Anti-shaking connecting structure and faucet assembly
Patent Information
- Application Number
- CN202522112056.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2035-09-30
AI Technical Summary
[0003]一、由于制造公差及结构设计的限制,龙头出水嘴的进水端与本体接合部位常存在一定间隙,未能形成紧密的对接;
[0019]1、本实用新型提出的一种防晃动连接结构,通过设置第一限位件与第二限位件,轴向与径向双重限位结构增强了出水嘴与座体组件之间连接的刚性和稳定性,能够有效抑制在使用过程中因水流冲击或外部触碰引起的径向晃动和轴向窜动。
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Figure CN224904146U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of bathroom technology, and in particular to an anti-shaking connection structure and faucet assembly. Background Technology
[0002] In current common double-handle basin faucets and kitchen faucets, the spout component is usually made of stainless steel and is fixed to the faucet body via a screw thread using a cap and C-ring. This structure has several obvious defects in actual assembly and use:
[0003] 1. Due to limitations in manufacturing tolerances and structural design, there is often a certain gap between the water inlet end of the faucet spout and the joint part of the body, which fails to form a tight connection.
[0004] Second, the fit between the C-ring used for locking and the water outlet is often not ideal, with some looseness or poor fit.
[0005] These two factors together cause the spout assembly to exhibit significant shaking under external force or water flow impact, which not only affects the product's appearance stability and user experience, but may also cause wear on sealing elements with long-term use, increasing the risk of leakage and weakening the overall structural rigidity of the faucet. Utility Model Content
[0006] In view of the shortcomings of the prior art, the purpose of this utility model is to provide an anti-shaking connection structure and a faucet assembly.
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] An anti-sway connection structure includes a water outlet and a base assembly. The base assembly has a water outlet channel. The water inlet end of the water outlet is installed in the base assembly and communicates with the water outlet channel. The structure also includes a first limiting member and a second limiting member. The outer side wall of the water outlet has a first limiting position, and the inner side wall of the base assembly has a second limiting position. The two sides of the first limiting member respectively engage with the first limiting position and the second limiting position to limit the displacement of the water outlet in the axial direction. The second limiting member is sleeved inside the water inlet of the water outlet and generates a force that presses the water outlet against the inner side wall of the base assembly to limit the displacement of the water outlet in the radial direction.
[0009] Furthermore, the first limiting member is sleeved on the outside of the water outlet. The inner and outer sides of the first limiting member are respectively provided with a first protrusion and a second protrusion extending inward and outward in the radial direction. The first limiting position is a first limiting groove, and the second limiting position is a second limiting groove. The first protrusion is engaged with the first limiting groove, and the second protrusion is engaged with the second limiting groove.
[0010] Furthermore, the first limiting groove and the second limiting groove are located at the same height or tend to be at the same height.
[0011] Furthermore, the first limiting member includes a lower helix disposed below the connection between the first protrusion, the second protrusion, or the first protrusion and the second protrusion, the lower helix abutting against the outer wall of the water outlet and the inner wall of the water outlet channel, respectively.
[0012] Furthermore, the second limiting member includes a clamping member and an abutting member connected to the clamping member. The abutting member extends radially outward along the clamping member. The clamping member is sleeved inside the inlet of the water outlet, thereby generating a force that presses the water outlet against the inner wall of the seat assembly. The abutting member is also interference-fitted with the water outlet channel.
[0013] Furthermore, the seat assembly includes a seat body and a pressure cap threaded to the seat body. The seat body is provided with the water outlet channel, and the pressure cap is provided with a through hole for the water outlet nozzle to pass through. When the pressure cap and the seat body are connected, a second limiting groove is provided between them, and a clearance space is provided between the water outlet nozzle and the seat body for accommodating the lower hem.
[0014] Furthermore, the inner wall of the pressure cap is provided with an inclined surface, and the space enclosed by the inclined surface and the end face of the seat body facing the inclined surface constitutes the second limiting groove.
[0015] Furthermore, the seat body has the clearance space on the inner side wall near the second limiting groove.
[0016] Furthermore, it also includes a wear-resistant sleeve, the outer wall of which is snapped into the pressure cap, and the inner side of which abuts against the outer wall of the water outlet.
