JPS6299086A - Vibrating drill - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

[Background technology] Vibration drills are generally used to drill holes in concrete or mortar, but depending on the material to be machined, the rotational speed of the drill bit and the vibration frequency or vibration amplitude per rotational speed can be adjusted. Being able to switch leads to improved drilling speed.

However, with conventional vibrating drills, although the number of revolutions can be changed, it is not possible to change the number of vibrations per number of revolutions or the vibration amplitude. This may lead to a decrease in drilling speed. In other words, as shown in Fig. 10, the horizontal axis represents the frequency (frequency per rotational speed) or the amplitude, and the vertical axis represents the drilling speed. Looking at the state of the drilling speed, the drilling speed increases as the vibration frequency or amplitude increases, regardless of whether the predetermined rotational speed is high or low. The load to generate vibration increases and the actual rotational speed decreases, resulting in a decrease in drilling speed.When operating at a certain rotational speed, there is no optimum value for the frequency or amplitude. When changing only the rotation speed as in the conventional example above, for example, even if the setting is set to the point where the drilling speed peaks at high speed rotation, the drilling speed will change when the rotation speed is set to low speed. The state deviated from the peak point, and the maximum drilling speed at that rotation speed could not be achieved.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to be able to switch the rotation speed depending on the object to be machined, and at the same time always exhibit a good drilling speed. It is possible to provide a vibrating drill.

[Disclosure of the Invention] Accordingly, the present invention includes a spindle that is freely movable in the axial direction and is rotationally driven by the output of a motor, and
A vibratory drill that is equipped with a vibration generating means that applies axial vibration to the spindle to which the drill bit is connected, and a switching means that switches the rotational speed of the spindle, and a vibration generating means that changes the number of vibrations per rotational speed of the spindle in conjunction with this switching means. or an interlocking switching means for switching at least one of the vibration amplitudes, and is characterized in that when the rotation speed is switched, the vibration frequency or amplitude suitable for the rotation speed is simultaneously set. It has the following.

The present invention will be described in detail below based on the illustrated embodiment. The housing 1 has a chuck 8 on which a bit 9 is attached to the front end.
As shown in FIG. 1, a grip 16 extends from the lower 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.

The motor 2, which is housed in the rear part of the housing 1 with its axial direction being the front-rear direction, has a pinion 21 attached to its output shaft 20.

This binion 21 has an intermediate shaft 23 supported at both front and rear ends.
It meshes with the gear 22 at one end of the . Further, the intermediate shaft 23 includes a pair of gears 24 and 25 having different numbers of teeth. Gears 26 and 27 that mesh with these gears 24 and 25 are attached to the drive shaft 3. Motor 2 and intermediate shaft 23
The drive shaft 3, which is installed parallel to the dowel 28 and is rotatable around the shaft by a bearing 40, supports the gears 26 and 27 so as to be rotatable around the shaft. Accordingly, one of the wheels 726 and 27 is connected to rotate together with the drive shaft 3. In other words, the drive shaft 3 is a combination of gears 24 and 26, or gears 25 and 27, which are meshed together to form the intermediate shaft 23.
The rotation is transmitted, and the gear 26 or the gear 27, which does not contribute to this rotation transmission, is in an idling state with respect to the drive shaft 3.

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 end of the drive shaft 3, an internal tooth IL42 integrally formed on the inner surface of the gear case 6, and a plurality of gears meshing with both. It consists of a planetary gear 43 and a planetary carrier 44 equipped with a shaft 45 that supports each planetary gear 43. The planetary carrier 44 here has a bit 9 at its front end.
A chuck 8 for holding the spindle 5 is integrally formed at the rear end of the spindle 5.

The vibration generating means for applying axial vibration to the spindle 5 is composed of a cam 62 that is press-fitted and fixed to the spindle 5, and a cam 62 that is loosely fitted to the spindle 5.
A cam 6 that can freely rotate and move in the axial direction relative to the
It is formed from 1. These cams 61.62 are
Teeth are formed on one side of the facing surface with an inclined surface that generates a sliding engagement. and cam 61
is a spring 63 installed between the back of the gear case 6 and the gear case 6.
The gear case 6 is biased in the direction of engagement with the cam 62, and is rotated by engaging a protrusion 65 protruding from the periphery with an axially long groove 69 formed on the inner surface of the gear case 6. It is made sure that there is no such thing. In the figure, 47 is a bearing that supports the spindle 5 rotatably and movably in the axial direction; 48 is a ring fixed to the spindle 5;
0 is a dust-proof rubber, 51 is a washer fixed to the front light surface of the gear case 6 with a screw, 52 is a support plate, and 80 is attached so as to pass through and cross the gear case 6, thereby forming a bearing 47. 81 is a retaining ring for regulating the movement of the cam 62 and the range of axial movement of the spindle 5.

