DESCRIPTION ELECTRIC EQUIPMENT PROTECTIVE DEVICE

Technical Field

The present invention relates to an electric equipment protective device of a compressor used for a refrigerating plant and others.

Background Art A conventional electric equipment protective device is disclosed, for example, in the official gazette of Japanese Patent Unexamined Publication No. 2-33478. Referring to Figs. 14 to 16, the conventional electrical equipment protective device will be explained below.

Fig. 14 is an exploded perspective view of the conventional electric equipment protective device, Fig. 15 is an enlarged side view showing a state in which the conventional electric equipment protective device is attached, and Fig. 16 is an enlarged upper view showing the state in which the conventional electric equipment protective device is attached. As shown in Figs. 14 to 16, glass terminal 15 for supplying electricity to an electric element (not shown) is attached to compressor body 10 in which the electric element is accommodated. Bracket 20, which is formed by bending a steel sheet such as a cold-rolled steel sheet or a hot-rolled steel sheet, is fixed to compressor body 10 in such a manner that bracket 20 surrounds glass terminal 15. Electric equipment 17 includes starting relay 17a and motor protector 17b. Starting relay 17a is used for controlling an electric

current to be supplied to the electric element so as to prevent the electric element from being burned when an excessively high intensity of electric current is supplied to the electric element. Motor protector 17b is used for preventing the compressor from being damaged, by stopping a supply of the electric current to the electric element at the time of an abnormal rise of temperature of the electric element. Bracket 20 has two engagement holes 21, wherein one is located on the right side and the other is located on the left side and these right and the left side are opposed to each other. Electric equipment cover 30, which is formed out of synthetic resin by means of injection molding, has tapered pawl portions 31, which are engaged with engagement holes 21, on inner wall faces at positions corresponding to the positions of engagement holes 21 provided in bracket 20. Electric power cord 40 for supplying electricity to the electric element of compressor body 10 through electric equipment 17 is fixed to cord outlet portion 41 so that electric power cord 40 can not be disconnected from electric equipment 17. Cord outlet portion 41 is fixed onto a lower side of electric equipment cover 30. Electric equipment cover 30 for covering electric equipment 17 attached to glass terminal 15 is inserted in such a manner that electric equipment cover 30 covers bracket 20 from the outside of bracket 20. At this time, tapered pawl portions 31 are engaged in engagement holes 21 of bracket 20. Therefore, electric equipment cover 30 can be fixed to bracket 20 by one-touch motion.

However, since electric equipment cover 30 is attached to bracket 20 by one -touch motion in the conventional constitution described above, a small gap is formed between an upper face portion of electric equipment

cover 30 and bracket 20. Therefore, in the case where a large quantity of water drops from an upper portion of electric equipment cover 30, there is a possibility that water enters the inside of electric equipment cover 30 from the gap formed between the upper face portion of electric equipment cover 30 and bracket 20.

Disclosure of the Invention

An electric equipment protective device includes ^: an electric equipment cover for accommodating electric equipment; and a hood portion which covers an upper portion of the electric equipment cover. The electric equipment cover includes a case having an opening portion. The electric equipment cover accommodates the electric equipment from the opening portion. The electric equipment cover includes a drain ditch on an upper face of the electric equipment cover opposed to the hood portion.

Brief Description of the Drawings

Fig. 1 is an exploded perspective view showing an electric equipment protective device of Embodiment 1 of the present invention.

Fig. 2 is a perspective view showing an electric equipment cover of Embodiment 1.

Fig. 3 is a view showing a state in which the electric equipment protective device of Embodiment 1 is attached.

Fig. 4 is a view showing a result of the second experiment made in Embodiment 1. Fig. 5 is an exploded perspective view showing an electric equipment

protective device of Embodiment 2 of the present invention.

Fig. 6 is a perspective view showing an electric equipment cover of Embodiment 2.

Fig. 7 is a view showing a state in which the electric equipment protective device of Embodiment 2 is attached.

Fig. 8 is a view showing a result of the second experiment made in Embodiment 2.

Fig. 9 is an exploded perspective view showing an electric equipment protective device of Embodiment 3 of the present invention. Fig. 10 is a perspective view showing an electric equipment cover of

Embodiment 3.

Fig. 11 is a view showing a state in which the electric equipment protective device of Embodiment 3 is attached.

