Patent Description:
A well-know type of washing machine is a washing machine having a tub with an introduction hole formed at the front and a drum rotatably provided in the tub. In order to prevent water leakage from the tub, an annular gasket is installed along the circumference of the laundry receiving hole of the tub. Nozzles for spraying water circulating by a circulation pump into the drum are formed in the gasket.

A conduit for guiding water pumped by the circulation pump to the circulation nozzles is coupled to the circumference of the gasket. A passage for guiding circulating water, pumped by the circumation pump, along a predetermined path is formed in the conduit, and a plurality of ports extends from the passage to supply the circulating water to the circulation nozzles.

This type of conduit is generally formed by extrusion molding. <FIG> schematically illustrates molds assembled according to a conventional manufacturing method (extrusion molding), and <FIG> illustrates an opened-up state of the mold.

As shown in <FIG>, in order to extrude a conduit in the aforementioned shape by the convensional method, a pair of molten parison sheets <NUM> and <NUM> are assembled with a left mold <NUM> and a right mold <NUM> therebetween, and air is injected into a space between the pair of parison sheets <NUM> and <NUM>. The parison expands by the injected air and is thereby molded into the shape of a cavity (corresponding to the exterior appearance of the conduit) formed in the molds <NUM> and <NUM>.

However, after a molded object is extracted from the molds <NUM> and <NUM>, this method requires a process of cutting the parison sheets or process an engaged portion of the parison sheets in order to completely extract the engaged portion of the both molds <NUM> and <NUM> from the parison sheets. In addition, there is a possibility of a leakage due to strap in a mold step and a parting line.

In addition, there is a problem that large part of the parison is wasted, as shown in a portion marked with oblique lines in <FIG>.

<CIT> relates a laundry washing machine with enhanced detergent activation. The laundry washing machine comprises a washing tub containing a rotatable drum, a detergent compartment in fluid communication with a liquid source, a supply pipe for liquid and detergent to flow into the tub, a recirculation circuit for drawing liquid from the bottom of the tub and feed it back into said drum, a control and monitoring unit designed to cause liquid and detergent to flow into the tub and to spray the interior of the drum with recirculated liquid through a plurality of nozzles.

An object of the present invention is to provide a washing machine with an improved process of manufacturing a conduit, which supplies circulating water to a plurality of circulation nozzles formed in a gasket, and a manufacturing method for the conduit.

A second object of the present invention is to solve the conventnional problem that water leaks due to manufacturing defects.

A third object of the present invention is to reduce a waste of resources in a manufacturing process for the conduit.

The present invention provides a washing machine, including: a casing having an introduction hole formed therein; a tub having an entrance opening formed therein to communicate with the introduction hole; a drum rotatably disposed in the tub; a pump configured to pump water discharged from the tub; an annular gasket allowing the introduction hole and the entrance opening of the tub to communicate with each other, and having a plurality of circulation nozzles configured to spray water into the drum; and a conduit fixed to the gasket, and guiding the water pumped by the pump to the plurality of circulation nozzles.

The conduit may include a transport pipe configured to guide water introduced through an inlet port and pumped by the pump, and a plurality of nozzle water supply ports configured to distributing the water guided along the transport pipe to the plurality of circulation nozzles.

An inlet port may be formed in the transport pipe to allow the water pumped by the pump to inflow through the inlet port. The transport pipe may bidirectionally divide the water introduced through the inlet port to be guided along the circumferential direction. The plurality of circulation nozzles are disposed in the transport pipe.

A plurality of communication holes respectively communicating with the plurality of nozzle water supply ports may be formed on an inner diameter part of the transport pipe, and a port connection groove with an entrance portion of each of the plurality of nozzle water supply ports to be inserted thereinto may be formed on a circumference of each of the plurality of communication holes. The entrance portion of each of the plurality of nozzle water supply ports may be bonded to the inner diameter part within the port connection groove.

