FIELD- The present invention relates to the technical field of electrical washing appliances, and in particular, to a dispensing assembly, a dispensing device, a washing machine and a washing agent dispensing method. 
BACKGROUND- A dispensing device is adopted in a washing machine to dispense washing agent, allowing convenient dispensing of the washing agent. However, the dispensing device in the related art has a problem that the washing agent cannot be dissolved quickly, resulting in poor cleaning. In addition, owing to the poor dissolving effect, a lot of agglomerations of the residual washing agent may increase the risk of pipeline blockage. EP2464779A1-  relates generally to a device for mixing at least one medium with water or for generating foam in a water-bearing household appliance. CN102677758A-  relates generally to a foam generating device. CN208579369U-  relates generally to a range hood having a self-cleaning function. 
SUMMARY- Aspects of the invention are set out in the claims. The present disclosure aims to solve at least one of the technical problems existing in the related art. To this end, an object of the present disclosure is to propose a dispensing assembly for dispensing a washing agent. The dispensing assembly allows the washing agent to be sufficiently dissolved in water flow, such that the cleaning effect can be improved and the risk of agglomeration of the residual washing agent as well as the risk of pipeline blockage can be reduced. In addition, the washing agent and gas can enter the main pipe housing through their independent channels, which reduces the risk of blockage of the gas passage. 
- The present invention further provides a dispensing device having the above-mentioned dispensing assembly. 
- The present invention further provides a washing machine having the above-mentioned dispensing device. 
- The present invention further provides a washing agent dispensing method for a washing machine. 
- According to an embodiment of the first aspect of the present invention, the dispensing assembly for dispensing a washing agent includes a main pipe housing having a liquid inlet end and a liquid outlet end. Water is allowed to flow into the main pipe housing through the liquid inlet end and to flow out of the main pipe housing through the liquid outlet end. The main pipe housing further has a gas inlet port and a suction port that are defined on a side wall thereof and are both located between the liquid inlet end and the liquid outlet end. The washing agent is allowed to flow into the main pipe housing through the suction port. Gas is allowed to flow into the main pipe housing through the gas inlet port. 
- In the dispensing assembly for dispensing the washing agent according to the embodiments of the present invention, by providing the gas inlet port, in the process of the washing agent flowing into the main pipe housing through the suction port, gas is introduced into the main pipe housing through the gas inlet port. Through the disturbance of the gas, the washing agent can be sufficiently dissolved in the water flow, which improves the foaming effect of the washing agent and the cleaning effect, and which reduces the risk of agglomeration of the residual washing agent and the risk of pipeline blockage. In addition, the washing agent and gas can enter the main pipe housing through independent channels, and thus the introduction of the washing agent and the introduction of gas do not affect each other. Therefore, even without flushing, the introduction of gas will not be affected by the agglomeration and condensation of the washing agent under the influence of air, reducing the risk of blockage of the gas passage. 
- According to some embodiments of the present invention, the main pipe housing is a Venturi pipe and includes a first pipe section, a second pipe section, and a third pipe section that connected in sequence, a flow area of the second pipe section being smaller than a flow area of the first pipe section and smaller than a flow area of the third pipe section, the liquid inlet end being located at the first pipe section, the liquid outlet end being located at the third pipe section, the suction port being defined in the first pipe section or the second pipe section, and the gas inlet port being defined in the first pipe section or the second pipe section. 
- According to some embodiments of the present invention, the gas inlet port and the suction port are spaced apart from each other. 
- According to some embodiments of the present invention, the gas inlet port and the suction port are adjacent to each other. 
- According to some optional embodiments of the present invention, both the suction port and the gas inlet port are defined in the first pipe section. 
- According to some optional embodiments of the present invention, the suction port is defined in the first pipe section, and the gas inlet port is defined in the second pipe section. 
- According to some embodiments of the present invention, the main pipe housing further has an inner pipe disposed therein; the inner pipe has an inlet adjacent to the liquid inlet end, and an outlet; and the water is allowed to flow into the inner pipe through the inlet and to flow into the main pipe housing through the outlet 
- According to some optional embodiments of the present invention, a flow space is defined between an outer side wall of the inner pipe and an inner side wall of the main pipe housing, the suction port being defined on an outer side wall of the flow space, and the gas inlet port being defined on the outer side wall of the flow space or located downstream of the flow space. 
- Optionally, the flow space has an annular cross section extending around the inner pipe. 
- In some optional embodiments of the present invention, the inner pipe includes a main section and a compression section that are connected to each other, the inlet being defined in the main section, the outlet being defined in the compression section, and a flow area of the compression section being smaller than a flow area of the main section. 
- Optionally, both the suction port and the gas inlet port are located upstream of the compression section. 
