JPH028874B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a vibratory drill that rotates a bit and vibrates in the axial direction at the same time.

[Background Art] In this vibratory drill, which generates axial vibration by using sliding engagement on the opposing contact surfaces of a pair of opposing cams, the operation of the spindle to which the bit is attached is controlled by rotation and axial vibration. An example of a device capable of switching between two operation modes, one in which the rotation is performed and the other in which only rotation is performed, is disclosed in Japanese Utility Model Publication No. 15924/1983. This is done by fixing one of a pair of cams to the spindle and the other cam to the housing, allowing the spindle to move in the axial direction, so that a contact state between both cams can be obtained, and the spindle In addition to making it possible to rotate and axially vibrate the bit, it also prevents the spindle from retracting when the bit is pressed against the surface to be drilled.
In other words, by preventing the spindle from moving in the axial direction, the pair of cams are always in contact with each other, so that the spindle only rotates. However, with such a structure, the stroke of the axial movement of the spindle must be set at a position where both cams are out of contact, and the stroke must be long. Since the output is transmitted to the housing, there is a problem in that large vibrations are transmitted to the hand holding the housing.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to obtain operation in only rotation mode and both rotation and vibration modes according to a switching operation, and to To provide a vibratory drill which has a short overall length in the axial direction and whose vibrations are transmitted to the hand holding the housing.

[Disclosure of the Invention] The present invention has a spindle that is rotatably driven by the deceleration output of a motor and is movable in the axial direction, and also has a spindle that is rotatably driven by a motor's deceleration output and is movable in the axial direction. In a vibration drill that includes a generating means and causes the spindle to vibrate in the axial direction, a repulsion that urges one cam that is movable in the axial direction toward the other cam that is fixed to the spindle. The cam is characterized in that it is provided with a stopper that prevents the movement of the movable cam against the bias of the repulsion member in response to the operation of the switching operation member, and is fixed to the spindle. The cam that contacts the cam is supported by the housing via a repulsive member, and the operation mode is switched by moving the cam in the axial direction.

The present invention will be described in detail below based on the illustrated embodiment.The housing 1 has a chuck 8 on the front end of which a bit 9 is attached, and as shown in FIG. The grip 16 has a battery pack 1 at its lower end.
7 is installed. 11 is the switch handle,
12 is a rotation direction switching handle, and 13 is a rotation speed switching lever.

A pinion 21 is attached to an output shaft 20 of the motor 2, which is housed in the rear part of the housing 1 with its axial direction being the front-rear direction. This pinion 21 meshes with a gear 22 at one end of an intermediate shaft 23 whose front and rear ends are supported.
Further, the intermediate shaft 23 has a pair of gears 24 having different numbers of teeth,
It is equipped with 25. And these gears 24, 2
Gears 26 and 27 that mesh with the drive shaft 3 are attached to the drive shaft 3. The drive shaft 3, which is installed parallel to the motor 2 and the intermediate shaft 23 and can freely rotate around the shaft by a bearing 40, supports the gears 26 and 27 so as to be slidable in the axial direction and capable of transmitting rotation. By moving the gears 26 and 27 by operating the rotation speed switching lever 13, the gears 24, 26,
Alternatively, any combination of gear 25 and gear 27 may be engaged. In the drawings, both combinations are shown to be in mesh with each other, but this is not the case in reality.

Now, a planetary mechanism 4 is provided at the tip of the drive shaft 3. This planetary mechanism 4 includes a sun gear 41 formed by providing teeth on the outer surface of the tip of the drive shaft 3.
It consists of an internal gear 42 fixed to the gear case 6, a plurality of planetary gears 43 that mesh with these two, and a planetary carrier 44 equipped with a shaft 45 that supports each planetary gear 43. The carrier 44 is integrally formed at the rear end of the spindle 5, which has a chuck 8 for holding the bit 9 at the front end.

The mechanism for imparting axial vibration to the spindle 5 consists of a cam 62 that is press-fitted into the spindle 5 and a cam 62 that is loosely fitted to the spindle 5 so that it can freely rotate and move in the axial direction with respect to the spindle 5. It is formed from a cam 61. These cams 61 and 62 have inclined surfaces formed on their opposing surfaces to generate a sliding engagement as shown in FIG. The cam 61 has a spring 63 installed between its back and the gear case 6.
The projecting piece 65 protruding from the periphery is biased in the direction of engagement with the cam 62 by the cam 62.
9, it is prevented from rotating. In the figure, 47 is a bearing that supports the spindle 5 rotatably and movably in the axial direction, and 48
is a ring fixed to the spindle 5, 50 is a dust-proof rubber, 51 is a washer fixed to the end surface of the gear case 6 with a screw, 52 is a support plate, 80 is a retaining ring for the bearing 47, 81 is a movement of the cam 62 and a retaining ring for regulating the axial movement range of the spindle 5.

