JPS62140779A - Power tool - 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 hand-held power tools such as drills and screwdrivers.

[Back technology 1] There is a strong demand for hand-held Ti power tools to be small and lightweight, so along with the development of small, high-power motors, a small housing with no dead space around the motor has been designed. There is. As a result of this reduction in size and weight, a heat dissipation method has been adopted in which the heat of the motor is directly transmitted from the outer skin to the housing and radiated to the outside, but this causes the following problems. I'm there. That is, the usage method as shown in FIG.
In other words, if the worker places his or her hand on the rear end of the main body housing where the motor is housed, the worker will feel uncomfortable because the housing is hot, and Heat is not dissipated sufficiently by hand, resulting in an increase in the temperature of the motor, which shortens its life.

[Objective of the Invention 1 The present invention has been made in view of the above points, and its purpose is to provide a system that is easy to use and safe, as well as
We are here to provide you with power tools that last a long time.

DISCLOSURE OF THE INVENTION 1 The present invention provides a power tool that includes a main body housing housing a motor and a handle portion extending from the rear of the main body housing, in which the rear end surface of the main body housing protrudes rearward from the handle portion. In addition, a heat insulating space is formed between the motor housed in the rear part of the main body housing and the inner surface of the main body housing, so that the heat of the motor is not directly transmitted to the main body housing. It is something that exists.

The present invention will be explained in detail below based on an embodiment of a hammer drill shown in the drawings. First, to explain the overall structure and operation, the main body housing 1 has a chunk part 41 at its front end into which the bit 38 is attached, and a handle part 3 extends from the lower part of the rear end. A storage chamber 50 for the storage battery 5 is integrally provided in front of the handle space 52, and an auxiliary handle 4 is detachably attached to the lower part of the 1ifi end. 12 in the figure is a switch,
Reference numeral 11 denotes a switch handle, which can be operated with the hand holding the handle part 3. The storage battery 5 housed in the storage chamber 50 whose inner surface is ri 51 has a terminal 55 installed on the upper surface of its rear end in contact with a contact spring 56 arranged inside the main body housing 1 .

In the figure, reference numerals 57, 58, and 59 are electrical circuit boards connecting the contact spring 56 and the switch 12.

The motor 2 is housed in the rear part of the main body housing 1 together with a control circuit box 13 with its axis oriented in the front-rear direction, and a pinion 21 is attached to an output shaft 20 of the motor 2 . This pinion 21 is rotatably supported at both ends by lees receivers 45° 45 in the gear case 6, and meshes with a gear 22 at one end of an intermediate glaze 23 whose axial direction is parallel to the axial direction of the morph 2. Further, the intermediate glaze 23 is provided with a pinion 24 at the other end, and a bevel gear 26 is freely rotatably attached to the intermediate glaze 23. Furthermore, the intermediate glaze 23 is spline-coupled to the intermediate glaze 23 at the center and is connected to the intermediate glaze 23 by a clutch spring 44. A biased clutch plate 43 is attached to the bevel gear 26 side. clutch plate 43
The engagement with the bevel gear 26 is controlled in accordance with the turning of the clutch switching lever 15. That is, as shown in FIG. 4, the switching lever 15 is attached to the switching M61.
When rotates, the eccentric pin 62 attached to the tip surface of the switching shaft 61 moves the clutch plate 43 in its axial direction,
It controls the meshing.

In FIG. 4, 63 is a screw that connects the switching lever 15 and the switching shaft 61, and 64 is a cap that hides the screw 6.

As is clear from FIG. 5, the switching lever 15 is disposed on the side surface of the main body housing 1, and a pair of stoppers 17 and 17 are provided on the side surface of the main body housing 1 where the switching lever 15 is disposed. , an arc-shaped id groove 19 are provided. Both stoppers 17.17 are connected to the switching lever 15.
When the switching lever 15 is rotated to control the engagement described above, the switching lever 15 comes into contact with the switching lever 15, thereby preventing the switching lever 15 from being turned too much. Also, the stopper 17.171± here
, m 7 1'173 U I6 Rltl 1. m
Show-t top; 1. m-J-in a'J: 5
- By setting σ higher than the height l of the switching lever 15, the switching lever 15 can be rotated with the other finger while the thumb is placed on the stopper 17.17, and the switching lever 15 from falling impact, etc.

A protrusion 65 attached to the switching lever 15 is slidably fitted into the idle groove 19.

At the front of the motor 2 in the axial direction, both the front and rear ends are provided with a lees tray 46.
A cylindrical sill 31 is installed coaxially with the motor 2 and is supported by 46 so as to be able to freely rotate around the pongee. This shilling-31 has a gear 25 fixed to the outer periphery of its rear end that engages with the pinion 2.t, and also houses a hammer 33 in the front and a piston 32 in the rear. hammer 3
The space between 3 and 3 is used as an air spring chamber. A crankshaft 28 is installed between the shilling 31 and the motor 2, and is rotatably supported by lees supports 47, , i7 with the axial direction being the vertical direction, and one end is connected to the piston 32. The other end of the connecting rod 30 is connected to the crankshaft 28 by a crank pin 29, and the bevel gear 26 is connected to the lower end of the crankshaft 28.
A bevel gear 27, which is similar to 11i8, is provided. The rotation of the crankshaft 28 causes the piston 32 to reciprocate and drive the hammer 33 via an air spring.