Fig. 12 is a sectional view taken on line 12 - 12 in Fig. 11. Fig. 13 is a view showing a result of the second experiment made in

Embodiment 3.

Fig. 14 is an exploded perspective view of the conventional electric equipment protective device.

Fig. 15 is an enlarged side view showing a state in which the conventional electric equipment protective device is attached.

Fig. 16 is an enlarged upper view showing the state in which the conventional electric equipment protective device is attached.

Detailed Description of the Preferred Embodiments Referring to the accompanying drawings, embodiments of the

present invention will be explained below. It should be noted that the present invention is not limited by the specific embodiments. (Embodiment l)

First of all, Embodiment 1 will be explained as follows. Fig. 1 is an exploded perspective view showing an electric equipment protective device of Embodiment 1 of the present invention, Fig. 2 is a perspective view showing an electric equipment cover, Fig. 3 is a view showing a state in which the electric equipment protective device is attached, and Fig. 4 is a view showing a result of the second experiment. In Figs. 1 to 3, an electric element (not shown) and a compressive element (not shown) driven by the electric element are accommodated in compressor body 101.

Electric equipment 111 includes starting relay Ilia and motor protector 111b. Starting relay Ilia is used for controlling an electric current, which energizes the electric element, so as to prevent the electric element from being burned by a supply of an excessively high intensity of electric current to the electric element. The electric element includes a main winding (not shown) and an auxiliary winding (not shown) arranged at a position, the electric angle of which is 90° with respect to that of the main winding. In the case of starting the electric element, a starting torque is generated when an electric current, the phase of which is different from that of the main winding, is made to flow in the auxiliary winding. However, a wire diameter of the auxiliary winding is so small that the heat capacity of the auxiliary winding is small. Therefore, when an electric current is made to flow over a predetermined period of time, there is a

possibility that burning of the auxiliary winding is caused. In order to prevent the occurrence of the above problem, the staring relay Ilia cuts an electric current flowing in the auxiliary winding after the electric element has started. Motor protector 111b detects the temperature of compressor body 101, that is, motor protector HIb detects the temperature of compressor body 101 (indirectly detects the temperature of the electric element). Therefore, when an abnormally high temperature is detected, motor protector IHb shuts off the electric current so as to stop the electric element. Glass terminal 103, to which electric equipment 111 is attached, is mounted on compressor body 101. Bracket 105 is fixed to compressor body 101 in such a manner that it surrounds glass terminal 103. Bracket 105 is formed out of a steel sheet of SPHC, which is a kind of hot-rolled mild steel, by means of bending by pressing. On the right and the left side of bracket 105, which are opposed to each other with respect to glass terminal 103, engagement hole 107 is respectively formed. In an upper portion of bracket 105, hood portion 109, the shape of which is flat, is integrally formed.

Electric equipment cover 113 is engaged with bracket 105 so that glass terminal 103 and electric equipment 111 can be protected from a shock given from the outside and so that water and others can be prevented from entering inside. Electric equipment cover 113 is formed out of synthetic resin such as PPE (polyphenylene ether), PC (polycarbonate), PP (polypropylene) or mixture of PBT (polybutylene terephthalate) with ABS (acrylonitrile-butadiene-styrene) by means of injection molding. Electric equipment cover 113 includes tapered pawl portion 115, which engages with

engagement hole 107, arranged on an inner wall at a position corresponding to engagement hole 107 provided in bracket 105.

In upper face portion 113a of electric equipment cover 113, rib portion 117 for forming a protrusion is provided. Rib portion 117 is formed in such a manner that first rib portion 117a and second rib portion 117b are arranged substantially in parallel with each other. A height of first rib 117a and second rib 117b is 1 mm in the neighborhood of the center of each rib where the height is the smallest. An interval between first rib 117a and second rib 117b is 5 mm. When first rib 117a and second rib 117b are formed substantially in parallel with each other at an interval, drain ditch 114 is formed, the cross-section of which is a U-shape and the ditch depth H (the smallest ditch depth) at the most shallow portion of which is 1 mm and the ditch width W of which is 5 mm. Drain ditch 114 is formed at a position where an upper portion of drain ditch 114 is opposed to hood portion 109 when electric equipment cover 113 is attached to bracket 105. Drain ditch 114 is formed in the width direction of hood portion 109. A bottom portion of drain ditch 114 is formed into an inclined face 127 which is inclined downward with respect to the horizontal direction. The bottom portion of drain ditch 114 is inclined downward as it comes from a central portion to both sides 122 of electric equipment cover 113. It is preferable that this inclination angle is not less than an inclination angle of compressor body 101. It is more preferable that this inclination angle is not less than 3°.

