JPS622916Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to prevention of disconnection of a stator winding in a power tool.

In the direct-wound type stator used in conventional power tools, a terminal block (terminal holder) is disposed at one end of the stator core, and the stator winding is wound in this state. There was a problem in that the terminal block installed in the stator caused slight vibrations due to vibrations when the power tool was operating, and stress was applied to the start and end of the stator winding, making it easy to break. .

An object of the present invention is to solve the problems of the prior art described above and to provide a simple mechanism, highly reliable, and inexpensive structure of a power tool.

In order to prevent disconnection of the stator windings due to slight vibrations of the terminal block during operation, the present invention has been developed by modifying the terminal block, which is a component of the stator, without adding any new parts. This design is designed to prevent the terminal block from moving relative to the terminal block.

An embodiment of the present invention is shown in FIGS. 1 to 7.
In the figure, a stator 2 is housed and fixed in a housing 1 with fixing screws 3. Stator 2 is the fourth
As shown in the figure, a stator winding 7 is wound around a terminal block (terminal holder) 4 connected to one end of a stator core 6. A winding start portion and a winding end portion (not shown) of the stator winding 7 are connected to a terminal 8 embedded in the terminal block 4.
The windings of the stator winding 7 are caused by the relative movement between the stator core 6 and the terminal block 4 due to vibrations during operation (such as vibrations caused by a tip tool attached to the tip of a power tool) (the tarlock slightly vibrates). Stress is applied to the start and end of the winding (near the connection with the terminal 8), making it easy to break the wire. In order to prevent this disconnection and improve reliability, it depends on how the slight vibrations of the terminal block 4 can be suppressed.

In the present invention, the inner diameter of the fixing through hole 5 of the terminal block, which is a component of the stator 2, is made smaller than the outer diameter of the fixing screw 3 (the state before the stator is assembled is shown in Fig. 7). By tightening the screws 3, the fixing screws 3 are tapped into the fixing through-holes 5, and the terminal block 4 is thereby drawn to the stator core 6 and attached to the stator core 6.
It will be fixed in close contact with the (6th
Shown as incorporated in the diagram. ) This work of attaching the stator core 6 and the terminal block 4 is done by fixing the stator 2 to the housing 1 with the screws 3.
This is done at the same time as the storage and fixing work.

If the terminal block 4 is a molded product made of a resin with good heat resistance, mechanical strength, and high electrical insulation, the inner diameter of the fixing through hole should be approximately 10% smaller than the outer diameter of the fixing screw. By keeping it in place, good adhesion and tapping conditions can be obtained.

According to the present invention, the through holes for fixing the terminal block are made smaller than the outer diameter of the fixing screws, so when the fixing screws are tightened, the terminal block is drawn to the stator core and fixed. It is possible to suppress vibration and prevent disconnection of the stator winding.

As described above, the present invention can provide a simple, highly reliable, and inexpensive structure as a measure to prevent disconnection without adding new parts.

[Brief explanation of the drawing]

Figure 1 is a front view showing the mounting state of the housing and stator in a general power tool, Figures 2 and 3 are sectional views taken along the line AA in Figure 1;
BB sectional view, Figure 4 is a front view of the stator, Figure 5
The figure is the right side view of Fig. 4, and Fig. 6 is the C of Fig. 3.
The enlarged partial view, FIG. 7, is a developed view showing the state of FIG. 6 before assembly. In the figure, 1 is the housing, 2 is the stator, and 3 is the housing.
is a fixing screw, 4 is a terminal block, 5 is a through hole for fixing, 6 is a stator core, 7 is a stator winding, 8
indicates a terminal.

Claims (1)

[Scope of utility model registration request] A stator fixed to the inside of a frame by fixing screws, a rotor rotatably supported by the frame, and a terminal block attached to an end of the stator to which a coil end of the stator is connected. In the power tool, the inner diameter of the fixing through hole of the terminal block is formed smaller than the outer diameter of the fixing screw, and the stator maintains a slight gap with the terminal block. A power tool configured to be supported by the frame, and configured to have the terminal block shifted and fixed to the end of the stator by the fixing screw.