- In some optional embodiments of the present invention, the inner pipe includes a connecting section configured to connect the main section to the compression section; along a direction from the main section to the compression section, an outer side wall of the connecting section extends obliquely towards a central axis of the main pipe housing; a minimum flow area of the connecting section is greater than or equal to a flow area of the compression section; and the suction port and the gas inlet port are located upstream of the connecting section. 
- According to some optional embodiments of the present invention, the main pipe housing is a Venturi pipe and includes a first pipe section, a second pipe section, and a third pipe section that are connected in sequence, a flow area of the second pipe section being smaller than a flow area of the first pipe section and smaller than a flow area of the third pipe section, the liquid inlet end being located at the first pipe section, the liquid outlet end being located in the third pipe section, and the inner pipe being defined in the first pipe section; the flow space is defined between the outer side wall of the inner pipe and an inner side wall of the first pipe section; the outlet is adjacent to the second pipe section; and the gas inlet port is defined on the outer side wall of the flow space or on the second pipe section. 
- According to some embodiments of the present invention, a control valve configured to open and close the gas inlet port is disposed at the gas inlet port. 
- According to some optional embodiments of the present invention, the main pipe housing is a Venturi pipe and includes a first pipe section, a second pipe section, and a third pipe section that are connected in sequence, a flow area of the second pipe section being smaller than a flow area of the first pipe section and smaller than a flow area of the third pipe section, the liquid inlet end being located at the first pipe section, the liquid outlet end being located in the third pipe section, the suction port being defined in the first pipe section or the second pipe section, and the gas inlet port being defined in the first pipe section or the second pipe section; and the control valve is a one-way valve for a one-way conduction in a direction from the gas inlet port to an inner cavity of the main pipe housing. 
- A dispensing device for dispensing a washing agent according to the embodiments of the second aspect of the present invention includes: the dispensing assembly according to the embodiments of the first aspect of the present disclosure; and a washing agent storage box disposed at an outside of the main pipe housing and connected to the main pipe housing. The washing agent storage box has an inner cavity in communication with the suction port, and wherein the washing agent in the washing agent storage box is allowed to flow into the main pipe housing through the suction port. 
- In the dispensing device for dispensing the washing agent according to the embodiments of the present invention, by providing the above-mentioned dispensing assembly, the washing agent can be sufficiently dissolved in the water flow. Thus, the foaming effect of the washing agent as well as the cleaning effect can be improved, and the risk of agglomeration of the residual washing agent and the risk of pipeline blockage can be lowered. In addition, the washing agent and gas can enter the main pipe housing through independent channels. Therefore, even without flushing, the introduction of gas will not be affected by the agglomeration and condensation of the washing agent under the influence of air, reducing the risk of blockage of the gas passage. 
- The washing machine according to the embodiments of the third aspect of the present invention includes a washing tub, and the dispensing device according to the embodiments of the second aspect of the present invention. The dispensing device is adapted to dispense a washing agent into the washing tub. The liquid outlet end is in communication with the washing tub. 
- In the washing machine according to the embodiments of the present invention, by providing the above-mentioned dispensing device, the washing agent can be sufficiently dissolved in the water flow. Thus, the foaming effect of the washing agent as well as the cleaning effect can be improved, and the risk of agglomeration of the residual washing agent and the risk of pipeline blockage can be lowered. In addition, the washing agent and gas can enter the main pipe housing through independent channels, which lowers the risk of blockage of the gas passage. 
- In a washing agent dispensing method for a washing machine according to the embodiments of the fourth aspect of the present invention, the washing machine includes a dispensing device for dispensing a washing agent into a washing tub of the washing machine; the dispensing device includes a dispensing assembly and a washing agent storage box; the dispensing assembly includes a main pipe housing having a liquid inlet end and a liquid outlet end, the liquid outlet end being in communication with the washing tub; water is allowed to flow into the main pipe housing through the liquid inlet end and flow out of the main pipe housing through the liquid outlet end; the main pipe housing further has a gas inlet port and a suction port that are defined on a side wall thereof and are both located between the liquid inlet end and the liquid outlet end; gas is allowed to flow into the main pipe housing through the gas inlet port; the washing agent storage box is disposed at an outside of the main pipe housing and connected to the main pipe housing; the washing agent storage box has an inner cavity in communication with the suction port; and the washing agent in the washing agent storage box is allowed to flow into the main pipe housing through the suction port. The washing agent dispensing method includes: controlling water to flow into the main pipe housing through the liquid inlet end; and controlling the washing agent and the gas to flow into the main pipe housing respectively from the suction port and the gas inlet port. 