As described above, electric equipment protective device 100 includes electric equipment cover 113, hood portion 109 and drain ditch 114.

There is provided electric power cord 119 for energizing the electric element via electric equipment 111. Cord outlet portion 121 for drawing out electric power cord 119 outside from between electric equipment cover 113 and bracket 105 is provided being fixed onto a lower side of electric equipment cover 113. Electric power cord 119 is fixed to cord outlet portion 121 so that electric power cord 119 can not be disconnected from electric equipment 111.

Operation and action of the electric equipment protective device 100 composed as described above will be explained below. When the electric equipment protective device 100 is assembled, first of all, electric equipment 111 is attached to glass terminal 103. After that, electric equipment cover 113 for covering electric equipment 111 is inserted into bracket 105 in the horizontal direction. At this time, tapered pawl portion 115 comes into contact with engagement hole 107 of bracket 105. Therefore, both sides 122 of electric equipment cover 113 are distorted outside with respect to the right and the left side of bracket 105. When electric equipment cover 113 is further inserted, tapered pawl portion 115 is engaged with engagement hole 107 of bracket 105. That is, electric equipment cover 113 is inserted into and attached to bracket 105 by one-touch motion.

When electric equipment cover 113 is attached, hood portion 109 of bracket 105 covers upper face portion 113a of electric equipment cover 113 from compressor body 101 side, that is, hood portion 109 of bracket 105 covers an upper portion of drain ditch 114. Therefore, it is possible to prevent water from directly dropping to open end portion 123 of electric

equipment cover 113 and from entering the inside of electric equipment cover 113.

It is possible to think that water, which has dropped or poured onto upper portions of electric equipment cover 113 and bracket 105, enters open end 123 side from first rib 117a side. In this case, since first rib 117a is a protruding portion, the height of which is not less than 1 mm, which protrudes from upper face portion 113a of electric equipment cover 113, first rib 117a fulfills a function of a wall for blocking water which enters from upper face portion 113a of electric equipment cover 113. Further, water can be discharged outside electric equipment cover 113.

However, in the case where a large quantity of water drops or pours onto electric equipment cover 113 and bracket 105, water gets over first rib 117a, which is a protruding portion, and passes through a small gap between hood portion 109 of bracket 105 and first rib 117a and enters the inside of electric equipment cover 113 in some cases. Even in this case, the water, which has gotten over first rib 117a, is blocked by next second rib 117b. Before the thus blocked water gets over second rib 117b, it is discharged onto both sides 122 of electric equipment cover 113 along inclined face 127 of drain ditch 114, the cross-section of which is a U-shape, formed by first rib 117a and second rib 117b. Accordingly, there is no possibility that the water gets over the second rib 117b and reaches open end portion 123 of electric equipment cover 113. Accordingly, it is possible to positively prevent the water from entering the inside of electric equipment cover 113 by drain ditch 114. When a gap formed between hood portion 109 of bracket 105 and rib

portion 117 is reduced as small as possible, energy of the water becomes weak, which enhances an effect of preventing the water from entering the inside of electric equipment cover 113. However, when the working property of attaching electric equipment cover 113 to bracket 105 through one-touch operation is improved and when the accuracy of parts and assembling work is enhanced, in order to prevent a rise of the manufacturing cost, a gap between hood portion 109 of bracket 105 and first rib 117a and a gap between hood portion 109 of bracket 105 and second rib 117b are extended. In this case, the number of ribs is increased and a plurality of drain ditches are formed. Due to this structure, it is possible to positively prevent the penetration of water.

Explanations will be made into two experiments actually made by the present inventors in detail.

First of all, the first experiment was made as follows. When depth H and width W of drain ditch 114 were respectively changed, it was confirmed whether or not water entered. Specifically, whether or not water entered was confirmed under the following conditions (a) and (b).

(a) A bottom portion of drain ditch 114, which was formed out of first rib 117a and second rib 117b, was not inclined in the horizontal direction.