The entrance portion of each of the plurality of nozzle water supply ports may include a flange that extends outwardly in a radial direction from an entrance thereof through which water discharged from a corresponding communication hole among the plurality of communication holes is introduced. The port connection groove may be formed in a shape corresponding to a shape of the flange, thereby allowing the flange to be bonded to the inner diameter part within the port connection groove.

The plurality of circulation nozzles may be provided in an inner circumferential part of the annular gasket, and the transport pipe in the conduit may be disposed in an outer circumferential part of the gasket, and the plurality of nozzle water supply ports may pass through the gasket from the outer circumferential part to the inner circumferential part to be respectively connected to the plurality of circulation nozzles.

The transport pipe may guide the water introduced through the inlet port to be divided bidirectionally.

The transport pipe and the plurality of water supply ports may be formed of different materials.

The present invention provides a method of manufacturing a conduit supplying circulating water to a plurality of circulation nozzles formed in a gasket of a washing machine, the method including: positioning a plurality of nozzle water supply ports in a cavity of a lower mold; forming a molten parison having a hollow opening, by extruding a raw material; positioning the parison in the cavity of the lower mold; assembling an upper mold and the lower mold; and injecting gas into the hollow opening.

A extrusion temperature of the parison may be from <NUM>° C to <NUM>°. A temperature of the parison may be from <NUM>° C and <NUM>° C at a time when the injecting of the gas into the hollow opening starts.

The method may further include: opening up the upper mold and the lower mold; extracting a molded object, in which the molten parison and the plurality of nozzle water supply ports are engaged, from the cavity; and removing the molten parison from the plurality of nozzle water supply ports.

The method may further include comprising processing an inlet port communicating with the hollow opening of the parison in the extracted molded object.

The method may further include, before the positioning of the parison in the cavity of the lower mold, positioning an inlet port in the cavity of the lower mold.

Advantages and features of the present invention and methods for achieving them will be made clear from the embodiments described below in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

<FIG> is a perspective view of a washing machine according to an embodiment of the present invention. <FIG> is a view illustrating part of the washing machine shown in <FIG>. <FIG> illustrates an assembly of a gasket and a conduit. <FIG> is a cross-sectional view taken along line IV-IV in <FIG>. <FIG> illustrates a conduit. <FIG> is an enlarged view of portion A in <FIG>, and <FIG> is an enlarged view of portion B in <FIG>.

Referring to <FIG>, a casing <NUM> forms an exterior appearance of a washing machine, and an introduction hole <NUM> through which laundry is to be loaded is formed on a front surface of the casing <NUM>. The casing <NUM> may include: a cabinet <NUM> having an open front surface, a left surface, right surface, and a rear surface; and a front panel <NUM> coupled to the open front surface of the cabinet <NUM> and having the introduction hole <NUM> formed therein.

The cabinet <NUM> may have an open bottom surface and an open top surface, and a horizontal base <NUM> supporting the washing machine may be coupled to the bottom surface of the cabinet <NUM>. In addition, the casing <NUM> may further include a top plate <NUM> covering the open top surface of the cabinet <NUM>, and a control panel <NUM> disposed over the front panel <NUM>.

A tub <NUM> for containing water may be disposed in the casing <NUM>. An entrance opening is formed on a front surface of the tub <NUM> so that laundry can be introduced. The cabinet <NUM> and the tub <NUM> are connected by the annular gasket <NUM> and thereby a passage for entrance and exit of laundry may be formed in a section from the entrance opening of the tub <NUM> to the introduction hole <NUM>.

The door <NUM> for openingand closing the introduction hole <NUM> may be rotatably coupled to the casing <NUM>. The door <NUM> may include: a door frame <NUM> being open at an approximately central portion thereof and rotatbly coupled to the front panel <NUM>; and a window <NUM> installed at the open central portion of the door frame <NUM>. The window <NUM> may be in a shape convex rearward, in which at leaat a portion of the window <NUM> is positioned in an area surrounded by an inner circumferential surface of the gasket <NUM>.