[0017] A faucet assembly includes an anti-shake connection structure, a switching valve, and at least one control valve. The switching valve is connected to the seat assembly and communicates with the water outlet channel. The control valve connects to a water supply source and controls whether the water supply source is connected to the switching valve.
[0018] The beneficial effects of this utility model are:
[0019] 1. The present invention proposes an anti-shaking connection structure, which enhances the rigidity and stability of the connection between the water outlet and the seat assembly by setting a first limiting member and a second limiting member, and the dual axial and radial limiting structure, effectively suppressing radial shaking and axial movement caused by water flow impact or external contact during use.
[0020] 2. The anti-shaking connection structure proposed in this utility model has a first limiting member cooperating with two corresponding limiting grooves to achieve precise and firm axial locking. The first limiting member is allowed to be deformed during assembly and then accurately locked into the groove, generating a continuous pre-tightening force.
[0021] 3. The anti-shaking connection structure proposed in this utility model limits the first limiting groove and the second limiting groove to be arranged in a radial direction. The aligned grooves allow the protrusion of the first limiting member to be inserted simultaneously and evenly, avoiding assembly difficulties, snap ring twisting or uneven stress that may occur due to misalignment.
[0022] 4. The anti-sway connection structure proposed in this utility model provides auxiliary axial support by setting an axially extended lower swing structure. The lower swing flexibly abuts against the outer wall of the water outlet and the inner wall of the channel, further consolidating the anti-sway effect. The large surface contact can effectively dampen and absorb the vibration energy transmitted by water flow or structure, reduce resonance and noise, and improve the quietness and comfort of the product.
[0023] 5. The anti-shaking connection structure proposed in this utility model, by setting a second limiting member and its interference fit abutting member, the radial pressure generated by the interference fit tightly presses the water outlet into the seat channel, completely eliminating the radial gap and fundamentally solving the problem of radial shaking.
[0024] 6. The anti-shaking connection structure proposed in this utility model provides a slope on the pressure cover. The slope can guide the first limiting member and its second protrusion to slide smoothly into the predetermined position, preventing jamming or damage during assembly and improving assembly efficiency. The wedge-shaped space formed by the slope and the end face makes the force direction of the limiting part more reasonable, reduces stress concentration, and improves the wear resistance and fatigue resistance of this part under long-term use.
[0025] 7. The anti-shaking connection structure proposed in this utility model converts the direct sliding friction between the water outlet and the metal cap into friction between the water outlet and the metal cap by setting a wear-resistant sleeve. The wear-resistant sleeve itself is made of a more wear-resistant material, which effectively protects the water outlet and the cap from wear. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is a schematic diagram of a faucet assembly according to the present invention;
[0028] Figure 2 This is an exploded view of a faucet assembly according to the present invention;
[0029] Figure 3 This is a cross-sectional view of a faucet assembly according to the present invention;
[0030] Figure 4 for Figure 3 A magnified view of point A;
[0031] Figure 5 This is a schematic diagram of the first limiting member of an anti-shaking connection structure according to the present invention;
[0032] Figure 6 This is a schematic diagram of the second limiting member of an anti-shaking connection structure according to the present invention;
[0033] Figure 7 This is a schematic diagram of a wear-resistant sleeve for an anti-shaking connection structure according to the present invention.
[0034] In the diagram, 10 is the water outlet; 101 is the first limiting groove; 102 is the sealing groove; 201 is the seat body; 202 is the pressure cap; 2021 is the inclined surface; 203 is the second limiting groove; 30 is the first retaining ring; 301 is the first protrusion; 302 is the second protrusion; 303 is the lower hem; 40 is the second retaining ring; 401 is the third protrusion; 50 is the wear-resistant sleeve; 501 is the connecting protrusion; 2022 is the receiving groove; 60 is the sealing ring; 70 is the switching valve; 701 is the upper outlet; 702 is the lower outlet; 703 is the water passage space; 704 is the plunger; 705 is the elastic element; 706 is the upper sealing gasket; 707 is the lower sealing gasket; 80 is the panel body; and 90 is the control valve. Detailed Implementation
[0035] The following is combined with Figures 1-7 This utility model will be described in detail.