A switching handle 7 is disposed at the distal end of the housing 1 and is supported between the distal end of the gear case 6 and a washer 51 and is rotatable around an axis. A switching ring 72, one surface of which is a cam surface, is fixed thereto. This switching ring 72 is in contact with the front end of a switching plate 71 serving as a stopper that is slidable along the groove 69 in the gear case 6 .

However, as shown in FIG. 1, when the switching plate 71 is positioned forward, the rotation of the drive shaft 3 due to the output of the motor 2 is decelerated by the planetary mechanism 21 and rotates the spindle 5 and the bit 9. let Further, when the pair of cams 61 and 62 are brought into contact with each other due to the reaction force of pressing the bit 9 against the surface to be drilled, the cam 62 rotates together with the spindle 5, while the cam 61 rotates with the gear case 6.
Because it is prevented from rotating due to engagement with
When the inclined surfaces of the opposing surfaces of the cam 61 and the cam 62 are engaged, the state shown in FIG. 1 exists, but as shown in FIG. Immediately after crossing over, the cam 61 hits the cam 62 under the force of the spring 63. As a result, axial vibration is transmitted to the bit 9.

However, when the switching handle 7 is rotated to push the switching plate 71 rearward via the switching ring 72, the switching plate 71 whose rear end is in contact with the protruding piece 65 of the cam 61 is 61 to spring 63
Push it backwards against the
Place it in a position where it will not come into contact with the cam 62. Since the rearward movement range of the spindle 5 is restricted by the ring 48 and the bearing 47, at this time, even if the bit 9 is pressed against the surface to be drilled, the cams 61 and 62 will not come into contact with each other. , Therefore, only rotation is transmitted to bit 9.

Other embodiments are shown in FIG. 8 and below. This uses a pair of permanent magnets 64, 64 as a member that biases the cam 61 toward the cam 62 instead of the spring 63 in the previous embodiment, and the permanent magnet 64 fixed to the gear case 6 and , the surface facing the permanent magnet 64 fixed to the cam 61 has the same polarity to utilize the repulsive force acting between both the permanent magnets 64, 64. Other points are the same as those in the previous embodiment, so detailed explanation will be omitted. In addition, when the permanent magnet 64 is used in this way, the permanent magnet 64 fixed to the gear case 6 touches the part of the planetary carrier 44 on the spindle 5 through the gear case 6 when not in operation, as shown in FIG. adsorb, move the spindle 5 forward, and both cams 6
1 and 62 are in a non-contact state, it is possible to prevent dry firing even when the switching handle 7 is in the rotational vibration mode. In addition, even though the permanent magnet 64 is attracted, as shown in FIG.
Since the suction force is weakened, at the start of work, the tip of the bit 9 is simply pressed lightly against the surface to be drilled, and both cams 61 and 62 come into contact. Furthermore, when such a permanent magnet 64 is used, even if cutting debris etc. enter the interior, the function will not be impaired, and when compared with the spring 63, there is no fatigue, so it can be used stably for a long period of time. You can get the action.

[Effects of the Invention] As described above, in the present invention, since the cam that contacts the cam fixed to the spindle is supported by the housing via the repulsion member, less vibration is transmitted to the hand holding the housing. and
Since the operating mode is switched by the axial movement of this cam, the axial movement range of the spindle is only necessary for generating vibrations, and the overall length can be shortened.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, FIG. 2 is an expanded sectional view of a pair of cams same as the above, and FIGS.
The figure is a vertical cross-sectional view during operation and only rotational movement, Figure 5 is an exploded perspective view of the same as above, Figures 6 a, b,
7 is a longitudinal sectional view showing the overall structure, FIGS. 8 to 10 are longitudinal sectional views of other embodiments, FIG. 11 is an exploded perspective view of the same, and FIG. 1
Figure 2 is a vertical sectional view showing the overall structure, in which 1 is a housing, 2 is a motor, 3 is a drive shaft, 5 is a spindle, 9 is a bit, 61 and 62 are cams, 63 is a spring as a repulsion member, and 64 Similarly, indicates a permanent magnet as a repulsive member.

Claims (1)

[Claims] 1. A spindle that is rotatably driven by the deceleration output of a motor and is movable in the axial direction, as well as an axial vibration generating means constituted by a sliding engagement mechanism consisting of a pair of cams. In the vibration drill that causes the spindle to vibrate in the axial direction using this generating means, a repulsion member is provided that urges one cam that is movable in the axial direction toward the other cam that is fixed to the spindle. ,
A vibratory drill characterized in that it is provided with a stopper that prevents the movement of the movable cam in response to the operation of the switching operation member against the bias of the repulsion member. 2. The vibration drill according to claim 1, wherein the repulsive member is a spring. 3. The vibration drill according to claim 1, wherein the repulsive member is a pair of permanent magnets with the same poles facing each other.