A front end and a rear end of the basket <NUM> are annular, and the gasket <NUM> is in a tubular shape extending from the front end to the rear end. The front end of the gasket <NUM> is fixed to the casing <NUM>, and the rear end of the gasket <NUM> is fixed to the circumference of the entrance opening of the tub <NUM>. The gasket <NUM> may be formed of a flexible or elastic material. The gasket <NUM> may be formed of rubber or synthetic resin. When the door <NUM> is closed, the front end of the gasket <NUM> is brought into contact with a rear surface of the door <NUM>, thereby preventing that water leaks from the tub <NUM> through an entrance opening of the gasket <NUM>.

Hereinafter, a position defines the inside of the tubular shape of the gasket <NUM> is referred to as an inner circumferential part (or an inner circumferential surface) of the gasket <NUM>, and a portion opposite thereto is referred to as an outer circumferential part (or an outer circumferential surface) of the gasket <NUM>.

The drum <NUM> may be rotatably provided in the tub <NUM>. The drum <NUM> is to receive laundry and disposed with an entrance opening hereof positioned at the front, the entrance opening through which laundry is to be introduced, and the drum <NUM> is rotated about an approximately horizontal axis. In this case, "horizontal" does not refer to the a mathematical definition thereof. That is, even in the case where the axis is inclined at a predetermined angle relative to a horizontal state, the axis may be considered substantially horizontal if the axis is more like in the horizontal state than in a vertical state. To allow water to flow from the tub <NUM> to the drum <NUM>, a plurality of through-holes <NUM> may be formed in the drum <NUM>.

A plurality of lifter 32a may be provided on an inner side surface of the drum <NUM>. The plurality of liters 32a may be disposed at a predetermined angle relative to the center of the drum <NUM>. When the drum <NUM> is rotated, laundry repeatsedly undergoes an operation of being lifted by the lifter 32a and falling.

A driving unit for rotating the drum <NUM> is further provided. A driving shaft (not shown) to be rotated by the driving unit may penetrate the rear of the tub <NUM> and be thereby coupled to the drum <NUM>.

Preferably, the driving unit includes a direct drive wash motor, and the wash motor may include a stator fixed to the rear of the tub <NUM>, and a rotor rotating by a magnetic force applying in relation with the stator. The driving shaft may rotate integrally with the rotor.

The tub <NUM> may be supported by a damper <NUM> installed at the base <NUM>. Vibration of the tub <NUM> caused by rotation of the drum <NUM> is attenuated by the damber <NUM>. In some embodiments, although not illustrated, a hanger (e.g., a spring) for hanging the tub <NUM> to the casing <NUM> may be further provided.

There may be provided at least one water supply hose (not shown) guiding water introduced from an external water source such as a water tap or the like, and a water supply unit <NUM> for controlling the water supplied through the at least one water supply hose to flow to at least one water supply pipe 34a, 34b, or 34c which will be described later.

A dispenser <NUM> for supplying additives such as detergent for washing, fabric softner, and the like into the tub <NUM> or the drum <NUM> may be provided. The additives are contained in the dispenser <NUM> separately by types thereof. The dispenser <NUM> may include a detergent container (not shown) for containing a detergent for washing, and a fabric softer container (not shown) for containing a fabric softner.

At least one water supply pipe 34a, 34b, or 34c for selectively guiding water, supplied from the water supply unit <NUM>, to each container of the dispenser <NUM> may be provided. The water supply unit <NUM> may include at least one water supply valve for regulating each of the at least one water supply pipe 34a, 34b, or 34c.

The at least one water supply pipe 34a, 34b, or 34c may include a first water supply pipe 34a for supplying cold water supplied through a cold water supply hose to the detergent container, a second water supply pipe 34b for supplying water supplied through the cold water supply hose to the fabric softer container; and a third water supply pipe 34c for supplying hot water supplied through a hot water supply hose to the detergent container.