[0036] An anti-shake connection structure, such as Figure 1 As shown, the device includes a water outlet 10 and a base assembly. The base assembly has a water outlet channel. The water inlet end of the water outlet 10 is installed inside the base assembly and communicates with the water outlet channel. The device also includes a first limiting member and a second limiting member. The outer side wall of the water outlet 10 has a first limiting position, and the inner side wall of the base assembly has a second limiting position. The two sides of the first limiting member are respectively engaged with the first limiting position and the second limiting position to limit the displacement of the water outlet 10 in the axial direction. The second limiting member is sleeved inside the water inlet of the water outlet 10 and generates a force that presses the water outlet 10 against the inner side wall of the base assembly to limit the displacement of the water outlet 10 in the radial direction.
[0037] Specifically, the base assembly has a through-flow water outlet channel to guide water flow. The water outlet 10 is typically in the shape of a curved tube, with its inlet end inserted into and installed within the receiving space of the base assembly, ensuring smooth communication between the inner cavity of the water outlet 10 and the water outlet channel of the base assembly, guaranteeing unobstructed water flow. The first limiting member serves as a connecting medium, with its two sides forming a tight concave-convex fit with the first and second limiting positions, respectively, such as the fit between a groove and a protrusion. This concave-convex fit effectively locks the water outlet 10's degree of freedom of movement along its axial direction.
[0038] The second limiting member is located inside the inlet of the water outlet 10. It generates an outward radial clamping force through its own elasticity or structural shape, firmly pressing the pipe wall of the water outlet 10 against the inner wall of the seat assembly, thereby strictly limiting any possible wobbling of the water outlet 10 in the radial plane. This dual constraint of axial and radial forces together constitutes a stable connection structure.
[0039] In this embodiment, as Figure 4-5 As shown, the first limiting member is sleeved on the outside of the water outlet 10. The inner and outer sides of the first limiting member are respectively provided with a first protrusion 301 and a second protrusion 302 extending inward and outward in the radial direction. The first limiting position is a first limiting groove 101, and the second limiting position is a second limiting groove 203. The first protrusion 301 is engaged with the first limiting groove 101, and the second protrusion 302 is engaged with the second limiting groove 203.
[0040] Specifically, the first limiting component is a first retaining ring 30, which extends radially inward and outward to form a first protrusion 301 and a second protrusion 302, respectively. The first retaining ring 30 can be made of metal or high-strength engineering plastic. Correspondingly, the first limiting position on the outer wall of the spout 10 is a ring-shaped first limiting groove 101, while the second limiting position on the inner wall of the seat assembly is also a ring-shaped second limiting groove 203. The first retaining ring 30 extends radially inward to form the first protrusion 301 and outward to form the second protrusion 302. During assembly, the first protrusion 301 engages and is embedded in the first limiting groove 101 on the spout 10, while the second protrusion 302 simultaneously engages in the second limiting groove 203 on the seat assembly. The fitting structure of the double protrusions and double limiting grooves firmly locks the axial displacement from both the inner and outer sides, resulting in extremely high stability.
[0041] In this embodiment, as Figure 4 As shown, the first limiting groove 101 and the second limiting groove 203 are located at the same height or approach the same height. The first limiting groove 101 and the second limiting groove 203 are arranged correspondingly to each other in the radial direction, that is, they are aligned in space, thereby ensuring that they can be aligned and embedded into their respective limiting grooves simultaneously and smoothly, avoiding misalignment or interference during the assembly process, making the installation operation simpler and more direct, and ensuring a uniform distribution of the limiting force.
[0042] In this embodiment, as Figure 5 As shown, the first limiting member includes a lower arm 303 located below the connection between the first protrusion 301, the second protrusion 302, or the connection between the first protrusion 301 and the second protrusion 302. The lower arm 303 abuts against the outer side wall of the water outlet 10 and the inner side wall of the water outlet channel, respectively.