(b) Water of 500 ml was dropped from a portion, the height of which was 50 mm with respect to electric equipment cover 113, for one minute to a boundary portion between electric equipment cover 113 and hood portion 109 of bracket 105, that is, to a neighborhood of first rib 117a. Table 1 shows a result of the experiment.

On Table 1, mark "O" shows that no water entered the inside of electric equipment cover 113 and mark "x" shows that water entered the inside of electric equipment cover 113.

Table 1

As shown on Table 1, the following could be confirmed by the experiment. When the depth of drain ditch 114 was not less than 1 mm and the width W of drain ditch 114 was not less than 5 mm, it was possible to prevent water from entering the inside of electric equipment cover 113.

The second experiment was made as follows. How far water entered in the lapse of time in the case where an inclination angle of inclined face 127 of drain ditch 114 was changed was confirmed in the following conditions (c) and (d). (c) Depth H of drain ditch 114 was 0.75 mm and width of drain ditch 114 was 5 mm.

(d) Water of 500 ml was dropped from a portion, the height of which is 50 mm with respect to electric equipment cover 113, for one minute to a boundary portion between electric equipment cover 113 and hood portion 109 of bracket 105, that is, to a neighborhood of first rib 117a.

Fig. 4 shows a result of the experiment. In Fig. 4, the axis of abscissas shows the lapse of time and the axis of ordinate shows a position

at which water enters. In Fig. 4, states of the penetration of water are shown in the cases where the inclination angles of inclined face 127 are 0°, 2° and 3°.

As shown in Fig. 4, the following was confirmed by the experiment. When depth H of drain ditch 114 formed in first rib 117a and second rib

117b was 0.75 mm, width of drain ditch 114 was 5 mm and an inclination angle of inclined face 127 was 3°, it was impossible for the water to reach open end 123 of electric equipment cover 113.

A result of the above experiment is described as follows. In the case of a drain ditch, the bottom portion of which was not inclined, when the ditch depth was not less than 1 mm and the ditch width was not less than 5 mm, it was possible to prevent water from entering. In the case of a drain ditch, the bottom portion of which was inclined by the angle 3°, when the ditch depth H was not less than 0.75 mm and the ditch width was 5 mm, it was possible to prevent water from entering.

This experiment was made under the condition that compressor body 101 was substantially horizontally set. However, in the case where compressor body 101 is set being inclined, it is preferable that inclined face 127 of the bottom portion of drain ditch 114 is inclined by an angle not less than the inclined angle of compressor body 101.

When drain ditch 114 is designed being formed out of first rib 117a and second rib 117b as described above, it is possible to positively prevent water from entering the inside of electric equipment cover 113. Therefore, it becomes possible to provide an electric equipment protective device of a compressor, the reliability of which is high.

In the present embodiment, hood portion 109 is formed being integrally extended from bracket 105. Therefore, compared with a case in which the hood portion and the bracket are respectively formed out of different parts, the following advantages can be provided. (i) It is possible to reduce the number of parts.

(ii) It is possible to reduce the number of man-days necessary for fixing the hood portion to an outer face of compressor body 101.

(iii) Due to the foregoing, it is possible to reduce the manufacturing cost. (iv) Relative positions of a plurality of parts can be accurately determined when the parts are fixed.

In the present embodiment, two ribs are provided so as to form one drain ditch. However, when three or more ribs are provided so as to form a _' plurality of drain ditches, it is possible to more positively prevent water from entering.

In the present embodiment, a central portion of inclined face 127 is formed in such a manner that an altitude of the central portion is high. However, as long as inclined face 127 is inclined downward toward both outsides of electric equipment cover 113, the invention can be embodied even when any portion except for the central portion of electric equipment cover 113 is elevated.

In electric equipment protective device of the present embodiment, the electric equipment cover is inserted by one-touch motion. However, as long as it is an electric equipment protective device capable of preventing water from entering the inside of the electric equipment cover, even when

the electric equipment cover is of the type in which the electric equipment cover is not inserted by one-touch motion, the present invention can be executed.

In the present embodiment, hood portion 109 is formed being integrally extended from bracket 105. However, even when hood portion and bracket are formed out of different parts, it is possible to positively prevent water from entering the inside of electric equipment cover 113. Therefore, it is possible to provide a highly reliable electric equipment protective device of a compressor. (Embodiment 2)

Next, Embodiment 2 will be explained below.