The gasket may include a direct water nozzle <NUM> for spraying water into the drum <NUM>, and a direct water supply pipe <NUM> for guiding water supplied from the water supply unit <NUM> to the direct water nozzle <NUM>. The direct water nozzle <NUM> may be a whirl nozzle or a spray nozzle, but aspects of the present invention are not necessarily limited thereto.

Water discharged from the dispenser <NUM> may be supplied to the tub <NUM> through a water supply bellows <NUM>. A water supply hole (not shown) connected to the water supply bellows <NUM> may be formed on a side surface of the tub <NUM>.

A drain hole for draining water may be formed in the tub <NUM>, and a drain bellows <NUM> may be connected to the drain hole. A pump <NUM> for pumping water drained from the tub <NUM> through the drain bellows <NUM> may be provided. A drain valve (not shown) for regulating the drain bellows <NUM> may be further provided. The water drained through the drain bellows <NUM> may be drained to the outside of the washing machine through a drain pipe (not shown).

The pump <NUM> may selectively perform a draininig function of puming water drained through the drain bellows <NUM> to the drain pipe, and a circulating function of pumping water to a circulation pipe <NUM>. There are already various well-known technologies for selectively implementing the draining function and the circulating function with one pump, and thus, a detailed description thereof is herein omitted.

However, aspects of the present invention are not limited thereto, and a circulation pump connected to the circulation pipe <NUM> to circulate water and a drain pump connected to the drain pipe to drain water may be provided separately.

Hereinafter, circulating water pumpbed by the pump <NUM> to be guided along the circulation pipe <NUM> may be referred to as circulating water.

A flow rate (or water discharge pressure) of the pump <NUM> is variable. To do so, a pump motor rotating an impeller may be a variable speed motor of which speed of rotation can be controlled. The pump motor may be appropriately a Brushless Direct Current Motor (BLDC) motor, but aspects of the present invention are not necessarily limited thereto. A driver for controlling speed of the pump motor may be further provided, and the driver may be an inverter driver. The inverter driver may convert AC power into DC power and input the converted power to the motor at a target frequency.

A controller (not shown) for controlling the above-described pump motors may be further provided. The controller may include a Proportional-Integral (PI) controller, a Proportional-Integral-Derivative (PID) controller), and the like. The controller may receive an output value (e.g., an output current) of a pump motor, and control an output value of the driver based on the received output value of the pump motor so as to control the number of times of rotation of the pump motor to follow a preset target number of times of rotation.

A plurality of circulation nozzles <NUM> for spraying water (circulating water) into the drum <NUM> is provided at the gasket <NUM>. The plurality of circulation nozzles <NUM> may be formed in the inner circumferential part of the gasket <NUM>. When the gasket <NUM> is viewed from the front, the plurality of circulation nozzles <NUM> may be disposed such that two nozzles are respectively and symmetrically positioned on the left side and the right side of the gasket <NUM>.

Out of two circulation nozzles <NUM> provided on one side of the gasket <NUM>, a first circulation nozzle <NUM> (a circulation nozzle connected to a nozzle water supply port 72b which will be described later) at a lower position sprays circulating water upward, whilst a second circulation nozzle <NUM> (a circulation nozzle connected to a nozzle water supply port 72a which will be described later) at an upper position sprays circulating water downward.

A conduit <NUM> guides circulating water, pumped by the pump <NUM>, to the plurality of circulation nozzles <NUM>, and the conduit <NUM> is fixed to the gasket <NUM>. The conduit <NUM> incluldes: a transport pipe <NUM> for guiding water introduced through an inlet port <NUM>; and a plurality of nozzle water supply ports 72a, 72b, 72c, and 72d for distributing the water guided along the transport pipe <NUM> into the plurality of circulation nozzles <NUM> provided at the gasket <NUM>. The transport pipe <NUM> may guide the water introduced through the inlet port <NUM> by dividing the water in both directions. The transport pipe <NUM> may be formed in a shape corresponding to the exterior appearance of the gasket <NUM>, thereby enabled to guide circulating water in an approximately circumferential direction (or a direction that extends along the annular outer circumferential part of the gasket <NUM>).