[0043] Specifically, a lower helix 303 extends from the end of the first retaining ring 30 facing upstream of the water flow direction. After the water outlet 10 and the first retaining ring 30 are fully installed in the base assembly, the two sides of the lower helix 303 abut against the outer wall of the water outlet 10 and the inner wall of the water outlet channel, respectively. This not only provides additional axial support points but also effectively absorbs and attenuates minor vibrations that may be caused by the water flow, improving the quietness and firmness of the connection.
[0044] In this embodiment, as Figure 4 and Figure 6 As shown, the second limiting member includes a clamping member and an abutment member connected to the clamping member. The abutment member extends outward along the radial direction of the clamping member. The clamping member is sleeved inside the inlet of the water outlet 10, thereby generating a force that presses the water outlet 10 against the inner wall of the seat assembly. The abutment member is interference-fitted with the water outlet channel.
[0045] Specifically, the clamping member is the second retaining ring 40, and the abutting member is the second retaining ring 40 extending radially outward to form a third protrusion 401. The water inlet of the water outlet 10 overlaps the outer side of the annular body of the second retaining ring 40 and the upper surface of the third protrusion 401. The third protrusion 401 is interference-fitted with the inner diameter of the water outlet channel.
[0046] During assembly, the end face of the water inlet of the nozzle 10 overlaps the outer surface of the second retaining ring 40 and the upper surface of the third protrusion 401, thus obtaining a radial support base. The outer edge dimension of the third protrusion 401 is designed to be slightly larger than the inner diameter of the water outlet channel inside the seat assembly, so that the two form an interference fit. When the seat assembly is pressed, the huge friction and radial pressure generated by the interference fit of the third protrusion 401 tightly holds the nozzle 10 in the seat assembly, completely eliminating the gap of radial wobble.
[0047] In this embodiment, as Figure 2As shown, the seat assembly includes a seat body 201 and a pressure cap 202 threadedly connected to the seat body 201. The seat body 201 has a water outlet channel, and the pressure cap 202 has a through hole for the water outlet 10 to pass through. When the pressure cap 202 and the seat body 201 are connected, a second limiting groove 203 is provided between them, and a clearance space is provided between the water outlet 10 and the seat body 201 to accommodate the lower hem 303. In this embodiment, the inner sidewall of the seat body 201 near the second limiting groove 203 has a clearance space.
[0048] Specifically, the seat assembly is composed of two independent parts: a pressure cap 202 and a seat body 201. The inner wall of the first end (lower end) of the pressure cap 202 is machined with internal threads, which engage with the external threads machined on the outer wall of the seat body 201. The inner wall of the second end (upper end) of the pressure cap 202 tapers inward, directly abutting against the outer wall of the water outlet 10, providing a certain degree of straightening. When the pressure cap 202 is tightened onto the seat body 201, an annular gap is formed at the junction of the two parts in the internal water outlet channel. This gap itself directly constitutes the second limiting groove 203 for engaging the second protrusion 302.
[0049] In this embodiment, as Figure 4 As shown, the inner wall of the pressure cap 202 is provided with an inclined surface 2021, and the space enclosed by the inclined surface 2021 and the end face of the seat body 201 facing the inclined surface 2021 constitutes the second limiting groove 203.
[0050] Specifically, the inner wall of the first end of the pressure cap 202 near the second end has a gradually tapering inclined surface 2021. The inclined surface 2021 forms a gap with the end face of the seat body 201, and the second protrusion 302 of the first retaining ring 30 abuts against the inclined surface 2021 and the end face of the seat body 201. When the pressure cap 202 is screwed into the seat body 201, the inclined surface 2021 gradually approaches the upper end face of the seat body 201, eventually forming the aforementioned gap (i.e., the second limiting groove 203). The second protrusion 302 of the first retaining ring 30 is finally tightly pressed into the wedge-shaped space formed by the inclined surface 2021 and the end face of the seat body 201. The inclined surface 2021 not only guides the retaining ring and the water outlet 10 into place smoothly during assembly, but also makes the limiting contact surface more optimal and the stress distribution more reasonable.
[0051] In this embodiment, as Figure 4-7 As shown, it also includes a wear-resistant sleeve 50, the outer wall of which is snapped into the pressure cap 202, and the inner side of which abuts against the outer wall of the water outlet 10.
