JP2003244889A - Terminal box for dynamo-electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a terminal box with high safety, capable of preventing breakage and splashing of terminal box component material caused by rise in the internal pressure by the action of the bursting device when layer short arc is generated at the terminal box for the dynamo-electric machine and also minimizing hazards, affecting on peripheral equipment or person due to jetting of arc or splash of the component material of the terminal box at bursting. <P>SOLUTION: In this terminal box 2, which is attached at the dynamo-electric machine so as to cover a lead wire 4 of the dynamo-electric machine 1 and a connecting terminal 5 which connects the lead wire with a power cable 6, the bursting device 9, in which a pressure avoidance plate 10 is installed is provided at a terminal box side wall which faces a side surface side, having a lead wire leading part 1a of the dynamo-electric machine 1 and is distant from the side surface. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a terminal box of a rotary electric machine.

[0002]

2. Description of the Related Art Generally, in a rotary electric machine, a connecting portion between a lead wire of the rotary electric machine and a power cable is covered with a terminal box to prevent contact of a human body and intrusion of rainwater or foreign matter into the terminal portion to prevent electric shock or interphase. Accidents such as short circuits are prevented.

FIG. 6 is a perspective view showing a state in which a terminal box is attached to the rotating electric machine body, and FIG. 7 is a cross-sectional view of the terminal box portion, in which a container-shaped terminal box 2 is provided on a side wall of the rotating electric machine body 1. The lead wire 4 which is attached and is drawn from the lead wire drawing portion 3 in the terminal box 2 is connected to the power cable 6 via the terminal 5, and the connecting portion is covered by the terminal box 2. Normally, in the terminal box 2, the lead wire 4, the terminal 5 and the power cable 6 of each phase are subjected to an insulation treatment after connection, so that the insulation property between the phases is maintained.

However, when the insulating property between the phases is lost due to some abnormal factor such as peeling off of the insulating material, there is a possibility that an interphase short circuit occurs. When a phase-to-phase short-circuit accident occurs, an arc discharge occurs between the terminals, and the heat generated at that time causes the air around the arc to expand instantaneously and extremely rapidly, so that the internal pressure of the terminal box 2 rapidly increases. In this case, the terminal box 2 is damaged due to the increase in internal pressure, and the expanded gas and arc and the constituent materials of the terminal box are scattered and ejected, which may cause damage to peripheral equipment and human body.

In order to prevent these problems, a pressure relief device is attached to the terminal box as a conventional technique. The structure and function of this conventional terminal box with pressure plate of a general rotary electric machine will be described with reference to FIG. In FIG. 8, a terminal box 2 including a main body portion 2a and a cover portion 2b
Is attached to the rotary electric machine body 1 and covers the lead wire 4 drawn from the lead wire drawing portion 3 and the terminal 5 for connection with the power cable 6. A fixed clamp 7 may be provided to hold at least one of the lead wire 4 and the power cable 6 so that the connection portion does not shake. Reference numeral 8 is a mounting bolt for mounting the cover portion 2b to the main body portion 2a.

The pressure release device 9 is attached to any wall surface of the terminal box 2, and is composed of a plate-shaped pressure plate 10, a frame-shaped holding plate 11 and a fixing bolt 12.
A hole 2c which is slightly smaller than the pressure plate 10 is formed in the mounting portion of the pressure plate 10 of the terminal box 2, and the strength of the pressure plate 10 is smaller than the other wall surfaces of the terminal box 2.

However, when an arc is generated due to a phase-to-phase short circuit or the like, and the internal pressure of the terminal box 2 rises, the pressure barrier 10 ruptures before the other components of the terminal box 2 are damaged. By releasing the internal pressure, it is possible to prevent the damage and scattering of the entire terminal box.

In addition to the above, as a conventional example of a terminal box of a rotary electric machine having a pressure release device, as shown in Japanese Utility Model Publication No. 62-6840, there is also a structure in which a pressure-relief plate bursts inside the main body of the rotary electric machine. Proposed.

