JPH0746470Y2 - Operation knob device for switching drills etc. - Google Patents

Abstract

The portable electric drill can operate in different ways. It has a bearing block (8) fixed in a pair of housing frames and accommodating a sliding and rotary spindle (13), also a driving spindle (9) coupled to it by a gear train (9a, 18a, 20a). A first coupling half (12a) on the block supports the sliding spindle, with which a second half (12b) is integral, the halves being engaged by sliding the spindle. A selector shaft (1) turning in the block protrudes from it at one end, while the other is opposite the sliding spindle and is cut away to form a semicylindrical portion and a flat (1a), so as to detach the coupling halves, or allow engagement when the flat is towards the spindle. A changeover knob (3) on the outer shaft end has a drilling accommodating a spring-loaded locking ball (5). A guide plate (24) has a series of hemispherical recesses (24a), engaged by the ball so as to lock the shaft in the desired angular position. The housing frames can be of resin, and the plate of rigid metal, with a central bore for the shaft. USE/ADVANTAGE - Simplicity, and firmly secures knob in position.

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching operation knob device used when switching the operating state of a drill or the like.

[0002]

2. Description of the Related Art In a drill or the like equipped with a split type resin housing, a switching operation knob device for switching the operating state may be provided at a mating surface portion of the housing. One of these is, for example, as follows. That is, as shown in FIG. 5, the switching rotary shaft 1 is rotatably provided at a fixed position of the housing 2, the operation knob 3 is fixed to the outer end of the rotary shaft 2, and the operation knob 3 is fixed at the fixed position. A coil spring 4 and a steel ball 5 to be pressed against the coil spring 4 are provided, and the ball 5 is provided with a plurality of spherical concave portions 6 formed on the surface of the housing 2 by rotating or rocking the operating knob 3.
To be engaged alternatively. Therefore, the rotation of the rotary shaft 1 is used, for example, in a drill as a normal drill in which the spindle is simply rotated, and in a vibration drill in which the spindle is reciprocally displaced in addition to the rotation. It acts to switch.

[0003]

In the conventional operation knob device for switching a drill or the like, when the operation knob 3 is repeatedly operated many times, the steel ball 5 is moved to the housing 2.
Since it is pressure-contacted with, the settling of the operation knob cannot be held reliably in the vicinity of the recessed portion 6, as compared with the wear of the main body mechanism such as a drill. Further, when the recessed portion 6 is provided on the mating surface of the housing 2,
It is difficult to form an accurate shape around the recessed portion 6 and it becomes complicated when the operation knob 3 and the steel ball 5 are assembled to the housing 2. Therefore, the recessed portion 6 is placed on a portion other than the mating surface of the housing 2. Since it is necessary to provide the operation knob 3, the stop position of the operation knob 3 is limited, and it becomes difficult to stop the operation knob 3 at the optimum position. An object of the present invention is to provide a switching operation knob device for a drill or the like that can solve such a problem.

[0004]

In order to achieve the above object, according to the present invention, there is provided a device disposed in the vicinity of a mating surface of a split type housing, wherein an operating knob is provided at an outer end exposed to the outside of the housing. A fixed switching rotary shaft is rotatably provided at a fixed position in the housing, and a spring and a ball pressed against the spring are arranged at the lower surface of the knob and face the knob. A guide plate provided with a recessed portion for engaging the ball is fitted on the outer surface of the housing.

[0005]

The ball slides on its surface while being pressed against the guide plate, so that the housing itself does not wear at all, and the guide plate can be made of a hard material such as an iron plate. If so, the settling around the recessed portion due to repeated use can be avoided.

Further, even when it is desired to provide a recessed portion at a portion serving as a mating surface of the housing, it can be dealt with by providing a recessed portion at a position corresponding to the mating surface portion on the guide plate. Therefore, it is not always necessary to form a recess having a precise shape at the mating surface of the housing where the recess is located, and the manufacture of the housing does not become difficult. Therefore, the operation knob is not restricted in its stop position in relation to the mating surface of the housing, and can be stopped at the optimum position.

