Refrigerant distribution unit for air conditioner

A refrigerant distribution unit for an air conditioner, includes: a pipe unit for distributing a refrigerant from a refrigerant pipe on an outdoor unit to branch refrigerant pipes on indoor units; and a main body including: upper and lower seal case which include first edge portions around the upper seal case and second edge portions around the lower seal case, and engage the second edge portions with the first edge portions for sealing an inside of the first and second seal cases to store the pipe unit; upper and lower insulator cases for covering the upper and lower seal cases; and upper and lower case constituting a contour of the refrigerant distribution unit. The pipe unit is fixed to a pipe mounting portion of the upper seal case using a pipe holder and a pipe hanging bracket.

This application claims priority from Japanese Patent Application No. 2010-148520, filed on Jun. 30, 2010, the entire contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present disclosure relates to a refrigerant distribution unit for an air conditioner, which incorporates therein a pipe unit for distributing a refrigerant from an outdoor unit of the air conditioner to multiple indoor units thereof and, more specifically, the invention relates to enhancement in the efficiency of maintenance on such refrigerant distribution unit.

DESCRIPTION OF RELATED ART

FIGS. 12A and 12Bshow a refrigerant distribution unit for an air conditioner according to a related art. The refrigerant distribution unit15includes a pipe unit in which refrigerant pipes, that is, a gas pipe210and a liquid pipe211respectively branch to multiple branch refrigerant pipes, that is, gas pipes220,230and240and liquid pipes221,231and241. Specifically, the refrigerant distribution unit15includes: a main body150for storing a pipe unit including multiple electronic expansion valves225,235and245which are used to adjust the degree of reduction of refrigerants within the multiple branch refrigerant pipes; an electric component box3including a control substrate30which is electrically connected to the multiple expansion valves225,235and245through wires respectively for the electronic expansion valves; an electric component box cover33for covering the electric component box3; and an electric component box mounting plate32(hereinafter described as mounting plate32) including a substrate fit pawl portion for mounting the electric component box3onto the main body150(see, for example, Japanese Patent Application Publication No. 2006-300381).

The main body150includes: a case6which is made of a metal plate and includes an upper case60and a lower case61respectively defining the outer shell portion of the main body150; an insulator case5including an upper insulator case50provided within the upper case60and a lower insulator case51proved within the lower case61; and, a seal case4including an upper seal case40provided within the upper insulator case50and a lower seal case41provided within the lower insulator case51.

The upper case60, upper insulator case50and upper seal case40are respectively divided vertically by a refrigerant pipe receiving portion151and a branch refrigerant pipe receiving portion152. Here, the refrigerant pipe receiving portion151is a portion through which the refrigerant pipes, that is, the gas pipe210and liquid pipe211can be inserted, while the branch refrigerant pipe receiving portion152is a portion through which the multiple branch refrigerant pipes, that is, the branch gas pipes220,230and240and branch liquid pipes221,231and241can be inserted. The refrigerant pipes are connected by a gas pipe joint212and a liquid pipe joint213to refrigerant pipes which are connected to the outdoor unit of the air conditioner. The multiple branch refrigerant pipes are connected by branch gas pipe joints222,232and242and branch liquid pipe joints223,233and243to refrigerant pipes which are connected to the multiple indoor units of the air conditioner.

In the case of the refrigerant pipes, the gas pipe210and liquid pipe211are bundled together by the refrigerant pipe receiving portion151, and are held horizontally by the vertically divided upper seal case40and lower seal case41and by the vertically divided upper insulator case50and lower insulator case51. In the case of the branch refrigerant pipes, the branch liquid pipe221and branch gas pipe220are bundled together, the branch liquid pipe231and branch gas pipe230are bundled together, the branch liquid pipe241and branch gas pipe240are bundled together. The vertically divided multiple branch refrigerant pipe receiving portions152are closely contacted with each other, whereby the branch refrigerant pipes can be held horizontally.

