JP2006051601A - Hammer drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hammer drill capable of miniaturizing a tool shaft outer periphery and a tool shaft direction.
A switching member 19 that is non-rotatable and axially movable on an intermediate shaft 11, a switching lever 25 that controls a moving position of the switching member 19 on the intermediate shaft 11, and an intermediate shaft 11 opposite to the intermediate shaft 11. A rotation locking member 22 that is positioned on the second gear 10 side and is non-rotatably held by the outer frame member is provided. The switching member 19 is operated by an operation of a switching lever 25 via an engaging portion 19a provided on the lower surface. A first state engaged with the second gear 10, a second state engaged with the rotation locking member via an engagement portion 19 a provided on the upper surface, the second gear 10 and the rotation locking member 10 is configured to be movable to a third state that is not engaged with.
[Selection] Figure 1

Description

  The present invention relates to a hammer drill including a hammer transmission switching mechanism, a rotation transmission switching mechanism, and an operation mode switching mechanism.

  The conventional hammer drill has a configuration in which the impact transmission switching mechanism is provided on the crankshaft shaft and the rotation transmission switching mechanism is provided on the tool shaft.

  In the conventional hammer drill having the above-described configuration, since the rotation transmission switching member constituting the rotation transmission switching mechanism is provided on the tool shaft, it is difficult to downsize the outer periphery of the tool shaft, and the rotation transmission switching member is used as a tool. Since the configuration is such that the tool is moved in the axial direction, there is a problem in that the tool axis direction becomes long, and as a result, the product cannot be miniaturized.

  An object of the present invention is to provide a hammer drill with an operation mode switching mechanism that can solve the above-mentioned problems and can reduce the outer circumference of the tool axis and the tool axis direction.

  The above-described object is to provide a switching member that is non-rotatable and axially movable on the intermediate shaft, a switching lever that controls the movement position of the switching member on the intermediate shaft, and an anti-second gear that sandwiches the intermediate shaft. A rotation locking member that is non-rotatably held by the outer frame member, and the switching member is operated by operating the switching lever and the second gear through an engaging portion provided on the lower surface. A first state that engages with the rotation locking member, a second state that engages with the rotation locking member via an engagement portion provided on the upper surface, and a state that does not engage with the second gear and the rotation locking member This is achieved by adopting a configuration that can move to the third state.

  According to the present invention, since the operation mode can be switched by operating one member without providing the rotation transmission switching mechanism on the tool shaft, the tool shaft outer periphery and the tool shaft direction can be reduced in size. Hammer drills can be provided.

  The hammer drill of the present invention will be described with reference to FIGS.

  The hammer drill shown in the figure transmits the rotation of the drive shaft 1 to the crankshaft 3 having the eccentric pin 3a through the first gear 2, and the piston 6 through the connecting rod 4 and the piston pin 5 pivotally attached to the eccentric pin 3a. Is moved by reciprocating, the striking element 7 is moved by the air spring, and the striking operation for striking the tip tool 9 through the intermediate element 8 and the rotation of the drive shaft 1 through the second gear 10 and the intermediate shaft having the tooth portion 11a. 11, and further transmitted to the cylinder 13 via the third gear 12 that meshes with the tooth portion 11 a, and the tool holding member 15 engaged with the cylinder 13 by the steel ball 14 is rotated to rotate the tip tool 9. And a rotation operation that gives

  As shown in FIG. 5, a claw portion 2 a is provided on the upper surface of the first gear 2, and the claw portion 2 a is a claw of the first switching member 16 provided on the crankshaft 3 so as not to be rotatable and axially movable. It can be engaged with the portion 16a. By engaging the claw portion 2 a of the first gear 2 and the claw portion 16 a of the first switching member 16, the rotation of the first gear 2 is transmitted to the crankshaft 3 via the first switching member 16. become. The first switching member 16 is always urged by the first spring 17 in the direction in which the claw portion 16 a engages with the claw portion 2 a of the first gear 2, and the first switching member 16 resists the urging force of the first spring 17. 1 By moving the switching member 16 in the axial direction of the crankshaft 3, the engagement between the claw portion 2a and the claw portion 16a can be released, and the rotation transmission to the crankshaft 3 is released to the tip tool 9. Can be released. Hereinafter, the claw portion 2a and the claw portion 16a are referred to as a first clutch mechanism.