Further, the guide plate functions as an auxiliary member when the steel ball is assembled between the operation knob and the housing, and facilitates the assembly of the device.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to FIGS.
Will be described in more detail. In the figure, A is a portable electric drill, the housing 2 of which is divided into two parts with a central longitudinal surface. Reference numeral 7 denotes a mating surface that appears when half of the housing 2 is removed. 8 is a bearing member and housing 2
It is fixed in the same body. Reference numeral 9 designates an output shaft of a motor which is rotatable at a fixed position via a bearing 10 and the like, and has a gear 9a at its tip and a cooling fan 11 midway in the axial direction.
Is fixed. Reference numeral 12a denotes a stepped cylindrical clutch member fitted and fixed to the bearing member 8 and has wavy teeth m1 radially formed on the outer end surface as shown in FIG. Reference numeral 13 denotes a spindle having a chuck 14 fixed to the tip thereof, which is rotatably supported by a bearing 15 disposed in the center hole of the clutch member 12a and a bearing 16 fixed to the housing 2 and axially displaced within a certain range. Another clutch member 12b, which is supported freely and is opposed to the clutch member 12a, is fixed midway in the axial direction.
As shown in FIG. 2, the corrugated teeth m1 are provided on one end surface of the 2b.
A corrugated tooth m2 is formed which is meshed with. Reference numeral 17 denotes a compression spring externally fitted to the spindle 13 between the side surface of the large diameter portion 13a of the spindle 13 and the end surface of the bearing 16.
Regardless of whether the drill A is used or not, the force is applied in the direction of arrow f1, that is, in the direction of pressing the base end surface of the spindle 13 against the switching rotary shaft 1. Reference numeral 18 denotes a moving gear that is spline-fitted through the spline portion 13b of the spindle 13, and can move and fix the axial position of the spindle 13 through a moving mechanism (not shown). Reference numeral 19 is a steel ball which is rotatably fitted in a hole provided in the base end surface of the spindle 13. Reference numeral 20 shown in FIG. 2 denotes a bearing 21 fitted in the bearing member 4 and a housing 2.
A gear shaft rotatably supported by a bearing 22 fixed to the gear shaft 23, which includes a gear 23 engaged with the gear 9a.
And two gears 20a, 20b which are selectively meshed with the moving gear 18 are integrally provided.

As shown in FIG. 4, the switching rotary shaft 1 is formed with cutouts 1a and 1b at each end, one end of which is exposed to the outside of the housing 2 and the other end of which is fitted into a hole of the bearing member 8. At the same time, the escape is restricted by an appropriate means so that it can rotate only at a fixed position. The inner end of the rotary shaft 1 is arranged so as to face the steel ball 19, and the steel ball 19 and the excision portion 1a are positively moved by rotating the switching rotary shaft 1. On the other hand, axial displacement of the spindle 13 in the arrow direction f1 can be permitted. The switching rotary shaft 1
An operation knob 3 is fixed to the outer end of the, and a hole 3a is provided at an appropriate portion thereof to insert a compression coil spring 4 and a steel ball 5 is brought into contact with the spring 4. It is the same as the conventional one. Reference numeral 24 designates a guide plate mounted on the surface of the housing 2 facing the operation knob 3, and as shown in FIG. 3, spherical recesses 24a ... With which the steel balls 5 are engaged are provided at appropriate positions. Yes, two are provided at symmetrical positions in this embodiment. The position of the recessed portion 24a does not matter even if it is at three mating surfaces of the housing 2, and the guide plate 24 is made of a relatively hard material such as an iron plate. Reference numeral 24b is a through hole through which the switching rotary shaft 1 is inserted.

In the device of the present invention constructed as described above, when the operating knob 3 is positioned in the state shown in FIG. 1, the steel ball 5 is engaged with the one recessed portion 24a by the elastic force of the coil spring 4 as shown in the same figure. Then, the position is regulated, and the operator senses it by the moderation sensation due to the engaging action. In this state, the switching rotary shaft 1
Since the inner circumferential surface of the spindle regulates the axial displacement of the spindle 13 via the steel balls 19, the spindle 13 is
And the state shown in FIG. 2 is maintained, so that the rotation of the motor is controlled by the rotation shaft 9, the gears 9a, 23, 18
The drill A functions as a normal drill in which the spindle 13 is simply rotated. When the drill A in this state is used, the reaction force acts on the spindle 13 in the direction of arrow f1 against the elastic force of the spring 17, but this reaction force is applied to the inner peripheral surface of the switching rotary shaft 1 by the steel. Since the drill A is supported via the ball 19, the drill A is constantly operated as a drill in a normal state. On the other hand, when the operation knob 3 is rotated 180 degrees from the state shown in FIGS. 1 and 2, the steel ball 5 is engaged with the other recessed portion 24a and its position is regulated in the same manner as described above. You will be able to feel it through this moderation. In this state, the inner end cutout portion 1a of the switching rotary shaft 1 faces the steel ball 19 as shown by an imaginary line k in FIG.
Is in a state where it can be displaced in the axial direction, and the rotation of the motor is transmitted to the spindle 13 via the rotary shaft 9 and the gears 9a, 23 and 18. When the operation knob 3 is rotated to the state shown in FIGS. 1 and 2, in the use state of the drill A, the spindle 13 causes the inner peripheral surface of the switching rotary shaft 1 via the steel ball 19 by the elastic force of the spring 17. Is abutted against. Therefore, the clutch members 12a, 12
b is a disassembled state, and the spindle 13 is held in the state of FIGS. 1 and 2 and simply rotated. In this state, no matter how much reaction force is applied to the spindle 13 in the direction of the arrow f1, the spindle 13 remains in the state of protruding forward and does not retract, so the spindle 13 simply rotates. However, when the operating knob 3 is rotated 180 degrees from the state shown in FIGS. 1 and 2, the spindle 13 comes into contact with the inner end cutout portion 1a of the switching rotary shaft 1 via the steel ball 19. That is, the spindle 13 naturally retracts due to the elastic force of the spring 17. For this reason, it meshes with one clutch member. When the drill A is in use, the spindle 13 receives a reaction force during processing in the direction of arrow f1. As a result, the one corrugated tooth m2 slides while being supported by the other corrugated tooth m1, and the spindle 13 moves to the corrugated tooth m1.
Reciprocal displacement in the axial direction is imparted within the meshing height range of 1 and m2. That is, the drill A acts as a vibration drill in which the spindle 13 is reciprocally displaced while being rotated. When functioning as a vibration drill, the steel balls 19 do not restrict the axial displacement of the spindle 13 even when the spindle 13 is in the most displaced state in the arrow direction f1.