The transport pipe <NUM> forms a channel along which circulating water flows, and the transport pipe <NUM> is connected to the exit of the inlet port <NUM>. The transport pipe <NUM> may include: a first pipe part 71a for guiding a first subflow Fl1 of circulating water, introduced through the inlet port <NUM>, in a first direction; and a second pipe part 71b for guiding a second subflow FL2 of the circulating water, introduced through the inlet port <NUM>, in a second direction. The first pipe part 71a and the second pipe part 71b may be symmetric to each other. In each of the first pipe part 71a and the second pipe part 71b, one end through which circulating water is introduced through the inlet port <NUM> is open and the other end is blocked.

The conduit includes a plurality of nozzle water supply ports 72a, 72b, 72c, and 72d protruding from the transport pipe <NUM>. The plurality of nozzle water supply ports 72a, 72b, 72c, and 72d is formed at positions respectively corresponding to the plurality of circulation nozzles <NUM>. In the present embodiment, as shown in <FIG>, the plurality of nozzle water supply ports 72a, 72b, 72c, and 72d are disposed such that two nozzle water supply ports are respectively positioned on the left side and the right side of the the inlet port <NUM>. However, aspects of the present invention are not limited thereto, and the number of the circulation nozzles <NUM> and the number of nozzle water supply ports 72a, 72b, 72c, and 72d corresponding thereby may vary.

Meanwhile, each of the nozzles <NUM> may include a nozzle inlet pipe <NUM> protruding inwardly from the inner circumferential part of the gasket <NUM> in a radial direction, and a nozzle head <NUM> connected to the nozzle inlet pipe <NUM>. The nozzle inlet pipe <NUM> has a port through-hole has one end, which is connected to the inner circumferential part of the gasket <NUM> and has a port through hole formed therein, and the other end, which is connected to a corresponding nozzle <NUM>.

The gasket <NUM> may include a plurality of port insertion pipes <NUM> protruding from the outer circumferential part of the gasket <NUM> at positions respectively corresponding to nozzle inlet pipes <NUM>. Each of the port insertion pipes <NUM> communicates with a corresponding nozzle inlet pipe <NUM>, and each of the nozzle water supply ports 72a, 72b, 72c, and 72d is inserted into a corresponding port insertion pipe <NUM>. Circulating water discharged from the nozzle water supply ports 72a, 72b, 72c, and 72d is supplied to the nozzle heads <NUM> through the nozzle inlet pipes <NUM>.

In the transport pipe <NUM>, at least one first nozzle water supply port 71a or 72b is formed on the first duct 71a along which the first subflow FL1 is guided. The first nozzle water supply ports 72a and 72b respectively discharges circulating water to the circulation nozzles <NUM> (circulation nozzles positioned on the left side when the gasket <NUM> is viewed from the front in the present embodiment).

The first pipe part 71a guides circulating water in a first direction (a clockwise direction when viewed from the front in the present embodiment) from the exit of the connection port <NUM> in a channel formed by the transport pipe <NUM>.

Similarly, in the transport pipe <NUM>, at least one nozzle water supply port 72c or 72d is formed on the second pipe part 71b along which the second subflow FL2 is guided. The second nozzle water supply ports 72c and 72d respectively discharge circulating water to the second circulation nozzles <NUM> (circulation nozzles positioned on the right side when the gasket <NUM> is viewed from the front in the present embodiment).

The second pipe part 71b guides circulating water in a second direction (a counter-clockwise direction when viewed from the front in the present invention) from the exit of the connection port <NUM> in the passage formed by the transport pipe <NUM>.