- In the washing agent dispensing method for the washing machine according to the embodiments of the present invention, in the process of the washing agent flowing into the main pipe housing through the suction port, the gas is introduced into the main pipe housing through the gas inlet port, and thus the washing agent can be sufficiently dissolved in the water flow. Thus, the foaming effect of the washing agent as well as the cleaning effect can be improved, and the risk of agglomeration of the residual washing agent and the risk of pipeline blockage can be lowered. In addition, by controlling the washing agent and gas to enter the main pipe housing after the water flow enters the main pipe housing, the washing agent and gas can contact the water flow from the beginning, which prevents the washing agent from accumulating in the pipeline. In this way, the dissolving effect of the washing agent can be improved, and the risk of agglomeration of the residual washing agent and the risk of pipeline blockage can be lowered. 
- Additional aspects and advantages of the present invention will be partially set forth in the following description and partially become apparent from the following description, or they may be learned by practice of the present invention. 
BRIEF DESCRIPTION OF DRAWINGS- The above-mentioned and/or additional aspects and advantages of the present disclosure will become apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, in which: 
- FIG. 1 is a schematic diagram of a part of a dispensing device according to some embodiments of the present disclosure; and
- FIG. 2 is a schematic diagram of a part of a dispensing device according to other embodiments of the present disclosure.
- Reference Symbols: 
- main pipe housing 1; suction port 101; gas inlet port 102; first pipe section 11; second pipe section 12; third pipe section 13;
- inner pipe 3; outlet 30; main section 31; compression section 32; connecting section 33; flow space 301;
- washing agent storage box 4.
DESCRIPTION OF EMBODIMENTS- Embodiments of the present disclosure will be described in detail below with reference to examples thereof as illustrated in the accompanying drawings, throughout which the same or similar elements, or the elements having same or similar functions, are denoted with same or similar reference numerals. The embodiments described below with reference to the drawings are illustrative only and are intended to explain, rather than limiting, the present disclosure. 
- A dispensing assembly for dispensing a washing agent according to an embodiment of the present disclosure is described below with reference toFIG. 1 and FIG. 2. 
- As illustrated inFIG. 1 and FIG. 2, according to the embodiment of the first aspect of the present disclosure, the dispensing assembly for dispensing the washing agent includes a main pipe housing 1. The main pipe housing 1 has a liquid inlet end and a liquid outlet end. Water can flow into the main pipe housing 1 through the liquid inlet end and flow out of the main pipe housing through the liquid outlet end. The main pipe housing 1 has a gas inlet port 102 and a suction port 101 that are defined on a side wall thereof. The gas inlet port 102 and the suction port 101 may be spaced apart from each other, and the suction port 101 and the gas inlet port 102 are both located between the liquid inlet end and the liquid outlet end. The washing agent can flow into the main pipe housing 1 through the suction port 101, and the gas can flow into the main pipe housing 1 through the gas inlet port 102. The gas flowing into through the gas inlet port 102 may be the air. 
- A negative pressure, which is generated by the flowing of the water flow in the main pipe housing 1, can act as a driving force to suck the washing agent into the main pipe housing 1 via the suction port 101. For example, the main pipe housing 1 may be a Venturi pipe. A pump, with its power source of suction, may be used to suck the washing agent into the main pipe housing 1 through the suction port 101. Alternatively, when the main pipe housing 1 is a Venturi pipe, the negative pressure generated by the flowing of the water flow in the main pipe housing 1 as well as the suction of the pump can be simultaneously utilized to suck the washing agent into the main pipe housing 1 via the suction port 101. 
- The negative pressure generated by the flowing of the water flow in the main pipe housing 1, as a driving force, can suck the gas into the main pipe housing 1 via the gas inlet port 102. For example, the main pipe housing 1 may be a Venturi pipe. A pump, a fan, or the like, may also be used as a driving force to suck, by means of the suction of the pump or fan, the gas into the main pipe housing 1 via the gas inlet port 102. Alternatively, when the main pipe housing 1 is a Venturi pipe, the negative pressure generated by the flowing of the water flow in the main pipe housing 1 as well as the suction of the pump or fan can be simultaneously used to suck the gas into the main pipe housing 1 via the gas inlet port 102. 
- Therefore, when the dispensing assembly is applied in a dispensing device of a washing machine, the dispensing device can dispense the washing agent into a washing tub of the washing machine. In the process of dispensing the washing agent with the dispensing assembly, the water enters the main pipe housing 1 through the liquid inlet end of the main pipe housing 1, and the washing agent sucked by the suction port 101 and the gas sucked by the gas inlet port 102 also enter the main pipe housing 1. The gas, water and washing agent are mixed in the main pipe housing 1, to sufficiently dissolve the washing agent. The sufficiently mixed and dissolved washing agent flows into the washing tub of the washing machine through the liquid outlet end. In this way, when the washing agent enters the main pipe housing 1, the washing agent has been dissolved in the water flow in the main pipe housing 1, and at the same time, due to the gas introduced in the main pipe housing 1, the gas, water and the washing agent has been sufficiently mixed, promoting the dissolving of the washing agent. For example, when the washing agent is a detergent, the foaming effect of the washing agent can be improved; the foam is more delicate; and the cleaning effect is improved. 