Fig. 5 is an exploded perspective view showing an electric equipment protective device of Embodiment 2 of the present invention, Fig. 6 is a perspective view showing an electric equipment cover, Fig. 7 is a view showing a state in which the electric equipment protective device is attached, and Fig. 8 is a view showing a result of the fourth experiment.

Reference numerals 201, 203, 205, 207, 209, 211, 211a, 211b, 215, 219, 221, 222 and 223. shown in Figs. 5 to 7 respectively correspond to reference numerals 101, 103, 105, 107, 109, 111, Ilia, 111b, 115, 119, 121, 122 and 123 shown in Figs. 1 to 3 of Embodiment 1.

Accordingly, explanations of the same portions of this embodiment as those of Embodiment 1 will be omitted here and only portions different from Embodiment 1 will be mainly explained here. A main point of

Embodiment 2 different from Embodiment 1 is a state of formation of drain ditch 214 and inclined face 227. Embodiment 2 has no rib portion 117

although Embodiment 1 has rib portion 117. Drain ditch 214 and inclined face 227 are formed when upper face 213a of electric equipment cover 213 is cut out.

As shown in Figs. 5 to 7, drain ditch 214, the cross-section of which is formed into a U-shape, is provided on upper face portion 213a of electronic equipment cover 213. Depth of drain ditch 214 at the central portion, in which the depth is the smallest, is 1 mm (minimum ditch depth D) and width V of the drain ditch 214 is 5 mm. This drain ditch 214 is formed at a position where an upper portion of drain ditch 214 is opposed to hood portion 209 when electric equipment cover 213 is attached to bracket 205. Drain ditch 114 is formed in the width direction of hood portion 109. A bottom portion of drain ditch 214 is inclined face 227 which is inclined downward in the horizontal direction. When the bottom portion of drain ditch 214 comes from the central portion to both sides ,222 of electric equipment cover 213, it is inclined downward. It is preferable that this inclination angle is not less than an inclination angle of compressor body 201. It is more preferable that this inclination angle is not less than 3°.

As described above, electric equipment protective device 200 includes electric equipment cover 213, hood portion 209 and drain ditch 214. When the electric equipment cover 213 is attached, hood portion 209 of bracket 205 covers an upper portion of upper face portion 213a of electric equipment cover 213, i.e., an upper portion of drain ditch 214, from the side of compressor body 201. Therefore, it is possible to prevent water from directly dropping to open end portion 223 of electric equipment cover 213 and from entering the inside of electric equipment cover 213.

The following can be considered. Concerning the route through which water enters the inside of the electric equipment cover 213, the following can be considered. Water, which has dropped or poured onto upper portions of electric equipment cover 213 and bracket 205, enters open end portion 223 from drain ditch 214 side of upper face portion 213a of electric equipment cover 213.

In this case, when a gap formed between hood portion 209 of bracket 205 and upper face portion 213a of electric equipment cover 213 is reduced to be small, this small gap can fulfill a function of suppressing the penetration of water. Therefore, almost all dropping water can be discharged outside electric equipment cover 213.

However, in some cases, water enters the inside electric equipment cover 213 through the small gap formed between hood portion 209 of bracket 205 and upper face portion 213a of electric equipment cover 213. In this case, water, which has entered, flows into drain ditch 214.

After water has flowed into drain ditch 214, it is possible to prevent water from further entering because the ditch depth is not less than 1 mm with respect to upper face portion 213a of electric equipment cover 213. Before water overflows drain ditch 214, it is discharged onto both sides 222 of electric equipment cover 213 along inclined face 227 of the bottom portion of drain ditch 214, the cross section of which is a U-shape. Therefore, it is possible to prevent water from entering the inside of electric equipment cover 213. The more the number of drain ditches 214 is, the more positively the penetration of water into electric equipment cover 213 can be prevented without overflowing of water from drain ditch 214 and arriving of

water at open end portion 223 of electric equipment cover 213.

When the gap formed between hood portion 209 of bracket 205 and upper face portion 213a of electric equipment cover 213 is reduced to be as small as possible, energy of water becomes weak and the effect of preventing water from entering can be enhanced. However, when the working property of attaching electric equipment cover 213 to bracket 205 is improved and when the accuracy of parts and assembling work is enhanced, in order to prevent a rise of the manufacturing cost, a gap between hood portion 209 of bracket 205 and upper face portion 213a of electric equipment cover 213 is extended. In this case, a large number of drain ditches are formed. Due to this structure, it is possible to positively prevent water from entering the inside of electric equipment cover 213.