[0009]

However, the device shown in FIG. 8 described above is insufficient in preventing damage to surrounding equipment and human body.

That is, since many rotating electric machines are installed at almost the same height as a person walks around because of the structure used in combination with other machines, the terminals are often provided on the side surface of the rotating electric machine. It is very likely that the box will be placed at almost the same height as the body. Therefore, if a person is right next to the pressure relief plate attached to the terminal box, if the pressure relief plate acts due to a short-circuit accident or the like, the gas or arc emitted from the opening directly goes to the human body, which is very dangerous. There is a problem such as.

The structure of the switchboard and the switch is generally more complicated than that of the terminal box of the rotating electric machine, and in many cases, a partition wall or a reinforcing material or a column for mounting equipment is provided inside. As shown in FIG. 8, the main body is often required to have a very simple structure and be inexpensive. Therefore, the terminal box of the rotating electric machine and the switchboard, switch, and the like have greatly different strengths in their housings. Generally, the terminal box of the rotating electric machine has a lower strength in the housing.

From the above, when the pressure relief device is provided in the terminal box of the rotating electric machine, the pressure-relief plate bursts in a short time and at once, before the terminal box body is damaged by the internal pressure, and the expanded gas is discharged. It must be noted that it will be discharged promptly. Further, in the pressure plate of the terminal box of the conventional rotating electric machine with the pressure release device shown in FIG. 8, when the internal pressure of the terminal box rises and the pressure plate ruptures, the fragments of the pressure plate ruptured and the terminal box There is a problem that the consideration that the problem that the components scatter and the peripheral equipment and the human body are damaged is insufficient.

Further, in the terminal box of a rotary electric machine disclosed in Japanese Utility Model Publication No. 62-6840, since the pressure relief plate is configured to rupture inside the main body of the rotary electric machine, fragments of the pressure relief plate and the terminal box in the case of an interphase short circuit accident. The components of the product will not be directly scattered to the surrounding equipment and human body and cause harm.
However, when adopting this example, it is necessary to make both the mounting parts of the terminal box and the rotating electric machine main body larger than a normal product without a pressure release device and to have a special size and shape. However, there is a problem that it is difficult to implement improvement.

Further, in the conventional example shown in FIG. 8, when the pressure-relief plate is made thin to reduce its strength for the purpose of easily rupturing the pressure-relief plate when the internal pressure rises, an external force such as hitting an object may occur. However, there is a problem that the pressure-relief plate is easily broken due to a mechanical factor.

The standard for rotating electrical machines is, for example, AS2380.
-1 (1989), Section 5.2.1. The specific content is, for example, a so-called impact test, such as "it is not damaged even if an object with a hemisphere with a tip of 25 mm and a mass of 1 kg is dropped from a height of 70 cm and hits the weakest part of the device". As a matter of course, the numerical value varies depending on the usage conditions. Since the example given here is not an international standard, whether or not there is a specification that "no matter what part hits something will be broken" depends on the discussion result between the manufacturer and the user, but if there is such a request, Figure 8
In the structure of only the pressure-relief plate shown in the conventional example, there is a problem that the structure is weak against a load from the outside and immediately cracks. On the contrary, if the strength of the pressure plate is increased so as to withstand an external load, the pressure plate will not immediately burst when the internal pressure of the terminal box rises, and the original function will not be fulfilled.

In view of the above points, the present invention prevents the damage and scattering of the terminal box constituent materials due to the rise of the internal pressure due to the function of the pressure release device when the interphase short circuit arc occurs in the terminal box of the rotating electric machine. In addition, the purpose of the present invention is to obtain a terminal box with high safety by reducing the damage to surrounding equipment or human body due to the arc spouting and the scattering of the constituent materials of the terminal box during pressure release.