- In the process of dispensing the washing agent with the above dispensing assembly, the gas is supplied before the washing agent. The water flow in the main pipe housing 1 is introduced before the dispensing of the gas and the washing The water flow in the main pipe housing 1 is introduced before the gas and the washing agent are dispensed, and thus the washing agent and the gas can contact the water flow from the beginning. In this way, the washing agent does not accumulate too much in the pipeline, and the washing agent can be sufficiently and uniformly dissolved, which reduces the risk of agglomeration of the residual washing agent and the risk of pipeline blockage. 
- The washing agent includes detergent, softener, disinfectant, etc. That is, the washing agent generally refers to an additive used in a laundry process. In a washing stage of a washing machine, the washing agent can enter the main pipe housing 1 through the suction port 101, and the gas can enter the main pipe housing 1 through the gas inlet port 102, allowing the washing agent to be sufficiently dissolved. Thus, the foaming effect of the washing agent and the cleaning performance can be improved. In a rinsing stage of the washing machine, the softener and disinfectant can enter the main pipe housing 1 through the suction port 101, and the gas can enter the main pipe housing 1 through the gas inlet port 102, allowing the softener and the disinfectant to be sufficiently dissolved. Thus, the hand feeling can be improved, and the disinfection and sterilization rate can be increased. In a washing stage and a rinsing stage of the washing machine, after the corresponding washing agent is dispensed, the suction port 101 can be flushed by sucking the water flow through the suction port 101. Since the washing agent can be sufficiently dissolved in water by means of the dispensing assembly, the washing agent can sufficiently effect in the washing process, for example, it can improve the cleaning effect, the hand feeling, and the disinfection and sterilization rate. 
- In an embodiment, the gas inlet port 102 and the suction port 101 are adjacent to each other. By adjacently disposing the gas inlet port 102 and the suction inlet 101, the washing agent and the gas, after entering the main pipe housing 1, can contact each other and can be sufficiently mixed in a very short time. In this way, the dissolving effect and foaming effect of the washing agent can be further improved. 
- The gas enters the main pipe housing 1 through the gas inlet port 102; the washing agent enters the main pipe housing 1 through the suction port 101; and the gas inlet port 102 and the suction port 101 are independent of each other. Thus, the washing agent and the gas enter the main pipe housing 1 through their independent channels, and thus the introduction of the washing agent and the introduction of gas do not affect each other. Therefore, even without flushing, the introduction of gas will not be affected by the agglomeration and condensation of the washing agent under the influence of air, reducing the risk of blockage of the gas passage. 
- In the dispensing assembly for dispensing washing agent according to the embodiment of the present disclosure, by providing the gas inlet port 102, in the process of the washing agent flowing into the main pipe housing 1 through the suction port 101, the gas can enter the main pipe housing 1 through the gas inlet port 102. Through the disturbance of gas, the washing agent can be sufficiently dissolved in the water flow, which improves the foaming effect of the washing agent and the cleaning effect, and which reduces the risk of agglomeration of the residual washing agent and the risk of pipeline blockage. In addition, the washing agent and gas can enter the main pipe housing 1 through their independent channels, and thus the introduction of the washing agent and the introduction of gas do not affect each other. Therefore, even without flushing, the introduction of gas will not be affected by the agglomeration and condensation of the washing agent under the influence of air, reducing the risk of blockage of the gas passage. 
- According to some embodiments of the present disclosure, referring toFIG. 1 and FIG. 2, the main pipe housing 1 is a Venturi pipe, and the main pipe housing 1 includes a first pipe section 11, a second pipe section 12, and a third pipe section 13, which are connected in sequence. A flow area of the second pipe section 12 is smaller than a flow area of the first pipe section 11 and smaller than a flow area of the third pipe section 13. The liquid inlet end is located at the first pipe section 11. The liquid outlet end is located at the third pipe section 13. The suction port 101 is defined in the first pipe section 11 or the second pipe section 11. The gas inlet port 102 is defined in the first pipe section 11 or the second pipe section 12. When the main pipe housing 1 is a Venturi pipe, the water flow enters the first pipe section 11 through the liquid inlet end, and then the water sequentially flows through the second pipe section 12 and the third pipe section 13. Since the flow area of the second pipe section 12 is relatively smaller, a greater negative pressure may be generated when the water flows through the second pipe section 12. 
- When the suction port 101 is defined in the first pipe section 11 or the second pipe section 12, under the effect the above-mentioned negative pressure, the washing agent can be sucked into the main pipe housing 1 through the suction port 101. When the gas inlet port 102 is defined in the first pipe section 11 or the second pipe section 12, under the effect the above-mentioned negative pressure, the gas can be sucked into the main pipe housing 1 through the gas inlet port 102. Both the washing agent and the gas can enter the main pipe housing 1 merely by means of the above-mentioned negative pressure. Alternatively, the gas enters the main pipe housing 1 under the above-mentioned negative pressure, while the washing agent enters the main pipe housing 1 through a suction effect of a pump. 