Explanations will be made into two experiments actually made by the present inventors in detail. First of all, the third experiment was made as follows. When depth

D and width V of drain ditch 214 were respectively changed, it was confirmed whether or not water entered. Specifically, depth D and width V of drain ditch 214 were respectively set at different values and whether or not water entered was confirmed under the following conditions (e) and (f). (e) A bottom portion of drain ditch 214 was not inclined with respect to the horizontal direction.

(f) Water of 500 ml was dropped from a portion, the height of which was 50 mm with respect to electric equipment cover 213, for one minute to a boundary portion between electric equipment cover 213 and hood portion 209 of bracket 205 and it was confirmed whether or not water entered.

Table 2 shows a result of the experiment.

Table 2

On Table 2, mark "0" shows that no water entered the inside of electric equipment cover 213 and mark "x" shows that water entered the inside of electric equipment cover 213.

As shown on Table 2, the following could be confirmed by the experiment. When the depth of drain ditch 214 was not less than 1 mm and the width V of drain ditch 214 was not less than 5 mm, water, which entered from the gap formed between the electric equipment cover 213 and the bracket 205, did not overflow drain ditch 214 and it was possible to prevent water from entering the inside of electric equipment cover 213.

The fourth experiment was made as follows. How far water entered in the lapse of time in the case where an inclination angle of inclined face 227 was changed was confirmed in the following conditions (g) and (W.

(g) Minimum depth D of drain ditch 214 was 0.75 mm and width of drain ditch 214 was 5 mm. (h) Water of 500 ml was dropped from a portion, the height of which was 50 mm with respect to electric equipment cover 213, for one minute to a boundary portion between electric equipment cover 213 and

hood portion 209 of bracket 205, that is, to a neighborhood of drain ditch 214.

Fig. 8 shows a result of the experiment. In Fig. 8, the axis of abscissas shows the lapse of time and the axis of ordinate shows a position at which water enters. In Fig. 8, states of the penetration of water are shown in the cases where the inclination angles of inclined face 227 are 0°,

2° and 3°.

As shown in Fig. 8, the following was confirmed by the experiment. When minimum depth D of drain ditch 214 was 0.75 mm and an inclination angle of inclined face 227 was 3°, it was impossible for the water to reach open end 223 of electric equipment cover 213.

A result of the above experiment is described as follows. In the case of a drain ditch, the bottom portion of which was not inclined, when the ditch depth was not less than 1 mm and the ditch width was not less than 5 mm, it was possible to prevent water from entering. In the case of a drain ditch, the bottom portion of which was inclined by the angle 3°, when the ditch depth was not less than 0.75 mm and the ditch width was 5 mm, it was possible to prevent water from entering.

This experiment was made under the condition that compressor body 201 was substantially horizontally set. However, in the case where compressor body 201 is set being inclined, it is preferable that inclined face

227 of the bottom portion of drain ditch 214 is inclined by an angle not less than the inclined angle of compressor body 201.

In the present embodiment, hood portion 209 is formed being integrally extended from bracket 205. Therefore, compared with a case in

which the hood portion and the bracket are respectively formed out of different parts, the following advantages can be provided.

(i) It is possible to reduce the number of parts.

(ii) It is possible to reduce the number of man-days necessary for fixing the hood portion to an outer face of compressor body 201.

(iii) Due to the foregoing, it is possible to reduce the manufacturing cost.

(iv) Relative positions of a plurality of parts can be accurately determined when the parts are fixed. When drain ditch 214 is designed as described above, the penetration of water into electric equipment cover 213 can be positively prevented. Therefore, it is possible to provide a highly reliable electric equipment protective device of a compressor.

In the present embodiment, one drain ditch is provided, however, when two or more drain ditches are provided, it is possible to more positively prevent water from entering.

In the present embodiment, a central portion of inclined face 227 is formed in such a manner that an altitude of the central portion is high. However, as long as inclined face 227 is inclined downward toward both outsides of electric equipment cover 213, the invention can be embodied even when any portion except for the central portion of electric equipment cover 213 is elevated.