As shown in FIG. 2, a claw portion 10 a is provided on the upper surface of the second gear 10, and the claw portion 10 a is a claw of a second switching member 19 provided on the intermediate shaft 11 so as not to rotate and to move in the axial direction. It can be engaged with the portion 19a. By engaging the claw portion 10 a of the second gear 10 and the claw portion 19 a of the second switching member 19, the rotation of the second gear 10 is transmitted to the intermediate shaft 11 via the second switching member 19. become.
The second switching member 19 is always urged by the second spring 20 in a direction in which the claw portion 19 a engages with the claw portion 10 a of the second gear 10, and the second switching member 19 is opposed to the urging force of the second spring 20. 2 By moving the switching member 19 in the axial direction of the intermediate shaft 11, the engagement between the claw portion 10 a and the claw portion 19 a can be released, the rotation transmission to the intermediate shaft 11 is released, and the tip tool 9 is released. Can be released. Hereinafter, the claw portion 10a and the claw portion 19a are referred to as a second clutch mechanism.

  Further, as shown in FIG. 2, a tooth portion 19 b is provided on the outer periphery of the second switching member 19, and the tooth portion 19 b is provided in the outer frame member 23 so as not to rotate and to be movable in the axial direction of the intermediate shaft 11. It is possible to engage with the tooth portion 22a of the rotation locking member 22 thus formed. By engaging the tooth portion 19 b of the second switching member 19 and the tooth portion 22 a of the rotation locking member 22, the rotation of the intermediate shaft 11, that is, the rotational movement of the tool holding member 15 and the tip tool 9 is restricted. Can do. The rotation locking member 22 is always urged toward the second switching member 19 by the third spring 28, and is in contact with a holding member 29 fixed to the outer frame member 23 with a screw 30. The tooth portion 22a of the rotation locking member 22 and the tooth portion 19b of the second switching member 19 are in a positional relationship that can be engaged when the second switching member 19 is positioned above the intermediate shaft 11 in the axial direction. ing. Hereinafter, the tooth portion 19a of the second switching member and the tooth portion 22a of the rotation locking member 22 are referred to as a third clutch mechanism.

  A switch lever 25 having a first eccentric pin 25 a and a second eccentric pin 25 b is rotatably provided on the outer frame member 23 in the vicinity of the crankshaft 3, and the first gear 2 and the second gear 10 are connected to each other. A switching auxiliary shaft 26 extending in parallel with the intermediate shaft 11 and the crankshaft 3 is provided therebetween, and the switching auxiliary shaft 26 is provided with a moving member 27 that cannot rotate and can move in the axial direction.

  As shown in FIG. 7, the moving member 27 has a shoulder portion 27 a located at a position where it does not interfere with the first switching member 16 and a shoulder portion 27 b located below the second switching member 19, and the fourth spring 24. Therefore, it is always biased toward the rotating shaft 1 side. When the moving member 27 is positioned at the lowermost end in the axial direction of the auxiliary switching shaft 26 by the urging force of the fourth spring 24, the shoulder portion 27 b is positioned below the second switching member 19 and the second switching member 19. When the moving member 27 is in the upper position in the axial direction of the auxiliary switching shaft 26, the shoulder 27b comes into contact with the second switching member 19 and the moving member 27 moves upward. The second switching member 19 moves upward in conjunction with it.

  The shoulder 27a of the moving member 27 can be brought into contact with the second eccentric pin 25b of the switching lever 25 at the lower end surface. The moving member 27 is moved by the second eccentric pin 25b when the switching lever 25 is rotated. The auxiliary spring 26 moves upward in the axial direction against the urging force of the four springs 24.

As shown in FIG. 6, the first eccentric pin 25 a of the switching lever 25 can come into contact with the first switching member 16, and the first switching member 16 has a first eccentricity when the switching lever 25 is rotated. The pin 25a moves upward in the axial direction of the crankshaft 3 against the urging force of the first spring 17. Hereinafter, the operation state of each mode of the hammer drill having the above configuration will be described.
(Rotation and blow mode)
In the state shown in FIG. 1, the first clutch mechanism and the second clutch mechanism are in an engaged state, and the third clutch mechanism is in a non-engaged state. That is, the claw portion 2a of the first gear 2 and the claw portion 16a of the first switching member 16 are engaged, and the claw portion 10a of the second gear 10 and the claw portion 19a of the second switching member 19 are engaged. Yes, the tooth portion 19b of the second switching member 19 and the tooth portion 22a of the rotation locking member 22 are in a disengaged state.