The refrigerant distribution unit15, in most cases, is installed (hanged) horizontally on a back face of an indoor ceiling. However, when the lower case61, lower insulator case51and lower seal case41are removed in maintenance on the unit15, since the pipe unit is not fixed to the main body150, the pipe unit is flexed downward due to its own weight. Due to this, in a state where the refrigerant distribution unit15remains hanging on the back face of the ceiling, maintenance on the peripheral parts of the pipe unit is impossible. Therefore, according to the related art, it is necessary to remove the refrigerant distribution unit15from the ceiling and take the refrigerant distribution unit15to pieces, which results in the poor efficiency of the maintenance.

SUMMARY OF INVENTION

Illustrative aspects of the present invention provide a refrigerant distribution unit for an air conditioner which, in a state where its main body is hanged, allows maintenance on the peripheral parts of its pipe unit without taking the refrigerant distribution unit to pieces.

According to a first aspect of the invention, a refrigerant distribution unit for an air conditioner, is provided with: a pipe unit for distributing a refrigerant from a refrigerant pipe provided on an outdoor unit to a plurality of branch refrigerant pipes respectively provided on a plurality of indoor units; and a main body including: an upper seal case and a lower seal case which include first edge portions in a periphery of the upper seal case and second edge portions in a periphery of the lower seal case, and engage the second edge portions with the first edge portions for sealing an inside of the first and second seal cases to store the pipe unit; an upper insulator case and a lower insulator case for covering the upper seal case and the lower seal case respectively; and an upper case and a lower case respectively constituting a contour of the refrigerant distribution unit, wherein the upper seal case includes a pipe mounting portion in which a contact face with the pipe unit is extended from the first edge portions, wherein the pipe unit is fixed to the pipe mounting portion using a pipe holder and a pipe hanging bracket, and wherein an upper portion of the pipe hanging bracket is fixed to the upper case, and a lower portion of the pipe hanging bracket is extended to a lower end of the pipe holder.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Now, description will be given below specifically of the best mode for carrying out the invention, using an exemplary embodiment thereof with reference toFIGS. 1 to 11B.

An air conditioner1shown inFIG. 1includes an outdoor unit11, and multiple indoor units12,13and14.

The outdoor unit11includes the following composing parts (none of which are shown): that is, an outdoor heat exchanger; a portion of a refrigerant circuit for a compressor, a four way valve and the like; a fan for blasting air in order to exchange heat between a refrigerant within the outdoor heat exchanger and the open air; a fan motor for driving the fan; and a control circuit for controlling the above composing parts.

The indoor units12,13and14respectively include the following composing parts (none of which are shown): that is, a portion of a refrigerant circuit for an indoor heat exchanger and the like; a fan for blasting air in order to exchange heat between a refrigerant within the indoor heat exchanger and the open air; a fan motor for driving the fan; and a control circuit for controlling the above composing parts.

The refrigerant circuit of the outdoor unit11is connected to the refrigerant circuits of the indoor units12,13and14through an outdoor unit side pipe110and indoor unit side pipes120,130and140respectively. Between the outdoor unit11and the multiple indoor units12,13and14, there is interposed a refrigerant distribution unit15which is used to distribute refrigerants uniformly refrigerant from the outdoor unit side pipe110to the indoor unit side pipes120,130and140.

The refrigerant distribution unit15shown inFIG. 2includes: a pipe unit2for connecting the outdoor unit side pipe110to the respective indoor unit side pipes120,130and140to distribute the refrigerant from the outdoor unit side pipe110to the indoor unit side pipes120,130and140; a main body150for storing the pipe unit2; and an electric component box3including a control portion for controlling the electric components that are mounted on the pipe unit2.

The refrigerant distribution unit15is horizontally hanged from and fixed to an indoor ceiling or the like by multiple pieces of ceiling-mounting brackets62. And, in order to adjust to the environment of the ceiling which is liable to be hot and humid, especially, the inside of the main body150is structured such that it has an insulating property which can prevent it against the influence of temperature variations and also that it is sealed in order to prevent it against the influence of humidity.

