JPH0698579B2 - Vibrating drill - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vibration drill that rotates a bit and simultaneously vibrates the bit in the axial direction.

BACKGROUND ART A vibration drill is generally used for drilling concrete or mortar. Depending on the material to be processed, both the rotation speed of the drill bit and the vibration frequency or vibration amplitude per rotation speed are used together. Being able to switch leads to an increase in the drilling speed.

However, in the conventional vibration drill, the number of rotations could be switched, but the frequency or vibration amplitude per number of rotations could not be switched.Therefore, when the number of rotations was switched according to the material to be processed, rather This sometimes caused a decrease in the drilling speed. That is, as shown in FIG. 10, the horizontal axis represents the frequency (frequency per rotation number) to amplitude, and the vertical axis represents the drilling speed. Looking at the state of the perforation speed, the perforation speed increases as the frequency or amplitude increases, regardless of whether the predetermined rotation speed is high or low, but if the frequency or amplitude is too large, this Since the load for generating vibration increases and the actual rotation speed decreases, the drilling speed decreases, and when operating at a certain rotation speed, the optimum value for the vibration frequency or amplitude is obtained. In the case of switching only the number of revolutions as in the above-mentioned conventional example, for example, even if it is set at the place where the drilling speed peaks at the time of high speed rotation, the drilling speed of Peaking A state shifted from Rutokoro and was not able to exhibit the maximum drilling speed where the number of rotations.

[Object of the Invention] The present invention has been made in view of the above point, and the object of the present invention is to make it possible to switch the number of revolutions according to the object to be machined, and at the same time always exhibit a good drilling speed. To provide a vibrating drill that can.

DISCLOSURE OF THE INVENTION The present invention, therefore, includes a spindle that can be moved in the axial direction freely within a predetermined range and is driven to rotate by the output of a motor, and imparts axial vibration to the spindle to which a drill bit is connected. A vibrating drill having a vibration generating means includes a switching means for switching the number of rotations of the spindle, and an interlocking switching means for interlocking with the switching means and switching at least one of the frequency and the vibration amplitude per number of rotations of the spindle. This is characterized in that, when the number of revolutions is switched, the frequency or amplitude suitable for the number of revolutions is simultaneously set.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. The housing 1 includes a chuck 8 having a bit 9 mounted on its front end.
As shown in FIG. 1, a grip 16 is extended from the lower portion of the rear end, and a battery pack 17 is attached to the lower end of the grip 16. 11 is a switch handle and 12 is a rotation direction switching handle.

A pinion 21 is attached to an output shaft 20 of the motor 2 housed in the rear portion of the housing 1 in a state where its axial direction is the front-back direction. The 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 includes a pair of gears 24 and 25 having different numbers of teeth. Then, the gear 2 that meshes with these gears 24 and 25
6,27 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 is rotatable about its axis by the bearing 40, supports the gears 26 and 27 rotatably around the shafts. With the movement of the key 28, one of the gears 26 and 27 is connected so as to rotate integrally with the drive shaft 3. That is, the drive shaft 3 is connected to the gear 24
And the gear 26, or the combination of the gear 25 and the gear 27, the rotation of the intermediate shaft 23 is transmitted, and the gear 26 or the gear 27 that does not contribute to the rotation transmission is transmitted.
Becomes idle with respect to the drive shaft 3.

A planetary mechanism 4 is provided at the tip of the drive shaft 3. The planetary mechanism 4 includes a sun gear 41 formed by providing teeth on the outer surface of the tip end of the drive shaft 3, an internal gear 42 integrally formed on the inner surface of the gear case 6, and a plurality of gears meshing with both. Planetary gears 43 and the shafts that support each planetary gear 43
It consists of a planet carrier 44 with 45, in which the planet carrier 44 is integrally formed at the rear end of the spindle 5 with the chuck 8 for holding the bit 9 at the front end.

A vibration generating means for applying axial vibration to the spindle 5 includes a cam 62 press-fitted and fixed to the spindle 5 and a rotation and axial movement with respect to the spindle 5 loosely fitted to the spindle 5. And a cam 61 which is formed. These cams 61, 62 have teeth formed on their opposite surfaces, each of which has an inclined surface for causing sliding engagement. The cam 61 is urged in the direction of meshing with the cam 62 by a spring 63 installed between the back surface of the cam 61 and the gear case 6, and a projecting piece 65 protruding from the peripheral edge is formed on the inner surface of the gear case 6. By engaging with the axially long groove 69, it is prevented from rotating. In the figure, 47 is a bearing that supports the spindle 5 rotatably and axially movably, 48 is a ring that is fixed to the spindle 5 and limits the retractable range of the spindle 5 with the bearing 47, and 50 is Dust-proof rubber, 51 is a washer fixed to the tip surface of the gear case 6 with screws, 52 is a support plate, and 80 is mounted so as to pass through the gear case 6 as shown in FIG. Reference numeral 81 denotes a stop pin for performing movement, and 81 denotes a stop ring for restricting the movement of the cam 62 and the axial movement range of the spindle 5.