In electric equipment protective device of the present embodiment, the electric equipment cover is inserted by one -touch motion. However, as long as it is an electric equipment protective device capable of preventing

water from entering the inside of the electric equipment cover, even when the electric equipment cover is of the type in which the electric equipment cover is not inserted by one -touch motion, the present invention can be executed. In the present embodiment, hood portion 209 is formed being integrally extended from bracket 205. However, even when hood portion and bracket are formed out of different parts, it is possible to positively prevent water from entering the inside of electric equipment cover 213.

Therefore, it is possible to provide a highly reliable electric equipment protective device of a compressor.

(Embodiment 3)

Next, Embodiment 3 will be explained below.

Fig. 9 is an exploded perspective view showing an electric equipment protective device of Embodiment 3 of the present invention, Fig. 10 is a perspective view showing an electric equipment cover, Fig. 11 is a view showing a state in which the electric equipment protective device is attached, Fig. 12 is a sectional view taken on line 12 ^■ 12 in Fig. 11, and Fig.

13 is a view showing a result of the second experiment.

Reference numerals 301, 303, 305, 307, 309, 311, 311a, 311b, 315, 319, 321, 322 and 323 shown in Figs. 9 to 12 respectively correspond to reference numerals 101, 103, 105, 107, 109, 111, Ilia, 111b, 115, 119, 121,

122 and 123 shown in Figs. 1 to 3 of Embodiment 1.

Accordingly, explanations of the same portions of this embodiment as those of Embodiment 1 will be omitted here and only portions different from Embodiment 1 will be mainly explained here. A main point of

Embodiment 3 different from Embodiment 1 is a state of formation of drain ditch 314 and arcuate portion 327. Embodiment 3 has no rib portion 117 although Embodiment 1 has rib portion 117. Drain ditch 314 and arcuate portion 327 are formed when upper face 313a of electric equipment cover 313 is cut out.

In upper face portion 313a of electric equipment cover 313, drain ditch 314, the cross-section of which is formed into a U-shape, is provided. Depth of drain ditch 314 at the central portion, in which the depth is the smallest, is 1 mm (minimum ditch depth M) and width Y of the drain ditch 314 is 5 mm. This drain ditch 314 is formed at a position where an upper portion of drain ditch 314 is opposed to hood portion 309 when electric equipment cover 313 is attached to bracket 305. Drain ditch 114 is formed in the width direction of hood portion 109. A bottom portion of drain ditch 314 is arcuate portion 327, the shape of which is formed into a substantial arc. A central portion is closest to hood portion and both sides 322 of electric equipment cover 313 are separate from hood portion. In order to obtain a sufficiently large capacity of discharging water, it is preferable that a radius of curvature of the arcuate shape is approximately 200 to 400 mm.

As described above, electric equipment protective device 300 includes electric equipment cover 313, hood portion 309 and drain ditch 314. Explanations will be made into two experiments actually made by the present inventors in detail.

First of all, the fifth experiment was made as follows. When depth M and width Y of drain ditch 314 were respectively changed, it was confirmed whether or not water entered. Specifically, whether water

entered or not was confirmed according to the following conditions (i) and (j).

(i) A bottom portion of drain ditch 314 was not an inclined face or an arcuate shape but a horizontal face.

(j) Water of 500 ml was dropped from a portion, the height of which was 50 mm with respect to electric equipment cover 313, for one minute to a boundary portion between electric equipment cover 313 and hood portion 309 of bracket 305.

Table 3 shows a result of the experiment. On Table 3, mark "O" shows that no water entered the inside of electric equipment cover 313 and mark "x" shows that water entered the inside of electric equipment cover 313.

Table 3

The following could be confirmed by the experiment. When the depth of drain ditch 314 was not less than 1 mm and the width Y of drain ditch 314 was not less than 5 mm as shown on Table 3, water, which entered from the gap formed between the electric equipment cover 313 and the bracket 305, did not overflow drain ditch 314 and it was possible to prevent water from entering the inside of electric equipment cover 313.

The sixth experiment was made as follows. A bottom portion of drain ditch 314 was formed into arcuate portion 327. How far water

entered in the lapse of time was confirmed in the following conditions (k) and (1).

(k) Minimum depth M of drain ditch 314 was 0.75 mm and width Y of drain ditch 314 was 5 mm. (1) Water of 500 ml was dropped from a portion, the height of which was 50 mm with respect to electric equipment cover 313, for one minute to a boundary portion between electric equipment cover 313 and hood portion 309 of bracket 305, that is, to a neighborhood of drain ditch 314.