The pipe unit2, as shown inFIGS. 2, 3, 4 and 5, includes a refrigerant pipe21to be connected to the outdoor unit side pipe110, a branch portion25to be stored into the main body150, and branch refrigerant pipes22,23and24respectively to be connected to their associated indoor unit side pipes120,130and140.

The refrigerant pipe21includes a gas pipe210and a liquid pipe211. The gas pipe210includes a gas pipe joint212in the vicinity of the refrigerant distribution unit15, while the liquid pipe211includes a liquid pipe joint213in the vicinity of the refrigerant distribution unit15. Due to the gas pipe joint212and liquid pipe joint213, the gas pipe210and liquid pipe211can be connected to and removed from the outdoor unit side pipe110.

The gas pipe210and liquid pipe211are arranged horizontally and are spaced 40 mm or more from each other, while they can be stored into the main body150from a refrigerant pipe receiving portion151.

The branch refrigerant pipes22,23and24include branch gas pipes220,230and240and branch liquid pipes221,231and241, respectively. The branch gas pipes220,230and240include branch gas pipe joints222,232and242in the vicinity of the refrigerant distribution unit15, respectively; and the branch liquid pipes221,231and241include branch liquid pipe joints223,233and243on a side of the refrigerant distribution unit15, respectively. Due to the branch gas pipe joints222,232and242and branch liquid pipe joints223,233and243, the branch refrigerant pipes22,23and24can be connected to and removed from the indoor unit side pipes120,130and140, respectively.

The branch gas pipes220,230and240are respectively formed to have a linear shape. The branch liquid pipes221,231and241are respectively disposed downwardly of and spaced a given distance from the branch gas pipes220,230and240, and are bent upwardly on the side of the main body150; after then, they are respectively bundled together by their associated rubber bushes26such that the branch gas pipe220and branch liquid pipe221are formed into a unified body, the branch gas pipe230and branch liquid pipe231are formed into a unified body, and the branch gas pipe240and branch liquid pipe241are formed into a unified body. Also, the branch refrigerant pipes22,23and24are arranged horizontally and are spaced 40 mm or more from each other, while the branch refrigerant pipes22,23and24can be stored into the main body150from a branch refrigerant pipe receiving portion152.

The branch portion25of the pipe unit2shown inFIG. 4includes: a branch pipe27which makes the gas pipe210branch to the branch gas pipes220,230and240; branch gas pipe temperature sensors224,234and244provided on the branch gas pipes220,230and240respectively; a flow divider28for diverging the refrigerant of the liquid pipe211to the branch liquid pipes221,231and241; electronic expansion valves225,235and245respectively for adjusting amounts of the refrigerants flowing through their associated branch liquid pipes221,231and241; branch liquid pipe temperature sensors226,236and246which are disposed nearer to the indoor units12,13and14than the electronic expansion valves225,235and245respectively; and, an on/off valve29for bypassing the refrigerant from the branch pipe27to the flow divider28.

To the branch gas pipe temperature sensors224,234and244and branch liquid pipe temperature sensors226,236and246, there are connected signal lines for transmitting the detected results of the sensors224,234,244,226,236and246to the control substrate30of the electric component box3. To the electronic expansion valves225,235and245as well as to the on/off valve29, there are connected wires which are used to drive the valves225,235,245and29respectively. The signal lines and wires are bundled together to provide a cable80, while the cable80is connected to the control substrate30of the electric component box3.

The main body150shown inFIG. 5is structured such that the pipe unit2can be held by a seal case4, an insulator case5and a case6which are arranged sequentially in this order from inside.

The seal case4is formed of synthetic resin and includes an upper seal case40and a lower seal case41which are divided vertically along centers of pipe diameters of the horizontally extending refrigerant pipe21and branch refrigerant pipes22,23and24.

The upper seal case40shown inFIGS. 3, 4 and 5includes a storage portion400for storing the branch portion25of the pipe unit2, and an edge portion401formed on the periphery of the storage portion400for keeping the seal property thereof.