[0052] Specifically, it also includes a wear-resistant sleeve 50. The inner side wall of the first end of the pressure cap 202 is provided with a receiving groove 2022 at a position away from the second end. The outer side wall of the wear-resistant sleeve 50 is provided with a connecting protrusion 501 that is adapted to the second receiving groove 2022. The connecting protrusion 501 and the receiving groove 2022 are in concave-convex fit. The two sides of the wear-resistant sleeve 50 abut against the inner side wall of the pressure cap 202 and the outer side wall of the water outlet 10, respectively.
[0053] The wear-resistant sleeve 50 is typically made of brass, stainless steel, or wear-resistant engineering plastic. An annular receiving groove 2022 is formed on the inner wall of the first end of the pressure cap 202, away from its second end. Correspondingly, a connecting protrusion 501 matching the shape of the receiving groove 2022 is machined on the outer wall of the wear-resistant sleeve 50. During assembly, the connecting protrusion 501 and the receiving groove 2022 are radially fixed through a convex-concave fit, and the inner ring of the wear-resistant sleeve 50 is tightly fitted onto the outer wall of the water outlet 10. The inner and outer side walls of the wear-resistant sleeve 50 abut against the outer wall of the water outlet 10 and the inner side wall of the pressure cap 202, respectively, thereby converting the direct friction between the water outlet 10 and the metal pressure cap 202 into indirect friction with the wear-resistant sleeve 50, significantly reducing the wear rate.
[0054] In this embodiment, as Figure 2 and Figure 4 As shown, it also includes a sealing ring 60. The outer side wall of the water outlet 10 is provided with a plurality of sealing grooves 102 for assembling the sealing ring 60 along its axial direction. The sealing ring 60 is sealed between the water outlet 10 and the seat body 201.
[0055] Specifically, the sealing ring 60 is typically made of an elastic material such as rubber or silicone. Several annular sealing grooves 102 are provided along the axial direction on the outer wall of the spout 10. These sealing grooves 102 are arranged at different heights depending on the number of sealing points, and the sealing ring 60 is tightly fitted within these sealing grooves 102. When the spout 10 is installed into the seat body 201, the sealing ring 60 is compressed and deformed until it fills all the assembly gaps between the outer wall of the spout 10 and the inner wall of the seat body 201, thereby forming a water seal and preventing water leakage from the connection.
[0056] This embodiment also provides a faucet assembly, such as Figure 1 and Figure 2 As shown, it includes an anti-sway connection structure, a switching valve 70, and at least one control valve 90. The switching valve 70 is connected to the seat assembly and communicates with the water outlet channel. The control valve 90 connects to the water supply source and controls whether the water supply source is connected to the switching valve 70.
[0057] Specifically, there are two control valves 90, and a switching valve 70 is threadedly connected to the inner wall of the seat body 201 and connected to the water outlet channel. The two control valves 90 are respectively connected to an external water source and control the flow of the external water source to the switching valve 70. The switching valve 70 is fixedly installed deep within the inner wall of the seat body 201 by means of threaded connection, and maintains water flow communication with the internal water passage. The two control valves 90 are respectively connected to external cold water and hot water sources, and can control the on / off state and flow rate of their respective water sources. The controlled hot and cold water is guided to the switching valve 70 to form a mixed water, and the mixing and output control of the water flow are achieved through the switching valve 70. The mixed water then flows out through the end of the nozzle.
[0058] In this embodiment, as Figure 1 and Figure 2 As shown, the faucet assembly also includes a mounting panel. The mounting panel comprises a panel body 80, a seat body 201 fixedly mounted on the panel body 80, and two valve body cavities. Two control valves 90 are respectively connected to the two valve body cavities. The mounting panel is used to fix the entire faucet assembly to a countertop or wall surface. The mounting panel includes a generally flat panel body 80, the seat body 201 and two valve body cavities for accommodating valve cores are pre-fixed on the panel body 80, and two control valves 90 are respectively installed in these two valve body cavities and connected to the cold and hot water handles via valve stems, forming a complete control mechanism.