Fig. 13 shows a result of the experiment. In Fig. 13, the axis of abscissas shows the lapse of time and the axis of ordinate shows a position at which water enters. In Fig. 13, a state of the penetration of water with the lapse of time is shown.

As shown in Fig. 13, the following was confirmed by the experiment.

, Even when minimum depth M of drain ditch 314 was 0.75 mm, water was discharged to both sides of electric equipment cover 313 by arcuate portion

327. Therefore, it was impossible for the water to reach open end 323 of electric equipment cover 313.

A result of the above experiment is described as follows. In the case of a drain ditch, the bottom portion of which was flat, when the ditch depth was not less than 1 mm and the ditch width was not less than 5 mm, it was possible to prevent water from entering. In the case of a drain ditch, the bottom portion of which was formed into an arcuate shape, the radius of curvature of which was 200 to 400 mm, when the ditch depth was not less than 0.75 mm and the ditch width was 5 mm, it was possible to prevent water from entering.

This experiment was made under the condition that compressor body 301 was substantially horizontally set. However, in the case where compressor body 301 is set being inclined with respect to the horizontal direction, when a bottom portion of drain ditch 314 is formed into arcuate portion 327, the shape of which is formed in such a manner that arcuate portion 327 is protruded toward hood portion 309 and lowered in directions of both sides 322 of electric equipment cover 313, irrespective of the inclination angle of compressor body 301, the bottom portion of drain ditch 314 is always lowered in the directions of both sides 322 of electric equipment cover 313. Therefore, water in drain ditch 314 can be quickly discharged toward both sides of electric equipment cover. Even when water continues to drop to upper face portion 313a of electric equipment cover 313 over a long period of time, water can be continuously discharged /to both sides of electric equipment cover 313 by drain ditch 314 and arcuate portion 327. Accordingly, the penetration of water from open end portion 323 of electric equipment cover 313 can be prevented.

In the present embodiment, hood portion 309 is formed being integrally extended from bracket 305. Therefore, compared with a case in which the hood portion and the bracket are respectively formed out of different parts, the following advantages can be provided, (i) It is possible to reduce the number of parts.

(ii) It is possible to reduce the number of man-days necessary for fixing the hood portion to an outer face of compressor body 301.

(iii) Due to the foregoing, it is possible to reduce the manufacturing cost.

(iv) Relative positions of a plurality of parts can be accurately determined when the parts are fixed.

When drain ditch 314 is designed as described above, it is possible to positively prevent water from entering the inside of electric equipment cover 313. Therefore, it becomes possible to provide an electric equipment protective device of a compressor, the reliability of which is high.

In the present embodiment, one drain ditch is provided. However, even when two or more drain ditches are provided, the penetration of water can be highly effectively prevented. In the present embodiment, arcuate portion 327 provided in the bottom portion of drain ditch 314 is formed in such a manner that an altitude of the central portion of arcuate portion 327 is high. However, when arcuate portion 327 provided in the bottom portion of drain ditch 314 is formed in such a manner that both sides of arcuate portion 327 are lowered toward both sides of electric equipment cover 313, the invention can be embodied even when any portion except for the central portion of electric equipment cover 313 is elevated.

In the electric equipment protective device of the present embodiment, the electric equipment cover is inserted by one-touch motion. However, as long as it is an electric equipment protective device capable of preventing water from entering the inside of the electric equipment cover, even when the electric equipment cover is of the type in which the electric equipment cover is not inserted by one-touch motion, the present invention can be executed in the same manner. In the present embodiment, hood portion 309 is formed being

integrally extended from bracket 305. However, even when hood portion 309 and bracket 305 are formed out of different parts, it is possible to positively prevent water from entering the inside of electric equipment cover 313. Therefore, it is possible to provide a highly reliable electric equipment protective device of a compressor.

Industrial Applicability

As described above, the present invention can provide a highly reliable electric equipment protective device of a compressor capable of preventing water from entering the inside of an electric equipment cover without deteriorating the working property of inserting the electric equipment cover by one-touch motion. Therefore, the electric equipment protective device of the present invention can be applied to all compressors incorporated into a refrigerator, air conditioner and refrigerating system.