In the edge portion401, specifically, on the refrigerant pipe receiving portion151for receiving the refrigerant pipe21and also on the branch refrigerant pipe receiving portion152for receiving the branch refrigerant pipes22,23,24, there are provided (there are extended continuously therefrom) pipe mounting portions402which respectively draw a semi-circular shape along the pipes. On the semi-circular right and left end portions of the pipe mounting portion402, there are erected anchors405which are respectively used to receive screws (which will be discussed later).

Also, there is also formed a cable draw-out portion403which has a semi-circular shape and is used to draw out the cable80. Further, in the edge portion401, there are provided projecting ribs404which extend in two lines in such a manner as to surround the storage portion400. On the projecting ribs404, there are bonded insulating seals44(seeFIG. 8) respectively.

Of the two-lined projecting ribs404, the projecting rib404disposed outside includes the anchors405which are respectively erected and are spaced from each other for receiving screws (which will be discussed later). The anchors405are further erected on the four corners of the edge portion401as well.

The lower seal case41includes a storage portion410for storing the branch portion25of the pipe unit2, and an edge portion411which is formed on the periphery of the storage portion410and is used to keep the sealing property of the storage portion410.

In the edge portion411, specifically, in such portions of the edge portion411as are to be contacted with the refrigerant pipe21and branch refrigerant pipes22,23and24, there are continuously formed pipe mounting portions412which respectively have a semi-circular shape; and also, there are continuously formed cable draw-out portions413which respectively have a semi-circular shape. Also, in the edge portion411, there are formed recessed ribs412which are used to receive the projecting ribs404respectively. Further, there are formed screw holes415which can be engaged with their associated anchors405.

The insulator case5is formed of highly heat-resisting styrene foam and has a constant thickness over the entire area thereof in order to enhance its heat-resisting property.

Such portions of the insulator case5as correspond to the refrigerant pipe receiving portion151and branch refrigerant pipe receiving portion152are respectively projected out in a cylindrical manner; and the insulator case5is divided into an upper insulator case50and a lower insulator case51along the centers of the pipe diameters of the refrigerant pipe21and branch refrigerant pipes22,23and24.

A shape of the inside of the upper insulator case50is formed to fit the outer shape of the upper seal case40. Also, the upper insulator case50includes a cable draw-out recessed portion500which is formed to fit the cable draw-out portion403of the upper seal case40. And, in the left side face of the upper insulator case50when viewed from the outdoor unit side, there is formed a cable side face recessed portion501which is used to introduce the cable80which has been drawn out, into the electric component box3.

A shape of the inside the lower insulator case51is formed to fit the outer shape of the lower seal case41. Also, the lower insulator case51includes a cable draw-out recessed portion510which is formed to fit the cable draw-out portion413of the lower seal case41. And, in the left side face of the lower insulator case51when viewed from the outdoor unit side, there is formed a cable side face recessed portion511which is used to introduce the cable80which has been drawn out, into the electric component box3. Further, in the bottom face of the lower insulator case51, there is formed a bottom face recessed portion512for the cable.

The case6, which constitutes the contour of the main body150, can be formed by bending a metal sheet. And, the case6includes an upper case60and a lower case61.

The upper case60has a box-like shape. Specifically, the upper case60includes an outdoor unit side lateral portion60a, an indoor unit side lateral portion60bwhich is disposed opposed to the outdoor unit side lateral portion60a, a first lateral portion60cdisposed on the left when the upper case60is viewed from the outdoor unit11side, and a second lateral portion60dwhich is situated on the right and is disposed opposed to the first lateral portion60cc.

The outdoor unit side lateral portion60aand indoor unit side lateral portion60brespectively include upper insulator receiving portions600which are formed by cutting out the lateral portions60aand60bin a semi-circular shape to fit the cylindrical shape of the upper insulator case50and each of which has such a length as extends to the centers of the pipe diameters of the refrigerant pipe21and branch refrigerant pipes22,23and24. And, in the right and left end portions of the lateral portions60aand60b, there are formed screw holes into which there can be engaged the ceiling-mounting brackets62for hanging down the refrigerant branch unit2from the ceiling; and, in the central portions of the lateral portions60aand60b, there are formed screw holes into which there can be engaged pipe hanging bracket63which will be discussed later.