- In addition, in the process of mixing the washing agent, gas and water flow in the second pipe section 12, the water flow speed increases due to the smaller flow area of the second pipe section 12, and thus the turbulent effect is better, which improves the mixing effect. In this way, the dissolving effect and foaming effect of the washing agent can be further improved, and the cleaning effect can be enhanced. 
- According to some optional embodiments of the present disclosure, referring toFIG. 1, both the suction port 101 and the gas inlet port 102 are defined in the first pipe section 11. Thus, the washing agent enters the first pipe section 11 through the suction port 101 and the gas enters the first pipe section 11 through the gas inlet port 102. The gas and the washing agent may be first mixed with the water flow in the first pipe section 11, and then the washing agent and gas flow to the second pipe section 12 with the water flow. Thus, before the gas and the washing agent flow into the second pipe section 12, they have been pre-mixed with the water flow in the first pipe section 11. When the washing agent and the gas flow into the second pipe section 12 with the water flow, the water flow speed is increased due the reduced flow area of the second pipe section 12, and the turbulent effect is better, which enhances the mixing effect. Thus, more fine foam can be generated, and the calculated value of Reynolds number may be more than 10,000; the dissolving effect and foaming effect of the washing agent as well as the cleaning effect can be improved; and more than 10% of the washing agent can be saved under the same cleaning and decontamination requirements. 
- According to some optional embodiments of the present disclosure, referring toFIG. 2, the suction port 101 is defined in the first pipe section 11. The washing agent can be sucked into the first pipe section 11 through the suction port 101, and then flows into the second pipe section 12 with the water flow. Before the washing agent flows into the second pipe section 12, the washing agent has been pre-mixed with the water flow. The gas inlet port 102 is defined in the second pipe section 12, and the gas enters the second pipe section 12 through the gas inlet port 102. The washing agent flowing into the second pipe section 12 along with the water flow can be mixed with the gas in the second pipe section 12. At the same time, due to the reduced flow area of the second pipe section 12, the water flow speed is increased, and the turbulent effect is better. Thus, the mixing effect is enhanced, and more fine foam can be generated, improving the dissolving effect and foaming effect of the washing agent, and improving the cleaning effect. 
- According to some embodiments of the present disclosure, referring toFIG. 1 and FIG. 2, the main pipe housing 1 has an inner pipe 3 disposed therein. The inner pipe 3 has an inlet adjacent to the liquid inlet end, and an outlet 30. Water can flow into the inner pipe 3 through the inlet and flow into the main pipe housing 1 through the outlet 30. The water may flow directly into the inner pipe 3 through the inlet, or the water may also flow into the liquid inlet end first and then flow into the inner pipe 3 through the inlet of the inner pipe 3. In this way, by disposing the inner pipe 3 in the main pipe housing 1 and allowing the water flow to flow into the inner pipe 3, as the cross-sectional area of the inner pipe 3 may be smaller than the cross-sectional area of the main pipe housing 1, the flow rate of the water flow may be increased, and the water flow rate may be increased after passing through the inner pipe 3. Thus, the water flow may be ejected at a higher flow rate from the outlet 30 of the inner pipe 3 to enhance the impact effect of the water flow, allowing the water, washing agent and gas to be sufficiently mixed and foamed. In this way, the dissolving effect and foaming effect of the washing agent, as well as the cleaning effect can be further improved. 
- According to some optional embodiments of the present disclosure, referring toFIG. 1 and FIG. 2, a flow space 301 is defined between an outer side wall of the inner pipe 3 and an inner side wall of the main pipe housing 1; the suction port 101 is defined on an outer side wall of the flow space 301; the gas inlet port 102 is defined on an outer side wall of the flow space 301 or located downstream of the flow space 301 ("the gas inlet port 102 located downstream of the flow space 301" indicates that the gas inlet port 102 is located downstream of the entire flow space 301 in a flowing direction of the water flow). Therefore, when the suction port 101 and the gas inlet port 102 are both defined on the outer side wall of the flow space 301, the washing agent and the gas may first enter the above flow space 301 through the suction port 101 and the gas inlet port 102, respectively. Thus, the washing agent and the gas can be sufficiently mixed before contacting the water flow. The sufficiently mixed washing agent and gas in the flow space 301 then contact the water flow, which can further improve the dissolving effect and foaming efficiency of the washing agent and further improve the cleaning effect. When the suction port 101 is defined on the outer side wall of the flow space 301 and the gas inlet port 102 is located downstream of the flow space 301, the washing agent enters the flow space 301 through the suction port 101 and flows to the downstream part of the main pipe housing 1, i.e., the flow space 301, where the washing agent is mixed with the water flow and the gas entered through the gas inlet port 102. In this way, the water, washing agent and gas are mixed and foamed, which can further improve the dissolving effect and foaming efficiency of the washing agent and thus can further improve the cleaning effect. 