  In such a state, the rotation of the drive shaft 1 is transmitted to the crankshaft 3 via the first gear 2 and the first switching member 16, and the impact transmission mechanism is driven to transmit the impact to the tip tool 9. . In the present embodiment, the impact transmission mechanism portion includes a connecting rod 4 pivotally attached to an eccentric pin 3 a of the crankshaft 3, a piston pin 5, a piston 6, a striker 7, and a piston 6 and the striker 7. However, the impact transmission mechanism may be any mechanism that transmits impact to the tip tool 9 when the crankshaft 3 rotates. Conceivable. Further, the rotation of the drive shaft 1 is transmitted to the intermediate shaft 11 via the second gear 10 and the second switching member 19, and the rotation transmission mechanism is driven to transmit the rotation to the tip tool 9. In the present embodiment, the rotation transmission mechanism has a cylinder 13 that rotates in response to the rotation of the intermediate shaft 11, and a tool holder 15 that is engaged with the cylinder 13 by a steel ball 14. The rotation transmission mechanism section may be a mechanism that transmits rotation to the tip tool 9 when the intermediate shaft 11 rotates, and various configurations are conceivable.

In the state as described above, an operation state of “rotation and impact mode” in which impact and rotation are transmitted to the tip tool 9 can be obtained.
(Neutral mode)
FIGS. 2 and 3 rotate the switching lever 25 provided on the outer frame member 23 from the rotation and impact mode shown in FIG. 1, and the first eccentric pin 25b assists the switching of the moving member 27 via the shoulder 27a. The state which moved to the axial direction upper direction of the axis | shaft 26 is shown. As shown in the figure, as the switching member 27 is moved upward, the shoulder 27b moves the second switching member 19 in the axial direction upward of the intermediate shaft 11 against the urging force of the second spring 20, and The two-clutch mechanism is not engaged.

In the state shown in the figure, the third clutch mechanism is in a disengaged state, that is, the tooth portion 19b of the second switching member 19 and the tooth portion 22a of the rotation locking member 22 are in a disengaged state. 9 is in an idling state, and a “neutral mode” in which the cutting edge of the tip tool 9 can be rotated in an arbitrary direction can be obtained.
(Strike only mode)
FIG. 4 shows a state in which the switching lever 25 is further rotated from the “neutral mode” state, and the moving member 27 is further moved upward in the axial direction of the auxiliary switching shaft 26 by the second eccentric pin 25b. The second switching member 19 is moved further upward in the axial direction of the intermediate shaft 11 in conjunction with the moving member 27, and the third clutch mechanism is engaged. Thereby, rotation of the 2nd switching member 19 can be suppressed, and rotation of the tip tool 9 can be suppressed via the holding member 15 grade | etc.,.

In the state described above, since the first clutch mechanism is engaged and the second clutch mechanism is in the disengaged state, it is possible to obtain a “blow only mode” in which only the hit transmission is performed to the tip tool 9.
(Rotation only mode)
FIGS. 5 and 6 illustrate the crankshaft in which the switching lever 25 is rotated from the “rotation and hitting mode” state, and the first switching member 16 is resisted against the urging force of the first spring 17 by the first eccentric pin 25a. 3, the first clutch mechanism is in a disengaged state.

  In this state, it is possible to obtain a “rotation only mode” in which the second clutch mechanism remains engaged and only rotation transmission to the tip tool 9 is performed.

  In the above-described embodiment, when the switching lever 25 is rotated to the left in the drawing with respect to the “rotation and hitting mode” as a reference, the “neutral mode” is set. If the rotation operation is performed from the “and hitting mode” to the right side in the figure, the “rotation only mode” is set.

  By adopting the configuration as described above, the rotation transmission switching member constituting the rotation transmission switching mechanism is provided on the tool axis and the rotation transmission switching member is not moved in the tool axis direction as in the prior art. It is possible to reduce the size of the outer circumference of the shaft and the direction of the tool axis, and it is possible to easily switch the operation mode by operating one switching lever 25 that is a switching member, thereby improving operability. Will be able to.

  In the above embodiment, the shoulder 27 b of the switching member 27 that moves the second switching member 19 in the axial direction of the intermediate shaft 11 against the urging force of the second spring 20 is one of the lower ends of the second switching member 19. The second switching member 19 has a shape that contacts only the portion, but the shoulder 27b has a ring shape and the entire upper surface of the ring-shaped shoulder 27b contacts the lower end of the second switching member 19. Can be smoothly moved in the axial direction.