The first lateral portion60cand second lateral portion60drespectively have such a length as reaches the bottom face of the main body; and, the first lateral portion60cand second lateral portion60drespectively include, at the four upper and lower portions of the right and left end portions thereof, electric component box securing holes601(hereinafter described as securing holes601) into which there can be engaged their associated electric component box securing pawls320(hereinafter described as securing pawls320, which will be discussed later) to thereby mount the electric component box3onto the case6. Downwardly of the positions of the securing holes601formed in the lower portions of the right and left ends portions, there are provided dowels602which can be removably secured to dowel holes612(which will be discussed later). Also, downwardly of the dowels602, there are formed screw mounting portions603which are extended up to the bottom surface of the case6.

In the first lateral portion60c, there is formed a first cable draw-out slot604constituted of a cut-out groove which exists on the outdoor unit11side and extends up to the vicinity of the ceiling surface of the case6; and, the first cable draw-out slot604is cut through from the bottom thereof to the top. In the second lateral portion60dshown inFIG. 6, there is formed a second cable draw-out slot605constituted of a cut-out groove which exists on the outdoor unit11side and extends up to the middle portion of the second lateral portion60d. In such portions of the first and second lateral portions60cand60das exist near to the ceiling surface60eand in the vicinity of the first and second cable draw-out slots604and605, there are formed cable draw-out slot cover holes606to which cable draw-out slot covers64(which will be discussed later) can be secured.

The lower case61has a U-like shape and includes an outdoor unit side lateral portion61a, an indoor unit side lateral portion61b, and a bottom face portion61e.

The outdoor unit side lateral portion61aand indoor unit side lateral portion61brespectively include upper insulator receiving portions610which are formed by cutting out the respective portions61aand61bin a semi-circular shape to fit the cylindrical shape of the lower insulator case51and also which respectively have a length reaching the centers of the pipe diameters of the refrigerant pipe21and branch refrigerant pipes22,23and24.

A metal plate, which is used to form the lower case61, includes flange portions611which are formed by extending two end portions of the bottom face portion61e, bending and spot welding the flange portions611to the outdoor unit side lateral portion61aand indoor unit side lateral portion61b.

The flange portions611respectively include dowel holes612to which, when the lower case61is assembled, there can be removably secured the dowels602. In such portions of the bottom face portion61eas exist near to the dowel holes612, there are formed holes for screws.

The electric component box3shown inFIGS. 5 and 6includes a control substrate30for controlling the refrigerant branch unit15, an electric component box main body31, two mounting plates32, and an electric component box cover33.

The electric component box main body31is constituted of a metal plate having a U-like shape; and, within the U-like shape, there are disposed the control plate30and multiple terminal bases34. In a portion of the electric component box main body31, there is formed a cable guide hole310which is used to guide the cables80; and, in such inside portion of the electric component box main body31as exists near to the cable guide hole310, there is provided a cable guide311which is used to bundle together the cables80and guide them to the control substrate30.

The mounting plates32respectively have a rectangular shape, include securing pawls320so formed in the two upper and lower portions thereof as to be bent inwardly symmetrically, and are welded to the right and left portions of the outside of the electric component box main body31.

The refrigerant branch unit15may be assembled in such a manner that, when compared with its installing state where it is hanged down from the ceiling, it is turned upside down. First, the upper case60is placed with its ceiling face portion60efacing downward and then the upper insulator case50is superimposed on top of the inside of the upper case60. The upper insulator case50is supported by the insulator receiving portion600of the upper case60.