As described above, the operating knob 3 is rotated every time the normal drill and the vibration drill are switched, and the steel ball 5 slides on the guide plate 24 while being pressed by the coil spring 4. However, since the guide plate 24 is a member separate from the housing 2, it can be formed of a material such as a relatively hard iron plate different from the housing material. Therefore, the operation knob 3 is repeatedly used around the recessed portion 24a. Will not easily be sagging. As a result, the conventional recessed portion 6 ... (Refer to FIG. 5), which was worn relatively quickly as compared with the service life of the drill A main body, is replaced with the recessed portion 24a ... with the same strength as the service life. Can be effectively used over the entire useful life.

Further, since the guide plate 24 is provided with the recessed portions 24a, ... It is easier to process than the case where it is provided on the housing 2 which often has a complicated shape, and the shape can be made accurate. Yes, and there is a recess 24a
There is no problem even if the position of is any position around the switching rotary shaft 1. On the other hand, a recessed space of approximately the same shape is formed in the portion of the housing 2 where the recessed portion 24a of the guide plate 24 is located. Since it is sufficient to provide the housing 2, the housing 2 can be easily manufactured. Further, if a recessed portion 24a is provided in a portion of the housing 2 where the mating surface 7 exists, a steel ball 19 is conventionally provided between the operation knob 3 and the housing 2.
Since it is difficult to assemble it, the recessed portion 24a is provided at other place as much as possible, but in the present invention, the steel ball 5 is sandwiched between the operation knob 3 and the guide plate 24, and is easily assembled in the housing 2. Therefore, the position of the recessed portion 24a is not limited from this point of view.

When changing the rotation ratio of the spindle 13 and the rotation shaft 9 of the motor, the moving gear 18 is moved to a position indicated by an imaginary line k1 in FIGS. 1 and 2 through a moving mechanism (not shown). The gear 20b is meshed.

[0014]

As described above, according to the present invention, it is possible to prevent the recessed portion from easily sagging even when the operating knob is repeatedly used, and the drill body can be used during its useful life. It will ensure effective use,
In addition, it is possible to easily provide a recessed portion at the location where the housing mating surface exists. Therefore, the recessed portion can be provided at the optimum location, and the housing can be manufactured easily, and the operation knob and the steel ball Can be easily incorporated into the housing.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a drill according to an embodiment of the present invention.

FIG. 2 is a side view showing an operating state switching knob device and an operating mechanism related thereto according to the present invention.

FIG. 3 shows a guide plate according to the present invention, (a) is a plan view and (b) is a central longitudinal sectional view.

FIG. 4 is a diagram showing a switching rotary shaft.

FIG. 5 is a diagram of a conventional example.

[Explanation of symbols]

 1 switching rotary shaft 2 housing 3 operation knob 4 spring 5 ball 7 mating surface 24 guide plate

Claims (1)

[Scope of utility model registration request] 1. A device arranged near a mating surface of a split type housing, wherein a switching rotary shaft having an operation knob fixed to an outer end exposed to the outside of the housing at a fixed position in the housing. A spring and a ball pressed by the spring toward the housing at the lower surface of the knob, and the ball is engaged with the outer surface of the housing facing the knob. A switching operation knob device for a drill or the like, which is fitted with a guide plate provided with a recessed portion.