The transport pipe <NUM> is disposed in the outer circumferential part of the gasket <NUM>, and the plurality of nozzle water supply ports 72a, 72b, 72c, and 72d may penetrates the gasket <NUM> from the outer circumferential part to the inner circumferential part to be connected to the plurality of circulation nozzles <NUM>, respectively.

In an inner diameter part <NUM> (an inner circumferential part connected to the nozzle water supply ports 72a, 72b, 72c, and 72d when the transport pipe <NUM> is viewed from front, as shown in <FIG>) of the transport pipe <NUM>, a plurality of communication holes <NUM> respectively communicating with the plurality of nozzle water supply ports is formed, and a port connection groove 71r with an entrance portion of each of the plurality of nozzle water supply ports 72a, 72b, 72c, and 72d to be inserted is formed on the circumference of each of the communication holes <NUM>. In addition, the entrance portion of each of the plurality of nozzle water supply ports 72a, 72b, 72c, and 72d is bonded to the inner diameter part <NUM> in the port connection groove 71r.

The entrance portion of each of the nozzle water supply ports 72a, 72b, 72c, and 72d may include a flange <NUM> that extends outwardly in a radial direction from an entrance thereof through which water discharged from the communication hole <NUM> is introduced. The port connection groove 71r of the inner diameter part <NUM> may be in a shape corresponding to a shape of the flange <NUM>.

In the port connection groove 71r, the flange <NUM> may be bonded to the inner diameter part <NUM>. In particular, the flange <NUM> is in a structure in which the entrance is formed on a first surface 722a in contact with a floor of the port connection grove 71r and in which an outer diameter of a second surface 722b spaced apart from the first surface 722a to thereby define a thickness of the flange <NUM> is smaller than an outer diameter of the first surface 722a, thereby forming a conical slope 722c connecting an outer circumference of the second surface and an outer circumference of the first surface 722a. However, this structure makes the flange <NUM> tightly fitted into the port connection groove 71r through a wedge structure, thereby allowing the nozzle water supply ports 72a, 72b, 72c, and 72d not to be easily separated from the transport pipe <NUM>. In particular, in the case of manufacturing the conduit <NUM> by inserting the nozzle water supply ports 72a, 72b, 72c, and 72d into molten material forming the transport pipe <NUM>, the slope 722c is embedded in the molten material, making the transport pipe <NUM> and the nozzle water supply ports 72a, 72b, 72c, and 72d to be tightly secured. In particular, the conduit <NUM> may be formed by blow molding which is the process of forming the transfer conduct <NUM> using parison. In this case, the nozzle water supply ports 72a, 72b, 72c, and 72d may be formed as separate molded object and then inserted into the parison. The parison may be formed of a material such as High-density polyethylene (HDPE), polypropylene (PP), or the like.

Preferably, the nozzle water supply ports 72a, 72b, 72c, and 72d and the parison or transfer conduit <NUM> are formed of the same material.

However, aspects of the present invention are not limited thereto, and the nozzle water supply ports 72a, 72b, 72c, and 72d and the parison or transfer conduit <NUM> may be formed of different materials.

<FIG> is a flowchart illustrating a manufacturing method according to an embodiment of the present invention. <FIG> illustrates steps of a manufacturing method according to an embodiment of the present invention.

Hereinafter, a manufacturing method according to an embodiment of the present invention with reference to <FIG> and <FIG> is a method for manufacturing a conduit <NUM> that supplies circulating water to a plurality of circulation nozzles <NUM> formed in a gasket <NUM> of a washing machine.

In the manufacturing method according to an embodiment of the present invention, while nozzle water supply ports 72a, 72b, 72c, and 72d are inserted into a mold, a transport pipe <NUM> is formed by extrusion molding using a molten parison <NUM>. The nozzle water supply ports 72a, 72b, 72c, and 72d may be molded objects, and a material thereof may be identical or different from a material of the parison <NUM>.