- Optionally, a cross section of the flow space 301 is an annular shape extending around the inner pipe 3. Therefore, the flow space 301 is relatively larger, and the washing agent and the gas can be sufficiently mixed in the flow space 301. 
- In some optional embodiments of the present disclosure, referring toFIG. 1 and FIG. 2, the inner pipe 3 includes a main section 31 and a compression section 32 that are connected to each other. The compression section 32 may be a pipe section with a uniform inner diameter. The inlet is defined in the main section 31, and the outlet 30 is defined in the compression section 32. A flow area of the compression section 32 is smaller than a flow area of the main section 31. Therefore, in the process of water flowing through the inner pipe 3, particularly in the process of the water flowing through the compression section 32, the water flow can be further accelerated, and thus the water flow can be ejected from the outlet 30 at a higher speed, to increase the impact force of the water flow. In this way, the water, washing agent and gas can be sufficiently mixed and foamed, to further improve the dissolving effect and foaming effect of the washing agent, and to improve the cleaning effect. 
- Optionally, referring toFIG. 1, both the suction port 101 and the gas inlet port 102 are located upstream of the compression section 32 ("both the suction port 101 and the gas inlet port 102 are located upstream of the compression section 32" refers to that the suction port 101 and the gas inlet port 102 are both located upstream of the entire compression section 32 in the flow direction of the water flow). Therefore, there is a certain distance between the suction port 101 and the outlet 30 of the inner pipe 3 and between the gas inlet port 102 and the outlet 30 of the inner pipe 3. The washing agent and gas, after entering the flow space 301 through the suction port 101 and the gas inlet port 102, respectively and before contacting the water flow, can be mixed in an adequate space and with enough time. 
- In the present disclosure, referring toFIG. 1, the inner pipe 3 includes a connecting section 33 connecting the main section 31 to the compression section 32. Along a direction from the main section 31 to the compression section 32, an outer side wall of the connecting section 33 extends obliquely towards a central axis of the main pipe housing 1. The minimum flow area of the connecting section 33 is greater than or equal to the flow area of the compression section 32. The suction port 101 and the gas inlet port 102 are located upstream of the connecting section 33 ("both the suction port 101 and the gas inlet port 102 are located upstream of the connecting section 33" means that the suction port 101 and the gas inlet port 102 are both located upstream of the entire connecting section 33 in the flow direction of the water flow). Therefore, by providing the connecting section 33, the change of the flow area from the main section 31 to the compression section 32 can be alleviated, and the flow loss can be reduced. In addition, by positioning both the suction port 101 and the gas inlet port 102 upstream of the connecting section 33, the distance between the suction port 101 and the outlet 30 of the inner pipe 3 and between the gas inlet port 102 and the outlet 30 of the inner pipe 3 can be further increased. Thus, before the washing agent and the gas contact the water flow, the washing agent and gas can be mixed in an adequate space and with enough time. In addition, after the washing agent introduced through the suction port 101 and the gas introduced through the gas inlet port 102 enter the flow space 301, the washing agent and the gas can flow smoothly to contact with the water flow, due to the guiding effect of the outer wall of the connecting section 33. 
- According to some optional embodiments of the present disclosure, referring toFIG. 1 and FIG. 2, the main pipe housing 1 is a Venturi pipe, and the main pipe housing 1 includes a first pipe section 11, a second pipe section 12, and a third pipe section 13, which are connected in sequence. A flow area of the second pipe section 12 is smaller than a flow area of the first pipe section 11 and smaller than a flow area of the third pipe section 13. The liquid inlet end is located at the first pipe section 11, and the liquid outlet end is located in the third pipe section 13. The inner pipe 3 is defined in the first pipe section 11. A flow space 301 is defined between the outer side wall of the inner pipe 3 and an inner side wall of the first pipe section 11. The outlet 30 is adjacent to the second pipe section 12. The gas inlet port 102 is defined on an outer side wall of the flow space 301 or defined on the second pipe section 12. When the main pipe housing 1 is a Venturi pipe, the water flow enters the first pipe section 11 through the liquid inlet end, and then flows to pass through the second pipe section 12 and the third pipe section 13 in sequence. Since the flow area is reduced at the second pipe section 12, a great negative pressure may be generated when the water flows through the second pipe section 12. Under the above-mentioned negative pressure, the washing agent and the gas can be sucked into the main pipe housing 1 through the suction port 101 and the gas inlet port 102, respectively. Both the washing agent and the gas may enter the main pipe housing 1 merely by means of the above-mentioned negative pressure. Alternatively, the gas enters the main pipe housing 1 under the above-mentioned negative pressure, while the washing agent enters the main pipe housing 1 through a suction effect of a pump. 
