GB2355117A

GB2355117A - Rotary inverter installation

Info

Publication number: GB2355117A
Application number: GB0004182A
Authority: GB
Inventors: Yong-Woon Han; Seong-Deog Jang; Kwang-Seok Kang; Han-Jun Sung
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 1999-10-04
Filing date: 2000-02-22
Publication date: 2001-04-11
Also published as: JP2001112270A; DE10023733A1; JP3167699B2; CN1290995A; GB0004182D0; KR20010035895A

Abstract

A mounting board (300) for a rotary inverter (20) has means (302, 305a, 305b) for locating and supporting a rotary inverter (20) and integral conductive paths for conducting current to and from an inverter (20) supported by the supporting means (302, 305a, 305b).

Description

2355117 Rotary Inverter Installation

Description

The present invention relates to the installation of a rotary inverter.

Usually, electronic appliances such as microwave ovens operate only from a supply of AC. Consequently, if only a DC supply is available, e.g. in a caravan, an inverter must be used to produce AC from the supplied DC.

lo Such a known inverter comprises a relay or semiconductor devices for converting DC into AC. Conventional solid-state inverter circuits, however, are expensive and are inefficient because of the heat generated during switching.

Figure 1 shows an inverter which does not embody the present invention.

Referring to Figure 1, the inverter 20 includes a DC motor 21 connected to a battery 10, a commutator 25 rotated by the motor 21 and a plurality of brushes 23 in contact with the circumferential surface of the commutator 25. The commutator 25 comprises two conductive parts 25a separated by insulating parts 25b. The conductive parts 25a come in contact with at least two neighboring brushes 23. The battery 10 is connected to two input brushes 23 and two output brushes are connected to the primary winding of a high- voltage transformer 30.

As the commutator 25 is rotated by the motor 21, the brushes 23 sequentially contact the conductive and insulting parts 25a, 25b of the commutator 25 causing AC to be supplied to the high-voltage transformer 30. The inverter 20 and the high voltage transformer 30 are, in this example, 3o arranged in an electrical component chamber of a microwave oven. Care must be taken with the installation of the inverter 20 because the motor 21 rotates at high speed and a large amount of heat is generated when it is operating. It should be borne in mind that the output current is in the region of 50A to 70A.

According to the present invention, there is provided a mounting boar'd for a rotary inverter, the board comprising support means for supporting a rotary inventor and integrated conductive paths for conducting current to and from an inverter supported by the support means.

Preferably, the support means comprises a hole and a wall at the edge of the lo hole. More preferably, the wall extends along the edge of the hole.

Preferably, the board is formed from plastics resin material and the conductive paths comprise metal conductors embedded the plastics resin material.

An inverter assembly may comprises a rotary inverter supported on a board according to present invention by said support means.

A microwave oven may include an inverter assembly according to the present invention.

An embodiment of the present invention will now be described, by way of example, with reference to Figures 2 to 8 of the accompanying drawings, in which:Figure 1 shows an inverter which does not embody the present invention; Figure 2 is a top view of board for an inverter assembly according to the present invention; Figure 3 is a sectional view, taken along the line X-X, of the board of Figure 2; Figure 4 is a bottom view of the board of Figure 2; Figure 5 is a sectional view, taken in the line Y-Y, of the board of Figure 2; Figure 6 is an exploded perspective view illustrating the process of fixing an inverter into the board of Figure 2; Figure 7 is a top view for showing the board of Figure 2 with an inverter installed; and Figure 8 is a partially cut away view of a microwave oven having an inverter assembly according to the present invention.

Referring to Figure 2, an inverter mounting board 300 has a support section 305, which includes a hole 302 for receiving the body of an inverter. The inverter mounting board 300 is made of nylon W6 by injection molding. In Figure 2, the hole 302 is formed in the left-hand half of the inverter mounting board 300.

The support section 305 includes a plurality of side supporting parts 305a, which project up from the edge of the hole 302 for supporting the body of an inverter, and a plurality of brush supporting parts 305b for guiding and supporting a plurality of brushes which protrude from the body of an inverter. The support section 305 includes the four side supporting parts 305a and the four brush supporting parts 305b. Upper portions of the side supporting parts 305a are tapered. The brush supporting parts 305b are formed on the surface of the fixture board 300 in the shape of cuboid corresponding to the plurality of brushes 23 protruding from the body of the inverter 20, to guide and support the brushes 23.

Electrical wiring is incorporated into the inverter mounting board 300 during molding thereof. The dotted line on the surface of the fixture board 300 in Figure 2 indicate conductive strips which are embedded in the fixture board 300. The conductive strips 310, 312, 314, 316, 318, 320 are made of copper and dimensioned to withstand the currents that must pass through them. Each of the conductive strips 310, 312, 314, 316, 318, 320 has a screw hole 322 at each end.

Referring to Figures 3 and 4, a plurality of supports 400 and mounting legs 402 project by the same amount from the lower surface of the inverter mounting board 300. Threaded holes 402a extends axially from the free ends of the mounting legs 402 for receiving mounting screws to fasten the board 300 to, for example, the floor of the electrical component chamber of a microwave oven.