[0017]

The invention according to claim 1 is
In the terminal box mounted on the rotating electric machine so as to cover the lead wire of the rotating electric machine and the connection terminal for connecting the lead wire to the power cable, the terminal box is opposed to the side surface side where the lead wire lead-out portion of the rotating electric machine is provided. At the same time, a pressure relief device having a pressure relief plate is provided on the side wall of the terminal box which is separated from the side surface.

The invention according to claim 2 is the invention according to claim 1, wherein the ratio A of the area A of the pressure-relief plate to the volume V of the terminal box is A.
/ V is 0.2 or more.

According to a third aspect of the present invention, in the terminal box mounted on the rotating electric machine so as to cover the lead wire of the rotating electric machine and the connection terminal for connecting the lead wire to the power cable, the terminal box is provided in the terminal box. At least one surface of the pressure relief plate of the pressure relief device is coated with varnish or resin.

According to a fourth aspect of the present invention, in the terminal box mounted on the rotary electric machine so as to cover the lead wire of the rotary electric machine and the connection terminal for connecting the lead wire to the power cable, the terminal box is provided outside the pressure relief device. It is characterized in that a protective cover for protecting the pressure plate is provided.

According to a fifth aspect of the invention, in the invention according to the fourth aspect, the protective cover is provided with a protective net for preventing the fragments of the pressure relief plate and the components inside the terminal box from scattering away. Is characterized by.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a first embodiment of the present invention, in which a side wall of a rotary electric machine main body 1 is
A container-shaped terminal box 2 composed of a main body portion 2a and a cover portion 2b is attached, and a lead wire 4 drawn from a lead wire drawing portion 3 in the terminal box 2 is connected to a power cable 6 via a terminal 5. Connection is made, and the connecting portion is covered with the terminal box 2.

The pressure relief device 9 is not at an arbitrary position of the terminal box as in the conventional example of FIG. It is attached to a side wall that is spaced from the side surface. The pressure plate 10 is made large so that a large opening area is formed at the time of rupture.

When a phase-to-phase short circuit occurs in the terminal 5 or another conductive portion (for example, a U or V phase short circuit), the internal pressure of the terminal box 2 suddenly rises due to arc discharge as described in the conventional example. At this time, due to the difference between the above-described conventional example and the present invention, the pressure-relief plate 10 bursts at a lower internal pressure rise and in a shorter time after the occurrence of the interphase short circuit. In this way, although the terminal box 2 may be slightly deformed in some cases, the terminal box 2
Holding plate 11 and mounting bolts 12 are scattered, and terminal box 2
Is greatly deformed to widen the gap of the terminal box cover mounting portion, and a large arc is not ejected from there, or the terminal box 2 is not damaged, that is, the pressure relief device normally functions, and the internal pressure of the terminal box 2 Is released. Moreover, since the debris such as the pressure plate is scattered between the rotating electric machine body 1 and the terminal box 2, which cannot be entered by a person, it is possible to prevent the occurrence of a personal injury or the like.

The following tests were conducted to confirm the effects of the present invention.

The terminal box 2 used as a sample has a shape according to FIG. 1, and its dimensions are as shown in Table 1. The material of the wall surface, the plate thickness, and the strength of each portion such as the joint with the lid are the same as those of the conventional one. It is equivalent to the terminal box that has been manufactured for general use. For comparison, the dimensions of each part, the plate thickness, the strength of the bolts at the joint, etc.
We also used a test product that was slightly changed so that it did not differ significantly from the conventional product. Furthermore, some test products are prepared in which the opening area of the pressure relief plate 10 is changed in size and the mounting position of the pressure relief plate 10 is changed, and it is assumed when an accident occurs under general installation conditions and usage conditions. An interphase short circuit test was actually performed under the short circuit condition.