Next, as shown inFIGS. 4 and 7, the upper seal case40is fitted into the upper insulator case50. And, the pipe unit2is fitted into the pipe mounting portions402of the upper seal case40. Such portions of the gas pipe210, liquid pipe211and branch refrigerant pipes22,23and24of the pipe unit2as are wound by the rubber bushes26are fitted into the pipe mounting portions402, and pipe holders91are fastened and fixed to the pipe mounting portions402from above the rubber bushes26using screws.

Next, as shown inFIGS. 7 to 9, for the gas pipe210and the pipe mounting portion402of the branch refrigerant pipe23, a pipe hanging bracket63with its upper end engaged with the upper case60is so provided as to extend over the upper insulator case50down to the lower end portion of the pipe holder91. And, the pipe hanging bracket63and pipe holder91are fastened together with a screw and are then fixed to the upper seal case40.

The cables80are bundled together by a binding tool82and are drawn out to the outside from the cable receiving portion403of the upper seal case40.

According to the above-mentioned configuration, the pipe unit2is fixed to the pipe mounting portion402of the upper seal case40by the pipe holder91and pipe hanging bracket63. The upper portion of the pipe hanging bracket63is fixed to the upper case60and the lower portion of the pipe hanging bracket63extends down to the lower end of the pipe holder91. Thus, the branch portion25, electronic expansion valves225,235and245, etc. respectively constituting the pipe unit2are exposed to the outside by removing the lower case60, lower insulator case51and lower seal case41. Therefore, it is possible to carry out maintenance on the pipe unit2without taking the main body150to pieces.

Next, the seal case securing hole410of the lower seal case41is inserted in such a manner that the seal case securing hole410can be engaged with the seal case securing pawl406projected from the upper seal case40. In the case that the upper seal case40and lower seal case41are engaged with each other, the recessed rib414of the lower seal case41is closely contacted with the projecting rib404of the upper seal case40through the insulating seal44with no gap between the projecting rib404and the recessed rib414. Next, screws94are engaged through screw holes415with the anchors405which are respectively provided in the multiple portions of the edge portion401.

As shown inFIG. 7, the pipe mounting portion412of the lower seal case41is structured such that the pipe mounting portion412can be fitted with the rubber bushes26of the gas pipe210and liquid pipe211respectively stored in the upper seal case40but is prevented from covering the pipe mounting portion402of the upper seal case40. Thus, the upper seal case40and lower seal case41are superimposed on top of each other with no gap between them, whereby the interior portion of the seal case4can be kept hermetically sealed. Owing to the hermetically sealed state of the interior portion of the seal case4, the branch portion25of the pipe unit2stored within the main body150is prevented from touching the air existing on the outside, thereby being able to prevent drain water from being generated.

Next, the lower insulator case51is placed on top of the lower seal case41. In this case, besides the lower insulator case51, the screws94, which have been engaged with the pipe holder91and pipe hanging bracket63, are also covered with the lower insulator case51. This can also prevent water or like from touching the screws94.

The electric component box3may be mounted onto any one of the first and second lateral portions60cand60dof the upper case60. When mounting the electric component box3onto the second lateral portion60dwhich is the right lateral face when viewed from the outdoor unit side, as shown inFIG. 10A, the cables80are guided along the draw-out recessed portion500of the upper insulator case and the draw-out recessed portion510of the lower insulator case to the first cable bottom face recessed portion512. The cables80, which have been guided to the cable bottom face recessed portion512, are turned back at the cable bottom face recessed portion512and are drawn out from the second cable draw-out slot605to the outside of the main body150.

The thus drawn-out cables80, as shown inFIG. 6, are guided from the cable guide hole310of the electric component box main body31into the electric component box3, are bundled to the electric component box main body31by the cable guide311, and are then connected to multiple connectors (not shown) which are provided on the control substrate30of the electric component box3.

The electric component box main body31, which has been connected to the cables80, inserts the securing pawl320of the mounting plate32welded to the electric component box main body31into the securing hole601of the upper case60. In this case, the securing pawl320, specifically, the upper pawl thereof is held in a state where the upper pawl is hanging down, whereby the electric component box3is provisionally fixed by the securing pawl320. Next, the electric component box3is engaged from inside of the electric component box main body31with the upper case60using screws. As a result, the electric component box3, which is provisionally fixed by the securing pawl320, is fixed. Then, the electric component box cover33is placed on top of the electric component box3.