- Referring toFIG. 2, when the gas inlet port 102 is defined in the second pipe section 12, due to the reduced flow area of the second pipe section 12, the generated negative pressure force has a greater effect, which can allow a larger amount of gas to enter the gas inlet port 102 and to flow faster. Therefore, the dissolution and foaming effect of the washing agent can be further improved. 
- In addition, in the process of mixing the washing agent, gas and water flow in the second pipe section 12, due to the smaller flow area of the second pipe section 12, the flowing speed of water can be increased, and thus the turbulent effect is better. Therefore, the mixing effect is good; the dissolving effect and foaming effect of the washing agent can be further improved; and the cleaning effect can be enhanced. 
- Further, by positioning the inner pipe 3 at the first pipe section 11, due to the smaller cross-sectional area of the inner pipe 3 than the main pipe housing 1, the flow rate of the water flow can be increased, and the flow rate may be increased after the water flow passes through the inner pipe 3. The water flow can be ejected from the outlet 30 of the inner pipe 3 into the second pipe section 12 at a relatively high flow rate, enhancing the impact effect of the water flow. Referring toFIG. 1, when both the gas inlet port 102 and the suction port 101 are defined on the outer side wall of the flow space 301, the washing agent and the gas flow into the flow space 301 to be sufficiently mixed and then flow into the second pipe section 12 to contact the water flow. Thus, the water, washing agent and gas can be sufficiently mixed and foamed in the main pipe housing 1, which can further improve the dissolving effect and foaming effect of the washing agent and can improve the cleaning effect. 
- According to some embodiments of the present disclosure, a control valve configured to open and close the gas inlet port 102 is disposed at the gas inlet port 102. Therefore, it is convenient to control the gas entering into the main pipe housing 1. For example, when the control valve is opened, gas may enter through the gas inlet port 102 and flow into the main pipe housing 1 through the suction port 101; and when the control valve is closed, the supply of gas to the main pipe housing 1 is stopped. 
- According to some optional embodiments of the present disclosure, the main pipe housing 1 is a Venturi pipe, and the main pipe housing 1 includes a first pipe section 11, a second pipe section 12, and a third pipe section 13, which are connected in sequence. A flow area of the second pipe section 12 is smaller than a flow area of the first pipe section 12 and smaller than a flow area of the third pipe section 13. The liquid inlet end is located at the first pipe section 11, and the liquid outlet end is located in the third pipe section 13. The suction port 101 is defined in the first pipe section 11 or the second pipe section 12, and the gas inlet port 102 is defined in the first pipe section 11 or the second pipe section 12. The control valve is a one-way valve for a one-way conduction in a direction from the gas inlet port 102 to an inner cavity of the main pipe housing 1. Therefore, when the main pipe housing 1 is a Venturi pipe, by defining the gas inlet port 102 in the first pipe section 11 or the second pipe section 12, the negative pressure can be generated by the water flow when flowing through the main pipe housing 1. In this case, the one-way valve is opened under the action of the pressure difference, to allow the gas such as the air to be introduced through the gas inlet port 102. When the water supply flow is stopped in the main pipe housing 1, the one-way valve is closed. Thus, the control of the control valve is convenient and reliable. 
- Referring toFIG. 1 and FIG. 2, according to the second aspect of the present disclosure, a dispensing device for dispensing a washing agent includes the dispensing assembly according to the first aspect of the present disclosure, and a washing agent storage box 4. 
- The washing agent storage box 4 is disposed at an outside of the main pipe housing 1 and connected to the main pipe housing 1. An inner cavity of the washing agent storage box 4 is in communication with the suction port 101. The washing agent in the washing agent storage box 4 can flow into the main pipe housing 1 through the suction port 101. 
- The washing agent storage box 4 may receive washing agent, and the washing agent storage box 4 may also receive various types of washing agents simultaneously, such as washing agents, softeners, and disinfectants. In a washing stage of a washing machine, the washing agent in the washing agent storage box 4 may enter the main pipe housing 1 through the suction port 101; and in a rinsing stage of the washing machine, the softener and disinfectant in the washing agent storage box 4 may enter the main pipe housing 1 through the suction port 101. In the washing stage and the rinsing stage of the washing machine, after the corresponding washing agent is dispensed, the suction port 101 may be flushed by introducing the water flow through the suction port 101. 
- In the dispensing device for dispensing the washing agent according to the embodiments of the present disclosure, by providing the above-mentioned dispensing assembly, the washing agent can be sufficiently dissolved in the water flow. Thus, the foaming effect of the washing agent as well as the cleaning effect can be improved, and the risk of agglomeration of the residual washing agent and the risk of pipeline blockage can be lowered. In addition, the washing agent and gas can enter the main pipe housing 1 through independent channels. Therefore, even without flushing, the introduction of gas will not be affected by the agglomeration and condensation of the washing agent under the influence of air, reducing the risk of blockage of the gas passage. 