A switching handle 7 is disposed at the distal end of the housing 1 and is supported by the distal end of the gear case 6 and a washer 51 and is rotatable about an axis. The switching handle 7 has two annular cam surfaces on its inner surface facing the tip end surface of the gear case 6, and has a switching plate 71 that is slidable along the groove 69 in the gear case 6. The front end of the switching shaft 29, which is disposed to be slidable in the longitudinal axis direction, is in contact with the cam surface on the outer circumference side. When the switching handle 7 is rotated, the switching shaft 29 moves back and forth in accordance with the ups and downs of the cam surface on the outer circumferential side, and the -! -28
The rotational speed is changed by moving the .

In addition, the switching plate 7 moves back and forth according to the ups and downs of the inner cam surface.
1, by changing the position of the cam 61, both cams 61.6
2. Controls the amount of engagement. Note that forward movement of the switching shaft 29 is performed by a return spring 30.

As for the teeth on both cams 61 and 62, as shown in FIG. Due to the movement of the cam 61 by the cam 71, the state shown in FIG. 8 and the state shown in FIG.
The state can be changed to a state where only the tall teeth shown in the figure can mesh with each other.

However, in this vibratory 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.
Furthermore, if 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;
Since the cam 61 is prevented from rotating due to its engagement with the gear case 6, the cam 62 changes from the state in which the respective inclined surfaces of the opposing surfaces of the cam 61 and the cam 62 are engaged to each other due to its rotation. Immediately after passing over the surface, the cam 61 hits the cam 62 under the force of the spring 63, and as a result, axial vibration is transmitted to the focus 9, and the bit 9 is rotated and axially Directional vibration and directional vibration are performed at the same time, but in this example, this operation is performed in two ways.
The state can be changed.

That is, when the switching shaft 29 and the key 28 are moved forward by operating the switching handle 7, and the rotation is transmitted to the spindle 5 through the meshing of the gears 25 and 27 as shown in Fig. fjS5, When the rotational speed is lowered, the switching plate 71 moves forward to increase the amount of engagement between the cams 61 and 62, as shown in FIG.
Although the amplitude of one of the rotations is small, the number of vibrations per rotational speed is large and the vibration amplitude is also large.

Conversely, as shown in FIG. 1, when the switching shaft 29 moves rearward and the rotation handle 7 is rotated so that the rotation is transmitted to the spindle 5 through the gears 24 and 26, the rotation of the spindle 5 is It is a high speed, and switching @7
1 is also pushed backwards, by pressing the protruding piece 65 of the cam 61, the cam 61 is pushed backwards against the spring 63,
As shown in FIG. 9, the amount of engagement between the cams 61 and 62 is reduced, and only the tall teeth are engaged with each other. As a result, the axial vibration applied to the spindle 5 has a small frequency per rotational speed and a small amplitude.

By setting both of the above conditions at the peaks of both characteristic curves shown in Figure 10, the maximum drilling speed can be achieved even when the rotational speed is changed according to the material to be machined. In other words, it can be done in such a way that it can demonstrate its full potential.

Incidentally, in the above embodiment, both the frequency of vibration per rotational speed and the vibration amplitude are switched as the rotational speed is changed, but it is possible to switch only the frequency or only the amplitude. Good too.

[Effects of the Invention] As described above, in the present invention, when the rotation speed is changed, the frequency or amplitude per rotation speed can be changed at the same time, and a good drilling speed can always be obtained. Therefore, there is no need to press the workpiece harder than necessary in an attempt to increase the drilling speed, and the burden on the user is reduced.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of one embodiment of the present invention, Fig. 2 is an enlarged longitudinal sectional view of the same, Figs. 3 and 4 are cross sectional views of the same, and Fig.
The figure is a longitudinal cross-sectional view of the same as above when rotating at low speed, and FIGS. Figure and p.
Figure lS9 is a developed cross-sectional view of the cam during low-speed rotation and high-speed rotation, respectively, and Figure IjS10 is a characteristic diagram showing the correlation between drilling speed, rotational speed, and vibration frequency or amplitude.
is the switching handle, 9 is the bit, 24, 25, 26, 27
is the gear for speed change, 29 is the switching shaft, 61.62 is the cam, 6
3 indicates a spring, and 71 indicates a switching plate. Agent Patent Attorney Ishi 1) Ai 7th figure 3' JPa4 figure 16 figure Shin 7 figure

Claims (2)

[Claims] (1) A vibratory drill that is equipped with a spindle that is freely movable in the axial direction and is rotationally driven by the output of a motor, and is also equipped with a vibration generating means that applies axial vibration to the spindle to which a drill bit is connected. A vibratory drill comprising: a switching means for switching the rotational speed of the spindle; and an interlocking switching means for switching at least one of the frequency of vibration per rotational speed of the spindle or the vibration amplitude in conjunction with the switching means. (2) The vibration generating means is composed of a sliding engagement mechanism consisting of a first cam fixed to the spindle and a second cam biased by a spring toward the first cam and loosely fitted to the spindle. Two types of teeth with different heights are formed alternately on the opposing surface of the cam.
2. The vibration drill according to claim 1, wherein the interlocking switching means controls the amount of engagement between both cams.