Also, as shown inFIG. 10B, when mounting the electric component box3onto the first lateral portion60cwhich is situated on the left when the upper case60is viewed from the outdoor unit side, the electric component box main body31is turned upside down and the securing pawl320of the mounting plate32is inserted into the securing hole601of the upper case6. Since the electric component box main body31is turned upside down, the cable guide hole310is moved to the ceiling side.

The cables80, which have been guided to the cable bottom face recessed portion512, are moved over the cable bottom face recessed portion512, are moved through the cable side face recessed portions501and511, are drawn out from above the first cable draw-out slot604to the outside of the main body150, and are guided from the cable guide hole310of the electric component box main body31into the electric component box3.

According to the mounting method, for example, even when moving the electric component box3from one place to the other place according to the site where the is electric component box3mounted in the air conditioner is installed, the electric component box3can be moved simply with the cables80remaining connected.

Next, a cable draw-out slot cover64is mounted onto any one of the first cable draw-out slot604and second cable draw-out slot605which are formed in the portion of the upper case60where the electric component box3is not installed. Since the cable draw-out slot cover64is formed longer than the cable draw-out slot604, and also since cable draw-out cover holes606are formed at the symmetric positions of the first and second lateral portions60cand60d, the cable draw-out slot cover64can be mounted onto any one of the lateral portions. The upper pawls of the cable draw-out slot cover64are secured to the cable draw-out slot cover holes606, and then the cable draw-out slot cover64is engaged with the upper case60using screws. According to this configuration, it is possible to hide the cable draw-out cover holes606from the outside. Therefore, the appearance of the upper case can be enhanced and also the invasion of dust into the inside of the upper case can be prevented.

Next, the lower case61is assembled to the upper case60in such a manner as shown inFIG. 11A. In this case, the dowel602provided on the upper case60is secured to a dowel hole612formed in the lower case61, thereby fixing the lower case61provisionally. Next, the screws94are engaged with the screw mounting portion603of the bottom face61eof the upper case60to thereby fix the upper case60and lower case61to each other.

When carrying out maintenance on the pipe unit2, the screws94engaged with the screw mounting portion603are removed. In this case, even when the screws94are removed, the lower case61is fixed provisionally because of engagement of the dowel602into the dowel hole612. Therefore, there is no fear that the lower case61can fall down unexpectedly.

Also, the base portion602aof the dowel602provided on the upper case60has a round surface (a curved surface). When a portion of the round surface (curved surface) is contacted with the peripheral edge of the dowel hole612, there can be formed a slight gap between such portions of the upper case60and lower case61as exist near to the dowel602. Due to this configuration, when the dowel hole612is removed from the dowel602by an operator placing his or her fingers on the lower case61, the dowel hole612can be removed smoothly and thus the lower case61can be removed easily.

As described above, the structure capable of provisionally fixing the lower case61to the upper case60in a removable manner is a structure which includes the dowel602provided on the upper case60and the dowel hole612formed in the lower case61. That is, the present structure is characterized in that it is possible to fix the lower case61provisionally without using any new parts.

Here, the dowel602and dowel hole612are not limited to the above-mentioned structures. And, there may also be employed a structure in which the dowel hole612is formed in the upper case60and the dowel602is provided on the lower case61.

As has been described heretofore, according to the exemplary embodiment, since the pipe unit2is fixed to the upper case60by the pipe hanging metal fittings63, it is possible to provide a refrigerant branch unit for use in an air conditioner, in which, when carrying out maintenance on the branch portion25, electronic expansion valve225,235,245and the like which constitute the pipe unit2, by removing the lower case61, lower insulator case51and lower seal case41with the main body150remaining mounted, the above-mentioned parts of the pipe unit2can be maintained without taking the main body150to pieces.