The plurality of supports 400 are formed at respective corners of the fixture board 300.

As shown in Figures 4 and 5, a low skirt 502 projects from the edge of the underside of the inverter mounting board 300. Raised portions 504, the same lo height as the skirt, protrude around the screw holes 322 in the conductive strips 310, 312, 314, 316, 318, 320.

Referring to Figure 6, four projections 706, which house brushes 23, are provided on the body 704 of an inverter 20. Electric wires 710a, 710b, 712a, 712b extend out of respective projections 706. Two of the electric wires 710a, 710b are the DC input of the inverter 20, while the other electric wires 712a, 712b are the AC output of the inverter 20.

During assembly, the lower end of the inverter 20 is inserted into the hole 302 in the inverter mounting board 300 until is it supported by the four side supporting parts 305a. The projections 706, holding the brushes 23, are positioned beside the four brush support parts 305b.

Referring to Figure 7, the electric wires 710a, 710b, 712a, 712b are connected to respective conductive strips 318, 312, 316, 310 by screws passing through respective screw holes 322. The two-dotted lines in Figure 7 indicate connections via relays.

The output terminals of the assembly are formed on two conductive strips 320, 310 and input terminals of the assembly are formed on two other conductive strips 312, 314.

Referring to Figure 8, a cooking chamber 204 and an electrical component chamber 208 are formed in the body 202 of an AC/DC type microwave oven 200. The cooking chamber 204 has a door 206 at its front and a control panel 210, having a plurality of control buttons, is mounted at the front of the electrical component chamber 208.

The inverter mounting board 300 and a high-voltage transformer 30 are mounted to the floor of the electrical component chamber 208., the fixture io board 300 and the high voltage transformer 30 are fixed. Screw holes (not shown) for formed in the floor of the electrical component chamber 208. These holes are arranged so that they can be aligned at the same time with respective mounting legs 402 of the inverter mounting board 300. The inverter mounting board 300 is held in place by screws passing through the holes in the floor of the electrical component chamber 208 and into the threaded holes 402a in the mounting legs 402.

The input leads 30a, 30b of the high voltage transformer 30 are conneded to the output terminals of the fixture board 300, i.e. connected with the output conductive strips 320, 310, and DC from a battery, when connected, is fed to the inverter through leads 10a, 10b connected to the input conductive strips 320,310.

As described above, in the inverter mounting board according to the present invention, the inverter is firstly supported by inserting the body 704 thereof into the inserting hole 302 formed on the support section 305, and secondly supported by the side supporting parts 305a which are formed along the circumference of the inserting hole 302 in the direction of insertion to support the body 704 of the inverter from the sides thereof, and finally, firmly fixed as the four brush supporting parts 305b radially extending from the circumference of the inserting hole 302 corresponding to the brushes 23 fix the projections 706 of the inverter.

Further, by the plurality of fixing parts for fixing the input and output ends of the electrically connective parts of the inverter, the wiring between the input 5 and output terminals becomes easier.

Further, by forming the electrically connective wiring of the inverter in the lower part of the fixture board 300 by injection molding, the electronic appliance becomes easy to handle, and has reduced possibility of short circuit lo caused due to the heat distortion.

Claims

1. A mounting board for a rotary inverter, the board comprising support means for supporting a rotary inventor and integrated conductive paths for conducting current to and from an inverter supported by the support means.

2. A mounting board according to claim 1, wherein the support means comprises a hole and a wall at the edge of the hole.

lo

3. A mounting board according to claim 2, wherein the wall extends along the edge of the hole.

4. A mounting board according to claim 1, 2 or 3, wherein the board is formed from plastics resin material and the conductive paths comprise metal conductors embedded the plastics resin material.

5. An inverter assembly comprising a rotary inverter supported on a board according to any preceding claim by said support means.

6. A microwave oven including an assembly according to claim 5.

7. A non-directional frequency generator fixture board comprising:

a supporting section for fixing the non-directional frequency generator; and a plurality of fixing sections for fixing input and output ends for electrically connecting the non-directional frequency generator, onto the fixture board.

8. The fixture board as claimed in claim 7, wherein the supporting section Comprises: an inserting hole for receiving a body of the non-directional frequency 8 - generator; a supporting part formed along the circumference of the inserting hole in the direction of insertion for supporting the body of the non-directional frequency generator from the sides thereof; and a brush supporting part for guiding and supporting a plurality of brushes protruding from the body of the non-directional frequency generator.

9. The fixture board as claimed in claim 7, wherein an electric connective wire for electrically connecting the non-directional frequency generator is built lo in the lower part of the fixture board by injection molding.

10. The fixture board as claimed in claim 9, wherein the electric connective wire is made of a copper.

11. The fixture board as claimed in claim 9, wherein the respective ends of the electric connective wire have screw holes formed therein.

12. A mounting board for an inverter, the mounting board being substantially as hereinbefore described in Figures 2 to 8 of the accornp,. anying drawings.