  Moreover, in the said embodiment, both the urging direction which urges | biases the 1st switching member 16 by the 1st urging means 17, and the urging direction which urges | biases the 2nd switching member 19 by the 2nd urging means 20 are FIG. The lower side shown in FIG. 6 and the switching members 16 and 19 are moved upward against the urging force of the urging means 17 and 20 by a predetermined rotation operation of the switching lever 25, thereby hitting the tip tool 9. However, for example, the switching members 16 and 19 are both upwardly biased by the biasing means 17 and 20, and the switching member 25 is switched by a predetermined rotation operation of the switching lever 25. 16 and 19 may be moved downward against the urging force of the urging means 17 and 20 to cancel the transmission of the striking operation and the rotation operation to the tip tool 9. Further, the direction in which the first switching member 16 is biased by the first biasing means 17 and the direction in which the second switching member 19 is biased by the second biasing means 20 may be different.

  Further, in the above embodiment, as shown in the figure, the switching lever 25 is relatively disposed on the first switching member 16 side, and the first eccentric pin 25a provided on the switching lever 25 is operated during a predetermined rotation operation of the switching lever 25. By acting on the first switching member 16 and moving the first switching member 16 against the urging force of the first urging means 17, the transmission of the striking operation to the tip tool 9 is released, and the second eccentric pin 25b. Acts on the second switching member 19 via the moving member 27 held so as to be movable in the axial direction by the auxiliary switching shaft 26 when the switching lever 25 is operated for a predetermined rotation. However, the switching lever 25 is disposed relatively to the second switching member 19 side and is provided on the switching lever 25. The first eccentric pin 25a is a switching lever. The transmission of the rotational motion to the tip tool 9 is canceled by acting on the second switching member 19 and moving the second switching member 19 against the urging force of the second urging means 20 during a predetermined rotation operation of 25. The second eccentric pin 25b acts on the first switching member 16 via the moving member 27 held so as to be axially movable on the switching auxiliary shaft 26 when the switching lever 25 is rotated by a predetermined amount. It is good also as a structure which cancels | releases transmission of the striking operation | movement to the tip tool 9 by moving against the urging | biasing force of the 1st urging means 17.

The principal part sectional view (rotation and hammering mode) which shows one embodiment of the hammer drill of the present invention. The principal part enlarged view of FIG. (Neutral mode) The principal part enlarged view of FIG. (Neutral mode) The principal part enlarged view of FIG. (Strike only mode) The principal part enlarged view of FIG. (Rotation only mode) B arrow principal part enlarged view of FIG. AA sectional view taken on the line AA of FIG.

Explanation of symbols

1 is a drive shaft, 2 is a first gear, 3 is a crankshaft, 10 is a second gear, 11 is an intermediate shaft, 12 is a third gear, 15 is a tool holding member, 16 is a first switching member, and 17 is a first gear. Spring, 19 is a second switching member, 20 is a second spring, 21 is a second clutch mechanism, 22 is a rotation locking member, 25 is a switching lever, 25a is a first eccentric pin, 25b is a second eccentric pin, and 26 is A switching auxiliary shaft, 27 is a moving member, 27a and 27b are shoulder portions, and 28 is a third spring.

Claims (3)

An electric motor having a drive shaft, a first gear and a second gear that are rotated by the rotation of the drive shaft and arranged in parallel to each other, and a crank that is rotated by the rotation of the drive shaft transmitted through the first gear A shaft, an impact transmission mechanism that converts the rotation of the crankshaft into an impact motion, and transmits the impact motion to a tip tool, an intermediate shaft that is rotated by the rotation of the drive shaft transmitted through the second gear, In a hammer drill having a rotation transmission mechanism for transmitting the rotational movement of the intermediate shaft to a tip tool, and an outer frame member incorporating at least the first gear and the second gear,
A switching member that is non-rotatable and axially movable on the intermediate shaft, a switching lever that controls the movement position of the switching member on the intermediate shaft, and the second gear side so as to sandwich the intermediate shaft. A rotation locking member held non-rotatably on the outer frame member, and the switching member engages with the second gear through an engagement portion provided on a lower surface by operation of the switching lever. A first state; a second state in which the rotation locking member is engaged via an engagement portion provided on the upper surface; and a third state in which the second gear and the rotation locking member are not engaged. A hammer drill characterized by being movable. The hammer drill according to claim 1, wherein the switching member is biased toward the second gear by a first biasing means. The hammer drill according to claim 1 or 2, wherein the rotation locking member is urged toward the second gear by a second urging means.

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