- According to an embodiment of the third aspect of the present disclosure, a washing machine includes a washing tub, and the dispensing device according to the embodiments of the second aspect of the present disclosure. The dispensing device is adapted to dispense a washing agent into the washing tub, and the liquid outlet end is in communication with the washing tub. During the operation of the washing machine, when the washing agent needs to be dispensed into the washing tub of the washing machine, the water flow may enter the main pipe housing 1 through the liquid inlet end, the washing agent enters the main pipe housing 1 through the suction port 101, and the gas enters the main pipe housing 1 through the gas inlet port 102. The washing agent, gas and water flow can be sufficiently mixed in the main pipe housing 1, and then, they flow into the washing tub through the liquid outlet end. 
- In the washing machine according to the embodiments of the present disclosure, by providing the above-mentioned dispensing device, the washing agent can be sufficiently dissolved in the water flow, which can improve the foaming effect of the washing agent, improve the cleaning effect. Thus, the foaming effect of the washing agent as well as the cleaning effect can be improved, and the risk of agglomeration of the residual washing agent and the risk of pipeline blockage can be lowered. In addition, the washing agent and gas can enter the main pipe housing 1 through independent channels, which lowers the risk of blockage of the gas passage. 
- In a washing agent dispensing method for a washing machine according to the fourth aspect of the present disclosure, the washing machine includes a dispensing device for dispensing a washing agent into a washing tub of the washing machine. The dispensing device includes a dispensing assembly and a washing agent storage box 4. The dispensing assembly includes a main pipe housing 1 having a liquid inlet end and a liquid outlet end. The liquid outlet end is in communication with the washing tub. Water can flow into the main pipe housing 1 through the liquid inlet end and flow out of the main pipe housing 1 through the liquid outlet end. The main pipe housing 1 has a gas inlet port 102 and a suction port 101 that are defined on a side wall thereof. The gas inlet port 102 and the suction port 101 may be spaced apart from each other. Both the suction port 101 and the gas inlet port 102 are located between the liquid inlet end and the liquid outlet end. The gas can flow into the main pipe housing 1 through the gas inlet port 102, the washing agent storage box 4 is disposed at an outside of the main pipe housing 1 and connected to the main pipe housing 1. An inner cavity of the washing agent storage box 4 is in communication with the suction port 101. The washing agent in the washing agent storage box 4 can flow into the main pipe housing 1 through the suction port 101. The washing agent dispensing method includes the following steps: controlling water to flow into the main pipe housing 1 through the liquid inlet end; and controlling the washing agent and the gas to flow into the main pipe housing respectively from the suction port 101 and the gas inlet port 102. 
- In this way, the water flow is first introduced into the main pipe housing 1 before the gas and the washing agent are dispensed, and thus the washing agent and the gas may contact the water flow from the beginning. Therefore, the washing agent can be sufficiently and evenly dissolved, instead of accumulating in the pipeline, which can lower the risk of agglomeration of the residual washing agent and thus lower the risk of pipeline blockage. 
- In the process of controlling the washing agent and gas to flow into the main pipe housing 1, the washing agent may be supplied first and then the gas, or the gas may be supplied before the washing agent, or the washing agent and the gas may be provided alternately. 
- In addition, for the specific structure and description of the dispensing device used in the dispensing method in this embodiment, reference may be made to the above, which will not be repeated herein. In addition, the dispensing device according to any one embodiment of the above second aspect may be used in the washing machine in this embodiment, and the washing agent dispensing method is adopted to dispense the washing agent. 
- In the washing agent dispensing method for the washing machine according to the embodiments of the present disclosure, in the process of the washing agent flowing into the main pipe housing 1 through the suction port 101, the gas is introduced into the main pipe housing 1 through the gas inlet port 102, and thus the washing agent can be sufficiently dissolved in the water flow. Thus, the foaming effect of the washing agent as well as the cleaning effect can be improved, and the risk of agglomeration of the residual washing agent and the risk of pipeline blockage can be lowered. In addition, by controlling the washing agent and gas to enter the main pipe housing 1 after the water flow enters the main pipe housing 1, the washing agent and gas can contact the water flow from the beginning, which prevents the washing agent from accumulating in the pipeline. In this way, the dissolving effect of the washing agent can be improved, and the risk of agglomeration of the residual washing agent and the risk of pipeline blockage can be lowered. 
- In the description of this specification, descriptions with reference to the terms "an embodiment," "some embodiments," "schematic embodiments," "examples," "specific examples," or "some examples", etc. mean that specific features, structure, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner.