, the deep bottom portion has a flat front end (ring-shaped bottom portion). However, like the impact driver 1 a shown in FIG. 2, the overlap portion 33 of the deep bottom portion 28 to the insertion hole 25 is formed. The inner peripheral side may have a tapered shape that is inclined along the tapered portion 29 of the insertion hole 25. In this way, the volume of the deep bottom portion 28 can be increased as much as possible between the insertion hole 25 and further improvement in lubricity and weight reduction can be expected.
In addition, the deep bottom portion is not limited to be provided with the same inner diameter as the bearing hole, but can be provided with an inner diameter larger than the bearing hole.

In addition, although one connection hole is provided in the above embodiment, a plurality of connection holes may be provided.
Further, for example, the housing is not limited to the main body housing and the hammer case, and the form of the housing and the striking mechanism can be changed as appropriate, such as an integral type of the main body housing and the hammer case, a type without an extending portion, or the like. . Of course, in addition to the impact driver, the present invention can be applied to other impact tools such as an angle impact driver and an impact wrench.

  1, 1a-Impact driver, 2-Body housing, 4-Motor, 5-Output shaft, 6-Hammer case, 7-Spindle, 8-Strike mechanism, 9-Anvil, 18- Hammer, 22 ·· Metal bearing, 23 ·· Bearing hole, 24 ·· Small diameter portion, 25 ·· Insertion hole, 28 ·· Deep bottom portion, 29 ·· Taper portion, 30 ·· Connection hole, 31 ·· Outer groove , 32 .. Receiving groove, 33 .. Overlap part.

Claims (5)

A spindle that is rotated by a motor in a housing filled with grease, and a front end that is coaxially supported on the housing via a metal bearing in front of the spindle and has a bit insertion hole protrudes forward of the housing. An anvil and a striking mechanism for transmitting the rotation of the spindle to the anvil as a rotational striking force, and the front end of the spindle is coaxially fitted in a bearing hole formed on the rear surface of the anvil, while the outer periphery of the anvil In addition, a ring-shaped outer groove facing the inner peripheral surface of the metal bearing is formed, and a connection hole is formed in the anvil in the radial direction for connecting the bearing hole and the outer groove to communicate with each other. An impact tool capable of discharging grease accumulated in the bearing hole into the outer groove through the connection hole,
A striking feature characterized in that a ring-shaped deep bottom portion protruding forward from the front end of the fitted spindle is connected to the front end serving as the bottom of the bearing hole, and the connection hole is connected to the deep bottom portion. tool.   The striking tool according to claim 1, wherein the deep bottom portion protrudes beyond the rear end of the insertion hole until it overlaps the outside of the insertion hole.   In the case where the rear end of the insertion hole becomes a taper portion tapered toward the rear, a taper shape in which the inner peripheral side of the overlap portion in the deep bottom portion is inclined along the taper portion; The impact tool according to claim 2, wherein A spindle that is rotated by a motor in a housing filled with grease, and a front end that is coaxially supported on the housing via a metal bearing in front of the spindle and has a bit insertion hole protrudes forward of the housing. An anvil and a striking mechanism for transmitting the rotation of the spindle as a rotational striking force to the anvil, and a fitting portion for coaxially fitting the anvil and the spindle is provided on the inner peripheral surface of the metal bearing. A striking tool having a receiving groove,
The anvil is provided with a communication path that allows the fitting portion and the receiving groove to communicate with each other to supply grease collected in the fitting portion to the receiving groove, and the communication path extends forward in the axial direction of the anvil. A first communication path, a second communication path connected to the first communication path and extending radially outward of the anvil, and a third connection connected to the second communication path and recessed in a ring shape on the outer peripheral surface of the anvil. As having a passage,
The striking tool characterized in that the third communication path is disposed radially outside the insertion hole. A spindle that is rotated by a motor in a housing filled with grease, and a front end that is coaxially supported on the housing via a metal bearing in front of the spindle and has a bit insertion hole protrudes forward of the housing. An anvil and a striking mechanism for transmitting the rotation of the spindle as a rotational striking force to the anvil. The front end of the spindle is coaxially fitted in a bearing hole formed on the rear surface of the anvil, and A striking tool having a receiving groove formed on its peripheral surface,
A ring-shaped deep bottom portion protruding forward from the front end of the fitted spindle is provided at the front end of the bearing hole, and the grease accumulated in the bearing hole is connected to the front end of the deep bottom portion and the receiving groove. Can be supplied to the receiving groove.

Images