The mold may include a lower mold <NUM> and an upper mold <NUM>. In the lower mold <NUM>, a first cavaty is formed in a shape corresponding to an external apperarnce of a lower portion (preferably, a half of the lower part) of a conduit placed in a horizontal direction, and the cavity has an open top surface so that the parison <NUM> can be positioned therein.

The upper mold <NUM> is assembled with the lower mold <NUM> from above, and, in the upper mold <NUM>, a second cavaty is formed in a shape corresponding to the rest part (approximately, a half of the upper part) of the conduit <NUM>, except a portion formed by the cavaty formed in the lower mold <NUM>.

<FIG> shows a state in which a plurality of nozzle water supply ports 72a, 72b, 72c, and 72d is positioned in the first cavity of the lower mold <NUM> while the molds <NUM> and <NUM> are opened up (S1). Here, the plurality of nozzle water supply ports 72a, 72b, 72c, and 72d is pre-molded and preferably molded objects.

The plurality of nozzle water supply ports 72a, 72b, 72c, and 72d corresponds to a kind of insert embedded in the molten parison <NUM> that is to be positioned in the cavity in the step S3 which will be described later. In some embodiments, even an inlet port <NUM> pre-molded prior to the step S3 may be positioned in the cavity of the lower mold <NUM>.

Thereafter, a molten parison <NUM> having a hollow opening may be formed by extruding a raw material or a material of the transport pipe <NUM> (S2). The parison <NUM> is extruded in a long tubular shape from an extruder (not shown), and temperature of the parison <NUM> being extruded from the extruder is approximately from <NUM>° C to <NUM>° C, and preferably <NUM> ° C.

The parison <NUM> from the extruder may be placed in the cabity where the insert (the nozzle water supply ports 72a, 72b, 72c, and 72d and/or the inlet port <NUM>) is positioned at the step S1. At the step S2, the parison <NUM> from the extruder may be cut by an approprimate length and then placed in the cavity. The process of cutting the parison <NUM> and inserting the same into the cavity may be automatically performed by equipment, but aspects of the present invention are not limited thereto, and the process may be manually performed by a person.

While the parison <NUM> is placed in the cavity of the lower mold <NUM>, the upper mold <NUM> and the lower mold <NUM> are assembled (S3). In this case, the both open ends of the parison <NUM> are sealed as being pressured by the upper mold <NUM> and the lower mold <NUM>. In this state, gas of high pressure is injected through a gas injection passage <NUM> formed in the molds <NUM> and <NUM> (S5). The gas may be air, but aspects of the present invention are not limited thereto. The process of injecting gas of high pressure is a technique widely used in blow extrusion molding, and thus, a detailed description thereof is herein omitted. Temperature of the parison <NUM> at the beginning of injecting gas may preferably be from <NUM>° C and <NUM>° C.

When gas is injected, a hollow hole in the parison <NUM> expands and thus the parison <NUM> is brought into an inner surface of the cavity in the molds <NUM> and <NUM>, thereby forming the transport pipe <NUM>. If gas of temperature lower than temperature of the parison <NUM> is injected, the temperature of the parison <NUM> is neutrally lowered in the course of injecting gas. However, as aspects of the present invention are not limited thereto, and an operation of forcibly lowering the temperature of the parison <NUM> before opening the mold may be further implemented or an operation of waiting until the parison <NUM> is naturally cooled may be further performed.

Thereafter, the upper mold <NUM> and the lower mold <NUM> are opened up (S6), and a molded product, in which the parison <NUM> and the plurality of nozzle water supply ports 72a, 72b, 72c, and 72d are engaged (in some embodiments, a molded object including even the input port <NUM> when the inlet port <NUM> is configured as an additional insert), is extracted (S7).