[0027]

[Table 1] The main results of the experiment are shown in FIG. 2, which summarizes the relationship between the volume V of the terminal box, the opening area A of the pressure relief plate, and whether or not the pressure relief device normally functions. As seen in Figure 2,
The condition for the pressure relief device to function normally is "A / V≥C (C:
Constant) ". Table 1 as a specific example
For the terminal box with the dimensions of
When the unit of volume V is m ² and m ³ , respectively, A / V is 0.2
At smaller sizes, the pressure relief device did not work properly.
From the above, the larger the opening area of the pressure relief plate,
It was shown that the A / V value increased and the safety increased.

Further, as a result of conducting a test under the same conditions except that the mounting position of the pressure relief device is changed, the rotary electric machine 1 faces the side surface of the rotary electric machine 1 on which the lead wire drawing portion 1a is provided, and When the pressure relief device 9 was attached to the side wall separated from the side face, when the pressure relief device 9 was attached to the other side face, the fragments of the pressure relief plate and the components of the terminal box were scattered farther. From the above, by installing the pressure relief device on the side wall of the terminal box that faces the side surface of the rotary electric machine 1 where the lead wire lead-out portion 1a is provided and is separated from the side surface of the rotary electric machine, safety is further improved. It was shown to increase.

Therefore, as is apparent from the above results, according to the present embodiment, in the above-mentioned situation, the pressure-relief plate bursts instantaneously and at once in a short time before the terminal box body is damaged by the internal pressure. Since the expansion gas can be quickly discharged and the damage to the surroundings can be further reduced, the safety can be improved as compared with the conventional terminal box.

In the embodiment of the present invention, the structure other than the pressure release device may be almost the same as that of the conventional terminal box, so that the mounting portion of the rotating electric machine main body and the terminal box is different from the existing terminal box. Since the same shape is sufficient, it is easy to improve the attachment of the terminal box of the present invention to an existing rotating electric machine.

In the above description, it is premised that the terminal box of the present invention is newly manufactured. However, since the structure of the parts other than the pressure release device may be almost the same as the conventional terminal box, the existing structure is not required. The object of the present invention can also be achieved by modifying the terminal box according to the embodiment of the present invention to mount the pressure relief device.

Further, the pressure shield plate 10 may have a film shape instead of a plate shape. Further, between the terminal box 1 and the pressure plate 10 and between the pressure plate 10 and the pressing plate 11, packing or sealing material may be inserted for waterproof and dustproof.

FIGS. 3 and 4 are views showing a second embodiment of the present invention, in which a varnish, resin or the like 1 is provided on at least one surface of the pressure-relief plate 10 which is a component of the pressure relief device.
3 is applied and dried.

However, if the pressure inside the terminal box rises due to a phase-to-phase short circuit accident, and the pressure relief plate 10 is deformed under pressure,
Varnish or resin, etc. that has been applied, dried, and hardened 13
Since a fine mesh-like crack is formed on one surface, the pressure-relief plate itself is likely to burst at once at the starting point. Therefore, the safety can be further enhanced.

Incidentally, when applying the varnish to the pressure relief plate, as shown in FIG.
As shown in FIG. 4, the same effect can be obtained even if the pressure-reducing plate 10 is not coated on the entire surface but only on the central portion.

Further, FIG. 5 is a diagram showing a third embodiment of the present invention, which is a tubular shape so as to surround the pressure-relief plate 10 from the outer peripheral portion of the pressure-rejection plate 10 toward the outside of the terminal box 2. A protective cover 14 is provided, and a protective net 15 is provided at an opening at the tip of the protective cover 14. Each of the terminal box 2, the protective cover 14, and the protective net 15 has a structural strength enough to withstand a load such as a falling object from the outside. The terminal box 2 and the protective cover 14 also have thermal strength capable of withstanding high temperatures. In FIG. 5, the protective cover 1
Although 4 has a structure which also functions as a holding plate of the pressure-relief plate 10, these may be constituted by separate parts.