The rotation of the shilling 31 is caused by a spindle 34, and the reciprocating movement of the piston 32 is caused by a hammer 33 and a striker 35.
is transmitted to bit 38 via.

The spindle 34 has a cylindrical shape with a rear end fixed to the front end of the sill 31 by a stop key 37, and supports a striker 35 slidably in the axial direction within the rear end thereof. A dustproof ring 48 is attached. Note that the sliding movement of the striker 35 is similar to that of the striker 35.
The range is regulated by the engagement of the stop key 37 with a long groove 36 extending in the axial direction formed in the stop key 37.

The bit 38 is held with its rear end contained within the front part of the spindle 34. The pit 38 can freely slide in the axial direction within a predetermined range by engaging the key 40 held by the spindle 34 with the three long axial grooves provided on the outer peripheral surface of the rear end of the pit 38. At the same time, the bit 38 is rotated together with the spindle 34. The focus 38 is attached and detached by retracting the chuck portion 41 against the fill spring 42 so that the key 40 can be moved outward.

However, in the lever hammer drill, when the motor 2 is rotated, the bit 38 is moved from the intermediate shaft 23 by a shilling.
31 and spindle 34 to rotate by receiving rotational force. Further, when the clutch formed by the clutch plate 43 and the bevel gear 26 is connected, the hammer 33 follows the reciprocating movement of the piston 32 caused by the crankshaft 28 and the connecting rod 30, and the hammer 33 hits the striker 35. The impact is transmitted to the rotating bit 38 via the striker 35.

Here, the gear case 6 in the main body housing 1
The storage section and the storage chamber 50 in which the storage battery 5 is stored are separated by a partition wall 18 provided in the main body housing 1. I,! 18, as is clear from FIG. 12, both the gear case 6, which is made of die-cast aluminum or the like, and the partition wall 18, which is a synthetic resin molded product, are made thin, and the storage chamber 50 is made as thin as possible. The axis passing through 38 [is approaching 7. This is done by reducing the overall height and downsizing, and at the same time moving the storage battery 5, which is a bulky object, closer to the axis so that the center of gravity is closer to the l1lI line.
The value of the moment acting during work is reduced to prevent tilting during drilling work or screw tightening work, especially downward work.

Now, regarding the main body housing 1 housing the motor 2 in its rear part, the rear end surface of the main body housing 1 is assumed to protrude rearward from the base of the handle part 3, so that the rear end surface of the main body housing 1 is connected to the rear end surface of the motor 2 and the control circuit block 13. In addition, the rear diameter of the main body housing 1 is made thicker than the front diameter and the outer diameter of the motor 2 (by making the rear diameter of the main housing 1 larger than the front diameter and the outer diameter of the motor 2).
Outer circumferential surface and] 1ille empty 1ilI Bhth j=
7. This is to prevent the heat of 1m1f and $-92 from being directly transferred to the main body housing 1, and even when working with your hand on the rear end of the main body housing 1 as shown in Figure 6. , the hands will not get hot and the worker will not feel any discomfort. Since the motor 2 is cooled by the air in the spaces A and B between the main body housing 1 and the motor 2, the temperature of the motor 2 does not rise excessively. Since cooling holes 60 are provided at the rear of the motor 2,
This allows for reliable cooling of the internal rotor, etc.

[Effect of the Invention 1] As described above, in the present invention, even when performing work that is easy to apply force such as drilling work or screw tightening work by placing your hand on the rear end surface of the main body housing, the heat of the motor is Since it is not directly transmitted to the housing, the worker does not experience F pleasure.

[Brief explanation of drawings]

Fig. 1 is an R cross-sectional view of an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line X-X in Fig. 1, Fig. fjS3 is a cross-sectional view taken along the Y-X line in Fig. 1, and Fig. 4 is the same as above. Fig. 5 is a side view of the switching part of the above, Fig. 6 is a fil11 showing the state of use of the above.
The top view, fpJ7, is a front view of the switching section as above, and FIG. 8 is a perspective view of the switching section as above, 1 is a main body housing song, 2
3 is the motor, 3 is the handle part, and A + B is the space for insulation. Agent Patent attorney II 1) 议 7 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) In a power tool that includes a main body housing that accommodates a motor and a handle that protrudes from the rear of the main housing, the rear end surface of the main housing protrudes rearward from the handle and is housed within the rear of the main housing. A power tool characterized in that a heat insulating space is formed between the motor and the inner surface of the main body housing. (2) The power tool according to claim 1, wherein the motor is provided with cooling holes at the rear of its case.