At the tip of the housing 1, the tip of the gear case 6 and the washer
A switching handle 7 is provided that is supported between the switching handle 7 and the shaft 51 and is rotatable about its axis. The switching handle 7 has two annular cam surfaces on the inner surface facing the tip end surface of the gear case 6, and is provided with a switching plate 71 slidable along the groove 69 in the gear case 6. The front end of the switching shaft 29 slidably arranged in the front-rear axis direction is in contact with the cam surface on the inner peripheral side, and the front end is in contact with the cam surface on the outer peripheral side. When the switching handle 7 is rotated, the switching shaft 29 moves back and forth according to the ups and downs of the cam surface on the outer peripheral side, and the key 28 is moved, so that the rotation speed is switched. Further, the switching plate 71, which moves back and forth according to the ups and downs of the cam surface on the inner peripheral side, changes the position of the cam 61 to control the meshing amount of both cams 61 and 62. The return spring 30 moves the switching shaft 29 forward.

The teeth on both cams 61 and 62 are
As shown in the figure, both tall teeth and short teeth are alternately formed, and the movement of the cam 61 by the switching plate 71 causes the state shown in FIG. As shown in the figure, it is possible to switch to a state in which only tall teeth can mesh with each other.

However, in the lever drill, the rotation of the drive shaft 3 due to the output of the motor 2 is decelerated by the planetary mechanism 4 to rotate the spindle 5 and the bit 9.
When the pair of cams 61 and 62 are brought into contact with each other by 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.
Is prevented from rotating due to the engagement with the gear case 6, the cam 62 is rotated by the rotation of the cam 61 from the state in which the respective inclined surfaces of the facing surfaces of the cam 61 and the cam 62 mesh with each other.
Immediately after passing over the inclined surface, the cam 61 strikes the cam 62 by the bias of the spring 63. As a result, bit 9
The axial vibration is transmitted to the shaft 9 and the bit 9 simultaneously performs rotation and axial vibration. In this embodiment, this operation can be switched between two states. There is.

That is, by operating the switching handle 7, the switching shaft 29 and the key 28 are moved forward to move the gear 25 as shown in FIG.
When rotation is transmitted to the spindle 5 by the meshing of the gear 27 with the gear 27, that is, when the rotation speed is lowered, the switching plate 71 moves forward and both cams 61, 6 are moved as shown in FIG.
Although the meshing amount of 2 is large and the amplitude of one of two times is small, the number of vibrations per rotation speed is large and the vibration amplitude is also large.

On the contrary, as shown in FIG. 1, the switching shaft 29 moves rearward to move the gear.
When the operation handle 7 is operated so that the rotation is transmitted to the spindle 5 through the gear 24 and the gear 26, the rotation of the spindle 5 becomes high speed, and the switching plate 71 is also pushed rearward so that the cam 61 is rotated. By pressing the projection 65 of the cam 61, the cam 61 is pushed backward against the spring 63, and as shown in FIG. 9, the amount of meshing between the cam 61 and the cam 62 is reduced and only the tall teeth are So that they are engaged. As a result, the axial vibration applied to the spindle 5 has a small vibration frequency per rotation speed and a small amplitude. By setting both of the above conditions at the peaks of both characteristic curves shown in FIG. 10,
Even when the number of rotations is switched according to the material to be processed,
Each can be made to exhibit the highest drilling speed.

In the above embodiment, both the vibration frequency and the vibration amplitude per rotation speed are switched together with the switching of the rotation speed, but only the vibration frequency or only the amplitude can be switched. Good.

[Advantages of the Invention] As described above, in the present invention, when the number of revolutions is switched, the frequency or amplitude per number of revolutions is also switched at the same time, and a good drilling speed can always be obtained. Therefore, it is possible to reduce the burden on the user because the situation that the object to be punched is pressed against the object more than necessary in order to increase the drilling speed.

[Brief description of drawings]

1 is a vertical sectional view of an embodiment of the present invention, FIG. 2 is an enlarged vertical sectional view of the same as above, and FIGS. 3 and 4 are horizontal sectional views of the same as above.
The figure is a longitudinal sectional view of the same at low speed rotation, and FIGS. 6 and 7 are exploded sectional views of the cam surface of the switching handle, where the solid line indicates high speed rotation and the chain line indicates low speed rotation. FIGS. 9 and 10 are developed cross-sectional views of the cam at low speed rotation and high speed rotation, respectively, and FIG. 10 is a characteristic diagram showing the correlation between the drilling speed, the rotation speed, and the frequency or amplitude. Is a switching handle, 9 is a bit, 24, 25, 26 and 27 are gears for shifting, 29 is a switching shaft, 61 and 62 are cams, 63 is a spring, and 71 is a switching plate.

Claims (2)

[Claims] Claim: What is claimed is: 1. A spindle which is freely movable in a predetermined range and which is rotationally driven by an output of a motor, and vibration generator which applies axial vibration to the spindle to which a drill bit is connected. In the oscillating drill, switching means for switching the rotation speed of the spindle,
An interlocking switching means for switching at least one of a vibration frequency and a vibration amplitude per rotation speed of a spindle in association with the switching means. 2. The vibration generating means is composed of a sliding meshing mechanism composed of a first cam fixed to the spindle and a second cam spring-biased toward the first cam and loosely fitted to the spindle. The teeth formed on the opposite surfaces of both cams are formed by alternately forming two kinds of teeth having different heights, and the interlocking switching means is limited by the movement amount of the second cam to the first cam side. The vibrating drill according to claim 1, wherein the vibrating drill controls the amount of engagement of both cams.