[0059] like Figure 4 As shown, the switching valve 70 also includes a valve core, which includes a movable valve chamber. The movable valve chamber includes an upper outlet 701, a lower outlet 702, and an intermediate inlet. The upper outlet 701 forms the main water outlet, the intermediate inlet connects to the water passage space 703, and the lower outlet 702 connects to the outlet end. The valve core also includes a plunger 704 and an elastic element 705. The plunger 704 moves within the movable valve chamber. One end of the plunger 704 is equipped with an upper sealing pad 706, and the other end is equipped with a lower sealing pad 707. The pressure-bearing area of the lower sealing pad 707 is greater than that of the upper sealing pad 706. When the elastic element 705 connects to the plunger 704 to push the lower sealing pad 707 to block the lower outlet 702, the upper outlet 701 connects to the water passage space 703. When the water flow is turned on, the water pressure pushes the plunger 704 to move so that the upper sealing pad 706 blocks the upper outlet 701, and the water passage space 703 connects to the lower outlet 702.
[0060] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the scope of protection of this utility model.
Claims
1. An anti-shake connection structure, characterized in that, The device includes a spout and a base assembly. The base assembly has a water outlet channel. The water inlet end of the spout is installed inside the base assembly and communicates with the water outlet channel. It also includes a first limiting member and a second limiting member. The outer side wall of the spout has a first limiting position, and the inner side wall of the base assembly has a second limiting position. The two sides of the first limiting member respectively engage with the first limiting position and the second limiting position to limit the displacement of the spout in the axial direction. The second limiting member is sleeved inside the water inlet of the spout and generates a force that presses the spout against the inner side wall of the base assembly to limit the displacement of the spout in the radial direction.
2. The anti-sway connection structure as described in claim 1, characterized in that, The first limiting member is sleeved on the outside of the water outlet. The inner and outer sides of the first limiting member are respectively provided with a first protrusion and a second protrusion extending inward and outward in the radial direction. The first limiting position is a first limiting groove, and the second limiting position is a second limiting groove. The first protrusion is engaged with the first limiting groove, and the second protrusion is engaged with the second limiting groove.
3. The anti-sway connection structure as described in claim 2, characterized in that, The first limiting groove and the second limiting groove are at the same height or tend to be at the same height.
4. The anti-sway connection structure as described in claim 2, characterized in that, The first limiting member includes a lower helix located below the connection between the first protrusion, the second protrusion, or the first protrusion and the second protrusion, the lower helix abutting against the outer wall of the water outlet and the inner wall of the water outlet channel, respectively.
5. The anti-sway connection structure as described in claim 2, characterized in that, The second limiting member includes a clamping member and an abutment member connected to the clamping member. The abutment member extends radially outward along the clamping member. The clamping member is sleeved inside the inlet of the water outlet, thereby generating a force that presses the water outlet against the inner wall of the seat assembly. The abutment member is also interference-fitted with the water outlet channel.
6. The anti-sway connection structure as described in claim 4, characterized in that, The seat assembly includes a seat body and a pressure cap threaded to the seat body. The seat body has the water outlet channel, and the pressure cap has a through hole for the water outlet nozzle to pass through. When the pressure cap and the seat body are connected, a second limiting groove is provided between them. A clearance space for accommodating the lower hem is provided between the water outlet nozzle and the seat body.
7. The anti-sway connection structure as described in claim 6, characterized in that, The inner wall of the pressure cap is provided with an inclined surface, and the space enclosed by the inclined surface and the end face of the seat body facing the inclined surface constitutes the second limiting groove.
8. The anti-sway connection structure as described in claim 6, characterized in that, The seat body has the clearance space on its inner side wall near the second limiting groove.
9. The anti-shake connection structure as described in claim 6, characterized in that, It also includes a wear-resistant sleeve, the outer wall of which is snapped into the pressure cap, and the inner side of which abuts against the outer wall of the water outlet.
10. A faucet assembly, comprising the anti-shake connection structure as described in any one of claims 1-9, characterized in that, It also includes a switching valve and at least one control valve, wherein the switching valve is connected to the seat assembly and communicates with the water outlet channel, and the control valve connects to the water supply source and controls whether the water supply source is connected to the switching valve.