As for the extracted molded product, the parison <NUM> expanded in the course of injecting gas at the step S5 intrudes even the nozzle water supply ports 72a, 72b, 72c, and 72d, and thus, the passage may be blocked by the parison <NUM>. Therefore, the operation (S8) of clearing the blocked passage is performed. In this case, the blocked passage may be cleared by an automatic pumching equipment or by a manual operation. In this case, if the inlet port <NUM> is inserted, the inlet port <NUM> may be cleared in the same manner of clearing the plurality of water supply ports 72a, 72b, 72c, and 72d.

Meanwhile, in the case where the inlet port <NUM> is not configured as an additional insert, an operation of processing the inlet port <NUM> communicating with the hollow opening of the parison <NUM> in a molded product (in a shape in which the plurality of nozzle water supply ports 72a, 72b, 72c, and 72d and the parison <NUM> are engaged) extracted from the molds <NUM> and <NUM> may be further performed.

The cavity of the molds <NUM> and <NUM> includes a portion corresponding to the inlet port <NUM>, and the parison <NUM> is inserted even into the aforementioned portion in the gas injection step (S5), thereby forming a protrusion forming the external appearace of the inlet port <NUM>. Although the protrusion protrudes from an outer circumferential surface of the ransfer duct <NUM>, a passage thereof is blocked. Therefore, the inlet port <NUM> is processed by a step of punching a passage communicating with the hollow opening in the protrusion.

The washing machine, and the method of manufacturing a conduit applied in the washing machine according to the present invention reduce a waste of materials disposed in the manufacturing process, thereby improving productivity.

Second, since the conduit is molded using a tubular-shaped having a hollow opening, it is possible to rule out a possibility of water leakage from a final product's pipe formed by the hollow opening.

Third, since blow molding is performed with pre-molded nozzle water supply ports being inserted into a mold, incomplete molding or molding defect of the nozzle water supply ports may be prevented, compared to the case where the nozzle water supply ports are molded integrally with the conduit.

Claim 1:
A washing machine, comprising:
a casing (<NUM>) having a laundry introduction hole (<NUM>) formed in a front surface of the casing (<NUM>) therein;
a tub (<NUM>) disposed in the casing (<NUM>) and having an entrance opening formed in a front surface of the tub (<NUM>) to communicate with the introduction hole (<NUM>);
a drum (<NUM>) rotatably disposed in the tub (<NUM>) and having an entrance opening through which laundry is introduced;
a pump (<NUM>) configured to pump water discharged from the tub (<NUM>);
an annular gasket (<NUM>) allowing the introduction hole (<NUM>) and the entrance opening of the tub (<NUM>) to communicate with each other, and having a plurality of circulation nozzles (<NUM>) configured to spray water into the drum (<NUM>); and
a conduit (<NUM>) fixed to the annular gasket (<NUM>), and configured to guide the water pumped by the pump (<NUM>) to the plurality of circulation nozzles (<NUM>),
wherein the conduit (<NUM>) comprises a transport pipe (<NUM>) configured to guide water introduced through an inlet port (<NUM>) and pumped by the pump (<NUM>), and
the conduit (<NUM>) further comprises a plurality of nozzle water supply ports (72a, 72b, 72c, 72d) configured to distribute the water guided along the transport pipe (<NUM>) to the plurality of circulation nozzles (<NUM>),
characterized in that
a plurality of communication holes (<NUM>) respectively communicating with the plurality of nozzle water supply ports (72a, 72b, 72c, 72d) is formed on an inner diameter part (<NUM>) of the transport pipe (<NUM>), and a port connection groove (71r) with an entrance portion of each of the plurality of nozzle water supply ports (72a, 72b, 72c, 72d) to be inserted thereinto is formed on a circumference of each of the plurality of communication holes (<NUM>), and
the entrance portion of each of the plurality of nozzle water supply ports (72a, 72b, 72c, 72d) is bonded to the inner diameter part (<NUM>) within the port connection groove (71r).