However, when the internal pressure of the terminal box 2 rises due to a phase-to-phase short circuit accident, the protective cover 14 and the protective net 15 can further suppress the fragments of the pressure plate 10 and the scattering of the components inside the terminal box.

The size of the mesh of the protective mesh is set to be slightly smaller than the fragments of the pressure-relief plate which are shattered.
It is possible to further prevent scattering of debris. However, in order to quickly discharge the expanded gas inside the terminal box, the mesh should not be too small.

Further, by considering the direction of the protective cover 14 and directing the short-circuit arc or the like in the direction where no one is present, it is possible to further suppress the harm to the human body in the event of an accident.

Therefore, as is clear from the above results, according to the present embodiment, the terminal box 2 of the rotating electric machine is required to have a specification that "the falling box does not break wherever it falls." Even if it does, the protective cover and the protective net can satisfy the specifications and further enhance the safety of the pressure release device. The second and third embodiments may be used in combination with the first embodiment. In this case, the safety can be further enhanced.

[0041]

As described above, according to the present invention, when an inter-phase short-circuit arc occurs in the terminal box of a rotary electric machine, the pressure release device works to prevent the terminal box constituent materials from being damaged or scattered due to an increase in internal pressure. In addition to the above, when the pressure is released, it is possible to reduce the harm to the surrounding equipment or the human body due to the ejection of the arc and the scattering of the constituent materials of the terminal box, and it is possible to improve the safety as compared with the conventional terminal box.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a terminal box showing a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a result of a short circuit test with respect to the first embodiment of the present invention.

FIG. 3 is a diagram showing an example of a terminal box pressure release device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing another example of the terminal box pressure release device according to the second embodiment of the present invention.

FIG. 5 is a diagram showing an example of a terminal box pressure release device showing a third embodiment of the present invention.

FIG. 6 is a perspective view showing a terminal box mounted state of a general rotating electric machine.

FIG. 7 is a configuration diagram of a terminal box of a conventional rotating electric machine.

FIG. 8 is a configuration diagram of a terminal box of a conventional rotary electric machine with a pressure release device.

[Explanation of symbols]

1 rotating electric machine body 2 terminal box 3 Lead wire lead-in section 4 lead wire 5 terminals 6 power cable 7 Cable fixing clamp 8 mounting bolts 10 Pressure plate 11 Pressure plate holding plate 12 Pressure plate fixing bolt 13 Varnish or resin 14 Pressure shield protective cover 15 Pressure plate protection net

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5H605 AA03 AA20 CC06 DD35 EC04                       EC12 EC14 EC18 GG21                 5H611 AA03 UA01

Claims (5)

[Claims] 1. A lead box of a rotating electric machine is provided in a terminal box mounted on the rotating electric machine so as to cover a lead wire of the rotating electric machine and a connection terminal for connecting the lead wire to a power cable. A terminal box for a rotating electrical machine, comprising a pressure relief device having a pressure relief plate attached to a side wall of the terminal box facing the side surface and spaced from the side surface. 2. A ratio A of the area A of the pressure plate and the volume V of the terminal box.
/ V is 0.2 or more, The terminal box of the rotary electric machine of Claim 1 characterized by the above-mentioned. 3. A terminal box mounted on the rotating electric machine so as to cover a lead wire of the rotating electric machine and a connection terminal for connecting the lead wire to a power cable, and a pressure relief plate for a pressure releasing device provided in the terminal box. A terminal box for a rotating electric machine, characterized in that at least one surface of the above is coated with varnish or resin. 4. A terminal box mounted on the rotating electric machine so as to cover a lead wire of the rotating electric machine and a connection terminal for connecting the lead wire to a power cable, in order to protect the pressure-relief plate outside the pressure releasing device. A terminal box for a rotating electric machine, characterized by being provided with a protective cover. 5. The terminal of a rotary electric machine according to claim 4, wherein the protective cover is provided with a protective net for preventing fragments of the pressure-relief plate and constituents inside the terminal box from scattering away. box.